1 files changed, 196 insertions, 0 deletions
diff --git a/lib/IO/Async/PID.pm b/lib/IO/Async/PID.pm
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@@ -0,0 +1,196 @@
+#  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, 2010-2011 -- leonerd@leonerd.org.uk
+
+package IO::Async::PID;
+
+use strict;
+use warnings;
+use base qw( IO::Async::Notifier );
+
+our $VERSION = '0.67';
+
+use Carp;
+
+=head1 NAME
+
+C<IO::Async::PID> - event callback on exit of a child process
+
+=head1 SYNOPSIS
+
+ use IO::Async::PID;
+ use POSIX qw( WEXITSTATUS );
+
+ use IO::Async::Loop;
+ my $loop = IO::Async::Loop->new;
+
+ my $kid = $loop->fork(
+    code => sub {
+       print "Child sleeping..\n";
+       sleep 10;
+       print "Child exiting\n";
+       return 20;
+    },
+ );
+
+ print "Child process $kid started\n";
+
+ my $pid = IO::Async::PID->new(
+    pid => $kid,
+
+    on_exit => sub {
+       my ( $self, $exitcode ) = @_;
+       printf "Child process %d exited with status %d\n",
+          $self->pid, WEXITSTATUS($exitcode);
+    },
+ );
+
+ $loop->add( $pid );
+
+ $loop->run;
+
+=head1 DESCRIPTION
+
+This subclass of L<IO::Async::Notifier> invokes its callback when a process
+exits.
+
+For most use cases, a L<IO::Async::Process> object provides more control of
+setting up the process, connecting filehandles to it, sending data to and
+receiving data from it.
+
+=cut
+
+=head1 EVENTS
+
+The following events are invoked, either using subclass methods or CODE
+references in parameters:
+
+=head2 on_exit $exitcode
+
+Invoked when the watched process exits.
+
+=cut
+
+=head1 PARAMETERS
+
+The following named parameters may be passed to C<new> or C<configure>:
+
+=head2 pid => INT
+
+The process ID to watch. Must be given before the object has been added to the
+containing C<IO::Async::Loop> object.
+
+=head2 on_exit => CODE
+
+CODE reference for the C<on_exit> event.
+
+Once the C<on_exit> continuation has been invoked, the C<IO::Async::PID>
+object is removed from the containing C<IO::Async::Loop> object.
+
+=cut
+
+sub configure
+{
+   my $self = shift;
+   my %params = @_;
+
+   if( exists $params{pid} ) {
+      $self->loop and croak "Cannot configure 'pid' after adding to Loop";
+      $self->{pid} = delete $params{pid};
+   }
+
+   if( exists $params{on_exit} ) {
+      $self->{on_exit} = delete $params{on_exit};
+
+      undef $self->{cb};
+
+      if( my $loop = $self->loop ) {
+         $self->_remove_from_loop( $loop );
+         $self->_add_to_loop( $loop );
+      }
+   }
+
+   $self->SUPER::configure( %params );
+}
+
+sub _add_to_loop
+{
+   my $self = shift;
+   my ( $loop ) = @_;
+
+   $self->pid or croak "Require a 'pid' in $self";
+
+   $self->SUPER::_add_to_loop( @_ );
+
+   # on_exit continuation gets passed PID value; need to replace that with
+   # $self
+   $self->{cb} ||= $self->_replace_weakself( sub {
+      my $self = shift or return;
+      my ( $exitcode ) = @_;
+
+      $self->invoke_event( on_exit => $exitcode );
+
+      # Since this is a oneshot, we'll have to remove it from the loop or
+      # parent Notifier
+      $self->remove_from_parent;
+   } );
+
+   $loop->watch_child( $self->pid, $self->{cb} );
+}
+
+sub _remove_from_loop
+{
+   my $self = shift;
+   my ( $loop ) = @_;
+
+   $loop->unwatch_child( $self->pid );
+}
+
+sub notifier_name
+{
+   my $self = shift;
+   if( length( my $name = $self->SUPER::notifier_name ) ) {
+      return $name;
+   }
+
+   return $self->{pid};
+}
+
+=head1 METHODS
+
+=cut
+
+=head2 $process_id = $pid->pid
+
+Returns the underlying process ID
+
+=cut
+
+sub pid
+{
+   my $self = shift;
+   return $self->{pid};
+}
+
+=head2 $pid->kill( $signal )
+
+Sends a signal to the process
+
+=cut
+
+sub kill
+{
+   my $self = shift;
+   my ( $signal ) = @_;
+
+   kill $signal, $self->pid or croak "Cannot kill() - $!";
+}
+
+=head1 AUTHOR
+
+Paul Evans <leonerd@leonerd.org.uk>
+
+=cut
+
+0x55AA;