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PEVANS / IO-Async-0.803 / lib / IO / Async / Timer / Absolute.pm 

            

              
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#  You may distribute under the terms of either the GNU General Public License
#  or the Artistic License (the same terms as Perl itself)
#
#  (C) Paul Evans, 2010-2024 -- leonerd@leonerd.org.uk
package IO::Async::Timer::Absolute 0.803;
use v5.14;
use warnings;
use base qw( IO::Async::Timer );
use Carp;
=head1 NAME
C<IO::Async::Timer::Absolute> - event callback at a fixed future time
=head1 SYNOPSIS
   use IO::Async::Timer::Absolute;
   use POSIX qw( mktime );
   use IO::Async::Loop;
   my $loop = IO::Async::Loop->new;
   my @time = gmtime;
   my $timer = IO::Async::Timer::Absolute->new(
      time => mktime( 0, 0, 0, $time[3]+1, $time[4], $time[5] ),
      on_expire => sub {
         print "It's midnight\n";
         $loop->stop;
      },
   );
   $loop->add( $timer );
   $loop->run;
=head1 DESCRIPTION
This subclass of L<IO::Async::Timer> implements one-shot events at a fixed
time in the future. The object waits for a given timestamp, and invokes its
callback at that point in the future.
For a C<Timer> object that waits for a delay relative to the time it is
started, see instead L<IO::Async::Timer::Countdown>.
=cut
=head1 EVENTS
The following events are invoked, either using subclass methods or CODE
references in parameters:
=head2 on_expire
Invoked when the timer expires.
=cut
=head1 PARAMETERS
The following named parameters may be passed to C<new> or C<configure>:
=head2 on_expire => CODE
CODE reference for the C<on_expire> event.
=head2 time => NUM
The epoch time at which the timer will expire.
Once constructed, the timer object will need to be added to the C<Loop> before
it will work.
Unlike other timers, it does not make sense to C<start> this object, because
its expiry time is absolute, and not relative to the time it is started.
=cut
sub configure
{
   my $self = shift;
   my %params = @_;
   if( exists $params{on_expire} ) {
      my $on_expire = delete $params{on_expire};
      ref $on_expire or croak "Expected 'on_expire' as a reference";
      $self->{on_expire} = $on_expire;
      undef $self->{cb}; # Will be lazily constructed when needed
   }
   if( exists $params{time} ) {
      my $time = delete $params{time};
      $self->stop if $self->is_running;
      $self->{time} = $time;
      $self->start if !$self->is_running;
   }
   unless( $self->can_event( 'on_expire' ) ) {
      croak 'Expected either a on_expire callback or an ->on_expire method';
   }
   $self->SUPER::configure( %params );
}
sub _make_cb
{
   my $self = shift;
   return $self->_capture_weakself( sub {
      my $self = shift or return;
      undef $self->{id};
      $self->invoke_event( "on_expire" );
   } );
}
sub _make_enqueueargs
{
   my $self = shift;
   return at => $self->{time};
}
=head1 AUTHOR
Paul Evans <leonerd@leonerd.org.uk>
=cut
0x55AA;