linux使用定时器回调函数示例

liunx使用setitimer（）函数设置定时器，一定间隔后触发回调函数。

#include 
#include 
#include 
#include 
#include 
#include 

void timer_handler (int signum)
{
    printf("trigger...\n");
}

int main ()
{
    printf("ok");
    struct sigaction sa;
    struct itimerval timer;

    /* Install timer_handler as the signal handler for SIGVTALRM. */
    memset(&sa, 0, sizeof (sa));
    sa.sa_handler = &timer_handler;
    sigaction (SIGVTALRM, &sa, NULL);

    /* Configure the timer to expire after 100 msec... */
    timer.it_value.tv_sec = 0;
    timer.it_value.tv_usec = 100000;
    /* ... and every 100 msec after that. */
    timer.it_interval.tv_sec = 0;
    timer.it_interval.tv_usec = 100000;
    /* Start a virtual timer. It counts down whenever this process is
    executing. */

    setitimer (ITIMER_VIRTUAL, &timer, NULL);

    /* Do busy work. */
    while(1)
    {
    }
    return 0;
}