C++11中lock_guard和unique_lock的區別
阿新 • • 發佈：2017-08-01
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c++11中有一個區域鎖lock_guard，還有第二個區域鎖unique_lock。
區域鎖lock_guard使用起來比較簡單，除了構造函數外沒有其他member function，在整個區域都有效。
區域鎖unique_guard除了lock_guard的功能外，提供了更多的member_function，相對來說更靈活一些。
unique_guard的最有用的一組函數為：
| lock | locks the associated mutex (public member function) |
| try_lock |
tries to lock the associated mutex, returns if the mutex is not available (public member function) |
| try_lock_for |
attempts to lock the associated TimedLockable mutex,
returns if the mutex has been unavailable for the specified time duration (public member function) |
| try_lock_until |
tries to lock the associated TimedLockable mutex,
returns if the mutex has been unavailable until specified time point has been reached (public member function) |
| unlock | unlocks the associated mutex |
通過上面的函數，可以通過lock/unlock可以比較靈活的控制鎖的範圍，減小鎖的粒度。
通過try_lock_for/try_lock_until則可以控制加鎖的等待時間，此時這種鎖為樂觀鎖。
C++11中lock_guard和unique_lock的區別