Subj : Re: Does pthread emit a sigchld signal on successful exit?
To   : comp.programming.threads
From : David Schwartz
Date : Thu Aug 18 2005 04:39 pm


"chuckles" <chuckleberryfinn@gmail.com> wrote in message 
news:1124401034.086073.309590@g44g2000cwa.googlegroups.com...

> Hullo all, as the subject says Does pthread emit a sigchld signal on
> successful exit?

    No.

> I have an app which starts a thread in response to a button press in a
> GUI. I can't join the thread but I need to know when it completes.

    So code it to tell you. Worst case, write your own thread startup 
function that calls pthread_clean_push and then calls the normal startup 
function.

> The
> time it takes for the thread to complete is variable and I don't want
> to have to poll the thread for completion.

    Why not? If the thread is not detached and it's your job to join the 
thread when it's done, you can call pthread_kill at any time to see if it's 
done.

> I would like to avoid having
> to use condition variables, so I thought setting up a signal handler to
> catch the SIGCHLD signal would be a neat solution, I've tried using
> signal() and sigaction to associate my handler with the SIGCHLD signal
> but the handler is never called.

    Of course not. A thread is not a child.

    DS

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