|
| |||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||||
| Member functions | ||||
| Modifiers | ||||
| Observers | ||||
stop_token::stop_requested | ||||
| Non-member functions | ||||
bool stop_requested()constnoexcept; | (since C++20) | |
Checks if thestop_token object has associated stop-state and that state has received a stop request. A default constructedstop_token has no associated stop-state, and thus has not had stop requested.
(none)
true if thestop_token object has associated stop-state and it received a stop request,false otherwise.
#include <chrono>#include <condition_variable>#include <iostream>#include <mutex>#include <string_view>#include <thread>usingnamespace std::chrono_literals; int main(){std::cout<<std::boolalpha;auto print=[](std::string_view name,conststd::stop_token& token){std::cout<< name<<": stop_possible = "<< token.stop_possible();std::cout<<", stop_requested = "<< token.stop_requested()<<'\n';}; // A worker thread that will listen to stop requestsauto stop_worker=std::jthread([](std::stop_token stoken){for(int i=10; i;--i){std::this_thread::sleep_for(300ms);if(stoken.stop_requested()){std::cout<<" Sleepy worker is requested to stop\n";return;}std::cout<<" Sleepy worker goes back to sleep\n";}}); // A worker thread that will only stop when completedauto inf_worker=std::jthread([](){for(int i=5; i;--i){std::this_thread::sleep_for(300ms);std::cout<<" Run as long as we want\n";}}); std::stop_token def_token;std::stop_token stop_token= stop_worker.get_stop_token();std::stop_token inf_token= inf_worker.get_stop_token(); print("def_token ", def_token); print("stop_token", stop_token); print("inf_token ", inf_token); std::cout<<"\nRequest and join stop_worker:\n"; stop_worker.request_stop(); stop_worker.join(); std::cout<<"\nRequest and join inf_worker:\n"; inf_worker.request_stop(); inf_worker.join();std::cout<<'\n'; print("def_token ", def_token); print("stop_token", stop_token); print("inf_token ", inf_token);}
Possible output:
def_token : stop_possible = false, stop_requested = falsestop_token: stop_possible = true, stop_requested = falseinf_token : stop_possible = true, stop_requested = false Request and join stop_worker: Run as long as we want Sleepy worker is requested to stop Request and join inf_worker: Run as long as we want Run as long as we want Run as long as we want Run as long as we want def_token : stop_possible = false, stop_requested = falsestop_token: stop_possible = true, stop_requested = trueinf_token : stop_possible = true, stop_requested = true