From cppreference.com
template<classClock,classDuration>booltry_lock_until(conststd::chrono::time_point<Clock,Duration>&timeout_time);(since C++11)Tries to lock the mutex. Blocks until specified timeout_time has been reached (timeout) or the lock is acquired (owns the mutex), whichever comes first. On successful lock acquisition returns true, otherwise returns false.
If timeout_time has already passed, this function behaves like
.
Clock must meet the
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
, 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
operation on the same mutex synchronizes-with (as defined in
) this operation if it returns true.
A thread may call try_lock_until on a recursive mutex repeatedly. Successful calls to try_lock_until increment the ownership count: the mutex will only be released after the thread makes a matching number of calls to
.
The maximum number of levels of ownership is unspecified. A call to try_lock_until will return false if this number is exceeded.
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 timeout_time (clocks, time points, and durations provided by the standard library never throw).
Example
Defect reports
The following behavior-changing defect reports were applied retroactively to previously published C++ standards.
DR Applied to Behavior as published Correct behavior
C++11 try_lock_until threw nothing throws timeout-related exceptions See also
locks the mutex, blocks if the mutex is not available
(public member function)
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
unavailable for the specified timeout duration
(public member function)
unlocks the mutex
(public member function)