stopping usleep function

allomeen · 12-19-2005, 05:33 PM

Hello everyone,
How can i stop the usleep function from sleeping but continue the program after that? What signal should I send?
for example:
while(1)
{
//code
...
usleep(X millisecons);
//code
...
}

the while loop is running on a thread. How can I stop the usleep() from the main thread or anywhere else and continue my code?

Thanks,
Al

FLLinux · 12-19-2005, 05:47 PM

Why is the thread using usleep? If it is waiting on something it might be good to use a semaphore or mutex to block the one thread and then signal it to run again.

paulsm4 · 12-19-2005, 05:58 PM

I totally agree with FLLinux.

ANYTIME you hear the word "sleep", it should generally raise yellow flags that maybe you've got a design flaw. A serious design flaw.

NEVER use a "sleep and check" polling loop, if you can simply block instead.

Polling is Bad; Blocking is Good...

Honest...

Hko · 12-19-2005, 06:20 PM

Quote:

How can i stop the usleep function from sleeping but continue the program after that? What signal should I send?

I mostly agree with the above postings. But there can be valid reasons to sleep (e.g. if it's not for polling).

So to answer the question: any signal that can be catched.

Just register a do-nothing signal-handler for the signal of your choice using sigaction(2). then when your thread has catched the signal, usleep() will return -1 with errno set to EINTR.

allomeen · 12-19-2005, 07:23 PM

Thank you guys. sigaction is what i need...