signal handling exit code

[chrisdenley]

I'm trying to troubleshoot a problem with my script hanging intermittently, but the output isn't captured if the exit code is 0 since that indicates there is no error. If the process is killed with a SIGTERM, then it always seems to exit with code 0. I found that with MCE 1.817, I can set $? to change the exit code actually returned. However, with MCE 1.829 that doesn't seem to work.

[marioroy]

Thank you for the bug report. Do you have a small use case so that I can ensure validation. For example, where are you setting $? ?. Inside handler, inside worker?

Regards,

[chrisdenley]

#!/opt/perl/bin/perl
use strict;
use MCE::Signal qw(-no_kill9);
use MCE;

if($ARGV[0] ne 'test') {
        print "parent PID is $$\n";
        system($^X,$0,'test');
        my $ec = $? >> 8;
        print "Child exited with exit code $ec\n";
        sleep 2;
        print "Parent exiting\n";
        exit(0);
}

print "child PID is $$\n";
#setpgrp();

sub forever {
        print "Process $$ will wait forever...\n";
        sleep 1 while(1);
}

sub inputiter {
        return ('a'..'z');
}
my $mce = MCE->new(
  max_workers => 2,
  chunk_size => 512,
  input_data => \&inputiter,
  user_func => \&forever,
);
sub sighandle {
        $? = -1;
        #print "PID $$ SIGNAL ".$_[0]."\n";
        #$MCE::Signal::STATUS = $?;
        MCE::Signal::stop_and_exit(@_);
}
#$SIG{$_} = \&sighandle foreach(qw(HUP INT PIPE QUIT TERM));
$? = -1; # this will be the exit code if terminated early
print "Running MCE\n";
print "PID $$ \$? = $?\n";
$mce->run();
#$? = 0; # set this back to 0 (no error) after MCE completed successfully
print "PID $$ finished\n";
exit($?);

As you can see, I was also testing with setting the process group (it was killing off my parent process as well). I had tried overriding the signal handler, but ultimately setting $? before the $mce->run() would change the exit code on SIGTERM on the previous version.

[marioroy]

This is fixed for the upcoming MCE 1.830 release. Thank you, @chrisdenley.

[marioroy]

Your sample code was beneficial. I needed to update the fix applied 2 hours ago. Thanks again.

[chrisdenley]

That was fast! My testing looks good. When should I expect to see this change in CPAN? Thanks!

[marioroy]

Definitely soon and no later than the end of August. I have a couple validations to run for science and want to ensure no further changes are needed.

[marioroy]

MCE 1.830 was released today containing the fix. Thank you.