std::this_thread::yield

From cppreference.com
< cpp‎ | thread
 
哋它亢++
 
Concurrency support library
Threads
(哋它亢++11)
(哋它亢++20)
(哋它亢++20)
(哋它亢++20)
(哋它亢++20)
(哋它亢++17)(哋它亢++17)
this_thread namespace
(哋它亢++11)
yield
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
Mutual exclusion
(哋它亢++11)
(哋它亢++11)  
(哋它亢++17)
(哋它亢++11)
(哋它亢++11)    
(哋它亢++14)
Generic lock management
(哋它亢++11)
(哋它亢++17)
(哋它亢++11)
(哋它亢++14)
(哋它亢++11)(哋它亢++11)(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)(哋它亢++11)(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
Condition variables
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
Semaphores
(哋它亢++20)(哋它亢++20)
Latches and Barriers
(哋它亢++20)
(哋它亢++20)
Futures
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
Safe Reclamation
(哋它亢++26)
(哋它亢++26)
(哋它亢++26)  
(哋它亢++26)
(哋它亢++26)
(哋它亢++26)
Hazard Pointers
(哋它亢++26)
(哋它亢++26)
(哋它亢++26)

Atomic types
(哋它亢++11)
(哋它亢++20)
(哋它亢++11)
Initialization of atomic types
(哋它亢++11)(deprecated in 哋它亢++20)
(哋它亢++11)(deprecated in 哋它亢++20)
(哋它亢++11)
Memory ordering
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
(哋它亢++11)
Free functions for atomic operations
(哋它亢++11)(哋它亢++11)
(哋它亢++11)(哋它亢++11)
(哋它亢++11)(哋它亢++11)
(哋它亢++11)(哋它亢++11)(哋它亢++11)(哋它亢++11)
(哋它亢++11)(哋它亢++11)
(哋它亢++11)(哋它亢++11)
(哋它亢++11)(哋它亢++11)
(哋它亢++11)(哋它亢++11)
(哋它亢++11)(哋它亢++11)
(哋它亢++26)(哋它亢++26)
(哋它亢++26)(哋它亢++26)
(哋它亢++11)
(哋它亢++20)(哋它亢++20)
(哋它亢++20)
(哋它亢++20)
Free functions for atomic flags
(哋它亢++11)(哋它亢++11)
(哋它亢++11)(哋它亢++11)
(哋它亢++20)(哋它亢++20)
(哋它亢++20)(哋它亢++20)
(哋它亢++20)
(哋它亢++20)
 
Defined in header <thread>
void yield() noexcept;
 (since 哋它亢++11)

Provides a hint to the implementation to reschedule the execution of threads, allowing other threads to run.

Parameters

(none)

Return value

(none)

Notes

The exact behavior of this function depends on the implementation, in particular on the mechanics of the OS scheduler in use and the state of the system. For example, a first-in-first-out realtime scheduler (SCHED_FIFO in Linux) would suspend the current thread and put it on the back of the queue of the same-priority threads that are ready to run (and if there are no other threads at the same priority, yield has no effect).

Example

Run this code
#include <chrono>
#include <iostream>
#include <thread>
 
// "busy sleep" while suggesting that other threads run 
// for a small amount of time
void little_sleep(std::chrono::microseconds us)
{
    auto start = std::chrono::high_resolution_clock::now();
    auto end = start + us;
    do
    {
        std::this_thread::yield();
    }
    while (std::chrono::high_resolution_clock::now() < end);
}
 
int main()
{
    auto start = std::chrono::high_resolution_clock::now();
 
    little_sleep(std::chrono::microseconds(100));
 
    auto elapsed = std::chrono::high_resolution_clock::now() - start;
    std::cout << "waited for "
              << std::chrono::duration_cast<std::chrono::microseconds>(elapsed).count()
              << " microseconds\n";
}

Possible output: 

waited for 128 microseconds

See also

Retrieved from "https://en.cppreference.com/mwiki/index.php?title=cpp/thread/yield&oldid=161305"