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28 #ifndef TALK_BASE_SHAREDEXCLUSIVELOCK_H_
29 #define TALK_BASE_SHAREDEXCLUSIVELOCK_H_
31 #include "talk/base/constructormagic.h"
32 #include "talk/base/criticalsection.h"
33 #include "talk/base/event.h"
37 // This class provides shared-exclusive lock. It can be used in cases like
38 // multiple-readers/single-writer model.
39 class SharedExclusiveLock {
41 SharedExclusiveLock();
43 // Locking/unlocking methods. It is encouraged to use SharedScope or
44 // ExclusiveScope for protection.
46 void UnlockExclusive();
51 talk_base::CriticalSection cs_exclusive_;
52 talk_base::CriticalSection cs_shared_;
53 talk_base::Event shared_count_is_zero_;
56 DISALLOW_COPY_AND_ASSIGN(SharedExclusiveLock);
61 explicit SharedScope(SharedExclusiveLock* lock) : lock_(lock) {
66 lock_->UnlockShared();
70 SharedExclusiveLock* lock_;
72 DISALLOW_COPY_AND_ASSIGN(SharedScope);
75 class ExclusiveScope {
77 explicit ExclusiveScope(SharedExclusiveLock* lock) : lock_(lock) {
78 lock_->LockExclusive();
82 lock_->UnlockExclusive();
86 SharedExclusiveLock* lock_;
88 DISALLOW_COPY_AND_ASSIGN(ExclusiveScope);
91 } // namespace talk_base
93 #endif // TALK_BASE_SHAREDEXCLUSIVELOCK_H_