std::stop_source::request_stop
bool request_stop() noexcept; |
(since C++20) | |
Issues a stop request to the stop-state, if the stop_source
object has a stop-state and it has not yet already had stop requested.
The determination is made atomically, and if stop was requested, the stop-state is atomically updated to avoid race conditions, such that:
- stop_requested() and stop_possible() can be concurrently invoked on other
stop_token
s andstop_source
s of the same stop-state; - request_stop() can be concurrently invoked on other
stop_source
objects, and only one will actually perform the stop request.
However, see the Notes section.
Contents |
[edit] Parameters
(none)
[edit] Return value
true if the stop_source
object has a stop-state and this invocation made a stop request, otherwise false.
[edit] Postconditions
stop_possible() is false or stop_requested() is true.
[edit] Notes
If the request_stop() does issue a stop request (i.e., returns true), then any stop_callback
s registered for the same associated stop-state will be invoked synchronously, on the same thread request_stop() is issued on. If an invocation of a callback exits via an exception, std::terminate is called.
If the stop_source
object has a stop-state but a stop request has already been made, this function returns false. However there is no guarantee that another stop_source
object which has just (successfully) requested stop is not still in the middle of invoking a stop_callback
function.
If the request_stop() does issue a stop request (i.e., returns true), then all condition variables of base type std::condition_variable_any registered with an interruptible wait for stop_token
s associated with the stop_source
's stop-state will be notified.
[edit] Example
This section is incomplete Reason: no example |