MooseX::Workers(3) User Contributed Perl Documentation MooseX::Workers(3)NAMEMooseX::Workers - Simple sub-process management for asynchronous tasks
SYNOPSIS
package Manager;
use Moose;
with qw(MooseX::Workers);
sub run {
$_[0]->spawn( sub { sleep 3; print "Hello World\n" } );
warn "Running now ... ";
POE::Kernel->run();
}
# Implement our Interface
sub worker_manager_start { warn 'started worker manager' }
sub worker_manager_stop { warn 'stopped worker manager' }
sub max_workers_reached { warn 'maximum worker count reached' }
sub worker_stdout { shift; warn join ' ', @_; }
sub worker_stderr { shift; warn join ' ', @_; }
sub worker_error { shift; warn join ' ', @_; }
sub worker_done { shift; warn join ' ', @_; }
sub worker_started { shift; warn join ' ', @_; }
sub sig_child { shift; warn join ' ', @_; }
sub sig_TERM { shift; warn 'Handled TERM' }
no Moose;
Manager->new->run();
DESCRIPTIONMooseX::Workers is a Role that provides easy delegation of long-running
tasks into a managed child process. Process managment is taken care of
via POE and it's POE::Wheel::Run module.
METHODS
spawn ($command)
fork ($command)
run_command ($command)
These three methods are the whole point of this module. They pass
$command through to the MooseX::Worker::Engine which will take care
of running $command for you.
spawn() and fork() both envoke POE::Kernel call(), which is
synchronous.
run_command() envokes POE::Kernel yield(), which is asynchronous.
If max_workers() has been reached, run_command() warns and does
nothing. It is up to you to re-submit $command. See enqueue() if
you want us to run $command as soon as another worker is free.
enqueue($command)
Just like run_command(), only that if max_workers() has been set
and that number of workers has been reached, then we add $command
to a FIFO command queue. As soon as any running worker exits, the
first $command in queue (if any) will be run.
check_worker_threshold
This will check to see how many workers you have compared to the
max_workers limit. It returns true if the $num_workers is >=
$max_workers;
max_workers($count)
An accessor for the maxium number of workers. This is delegated to
the MooseX::Workers::Engine object.
has_workers
Check to see if we have *any* workers currently. This is delegated
to the MooseX::Workers::Engine object.
num_workers
Return the current number of workers. This is delegated to the
MooseX::Workers::Engine object.
meta
The Metaclass for MooseX::Workers::Engine see Moose's
documentation.
INTERFACE
MooseX::Worker::Engine supports the following callbacks:
worker_manager_start
Called when the managing session is started
worker_manager_stop
Called when the managing session stops
max_workers_reached
Called when we reach the maximum number of workers
worker_stdout
Called when a child prints to STDOUT
worker_stderr
Called when a child prints to STDERR
worker_error
Called when there is an error condition detected with the child.
worker_done
Called when a worker completes $command
worker_started
Called when a worker starts $command
sig_child
Called when the mangaging session recieves a SIG CHDL event
sig_*
Called when the underlying POE Kernel receives a signal; this is
not limited to OS signals (ie. what you'd usually handle in Perl's
%SIG) so will also accept arbitrary POE signals (sent via
POE::Kernel->signal), but does exclude SIGCHLD/SIGCHILD, which is
instead handled by sig_child above.
These interface methods are automatically inserted when
MooseX::Worker::Engine detects that your manager class contains any
methods beginning with sig_. Signals are case-sensitive, so if you
wish to handle a TERM signal, you must define a sig_TERM() method.
Note also that this action is performed upon MooseX::Worker::Engine
startup, so any run-time modification of your class which 'does'
MooseX::Workers is not likely to be detected.
See the sig_TERM handler in the SYNOPSIS for an example.
See MooseX::Workers::Engine for more details. Also see
MooseX::Workers::Job if you'd like to give your tasks names, or set
timeouts on them.
CONFIGURATION AND ENVIRONMENTMooseX::Workers requires no configuration files or environment
variables.
DEPENDENCIES
Moose, POE, POE::Wheel::Run
INCOMPATIBILITIES
None reported.
BUGS AND LIMITATIONS
No bugs have been reported.
Please report any bugs or feature requests to
"bug-moosex-workers@rt.cpan.org", or through the web interface at
<http://rt.cpan.org>.
AUTHORS
Chris Prather "<perigrin@cpan.org>"
Tom Lanyon "<dec@cpan.org>"
Jay Hannah "<jay@jays.net>"
Justin Hunter "<justin.d.hunter@gmail.com>"
LICENCE AND COPYRIGHT
Copyright (c) 2007-2010, Chris Prather "<perigrin@cpan.org>". Some
rights reserved.
This module is free software; you can redistribute it and/or modify it
under the same terms as Perl itself. See perlartistic.
DISCLAIMER OF WARRANTY
BECAUSE THIS SOFTWARE IS LICENSED FREE OF CHARGE, THERE IS NO WARRANTY
FOR THE SOFTWARE, TO THE EXTENT PERMITTED BY APPLICABLE LAW. EXCEPT
WHEN OTHERWISE STATED IN WRITING THE COPYRIGHT HOLDERS AND/OR OTHER
PARTIES PROVIDE THE SOFTWARE "AS IS" WITHOUT WARRANTY OF ANY KIND,
EITHER EXPRESSED OR IMPLIED, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE
ENTIRE RISK AS TO THE QUALITY AND PERFORMANCE OF THE SOFTWARE IS WITH
YOU. SHOULD THE SOFTWARE PROVE DEFECTIVE, YOU ASSUME THE COST OF ALL
NECESSARY SERVICING, REPAIR, OR CORRECTION.
IN NO EVENT UNLESS REQUIRED BY APPLICABLE LAW OR AGREED TO IN WRITING
WILL ANY COPYRIGHT HOLDER, OR ANY OTHER PARTY WHO MAY MODIFY AND/OR
REDISTRIBUTE THE SOFTWARE AS PERMITTED BY THE ABOVE LICENCE, BE LIABLE
TO YOU FOR DAMAGES, INCLUDING ANY GENERAL, SPECIAL, INCIDENTAL, OR
CONSEQUENTIAL DAMAGES ARISING OUT OF THE USE OR INABILITY TO USE THE
SOFTWARE (INCLUDING BUT NOT LIMITED TO LOSS OF DATA OR DATA BEING
RENDERED INACCURATE OR LOSSES SUSTAINED BY YOU OR THIRD PARTIES OR A
FAILURE OF THE SOFTWARE TO OPERATE WITH ANY OTHER SOFTWARE), EVEN IF
SUCH HOLDER OR OTHER PARTY HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
DAMAGES.
POD ERRORS
Hey! The above document had some coding errors, which are explained
below:
Around line 205:
=back without =over
perl v5.14.1 2010-03-05 MooseX::Workers(3)
