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Greetings liz,

A mutex is necessary whenever the Perl-like behavior, via the TIE interface, involves 2 IPC calls { FETCH and STORE }.

use strict; use warnings; use feature 'say'; use MCE::Hobo; use MCE::Mutex; use MCE::Shared; my $mutex = MCE::Mutex->new(); tie my $var, 'MCE::Shared', 0; sub task { for ( 1 .. 2000 ) { $mutex->enter(sub { $var += 1; # FETCH, STORE $var += 4; # Ditto }); } } MCE::Hobo->create(\&task) for 1 .. 4; MCE::Hobo->waitall; say $var; # 40000

A mutex is not necessary via the OO interface. MCE::Shared::{ Array, Hash, and Scalar } include sugar methods.

use strict; use warnings; use feature 'say'; use MCE::Hobo; use MCE::Shared; my $var = MCE::Shared->scalar(0); sub task { for ( 1 .. 2000 ) { $var->incr; $var->incrby(4); } } MCE::Hobo->create(\&task) for 1 .. 4; MCE::Hobo->waitall; say $var->get; # 40000

MCE::Shared works with threads and other parallel modules. Below, the same thing using threads.

use strict; use warnings; use feature 'say'; use threads; use MCE::Shared; my $var = MCE::Shared->scalar(0); sub task { for ( 1 .. 2000 ) { $var->incr; $var->incrby(4); } } threads->create(\&task) for 1 .. 4; $_->join for threads->list; say $var->get; # 40000

One may also customize the shared class feasibly.

use strict; use warnings; package My::Scalar; use MCE::Shared::Scalar; use base 'MCE::Shared::Scalar'; sub set_if_max { # my ( $self, $value ) = @_; ${ $_[0] } = $_[1] if ( $_[1] > ${ $_[0] } ); 1; } 1; package main; use feature 'say'; use MCE::Shared; my $var = MCE::Shared->share( { module => 'My::Scalar' }, 0 ); $var->set_if_max(42); $var->set_if_max(11); say $var->get; # 42

Regards, Mario


In reply to Re^8: Why should any one use/learn Perl 6? by marioroy
in thread Why should any one use/learn Perl 6? by skooma

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