On Fri Feb 13 19:27:58 2009, aveckey wrote:
Show quoted text> Because the $SIG{CHLD} is not being reset in the child process within
> the start() function, sometimes <defunct> processes can pile up.
>
> Another item is if the child process is performing system commands
> itself, the exit statuses of those system commands are not always
> reflected correctly.
>
>
> The observation is that the $SIG{CHLD} is still set to \&THE_REAPER and
> Proc::Simple has no record of those grandchild processes, so they are
> left <defunct>, waiting to be reaped.
>
>
> The fix is to add as the first line in the start() functions child
> process a 'local $SIG{CHLD};' in order to reset the CHLD signal handle
> for the child.
The below will reproduce the results I am seeing, note that within the
child process 'test()' function, the $SIG{CHLD} is still set. The
<defunct> processes will accumulate under the child processes, so keep
monitoring the whole process tree, once the original child is reaped,
the <defunct> processes will be purged too (but I have seen cases where
they remain).
I am running this on Perl 5.8.8
SunOS il93hsrv41 5.9 Generic_118558-39 sun4u sparc SUNW,Sun-Fire-V440
Solaris
use Proc::Simple;
use Cwd;
my %procs = ();
foreach my $cnt (1..4)
{
$procs{$cnt} = new Proc::Simple();
$procs{$cnt}->start(\&test, $cnt, @ARGV);
}
print "Current directory is ", cwd(), "\n";
print "Current directory is ", cwd(), "\n";
print "Current directory is ", cwd(), "\n";
print "Press <enter> to continue ($$)\n"; <STDIN>;
sub test
{
my $iteration = shift;
print "Passed was $iteration\n";
foreach my $cnt (0..20)
{
printf "%d Waiting %d more seconds ...\n",$$, 20 - $cnt;
print "Current directory is ", cwd(), "\n";
my $sys = system(qq(perl -e 'exit($cnt);'));
printf "%d should be %d (%d)\n", $cnt, $sys, $sys / 256;
print "SIG = $SIG{CHLD}\n";
sleep(1);
}
print "-------------------------$$ done.\n";
}
