Is this Proc::Queue error

chanakya has asked for the wisdom of the Perl Monks concerning the following question:

Dear Monks,

I have a script which forks 3 childs at a given time and this is taken care by Proc::Queue.
Everything worked fine until I moved the line "next if" above the Proc::Queue::run_back_now{} method

After the above change the script spawns unlimited childs. For example, I have an array of 50 files
the script spawns 50 childs.

Is this the problem of Proc::Queue or is this script error. Below is my code

#!/usr/bin/perl -w
use POSIX 'WNOHANG';
use Proc::Queue ':all';
use Getopt::Long 'GetOptions';
my $numChilds=3;
GetOptions(
    'childs|c=i'    => \$opt_numChilds
,   'help|h'        => \&USAGE
) || USAGE() ;

($opt_numChilds) ? $numChilds=$opt_numChilds : $numChilds;
Proc::Queue::size($numChilds); #update
my $src="/data/files";
my @allfiles = ("$src/file1", "$src/file2", "$src/file3","$src/file4",
+"$src/file5","$src/file6");
my $log = "/tmp/data.log";
open(STAT, $log) || die ("Can't open file $log: $!");
my @pids;
foreach my $file (@allfiles) {
    my ($root=$file);
    ($root=$file)=~tr/a-z/A-Z/;
     next if (!-f"$srcdir/ok");

    push @pids, Proc::Queue::run_back_now{
        #code here
        system("dataload.pl -file $file > file.err 2>&1");
    };
    
}
waitpids(@pids);
    
close STAT;

exit;
[download]

Many thanks

Comment on Is this Proc::Queue error Download Code

Replies are listed 'Best First'.
Re: Is this Proc::Queue error by johngg (Canon) on Dec 06, 2006 at 15:36 UTC
I don't think your processing of `$opt_numChilds` is doing what you think. Instead of `my $numChilds=3; ... ($opt_numChilds) ? $numChilds=$opt_numChilds : $numChilds;` [download] try `my $numChilds = $opt_numChilds ? $opt_numChilds : 3;` [download] Your code gives a "Useless use of private variable in void context" message. Cheers, JohnGG	[reply] [d/l] [select]
Re: Is this Proc::Queue error by salva (Canon) on Dec 06, 2006 at 16:01 UTC
You have to use `run_back` instead of `run_back_now`. The `*_now` functions ignore (on purpose) the limit on the number of childs that can be forked.	[reply] [d/l] [select]
Re: Is this Proc::Queue error by derby (Abbot) on Dec 06, 2006 at 15:11 UTC
I'm no expert on Proc::Queue but should you either do `use Proc::Queue size => 3` or call `Proc::Queue::size(3)`? I'm not seeing how your numChilds is affecting Proc::Queue. -derby	[reply] [d/l] [select]
Re: Is this Proc::Queue error by chanakya (Friar) on Dec 06, 2006 at 15:16 UTC
Derby I missed posting the line `Proc::Queue::size($numChilds);` I have updated the code with the missing line	[reply] [d/l]


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