std::counting_semaphore<LeastMaxValue>:: try_acquire_until
|
|
|||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Member functions | ||||
| Operations | ||||
|
counting_semaphore::try_acquire_until
|
||||
| Constants | ||||
|
template
<
class
Clock,
class
Duration
>
bool try_acquire_until ( const std:: chrono :: time_point < Clock, Duration > & abs_time ) ; |
(since C++20) | |
Tries to atomically decrement the internal counter by 1 if it is greater than 0 ; otherwise blocks until it is greater than 0 and can successfully decrement the internal counter, or the abs_time time point has been passed.
The programs is ill-formed if std:: chrono :: is_clock_v < Clock > is false .
Preconditions
Clock
meets the
Clock
requirements.
Parameters
| abs_time | - | the earliest time the function must wait until in order to fail |
Return value
true if it decremented the internal counter, otherwise false .
Exceptions
May throw std::system_error or a timeout-related exception.
Notes
In practice the function may take longer than abs_time to fail.
See also
|
increments the internal counter and unblocks acquirers
(public member function) |
|
|
decrements the internal counter or blocks until it can
(public member function) |
|
|
tries to decrement the internal counter without blocking
(public member function) |
|
|
tries to decrement the internal counter, blocking for up to a duration time
(public member function) |