diff options
Diffstat (limited to 'xpcom/threads/nsThread.cpp')
| -rw-r--r-- | xpcom/threads/nsThread.cpp | 1609 |
1 files changed, 1609 insertions, 0 deletions
diff --git a/xpcom/threads/nsThread.cpp b/xpcom/threads/nsThread.cpp new file mode 100644 index 0000000000..772f6b7738 --- /dev/null +++ b/xpcom/threads/nsThread.cpp @@ -0,0 +1,1609 @@ +/* -*- 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 "nsThread.h" + +#include "base/message_loop.h" +#include "base/platform_thread.h" + +// Chromium's logging can sometimes leak through... +#ifdef LOG +# undef LOG +#endif + +#include "mozilla/ReentrantMonitor.h" +#include "nsMemoryPressure.h" +#include "nsThreadManager.h" +#include "nsIClassInfoImpl.h" +#include "nsCOMPtr.h" +#include "nsQueryObject.h" +#include "pratom.h" +#include "mozilla/BackgroundHangMonitor.h" +#include "mozilla/CycleCollectedJSContext.h" +#include "mozilla/DebugOnly.h" +#include "mozilla/Logging.h" +#include "nsIObserverService.h" +#include "mozilla/IOInterposer.h" +#include "mozilla/ipc/MessageChannel.h" +#include "mozilla/ipc/BackgroundChild.h" +#include "mozilla/Preferences.h" +#include "mozilla/ProfilerRunnable.h" +#include "mozilla/SchedulerGroup.h" +#include "mozilla/Services.h" +#include "mozilla/SpinEventLoopUntil.h" +#include "mozilla/StaticLocalPtr.h" +#include "mozilla/StaticPrefs_threads.h" +#include "mozilla/TaskController.h" +#include "nsXPCOMPrivate.h" +#include "mozilla/ChaosMode.h" +#include "mozilla/Telemetry.h" +#include "mozilla/TimeStamp.h" +#include "mozilla/Unused.h" +#include "mozilla/dom/DocGroup.h" +#include "mozilla/dom/ScriptSettings.h" +#include "nsThreadSyncDispatch.h" +#include "nsServiceManagerUtils.h" +#include "GeckoProfiler.h" +#include "ThreadEventQueue.h" +#include "ThreadEventTarget.h" +#include "ThreadDelay.h" + +#include <limits> + +#ifdef XP_LINUX +# ifdef __GLIBC__ +# include <gnu/libc-version.h> +# endif +# include <sys/mman.h> +# include <sys/time.h> +# include <sys/resource.h> +# include <sched.h> +# include <stdio.h> +#endif + +#ifdef XP_WIN +# include "mozilla/DynamicallyLinkedFunctionPtr.h" + +# include <winbase.h> + +using GetCurrentThreadStackLimitsFn = void(WINAPI*)(PULONG_PTR LowLimit, + PULONG_PTR HighLimit); +#endif + +#define HAVE_UALARM \ + _BSD_SOURCE || \ + (_XOPEN_SOURCE >= 500 || _XOPEN_SOURCE && _XOPEN_SOURCE_EXTENDED) && \ + !(_POSIX_C_SOURCE >= 200809L || _XOPEN_SOURCE >= 700) + +#if defined(XP_LINUX) && !defined(ANDROID) && defined(_GNU_SOURCE) +# define HAVE_SCHED_SETAFFINITY +#endif + +#ifdef XP_MACOSX +# include <mach/mach.h> +# include <mach/thread_policy.h> +# include <sys/qos.h> +#endif + +#ifdef MOZ_CANARY +# include <unistd.h> +# include <execinfo.h> +# include <signal.h> +# include <fcntl.h> +# include "nsXULAppAPI.h" +#endif + +using namespace mozilla; + +extern void InitThreadLocalVariables(); + +static LazyLogModule sThreadLog("nsThread"); +#ifdef LOG +# undef LOG +#endif +#define LOG(args) MOZ_LOG(sThreadLog, mozilla::LogLevel::Debug, args) + +NS_DECL_CI_INTERFACE_GETTER(nsThread) + +Array<char, nsThread::kRunnableNameBufSize> nsThread::sMainThreadRunnableName; + +#ifdef EARLY_BETA_OR_EARLIER +const uint32_t kTelemetryWakeupCountLimit = 100; +#endif + +//----------------------------------------------------------------------------- +// Because we do not have our own nsIFactory, we have to implement nsIClassInfo +// somewhat manually. + +class nsThreadClassInfo : public nsIClassInfo { + public: + NS_DECL_ISUPPORTS_INHERITED // no mRefCnt + NS_DECL_NSICLASSINFO + + nsThreadClassInfo() = default; +}; + +NS_IMETHODIMP_(MozExternalRefCountType) +nsThreadClassInfo::AddRef() { return 2; } +NS_IMETHODIMP_(MozExternalRefCountType) +nsThreadClassInfo::Release() { return 1; } +NS_IMPL_QUERY_INTERFACE(nsThreadClassInfo, nsIClassInfo) + +NS_IMETHODIMP +nsThreadClassInfo::GetInterfaces(nsTArray<nsIID>& aArray) { + return NS_CI_INTERFACE_GETTER_NAME(nsThread)(aArray); +} + +NS_IMETHODIMP +nsThreadClassInfo::GetScriptableHelper(nsIXPCScriptable** aResult) { + *aResult = nullptr; + return NS_OK; +} + +NS_IMETHODIMP +nsThreadClassInfo::GetContractID(nsACString& aResult) { + aResult.SetIsVoid(true); + return NS_OK; +} + +NS_IMETHODIMP +nsThreadClassInfo::GetClassDescription(nsACString& aResult) { + aResult.SetIsVoid(true); + return NS_OK; +} + +NS_IMETHODIMP +nsThreadClassInfo::GetClassID(nsCID** aResult) { + *aResult = nullptr; + return NS_OK; +} + +NS_IMETHODIMP +nsThreadClassInfo::GetFlags(uint32_t* aResult) { + *aResult = THREADSAFE; + return NS_OK; +} + +NS_IMETHODIMP +nsThreadClassInfo::GetClassIDNoAlloc(nsCID* aResult) { + return NS_ERROR_NOT_AVAILABLE; +} + +//----------------------------------------------------------------------------- + +NS_IMPL_ADDREF(nsThread) +NS_IMPL_RELEASE(nsThread) +NS_INTERFACE_MAP_BEGIN(nsThread) + NS_INTERFACE_MAP_ENTRY(nsIThread) + NS_INTERFACE_MAP_ENTRY(nsIThreadInternal) + NS_INTERFACE_MAP_ENTRY(nsIEventTarget) + NS_INTERFACE_MAP_ENTRY(nsISerialEventTarget) + NS_INTERFACE_MAP_ENTRY(nsISupportsPriority) + NS_INTERFACE_MAP_ENTRY(nsIDirectTaskDispatcher) + NS_INTERFACE_MAP_ENTRY_AMBIGUOUS(nsISupports, nsIThread) + if (aIID.Equals(NS_GET_IID(nsIClassInfo))) { + static nsThreadClassInfo sThreadClassInfo; + foundInterface = static_cast<nsIClassInfo*>(&sThreadClassInfo); + } else +NS_INTERFACE_MAP_END +NS_IMPL_CI_INTERFACE_GETTER(nsThread, nsIThread, nsIThreadInternal, + nsIEventTarget, nsISerialEventTarget, + nsISupportsPriority) + +//----------------------------------------------------------------------------- + +// This event is responsible for notifying nsThread::Shutdown that it is time +// to call PR_JoinThread. It implements nsICancelableRunnable so that it can +// run on a DOM Worker thread (where all events must implement +// nsICancelableRunnable.) +class nsThreadShutdownAckEvent : public CancelableRunnable { + public: + explicit nsThreadShutdownAckEvent(NotNull<nsThreadShutdownContext*> aCtx) + : CancelableRunnable("nsThreadShutdownAckEvent"), + mShutdownContext(aCtx) {} + NS_IMETHOD Run() override { + mShutdownContext->mTerminatingThread->ShutdownComplete(mShutdownContext); + return NS_OK; + } + nsresult Cancel() override { return Run(); } + + private: + virtual ~nsThreadShutdownAckEvent() = default; + + NotNull<RefPtr<nsThreadShutdownContext>> mShutdownContext; +}; + +// This event is responsible for setting mShutdownContext +class nsThreadShutdownEvent : public Runnable { + public: + nsThreadShutdownEvent(NotNull<nsThread*> aThr, + NotNull<nsThreadShutdownContext*> aCtx) + : Runnable("nsThreadShutdownEvent"), + mThread(aThr), + mShutdownContext(aCtx) {} + NS_IMETHOD Run() override { + // Creates a cycle between `mThread` and the shutdown context which will be + // broken when the thread exits. + mThread->mShutdownContext = mShutdownContext; + MessageLoop::current()->Quit(); +#ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED + // Let's leave a trace that we passed here in the thread's name. + nsAutoCString threadName(PR_GetThreadName(PR_GetCurrentThread())); + threadName.Append(",SHDRCV"_ns); + NS_SetCurrentThreadName(threadName.get()); +#endif + return NS_OK; + } + + private: + NotNull<RefPtr<nsThread>> mThread; + NotNull<RefPtr<nsThreadShutdownContext>> mShutdownContext; +}; + +//----------------------------------------------------------------------------- + +static void SetThreadAffinity(unsigned int cpu) { +#ifdef HAVE_SCHED_SETAFFINITY + cpu_set_t cpus; + CPU_ZERO(&cpus); + CPU_SET(cpu, &cpus); + sched_setaffinity(0, sizeof(cpus), &cpus); + // Don't assert sched_setaffinity's return value because it intermittently (?) + // fails with EINVAL on Linux x64 try runs. +#elif defined(XP_MACOSX) + // OS X does not provide APIs to pin threads to specific processors, but you + // can tag threads as belonging to the same "affinity set" and the OS will try + // to run them on the same processor. To run threads on different processors, + // tag them as belonging to different affinity sets. Tag 0, the default, means + // "no affinity" so let's pretend each CPU has its own tag `cpu+1`. + thread_affinity_policy_data_t policy; + policy.affinity_tag = cpu + 1; + kern_return_t kr = thread_policy_set( + mach_thread_self(), THREAD_AFFINITY_POLICY, &policy.affinity_tag, 1); + // Setting the thread affinity is not supported on ARM. + MOZ_ALWAYS_TRUE(kr == KERN_SUCCESS || kr == KERN_NOT_SUPPORTED); +#elif defined(XP_WIN) + MOZ_ALWAYS_TRUE(SetThreadIdealProcessor(GetCurrentThread(), cpu) != + (DWORD)-1); +#endif +} + +static void SetupCurrentThreadForChaosMode() { + if (!ChaosMode::isActive(ChaosFeature::ThreadScheduling)) { + return; + } + +#ifdef XP_LINUX + // PR_SetThreadPriority doesn't really work since priorities > + // PR_PRIORITY_NORMAL can't be set by non-root users. Instead we'll just use + // setpriority(2) to set random 'nice values'. In regular Linux this is only + // a dynamic adjustment so it still doesn't really do what we want, but tools + // like 'rr' can be more aggressive about honoring these values. + // Some of these calls may fail due to trying to lower the priority + // (e.g. something may have already called setpriority() for this thread). + // This makes it hard to have non-main threads with higher priority than the + // main thread, but that's hard to fix. Tools like rr can choose to honor the + // requested values anyway. + // Use just 4 priorities so there's a reasonable chance of any two threads + // having equal priority. + setpriority(PRIO_PROCESS, 0, ChaosMode::randomUint32LessThan(4)); +#else + // We should set the affinity here but NSPR doesn't provide a way to expose + // it. + uint32_t priority = ChaosMode::randomUint32LessThan(PR_PRIORITY_LAST + 1); + PR_SetThreadPriority(PR_GetCurrentThread(), PRThreadPriority(priority)); +#endif + + // Force half the threads to CPU 0 so they compete for CPU + if (ChaosMode::randomUint32LessThan(2)) { + SetThreadAffinity(0); + } +} + +namespace { + +struct ThreadInitData { + nsThread* thread; + nsCString name; +}; + +} // namespace + +/* static */ mozilla::OffTheBooksMutex& nsThread::ThreadListMutex() { + static StaticLocalAutoPtr<OffTheBooksMutex> sMutex( + new OffTheBooksMutex("nsThread::ThreadListMutex")); + return *sMutex; +} + +/* static */ LinkedList<nsThread>& nsThread::ThreadList() { + static StaticLocalAutoPtr<LinkedList<nsThread>> sList( + new LinkedList<nsThread>()); + return *sList; +} + +/* static */ +nsThreadEnumerator nsThread::Enumerate() { return {}; } + +void nsThread::AddToThreadList() { + OffTheBooksMutexAutoLock mal(ThreadListMutex()); + MOZ_ASSERT(!isInList()); + + ThreadList().insertBack(this); +} + +void nsThread::MaybeRemoveFromThreadList() { + OffTheBooksMutexAutoLock mal(ThreadListMutex()); + if (isInList()) { + removeFrom(ThreadList()); + } +} + +/*static*/ +void nsThread::ThreadFunc(void* aArg) { + using mozilla::ipc::BackgroundChild; + + UniquePtr<ThreadInitData> initData(static_cast<ThreadInitData*>(aArg)); + nsThread* self = initData->thread; // strong reference + + MOZ_ASSERT(self->mEventTarget); + MOZ_ASSERT(self->mEvents); + + // Note: see the comment in nsThread::Init, where we set these same values. + DebugOnly<PRThread*> prev = self->mThread.exchange(PR_GetCurrentThread()); + MOZ_ASSERT(!prev || prev == PR_GetCurrentThread()); + self->mEventTarget->SetCurrentThread(self->mThread); + SetupCurrentThreadForChaosMode(); + + if (!initData->name.IsEmpty()) { + NS_SetCurrentThreadName(initData->name.BeginReading()); + } + + self->InitCommon(); + + // Inform the ThreadManager + nsThreadManager::get().RegisterCurrentThread(*self); + + mozilla::IOInterposer::RegisterCurrentThread(); + + // This must come after the call to nsThreadManager::RegisterCurrentThread(), + // because that call is needed to properly set up this thread as an nsThread, + // which profiler_register_thread() requires. See bug 1347007. + const bool registerWithProfiler = !initData->name.IsEmpty(); + if (registerWithProfiler) { + PROFILER_REGISTER_THREAD(initData->name.BeginReading()); + } + + { + // Scope for MessageLoop. + MessageLoop loop( +#if defined(XP_WIN) || defined(XP_MACOSX) + self->mIsUiThread ? MessageLoop::TYPE_MOZILLA_NONMAINUITHREAD + : MessageLoop::TYPE_MOZILLA_NONMAINTHREAD, +#else + MessageLoop::TYPE_MOZILLA_NONMAINTHREAD, +#endif + self); + + // Now, process incoming events... + loop.Run(); + + self->mEvents->RunShutdownTasks(); + + BackgroundChild::CloseForCurrentThread(); + + // NB: The main thread does not shut down here! It shuts down via + // nsThreadManager::Shutdown. + + // Do NS_ProcessPendingEvents but with special handling to set + // mEventsAreDoomed atomically with the removal of the last event. The key + // invariant here is that we will never permit PutEvent to succeed if the + // event would be left in the queue after our final call to + // NS_ProcessPendingEvents. We also have to keep processing events as long + // as we have outstanding mRequestedShutdownContexts. + while (true) { + // Check and see if we're waiting on any threads. + self->WaitForAllAsynchronousShutdowns(); + + if (self->mEvents->ShutdownIfNoPendingEvents()) { + break; + } + NS_ProcessPendingEvents(self); + } + } + + mozilla::IOInterposer::UnregisterCurrentThread(); + + // Inform the threadmanager that this thread is going away + nsThreadManager::get().UnregisterCurrentThread(*self); + + // The thread should only unregister itself if it was registered above. + if (registerWithProfiler) { + PROFILER_UNREGISTER_THREAD(); + } + + NotNull<RefPtr<nsThreadShutdownContext>> context = + WrapNotNull(self->mShutdownContext); + self->mShutdownContext = nullptr; + MOZ_ASSERT(context->mTerminatingThread == self); + + // Take the joining thread from our shutdown context. This may have been + // cleared by the joining thread if it decided to cancel waiting on us, in + // which case we won't notify our caller, and leak. + RefPtr<nsThread> joiningThread; + { + MutexAutoLock lock(context->mJoiningThreadMutex); + joiningThread = context->mJoiningThread.forget(); + MOZ_RELEASE_ASSERT(joiningThread || context->mThreadLeaked); + } + if (joiningThread) { + // Dispatch shutdown ACK + nsCOMPtr<nsIRunnable> event = new nsThreadShutdownAckEvent(context); + nsresult dispatch_ack_rv = + joiningThread->Dispatch(event, NS_DISPATCH_NORMAL); + + // We do not expect this to ever happen, but If we cannot dispatch + // the ack event, someone probably blocks waiting on us and will + // crash with a hang later anyways. The best we can do is to tell + // the world what happened right here. + MOZ_RELEASE_ASSERT(NS_SUCCEEDED(dispatch_ack_rv)); + +#ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED + // Let's leave a trace that we passed here in the thread's name. + nsAutoCString threadName(PR_GetThreadName(PR_GetCurrentThread())); + threadName.Append(",SHDACK"_ns); + NS_SetCurrentThreadName(threadName.get()); +#endif + } else { + NS_WARNING( + "nsThread exiting after StopWaitingAndLeakThread was called, thread " + "resources will be leaked!"); + } + + // Release any observer of the thread here. + self->SetObserver(nullptr); + + // The PRThread will be deleted in PR_JoinThread(), so clear references. + self->mThread = nullptr; + self->mEventTarget->ClearCurrentThread(); + NS_RELEASE(self); +} + +void nsThread::InitCommon() { + mThreadId = uint32_t(PlatformThread::CurrentId()); + + { +#if defined(XP_LINUX) + pthread_attr_t attr; + pthread_attr_init(&attr); + pthread_getattr_np(pthread_self(), &attr); + + size_t stackSize; + pthread_attr_getstack(&attr, &mStackBase, &stackSize); + + // Glibc prior to 2.27 reports the stack size and base including the guard + // region, so we need to compensate for it to get accurate accounting. + // Also, this behavior difference isn't guarded by a versioned symbol, so we + // actually need to check the runtime glibc version, not the version we were + // compiled against. + static bool sAdjustForGuardSize = ({ +# ifdef __GLIBC__ + unsigned major, minor; + sscanf(gnu_get_libc_version(), "%u.%u", &major, &minor) < 2 || + major < 2 || (major == 2 && minor < 27); +# else + false; +# endif + }); + if (sAdjustForGuardSize) { + size_t guardSize; + pthread_attr_getguardsize(&attr, &guardSize); + + // Note: This assumes that the stack grows down, as is the case on all of + // our tier 1 platforms. On platforms where the stack grows up, the + // mStackBase adjustment is unnecessary, but doesn't cause any harm other + // than under-counting stack memory usage by one page. + mStackBase = reinterpret_cast<char*>(mStackBase) + guardSize; + stackSize -= guardSize; + } + + mStackSize = stackSize; + + // This is a bit of a hack. + // + // We really do want the NOHUGEPAGE flag on our thread stacks, since we + // don't expect any of them to need anywhere near 2MB of space. But setting + // it here is too late to have an effect, since the first stack page has + // already been faulted in existence, and NSPR doesn't give us a way to set + // it beforehand. + // + // What this does get us, however, is a different set of VM flags on our + // thread stacks compared to normal heap memory. Which makes the Linux + // kernel report them as separate regions, even when they are adjacent to + // heap memory. This allows us to accurately track the actual memory + // consumption of our allocated stacks. + madvise(mStackBase, stackSize, MADV_NOHUGEPAGE); + + pthread_attr_destroy(&attr); +#elif defined(XP_WIN) + static const StaticDynamicallyLinkedFunctionPtr< + GetCurrentThreadStackLimitsFn> + sGetStackLimits(L"kernel32.dll", "GetCurrentThreadStackLimits"); + + if (sGetStackLimits) { + ULONG_PTR stackBottom, stackTop; + sGetStackLimits(&stackBottom, &stackTop); + mStackBase = reinterpret_cast<void*>(stackBottom); + mStackSize = stackTop - stackBottom; + } +#endif + } + + InitThreadLocalVariables(); + AddToThreadList(); +} + +//----------------------------------------------------------------------------- + +#ifdef MOZ_CANARY +int sCanaryOutputFD = -1; +#endif + +nsThread::nsThread(NotNull<SynchronizedEventQueue*> aQueue, + MainThreadFlag aMainThread, + nsIThreadManager::ThreadCreationOptions aOptions) + : mEvents(aQueue.get()), + mEventTarget(new ThreadEventTarget( + mEvents.get(), aMainThread == MAIN_THREAD, aOptions.blockDispatch)), + mOutstandingShutdownContexts(0), + mShutdownContext(nullptr), + mScriptObserver(nullptr), + mThreadName("<uninitialized>"), + mStackSize(aOptions.stackSize), + mNestedEventLoopDepth(0), + mShutdownRequired(false), + mPriority(PRIORITY_NORMAL), + mIsMainThread(aMainThread == MAIN_THREAD), + mUseHangMonitor(aMainThread == MAIN_THREAD), + mIsUiThread(aOptions.isUiThread), + mIsAPoolThreadFree(nullptr), + mCanInvokeJS(false), +#ifdef EARLY_BETA_OR_EARLIER + mLastWakeupCheckTime(TimeStamp::Now()), +#endif + mPerformanceCounterState(mNestedEventLoopDepth, mIsMainThread) { +#if !(defined(XP_WIN) || defined(XP_MACOSX)) + MOZ_ASSERT(!mIsUiThread, + "Non-main UI threads are only supported on Windows and macOS"); +#endif + if (mIsMainThread) { + MOZ_ASSERT(!mIsUiThread, + "Setting isUIThread is not supported for main threads"); + mozilla::TaskController::Get()->SetPerformanceCounterState( + &mPerformanceCounterState); + } +} + +nsThread::nsThread() + : mEvents(nullptr), + mEventTarget(nullptr), + mOutstandingShutdownContexts(0), + mShutdownContext(nullptr), + mScriptObserver(nullptr), + mThreadName("<uninitialized>"), + mStackSize(0), + mNestedEventLoopDepth(0), + mShutdownRequired(false), + mPriority(PRIORITY_NORMAL), + mIsMainThread(false), + mUseHangMonitor(false), + mIsUiThread(false), + mCanInvokeJS(false), +#ifdef EARLY_BETA_OR_EARLIER + mLastWakeupCheckTime(TimeStamp::Now()), +#endif + mPerformanceCounterState(mNestedEventLoopDepth, mIsMainThread) { + MOZ_ASSERT(!NS_IsMainThread()); +} + +nsThread::~nsThread() { + NS_ASSERTION(mOutstandingShutdownContexts == 0, + "shouldn't be waiting on other threads to shutdown"); + + MaybeRemoveFromThreadList(); +} + +nsresult nsThread::Init(const nsACString& aName) { + MOZ_ASSERT(mEvents); + MOZ_ASSERT(mEventTarget); + MOZ_ASSERT(!mThread); + + NS_ADDREF_THIS(); + + SetThreadNameInternal(aName); + + mShutdownRequired = true; + + UniquePtr<ThreadInitData> initData( + new ThreadInitData{this, nsCString(aName)}); + + PRThread* thread = nullptr; + // ThreadFunc is responsible for setting mThread + if (!(thread = PR_CreateThread(PR_USER_THREAD, ThreadFunc, initData.get(), + PR_PRIORITY_NORMAL, PR_GLOBAL_THREAD, + PR_JOINABLE_THREAD, mStackSize))) { + NS_RELEASE_THIS(); + return NS_ERROR_OUT_OF_MEMORY; + } + + // The created thread now owns initData, so release our ownership of it. + Unused << initData.release(); + + // Note: we set these both here and inside ThreadFunc, to what should be + // the same value. This is because calls within ThreadFunc need these values + // to be set, and our callers need these values to be set. + DebugOnly<PRThread*> prev = mThread.exchange(thread); + MOZ_ASSERT(!prev || prev == thread); + + mEventTarget->SetCurrentThread(thread); + return NS_OK; +} + +nsresult nsThread::InitCurrentThread() { + mThread = PR_GetCurrentThread(); + SetupCurrentThreadForChaosMode(); + InitCommon(); + + nsThreadManager::get().RegisterCurrentThread(*this); + return NS_OK; +} + +void nsThread::GetThreadName(nsACString& aNameBuffer) { + auto lock = mThreadName.Lock(); + aNameBuffer = lock.ref(); +} + +void nsThread::SetThreadNameInternal(const nsACString& aName) { + auto lock = mThreadName.Lock(); + lock->Assign(aName); +} + +//----------------------------------------------------------------------------- +// nsIEventTarget + +NS_IMETHODIMP +nsThread::DispatchFromScript(nsIRunnable* aEvent, uint32_t aFlags) { + MOZ_ASSERT(mEventTarget); + NS_ENSURE_TRUE(mEventTarget, NS_ERROR_NOT_IMPLEMENTED); + + nsCOMPtr<nsIRunnable> event(aEvent); + return mEventTarget->Dispatch(event.forget(), aFlags); +} + +NS_IMETHODIMP +nsThread::Dispatch(already_AddRefed<nsIRunnable> aEvent, uint32_t aFlags) { + MOZ_ASSERT(mEventTarget); + NS_ENSURE_TRUE(mEventTarget, NS_ERROR_NOT_IMPLEMENTED); + + LOG(("THRD(%p) Dispatch [%p %x]\n", this, /* XXX aEvent */ nullptr, aFlags)); + + return mEventTarget->Dispatch(std::move(aEvent), aFlags); +} + +NS_IMETHODIMP +nsThread::DelayedDispatch(already_AddRefed<nsIRunnable> aEvent, + uint32_t aDelayMs) { + MOZ_ASSERT(mEventTarget); + NS_ENSURE_TRUE(mEventTarget, NS_ERROR_NOT_IMPLEMENTED); + + return mEventTarget->DelayedDispatch(std::move(aEvent), aDelayMs); +} + +NS_IMETHODIMP +nsThread::RegisterShutdownTask(nsITargetShutdownTask* aTask) { + MOZ_ASSERT(mEventTarget); + NS_ENSURE_TRUE(mEventTarget, NS_ERROR_NOT_IMPLEMENTED); + + return mEventTarget->RegisterShutdownTask(aTask); +} + +NS_IMETHODIMP +nsThread::UnregisterShutdownTask(nsITargetShutdownTask* aTask) { + MOZ_ASSERT(mEventTarget); + NS_ENSURE_TRUE(mEventTarget, NS_ERROR_NOT_IMPLEMENTED); + + return mEventTarget->UnregisterShutdownTask(aTask); +} + +NS_IMETHODIMP +nsThread::GetRunningEventDelay(TimeDuration* aDelay, TimeStamp* aStart) { + if (mIsAPoolThreadFree && *mIsAPoolThreadFree) { + // if there are unstarted threads in the pool, a new event to the + // pool would not be delayed at all (beyond thread start time) + *aDelay = TimeDuration(); + *aStart = TimeStamp(); + } else { + *aDelay = mLastEventDelay; + *aStart = mLastEventStart; + } + return NS_OK; +} + +NS_IMETHODIMP +nsThread::SetRunningEventDelay(TimeDuration aDelay, TimeStamp aStart) { + mLastEventDelay = aDelay; + mLastEventStart = aStart; + return NS_OK; +} + +NS_IMETHODIMP +nsThread::IsOnCurrentThread(bool* aResult) { + if (mEventTarget) { + return mEventTarget->IsOnCurrentThread(aResult); + } + *aResult = PR_GetCurrentThread() == mThread; + return NS_OK; +} + +NS_IMETHODIMP_(bool) +nsThread::IsOnCurrentThreadInfallible() { + // This method is only going to be called if `mThread` is null, which + // only happens when the thread has exited the event loop. Therefore, when + // we are called, we can never be on this thread. + return false; +} + +//----------------------------------------------------------------------------- +// nsIThread + +NS_IMETHODIMP +nsThread::GetPRThread(PRThread** aResult) { + PRThread* thread = mThread; // atomic load + *aResult = thread; + return thread ? NS_OK : NS_ERROR_NOT_AVAILABLE; +} + +NS_IMETHODIMP +nsThread::GetCanInvokeJS(bool* aResult) { + *aResult = mCanInvokeJS; + return NS_OK; +} + +NS_IMETHODIMP +nsThread::SetCanInvokeJS(bool aCanInvokeJS) { + mCanInvokeJS = aCanInvokeJS; + return NS_OK; +} + +NS_IMETHODIMP +nsThread::GetLastLongTaskEnd(TimeStamp* _retval) { + *_retval = mPerformanceCounterState.LastLongTaskEnd(); + return NS_OK; +} + +NS_IMETHODIMP +nsThread::GetLastLongNonIdleTaskEnd(TimeStamp* _retval) { + *_retval = mPerformanceCounterState.LastLongNonIdleTaskEnd(); + return NS_OK; +} + +NS_IMETHODIMP +nsThread::SetNameForWakeupTelemetry(const nsACString& aName) { +#ifdef EARLY_BETA_OR_EARLIER + mNameForWakeupTelemetry = aName; +#endif + return NS_OK; +} + +NS_IMETHODIMP +nsThread::AsyncShutdown() { + LOG(("THRD(%p) async shutdown\n", this)); + + nsCOMPtr<nsIThreadShutdown> shutdown; + BeginShutdown(getter_AddRefs(shutdown)); + return NS_OK; +} + +NS_IMETHODIMP +nsThread::BeginShutdown(nsIThreadShutdown** aShutdown) { + LOG(("THRD(%p) begin shutdown\n", this)); + + MOZ_ASSERT(mEvents); + MOZ_ASSERT(mEventTarget); + MOZ_ASSERT(mThread != PR_GetCurrentThread()); + if (NS_WARN_IF(mThread == PR_GetCurrentThread())) { + return NS_ERROR_UNEXPECTED; + } + + // Prevent multiple calls to this method. + if (!mShutdownRequired.compareExchange(true, false)) { + return NS_ERROR_UNEXPECTED; + } + MOZ_ASSERT(mThread); + + MaybeRemoveFromThreadList(); + + RefPtr<nsThread> currentThread = nsThreadManager::get().GetCurrentThread(); + + MOZ_DIAGNOSTIC_ASSERT(currentThread->EventQueue(), + "Shutdown() may only be called from an XPCOM thread"); + + // Allocate a shutdown context, and record that we're waiting for it. + RefPtr<nsThreadShutdownContext> context = + new nsThreadShutdownContext(WrapNotNull(this), currentThread); + + ++currentThread->mOutstandingShutdownContexts; + nsCOMPtr<nsIRunnable> clearOutstanding = NS_NewRunnableFunction( + "nsThread::ClearOutstandingShutdownContext", + [currentThread] { --currentThread->mOutstandingShutdownContexts; }); + context->OnCompletion(clearOutstanding); + + // Set mShutdownContext and wake up the thread in case it is waiting for + // events to process. + nsCOMPtr<nsIRunnable> event = + new nsThreadShutdownEvent(WrapNotNull(this), WrapNotNull(context)); + if (!mEvents->PutEvent(event.forget(), EventQueuePriority::Normal)) { + // We do not expect this to happen. Let's collect some diagnostics. + nsAutoCString threadName; + GetThreadName(threadName); + MOZ_CRASH_UNSAFE_PRINTF("Attempt to shutdown an already dead thread: %s", + threadName.get()); + } + + // We could still end up with other events being added after the shutdown + // task, but that's okay because we process pending events in ThreadFunc + // after setting mShutdownContext just before exiting. + context.forget(aShutdown); + return NS_OK; +} + +void nsThread::ShutdownComplete(NotNull<nsThreadShutdownContext*> aContext) { + MOZ_ASSERT(mEvents); + MOZ_ASSERT(mEventTarget); + MOZ_ASSERT(aContext->mTerminatingThread == this); + +#ifdef MOZ_DIAGNOSTIC_ASSERT_ENABLED + { + MutexAutoLock lock(aContext->mJoiningThreadMutex); + + // StopWaitingAndLeakThread is explicitely meant to not cause a + // nsThreadShutdownAckEvent on the joining thread, which is the only + // caller of ShutdownComplete. + MOZ_DIAGNOSTIC_ASSERT(!aContext->mThreadLeaked); + } +#endif + + MaybeRemoveFromThreadList(); + + // Now, it should be safe to join without fear of dead-locking. + PR_JoinThread(aContext->mTerminatingPRThread); + MOZ_ASSERT(!mThread); + +#ifdef DEBUG + nsCOMPtr<nsIThreadObserver> obs = mEvents->GetObserver(); + MOZ_ASSERT(!obs, "Should have been cleared at shutdown!"); +#endif + + aContext->MarkCompleted(); +} + +void nsThread::WaitForAllAsynchronousShutdowns() { + // This is the motivating example for why SpinEventLoopUntil + // has the template parameter we are providing here. + SpinEventLoopUntil<ProcessFailureBehavior::IgnoreAndContinue>( + "nsThread::WaitForAllAsynchronousShutdowns"_ns, + [&]() { return mOutstandingShutdownContexts == 0; }, this); +} + +NS_IMETHODIMP +nsThread::Shutdown() { + LOG(("THRD(%p) sync shutdown\n", this)); + + nsCOMPtr<nsIThreadShutdown> context; + nsresult rv = BeginShutdown(getter_AddRefs(context)); + if (NS_FAILED(rv)) { + return NS_OK; // The thread has already shut down. + } + + // If we are going to hang here we want to see the thread's name + nsAutoCString threadName; + GetThreadName(threadName); + + // Process events on the current thread until we receive a shutdown ACK. + // Allows waiting; ensure no locks are held that would deadlock us! + SpinEventLoopUntil("nsThread::Shutdown: "_ns + threadName, + [&]() { return context->GetCompleted(); }); + + return NS_OK; +} + +NS_IMETHODIMP +nsThread::HasPendingEvents(bool* aResult) { + if (NS_WARN_IF(PR_GetCurrentThread() != mThread)) { + return NS_ERROR_NOT_SAME_THREAD; + } + + if (mIsMainThread) { + *aResult = TaskController::Get()->HasMainThreadPendingTasks(); + } else { + *aResult = mEvents->HasPendingEvent(); + } + return NS_OK; +} + +NS_IMETHODIMP +nsThread::HasPendingHighPriorityEvents(bool* aResult) { + if (NS_WARN_IF(PR_GetCurrentThread() != mThread)) { + return NS_ERROR_NOT_SAME_THREAD; + } + + // This function appears to never be called anymore. + *aResult = false; + return NS_OK; +} + +NS_IMETHODIMP +nsThread::DispatchToQueue(already_AddRefed<nsIRunnable> aEvent, + EventQueuePriority aQueue) { + nsCOMPtr<nsIRunnable> event = aEvent; + + if (NS_WARN_IF(!event)) { + return NS_ERROR_INVALID_ARG; + } + + if (!mEvents->PutEvent(event.forget(), aQueue)) { + NS_WARNING( + "An idle event was posted to a thread that will never run it " + "(rejected)"); + return NS_ERROR_UNEXPECTED; + } + + return NS_OK; +} + +NS_IMETHODIMP nsThread::SetThreadQoS(nsIThread::QoSPriority aPriority) { + if (!StaticPrefs::threads_use_low_power_enabled()) { + return NS_OK; + } + // The approach here is to have a thread set itself for its QoS level, + // so we assert if we aren't on the current thread. + MOZ_ASSERT(IsOnCurrentThread(), "Can only change the current thread's QoS"); + +#if defined(XP_MACOSX) + // Only arm64 macs may possess heterogeneous cores. On these, we can tell + // a thread to set its own QoS status. On intel macs things should behave + // normally, and the OS will ignore the QoS state of the thread. + if (aPriority == nsIThread::QOS_PRIORITY_LOW) { + pthread_set_qos_class_self_np(QOS_CLASS_BACKGROUND, 0); + } else if (NS_IsMainThread()) { + // MacOS documentation specifies that a main thread should be initialized at + // the USER_INTERACTIVE priority, so when we restore thread priorities the + // main thread should be setting itself to this. + pthread_set_qos_class_self_np(QOS_CLASS_USER_INTERACTIVE, 0); + } else { + pthread_set_qos_class_self_np(QOS_CLASS_DEFAULT, 0); + } +#endif + // Do nothing if an OS-specific implementation is unavailable. + return NS_OK; +} + +#ifdef MOZ_CANARY +void canary_alarm_handler(int signum); + +class Canary { + // XXX ToDo: support nested loops + public: + Canary() { + if (sCanaryOutputFD > 0 && EventLatencyIsImportant()) { + signal(SIGALRM, canary_alarm_handler); + ualarm(15000, 0); + } + } + + ~Canary() { + if (sCanaryOutputFD != 0 && EventLatencyIsImportant()) { + ualarm(0, 0); + } + } + + static bool EventLatencyIsImportant() { + return NS_IsMainThread() && XRE_IsParentProcess(); + } +}; + +void canary_alarm_handler(int signum) { + void* array[30]; + const char msg[29] = "event took too long to run:\n"; + // use write to be safe in the signal handler + write(sCanaryOutputFD, msg, sizeof(msg)); + backtrace_symbols_fd(array, backtrace(array, 30), sCanaryOutputFD); +} + +#endif + +#define NOTIFY_EVENT_OBSERVERS(observers_, func_, params_) \ + do { \ + if (!observers_.IsEmpty()) { \ + for (nsCOMPtr<nsIThreadObserver> obs_ : observers_.ForwardRange()) { \ + obs_->func_ params_; \ + } \ + } \ + } while (0) + +#ifdef MOZ_COLLECTING_RUNNABLE_TELEMETRY +// static +bool nsThread::GetLabeledRunnableName(nsIRunnable* aEvent, nsACString& aName, + EventQueuePriority aPriority) { + bool labeled = false; + if (RefPtr<SchedulerGroup::Runnable> groupRunnable = do_QueryObject(aEvent)) { + labeled = true; + MOZ_ALWAYS_TRUE(NS_SUCCEEDED(groupRunnable->GetName(aName))); + } else if (nsCOMPtr<nsINamed> named = do_QueryInterface(aEvent)) { + MOZ_ALWAYS_TRUE(NS_SUCCEEDED(named->GetName(aName))); + } else { + aName.AssignLiteral("non-nsINamed runnable"); + } + if (aName.IsEmpty()) { + aName.AssignLiteral("anonymous runnable"); + } + + if (!labeled && aPriority > EventQueuePriority::InputHigh) { + aName.AppendLiteral("(unlabeled)"); + } + + return labeled; +} +#endif + +mozilla::PerformanceCounter* nsThread::GetPerformanceCounter( + nsIRunnable* aEvent) const { + return GetPerformanceCounterBase(aEvent); +} + +// static +mozilla::PerformanceCounter* nsThread::GetPerformanceCounterBase( + nsIRunnable* aEvent) { + RefPtr<SchedulerGroup::Runnable> docRunnable = do_QueryObject(aEvent); + if (docRunnable) { + return docRunnable->GetPerformanceCounter(); + } + return nullptr; +} + +size_t nsThread::ShallowSizeOfIncludingThis( + mozilla::MallocSizeOf aMallocSizeOf) const { + size_t n = 0; + if (mShutdownContext) { + n += aMallocSizeOf(mShutdownContext); + } + return aMallocSizeOf(this) + aMallocSizeOf(mThread) + n; +} + +size_t nsThread::SizeOfEventQueues(mozilla::MallocSizeOf aMallocSizeOf) const { + size_t n = 0; + if (mEventTarget) { + // The size of mEvents is reported by mEventTarget. + n += mEventTarget->SizeOfIncludingThis(aMallocSizeOf); + } + return n; +} + +size_t nsThread::SizeOfIncludingThis( + mozilla::MallocSizeOf aMallocSizeOf) const { + return ShallowSizeOfIncludingThis(aMallocSizeOf) + + SizeOfEventQueues(aMallocSizeOf); +} + +NS_IMETHODIMP +nsThread::ProcessNextEvent(bool aMayWait, bool* aResult) { + MOZ_ASSERT(mEvents); + NS_ENSURE_TRUE(mEvents, NS_ERROR_NOT_IMPLEMENTED); + + LOG(("THRD(%p) ProcessNextEvent [%u %u]\n", this, aMayWait, + mNestedEventLoopDepth)); + + if (NS_WARN_IF(PR_GetCurrentThread() != mThread)) { + return NS_ERROR_NOT_SAME_THREAD; + } + + // The toplevel event loop normally blocks waiting for the next event, but + // if we're trying to shut this thread down, we must exit the event loop + // when the event queue is empty. This only applys to the toplevel event + // loop! Nested event loops (e.g. during sync dispatch) are waiting for + // some state change and must be able to block even if something has + // requested shutdown of the thread. Otherwise we'll just busywait as we + // endlessly look for an event, fail to find one, and repeat the nested + // event loop since its state change hasn't happened yet. + bool reallyWait = aMayWait && (mNestedEventLoopDepth > 0 || !ShuttingDown()); + + Maybe<dom::AutoNoJSAPI> noJSAPI; + + if (mUseHangMonitor && reallyWait) { + BackgroundHangMonitor().NotifyWait(); + } + + if (mIsMainThread) { + DoMainThreadSpecificProcessing(); + } + + ++mNestedEventLoopDepth; + + // We only want to create an AutoNoJSAPI on threads that actually do DOM + // stuff (including workers). Those are exactly the threads that have an + // mScriptObserver. + bool callScriptObserver = !!mScriptObserver; + if (callScriptObserver) { + noJSAPI.emplace(); + mScriptObserver->BeforeProcessTask(reallyWait); + } + + DrainDirectTasks(); + +#ifdef EARLY_BETA_OR_EARLIER + // Need to capture mayWaitForWakeup state before OnProcessNextEvent, + // since on the main thread OnProcessNextEvent ends up waiting for the new + // events. + bool mayWaitForWakeup = reallyWait && !mEvents->HasPendingEvent(); +#endif + + nsCOMPtr<nsIThreadObserver> obs = mEvents->GetObserverOnThread(); + if (obs) { + obs->OnProcessNextEvent(this, reallyWait); + } + + NOTIFY_EVENT_OBSERVERS(EventQueue()->EventObservers(), OnProcessNextEvent, + (this, reallyWait)); + + DrainDirectTasks(); + +#ifdef MOZ_CANARY + Canary canary; +#endif + nsresult rv = NS_OK; + + { + // Scope for |event| to make sure that its destructor fires while + // mNestedEventLoopDepth has been incremented, since that destructor can + // also do work. + nsCOMPtr<nsIRunnable> event; + bool usingTaskController = mIsMainThread; + if (usingTaskController) { + event = TaskController::Get()->GetRunnableForMTTask(reallyWait); + } else { + event = mEvents->GetEvent(reallyWait, &mLastEventDelay); + } + + *aResult = (event.get() != nullptr); + + if (event) { +#ifdef EARLY_BETA_OR_EARLIER + if (mayWaitForWakeup && mThread) { + ++mWakeupCount; + if (mWakeupCount == kTelemetryWakeupCountLimit) { + TimeStamp now = TimeStamp::Now(); + double ms = (now - mLastWakeupCheckTime).ToMilliseconds(); + if (ms < 0) { + ms = 0; + } + const char* name = !mNameForWakeupTelemetry.IsEmpty() + ? mNameForWakeupTelemetry.get() + : PR_GetThreadName(mThread); + if (!name) { + name = mIsMainThread ? "MainThread" : "(nameless thread)"; + } + nsDependentCString key(name); + Telemetry::Accumulate(Telemetry::THREAD_WAKEUP, key, + static_cast<uint32_t>(ms)); + mLastWakeupCheckTime = now; + mWakeupCount = 0; + } + } +#endif + + LOG(("THRD(%p) running [%p]\n", this, event.get())); + + Maybe<LogRunnable::Run> log; + + if (!usingTaskController) { + log.emplace(event); + } + + // Delay event processing to encourage whoever dispatched this event + // to run. + DelayForChaosMode(ChaosFeature::TaskRunning, 1000); + + mozilla::TimeStamp now = mozilla::TimeStamp::Now(); + + if (mUseHangMonitor) { + BackgroundHangMonitor().NotifyActivity(); + } + + Maybe<PerformanceCounterState::Snapshot> snapshot; + if (!usingTaskController) { + snapshot.emplace(mPerformanceCounterState.RunnableWillRun( + GetPerformanceCounter(event), now, false)); + } + + mLastEventStart = now; + + if (!usingTaskController) { + AUTO_PROFILE_FOLLOWING_RUNNABLE(event); + event->Run(); + } else { + // Avoid generating "Runnable" profiler markers for the + // "TaskController::ExecutePendingMTTasks" runnables created + // by TaskController, which already adds "Runnable" markers + // when executing tasks. + event->Run(); + } + + if (usingTaskController) { + *aResult = TaskController::Get()->MTTaskRunnableProcessedTask(); + } else { + mPerformanceCounterState.RunnableDidRun(EmptyCString(), + std::move(snapshot.ref())); + } + + // To cover the event's destructor code inside the LogRunnable span. + event = nullptr; + } else { + mLastEventDelay = TimeDuration(); + mLastEventStart = TimeStamp(); + if (aMayWait) { + MOZ_ASSERT(ShuttingDown(), + "This should only happen when shutting down"); + rv = NS_ERROR_UNEXPECTED; + } + } + } + + DrainDirectTasks(); + + NOTIFY_EVENT_OBSERVERS(EventQueue()->EventObservers(), AfterProcessNextEvent, + (this, *aResult)); + + if (obs) { + obs->AfterProcessNextEvent(this, *aResult); + } + + // In case some EventObserver dispatched some direct tasks; process them + // now. + DrainDirectTasks(); + + if (callScriptObserver) { + if (mScriptObserver) { + mScriptObserver->AfterProcessTask(mNestedEventLoopDepth); + } + noJSAPI.reset(); + } + + --mNestedEventLoopDepth; + + return rv; +} + +//----------------------------------------------------------------------------- +// nsISupportsPriority + +NS_IMETHODIMP +nsThread::GetPriority(int32_t* aPriority) { + *aPriority = mPriority; + return NS_OK; +} + +NS_IMETHODIMP +nsThread::SetPriority(int32_t aPriority) { + if (NS_WARN_IF(!mThread)) { + return NS_ERROR_NOT_INITIALIZED; + } + + // NSPR defines the following four thread priorities: + // PR_PRIORITY_LOW + // PR_PRIORITY_NORMAL + // PR_PRIORITY_HIGH + // PR_PRIORITY_URGENT + // We map the priority values defined on nsISupportsPriority to these + // values. + + mPriority = aPriority; + + PRThreadPriority pri; + if (mPriority <= PRIORITY_HIGHEST) { + pri = PR_PRIORITY_URGENT; + } else if (mPriority < PRIORITY_NORMAL) { + pri = PR_PRIORITY_HIGH; + } else if (mPriority > PRIORITY_NORMAL) { + pri = PR_PRIORITY_LOW; + } else { + pri = PR_PRIORITY_NORMAL; + } + // If chaos mode is active, retain the randomly chosen priority + if (!ChaosMode::isActive(ChaosFeature::ThreadScheduling)) { + PR_SetThreadPriority(mThread, pri); + } + + return NS_OK; +} + +NS_IMETHODIMP +nsThread::AdjustPriority(int32_t aDelta) { + return SetPriority(mPriority + aDelta); +} + +//----------------------------------------------------------------------------- +// nsIThreadInternal + +NS_IMETHODIMP +nsThread::GetObserver(nsIThreadObserver** aObs) { + MOZ_ASSERT(mEvents); + NS_ENSURE_TRUE(mEvents, NS_ERROR_NOT_IMPLEMENTED); + + nsCOMPtr<nsIThreadObserver> obs = mEvents->GetObserver(); + obs.forget(aObs); + return NS_OK; +} + +NS_IMETHODIMP +nsThread::SetObserver(nsIThreadObserver* aObs) { + MOZ_ASSERT(mEvents); + NS_ENSURE_TRUE(mEvents, NS_ERROR_NOT_IMPLEMENTED); + + if (NS_WARN_IF(PR_GetCurrentThread() != mThread)) { + return NS_ERROR_NOT_SAME_THREAD; + } + + mEvents->SetObserver(aObs); + return NS_OK; +} + +uint32_t nsThread::RecursionDepth() const { + MOZ_ASSERT(PR_GetCurrentThread() == mThread); + return mNestedEventLoopDepth; +} + +NS_IMETHODIMP +nsThread::AddObserver(nsIThreadObserver* aObserver) { + MOZ_ASSERT(mEvents); + NS_ENSURE_TRUE(mEvents, NS_ERROR_NOT_IMPLEMENTED); + + if (NS_WARN_IF(!aObserver)) { + return NS_ERROR_INVALID_ARG; + } + if (NS_WARN_IF(PR_GetCurrentThread() != mThread)) { + return NS_ERROR_NOT_SAME_THREAD; + } + + EventQueue()->AddObserver(aObserver); + + return NS_OK; +} + +NS_IMETHODIMP +nsThread::RemoveObserver(nsIThreadObserver* aObserver) { + MOZ_ASSERT(mEvents); + NS_ENSURE_TRUE(mEvents, NS_ERROR_NOT_IMPLEMENTED); + + if (NS_WARN_IF(PR_GetCurrentThread() != mThread)) { + return NS_ERROR_NOT_SAME_THREAD; + } + + EventQueue()->RemoveObserver(aObserver); + + return NS_OK; +} + +void nsThread::SetScriptObserver( + mozilla::CycleCollectedJSContext* aScriptObserver) { + if (!aScriptObserver) { + mScriptObserver = nullptr; + return; + } + + MOZ_ASSERT(!mScriptObserver); + mScriptObserver = aScriptObserver; +} + +void NS_DispatchMemoryPressure(); + +void nsThread::DoMainThreadSpecificProcessing() const { + MOZ_ASSERT(mIsMainThread); + + ipc::CancelCPOWs(); + + // Fire a memory pressure notification, if one is pending. + if (!ShuttingDown()) { + NS_DispatchMemoryPressure(); + } +} + +//----------------------------------------------------------------------------- +// nsIDirectTaskDispatcher + +NS_IMETHODIMP +nsThread::DispatchDirectTask(already_AddRefed<nsIRunnable> aEvent) { + if (!IsOnCurrentThread()) { + return NS_ERROR_FAILURE; + } + mDirectTasks.AddTask(std::move(aEvent)); + return NS_OK; +} + +NS_IMETHODIMP nsThread::DrainDirectTasks() { + if (!IsOnCurrentThread()) { + return NS_ERROR_FAILURE; + } + mDirectTasks.DrainTasks(); + return NS_OK; +} + +NS_IMETHODIMP nsThread::HaveDirectTasks(bool* aValue) { + if (!IsOnCurrentThread()) { + return NS_ERROR_FAILURE; + } + + *aValue = mDirectTasks.HaveTasks(); + return NS_OK; +} + +NS_IMPL_ISUPPORTS(nsThreadShutdownContext, nsIThreadShutdown) + +NS_IMETHODIMP +nsThreadShutdownContext::OnCompletion(nsIRunnable* aEvent) { + if (mCompleted) { + aEvent->Run(); + } else { + mCompletionCallbacks.AppendElement(aEvent); + } + return NS_OK; +} + +NS_IMETHODIMP +nsThreadShutdownContext::GetCompleted(bool* aCompleted) { + *aCompleted = mCompleted; + return NS_OK; +} + +NS_IMETHODIMP +nsThreadShutdownContext::StopWaitingAndLeakThread() { + // Take the joining thread from `mJoiningThread` so that the terminating + // thread won't try to dispatch nsThreadShutdownAckEvent to us anymore. + RefPtr<nsThread> joiningThread; + { + MutexAutoLock lock(mJoiningThreadMutex); + if (!mJoiningThread) { + // Shutdown is already being resolved, so there's nothing for us to do. + return NS_ERROR_NOT_AVAILABLE; + } + joiningThread = mJoiningThread.forget(); + mThreadLeaked = true; + } + + MOZ_DIAGNOSTIC_ASSERT(joiningThread->IsOnCurrentThread()); + + MarkCompleted(); + + return NS_OK; +} + +void nsThreadShutdownContext::MarkCompleted() { + MOZ_ASSERT(!mCompleted); + mCompleted = true; + nsTArray<nsCOMPtr<nsIRunnable>> callbacks(std::move(mCompletionCallbacks)); + for (auto& callback : callbacks) { + callback->Run(); + } +} + +namespace mozilla { +PerformanceCounterState::Snapshot PerformanceCounterState::RunnableWillRun( + PerformanceCounter* aCounter, TimeStamp aNow, bool aIsIdleRunnable) { + if (IsNestedRunnable()) { + // Flush out any accumulated time that should be accounted to the + // current runnable before we start running a nested runnable. + MaybeReportAccumulatedTime("nested runnable"_ns, aNow); + } + + Snapshot snapshot(mCurrentEventLoopDepth, mCurrentPerformanceCounter, + mCurrentRunnableIsIdleRunnable); + + mCurrentEventLoopDepth = mNestedEventLoopDepth; + mCurrentPerformanceCounter = aCounter; + mCurrentRunnableIsIdleRunnable = aIsIdleRunnable; + mCurrentTimeSliceStart = aNow; + + return snapshot; +} + +void PerformanceCounterState::RunnableDidRun(const nsCString& aName, + Snapshot&& aSnapshot) { + // First thing: Restore our mCurrentEventLoopDepth so we can use + // IsNestedRunnable(). + mCurrentEventLoopDepth = aSnapshot.mOldEventLoopDepth; + + // We may not need the current timestamp; don't bother computing it if we + // don't. + TimeStamp now; + if (mCurrentPerformanceCounter || mIsMainThread || IsNestedRunnable()) { + now = TimeStamp::Now(); + } + if (mCurrentPerformanceCounter || mIsMainThread) { + MaybeReportAccumulatedTime(aName, now); + } + + // And now restore the rest of our state. + mCurrentPerformanceCounter = std::move(aSnapshot.mOldPerformanceCounter); + mCurrentRunnableIsIdleRunnable = aSnapshot.mOldIsIdleRunnable; + if (IsNestedRunnable()) { + // Reset mCurrentTimeSliceStart to right now, so our parent runnable's + // next slice can be properly accounted for. + mCurrentTimeSliceStart = now; + } else { + // We are done at the outermost level; we are no longer in a timeslice. + mCurrentTimeSliceStart = TimeStamp(); + } +} + +void PerformanceCounterState::MaybeReportAccumulatedTime(const nsCString& aName, + TimeStamp aNow) { + MOZ_ASSERT(mCurrentTimeSliceStart, + "How did we get here if we're not in a timeslice?"); + + if (!mCurrentPerformanceCounter && !mIsMainThread) { + // No one cares about this timeslice. + return; + } + + TimeDuration duration = aNow - mCurrentTimeSliceStart; + if (mCurrentPerformanceCounter) { + mCurrentPerformanceCounter->IncrementExecutionDuration( + duration.ToMicroseconds()); + } + +#ifdef MOZ_COLLECTING_RUNNABLE_TELEMETRY + if (mIsMainThread && duration.ToMilliseconds() > LONGTASK_TELEMETRY_MS) { + Telemetry::Accumulate(Telemetry::EVENT_LONGTASK, aName, + duration.ToMilliseconds()); + } +#endif + + // Long tasks only matter on the main thread. + if (mIsMainThread && duration.ToMilliseconds() > LONGTASK_BUSY_WINDOW_MS) { + // Idle events (gc...) don't *really* count here + if (!mCurrentRunnableIsIdleRunnable) { + mLastLongNonIdleTaskEnd = aNow; + } + mLastLongTaskEnd = aNow; + + if (profiler_thread_is_being_profiled_for_markers()) { + struct LongTaskMarker { + static constexpr Span<const char> MarkerTypeName() { + return MakeStringSpan("MainThreadLongTask"); + } + static void StreamJSONMarkerData( + baseprofiler::SpliceableJSONWriter& aWriter) { + aWriter.StringProperty("category", "LongTask"); + } + static MarkerSchema MarkerTypeDisplay() { + using MS = MarkerSchema; + MS schema{MS::Location::MarkerChart, MS::Location::MarkerTable}; + schema.AddKeyLabelFormatSearchable("category", "Type", + MS::Format::String, + MS::Searchable::Searchable); + return schema; + } + }; + + profiler_add_marker(mCurrentRunnableIsIdleRunnable + ? ProfilerString8View("LongIdleTask") + : ProfilerString8View("LongTask"), + geckoprofiler::category::OTHER, + MarkerTiming::Interval(mCurrentTimeSliceStart, aNow), + LongTaskMarker{}); + } + } +} + +} // namespace mozilla |