[ale] Mixing Alarm and Sleep

[Kevin J. Schmidt]

>From the sleep man page:

BUGS
       sleep() may be implemented using SIGALRM; mixing calls  to
       alarm() and sleep() is a bad idea.

       Using  longjmp()  from  a  signal handler or modifying the
       handling of SIGALRM while sleeping  will  cause  undefined
       results.

I think you might be able to use nanosleep (man nanosleep) for what you
want. 

On Mon, 2002-01-21 at 14:53, Chris Fowler wrote:
> 
> Ah!  I'm having some issues using the alarm() call and the sleep() call in the same program.  The alarm call is in a library function.  Basically, another piece of source code.  It uses the alarm to timeout on sending
> and receiveing data over udp.   I nede to loop and sleep for 30 seconds.    The sleep is not sleeping for 30 seconds.   Bacically it would look like this.
> 
> 
> 
> send.c - part of a library
> --------------------------
> 
> catchAlarm(int signum)
> {
> 	ALARM=1
> }
> 
> int
> send{char *ip)
> {
> 	signal(SIGALRM, catchAlarm)
> 	alarm(60);
> 	
> 	/* send */
> 
> 	/* receive */
> 
> 	alarm(0);
> 
> 	return CODE;
> }
> 
> 
> --------------------------------
> daemon.c
> 
> 
> int
> main(int argc, char *argv[])
> {
> 
> 	int code;
> 
> 	for(;;)
> 	{
> 		code = send("127.0.0.1");
> 		
> 		/* Do something */
> 
> 		sleep(30);
> 	}
> 
> 	reutrn 0;
> }
> 
> 
> ---
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-- 
-kjs, 0x4765656b


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