issue with multiprocess - fork

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My script is using fork so there are child processes. Sometimes my
script runs properly and output is correct. But sometime my script
gets stuck just after exiting child process.

Below is psudo code. (not sure if this helps, it is juist snap shot)

foreach my $w (keys %worklist) {
        my $child;
        unless ($child = fork()) {
        die("connot for: $!") unless defined $child;

                foreach my $file (@}) {
                          #reading files processing of data and
creating hash tables.

               #ouput files from hash tables. outfile files will be
for each child.

                        print "Worker $w $$ exiting\n";
(#it gets stuck after printing this statement)

           push(@workers, $child);             #array of child PID


#wating for each child to finish.
foreach my $pid (@workers) {
                 $s = waitpid($pid, 0);
        print "$s finished\n";


The freeze happens sometimes.

And I check the trace(truss -p on sun). I found that sometimes one of
the child goes to sleeping and parent is still waiting for that child
exit status. But it never gets that bcoz child is sleeping.

And suggestion what can be problem or else how can I debug more.


Re: issue with multiprocess - fork wrote:
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Asking the same question under a different subject line is more likely
to annoy the people you want to help you, than it is to get you more help.

Threads exist for a reason.


Re: issue with multiprocess - fork

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Indeed, as I had killfiled this OP in April when he crossposted
the first time.

I thought at the time that it was perhaps a bit harsh to banish
him to perpetual invisibility, but I did it anyway.

Seeing that he still does it after being warned about it makes
me feel better about my original decision.

Tad McClellan
email: perl -le "print scalar reverse qq/moc.noitatibaher0cmdat/"

Re: issue with multiprocess - fork

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sorry about that. I thought it 3days so people might not see the
thread and I am stuck at that problem. so I posted new thread.

will be careful next time

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