76 lines
2.0 KiB
C
76 lines
2.0 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 LOCKABLE SharedExclusiveLock {
|
||
|
|
public:
|
||
|
|
SharedExclusiveLock();
|
||
|
|
|
||
|
|
// Locking/unlocking methods. It is encouraged to use SharedScope or
|
||
|
|
// ExclusiveScope for protection.
|
||
|
|
void LockExclusive() EXCLUSIVE_LOCK_FUNCTION();
|
||
|
|
void UnlockExclusive() UNLOCK_FUNCTION();
|
||
|
|
void LockShared();
|
||
|
|
void UnlockShared();
|
||
|
|
|
||
|
|
private:
|
||
|
|
rtc::CriticalSection cs_exclusive_;
|
||
|
|
rtc::CriticalSection cs_shared_;
|
||
|
|
rtc::Event shared_count_is_zero_;
|
||
|
|
int shared_count_;
|
||
|
|
|
||
|
|
RTC_DISALLOW_COPY_AND_ASSIGN(SharedExclusiveLock);
|
||
|
|
};
|
||
|
|
|
||
|
|
class SCOPED_LOCKABLE SharedScope {
|
||
|
|
public:
|
||
|
|
explicit SharedScope(SharedExclusiveLock* lock) SHARED_LOCK_FUNCTION(lock)
|
||
|
|
: lock_(lock) {
|
||
|
|
lock_->LockShared();
|
||
|
|
}
|
||
|
|
|
||
|
|
~SharedScope() UNLOCK_FUNCTION() { lock_->UnlockShared(); }
|
||
|
|
|
||
|
|
private:
|
||
|
|
SharedExclusiveLock* lock_;
|
||
|
|
|
||
|
|
RTC_DISALLOW_COPY_AND_ASSIGN(SharedScope);
|
||
|
|
};
|
||
|
|
|
||
|
|
class SCOPED_LOCKABLE ExclusiveScope {
|
||
|
|
public:
|
||
|
|
explicit ExclusiveScope(SharedExclusiveLock* lock)
|
||
|
|
EXCLUSIVE_LOCK_FUNCTION(lock)
|
||
|
|
: lock_(lock) {
|
||
|
|
lock_->LockExclusive();
|
||
|
|
}
|
||
|
|
|
||
|
|
~ExclusiveScope() UNLOCK_FUNCTION() { lock_->UnlockExclusive(); }
|
||
|
|
|
||
|
|
private:
|
||
|
|
SharedExclusiveLock* lock_;
|
||
|
|
|
||
|
|
RTC_DISALLOW_COPY_AND_ASSIGN(ExclusiveScope);
|
||
|
|
};
|
||
|
|
|
||
|
|
} // namespace rtc
|
||
|
|
|
||
|
|
#endif // WEBRTC_BASE_SHAREDEXCLUSIVELOCK_H_
|