alarm(2) and wait(2) under 3.1

[Goldberg]

An application I wrote originally under Ultrix version 2.3 no longer
times out properly.  I set an alarm(2) for 4 minutes, do some
processing, then fork a subprocess to do some more processing and user
interaction.  The parent waits for the subprogram to finish, using the
return status to determine it's next step.  The problem: under 2.3, if
the user waited too long, the SIGALARM would be generated, and the
whole program would time out, as expected.  Under 3.1, the SIGALARM is
apparently not being generated (I tested this by sending one myself
with kill(1) after waiting over 10 minutes).  After I sent the
SIGALARM, the program caught it, and timed out as I expected it to.  I
also found that the SIGALARM is properly generated if there is no
subprocess/wait going on.  Is this a known bug (Hopefully fixed under
4.X)?  Or was the behavior under 2.3 the bug?

Thanks in advance for any help.

--
Dave Goldberg                     UNIX Systems Programmer/Administrator
The Mitre Corporation   MS B020   Bedford, MA 01730        617-271-2460
Domain: dsg at mbunix.mitre.org      UUCP: linus!mbunix!dsg