Subj : Re: Issues with multi-threading and fork
To   : comp.programming.threads
From : loic-dev
Date : Thu Mar 31 2005 05:44 am

Salut Jerome,

> busy-wait for the child process to terminate by the means of:
>
> cnt = timeout;
> while (waitpid (pid , &status, WNOHANG) == 0 && cnt != 0)
> {
>   sleep (1);
>   --cnt;
> }
>
> (I didn't find any other way to implement timeouted waitpid in
> a mutil-threaded context since one cannot use signals)

Why? Ok with LinuxThreads things are not so easy. But in your case, the
signal would be delivered to the thread that forked the child (POSIX
states that the SIGCHLD  is delivered to any thread that has that
signal unblocked).


>> From time to times, the timeout mysteriously expires, so I searched
> for the causes.
>
> After some investigation, it seems that the child process hangs right
> after the fork and does not go further.

[snip]

> Any idea about what might be happening?

Hmmm... difficult to say what's wrong... Perhaps an issue in
LinuxThreads?
The best thing would be to post a stripped example that still shows
your issue. We could then make some deeper investigations.


Cheers,
Loic.

.