Re^6: How to tell a child what to do?


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Re^6: How to tell a child what to do?

by Anonymous Monk

on Sep 21, 2005 at 12:25 UTC ( [id://493755]=note: print w/replies, xml )

Need Help??

in reply to Re^5: How to tell a child what to do?
in thread How to tell a child what to do?

I've played with the code a bit more, and it's failing for me as well. But not always. How often it fails, depends on the number of spawned children. Trying 1, 2, 3, 4, and 5 children, each 10 times, I get success rates of 100%, 90%, 40%, 10% and 0%.

Something is wrong, but I do not know what. I'll have to consult Stevens.

Comment on Re^6: How to tell a child what to do?

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Re^7: How to tell a child what to do?
by Eyck (Priest) on Sep 23, 2005 at 07:07 UTC

This may have something to do with perl's buffering, in particular, when instead of while (<>) I wrote this:

        my $q;
        $q=<STDIN>;
        print "Received(child $$): $q\n";
[download]

close($fd)

When I traced what is happening when it hangs, it looks like parent is waiting waitpid(..) (close($fd) on pipe is supposed to do that), while child blissfully unaware is running read...

Now I can safely go and try to understand merlyn's code.

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