Initial Commit

database/perl/lib/IO/Poll.pm

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+
+# IO::Poll.pm
+#
+# Copyright (c) 1997-8 Graham Barr <gbarr@pobox.com>. All rights reserved.
+# This program is free software; you can redistribute it and/or
+# modify it under the same terms as Perl itself.
+
+package IO::Poll;
+
+use strict;
+use IO::Handle;
+use Exporter ();
+
+our @ISA = qw(Exporter);
+our $VERSION = "1.45";
+
+our @EXPORT = qw( POLLIN
+	      POLLOUT
+	      POLLERR
+	      POLLHUP
+	      POLLNVAL
+	    );
+
+our @EXPORT_OK = qw(
+ POLLPRI
+ POLLRDNORM
+ POLLWRNORM
+ POLLRDBAND
+ POLLWRBAND
+ POLLNORM
+	       );
+
+# [0] maps fd's to requested masks
+# [1] maps fd's to returned  masks
+# [2] maps fd's to handles
+sub new {
+    my $class = shift;
+
+    my $self = bless [{},{},{}], $class;
+
+    $self;
+}
+
+sub mask {
+    my $self = shift;
+    my $io = shift;
+    my $fd = fileno($io);
+    return unless defined $fd;
+    if (@_) {
+	my $mask = shift;
+	if($mask) {
+	  $self->[0]{$fd}{$io} = $mask; # the error events are always returned
+	  $self->[1]{$fd}      = 0;     # output mask
+	  $self->[2]{$io}      = $io;   # remember handle
+	} else {
+          delete $self->[0]{$fd}{$io};
+          unless(%{$self->[0]{$fd}}) {
+            # We no longer have any handles for this FD
+            delete $self->[1]{$fd};
+            delete $self->[0]{$fd};
+          }
+          delete $self->[2]{$io};
+	}
+    }
+    
+    return unless exists $self->[0]{$fd} and exists $self->[0]{$fd}{$io};
+	return $self->[0]{$fd}{$io};
+}
+
+
+sub poll {
+    my($self,$timeout) = @_;
+
+    $self->[1] = {};
+
+    my($fd,$mask,$iom);
+    my @poll = ();
+
+    while(($fd,$iom) = each %{$self->[0]}) {
+	$mask   = 0;
+	$mask  |= $_ for values(%$iom);
+	push(@poll,$fd => $mask);
+    }
+
+    my $ret = _poll(defined($timeout) ? $timeout * 1000 : -1,@poll);
+
+    return $ret
+	unless $ret > 0;
+
+    while(@poll) {
+	my($fd,$got) = splice(@poll,0,2);
+	$self->[1]{$fd} = $got if $got;
+    }
+
+    return $ret;  
+}
+
+sub events {
+    my $self = shift;
+    my $io = shift;
+    my $fd = fileno($io);
+    exists $self->[1]{$fd} and exists $self->[0]{$fd}{$io} 
+                ? $self->[1]{$fd} & ($self->[0]{$fd}{$io}|POLLHUP|POLLERR|POLLNVAL)
+	: 0;
+}
+
+sub remove {
+    my $self = shift;
+    my $io = shift;
+    $self->mask($io,0);
+}
+
+sub handles {
+    my $self = shift;
+    return values %{$self->[2]} unless @_;
+
+    my $events = shift || 0;
+    my($fd,$ev,$io,$mask);
+    my @handles = ();
+
+    while(($fd,$ev) = each %{$self->[1]}) {
+	while (($io,$mask) = each %{$self->[0]{$fd}}) {
+	    $mask |= POLLHUP|POLLERR|POLLNVAL;  # must allow these
+	    push @handles,$self->[2]{$io} if ($ev & $mask) & $events;
+	}
+    }
+    return @handles;
+}
+
+1;
+
+__END__
+
+=head1 NAME
+
+IO::Poll - Object interface to system poll call
+
+=head1 SYNOPSIS
+
+    use IO::Poll qw(POLLRDNORM POLLWRNORM POLLIN POLLHUP);
+
+    $poll = IO::Poll->new();
+
+    $poll->mask($input_handle => POLLIN);
+    $poll->mask($output_handle => POLLOUT);
+
+    $poll->poll($timeout);
+
+    $ev = $poll->events($input);
+
+=head1 DESCRIPTION
+
+C<IO::Poll> is a simple interface to the system level poll routine.
+
+=head1 METHODS
+
+=over 4
+
+=item mask ( IO [, EVENT_MASK ] )
+
+If EVENT_MASK is given, then, if EVENT_MASK is non-zero, IO is added to the
+list of file descriptors and the next call to poll will check for
+any event specified in EVENT_MASK. If EVENT_MASK is zero then IO will be
+removed from the list of file descriptors.
+
+If EVENT_MASK is not given then the return value will be the current
+event mask value for IO.
+
+=item poll ( [ TIMEOUT ] )
+
+Call the system level poll routine. If TIMEOUT is not specified then the
+call will block. Returns the number of handles which had events
+happen, or -1 on error.
+
+=item events ( IO )
+
+Returns the event mask which represents the events that happened on IO
+during the last call to C<poll>.
+
+=item remove ( IO )
+
+Remove IO from the list of file descriptors for the next poll.
+
+=item handles( [ EVENT_MASK ] )
+
+Returns a list of handles. If EVENT_MASK is not given then a list of all
+handles known will be returned. If EVENT_MASK is given then a list
+of handles will be returned which had one of the events specified by
+EVENT_MASK happen during the last call ti C<poll>
+
+=back
+
+=head1 SEE ALSO
+
+L<poll(2)>, L<IO::Handle>, L<IO::Select>
+
+=head1 AUTHOR
+
+Graham Barr. Currently maintained by the Perl Porters.  Please report all
+bugs to <perlbug@perl.org>.
+
+=head1 COPYRIGHT
+
+Copyright (c) 1997-8 Graham Barr <gbarr@pobox.com>. All rights reserved.
+This program is free software; you can redistribute it and/or
+modify it under the same terms as Perl itself.
+
+=cut