#include <windows.h>
#include "debug.h"

// this tests the
//  
//  - how often GetTickCount takes steps > 2
//  - how accurate Sleep() is
//       measured using GetTickCount 
//       measured using QueryPerformanceCounter 
//  - how accurate WaitForSingleObject() timeout is
//       measured using GetTickCount 
//       measured using QueryPerformanceCounter 
int WINAPI WinMain( HINSTANCE hInstance,
                   HINSTANCE hPrevInstance,
                   LPTSTR    lpCmdLine,
                   int       nCmdShow)
{
    DebugSetLogfile("tstclock.log");

#define CLEANTICKS 65536
#define SLEEPTICKS 1024
#define SLEEPLOOPS 16
    int i,j;
    DWORD *v= (DWORD*)LocalAlloc(LPTR, (CLEANTICKS+2*SLEEPTICKS*SLEEPLOOPS)*sizeof(DWORD));
    DWORD *p= v;

    DWORD t= GetTickCount();
    DWORD s;
    i=0;
    while (i<5) {
        s= GetTickCount();

        if (s-t>2) {
            debug("%d\n", s-t);
            i++;
            t=GetTickCount();
        }
    }
    *p++= 0;
    for (i=1 ; i<CLEANTICKS ; i++) {
        *p++= GetTickCount();
    }

    for (j=0 ; j<SLEEPLOOPS ; j++) {
        *p++= 0;
        for (i=1 ; i<SLEEPTICKS ; i++) {
            *p++ = GetTickCount();
            Sleep(j);
        }
    }

    HANDLE hEv= CreateEvent(0,0,0,0);
    for (j=0 ; j<SLEEPLOOPS ; j++) {
        *p++= 0;
        for (i=1 ; i<SLEEPTICKS ; i++) {
            *p++ = GetTickCount();
            WaitForSingleObject(hEv, j);
        }
    }
    FILE *f= fopen("timerlog.dat", "w+b");
    if (f) {
        fwrite(v, (CLEANTICKS+2*SLEEPTICKS*SLEEPLOOPS), sizeof(DWORD), f);
    }
    fclose(f);

    // --------------------------------------------------------------------------

    LARGE_INTEGER fq;
    if (!QueryPerformanceFrequency(&fq)) {
        error("QueryPerformanceFrequency");
    }
    debug("pfreq=%08lx%08lx\n", fq.HighPart, fq.LowPart);

    LARGE_INTEGER *w= (LARGE_INTEGER*)LocalAlloc(LPTR, (CLEANTICKS+2*SLEEPTICKS*SLEEPLOOPS)*sizeof(LARGE_INTEGER));
    memset(w, 0, (CLEANTICKS+2*SLEEPTICKS*SLEEPLOOPS)*sizeof(LARGE_INTEGER));
    LARGE_INTEGER *q= w;

    q++;
    for (i=1 ; i<CLEANTICKS ; i++) {
        QueryPerformanceCounter(q++);
    }

    for (j=0 ; j<SLEEPLOOPS ; j++) {
        q++;
        for (i=1 ; i<SLEEPTICKS ; i++) {
            QueryPerformanceCounter(q++);
            Sleep(j);
        }
    }

    for (j=0 ; j<SLEEPLOOPS ; j++) {
        q++;
        for (i=1 ; i<SLEEPTICKS ; i++) {
            QueryPerformanceCounter(q++);
            WaitForSingleObject(hEv, j);
        }
    }
    f= fopen("wtimerlog.dat", "w+b");
    if (f) {
        fwrite(w, (CLEANTICKS+2*SLEEPTICKS*SLEEPLOOPS), sizeof(LARGE_INTEGER), f);
    }
    fclose(f);

    return 0;
}