Subj : Re: nptl and signals
To   : comp.programming.threads
From : Christian Parpart
Date : Tue Aug 23 2005 10:01 am

divijbhatt@gmail.com wrote:

> Hi,
>    I want to know that how can I set the timer on a per thread basis in
> POSIX threads (NPTL) Linux.

to setup the timer, do:

#include <singal.h>
#include <time.h>
#include <string.h>
#include <errno.h>

timer_t handle;

struct sigevent ev;
ev.sigev_value.sival_ptr = your.private.ptr;
ev.sigev_signo = 0;
ev.sigev_notify = SIGEV_THREAD; /* for threaded timer notification */
ev.sigev_notify_function = &timerNotify;
ev.sigev_notify_attributes = 0;

if (timer_create(CLOCK_REALTIME, &ev, &handle) != -1) {
    struct itimerspec it;
    /* first notify comes within 1 seconds */
    it.it_value.tv_sec = 1;
    it.it_value.tv_nsec = 0;
    /* each further notify has the same timespan */
    it.it_interval.tv_sec = it.it_value.tv_sec;
    it.it_interval.tv_nsec = it.it_value.tv_nsec;

    if (timer_settime(handle, 0, &it, 0) != -1)
        fprintf(stderr, "Timer initialized\n");
    else
        fprintf(stderr, "timer_settime: %s\n", strerror(errno));
} else
    fprintf(stderr, "timer_create: %s\n", strerror(errno));

your timerNotify could look like:

void timerNotify(sigval_t ASignalValue) {
    fprintf(stderr, "Blah!\n");
}

to stop the timer, do:

timer_delete(handle);
handle = 0;

.