std::jthread::get_stop_source

 

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std::jthread

Member functions

jthread::jthread

jthread::~jthread

jthread::operator=

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jthread::joinable

jthread::get_id

jthread::native_handle

jthread::hardware_concurrency

Operations

jthread::join

jthread::detach

jthread::swap

Stop token handling

jthread::get_stop_source

jthread::get_stop_token

jthread::request_stop

Non-member functions

swap(std::jthread)

 

std::stop_source get_stop_source() noexcept;		(since C++20)

Returns a std::stop_source associated with the same shared stop-state as held internally by the jthread object.

Parameters

(none)

Return value

A value of type std::stop_source associated with stop-state held internally by jthread object.

Example

Run this code

#include <chrono>
#include <condition_variable>
#include <iostream>
#include <mutex>
#include <string_view>
#include <thread>
 
using namespace std::chrono_literals;
 
int main()
{
    std::cout << std::boolalpha;
    auto print = [](std::string_view name, const std::stop_source& source)
    {
        std::cout << name << ": stop_possible = " << source.stop_possible();
        std::cout << ", stop_requested = " << source.stop_requested() << '\n';
    };
 
    // A worker thread
    auto 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";
        }
    });
 
    std::stop_source stop_source = worker.get_stop_source();
    print("stop_source", stop_source);
 
    std::cout << "\nPass source to other thread:\n";
    auto stopper = std::thread(
        [](std::stop_source source)
        {
            std::this_thread::sleep_for(500ms);
            std::cout << "Request stop for worker via source\n";
            source.request_stop();
        },
        stop_source);
    stopper.join();
    std::this_thread::sleep_for(200ms);
    std::cout << '\n';
 
    print("stop_source", stop_source);
}

Possible output:

stop_source: stop_possible = true, stop_requested = false
 
Pass source to other thread:
  Sleepy worker goes back to sleep
Request stop for worker via source
  Sleepy worker is requested to stop
 
stop_source: stop_possible = true, stop_requested = true