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Parallel::Fork::BossWorker
Perl extension for easiliy creating forking queue processing applications.

Parallel::Fork::BossWorker - Perl extension for easiliy creating forking queue processing applications.


NAME

Parallel::Fork::BossWorker - Perl extension for easiliy creating forking queue processing applications.


SYNOPSIS

The minimal usage of Parallel::Fork::BossWorker requires you supply the work_handler argument which returns a hash reference.


        use Parallel::Fork::BossWorker;

        

        # Create new BossWorker instance

        my $bw = new Parallel::Fork::BossWorker(

                work_handler => sub {

                                my $work = shift;

                                ... do work here ...

                                return {};

                        }

        );

        

        $bw->add_work({key=>"value"});

        $bw->process();

Additionally, you could specify the result_handler argument, which is passed the hash reference returned from your work_handler.


        use Parallel::Fork::BossWorker;

        

        # Create new BossWorker instance

        my $bw = new Parallel::Fork::BossWorker(

                work_handler => sub {

                                my $work = shift;

                                ... do work here ...

                                return {result => "Looks good"};

                        },

                result_handler => sub {

                        my $result = shift;

                        print "$result->{result}\n";

                }

        );


DESCRIPTION

Parallel::Fork::BossWorker makes creating multiprocess applications easy.

The module is designed to work in a queue style of setup; with the worker processes requesting 'work' from the boss process. The boss process transparently serializes and sends the work data to your work handler, to be consumed and worked. The worker process then transparently serializes and sends optional data back to the boss process to be handled in your result handler.

This process repeats until the work queue is empty.


METHODS

new(...)

Creates and returns a new Parallel::Fork::BossWorker object.


        my $bw = Parallel::Fork::BossWorker->new(work_handler => \&routine)

Parallel::Fork::BossWorker has options which allow you to customize how exactly the queue is handled and what is done with the data.

  • work_handler => \&routine
  • The work_handler argument is required, the sub is called with it's first and only argument being one of the values in the work queue. Each worker calls this sub each time it receives work from the boss process. The handler may trap $SIG{ALRM}, which may be called if global_timeout is specified.

    The work_handler should clean up after itself, as the workers may call the work_handler more than once.

  • result_handler => \&routine
  • The result_handler argument is optional, the sub is called with it's first and only argument being the return value of work_handler. The boss process calls this sub each time a worker returns data. This subroutine is not affected by the value of global_timeout.

  • global_timeout => $seconds
  • By default, a handler can execute forever. If global_timeout is specified, an alarm is setup to terminate the work_handler so processing can continue.

  • worker_count => $count
  • By default, 10 workers are started to process the data queue. Specifying worker_count can scale the worker count to any number of workers you wish.

    Take care though, as too many workers can adversely impact performance, though the optimal number of workers will depend on what your handlers do.

  • msg_delimiter => $delimiter
  • Sending messages to and from the child processes is accomplished using Data::Dumper. When transmitting data, a delimiter must be used to identify the breaks in messages. By default, this delimiter is ``\0\0\0'', this delimiter may not appear in your data.

add_work(\%work)

Adds work to the instance's queue.


        $bw->add_work({data => "my data"});



process()

Forks off the child processes and begins processing data.


        $bw->process();




REQUIREMENTS

This module depends on the following modules:

Carp

Data::Dumper

IO::Handle


BUGS

None I'm aware of yet, but I'm sure I'll receive reports :)


SEE ALSO


AUTHOR

Jeff Rodriguez, <jeff@jeffrodriguez.com>


COPYRIGHT AND LICENSE

Copyright (c) 2007, Jeff Rodriguez

All rights reserved.

Redistribution and use in source and binary forms, with or without modification, are permitted provided that the following conditions are met:


   * Redistributions of source code must retain the above copyright notice,

     this list of conditions and the following disclaimer.




   * Redistributions in binary form must reproduce the above copyright notice,

     this list of conditions and the following disclaimer in the documentation

     and/or other materials provided with the distribution.




   * Neither the name of the <ORGANIZATION> nor the names of its contributors

     may be used to endorse or promote products derived from this software

     without specific prior written permission.



THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

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