lib/perl5/5.6.1/msys/IO/Poll.pm

   1
   2 # IO::Poll.pm
   3 #
   4 # Copyright (c) 1997-8 Graham Barr <gbarr@pobox.com>. All rights reserved.
   5 # This program is free software; you can redistribute it and/or
   6 # modify it under the same terms as Perl itself.
   7
   8 package IO::Poll;
   9
  10 use strict;
  11 use IO::Handle;
  12 use Exporter ();
  13 our(@ISA, @EXPORT_OK, @EXPORT, $VERSION);
  14
  15 @ISA = qw(Exporter);
  16 $VERSION = "0.05";
  17
  18 @EXPORT = qw( POLLIN
  19               POLLOUT
  20               POLLERR
  21               POLLHUP
  22               POLLNVAL
  23             );
  24
  25 @EXPORT_OK = qw(
  26  POLLPRI
  27  POLLRDNORM
  28  POLLWRNORM
  29  POLLRDBAND
  30  POLLWRBAND
  31  POLLNORM
  32                );
  33
  34 # [0] maps fd's to requested masks
  35 # [1] maps fd's to returned  masks
  36 # [2] maps fd's to handles
  37 sub new {
  38     my $class = shift;
  39
  40     my $self = bless [{},{},{}], $class;
  41
  42     $self;
  43 }
  44
  45 sub mask {
  46     my $self = shift;
  47     my $io = shift;
  48     my $fd = fileno($io);
  49     if (@_) {
  50         my $mask = shift;
  51         if($mask) {
  52           $self->[0]{$fd}{$io} = $mask; # the error events are always returned
  53           $self->[1]{$fd}      = 0;     # output mask
  54           $self->[2]{$io}      = $io;   # remember handle
  55         } else {
  56             delete $self->[0]{$fd}{$io};
  57           delete $self->[1]{$fd} unless %{$self->[0]{$fd}};
  58           delete $self->[2]{$io};
  59         }
  60     }
  61
  62     return unless exists $self->[0]{$fd} and exists $self->[0]{$fd}{$io};
  63         return $self->[0]{$fd}{$io};
  64 }
  65
  66
  67 sub poll {
  68     my($self,$timeout) = @_;
  69
  70     $self->[1] = {};
  71
  72     my($fd,$mask,$iom);
  73     my @poll = ();
  74
  75     while(($fd,$iom) = each %{$self->[0]}) {
  76         $mask   = 0;
  77         $mask  |= $_ for values(%$iom);
  78         push(@poll,$fd => $mask);
  79     }
  80
  81     my $ret = @poll ? _poll(defined($timeout) ? $timeout * 1000 : -1,@poll) : 0;
  82
  83     return $ret
  84         unless $ret > 0;
  85
  86     while(@poll) {
  87         my($fd,$got) = splice(@poll,0,2);
  88         $self->[1]{$fd} = $got if $got;
  89     }
  90
  91     return $ret;
  92 }
  93
  94 sub events {
  95     my $self = shift;
  96     my $io = shift;
  97     my $fd = fileno($io);
  98     exists $self->[1]{$fd} and exists $self->[0]{$fd}{$io}
  99                 ? $self->[1]{$fd} & ($self->[0]{$fd}{$io}|POLLHUP|POLLERR|POLLNVAL)
 100         : 0;
 101 }
 102
 103 sub remove {
 104     my $self = shift;
 105     my $io = shift;
 106     $self->mask($io,0);
 107 }
 108
 109 sub handles {
 110     my $self = shift;
 111     return values %{$self->[2]} unless @_;
 112
 113     my $events = shift || 0;
 114     my($fd,$ev,$io,$mask);
 115     my @handles = ();
 116
 117     while(($fd,$ev) = each %{$self->[1]}) {
 118         while (($io,$mask) = each %{$self->[0]{$fd}}) {
 119             $mask |= POLLHUP|POLLERR|POLLNVAL;  # must allow these
 120             push @handles,$self->[2]{$io} if ($ev & $mask) & $events;
 121         }
 122     }
 123     return @handles;
 124 }
 125
 126 1;
 127
 128 __END__
 129
 130 =head1 NAME
 131
 132 IO::Poll - Object interface to system poll call
 133
 134 =head1 SYNOPSIS
 135
 136     use IO::Poll qw(POLLRDNORM POLLWRNORM POLLIN POLLHUP);
 137
 138     $poll = new IO::Poll;
 139
 140     $poll->mask($input_handle => POLLIN);
 141     $poll->mask($output_handle => POLLOUT);
 142
 143     $poll->poll($timeout);
 144
 145     $ev = $poll->events($input);
 146
 147 =head1 DESCRIPTION
 148
 149 C<IO::Poll> is a simple interface to the system level poll routine.
 150
 151 =head1 METHODS
 152
 153 =over 4
 154
 155 =item mask ( IO [, EVENT_MASK ] )
 156
 157 If EVENT_MASK is given, then, if EVENT_MASK is non-zero, IO is added to the
 158 list of file descriptors and the next call to poll will check for
 159 any event specified in EVENT_MASK. If EVENT_MASK is zero then IO will be
 160 removed from the list of file descriptors.
 161
 162 If EVENT_MASK is not given then the return value will be the current
 163 event mask value for IO.
 164
 165 =item poll ( [ TIMEOUT ] )
 166
 167 Call the system level poll routine. If TIMEOUT is not specified then the
 168 call will block. Returns the number of handles which had events
 169 happen, or -1 on error.
 170
 171 =item events ( IO )
 172
 173 Returns the event mask which represents the events that happend on IO
 174 during the last call to C<poll>.
 175
 176 =item remove ( IO )
 177
 178 Remove IO from the list of file descriptors for the next poll.
 179
 180 =item handles( [ EVENT_MASK ] )
 181
 182 Returns a list of handles. If EVENT_MASK is not given then a list of all
 183 handles known will be returned. If EVENT_MASK is given then a list
 184 of handles will be returned which had one of the events specified by
 185 EVENT_MASK happen during the last call ti C<poll>
 186
 187 =back
 188
 189 =head1 SEE ALSO
 190
 191 L<poll(2)>, L<IO::Handle>, L<IO::Select>
 192
 193 =head1 AUTHOR
 194
 195 Graham Barr. Currently maintained by the Perl Porters.  Please report all
 196 bugs to <perl5-porters@perl.org>.
 197
 198 =head1 COPYRIGHT
 199
 200 Copyright (c) 1997-8 Graham Barr <gbarr@pobox.com>. All rights reserved.
 201 This program is free software; you can redistribute it and/or
 202 modify it under the same terms as Perl itself.
 203
 204 =cut