The Tor Browser: xpcom/threads/nsThread.h@b8a032363ba2 (annotated)

xpcom/threads/nsThread.h@b8a032363ba2 (annotated)

xpcom/threads/nsThread.h

Thu, 22 Jan 2015 13:21:57 +0100

author: Michael Schloh von Bennewitz <michael@schloh.com>
date: Thu, 22 Jan 2015 13:21:57 +0100
branch: TOR_BUG_9701
changeset 15: b8a032363ba2
permissions: -rw-r--r--

Incorporate requested changes from Mozilla in review:
https://bugzilla.mozilla.org/show_bug.cgi?id=1123480#c6

 /* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
 /* vim:set ts=2 sw=2 sts=2 et cindent: */
 /* 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 "nsIThreadInternal.h"
 #include "nsISupportsPriority.h"
 #include "nsEventQueue.h"
 #include "nsThreadUtils.h"
 #include "nsString.h"
 #include "nsTObserverArray.h"
 #include "mozilla/Attributes.h"
 #include "nsAutoPtr.h"
 // 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
   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(); }
   static nsresult
   SetMainThreadObserver(nsIThreadObserver* aObserver);
 protected:
   static nsIThreadObserver* sMainThreadObserver;
   class nsChainedEventQueue;
   class nsNestedEventTarget;
   friend class nsNestedEventTarget;
   friend class nsThreadShutdownEvent;
   virtual ~nsThread();
   bool ShuttingDown() { return mShutdownContext != nullptr; }
   static void ThreadFunc(void *arg);
   // Helper
   already_AddRefed<nsIThreadObserver> GetObserver() {
     nsIThreadObserver *obs;
     nsThread::GetObserver(&obs);
     return already_AddRefed<nsIThreadObserver>(obs);
   }
   // Wrappers for event queue methods:
   bool GetEvent(bool mayWait, nsIRunnable **event) {
     return mEvents->GetEvent(mayWait, event);
   }
   nsresult PutEvent(nsIRunnable *event, nsNestedEventTarget *target);
   nsresult DispatchInternal(nsIRunnable *event, uint32_t flags,
                             nsNestedEventTarget *target);
   // Wrapper for nsEventQueue that supports chaining.
   class nsChainedEventQueue {
   public:
     nsChainedEventQueue()
       : mNext(nullptr) {
     }
     bool GetEvent(bool mayWait, nsIRunnable **event) {
       return mQueue.GetEvent(mayWait, event);
     }
     bool PutEvent(nsIRunnable *event) {
       return mQueue.PutEvent(event);
     }
     bool HasPendingEvent() {
       return mQueue.HasPendingEvent();
     }
     nsChainedEventQueue *mNext;
     nsRefPtr<nsNestedEventTarget> mEventTarget;
   private:
     nsEventQueue mQueue;
   };
   class nsNestedEventTarget MOZ_FINAL : public nsIEventTarget {
   public:
     NS_DECL_THREADSAFE_ISUPPORTS
     NS_DECL_NSIEVENTTARGET
     nsNestedEventTarget(nsThread *thread, nsChainedEventQueue *queue)
       : mThread(thread), mQueue(queue) {
     }
     nsRefPtr<nsThread> mThread;
     // This is protected by mThread->mLock.
     nsChainedEventQueue* mQueue;
   private:
     ~nsNestedEventTarget() {}
   };
   // This lock protects access to mObserver, mEvents 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;
   // Only accessed on the target thread.
   nsAutoTObserverArray<nsCOMPtr<nsIThreadObserver>, 2> mEventObservers;
   nsChainedEventQueue *mEvents;   // never null
   nsChainedEventQueue  mEventsRoot;
   int32_t   mPriority;
   PRThread *mThread;
   uint32_t  mRunningEvent;  // counter
   uint32_t  mStackSize;
   struct nsThreadShutdownContext *mShutdownContext;
   bool mShutdownRequired;
   // Set to true when events posted to this thread will never run.
   bool mEventsAreDoomed;
   MainThreadFlag mIsMainThread;
 };
 //-----------------------------------------------------------------------------
 class nsThreadSyncDispatch : public nsRunnable {
 public:
   nsThreadSyncDispatch(nsIThread *origin, nsIRunnable *task)
     : mOrigin(origin), mSyncTask(task), mResult(NS_ERROR_NOT_INITIALIZED) {
   }
   bool IsPending() {
     return mSyncTask != nullptr;
   }
   nsresult Result() {
     return mResult;
   }
 private:
   NS_DECL_NSIRUNNABLE
   nsCOMPtr<nsIThread> mOrigin;
   nsCOMPtr<nsIRunnable> mSyncTask;
   nsresult mResult;
 };
 #if defined(XP_UNIX) && !defined(ANDROID) && !defined(DEBUG) && HAVE_UALARM \
   && defined(_GNU_SOURCE)
 # define MOZ_CANARY
 extern int sCanaryOutputFD;
 #endif
 #endif  // nsThread_h__

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xpcom/threads/nsThread.h@b8a032363ba2 (annotated)

xpcom/threads/nsThread.h