This code snippet is about asking Windows for the highest possible execution priority. Basically, we have to ask for real-time priority class for the entire process, after which each thread has to ask for real-time thread priorities. However, since Windows Vista, whatever is the program that needs the real-time priority, it must be asked to be run in administrator privilege level.The demonstration program I provide simply loops for 7 seconds. During that period, your system should be frozen (try pressing Caps Lock; should not switch the Caps Lock light). Also, if you put on some audio, the sound card will repeat its contents of the sound buffer over and over again.rtprio.h:#pragma once#include <Windows.h>BOOL RealTimePriorityClass(){    return SetPriorityClass(GetCurrentProcess(), REALTIME_PRIORITY_CLASS);}BOOL RealTimeThreadPriority(){    return SetThreadPriority(GetCurrentThread(), THREAD_PRIORITY_TIME_CRITICAL);}main.cpp:#include <windows.h>#include rtprio.hstatic const DWORD dwInterval = 7000; // millseconds.DWORD WINAPI ThreadProc(LPVOID lpParams);int WINAPI WinMain(HINSTANCE hInst,    HINSTANCE hPrev,    LPSTR lpCmdLine,    int nShowCmd){    DWORD       i;    DWORD       dwInitTicks;    DWORD       dwCores;    SYSTEM_INFO sysInfo;    GetSystemInfo(&sysInfo);    dwCores = sysInfo.dwNumberOfProcessors;    // Ask real-time priority class for the entire process.    RealTimePriorityClass();    for (i = 0; i < dwCores - 1; i++)    {        CreateThread(NULL,                     0,                     ThreadProc,                     NULL,                     0,                     NULL);    }    RealTimeThreadPriority();    dwInitTicks = GetTickCount();    while (GetTickCount() - dwInitTicks < dwInterval);    return 0;}DWORD WINAPI ThreadProc(LPVOID lpParams){    // Ask for real-time priority for this thread.    RealTimeThreadPriority();    // Freeze the system for dwInterval milliseconds.    while (TRUE) {}    return 0;}
Asking Windows for real-time priority
c++;windows;winapi