I met to add that MCE::Hobo and MCE::Shared provide capabilities similar to threads and threads::shared respectively. One isn't required to use MCE workers. In fact, MCE::Shared works also with threads, Parallel::ForkManager, and workers spawned with fork.

If using non-MCE workers, then call MCE::Shared->init inside the child. That will spread IPC communication across 10 data channels. The channel assignment is done automatically for threads and MCE workers (i.e. MCE, MCE::Child, and MCE::Hobo).

unless (fork)
{
    # This assigns the worker 1 of 10 data channels in a
    # round-robin fashion for the life of the worker.
    MCE::Shared->init();

    do_subroutine ();
    exit;
}
[download]

Update: Added demonstrations.

Below, please find two demonstrations which one may run for comparison. Parallel data channels are helpful especially when a reply is not needed i.e. incrementing a value or writing to a shared output object. Each worker increments the value 100,000 times.

use strict;
use warnings;
use MCE::Shared;
use Time::HiRes 'time';

my $number = MCE::Shared->scalar(0);

sub do_subroutine { $number->incr for 1..1e5; }

my @pids;
my $start = time;

for (1..10) {
    my $pid;
    unless ($pid = fork) {
        do_subroutine ();
        exit;
    }
    push @pids, $pid if defined $pid;
}

waitpid $_, 0 for @pids;

printf "number  %d\n", $number->get;
printf "seconds %.03f\n", time - $start;

__END__

number  1000000
seconds 5.234
[download]

That's quite fast considering incrementing the value involves IPC. Faster is possible if you want non-MCE workers to reach levels capable of threads and MCE workers which call MCE::Shared->init automatically.

MCE::Shared->init

Calling MCE::Shared->init is beneficial for non-MCE workers.

use strict;
use warnings;
use MCE::Shared;
use Time::HiRes 'time';

my $number = MCE::Shared->scalar(0);

sub do_subroutine { $number->incr for 1..1e5; }

my @pids;
my $start = time;

for (1..10) {
    my $pid;
    unless ($pid = fork) {
        MCE::Shared->init;  # enables multi-channel
        do_subroutine ();
        exit;
    }
    push @pids, $pid if defined $pid;
}

waitpid $_, 0 for @pids;

printf "number  %d\n", $number->get;
printf "seconds %.03f\n", time - $start;

__END__

number  1000000
seconds 2.086
[download]

That is shy of 500k per second on Clear Linux.

threads demonstration

For completeness adding threads and MCE::Hobo demonstrations. They benefit from multi-channel IPC automatically and not necessary to call MCE::Shared->init.

use strict;
use warnings;
use threads;
use MCE::Shared;
use Time::HiRes 'time';

my $number = MCE::Shared->scalar(0);
my $start = time;

sub do_subroutine { $number->incr for 1..1e5; }

threads->create('do_subroutine') for 1..10;
$_->join for threads->list;

printf "number  %d\n", $number->get;
printf "seconds %.03f\n", time - $start;

__END__

number  1000000
seconds 2.142
[download]

MCE::Hobo demonstration

use strict;
use warnings;
use MCE::Hobo;
use MCE::Shared;
use Time::HiRes 'time';

my $number = MCE::Shared->scalar(0);
my $start = time;

sub do_subroutine { $number->incr for 1..1e5; }

MCE::Hobo->create('do_subroutine') for 1..10;
$_->join for MCE::Hobo->list; # same as MCE::Hobo->wait_all

printf "number  %d\n", $number->get;
printf "seconds %.03f\n", time - $start;

__END__

number  1000000
seconds 2.087
[download]

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