diff -r 000000000000 -r 6474c204b198 xpcom/threads/nsThreadManager.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/xpcom/threads/nsThreadManager.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,87 @@
+/* -*- 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 nsThreadManager_h__
+#define nsThreadManager_h__
+
+#include "mozilla/Mutex.h"
+#include "nsIThreadManager.h"
+#include "nsRefPtrHashtable.h"
+#include "nsThread.h"
+
+class nsIRunnable;
+
+class nsThreadManager : public nsIThreadManager
+{
+public:
+  NS_DECL_ISUPPORTS
+  NS_DECL_NSITHREADMANAGER
+
+  static nsThreadManager *get() {
+    static nsThreadManager sInstance;
+    return &sInstance;
+  }
+
+  nsresult Init();
+
+  // Shutdown all threads.  This function should only be called on the main
+  // thread of the application process.
+  void Shutdown();
+
+  // Called by nsThread to inform the ThreadManager it exists.  This method
+  // must be called when the given thread is the current thread.
+  void RegisterCurrentThread(nsThread *thread);
+
+  // Called by nsThread to inform the ThreadManager it is going away.  This
+  // method must be called when the given thread is the current thread.
+  void UnregisterCurrentThread(nsThread *thread);
+
+  // Returns the current thread.  Returns null if OOM or if ThreadManager isn't
+  // initialized.
+  nsThread *GetCurrentThread();
+
+  // Returns the maximal number of threads that have been in existence
+  // simultaneously during the execution of the thread manager.
+  uint32_t GetHighestNumberOfThreads();
+
+  // This needs to be public in order to support static instantiation of this
+  // class with older compilers (e.g., egcs-2.91.66).
+  ~nsThreadManager() {}
+
+private:
+  nsThreadManager()
+    : mCurThreadIndex(0)
+    , mMainPRThread(nullptr)
+    , mLock(nullptr)
+    , mInitialized(false)
+    , mCurrentNumberOfThreads(1)
+    , mHighestNumberOfThreads(1) {
+  }
+
+  nsRefPtrHashtable<nsPtrHashKey<PRThread>, nsThread> mThreadsByPRThread;
+  unsigned             mCurThreadIndex;  // thread-local-storage index
+  nsRefPtr<nsThread>  mMainThread;
+  PRThread           *mMainPRThread;
+  // This is a pointer in order to allow creating nsThreadManager from
+  // the static context in debug builds.
+  nsAutoPtr<mozilla::Mutex> mLock;  // protects tables
+  bool                mInitialized;
+
+   // The current number of threads
+   uint32_t           mCurrentNumberOfThreads;
+   // The highest number of threads encountered so far during the session
+   uint32_t           mHighestNumberOfThreads;
+};
+
+#define NS_THREADMANAGER_CID                       \
+{ /* 7a4204c6-e45a-4c37-8ebb-6709a22c917c */       \
+  0x7a4204c6,                                      \
+  0xe45a,                                          \
+  0x4c37,                                          \
+  {0x8e, 0xbb, 0x67, 0x09, 0xa2, 0x2c, 0x91, 0x7c} \
+}
+
+#endif  // nsThreadManager_h__