Re: Change in process.c

[Sam Steingold <sds@gnu.org>]

Chong Yidong wrote:
> Richard Stallman <rms@gnu.org> writes:
> 
>> I don't mind making a change to fix this,
>> but it must not do a full-second sleep before the first wait3,
>> and it must not use usleep since that is obsolete.
> 
> Does this version work?

no, absolutely NOT.
there must be a sleep BEFORE the first wait.
something equivalent to your version was tried and found lacking.

> *** emacs/src/process.c.~1.508.~	2007-03-27 16:47:03.000000000 -0400
> --- emacs/src/process.c	2007-03-27 17:13:31.000000000 -0400
> ***************
> *** 6500,6516 ****
>   #define WUNTRACED 0
>   #endif /* no WUNTRACED */
>         /* Keep trying to get a status until we get a definitive result.  */
> !       do
>           {
>   	  /* For some reason, this sleep() prevents Emacs from sending
>                loadavg to 5-8(!) for ~10 seconds.
>                See http://thread.gmane.org/gmane.emacs.devel/67722 or
>                http://www.google.com/search?q=busyloop+in+sigchld_handler */
> !           usleep (1000);
>   	  errno = 0;
>   	  pid = wait3 (&w, WNOHANG | WUNTRACED, 0);
>   	}
> -       while (pid < 0 && errno == EINTR);
>   
>         if (pid <= 0)
>   	{
> --- 6500,6518 ----
>   #define WUNTRACED 0
>   #endif /* no WUNTRACED */
>         /* Keep trying to get a status until we get a definitive result.  */
> ! 
> !       errno = 0;
> !       pid = wait3 (&w, WNOHANG | WUNTRACED, 0);
> !       while (pid < 0 && errno == EINTR)
>           {
>   	  /* For some reason, this sleep() prevents Emacs from sending
>                loadavg to 5-8(!) for ~10 seconds.
>                See http://thread.gmane.org/gmane.emacs.devel/67722 or
>                http://www.google.com/search?q=busyloop+in+sigchld_handler */
> !           sleep (1);
>   	  errno = 0;
>   	  pid = wait3 (&w, WNOHANG | WUNTRACED, 0);
>   	}
>   
>         if (pid <= 0)
>   	{