How Windows programming gets the number of CPUs in the system

With the popularization of multi-core CPUs, it is necessary to consider using multi-core advantages to improve performance. For example, when creating a thread pool or process pool, you can set the thread pool/process pool size according to the number of system CPUs.

The following code example gets the number of CPUs.

typedef void (WINAPI *pgnsi) (lpsystem_info); DWORD getnumberofprocessors () {system_info si;//call Getnativesysteminfo if supported or GetSystemInfo otherwise. Pgnsi Pfngnsi = (pgnsi) GetProcAddress (GetModuleHandle (_t ("kernel32.dll")), "Getnativesysteminfo"); if (Pfngnsi) {pfngnsi (&si);} else {getsysteminfo (&si);} return si.dwnumberofprocessors; }

　 　 [Ctrl + A ALL SELECT hint: You can modify some of the code, and then run]

Source: http://blog.csdn.net/WinGeek/