std::thread::hardware_concurrency (3) - Linux Man Pages

std::thread::hardware_concurrency: std::thread::hardware_concurrency

NAME

std::thread::hardware_concurrency - std::thread::hardware_concurrency

Synopsis


static unsigned int hardware_concurrency() noexcept; (since C++11)


Returns the number of concurrent threads supported by the implementation. The value should be considered only a hint.

Parameters


(none)

Return value


Number of concurrent threads supported. If the value is not well defined or not computable, returns 0.

Example


// Run this code


  #include <iostream>
  #include <thread>


  int main() {
      unsigned int n = std::thread::hardware_concurrency();
      std::cout << n << " concurrent threads are supported.\n";
  }

Possible output:


  4 concurrent threads are supported.

See also


hardware_destructive_interference_size min offset to avoid false sharing
hardware_constructive_interference_size max offset to promote true sharing
                                        (constant)
(C++17)