diff -r 000000000000 -r 6474c204b198 xpcom/glue/Monitor.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/xpcom/glue/Monitor.h	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,158 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
+ * vim: sw=2 ts=8 et :
+ */
+/* 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 mozilla_Monitor_h
+#define mozilla_Monitor_h
+
+#include "mozilla/CondVar.h"
+#include "mozilla/Mutex.h"
+
+namespace mozilla {
+
+/**
+ * Monitor provides a *non*-reentrant monitor: *not* a Java-style
+ * monitor.  If your code needs support for reentrancy, use
+ * ReentrantMonitor instead.  (Rarely should reentrancy be needed.)
+ *
+ * Instead of directly calling Monitor methods, it's safer and simpler
+ * to instead use the RAII wrappers MonitorAutoLock and
+ * MonitorAutoUnlock.
+ */
+class NS_COM_GLUE Monitor
+{
+public:
+    Monitor(const char* aName) :
+        mMutex(aName),
+        mCondVar(mMutex, "[Monitor.mCondVar]")
+    {}
+
+    ~Monitor() {}
+
+    void Lock()
+    {
+        mMutex.Lock();
+    }
+
+    void Unlock()
+    {
+        mMutex.Unlock();
+    }
+
+    nsresult Wait(PRIntervalTime interval = PR_INTERVAL_NO_TIMEOUT)
+    {
+        return mCondVar.Wait(interval);
+    }
+
+    nsresult Notify()
+    {
+        return mCondVar.Notify();
+    }
+
+    nsresult NotifyAll()
+    {
+        return mCondVar.NotifyAll();
+    }
+
+    void AssertCurrentThreadOwns() const
+    {
+        mMutex.AssertCurrentThreadOwns();
+    }
+
+    void AssertNotCurrentThreadOwns() const
+    {
+        mMutex.AssertNotCurrentThreadOwns();
+    }
+
+private:
+    Monitor();
+    Monitor(const Monitor&);
+    Monitor& operator =(const Monitor&);
+
+    Mutex mMutex;
+    CondVar mCondVar;
+};
+
+/**
+ * Lock the monitor for the lexical scope instances of this class are
+ * bound to (except for MonitorAutoUnlock in nested scopes).
+ *
+ * The monitor must be unlocked when instances of this class are
+ * created.
+ */
+class NS_COM_GLUE MOZ_STACK_CLASS MonitorAutoLock
+{
+public:
+    MonitorAutoLock(Monitor& aMonitor) :
+        mMonitor(&aMonitor)
+    {
+        mMonitor->Lock();
+    }
+    
+    ~MonitorAutoLock()
+    {
+        mMonitor->Unlock();
+    }
+ 
+    nsresult Wait(PRIntervalTime interval = PR_INTERVAL_NO_TIMEOUT)
+    {
+       return mMonitor->Wait(interval);
+    }
+
+    nsresult Notify()
+    {
+        return mMonitor->Notify();
+    }
+
+    nsresult NotifyAll()
+    {
+        return mMonitor->NotifyAll();
+    }
+
+private:
+    MonitorAutoLock();
+    MonitorAutoLock(const MonitorAutoLock&);
+    MonitorAutoLock& operator =(const MonitorAutoLock&);
+    static void* operator new(size_t) CPP_THROW_NEW;
+    static void operator delete(void*);
+
+    Monitor* mMonitor;
+};
+
+/**
+ * Unlock the monitor for the lexical scope instances of this class
+ * are bound to (except for MonitorAutoLock in nested scopes).
+ *
+ * The monitor must be locked by the current thread when instances of
+ * this class are created.
+ */
+class NS_COM_GLUE MOZ_STACK_CLASS MonitorAutoUnlock
+{
+public:
+    MonitorAutoUnlock(Monitor& aMonitor) :
+        mMonitor(&aMonitor)
+    {
+        mMonitor->Unlock();
+    }
+    
+    ~MonitorAutoUnlock()
+    {
+        mMonitor->Lock();
+    }
+ 
+private:
+    MonitorAutoUnlock();
+    MonitorAutoUnlock(const MonitorAutoUnlock&);
+    MonitorAutoUnlock& operator =(const MonitorAutoUnlock&);
+    static void* operator new(size_t) CPP_THROW_NEW;
+    static void operator delete(void*);
+
+    Monitor* mMonitor;
+};
+
+} // namespace mozilla
+
+#endif // mozilla_Monitor_h