論理／物理プロセッサコア数の取得

Boost.Thread 1.56.0では、従来からあるシステムの論理プロセッサコア数取得関数に加えて、物理プロセッサコア数取得関数が追加された。

#include <boost/thread.hpp>

int vnum = boost::thread::hardware_concurrency();  // 論理コア数
int pnum = boost::thread::physical_concurrency();  // 物理コア数
// 例：論理8コア/物理4コア環境ならば vnum==8 && pnum==4

unsigned hardware_concurrency() noexecpt;
Returns:
　The number of hardware threads available on the current system (e.g. number of CPUs or cores or hyperthreading units), or 0 if this information is not available.

unsigned physical_concurrency() noexecpt;
Returns:
　The number of physical cores available on the current system. In contrast to hardware_concurrency() it does not return the number of virtual cores, but it counts only physical cores.

Boost.Thread - Thread Management

関連URL

• cppreference thread::hardware_concurrency
• cpprefjp thread::hardware_concurrency