Re: Re: [UnixOS2] waitpid : why does this not work?

On Fri, Sep 19, 2003 at 01:36:56AM +0200, Andreas Buening wrote:

> SIGCHLD is different on OS/2.

Nonsense.  There is no SIGCHLD on OS/2.  However, there are some on EMX.

In fact, there are too many: out of many different semantics of signal
processing, EMX supports two - distinguished by -Zbsd-signals and
-Zsysv-signals flags.

> If you use -Zsys, you don't have SIGCHLD.

-Zsys supports very small subset of POSIX indeed.

> If you uncritically compile Unix programs that use a
> SIGCHLD handler, there is a good chance that your program will
> produce a deadlock.

Same is true on Unix: there are many different semantics.  If
possible, one should use POSIX interface...

So one needs to find out which semantic is expected by a program.  As
voodoo programming goes, just try both variants of -Z*-signals; maybe
you will get an improvement...

Hope this helps,
Ilya