시간측정 :: sysconf, times

실행시간 측정방법 (POSIX)

#include <unistd.h>
#include <sys/times.h>

timeMeasure()
{
    double ticksPerSec, diff;
    struct tms start, end;
    clock_t startTick, endTick, userTicks, systemTicks;;

    ticksPerSec = (double)sysconf(_SC_CLK_TCK);

    startTick = times(&start);

    funcToBeTested();

    endTick = times(&end);

    userTicks = end.tms_utime - start.tms_utime;
    systemTicks = end.tms_stime - start.tms_stime;

    diff = (double)userTicks / ticksPerSec;
    printf("user mode CPU time : %f\n", diff);

    diff = (double)systemTicks / ticksPerSec;
    printf("system mode CPU time : %f\n", diff);

    diff = (double)(endTick - startTick) / ticksPerSec;
    printf("elapsed real-world time : %f\n", diff);
}