std::this_thread::yield
From cppreference.com
Defined in header
<thread>
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void yield();
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(since C++11) | |
Provides a hint to the implementation to reschedule the execution of threads, allowing other threads to run.
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[edit] Parameters
(none)
[edit] Return value
(none)
[edit] 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).
[edit] Example
Run this code
#include <iostream> #include <chrono> #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