xpcom/threads/nsThreadManager.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 nsThreadManager_h__
   8 #define nsThreadManager_h__
   9
  10 #include "mozilla/Mutex.h"
  11 #include "nsIThreadManager.h"
  12 #include "nsRefPtrHashtable.h"
  13 #include "nsThread.h"
  14
  15 class nsIRunnable;
  16
  17 class nsThreadManager : public nsIThreadManager
  18 {
  19 public:
  20   NS_DECL_ISUPPORTS
  21   NS_DECL_NSITHREADMANAGER
  22
  23   static nsThreadManager* get()
  24   {
  25     static nsThreadManager sInstance;
  26     return &sInstance;
  27   }
  28
  29   nsresult Init();
  30
  31   // Shutdown all threads.  This function should only be called on the main
  32   // thread of the application process.
  33   void Shutdown();
  34
  35   // Called by nsThread to inform the ThreadManager it exists.  This method
  36   // must be called when the given thread is the current thread.
  37   void RegisterCurrentThread(nsThread* aThread);
  38
  39   // Called by nsThread to inform the ThreadManager it is going away.  This
  40   // method must be called when the given thread is the current thread.
  41   void UnregisterCurrentThread(nsThread* aThread);
  42
  43   // Returns the current thread.  Returns null if OOM or if ThreadManager isn't
  44   // initialized.
  45   nsThread* GetCurrentThread();
  46
  47   // Returns the maximal number of threads that have been in existence
  48   // simultaneously during the execution of the thread manager.
  49   uint32_t GetHighestNumberOfThreads();
  50
  51   // This needs to be public in order to support static instantiation of this
  52   // class with older compilers (e.g., egcs-2.91.66).
  53   ~nsThreadManager()
  54   {
  55   }
  56
  57 private:
  58   nsThreadManager()
  59     : mCurThreadIndex(0)
  60     , mMainPRThread(nullptr)
  61     , mLock(nullptr)
  62     , mInitialized(false)
  63     , mCurrentNumberOfThreads(1)
  64     , mHighestNumberOfThreads(1)
  65   {
  66   }
  67
  68   nsRefPtrHashtable<nsPtrHashKey<PRThread>, nsThread> mThreadsByPRThread;
  69   unsigned             mCurThreadIndex;  // thread-local-storage index
  70   nsRefPtr<nsThread>  mMainThread;
  71   PRThread*           mMainPRThread;
  72   // This is a pointer in order to allow creating nsThreadManager from
  73   // the static context in debug builds.
  74   nsAutoPtr<mozilla::Mutex> mLock;  // protects tables
  75   bool                mInitialized;
  76
  77   // The current number of threads
  78   uint32_t            mCurrentNumberOfThreads;
  79   // The highest number of threads encountered so far during the session
  80   uint32_t            mHighestNumberOfThreads;
  81 };
  82
  83 #define NS_THREADMANAGER_CID                       \
  84 { /* 7a4204c6-e45a-4c37-8ebb-6709a22c917c */       \
  85   0x7a4204c6,                                      \
  86   0xe45a,                                          \
  87   0x4c37,                                          \
  88   {0x8e, 0xbb, 0x67, 0x09, 0xa2, 0x2c, 0x91, 0x7c} \
  89 }
  90
  91 #endif  // nsThreadManager_h__