Subj : Re: threaded program and wait() call
To   : comp.programming.threads
From : tadek
Date : Tue Aug 09 2005 12:02 pm

Hello Patrick,
I have solved it!  And the solution was quite simple:
1) program was using old-fashioned, deprecated signal() call to install
signal handler
2)gcc defaults sigaction's sa_flags to SA_RESTART on my RHEL4!!!
3) it means when wait() is interrupted it does not return EINTR error
code
4) solution: use sigaction() instead of signal() and initialize
sigaction structure (fill it with zeroes)
5) alternative is to use Feature Test Macros. "when you don't specify
with sigaction what a particular handler should do, it uses a default
choice. The default choice in the GNU library depends on the feature
test macros you have defined.  If you define _BSD_SOURCE or _GNU_SOURCE
before calling signal, the default is to resume primitives"

Bottom line is that man page for waitpid()/wait() is not very precise.

Your comment about posix_spawn() is very valid and I will take your
advise.

Thank you for your help.
Usefull links:
Process Completion
http://www.gnu.org/software/libc/manual/html_node/Process-Completion.html#Process-Completion

Primitives Interrupted by Signals:
http://www.gnu.org/software/libc/manual/html_node/Interrupted-Primitives.html#Interrupted-Primitives

.