std::stop_source::request_stop - cppreference.com (original) (raw)
| 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_tokens andstop_sources of the same stop-state; - request_stop() can be concurrently invoked on other
stop_sourceobjects, and only one will actually perform the stop request.
However, see the Notes section.
[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_callbacks 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_tokens associated with the stop_source's stop-state will be notified.