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-rw-r--r--xpcom/threads/nsThread.h284
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diff --git a/xpcom/threads/nsThread.h b/xpcom/threads/nsThread.h
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+/* -*- 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 nsThread_h__
+#define nsThread_h__
+
+#include "mozilla/Mutex.h"
+#include "nsIIdlePeriod.h"
+#include "nsIThreadInternal.h"
+#include "nsISupportsPriority.h"
+#include "nsEventQueue.h"
+#include "nsThreadUtils.h"
+#include "nsString.h"
+#include "nsTObserverArray.h"
+#include "mozilla/Attributes.h"
+#include "mozilla/NotNull.h"
+#include "nsAutoPtr.h"
+#include "mozilla/AlreadyAddRefed.h"
+#include "mozilla/UniquePtr.h"
+
+namespace mozilla {
+class CycleCollectedJSContext;
+}
+
+using mozilla::NotNull;
+
+// A native thread
+class nsThread
+ : public nsIThreadInternal
+ , public nsISupportsPriority
+{
+public:
+ NS_DECL_THREADSAFE_ISUPPORTS
+ NS_DECL_NSIEVENTTARGET
+ NS_DECL_NSITHREAD
+ NS_DECL_NSITHREADINTERNAL
+ NS_DECL_NSISUPPORTSPRIORITY
+ using nsIEventTarget::Dispatch;
+
+ enum MainThreadFlag
+ {
+ MAIN_THREAD,
+ NOT_MAIN_THREAD
+ };
+
+ nsThread(MainThreadFlag aMainThread, uint32_t aStackSize);
+
+ // Initialize this as a wrapper for a new PRThread.
+ nsresult Init();
+
+ // Initialize this as a wrapper for the current PRThread.
+ nsresult InitCurrentThread();
+
+ // The PRThread corresponding to this thread.
+ PRThread* GetPRThread()
+ {
+ return mThread;
+ }
+
+ // If this flag is true, then the nsThread was created using
+ // nsIThreadManager::NewThread.
+ bool ShutdownRequired()
+ {
+ return mShutdownRequired;
+ }
+
+ // Clear the observer list.
+ void ClearObservers()
+ {
+ mEventObservers.Clear();
+ }
+
+ void
+ SetScriptObserver(mozilla::CycleCollectedJSContext* aScriptObserver);
+
+ uint32_t
+ RecursionDepth() const;
+
+ void ShutdownComplete(NotNull<struct nsThreadShutdownContext*> aContext);
+
+ void WaitForAllAsynchronousShutdowns();
+
+#ifdef MOZ_CRASHREPORTER
+ enum class ShouldSaveMemoryReport
+ {
+ kMaybeReport,
+ kForceReport
+ };
+
+ static bool SaveMemoryReportNearOOM(ShouldSaveMemoryReport aShouldSave);
+#endif
+
+private:
+ void DoMainThreadSpecificProcessing(bool aReallyWait);
+
+ void GetIdleEvent(nsIRunnable** aEvent, mozilla::MutexAutoLock& aProofOfLock);
+ void GetEvent(bool aWait, nsIRunnable** aEvent,
+ mozilla::MutexAutoLock& aProofOfLock);
+
+protected:
+ class nsChainedEventQueue;
+
+ class nsNestedEventTarget;
+ friend class nsNestedEventTarget;
+
+ friend class nsThreadShutdownEvent;
+
+ virtual ~nsThread();
+
+ bool ShuttingDown()
+ {
+ return mShutdownContext != nullptr;
+ }
+
+ static void ThreadFunc(void* aArg);
+
+ // Helper
+ already_AddRefed<nsIThreadObserver> GetObserver()
+ {
+ nsIThreadObserver* obs;
+ nsThread::GetObserver(&obs);
+ return already_AddRefed<nsIThreadObserver>(obs);
+ }
+
+ // Wrappers for event queue methods:
+ nsresult PutEvent(nsIRunnable* aEvent, nsNestedEventTarget* aTarget);
+ nsresult PutEvent(already_AddRefed<nsIRunnable> aEvent,
+ nsNestedEventTarget* aTarget);
+
+ nsresult DispatchInternal(already_AddRefed<nsIRunnable> aEvent,
+ uint32_t aFlags, nsNestedEventTarget* aTarget);
+
+ struct nsThreadShutdownContext* ShutdownInternal(bool aSync);
+
+ // Wrapper for nsEventQueue that supports chaining.
+ class nsChainedEventQueue
+ {
+ public:
+ explicit nsChainedEventQueue(mozilla::Mutex& aLock)
+ : mNext(nullptr)
+ , mEventsAvailable(aLock, "[nsChainedEventQueue.mEventsAvailable]")
+ , mProcessSecondaryQueueRunnable(false)
+ {
+ mNormalQueue =
+ mozilla::MakeUnique<nsEventQueue>(mEventsAvailable,
+ nsEventQueue::eSharedCondVarQueue);
+ // Both queues need to use the same CondVar!
+ mSecondaryQueue =
+ mozilla::MakeUnique<nsEventQueue>(mEventsAvailable,
+ nsEventQueue::eSharedCondVarQueue);
+ }
+
+ bool GetEvent(bool aMayWait, nsIRunnable** aEvent,
+ mozilla::MutexAutoLock& aProofOfLock);
+
+ void PutEvent(nsIRunnable* aEvent, mozilla::MutexAutoLock& aProofOfLock)
+ {
+ RefPtr<nsIRunnable> event(aEvent);
+ PutEvent(event.forget(), aProofOfLock);
+ }
+
+ void PutEvent(already_AddRefed<nsIRunnable> aEvent,
+ mozilla::MutexAutoLock& aProofOfLock)
+ {
+ RefPtr<nsIRunnable> event(aEvent);
+ nsCOMPtr<nsIRunnablePriority> runnablePrio =
+ do_QueryInterface(event);
+ uint32_t prio = nsIRunnablePriority::PRIORITY_NORMAL;
+ if (runnablePrio) {
+ runnablePrio->GetPriority(&prio);
+ }
+ MOZ_ASSERT(prio == nsIRunnablePriority::PRIORITY_NORMAL ||
+ prio == nsIRunnablePriority::PRIORITY_HIGH);
+ if (prio == nsIRunnablePriority::PRIORITY_NORMAL) {
+ mNormalQueue->PutEvent(event.forget(), aProofOfLock);
+ } else {
+ mSecondaryQueue->PutEvent(event.forget(), aProofOfLock);
+ }
+ }
+
+ bool HasPendingEvent(mozilla::MutexAutoLock& aProofOfLock)
+ {
+ return mNormalQueue->HasPendingEvent(aProofOfLock) ||
+ mSecondaryQueue->HasPendingEvent(aProofOfLock);
+ }
+
+ nsChainedEventQueue* mNext;
+ RefPtr<nsNestedEventTarget> mEventTarget;
+
+ private:
+ mozilla::CondVar mEventsAvailable;
+ mozilla::UniquePtr<nsEventQueue> mNormalQueue;
+ mozilla::UniquePtr<nsEventQueue> mSecondaryQueue;
+
+ // Try to process one high priority runnable after each normal
+ // priority runnable. This gives the processing model HTML spec has for
+ // 'Update the rendering' in the case only vsync messages are in the
+ // secondary queue and prevents starving the normal queue.
+ bool mProcessSecondaryQueueRunnable;
+ };
+
+ class nsNestedEventTarget final : public nsIEventTarget
+ {
+ public:
+ NS_DECL_THREADSAFE_ISUPPORTS
+ NS_DECL_NSIEVENTTARGET
+
+ nsNestedEventTarget(NotNull<nsThread*> aThread,
+ NotNull<nsChainedEventQueue*> aQueue)
+ : mThread(aThread)
+ , mQueue(aQueue)
+
+
+
+ {
+ }
+
+ NotNull<RefPtr<nsThread>> mThread;
+
+ // This is protected by mThread->mLock.
+ nsChainedEventQueue* mQueue;
+
+ private:
+ ~nsNestedEventTarget()
+ {
+ }
+ };
+
+ // This lock protects access to mObserver, mEvents, mIdleEvents,
+ // mIdlePeriod and mEventsAreDoomed. All of those fields are only
+ // modified on the thread itself (never from another thread). This
+ // means that we can avoid holding the lock while using mObserver
+ // and mEvents on the thread itself. When calling PutEvent on
+ // mEvents, we have to hold the lock to synchronize with
+ // PopEventQueue.
+ mozilla::Mutex mLock;
+
+ nsCOMPtr<nsIThreadObserver> mObserver;
+ mozilla::CycleCollectedJSContext* mScriptObserver;
+
+ // Only accessed on the target thread.
+ nsAutoTObserverArray<NotNull<nsCOMPtr<nsIThreadObserver>>, 2> mEventObservers;
+
+ NotNull<nsChainedEventQueue*> mEvents; // never null
+ nsChainedEventQueue mEventsRoot;
+
+ // mIdlePeriod keeps track of the current idle period. If at any
+ // time the main event queue is empty, calling
+ // mIdlePeriod->GetIdlePeriodHint() will give an estimate of when
+ // the current idle period will end.
+ nsCOMPtr<nsIIdlePeriod> mIdlePeriod;
+ mozilla::CondVar mIdleEventsAvailable;
+ nsEventQueue mIdleEvents;
+
+ int32_t mPriority;
+ PRThread* mThread;
+ uint32_t mNestedEventLoopDepth;
+ uint32_t mStackSize;
+
+ // The shutdown context for ourselves.
+ struct nsThreadShutdownContext* mShutdownContext;
+ // The shutdown contexts for any other threads we've asked to shut down.
+ nsTArray<nsAutoPtr<struct nsThreadShutdownContext>> mRequestedShutdownContexts;
+
+ bool mShutdownRequired;
+ // Set to true when events posted to this thread will never run.
+ bool mEventsAreDoomed;
+ MainThreadFlag mIsMainThread;
+
+ // Set to true if this thread creates a JSRuntime.
+ bool mCanInvokeJS;
+};
+
+#if defined(XP_UNIX) && !defined(ANDROID) && !defined(DEBUG) && HAVE_UALARM \
+ && defined(_GNU_SOURCE)
+# define MOZ_CANARY
+
+extern int sCanaryOutputFD;
+#endif
+
+#endif // nsThread_h__