Files
platform-external-webrtc/webrtc/base/sharedexclusivelock.h
henrike@webrtc.org f048872e91 Adds a modified copy of talk/base to webrtc/base. It is the first step in
migrating talk/base to webrtc/base.

BUG=N/A
R=niklas.enbom@webrtc.org

Review URL: https://webrtc-codereview.appspot.com/17479005

git-svn-id: http://webrtc.googlecode.com/svn/trunk@6129 4adac7df-926f-26a2-2b94-8c16560cd09d
2014-05-13 18:00:26 +00:00

77 lines
1.8 KiB
C++

/*
* Copyright 2011 The WebRTC Project Authors. All rights reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be found
* in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#ifndef WEBRTC_BASE_SHAREDEXCLUSIVELOCK_H_
#define WEBRTC_BASE_SHAREDEXCLUSIVELOCK_H_
#include "webrtc/base/constructormagic.h"
#include "webrtc/base/criticalsection.h"
#include "webrtc/base/event.h"
namespace rtc {
// This class provides shared-exclusive lock. It can be used in cases like
// multiple-readers/single-writer model.
class SharedExclusiveLock {
public:
SharedExclusiveLock();
// Locking/unlocking methods. It is encouraged to use SharedScope or
// ExclusiveScope for protection.
void LockExclusive();
void UnlockExclusive();
void LockShared();
void UnlockShared();
private:
rtc::CriticalSection cs_exclusive_;
rtc::CriticalSection cs_shared_;
rtc::Event shared_count_is_zero_;
int shared_count_;
DISALLOW_COPY_AND_ASSIGN(SharedExclusiveLock);
};
class SharedScope {
public:
explicit SharedScope(SharedExclusiveLock* lock) : lock_(lock) {
lock_->LockShared();
}
~SharedScope() {
lock_->UnlockShared();
}
private:
SharedExclusiveLock* lock_;
DISALLOW_COPY_AND_ASSIGN(SharedScope);
};
class ExclusiveScope {
public:
explicit ExclusiveScope(SharedExclusiveLock* lock) : lock_(lock) {
lock_->LockExclusive();
}
~ExclusiveScope() {
lock_->UnlockExclusive();
}
private:
SharedExclusiveLock* lock_;
DISALLOW_COPY_AND_ASSIGN(ExclusiveScope);
};
} // namespace rtc
#endif // WEBRTC_BASE_SHAREDEXCLUSIVELOCK_H_