gecko-dev/xpcom/glue/Monitor.h

192 lines
4.9 KiB
C++

/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: sw=2 ts=8 et :
*/
/* ***** BEGIN LICENSE BLOCK *****
* Version: MPL 1.1/GPL 2.0/LGPL 2.1
*
* The contents of this file are subject to the Mozilla Public License Version
* 1.1 (the "License"); you may not use this file except in compliance with
* the License. You may obtain a copy of the License at:
* http://www.mozilla.org/MPL/
*
* Software distributed under the License is distributed on an "AS IS" basis,
* WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
* for the specific language governing rights and limitations under the
* License.
*
* The Original Code is Mozilla Code.
*
* The Initial Developer of the Original Code is
* The Mozilla Foundation
* Portions created by the Initial Developer are Copyrigght (C) 2011
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Chris Jones <jones.chris.g@gmail.com>
*
* Alternatively, the contents of this file may be used under the terms of
* either the GNU General Public License Version 2 or later (the "GPL"), or
* the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
* in which case the provisions of the GPL or the LGPL are applicable instead
* of those above. If you wish to allow use of your version of this file only
* under the terms of either the GPL or the LGPL, and not to allow others to
* use your version of this file under the terms of the MPL, indicate your
* decision by deleting the provisions above and replace them with the notice
* and other provisions required by the GPL or the LGPL. If you do not delete
* the provisions above, a recipient may use your version of this file under
* the terms of any one of the MPL, the GPL or the LGPL.
*
* ***** END LICENSE BLOCK ***** */
#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 NS_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 NS_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