This file is indexed.

/usr/share/perl5/IO/Async/Handle.pm is in libio-async-perl 0.71-1.

This file is owned by root:root, with mode 0o644.

The actual contents of the file can be viewed below.

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
#  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, 2006-2015 -- leonerd@leonerd.org.uk

package IO::Async::Handle;

use strict;
use warnings;
use base qw( IO::Async::Notifier );

our $VERSION = '0.71';

use Carp;

use IO::Handle; # give methods to bare IO handles

use Future;
use Future::Utils qw( try_repeat );

use IO::Async::OS;

=head1 NAME

C<IO::Async::Handle> - event callbacks for a non-blocking file descriptor

=head1 SYNOPSIS

This class is likely not to be used directly, because subclasses of it exist
to handle more specific cases. Here is an example of how it would be used to
watch a listening socket for new connections. In real code, it is likely that
the C<< Loop->listen >> method would be used instead.

 use IO::Socket::INET;
 use IO::Async::Handle;

 use IO::Async::Loop;
 my $loop = IO::Async::Loop->new;

 my $socket = IO::Socket::INET->new( LocalPort => 1234, Listen => 1 );

 my $handle = IO::Async::Handle->new(
    handle => $socket,

    on_read_ready  => sub {
       my $new_client = $socket->accept; 
       ...
    },
 );

 $loop->add( $handle );

For most other uses with sockets, pipes or other filehandles that carry a byte
stream, the L<IO::Async::Stream> class is likely to be more suitable. For
non-stream sockets, see L<IO::Async::Socket>.

=head1 DESCRIPTION

This subclass of L<IO::Async::Notifier> allows non-blocking IO on filehandles.
It provides event handlers for when the filehandle is read- or write-ready.

=cut

=head1 EVENTS

The following events are invoked, either using subclass methods or CODE
references in parameters:

=head2 on_read_ready

Invoked when the read handle becomes ready for reading.

=head2 on_write_ready

Invoked when the write handle becomes ready for writing.

=head2 on_closed

Optional. Invoked when the handle becomes closed.

This handler is invoked before the filehandles are closed and the Handle
removed from its containing Loop. The C<loop> will still return the containing
Loop object.

=cut

=head1 PARAMETERS

The following named parameters may be passed to C<new> or C<configure>:

=head2 read_handle => IO

=head2 write_handle => IO

The reading and writing IO handles. Each must implement the C<fileno> method.
Primarily used for passing C<STDIN> / C<STDOUT>; see the SYNOPSIS section of
L<IO::Async::Stream> for an example.

=head2 handle => IO

The IO handle for both reading and writing; instead of passing each separately
as above. Must implement C<fileno> method in way that C<IO::Handle> does.

=head2 read_fileno => INT

=head2 write_fileno => INT

File descriptor numbers for reading and writing. If these are given as an
alternative to C<read_handle> or C<write_handle> then a new C<IO::Handle>
instance will be constructed around each.

=head2 on_read_ready => CODE

=head2 on_write_ready => CODE

=head2 on_closed => CODE

CODE references for event handlers.

=head2 want_readready => BOOL

=head2 want_writeready => BOOL

If present, enable or disable read- or write-ready notification as per the
C<want_readready> and C<want_writeready> methods.

It is required that a matching C<on_read_ready> or C<on_write_ready> are
available for any handle that is provided; either passed as a callback CODE
reference or as an overridden the method. I.e. if only a C<read_handle> is
given, then C<on_write_ready> can be absent. If C<handle> is used as a
shortcut, then both read and write-ready callbacks or methods are required.

If no IO handles are provided at construction time, the object is still
created but will not yet be fully-functional as a Handle. IO handles can be
assigned later using the C<set_handle> or C<set_handles> methods, or by
C<configure>. This may be useful when constructing an object to represent a
network connection, before the C<connect(2)> has actually been performed yet.

=cut

sub configure
{
   my $self = shift;
   my %params = @_;

   if( exists $params{on_read_ready} ) {
      $self->{on_read_ready} = delete $params{on_read_ready};
      undef $self->{cb_r};

      $self->_watch_read(0), $self->_watch_read(1) if $self->want_readready;
   }

   if( exists $params{on_write_ready} ) {
      $self->{on_write_ready} = delete $params{on_write_ready};
      undef $self->{cb_w};

      $self->_watch_write(0), $self->_watch_write(1) if $self->want_writeready;
   }

   if( exists $params{on_closed} ) {
      $self->{on_closed} = delete $params{on_closed};
   }

   if( defined $params{read_fileno} and defined $params{write_fileno} and
       $params{read_fileno} == $params{write_fileno} ) {
      $params{handle} = IO::Handle->new_from_fd( $params{read_fileno}, "r+" );

      delete $params{read_fileno};
      delete $params{write_fileno};
   }
   else {
      $params{read_handle} = IO::Handle->new_from_fd( delete $params{read_fileno}, "r" )
         if defined $params{read_fileno};

      $params{write_handle} = IO::Handle->new_from_fd( delete $params{write_fileno}, "w" )
         if defined $params{write_fileno};
   }

   # 'handle' is a shortcut for setting read_ and write_
   if( exists $params{handle} ) {
      $params{read_handle}  = $params{handle};
      $params{write_handle} = $params{handle};
      delete $params{handle};
   }

   if( exists $params{read_handle} ) {
      my $read_handle = delete $params{read_handle};

      if( defined $read_handle ) {
         if( !defined eval { $read_handle->fileno } ) {
            croak 'Expected that read_handle can ->fileno';
         }

         unless( $self->can_event( 'on_read_ready' ) ) {
            croak 'Expected either a on_read_ready callback or an ->on_read_ready method';
         }

         my @layers = PerlIO::get_layers( $read_handle );
         if( grep m/^encoding\(/, @layers or grep m/^utf8$/, @layers ) {
            # Only warn for now, because if it's UTF-8 by default but only
            # passes ASCII then all will be well
            carp "Constructing a ".ref($self)." with an encoding-enabled handle may not read correctly";
         }

         $self->{read_handle} = $read_handle;

         $self->want_readready( defined $read_handle );
      }
      else {
         $self->want_readready( 0 );

         undef $self->{read_handle};
      }

      # In case someone has reopened the filehandles during an on_closed handler
      undef $self->{handle_closing};
   }

   if( exists $params{write_handle} ) {
      my $write_handle = delete $params{write_handle};

      if( defined $write_handle ) {
         if( !defined eval { $write_handle->fileno } ) {
            croak 'Expected that write_handle can ->fileno';
         }

         unless( $self->can_event( 'on_write_ready' ) ) {
            # This used not to be fatal. Make it just a warning for now.
            carp 'A write handle was provided but neither a on_write_ready callback nor an ->on_write_ready method were. Perhaps you mean \'read_handle\' instead?';
         }

         $self->{write_handle} = $write_handle;
      }
      else {
         $self->want_writeready( 0 );

         undef $self->{write_handle};
      }

      # In case someone has reopened the filehandles during an on_closed handler
      undef $self->{handle_closing};
   }

   if( exists $params{want_readready} ) {
      $self->want_readready( delete $params{want_readready} );
   }

   if( exists $params{want_writeready} ) {
      $self->want_writeready( delete $params{want_writeready} );
   }

   $self->SUPER::configure( %params );
}

# We'll be calling these any of three times
#   adding to/removing from loop
#   caller en/disables readiness checking
#   changing filehandle

sub _watch_read
{
   my $self = shift;
   my ( $want ) = @_;

   my $loop = $self->loop or return;
   my $fh = $self->read_handle or return;

   if( $want ) {
      $self->{cb_r} ||= $self->make_event_cb( 'on_read_ready' );

      $loop->watch_io(
         handle => $fh,
         on_read_ready => $self->{cb_r},
      );
   }
   else {
      $loop->unwatch_io(
         handle => $fh,
         on_read_ready => 1,
      );
   }
}

sub _watch_write
{
   my $self = shift;
   my ( $want ) = @_;

   my $loop = $self->loop or return;
   my $fh = $self->write_handle or return;

   if( $want ) {
      $self->{cb_w} ||= $self->make_event_cb( 'on_write_ready' );

      $loop->watch_io(
         handle => $fh,
         on_write_ready => $self->{cb_w},
      );
   }
   else {
      $loop->unwatch_io(
         handle => $fh,
         on_write_ready => 1,
      );
   }
}

sub _add_to_loop
{
   my $self = shift;
   my ( $loop ) = @_;

   $self->_watch_read(1)  if $self->want_readready;
   $self->_watch_write(1) if $self->want_writeready;
}

sub _remove_from_loop
{
   my $self = shift;
   my ( $loop ) = @_;

   $self->_watch_read(0);
   $self->_watch_write(0);
}

sub notifier_name
{
   my $self = shift;
   if( length( my $name = $self->SUPER::notifier_name ) ) {
      return $name;
   }

   my $r = $self->read_fileno;
   my $w = $self->write_fileno;
   return "rw=$r"     if defined $r and defined $w and $r == $w;
   return "r=$r,w=$w" if defined $r and defined $w;
   return "r=$r"      if defined $r;
   return "w=$w"      if defined $w;
   return "no";
}

=head1 METHODS

The following methods documented with a trailing call to C<< ->get >> return
L<Future> instances.

=cut

=head2 set_handle

   $handle->set_handles( %params )

Sets new reading or writing filehandles. Equivalent to calling the
C<configure> method with the same parameters.

=cut

sub set_handles
{
   my $self = shift;
   my %params = @_;

   $self->configure(
      exists $params{read_handle}  ? ( read_handle  => $params{read_handle} )  : (),
      exists $params{write_handle} ? ( write_handle => $params{write_handle} ) : (),
   );
}

=head2 set_handle

   $handle->set_handle( $fh )

Shortcut for

 $handle->configure( handle => $fh )

=cut

sub set_handle
{
   my $self = shift;
   my ( $fh ) = @_;

   $self->configure( handle => $fh );
}

=head2 close

   $handle->close

This method calls C<close> on the underlying IO handles. This method will then
remove the handle from its containing loop.

=cut

sub close
{
   my $self = shift;

   # Prevent infinite loops if there's two crosslinked handles
   return if $self->{handle_closing};
   $self->{handle_closing} = 1;

   $self->want_readready( 0 );
   $self->want_writeready( 0 );

   my $read_handle = delete $self->{read_handle};
   $read_handle->close if defined $read_handle;

   my $write_handle = delete $self->{write_handle};
   $write_handle->close if defined $write_handle;

   $self->_closed;
}

sub _closed
{
   my $self = shift;

   $self->maybe_invoke_event( on_closed => );
   if( $self->{close_futures} ) {
      $_->done for @{ $self->{close_futures} };
   }
   $self->remove_from_parent;
}

=head2 close_read

=head2 close_write

   $handle->close_read

   $handle->close_write

Closes the underlying read or write handle, and deconfigures it from the
object. Neither of these methods will invoke the C<on_closed> event, nor
remove the object from the Loop if there is still one open handle in the
object. Only when both handles are closed, will C<on_closed> be fired, and the
object removed.

=cut

sub close_read
{
   my $self = shift;

   $self->want_readready( 0 );

   my $read_handle = delete $self->{read_handle};
   $read_handle->close if defined $read_handle;

   $self->_closed if !$self->{write_handle};
}

sub close_write
{
   my $self = shift;

   $self->want_writeready( 0 );

   my $write_handle = delete $self->{write_handle};
   $write_handle->close if defined $write_handle;

   $self->_closed if !$self->{read_handle};
}

=head2 new_close_future

   $handle->new_close_future->get

Returns a new L<IO::Async::Future> object which will become done when the
handle is closed. Cancelling the C<$future> will remove this notification
ability but will not otherwise affect the C<$handle>.

=cut

sub new_close_future
{
   my $self = shift;

   push @{ $self->{close_futures} }, my $future = $self->loop->new_future;
   $future->on_cancel(
      $self->_capture_weakself( sub {
         my $self = shift or return;
         my $future = shift;

         @{ $self->{close_futures} } = grep { $_ != $future } @{ $self->{close_futures} };
      })
   );

   return $future;
}

=head2 read_handle

=head2 write_handle

   $handle = $handle->read_handle

   $handle = $handle->write_handle

These accessors return the underlying IO handles.

=cut

sub read_handle
{
   my $self = shift;
   return $self->{read_handle};
}

sub write_handle
{
   my $self = shift;
   return $self->{write_handle};
}

=head2 read_fileno

=head2 write_fileno

   $fileno = $handle->read_fileno

   $fileno = $handle->write_fileno

These accessors return the file descriptor numbers of the underlying IO
handles.

=cut

sub read_fileno
{
   my $self = shift;
   my $handle = $self->read_handle or return undef;
   return $handle->fileno;
}

sub write_fileno
{
   my $self = shift;
   my $handle = $self->write_handle or return undef;
   return $handle->fileno;
}

=head2 want_readready

=head2 want_writeready

   $value = $handle->want_readready

   $oldvalue = $handle->want_readready( $newvalue )

   $value = $handle->want_writeready

   $oldvalue = $handle->want_writeready( $newvalue )

These are the accessor for the C<want_readready> and C<want_writeready>
properties, which define whether the object is interested in knowing about 
read- or write-readiness on the underlying file handle.

=cut

sub want_readready
{
   my $self = shift;
   if( @_ ) {
      my ( $new ) = @_;

      $new = !!$new;
      return $new if !$new == !$self->{want_readready}; # compare bools

      if( $new ) {
         defined $self->read_handle or
            croak 'Cannot want_readready in a Handle with no read_handle';
      }

      my $old = $self->{want_readready};
      $self->{want_readready} = $new;

      $self->_watch_read( $new );

      return $old;
   }
   else {
      return $self->{want_readready};
   }
}

sub want_writeready
{
   my $self = shift;
   if( @_ ) {
      my ( $new ) = @_;

      $new = !!$new;
      return $new if !$new == !$self->{want_writeready}; # compare bools

      if( $new ) {
         defined $self->write_handle or
            croak 'Cannot want_writeready in a Handle with no write_handle';
      }

      my $old = $self->{want_writeready};
      $self->{want_writeready} = $new;

      $self->_watch_write( $new );

      return $old;
   }
   else {
      return $self->{want_writeready};
   }
}

=head2 socket

   $handle->socket( $ai )

Convenient shortcut to creating a socket handle, as given by an addrinfo
structure, and setting it as the read and write handle for the object.

C<$ai> may be either a C<HASH> or C<ARRAY> reference of the same form as given
to L<IO::Async::OS>'s C<extract_addrinfo> method.

This method returns nothing if it succeeds, or throws an exception if it
fails.

=cut

sub socket
{
   my $self = shift;
   my ( $ai ) = @_;

   # TODO: Something about closing the old one?

   my ( $family, $socktype, $protocol ) = IO::Async::OS->extract_addrinfo( $ai );

   my $sock = IO::Async::OS->socket( $family, $socktype, $protocol );
   $self->set_handle( $sock );
}

=head2 bind

   $handle = $handle->bind( %args )->get

Performs a C<getaddrinfo> resolver operation with the C<passive> flag set,
and then attempts to bind a socket handle of any of the return values.

=head2 bind (1 argument)

   $handle = $handle->bind( $ai )->get

When invoked with a single argument, this method is a convenient shortcut to
creating a socket handle and C<bind()>ing it to the address as given by an
addrinfo structure, and setting it as the read and write handle for the
object.

C<$ai> may be either a C<HASH> or C<ARRAY> reference of the same form as given
to L<IO::Async::OS>'s C<extract_addrinfo> method.

The returned future returns the handle object itself for convenience.

=cut

sub bind
{
   my $self = shift;

   if( @_ == 1 ) {
      my ( $ai ) = @_;

      $self->socket( $ai );
      my $addr = ( IO::Async::OS->extract_addrinfo( $ai ) )[3];

      $self->read_handle->bind( $addr ) or
         return Future->fail( "Cannot bind - $!", bind => $self->read_handle, $addr, $! );

      return Future->done( $self );
   }

   $self->loop->resolver->getaddrinfo( passive => 1, @_ )->then( sub {
      my @addrs = @_;

      try_repeat {
         my $ai = shift;

         $self->bind( $ai );
      } foreach => \@addrs,
        until => sub { shift->is_done };
   });
}

=head2 connect

   $handle = $handle->connect( %args )->get

A convenient wrapper for calling the C<connect> method on the underlying
L<IO::Async::Loop> object.

=cut

sub connect
{
   my $self = shift;
   my %args = @_;

   my $loop = $self->loop or croak "Cannot ->connect a Handle that is not in a Loop";

   $self->debug_printf( "CONNECT " . join( ", ",
      # These args should be stringy
      ( map { defined $args{$_} ? "$_=$args{$_}" : () } qw( host service family socktype protocol local_host local_service ) )
   ) );

   return $self->loop->connect( %args, handle => $self );
}

=head1 SEE ALSO

=over 4

=item *

L<IO::Handle> - Supply object methods for I/O handles

=back

=head1 AUTHOR

Paul Evans <leonerd@leonerd.org.uk>

=cut

0x55AA;