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std::stop_source(3) C++ Standard Libary std::stop_source(3)


std::stop_source - std::stop_source


Defined in header <stop_token>
class stop_source; (since C++20)

The stop_source class provides the means to issue a stop request, such as for
std::jthread cancellation. A stop request made for one stop_source object is visible
to all stop_sources and std::stop_tokens of the same associated stop-state; any
std::stop_callback(s) registered for associated std::stop_token(s) will be invoked,
and any std::condition_variable_any objects waiting on associated std::stop_token(s)
will be awoken.

Once a stop is requested, it cannot be withdrawn. Additional stop requests have no

Member functions

constructor constructs new stop_source object
(public member function)
destructor destructs the stop_source object
(public member function)
operator= assigns the stop_source object
(public member function)


request_stop makes a stop request for the associated stop-state, if any
(public member function)
swap swaps two stop_source objects
(public member function)


get_token returns a stop_token for the associated stop-state
(public member function)
stop_requested checks whether the associated stop-state has been requested to stop
(public member function)
stop_possible checks whether associated stop-state can be requested to stop
(public member function)

Non-member functions

operator== compares two std::stop_source objects
swap(std::stop_source) specializes the std::swap algorithm
(C++20) (function)

Helper constants

nostopstate a std::nostopstate_t instance for use in stop_source constructor
(C++20) (constant)

Helper classes

nostopstate_t placeholder type for use in stop_source constructor
(C++20) (class)


For the purposes of std::jthread cancellation the stop_source object should be
retrieved from the std::jthread object using get_stop_source(); or stop should be
requested directly from the std::jthread object using request_stop(). This will then
use the same associated stop-state as that passed into the std::jthread's invoked
function argument (i.e., the function being executed on its thread).

For other uses, however, a stop_source can be constructed separately using the
default constructor, which creates new stop-state.

Feature-test macro: __cpp_lib_jthread


This section is incomplete
Reason: no example