std::shared_timed_mutex::try_lock_until

template< class Clock, class Duration >
bool try_lock_until( const std::chrono::time_point<Clock,Duration>& timeout_time );

Tries to lock the mutex. Blocks until specified timeout_time has been reached or the lock is acquired, whichever comes first. On successful lock acquisition returns true, otherwise returns false.

If timeout_time has already passed, this function behaves like try_lock().

Clock must meet the Clock requirements. The program is ill-formed if std::chrono::is_clock_v<Clock> is false (since C++20).

The standard recommends that the clock tied to timeout_time be used, in which case adjustments of the clock may be taken into account. Thus, the duration of the block might be more or less than timeout_time - Clock::now() at the time of the call, depending on the direction of the adjustment and whether it is honored by the implementation. The function also may block until after timeout_time has been reached due to process scheduling or resource contention delays.

As with try_lock(), this function is allowed to fail spuriously and return false even if the mutex was not locked by any other thread at some point before timeout_time.

Prior unlock() operation on the same mutex synchronizes-with (as defined in std::memory_order) this operation if it returns true.

If try_lock_until is called by a thread that already owns the mutex in any mode (shared or exclusive), the behavior is undefined.

Parameters

Return value

true if the lock was acquired successfully, otherwise false.

Exceptions

Any exception thrown by clock, time_point, or duration during the execution (clocks, time points, and durations provided by the standard library never throw).

Example

#include <thread>
#include <iostream>
#include <chrono>
#include <mutex>
 
std::shared_timed_mutex test_mutex;
 
void f()
{
    auto now=std::chrono::steady_clock::now();
    test_mutex.try_lock_until(now + std::chrono::seconds(10));
    std::cout << "hello world\n";
}
 
int main()
{
    std::lock_guard<std::shared_timed_mutex> l(test_mutex);
    std::thread t(f);
    t.join();
}

See also