diff options
Diffstat (limited to 'js/xpconnect/loader')
25 files changed, 7180 insertions, 0 deletions
diff --git a/js/xpconnect/loader/AutoMemMap.cpp b/js/xpconnect/loader/AutoMemMap.cpp new file mode 100644 index 0000000000..92cb5bfd55 --- /dev/null +++ b/js/xpconnect/loader/AutoMemMap.cpp @@ -0,0 +1,154 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "AutoMemMap.h" +#include "ScriptPreloader-inl.h" + +#include "mozilla/Unused.h" +#include "mozilla/ipc/FileDescriptor.h" +#include "nsIFile.h" + +#include <private/pprio.h> + +namespace mozilla { +namespace loader { + +using namespace mozilla::ipc; + +AutoMemMap::~AutoMemMap() { reset(); } + +FileDescriptor AutoMemMap::cloneFileDescriptor() const { + if (fd.get()) { + auto handle = + FileDescriptor::PlatformHandleType(PR_FileDesc2NativeHandle(fd.get())); + return FileDescriptor(handle); + } + return FileDescriptor(); +} + +Result<Ok, nsresult> AutoMemMap::init(nsIFile* file, int flags, int mode, + PRFileMapProtect prot) { + MOZ_ASSERT(!fd); + + MOZ_TRY(file->OpenNSPRFileDesc(flags, mode, &fd.rwget())); + + return initInternal(prot); +} + +Result<Ok, nsresult> AutoMemMap::init(const FileDescriptor& file, + PRFileMapProtect prot, size_t maybeSize) { + MOZ_ASSERT(!fd); + if (!file.IsValid()) { + return Err(NS_ERROR_INVALID_ARG); + } + + auto handle = file.ClonePlatformHandle(); + + fd = PR_ImportFile(PROsfd(handle.get())); + if (!fd) { + return Err(NS_ERROR_FAILURE); + } + Unused << handle.release(); + + return initInternal(prot, maybeSize); +} + +Result<Ok, nsresult> AutoMemMap::initInternal(PRFileMapProtect prot, + size_t maybeSize) { + MOZ_ASSERT(!fileMap); + MOZ_ASSERT(!addr); + + if (maybeSize > 0) { + // Some OSes' shared memory objects can't be stat()ed, either at + // all (Android) or without loosening the sandbox (Mac) so just + // use the size. + size_ = maybeSize; + } else { + // But if we don't have the size, assume it's a regular file and + // ask for it. + PRFileInfo64 fileInfo; + MOZ_TRY(PR_GetOpenFileInfo64(fd.get(), &fileInfo)); + + if (fileInfo.size > UINT32_MAX) { + return Err(NS_ERROR_INVALID_ARG); + } + size_ = fileInfo.size; + } + + fileMap = PR_CreateFileMap(fd, 0, prot); + if (!fileMap) { + return Err(NS_ERROR_FAILURE); + } + + addr = PR_MemMap(fileMap, 0, size_); + if (!addr) { + return Err(NS_ERROR_FAILURE); + } + + return Ok(); +} + +#ifdef XP_WIN + +Result<Ok, nsresult> AutoMemMap::initWithHandle(const FileDescriptor& file, + size_t size, + PRFileMapProtect prot) { + MOZ_ASSERT(!fd); + MOZ_ASSERT(!handle_); + if (!file.IsValid()) { + return Err(NS_ERROR_INVALID_ARG); + } + + handle_ = file.ClonePlatformHandle().release(); + + MOZ_ASSERT(!addr); + + size_ = size; + + addr = MapViewOfFile( + handle_, prot == PR_PROT_READONLY ? FILE_MAP_READ : FILE_MAP_ALL_ACCESS, + 0, 0, size); + + return Ok(); +} + +FileDescriptor AutoMemMap::cloneHandle() const { + return FileDescriptor(handle_); +} + +#else + +Result<Ok, nsresult> AutoMemMap::initWithHandle(const FileDescriptor& file, + size_t size, + PRFileMapProtect prot) { + MOZ_DIAGNOSTIC_ASSERT(size > 0); + return init(file, prot, size); +} + +FileDescriptor AutoMemMap::cloneHandle() const { return cloneFileDescriptor(); } + +#endif + +void AutoMemMap::reset() { + if (addr && !persistent_) { + Unused << NS_WARN_IF(PR_MemUnmap(addr, size()) != PR_SUCCESS); + addr = nullptr; + } + if (fileMap) { + Unused << NS_WARN_IF(PR_CloseFileMap(fileMap) != PR_SUCCESS); + fileMap = nullptr; + } +#ifdef XP_WIN + if (handle_) { + CloseHandle(handle_); + handle_ = nullptr; + } +#endif + fd.dispose(); +} + +} // namespace loader +} // namespace mozilla diff --git a/js/xpconnect/loader/AutoMemMap.h b/js/xpconnect/loader/AutoMemMap.h new file mode 100644 index 0000000000..54180d09e3 --- /dev/null +++ b/js/xpconnect/loader/AutoMemMap.h @@ -0,0 +1,100 @@ +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2; -*- */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef loader_AutoMemMap_h +#define loader_AutoMemMap_h + +#include "mozilla/FileUtils.h" +#include "mozilla/MemoryReporting.h" +#include "mozilla/RangedPtr.h" +#include "mozilla/Result.h" + +#include <prio.h> + +class nsIFile; + +namespace mozilla { +namespace ipc { +class FileDescriptor; +} + +namespace loader { + +class AutoMemMap { + typedef mozilla::ipc::FileDescriptor FileDescriptor; + + public: + AutoMemMap() = default; + + ~AutoMemMap(); + + Result<Ok, nsresult> init(nsIFile* file, int flags = PR_RDONLY, int mode = 0, + PRFileMapProtect prot = PR_PROT_READONLY); + + Result<Ok, nsresult> init(const FileDescriptor& file, + PRFileMapProtect prot = PR_PROT_READONLY, + size_t maybeSize = 0); + + // Initializes the mapped memory with a shared memory handle. On + // Unix-like systems, this is identical to the above init() method. On + // Windows, the FileDescriptor must be a handle for a file mapping, + // rather than a file descriptor. + Result<Ok, nsresult> initWithHandle(const FileDescriptor& file, size_t size, + PRFileMapProtect prot = PR_PROT_READONLY); + + void reset(); + + bool initialized() const { return addr; } + + uint32_t size() const { return size_; } + + template <typename T = void> + RangedPtr<T> get() { + MOZ_ASSERT(addr); + return {static_cast<T*>(addr), size_}; + } + + template <typename T = void> + const RangedPtr<T> get() const { + MOZ_ASSERT(addr); + return {static_cast<T*>(addr), size_}; + } + + size_t nonHeapSizeOfExcludingThis() { return size_; } + + FileDescriptor cloneFileDescriptor() const; + FileDescriptor cloneHandle() const; + + // Makes this mapping persistent. After calling this, the mapped memory + // will remained mapped, even after this instance is destroyed. + void setPersistent() { persistent_ = true; } + + private: + Result<Ok, nsresult> initInternal(PRFileMapProtect prot, + size_t maybeSize = 0); + + AutoFDClose fd; + PRFileMap* fileMap = nullptr; + +#ifdef XP_WIN + // We can't include windows.h in this header, since it gets included + // by some binding headers (which are explicitly incompatible with + // windows.h). So we can't use the HANDLE type here. + void* handle_ = nullptr; +#endif + + uint32_t size_ = 0; + void* addr = nullptr; + + bool persistent_ = 0; + + AutoMemMap(const AutoMemMap&) = delete; + void operator=(const AutoMemMap&) = delete; +}; + +} // namespace loader +} // namespace mozilla + +#endif // loader_AutoMemMap_h diff --git a/js/xpconnect/loader/ChromeScriptLoader.cpp b/js/xpconnect/loader/ChromeScriptLoader.cpp new file mode 100644 index 0000000000..210dd8ffd4 --- /dev/null +++ b/js/xpconnect/loader/ChromeScriptLoader.cpp @@ -0,0 +1,374 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "PrecompiledScript.h" + +#include "nsIIncrementalStreamLoader.h" +#include "nsIURI.h" +#include "nsIChannel.h" +#include "nsNetUtil.h" +#include "nsThreadUtils.h" + +#include "jsapi.h" +#include "jsfriendapi.h" +#include "js/CompilationAndEvaluation.h" +#include "js/SourceText.h" +#include "js/Utility.h" + +#include "mozilla/Attributes.h" +#include "mozilla/SchedulerGroup.h" +#include "mozilla/dom/ChromeUtils.h" +#include "mozilla/dom/Promise.h" +#include "mozilla/dom/ScriptLoader.h" +#include "mozilla/HoldDropJSObjects.h" +#include "nsCCUncollectableMarker.h" +#include "nsCycleCollectionParticipant.h" + +using namespace JS; +using namespace mozilla; +using namespace mozilla::dom; + +class AsyncScriptCompiler final : public nsIIncrementalStreamLoaderObserver, + public Runnable { + public: + // Note: References to this class are never held by cycle-collected objects. + // If at any point a reference is returned to a caller, please update this + // class to implement cycle collection. + NS_DECL_ISUPPORTS_INHERITED + NS_DECL_NSIINCREMENTALSTREAMLOADEROBSERVER + NS_DECL_NSIRUNNABLE + + AsyncScriptCompiler(JSContext* aCx, nsIGlobalObject* aGlobal, + const nsACString& aURL, Promise* aPromise) + : mozilla::Runnable("AsyncScriptCompiler"), + mOptions(aCx), + mURL(aURL), + mGlobalObject(aGlobal), + mPromise(aPromise), + mToken(nullptr), + mScriptLength(0) {} + + MOZ_MUST_USE nsresult Start(JSContext* aCx, + const CompileScriptOptionsDictionary& aOptions, + nsIPrincipal* aPrincipal); + + inline void SetToken(JS::OffThreadToken* aToken) { mToken = aToken; } + + protected: + virtual ~AsyncScriptCompiler() { + if (mPromise->State() == Promise::PromiseState::Pending) { + mPromise->MaybeReject(NS_ERROR_FAILURE); + } + } + + private: + void Reject(JSContext* aCx); + void Reject(JSContext* aCx, const char* aMxg); + + bool StartCompile(JSContext* aCx); + void FinishCompile(JSContext* aCx); + void Finish(JSContext* aCx, Handle<JSScript*> script); + + OwningCompileOptions mOptions; + nsCString mURL; + nsCOMPtr<nsIGlobalObject> mGlobalObject; + RefPtr<Promise> mPromise; + nsString mCharset; + JS::OffThreadToken* mToken; + UniqueTwoByteChars mScriptText; + size_t mScriptLength; +}; + +NS_IMPL_QUERY_INTERFACE_INHERITED(AsyncScriptCompiler, Runnable, + nsIIncrementalStreamLoaderObserver) +NS_IMPL_ADDREF_INHERITED(AsyncScriptCompiler, Runnable) +NS_IMPL_RELEASE_INHERITED(AsyncScriptCompiler, Runnable) + +nsresult AsyncScriptCompiler::Start( + JSContext* aCx, const CompileScriptOptionsDictionary& aOptions, + nsIPrincipal* aPrincipal) { + mCharset = aOptions.mCharset; + + CompileOptions options(aCx); + options.setFile(mURL.get()).setNoScriptRval(!aOptions.mHasReturnValue); + + if (!aOptions.mLazilyParse) { + options.setForceFullParse(); + } + + if (NS_WARN_IF(!mOptions.copy(aCx, options))) { + return NS_ERROR_OUT_OF_MEMORY; + } + + nsCOMPtr<nsIURI> uri; + nsresult rv = NS_NewURI(getter_AddRefs(uri), mURL); + NS_ENSURE_SUCCESS(rv, rv); + + nsCOMPtr<nsIChannel> channel; + rv = NS_NewChannel( + getter_AddRefs(channel), uri, aPrincipal, + nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_SEC_CONTEXT_IS_NULL, + nsIContentPolicy::TYPE_INTERNAL_CHROMEUTILS_COMPILED_SCRIPT); + NS_ENSURE_SUCCESS(rv, rv); + + // allow deprecated HTTP request from SystemPrincipal + nsCOMPtr<nsILoadInfo> loadInfo = channel->LoadInfo(); + loadInfo->SetAllowDeprecatedSystemRequests(true); + nsCOMPtr<nsIIncrementalStreamLoader> loader; + rv = NS_NewIncrementalStreamLoader(getter_AddRefs(loader), this); + NS_ENSURE_SUCCESS(rv, rv); + + return channel->AsyncOpen(loader); +} + +static void OffThreadScriptLoaderCallback(JS::OffThreadToken* aToken, + void* aCallbackData) { + RefPtr<AsyncScriptCompiler> scriptCompiler = + dont_AddRef(static_cast<AsyncScriptCompiler*>(aCallbackData)); + + scriptCompiler->SetToken(aToken); + + SchedulerGroup::Dispatch(TaskCategory::Other, scriptCompiler.forget()); +} + +bool AsyncScriptCompiler::StartCompile(JSContext* aCx) { + Rooted<JSObject*> global(aCx, mGlobalObject->GetGlobalJSObject()); + + JS::SourceText<char16_t> srcBuf; + if (!srcBuf.init(aCx, std::move(mScriptText), mScriptLength)) { + return false; + } + + if (JS::CanCompileOffThread(aCx, mOptions, mScriptLength)) { + if (!JS::CompileOffThread(aCx, mOptions, srcBuf, + OffThreadScriptLoaderCallback, + static_cast<void*>(this))) { + return false; + } + + NS_ADDREF(this); + return true; + } + + Rooted<JSScript*> script(aCx, JS::Compile(aCx, mOptions, srcBuf)); + if (!script) { + return false; + } + + Finish(aCx, script); + return true; +} + +NS_IMETHODIMP +AsyncScriptCompiler::Run() { + AutoJSAPI jsapi; + if (jsapi.Init(mGlobalObject)) { + FinishCompile(jsapi.cx()); + } else { + jsapi.Init(); + JS::CancelOffThreadScript(jsapi.cx(), mToken); + + mPromise->MaybeReject(NS_ERROR_FAILURE); + } + + return NS_OK; +} + +void AsyncScriptCompiler::FinishCompile(JSContext* aCx) { + Rooted<JSScript*> script(aCx, JS::FinishOffThreadScript(aCx, mToken)); + if (script) { + Finish(aCx, script); + } else { + Reject(aCx); + } +} + +void AsyncScriptCompiler::Finish(JSContext* aCx, Handle<JSScript*> aScript) { + RefPtr<PrecompiledScript> result = + new PrecompiledScript(mGlobalObject, aScript, mOptions); + + mPromise->MaybeResolve(result); +} + +void AsyncScriptCompiler::Reject(JSContext* aCx) { + RootedValue value(aCx, JS::UndefinedValue()); + if (JS_GetPendingException(aCx, &value)) { + JS_ClearPendingException(aCx); + } + mPromise->MaybeReject(value); +} + +void AsyncScriptCompiler::Reject(JSContext* aCx, const char* aMsg) { + nsAutoString msg; + msg.AppendASCII(aMsg); + msg.AppendLiteral(": "); + AppendUTF8toUTF16(mURL, msg); + + RootedValue exn(aCx); + if (xpc::NonVoidStringToJsval(aCx, msg, &exn)) { + JS_SetPendingException(aCx, exn); + } + + Reject(aCx); +} + +NS_IMETHODIMP +AsyncScriptCompiler::OnIncrementalData(nsIIncrementalStreamLoader* aLoader, + nsISupports* aContext, + uint32_t aDataLength, + const uint8_t* aData, + uint32_t* aConsumedData) { + return NS_OK; +} + +NS_IMETHODIMP +AsyncScriptCompiler::OnStreamComplete(nsIIncrementalStreamLoader* aLoader, + nsISupports* aContext, nsresult aStatus, + uint32_t aLength, const uint8_t* aBuf) { + AutoJSAPI jsapi; + if (!jsapi.Init(mGlobalObject)) { + mPromise->MaybeReject(NS_ERROR_FAILURE); + return NS_OK; + } + + JSContext* cx = jsapi.cx(); + + if (NS_FAILED(aStatus)) { + Reject(cx, "Unable to load script"); + return NS_OK; + } + + nsresult rv = ScriptLoader::ConvertToUTF16( + nullptr, aBuf, aLength, mCharset, nullptr, mScriptText, mScriptLength); + if (NS_FAILED(rv)) { + Reject(cx, "Unable to decode script"); + return NS_OK; + } + + if (!StartCompile(cx)) { + Reject(cx); + } + + return NS_OK; +} + +namespace mozilla { +namespace dom { + +/* static */ +already_AddRefed<Promise> ChromeUtils::CompileScript( + GlobalObject& aGlobal, const nsAString& aURL, + const CompileScriptOptionsDictionary& aOptions, ErrorResult& aRv) { + nsCOMPtr<nsIGlobalObject> global = do_QueryInterface(aGlobal.GetAsSupports()); + MOZ_ASSERT(global); + + RefPtr<Promise> promise = Promise::Create(global, aRv); + if (aRv.Failed()) { + return nullptr; + } + + NS_ConvertUTF16toUTF8 url(aURL); + RefPtr<AsyncScriptCompiler> compiler = + new AsyncScriptCompiler(aGlobal.Context(), global, url, promise); + + nsresult rv = compiler->Start(aGlobal.Context(), aOptions, + aGlobal.GetSubjectPrincipal()); + if (NS_FAILED(rv)) { + promise->MaybeReject(rv); + } + + return promise.forget(); +} + +PrecompiledScript::PrecompiledScript(nsISupports* aParent, + Handle<JSScript*> aScript, + JS::ReadOnlyCompileOptions& aOptions) + : mParent(aParent), + mScript(aScript), + mURL(aOptions.filename()), + mHasReturnValue(!aOptions.noScriptRval) { + MOZ_ASSERT(aParent); + MOZ_ASSERT(aScript); + + mozilla::HoldJSObjects(this); +}; + +PrecompiledScript::~PrecompiledScript() { mozilla::DropJSObjects(this); } + +void PrecompiledScript::ExecuteInGlobal(JSContext* aCx, HandleObject aGlobal, + MutableHandleValue aRval, + ErrorResult& aRv) { + { + RootedObject targetObj(aCx, JS_FindCompilationScope(aCx, aGlobal)); + JSAutoRealm ar(aCx, targetObj); + + Rooted<JSScript*> script(aCx, mScript); + if (!JS::CloneAndExecuteScript(aCx, script, aRval)) { + aRv.NoteJSContextException(aCx); + return; + } + } + + JS_WrapValue(aCx, aRval); +} + +void PrecompiledScript::GetUrl(nsAString& aUrl) { CopyUTF8toUTF16(mURL, aUrl); } + +bool PrecompiledScript::HasReturnValue() { return mHasReturnValue; } + +JSObject* PrecompiledScript::WrapObject(JSContext* aCx, + HandleObject aGivenProto) { + return PrecompiledScript_Binding::Wrap(aCx, this, aGivenProto); +} + +bool PrecompiledScript::IsBlackForCC(bool aTracingNeeded) { + return (nsCCUncollectableMarker::sGeneration && HasKnownLiveWrapper() && + (!aTracingNeeded || HasNothingToTrace(this))); +} + +NS_IMPL_CYCLE_COLLECTION_CLASS(PrecompiledScript) + +NS_INTERFACE_MAP_BEGIN_CYCLE_COLLECTION(PrecompiledScript) + NS_WRAPPERCACHE_INTERFACE_MAP_ENTRY + NS_INTERFACE_MAP_ENTRY(nsISupports) +NS_INTERFACE_MAP_END + +NS_IMPL_CYCLE_COLLECTION_UNLINK_BEGIN(PrecompiledScript) + NS_IMPL_CYCLE_COLLECTION_UNLINK(mParent) + NS_IMPL_CYCLE_COLLECTION_UNLINK_PRESERVED_WRAPPER + + tmp->mScript = nullptr; +NS_IMPL_CYCLE_COLLECTION_UNLINK_END + +NS_IMPL_CYCLE_COLLECTION_TRAVERSE_BEGIN(PrecompiledScript) + NS_IMPL_CYCLE_COLLECTION_TRAVERSE(mParent) +NS_IMPL_CYCLE_COLLECTION_TRAVERSE_END + +NS_IMPL_CYCLE_COLLECTION_TRACE_BEGIN(PrecompiledScript) + NS_IMPL_CYCLE_COLLECTION_TRACE_JS_MEMBER_CALLBACK(mScript) + NS_IMPL_CYCLE_COLLECTION_TRACE_PRESERVED_WRAPPER +NS_IMPL_CYCLE_COLLECTION_TRACE_END + +NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_BEGIN(PrecompiledScript) + if (tmp->IsBlackForCC(false)) { + tmp->mScript.exposeToActiveJS(); + return true; + } +NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_END + +NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_BEGIN(PrecompiledScript) + return tmp->IsBlackForCC(true); +NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_IN_CC_END + +NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_BEGIN(PrecompiledScript) + return tmp->IsBlackForCC(false); +NS_IMPL_CYCLE_COLLECTION_CAN_SKIP_THIS_END + +NS_IMPL_CYCLE_COLLECTING_ADDREF(PrecompiledScript) +NS_IMPL_CYCLE_COLLECTING_RELEASE(PrecompiledScript) + +} // namespace dom +} // namespace mozilla diff --git a/js/xpconnect/loader/ComponentUtils.jsm b/js/xpconnect/loader/ComponentUtils.jsm new file mode 100644 index 0000000000..664d13a7db --- /dev/null +++ b/js/xpconnect/loader/ComponentUtils.jsm @@ -0,0 +1,120 @@ +/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- + * vim: sw=2 ts=2 sts=2 et filetype=javascript + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +/** + * Deprecated utilities for JavaScript components loaded by the JS component + * loader. + * + * Import into a JS component using + * 'Components.utils.import("resource://gre/modules/ComponentUtils.jsm");' + * + * Exposing a JS 'class' as a component using these utility methods consists + * of several steps: + * 0. Import ComponentUtils, as described above. + * 1. Declare the 'class' (or multiple classes) implementing the component(s): + * function MyComponent() { + * // constructor + * } + * MyComponent.prototype = { + * // properties required for XPCOM registration: + * classID: Components.ID("{xxxxxxxx-xxxx-xxxx-xxxx-xxxxxxxxxxxx}"), + * + * // [optional] custom factory (an object implementing nsIFactory). If not + * // provided, the default factory is used, which returns + * // |(new MyComponent()).QueryInterface(iid)| in its createInstance(). + * _xpcom_factory: { ... }, + * + * // QueryInterface implementation, e.g. using the generateQI helper + * QueryInterface: ChromeUtils.generateQI( + * [Components.interfaces.nsIObserver, + * Components.interfaces.nsIMyInterface, + * "nsIFoo", + * "nsIBar" ]), + * + * // The following properties were used prior to Mozilla 2, but are no + * // longer supported. They may still be included for compatibility with + * // prior versions of ComponentUtils. In Mozilla 2, this information is + * // included in the .manifest file which registers this JS component. + * classDescription: "unique text description", + * contractID: "@example.com/xxx;1", + * + * // ...component implementation... + * }; + * + * 2. Create an array of component constructors (like the one + * created in step 1): + * var components = [MyComponent]; + * + * 3. Define the NSGetFactory entry point: + * this.NSGetFactory = ComponentUtils.generateNSGetFactory(components); + */ + +var EXPORTED_SYMBOLS = ["ComponentUtils"]; + +const nsIFactoryQI = ChromeUtils.generateQI(["nsIFactory"]); + +var ComponentUtils = { + /** + * Generate a NSGetFactory function given an array of components. + */ + generateNSGetFactory: function XPCU_generateNSGetFactory(componentsArray) { + let classes = {}; + for (let i = 0; i < componentsArray.length; i++) { + let component = componentsArray[i]; + if (!(component.prototype.classID instanceof Components.ID)) + throw Error("In generateNSGetFactory, classID missing or incorrect for component " + component); + + classes[component.prototype.classID] = this._getFactory(component); + } + return function NSGetFactory(cid) { + let cidstring = cid.toString(); + if (cidstring in classes) + return classes[cidstring]; + throw Cr.NS_ERROR_FACTORY_NOT_REGISTERED; + } + }, + + /** + * Returns an nsIFactory for |component|. + */ + _getFactory: function XPCOMUtils__getFactory(component) { + var factory = component.prototype._xpcom_factory; + if (!factory) { + factory = { + createInstance: function(outer, iid) { + if (outer) + throw Cr.NS_ERROR_NO_AGGREGATION; + return (new component()).QueryInterface(iid); + }, + QueryInterface: nsIFactoryQI + } + } + return factory; + }, + + /** + * generates a singleton nsIFactory implementation that can be used as + * the _xpcom_factory of the component. + * @param aServiceConstructor + * Constructor function of the component. + */ + generateSingletonFactory: + function XPCOMUtils_generateSingletonFactory(aServiceConstructor) { + return { + _instance: null, + createInstance: function XPCU_SF_createInstance(aOuter, aIID) { + if (aOuter !== null) { + throw Cr.NS_ERROR_NO_AGGREGATION; + } + if (this._instance === null) { + this._instance = new aServiceConstructor(); + } + return this._instance.QueryInterface(aIID); + }, + QueryInterface: nsIFactoryQI + }; + }, +}; diff --git a/js/xpconnect/loader/IOBuffers.h b/js/xpconnect/loader/IOBuffers.h new file mode 100644 index 0000000000..e26b0c3bca --- /dev/null +++ b/js/xpconnect/loader/IOBuffers.h @@ -0,0 +1,148 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2; -*- */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef IOBuffers_h +#define IOBuffers_h + +#include "mozilla/Assertions.h" +#include "mozilla/CheckedInt.h" +#include "mozilla/EndianUtils.h" +#include "mozilla/EnumSet.h" +#include "mozilla/Range.h" +#include "mozilla/Span.h" +#include "nsString.h" +#include "nsTArray.h" + +namespace mozilla { +namespace loader { + +class OutputBuffer { + public: + OutputBuffer() {} + + uint8_t* write(size_t size) { + auto buf = data.AppendElements(size); + cursor_ += size; + return buf; + } + + void codeUint8(const uint8_t& val) { *write(sizeof val) = val; } + + template <typename T> + void codeUint8(const EnumSet<T>& val) { + // EnumSets are always represented as uint32_t values, so we need to + // assert that the value actually fits in a uint8 before writing it. + uint32_t value = val.serialize(); + codeUint8(CheckedUint8(value).value()); + } + + void codeUint16(const uint16_t& val) { + LittleEndian::writeUint16(write(sizeof val), val); + } + + void codeUint32(const uint32_t& val) { + LittleEndian::writeUint32(write(sizeof val), val); + } + + void codeString(const nsCString& str) { + auto len = CheckedUint16(str.Length()).value(); + + codeUint16(len); + memcpy(write(len), str.BeginReading(), len); + } + + size_t cursor() const { return cursor_; } + + uint8_t* Get() { return data.Elements(); } + + const uint8_t* Get() const { return data.Elements(); } + + private: + nsTArray<uint8_t> data; + size_t cursor_ = 0; +}; + +class InputBuffer { + public: + explicit InputBuffer(const Range<uint8_t>& buffer) : data(buffer) {} + + const uint8_t* read(size_t size) { + MOZ_ASSERT(checkCapacity(size)); + + auto buf = &data[cursor_]; + cursor_ += size; + return buf; + } + + bool codeUint8(uint8_t& val) { + if (checkCapacity(sizeof val)) { + val = *read(sizeof val); + } + return !error_; + } + + template <typename T> + bool codeUint8(EnumSet<T>& val) { + uint8_t value; + if (codeUint8(value)) { + val.deserialize(value); + } + return !error_; + } + + bool codeUint16(uint16_t& val) { + if (checkCapacity(sizeof val)) { + val = LittleEndian::readUint16(read(sizeof val)); + } + return !error_; + } + + bool codeUint32(uint32_t& val) { + if (checkCapacity(sizeof val)) { + val = LittleEndian::readUint32(read(sizeof val)); + } + return !error_; + } + + bool codeString(nsCString& str) { + uint16_t len; + if (codeUint16(len)) { + if (checkCapacity(len)) { + str.SetLength(len); + memcpy(str.BeginWriting(), read(len), len); + } + } + return !error_; + } + + bool error() { return error_; } + + bool finished() { return error_ || !remainingCapacity(); } + + size_t remainingCapacity() { return data.length() - cursor_; } + + size_t cursor() const { return cursor_; } + + const uint8_t* Get() const { return data.begin().get(); } + + private: + bool checkCapacity(size_t size) { + if (size > remainingCapacity()) { + error_ = true; + } + return !error_; + } + + bool error_ = false; + + public: + const Range<uint8_t>& data; + size_t cursor_ = 0; +}; + +} // namespace loader +} // namespace mozilla + +#endif // IOBuffers_h diff --git a/js/xpconnect/loader/PScriptCache.ipdl b/js/xpconnect/loader/PScriptCache.ipdl new file mode 100644 index 0000000000..20485e03ca --- /dev/null +++ b/js/xpconnect/loader/PScriptCache.ipdl @@ -0,0 +1,33 @@ +/* -*- Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil; tab-width: 8 -*- */ +/* vim: set sw=4 ts=8 et tw=80 ft=cpp : */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +include protocol PContent; + +using class mozilla::TimeStamp from "mozilla/TimeStamp.h"; +using struct mozilla::void_t from "mozilla/ipc/IPCCore.h"; + +namespace mozilla { +namespace loader { + +struct ScriptData { + nsCString url; + nsCString cachePath; + TimeStamp loadTime; + // This will be an empty array if script data is present in the previous + // session's cache. + uint8_t[] xdrData; +}; + +protocol PScriptCache +{ + manager PContent; + +parent: + async __delete__(ScriptData[] scripts); +}; + +} // namespace loader +} // namespace mozilla diff --git a/js/xpconnect/loader/PrecompiledScript.h b/js/xpconnect/loader/PrecompiledScript.h new file mode 100644 index 0000000000..29212db0e4 --- /dev/null +++ b/js/xpconnect/loader/PrecompiledScript.h @@ -0,0 +1,62 @@ +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2; -*- */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef mozilla_dom_PrecompiledScript_h +#define mozilla_dom_PrecompiledScript_h + +#include "mozilla/dom/BindingDeclarations.h" +#include "mozilla/dom/PrecompiledScriptBinding.h" + +#include "js/RootingAPI.h" +#include "js/TypeDecls.h" + +#include "nsCOMPtr.h" +#include "nsCycleCollectionParticipant.h" +#include "nsISupports.h" +#include "nsWrapperCache.h" + +namespace JS { +class ReadOnlyCompileOptions; +} + +namespace mozilla { +namespace dom { +class PrecompiledScript : public nsISupports, public nsWrapperCache { + NS_DECL_CYCLE_COLLECTING_ISUPPORTS + NS_DECL_CYCLE_COLLECTION_SKIPPABLE_SCRIPT_HOLDER_CLASS(PrecompiledScript) + + explicit PrecompiledScript(nsISupports* aParent, + JS::Handle<JSScript*> aScript, + JS::ReadOnlyCompileOptions& aOptions); + + void ExecuteInGlobal(JSContext* aCx, JS::HandleObject aGlobal, + JS::MutableHandleValue aRval, ErrorResult& aRv); + + void GetUrl(nsAString& aUrl); + + bool HasReturnValue(); + + nsISupports* GetParentObject() const { return mParent; } + + virtual JSObject* WrapObject(JSContext* aCx, + JS::Handle<JSObject*> aGivenProto) override; + + protected: + virtual ~PrecompiledScript(); + + private: + bool IsBlackForCC(bool aTracingNeeded); + + nsCOMPtr<nsISupports> mParent; + + JS::Heap<JSScript*> mScript; + nsCString mURL; + const bool mHasReturnValue; +}; + +} // namespace dom +} // namespace mozilla + +#endif // mozilla_dom_PrecompiledScript_h diff --git a/js/xpconnect/loader/ScriptCacheActors.cpp b/js/xpconnect/loader/ScriptCacheActors.cpp new file mode 100644 index 0000000000..b074b7cbb8 --- /dev/null +++ b/js/xpconnect/loader/ScriptCacheActors.cpp @@ -0,0 +1,92 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "mozilla/ScriptPreloader.h" +#include "ScriptPreloader-inl.h" +#include "mozilla/loader/ScriptCacheActors.h" + +#include "mozilla/dom/ContentParent.h" + +namespace mozilla { +namespace loader { + +void ScriptCacheChild::Init(const Maybe<FileDescriptor>& cacheFile, + bool wantCacheData) { + mWantCacheData = wantCacheData; + + auto& cache = ScriptPreloader::GetChildSingleton(); + Unused << cache.InitCache(cacheFile, this); + + if (!wantCacheData) { + // If the parent process isn't expecting any cache data from us, we're + // done. + Send__delete__(this, AutoTArray<ScriptData, 0>()); + } +} + +// Finalize the script cache for the content process, and send back data about +// any scripts executed up to this point. +void ScriptCacheChild::SendScriptsAndFinalize( + ScriptPreloader::ScriptHash& scripts) { + MOZ_ASSERT(mWantCacheData); + + AutoSafeJSAPI jsapi; + + auto matcher = ScriptPreloader::Match<ScriptPreloader::ScriptStatus::Saved>(); + + nsTArray<ScriptData> dataArray; + for (auto& script : IterHash(scripts, matcher)) { + if (!script->mSize && !script->XDREncode(jsapi.cx())) { + continue; + } + + auto data = dataArray.AppendElement(); + + data->url() = script->mURL; + data->cachePath() = script->mCachePath; + data->loadTime() = script->mLoadTime; + + if (script->HasBuffer()) { + auto& xdrData = script->Buffer(); + data->xdrData().AppendElements(xdrData.begin(), xdrData.length()); + script->FreeData(); + } + } + + Send__delete__(this, dataArray); +} + +void ScriptCacheChild::ActorDestroy(ActorDestroyReason aWhy) { + auto& cache = ScriptPreloader::GetChildSingleton(); + cache.mChildActor = nullptr; +} + +IPCResult ScriptCacheParent::Recv__delete__(nsTArray<ScriptData>&& scripts) { + if (!mWantCacheData && scripts.Length()) { + return IPC_FAIL(this, "UnexpectedScriptData"); + } + + // We don't want any more data from the process at this point. + mWantCacheData = false; + + // Merge the child's script data with the parent's. + auto parent = static_cast<dom::ContentParent*>(Manager()); + auto processType = + ScriptPreloader::GetChildProcessType(parent->GetRemoteType()); + + auto& cache = ScriptPreloader::GetChildSingleton(); + for (auto& script : scripts) { + cache.NoteScript(script.url(), script.cachePath(), processType, + std::move(script.xdrData()), script.loadTime()); + } + + return IPC_OK(); +} + +void ScriptCacheParent::ActorDestroy(ActorDestroyReason aWhy) {} + +} // namespace loader +} // namespace mozilla diff --git a/js/xpconnect/loader/ScriptCacheActors.h b/js/xpconnect/loader/ScriptCacheActors.h new file mode 100644 index 0000000000..92148464ea --- /dev/null +++ b/js/xpconnect/loader/ScriptCacheActors.h @@ -0,0 +1,59 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2; -*- */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef ScriptCache_h +#define ScriptCache_h + +#include "mozilla/ScriptPreloader.h" +#include "mozilla/loader/PScriptCacheChild.h" +#include "mozilla/loader/PScriptCacheParent.h" + +namespace mozilla { +namespace ipc { +class FileDescriptor; +} + +namespace loader { + +using mozilla::ipc::FileDescriptor; +using mozilla::ipc::IPCResult; + +class ScriptCacheParent final : public PScriptCacheParent { + friend class PScriptCacheParent; + + public: + explicit ScriptCacheParent(bool wantCacheData) + : mWantCacheData(wantCacheData) {} + + protected: + IPCResult Recv__delete__(nsTArray<ScriptData>&& scripts); + + virtual void ActorDestroy(ActorDestroyReason aWhy) override; + + private: + bool mWantCacheData; +}; + +class ScriptCacheChild final : public PScriptCacheChild { + friend class mozilla::ScriptPreloader; + + public: + ScriptCacheChild() = default; + + void Init(const Maybe<FileDescriptor>& cacheFile, bool wantCacheData); + + protected: + virtual void ActorDestroy(ActorDestroyReason aWhy) override; + + void SendScriptsAndFinalize(ScriptPreloader::ScriptHash& scripts); + + private: + bool mWantCacheData = false; +}; + +} // namespace loader +} // namespace mozilla + +#endif // ScriptCache_h diff --git a/js/xpconnect/loader/ScriptPreloader-inl.h b/js/xpconnect/loader/ScriptPreloader-inl.h new file mode 100644 index 0000000000..86422ad084 --- /dev/null +++ b/js/xpconnect/loader/ScriptPreloader-inl.h @@ -0,0 +1,153 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2; -*- */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef ScriptPreloader_inl_h +#define ScriptPreloader_inl_h + +#include "mozilla/Attributes.h" +#include "mozilla/Assertions.h" +#include "mozilla/CheckedInt.h" +#include "mozilla/EndianUtils.h" +#include "mozilla/EnumSet.h" +#include "mozilla/Range.h" +#include "mozilla/ResultExtensions.h" +#include "mozilla/Unused.h" +#include "mozilla/dom/ScriptSettings.h" +#include "nsString.h" +#include "nsTArray.h" + +#include <prio.h> + +namespace mozilla { + +namespace loader { + +using mozilla::dom::AutoJSAPI; + +static inline Result<Ok, nsresult> Write(PRFileDesc* fd, const void* data, + int32_t len) { + if (PR_Write(fd, data, len) != len) { + return Err(NS_ERROR_FAILURE); + } + return Ok(); +} + +struct MOZ_RAII AutoSafeJSAPI : public AutoJSAPI { + AutoSafeJSAPI() { Init(); } +}; + +template <typename T> +struct Matcher; + +// Wraps the iterator for a nsTHashTable so that it may be used as a range +// iterator. Each iterator result acts as a smart pointer to the hash element, +// and has a Remove() method which will remove the element from the hash. +// +// It also accepts an optional Matcher instance against which to filter the +// elements which should be iterated over. +// +// Example: +// +// for (auto& elem : HashElemIter<HashType>(hash)) { +// if (elem->IsDead()) { +// elem.Remove(); +// } +// } +template <typename T> +class HashElemIter { + using Iterator = typename T::Iterator; + using ElemType = typename T::UserDataType; + + T& hash_; + Matcher<ElemType>* matcher_; + Maybe<Iterator> iter_; + + public: + explicit HashElemIter(T& hash, Matcher<ElemType>* matcher = nullptr) + : hash_(hash), matcher_(matcher) { + iter_.emplace(std::move(hash.Iter())); + } + + class Elem { + friend class HashElemIter<T>; + + HashElemIter<T>& iter_; + bool done_; + + Elem(HashElemIter& iter, bool done) : iter_(iter), done_(done) { + skipNonMatching(); + } + + Iterator& iter() { return iter_.iter_.ref(); } + + void skipNonMatching() { + if (iter_.matcher_) { + while (!done_ && !iter_.matcher_->Matches(get())) { + iter().Next(); + done_ = iter().Done(); + } + } + } + + public: + Elem& operator*() { return *this; } + + ElemType get() { + if (done_) { + return nullptr; + } + return iter().UserData(); + } + + const ElemType get() const { return const_cast<Elem*>(this)->get(); } + + ElemType operator->() { return get(); } + + const ElemType operator->() const { return get(); } + + operator ElemType() { return get(); } + + void Remove() { iter().Remove(); } + + Elem& operator++() { + MOZ_ASSERT(!done_); + + iter().Next(); + done_ = iter().Done(); + + skipNonMatching(); + return *this; + } + + bool operator!=(Elem& other) { + return done_ != other.done_ || this->get() != other.get(); + } + }; + + Elem begin() { return Elem(*this, iter_->Done()); } + + Elem end() { return Elem(*this, true); } +}; + +template <typename T> +HashElemIter<T> IterHash(T& hash, + Matcher<typename T::UserDataType>* matcher = nullptr) { + return HashElemIter<T>(hash, matcher); +} + +template <typename T, typename F> +bool Find(T&& iter, F&& match) { + for (auto& elem : iter) { + if (match(elem)) { + return true; + } + } + return false; +} + +}; // namespace loader +}; // namespace mozilla + +#endif // ScriptPreloader_inl_h diff --git a/js/xpconnect/loader/ScriptPreloader.cpp b/js/xpconnect/loader/ScriptPreloader.cpp new file mode 100644 index 0000000000..f53498a5e0 --- /dev/null +++ b/js/xpconnect/loader/ScriptPreloader.cpp @@ -0,0 +1,1247 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "ScriptPreloader-inl.h" +#include "mozilla/ScriptPreloader.h" +#include "mozilla/loader/ScriptCacheActors.h" + +#include "mozilla/URLPreloader.h" + +#include "mozilla/ArrayUtils.h" +#include "mozilla/ClearOnShutdown.h" +#include "mozilla/Components.h" +#include "mozilla/FileUtils.h" +#include "mozilla/IOBuffers.h" +#include "mozilla/Logging.h" +#include "mozilla/ScopeExit.h" +#include "mozilla/Services.h" +#include "mozilla/Telemetry.h" +#include "mozilla/Unused.h" +#include "mozilla/dom/ContentChild.h" +#include "mozilla/dom/ContentParent.h" +#include "mozilla/dom/Document.h" + +#include "js/CompileOptions.h" // JS::ReadOnlyCompileOptions +#include "MainThreadUtils.h" +#include "nsDebug.h" +#include "nsDirectoryServiceUtils.h" +#include "nsIFile.h" +#include "nsIObserverService.h" +#include "nsJSUtils.h" +#include "nsMemoryReporterManager.h" +#include "nsNetUtil.h" +#include "nsProxyRelease.h" +#include "nsThreadUtils.h" +#include "nsXULAppAPI.h" +#include "xpcpublic.h" + +#define STARTUP_COMPLETE_TOPIC "browser-delayed-startup-finished" +#define DOC_ELEM_INSERTED_TOPIC "document-element-inserted" +#define CONTENT_DOCUMENT_LOADED_TOPIC "content-document-loaded" +#define CACHE_WRITE_TOPIC "browser-idle-startup-tasks-finished" +#define CLEANUP_TOPIC "xpcom-shutdown" +#define CACHE_INVALIDATE_TOPIC "startupcache-invalidate" + +// The maximum time we'll wait for a child process to finish starting up before +// we send its script data back to the parent. +constexpr uint32_t CHILD_STARTUP_TIMEOUT_MS = 8000; + +namespace mozilla { +namespace { +static LazyLogModule gLog("ScriptPreloader"); + +#define LOG(level, ...) MOZ_LOG(gLog, LogLevel::level, (__VA_ARGS__)) +} // namespace + +using mozilla::dom::AutoJSAPI; +using mozilla::dom::ContentChild; +using mozilla::dom::ContentParent; +using namespace mozilla::loader; + +ProcessType ScriptPreloader::sProcessType; + +nsresult ScriptPreloader::CollectReports(nsIHandleReportCallback* aHandleReport, + nsISupports* aData, bool aAnonymize) { + MOZ_COLLECT_REPORT( + "explicit/script-preloader/heap/saved-scripts", KIND_HEAP, UNITS_BYTES, + SizeOfHashEntries<ScriptStatus::Saved>(mScripts, MallocSizeOf), + "Memory used to hold the scripts which have been executed in this " + "session, and will be written to the startup script cache file."); + + MOZ_COLLECT_REPORT( + "explicit/script-preloader/heap/restored-scripts", KIND_HEAP, UNITS_BYTES, + SizeOfHashEntries<ScriptStatus::Restored>(mScripts, MallocSizeOf), + "Memory used to hold the scripts which have been restored from the " + "startup script cache file, but have not been executed in this session."); + + MOZ_COLLECT_REPORT("explicit/script-preloader/heap/other", KIND_HEAP, + UNITS_BYTES, ShallowHeapSizeOfIncludingThis(MallocSizeOf), + "Memory used by the script cache service itself."); + + // Since the mem-mapped cache file is mapped into memory, we want to report + // it as explicit memory somewhere. But since the child cache is shared + // between all processes, we don't want to report it as explicit memory for + // all of them. So we report it as explicit only in the parent process, and + // non-explicit everywhere else. + if (XRE_IsParentProcess()) { + MOZ_COLLECT_REPORT("explicit/script-preloader/non-heap/memmapped-cache", + KIND_NONHEAP, UNITS_BYTES, + mCacheData.nonHeapSizeOfExcludingThis(), + "The memory-mapped startup script cache file."); + } else { + MOZ_COLLECT_REPORT("script-preloader-memmapped-cache", KIND_NONHEAP, + UNITS_BYTES, mCacheData.nonHeapSizeOfExcludingThis(), + "The memory-mapped startup script cache file."); + } + + return NS_OK; +} + +ScriptPreloader& ScriptPreloader::GetSingleton() { + static RefPtr<ScriptPreloader> singleton; + + if (!singleton) { + if (XRE_IsParentProcess()) { + singleton = new ScriptPreloader(); + singleton->mChildCache = &GetChildSingleton(); + Unused << singleton->InitCache(); + } else { + singleton = &GetChildSingleton(); + } + + ClearOnShutdown(&singleton); + } + + return *singleton; +} + +// The child singleton is available in all processes, including the parent, and +// is used for scripts which are expected to be loaded into child processes +// (such as process and frame scripts), or scripts that have already been loaded +// into a child. The child caches are managed as follows: +// +// - Every startup, we open the cache file from the last session, move it to a +// new location, and begin pre-loading the scripts that are stored in it. There +// is a separate cache file for parent and content processes, but the parent +// process opens both the parent and content cache files. +// +// - Once startup is complete, we write a new cache file for the next session, +// containing only the scripts that were used during early startup, so we +// don't waste pre-loading scripts that may not be needed. +// +// - For content processes, opening and writing the cache file is handled in the +// parent process. The first content process of each type sends back the data +// for scripts that were loaded in early startup, and the parent merges them +// and writes them to a cache file. +// +// - Currently, content processes only benefit from the cache data written +// during the *previous* session. Ideally, new content processes should +// probably use the cache data written during this session if there was no +// previous cache file, but I'd rather do that as a follow-up. +ScriptPreloader& ScriptPreloader::GetChildSingleton() { + static RefPtr<ScriptPreloader> singleton; + + if (!singleton) { + singleton = new ScriptPreloader(); + if (XRE_IsParentProcess()) { + Unused << singleton->InitCache(u"scriptCache-child"_ns); + } + ClearOnShutdown(&singleton); + } + + return *singleton; +} + +void ScriptPreloader::InitContentChild(ContentParent& parent) { + auto& cache = GetChildSingleton(); + + // We want startup script data from the first process of a given type. + // That process sends back its script data before it executes any + // untrusted code, and then we never accept further script data for that + // type of process for the rest of the session. + // + // The script data from each process type is merged with the data from the + // parent process's frame and process scripts, and shared between all + // content process types in the next session. + // + // Note that if the first process of a given type crashes or shuts down + // before sending us its script data, we silently ignore it, and data for + // that process type is not included in the next session's cache. This + // should be a sufficiently rare occurrence that it's not worth trying to + // handle specially. + auto processType = GetChildProcessType(parent.GetRemoteType()); + bool wantScriptData = !cache.mInitializedProcesses.contains(processType); + cache.mInitializedProcesses += processType; + + auto fd = cache.mCacheData.cloneFileDescriptor(); + // Don't send original cache data to new processes if the cache has been + // invalidated. + if (fd.IsValid() && !cache.mCacheInvalidated) { + Unused << parent.SendPScriptCacheConstructor(fd, wantScriptData); + } else { + Unused << parent.SendPScriptCacheConstructor(NS_ERROR_FILE_NOT_FOUND, + wantScriptData); + } +} + +ProcessType ScriptPreloader::GetChildProcessType(const nsACString& remoteType) { + if (remoteType == EXTENSION_REMOTE_TYPE) { + return ProcessType::Extension; + } + if (remoteType == PRIVILEGEDABOUT_REMOTE_TYPE) { + return ProcessType::PrivilegedAbout; + } + return ProcessType::Web; +} + +namespace { + +static void TraceOp(JSTracer* trc, void* data) { + auto preloader = static_cast<ScriptPreloader*>(data); + + preloader->Trace(trc); +} + +} // anonymous namespace + +void ScriptPreloader::Trace(JSTracer* trc) { + for (auto& script : IterHash(mScripts)) { + script->mScript.Trace(trc); + } +} + +ScriptPreloader::ScriptPreloader() + : mMonitor("[ScriptPreloader.mMonitor]"), + mSaveMonitor("[ScriptPreloader.mSaveMonitor]") { + // We do not set the process type for child processes here because the + // remoteType in ContentChild is not ready yet. + if (XRE_IsParentProcess()) { + sProcessType = ProcessType::Parent; + } + + nsCOMPtr<nsIObserverService> obs = services::GetObserverService(); + MOZ_RELEASE_ASSERT(obs); + + if (XRE_IsParentProcess()) { + // In the parent process, we want to freeze the script cache as soon + // as idle tasks for the first browser window have completed. + obs->AddObserver(this, STARTUP_COMPLETE_TOPIC, false); + obs->AddObserver(this, CACHE_WRITE_TOPIC, false); + } + + obs->AddObserver(this, CLEANUP_TOPIC, false); + obs->AddObserver(this, CACHE_INVALIDATE_TOPIC, false); + + AutoSafeJSAPI jsapi; + JS_AddExtraGCRootsTracer(jsapi.cx(), TraceOp, this); +} + +void ScriptPreloader::Cleanup() { + // Wait for any pending parses to finish before clearing the mScripts + // hashtable, since the parse tasks depend on memory allocated by those + // scripts. + { + MonitorAutoLock mal(mMonitor); + FinishPendingParses(mal); + + mScripts.Clear(); + } + + AutoSafeJSAPI jsapi; + JS_RemoveExtraGCRootsTracer(jsapi.cx(), TraceOp, this); + + UnregisterWeakMemoryReporter(this); +} + +void ScriptPreloader::StartCacheWrite() { + MOZ_DIAGNOSTIC_ASSERT(!mSaveThread); + + Unused << NS_NewNamedThread("SaveScripts", getter_AddRefs(mSaveThread), this); + + nsCOMPtr<nsIAsyncShutdownClient> barrier = GetShutdownBarrier(); + barrier->AddBlocker(this, NS_LITERAL_STRING_FROM_CSTRING(__FILE__), __LINE__, + u""_ns); +} + +void ScriptPreloader::InvalidateCache() { + { + mMonitor.AssertNotCurrentThreadOwns(); + MonitorAutoLock mal(mMonitor); + + // Wait for pending off-thread parses to finish, since they depend on the + // memory allocated by our CachedScripts, and can't be canceled + // asynchronously. + FinishPendingParses(mal); + + // Pending scripts should have been cleared by the above, and new parses + // should not have been queued. + MOZ_ASSERT(mParsingScripts.empty()); + MOZ_ASSERT(mParsingSources.empty()); + MOZ_ASSERT(mPendingScripts.isEmpty()); + + for (auto& script : IterHash(mScripts)) { + script.Remove(); + } + + // If we've already finished saving the cache at this point, start a new + // delayed save operation. This will write out an empty cache file in place + // of any cache file we've already written out this session, which will + // prevent us from falling back to the current session's cache file on the + // next startup. + if (mSaveComplete && mChildCache) { + mSaveComplete = false; + + StartCacheWrite(); + } + } + + { + MonitorAutoLock saveMonitorAutoLock(mSaveMonitor); + + mCacheInvalidated = true; + } + + // If we're waiting on a timeout to finish saving, interrupt it and just save + // immediately. + mSaveMonitor.NotifyAll(); +} + +nsresult ScriptPreloader::Observe(nsISupports* subject, const char* topic, + const char16_t* data) { + nsCOMPtr<nsIObserverService> obs = services::GetObserverService(); + if (!strcmp(topic, STARTUP_COMPLETE_TOPIC)) { + obs->RemoveObserver(this, STARTUP_COMPLETE_TOPIC); + + MOZ_ASSERT(XRE_IsParentProcess()); + + mStartupFinished = true; + } else if (!strcmp(topic, CACHE_WRITE_TOPIC)) { + obs->RemoveObserver(this, CACHE_WRITE_TOPIC); + + MOZ_ASSERT(mStartupFinished); + MOZ_ASSERT(XRE_IsParentProcess()); + + if (mChildCache && !mSaveComplete && !mSaveThread) { + StartCacheWrite(); + } + } else if (mContentStartupFinishedTopic.Equals(topic)) { + // If this is an uninitialized about:blank viewer or a chrome: document + // (which should always be an XBL binding document), ignore it. We don't + // have to worry about it loading malicious content. + if (nsCOMPtr<dom::Document> doc = do_QueryInterface(subject)) { + nsCOMPtr<nsIURI> uri = doc->GetDocumentURI(); + + if ((NS_IsAboutBlank(uri) && + doc->GetReadyStateEnum() == doc->READYSTATE_UNINITIALIZED) || + uri->SchemeIs("chrome")) { + return NS_OK; + } + } + FinishContentStartup(); + } else if (!strcmp(topic, "timer-callback")) { + FinishContentStartup(); + } else if (!strcmp(topic, CLEANUP_TOPIC)) { + Cleanup(); + } else if (!strcmp(topic, CACHE_INVALIDATE_TOPIC)) { + InvalidateCache(); + } + + return NS_OK; +} + +void ScriptPreloader::FinishContentStartup() { + MOZ_ASSERT(XRE_IsContentProcess()); + +#ifdef DEBUG + if (mContentStartupFinishedTopic.Equals(CONTENT_DOCUMENT_LOADED_TOPIC)) { + MOZ_ASSERT(sProcessType == ProcessType::PrivilegedAbout); + } else { + MOZ_ASSERT(sProcessType != ProcessType::PrivilegedAbout); + } +#endif /* DEBUG */ + + nsCOMPtr<nsIObserverService> obs = services::GetObserverService(); + obs->RemoveObserver(this, mContentStartupFinishedTopic.get()); + + mSaveTimer = nullptr; + + mStartupFinished = true; + + if (mChildActor) { + mChildActor->SendScriptsAndFinalize(mScripts); + } + +#ifdef XP_WIN + // Record the amount of USS at startup. This is Windows-only for now, + // we could turn it on for Linux relatively cheaply. On macOS it can have + // a perf impact. Only record this for non-privileged processes because + // privileged processes record this value at a different time, leading to + // a higher value which skews the telemetry. + if (sProcessType != ProcessType::PrivilegedAbout) { + mozilla::Telemetry::Accumulate( + mozilla::Telemetry::MEMORY_UNIQUE_CONTENT_STARTUP, + nsMemoryReporterManager::ResidentUnique() / 1024); + } +#endif +} + +bool ScriptPreloader::WillWriteScripts() { + return !mDataPrepared && (XRE_IsParentProcess() || mChildActor); +} + +Result<nsCOMPtr<nsIFile>, nsresult> ScriptPreloader::GetCacheFile( + const nsAString& suffix) { + NS_ENSURE_TRUE(mProfD, Err(NS_ERROR_NOT_INITIALIZED)); + + nsCOMPtr<nsIFile> cacheFile; + MOZ_TRY(mProfD->Clone(getter_AddRefs(cacheFile))); + + MOZ_TRY(cacheFile->AppendNative("startupCache"_ns)); + Unused << cacheFile->Create(nsIFile::DIRECTORY_TYPE, 0777); + + MOZ_TRY(cacheFile->Append(mBaseName + suffix)); + + return std::move(cacheFile); +} + +static const uint8_t MAGIC[] = "mozXDRcachev002"; + +Result<Ok, nsresult> ScriptPreloader::OpenCache() { + MOZ_TRY(NS_GetSpecialDirectory("ProfLDS", getter_AddRefs(mProfD))); + + nsCOMPtr<nsIFile> cacheFile; + MOZ_TRY_VAR(cacheFile, GetCacheFile(u".bin"_ns)); + + bool exists; + MOZ_TRY(cacheFile->Exists(&exists)); + if (exists) { + MOZ_TRY(cacheFile->MoveTo(nullptr, mBaseName + u"-current.bin"_ns)); + } else { + MOZ_TRY(cacheFile->SetLeafName(mBaseName + u"-current.bin"_ns)); + MOZ_TRY(cacheFile->Exists(&exists)); + if (!exists) { + return Err(NS_ERROR_FILE_NOT_FOUND); + } + } + + MOZ_TRY(mCacheData.init(cacheFile)); + + return Ok(); +} + +// Opens the script cache file for this session, and initializes the script +// cache based on its contents. See WriteCache for details of the cache file. +Result<Ok, nsresult> ScriptPreloader::InitCache(const nsAString& basePath) { + mCacheInitialized = true; + mBaseName = basePath; + + RegisterWeakMemoryReporter(this); + + if (!XRE_IsParentProcess()) { + return Ok(); + } + + // Grab the compilation scope before initializing the URLPreloader, since + // it's not safe to run component loader code during its critical section. + AutoSafeJSAPI jsapi; + JS::RootedObject scope(jsapi.cx(), xpc::CompilationScope()); + + // Note: Code on the main thread *must not access Omnijar in any way* until + // this AutoBeginReading guard is destroyed. + URLPreloader::AutoBeginReading abr; + + MOZ_TRY(OpenCache()); + + return InitCacheInternal(scope); +} + +Result<Ok, nsresult> ScriptPreloader::InitCache( + const Maybe<ipc::FileDescriptor>& cacheFile, ScriptCacheChild* cacheChild) { + MOZ_ASSERT(XRE_IsContentProcess()); + + mCacheInitialized = true; + mChildActor = cacheChild; + sProcessType = + GetChildProcessType(dom::ContentChild::GetSingleton()->GetRemoteType()); + + nsCOMPtr<nsIObserverService> obs = services::GetObserverService(); + MOZ_RELEASE_ASSERT(obs); + + if (sProcessType == ProcessType::PrivilegedAbout) { + // Since we control all of the documents loaded in the privileged + // content process, we can increase the window of active time for the + // ScriptPreloader to include the scripts that are loaded until the + // first document finishes loading. + mContentStartupFinishedTopic.AssignLiteral(CONTENT_DOCUMENT_LOADED_TOPIC); + } else { + // In the child process, we need to freeze the script cache before any + // untrusted code has been executed. The insertion of the first DOM + // document element may sometimes be earlier than is ideal, but at + // least it should always be safe. + mContentStartupFinishedTopic.AssignLiteral(DOC_ELEM_INSERTED_TOPIC); + } + obs->AddObserver(this, mContentStartupFinishedTopic.get(), false); + + RegisterWeakMemoryReporter(this); + + auto cleanup = MakeScopeExit([&] { + // If the parent is expecting cache data from us, make sure we send it + // before it writes out its cache file. For normal proceses, this isn't + // a concern, since they begin loading documents quite early. For the + // preloaded process, we may end up waiting a long time (or, indeed, + // never loading a document), so we need an additional timeout. + if (cacheChild) { + NS_NewTimerWithObserver(getter_AddRefs(mSaveTimer), this, + CHILD_STARTUP_TIMEOUT_MS, + nsITimer::TYPE_ONE_SHOT); + } + }); + + if (cacheFile.isNothing()) { + return Ok(); + } + + MOZ_TRY(mCacheData.init(cacheFile.ref())); + + return InitCacheInternal(); +} + +Result<Ok, nsresult> ScriptPreloader::InitCacheInternal( + JS::HandleObject scope) { + auto size = mCacheData.size(); + + uint32_t headerSize; + if (size < sizeof(MAGIC) + sizeof(headerSize)) { + return Err(NS_ERROR_UNEXPECTED); + } + + auto data = mCacheData.get<uint8_t>(); + auto end = data + size; + + if (memcmp(MAGIC, data.get(), sizeof(MAGIC))) { + return Err(NS_ERROR_UNEXPECTED); + } + data += sizeof(MAGIC); + + headerSize = LittleEndian::readUint32(data.get()); + data += sizeof(headerSize); + + if (data + headerSize > end) { + return Err(NS_ERROR_UNEXPECTED); + } + + { + auto cleanup = MakeScopeExit([&]() { mScripts.Clear(); }); + + LinkedList<CachedScript> scripts; + + Range<uint8_t> header(data, data + headerSize); + data += headerSize; + + InputBuffer buf(header); + + size_t offset = 0; + while (!buf.finished()) { + auto script = MakeUnique<CachedScript>(*this, buf); + MOZ_RELEASE_ASSERT(script); + + auto scriptData = data + script->mOffset; + if (scriptData + script->mSize > end) { + return Err(NS_ERROR_UNEXPECTED); + } + + // Make sure offsets match what we'd expect based on script ordering and + // size, as a basic sanity check. + if (script->mOffset != offset) { + return Err(NS_ERROR_UNEXPECTED); + } + offset += script->mSize; + + script->mXDRRange.emplace(scriptData, scriptData + script->mSize); + + // Don't pre-decode the script unless it was used in this process type + // during the previous session. + if (script->mOriginalProcessTypes.contains(CurrentProcessType())) { + scripts.insertBack(script.get()); + } else { + script->mReadyToExecute = true; + } + + mScripts.Put(script->mCachePath, script.get()); + Unused << script.release(); + } + + if (buf.error()) { + return Err(NS_ERROR_UNEXPECTED); + } + + mPendingScripts = std::move(scripts); + cleanup.release(); + } + + DecodeNextBatch(OFF_THREAD_FIRST_CHUNK_SIZE, scope); + return Ok(); +} + +void ScriptPreloader::PrepareCacheWriteInternal() { + MOZ_ASSERT(NS_IsMainThread()); + + mMonitor.AssertCurrentThreadOwns(); + + auto cleanup = MakeScopeExit([&]() { + if (mChildCache) { + mChildCache->PrepareCacheWrite(); + } + }); + + if (mDataPrepared) { + return; + } + + AutoSafeJSAPI jsapi; + bool found = false; + for (auto& script : IterHash(mScripts, Match<ScriptStatus::Saved>())) { + // Don't write any scripts that are also in the child cache. They'll be + // loaded from the child cache in that case, so there's no need to write + // them twice. + CachedScript* childScript = + mChildCache ? mChildCache->mScripts.Get(script->mCachePath) : nullptr; + if (childScript && !childScript->mProcessTypes.isEmpty()) { + childScript->UpdateLoadTime(script->mLoadTime); + childScript->mProcessTypes += script->mProcessTypes; + script.Remove(); + continue; + } + + if (!(script->mProcessTypes == script->mOriginalProcessTypes)) { + // Note: EnumSet doesn't support operator!=, hence the weird form above. + found = true; + } + + if (!script->mSize && !script->XDREncode(jsapi.cx())) { + script.Remove(); + } + } + + if (!found) { + mSaveComplete = true; + return; + } + + mDataPrepared = true; +} + +void ScriptPreloader::PrepareCacheWrite() { + MonitorAutoLock mal(mMonitor); + + PrepareCacheWriteInternal(); +} + +// Writes out a script cache file for the scripts accessed during early +// startup in this session. The cache file is a little-endian binary file with +// the following format: +// +// - A uint32 containing the size of the header block. +// +// - A header entry for each file stored in the cache containing: +// - The URL that the script was originally read from. +// - Its cache key. +// - The offset of its XDR data within the XDR data block. +// - The size of its XDR data in the XDR data block. +// - A bit field describing which process types the script is used in. +// +// - A block of XDR data for the encoded scripts, with each script's data at +// an offset from the start of the block, as specified above. +Result<Ok, nsresult> ScriptPreloader::WriteCache() { + MOZ_ASSERT(!NS_IsMainThread()); + + if (!mDataPrepared && !mSaveComplete) { + MonitorAutoUnlock mau(mSaveMonitor); + + NS_DispatchToMainThread( + NewRunnableMethod("ScriptPreloader::PrepareCacheWrite", this, + &ScriptPreloader::PrepareCacheWrite), + NS_DISPATCH_SYNC); + } + + if (mSaveComplete) { + // If we don't have anything we need to save, we're done. + return Ok(); + } + + nsCOMPtr<nsIFile> cacheFile; + MOZ_TRY_VAR(cacheFile, GetCacheFile(u"-new.bin"_ns)); + + bool exists; + MOZ_TRY(cacheFile->Exists(&exists)); + if (exists) { + MOZ_TRY(cacheFile->Remove(false)); + } + + { + AutoFDClose fd; + MOZ_TRY(cacheFile->OpenNSPRFileDesc(PR_WRONLY | PR_CREATE_FILE, 0644, + &fd.rwget())); + + // We also need to hold mMonitor while we're touching scripts in + // mScripts, or they may be freed before we're done with them. + mMonitor.AssertNotCurrentThreadOwns(); + MonitorAutoLock mal(mMonitor); + + nsTArray<CachedScript*> scripts; + for (auto& script : IterHash(mScripts, Match<ScriptStatus::Saved>())) { + scripts.AppendElement(script); + } + + // Sort scripts by load time, with async loaded scripts before sync scripts. + // Since async scripts are always loaded immediately at startup, it helps to + // have them stored contiguously. + scripts.Sort(CachedScript::Comparator()); + + OutputBuffer buf; + size_t offset = 0; + for (auto script : scripts) { + script->mOffset = offset; + script->Code(buf); + + offset += script->mSize; + } + + uint8_t headerSize[4]; + LittleEndian::writeUint32(headerSize, buf.cursor()); + + MOZ_TRY(Write(fd, MAGIC, sizeof(MAGIC))); + MOZ_TRY(Write(fd, headerSize, sizeof(headerSize))); + MOZ_TRY(Write(fd, buf.Get(), buf.cursor())); + for (auto script : scripts) { + MOZ_TRY(Write(fd, script->Range().begin().get(), script->mSize)); + + if (script->mScript) { + script->FreeData(); + } + } + } + + MOZ_TRY(cacheFile->MoveTo(nullptr, mBaseName + u".bin"_ns)); + + return Ok(); +} + +// Runs in the mSaveThread thread, and writes out the cache file for the next +// session after a reasonable delay. +nsresult ScriptPreloader::Run() { + MonitorAutoLock mal(mSaveMonitor); + + // Ideally wait about 10 seconds before saving, to avoid unnecessary IO + // during early startup. But only if the cache hasn't been invalidated, + // since that can trigger a new write during shutdown, and we don't want to + // cause shutdown hangs. + if (!mCacheInvalidated) { + mal.Wait(TimeDuration::FromSeconds(10)); + } + + auto result = URLPreloader::GetSingleton().WriteCache(); + Unused << NS_WARN_IF(result.isErr()); + + result = WriteCache(); + Unused << NS_WARN_IF(result.isErr()); + + result = mChildCache->WriteCache(); + Unused << NS_WARN_IF(result.isErr()); + + NS_DispatchToMainThread( + NewRunnableMethod("ScriptPreloader::CacheWriteComplete", this, + &ScriptPreloader::CacheWriteComplete), + NS_DISPATCH_NORMAL); + return NS_OK; +} + +void ScriptPreloader::CacheWriteComplete() { + mSaveThread->AsyncShutdown(); + mSaveThread = nullptr; + mSaveComplete = true; + + nsCOMPtr<nsIAsyncShutdownClient> barrier = GetShutdownBarrier(); + barrier->RemoveBlocker(this); +} + +void ScriptPreloader::NoteScript(const nsCString& url, + const nsCString& cachePath, + JS::HandleScript jsscript, bool isRunOnce) { + if (!Active()) { + if (isRunOnce) { + if (auto script = mScripts.Get(cachePath)) { + script->mIsRunOnce = true; + script->MaybeDropScript(); + } + } + return; + } + + // Don't bother trying to cache any URLs with cache-busting query + // parameters. + if (cachePath.FindChar('?') >= 0) { + return; + } + + // Don't bother caching files that belong to the mochitest harness. + constexpr auto mochikitPrefix = "chrome://mochikit/"_ns; + if (StringHead(url, mochikitPrefix.Length()) == mochikitPrefix) { + return; + } + + auto script = + mScripts.LookupOrAdd(cachePath, *this, url, cachePath, jsscript); + if (isRunOnce) { + script->mIsRunOnce = true; + } + + if (!script->MaybeDropScript() && !script->mScript) { + MOZ_ASSERT(jsscript); + script->mScript.Set(jsscript); + script->mReadyToExecute = true; + } + + script->UpdateLoadTime(TimeStamp::Now()); + script->mProcessTypes += CurrentProcessType(); +} + +void ScriptPreloader::NoteScript(const nsCString& url, + const nsCString& cachePath, + ProcessType processType, + nsTArray<uint8_t>&& xdrData, + TimeStamp loadTime) { + // After data has been prepared, there's no point in noting further scripts, + // since the cache either has already been written, or is about to be + // written. Any time prior to the data being prepared, we can safely mutate + // mScripts without locking. After that point, the save thread is free to + // access it, and we can't alter it without locking. + if (mDataPrepared) { + return; + } + + auto script = mScripts.LookupOrAdd(cachePath, *this, url, cachePath, nullptr); + + if (!script->HasRange()) { + MOZ_ASSERT(!script->HasArray()); + + script->mSize = xdrData.Length(); + script->mXDRData.construct<nsTArray<uint8_t>>( + std::forward<nsTArray<uint8_t>>(xdrData)); + + auto& data = script->Array(); + script->mXDRRange.emplace(data.Elements(), data.Length()); + } + + if (!script->mSize && !script->mScript) { + // If the content process is sending us a script entry for a script + // which was in the cache at startup, it expects us to already have this + // script data, so it doesn't send it. + // + // However, the cache may have been invalidated at this point (usually + // due to the add-on manager installing or uninstalling a legacy + // extension during very early startup), which means we may no longer + // have an entry for this script. Since that means we have no data to + // write to the new cache, and no JSScript to generate it from, we need + // to discard this entry. + mScripts.Remove(cachePath); + return; + } + + script->UpdateLoadTime(loadTime); + script->mProcessTypes += processType; +} + +/* static */ +void ScriptPreloader::FillCompileOptionsForCachedScript( + JS::CompileOptions& options) { + // See IsMultiDecodeCompileOptionsMatching in js/src/vm/JSScript.cpp. + options.setNoScriptRval(true); + MOZ_ASSERT(!options.selfHostingMode); + MOZ_ASSERT(!options.isRunOnce); +} + +JSScript* ScriptPreloader::GetCachedScript( + JSContext* cx, const JS::ReadOnlyCompileOptions& options, + const nsCString& path) { + // If a script is used by both the parent and the child, it's stored only + // in the child cache. + if (mChildCache) { + RootedScript script( + cx, mChildCache->GetCachedScriptInternal(cx, options, path)); + if (script) { + Telemetry::AccumulateCategorical( + Telemetry::LABELS_SCRIPT_PRELOADER_REQUESTS::HitChild); + return script; + } + } + + RootedScript script(cx, GetCachedScriptInternal(cx, options, path)); + Telemetry::AccumulateCategorical( + script ? Telemetry::LABELS_SCRIPT_PRELOADER_REQUESTS::Hit + : Telemetry::LABELS_SCRIPT_PRELOADER_REQUESTS::Miss); + return script; +} + +JSScript* ScriptPreloader::GetCachedScriptInternal( + JSContext* cx, const JS::ReadOnlyCompileOptions& options, + const nsCString& path) { + auto script = mScripts.Get(path); + if (script) { + return WaitForCachedScript(cx, options, script); + } + + return nullptr; +} + +JSScript* ScriptPreloader::WaitForCachedScript( + JSContext* cx, const JS::ReadOnlyCompileOptions& options, + CachedScript* script) { + // Always check for finished operations so that we can move on to decoding the + // next batch as soon as possible after the pending batch is ready. If we wait + // until we hit an unfinished script, we wind up having at most one batch of + // buffered scripts, and occasionally under-running that buffer. + if (JS::OffThreadToken* token = mToken.exchange(nullptr)) { + FinishOffThreadDecode(token); + } + + if (!script->mReadyToExecute) { + LOG(Info, "Must wait for async script load: %s\n", script->mURL.get()); + auto start = TimeStamp::Now(); + + // If script is small enough, we'd rather recompile on main-thread than wait + // for a decode task to complete. + if (script->mSize < MAX_MAINTHREAD_DECODE_SIZE) { + LOG(Info, "Script is small enough to recompile on main thread\n"); + + script->mReadyToExecute = true; + Telemetry::ScalarAdd( + Telemetry::ScalarID::SCRIPT_PRELOADER_MAINTHREAD_RECOMPILE, 1); + } else { + MonitorAutoLock mal(mMonitor); + + // Process script batches until our target is found. + while (!script->mReadyToExecute) { + if (JS::OffThreadToken* token = mToken.exchange(nullptr)) { + MonitorAutoUnlock mau(mMonitor); + FinishOffThreadDecode(token); + } else { + MOZ_ASSERT(!mParsingScripts.empty()); + mWaitingForDecode = true; + mal.Wait(); + mWaitingForDecode = false; + } + } + } + + double waitedMS = (TimeStamp::Now() - start).ToMilliseconds(); + Telemetry::Accumulate(Telemetry::SCRIPT_PRELOADER_WAIT_TIME, int(waitedMS)); + LOG(Debug, "Waited %fms\n", waitedMS); + } + + return script->GetJSScript(cx, options); +} + +/* static */ +void ScriptPreloader::OffThreadDecodeCallback(JS::OffThreadToken* token, + void* context) { + auto cache = static_cast<ScriptPreloader*>(context); + + // Make the token available to main-thread asynchronously. The lock below is + // used for Wait/Notify machinery and isn't needed to update the token itself. + MOZ_ALWAYS_FALSE(cache->mToken.exchange(token)); + + cache->mMonitor.AssertNotCurrentThreadOwns(); + MonitorAutoLock mal(cache->mMonitor); + + if (cache->mWaitingForDecode) { + // Wake up the blocked main thread. + mal.Notify(); + } else if (!cache->mFinishDecodeRunnablePending) { + // Issue a Runnable to ensure batches continue to decode even if the next + // WaitForCachedScript call has not happened yet. + cache->mFinishDecodeRunnablePending = true; + NS_DispatchToMainThread( + NewRunnableMethod("ScriptPreloader::DoFinishOffThreadDecode", cache, + &ScriptPreloader::DoFinishOffThreadDecode)); + } +} + +void ScriptPreloader::FinishPendingParses(MonitorAutoLock& aMal) { + mMonitor.AssertCurrentThreadOwns(); + + // Clear out scripts that we have not issued batch for yet. + mPendingScripts.clear(); + + // Process any pending decodes that are in flight. + while (!mParsingScripts.empty()) { + if (JS::OffThreadToken* token = mToken.exchange(nullptr)) { + MonitorAutoUnlock mau(mMonitor); + FinishOffThreadDecode(token); + } else { + mWaitingForDecode = true; + aMal.Wait(); + mWaitingForDecode = false; + } + } +} + +void ScriptPreloader::DoFinishOffThreadDecode() { + { + MonitorAutoLock mal(mMonitor); + mFinishDecodeRunnablePending = false; + } + + if (JS::OffThreadToken* token = mToken.exchange(nullptr)) { + FinishOffThreadDecode(token); + } +} + +void ScriptPreloader::FinishOffThreadDecode(JS::OffThreadToken* token) { + mMonitor.AssertNotCurrentThreadOwns(); + MOZ_ASSERT(token); + + auto cleanup = MakeScopeExit([&]() { + mParsingSources.clear(); + mParsingScripts.clear(); + + DecodeNextBatch(OFF_THREAD_CHUNK_SIZE); + }); + + AutoSafeJSAPI jsapi; + JSContext* cx = jsapi.cx(); + + JSAutoRealm ar(cx, xpc::CompilationScope()); + JS::Rooted<JS::ScriptVector> jsScripts(cx, JS::ScriptVector(cx)); + + // If this fails, we still need to mark the scripts as finished. Any that + // weren't successfully compiled in this operation (which should never + // happen under ordinary circumstances) will be re-decoded on the main + // thread, and raise the appropriate errors when they're executed. + // + // The exception from the off-thread decode operation will be reported when + // we pop the AutoJSAPI off the stack. + Unused << JS::FinishMultiOffThreadScriptsDecoder(cx, token, &jsScripts); + + unsigned i = 0; + for (auto script : mParsingScripts) { + LOG(Debug, "Finished off-thread decode of %s\n", script->mURL.get()); + if (i < jsScripts.length()) { + script->mScript.Set(jsScripts[i++]); + } + script->mReadyToExecute = true; + } +} + +void ScriptPreloader::DecodeNextBatch(size_t chunkSize, + JS::HandleObject scope) { + MOZ_ASSERT(mParsingSources.length() == 0); + MOZ_ASSERT(mParsingScripts.length() == 0); + + auto cleanup = MakeScopeExit([&]() { + mParsingScripts.clearAndFree(); + mParsingSources.clearAndFree(); + }); + + auto start = TimeStamp::Now(); + LOG(Debug, "Off-thread decoding scripts...\n"); + + size_t size = 0; + for (CachedScript* next = mPendingScripts.getFirst(); next;) { + auto script = next; + next = script->getNext(); + + // Skip any scripts that we decoded on the main thread rather than + // waiting for an off-thread operation to complete. + if (script->mReadyToExecute) { + script->remove(); + continue; + } + // If we have enough data for one chunk and this script would put us + // over our chunk size limit, we're done. + if (size > SMALL_SCRIPT_CHUNK_THRESHOLD && + size + script->mSize > chunkSize) { + break; + } + if (!mParsingScripts.append(script) || + !mParsingSources.emplaceBack(script->Range(), script->mURL.get(), 0)) { + break; + } + + LOG(Debug, "Beginning off-thread decode of script %s (%u bytes)\n", + script->mURL.get(), script->mSize); + + script->remove(); + size += script->mSize; + } + + if (size == 0 && mPendingScripts.isEmpty()) { + return; + } + + AutoSafeJSAPI jsapi; + JSContext* cx = jsapi.cx(); + JSAutoRealm ar(cx, scope ? scope : xpc::CompilationScope()); + + JS::CompileOptions options(cx); + FillCompileOptionsForCachedScript(options); + options.setSourceIsLazy(true); + + if (!JS::CanCompileOffThread(cx, options, size) || + !JS::DecodeMultiOffThreadScripts(cx, options, mParsingSources, + OffThreadDecodeCallback, + static_cast<void*>(this))) { + // If we fail here, we don't move on to process the next batch, so make + // sure we don't have any other scripts left to process. + MOZ_ASSERT(mPendingScripts.isEmpty()); + for (auto script : mPendingScripts) { + script->mReadyToExecute = true; + } + + LOG(Info, "Can't decode %lu bytes of scripts off-thread", + (unsigned long)size); + for (auto script : mParsingScripts) { + script->mReadyToExecute = true; + } + return; + } + + cleanup.release(); + + LOG(Debug, "Initialized decoding of %u scripts (%u bytes) in %fms\n", + (unsigned)mParsingSources.length(), (unsigned)size, + (TimeStamp::Now() - start).ToMilliseconds()); +} + +ScriptPreloader::CachedScript::CachedScript(ScriptPreloader& cache, + InputBuffer& buf) + : mCache(cache) { + Code(buf); + + // Swap the mProcessTypes and mOriginalProcessTypes values, since we want to + // start with an empty set of processes loaded into for this session, and + // compare against last session's values later. + mOriginalProcessTypes = mProcessTypes; + mProcessTypes = {}; +} + +// JS::TraceEdge() can change the value of mScript, but not whether it is +// null, so we don't update mHasScript to avoid a race. +void ScriptPreloader::CachedScript::ScriptHolder::Trace(JSTracer* trc) { + JS::TraceEdge(trc, &mScript, "ScriptPreloader::CachedScript.mScript"); +} + +void ScriptPreloader::CachedScript::ScriptHolder::Set( + JS::HandleScript jsscript) { + MOZ_ASSERT(NS_IsMainThread()); + mScript = jsscript; + mHasScript = mScript; +} + +void ScriptPreloader::CachedScript::ScriptHolder::Clear() { + MOZ_ASSERT(NS_IsMainThread()); + mScript = nullptr; + mHasScript = false; +} + +bool ScriptPreloader::CachedScript::XDREncode(JSContext* cx) { + auto cleanup = MakeScopeExit([&]() { MaybeDropScript(); }); + + JSAutoRealm ar(cx, mScript.Get()); + JS::RootedScript jsscript(cx, mScript.Get()); + + mXDRData.construct<JS::TranscodeBuffer>(); + + JS::TranscodeResult code = JS::EncodeScript(cx, Buffer(), jsscript); + if (code == JS::TranscodeResult_Ok) { + mXDRRange.emplace(Buffer().begin(), Buffer().length()); + mSize = Range().length(); + return true; + } + mXDRData.destroy(); + JS_ClearPendingException(cx); + return false; +} + +JSScript* ScriptPreloader::CachedScript::GetJSScript( + JSContext* cx, const JS::ReadOnlyCompileOptions& options) { + MOZ_ASSERT(mReadyToExecute); + if (mScript) { + if (JS::CheckCompileOptionsMatch(options, mScript.Get())) { + return mScript.Get(); + } + LOG(Error, "Cached script %s has different options\n", mURL.get()); + MOZ_DIAGNOSTIC_ASSERT(false, "Cached script has different options"); + } + + if (!HasRange()) { + // We've already executed the script, and thrown it away. But it wasn't + // in the cache at startup, so we don't have any data to decode. Give + // up. + return nullptr; + } + + // If we have no script at this point, the script was too small to decode + // off-thread, or it was needed before the off-thread compilation was + // finished, and is small enough to decode on the main thread rather than + // wait for the off-thread decoding to finish. In either case, we decode + // it synchronously the first time it's needed. + + auto start = TimeStamp::Now(); + LOG(Info, "Decoding script %s on main thread...\n", mURL.get()); + + JS::RootedScript script(cx); + if (JS::DecodeScript(cx, options, Range(), &script)) { + mScript.Set(script); + + if (mCache.mSaveComplete) { + FreeData(); + } + } + + LOG(Debug, "Finished decoding in %fms", + (TimeStamp::Now() - start).ToMilliseconds()); + + return mScript.Get(); +} + +// nsIAsyncShutdownBlocker + +nsresult ScriptPreloader::GetName(nsAString& aName) { + aName.AssignLiteral(u"ScriptPreloader: Saving bytecode cache"); + return NS_OK; +} + +nsresult ScriptPreloader::GetState(nsIPropertyBag** aState) { + *aState = nullptr; + return NS_OK; +} + +nsresult ScriptPreloader::BlockShutdown( + nsIAsyncShutdownClient* aBarrierClient) { + // If we're waiting on a timeout to finish saving, interrupt it and just save + // immediately. + mSaveMonitor.NotifyAll(); + return NS_OK; +} + +already_AddRefed<nsIAsyncShutdownClient> ScriptPreloader::GetShutdownBarrier() { + nsCOMPtr<nsIAsyncShutdownService> svc = components::AsyncShutdown::Service(); + MOZ_RELEASE_ASSERT(svc); + + nsCOMPtr<nsIAsyncShutdownClient> barrier; + Unused << svc->GetXpcomWillShutdown(getter_AddRefs(barrier)); + MOZ_RELEASE_ASSERT(barrier); + + return barrier.forget(); +} + +NS_IMPL_ISUPPORTS(ScriptPreloader, nsIObserver, nsIRunnable, nsIMemoryReporter, + nsIAsyncShutdownBlocker) + +#undef LOG + +} // namespace mozilla diff --git a/js/xpconnect/loader/ScriptPreloader.h b/js/xpconnect/loader/ScriptPreloader.h new file mode 100644 index 0000000000..7b04b7fe74 --- /dev/null +++ b/js/xpconnect/loader/ScriptPreloader.h @@ -0,0 +1,563 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2; -*- */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef ScriptPreloader_h +#define ScriptPreloader_h + +#include "mozilla/Atomics.h" +#include "mozilla/CheckedInt.h" +#include "mozilla/EnumSet.h" +#include "mozilla/LinkedList.h" +#include "mozilla/MemoryReporting.h" +#include "mozilla/Maybe.h" +#include "mozilla/MaybeOneOf.h" +#include "mozilla/Monitor.h" +#include "mozilla/Range.h" +#include "mozilla/Vector.h" +#include "mozilla/Result.h" +#include "mozilla/loader/AutoMemMap.h" +#include "nsClassHashtable.h" +#include "nsIAsyncShutdown.h" +#include "nsIFile.h" +#include "nsIMemoryReporter.h" +#include "nsIObserver.h" +#include "nsIThread.h" +#include "nsITimer.h" + +#include "js/GCAnnotations.h" // for JS_HAZ_NON_GC_POINTER +#include "js/RootingAPI.h" // for Handle, Heap +#include "js/Transcoding.h" // for TranscodeBuffer, TranscodeRange, TranscodeSources +#include "js/TypeDecls.h" // for HandleObject, HandleScript + +#include <prio.h> + +namespace JS { +class CompileOptions; +class OffThreadToken; +} // namespace JS + +namespace mozilla { +namespace dom { +class ContentParent; +} +namespace ipc { +class FileDescriptor; +} +namespace loader { +class InputBuffer; +class ScriptCacheChild; + +enum class ProcessType : uint8_t { + Uninitialized, + Parent, + Web, + Extension, + PrivilegedAbout, +}; + +template <typename T> +struct Matcher { + virtual bool Matches(T) = 0; +}; +} // namespace loader + +using namespace mozilla::loader; + +class ScriptPreloader : public nsIObserver, + public nsIMemoryReporter, + public nsIRunnable, + public nsIAsyncShutdownBlocker { + MOZ_DEFINE_MALLOC_SIZE_OF(MallocSizeOf) + + friend class mozilla::loader::ScriptCacheChild; + + public: + NS_DECL_THREADSAFE_ISUPPORTS + NS_DECL_NSIOBSERVER + NS_DECL_NSIMEMORYREPORTER + NS_DECL_NSIRUNNABLE + NS_DECL_NSIASYNCSHUTDOWNBLOCKER + + static ScriptPreloader& GetSingleton(); + static ScriptPreloader& GetChildSingleton(); + + static ProcessType GetChildProcessType(const nsACString& remoteType); + + // Fill some options that should be consistent across all scripts stored + // into preloader cache. + static void FillCompileOptionsForCachedScript(JS::CompileOptions& options); + + // Retrieves the script with the given cache key from the script cache. + // Returns null if the script is not cached. + JSScript* GetCachedScript(JSContext* cx, + const JS::ReadOnlyCompileOptions& options, + const nsCString& path); + + // Notes the execution of a script with the given URL and cache key. + // Depending on the stage of startup, the script may be serialized and + // stored to the startup script cache. + // + // If isRunOnce is true, this script is expected to run only once per + // process per browser session. A cached instance will not be kept alive + // for repeated execution. + void NoteScript(const nsCString& url, const nsCString& cachePath, + JS::HandleScript script, bool isRunOnce = false); + + void NoteScript(const nsCString& url, const nsCString& cachePath, + ProcessType processType, nsTArray<uint8_t>&& xdrData, + TimeStamp loadTime); + + // Initializes the script cache from the startup script cache file. + Result<Ok, nsresult> InitCache(const nsAString& = u"scriptCache"_ns); + + Result<Ok, nsresult> InitCache(const Maybe<ipc::FileDescriptor>& cacheFile, + ScriptCacheChild* cacheChild); + + bool Active() { return mCacheInitialized && !mStartupFinished; } + + private: + Result<Ok, nsresult> InitCacheInternal(JS::HandleObject scope = nullptr); + JSScript* GetCachedScriptInternal(JSContext* cx, + const JS::ReadOnlyCompileOptions& options, + const nsCString& path); + + public: + void Trace(JSTracer* trc); + + static ProcessType CurrentProcessType() { + MOZ_ASSERT(sProcessType != ProcessType::Uninitialized); + return sProcessType; + } + + static void InitContentChild(dom::ContentParent& parent); + + protected: + virtual ~ScriptPreloader() = default; + + private: + enum class ScriptStatus { + Restored, + Saved, + }; + + // Represents a cached JS script, either initially read from the script + // cache file, to be added to the next session's script cache file, or + // both. + // + // A script which was read from the cache file may be in any of the + // following states: + // + // - Read from the cache, and being compiled off thread. In this case, + // mReadyToExecute is false, and mToken is null. + // - Off-thread compilation has finished, but the script has not yet been + // executed. In this case, mReadyToExecute is true, and mToken has a + // non-null value. + // - Read from the cache, but too small or needed to immediately to be + // compiled off-thread. In this case, mReadyToExecute is true, and both + // mToken and mScript are null. + // - Fully decoded, and ready to be added to the next session's cache + // file. In this case, mReadyToExecute is true, and mScript is non-null. + // + // A script to be added to the next session's cache file always has a + // non-null mScript value. If it was read from the last session's cache + // file, it also has a non-empty mXDRRange range, which will be stored in + // the next session's cache file. If it was compiled in this session, its + // mXDRRange will initially be empty, and its mXDRData buffer will be + // populated just before it is written to the cache file. + class CachedScript : public LinkedListElement<CachedScript> { + public: + CachedScript(CachedScript&&) = delete; + + CachedScript(ScriptPreloader& cache, const nsCString& url, + const nsCString& cachePath, JSScript* script) + : mCache(cache), + mURL(url), + mCachePath(cachePath), + mScript(script), + mReadyToExecute(true), + mIsRunOnce(false) {} + + inline CachedScript(ScriptPreloader& cache, InputBuffer& buf); + + ~CachedScript() = default; + + ScriptStatus Status() const { + return mProcessTypes.isEmpty() ? ScriptStatus::Restored + : ScriptStatus::Saved; + } + + // For use with nsTArray::Sort. + // + // Orders scripts by script load time, so that scripts which are needed + // earlier are stored earlier, and scripts needed at approximately the + // same time are stored approximately contiguously. + struct Comparator { + bool Equals(const CachedScript* a, const CachedScript* b) const { + return a->mLoadTime == b->mLoadTime; + } + + bool LessThan(const CachedScript* a, const CachedScript* b) const { + return a->mLoadTime < b->mLoadTime; + } + }; + + struct StatusMatcher final : public Matcher<CachedScript*> { + explicit StatusMatcher(ScriptStatus status) : mStatus(status) {} + + virtual bool Matches(CachedScript* script) override { + return script->Status() == mStatus; + } + + const ScriptStatus mStatus; + }; + + // The purpose of this helper class is to avoid a race between + // ScriptPreloader::WriteCache() and the GC on a JSScript*. + // The former checks if the actual JSScript* is null on the save thread + // while holding mMonitor. Aside from GC tracing, all places that mutate + // the JSScript* either hold mMonitor or don't run at the same time as the + // save thread. The GC can move the script, which will cause the value to + // change, but this will not change whether it is null or not. + // + // We can't hold mMonitor while tracing, because we can end running the + // GC while the current thread already holds mMonitor. Instead, this class + // avoids the race by storing a separate field to indicate if the script is + // null or not. To enforce this, the mutation by the GC that cannot affect + // the nullness of the script is split out from other mutation. + class MOZ_HEAP_CLASS ScriptHolder { + public: + explicit ScriptHolder(JSScript* script) + : mScript(script), mHasScript(script) {} + ScriptHolder() : mHasScript(false) {} + + // This should only be called on the main thread (either while holding + // the preloader's mMonitor or while the save thread isn't running), or on + // the save thread while holding the preloader's mMonitor. + explicit operator bool() const { return mHasScript; } + + // This should only be called on the main thread. + JSScript* Get() const { + MOZ_ASSERT(NS_IsMainThread()); + return mScript; + } + + // This should only be called on the main thread (or from a GC thread + // while the main thread is GCing). + void Trace(JSTracer* trc); + + // These should only be called on the main thread, either while holding + // the preloader's mMonitor or while the save thread isn't running. + void Set(JS::HandleScript jsscript); + void Clear(); + + private: + JS::Heap<JSScript*> mScript; + bool mHasScript; // true iff mScript is non-null. + }; + + void FreeData() { + // If the script data isn't mmapped, we need to release both it + // and the Range that points to it at the same time. + if (!mXDRData.empty()) { + mXDRRange.reset(); + mXDRData.destroy(); + } + } + + void UpdateLoadTime(const TimeStamp& loadTime) { + if (mLoadTime.IsNull() || loadTime < mLoadTime) { + mLoadTime = loadTime; + } + } + + // Checks whether the cached JSScript for this entry will be needed + // again and, if not, drops it and returns true. This is the case for + // run-once scripts that do not still need to be encoded into the + // cache. + // + // If this method returns false, callers may set mScript to a cached + // JSScript instance for this entry. If it returns true, they should + // not. + bool MaybeDropScript() { + if (mIsRunOnce && (HasRange() || !mCache.WillWriteScripts())) { + mScript.Clear(); + return true; + } + return false; + } + + // Encodes this script into XDR data, and stores the result in mXDRData. + // Returns true on success, false on failure. + bool XDREncode(JSContext* cx); + + // Encodes or decodes this script, in the storage format required by the + // script cache file. + template <typename Buffer> + void Code(Buffer& buffer) { + buffer.codeString(mURL); + buffer.codeString(mCachePath); + buffer.codeUint32(mOffset); + buffer.codeUint32(mSize); + buffer.codeUint8(mProcessTypes); + } + + // Returns the XDR data generated for this script during this session. See + // mXDRData. + JS::TranscodeBuffer& Buffer() { + MOZ_ASSERT(HasBuffer()); + return mXDRData.ref<JS::TranscodeBuffer>(); + } + + bool HasBuffer() { return mXDRData.constructed<JS::TranscodeBuffer>(); } + + // Returns the read-only XDR data for this script. See mXDRRange. + const JS::TranscodeRange& Range() { + MOZ_ASSERT(HasRange()); + return mXDRRange.ref(); + } + + bool HasRange() { return mXDRRange.isSome(); } + + nsTArray<uint8_t>& Array() { + MOZ_ASSERT(HasArray()); + return mXDRData.ref<nsTArray<uint8_t>>(); + } + + bool HasArray() { return mXDRData.constructed<nsTArray<uint8_t>>(); } + + JSScript* GetJSScript(JSContext* cx, + const JS::ReadOnlyCompileOptions& options); + + size_t HeapSizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) { + auto size = mallocSizeOf(this); + + if (HasArray()) { + size += Array().ShallowSizeOfExcludingThis(mallocSizeOf); + } else if (HasBuffer()) { + size += Buffer().sizeOfExcludingThis(mallocSizeOf); + } else { + return size; + } + + // Note: mURL and mCachePath use the same string for scripts loaded + // by the message manager. The following statement avoids + // double-measuring in that case. + size += (mURL.SizeOfExcludingThisIfUnshared(mallocSizeOf) + + mCachePath.SizeOfExcludingThisEvenIfShared(mallocSizeOf)); + + return size; + } + + ScriptPreloader& mCache; + + // The URL from which this script was initially read and compiled. + nsCString mURL; + // A unique identifier for this script's filesystem location, used as a + // primary cache lookup value. + nsCString mCachePath; + + // The offset of this script in the cache file, from the start of the XDR + // data block. + uint32_t mOffset = 0; + // The size of this script's encoded XDR data. + uint32_t mSize = 0; + + TimeStamp mLoadTime{}; + + ScriptHolder mScript; + + // True if this script is ready to be executed. This means that either the + // off-thread portion of an off-thread decode has finished, or the script + // is too small to be decoded off-thread, and may be immediately decoded + // whenever it is first executed. + bool mReadyToExecute = false; + + // True if this script is expected to run once per process. If so, its + // JSScript instance will be dropped as soon as the script has + // executed and been encoded into the cache. + bool mIsRunOnce = false; + + // The set of processes in which this script has been used. + EnumSet<ProcessType> mProcessTypes{}; + + // The set of processes which the script was loaded into during the + // last session, as read from the cache file. + EnumSet<ProcessType> mOriginalProcessTypes{}; + + // The read-only XDR data for this script, which was either read from an + // existing cache file, or generated by encoding a script which was + // compiled during this session. + Maybe<JS::TranscodeRange> mXDRRange; + + // XDR data which was generated from a script compiled during this + // session, and will be written to the cache file. + MaybeOneOf<JS::TranscodeBuffer, nsTArray<uint8_t>> mXDRData; + } JS_HAZ_NON_GC_POINTER; + + template <ScriptStatus status> + static Matcher<CachedScript*>* Match() { + static CachedScript::StatusMatcher matcher{status}; + return &matcher; + } + + // There's a significant setup cost for each off-thread decode operation, + // so scripts are decoded in chunks to minimize the overhead. There's a + // careful balancing act in choosing the size of chunks, to minimize the + // number of decode operations, while also minimizing the number of buffer + // underruns that require the main thread to wait for a script to finish + // decoding. + // + // For the first chunk, we don't have much time between the start of the + // decode operation and the time the first script is needed, so that chunk + // needs to be fairly small. After the first chunk is finished, we have + // some buffered scripts to fall back on, and a lot more breathing room, + // so the chunks can be a bit bigger, but still not too big. + static constexpr int OFF_THREAD_FIRST_CHUNK_SIZE = 128 * 1024; + static constexpr int OFF_THREAD_CHUNK_SIZE = 512 * 1024; + + // Ideally, we want every chunk to be smaller than the chunk sizes + // specified above. However, if we have some number of small scripts + // followed by a huge script that would put us over the normal chunk size, + // we're better off processing them as a single chunk. + // + // In order to guarantee that the JS engine will process a chunk + // off-thread, it needs to be at least 100K (which is an implementation + // detail that can change at any time), so make sure that we always hit at + // least that size, with a bit of breathing room to be safe. + static constexpr int SMALL_SCRIPT_CHUNK_THRESHOLD = 128 * 1024; + + // The maximum size of scripts to re-decode on the main thread if off-thread + // decoding hasn't finished yet. In practice, we don't hit this very often, + // but when we do, re-decoding some smaller scripts on the main thread gives + // the background decoding a chance to catch up without blocking the main + // thread for quite as long. + static constexpr int MAX_MAINTHREAD_DECODE_SIZE = 50 * 1024; + + ScriptPreloader(); + + void Cleanup(); + + void FinishPendingParses(MonitorAutoLock& aMal); + void InvalidateCache(); + + // Opens the cache file for reading. + Result<Ok, nsresult> OpenCache(); + + // Writes a new cache file to disk. Must not be called on the main thread. + Result<Ok, nsresult> WriteCache(); + + void StartCacheWrite(); + + // Prepares scripts for writing to the cache, serializing new scripts to + // XDR, and calculating their size-based offsets. + void PrepareCacheWrite(); + + void PrepareCacheWriteInternal(); + + void CacheWriteComplete(); + + void FinishContentStartup(); + + // Returns true if scripts added to the cache now will be encoded and + // written to the cache. If we've already encoded scripts for the cache + // write, or this is a content process which hasn't been asked to return + // script bytecode, this will return false. + bool WillWriteScripts(); + + // Returns a file pointer for the cache file with the given name in the + // current profile. + Result<nsCOMPtr<nsIFile>, nsresult> GetCacheFile(const nsAString& suffix); + + // Waits for the given cached script to finish compiling off-thread, or + // decodes it synchronously on the main thread, as appropriate. + JSScript* WaitForCachedScript(JSContext* cx, + const JS::ReadOnlyCompileOptions& options, + CachedScript* script); + + void DecodeNextBatch(size_t chunkSize, JS::HandleObject scope = nullptr); + + static void OffThreadDecodeCallback(JS::OffThreadToken* token, void* context); + void FinishOffThreadDecode(JS::OffThreadToken* token); + void DoFinishOffThreadDecode(); + + already_AddRefed<nsIAsyncShutdownClient> GetShutdownBarrier(); + + size_t ShallowHeapSizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) { + return (mallocSizeOf(this) + + mScripts.ShallowSizeOfExcludingThis(mallocSizeOf) + + mallocSizeOf(mSaveThread.get()) + mallocSizeOf(mProfD.get())); + } + + using ScriptHash = nsClassHashtable<nsCStringHashKey, CachedScript>; + + template <ScriptStatus status> + static size_t SizeOfHashEntries(ScriptHash& scripts, + mozilla::MallocSizeOf mallocSizeOf) { + size_t size = 0; + for (auto elem : IterHash(scripts, Match<status>())) { + size += elem->HeapSizeOfIncludingThis(mallocSizeOf); + } + return size; + } + + ScriptHash mScripts; + + // True after we've shown the first window, and are no longer adding new + // scripts to the cache. + bool mStartupFinished = false; + + bool mCacheInitialized = false; + bool mSaveComplete = false; + bool mDataPrepared = false; + // May only be changed on the main thread, while `mSaveMonitor` is held. + bool mCacheInvalidated = false; + + // The list of scripts that we read from the initial startup cache file, + // but have yet to initiate a decode task for. + LinkedList<CachedScript> mPendingScripts; + + // The lists of scripts and their sources that make up the chunk currently + // being decoded in a background thread. + JS::TranscodeSources mParsingSources; + Vector<CachedScript*> mParsingScripts; + + // The token for the completed off-thread decode task. + Atomic<JS::OffThreadToken*, ReleaseAcquire> mToken{nullptr}; + + // True if a runnable has been dispatched to the main thread to finish an + // off-thread decode operation. Access only while 'mMonitor' is held. + bool mFinishDecodeRunnablePending = false; + + // True is main-thread is blocked and we should notify with Monitor. Access + // only while `mMonitor` is held. + bool mWaitingForDecode = false; + + // The process type of the current process. + static ProcessType sProcessType; + + // The process types for which remote processes have been initialized, and + // are expected to send back script data. + EnumSet<ProcessType> mInitializedProcesses{}; + + RefPtr<ScriptPreloader> mChildCache; + ScriptCacheChild* mChildActor = nullptr; + + nsString mBaseName; + nsCString mContentStartupFinishedTopic; + + nsCOMPtr<nsIFile> mProfD; + nsCOMPtr<nsIThread> mSaveThread; + nsCOMPtr<nsITimer> mSaveTimer; + + // The mmapped cache data from this session's cache file. + AutoMemMap mCacheData; + + Monitor mMonitor; + Monitor mSaveMonitor; +}; + +} // namespace mozilla + +#endif // ScriptPreloader_h diff --git a/js/xpconnect/loader/URLPreloader.cpp b/js/xpconnect/loader/URLPreloader.cpp new file mode 100644 index 0000000000..912b13235f --- /dev/null +++ b/js/xpconnect/loader/URLPreloader.cpp @@ -0,0 +1,682 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "ScriptPreloader-inl.h" +#include "mozilla/URLPreloader.h" +#include "mozilla/loader/AutoMemMap.h" + +#include "mozilla/ArrayUtils.h" +#include "mozilla/ClearOnShutdown.h" +#include "mozilla/FileUtils.h" +#include "mozilla/Logging.h" +#include "mozilla/ScopeExit.h" +#include "mozilla/Services.h" +#include "mozilla/Unused.h" +#include "mozilla/Vector.h" + +#include "MainThreadUtils.h" +#include "nsPrintfCString.h" +#include "nsDebug.h" +#include "nsIFile.h" +#include "nsIFileURL.h" +#include "nsIObserverService.h" +#include "nsNetUtil.h" +#include "nsPromiseFlatString.h" +#include "nsProxyRelease.h" +#include "nsThreadUtils.h" +#include "nsXULAppAPI.h" +#include "nsZipArchive.h" +#include "xpcpublic.h" + +#undef DELAYED_STARTUP_TOPIC +#define DELAYED_STARTUP_TOPIC "sessionstore-windows-restored" + +namespace mozilla { +namespace { +static LazyLogModule gURLLog("URLPreloader"); + +#define LOG(level, ...) MOZ_LOG(gURLLog, LogLevel::level, (__VA_ARGS__)) + +template <typename T> +bool StartsWith(const T& haystack, const T& needle) { + return StringHead(haystack, needle.Length()) == needle; +} +} // anonymous namespace + +using namespace mozilla::loader; + +nsresult URLPreloader::CollectReports(nsIHandleReportCallback* aHandleReport, + nsISupports* aData, bool aAnonymize) { + MOZ_COLLECT_REPORT("explicit/url-preloader/other", KIND_HEAP, UNITS_BYTES, + ShallowSizeOfIncludingThis(MallocSizeOf), + "Memory used by the URL preloader service itself."); + + for (const auto& elem : IterHash(mCachedURLs)) { + nsAutoCString pathName; + pathName.Append(elem->mPath); + // The backslashes will automatically be replaced with slashes in + // about:memory, without splitting each path component into a separate + // branch in the memory report tree. + pathName.ReplaceChar('/', '\\'); + + nsPrintfCString path("explicit/url-preloader/cached-urls/%s/[%s]", + elem->TypeString(), pathName.get()); + + aHandleReport->Callback( + ""_ns, path, KIND_HEAP, UNITS_BYTES, + elem->SizeOfIncludingThis(MallocSizeOf), + nsLiteralCString("Memory used to hold cache data for files which " + "have been read or pre-loaded during this session."), + aData); + } + + return NS_OK; +} + +// static +already_AddRefed<URLPreloader> URLPreloader::Create(bool* aInitialized) { + // The static APIs like URLPreloader::Read work in the child process because + // they fall back to a synchronous read. The actual preloader must be + // explicitly initialized, and this should only be done in the parent. + MOZ_RELEASE_ASSERT(XRE_IsParentProcess()); + + RefPtr<URLPreloader> preloader = new URLPreloader(); + if (preloader->InitInternal().isOk()) { + *aInitialized = true; + RegisterWeakMemoryReporter(preloader); + } else { + *aInitialized = false; + } + + return preloader.forget(); +} + +URLPreloader& URLPreloader::GetSingleton() { + if (!sSingleton) { + sSingleton = Create(&sInitialized); + ClearOnShutdown(&sSingleton); + } + + return *sSingleton; +} + +bool URLPreloader::sInitialized = false; + +StaticRefPtr<URLPreloader> URLPreloader::sSingleton; + +URLPreloader::~URLPreloader() { + if (sInitialized) { + UnregisterWeakMemoryReporter(this); + sInitialized = false; + } +} + +Result<Ok, nsresult> URLPreloader::InitInternal() { + MOZ_RELEASE_ASSERT(NS_IsMainThread()); + + if (Omnijar::HasOmnijar(Omnijar::GRE)) { + MOZ_TRY(Omnijar::GetURIString(Omnijar::GRE, mGREPrefix)); + } + if (Omnijar::HasOmnijar(Omnijar::APP)) { + MOZ_TRY(Omnijar::GetURIString(Omnijar::APP, mAppPrefix)); + } + + nsresult rv; + nsCOMPtr<nsIIOService> ios = do_GetIOService(&rv); + MOZ_TRY(rv); + + nsCOMPtr<nsIProtocolHandler> ph; + MOZ_TRY(ios->GetProtocolHandler("resource", getter_AddRefs(ph))); + + mResProto = do_QueryInterface(ph, &rv); + MOZ_TRY(rv); + + mChromeReg = services::GetChromeRegistry(); + if (!mChromeReg) { + return Err(NS_ERROR_UNEXPECTED); + } + + nsCOMPtr<nsIObserverService> obs = services::GetObserverService(); + + MOZ_TRY(obs->AddObserver(this, DELAYED_STARTUP_TOPIC, false)); + + MOZ_TRY(NS_GetSpecialDirectory("ProfLDS", getter_AddRefs(mProfD))); + + return Ok(); +} + +URLPreloader& URLPreloader::ReInitialize() { + MOZ_ASSERT(sSingleton); + sSingleton = Create(&sInitialized); + return *sSingleton; +} + +Result<nsCOMPtr<nsIFile>, nsresult> URLPreloader::GetCacheFile( + const nsAString& suffix) { + if (!mProfD) { + return Err(NS_ERROR_NOT_INITIALIZED); + } + + nsCOMPtr<nsIFile> cacheFile; + MOZ_TRY(mProfD->Clone(getter_AddRefs(cacheFile))); + + MOZ_TRY(cacheFile->AppendNative("startupCache"_ns)); + Unused << cacheFile->Create(nsIFile::DIRECTORY_TYPE, 0777); + + MOZ_TRY(cacheFile->Append(u"urlCache"_ns + suffix)); + + return std::move(cacheFile); +} + +static const uint8_t URL_MAGIC[] = "mozURLcachev002"; + +Result<nsCOMPtr<nsIFile>, nsresult> URLPreloader::FindCacheFile() { + nsCOMPtr<nsIFile> cacheFile; + MOZ_TRY_VAR(cacheFile, GetCacheFile(u".bin"_ns)); + + bool exists; + MOZ_TRY(cacheFile->Exists(&exists)); + if (exists) { + MOZ_TRY(cacheFile->MoveTo(nullptr, u"urlCache-current.bin"_ns)); + } else { + MOZ_TRY(cacheFile->SetLeafName(u"urlCache-current.bin"_ns)); + MOZ_TRY(cacheFile->Exists(&exists)); + if (!exists) { + return Err(NS_ERROR_FILE_NOT_FOUND); + } + } + + return std::move(cacheFile); +} + +Result<Ok, nsresult> URLPreloader::WriteCache() { + MOZ_ASSERT(!NS_IsMainThread()); + + // The script preloader might call us a second time, if it has to re-write + // its cache after a cache flush. We don't care about cache flushes, since + // our cache doesn't store any file data, only paths. And we currently clear + // our cached file list after the first write, which means that a second + // write would (aside from breaking the invariant that we never touch + // mCachedURLs off-main-thread after the first write, and trigger a data + // race) mean we get no pre-loading on the next startup. + if (mCacheWritten) { + return Ok(); + } + mCacheWritten = true; + + LOG(Debug, "Writing cache..."); + + nsCOMPtr<nsIFile> cacheFile; + MOZ_TRY_VAR(cacheFile, GetCacheFile(u"-new.bin"_ns)); + + bool exists; + MOZ_TRY(cacheFile->Exists(&exists)); + if (exists) { + MOZ_TRY(cacheFile->Remove(false)); + } + + { + AutoFDClose fd; + MOZ_TRY(cacheFile->OpenNSPRFileDesc(PR_WRONLY | PR_CREATE_FILE, 0644, + &fd.rwget())); + + nsTArray<URLEntry*> entries; + for (auto& entry : IterHash(mCachedURLs)) { + if (entry->mReadTime) { + entries.AppendElement(entry); + } + } + + entries.Sort(URLEntry::Comparator()); + + OutputBuffer buf; + for (auto entry : entries) { + entry->Code(buf); + } + + uint8_t headerSize[4]; + LittleEndian::writeUint32(headerSize, buf.cursor()); + + MOZ_TRY(Write(fd, URL_MAGIC, sizeof(URL_MAGIC))); + MOZ_TRY(Write(fd, headerSize, sizeof(headerSize))); + MOZ_TRY(Write(fd, buf.Get(), buf.cursor())); + } + + MOZ_TRY(cacheFile->MoveTo(nullptr, u"urlCache.bin"_ns)); + + NS_DispatchToMainThread( + NewRunnableMethod("URLPreloader::Cleanup", this, &URLPreloader::Cleanup)); + + return Ok(); +} + +void URLPreloader::Cleanup() { mCachedURLs.Clear(); } + +Result<Ok, nsresult> URLPreloader::ReadCache( + LinkedList<URLEntry>& pendingURLs) { + LOG(Debug, "Reading cache..."); + + nsCOMPtr<nsIFile> cacheFile; + MOZ_TRY_VAR(cacheFile, FindCacheFile()); + + AutoMemMap cache; + MOZ_TRY(cache.init(cacheFile)); + + auto size = cache.size(); + + uint32_t headerSize; + if (size < sizeof(URL_MAGIC) + sizeof(headerSize)) { + return Err(NS_ERROR_UNEXPECTED); + } + + auto data = cache.get<uint8_t>(); + auto end = data + size; + + if (memcmp(URL_MAGIC, data.get(), sizeof(URL_MAGIC))) { + return Err(NS_ERROR_UNEXPECTED); + } + data += sizeof(URL_MAGIC); + + headerSize = LittleEndian::readUint32(data.get()); + data += sizeof(headerSize); + + if (data + headerSize > end) { + return Err(NS_ERROR_UNEXPECTED); + } + + { + mMonitor.AssertCurrentThreadOwns(); + + auto cleanup = MakeScopeExit([&]() { + while (auto* elem = pendingURLs.getFirst()) { + elem->remove(); + } + mCachedURLs.Clear(); + }); + + Range<uint8_t> header(data, data + headerSize); + data += headerSize; + + InputBuffer buf(header); + while (!buf.finished()) { + CacheKey key(buf); + + LOG(Debug, "Cached file: %s %s", key.TypeString(), key.mPath.get()); + + auto entry = mCachedURLs.LookupOrAdd(key, key); + entry->mResultCode = NS_ERROR_NOT_INITIALIZED; + + pendingURLs.insertBack(entry); + } + + if (buf.error()) { + return Err(NS_ERROR_UNEXPECTED); + } + + cleanup.release(); + } + + return Ok(); +} + +void URLPreloader::BackgroundReadFiles() { + auto cleanup = MakeScopeExit([&]() { + auto lock = mReaderThread.Lock(); + auto& readerThread = lock.ref(); + NS_DispatchToMainThread(NewRunnableMethod( + "nsIThread::AsyncShutdown", readerThread, &nsIThread::AsyncShutdown)); + + readerThread = nullptr; + }); + + Vector<nsZipCursor> cursors; + LinkedList<URLEntry> pendingURLs; + { + MonitorAutoLock mal(mMonitor); + + if (ReadCache(pendingURLs).isErr()) { + mReaderInitialized = true; + mal.NotifyAll(); + return; + } + + int numZipEntries = 0; + for (auto entry : pendingURLs) { + if (entry->mType != entry->TypeFile) { + numZipEntries++; + } + } + MOZ_RELEASE_ASSERT(cursors.reserve(numZipEntries)); + + // Initialize the zip cursors for all files in Omnijar while the monitor + // is locked. Omnijar is not threadsafe, so the caller of + // AutoBeginReading guard must ensure that no code accesses Omnijar + // until this segment is done. Once the cursors have been initialized, + // the actual reading and decompression can safely be done off-thread, + // as is the case for thread-retargeted jar: channels. + for (auto entry : pendingURLs) { + if (entry->mType == entry->TypeFile) { + continue; + } + + RefPtr<nsZipArchive> zip = entry->Archive(); + if (!zip) { + MOZ_CRASH_UNSAFE_PRINTF( + "Failed to get Omnijar %s archive for entry (path: \"%s\")", + entry->TypeString(), entry->mPath.get()); + } + + auto item = zip->GetItem(entry->mPath.get()); + if (!item) { + entry->mResultCode = NS_ERROR_FILE_NOT_FOUND; + continue; + } + + size_t size = item->RealSize(); + + entry->mData.SetLength(size); + auto data = entry->mData.BeginWriting(); + + cursors.infallibleEmplaceBack(item, zip, reinterpret_cast<uint8_t*>(data), + size, true); + } + + mReaderInitialized = true; + mal.NotifyAll(); + } + + // Loop over the entries, read the file's contents, store them in the + // entry's mData pointer, and notify any waiting threads to check for + // completion. + uint32_t i = 0; + for (auto entry : pendingURLs) { + // If there is any other error code, the entry has already failed at + // this point, so don't bother trying to read it again. + if (entry->mResultCode != NS_ERROR_NOT_INITIALIZED) { + continue; + } + + nsresult rv = NS_OK; + + LOG(Debug, "Background reading %s file %s", entry->TypeString(), + entry->mPath.get()); + + if (entry->mType == entry->TypeFile) { + auto result = entry->Read(); + if (result.isErr()) { + rv = result.unwrapErr(); + } + } else { + auto& cursor = cursors[i++]; + + uint32_t len; + cursor.Copy(&len); + if (len != entry->mData.Length()) { + entry->mData.Truncate(); + rv = NS_ERROR_FAILURE; + } + } + + entry->mResultCode = rv; + mMonitor.NotifyAll(); + } + + // We're done reading pending entries, so clear the list. + pendingURLs.clear(); +} + +void URLPreloader::BeginBackgroundRead() { + auto lock = mReaderThread.Lock(); + auto& readerThread = lock.ref(); + if (!readerThread && !mReaderInitialized && sInitialized) { + nsresult rv; + rv = NS_NewNamedThread("BGReadURLs", getter_AddRefs(readerThread)); + if (NS_WARN_IF(NS_FAILED(rv))) { + return; + } + + nsCOMPtr<nsIRunnable> runnable = + NewRunnableMethod("URLPreloader::BackgroundReadFiles", this, + &URLPreloader::BackgroundReadFiles); + rv = readerThread->Dispatch(runnable.forget(), NS_DISPATCH_NORMAL); + if (NS_WARN_IF(NS_FAILED(rv))) { + // If we can't launch the task, just destroy the thread + readerThread = nullptr; + return; + } + } +} + +Result<nsCString, nsresult> URLPreloader::ReadInternal(const CacheKey& key, + ReadType readType) { + if (mStartupFinished) { + URLEntry entry(key); + + return entry.Read(); + } + + auto entry = mCachedURLs.LookupOrAdd(key, key); + + entry->UpdateUsedTime(); + + return entry->ReadOrWait(readType); +} + +Result<nsCString, nsresult> URLPreloader::ReadURIInternal(nsIURI* uri, + ReadType readType) { + CacheKey key; + MOZ_TRY_VAR(key, ResolveURI(uri)); + + return ReadInternal(key, readType); +} + +/* static */ Result<nsCString, nsresult> URLPreloader::Read(const CacheKey& key, + ReadType readType) { + // If we're being called before the preloader has been initialized (i.e., + // before the profile has been initialized), just fall back to a synchronous + // read. This happens when we're reading .ini and preference files that are + // needed to locate and initialize the profile. + if (!sInitialized) { + return URLEntry(key).Read(); + } + + return GetSingleton().ReadInternal(key, readType); +} + +/* static */ Result<nsCString, nsresult> URLPreloader::ReadURI( + nsIURI* uri, ReadType readType) { + if (!sInitialized) { + return Err(NS_ERROR_NOT_INITIALIZED); + } + + return GetSingleton().ReadURIInternal(uri, readType); +} + +/* static */ Result<nsCString, nsresult> URLPreloader::ReadFile( + nsIFile* file, ReadType readType) { + return Read(CacheKey(file), readType); +} + +/* static */ Result<nsCString, nsresult> URLPreloader::Read( + FileLocation& location, ReadType readType) { + if (location.IsZip()) { + if (location.GetBaseZip()) { + nsCString path; + location.GetPath(path); + return ReadZip(location.GetBaseZip(), path); + } + return URLEntry::ReadLocation(location); + } + + nsCOMPtr<nsIFile> file = location.GetBaseFile(); + return ReadFile(file, readType); +} + +/* static */ Result<nsCString, nsresult> URLPreloader::ReadZip( + nsZipArchive* zip, const nsACString& path, ReadType readType) { + // If the zip archive belongs to an Omnijar location, map it to a cache + // entry, and cache it as normal. Otherwise, simply read the entry + // synchronously, since other JAR archives are currently unsupported by the + // cache. + RefPtr<nsZipArchive> reader = Omnijar::GetReader(Omnijar::GRE); + if (zip == reader) { + CacheKey key(CacheKey::TypeGREJar, path); + return Read(key, readType); + } + + reader = Omnijar::GetReader(Omnijar::APP); + if (zip == reader) { + CacheKey key(CacheKey::TypeAppJar, path); + return Read(key, readType); + } + + // Not an Omnijar archive, so just read it directly. + FileLocation location(zip, PromiseFlatCString(path).BeginReading()); + return URLEntry::ReadLocation(location); +} + +Result<URLPreloader::CacheKey, nsresult> URLPreloader::ResolveURI(nsIURI* uri) { + nsCString spec; + nsCString scheme; + MOZ_TRY(uri->GetSpec(spec)); + MOZ_TRY(uri->GetScheme(scheme)); + + nsCOMPtr<nsIURI> resolved; + + // If the URI is a resource: or chrome: URI, first resolve it to the + // underlying URI that it wraps. + if (scheme.EqualsLiteral("resource")) { + MOZ_TRY(mResProto->ResolveURI(uri, spec)); + MOZ_TRY(NS_NewURI(getter_AddRefs(resolved), spec)); + } else if (scheme.EqualsLiteral("chrome")) { + MOZ_TRY(mChromeReg->ConvertChromeURL(uri, getter_AddRefs(resolved))); + MOZ_TRY(resolved->GetSpec(spec)); + } else { + resolved = uri; + } + MOZ_TRY(resolved->GetScheme(scheme)); + + // Try the GRE and App Omnijar prefixes. + if (mGREPrefix.Length() && StartsWith(spec, mGREPrefix)) { + return CacheKey(CacheKey::TypeGREJar, Substring(spec, mGREPrefix.Length())); + } + + if (mAppPrefix.Length() && StartsWith(spec, mAppPrefix)) { + return CacheKey(CacheKey::TypeAppJar, Substring(spec, mAppPrefix.Length())); + } + + // Try for a file URI. + if (scheme.EqualsLiteral("file")) { + nsCOMPtr<nsIFileURL> fileURL = do_QueryInterface(resolved); + MOZ_ASSERT(fileURL); + + nsCOMPtr<nsIFile> file; + MOZ_TRY(fileURL->GetFile(getter_AddRefs(file))); + + nsString path; + MOZ_TRY(file->GetPath(path)); + + return CacheKey(CacheKey::TypeFile, NS_ConvertUTF16toUTF8(path)); + } + + // Not a file or Omnijar URI, so currently unsupported. + return Err(NS_ERROR_INVALID_ARG); +} + +size_t URLPreloader::ShallowSizeOfIncludingThis( + mozilla::MallocSizeOf mallocSizeOf) { + return (mallocSizeOf(this) + + mAppPrefix.SizeOfExcludingThisEvenIfShared(mallocSizeOf) + + mGREPrefix.SizeOfExcludingThisEvenIfShared(mallocSizeOf) + + mCachedURLs.ShallowSizeOfExcludingThis(mallocSizeOf)); +} + +Result<FileLocation, nsresult> URLPreloader::CacheKey::ToFileLocation() { + if (mType == TypeFile) { + nsCOMPtr<nsIFile> file; + MOZ_TRY(NS_NewLocalFile(NS_ConvertUTF8toUTF16(mPath), false, + getter_AddRefs(file))); + return FileLocation(file); + } + + RefPtr<nsZipArchive> zip = Archive(); + return FileLocation(zip, mPath.get()); +} + +Result<nsCString, nsresult> URLPreloader::URLEntry::Read() { + FileLocation location; + MOZ_TRY_VAR(location, ToFileLocation()); + + MOZ_TRY_VAR(mData, ReadLocation(location)); + return mData; +} + +/* static */ Result<nsCString, nsresult> URLPreloader::URLEntry::ReadLocation( + FileLocation& location) { + FileLocation::Data data; + MOZ_TRY(location.GetData(data)); + + uint32_t size; + MOZ_TRY(data.GetSize(&size)); + + nsCString result; + result.SetLength(size); + MOZ_TRY(data.Copy(result.BeginWriting(), size)); + + return std::move(result); +} + +Result<nsCString, nsresult> URLPreloader::URLEntry::ReadOrWait( + ReadType readType) { + auto now = TimeStamp::Now(); + LOG(Info, "Reading %s\n", mPath.get()); + auto cleanup = MakeScopeExit([&]() { + LOG(Info, "Read in %fms\n", (TimeStamp::Now() - now).ToMilliseconds()); + }); + + if (mResultCode == NS_ERROR_NOT_INITIALIZED) { + MonitorAutoLock mal(GetSingleton().mMonitor); + + while (mResultCode == NS_ERROR_NOT_INITIALIZED) { + mal.Wait(); + } + } + + if (mResultCode == NS_OK && mData.IsVoid()) { + LOG(Info, "Reading synchronously...\n"); + return Read(); + } + + if (NS_FAILED(mResultCode)) { + return Err(mResultCode); + } + + nsCString res = mData; + + if (readType == Forget) { + mData.SetIsVoid(true); + } + return res; +} + +inline URLPreloader::CacheKey::CacheKey(InputBuffer& buffer) { Code(buffer); } + +nsresult URLPreloader::Observe(nsISupports* subject, const char* topic, + const char16_t* data) { + nsCOMPtr<nsIObserverService> obs = services::GetObserverService(); + if (!strcmp(topic, DELAYED_STARTUP_TOPIC)) { + obs->RemoveObserver(this, DELAYED_STARTUP_TOPIC); + mStartupFinished = true; + } + + return NS_OK; +} + +NS_IMPL_ISUPPORTS(URLPreloader, nsIObserver, nsIMemoryReporter) + +#undef LOG + +} // namespace mozilla diff --git a/js/xpconnect/loader/URLPreloader.h b/js/xpconnect/loader/URLPreloader.h new file mode 100644 index 0000000000..77daa680b7 --- /dev/null +++ b/js/xpconnect/loader/URLPreloader.h @@ -0,0 +1,316 @@ +/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 2; -*- */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef URLPreloader_h +#define URLPreloader_h + +#include "mozilla/DataMutex.h" +#include "mozilla/FileLocation.h" +#include "mozilla/HashFunctions.h" +#include "mozilla/LinkedList.h" +#include "mozilla/MemoryReporting.h" +#include "mozilla/Monitor.h" +#include "mozilla/Omnijar.h" +#include "mozilla/Range.h" +#include "mozilla/Vector.h" +#include "mozilla/Result.h" +#include "nsClassHashtable.h" +#include "nsHashKeys.h" +#include "nsIChromeRegistry.h" +#include "nsIFile.h" +#include "nsIURI.h" +#include "nsIMemoryReporter.h" +#include "nsIObserver.h" +#include "nsIResProtocolHandler.h" +#include "nsIThread.h" +#include "nsReadableUtils.h" + +class nsZipArchive; + +namespace mozilla { +namespace loader { +class InputBuffer; +} + +using namespace mozilla::loader; + +class ScriptPreloader; + +/** + * A singleton class to manage loading local URLs during startup, recording + * them, and pre-loading them during early startup in the next session. URLs + * that are not already loaded (or already being pre-loaded) when required are + * read synchronously from disk, and (if startup is not already complete) + * added to the pre-load list for the next session. + */ +class URLPreloader final : public nsIObserver, public nsIMemoryReporter { + MOZ_DEFINE_MALLOC_SIZE_OF(MallocSizeOf) + + URLPreloader() = default; + + public: + NS_DECL_THREADSAFE_ISUPPORTS + NS_DECL_NSIOBSERVER + NS_DECL_NSIMEMORYREPORTER + + static URLPreloader& GetSingleton(); + + // The type of read operation to perform. + enum ReadType { + // Read the file and then immediately forget its data. + Forget, + // Read the file and retain its data for the next caller. + Retain, + }; + + // Helpers to read the contents of files or JAR archive entries with various + // representations. If the preloader has not yet been initialized, or the + // given location is not supported by the cache, the entries will be read + // synchronously, and not stored in the cache. + static Result<nsCString, nsresult> Read(FileLocation& location, + ReadType readType = Forget); + + static Result<nsCString, nsresult> ReadURI(nsIURI* uri, + ReadType readType = Forget); + + static Result<nsCString, nsresult> ReadFile(nsIFile* file, + ReadType readType = Forget); + + static Result<nsCString, nsresult> ReadZip(nsZipArchive* archive, + const nsACString& path, + ReadType readType = Forget); + + private: + struct CacheKey; + + Result<nsCString, nsresult> ReadInternal(const CacheKey& key, + ReadType readType); + + Result<nsCString, nsresult> ReadURIInternal(nsIURI* uri, ReadType readType); + + Result<nsCString, nsresult> ReadFileInternal(nsIFile* file, + ReadType readType); + + static Result<nsCString, nsresult> Read(const CacheKey& key, + ReadType readType); + + static bool sInitialized; + + static mozilla::StaticRefPtr<URLPreloader> sSingleton; + + protected: + friend class AddonManagerStartup; + friend class ScriptPreloader; + + virtual ~URLPreloader(); + + Result<Ok, nsresult> WriteCache(); + + static URLPreloader& ReInitialize(); + + // Clear leftover entries after the cache has been written. + void Cleanup(); + + // Begins reading files off-thread, and ensures that initialization has + // completed before leaving the current scope. The caller *must* ensure that + // no code on the main thread access Omnijar, either directly or indirectly, + // for the lifetime of this guard object. + struct MOZ_RAII AutoBeginReading final { + AutoBeginReading() { GetSingleton().BeginBackgroundRead(); } + + ~AutoBeginReading() { + auto& reader = GetSingleton(); + + MonitorAutoLock mal(reader.mMonitor); + + while (!reader.mReaderInitialized && URLPreloader::sInitialized) { + mal.Wait(); + } + } + }; + + private: + // Represents a key for an entry in the URI cache, based on its file or JAR + // location. + struct CacheKey { + // The type of the entry. TypeAppJar and TypeGREJar entries are in the + // app-specific or toolkit Omnijar files, and are handled specially. + // TypeFile entries are plain files in the filesystem. + enum EntryType : uint8_t { + TypeAppJar, + TypeGREJar, + TypeFile, + }; + + CacheKey() = default; + CacheKey(const CacheKey& other) = default; + + CacheKey(EntryType type, const nsACString& path) + : mType(type), mPath(path) {} + + explicit CacheKey(nsIFile* file) : mType(TypeFile) { + nsString path; + MOZ_ALWAYS_SUCCEEDS(file->GetPath(path)); + CopyUTF16toUTF8(path, mPath); + } + + explicit inline CacheKey(InputBuffer& buffer); + + // Encodes or decodes the cache key for storage in a session cache file. + template <typename Buffer> + void Code(Buffer& buffer) { + buffer.codeUint8(*reinterpret_cast<uint8_t*>(&mType)); + buffer.codeString(mPath); + } + + uint32_t Hash() const { return HashGeneric(mType, HashString(mPath)); } + + bool operator==(const CacheKey& other) const { + return mType == other.mType && mPath == other.mPath; + } + + // Returns the Omnijar type for this entry. This may *only* be called + // for Omnijar entries. + Omnijar::Type OmnijarType() { + switch (mType) { + case TypeAppJar: + return Omnijar::APP; + case TypeGREJar: + return Omnijar::GRE; + default: + MOZ_CRASH("Unexpected entry type"); + return Omnijar::GRE; + } + } + + const char* TypeString() { + switch (mType) { + case TypeAppJar: + return "AppJar"; + case TypeGREJar: + return "GREJar"; + case TypeFile: + return "File"; + } + MOZ_ASSERT_UNREACHABLE("no such type"); + return ""; + } + + already_AddRefed<nsZipArchive> Archive() { + return Omnijar::GetReader(OmnijarType()); + } + + Result<FileLocation, nsresult> ToFileLocation(); + + EntryType mType = TypeFile; + + // The path of the entry. For Type*Jar entries, this is the path within + // the Omnijar archive. For TypeFile entries, this is the full path to + // the file. + nsCString mPath{}; + }; + + // Represents an entry in the URI cache. + struct URLEntry final : public CacheKey, public LinkedListElement<URLEntry> { + MOZ_IMPLICIT URLEntry(const CacheKey& key) + : CacheKey(key), mData(VoidCString()) {} + + explicit URLEntry(nsIFile* file) : CacheKey(file) {} + + // For use with nsTArray::Sort. + // + // Sorts entries by the time they were initially read during this + // session. + struct Comparator final { + bool Equals(const URLEntry* a, const URLEntry* b) const { + return a->mReadTime == b->mReadTime; + } + + bool LessThan(const URLEntry* a, const URLEntry* b) const { + return a->mReadTime < b->mReadTime; + } + }; + + // Sets the first-used time of this file to the earlier of its current + // first-use time or the given timestamp. + void UpdateUsedTime(const TimeStamp& time = TimeStamp::Now()) { + if (!mReadTime || time < mReadTime) { + mReadTime = time; + } + } + + Result<nsCString, nsresult> Read(); + static Result<nsCString, nsresult> ReadLocation(FileLocation& location); + + size_t SizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf) const { + return (mallocSizeOf(this) + + mPath.SizeOfExcludingThisEvenIfShared(mallocSizeOf) + + mData.SizeOfExcludingThisEvenIfShared(mallocSizeOf)); + } + + // Reads the contents of the file referenced by this entry, or wait for + // an off-thread read operation to finish if it is currently pending, + // and return the file's contents. + Result<nsCString, nsresult> ReadOrWait(ReadType readType); + + nsCString mData; + + TimeStamp mReadTime{}; + + nsresult mResultCode = NS_OK; + }; + + // Resolves the given URI to a CacheKey, if the URI is cacheable. + Result<CacheKey, nsresult> ResolveURI(nsIURI* uri); + + static already_AddRefed<URLPreloader> Create(bool* aInitialized); + + Result<Ok, nsresult> InitInternal(); + + // Returns a file pointer to the (possibly nonexistent) cache file with the + // given suffix. + Result<nsCOMPtr<nsIFile>, nsresult> GetCacheFile(const nsAString& suffix); + // Finds the correct cache file to use for this session. + Result<nsCOMPtr<nsIFile>, nsresult> FindCacheFile(); + + Result<Ok, nsresult> ReadCache(LinkedList<URLEntry>& pendingURLs); + + void BackgroundReadFiles(); + void BeginBackgroundRead(); + + using HashType = nsClassHashtable<nsGenericHashKey<CacheKey>, URLEntry>; + + size_t ShallowSizeOfIncludingThis(mozilla::MallocSizeOf mallocSizeOf); + + bool mStartupFinished = false; + bool mReaderInitialized = false; + + // Only to be accessed from the cache write thread. + bool mCacheWritten = false; + + // The prefix URLs for files in the GRE and App omni jar archives. + nsCString mGREPrefix; + nsCString mAppPrefix; + + nsCOMPtr<nsIResProtocolHandler> mResProto; + nsCOMPtr<nsIChromeRegistry> mChromeReg; + nsCOMPtr<nsIFile> mProfD; + + // Note: We use a RefPtr rather than an nsCOMPtr here because the + // AssertNoQueryNeeded checks done by getter_AddRefs happen at a time that + // violate data access invariants. It's wrapped in a mutex because + // the reader thread needs to be able to null this out to terminate itself. + DataMutex<RefPtr<nsIThread>> mReaderThread{"ReaderThread"}; + + // A map of URL entries which have were either read this session, or read + // from the last session's cache file. + HashType mCachedURLs; + + Monitor mMonitor{"[URLPreloader::mMutex]"}; +}; + +} // namespace mozilla + +#endif // URLPreloader_h diff --git a/js/xpconnect/loader/XPCOMUtils.jsm b/js/xpconnect/loader/XPCOMUtils.jsm new file mode 100644 index 0000000000..1a18c7a69b --- /dev/null +++ b/js/xpconnect/loader/XPCOMUtils.jsm @@ -0,0 +1,547 @@ +/* -*- indent-tabs-mode: nil; js-indent-level: 2 -*- + * vim: sw=2 ts=2 sts=2 et filetype=javascript + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +var EXPORTED_SYMBOLS = ["XPCOMUtils"]; + +let global = Cu.getGlobalForObject({}); + +// Some global imports expose additional symbols; for example, +// `Cu.importGlobalProperties(["MessageChannel"])` imports `MessageChannel` +// and `MessagePort`. This table maps those extra symbols to the main +// import name. +const EXTRA_GLOBAL_NAME_TO_IMPORT_NAME = { + Headers: "fetch", + MessagePort: "MessageChannel", + Request: "fetch", + Response: "fetch", +}; + +/** + * Redefines the given property on the given object with the given + * value. This can be used to redefine getter properties which do not + * implement setters. + */ +function redefine(object, prop, value) { + Object.defineProperty(object, prop, { + configurable: true, + enumerable: true, + value, + writable: true, + }); + return value; +} + +var XPCOMUtils = { + /** + * Defines a getter on a specified object that will be created upon first use. + * + * @param aObject + * The object to define the lazy getter on. + * @param aName + * The name of the getter to define on aObject. + * @param aLambda + * A function that returns what the getter should return. This will + * only ever be called once. + */ + defineLazyGetter: function XPCU_defineLazyGetter(aObject, aName, aLambda) + { + let redefining = false; + Object.defineProperty(aObject, aName, { + get: function () { + if (!redefining) { + // Make sure we don't get into an infinite recursion loop if + // the getter lambda does something shady. + redefining = true; + return redefine(aObject, aName, aLambda.apply(aObject)); + } + }, + configurable: true, + enumerable: true + }); + }, + + /** + * Defines a getter on a specified object for a script. The script will not + * be loaded until first use. + * + * @param aObject + * The object to define the lazy getter on. + * @param aNames + * The name of the getter to define on aObject for the script. + * This can be a string if the script exports only one symbol, + * or an array of strings if the script can be first accessed + * from several different symbols. + * @param aResource + * The URL used to obtain the script. + */ + defineLazyScriptGetter: function XPCU_defineLazyScriptGetter(aObject, aNames, + aResource) + { + if (!Array.isArray(aNames)) { + aNames = [aNames]; + } + for (let name of aNames) { + Object.defineProperty(aObject, name, { + get: function() { + Services.scriptloader.loadSubScript(aResource, aObject); + return aObject[name]; + }, + set(value) { + redefine(aObject, name, value); + }, + configurable: true, + enumerable: true + }); + } + }, + + /** + * Defines a getter property on the given object for each of the given + * global names as accepted by Cu.importGlobalProperties. These + * properties are imported into the shared JSM module global, and then + * copied onto the given object, no matter which global the object + * belongs to. + * + * @param {object} aObject + * The object on which to define the properties. + * @param {string[]} aNames + * The list of global properties to define. + */ + defineLazyGlobalGetters(aObject, aNames) { + for (let name of aNames) { + this.defineLazyGetter(aObject, name, () => { + if (!(name in global)) { + let importName = EXTRA_GLOBAL_NAME_TO_IMPORT_NAME[name] || name; + Cu.importGlobalProperties([importName]); + } + return global[name]; + }); + } + }, + + /** + * Defines a getter on a specified object for a service. The service will not + * be obtained until first use. + * + * @param aObject + * The object to define the lazy getter on. + * @param aName + * The name of the getter to define on aObject for the service. + * @param aContract + * The contract used to obtain the service. + * @param aInterfaceName + * The name of the interface to query the service to. + */ + defineLazyServiceGetter: function XPCU_defineLazyServiceGetter(aObject, aName, + aContract, + aInterfaceName) + { + this.defineLazyGetter(aObject, aName, function XPCU_serviceLambda() { + if (aInterfaceName) { + return Cc[aContract].getService(Ci[aInterfaceName]); + } + return Cc[aContract].getService().wrappedJSObject; + }); + }, + + /** + * Defines a lazy service getter on a specified object for each + * property in the given object. + * + * @param aObject + * The object to define the lazy getter on. + * @param aServices + * An object with a property for each service to be + * imported, where the property name is the name of the + * symbol to define, and the value is a 1 or 2 element array + * containing the contract ID and, optionally, the interface + * name of the service, as passed to defineLazyServiceGetter. + */ + defineLazyServiceGetters: function XPCU_defineLazyServiceGetters( + aObject, aServices) + { + for (let [name, service] of Object.entries(aServices)) { + // Note: This is hot code, and cross-compartment array wrappers + // are not JIT-friendly to destructuring or spread operators, so + // we need to use indexed access instead. + this.defineLazyServiceGetter(aObject, name, service[0], service[1] || null); + } + }, + + /** + * Defines a getter on a specified object for a module. The module will not + * be imported until first use. The getter allows to execute setup and + * teardown code (e.g. to register/unregister to services) and accepts + * a proxy object which acts on behalf of the module until it is imported. + * + * @param aObject + * The object to define the lazy getter on. + * @param aName + * The name of the getter to define on aObject for the module. + * @param aResource + * The URL used to obtain the module. + * @param aSymbol + * The name of the symbol exported by the module. + * This parameter is optional and defaults to aName. + * @param aPreLambda + * A function that is executed when the proxy is set up. + * This will only ever be called once. + * @param aPostLambda + * A function that is executed when the module has been imported to + * run optional teardown procedures on the proxy object. + * This will only ever be called once. + * @param aProxy + * An object which acts on behalf of the module to be imported until + * the module has been imported. + */ + defineLazyModuleGetter: function XPCU_defineLazyModuleGetter( + aObject, aName, aResource, aSymbol, + aPreLambda, aPostLambda, aProxy) + { + if (arguments.length == 3) { + return ChromeUtils.defineModuleGetter(aObject, aName, aResource); + } + + let proxy = aProxy || {}; + + if (typeof(aPreLambda) === "function") { + aPreLambda.apply(proxy); + } + + this.defineLazyGetter(aObject, aName, function XPCU_moduleLambda() { + var temp = {}; + try { + ChromeUtils.import(aResource, temp); + + if (typeof(aPostLambda) === "function") { + aPostLambda.apply(proxy); + } + } catch (ex) { + Cu.reportError("Failed to load module " + aResource + "."); + throw ex; + } + return temp[aSymbol || aName]; + }); + }, + + /** + * Defines a lazy module getter on a specified object for each + * property in the given object. + * + * @param aObject + * The object to define the lazy getter on. + * @param aModules + * An object with a property for each module property to be + * imported, where the property name is the name of the + * imported symbol and the value is the module URI. + */ + defineLazyModuleGetters: function XPCU_defineLazyModuleGetters( + aObject, aModules) + { + for (let [name, module] of Object.entries(aModules)) { + ChromeUtils.defineModuleGetter(aObject, name, module); + } + }, + + /** + * Defines a getter on a specified object for preference value. The + * preference is read the first time that the property is accessed, + * and is thereafter kept up-to-date using a preference observer. + * + * @param aObject + * The object to define the lazy getter on. + * @param aName + * The name of the getter property to define on aObject. + * @param aPreference + * The name of the preference to read. + * @param aDefaultValue + * The default value to use, if the preference is not defined. + * @param aOnUpdate + * A function to call upon update. Receives as arguments + * `(aPreference, previousValue, newValue)` + * @param aTransform + * An optional function to transform the value. If provided, + * this function receives the new preference value as an argument + * and its return value is used by the getter. + */ + defineLazyPreferenceGetter: function XPCU_defineLazyPreferenceGetter( + aObject, aName, aPreference, + aDefaultValue = null, + aOnUpdate = null, + aTransform = val => val) + { + // Note: We need to keep a reference to this observer alive as long + // as aObject is alive. This means that all of our getters need to + // explicitly close over the variable that holds the object, and we + // cannot define a value in place of a getter after we read the + // preference. + let observer = { + QueryInterface: XPCU_lazyPreferenceObserverQI, + + value: undefined, + + observe(subject, topic, data) { + if (data == aPreference) { + if (aOnUpdate) { + let previous = this.value; + + // Fetch and cache value. + this.value = undefined; + let latest = lazyGetter(); + aOnUpdate(data, previous, latest); + } else { + + // Empty cache, next call to the getter will cause refetch. + this.value = undefined; + } + } + }, + } + + let defineGetter = get => { + Object.defineProperty(aObject, aName, { + configurable: true, + enumerable: true, + get, + }); + }; + + function lazyGetter() { + if (observer.value === undefined) { + let prefValue; + switch (Services.prefs.getPrefType(aPreference)) { + case Ci.nsIPrefBranch.PREF_STRING: + prefValue = Services.prefs.getStringPref(aPreference); + break; + + case Ci.nsIPrefBranch.PREF_INT: + prefValue = Services.prefs.getIntPref(aPreference); + break; + + case Ci.nsIPrefBranch.PREF_BOOL: + prefValue = Services.prefs.getBoolPref(aPreference); + break; + + case Ci.nsIPrefBranch.PREF_INVALID: + prefValue = aDefaultValue; + break; + + default: + // This should never happen. + throw new Error(`Error getting pref ${aPreference}; its value's type is ` + + `${Services.prefs.getPrefType(aPreference)}, which I don't ` + + `know how to handle.`); + } + + observer.value = aTransform(prefValue); + } + return observer.value; + } + + defineGetter(() => { + Services.prefs.addObserver(aPreference, observer, true); + + defineGetter(lazyGetter); + return lazyGetter(); + }); + }, + + /** + * Defines a non-writable property on an object. + */ + defineConstant: function XPCOMUtils__defineConstant(aObj, aName, aValue) { + Object.defineProperty(aObj, aName, { + value: aValue, + enumerable: true, + writable: false + }); + }, + + /** + * Defines a proxy which acts as a lazy object getter that can be passed + * around as a reference, and will only be evaluated when something in + * that object gets accessed. + * + * The evaluation can be triggered by a function call, by getting or + * setting a property, calling this as a constructor, or enumerating + * the properties of this object (e.g. during an iteration). + * + * Please note that, even after evaluated, the object given to you + * remains being the proxy object (which forwards everything to the + * real object). This is important to correctly use these objects + * in pairs of add+remove listeners, for example. + * If your use case requires access to the direct object, you can + * get it through the untrap callback. + * + * @param aObject + * The object to define the lazy getter on. + * + * You can pass null to aObject if you just want to get this + * proxy through the return value. + * + * @param aName + * The name of the getter to define on aObject. + * + * @param aInitFuncOrResource + * A function or a module that defines what this object actually + * should be when it gets evaluated. This will only ever be called once. + * + * Short-hand: If you pass a string to this parameter, it will be treated + * as the URI of a module to be imported, and aName will be used as + * the symbol to retrieve from the module. + * + * @param aStubProperties + * In this parameter, you can provide an object which contains + * properties from the original object that, when accessed, will still + * prevent the entire object from being evaluated. + * + * These can be copies or simplified versions of the original properties. + * + * One example is to provide an alternative QueryInterface implementation + * to avoid the entire object from being evaluated when it's added as an + * observer (as addObserver calls object.QueryInterface(Ci.nsIObserver)). + * + * Once the object has been evaluated, the properties from the real + * object will be used instead of the ones provided here. + * + * @param aUntrapCallback + * A function that gets called once when the object has just been evaluated. + * You can use this to do some work (e.g. setting properties) that you need + * to do on this object but that can wait until it gets evaluated. + * + * Another use case for this is to use during code development to log when + * this object gets evaluated, to make sure you're not accidentally triggering + * it earlier than expected. + */ + defineLazyProxy: function XPCOMUtils__defineLazyProxy(aObject, aName, aInitFuncOrResource, + aStubProperties, aUntrapCallback) { + let initFunc = aInitFuncOrResource; + + if (typeof(aInitFuncOrResource) == "string") { + initFunc = function () { + let tmp = {}; + ChromeUtils.import(aInitFuncOrResource, tmp); + return tmp[aName]; + }; + } + + let handler = new LazyProxyHandler(aName, initFunc, + aStubProperties, aUntrapCallback); + + /* + * We cannot simply create a lazy getter for the underlying + * object and pass it as the target of the proxy, because + * just passing it in `new Proxy` means it would get + * evaluated. Becase of this, a full handler needs to be + * implemented (the LazyProxyHandler). + * + * So, an empty object is used as the target, and the handler + * replaces it on every call with the real object. + */ + let proxy = new Proxy({}, handler); + + if (aObject) { + Object.defineProperty(aObject, aName, { + value: proxy, + enumerable: true, + writable: true, + }); + } + + return proxy; + }, +}; + +/** + * LazyProxyHandler + * This class implements the handler used + * in the proxy from defineLazyProxy. + * + * This handler forwards all calls to an underlying object, + * stored as `this.realObject`, which is obtained as the returned + * value from aInitFunc, which will be called on the first time + * time that it needs to be used (with an exception in the get() trap + * for the properties provided in the `aStubProperties` parameter). + */ + +class LazyProxyHandler { + constructor(aName, aInitFunc, aStubProperties, aUntrapCallback) { + this.pending = true; + this.name = aName; + this.initFuncOrResource = aInitFunc; + this.stubProperties = aStubProperties; + this.untrapCallback = aUntrapCallback; + } + + getObject() { + if (this.pending) { + this.realObject = this.initFuncOrResource.call(null); + + if (this.untrapCallback) { + this.untrapCallback.call(null, this.realObject); + this.untrapCallback = null; + } + + this.pending = false; + this.stubProperties = null; + } + return this.realObject; + } + + getPrototypeOf(target) { + return Reflect.getPrototypeOf(this.getObject()); + } + + setPrototypeOf(target, prototype) { + return Reflect.setPrototypeOf(this.getObject(), prototype); + } + + isExtensible(target) { + return Reflect.isExtensible(this.getObject()); + } + + preventExtensions(target) { + return Reflect.preventExtensions(this.getObject()); + } + + getOwnPropertyDescriptor(target, prop) { + return Reflect.getOwnPropertyDescriptor(this.getObject(), prop); + } + + defineProperty(target, prop, descriptor) { + return Reflect.defineProperty(this.getObject(), prop, descriptor); + } + + has(target, prop) { + return Reflect.has(this.getObject(), prop); + } + + get(target, prop, receiver) { + if (this.pending && + this.stubProperties && + Object.prototype.hasOwnProperty.call(this.stubProperties, prop)) { + return this.stubProperties[prop]; + } + return Reflect.get(this.getObject(), prop, receiver); + } + + set(target, prop, value, receiver) { + return Reflect.set(this.getObject(), prop, value, receiver); + } + + deleteProperty(target, prop) { + return Reflect.deleteProperty(this.getObject(), prop); + } + + ownKeys(target) { + return Reflect.ownKeys(this.getObject()); + } +} + +var XPCU_lazyPreferenceObserverQI = ChromeUtils.generateQI(["nsIObserver", "nsISupportsWeakReference"]); + +ChromeUtils.defineModuleGetter(this, "Services", + "resource://gre/modules/Services.jsm"); diff --git a/js/xpconnect/loader/moz.build b/js/xpconnect/loader/moz.build new file mode 100644 index 0000000000..926d3ce0de --- /dev/null +++ b/js/xpconnect/loader/moz.build @@ -0,0 +1,63 @@ +# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*- +# vim: set filetype=python: +# This Source Code Form is subject to the terms of the Mozilla Public +# License, v. 2.0. If a copy of the MPL was not distributed with this +# file, You can obtain one at http://mozilla.org/MPL/2.0/. + +UNIFIED_SOURCES += [ + "AutoMemMap.cpp", + "ChromeScriptLoader.cpp", + "mozJSLoaderUtils.cpp", + "mozJSSubScriptLoader.cpp", + "nsImportModule.cpp", + "ScriptCacheActors.cpp", + "ScriptPreloader.cpp", + "URLPreloader.cpp", +] + +# mozJSComponentLoader.cpp cannot be built in unified mode because it uses +# windows.h +SOURCES += [ + "mozJSComponentLoader.cpp", +] + +IPDL_SOURCES += [ + "PScriptCache.ipdl", +] + +EXPORTS += ["nsImportModule.h"] + +EXPORTS.mozilla += [ + "AutoMemMap.h", + "IOBuffers.h", + "ScriptPreloader.h", + "URLPreloader.h", +] + +EXPORTS.mozilla.dom += [ + "PrecompiledScript.h", +] + +EXPORTS.mozilla.loader += [ + "AutoMemMap.h", + "ScriptCacheActors.h", +] + +EXTRA_JS_MODULES += [ + "ComponentUtils.jsm", + "XPCOMUtils.jsm", +] + +FINAL_LIBRARY = "xul" + +LOCAL_INCLUDES += [ + "../src", + "../wrappers", + "/dom/base", + "/xpcom/base/", +] + +include("/ipc/chromium/chromium-config.mozbuild") + +if CONFIG["CC_TYPE"] in ("clang", "gcc"): + CXXFLAGS += ["-Wno-shadow"] diff --git a/js/xpconnect/loader/mozJSComponentLoader.cpp b/js/xpconnect/loader/mozJSComponentLoader.cpp new file mode 100644 index 0000000000..23c5e1d0c3 --- /dev/null +++ b/js/xpconnect/loader/mozJSComponentLoader.cpp @@ -0,0 +1,1356 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "mozilla/Attributes.h" +#include "mozilla/Utf8.h" // mozilla::Utf8Unit + +#include <cstdarg> + +#include "mozilla/Logging.h" +#ifdef ANDROID +# include <android/log.h> +#endif +#ifdef XP_WIN +# include <windows.h> +#endif + +#include "jsapi.h" +#include "js/Array.h" // JS::GetArrayLength, JS::IsArrayObject +#include "js/CharacterEncoding.h" +#include "js/CompilationAndEvaluation.h" +#include "js/CompileOptions.h" // JS::CompileOptions +#include "js/friend/JSMEnvironment.h" // JS::ExecuteInJSMEnvironment, JS::GetJSMEnvironmentOfScriptedCaller, JS::NewJSMEnvironment +#include "js/Object.h" // JS::GetCompartment +#include "js/Printf.h" +#include "js/PropertySpec.h" +#include "js/SourceText.h" // JS::SourceText +#include "nsCOMPtr.h" +#include "nsExceptionHandler.h" +#include "nsIComponentManager.h" +#include "mozilla/Module.h" +#include "nsIFile.h" +#include "mozJSComponentLoader.h" +#include "mozJSLoaderUtils.h" +#include "nsIFileURL.h" +#include "nsIJARURI.h" +#include "nsIChannel.h" +#include "nsNetUtil.h" +#include "nsJSPrincipals.h" +#include "nsJSUtils.h" +#include "xpcprivate.h" +#include "xpcpublic.h" +#include "nsContentUtils.h" +#include "nsReadableUtils.h" +#include "nsXULAppAPI.h" +#include "GeckoProfiler.h" +#include "WrapperFactory.h" + +#include "AutoMemMap.h" +#include "ScriptPreloader-inl.h" + +#include "mozilla/scache/StartupCache.h" +#include "mozilla/scache/StartupCacheUtils.h" +#include "mozilla/ClearOnShutdown.h" +#include "mozilla/MacroForEach.h" +#include "mozilla/Preferences.h" +#include "mozilla/ResultExtensions.h" +#include "mozilla/ScriptPreloader.h" +#include "mozilla/ScopeExit.h" +#include "mozilla/dom/ScriptSettings.h" +#include "mozilla/ResultExtensions.h" +#include "mozilla/UniquePtrExtensions.h" +#include "mozilla/Unused.h" + +using namespace mozilla; +using namespace mozilla::scache; +using namespace mozilla::loader; +using namespace xpc; +using namespace JS; + +#define JS_CACHE_PREFIX(aType) "jsloader/" aType + +/** + * Buffer sizes for serialization and deserialization of scripts. + * FIXME: bug #411579 (tune this macro!) Last updated: Jan 2008 + */ +#define XPC_SERIALIZATION_BUFFER_SIZE (64 * 1024) +#define XPC_DESERIALIZATION_BUFFER_SIZE (12 * 8192) + +// MOZ_LOG=JSComponentLoader:5 +static LazyLogModule gJSCLLog("JSComponentLoader"); + +#define LOG(args) MOZ_LOG(gJSCLLog, mozilla::LogLevel::Debug, args) + +// Components.utils.import error messages +#define ERROR_SCOPE_OBJ "%s - Second argument must be an object." +#define ERROR_NO_TARGET_OBJECT "%s - Couldn't find target object for import." +#define ERROR_NOT_PRESENT "%s - EXPORTED_SYMBOLS is not present." +#define ERROR_NOT_AN_ARRAY "%s - EXPORTED_SYMBOLS is not an array." +#define ERROR_GETTING_ARRAY_LENGTH \ + "%s - Error getting array length of EXPORTED_SYMBOLS." +#define ERROR_ARRAY_ELEMENT "%s - EXPORTED_SYMBOLS[%d] is not a string." +#define ERROR_GETTING_SYMBOL "%s - Could not get symbol '%s'." +#define ERROR_SETTING_SYMBOL "%s - Could not set symbol '%s' on target object." +#define ERROR_UNINITIALIZED_SYMBOL \ + "%s - Symbol '%s' accessed before initialization. Cyclic import?" + +static bool Dump(JSContext* cx, unsigned argc, Value* vp) { + if (!nsJSUtils::DumpEnabled()) { + return true; + } + + CallArgs args = CallArgsFromVp(argc, vp); + + if (args.length() == 0) { + return true; + } + + RootedString str(cx, JS::ToString(cx, args[0])); + if (!str) { + return false; + } + + JS::UniqueChars utf8str = JS_EncodeStringToUTF8(cx, str); + if (!utf8str) { + return false; + } + +#ifdef ANDROID + __android_log_print(ANDROID_LOG_INFO, "Gecko", "%s", utf8str.get()); +#endif +#ifdef XP_WIN + if (IsDebuggerPresent()) { + nsAutoJSString wstr; + if (!wstr.init(cx, str)) { + return false; + } + OutputDebugStringW(wstr.get()); + } +#endif + fputs(utf8str.get(), stdout); + fflush(stdout); + return true; +} + +static bool Debug(JSContext* cx, unsigned argc, Value* vp) { +#ifdef DEBUG + return Dump(cx, argc, vp); +#else + return true; +#endif +} + +static const JSFunctionSpec gGlobalFun[] = { + JS_FN("dump", Dump, 1, 0), JS_FN("debug", Debug, 1, 0), + JS_FN("atob", Atob, 1, 0), JS_FN("btoa", Btoa, 1, 0), JS_FS_END}; + +class MOZ_STACK_CLASS JSCLContextHelper { + public: + explicit JSCLContextHelper(JSContext* aCx); + ~JSCLContextHelper(); + + void reportErrorAfterPop(UniqueChars&& buf); + + private: + JSContext* mContext; + UniqueChars mBuf; + + // prevent copying and assignment + JSCLContextHelper(const JSCLContextHelper&) = delete; + const JSCLContextHelper& operator=(const JSCLContextHelper&) = delete; +}; + +static nsresult MOZ_FORMAT_PRINTF(2, 3) + ReportOnCallerUTF8(JSContext* callerContext, const char* format, ...) { + if (!callerContext) { + return NS_ERROR_FAILURE; + } + + va_list ap; + va_start(ap, format); + + UniqueChars buf = JS_vsmprintf(format, ap); + if (!buf) { + va_end(ap); + return NS_ERROR_OUT_OF_MEMORY; + } + + JS_ReportErrorUTF8(callerContext, "%s", buf.get()); + + va_end(ap); + return NS_OK; +} + +mozJSComponentLoader::mozJSComponentLoader() + : mModules(16), + mImports(16), + mInProgressImports(16), + mLocations(16), + mInitialized(false), + mLoaderGlobal(dom::RootingCx()) { + MOZ_ASSERT(!sSelf, "mozJSComponentLoader should be a singleton"); +} + +#define ENSURE_DEP(name) \ + { \ + nsresult rv = Ensure##name(); \ + NS_ENSURE_SUCCESS(rv, rv); \ + } +#define ENSURE_DEPS(...) MOZ_FOR_EACH(ENSURE_DEP, (), (__VA_ARGS__)); +#define BEGIN_ENSURE(self, ...) \ + { \ + if (m##self) return NS_OK; \ + ENSURE_DEPS(__VA_ARGS__); \ + } + +class MOZ_STACK_CLASS ComponentLoaderInfo { + public: + explicit ComponentLoaderInfo(const nsACString& aLocation) + : mLocation(aLocation) {} + + nsIIOService* IOService() { + MOZ_ASSERT(mIOService); + return mIOService; + } + nsresult EnsureIOService() { + if (mIOService) { + return NS_OK; + } + nsresult rv; + mIOService = do_GetIOService(&rv); + return rv; + } + + nsIURI* URI() { + MOZ_ASSERT(mURI); + return mURI; + } + nsresult EnsureURI() { + BEGIN_ENSURE(URI, IOService); + return mIOService->NewURI(mLocation, nullptr, nullptr, + getter_AddRefs(mURI)); + } + + nsIChannel* ScriptChannel() { + MOZ_ASSERT(mScriptChannel); + return mScriptChannel; + } + nsresult EnsureScriptChannel() { + BEGIN_ENSURE(ScriptChannel, IOService, URI); + return NS_NewChannel( + getter_AddRefs(mScriptChannel), mURI, + nsContentUtils::GetSystemPrincipal(), + nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_SEC_CONTEXT_IS_NULL, + nsIContentPolicy::TYPE_SCRIPT, + nullptr, // nsICookieJarSettings + nullptr, // aPerformanceStorage + nullptr, // aLoadGroup + nullptr, // aCallbacks + nsIRequest::LOAD_NORMAL, mIOService); + } + + nsIURI* ResolvedURI() { + MOZ_ASSERT(mResolvedURI); + return mResolvedURI; + } + nsresult EnsureResolvedURI() { + BEGIN_ENSURE(ResolvedURI, URI); + return ResolveURI(mURI, getter_AddRefs(mResolvedURI)); + } + + const nsACString& Key() { return mLocation; } + + MOZ_MUST_USE nsresult GetLocation(nsCString& aLocation) { + nsresult rv = EnsureURI(); + NS_ENSURE_SUCCESS(rv, rv); + return mURI->GetSpec(aLocation); + } + + private: + const nsACString& mLocation; + nsCOMPtr<nsIIOService> mIOService; + nsCOMPtr<nsIURI> mURI; + nsCOMPtr<nsIChannel> mScriptChannel; + nsCOMPtr<nsIURI> mResolvedURI; +}; + +template <typename... Args> +static nsresult ReportOnCallerUTF8(JSCLContextHelper& helper, + const char* format, + ComponentLoaderInfo& info, Args... args) { + nsCString location; + MOZ_TRY(info.GetLocation(location)); + + UniqueChars buf = JS_smprintf(format, location.get(), args...); + if (!buf) { + return NS_ERROR_OUT_OF_MEMORY; + } + + helper.reportErrorAfterPop(std::move(buf)); + return NS_ERROR_FAILURE; +} + +#undef BEGIN_ENSURE +#undef ENSURE_DEPS +#undef ENSURE_DEP + +mozJSComponentLoader::~mozJSComponentLoader() { + MOZ_ASSERT(!mInitialized, + "UnloadModules() was not explicitly called before cleaning up " + "mozJSComponentLoader"); + + if (mInitialized) { + UnloadModules(); + } + + sSelf = nullptr; +} + +StaticRefPtr<mozJSComponentLoader> mozJSComponentLoader::sSelf; + +// For terrible compatibility reasons, we need to consider both the global +// lexical environment and the global of modules when searching for exported +// symbols. +static JSObject* ResolveModuleObjectProperty(JSContext* aCx, + HandleObject aModObj, + const char* name) { + if (JS_HasExtensibleLexicalEnvironment(aModObj)) { + RootedObject lexical(aCx, JS_ExtensibleLexicalEnvironment(aModObj)); + bool found; + if (!JS_HasOwnProperty(aCx, lexical, name, &found)) { + return nullptr; + } + if (found) { + return lexical; + } + } + return aModObj; +} + +static mozilla::Result<nsCString, nsresult> ReadScript( + ComponentLoaderInfo& aInfo); + +static nsresult AnnotateScriptContents(CrashReporter::Annotation aName, + const nsACString& aURI) { + ComponentLoaderInfo info(aURI); + + nsCString str; + MOZ_TRY_VAR(str, ReadScript(info)); + + // The crash reporter won't accept any strings with embedded nuls. We + // shouldn't have any here, but if we do because of data corruption, we + // still want the annotation. So replace any embedded nuls before + // annotating. + str.ReplaceSubstring("\0"_ns, "\\0"_ns); + + CrashReporter::AnnotateCrashReport(aName, str); + + return NS_OK; +} + +nsresult mozJSComponentLoader::AnnotateCrashReport() { + Unused << AnnotateScriptContents( + CrashReporter::Annotation::nsAsyncShutdownComponent, + "resource://gre/components/nsAsyncShutdown.js"_ns); + + Unused << AnnotateScriptContents( + CrashReporter::Annotation::AsyncShutdownModule, + "resource://gre/modules/AsyncShutdown.jsm"_ns); + + return NS_OK; +} + +const mozilla::Module* mozJSComponentLoader::LoadModule(FileLocation& aFile) { + if (!NS_IsMainThread()) { + MOZ_ASSERT(false, "Don't use JS components off the main thread"); + return nullptr; + } + + nsCOMPtr<nsIFile> file = aFile.GetBaseFile(); + + nsCString spec; + aFile.GetURIString(spec); + ComponentLoaderInfo info(spec); + nsresult rv = info.EnsureURI(); + NS_ENSURE_SUCCESS(rv, nullptr); + + mInitialized = true; + + AUTO_PROFILER_LABEL_DYNAMIC_NSCSTRING("mozJSComponentLoader::LoadModule", + OTHER, spec); + AUTO_PROFILER_MARKER_TEXT("JS XPCOM", JS, MarkerStack::Capture(), spec); + + ModuleEntry* mod; + if (mModules.Get(spec, &mod)) { + return mod; + } + + dom::AutoJSAPI jsapi; + jsapi.Init(); + JSContext* cx = jsapi.cx(); + + bool isCriticalModule = StringEndsWith(spec, "/nsAsyncShutdown.js"_ns); + + auto entry = MakeUnique<ModuleEntry>(RootingContext::get(cx)); + RootedValue exn(cx); + rv = ObjectForLocation(info, file, &entry->obj, &entry->thisObjectKey, + &entry->location, isCriticalModule, &exn); + if (NS_FAILED(rv)) { + // Temporary debugging assertion for bug 1403348: + if (isCriticalModule && !exn.isUndefined()) { + AnnotateCrashReport(); + + JSAutoRealm ar(cx, xpc::PrivilegedJunkScope()); + JS_WrapValue(cx, &exn); + + nsAutoCString file; + uint32_t line; + uint32_t column; + nsAutoString msg; + nsContentUtils::ExtractErrorValues(cx, exn, file, &line, &column, msg); + + NS_ConvertUTF16toUTF8 cMsg(msg); + MOZ_CRASH_UNSAFE_PRINTF( + "Failed to load module \"%s\": " + "[\"%s\" {file: \"%s\", line: %u}]", + spec.get(), cMsg.get(), file.get(), line); + } + return nullptr; + } + + nsCOMPtr<nsIComponentManager> cm; + rv = NS_GetComponentManager(getter_AddRefs(cm)); + if (NS_FAILED(rv)) { + return nullptr; + } + + JSAutoRealm ar(cx, entry->obj); + RootedObject entryObj(cx, entry->obj); + + RootedObject NSGetFactoryHolder( + cx, ResolveModuleObjectProperty(cx, entryObj, "NSGetFactory")); + RootedValue NSGetFactory_val(cx); + if (!NSGetFactoryHolder || + !JS_GetProperty(cx, NSGetFactoryHolder, "NSGetFactory", + &NSGetFactory_val) || + NSGetFactory_val.isUndefined()) { + return nullptr; + } + + if (JS_TypeOfValue(cx, NSGetFactory_val) != JSTYPE_FUNCTION) { + /* + * spec's encoding is ASCII unless it's zip file, otherwise it's + * random encoding. Latin1 variant is safe for random encoding. + */ + JS_ReportErrorLatin1( + cx, "%s has NSGetFactory property that is not a function", spec.get()); + return nullptr; + } + + RootedObject jsGetFactoryObj(cx); + if (!JS_ValueToObject(cx, NSGetFactory_val, &jsGetFactoryObj) || + !jsGetFactoryObj) { + /* XXX report error properly */ + return nullptr; + } + + rv = nsXPConnect::XPConnect()->WrapJS(cx, jsGetFactoryObj, + NS_GET_IID(xpcIJSGetFactory), + getter_AddRefs(entry->getfactoryobj)); + if (NS_FAILED(rv)) { + /* XXX report error properly */ +#ifdef DEBUG + fprintf(stderr, "mJCL: couldn't get nsIModule from jsval\n"); +#endif + return nullptr; + } + +#if defined(NIGHTLY_BUILD) || defined(DEBUG) + if (Preferences::GetBool("browser.startup.record", false)) { + entry->importStack = xpc_PrintJSStack(cx, false, false, false).get(); + } +#endif + + // Cache this module for later + mModules.Put(spec, entry.get()); + + // The hash owns the ModuleEntry now, forget about it + return entry.release(); +} + +void mozJSComponentLoader::FindTargetObject(JSContext* aCx, + MutableHandleObject aTargetObject) { + aTargetObject.set(JS::GetJSMEnvironmentOfScriptedCaller(aCx)); + + // The above could fail if the scripted caller is not a component/JSM (it + // could be a DOM scope, for instance). + // + // If the target object was not in the JSM shared global, return the global + // instead. This is needed when calling the subscript loader within a frame + // script, since it the FrameScript NSVO will have been found. + if (!aTargetObject || + !IsLoaderGlobal(JS::GetNonCCWObjectGlobal(aTargetObject))) { + aTargetObject.set(JS::GetScriptedCallerGlobal(aCx)); + + // Return nullptr if the scripted caller is in a different compartment. + if (JS::GetCompartment(aTargetObject) != js::GetContextCompartment(aCx)) { + aTargetObject.set(nullptr); + } + } +} + +void mozJSComponentLoader::InitStatics() { + MOZ_ASSERT(!sSelf); + sSelf = new mozJSComponentLoader(); +} + +void mozJSComponentLoader::Unload() { + if (sSelf) { + sSelf->UnloadModules(); + } +} + +void mozJSComponentLoader::Shutdown() { + MOZ_ASSERT(sSelf); + sSelf = nullptr; +} + +// This requires that the keys be strings and the values be pointers. +template <class Key, class Data, class UserData, class Converter> +static size_t SizeOfTableExcludingThis( + const nsBaseHashtable<Key, Data, UserData, Converter>& aTable, + MallocSizeOf aMallocSizeOf) { + size_t n = aTable.ShallowSizeOfExcludingThis(aMallocSizeOf); + for (auto iter = aTable.ConstIter(); !iter.Done(); iter.Next()) { + n += iter.Key().SizeOfExcludingThisIfUnshared(aMallocSizeOf); + n += iter.Data()->SizeOfIncludingThis(aMallocSizeOf); + } + return n; +} + +size_t mozJSComponentLoader::SizeOfIncludingThis(MallocSizeOf aMallocSizeOf) { + size_t n = aMallocSizeOf(this); + n += SizeOfTableExcludingThis(mModules, aMallocSizeOf); + n += SizeOfTableExcludingThis(mImports, aMallocSizeOf); + n += mLocations.ShallowSizeOfExcludingThis(aMallocSizeOf); + n += SizeOfTableExcludingThis(mInProgressImports, aMallocSizeOf); + return n; +} + +void mozJSComponentLoader::CreateLoaderGlobal(JSContext* aCx, + const nsACString& aLocation, + MutableHandleObject aGlobal) { + auto backstagePass = MakeRefPtr<BackstagePass>(); + RealmOptions options; + + options.creationOptions().setNewCompartmentInSystemZone(); + xpc::SetPrefableRealmOptions(options); + + // Defer firing OnNewGlobalObject until after the __URI__ property has + // been defined so the JS debugger can tell what module the global is + // for + RootedObject global(aCx); + nsresult rv = xpc::InitClassesWithNewWrappedGlobal( + aCx, static_cast<nsIGlobalObject*>(backstagePass), + nsContentUtils::GetSystemPrincipal(), xpc::DONT_FIRE_ONNEWGLOBALHOOK, + options, &global); + NS_ENSURE_SUCCESS_VOID(rv); + + NS_ENSURE_TRUE_VOID(global); + + backstagePass->SetGlobalObject(global); + + JSAutoRealm ar(aCx, global); + if (!JS_DefineFunctions(aCx, global, gGlobalFun)) { + return; + } + + // Set the location information for the new global, so that tools like + // about:memory may use that information + xpc::SetLocationForGlobal(global, aLocation); + + aGlobal.set(global); +} + +JSObject* mozJSComponentLoader::GetSharedGlobal(JSContext* aCx) { + if (!mLoaderGlobal) { + JS::RootedObject globalObj(aCx); + CreateLoaderGlobal(aCx, "shared JSM global"_ns, &globalObj); + + // If we fail to create a module global this early, we're not going to + // get very far, so just bail out now. + MOZ_RELEASE_ASSERT(globalObj); + mLoaderGlobal = globalObj; + + // AutoEntryScript required to invoke debugger hook, which is a + // Gecko-specific concept at present. + dom::AutoEntryScript aes(globalObj, "component loader report global"); + JS_FireOnNewGlobalObject(aes.cx(), globalObj); + } + + return mLoaderGlobal; +} + +JSObject* mozJSComponentLoader::PrepareObjectForLocation( + JSContext* aCx, nsIFile* aComponentFile, nsIURI* aURI, bool* aRealFile) { + nsAutoCString nativePath; + NS_ENSURE_SUCCESS(aURI->GetSpec(nativePath), nullptr); + + RootedObject globalObj(aCx, GetSharedGlobal(aCx)); + + // |thisObj| is the object we set properties on for a particular .jsm. + RootedObject thisObj(aCx, globalObj); + NS_ENSURE_TRUE(thisObj, nullptr); + + JSAutoRealm ar(aCx, thisObj); + + thisObj = JS::NewJSMEnvironment(aCx); + NS_ENSURE_TRUE(thisObj, nullptr); + + *aRealFile = false; + + // need to be extra careful checking for URIs pointing to files + // EnsureFile may not always get called, especially on resource URIs + // so we need to call GetFile to make sure this is a valid file + { + // Create an extra scope so that ~nsCOMPtr will run before the returned + // JSObject* is placed on the stack, since otherwise a GC in the destructor + // would invalidate the return value. + nsresult rv = NS_OK; + nsCOMPtr<nsIFileURL> fileURL = do_QueryInterface(aURI, &rv); + nsCOMPtr<nsIFile> testFile; + if (NS_SUCCEEDED(rv)) { + fileURL->GetFile(getter_AddRefs(testFile)); + } + + if (testFile) { + *aRealFile = true; + + if (XRE_IsParentProcess()) { + RootedObject locationObj(aCx); + + rv = nsXPConnect::XPConnect()->WrapNative(aCx, thisObj, aComponentFile, + NS_GET_IID(nsIFile), + locationObj.address()); + NS_ENSURE_SUCCESS(rv, nullptr); + NS_ENSURE_TRUE(locationObj, nullptr); + + if (!JS_DefineProperty(aCx, thisObj, "__LOCATION__", locationObj, 0)) { + return nullptr; + } + } + } + } + + // Expose the URI from which the script was imported through a special + // variable that we insert into the JSM. + RootedString exposedUri( + aCx, JS_NewStringCopyN(aCx, nativePath.get(), nativePath.Length())); + NS_ENSURE_TRUE(exposedUri, nullptr); + + if (!JS_DefineProperty(aCx, thisObj, "__URI__", exposedUri, 0)) { + return nullptr; + } + + return thisObj; +} + +static mozilla::Result<nsCString, nsresult> ReadScript( + ComponentLoaderInfo& aInfo) { + MOZ_TRY(aInfo.EnsureScriptChannel()); + + nsCOMPtr<nsIInputStream> scriptStream; + MOZ_TRY(NS_MaybeOpenChannelUsingOpen(aInfo.ScriptChannel(), + getter_AddRefs(scriptStream))); + + uint64_t len64; + uint32_t bytesRead; + + MOZ_TRY(scriptStream->Available(&len64)); + NS_ENSURE_TRUE(len64 < UINT32_MAX, Err(NS_ERROR_FILE_TOO_BIG)); + NS_ENSURE_TRUE(len64, Err(NS_ERROR_FAILURE)); + uint32_t len = (uint32_t)len64; + + /* malloc an internal buf the size of the file */ + nsCString str; + if (!str.SetLength(len, fallible)) { + return Err(NS_ERROR_OUT_OF_MEMORY); + } + + /* read the file in one swoop */ + MOZ_TRY(scriptStream->Read(str.BeginWriting(), len, &bytesRead)); + if (bytesRead != len) { + return Err(NS_BASE_STREAM_OSERROR); + } + + return std::move(str); +} + +nsresult mozJSComponentLoader::ObjectForLocation( + ComponentLoaderInfo& aInfo, nsIFile* aComponentFile, + MutableHandleObject aObject, MutableHandleScript aTableScript, + char** aLocation, bool aPropagateExceptions, + MutableHandleValue aException) { + MOZ_ASSERT(NS_IsMainThread(), "Must be on main thread."); + + dom::AutoJSAPI jsapi; + jsapi.Init(); + JSContext* cx = jsapi.cx(); + + bool realFile = false; + nsresult rv = aInfo.EnsureURI(); + NS_ENSURE_SUCCESS(rv, rv); + RootedObject obj( + cx, PrepareObjectForLocation(cx, aComponentFile, aInfo.URI(), &realFile)); + NS_ENSURE_TRUE(obj, NS_ERROR_FAILURE); + MOZ_ASSERT(!JS_IsGlobalObject(obj)); + + JSAutoRealm ar(cx, obj); + + RootedScript script(cx); + + nsAutoCString nativePath; + rv = aInfo.URI()->GetSpec(nativePath); + NS_ENSURE_SUCCESS(rv, rv); + + // Before compiling the script, first check to see if we have it in + // the startupcache. Note: as a rule, startupcache errors are not fatal + // to loading the script, since we can always slow-load. + + bool writeToCache = false; + StartupCache* cache = StartupCache::GetSingleton(); + + aInfo.EnsureResolvedURI(); + + nsAutoCString cachePath(JS_CACHE_PREFIX("non-syntactic")); + rv = PathifyURI(aInfo.ResolvedURI(), cachePath); + NS_ENSURE_SUCCESS(rv, rv); + + CompileOptions options(cx); + ScriptPreloader::FillCompileOptionsForCachedScript(options); + options.setForceStrictMode() + .setFileAndLine(nativePath.get(), 1) + .setSourceIsLazy(true) + .setNonSyntacticScope(true); + + script = + ScriptPreloader::GetSingleton().GetCachedScript(cx, options, cachePath); + if (!script && cache) { + ReadCachedScript(cache, cachePath, cx, options, &script); + } + + if (script) { + LOG(("Successfully loaded %s from startupcache\n", nativePath.get())); + } else if (cache) { + // This is ok, it just means the script is not yet in the + // cache. Could mean that the cache was corrupted and got removed, + // but either way we're going to write this out. + writeToCache = true; + // ReadCachedScript may have set a pending exception. + JS_ClearPendingException(cx); + } + + if (!script) { + // The script wasn't in the cache , so compile it now. + LOG(("Slow loading %s\n", nativePath.get())); + + // If we can no longer write to caches, we should stop using lazy sources + // and instead let normal syntax parsing occur. This can occur in content + // processes after the ScriptPreloader is flushed where we can read but no + // longer write. + if (!cache && !ScriptPreloader::GetSingleton().Active()) { + options.setSourceIsLazy(false); + } + + if (realFile) { + AutoMemMap map; + MOZ_TRY(map.init(aComponentFile)); + + // Note: exceptions will get handled further down; + // don't early return for them here. + auto buf = map.get<char>(); + + JS::SourceText<mozilla::Utf8Unit> srcBuf; + if (srcBuf.init(cx, buf.get(), map.size(), + JS::SourceOwnership::Borrowed)) { + script = Compile(cx, options, srcBuf); + } else { + MOZ_ASSERT(!script); + } + } else { + nsCString str; + MOZ_TRY_VAR(str, ReadScript(aInfo)); + + JS::SourceText<mozilla::Utf8Unit> srcBuf; + if (srcBuf.init(cx, str.get(), str.Length(), + JS::SourceOwnership::Borrowed)) { + script = Compile(cx, options, srcBuf); + } else { + MOZ_ASSERT(!script); + } + } + // Propagate the exception, if one exists. Also, don't leave the stale + // exception on this context. + if (!script && aPropagateExceptions && jsapi.HasException()) { + if (!jsapi.StealException(aException)) { + return NS_ERROR_OUT_OF_MEMORY; + } + } + } + + if (!script) { + return NS_ERROR_FAILURE; + } + + MOZ_ASSERT_IF(ScriptPreloader::GetSingleton().Active(), options.sourceIsLazy); + ScriptPreloader::GetSingleton().NoteScript(nativePath, cachePath, script); + + if (writeToCache) { + MOZ_ASSERT(options.sourceIsLazy); + + // We successfully compiled the script, so cache it. + rv = WriteCachedScript(cache, cachePath, cx, script); + + // Don't treat failure to write as fatal, since we might be working + // with a read-only cache. + if (NS_SUCCEEDED(rv)) { + LOG(("Successfully wrote to cache\n")); + } else { + LOG(("Failed to write to cache\n")); + } + } + + // Assign aObject here so that it's available to recursive imports. + // See bug 384168. + aObject.set(obj); + + aTableScript.set(script); + + { // Scope for AutoEntryScript + AutoAllowLegacyScriptExecution exemption; + + // We're going to run script via JS_ExecuteScript, so we need an + // AutoEntryScript. This is Gecko-specific and not in any spec. + dom::AutoEntryScript aes(CurrentGlobalOrNull(cx), + "component loader load module"); + JSContext* aescx = aes.cx(); + + bool executeOk = false; + if (JS_IsGlobalObject(obj)) { + JS::RootedValue rval(cx); + executeOk = JS::CloneAndExecuteScript(aescx, script, &rval); + } else { + executeOk = JS::ExecuteInJSMEnvironment(aescx, script, obj); + } + + if (!executeOk) { + if (aPropagateExceptions && aes.HasException()) { + // Ignore return value because we're returning an error code + // anyway. + Unused << aes.StealException(aException); + } + aObject.set(nullptr); + aTableScript.set(nullptr); + return NS_ERROR_FAILURE; + } + } + + /* Freed when we remove from the table. */ + *aLocation = ToNewCString(nativePath, mozilla::fallible); + if (!*aLocation) { + aObject.set(nullptr); + aTableScript.set(nullptr); + return NS_ERROR_OUT_OF_MEMORY; + } + + return NS_OK; +} + +void mozJSComponentLoader::UnloadModules() { + mInitialized = false; + + if (mLoaderGlobal) { + MOZ_ASSERT(JS_HasExtensibleLexicalEnvironment(mLoaderGlobal)); + JS::RootedObject lexicalEnv(dom::RootingCx(), + JS_ExtensibleLexicalEnvironment(mLoaderGlobal)); + JS_SetAllNonReservedSlotsToUndefined(lexicalEnv); + JS_SetAllNonReservedSlotsToUndefined(mLoaderGlobal); + mLoaderGlobal = nullptr; + } + + mInProgressImports.Clear(); + mImports.Clear(); + mLocations.Clear(); + + for (auto iter = mModules.Iter(); !iter.Done(); iter.Next()) { + iter.Data()->Clear(); + iter.Remove(); + } +} + +nsresult mozJSComponentLoader::ImportInto(const nsACString& registryLocation, + HandleValue targetValArg, + JSContext* cx, uint8_t optionalArgc, + MutableHandleValue retval) { + MOZ_ASSERT(nsContentUtils::IsCallerChrome()); + + RootedValue targetVal(cx, targetValArg); + RootedObject targetObject(cx, nullptr); + + if (optionalArgc) { + // The caller passed in the optional second argument. Get it. + if (targetVal.isObject()) { + // If we're passing in something like a content DOM window, chances + // are the caller expects the properties to end up on the object + // proper and not on the Xray holder. This is dubious, but can be used + // during testing. Given that dumb callers can already leak JSMs into + // content by passing a raw content JS object (where Xrays aren't + // possible), we aim for consistency here. Waive xray. + if (WrapperFactory::IsXrayWrapper(&targetVal.toObject()) && + !WrapperFactory::WaiveXrayAndWrap(cx, &targetVal)) { + return NS_ERROR_FAILURE; + } + targetObject = &targetVal.toObject(); + } else if (!targetVal.isNull()) { + // If targetVal isNull(), we actually want to leave targetObject null. + // Not doing so breaks |make package|. + return ReportOnCallerUTF8(cx, ERROR_SCOPE_OBJ, + PromiseFlatCString(registryLocation).get()); + } + } else { + FindTargetObject(cx, &targetObject); + if (!targetObject) { + return ReportOnCallerUTF8(cx, ERROR_NO_TARGET_OBJECT, + PromiseFlatCString(registryLocation).get()); + } + } + + js::AssertSameCompartment(cx, targetObject); + + RootedObject global(cx); + nsresult rv = ImportInto(registryLocation, targetObject, cx, &global); + + if (global) { + if (!JS_WrapObject(cx, &global)) { + NS_ERROR("can't wrap return value"); + return NS_ERROR_FAILURE; + } + + retval.setObject(*global); + } + return rv; +} + +nsresult mozJSComponentLoader::IsModuleLoaded(const nsACString& aLocation, + bool* retval) { + MOZ_ASSERT(nsContentUtils::IsCallerChrome()); + + mInitialized = true; + ComponentLoaderInfo info(aLocation); + *retval = !!mImports.Get(info.Key()); + return NS_OK; +} + +void mozJSComponentLoader::GetLoadedModules( + nsTArray<nsCString>& aLoadedModules) { + aLoadedModules.SetCapacity(mImports.Count()); + for (auto iter = mImports.Iter(); !iter.Done(); iter.Next()) { + aLoadedModules.AppendElement(iter.Data()->location); + } +} + +void mozJSComponentLoader::GetLoadedComponents( + nsTArray<nsCString>& aLoadedComponents) { + aLoadedComponents.SetCapacity(mModules.Count()); + for (auto iter = mModules.Iter(); !iter.Done(); iter.Next()) { + aLoadedComponents.AppendElement(iter.Data()->location); + } +} + +nsresult mozJSComponentLoader::GetModuleImportStack(const nsACString& aLocation, + nsACString& retval) { +#ifdef STARTUP_RECORDER_ENABLED + MOZ_ASSERT(nsContentUtils::IsCallerChrome()); + MOZ_ASSERT(mInitialized); + + ComponentLoaderInfo info(aLocation); + + ModuleEntry* mod; + if (!mImports.Get(info.Key(), &mod)) { + return NS_ERROR_FAILURE; + } + + retval = mod->importStack; + return NS_OK; +#else + return NS_ERROR_NOT_IMPLEMENTED; +#endif +} + +nsresult mozJSComponentLoader::GetComponentLoadStack( + const nsACString& aLocation, nsACString& retval) { +#ifdef STARTUP_RECORDER_ENABLED + MOZ_ASSERT(nsContentUtils::IsCallerChrome()); + MOZ_ASSERT(mInitialized); + + ComponentLoaderInfo info(aLocation); + nsresult rv = info.EnsureURI(); + NS_ENSURE_SUCCESS(rv, rv); + + ModuleEntry* mod; + if (!mModules.Get(info.Key(), &mod)) { + return NS_ERROR_FAILURE; + } + + retval = mod->importStack; + return NS_OK; +#else + return NS_ERROR_NOT_IMPLEMENTED; +#endif +} + +static JSObject* ResolveModuleObjectPropertyById(JSContext* aCx, + HandleObject aModObj, + HandleId id) { + if (JS_HasExtensibleLexicalEnvironment(aModObj)) { + RootedObject lexical(aCx, JS_ExtensibleLexicalEnvironment(aModObj)); + bool found; + if (!JS_HasOwnPropertyById(aCx, lexical, id, &found)) { + return nullptr; + } + if (found) { + return lexical; + } + } + return aModObj; +} + +nsresult mozJSComponentLoader::ImportInto(const nsACString& aLocation, + HandleObject targetObj, JSContext* cx, + MutableHandleObject vp) { + vp.set(nullptr); + + JS::RootedObject exports(cx); + MOZ_TRY(Import(cx, aLocation, vp, &exports, !targetObj)); + + if (targetObj) { + JS::Rooted<JS::IdVector> ids(cx, JS::IdVector(cx)); + if (!JS_Enumerate(cx, exports, &ids)) { + return NS_ERROR_OUT_OF_MEMORY; + } + + JS::RootedValue value(cx); + JS::RootedId id(cx); + for (jsid idVal : ids) { + id = idVal; + if (!JS_GetPropertyById(cx, exports, id, &value) || + !JS_SetPropertyById(cx, targetObj, id, value)) { + return NS_ERROR_FAILURE; + } + } + } + + return NS_OK; +} + +nsresult mozJSComponentLoader::ExtractExports( + JSContext* aCx, ComponentLoaderInfo& aInfo, ModuleEntry* aMod, + JS::MutableHandleObject aExports) { + // cxhelper must be created before jsapi, so that jsapi is destroyed and + // pops any context it has pushed before we report to the caller context. + JSCLContextHelper cxhelper(aCx); + + // Even though we are calling JS_SetPropertyById on targetObj, we want + // to ensure that we never run script here, so we use an AutoJSAPI and + // not an AutoEntryScript. + dom::AutoJSAPI jsapi; + jsapi.Init(); + JSContext* cx = jsapi.cx(); + JSAutoRealm ar(cx, aMod->obj); + + RootedValue symbols(cx); + { + RootedObject obj( + cx, ResolveModuleObjectProperty(cx, aMod->obj, "EXPORTED_SYMBOLS")); + if (!obj || !JS_GetProperty(cx, obj, "EXPORTED_SYMBOLS", &symbols)) { + return ReportOnCallerUTF8(cxhelper, ERROR_NOT_PRESENT, aInfo); + } + } + + bool isArray; + if (!JS::IsArrayObject(cx, symbols, &isArray)) { + return NS_ERROR_FAILURE; + } + if (!isArray) { + return ReportOnCallerUTF8(cxhelper, ERROR_NOT_AN_ARRAY, aInfo); + } + + RootedObject symbolsObj(cx, &symbols.toObject()); + + // Iterate over symbols array, installing symbols on targetObj: + + uint32_t symbolCount = 0; + if (!JS::GetArrayLength(cx, symbolsObj, &symbolCount)) { + return ReportOnCallerUTF8(cxhelper, ERROR_GETTING_ARRAY_LENGTH, aInfo); + } + +#ifdef DEBUG + nsAutoCString logBuffer; +#endif + + aExports.set(JS_NewPlainObject(cx)); + if (!aExports) { + return NS_ERROR_OUT_OF_MEMORY; + } + + bool missing = false; + + RootedValue value(cx); + RootedId symbolId(cx); + RootedObject symbolHolder(cx); + for (uint32_t i = 0; i < symbolCount; ++i) { + if (!JS_GetElement(cx, symbolsObj, i, &value) || !value.isString() || + !JS_ValueToId(cx, value, &symbolId)) { + return ReportOnCallerUTF8(cxhelper, ERROR_ARRAY_ELEMENT, aInfo, i); + } + + symbolHolder = ResolveModuleObjectPropertyById(cx, aMod->obj, symbolId); + if (!symbolHolder || + !JS_GetPropertyById(cx, symbolHolder, symbolId, &value)) { + RootedString symbolStr(cx, JSID_TO_STRING(symbolId)); + JS::UniqueChars bytes = JS_EncodeStringToUTF8(cx, symbolStr); + if (!bytes) { + return NS_ERROR_FAILURE; + } + return ReportOnCallerUTF8(cxhelper, ERROR_GETTING_SYMBOL, aInfo, + bytes.get()); + } + + // It's possible |value| is the uninitialized lexical MagicValue when + // there's a cyclic import: const obj = ChromeUtils.import("parent.jsm"). + if (value.isMagic(JS_UNINITIALIZED_LEXICAL)) { + RootedString symbolStr(cx, JSID_TO_STRING(symbolId)); + JS::UniqueChars bytes = JS_EncodeStringToUTF8(cx, symbolStr); + if (!bytes) { + return NS_ERROR_FAILURE; + } + return ReportOnCallerUTF8(cxhelper, ERROR_UNINITIALIZED_SYMBOL, aInfo, + bytes.get()); + } + + if (value.isUndefined()) { + missing = true; + } + + if (!JS_SetPropertyById(cx, aExports, symbolId, value)) { + RootedString symbolStr(cx, JSID_TO_STRING(symbolId)); + JS::UniqueChars bytes = JS_EncodeStringToUTF8(cx, symbolStr); + if (!bytes) { + return NS_ERROR_FAILURE; + } + return ReportOnCallerUTF8(cxhelper, ERROR_GETTING_SYMBOL, aInfo, + bytes.get()); + } +#ifdef DEBUG + if (i == 0) { + logBuffer.AssignLiteral("Installing symbols [ "); + } + JS::UniqueChars bytes = + JS_EncodeStringToLatin1(cx, JSID_TO_STRING(symbolId)); + if (!!bytes) { + logBuffer.Append(bytes.get()); + } + logBuffer.Append(' '); + if (i == symbolCount - 1) { + nsCString location; + MOZ_TRY(aInfo.GetLocation(location)); + LOG(("%s] from %s\n", logBuffer.get(), location.get())); + } +#endif + } + + // Don't cache the exports object if any of its exported symbols are + // missing. If the module hasn't finished loading yet, they may be + // defined the next time we try to import it. + if (!missing) { + aMod->exports = aExports; + } + return NS_OK; +} + +nsresult mozJSComponentLoader::Import(JSContext* aCx, + const nsACString& aLocation, + JS::MutableHandleObject aModuleGlobal, + JS::MutableHandleObject aModuleExports, + bool aIgnoreExports) { + mInitialized = true; + + AUTO_PROFILER_MARKER_TEXT("ChromeUtils.import", JS, MarkerStack::Capture(), + aLocation); + + ComponentLoaderInfo info(aLocation); + + nsresult rv; + ModuleEntry* mod; + UniquePtr<ModuleEntry> newEntry; + if (!mImports.Get(info.Key(), &mod) && + !mInProgressImports.Get(info.Key(), &mod)) { + // We're trying to import a new JSM, but we're late in shutdown and this + // will likely not succeed and might even crash, so fail here. + if (PastShutdownPhase(ShutdownPhase::ShutdownFinal)) { + return NS_ERROR_ILLEGAL_DURING_SHUTDOWN; + } + + newEntry = MakeUnique<ModuleEntry>(RootingContext::get(aCx)); + + // Note: This implies EnsureURI(). + MOZ_TRY(info.EnsureResolvedURI()); + + // get the JAR if there is one + nsCOMPtr<nsIJARURI> jarURI; + jarURI = do_QueryInterface(info.ResolvedURI(), &rv); + nsCOMPtr<nsIFileURL> baseFileURL; + if (NS_SUCCEEDED(rv)) { + nsCOMPtr<nsIURI> baseURI; + while (jarURI) { + jarURI->GetJARFile(getter_AddRefs(baseURI)); + jarURI = do_QueryInterface(baseURI, &rv); + } + baseFileURL = do_QueryInterface(baseURI, &rv); + NS_ENSURE_SUCCESS(rv, rv); + } else { + baseFileURL = do_QueryInterface(info.ResolvedURI(), &rv); + NS_ENSURE_SUCCESS(rv, rv); + } + + nsCOMPtr<nsIFile> sourceFile; + rv = baseFileURL->GetFile(getter_AddRefs(sourceFile)); + NS_ENSURE_SUCCESS(rv, rv); + + rv = info.ResolvedURI()->GetSpec(newEntry->resolvedURL); + NS_ENSURE_SUCCESS(rv, rv); + + nsCString* existingPath; + if (mLocations.Get(newEntry->resolvedURL, &existingPath) && + *existingPath != info.Key()) { + return NS_ERROR_UNEXPECTED; + } + + mLocations.Put(newEntry->resolvedURL, new nsCString(info.Key())); + + RootedValue exception(aCx); + { + mInProgressImports.Put(info.Key(), newEntry.get()); + auto cleanup = + MakeScopeExit([&]() { mInProgressImports.Remove(info.Key()); }); + + rv = ObjectForLocation(info, sourceFile, &newEntry->obj, + &newEntry->thisObjectKey, &newEntry->location, + true, &exception); + } + + if (NS_FAILED(rv)) { + if (!exception.isUndefined()) { + // An exception was thrown during compilation. Propagate it + // out to our caller so they can report it. + if (!JS_WrapValue(aCx, &exception)) { + return NS_ERROR_OUT_OF_MEMORY; + } + JS_SetPendingException(aCx, exception); + return NS_ERROR_FAILURE; + } + + // Something failed, but we don't know what it is, guess. + return NS_ERROR_FILE_NOT_FOUND; + } + +#ifdef STARTUP_RECORDER_ENABLED + if (Preferences::GetBool("browser.startup.record", false)) { + newEntry->importStack = xpc_PrintJSStack(aCx, false, false, false).get(); + } +#endif + + mod = newEntry.get(); + } + + MOZ_ASSERT(mod->obj, "Import table contains entry with no object"); + aModuleGlobal.set(mod->obj); + + JS::RootedObject exports(aCx, mod->exports); + if (!exports && !aIgnoreExports) { + MOZ_TRY(ExtractExports(aCx, info, mod, &exports)); + } + + if (exports && !JS_WrapObject(aCx, &exports)) { + return NS_ERROR_FAILURE; + } + aModuleExports.set(exports); + + // Cache this module for later + if (newEntry) { + mImports.Put(info.Key(), newEntry.release()); + } + + return NS_OK; +} + +nsresult mozJSComponentLoader::Unload(const nsACString& aLocation) { + if (!mInitialized) { + return NS_OK; + } + + ComponentLoaderInfo info(aLocation); + + ModuleEntry* mod; + if (mImports.Get(info.Key(), &mod)) { + mLocations.Remove(mod->resolvedURL); + mImports.Remove(info.Key()); + } + + // If this is the last module to be unloaded, we will leak mLoaderGlobal + // until UnloadModules is called. So be it. + + return NS_OK; +} + +size_t mozJSComponentLoader::ModuleEntry::SizeOfIncludingThis( + MallocSizeOf aMallocSizeOf) const { + size_t n = aMallocSizeOf(this); + n += aMallocSizeOf(location); + + return n; +} + +/* static */ +already_AddRefed<nsIFactory> mozJSComponentLoader::ModuleEntry::GetFactory( + const mozilla::Module& module, const mozilla::Module::CIDEntry& entry) { + const ModuleEntry& self = static_cast<const ModuleEntry&>(module); + MOZ_ASSERT(self.getfactoryobj, "Handing out an uninitialized module?"); + + nsCOMPtr<nsIFactory> f; + nsresult rv = self.getfactoryobj->Get(*entry.cid, getter_AddRefs(f)); + if (NS_FAILED(rv)) { + return nullptr; + } + + return f.forget(); +} + +//---------------------------------------------------------------------- + +JSCLContextHelper::JSCLContextHelper(JSContext* aCx) + : mContext(aCx), mBuf(nullptr) {} + +JSCLContextHelper::~JSCLContextHelper() { + if (mBuf) { + JS_ReportErrorUTF8(mContext, "%s", mBuf.get()); + } +} + +void JSCLContextHelper::reportErrorAfterPop(UniqueChars&& buf) { + MOZ_ASSERT(!mBuf, "Already called reportErrorAfterPop"); + mBuf = std::move(buf); +} diff --git a/js/xpconnect/loader/mozJSComponentLoader.h b/js/xpconnect/loader/mozJSComponentLoader.h new file mode 100644 index 0000000000..920fe5163d --- /dev/null +++ b/js/xpconnect/loader/mozJSComponentLoader.h @@ -0,0 +1,194 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef mozJSComponentLoader_h +#define mozJSComponentLoader_h + +#include "mozilla/dom/ScriptSettings.h" +#include "mozilla/FileLocation.h" +#include "mozilla/MemoryReporting.h" +#include "mozilla/Module.h" +#include "mozilla/StaticPtr.h" +#include "mozilla/UniquePtr.h" +#include "nsISupports.h" +#include "nsIURI.h" +#include "nsClassHashtable.h" +#include "nsDataHashtable.h" +#include "jsapi.h" + +#include "xpcIJSGetFactory.h" +#include "xpcpublic.h" + +class nsIFile; +class ComponentLoaderInfo; + +namespace mozilla { +class ScriptPreloader; +} // namespace mozilla + +#if defined(NIGHTLY_BUILD) || defined(MOZ_DEV_EDITION) || defined(DEBUG) +# define STARTUP_RECORDER_ENABLED +#endif + +class mozJSComponentLoader final { + public: + NS_INLINE_DECL_REFCOUNTING(mozJSComponentLoader); + + void GetLoadedModules(nsTArray<nsCString>& aLoadedModules); + void GetLoadedComponents(nsTArray<nsCString>& aLoadedComponents); + nsresult GetModuleImportStack(const nsACString& aLocation, + nsACString& aRetval); + nsresult GetComponentLoadStack(const nsACString& aLocation, + nsACString& aRetval); + + const mozilla::Module* LoadModule(mozilla::FileLocation& aFile); + + void FindTargetObject(JSContext* aCx, JS::MutableHandleObject aTargetObject); + + static void InitStatics(); + static void Unload(); + static void Shutdown(); + + static mozJSComponentLoader* Get() { + MOZ_ASSERT(sSelf, "Should have already created the component loader"); + return sSelf; + } + + nsresult ImportInto(const nsACString& aResourceURI, + JS::HandleValue aTargetObj, JSContext* aCx, uint8_t aArgc, + JS::MutableHandleValue aRetval); + + nsresult Import(JSContext* aCx, const nsACString& aResourceURI, + JS::MutableHandleObject aModuleGlobal, + JS::MutableHandleObject aModuleExports, + bool aIgnoreExports = false); + + nsresult Unload(const nsACString& aResourceURI); + nsresult IsModuleLoaded(const nsACString& aResourceURI, bool* aRetval); + bool IsLoaderGlobal(JSObject* aObj) { return mLoaderGlobal == aObj; } + + size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf); + + /** + * Temporary diagnostic function for startup crashes in bug 1403348: + * + * Annotate the crash report with the contents of the async shutdown + * module/component scripts. + */ + nsresult AnnotateCrashReport(); + + protected: + mozJSComponentLoader(); + ~mozJSComponentLoader(); + + friend class XPCJSRuntime; + + private: + static mozilla::StaticRefPtr<mozJSComponentLoader> sSelf; + + void UnloadModules(); + + void CreateLoaderGlobal(JSContext* aCx, const nsACString& aLocation, + JS::MutableHandleObject aGlobal); + + JSObject* GetSharedGlobal(JSContext* aCx); + + JSObject* PrepareObjectForLocation(JSContext* aCx, nsIFile* aComponentFile, + nsIURI* aComponent, bool* aRealFile); + + nsresult ObjectForLocation(ComponentLoaderInfo& aInfo, + nsIFile* aComponentFile, + JS::MutableHandleObject aObject, + JS::MutableHandleScript aTableScript, + char** location, bool aCatchException, + JS::MutableHandleValue aException); + + nsresult ImportInto(const nsACString& aLocation, JS::HandleObject targetObj, + JSContext* callercx, JS::MutableHandleObject vp); + + nsCOMPtr<nsIComponentManager> mCompMgr; + + class ModuleEntry : public mozilla::Module { + public: + explicit ModuleEntry(JS::RootingContext* aRootingCx) + : mozilla::Module(), + obj(aRootingCx), + exports(aRootingCx), + thisObjectKey(aRootingCx) { + mVersion = mozilla::Module::kVersion; + mCIDs = nullptr; + mContractIDs = nullptr; + mCategoryEntries = nullptr; + getFactoryProc = GetFactory; + loadProc = nullptr; + unloadProc = nullptr; + + location = nullptr; + } + + ~ModuleEntry() { Clear(); } + + void Clear() { + getfactoryobj = nullptr; + + if (obj) { + if (JS_HasExtensibleLexicalEnvironment(obj)) { + JS::RootedObject lexicalEnv(mozilla::dom::RootingCx(), + JS_ExtensibleLexicalEnvironment(obj)); + JS_SetAllNonReservedSlotsToUndefined(lexicalEnv); + } + JS_SetAllNonReservedSlotsToUndefined(obj); + obj = nullptr; + thisObjectKey = nullptr; + } + + if (location) { + free(location); + } + + obj = nullptr; + thisObjectKey = nullptr; + location = nullptr; +#ifdef STARTUP_RECORDER_ENABLED + importStack.Truncate(); +#endif + } + + size_t SizeOfIncludingThis(mozilla::MallocSizeOf aMallocSizeOf) const; + + static already_AddRefed<nsIFactory> GetFactory( + const mozilla::Module& module, const mozilla::Module::CIDEntry& entry); + + nsCOMPtr<xpcIJSGetFactory> getfactoryobj; + JS::PersistentRootedObject obj; + JS::PersistentRootedObject exports; + JS::PersistentRootedScript thisObjectKey; + char* location; + nsCString resolvedURL; +#ifdef STARTUP_RECORDER_ENABLED + nsCString importStack; +#endif + }; + + nsresult ExtractExports(JSContext* aCx, ComponentLoaderInfo& aInfo, + ModuleEntry* aMod, JS::MutableHandleObject aExports); + + // Modules are intentionally leaked, but still cleared. + nsDataHashtable<nsCStringHashKey, ModuleEntry*> mModules; + + nsClassHashtable<nsCStringHashKey, ModuleEntry> mImports; + nsDataHashtable<nsCStringHashKey, ModuleEntry*> mInProgressImports; + + // A map of on-disk file locations which are loaded as modules to the + // pre-resolved URIs they were loaded from. Used to prevent the same file + // from being loaded separately, from multiple URLs. + nsClassHashtable<nsCStringHashKey, nsCString> mLocations; + + bool mInitialized; + JS::PersistentRooted<JSObject*> mLoaderGlobal; +}; + +#endif diff --git a/js/xpconnect/loader/mozJSLoaderUtils.cpp b/js/xpconnect/loader/mozJSLoaderUtils.cpp new file mode 100644 index 0000000000..522d85c304 --- /dev/null +++ b/js/xpconnect/loader/mozJSLoaderUtils.cpp @@ -0,0 +1,78 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "mozilla/scache/StartupCache.h" + +#include "jsapi.h" +#include "jsfriendapi.h" + +#include "mozilla/BasePrincipal.h" + +using namespace JS; +using namespace mozilla::scache; +using mozilla::UniquePtr; + +// We only serialize scripts with system principals. So we don't serialize the +// principals when writing a script. Instead, when reading it back, we set the +// principals to the system principals. +nsresult ReadCachedScript(StartupCache* cache, nsACString& uri, JSContext* cx, + const JS::ReadOnlyCompileOptions& options, + MutableHandleScript scriptp) { + const char* buf; + uint32_t len; + nsresult rv = cache->GetBuffer(PromiseFlatCString(uri).get(), &buf, &len); + if (NS_FAILED(rv)) { + return rv; // don't warn since NOT_AVAILABLE is an ok error + } + void* copy = malloc(len); + if (!copy) { + return NS_ERROR_OUT_OF_MEMORY; + } + memcpy(copy, buf, len); + JS::TranscodeBuffer buffer; + buffer.replaceRawBuffer(reinterpret_cast<uint8_t*>(copy), len); + JS::TranscodeResult code = JS::DecodeScript(cx, options, buffer, scriptp); + if (code == JS::TranscodeResult_Ok) { + return NS_OK; + } + + if ((code & JS::TranscodeResult_Failure) != 0) { + return NS_ERROR_FAILURE; + } + + MOZ_ASSERT((code & JS::TranscodeResult_Throw) != 0); + JS_ClearPendingException(cx); + return NS_ERROR_OUT_OF_MEMORY; +} + +nsresult WriteCachedScript(StartupCache* cache, nsACString& uri, JSContext* cx, + HandleScript script) { + MOZ_ASSERT( + nsJSPrincipals::get(JS_GetScriptPrincipals(script))->IsSystemPrincipal()); + + JS::TranscodeBuffer buffer; + JS::TranscodeResult code = JS::EncodeScript(cx, buffer, script); + if (code != JS::TranscodeResult_Ok) { + if ((code & JS::TranscodeResult_Failure) != 0) { + return NS_ERROR_FAILURE; + } + MOZ_ASSERT((code & JS::TranscodeResult_Throw) != 0); + JS_ClearPendingException(cx); + return NS_ERROR_OUT_OF_MEMORY; + } + + size_t size = buffer.length(); + if (size > UINT32_MAX) { + return NS_ERROR_FAILURE; + } + + // Move the vector buffer into a unique pointer buffer. + UniquePtr<char[]> buf( + reinterpret_cast<char*>(buffer.extractOrCopyRawBuffer())); + nsresult rv = + cache->PutBuffer(PromiseFlatCString(uri).get(), std::move(buf), size); + return rv; +} diff --git a/js/xpconnect/loader/mozJSLoaderUtils.h b/js/xpconnect/loader/mozJSLoaderUtils.h new file mode 100644 index 0000000000..74097c39c6 --- /dev/null +++ b/js/xpconnect/loader/mozJSLoaderUtils.h @@ -0,0 +1,29 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef mozJSLoaderUtils_h +#define mozJSLoaderUtils_h + +#include "nsString.h" + +#include "js/CompileOptions.h" // JS::ReadOnlyCompileOptions + +namespace mozilla { +namespace scache { +class StartupCache; +} // namespace scache +} // namespace mozilla + +nsresult ReadCachedScript(mozilla::scache::StartupCache* cache, nsACString& uri, + JSContext* cx, + const JS::ReadOnlyCompileOptions& options, + JS::MutableHandleScript scriptp); + +nsresult WriteCachedScript(mozilla::scache::StartupCache* cache, + nsACString& uri, JSContext* cx, + JS::HandleScript script); + +#endif /* mozJSLoaderUtils_h */ diff --git a/js/xpconnect/loader/mozJSSubScriptLoader.cpp b/js/xpconnect/loader/mozJSSubScriptLoader.cpp new file mode 100644 index 0000000000..00577f378d --- /dev/null +++ b/js/xpconnect/loader/mozJSSubScriptLoader.cpp @@ -0,0 +1,507 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "mozJSSubScriptLoader.h" +#include "mozJSComponentLoader.h" +#include "mozJSLoaderUtils.h" + +#include "nsIURI.h" +#include "nsIIOService.h" +#include "nsIChannel.h" +#include "nsIInputStream.h" +#include "nsNetCID.h" +#include "nsNetUtil.h" + +#include "jsapi.h" +#include "jsfriendapi.h" +#include "xpcprivate.h" // xpc::OptionsBase +#include "js/CompilationAndEvaluation.h" // JS::Compile +#include "js/CompileOptions.h" // JS::ReadOnlyCompileOptions +#include "js/friend/JSMEnvironment.h" // JS::ExecuteInJSMEnvironment, JS::IsJSMEnvironment +#include "js/SourceText.h" // JS::Source{Ownership,Text} +#include "js/Wrapper.h" + +#include "mozilla/ContentPrincipal.h" +#include "mozilla/dom/ScriptLoader.h" +#include "mozilla/ScriptPreloader.h" +#include "mozilla/SystemPrincipal.h" +#include "mozilla/scache/StartupCache.h" +#include "mozilla/scache/StartupCacheUtils.h" +#include "mozilla/Unused.h" +#include "mozilla/Utf8.h" // mozilla::Utf8Unit +#include "nsContentUtils.h" +#include "nsString.h" +#include "GeckoProfiler.h" + +using namespace mozilla::scache; +using namespace JS; +using namespace xpc; +using namespace mozilla; +using namespace mozilla::dom; + +class MOZ_STACK_CLASS LoadSubScriptOptions : public OptionsBase { + public: + explicit LoadSubScriptOptions(JSContext* cx = xpc_GetSafeJSContext(), + JSObject* options = nullptr) + : OptionsBase(cx, options), + target(cx), + ignoreCache(false), + wantReturnValue(false) {} + + virtual bool Parse() override { + return ParseObject("target", &target) && + ParseBoolean("ignoreCache", &ignoreCache) && + ParseBoolean("wantReturnValue", &wantReturnValue); + } + + RootedObject target; + bool ignoreCache; + bool wantReturnValue; +}; + +/* load() error msgs, XXX localize? */ +#define LOAD_ERROR_NOSERVICE "Error creating IO Service." +#define LOAD_ERROR_NOURI "Error creating URI (invalid URL scheme?)" +#define LOAD_ERROR_NOSCHEME "Failed to get URI scheme. This is bad." +#define LOAD_ERROR_URI_NOT_LOCAL "Trying to load a non-local URI." +#define LOAD_ERROR_NOSTREAM "Error opening input stream (invalid filename?)" +#define LOAD_ERROR_NOCONTENT "ContentLength not available (not a local URL?)" +#define LOAD_ERROR_BADCHARSET "Error converting to specified charset" +#define LOAD_ERROR_NOSPEC "Failed to get URI spec. This is bad." +#define LOAD_ERROR_CONTENTTOOBIG "ContentLength is too large" + +mozJSSubScriptLoader::mozJSSubScriptLoader() = default; + +mozJSSubScriptLoader::~mozJSSubScriptLoader() = default; + +NS_IMPL_ISUPPORTS(mozJSSubScriptLoader, mozIJSSubScriptLoader) + +#define JSSUB_CACHE_PREFIX(aType) "jssubloader/" aType + +static void SubscriptCachePath(JSContext* cx, nsIURI* uri, + JS::HandleObject targetObj, + nsACString& cachePath) { + // StartupCache must distinguish between non-syntactic vs global when + // computing the cache key. + if (!JS_IsGlobalObject(targetObj)) { + cachePath.AssignLiteral(JSSUB_CACHE_PREFIX("non-syntactic")); + } else { + cachePath.AssignLiteral(JSSUB_CACHE_PREFIX("global")); + } + PathifyURI(uri, cachePath); +} + +static void ReportError(JSContext* cx, const nsACString& msg) { + NS_ConvertUTF8toUTF16 ucMsg(msg); + + RootedValue exn(cx); + if (xpc::NonVoidStringToJsval(cx, ucMsg, &exn)) { + JS_SetPendingException(cx, exn); + } +} + +static void ReportError(JSContext* cx, const char* origMsg, nsIURI* uri) { + if (!uri) { + ReportError(cx, nsDependentCString(origMsg)); + return; + } + + nsAutoCString spec; + nsresult rv = uri->GetSpec(spec); + if (NS_FAILED(rv)) { + spec.AssignLiteral("(unknown)"); + } + + nsAutoCString msg(origMsg); + msg.AppendLiteral(": "); + msg.Append(spec); + ReportError(cx, msg); +} + +static void FillCompileOptions(JS::CompileOptions& options, const char* uriStr, + bool wantGlobalScript, bool wantReturnValue) { + options.setFileAndLine(uriStr, 1).setNoScriptRval(!wantReturnValue); + + // This presumes that no one else might be compiling a script for this + // (URL, syntactic-or-not) key *not* using UTF-8. Seeing as JS source can + // only be compiled as UTF-8 or UTF-16 now -- there isn't a JSAPI function to + // compile Latin-1 now -- this presumption seems relatively safe. + // + // This also presumes that lazy parsing is disabled, for the sake of the + // startup cache. If lazy parsing is ever enabled for pertinent scripts that + // pass through here, we may need to disable lazy source for them. + options.setSourceIsLazy(true); + + if (!wantGlobalScript) { + options.setNonSyntacticScope(true); + } +} + +static JSScript* PrepareScript(nsIURI* uri, JSContext* cx, + const JS::ReadOnlyCompileOptions& options, + const char* buf, int64_t len) { + JS::SourceText<Utf8Unit> srcBuf; + if (!srcBuf.init(cx, buf, len, JS::SourceOwnership::Borrowed)) { + return nullptr; + } + + return JS::Compile(cx, options, srcBuf); +} + +static bool EvalScript(JSContext* cx, HandleObject targetObj, + HandleObject loadScope, MutableHandleValue retval, + nsIURI* uri, bool startupCache, bool preloadCache, + MutableHandleScript script) { + MOZ_ASSERT(!js::IsWrapper(targetObj)); + + if (JS_IsGlobalObject(targetObj)) { + if (!JS::CloneAndExecuteScript(cx, script, retval)) { + return false; + } + } else if (JS::IsJSMEnvironment(targetObj)) { + if (!JS::ExecuteInJSMEnvironment(cx, script, targetObj)) { + return false; + } + retval.setUndefined(); + } else { + JS::RootedObjectVector envChain(cx); + if (!envChain.append(targetObj)) { + return false; + } + if (!loadScope) { + // A null loadScope means we are cross-realm. In this case, we should + // check the target isn't in the JSM loader shared-global or we will + // contaminate all JSMs in the realm. + // + // NOTE: If loadScope is already a shared-global JSM, we can't + // determine which JSM the target belongs to and have to assume it + // is in our JSM. +#ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED + JSObject* targetGlobal = JS::GetNonCCWObjectGlobal(targetObj); + MOZ_DIAGNOSTIC_ASSERT( + !mozJSComponentLoader::Get()->IsLoaderGlobal(targetGlobal), + "Don't load subscript into target in a shared-global JSM"); +#endif + if (!JS::CloneAndExecuteScript(cx, envChain, script, retval)) { + return false; + } + } else if (JS_IsGlobalObject(loadScope)) { + if (!JS::CloneAndExecuteScript(cx, envChain, script, retval)) { + return false; + } + } else { + MOZ_ASSERT(JS::IsJSMEnvironment(loadScope)); + if (!JS::ExecuteInJSMEnvironment(cx, script, loadScope, envChain)) { + return false; + } + retval.setUndefined(); + } + } + + JSAutoRealm rar(cx, targetObj); + if (!JS_WrapValue(cx, retval)) { + return false; + } + + if (script && (startupCache || preloadCache)) { + nsAutoCString cachePath; + SubscriptCachePath(cx, uri, targetObj, cachePath); + + nsCString uriStr; + if (preloadCache && NS_SUCCEEDED(uri->GetSpec(uriStr))) { + // Note that, when called during startup, this will keep the + // original JSScript object alive for an indefinite amount of time. + // This has the side-effect of keeping the global that the script + // was compiled for alive, too. + // + // For most startups, the global in question will be the + // CompilationScope, since we pre-compile any scripts that were + // needed during the last startup in that scope. But for startups + // when a non-cached script is used (e.g., after add-on + // installation), this may be a Sandbox global, which may be + // nuked but held alive by the JSScript. We can avoid this problem + // by using a different scope when compiling the script. See + // useCompilationScope in ReadScript(). + // + // In general, this isn't a problem, since add-on Sandboxes which + // use the script preloader are not destroyed until add-on shutdown, + // and when add-ons are uninstalled or upgraded, the preloader cache + // is immediately flushed after shutdown. But it's possible to + // disable and reenable an add-on without uninstalling it, leading + // to cached scripts being held alive, and tied to nuked Sandbox + // globals. Given the unusual circumstances required to trigger + // this, it's not a major concern. But it should be kept in mind. + ScriptPreloader::GetSingleton().NoteScript(uriStr, cachePath, script); + } + + if (startupCache) { + JSAutoRealm ar(cx, script); + WriteCachedScript(StartupCache::GetSingleton(), cachePath, cx, script); + } + } + + return true; +} + +bool mozJSSubScriptLoader::ReadScript(JS::MutableHandle<JSScript*> script, + nsIURI* uri, JSContext* cx, + const JS::ReadOnlyCompileOptions& options, + nsIIOService* serv, + bool useCompilationScope) { + // We create a channel and call SetContentType, to avoid expensive MIME type + // lookups (bug 632490). + nsCOMPtr<nsIChannel> chan; + nsCOMPtr<nsIInputStream> instream; + nsresult rv; + rv = NS_NewChannel(getter_AddRefs(chan), uri, + nsContentUtils::GetSystemPrincipal(), + nsILoadInfo::SEC_ALLOW_CROSS_ORIGIN_SEC_CONTEXT_IS_NULL, + nsIContentPolicy::TYPE_OTHER, + nullptr, // nsICookieJarSettings + nullptr, // PerformanceStorage + nullptr, // aLoadGroup + nullptr, // aCallbacks + nsIRequest::LOAD_NORMAL, serv); + + if (NS_SUCCEEDED(rv)) { + chan->SetContentType("application/javascript"_ns); + rv = chan->Open(getter_AddRefs(instream)); + } + + if (NS_FAILED(rv)) { + ReportError(cx, LOAD_ERROR_NOSTREAM, uri); + return false; + } + + int64_t len = -1; + + rv = chan->GetContentLength(&len); + if (NS_FAILED(rv)) { + ReportError(cx, LOAD_ERROR_NOCONTENT, uri); + return false; + } + + if (len > INT32_MAX) { + ReportError(cx, LOAD_ERROR_CONTENTTOOBIG, uri); + return false; + } + + nsCString buf; + rv = NS_ReadInputStreamToString(instream, buf, len); + NS_ENSURE_SUCCESS(rv, false); + + if (len < 0) { + len = buf.Length(); + } + +#ifdef DEBUG + int64_t currentLength = -1; + // if getting content length succeeded above, it should not fail now + MOZ_ASSERT(chan->GetContentLength(¤tLength) == NS_OK); + // if content length was not known when GetContentLength() was called before, + // 'len' would be set to -1 until NS_ReadInputStreamToString() set its correct + // value. Every subsequent call to GetContentLength() should return the same + // length as that value. + MOZ_ASSERT(currentLength == len); +#endif + + Maybe<JSAutoRealm> ar; + + // Note that when using the ScriptPreloader cache with loadSubScript, there + // will be a side-effect of keeping the global that the script was compiled + // for alive. See note above in EvalScript(). + // + // This will compile the script in XPConnect compilation scope. When the + // script is evaluated, it will be cloned into the target scope to be + // executed, avoiding leaks on the first session when we don't have a + // startup cache. + if (useCompilationScope) { + ar.emplace(cx, xpc::CompilationScope()); + } + + JSScript* ret = PrepareScript(uri, cx, options, buf.get(), len); + if (!ret) { + return false; + } + + script.set(ret); + return true; +} + +NS_IMETHODIMP +mozJSSubScriptLoader::LoadSubScript(const nsAString& url, HandleValue target, + JSContext* cx, MutableHandleValue retval) { + /* + * Loads a local url, referring to UTF-8-encoded data, and evals it into the + * current cx. Synchronous. ChromeUtils.compileScript() should be used for + * async loads. + * url: The url to load. Must be local so that it can be loaded + * synchronously. + * targetObj: Optional object to eval the script onto (defaults to context + * global) + * returns: Whatever jsval the script pointed to by the url returns. + * Should ONLY (O N L Y !) be called from JavaScript code. + */ + LoadSubScriptOptions options(cx); + options.target = target.isObject() ? &target.toObject() : nullptr; + return DoLoadSubScriptWithOptions(url, options, cx, retval); +} + +NS_IMETHODIMP +mozJSSubScriptLoader::LoadSubScriptWithOptions(const nsAString& url, + HandleValue optionsVal, + JSContext* cx, + MutableHandleValue retval) { + if (!optionsVal.isObject()) { + return NS_ERROR_INVALID_ARG; + } + + LoadSubScriptOptions options(cx, &optionsVal.toObject()); + if (!options.Parse()) { + return NS_ERROR_INVALID_ARG; + } + + return DoLoadSubScriptWithOptions(url, options, cx, retval); +} + +nsresult mozJSSubScriptLoader::DoLoadSubScriptWithOptions( + const nsAString& url, LoadSubScriptOptions& options, JSContext* cx, + MutableHandleValue retval) { + nsresult rv = NS_OK; + RootedObject targetObj(cx); + RootedObject loadScope(cx); + mozJSComponentLoader* loader = mozJSComponentLoader::Get(); + loader->FindTargetObject(cx, &loadScope); + + if (options.target) { + targetObj = options.target; + } else { + targetObj = loadScope; + } + + targetObj = JS_FindCompilationScope(cx, targetObj); + if (!targetObj || !loadScope) { + return NS_ERROR_FAILURE; + } + + MOZ_ASSERT(!js::IsWrapper(targetObj), "JS_FindCompilationScope must unwrap"); + + if (js::GetNonCCWObjectRealm(loadScope) != + js::GetNonCCWObjectRealm(targetObj)) { + loadScope = nullptr; + } + + /* load up the url. From here on, failures are reflected as ``custom'' + * js exceptions */ + nsCOMPtr<nsIURI> uri; + nsAutoCString uriStr; + nsAutoCString scheme; + + // Figure out who's calling us + JS::AutoFilename filename; + if (!JS::DescribeScriptedCaller(cx, &filename)) { + // No scripted frame means we don't know who's calling, bail. + return NS_ERROR_FAILURE; + } + + JSAutoRealm ar(cx, targetObj); + + nsCOMPtr<nsIIOService> serv = do_GetService(NS_IOSERVICE_CONTRACTID); + if (!serv) { + ReportError(cx, nsLiteralCString(LOAD_ERROR_NOSERVICE)); + return NS_OK; + } + + NS_LossyConvertUTF16toASCII asciiUrl(url); + AUTO_PROFILER_LABEL_DYNAMIC_NSCSTRING_NONSENSITIVE( + "mozJSSubScriptLoader::DoLoadSubScriptWithOptions", OTHER, asciiUrl); + AUTO_PROFILER_MARKER_TEXT("SubScript", JS, MarkerStack::Capture(), asciiUrl); + + // Make sure to explicitly create the URI, since we'll need the + // canonicalized spec. + rv = NS_NewURI(getter_AddRefs(uri), asciiUrl); + if (NS_FAILED(rv)) { + ReportError(cx, nsLiteralCString(LOAD_ERROR_NOURI)); + return NS_OK; + } + + rv = uri->GetSpec(uriStr); + if (NS_FAILED(rv)) { + ReportError(cx, nsLiteralCString(LOAD_ERROR_NOSPEC)); + return NS_OK; + } + + rv = uri->GetScheme(scheme); + if (NS_FAILED(rv)) { + ReportError(cx, LOAD_ERROR_NOSCHEME, uri); + return NS_OK; + } + + // Suppress caching if we're compiling as content or if we're loading a + // blob: URI. + bool useCompilationScope = false; + auto* principal = BasePrincipal::Cast(GetObjectPrincipal(targetObj)); + bool isSystem = principal->Is<SystemPrincipal>(); + if (!isSystem && principal->Is<ContentPrincipal>()) { + auto* content = principal->As<ContentPrincipal>(); + + nsAutoCString scheme; + content->mURI->GetScheme(scheme); + + // We want to enable caching for scripts with Activity Stream's + // codebase URLs. + if (scheme.EqualsLiteral("about")) { + nsAutoCString filePath; + content->mURI->GetFilePath(filePath); + + useCompilationScope = filePath.EqualsLiteral("home") || + filePath.EqualsLiteral("newtab") || + filePath.EqualsLiteral("welcome"); + isSystem = true; + } + } + bool ignoreCache = + options.ignoreCache || !isSystem || scheme.EqualsLiteral("blob"); + + StartupCache* cache = ignoreCache ? nullptr : StartupCache::GetSingleton(); + + nsAutoCString cachePath; + SubscriptCachePath(cx, uri, targetObj, cachePath); + + JS::CompileOptions compileOptions(cx); + FillCompileOptions(compileOptions, uriStr.get(), JS_IsGlobalObject(targetObj), + options.wantReturnValue); + + RootedScript script(cx); + if (!options.ignoreCache) { + if (!options.wantReturnValue) { + script = ScriptPreloader::GetSingleton().GetCachedScript( + cx, compileOptions, cachePath); + } + if (!script && cache) { + rv = ReadCachedScript(cache, cachePath, cx, compileOptions, &script); + } + if (NS_FAILED(rv) || !script) { + // ReadCachedScript may have set a pending exception. + JS_ClearPendingException(cx); + } + } + + if (script) { + // |script| came from the cache, so don't bother writing it + // |back there. + cache = nullptr; + } else { + if (!ReadScript(&script, uri, cx, compileOptions, serv, + useCompilationScope)) { + return NS_OK; + } + } + + Unused << EvalScript(cx, targetObj, loadScope, retval, uri, !!cache, + !ignoreCache && !options.wantReturnValue, &script); + return NS_OK; +} diff --git a/js/xpconnect/loader/mozJSSubScriptLoader.h b/js/xpconnect/loader/mozJSSubScriptLoader.h new file mode 100644 index 0000000000..085e089539 --- /dev/null +++ b/js/xpconnect/loader/mozJSSubScriptLoader.h @@ -0,0 +1,49 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "nsCOMPtr.h" +#include "mozIJSSubScriptLoader.h" + +#include "js/CompileOptions.h" // JS::ReadOnlyCompileOptions + +class nsIPrincipal; +class nsIURI; +class LoadSubScriptOptions; + +#define MOZ_JSSUBSCRIPTLOADER_CID \ + { /* 829814d6-1dd2-11b2-8e08-82fa0a339b00 */ \ + 0x929814d6, 0x1dd2, 0x11b2, { \ + 0x8e, 0x08, 0x82, 0xfa, 0x0a, 0x33, 0x9b, 0x00 \ + } \ + } + +class nsIIOService; + +class mozJSSubScriptLoader : public mozIJSSubScriptLoader { + public: + mozJSSubScriptLoader(); + + // all the interface method declarations... + NS_DECL_ISUPPORTS + NS_DECL_MOZIJSSUBSCRIPTLOADER + + private: + virtual ~mozJSSubScriptLoader(); + + bool ReadScript(JS::MutableHandle<JSScript*> script, nsIURI* uri, + JSContext* cx, const JS::ReadOnlyCompileOptions& options, + nsIIOService* serv, bool useCompilationScope); + + nsresult ReadScriptAsync(nsIURI* uri, JS::HandleObject targetObj, + JS::HandleObject loadScope, nsIIOService* serv, + bool wantReturnValue, bool cache, + JS::MutableHandleValue retval); + + nsresult DoLoadSubScriptWithOptions(const nsAString& url, + LoadSubScriptOptions& options, + JSContext* cx, + JS::MutableHandleValue retval); +}; diff --git a/js/xpconnect/loader/nsImportModule.cpp b/js/xpconnect/loader/nsImportModule.cpp new file mode 100644 index 0000000000..372ca6de75 --- /dev/null +++ b/js/xpconnect/loader/nsImportModule.cpp @@ -0,0 +1,46 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "nsImportModule.h" + +#include "mozilla/ResultExtensions.h" +#include "mozilla/dom/ScriptSettings.h" +#include "mozJSComponentLoader.h" +#include "xpcpublic.h" +#include "xpcprivate.h" + +using mozilla::dom::AutoJSAPI; + +namespace mozilla { +namespace loader { + +nsresult ImportModule(const char* aURI, const char* aExportName, + const nsIID& aIID, void** aResult) { + AutoJSAPI jsapi; + MOZ_ALWAYS_TRUE(jsapi.Init(xpc::PrivilegedJunkScope())); + JSContext* cx = jsapi.cx(); + + JS::RootedObject global(cx); + JS::RootedObject exports(cx); + MOZ_TRY(mozJSComponentLoader::Get()->Import(cx, nsDependentCString(aURI), + &global, &exports)); + + if (aExportName) { + JS::RootedValue namedExport(cx); + if (!JS_GetProperty(cx, exports, aExportName, &namedExport)) { + return NS_ERROR_FAILURE; + } + if (!namedExport.isObject()) { + return NS_ERROR_XPC_BAD_CONVERT_JS; + } + exports.set(&namedExport.toObject()); + } + + return nsXPConnect::XPConnect()->WrapJS(cx, exports, aIID, aResult); +} + +} // namespace loader +} // namespace mozilla diff --git a/js/xpconnect/loader/nsImportModule.h b/js/xpconnect/loader/nsImportModule.h new file mode 100644 index 0000000000..b1105278d3 --- /dev/null +++ b/js/xpconnect/loader/nsImportModule.h @@ -0,0 +1,113 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */ +/* vim: set ts=8 sts=2 et sw=2 tw=80: */ +/* This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#ifndef nsImportModule_h +#define nsImportModule_h + +#include "mozilla/Attributes.h" + +#include "nsCOMPtr.h" +#include "mozilla/RefPtr.h" + +namespace mozilla { +namespace loader { + +nsresult ImportModule(const char* aURI, const char* aExportName, + const nsIID& aIID, void** aResult); + +} // namespace loader +} // namespace mozilla + +class MOZ_STACK_CLASS nsImportModule final : public nsCOMPtr_helper { + public: + nsImportModule(const char* aURI, const char* aExportName, nsresult* aErrorPtr) + : mURI(aURI), mExportName(aExportName), mErrorPtr(aErrorPtr) {} + + virtual nsresult NS_FASTCALL operator()(const nsIID& aIID, + void** aResult) const override { + nsresult rv = + ::mozilla::loader::ImportModule(mURI, mExportName, aIID, aResult); + if (mErrorPtr) { + *mErrorPtr = rv; + } + return rv; + } + + private: + const char* mURI; + const char* mExportName; + nsresult* mErrorPtr; +}; + +/** + * These helpers make it considerably easier for C++ code to import a JS module + * and wrap it in an appropriately-defined XPIDL interface for its exports. + * Typical usage is something like: + * + * Foo.jsm: + * + * var EXPORTED_SYMBOLS = ["foo"]; + * + * function foo(bar) { + * return bar.toString(); + * } + * + * mozIFoo.idl: + * + * interface mozIFoo : nsISupports { + * AString foo(double meh); + * } + * + * Thing.cpp: + * + * nsCOMPtr<mozIFoo> foo = do_ImportModule( + * "resource://meh/Foo.jsm"); + * + * MOZ_TRY(foo->Foo(42)); + * + * For JS modules which export all fields within a single named object, a second + * argument can be passed naming that object. + * + * Foo.jsm: + * + * var EXPORTED_SYMBOLS = ["Foo"]; + * + * var Foo = { + * function foo(bar) { + * return bar.toString(); + * } + * }; + * + * Thing.cpp: + * + * nsCOMPtr<mozIFoo> foo = do_ImportModule( + * "resource:://meh/Foo.jsm", "Foo"); + */ + +template <size_t N> +inline nsImportModule do_ImportModule(const char (&aURI)[N]) { + return {aURI, nullptr, nullptr}; +} + +template <size_t N> +inline nsImportModule do_ImportModule(const char (&aURI)[N], nsresult* aRv) { + return {aURI, nullptr, aRv}; +} + +template <size_t N, size_t N2> +inline nsImportModule do_ImportModule(const char (&aURI)[N], + const char (&aExportName)[N2]) { + return {aURI, aExportName, nullptr}; +} + +template <size_t N, size_t N2> +inline nsImportModule do_ImportModule(const char (&aURI)[N], + const char (&aExportName)[N2], + nsresult* aRv) { + return {aURI, aExportName, aRv}; +} + +#endif // defined nsImportModule_h diff --git a/js/xpconnect/loader/script_cache.py b/js/xpconnect/loader/script_cache.py new file mode 100755 index 0000000000..ecf5d8ae2e --- /dev/null +++ b/js/xpconnect/loader/script_cache.py @@ -0,0 +1,95 @@ +#!/usr/bin/env python + +from __future__ import absolute_import, print_function + +# This Source Code Form is subject to the terms of the Mozilla Public +# License, v. 2.0. If a copy of the MPL was not distributed with this file, +# You can obtain one at http://mozilla.org/MPL/2.0/. + +import io +import os +import struct +import sys + +MAGIC = b"mozXDRcachev002\0" + + +def usage(): + print( + """Usage: script_cache.py <file.bin> ... + + Decodes and prints out the contents of a startup script cache file + (e.g., startupCache/scriptCache.bin) in human-readable form.""" + ) + + sys.exit(1) + + +class ProcessTypes: + Uninitialized = 0 + Parent = 1 + Web = 2 + Extension = 3 + Privileged = 4 + + def __init__(self, val): + self.val = val + + def __str__(self): + res = [] + if self.val & (1 << self.Uninitialized): + raise Exception("Uninitialized process type") + if self.val & (1 << self.Parent): + res.append("Parent") + if self.val & (1 << self.Web): + res.append("Web") + if self.val & (1 << self.Extension): + res.append("Extension") + if self.val & (1 << self.Privileged): + res.append("Privileged") + return "|".join(res) + + +class InputBuffer(object): + def __init__(self, data): + self.data = data + self.offset = 0 + + @property + def remaining(self): + return len(self.data) - self.offset + + def unpack(self, fmt): + res = struct.unpack_from(fmt, self.data, self.offset) + self.offset += struct.calcsize(fmt) + return res + + def unpack_str(self): + (size,) = self.unpack("<H") + res = self.data[self.offset : self.offset + size].decode("utf-8") + self.offset += size + return res + + +if len(sys.argv) < 2 or not os.path.exists(sys.argv[1]): + usage() + +for filename in sys.argv[1:]: + with io.open(filename, "rb") as f: + magic = f.read(len(MAGIC)) + if magic != MAGIC: + raise Exception("Bad magic number") + + (hdrSize,) = struct.unpack("<I", f.read(4)) + + hdr = InputBuffer(f.read(hdrSize)) + + i = 0 + while hdr.remaining: + i += 1 + print("{}: {}".format(i, hdr.unpack_str())) + print(" Key: {}".format(hdr.unpack_str())) + print(" Offset: {:>9,}".format(*hdr.unpack("<I"))) + print(" Size: {:>9,}".format(*hdr.unpack("<I"))) + print(" Processes: {}".format(ProcessTypes(*hdr.unpack("B")))) + print("") |