Hi,

I am trying to integrate IPC::Shareable module to Parallel::Forkmanager module, but having troubles with global variables.

I have developed a proof of concept script for myself to see how IPC::Shareable is actually working. 

use Parallel::ForkManager;
use IPC::Shareable;


my $pm = new Parallel::ForkManager(10);

my %options = (
    create    => 1,
    exclusive => 0,
    mode      => 0644,
    destroy   => 1,
);

my $testvr = 0;


tie $testvr, 'IPC::Shareable', 'data', \%options;

for(my $i = 0; $i < 100; $i++) {
        $pm->start and next;
        (tied $testvr)->shlock;
        $testvr++;
        (tied $testvr)->shunlock;
        print $testvr . "\n";
        $pm->finish;
}
$pm->wait_all_children;

[download]

This script works as intended, but when I try to modify $testvr variable inside for loop, it is not working correctly. What should I do to fix this issue? Any ideas?

Example:

for(my $i = 0; $i < 100; $i++) {
        $pm->start and next;
        if($testvr >= 5) {
            $testvr = 0;
         }
        (tied $testvr)->shlock;
        $testvr++;
        (tied $testvr)->shunlock;
        print $testvr . "\n";
        $pm->finish;
}
$pm->wait_all_children;

[download]

The output should be:

1
2
3
4
5
1
2
3
4
5
...

but it is:

1
2
3
4
5
1
1
2
3
4
5
6

(locking variable inside if statement is not working)

I am sure I am missing something obvious but could not find solution.

Thanks in advance,

In reply to IPC::Shareable and Parallel::Forkmanager Question by anlamarama

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