io::async::routine(3pm) [debian man page]

IO::Async::Routine(3pm) 				User Contributed Perl Documentation				   IO::Async::Routine(3pm)

NAME

       "IO::Async::Routine" - execute code in an independent sub-process

SYNOPSIS

	use IO::Async::Routine;
	use IO::Async::Channel;

	use IO::Async::Loop;
	my $loop = IO::Async::Loop->new;

	my $nums_ch = IO::Async::Channel->new;
	my $ret_ch  = IO::Async::Channel->new;

	my $routine = IO::Async::Routine->new(
	   channels_in	=> [ $nums_ch ],
	   channels_out => [ $ret_ch ],

	   code => sub {
	      my @nums = @{ $nums_ch->recv };
	      my $ret = 0; $ret += $_ for @nums;

	      # Can only send references
	      $ret_ch->send( $ret );
	   },

	   on_finish => sub {
	      say "The routine aborted early - $_[-1]";
	      $loop->stop;
	   },
	);

	$loop->add( $routine );

	$nums_ch->send( [ 10, 20, 30 ] );
	$ret_ch->recv(
	   on_recv => sub {
	      my ( $ch, $totalref ) = @_;
	      say "The total of 10, 20, 30 is: $$totalref";
	      $loop->stop;
	   }
	);

	$loop->run;

DESCRIPTION

       This subclass of IO::Async::Process contains a body of code and executes it in a sub-process, allowing it to act independently of the main
       program. Once set up, all communication with the code happens by values passed into or out of the Routine via IO::Async::Channel objects.

       Because the code running inside the Routine runs within its own process, it is isolated from the rest of the program, in terms of memory,
       CPU time, and other resources, and perhaps most importantly in terms of control flow. The code contained within the Routine is free to make
       blocking calls without stalling the rest of the program. This makes it useful for using existing code which has no option not to block
       within an "IO::Async"-based program.

       To create asynchronous wrappers of functions that return a value based only on their arguments, and do not generally maintain state within
       the process it may be more convenient to use an IO::Async::Function instead, which uses an "IO::Async::Routine" to contain the body of the
       function and manages the Channels itself.

PARAMETERS

       The following named parameters may be passed to "new" or "configure":

       channels_in => ARRAY of IO::Async::Channel
	       ARRAY reference of "IO::Async::Channel" objects to set up for passing values in to the Routine.

       channels_out => ARRAY of IO::Async::Channel
	       ARRAY reference of "IO::Async::Channel" objects to set up for passing values out of the Routine.

       code => CODE
	       CODE reference to the body of the Routine, to execute once the channels are set up.

METHODS

       This class provides no additional methods, other than those provided by IO::Async::Process.

AUTHOR

       Paul Evans <leonerd@leonerd.org.uk>

perl v5.14.2							    2012-10-24						   IO::Async::Routine(3pm)

Check Out this Related Man Page

IO::Async::MergePoint(3pm)				User Contributed Perl Documentation				IO::Async::MergePoint(3pm)

NAME

       "IO::Async::MergePoint" - resynchronise diverged control flow

SYNOPSIS

       This module as now been moved to its own dist of Async::MergePoint.

       It is kept here as a trivial subclass for backward compatibility. Eventually this subclass may be removed. Any code using
       "IO::Async::MergePoint" should instead use Async::MergePoint.

	use Async::MergePoint;

	my $merge = Async::MergePoint->new(
	   needs => [ "leaves", "water" ],

	   on_finished => sub {
	      my %items = @_;
	      # Make tea using $items{leaves} and $items{water}
	   }
	);

	Kettle->boil(
	   on_boiled => sub { $merge->done( "water", $_[0] ) }
	);

	Cupboard->get_tea_leaves(
	   on_fetched => sub { $merge->done( "leaves", $_[0] ) }
	);

DESCRIPTION

       Often in program logic, multiple different steps need to be taken that are independent of each other, but their total result is needed
       before the next step can be taken. In synchonous code, the usual approach is to do them sequentially.

       An "IO::Async"-based program could do this, but if each step involves some IO idle time, better overall performance can often be gained by
       running the steps in parallel. A Async::MergePoint object can then be used to wait for all of the steps to complete, before passing the
       combined result of each step on to the next stage.

       A merge point maintains a set of outstanding operations it is waiting on; these are arbitrary string values provided at the object's
       construction. Each time the "done" method is called, the named item is marked as being complete. When all of the required items are so
       marked, the "on_finished" continuation is invoked.

       When an item is marked as complete, a value can also be provided, which would contain the results of that step. The "on_finished" callback
       is passed a hash (in list form, rather than by reference) of the collected item values.

AUTHOR

       Paul Evans <leonerd@leonerd.org.uk>

perl v5.14.2							    2012-10-24						IO::Async::MergePoint(3pm)

Linux and UNIX Man Pages

io::async::routine(3pm) [debian man page]

Check Out this Related Man Page