From 26a029d407be480d791972afb5975cf62c9360a6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 19 Apr 2024 02:47:55 +0200 Subject: Adding upstream version 124.0.1. Signed-off-by: Daniel Baumann --- xpcom/threads/nsThreadUtils.cpp | 769 ++++++++++++++++++++++++++++++++++++++++ 1 file changed, 769 insertions(+) create mode 100644 xpcom/threads/nsThreadUtils.cpp (limited to 'xpcom/threads/nsThreadUtils.cpp') diff --git a/xpcom/threads/nsThreadUtils.cpp b/xpcom/threads/nsThreadUtils.cpp new file mode 100644 index 0000000000..68d36605b3 --- /dev/null +++ b/xpcom/threads/nsThreadUtils.cpp @@ -0,0 +1,769 @@ +/* -*- 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 "nsThreadUtils.h" + +#include "chrome/common/ipc_message.h" // for IPC::Message +#include "LeakRefPtr.h" +#include "mozilla/Attributes.h" +#include "mozilla/Likely.h" +#include "mozilla/TaskQueue.h" +#include "mozilla/TimeStamp.h" +#include "nsComponentManagerUtils.h" +#include "nsExceptionHandler.h" +#include "nsIEventTarget.h" +#include "nsITimer.h" +#include "nsString.h" +#include "nsThreadSyncDispatch.h" +#include "nsTimerImpl.h" +#include "prsystem.h" + +#include "nsThreadManager.h" +#include "nsThreadPool.h" +#include "TaskController.h" + +#ifdef XP_WIN +# include +#elif defined(XP_MACOSX) +# include +#endif + +#if defined(ANDROID) +# include +#endif + +static mozilla::LazyLogModule sEventDispatchAndRunLog("events"); +#ifdef LOG1 +# undef LOG1 +#endif +#define LOG1(args) \ + MOZ_LOG(sEventDispatchAndRunLog, mozilla::LogLevel::Error, args) +#define LOG1_ENABLED() \ + MOZ_LOG_TEST(sEventDispatchAndRunLog, mozilla::LogLevel::Error) + +using namespace mozilla; + +#ifndef XPCOM_GLUE_AVOID_NSPR + +NS_IMPL_ISUPPORTS(IdlePeriod, nsIIdlePeriod) + +NS_IMETHODIMP +IdlePeriod::GetIdlePeriodHint(TimeStamp* aIdleDeadline) { + *aIdleDeadline = TimeStamp(); + return NS_OK; +} + +// NS_IMPL_NAMED_* relies on the mName field, which is not present on +// release or beta. Instead, fall back to using "Runnable" for all +// runnables. +# ifndef MOZ_COLLECTING_RUNNABLE_TELEMETRY +NS_IMPL_ISUPPORTS(Runnable, nsIRunnable) +# else +NS_IMPL_NAMED_ADDREF(Runnable, mName) +NS_IMPL_NAMED_RELEASE(Runnable, mName) +NS_IMPL_QUERY_INTERFACE(Runnable, nsIRunnable, nsINamed) +# endif + +NS_IMETHODIMP +Runnable::Run() { + // Do nothing + return NS_OK; +} + +# ifdef MOZ_COLLECTING_RUNNABLE_TELEMETRY +NS_IMETHODIMP +Runnable::GetName(nsACString& aName) { + if (mName) { + aName.AssignASCII(mName); + } else { + aName.Truncate(); + } + return NS_OK; +} +# endif + +NS_IMPL_ISUPPORTS_INHERITED(DiscardableRunnable, Runnable, + nsIDiscardableRunnable) + +NS_IMPL_ISUPPORTS_INHERITED(CancelableRunnable, DiscardableRunnable, + nsICancelableRunnable) + +void CancelableRunnable::OnDiscard() { + // Tasks that implement Cancel() can be safely cleaned up if it turns out + // that the task will not run. + (void)NS_WARN_IF(NS_FAILED(Cancel())); +} + +NS_IMPL_ISUPPORTS_INHERITED(IdleRunnable, DiscardableRunnable, nsIIdleRunnable) + +NS_IMPL_ISUPPORTS_INHERITED(CancelableIdleRunnable, CancelableRunnable, + nsIIdleRunnable) + +NS_IMPL_ISUPPORTS_INHERITED(PrioritizableRunnable, Runnable, + nsIRunnablePriority) + +PrioritizableRunnable::PrioritizableRunnable( + already_AddRefed&& aRunnable, uint32_t aPriority) + // Real runnable name is managed by overridding the GetName function. + : Runnable("PrioritizableRunnable"), + mRunnable(std::move(aRunnable)), + mPriority(aPriority) { +# if DEBUG + nsCOMPtr runnablePrio = do_QueryInterface(mRunnable); + MOZ_ASSERT(!runnablePrio); +# endif +} + +# ifdef MOZ_COLLECTING_RUNNABLE_TELEMETRY +NS_IMETHODIMP +PrioritizableRunnable::GetName(nsACString& aName) { + // Try to get a name from the underlying runnable. + nsCOMPtr named = do_QueryInterface(mRunnable); + if (named) { + named->GetName(aName); + } + return NS_OK; +} +# endif + +NS_IMETHODIMP +PrioritizableRunnable::Run() { + MOZ_RELEASE_ASSERT(NS_IsMainThread()); + return mRunnable->Run(); +} + +NS_IMETHODIMP +PrioritizableRunnable::GetPriority(uint32_t* aPriority) { + *aPriority = mPriority; + return NS_OK; +} + +already_AddRefed mozilla::CreateRenderBlockingRunnable( + already_AddRefed&& aRunnable) { + nsCOMPtr runnable = new PrioritizableRunnable( + std::move(aRunnable), nsIRunnablePriority::PRIORITY_RENDER_BLOCKING); + return runnable.forget(); +} + +NS_IMPL_ISUPPORTS_INHERITED(PrioritizableCancelableRunnable, CancelableRunnable, + nsIRunnablePriority) + +NS_IMETHODIMP +PrioritizableCancelableRunnable::GetPriority(uint32_t* aPriority) { + *aPriority = mPriority; + return NS_OK; +} + +#endif // XPCOM_GLUE_AVOID_NSPR + +//----------------------------------------------------------------------------- + +nsresult NS_NewNamedThread(const nsACString& aName, nsIThread** aResult, + nsIRunnable* aInitialEvent, + nsIThreadManager::ThreadCreationOptions aOptions) { + nsCOMPtr event = aInitialEvent; + return NS_NewNamedThread(aName, aResult, event.forget(), aOptions); +} + +nsresult NS_NewNamedThread(const nsACString& aName, nsIThread** aResult, + already_AddRefed aInitialEvent, + nsIThreadManager::ThreadCreationOptions aOptions) { + nsCOMPtr event = std::move(aInitialEvent); + nsCOMPtr thread; + nsresult rv = nsThreadManager::get().nsThreadManager::NewNamedThread( + aName, aOptions, getter_AddRefs(thread)); + if (NS_WARN_IF(NS_FAILED(rv))) { + return rv; + } + + if (event) { + rv = thread->Dispatch(event.forget(), NS_DISPATCH_IGNORE_BLOCK_DISPATCH); + if (NS_WARN_IF(NS_FAILED(rv))) { + return rv; + } + } + + *aResult = nullptr; + thread.swap(*aResult); + return NS_OK; +} + +nsresult NS_GetCurrentThread(nsIThread** aResult) { + return nsThreadManager::get().nsThreadManager::GetCurrentThread(aResult); +} + +nsresult NS_GetMainThread(nsIThread** aResult) { + return nsThreadManager::get().nsThreadManager::GetMainThread(aResult); +} + +nsresult NS_DispatchToCurrentThread(already_AddRefed&& aEvent) { + nsresult rv; + nsCOMPtr event(aEvent); + // XXX: Consider using GetCurrentSerialEventTarget() to support TaskQueues. + nsISerialEventTarget* thread = NS_GetCurrentThread(); + if (!thread) { + return NS_ERROR_UNEXPECTED; + } + // To keep us from leaking the runnable if dispatch method fails, + // we grab the reference on failures and release it. + nsIRunnable* temp = event.get(); + rv = thread->Dispatch(event.forget(), NS_DISPATCH_NORMAL); + if (NS_WARN_IF(NS_FAILED(rv))) { + // Dispatch() leaked the reference to the event, but due to caller's + // assumptions, we shouldn't leak here. And given we are on the same + // thread as the dispatch target, it's mostly safe to do it here. + NS_RELEASE(temp); + } + return rv; +} + +// It is common to call NS_DispatchToCurrentThread with a newly +// allocated runnable with a refcount of zero. To keep us from leaking +// the runnable if the dispatch method fails, we take a death grip. +nsresult NS_DispatchToCurrentThread(nsIRunnable* aEvent) { + nsCOMPtr event(aEvent); + return NS_DispatchToCurrentThread(event.forget()); +} + +nsresult NS_DispatchToMainThread(already_AddRefed&& aEvent, + uint32_t aDispatchFlags) { + LeakRefPtr event(std::move(aEvent)); + nsCOMPtr thread; + nsresult rv = NS_GetMainThread(getter_AddRefs(thread)); + if (NS_WARN_IF(NS_FAILED(rv))) { + NS_ASSERTION(false, + "Failed NS_DispatchToMainThread() in shutdown; leaking"); + // NOTE: if you stop leaking here, adjust Promise::MaybeReportRejected(), + // which assumes a leak here, or split into leaks and no-leaks versions + return rv; + } + return thread->Dispatch(event.take(), aDispatchFlags); +} + +// In the case of failure with a newly allocated runnable with a +// refcount of zero, we intentionally leak the runnable, because it is +// likely that the runnable is being dispatched to the main thread +// because it owns main thread only objects, so it is not safe to +// release them here. +nsresult NS_DispatchToMainThread(nsIRunnable* aEvent, uint32_t aDispatchFlags) { + nsCOMPtr event(aEvent); + return NS_DispatchToMainThread(event.forget(), aDispatchFlags); +} + +nsresult NS_DelayedDispatchToCurrentThread( + already_AddRefed&& aEvent, uint32_t aDelayMs) { + nsCOMPtr event(aEvent); + + // XXX: Consider using GetCurrentSerialEventTarget() to support TaskQueues. + nsISerialEventTarget* thread = NS_GetCurrentThread(); + if (!thread) { + return NS_ERROR_UNEXPECTED; + } + + return thread->DelayedDispatch(event.forget(), aDelayMs); +} + +nsresult NS_DispatchToThreadQueue(already_AddRefed&& aEvent, + nsIThread* aThread, + EventQueuePriority aQueue) { + nsresult rv; + nsCOMPtr event(aEvent); + NS_ENSURE_TRUE(event, NS_ERROR_INVALID_ARG); + if (!aThread) { + return NS_ERROR_UNEXPECTED; + } + // To keep us from leaking the runnable if dispatch method fails, + // we grab the reference on failures and release it. + nsIRunnable* temp = event.get(); + rv = aThread->DispatchToQueue(event.forget(), aQueue); + if (NS_WARN_IF(NS_FAILED(rv))) { + // Dispatch() leaked the reference to the event, but due to caller's + // assumptions, we shouldn't leak here. And given we are on the same + // thread as the dispatch target, it's mostly safe to do it here. + NS_RELEASE(temp); + } + + return rv; +} + +nsresult NS_DispatchToCurrentThreadQueue(already_AddRefed&& aEvent, + EventQueuePriority aQueue) { + return NS_DispatchToThreadQueue(std::move(aEvent), NS_GetCurrentThread(), + aQueue); +} + +extern nsresult NS_DispatchToMainThreadQueue( + already_AddRefed&& aEvent, EventQueuePriority aQueue) { + nsCOMPtr mainThread; + nsresult rv = NS_GetMainThread(getter_AddRefs(mainThread)); + if (NS_SUCCEEDED(rv)) { + return NS_DispatchToThreadQueue(std::move(aEvent), mainThread, aQueue); + } + return rv; +} + +class IdleRunnableWrapper final : public Runnable, + public nsIDiscardableRunnable, + public nsIIdleRunnable { + public: + explicit IdleRunnableWrapper(already_AddRefed&& aEvent) + : Runnable("IdleRunnableWrapper"), + mRunnable(std::move(aEvent)), + mDiscardable(do_QueryInterface(mRunnable)) {} + + NS_DECL_ISUPPORTS_INHERITED + + NS_IMETHOD Run() override { + if (!mRunnable) { + return NS_OK; + } + CancelTimer(); + // Don't clear mDiscardable because that would cause QueryInterface to + // change behavior during the lifetime of an instance. + nsCOMPtr runnable = std::move(mRunnable); + return runnable->Run(); + } + + // nsIDiscardableRunnable + void OnDiscard() override { + if (!mRunnable) { + // Run() was already called from TimedOut(). + return; + } + mDiscardable->OnDiscard(); + mRunnable = nullptr; + } + + static void TimedOut(nsITimer* aTimer, void* aClosure) { + RefPtr runnable = + static_cast(aClosure); + LogRunnable::Run log(runnable); + runnable->Run(); + runnable = nullptr; + } + + void SetTimer(uint32_t aDelay, nsIEventTarget* aTarget) override { + MOZ_ASSERT(aTarget); + MOZ_ASSERT(!mTimer); + NS_NewTimerWithFuncCallback(getter_AddRefs(mTimer), TimedOut, this, aDelay, + nsITimer::TYPE_ONE_SHOT, + "IdleRunnableWrapper::SetTimer", aTarget); + } + +#ifdef MOZ_COLLECTING_RUNNABLE_TELEMETRY + NS_IMETHOD GetName(nsACString& aName) override { + aName.AssignLiteral("IdleRunnableWrapper"); + if (nsCOMPtr named = do_QueryInterface(mRunnable)) { + nsAutoCString name; + named->GetName(name); + if (!name.IsEmpty()) { + aName.AppendLiteral(" for "); + aName.Append(name); + } + } + return NS_OK; + } +#endif + + private: + ~IdleRunnableWrapper() { CancelTimer(); } + + void CancelTimer() { + if (mTimer) { + mTimer->Cancel(); + } + } + + nsCOMPtr mTimer; + nsCOMPtr mRunnable; + nsCOMPtr mDiscardable; +}; + +NS_IMPL_ADDREF_INHERITED(IdleRunnableWrapper, Runnable) +NS_IMPL_RELEASE_INHERITED(IdleRunnableWrapper, Runnable) + +NS_INTERFACE_MAP_BEGIN(IdleRunnableWrapper) + NS_INTERFACE_MAP_ENTRY(nsIIdleRunnable) + NS_INTERFACE_MAP_ENTRY_CONDITIONAL(nsIDiscardableRunnable, mDiscardable) +NS_INTERFACE_MAP_END_INHERITING(Runnable) + +extern nsresult NS_DispatchToThreadQueue(already_AddRefed&& aEvent, + uint32_t aTimeout, nsIThread* aThread, + EventQueuePriority aQueue) { + nsCOMPtr event(std::move(aEvent)); + NS_ENSURE_TRUE(event, NS_ERROR_INVALID_ARG); + MOZ_ASSERT(aQueue == EventQueuePriority::Idle || + aQueue == EventQueuePriority::DeferredTimers); + if (!aThread) { + return NS_ERROR_UNEXPECTED; + } + + nsCOMPtr idleEvent = do_QueryInterface(event); + + if (!idleEvent) { + idleEvent = new IdleRunnableWrapper(event.forget()); + event = do_QueryInterface(idleEvent); + MOZ_DIAGNOSTIC_ASSERT(event); + } + idleEvent->SetTimer(aTimeout, aThread); + + nsresult rv = NS_DispatchToThreadQueue(event.forget(), aThread, aQueue); + if (NS_SUCCEEDED(rv)) { + // This is intended to bind with the "DISP" log made from inside + // NS_DispatchToThreadQueue for the `event`. There is no possibly to inject + // another "DISP" for a different event on this thread. + LOG1(("TIMEOUT %u", aTimeout)); + } + + return rv; +} + +extern nsresult NS_DispatchToCurrentThreadQueue( + already_AddRefed&& aEvent, uint32_t aTimeout, + EventQueuePriority aQueue) { + return NS_DispatchToThreadQueue(std::move(aEvent), aTimeout, + NS_GetCurrentThread(), aQueue); +} + +#ifndef XPCOM_GLUE_AVOID_NSPR +nsresult NS_ProcessPendingEvents(nsIThread* aThread, PRIntervalTime aTimeout) { + nsresult rv = NS_OK; + + if (!aThread) { + aThread = NS_GetCurrentThread(); + if (NS_WARN_IF(!aThread)) { + return NS_ERROR_UNEXPECTED; + } + } + + PRIntervalTime start = PR_IntervalNow(); + for (;;) { + bool processedEvent; + rv = aThread->ProcessNextEvent(false, &processedEvent); + if (NS_FAILED(rv) || !processedEvent) { + break; + } + if (PR_IntervalNow() - start > aTimeout) { + break; + } + } + return rv; +} +#endif // XPCOM_GLUE_AVOID_NSPR + +inline bool hasPendingEvents(nsIThread* aThread) { + bool val; + return NS_SUCCEEDED(aThread->HasPendingEvents(&val)) && val; +} + +bool NS_HasPendingEvents(nsIThread* aThread) { + if (!aThread) { + aThread = NS_GetCurrentThread(); + if (NS_WARN_IF(!aThread)) { + return false; + } + } + return hasPendingEvents(aThread); +} + +bool NS_ProcessNextEvent(nsIThread* aThread, bool aMayWait) { + if (!aThread) { + aThread = NS_GetCurrentThread(); + if (NS_WARN_IF(!aThread)) { + return false; + } + } + bool val; + return NS_SUCCEEDED(aThread->ProcessNextEvent(aMayWait, &val)) && val; +} + +void NS_SetCurrentThreadName(const char* aName) { + PR_SetCurrentThreadName(aName); +#if defined(ANDROID) && defined(DEBUG) + // Check nspr does the right thing on Android. + char buffer[16] = {'\0'}; + prctl(PR_GET_NAME, buffer); + MOZ_ASSERT(0 == strncmp(buffer, aName, 15)); +#endif + if (nsThreadManager::get().IsNSThread()) { + nsThread* thread = nsThreadManager::get().GetCurrentThread(); + thread->SetThreadNameInternal(nsDependentCString(aName)); + } +} + +nsIThread* NS_GetCurrentThread() { + return nsThreadManager::get().GetCurrentThread(); +} + +nsIThread* NS_GetCurrentThreadNoCreate() { + if (nsThreadManager::get().IsNSThread()) { + return NS_GetCurrentThread(); + } + return nullptr; +} + +// nsThreadPoolNaming +nsCString nsThreadPoolNaming::GetNextThreadName(const nsACString& aPoolName) { + nsCString name(aPoolName); + name.AppendLiteral(" #"); + name.AppendInt(++mCounter, 10); // The counter is declared as atomic + return name; +} + +nsresult NS_DispatchBackgroundTask(already_AddRefed aEvent, + uint32_t aDispatchFlags) { + nsCOMPtr event(aEvent); + return nsThreadManager::get().DispatchToBackgroundThread(event, + aDispatchFlags); +} + +// nsAutoLowPriorityIO +nsAutoLowPriorityIO::nsAutoLowPriorityIO() { +#if defined(XP_WIN) + lowIOPrioritySet = + SetThreadPriority(GetCurrentThread(), THREAD_MODE_BACKGROUND_BEGIN); +#elif defined(XP_MACOSX) + oldPriority = getiopolicy_np(IOPOL_TYPE_DISK, IOPOL_SCOPE_THREAD); + lowIOPrioritySet = + oldPriority != -1 && + setiopolicy_np(IOPOL_TYPE_DISK, IOPOL_SCOPE_THREAD, IOPOL_THROTTLE) != -1; +#else + lowIOPrioritySet = false; +#endif +} + +nsAutoLowPriorityIO::~nsAutoLowPriorityIO() { +#if defined(XP_WIN) + if (MOZ_LIKELY(lowIOPrioritySet)) { + // On Windows the old thread priority is automatically restored + SetThreadPriority(GetCurrentThread(), THREAD_MODE_BACKGROUND_END); + } +#elif defined(XP_MACOSX) + if (MOZ_LIKELY(lowIOPrioritySet)) { + setiopolicy_np(IOPOL_TYPE_DISK, IOPOL_SCOPE_THREAD, oldPriority); + } +#endif +} + +namespace mozilla { + +nsISerialEventTarget* GetCurrentSerialEventTarget() { + if (nsISerialEventTarget* current = + SerialEventTargetGuard::GetCurrentSerialEventTarget()) { + return current; + } + + MOZ_DIAGNOSTIC_ASSERT(!nsThreadPool::GetCurrentThreadPool(), + "Call to GetCurrentSerialEventTarget() from thread " + "pool without an active TaskQueue"); + + nsCOMPtr thread; + nsresult rv = NS_GetCurrentThread(getter_AddRefs(thread)); + if (NS_FAILED(rv)) { + return nullptr; + } + + return thread; +} + +nsISerialEventTarget* GetMainThreadSerialEventTarget() { + return static_cast(nsThreadManager::get().GetMainThreadWeak()); +} + +size_t GetNumberOfProcessors() { +#if defined(XP_LINUX) && defined(MOZ_SANDBOX) + static const PRInt32 procs = PR_GetNumberOfProcessors(); +#else + PRInt32 procs = PR_GetNumberOfProcessors(); +#endif + MOZ_ASSERT(procs > 0); + return static_cast(procs); +} + +template +void LogTaskBase::LogDispatch(T* aEvent) { + LOG1(("DISP %p", aEvent)); +} +template +void LogTaskBase::LogDispatch(T* aEvent, void* aContext) { + LOG1(("DISP %p (%p)", aEvent, aContext)); +} + +template <> +void LogTaskBase::LogDispatchWithPid(IPC::Message* aEvent, + int32_t aPid) { + if (aEvent->seqno() && aPid > 0) { + LOG1(("SEND %p %d %d", aEvent, aEvent->seqno(), aPid)); + } +} + +template +LogTaskBase::Run::Run(T* aEvent, bool aWillRunAgain) + : mWillRunAgain(aWillRunAgain) { + // Logging address of this RAII so that we can use it to identify the DONE log + // while not keeping any ref to the event that could be invalid at the dtor + // time. + LOG1(("EXEC %p %p", aEvent, this)); +} +template +LogTaskBase::Run::Run(T* aEvent, void* aContext, bool aWillRunAgain) + : mWillRunAgain(aWillRunAgain) { + LOG1(("EXEC %p (%p) %p", aEvent, aContext, this)); +} + +template <> +LogTaskBase::Run::Run(nsIRunnable* aEvent, bool aWillRunAgain) + : mWillRunAgain(aWillRunAgain) { + if (!LOG1_ENABLED()) { + return; + } + + nsCOMPtr named(do_QueryInterface(aEvent)); + if (!named) { + LOG1(("EXEC %p %p", aEvent, this)); + return; + } + + nsAutoCString name; + named->GetName(name); + LOG1(("EXEC %p %p [%s]", aEvent, this, name.BeginReading())); +} + +template <> +LogTaskBase::Run::Run(Task* aTask, bool aWillRunAgain) + : mWillRunAgain(aWillRunAgain) { + if (!LOG1_ENABLED()) { + return; + } + + nsAutoCString name; + if (!aTask->GetName(name)) { + LOG1(("EXEC %p %p", aTask, this)); + return; + } + + LOG1(("EXEC %p %p [%s]", aTask, this, name.BeginReading())); +} + +template <> +LogTaskBase::Run::Run(IPC::Message* aMessage, bool aWillRunAgain) + : mWillRunAgain(aWillRunAgain) { + LOG1(("RECV %p %p %d [%s]", aMessage, this, aMessage->seqno(), + aMessage->name())); +} + +template <> +LogTaskBase::Run::Run(nsTimerImpl* aEvent, bool aWillRunAgain) + : mWillRunAgain(aWillRunAgain) { + // The name of the timer will be logged when running it on the target thread. + // Logging it here (on the `Timer` thread) would be redundant. + LOG1(("EXEC %p %p [nsTimerImpl]", aEvent, this)); +} + +template +LogTaskBase::Run::~Run() { + LOG1((mWillRunAgain ? "INTERRUPTED %p" : "DONE %p", this)); +} + +template class LogTaskBase; +template class LogTaskBase; +template class LogTaskBase; +template class LogTaskBase; +template class LogTaskBase; +template class LogTaskBase; +template class LogTaskBase; + +MOZ_THREAD_LOCAL(nsISerialEventTarget*) +SerialEventTargetGuard::sCurrentThreadTLS; +void SerialEventTargetGuard::InitTLS() { + MOZ_ASSERT(NS_IsMainThread()); + if (!sCurrentThreadTLS.init()) { + MOZ_CRASH(); + } +} + +} // namespace mozilla + +bool nsIEventTarget::IsOnCurrentThread() { + if (mThread) { + return mThread == PR_GetCurrentThread(); + } + return IsOnCurrentThreadInfallible(); +} + +extern "C" { +// These functions use the C language linkage because they're exposed to Rust +// via the xpcom/rust/moz_task crate, which wraps them in safe Rust functions +// that enable Rust code to get/create threads and dispatch runnables on them. + +nsresult NS_GetCurrentThreadRust(nsIThread** aResult) { + return NS_GetCurrentThread(aResult); +} + +nsresult NS_GetMainThreadRust(nsIThread** aResult) { + return NS_GetMainThread(aResult); +} + +// NS_NewNamedThread's aStackSize parameter has the default argument +// nsIThreadManager::DEFAULT_STACK_SIZE, but we can't omit default arguments +// when calling a C++ function from Rust, and we can't access +// nsIThreadManager::DEFAULT_STACK_SIZE in Rust to pass it explicitly, +// since it is defined in a %{C++ ... %} block within nsIThreadManager.idl. +// So we indirect through this function. +nsresult NS_NewNamedThreadWithDefaultStackSize(const nsACString& aName, + nsIThread** aResult, + nsIRunnable* aEvent) { + return NS_NewNamedThread(aName, aResult, aEvent); +} + +bool NS_IsOnCurrentThread(nsIEventTarget* aTarget) { + return aTarget->IsOnCurrentThread(); +} + +nsresult NS_DispatchBackgroundTask(nsIRunnable* aEvent, + uint32_t aDispatchFlags) { + return nsThreadManager::get().DispatchToBackgroundThread(aEvent, + aDispatchFlags); +} + +nsresult NS_CreateBackgroundTaskQueue(const char* aName, + nsISerialEventTarget** aTarget) { + nsCOMPtr target = + nsThreadManager::get().CreateBackgroundTaskQueue(aName); + if (!target) { + return NS_ERROR_FAILURE; + } + + target.forget(aTarget); + return NS_OK; +} + +} // extern "C" + +nsresult NS_DispatchAndSpinEventLoopUntilComplete( + const nsACString& aVeryGoodReasonToDoThis, nsIEventTarget* aEventTarget, + already_AddRefed aEvent) { + // NOTE: Get the current thread specifically, as `SpinEventLoopUntil` can + // only spin that event target's loop. The reply will specify + // NS_DISPATCH_IGNORE_BLOCK_DISPATCH to ensure the reply is received even if + // the caller is a threadpool thread. + nsCOMPtr current = NS_GetCurrentThread(); + if (NS_WARN_IF(!current)) { + return NS_ERROR_NOT_AVAILABLE; + } + + RefPtr wrapper = + new nsThreadSyncDispatch(current.forget(), std::move(aEvent)); + nsresult rv = aEventTarget->Dispatch(do_AddRef(wrapper)); + if (NS_WARN_IF(NS_FAILED(rv))) { + // FIXME: Consider avoiding leaking the `nsThreadSyncDispatch` as well by + // using a fallible version of `Dispatch` once that is added. + return rv; + } + + wrapper->SpinEventLoopUntilComplete(aVeryGoodReasonToDoThis); + return NS_OK; +} -- cgit v1.2.3