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Parallel::Prefork::SpaUserrContributed Perl Parallel::Prefork::SpareWorkers(3)

NAME
       Parallel::Prefork::SpareWorkers - A prefork server framework with
       support for (min|max)spareservers

SYNOPSIS
	 use Parallel::Prefork::SpareWorkers qw(:status);

	 my $pm	= Parallel::Prefork::SpareWorkers->new({
	   max_workers	     =>	40,
	   min_spare_workers =>	5,
	   max_spare_workers =>	10,
	   trap_signals	     =>	{
	     TERM => 'TERM',
	     HUP  => 'TERM',
	     USR1 => undef,
	   },
	 });

	 while ($pm->signal_received ne	'TERM')	{
	   load_config();
	   $pm->start and next;

	   # do	what ever you like, as follows
	   while (my $sock = $listener->accept()) {
	     $pm->set_status('A');
	     ...
	     $sock->close();
	     $pm->set_status(STATUS_IDLE);
	   }

	   $pm->finish;
	 }

	 $pm->wait_all_children;

DESCRIPTION
       "Parallel::Prefork::SpareWorkers" is a subclass of "Parallel::Prefork"
       that supports setting minimum and maximum number	of spare worker
       processes, a feature commonly found in network servers.	The module
       adds to "Parallel::Prefork" several initialization parameters,
       constants, and a	method to set state of the worker processes.

METHODS
   new
       Instantiation.  "Parallel::Prefork::ShpareWorkers" recognizes the
       following parameters in addition	to those defined by
       "Parallel::Prefork".  The parameters can	be accessed using accessors
       with same names as well.

       min_spare_workers

       minimum number of spare workers (mandatory)

       max_spare_workers

       maxmum number of	spare workers (default:	max_workers)

       heartbeat

       a fractional period (in seconds)	of child amount	checking. Do not use
       very small numbers to avoid frequent use	of CPU (default: 0.25)

       scoreboard_file

       filename	of scoreboard.	If not set, "Parallel::Prefork::SpareWorkers"
       will create a temporary file.

   set_status
       sets a single-byte character state of the worker	process.  Worker
       processes should	set any	character of their choice using	the function
       (but not	one of the reserved characters)	to declare that	it is running
       some kind of task.  Or the state	should be set to "STATUS_IDLE" '_'
       once the	worker enters idle state.  The other reserved character	is
       "STATUS_NEXIST" '.' which should	never be set directly by applications.

CONSTANTS
   STATUS_NEXIST
       scoreboard status character '.',	meaning	no worker process is assigned
       to the slot of the scoreboard.  Applications should never set this
       value directly.

   STATUS_IDLE
       scoreboard status character '_',	meaning	that a worker process is in
       idle state

LICENSE
       This program is free software; you can redistribute it and/or modify it
       under the same terms as Perl itself.

       See http://www.perl.com/perl/misc/Artistic.html

perl v5.32.0			  2014-05-13Parallel::Prefork::SpareWorkers(3)

NAME | SYNOPSIS | DESCRIPTION | METHODS | CONSTANTS | LICENSE

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