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Comparing AnyEvent/lib/AnyEvent/Handle.pm (file contents):
Revision 1.77 by root, Sun Jul 27 07:25:39 2008 UTC vs.
Revision 1.132 by elmex, Thu Jul 2 22:25:13 2009 UTC

1package AnyEvent::Handle; 1package AnyEvent::Handle;
2 2
3no warnings; 3no warnings;
4use strict; 4use strict qw(subs vars);
5 5
6use AnyEvent (); 6use AnyEvent ();
7use AnyEvent::Util qw(WSAEWOULDBLOCK); 7use AnyEvent::Util qw(WSAEWOULDBLOCK);
8use Scalar::Util (); 8use Scalar::Util ();
9use Carp (); 9use Carp ();
14 14
15AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent 15AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent
16 16
17=cut 17=cut
18 18
19our $VERSION = 4.22; 19our $VERSION = 4.45;
20 20
21=head1 SYNOPSIS 21=head1 SYNOPSIS
22 22
23 use AnyEvent; 23 use AnyEvent;
24 use AnyEvent::Handle; 24 use AnyEvent::Handle;
27 27
28 my $handle = 28 my $handle =
29 AnyEvent::Handle->new ( 29 AnyEvent::Handle->new (
30 fh => \*STDIN, 30 fh => \*STDIN,
31 on_eof => sub { 31 on_eof => sub {
32 $cv->broadcast; 32 $cv->send;
33 }, 33 },
34 ); 34 );
35 35
36 # send some request line 36 # send some request line
37 $handle->push_write ("getinfo\015\012"); 37 $handle->push_write ("getinfo\015\012");
49 49
50This module is a helper module to make it easier to do event-based I/O on 50This module is a helper module to make it easier to do event-based I/O on
51filehandles. For utility functions for doing non-blocking connects and accepts 51filehandles. For utility functions for doing non-blocking connects and accepts
52on sockets see L<AnyEvent::Util>. 52on sockets see L<AnyEvent::Util>.
53 53
54The L<AnyEvent::Intro> tutorial contains some well-documented
55AnyEvent::Handle examples.
56
54In the following, when the documentation refers to of "bytes" then this 57In the following, when the documentation refers to of "bytes" then this
55means characters. As sysread and syswrite are used for all I/O, their 58means characters. As sysread and syswrite are used for all I/O, their
56treatment of characters applies to this module as well. 59treatment of characters applies to this module as well.
57 60
58All callbacks will be invoked with the handle object as their first 61All callbacks will be invoked with the handle object as their first
60 63
61=head1 METHODS 64=head1 METHODS
62 65
63=over 4 66=over 4
64 67
65=item B<new (%args)> 68=item $handle = B<new> AnyEvent::TLS fh => $filehandle, key => value...
66 69
67The constructor supports these arguments (all as key => value pairs). 70The constructor supports these arguments (all as C<< key => value >> pairs).
68 71
69=over 4 72=over 4
70 73
71=item fh => $filehandle [MANDATORY] 74=item fh => $filehandle [MANDATORY]
72 75
73The filehandle this L<AnyEvent::Handle> object will operate on. 76The filehandle this L<AnyEvent::Handle> object will operate on.
74 77
75NOTE: The filehandle will be set to non-blocking (using 78NOTE: The filehandle will be set to non-blocking mode (using
76AnyEvent::Util::fh_nonblocking). 79C<AnyEvent::Util::fh_nonblocking>) by the constructor and needs to stay in
80that mode.
77 81
78=item on_eof => $cb->($handle) 82=item on_eof => $cb->($handle)
79 83
80Set the callback to be called when an end-of-file condition is detected, 84Set the callback to be called when an end-of-file condition is detected,
81i.e. in the case of a socket, when the other side has closed the 85i.e. in the case of a socket, when the other side has closed the
82connection cleanly. 86connection cleanly.
83 87
88For sockets, this just means that the other side has stopped sending data,
89you can still try to write data, and, in fact, one can return from the EOF
90callback and continue writing data, as only the read part has been shut
91down.
92
84While not mandatory, it is highly recommended to set an eof callback, 93While not mandatory, it is I<highly> recommended to set an EOF callback,
85otherwise you might end up with a closed socket while you are still 94otherwise you might end up with a closed socket while you are still
86waiting for data. 95waiting for data.
96
97If an EOF condition has been detected but no C<on_eof> callback has been
98set, then a fatal error will be raised with C<$!> set to <0>.
87 99
88=item on_error => $cb->($handle, $fatal) 100=item on_error => $cb->($handle, $fatal)
89 101
90This is the error callback, which is called when, well, some error 102This is the error callback, which is called when, well, some error
91occured, such as not being able to resolve the hostname, failure to 103occured, such as not being able to resolve the hostname, failure to
92connect or a read error. 104connect or a read error.
93 105
94Some errors are fatal (which is indicated by C<$fatal> being true). On 106Some errors are fatal (which is indicated by C<$fatal> being true). On
95fatal errors the handle object will be shut down and will not be 107fatal errors the handle object will be shut down and will not be usable
108(but you are free to look at the current C<< ->rbuf >>). Examples of fatal
109errors are an EOF condition with active (but unsatisifable) read watchers
110(C<EPIPE>) or I/O errors.
111
96usable. Non-fatal errors can be retried by simply returning, but it is 112Non-fatal errors can be retried by simply returning, but it is recommended
97recommended to simply ignore this parameter and instead abondon the handle 113to simply ignore this parameter and instead abondon the handle object
98object when this callback is invoked. 114when this callback is invoked. Examples of non-fatal errors are timeouts
115C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
99 116
100On callback entrance, the value of C<$!> contains the operating system 117On callback entrance, the value of C<$!> contains the operating system
101error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>). 118error (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT> or C<EBADMSG>).
102 119
103While not mandatory, it is I<highly> recommended to set this callback, as 120While not mandatory, it is I<highly> recommended to set this callback, as
110and no read request is in the queue (unlike read queue callbacks, this 127and no read request is in the queue (unlike read queue callbacks, this
111callback will only be called when at least one octet of data is in the 128callback will only be called when at least one octet of data is in the
112read buffer). 129read buffer).
113 130
114To access (and remove data from) the read buffer, use the C<< ->rbuf >> 131To access (and remove data from) the read buffer, use the C<< ->rbuf >>
115method or access the C<$handle->{rbuf}> member directly. 132method or access the C<$handle->{rbuf}> member directly. Note that you
133must not enlarge or modify the read buffer, you can only remove data at
134the beginning from it.
116 135
117When an EOF condition is detected then AnyEvent::Handle will first try to 136When an EOF condition is detected then AnyEvent::Handle will first try to
118feed all the remaining data to the queued callbacks and C<on_read> before 137feed all the remaining data to the queued callbacks and C<on_read> before
119calling the C<on_eof> callback. If no progress can be made, then a fatal 138calling the C<on_eof> callback. If no progress can be made, then a fatal
120error will be raised (with C<$!> set to C<EPIPE>). 139error will be raised (with C<$!> set to C<EPIPE>).
135=item timeout => $fractional_seconds 154=item timeout => $fractional_seconds
136 155
137If non-zero, then this enables an "inactivity" timeout: whenever this many 156If non-zero, then this enables an "inactivity" timeout: whenever this many
138seconds pass without a successful read or write on the underlying file 157seconds pass without a successful read or write on the underlying file
139handle, the C<on_timeout> callback will be invoked (and if that one is 158handle, the C<on_timeout> callback will be invoked (and if that one is
140missing, an C<ETIMEDOUT> error will be raised). 159missing, a non-fatal C<ETIMEDOUT> error will be raised).
141 160
142Note that timeout processing is also active when you currently do not have 161Note that timeout processing is also active when you currently do not have
143any outstanding read or write requests: If you plan to keep the connection 162any outstanding read or write requests: If you plan to keep the connection
144idle then you should disable the timout temporarily or ignore the timeout 163idle then you should disable the timout temporarily or ignore the timeout
145in the C<on_timeout> callback. 164in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
165restart the timeout.
146 166
147Zero (the default) disables this timeout. 167Zero (the default) disables this timeout.
148 168
149=item on_timeout => $cb->($handle) 169=item on_timeout => $cb->($handle)
150 170
154 174
155=item rbuf_max => <bytes> 175=item rbuf_max => <bytes>
156 176
157If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>) 177If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
158when the read buffer ever (strictly) exceeds this size. This is useful to 178when the read buffer ever (strictly) exceeds this size. This is useful to
159avoid denial-of-service attacks. 179avoid some forms of denial-of-service attacks.
160 180
161For example, a server accepting connections from untrusted sources should 181For example, a server accepting connections from untrusted sources should
162be configured to accept only so-and-so much data that it cannot act on 182be configured to accept only so-and-so much data that it cannot act on
163(for example, when expecting a line, an attacker could send an unlimited 183(for example, when expecting a line, an attacker could send an unlimited
164amount of data without a callback ever being called as long as the line 184amount of data without a callback ever being called as long as the line
165isn't finished). 185isn't finished).
166 186
167=item autocork => <boolean> 187=item autocork => <boolean>
168 188
169When disabled (the default), then C<push_write> will try to immediately 189When disabled (the default), then C<push_write> will try to immediately
170write the data to the handle if possible. This avoids having to register 190write the data to the handle, if possible. This avoids having to register
171a write watcher and wait for the next event loop iteration, but can be 191a write watcher and wait for the next event loop iteration, but can
172inefficient if you write multiple small chunks (this disadvantage is 192be inefficient if you write multiple small chunks (on the wire, this
173usually avoided by your kernel's nagle algorithm, see C<low_delay>). 193disadvantage is usually avoided by your kernel's nagle algorithm, see
194C<no_delay>, but this option can save costly syscalls).
174 195
175When enabled, then writes will always be queued till the next event loop 196When enabled, then writes will always be queued till the next event loop
176iteration. This is efficient when you do many small writes per iteration, 197iteration. This is efficient when you do many small writes per iteration,
177but less efficient when you do a single write only. 198but less efficient when you do a single write only per iteration (or when
199the write buffer often is full). It also increases write latency.
178 200
179=item no_delay => <boolean> 201=item no_delay => <boolean>
180 202
181When doing small writes on sockets, your operating system kernel might 203When doing small writes on sockets, your operating system kernel might
182wait a bit for more data before actually sending it out. This is called 204wait a bit for more data before actually sending it out. This is called
183the Nagle algorithm, and usually it is beneficial. 205the Nagle algorithm, and usually it is beneficial.
184 206
185In some situations you want as low a delay as possible, which cna be 207In some situations you want as low a delay as possible, which can be
186accomplishd by setting this option to true. 208accomplishd by setting this option to a true value.
187 209
188The default is your opertaing system's default behaviour, this option 210The default is your opertaing system's default behaviour (most likely
189explicitly enables or disables it, if possible. 211enabled), this option explicitly enables or disables it, if possible.
190 212
191=item read_size => <bytes> 213=item read_size => <bytes>
192 214
193The default read block size (the amount of bytes this module will try to read 215The default read block size (the amount of bytes this module will
194during each (loop iteration). Default: C<8192>. 216try to read during each loop iteration, which affects memory
217requirements). Default: C<8192>.
195 218
196=item low_water_mark => <bytes> 219=item low_water_mark => <bytes>
197 220
198Sets the amount of bytes (default: C<0>) that make up an "empty" write 221Sets the amount of bytes (default: C<0>) that make up an "empty" write
199buffer: If the write reaches this size or gets even samller it is 222buffer: If the write reaches this size or gets even samller it is
200considered empty. 223considered empty.
201 224
225Sometimes it can be beneficial (for performance reasons) to add data to
226the write buffer before it is fully drained, but this is a rare case, as
227the operating system kernel usually buffers data as well, so the default
228is good in almost all cases.
229
202=item linger => <seconds> 230=item linger => <seconds>
203 231
204If non-zero (default: C<3600>), then the destructor of the 232If non-zero (default: C<3600>), then the destructor of the
205AnyEvent::Handle object will check wether there is still outstanding write 233AnyEvent::Handle object will check whether there is still outstanding
206data and will install a watcher that will write out this data. No errors 234write data and will install a watcher that will write this data to the
207will be reported (this mostly matches how the operating system treats 235socket. No errors will be reported (this mostly matches how the operating
208outstanding data at socket close time). 236system treats outstanding data at socket close time).
209 237
210This will not work for partial TLS data that could not yet been 238This will not work for partial TLS data that could not be encoded
211encoded. This data will be lost. 239yet. This data will be lost. Calling the C<stoptls> method in time might
240help.
241
242=item common_name => $string
243
244The common name used by some verification methods (most notably SSL/TLS)
245associated with this connection. Usually this is the remote hostname used
246to connect, but can be almost anything.
212 247
213=item tls => "accept" | "connect" | Net::SSLeay::SSL object 248=item tls => "accept" | "connect" | Net::SSLeay::SSL object
214 249
215When this parameter is given, it enables TLS (SSL) mode, that means it 250When this parameter is given, it enables TLS (SSL) mode, that means
216will start making tls handshake and will transparently encrypt/decrypt 251AnyEvent will start a TLS handshake as soon as the conenction has been
217data. 252established and will transparently encrypt/decrypt data afterwards.
218 253
219TLS mode requires Net::SSLeay to be installed (it will be loaded 254TLS mode requires Net::SSLeay to be installed (it will be loaded
220automatically when you try to create a TLS handle). 255automatically when you try to create a TLS handle): this module doesn't
256have a dependency on that module, so if your module requires it, you have
257to add the dependency yourself.
221 258
222For the TLS server side, use C<accept>, and for the TLS client side of a 259Unlike TCP, TLS has a server and client side: for the TLS server side, use
223connection, use C<connect> mode. 260C<accept>, and for the TLS client side of a connection, use C<connect>
261mode.
224 262
225You can also provide your own TLS connection object, but you have 263You can also provide your own TLS connection object, but you have
226to make sure that you call either C<Net::SSLeay::set_connect_state> 264to make sure that you call either C<Net::SSLeay::set_connect_state>
227or C<Net::SSLeay::set_accept_state> on it before you pass it to 265or C<Net::SSLeay::set_accept_state> on it before you pass it to
228AnyEvent::Handle. 266AnyEvent::Handle. Also, this module will take ownership of this connection
267object.
229 268
269At some future point, AnyEvent::Handle might switch to another TLS
270implementation, then the option to use your own session object will go
271away.
272
273B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
274passing in the wrong integer will lead to certain crash. This most often
275happens when one uses a stylish C<< tls => 1 >> and is surprised about the
276segmentation fault.
277
230See the C<starttls> method if you need to start TLS negotiation later. 278See the C<< ->starttls >> method for when need to start TLS negotiation later.
231 279
232=item tls_ctx => $ssl_ctx 280=item tls_ctx => $anyevent_tls
233 281
234Use the given Net::SSLeay::CTX object to create the new TLS connection 282Use the given C<AnyEvent::TLS> object to create the new TLS connection
235(unless a connection object was specified directly). If this parameter is 283(unless a connection object was specified directly). If this parameter is
236missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>. 284missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>.
237 285
286Instead of an object, you can also specify a hash reference with C<< key
287=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
288new TLS context object.
289
238=item json => JSON or JSON::XS object 290=item json => JSON or JSON::XS object
239 291
240This is the json coder object used by the C<json> read and write types. 292This is the json coder object used by the C<json> read and write types.
241 293
242If you don't supply it, then AnyEvent::Handle will create and use a 294If you don't supply it, then AnyEvent::Handle will create and use a
243suitable one, which will write and expect UTF-8 encoded JSON texts. 295suitable one (on demand), which will write and expect UTF-8 encoded JSON
296texts.
244 297
245Note that you are responsible to depend on the JSON module if you want to 298Note that you are responsible to depend on the JSON module if you want to
246use this functionality, as AnyEvent does not have a dependency itself. 299use this functionality, as AnyEvent does not have a dependency itself.
247 300
248=item filter_r => $cb
249
250=item filter_w => $cb
251
252These exist, but are undocumented at this time.
253
254=back 301=back
255 302
256=cut 303=cut
257 304
258sub new { 305sub new {
259 my $class = shift; 306 my $class = shift;
260
261 my $self = bless { @_ }, $class; 307 my $self = bless { @_ }, $class;
262 308
263 $self->{fh} or Carp::croak "mandatory argument fh is missing"; 309 $self->{fh} or Carp::croak "mandatory argument fh is missing";
264 310
265 AnyEvent::Util::fh_nonblocking $self->{fh}, 1; 311 AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
266
267 if ($self->{tls}) {
268 require Net::SSLeay;
269 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx});
270 }
271 312
272 $self->{_activity} = AnyEvent->now; 313 $self->{_activity} = AnyEvent->now;
273 $self->_timeout; 314 $self->_timeout;
274 315
316 $self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
317
318 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
319 if $self->{tls};
320
275 $self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain}; 321 $self->on_drain (delete $self->{on_drain}) if exists $self->{on_drain};
276 $self->no_delay (delete $self->{no_delay}) if exists $self->{no_delay};
277 322
278 $self->start_read 323 $self->start_read
279 if $self->{on_read}; 324 if $self->{on_read};
280 325
281 $self 326 $self->{fh} && $self
282} 327}
283 328
284sub _shutdown { 329sub _shutdown {
285 my ($self) = @_; 330 my ($self) = @_;
286 331
287 delete $self->{_tw}; 332 delete @$self{qw(_tw _rw _ww fh wbuf on_read _queue)};
288 delete $self->{_rw}; 333 $self->{_eof} = 1; # tell starttls et. al to stop trying
289 delete $self->{_ww};
290 delete $self->{fh};
291 334
292 $self->stoptls; 335 &_freetls;
293} 336}
294 337
295sub _error { 338sub _error {
296 my ($self, $errno, $fatal) = @_; 339 my ($self, $errno, $fatal) = @_;
297 340
300 343
301 $! = $errno; 344 $! = $errno;
302 345
303 if ($self->{on_error}) { 346 if ($self->{on_error}) {
304 $self->{on_error}($self, $fatal); 347 $self->{on_error}($self, $fatal);
305 } else { 348 } elsif ($self->{fh}) {
306 Carp::croak "AnyEvent::Handle uncaught error: $!"; 349 Carp::croak "AnyEvent::Handle uncaught error: $!";
307 } 350 }
308} 351}
309 352
310=item $fh = $handle->fh 353=item $fh = $handle->fh
311 354
312This method returns the file handle of the L<AnyEvent::Handle> object. 355This method returns the file handle used to create the L<AnyEvent::Handle> object.
313 356
314=cut 357=cut
315 358
316sub fh { $_[0]{fh} } 359sub fh { $_[0]{fh} }
317 360
335 $_[0]{on_eof} = $_[1]; 378 $_[0]{on_eof} = $_[1];
336} 379}
337 380
338=item $handle->on_timeout ($cb) 381=item $handle->on_timeout ($cb)
339 382
340Replace the current C<on_timeout> callback, or disables the callback 383Replace the current C<on_timeout> callback, or disables the callback (but
341(but not the timeout) if C<$cb> = C<undef>. See C<timeout> constructor 384not the timeout) if C<$cb> = C<undef>. See the C<timeout> constructor
342argument. 385argument and method.
343 386
344=cut 387=cut
345 388
346sub on_timeout { 389sub on_timeout {
347 $_[0]{on_timeout} = $_[1]; 390 $_[0]{on_timeout} = $_[1];
348} 391}
349 392
350=item $handle->autocork ($boolean) 393=item $handle->autocork ($boolean)
351 394
352Enables or disables the current autocork behaviour (see C<autocork> 395Enables or disables the current autocork behaviour (see C<autocork>
353constructor argument). 396constructor argument). Changes will only take effect on the next write.
354 397
355=cut 398=cut
399
400sub autocork {
401 $_[0]{autocork} = $_[1];
402}
356 403
357=item $handle->no_delay ($boolean) 404=item $handle->no_delay ($boolean)
358 405
359Enables or disables the C<no_delay> setting (see constructor argument of 406Enables or disables the C<no_delay> setting (see constructor argument of
360the same name for details). 407the same name for details).
453 my ($self, $cb) = @_; 500 my ($self, $cb) = @_;
454 501
455 $self->{on_drain} = $cb; 502 $self->{on_drain} = $cb;
456 503
457 $cb->($self) 504 $cb->($self)
458 if $cb && $self->{low_water_mark} >= length $self->{wbuf}; 505 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
459} 506}
460 507
461=item $handle->push_write ($data) 508=item $handle->push_write ($data)
462 509
463Queues the given scalar to be written. You can push as much data as you 510Queues the given scalar to be written. You can push as much data as you
480 substr $self->{wbuf}, 0, $len, ""; 527 substr $self->{wbuf}, 0, $len, "";
481 528
482 $self->{_activity} = AnyEvent->now; 529 $self->{_activity} = AnyEvent->now;
483 530
484 $self->{on_drain}($self) 531 $self->{on_drain}($self)
485 if $self->{low_water_mark} >= length $self->{wbuf} 532 if $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf})
486 && $self->{on_drain}; 533 && $self->{on_drain};
487 534
488 delete $self->{_ww} unless length $self->{wbuf}; 535 delete $self->{_ww} unless length $self->{wbuf};
489 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) { 536 } elsif ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK) {
490 $self->_error ($!, 1); 537 $self->_error ($!, 1);
514 561
515 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write") 562 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write")
516 ->($self, @_); 563 ->($self, @_);
517 } 564 }
518 565
519 if ($self->{filter_w}) { 566 if ($self->{tls}) {
520 $self->{filter_w}($self, \$_[0]); 567 $self->{_tls_wbuf} .= $_[0];
568
569 &_dotls ($self);
521 } else { 570 } else {
522 $self->{wbuf} .= $_[0]; 571 $self->{wbuf} .= $_[0];
523 $self->_drain_wbuf; 572 $self->_drain_wbuf;
524 } 573 }
525} 574}
542=cut 591=cut
543 592
544register_write_type netstring => sub { 593register_write_type netstring => sub {
545 my ($self, $string) = @_; 594 my ($self, $string) = @_;
546 595
547 sprintf "%d:%s,", (length $string), $string 596 (length $string) . ":$string,"
548}; 597};
549 598
550=item packstring => $format, $data 599=item packstring => $format, $data
551 600
552An octet string prefixed with an encoded length. The encoding C<$format> 601An octet string prefixed with an encoded length. The encoding C<$format>
726 775
727 if ( 776 if (
728 defined $self->{rbuf_max} 777 defined $self->{rbuf_max}
729 && $self->{rbuf_max} < length $self->{rbuf} 778 && $self->{rbuf_max} < length $self->{rbuf}
730 ) { 779 ) {
731 return $self->_error (&Errno::ENOSPC, 1); 780 $self->_error (&Errno::ENOSPC, 1), return;
732 } 781 }
733 782
734 while () { 783 while () {
735 no strict 'refs'; 784 # we need to use a separate tls read buffer, as we must not receive data while
785 # we are draining the buffer, and this can only happen with TLS.
786 $self->{rbuf} .= delete $self->{_tls_rbuf} if exists $self->{_tls_rbuf};
736 787
737 my $len = length $self->{rbuf}; 788 my $len = length $self->{rbuf};
738 789
739 if (my $cb = shift @{ $self->{_queue} }) { 790 if (my $cb = shift @{ $self->{_queue} }) {
740 unless ($cb->($self)) { 791 unless ($cb->($self)) {
741 if ($self->{_eof}) { 792 if ($self->{_eof}) {
742 # no progress can be made (not enough data and no data forthcoming) 793 # no progress can be made (not enough data and no data forthcoming)
743 $self->_error (&Errno::EPIPE, 1), last; 794 $self->_error (&Errno::EPIPE, 1), return;
744 } 795 }
745 796
746 unshift @{ $self->{_queue} }, $cb; 797 unshift @{ $self->{_queue} }, $cb;
747 last; 798 last;
748 } 799 }
756 && !@{ $self->{_queue} } # and the queue is still empty 807 && !@{ $self->{_queue} } # and the queue is still empty
757 && $self->{on_read} # but we still have on_read 808 && $self->{on_read} # but we still have on_read
758 ) { 809 ) {
759 # no further data will arrive 810 # no further data will arrive
760 # so no progress can be made 811 # so no progress can be made
761 $self->_error (&Errno::EPIPE, 1), last 812 $self->_error (&Errno::EPIPE, 1), return
762 if $self->{_eof}; 813 if $self->{_eof};
763 814
764 last; # more data might arrive 815 last; # more data might arrive
765 } 816 }
766 } else { 817 } else {
767 # read side becomes idle 818 # read side becomes idle
768 delete $self->{_rw}; 819 delete $self->{_rw} unless $self->{tls};
769 last; 820 last;
770 } 821 }
771 } 822 }
772 823
824 if ($self->{_eof}) {
825 if ($self->{on_eof}) {
773 $self->{on_eof}($self) 826 $self->{on_eof}($self)
774 if $self->{_eof} && $self->{on_eof}; 827 } else {
828 $self->_error (0, 1);
829 }
830 }
775 831
776 # may need to restart read watcher 832 # may need to restart read watcher
777 unless ($self->{_rw}) { 833 unless ($self->{_rw}) {
778 $self->start_read 834 $self->start_read
779 if $self->{on_read} || @{ $self->{_queue} }; 835 if $self->{on_read} || @{ $self->{_queue} };
797 853
798=item $handle->rbuf 854=item $handle->rbuf
799 855
800Returns the read buffer (as a modifiable lvalue). 856Returns the read buffer (as a modifiable lvalue).
801 857
802You can access the read buffer directly as the C<< ->{rbuf} >> member, if 858You can access the read buffer directly as the C<< ->{rbuf} >>
803you want. 859member, if you want. However, the only operation allowed on the
860read buffer (apart from looking at it) is removing data from its
861beginning. Otherwise modifying or appending to it is not allowed and will
862lead to hard-to-track-down bugs.
804 863
805NOTE: The read buffer should only be used or modified if the C<on_read>, 864NOTE: The read buffer should only be used or modified if the C<on_read>,
806C<push_read> or C<unshift_read> methods are used. The other read methods 865C<push_read> or C<unshift_read> methods are used. The other read methods
807automatically manage the read buffer. 866automatically manage the read buffer.
808 867
904 $len <= length $_[0]{rbuf} or return; 963 $len <= length $_[0]{rbuf} or return;
905 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, ""); 964 $cb->($_[0], substr $_[0]{rbuf}, 0, $len, "");
906 1 965 1
907 } 966 }
908}; 967};
909
910# compatibility with older API
911sub push_read_chunk {
912 $_[0]->push_read (chunk => $_[1], $_[2]);
913}
914
915sub unshift_read_chunk {
916 $_[0]->unshift_read (chunk => $_[1], $_[2]);
917}
918 968
919=item line => [$eol, ]$cb->($handle, $line, $eol) 969=item line => [$eol, ]$cb->($handle, $line, $eol)
920 970
921The callback will be called only once a full line (including the end of 971The callback will be called only once a full line (including the end of
922line marker, C<$eol>) has been read. This line (excluding the end of line 972line marker, C<$eol>) has been read. This line (excluding the end of line
958 $cb->($_[0], $1, $2); 1008 $cb->($_[0], $1, $2);
959 1 1009 1
960 } 1010 }
961 } 1011 }
962}; 1012};
963
964# compatibility with older API
965sub push_read_line {
966 my $self = shift;
967 $self->push_read (line => @_);
968}
969
970sub unshift_read_line {
971 my $self = shift;
972 $self->unshift_read (line => @_);
973}
974 1013
975=item regex => $accept[, $reject[, $skip], $cb->($handle, $data) 1014=item regex => $accept[, $reject[, $skip], $cb->($handle, $data)
976 1015
977Makes a regex match against the regex object C<$accept> and returns 1016Makes a regex match against the regex object C<$accept> and returns
978everything up to and including the match. 1017everything up to and including the match.
1083An octet string prefixed with an encoded length. The encoding C<$format> 1122An octet string prefixed with an encoded length. The encoding C<$format>
1084uses the same format as a Perl C<pack> format, but must specify a single 1123uses the same format as a Perl C<pack> format, but must specify a single
1085integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an 1124integer only (only one of C<cCsSlLqQiInNvVjJw> is allowed, plus an
1086optional C<!>, C<< < >> or C<< > >> modifier). 1125optional C<!>, C<< < >> or C<< > >> modifier).
1087 1126
1088DNS over TCP uses a prefix of C<n>, EPP uses a prefix of C<N>. 1127For example, DNS over TCP uses a prefix of C<n> (2 octet network order),
1128EPP uses a prefix of C<N> (4 octtes).
1089 1129
1090Example: read a block of data prefixed by its length in BER-encoded 1130Example: read a block of data prefixed by its length in BER-encoded
1091format (very efficient). 1131format (very efficient).
1092 1132
1093 $handle->push_read (packstring => "w", sub { 1133 $handle->push_read (packstring => "w", sub {
1123 } 1163 }
1124}; 1164};
1125 1165
1126=item json => $cb->($handle, $hash_or_arrayref) 1166=item json => $cb->($handle, $hash_or_arrayref)
1127 1167
1128Reads a JSON object or array, decodes it and passes it to the callback. 1168Reads a JSON object or array, decodes it and passes it to the
1169callback. When a parse error occurs, an C<EBADMSG> error will be raised.
1129 1170
1130If a C<json> object was passed to the constructor, then that will be used 1171If a C<json> object was passed to the constructor, then that will be used
1131for the final decode, otherwise it will create a JSON coder expecting UTF-8. 1172for the final decode, otherwise it will create a JSON coder expecting UTF-8.
1132 1173
1133This read type uses the incremental parser available with JSON version 1174This read type uses the incremental parser available with JSON version
1150 my $rbuf = \$self->{rbuf}; 1191 my $rbuf = \$self->{rbuf};
1151 1192
1152 my $json = $self->{json} ||= JSON->new->utf8; 1193 my $json = $self->{json} ||= JSON->new->utf8;
1153 1194
1154 sub { 1195 sub {
1155 my $ref = $json->incr_parse ($self->{rbuf}); 1196 my $ref = eval { $json->incr_parse ($self->{rbuf}) };
1156 1197
1157 if ($ref) { 1198 if ($ref) {
1158 $self->{rbuf} = $json->incr_text; 1199 $self->{rbuf} = $json->incr_text;
1159 $json->incr_text = ""; 1200 $json->incr_text = "";
1160 $cb->($self, $ref); 1201 $cb->($self, $ref);
1161 1202
1162 1 1203 1
1204 } elsif ($@) {
1205 # error case
1206 $json->incr_skip;
1207
1208 $self->{rbuf} = $json->incr_text;
1209 $json->incr_text = "";
1210
1211 $self->_error (&Errno::EBADMSG);
1212
1213 ()
1163 } else { 1214 } else {
1164 $self->{rbuf} = ""; 1215 $self->{rbuf} = "";
1216
1165 () 1217 ()
1166 } 1218 }
1167 } 1219 }
1168}; 1220};
1169 1221
1246Note that AnyEvent::Handle will automatically C<start_read> for you when 1298Note that AnyEvent::Handle will automatically C<start_read> for you when
1247you change the C<on_read> callback or push/unshift a read callback, and it 1299you change the C<on_read> callback or push/unshift a read callback, and it
1248will automatically C<stop_read> for you when neither C<on_read> is set nor 1300will automatically C<stop_read> for you when neither C<on_read> is set nor
1249there are any read requests in the queue. 1301there are any read requests in the queue.
1250 1302
1303These methods will have no effect when in TLS mode (as TLS doesn't support
1304half-duplex connections).
1305
1251=cut 1306=cut
1252 1307
1253sub stop_read { 1308sub stop_read {
1254 my ($self) = @_; 1309 my ($self) = @_;
1255 1310
1256 delete $self->{_rw}; 1311 delete $self->{_rw} unless $self->{tls};
1257} 1312}
1258 1313
1259sub start_read { 1314sub start_read {
1260 my ($self) = @_; 1315 my ($self) = @_;
1261 1316
1262 unless ($self->{_rw} || $self->{_eof}) { 1317 unless ($self->{_rw} || $self->{_eof}) {
1263 Scalar::Util::weaken $self; 1318 Scalar::Util::weaken $self;
1264 1319
1265 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub { 1320 $self->{_rw} = AnyEvent->io (fh => $self->{fh}, poll => "r", cb => sub {
1266 my $rbuf = $self->{filter_r} ? \my $buf : \$self->{rbuf}; 1321 my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
1267 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf; 1322 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf;
1268 1323
1269 if ($len > 0) { 1324 if ($len > 0) {
1270 $self->{_activity} = AnyEvent->now; 1325 $self->{_activity} = AnyEvent->now;
1271 1326
1272 $self->{filter_r} 1327 if ($self->{tls}) {
1273 ? $self->{filter_r}($self, $rbuf) 1328 Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
1274 : $self->{_in_drain} || $self->_drain_rbuf; 1329
1330 &_dotls ($self);
1331 } else {
1332 $self->_drain_rbuf unless $self->{_in_drain};
1333 }
1275 1334
1276 } elsif (defined $len) { 1335 } elsif (defined $len) {
1277 delete $self->{_rw}; 1336 delete $self->{_rw};
1278 $self->{_eof} = 1; 1337 $self->{_eof} = 1;
1279 $self->_drain_rbuf unless $self->{_in_drain}; 1338 $self->_drain_rbuf unless $self->{_in_drain};
1283 } 1342 }
1284 }); 1343 });
1285 } 1344 }
1286} 1345}
1287 1346
1347# poll the write BIO and send the data if applicable
1288sub _dotls { 1348sub _dotls {
1289 my ($self) = @_; 1349 my ($self) = @_;
1290 1350
1291 my $buf; 1351 my $tmp;
1292 1352
1293 if (length $self->{_tls_wbuf}) { 1353 if (length $self->{_tls_wbuf}) {
1294 while ((my $len = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) { 1354 while (($tmp = Net::SSLeay::write ($self->{tls}, $self->{_tls_wbuf})) > 0) {
1295 substr $self->{_tls_wbuf}, 0, $len, ""; 1355 substr $self->{_tls_wbuf}, 0, $tmp, "";
1296 } 1356 }
1297 } 1357 }
1298 1358
1299 if (length ($buf = Net::SSLeay::BIO_read ($self->{_wbio}))) {
1300 $self->{wbuf} .= $buf;
1301 $self->_drain_wbuf;
1302 }
1303
1304 while (defined ($buf = Net::SSLeay::read ($self->{tls}))) { 1359 while (defined ($tmp = Net::SSLeay::read ($self->{tls}))) {
1305 if (length $buf) { 1360 unless (length $tmp) {
1306 $self->{rbuf} .= $buf;
1307 $self->_drain_rbuf unless $self->{_in_drain};
1308 } else {
1309 # let's treat SSL-eof as we treat normal EOF 1361 # let's treat SSL-eof as we treat normal EOF
1362 delete $self->{_rw};
1310 $self->{_eof} = 1; 1363 $self->{_eof} = 1;
1311 $self->_shutdown; 1364 &_freetls;
1312 return;
1313 } 1365 }
1314 }
1315 1366
1367 $self->{_tls_rbuf} .= $tmp;
1368 $self->_drain_rbuf unless $self->{_in_drain};
1369 $self->{tls} or return; # tls session might have gone away in callback
1370 }
1371
1316 my $err = Net::SSLeay::get_error ($self->{tls}, -1); 1372 $tmp = Net::SSLeay::get_error ($self->{tls}, -1);
1317 1373
1318 if ($err!= Net::SSLeay::ERROR_WANT_READ ()) { 1374 if ($tmp != Net::SSLeay::ERROR_WANT_READ ()) {
1319 if ($err == Net::SSLeay::ERROR_SYSCALL ()) { 1375 if ($tmp == Net::SSLeay::ERROR_SYSCALL ()) {
1320 return $self->_error ($!, 1); 1376 return $self->_error ($!, 1);
1321 } elsif ($err == Net::SSLeay::ERROR_SSL ()) { 1377 } elsif ($tmp == Net::SSLeay::ERROR_SSL ()) {
1322 return $self->_error (&Errno::EIO, 1); 1378 return $self->_error (&Errno::EIO, 1);
1323 } 1379 }
1324 1380
1325 # all others are fine for our purposes 1381 # all other errors are fine for our purposes
1382 }
1383
1384 while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
1385 $self->{wbuf} .= $tmp;
1386 $self->_drain_wbuf;
1326 } 1387 }
1327} 1388}
1328 1389
1329=item $handle->starttls ($tls[, $tls_ctx]) 1390=item $handle->starttls ($tls[, $tls_ctx])
1330 1391
1333C<starttls>. 1394C<starttls>.
1334 1395
1335The first argument is the same as the C<tls> constructor argument (either 1396The first argument is the same as the C<tls> constructor argument (either
1336C<"connect">, C<"accept"> or an existing Net::SSLeay object). 1397C<"connect">, C<"accept"> or an existing Net::SSLeay object).
1337 1398
1338The second argument is the optional C<Net::SSLeay::CTX> object that is 1399The second argument is the optional C<AnyEvent::TLS> object that is used
1339used when AnyEvent::Handle has to create its own TLS connection object. 1400when AnyEvent::Handle has to create its own TLS connection object, or
1401a hash reference with C<< key => value >> pairs that will be used to
1402construct a new context.
1340 1403
1341The TLS connection object will end up in C<< $handle->{tls} >> after this 1404The TLS connection object will end up in C<< $handle->{tls} >>, the TLS
1342call and can be used or changed to your liking. Note that the handshake 1405context in C<< $handle->{tls_ctx} >> after this call and can be used or
1343might have already started when this function returns. 1406changed to your liking. Note that the handshake might have already started
1407when this function returns.
1408
1409If it an error to start a TLS handshake more than once per
1410AnyEvent::Handle object (this is due to bugs in OpenSSL).
1344 1411
1345=cut 1412=cut
1346 1413
1347sub starttls { 1414sub starttls {
1348 my ($self, $ssl, $ctx) = @_; 1415 my ($self, $ssl, $ctx) = @_;
1349 1416
1350 $self->stoptls; 1417 require Net::SSLeay;
1351 1418
1352 if ($ssl eq "accept") { 1419 Carp::croak "it is an error to call starttls more than once on an AnyEvent::Handle object"
1353 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1420 if $self->{tls};
1354 Net::SSLeay::set_accept_state ($ssl); 1421
1355 } elsif ($ssl eq "connect") { 1422 $ctx ||= $self->{tls_ctx};
1356 $ssl = Net::SSLeay::new ($ctx || TLS_CTX ()); 1423
1357 Net::SSLeay::set_connect_state ($ssl); 1424 if ("HASH" eq ref $ctx) {
1425 require AnyEvent::TLS;
1426
1427 local $Carp::CarpLevel = 1; # skip ourselves when creating a new context
1428 $ctx = new AnyEvent::TLS %$ctx;
1429 }
1358 } 1430
1359 1431 $self->{tls_ctx} = $ctx || TLS_CTX ();
1360 $self->{tls} = $ssl; 1432 $self->{tls} = $ssl = $self->{tls_ctx}->_get_session ($ssl, $self);
1361 1433
1362 # basically, this is deep magic (because SSL_read should have the same issues) 1434 # basically, this is deep magic (because SSL_read should have the same issues)
1363 # but the openssl maintainers basically said: "trust us, it just works". 1435 # but the openssl maintainers basically said: "trust us, it just works".
1364 # (unfortunately, we have to hardcode constants because the abysmally misdesigned 1436 # (unfortunately, we have to hardcode constants because the abysmally misdesigned
1365 # and mismaintained ssleay-module doesn't even offer them). 1437 # and mismaintained ssleay-module doesn't even offer them).
1366 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html 1438 # http://www.mail-archive.com/openssl-dev@openssl.org/msg22420.html
1439 #
1440 # in short: this is a mess.
1441 #
1442 # note that we do not try to keep the length constant between writes as we are required to do.
1443 # we assume that most (but not all) of this insanity only applies to non-blocking cases,
1444 # and we drive openssl fully in blocking mode here. Or maybe we don't - openssl seems to
1445 # have identity issues in that area.
1367 Net::SSLeay::CTX_set_mode ($self->{tls}, 1446# Net::SSLeay::CTX_set_mode ($ssl,
1368 (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1) 1447# (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ENABLE_PARTIAL_WRITE () } || 1)
1369 | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2)); 1448# | (eval { local $SIG{__DIE__}; Net::SSLeay::MODE_ACCEPT_MOVING_WRITE_BUFFER () } || 2));
1449 Net::SSLeay::CTX_set_mode ($ssl, 1|2);
1370 1450
1371 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1451 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1372 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 1452 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1373 1453
1374 Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio}); 1454 Net::SSLeay::set_bio ($ssl, $self->{_rbio}, $self->{_wbio});
1375 1455
1376 $self->{filter_w} = sub { 1456 &_dotls; # need to trigger the initial handshake
1377 $_[0]{_tls_wbuf} .= ${$_[1]}; 1457 $self->start_read; # make sure we actually do read
1378 &_dotls;
1379 };
1380 $self->{filter_r} = sub {
1381 Net::SSLeay::BIO_write ($_[0]{_rbio}, ${$_[1]});
1382 &_dotls;
1383 };
1384} 1458}
1385 1459
1386=item $handle->stoptls 1460=item $handle->stoptls
1387 1461
1388Destroys the SSL connection, if any. Partial read or write data will be 1462Shuts down the SSL connection - this makes a proper EOF handshake by
1389lost. 1463sending a close notify to the other side, but since OpenSSL doesn't
1464support non-blocking shut downs, it is not possible to re-use the stream
1465afterwards.
1390 1466
1391=cut 1467=cut
1392 1468
1393sub stoptls { 1469sub stoptls {
1394 my ($self) = @_; 1470 my ($self) = @_;
1395 1471
1396 Net::SSLeay::free (delete $self->{tls}) if $self->{tls}; 1472 if ($self->{tls}) {
1473 Net::SSLeay::shutdown ($self->{tls});
1397 1474
1398 delete $self->{_rbio}; 1475 &_dotls;
1399 delete $self->{_wbio}; 1476
1400 delete $self->{_tls_wbuf}; 1477 # we don't give a shit. no, we do, but we can't. no...
1401 delete $self->{filter_r}; 1478 # we, we... have to use openssl :/
1402 delete $self->{filter_w}; 1479 &_freetls;
1480 }
1481}
1482
1483sub _freetls {
1484 my ($self) = @_;
1485
1486 return unless $self->{tls};
1487
1488 $self->{tls_ctx}->_put_session (delete $self->{tls});
1489
1490 delete @$self{qw(_rbio _wbio _tls_wbuf)};
1403} 1491}
1404 1492
1405sub DESTROY { 1493sub DESTROY {
1406 my $self = shift; 1494 my ($self) = @_;
1407 1495
1408 $self->stoptls; 1496 &_freetls;
1409 1497
1410 my $linger = exists $self->{linger} ? $self->{linger} : 3600; 1498 my $linger = exists $self->{linger} ? $self->{linger} : 3600;
1411 1499
1412 if ($linger && length $self->{wbuf}) { 1500 if ($linger && length $self->{wbuf}) {
1413 my $fh = delete $self->{fh}; 1501 my $fh = delete $self->{fh};
1428 @linger = (); 1516 @linger = ();
1429 }); 1517 });
1430 } 1518 }
1431} 1519}
1432 1520
1521=item $handle->destroy
1522
1523Shuts down the handle object as much as possible - this call ensures that
1524no further callbacks will be invoked and resources will be freed as much
1525as possible. You must not call any methods on the object afterwards.
1526
1527Normally, you can just "forget" any references to an AnyEvent::Handle
1528object and it will simply shut down. This works in fatal error and EOF
1529callbacks, as well as code outside. It does I<NOT> work in a read or write
1530callback, so when you want to destroy the AnyEvent::Handle object from
1531within such an callback. You I<MUST> call C<< ->destroy >> explicitly in
1532that case.
1533
1534The handle might still linger in the background and write out remaining
1535data, as specified by the C<linger> option, however.
1536
1537=cut
1538
1539sub destroy {
1540 my ($self) = @_;
1541
1542 $self->DESTROY;
1543 %$self = ();
1544}
1545
1433=item AnyEvent::Handle::TLS_CTX 1546=item AnyEvent::Handle::TLS_CTX
1434 1547
1435This function creates and returns the Net::SSLeay::CTX object used by 1548This function creates and returns the AnyEvent::TLS object used by default
1436default for TLS mode. 1549for TLS mode.
1437 1550
1438The context is created like this: 1551The context is created by calling L<AnyEvent::TLS> without any arguments.
1439
1440 Net::SSLeay::load_error_strings;
1441 Net::SSLeay::SSLeay_add_ssl_algorithms;
1442 Net::SSLeay::randomize;
1443
1444 my $CTX = Net::SSLeay::CTX_new;
1445
1446 Net::SSLeay::CTX_set_options $CTX, Net::SSLeay::OP_ALL
1447 1552
1448=cut 1553=cut
1449 1554
1450our $TLS_CTX; 1555our $TLS_CTX;
1451 1556
1452sub TLS_CTX() { 1557sub TLS_CTX() {
1453 $TLS_CTX || do { 1558 $TLS_CTX ||= do {
1454 require Net::SSLeay; 1559 require AnyEvent::TLS;
1455 1560
1456 Net::SSLeay::load_error_strings (); 1561 new AnyEvent::TLS
1457 Net::SSLeay::SSLeay_add_ssl_algorithms ();
1458 Net::SSLeay::randomize ();
1459
1460 $TLS_CTX = Net::SSLeay::CTX_new ();
1461
1462 Net::SSLeay::CTX_set_options ($TLS_CTX, Net::SSLeay::OP_ALL ());
1463
1464 $TLS_CTX
1465 } 1562 }
1466} 1563}
1467 1564
1468=back 1565=back
1566
1567
1568=head1 NONFREQUENTLY ASKED QUESTIONS
1569
1570=over 4
1571
1572=item I C<undef> the AnyEvent::Handle reference inside my callback and
1573still get further invocations!
1574
1575That's because AnyEvent::Handle keeps a reference to itself when handling
1576read or write callbacks.
1577
1578It is only safe to "forget" the reference inside EOF or error callbacks,
1579from within all other callbacks, you need to explicitly call the C<<
1580->destroy >> method.
1581
1582=item I get different callback invocations in TLS mode/Why can't I pause
1583reading?
1584
1585Unlike, say, TCP, TLS connections do not consist of two independent
1586communication channels, one for each direction. Or put differently. The
1587read and write directions are not independent of each other: you cannot
1588write data unless you are also prepared to read, and vice versa.
1589
1590This can mean than, in TLS mode, you might get C<on_error> or C<on_eof>
1591callback invocations when you are not expecting any read data - the reason
1592is that AnyEvent::Handle always reads in TLS mode.
1593
1594During the connection, you have to make sure that you always have a
1595non-empty read-queue, or an C<on_read> watcher. At the end of the
1596connection (or when you no longer want to use it) you can call the
1597C<destroy> method.
1598
1599=item How do I read data until the other side closes the connection?
1600
1601If you just want to read your data into a perl scalar, the easiest way
1602to achieve this is by setting an C<on_read> callback that does nothing,
1603clearing the C<on_eof> callback and in the C<on_error> callback, the data
1604will be in C<$_[0]{rbuf}>:
1605
1606 $handle->on_read (sub { });
1607 $handle->on_eof (undef);
1608 $handle->on_error (sub {
1609 my $data = delete $_[0]{rbuf};
1610 undef $handle;
1611 });
1612
1613The reason to use C<on_error> is that TCP connections, due to latencies
1614and packets loss, might get closed quite violently with an error, when in
1615fact, all data has been received.
1616
1617It is usually better to use acknowledgements when transferring data,
1618to make sure the other side hasn't just died and you got the data
1619intact. This is also one reason why so many internet protocols have an
1620explicit QUIT command.
1621
1622=item I don't want to destroy the handle too early - how do I wait until
1623all data has been written?
1624
1625After writing your last bits of data, set the C<on_drain> callback
1626and destroy the handle in there - with the default setting of
1627C<low_water_mark> this will be called precisely when all data has been
1628written to the socket:
1629
1630 $handle->push_write (...);
1631 $handle->on_drain (sub {
1632 warn "all data submitted to the kernel\n";
1633 undef $handle;
1634 });
1635
1636=back
1637
1469 1638
1470=head1 SUBCLASSING AnyEvent::Handle 1639=head1 SUBCLASSING AnyEvent::Handle
1471 1640
1472In many cases, you might want to subclass AnyEvent::Handle. 1641In many cases, you might want to subclass AnyEvent::Handle.
1473 1642

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