std::shared_timed_mutex::unlock

 

C++

Language

Standard library headers

Concepts

Utilities library

Strings library

Containers library

Algorithms library

Iterators library

Numerics library

Input/output library

Localizations library

Regular expressions library (C++11)

Atomic operations library (C++11)

Thread support library (C++11)

 

Thread support library

Threads
thread (C++11)
this_thread namespace
get_id (C++11) yield (C++11)	sleep_for (C++11) sleep_until (C++11)
Mutual exclusion
mutex (C++11) timed_mutex (C++11) shared_timed_mutex (C++14)	recursive_mutex (C++11) recursive_timed_mutex (C++11)
Generic lock management
lock_guard (C++11) unique_lock (C++11) shared_lock (C++14) defer_lock_ttry_to_lock_tadopt_lock_t (C++11)(C++11)(C++11)	lock (C++11) try_lock (C++11) defer_locktry_to_lockadopt_lock (C++11)(C++11)(C++11) once_flag (C++11) call_once (C++11)
Condition variables
condition_variable (C++11)
condition_variable_any (C++11)
notify_all_at_thread_exit (C++11)
cv_status (C++11)
Futures
promise (C++11) future (C++11) shared_future (C++11) packaged_task (C++11) async (C++11)	launch (C++11) future_status (C++11) future_error (C++11) future_category (C++11) future_errc (C++11)

 

std::shared_timed_mutex

Member functions

shared_timed_mutex::shared_timed_mutex

Exclusive locking

shared_timed_mutex::lock

shared_timed_mutex::try_lock

shared_timed_mutex::try_lock_for

shared_timed_mutex::try_lock_until

shared_timed_mutex::unlock

Shared locking

shared_timed_mutex::lock_shared

shared_timed_mutex::try_lock_shared

shared_timed_mutex::try_lock_shared_for

shared_timed_mutex::try_lock_shared_until

shared_timed_mutex::unlock_shared

 

void unlock();		(since C++14)

Unlocks the mutex.

The mutex must be locked by the current thread of execution, otherwise, the behavior is undefined.

This operation synchronizes-with (as defined in std::memory_order) any subsequent lock operation that obtains ownership of the same mutex.

Parameters

(none)

Return value

(none)

Exceptions

(none)

Notes

unlock() is usually not called directly: std::unique_lock and std::lock_guard are used to manage exclusive locking.

Example

This example shows lock, try_lock and unlock in action:

Run this code

#include <iostream>
#include <mutex>
 
int main()
{
    std::mutex test;
    if (test.try_lock()) {
        std::cout << "first try_lock successful\n";
    } else {
        std::cout << "first try_lock NOT successful\n";
        return 0;
    }
 
    test.unlock();
    test.lock();
 
    if (test.try_lock()) {
        std::cout << "second try_lock successful\n";
    } else {
        std::cout << "second try_lock NOT successful\n";
    }
 
    test.lock();  // trying to lock an already-locked std::mutex will 
                  // block program execution, so we'll hang here
}

Possible output:

first try_lock successful
second try_lock NOT successful
(program hangs)

See also

lock	locks the mutex, blocks if the mutex is not available (public member function)
try_lock	tries to lock the mutex, returns if the mutex is not available (public member function)