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clock_nanosleep避免过度睡眠
/*
* “oversleeping” problem is particularly marked for a process that uses a loop to re start
* a sleep that is interrupted by a signal handler. If signals are delivered at a high rate
* , then a relative sleep (of the type performed by nanosleep()) can lead to large inaccuracies
* in the time a process spends sleeping. We can avoid the oversleeping problem by making an
* initial call to clock_gettime() to retrieve the time, adding the desired amount to that time,
* and then calling clock_nanosleep() with the TIMER_ABSTIME flag (and restarting the system
* call if it is interrupted by a signal handler).
*/
struct timespec request;
/* Retrieve current value of CLOCK_REALTIME clock */
if (clock_gettime(CLOCK_REALTIME, &request) == -1)
errExit("clock_gettime");
request.tv_sec += 20; /* Sleep for 20 seconds from now */
s = clock_nanosleep(CLOCK_REALTIME, TIMER_ABSTIME, &request, NULL);
if (s != 0) {
if (s == EINTR)
printf("Interrupted by signal handler\n");
else
errExitEN(s, "clock_nanosleep");
}
最后更新：2017-04-03 12:55:25