std::condition_variable_any
| Defined in header
<condition_variable>
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| class condition_variable_any;
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(since C++11) | |
The condition_variable_any class is a generalization of std::condition_variable. Whereas std::condition_variable works only on std::unique_lock<std::mutex>, condition_variable_any can operate on any user-defined lock that meets the BasicLockable requirements.
condition_variable_any provides similar functionality to std::condition_variable. It is a synchronization primitive that can be used to block some number of threads until:
- a notification is received from another thread
- a timeout expires, or
- a spurious wakeup occurs
Any thread that intends to wait on std::condition_variable_any has to acquire a lock first. The wait operations atomically release the lock and suspend the execution of the thread. When the condition variable is notified, the thread is awakened, and the lock is reacquired.
The class std::condition_variable_any is a standard-layout class. It is not copy-constructible, move-constructible, copy-assignable, or move-assignable.
If the lock is std::unique_lock, std::condition_variable may provide better performance.
Contents |
[edit] Member functions
| constructs the object (public member function) |
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| destructs the object (public member function) |
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| operator=
[deleted]
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not copy-assignable (public member function) |
Notification |
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| notifies one waiting thread (public member function) |
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| notifies all waiting threads (public member function) |
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Waiting |
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| blocks the current thread until the condition variable is woken up (public member function) |
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| blocks the current thread until the condition variable is woken up or after the specified timeout duration (public member function) |
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| blocks the current thread until the condition variable is woken up or until specified time point has been reached (public member function) |
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[edit] Notes
A possible use for std::condition_variable_any with custom Lockable types is to provide convenient interruptible waits: the custom lock operation would both lock the associated mutex as expected, and also perform the necessary setup to notify this condition variable when the interrupting signal is received.[1]
[edit] References
- ↑ A. Williams (2012), "C++ concurrency in action" 9.2.4 Interupting a wait on std::condition_variable_any