NAME¶

std::shared_timed_mutex::try_lock_until - std::shared_timed_mutex::try_lock_until

Synopsis¶

template< class Clock, class Duration >
bool try_lock_until( const std::chrono::time_point<Clock,Duration>& (since C++14)
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 programs 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, but might not, be less or more 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 for longer than until after
timeout_time has been reached due to 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¶

timeout_time - maximum time point to block until

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¶

This example shows a 10 seconds block

// Run this code

#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¶

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)
tries to lock the mutex, returns if the mutex has been
try_lock_for unavailable for the specified timeout duration
(public member function)
unlock unlocks the mutex
(public member function)