New Multi-Threaded Pi Program - Faster than SuperPi and PiFast

[Calmatory]

By performance timers do you mean getting the time delta from the start of the run and the end of the run? If so, don't use ctime/time.h for gathering the elapsed time, it is inaccurate. Instead, you have to use <sys/time.h> in linux to gather the elapsed time.

The way how it works:

#include <iostream>
#include <sys/time.h>


void init_timer(timeval &tv) {
    /* Update tv to the current time */
    gettimeofday(&tv, 0);
};

unsigned int get_time(timeval &start, timeval &end) {
    /* Update end to current time, at this point start should be updated earlier by init_timer() */
    gettimeofday(&end, 0);
    /* Calculate the difference in microseconds(tv_usec) and convert it to milliseconds, do the same to seconds(tv_sec) */
    return (end.tv_usec-start.tv_usec)/1000 + (end.tv_sec-start.tv_sec)*1000;
};

int main() {

    timeval tv_start;
    timeval tv_end;

    init_timer(tv_start);
    /* Do something */
    std::cout << get_time(tv_start, tv_end) << std::endl;
    return 0;
};

timeval structure and gettimeofday(timeval &) gives microsecond accuracy, which is then truncated to milliseconds which should be precise enough. At least has been for my use.

The good thing about sys/time.h is that it is part of C POSIX library, so it should work with any POSIX compicant operating systems.