std::jthread::get_stop_source

 

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Concurrency support library

Threads thread (C++11) jthread (C++20) stop_token (C++20) stop_source (C++20) stop_callback (C++20) hardware_destructive_interference_sizehardware_constructive_interference_size (C++17)(C++17)     this_thread namespace get_id (C++11) yield (C++11) sleep_for (C++11) sleep_until (C++11) Atomic types atomic (C++11) atomic_ref (C++20) atomic_flag (C++11) Initialization of atomic types atomic_init (C++11)(deprecated in C++20) ATOMIC_VAR_INIT (C++11)(deprecated in C++20) ATOMIC_FLAG_INIT (C++11) Free functions for atomic operations atomic_storeatomic_store_explicit (C++11)(C++11) atomic_loadatomic_load_explicit (C++11)(C++11) atomic_exchangeatomic_exchange_explicit (C++11)(C++11) atomic_compare_exchange_weakatomic_compare_exchange_weak_explicitatomic_compare_exchange_strongatomic_compare_exchange_strong_explicit (C++11)(C++11)(C++11)(C++11) atomic_fetch_addatomic_fetch_add_explicit (C++11)(C++11) atomic_fetch_subatomic_fetch_sub_explicit (C++11)(C++11) atomic_fetch_andatomic_fetch_and_explicit (C++11)(C++11) atomic_fetch_oratomic_fetch_or_explicit (C++11)(C++11) atomic_fetch_xoratomic_fetch_xor_explicit (C++11)(C++11) atomic_is_lock_free (C++11) atomic_waitatomic_wait_explicit (C++20)(C++20) atomic_notify_one (C++20) atomic_notify_all (C++20)

Free functions for atomic flags atomic_flag_test_and_setatomic_flag_test_and_set_explicit (C++11)(C++11) atomic_flag_clearatomic_flag_clear_explicit (C++11)(C++11) atomic_flag_testatomic_flag_test_explicit (C++20)(C++20) atomic_flag_waitatomic_flag_wait_explicit (C++20)(C++20) atomic_flag_notify_one (C++20) atomic_flag_notify_all (C++20) Memory ordering memory_order (C++11) kill_dependency (C++11) atomic_thread_fence (C++11) atomic_signal_fence (C++11) Mutual exclusion mutex (C++11) recursive_mutex (C++11) shared_mutex (C++17) timed_mutex (C++11) recursive_timed_mutex (C++11) shared_timed_mutex (C++14) Generic lock management lock_guard (C++11) scoped_lock (C++17) unique_lock (C++11) shared_lock (C++14) defer_lock_ttry_to_lock_tadopt_lock_t (C++11)(C++11)(C++11) lock (C++11) try_lock (C++11) defer_locktry_to_lockadopt_lock (C++11)(C++11)(C++11) once_flag (C++11) call_once (C++11) Condition variables condition_variable (C++11) condition_variable_any (C++11) notify_all_at_thread_exit (C++11) cv_status (C++11) Semaphores counting_semaphorebinary_semaphore (C++20)(C++20) Latches and barriers latch (C++20) barrier (C++20) Futures promise (C++11) future (C++11) shared_future (C++11) packaged_task (C++11) async (C++11) launch (C++11) future_status (C++11) future_error (C++11) future_category (C++11) future_errc (C++11)

 

std::jthread

Member functions

jthread::jthread

jthread::~jthread

jthread::operator=

Observers

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