cps::governor(3pm) [debian man page]

CPS::Governor(3pm)					User Contributed Perl Documentation					CPS::Governor(3pm)

NAME

       "CPS::Governor" - control the iteration of the "CPS" functions

DESCRIPTION

       Objects based on this abstract class are used by the "gk*" variants of the CPS functions, to control their behavior. These objects are
       expected to provide a method, "again", which the functions will use to re-invoke iterations of loops, and so on. By providing a different
       implementation of this method, governor objects can provide such behaviours as rate-limiting, asynchronisation or parallelism, and
       integration with event-based IO frameworks.

CONSTRUCTOR

   $gov = CPS::Governor->new
       Must be called on a subclass which implements the "again" method. Returns a new instance of a governor object in that class.

SUBCLASS METHODS

       Because this is an abstract class, instances of it can only be constructed on a subclass which implements the following methods:

   $gov->again( $code, @args )
       Execute the function given in the "CODE" reference $code, passing in the arguments @args. If this is going to be executed immediately, it
       should be invoked using a tail-call directly by the "again" method, so that the stack does not grow arbitrarily. This can be achieved by,
       for example:

	@_ = @args;
	goto &$code;

       Alternatively, the Sub::Call::Tail may be used to apply syntactic sugar, allowing you to write instead:

	use Sub::Call::Tail;
	...
	tail $code->( @args );

EXAMPLES

   A Governor With A Time Delay
       Consider the following subclass, which implements a "CPS::Governor" subclass that calls "sleep()" between every invocation.

	package Governor::Sleep

	use base qw( CPS::Governor );

	sub new
	{
	   my $class = shift;
	   my ( $delay ) = @_;

	   my $self = $class->SUPER::new;
	   $self->{delay} = $delay;

	   return $self;
	}

	sub again
	{
	   my $self = shift;
	   my $code = shift;

	   sleep $self->{delay};

	   # @args are still in @_
	   goto &$code;
	}

SEE ALSO

       o   Sub::Call::Tail - Tail calls for subroutines and methods

AUTHOR

       Paul Evans <leonerd@leonerd.org.uk>

perl v5.14.2							    2012-06-27							CPS::Governor(3pm)

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Mojo::IOLoop::Delay(3pm)				User Contributed Perl Documentation				  Mojo::IOLoop::Delay(3pm)

NAME

       Mojo::IOLoop::Delay - Synchronize events

SYNOPSIS

	 use Mojo::IOLoop::Delay;

	 # Synchronize multiple events
	 my $delay = Mojo::IOLoop::Delay->new;
	 $delay->on(finish => sub { say 'BOOM!' });
	 for my $i (1 .. 10) {
	   $delay->begin;
	   Mojo::IOLoop->timer($i => sub {
	     say 10 - $i;
	     $delay->end;
	   });
	 }

	 # Wait for events if necessary
	 $delay->wait unless Mojo::IOLoop->is_running;

DESCRIPTION

       Mojo::IOLoop::Delay synchronizes events for Mojo::IOLoop.

EVENTS

       Mojo::IOLoop::Delay can emit the following events.

   "finish"
	 $delay->on(finish => sub {
	   my $delay = shift;
	   ...
	 });

       Emitted safely once the active event counter reaches zero.

ATTRIBUTES

       Mojo::IOLoop::Delay implements the following attributes.

   "ioloop"
	 my $ioloop = $delay->ioloop;
	 $delay     = $delay->ioloop(Mojo::IOLoop->new);

       Loop object to control, defaults to the global Mojo::IOLoop singleton.

METHODS

       Mojo::IOLoop::Delay inherits all methods from Mojo::EventEmitter and implements the following new ones.

   "begin"
	 my $cb = $delay->begin;

       Increment active event counter, the returned callback can be used instead of "end".

	 my $delay = Mojo::IOLoop->delay;
	 Mojo::UserAgent->new->get('mojolicio.us' => $delay->begin);
	 my $tx = $delay->wait;

   "end"
	 $delay->end;
	 $delay->end(@args);

       Decrement active event counter.

   "wait"
	 my @args = $delay->wait;

       Start "ioloop" and stop it again once the "finish" event gets emitted, only works when "ioloop" is not running already.

	 # Use the "finish" event to synchronize portably
	 $delay->on(finish => sub {
	   my ($delay, @args) = @_;
	   ...
	 });
	 $delay->wait unless $delay->ioloop->is_running;

SEE ALSO

       Mojolicious, Mojolicious::Guides, <http://mojolicio.us>.

perl v5.14.2							    2012-09-05						  Mojo::IOLoop::Delay(3pm)

Linux and UNIX Man Pages

cps::governor(3pm) [debian man page]

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