dom/workers/WorkerThread.h

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #ifndef mozilla_dom_workers_WorkerThread_h__
   8 #define mozilla_dom_workers_WorkerThread_h__
   9
  10 #include "mozilla/AlreadyAddRefed.h"
  11 #include "mozilla/CondVar.h"
  12 #include "mozilla/Mutex.h"
  13 #include "mozilla/RefPtr.h"
  14 #include "mozilla/dom/SafeRefPtr.h"
  15 #include "nsISupports.h"
  16 #include "nsThread.h"
  17 #include "nscore.h"
  18
  19 class nsIRunnable;
  20
  21 namespace mozilla {
  22 class Runnable;
  23
  24 namespace dom {
  25
  26 class WorkerRunnable;
  27 class WorkerPrivate;
  28 namespace workerinternals {
  29 class RuntimeService;
  30 }
  31
  32 // This class lets us restrict the public methods that can be called on
  33 // WorkerThread to RuntimeService and WorkerPrivate without letting them gain
  34 // full access to private methods (as would happen if they were simply friends).
  35 class WorkerThreadFriendKey {
  36   friend class workerinternals::RuntimeService;
  37   friend class WorkerPrivate;
  38
  39   WorkerThreadFriendKey();
  40   ~WorkerThreadFriendKey();
  41 };
  42
  43 class WorkerThread final : public nsThread {
  44   class Observer;
  45
  46   Mutex mLock MOZ_UNANNOTATED;
  47   CondVar mWorkerPrivateCondVar;
  48
  49   // Protected by nsThread::mLock.
  50   WorkerPrivate* mWorkerPrivate;
  51
  52   // Only touched on the target thread.
  53   RefPtr<Observer> mObserver;
  54
  55   // Protected by nsThread::mLock and waited on with mWorkerPrivateCondVar.
  56   uint32_t mOtherThreadsDispatchingViaEventTarget;
  57
  58 #ifdef DEBUG
  59   // Protected by nsThread::mLock.
  60   bool mAcceptingNonWorkerRunnables;
  61 #endif
  62
  63   // Using this struct we restrict access to the constructor while still being
  64   // able to use MakeSafeRefPtr.
  65   struct ConstructorKey {};
  66
  67  public:
  68   explicit WorkerThread(ConstructorKey);
  69
  70   static SafeRefPtr<WorkerThread> Create(const WorkerThreadFriendKey& aKey);
  71
  72   void SetWorker(const WorkerThreadFriendKey& aKey,
  73                  WorkerPrivate* aWorkerPrivate);
  74
  75   // This method is used to decouple the connection with the WorkerPrivate which
  76   // is set in SetWorker(). And it also clears all pending runnables on this
  77   // WorkerThread.
  78   // After decoupling, WorkerThreadRunnable can not run on this WorkerThread
  79   // anymore, since WorkerPrivate is invalid.
  80   void ClearEventQueueAndWorker(const WorkerThreadFriendKey& aKey);
  81
  82   nsresult DispatchPrimaryRunnable(const WorkerThreadFriendKey& aKey,
  83                                    already_AddRefed<nsIRunnable> aRunnable);
  84
  85   nsresult DispatchAnyThread(const WorkerThreadFriendKey& aKey,
  86                              already_AddRefed<WorkerRunnable> aWorkerRunnable);
  87
  88   uint32_t RecursionDepth(const WorkerThreadFriendKey& aKey) const;
  89
  90   // Override HasPendingEvents to allow HasPendingEvents could be accessed by
  91   // the parent thread. WorkerPrivate::IsEligibleForCC calls this method on the
  92   // parent thread to check if there is any pending events on the worker thread.
  93   NS_IMETHOD HasPendingEvents(bool* aHasPendingEvents) override;
  94
  95   NS_INLINE_DECL_REFCOUNTING_INHERITED(WorkerThread, nsThread)
  96
  97  private:
  98   ~WorkerThread();
  99
 100   // This should only be called by consumers that have an
 101   // nsIEventTarget/nsIThread pointer.
 102   NS_IMETHOD
 103   Dispatch(already_AddRefed<nsIRunnable> aRunnable, uint32_t aFlags) override;
 104
 105   NS_IMETHOD
 106   DispatchFromScript(nsIRunnable* aRunnable, uint32_t aFlags) override;
 107
 108   NS_IMETHOD
 109   DelayedDispatch(already_AddRefed<nsIRunnable>, uint32_t) override;
 110 };
 111
 112 }  // namespace dom
 113 }  // namespace mozilla
 114
 115 #endif  // mozilla_dom_workers_WorkerThread_h__