28e2075280
trunk/talk git-svn-id: http://webrtc.googlecode.com/svn/trunk@4318 4adac7df-926f-26a2-2b94-8c16560cd09d
94 lines
2.8 KiB
C++
94 lines
2.8 KiB
C++
/*
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* libjingle
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* Copyright 2011, Google Inc.
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*
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* Redistribution and use in source and binary forms, with or without
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* modification, are permitted provided that the following conditions are met:
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*
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* 1. Redistributions of source code must retain the above copyright notice,
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* this list of conditions and the following disclaimer.
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* 2. Redistributions in binary form must reproduce the above copyright notice,
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* this list of conditions and the following disclaimer in the documentation
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* and/or other materials provided with the distribution.
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* 3. The name of the author may not be used to endorse or promote products
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* derived from this software without specific prior written permission.
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*
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* THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
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* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
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* MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO
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* EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
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* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
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* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
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* OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
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* WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
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* OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
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* ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
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*/
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#ifndef TALK_BASE_SHAREDEXCLUSIVELOCK_H_
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#define TALK_BASE_SHAREDEXCLUSIVELOCK_H_
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#include "talk/base/constructormagic.h"
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#include "talk/base/criticalsection.h"
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#include "talk/base/event.h"
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namespace talk_base {
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// This class provides shared-exclusive lock. It can be used in cases like
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// multiple-readers/single-writer model.
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class SharedExclusiveLock {
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public:
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SharedExclusiveLock();
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// Locking/unlocking methods. It is encouraged to use SharedScope or
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// ExclusiveScope for protection.
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void LockExclusive();
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void UnlockExclusive();
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void LockShared();
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void UnlockShared();
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private:
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talk_base::CriticalSection cs_exclusive_;
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talk_base::CriticalSection cs_shared_;
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talk_base::Event shared_count_is_zero_;
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int shared_count_;
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DISALLOW_COPY_AND_ASSIGN(SharedExclusiveLock);
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};
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class SharedScope {
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public:
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explicit SharedScope(SharedExclusiveLock* lock) : lock_(lock) {
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lock_->LockShared();
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}
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~SharedScope() {
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lock_->UnlockShared();
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}
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private:
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SharedExclusiveLock* lock_;
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DISALLOW_COPY_AND_ASSIGN(SharedScope);
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};
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class ExclusiveScope {
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public:
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explicit ExclusiveScope(SharedExclusiveLock* lock) : lock_(lock) {
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lock_->LockExclusive();
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}
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~ExclusiveScope() {
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lock_->UnlockExclusive();
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}
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private:
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SharedExclusiveLock* lock_;
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DISALLOW_COPY_AND_ASSIGN(ExclusiveScope);
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};
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} // namespace talk_base
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#endif // TALK_BASE_SHAREDEXCLUSIVELOCK_H_
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