gecko-dev/xpcom/glue/CondVar.h

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/* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
* vim: sw=4 ts=4 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.org code.
*
* The Initial Developer of the Original Code is
* Netscape Communications Corporation.
* Portions created by the Initial Developer are Copyright (C) 1998
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
*
* Alternatively, the contents of this file may be used under the terms of
* either of 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_CondVar_h
#define mozilla_CondVar_h
#include "prcvar.h"
#include "mozilla/BlockingResourceBase.h"
#include "mozilla/Mutex.h"
namespace mozilla {
/**
* CondVar
* Vanilla condition variable. Please don't use this unless you have a
* compelling reason --- Monitor provides a better API.
**/
class NS_COM_GLUE CondVar : BlockingResourceBase
{
public:
/**
* CondVar
*
* The CALLER owns |lock|.
*
* @param aLock A Mutex to associate with this condition variable.
* @param aName A name which can reference this monitor
* @returns If failure, nsnull.
* If success, a valid Monitor* which must be destroyed
* by Monitor::DestroyMonitor()
**/
CondVar(Mutex& aLock, const char* aName) :
BlockingResourceBase(aName, eCondVar),
mLock(&aLock)
{
// |lock| must necessarily already be known to the deadlock detector
mCvar = PR_NewCondVar(mLock->mLock);
if (!mCvar)
NS_RUNTIMEABORT("Can't allocate mozilla::CondVar");
}
/**
* ~CondVar
* Clean up after this CondVar, but NOT its associated Mutex.
**/
~CondVar()
{
NS_ASSERTION(mCvar && mLock,
"improperly constructed CondVar or double free");
PR_DestroyCondVar(mCvar);
mCvar = 0;
mLock = 0;
}
#ifndef DEBUG
/**
* Wait
* @see prcvar.h
**/
nsresult Wait(PRIntervalTime interval = PR_INTERVAL_NO_TIMEOUT)
{
// NSPR checks for lock ownership
return PR_WaitCondVar(mCvar, interval) == PR_SUCCESS
? NS_OK : NS_ERROR_FAILURE;
}
#else
nsresult Wait(PRIntervalTime interval = PR_INTERVAL_NO_TIMEOUT);
#endif // ifndef DEBUG
/**
* Notify
* @see prcvar.h
**/
nsresult Notify()
{
// NSPR checks for lock ownership
return PR_NotifyCondVar(mCvar) == PR_SUCCESS
? NS_OK : NS_ERROR_FAILURE;
}
/**
* NotifyAll
* @see prcvar.h
**/
nsresult NotifyAll()
{
// NSPR checks for lock ownership
return PR_NotifyAllCondVar(mCvar) == PR_SUCCESS
? NS_OK : NS_ERROR_FAILURE;
}
#ifdef DEBUG
/**
* AssertCurrentThreadOwnsMutex
* @see Mutex::AssertCurrentThreadOwns
**/
void AssertCurrentThreadOwnsMutex()
{
mLock->AssertCurrentThreadOwns();
}
/**
* AssertNotCurrentThreadOwnsMutex
* @see Mutex::AssertNotCurrentThreadOwns
**/
void AssertNotCurrentThreadOwnsMutex()
{
mLock->AssertNotCurrentThreadOwns();
}
#else
void AssertCurrentThreadOwnsMutex()
{
}
void AssertNotCurrentThreadOwnsMutex()
{
}
#endif // ifdef DEBUG
private:
CondVar();
CondVar(CondVar&);
CondVar& operator=(CondVar&);
Mutex* mLock;
PRCondVar* mCvar;
};
} // namespace mozilla
#endif // ifndef mozilla_CondVar_h