How to create a high resolution timer in Linux to

Question

I'm trying to compare GPU to CPU performance. For the NVIDIA GPU I've been using the cudaEvent_t types to get a very precise timing.

For the CPU I've been using the following code:

// Timers
clock_t start, stop;
float elapsedTime = 0;

// Capture the start time

start = clock();

// Do something here
.......

// Capture the stop time
stop = clock();
// Retrieve time elapsed in milliseconds
elapsedTime = (float)(stop - start) / (float)CLOCKS_PER_SEC * 1000.0f;

Apparently, that piece of code is only good if you're counting in seconds. Also, the results sometime come out quite strange.

Does anyone know of some way to create a high resolution timer in Linux?

Answer 1

epoll implemention: https://github.com/ielife/simple-timer-for-c-language

use like this:

timer_server_handle_t *timer_handle = timer_server_init(1024);
if (NULL == timer_handle) {
    fprintf(stderr, "timer_server_init failed\n");
    return -1;
}
ctimer timer1;
    timer1.count_ = 3;
    timer1.timer_internal_ = 0.5;
    timer1.timer_cb_ = timer_cb1;
    int *user_data1 = (int *)malloc(sizeof(int));
    *user_data1 = 100;
    timer1.user_data_ = user_data1;
    timer_server_addtimer(timer_handle, &timer1);

    ctimer timer2;
    timer2.count_ = -1;
    timer2.timer_internal_ = 0.5;
    timer2.timer_cb_ = timer_cb2;
    int *user_data2 = (int *)malloc(sizeof(int));
    *user_data2 = 10;
    timer2.user_data_ = user_data2;
    timer_server_addtimer(timer_handle, &timer2);

    sleep(10);

    timer_server_deltimer(timer_handle, timer1.fd);
    timer_server_deltimer(timer_handle, timer2.fd);
    timer_server_uninit(timer_handle);