in reply to Re: Limiting the number of forks
in thread Limiting the number of forks

Hi Abigail-II,

Sorry to barge in to the middle of a discussion with a new question, but this code piqued my interest on your answer:

exit $code -> ($c) unless $pid;

In your discussion, you mentioned that $code should be a coderef. However, unless I'm mistaken (which is entirely possible) the above will not lead to the expected result in that case. I would rather expect something like:

exit &$code unless $pid;

I can make sense of your code if $code is in fact an object which implements $c methods (probably through autoloading).

Could you throw some light on the darkness of my confusion?

CU
Robartes-

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Re: Limiting the number of forks
by Abigail-II (Bishop) on Oct 02, 2002 at 14:07 UTC
    You didn't try, did you? 
    use strict;
use warnings 'all';

sub mfork ($$&) {
    my ($count, $max, $code) = @_;

    foreach my $c (1 .. $count) {
        wait unless $c <= $max;
        die "Fork failed: $!\n" unless defined (my $pid = fork);
        exit $code -> ($c) unless $pid;
    }

    1 until -1 == wait;
}


mfork 10, 3, sub {
    print "$$: " . localtime () . ": Starting\n";
    select undef, undef, undef, 2 + rand 2;
    print "$$: " . localtime () . ": Exiting\n";
};
__END__
972: Wed Oct  2 16:06:32 2002: Starting
973: Wed Oct  2 16:06:32 2002: Starting
974: Wed Oct  2 16:06:32 2002: Starting
973: Wed Oct  2 16:06:34 2002: Exiting
975: Wed Oct  2 16:06:34 2002: Starting
972: Wed Oct  2 16:06:35 2002: Exiting
976: Wed Oct  2 16:06:35 2002: Starting
974: Wed Oct  2 16:06:35 2002: Exiting
977: Wed Oct  2 16:06:35 2002: Starting
975: Wed Oct  2 16:06:38 2002: Exiting
978: Wed Oct  2 16:06:38 2002: Starting
977: Wed Oct  2 16:06:39 2002: Exiting
979: Wed Oct  2 16:06:39 2002: Starting
976: Wed Oct  2 16:06:39 2002: Exiting
980: Wed Oct  2 16:06:39 2002: Starting
978: Wed Oct  2 16:06:41 2002: Exiting
981: Wed Oct  2 16:06:41 2002: Starting
979: Wed Oct  2 16:06:41 2002: Exiting
980: Wed Oct  2 16:06:42 2002: Exiting
981: Wed Oct  2 16:06:45 2002: Exiting

    [download]

    Please consult the perlref manual page for syntax details dealing with references.

    Abigail

[reply]
[d/l]
      Robartes chastened

      I stand corrected. $coderef -> ($c) calls the referenced function with $c as argument. Thanks!

      CU
      Robartes-

[reply]

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