use strict;
use warnings;
use IPC::Shareable;
my $options = {
create => 1,
exclusive => 0,
mode => 0644,
destroy => 1,
};
tie my $cntr, 'IPC::Shareable', $options;
my $val;
$cntr = 0;
if ( ! defined ( my $pid = fork() ) ) {
die "Cannot fork!: $!";
}
elsif ( $pid == 0 ) {
# Child
for ( 1 .. 10000 ) {
( tied $cntr )->shlock;
$val = $cntr++;
( tied $cntr )->shunlock;
}
}
else {
# Parent
for ( 1 .. 10000 ) {
( tied $cntr )->shlock;
$val = $cntr++;
( tied $cntr )->shunlock;
}
waitpid $pid, 0;
print "counter: ", $cntr, "\n";
}
2) mce_shared.pl
use strict;
use warnings;
use MCE::Mutex;
use MCE::Shared;
my $mutex = MCE::Mutex->new();
tie my $cntr, 'MCE::Shared', 0;
my $val;
if ( ! defined ( my $pid = fork() ) ) {
die "Cannot fork!: $!";
}
elsif ( $pid == 0 ) {
# Child
for ( 1 .. 10000 ) {
$mutex->lock;
$val = $cntr++;
$mutex->unlock;
}
}
else {
# Parent
for ( 1 .. 10000 ) {
$mutex->lock;
$val = $cntr++;
$mutex->unlock;
}
waitpid( $pid, 0 );
print "counter: ", $cntr, "\n";
}
3) mce_shared_oo.pl
use strict;
use warnings;
use MCE::Shared;
my $cntr = MCE::Shared->scalar( 0 );
my $val;
if ( ! defined ( my $pid = fork() ) ) {
die "Cannot fork!: $!";
}
elsif ( $pid == 0 ) {
# Child
for ( 1 .. 10000 ) {
$val = $cntr->incr;
}
}
else {
# Parent
for ( 1 .. 10000 ) {
$val = $cntr->incr;
}
waitpid( $pid, 0 );
print "counter: ", $cntr->get, "\n";
}
Results
time in seconds : FreeBSD Linux Mac OSX
ipc_shareable.pl : 1.80 1.87 1.79
mce_shared.pl : 0.68 0.97 0.58
mce_shared_oo.pl : 0.38 0.73 0.41
counter: 20000
Fetches require more time on Linux than BSD-based OS in regards to sockets. This is seen not only with Perl/MCE::Shared but also with other languages. I'm not sure why.
MCE::Shared is fully wantarray-aware and performs fetches only when requested. Sadly, that is not the case via the TIE interface. Perhaps, this is an unnecessary overhead IMHO in regards to the TIE implementation inside Perl.
The following results were obtained by omitting fetches: e.g. $cntr++, $cntr->incr. Fortunately, stores perform similarly between BSD and Linux via the OO interface.
time in seconds : FreeBSD Linux Mac OSX
ipc_shareable.pl : 1.77 1.86 1.61
mce_shared.pl : 0.68 0.95 0.58
mce_shared_oo.pl : 0.19 0.17 0.16
counter: 20000
The above is only a glimpse of what is possible with MCE::Shared. The use of parallel data-channels (enabled automatically) for MCE, MCE::Hobo, and threads further reduce latency for the shared-manager process. Calling MCE::Shared->init(), inside the worker, enables the optimization for fork and other parallel modules.
This has been an interesting exercise. Thank you Bloehdian for the initial post.
Tests were conducted on a Macbook Pro laptop (Haswell architecture) OS X 10.11.6 running at 2.6 GHz 1600 MHz RAM. FreeBSD and Linux are virtual machines managed by Parallels Desktop 11.2.1.
Regards, Mario. |