gecko/ipc/glue/CrossProcessMutex_windows.cpp

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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* ***** 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 Corporation code.
*
* The Initial Developer of the Original Code is Mozilla Foundation.
* Portions created by the Initial Developer are Copyright (C) 2011
* the Initial Developer. All Rights Reserved.
*
* Contributor(s):
* Bas Schouten <bschouten@mozilla.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 ***** */
#include <windows.h>
#include "base/process_util.h"
#include "CrossProcessMutex.h"
#include "nsDebug.h"
#include "nsTraceRefcnt.h"
using namespace base;
namespace mozilla {
CrossProcessMutex::CrossProcessMutex(const char*)
{
// We explicitly share this using DuplicateHandle, we do -not- want this to
// be inherited by child processes by default! So no security attributes are
// given.
mMutex = ::CreateMutexA(NULL, FALSE, NULL);
if (!mMutex) {
NS_RUNTIMEABORT("This shouldn't happen - failed to create mutex!");
}
MOZ_COUNT_CTOR(CrossProcessMutex);
}
CrossProcessMutex::CrossProcessMutex(CrossProcessMutexHandle aHandle)
{
DWORD flags;
if (!::GetHandleInformation(aHandle, &flags)) {
NS_RUNTIMEABORT("Attempt to construct a mutex from an invalid handle!");
}
mMutex = aHandle;
}
CrossProcessMutex::~CrossProcessMutex()
{
NS_ASSERTION(mMutex, "Improper construction of mutex or double free.");
::CloseHandle(mMutex);
MOZ_COUNT_DTOR(CrossProcessMutex);
}
void
CrossProcessMutex::Lock()
{
NS_ASSERTION(mMutex, "Improper construction of mutex.");
::WaitForSingleObject(mMutex, INFINITE);
}
void
CrossProcessMutex::Unlock()
{
NS_ASSERTION(mMutex, "Improper construction of mutex.");
::ReleaseMutex(mMutex);
}
CrossProcessMutexHandle
CrossProcessMutex::ShareToProcess(ProcessHandle aHandle)
{
HANDLE newHandle;
bool succeeded = ::DuplicateHandle(GetCurrentProcessHandle(),
mMutex, aHandle, &newHandle,
NULL, FALSE, DUPLICATE_SAME_ACCESS);
if (!succeeded) {
return NULL;
}
return newHandle;
}
}