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Revision 1.194 by root, Thu May 20 21:22:21 2010 UTC vs.
Revision 1.222 by root, Thu Aug 25 03:08:48 2011 UTC

… …
11 11
12 my $hdl; $hdl = new AnyEvent::Handle 12 my $hdl; $hdl = new AnyEvent::Handle
13 fh => \*STDIN, 13 fh => \*STDIN,
14 on_error => sub { 14 on_error => sub {
15 my ($hdl, $fatal, $msg) = @_; 15 my ($hdl, $fatal, $msg) = @_;
16 warn "got error $msg\n"; 16 AE::log warn => "got error $msg\n";
17 $hdl->destroy; 17 $hdl->destroy;
18 $cv->send; 18 $cv->send;
19 }; 19 };
20 20
21 # send some request line 21 # send some request line
22 $hdl->push_write ("getinfo\015\012"); 22 $hdl->push_write ("getinfo\015\012");
23 23
24 # read the response line 24 # read the response line
25 $hdl->push_read (line => sub { 25 $hdl->push_read (line => sub {
26 my ($hdl, $line) = @_; 26 my ($hdl, $line) = @_;
27 warn "got line <$line>\n"; 27 AE::log warn => "got line <$line>\n";
28 $cv->send; 28 $cv->send;
29 }); 29 });
30 30
31 $cv->recv; 31 $cv->recv;
32 32
33=head1 DESCRIPTION 33=head1 DESCRIPTION
34 34
35This module is a helper module to make it easier to do event-based I/O on 35This is a helper module to make it easier to do event-based I/O on
36stream-based filehandles (sockets, pipes or other stream things). 36stream-based filehandles (sockets, pipes, and other stream things).
37 37
38The L<AnyEvent::Intro> tutorial contains some well-documented 38The L<AnyEvent::Intro> tutorial contains some well-documented
39AnyEvent::Handle examples. 39AnyEvent::Handle examples.
40 40
41In the following, when the documentation refers to of "bytes" then this 41In the following, where the documentation refers to "bytes", it means
42means characters. As sysread and syswrite are used for all I/O, their 42characters. As sysread and syswrite are used for all I/O, their
43treatment of characters applies to this module as well. 43treatment of characters applies to this module as well.
44 44
45At the very minimum, you should specify C<fh> or C<connect>, and the 45At the very minimum, you should specify C<fh> or C<connect>, and the
46C<on_error> callback. 46C<on_error> callback.
47 47
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75 } 75 }
76 76
77 \&$func 77 \&$func
78} 78}
79 79
80sub MAX_READ_SIZE() { 131072 }
81
80=head1 METHODS 82=head1 METHODS
81 83
82=over 4 84=over 4
83 85
84=item $handle = B<new> AnyEvent::Handle fh => $filehandle, key => value... 86=item $handle = B<new> AnyEvent::Handle fh => $filehandle, key => value...
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112=over 4 114=over 4
113 115
114=item on_prepare => $cb->($handle) 116=item on_prepare => $cb->($handle)
115 117
116This (rarely used) callback is called before a new connection is 118This (rarely used) callback is called before a new connection is
117attempted, but after the file handle has been created. It could be used to 119attempted, but after the file handle has been created (you can access that
120file handle via C<< $handle->{fh} >>). It could be used to prepare the
118prepare the file handle with parameters required for the actual connect 121file handle with parameters required for the actual connect (as opposed to
119(as opposed to settings that can be changed when the connection is already 122settings that can be changed when the connection is already established).
120established).
121 123
122The return value of this callback should be the connect timeout value in 124The return value of this callback should be the connect timeout value in
123seconds (or C<0>, or C<undef>, or the empty list, to indicate the default 125seconds (or C<0>, or C<undef>, or the empty list, to indicate that the
124timeout is to be used). 126default timeout is to be used).
125 127
126=item on_connect => $cb->($handle, $host, $port, $retry->()) 128=item on_connect => $cb->($handle, $host, $port, $retry->())
127 129
128This callback is called when a connection has been successfully established. 130This callback is called when a connection has been successfully established.
129 131
130The actual numeric host and port (the socket peername) are passed as 132The peer's numeric host and port (the socket peername) are passed as
131parameters, together with a retry callback. 133parameters, together with a retry callback.
132 134
133When, for some reason, the handle is not acceptable, then calling 135If, for some reason, the handle is not acceptable, calling C<$retry>
134C<$retry> will continue with the next connection target (in case of 136will continue with the next connection target (in case of multi-homed
135multi-homed hosts or SRV records there can be multiple connection 137hosts or SRV records there can be multiple connection endpoints). At the
136endpoints). At the time it is called the read and write queues, eof 138time it is called the read and write queues, eof status, tls status and
137status, tls status and similar properties of the handle will have been 139similar properties of the handle will have been reset.
138reset.
139 140
140In most cases, ignoring the C<$retry> parameter is the way to go. 141In most cases, you should ignore the C<$retry> parameter.
141 142
142=item on_connect_error => $cb->($handle, $message) 143=item on_connect_error => $cb->($handle, $message)
143 144
144This callback is called when the connection could not be 145This callback is called when the connection could not be
145established. C<$!> will contain the relevant error code, and C<$message> a 146established. C<$!> will contain the relevant error code, and C<$message> a
… …
152 153
153=item on_error => $cb->($handle, $fatal, $message) 154=item on_error => $cb->($handle, $fatal, $message)
154 155
155This is the error callback, which is called when, well, some error 156This is the error callback, which is called when, well, some error
156occured, such as not being able to resolve the hostname, failure to 157occured, such as not being able to resolve the hostname, failure to
157connect or a read error. 158connect, or a read error.
158 159
159Some errors are fatal (which is indicated by C<$fatal> being true). On 160Some errors are fatal (which is indicated by C<$fatal> being true). On
160fatal errors the handle object will be destroyed (by a call to C<< -> 161fatal errors the handle object will be destroyed (by a call to C<< ->
161destroy >>) after invoking the error callback (which means you are free to 162destroy >>) after invoking the error callback (which means you are free to
162examine the handle object). Examples of fatal errors are an EOF condition 163examine the handle object). Examples of fatal errors are an EOF condition
163with active (but unsatisifable) read watchers (C<EPIPE>) or I/O errors. In 164with active (but unsatisfiable) read watchers (C<EPIPE>) or I/O errors. In
164cases where the other side can close the connection at their will it is 165cases where the other side can close the connection at will, it is
165often easiest to not report C<EPIPE> errors in this callback. 166often easiest to not report C<EPIPE> errors in this callback.
166 167
167AnyEvent::Handle tries to find an appropriate error code for you to check 168AnyEvent::Handle tries to find an appropriate error code for you to check
168against, but in some cases (TLS errors), this does not work well. It is 169against, but in some cases (TLS errors), this does not work well. It is
169recommended to always output the C<$message> argument in human-readable 170recommended to always output the C<$message> argument in human-readable
170error messages (it's usually the same as C<"$!">). 171error messages (it's usually the same as C<"$!">).
171 172
172Non-fatal errors can be retried by simply returning, but it is recommended 173Non-fatal errors can be retried by returning, but it is recommended
173to simply ignore this parameter and instead abondon the handle object 174to simply ignore this parameter and instead abondon the handle object
174when this callback is invoked. Examples of non-fatal errors are timeouts 175when this callback is invoked. Examples of non-fatal errors are timeouts
175C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>). 176C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
176 177
177On callback entrance, the value of C<$!> contains the operating system 178On entry to the callback, the value of C<$!> contains the operating
178error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or 179system error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
179C<EPROTO>). 180C<EPROTO>).
180 181
181While not mandatory, it is I<highly> recommended to set this callback, as 182While not mandatory, it is I<highly> recommended to set this callback, as
182you will not be notified of errors otherwise. The default simply calls 183you will not be notified of errors otherwise. The default just calls
183C<croak>. 184C<croak>.
184 185
185=item on_read => $cb->($handle) 186=item on_read => $cb->($handle)
186 187
187This sets the default read callback, which is called when data arrives 188This sets the default read callback, which is called when data arrives
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192To access (and remove data from) the read buffer, use the C<< ->rbuf >> 193To access (and remove data from) the read buffer, use the C<< ->rbuf >>
193method or access the C<< $handle->{rbuf} >> member directly. Note that you 194method or access the C<< $handle->{rbuf} >> member directly. Note that you
194must not enlarge or modify the read buffer, you can only remove data at 195must not enlarge or modify the read buffer, you can only remove data at
195the beginning from it. 196the beginning from it.
196 197
198You can also call C<< ->push_read (...) >> or any other function that
199modifies the read queue. Or do both. Or ...
200
197When an EOF condition is detected then AnyEvent::Handle will first try to 201When an EOF condition is detected, AnyEvent::Handle will first try to
198feed all the remaining data to the queued callbacks and C<on_read> before 202feed all the remaining data to the queued callbacks and C<on_read> before
199calling the C<on_eof> callback. If no progress can be made, then a fatal 203calling the C<on_eof> callback. If no progress can be made, then a fatal
200error will be raised (with C<$!> set to C<EPIPE>). 204error will be raised (with C<$!> set to C<EPIPE>).
201 205
202Note that, unlike requests in the read queue, an C<on_read> callback 206Note that, unlike requests in the read queue, an C<on_read> callback
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221set, then a fatal error will be raised with C<$!> set to <0>. 225set, then a fatal error will be raised with C<$!> set to <0>.
222 226
223=item on_drain => $cb->($handle) 227=item on_drain => $cb->($handle)
224 228
225This sets the callback that is called when the write buffer becomes empty 229This sets the callback that is called when the write buffer becomes empty
226(or when the callback is set and the buffer is empty already). 230(or immediately if the buffer is empty already).
227 231
228To append to the write buffer, use the C<< ->push_write >> method. 232To append to the write buffer, use the C<< ->push_write >> method.
229 233
230This callback is useful when you don't want to put all of your write data 234This callback is useful when you don't want to put all of your write data
231into the queue at once, for example, when you want to write the contents 235into the queue at once, for example, when you want to write the contents
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243many seconds pass without a successful read or write on the underlying 247many seconds pass without a successful read or write on the underlying
244file handle (or a call to C<timeout_reset>), the C<on_timeout> callback 248file handle (or a call to C<timeout_reset>), the C<on_timeout> callback
245will be invoked (and if that one is missing, a non-fatal C<ETIMEDOUT> 249will be invoked (and if that one is missing, a non-fatal C<ETIMEDOUT>
246error will be raised). 250error will be raised).
247 251
248There are three variants of the timeouts that work fully independent 252There are three variants of the timeouts that work independently of each
249of each other, for both read and write, just read, and just write: 253other, for both read and write (triggered when nothing was read I<OR>
254written), just read (triggered when nothing was read), and just write:
250C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks 255C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks
251C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions 256C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions
252C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>. 257C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>.
253 258
254Note that timeout processing is also active when you currently do not have 259Note that timeout processing is active even when you do not have any
255any outstanding read or write requests: If you plan to keep the connection 260outstanding read or write requests: If you plan to keep the connection
256idle then you should disable the timout temporarily or ignore the timeout 261idle then you should disable the timeout temporarily or ignore the
257in the C<on_timeout> callback, in which case AnyEvent::Handle will simply 262timeout in the corresponding C<on_timeout> callback, in which case
258restart the timeout. 263AnyEvent::Handle will simply restart the timeout.
259 264
260Zero (the default) disables this timeout. 265Zero (the default) disables the corresponding timeout.
261 266
262=item on_timeout => $cb->($handle) 267=item on_timeout => $cb->($handle)
268
269=item on_rtimeout => $cb->($handle)
270
271=item on_wtimeout => $cb->($handle)
263 272
264Called whenever the inactivity timeout passes. If you return from this 273Called whenever the inactivity timeout passes. If you return from this
265callback, then the timeout will be reset as if some activity had happened, 274callback, then the timeout will be reset as if some activity had happened,
266so this condition is not fatal in any way. 275so this condition is not fatal in any way.
267 276
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275be configured to accept only so-and-so much data that it cannot act on 284be configured to accept only so-and-so much data that it cannot act on
276(for example, when expecting a line, an attacker could send an unlimited 285(for example, when expecting a line, an attacker could send an unlimited
277amount of data without a callback ever being called as long as the line 286amount of data without a callback ever being called as long as the line
278isn't finished). 287isn't finished).
279 288
289=item wbuf_max => <bytes>
290
291If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
292when the write buffer ever (strictly) exceeds this size. This is useful to
293avoid some forms of denial-of-service attacks.
294
295Although the units of this parameter is bytes, this is the I<raw> number
296of bytes not yet accepted by the kernel. This can make a difference when
297you e.g. use TLS, as TLS typically makes your write data larger (but it
298can also make it smaller due to compression).
299
300As an example of when this limit is useful, take a chat server that sends
301chat messages to a client. If the client does not read those in a timely
302manner then the send buffer in the server would grow unbounded.
303
280=item autocork => <boolean> 304=item autocork => <boolean>
281 305
282When disabled (the default), then C<push_write> will try to immediately 306When disabled (the default), C<push_write> will try to immediately
283write the data to the handle, if possible. This avoids having to register 307write the data to the handle if possible. This avoids having to register
284a write watcher and wait for the next event loop iteration, but can 308a write watcher and wait for the next event loop iteration, but can
285be inefficient if you write multiple small chunks (on the wire, this 309be inefficient if you write multiple small chunks (on the wire, this
286disadvantage is usually avoided by your kernel's nagle algorithm, see 310disadvantage is usually avoided by your kernel's nagle algorithm, see
287C<no_delay>, but this option can save costly syscalls). 311C<no_delay>, but this option can save costly syscalls).
288 312
289When enabled, then writes will always be queued till the next event loop 313When enabled, writes will always be queued till the next event loop
290iteration. This is efficient when you do many small writes per iteration, 314iteration. This is efficient when you do many small writes per iteration,
291but less efficient when you do a single write only per iteration (or when 315but less efficient when you do a single write only per iteration (or when
292the write buffer often is full). It also increases write latency. 316the write buffer often is full). It also increases write latency.
293 317
294=item no_delay => <boolean> 318=item no_delay => <boolean>
… …
298the Nagle algorithm, and usually it is beneficial. 322the Nagle algorithm, and usually it is beneficial.
299 323
300In some situations you want as low a delay as possible, which can be 324In some situations you want as low a delay as possible, which can be
301accomplishd by setting this option to a true value. 325accomplishd by setting this option to a true value.
302 326
303The default is your opertaing system's default behaviour (most likely 327The default is your operating system's default behaviour (most likely
304enabled), this option explicitly enables or disables it, if possible. 328enabled). This option explicitly enables or disables it, if possible.
305 329
306=item keepalive => <boolean> 330=item keepalive => <boolean>
307 331
308Enables (default disable) the SO_KEEPALIVE option on the stream socket: 332Enables (default disable) the SO_KEEPALIVE option on the stream socket:
309normally, TCP connections have no time-out once established, so TCP 333normally, TCP connections have no time-out once established, so TCP
310connections, once established, can stay alive forever even when the other 334connections, once established, can stay alive forever even when the other
311side has long gone. TCP keepalives are a cheap way to take down long-lived 335side has long gone. TCP keepalives are a cheap way to take down long-lived
312TCP connections whent he other side becomes unreachable. While the default 336TCP connections when the other side becomes unreachable. While the default
313is OS-dependent, TCP keepalives usually kick in after around two hours, 337is OS-dependent, TCP keepalives usually kick in after around two hours,
314and, if the other side doesn't reply, take down the TCP connection some 10 338and, if the other side doesn't reply, take down the TCP connection some 10
315to 15 minutes later. 339to 15 minutes later.
316 340
317It is harmless to specify this option for file handles that do not support 341It is harmless to specify this option for file handles that do not support
… …
335already have occured on BSD systems), but at least it will protect you 359already have occured on BSD systems), but at least it will protect you
336from most attacks. 360from most attacks.
337 361
338=item read_size => <bytes> 362=item read_size => <bytes>
339 363
340The default read block size (the amount of bytes this module will 364The initial read block size, the number of bytes this module will try
341try to read during each loop iteration, which affects memory 365to read during each loop iteration. Each handle object will consume
342requirements). Default: C<8192>. 366at least this amount of memory for the read buffer as well, so when
367handling many connections watch out for memory requirements). See also
368C<max_read_size>. Default: C<2048>.
369
370=item max_read_size => <bytes>
371
372The maximum read buffer size used by the dynamic adjustment
373algorithm: Each time AnyEvent::Handle can read C<read_size> bytes in
374one go it will double C<read_size> up to the maximum given by this
375option. Default: C<131072> or C<read_size>, whichever is higher.
343 376
344=item low_water_mark => <bytes> 377=item low_water_mark => <bytes>
345 378
346Sets the amount of bytes (default: C<0>) that make up an "empty" write 379Sets the number of bytes (default: C<0>) that make up an "empty" write
347buffer: If the write reaches this size or gets even samller it is 380buffer: If the buffer reaches this size or gets even samller it is
348considered empty. 381considered empty.
349 382
350Sometimes it can be beneficial (for performance reasons) to add data to 383Sometimes it can be beneficial (for performance reasons) to add data to
351the write buffer before it is fully drained, but this is a rare case, as 384the write buffer before it is fully drained, but this is a rare case, as
352the operating system kernel usually buffers data as well, so the default 385the operating system kernel usually buffers data as well, so the default
353is good in almost all cases. 386is good in almost all cases.
354 387
355=item linger => <seconds> 388=item linger => <seconds>
356 389
357If non-zero (default: C<3600>), then the destructor of the 390If this is non-zero (default: C<3600>), the destructor of the
358AnyEvent::Handle object will check whether there is still outstanding 391AnyEvent::Handle object will check whether there is still outstanding
359write data and will install a watcher that will write this data to the 392write data and will install a watcher that will write this data to the
360socket. No errors will be reported (this mostly matches how the operating 393socket. No errors will be reported (this mostly matches how the operating
361system treats outstanding data at socket close time). 394system treats outstanding data at socket close time).
362 395
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369A string used to identify the remote site - usually the DNS hostname 402A string used to identify the remote site - usually the DNS hostname
370(I<not> IDN!) used to create the connection, rarely the IP address. 403(I<not> IDN!) used to create the connection, rarely the IP address.
371 404
372Apart from being useful in error messages, this string is also used in TLS 405Apart from being useful in error messages, this string is also used in TLS
373peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This 406peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
374verification will be skipped when C<peername> is not specified or 407verification will be skipped when C<peername> is not specified or is
375C<undef>. 408C<undef>.
376 409
377=item tls => "accept" | "connect" | Net::SSLeay::SSL object 410=item tls => "accept" | "connect" | Net::SSLeay::SSL object
378 411
379When this parameter is given, it enables TLS (SSL) mode, that means 412When this parameter is given, it enables TLS (SSL) mode, that means
… …
405B<IMPORTANT:> since Net::SSLeay "objects" are really only integers, 438B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
406passing in the wrong integer will lead to certain crash. This most often 439passing in the wrong integer will lead to certain crash. This most often
407happens when one uses a stylish C<< tls => 1 >> and is surprised about the 440happens when one uses a stylish C<< tls => 1 >> and is surprised about the
408segmentation fault. 441segmentation fault.
409 442
410See the C<< ->starttls >> method for when need to start TLS negotiation later. 443Use the C<< ->starttls >> method if you need to start TLS negotiation later.
411 444
412=item tls_ctx => $anyevent_tls 445=item tls_ctx => $anyevent_tls
413 446
414Use the given C<AnyEvent::TLS> object to create the new TLS connection 447Use the given C<AnyEvent::TLS> object to create the new TLS connection
415(unless a connection object was specified directly). If this parameter is 448(unless a connection object was specified directly). If this
416missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>. 449parameter is missing (or C<undef>), then AnyEvent::Handle will use
450C<AnyEvent::Handle::TLS_CTX>.
417 451
418Instead of an object, you can also specify a hash reference with C<< key 452Instead of an object, you can also specify a hash reference with C<< key
419=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a 453=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
420new TLS context object. 454new TLS context object.
421 455
… …
430 464
431TLS handshake failures will not cause C<on_error> to be invoked when this 465TLS handshake failures will not cause C<on_error> to be invoked when this
432callback is in effect, instead, the error message will be passed to C<on_starttls>. 466callback is in effect, instead, the error message will be passed to C<on_starttls>.
433 467
434Without this callback, handshake failures lead to C<on_error> being 468Without this callback, handshake failures lead to C<on_error> being
435called, as normal. 469called as usual.
436 470
437Note that you cannot call C<starttls> right again in this callback. If you 471Note that you cannot just call C<starttls> again in this callback. If you
438need to do that, start an zero-second timer instead whose callback can 472need to do that, start an zero-second timer instead whose callback can
439then call C<< ->starttls >> again. 473then call C<< ->starttls >> again.
440 474
441=item on_stoptls => $cb->($handle) 475=item on_stoptls => $cb->($handle)
442 476
… …
490 $self->{connect}[0], 524 $self->{connect}[0],
491 $self->{connect}[1], 525 $self->{connect}[1],
492 sub { 526 sub {
493 my ($fh, $host, $port, $retry) = @_; 527 my ($fh, $host, $port, $retry) = @_;
494 528
529 delete $self->{_connect}; # no longer needed
530
495 if ($fh) { 531 if ($fh) {
496 $self->{fh} = $fh; 532 $self->{fh} = $fh;
497 533
498 delete $self->{_skip_drain_rbuf}; 534 delete $self->{_skip_drain_rbuf};
499 $self->_start; 535 $self->_start;
… …
506 }); 542 });
507 543
508 } else { 544 } else {
509 if ($self->{on_connect_error}) { 545 if ($self->{on_connect_error}) {
510 $self->{on_connect_error}($self, "$!"); 546 $self->{on_connect_error}($self, "$!");
511 $self->destroy; 547 $self->destroy if $self;
512 } else { 548 } else {
513 $self->_error ($!, 1); 549 $self->_error ($!, 1);
514 } 550 }
515 } 551 }
516 }, 552 },
517 sub { 553 sub {
518 local $self->{fh} = $_[0]; 554 local $self->{fh} = $_[0];
519 555
520 $self->{on_prepare} 556 $self->{on_prepare}
521 ? $self->{on_prepare}->($self) 557 ? $self->{on_prepare}->($self)
522 : () 558 : ()
523 } 559 }
524 ); 560 );
525 } 561 }
526 562
… …
534sub _start { 570sub _start {
535 my ($self) = @_; 571 my ($self) = @_;
536 572
537 # too many clueless people try to use udp and similar sockets 573 # too many clueless people try to use udp and similar sockets
538 # with AnyEvent::Handle, do them a favour. 574 # with AnyEvent::Handle, do them a favour.
539 if (Socket::SOCK_STREAM != unpack "I", getsockopt $self->{fh}, Socket::SOL_SOCKET (), Socket::SO_TYPE ()) { 575 my $type = getsockopt $self->{fh}, Socket::SOL_SOCKET (), Socket::SO_TYPE ();
540 Carp::croak "AnyEvent::Handle: only stream sockets supported, anything else will NOT work!"; 576 Carp::croak "AnyEvent::Handle: only stream sockets supported, anything else will NOT work!"
541 } 577 if Socket::SOCK_STREAM () != (unpack "I", $type) && defined $type;
542 578
543 AnyEvent::Util::fh_nonblocking $self->{fh}, 1; 579 AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
544 580
545 $self->{_activity} = 581 $self->{_activity} =
546 $self->{_ractivity} = 582 $self->{_ractivity} =
547 $self->{_wactivity} = AE::now; 583 $self->{_wactivity} = AE::now;
548 584
585 $self->{read_size} ||= 2048;
586 $self->{max_read_size} = $self->{read_size}
587 if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
588
549 $self->timeout (delete $self->{timeout} ) if $self->{timeout}; 589 $self->timeout (delete $self->{timeout} ) if $self->{timeout};
550 $self->rtimeout (delete $self->{rtimeout} ) if $self->{rtimeout}; 590 $self->rtimeout (delete $self->{rtimeout} ) if $self->{rtimeout};
551 $self->wtimeout (delete $self->{wtimeout} ) if $self->{wtimeout}; 591 $self->wtimeout (delete $self->{wtimeout} ) if $self->{wtimeout};
552 592
553 $self->no_delay (delete $self->{no_delay} ) if exists $self->{no_delay} && $self->{no_delay}; 593 $self->no_delay (delete $self->{no_delay} ) if exists $self->{no_delay} && $self->{no_delay};
… …
556 $self->oobinline (exists $self->{oobinline} ? delete $self->{oobinline} : 1); 596 $self->oobinline (exists $self->{oobinline} ? delete $self->{oobinline} : 1);
557 597
558 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx}) 598 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
559 if $self->{tls}; 599 if $self->{tls};
560 600
561 $self->on_drain (delete $self->{on_drain}) if $self->{on_drain}; 601 $self->on_drain (delete $self->{on_drain} ) if $self->{on_drain};
562 602
563 $self->start_read 603 $self->start_read
564 if $self->{on_read} || @{ $self->{_queue} }; 604 if $self->{on_read} || @{ $self->{_queue} };
565 605
566 $self->_drain_wbuf; 606 $self->_drain_wbuf;
… …
642=cut 682=cut
643 683
644sub no_delay { 684sub no_delay {
645 $_[0]{no_delay} = $_[1]; 685 $_[0]{no_delay} = $_[1];
646 686
647 eval {
648 local $SIG{__DIE__};
649 setsockopt $_[0]{fh}, Socket::IPPROTO_TCP (), Socket::TCP_NODELAY (), int $_[1] 687 setsockopt $_[0]{fh}, Socket::IPPROTO_TCP (), Socket::TCP_NODELAY (), int $_[1]
650 if $_[0]{fh}; 688 if $_[0]{fh};
651 };
652} 689}
653 690
654=item $handle->keepalive ($boolean) 691=item $handle->keepalive ($boolean)
655 692
656Enables or disables the C<keepalive> setting (see constructor argument of 693Enables or disables the C<keepalive> setting (see constructor argument of
… …
724 761
725=item $handle->rbuf_max ($max_octets) 762=item $handle->rbuf_max ($max_octets)
726 763
727Configures the C<rbuf_max> setting (C<undef> disables it). 764Configures the C<rbuf_max> setting (C<undef> disables it).
728 765
766=item $handle->wbuf_max ($max_octets)
767
768Configures the C<wbuf_max> setting (C<undef> disables it).
769
729=cut 770=cut
730 771
731sub rbuf_max { 772sub rbuf_max {
732 $_[0]{rbuf_max} = $_[1]; 773 $_[0]{rbuf_max} = $_[1];
733} 774}
734 775
776sub wbuf_max {
777 $_[0]{wbuf_max} = $_[1];
778}
779
735############################################################################# 780#############################################################################
736 781
737=item $handle->timeout ($seconds) 782=item $handle->timeout ($seconds)
738 783
739=item $handle->rtimeout ($seconds) 784=item $handle->rtimeout ($seconds)
740 785
741=item $handle->wtimeout ($seconds) 786=item $handle->wtimeout ($seconds)
742 787
743Configures (or disables) the inactivity timeout. 788Configures (or disables) the inactivity timeout.
789
790The timeout will be checked instantly, so this method might destroy the
791handle before it returns.
744 792
745=item $handle->timeout_reset 793=item $handle->timeout_reset
746 794
747=item $handle->rtimeout_reset 795=item $handle->rtimeout_reset
748 796
… …
765 $_[0]{$on_timeout} = $_[1]; 813 $_[0]{$on_timeout} = $_[1];
766 }; 814 };
767 815
768 *$timeout = sub { 816 *$timeout = sub {
769 my ($self, $new_value) = @_; 817 my ($self, $new_value) = @_;
818
819 $new_value >= 0
820 or Carp::croak "AnyEvent::Handle->$timeout called with negative timeout ($new_value), caught";
770 821
771 $self->{$timeout} = $new_value; 822 $self->{$timeout} = $new_value;
772 delete $self->{$tw}; &$cb; 823 delete $self->{$tw}; &$cb;
773 }; 824 };
774 825
… …
854 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf}); 905 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
855} 906}
856 907
857=item $handle->push_write ($data) 908=item $handle->push_write ($data)
858 909
859Queues the given scalar to be written. You can push as much data as you 910Queues the given scalar to be written. You can push as much data as
860want (only limited by the available memory), as C<AnyEvent::Handle> 911you want (only limited by the available memory and C<wbuf_max>), as
861buffers it independently of the kernel. 912C<AnyEvent::Handle> buffers it independently of the kernel.
862 913
863This method may invoke callbacks (and therefore the handle might be 914This method may invoke callbacks (and therefore the handle might be
864destroyed after it returns). 915destroyed after it returns).
865 916
866=cut 917=cut
… …
894 $cb->() unless $self->{autocork}; 945 $cb->() unless $self->{autocork};
895 946
896 # if still data left in wbuf, we need to poll 947 # if still data left in wbuf, we need to poll
897 $self->{_ww} = AE::io $self->{fh}, 1, $cb 948 $self->{_ww} = AE::io $self->{fh}, 1, $cb
898 if length $self->{wbuf}; 949 if length $self->{wbuf};
950
951 if (
952 defined $self->{wbuf_max}
953 && $self->{wbuf_max} < length $self->{wbuf}
954 ) {
955 $self->_error (Errno::ENOSPC, 1), return;
956 }
899 }; 957 };
900} 958}
901 959
902our %WH; 960our %WH;
903 961
… …
933 991
934Instead of formatting your data yourself, you can also let this module 992Instead of formatting your data yourself, you can also let this module
935do the job by specifying a type and type-specific arguments. You 993do the job by specifying a type and type-specific arguments. You
936can also specify the (fully qualified) name of a package, in which 994can also specify the (fully qualified) name of a package, in which
937case AnyEvent tries to load the package and then expects to find the 995case AnyEvent tries to load the package and then expects to find the
938C<anyevent_read_type> function inside (see "custom write types", below). 996C<anyevent_write_type> function inside (see "custom write types", below).
939 997
940Predefined types are (if you have ideas for additional types, feel free to 998Predefined types are (if you have ideas for additional types, feel free to
941drop by and tell us): 999drop by and tell us):
942 1000
943=over 4 1001=over 4
… …
1038before it was actually written. One way to do that is to replace your 1096before it was actually written. One way to do that is to replace your
1039C<on_drain> handler by a callback that shuts down the socket (and set 1097C<on_drain> handler by a callback that shuts down the socket (and set
1040C<low_water_mark> to C<0>). This method is a shorthand for just that, and 1098C<low_water_mark> to C<0>). This method is a shorthand for just that, and
1041replaces the C<on_drain> callback with: 1099replaces the C<on_drain> callback with:
1042 1100
1043 sub { shutdown $_[0]{fh}, 1 } # for push_shutdown 1101 sub { shutdown $_[0]{fh}, 1 }
1044 1102
1045This simply shuts down the write side and signals an EOF condition to the 1103This simply shuts down the write side and signals an EOF condition to the
1046the peer. 1104the peer.
1047 1105
1048You can rely on the normal read queue and C<on_eof> handling 1106You can rely on the normal read queue and C<on_eof> handling
… …
1107ways, the "simple" way, using only C<on_read> and the "complex" way, using 1165ways, the "simple" way, using only C<on_read> and the "complex" way, using
1108a queue. 1166a queue.
1109 1167
1110In the simple case, you just install an C<on_read> callback and whenever 1168In the simple case, you just install an C<on_read> callback and whenever
1111new data arrives, it will be called. You can then remove some data (if 1169new data arrives, it will be called. You can then remove some data (if
1112enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna 1170enough is there) from the read buffer (C<< $handle->rbuf >>). Or you can
1113leave the data there if you want to accumulate more (e.g. when only a 1171leave the data there if you want to accumulate more (e.g. when only a
1114partial message has been received so far). 1172partial message has been received so far), or change the read queue with
1173e.g. C<push_read>.
1115 1174
1116In the more complex case, you want to queue multiple callbacks. In this 1175In the more complex case, you want to queue multiple callbacks. In this
1117case, AnyEvent::Handle will call the first queued callback each time new 1176case, AnyEvent::Handle will call the first queued callback each time new
1118data arrives (also the first time it is queued) and removes it when it has 1177data arrives (also the first time it is queued) and remove it when it has
1119done its job (see C<push_read>, below). 1178done its job (see C<push_read>, below).
1120 1179
1121This way you can, for example, push three line-reads, followed by reading 1180This way you can, for example, push three line-reads, followed by reading
1122a chunk of data, and AnyEvent::Handle will execute them in order. 1181a chunk of data, and AnyEvent::Handle will execute them in order.
1123 1182
… …
1268 $self->_drain_rbuf if $cb; 1327 $self->_drain_rbuf if $cb;
1269} 1328}
1270 1329
1271=item $handle->rbuf 1330=item $handle->rbuf
1272 1331
1273Returns the read buffer (as a modifiable lvalue). 1332Returns the read buffer (as a modifiable lvalue). You can also access the
1333read buffer directly as the C<< ->{rbuf} >> member, if you want (this is
1334much faster, and no less clean).
1274 1335
1275You can access the read buffer directly as the C<< ->{rbuf} >> 1336The only operation allowed on the read buffer (apart from looking at it)
1276member, if you want. However, the only operation allowed on the 1337is removing data from its beginning. Otherwise modifying or appending to
1277read buffer (apart from looking at it) is removing data from its 1338it is not allowed and will lead to hard-to-track-down bugs.
1278beginning. Otherwise modifying or appending to it is not allowed and will
1279lead to hard-to-track-down bugs.
1280 1339
1281NOTE: The read buffer should only be used or modified if the C<on_read>, 1340NOTE: The read buffer should only be used or modified in the C<on_read>
1282C<push_read> or C<unshift_read> methods are used. The other read methods 1341callback or when C<push_read> or C<unshift_read> are used with a single
1283automatically manage the read buffer. 1342callback (i.e. untyped). Typed C<push_read> and C<unshift_read> methods
1343will manage the read buffer on their own.
1284 1344
1285=cut 1345=cut
1286 1346
1287sub rbuf : lvalue { 1347sub rbuf : lvalue {
1288 $_[0]{rbuf} 1348 $_[0]{rbuf}
… …
1339 my $cb = pop; 1399 my $cb = pop;
1340 1400
1341 if (@_) { 1401 if (@_) {
1342 my $type = shift; 1402 my $type = shift;
1343 1403
1404 $cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
1344 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read") 1405 or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::unshift_read")
1345 ->($self, $cb, @_); 1406 ->($self, $cb, @_);
1346 } 1407 }
1347 1408
1348 unshift @{ $self->{_queue} }, $cb; 1409 unshift @{ $self->{_queue} }, $cb;
1349 $self->_drain_rbuf; 1410 $self->_drain_rbuf;
… …
1371data. 1432data.
1372 1433
1373Example: read 2 bytes. 1434Example: read 2 bytes.
1374 1435
1375 $handle->push_read (chunk => 2, sub { 1436 $handle->push_read (chunk => 2, sub {
1376 warn "yay ", unpack "H*", $_[1]; 1437 AE::log debug => "yay " . unpack "H*", $_[1];
1377 }); 1438 });
1378 1439
1379=cut 1440=cut
1380 1441
1381register_read_type chunk => sub { 1442register_read_type chunk => sub {
… …
1457the receive buffer when neither C<$accept> nor C<$reject> match, 1518the receive buffer when neither C<$accept> nor C<$reject> match,
1458and everything preceding and including the match will be accepted 1519and everything preceding and including the match will be accepted
1459unconditionally. This is useful to skip large amounts of data that you 1520unconditionally. This is useful to skip large amounts of data that you
1460know cannot be matched, so that the C<$accept> or C<$reject> regex do not 1521know cannot be matched, so that the C<$accept> or C<$reject> regex do not
1461have to start matching from the beginning. This is purely an optimisation 1522have to start matching from the beginning. This is purely an optimisation
1462and is usually worth only when you expect more than a few kilobytes. 1523and is usually worth it only when you expect more than a few kilobytes.
1463 1524
1464Example: expect a http header, which ends at C<\015\012\015\012>. Since we 1525Example: expect a http header, which ends at C<\015\012\015\012>. Since we
1465expect the header to be very large (it isn't in practise, but...), we use 1526expect the header to be very large (it isn't in practice, but...), we use
1466a skip regex to skip initial portions. The skip regex is tricky in that 1527a skip regex to skip initial portions. The skip regex is tricky in that
1467it only accepts something not ending in either \015 or \012, as these are 1528it only accepts something not ending in either \015 or \012, as these are
1468required for the accept regex. 1529required for the accept regex.
1469 1530
1470 $handle->push_read (regex => 1531 $handle->push_read (regex =>
… …
1483 1544
1484 sub { 1545 sub {
1485 # accept 1546 # accept
1486 if ($$rbuf =~ $accept) { 1547 if ($$rbuf =~ $accept) {
1487 $data .= substr $$rbuf, 0, $+[0], ""; 1548 $data .= substr $$rbuf, 0, $+[0], "";
1488 $cb->($self, $data); 1549 $cb->($_[0], $data);
1489 return 1; 1550 return 1;
1490 } 1551 }
1491 1552
1492 # reject 1553 # reject
1493 if ($reject && $$rbuf =~ $reject) { 1554 if ($reject && $$rbuf =~ $reject) {
1494 $self->_error (Errno::EBADMSG); 1555 $_[0]->_error (Errno::EBADMSG);
1495 } 1556 }
1496 1557
1497 # skip 1558 # skip
1498 if ($skip && $$rbuf =~ $skip) { 1559 if ($skip && $$rbuf =~ $skip) {
1499 $data .= substr $$rbuf, 0, $+[0], ""; 1560 $data .= substr $$rbuf, 0, $+[0], "";
… …
1515 my ($self, $cb) = @_; 1576 my ($self, $cb) = @_;
1516 1577
1517 sub { 1578 sub {
1518 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) { 1579 unless ($_[0]{rbuf} =~ s/^(0|[1-9][0-9]*)://) {
1519 if ($_[0]{rbuf} =~ /[^0-9]/) { 1580 if ($_[0]{rbuf} =~ /[^0-9]/) {
1520 $self->_error (Errno::EBADMSG); 1581 $_[0]->_error (Errno::EBADMSG);
1521 } 1582 }
1522 return; 1583 return;
1523 } 1584 }
1524 1585
1525 my $len = $1; 1586 my $len = $1;
1526 1587
1527 $self->unshift_read (chunk => $len, sub { 1588 $_[0]->unshift_read (chunk => $len, sub {
1528 my $string = $_[1]; 1589 my $string = $_[1];
1529 $_[0]->unshift_read (chunk => 1, sub { 1590 $_[0]->unshift_read (chunk => 1, sub {
1530 if ($_[1] eq ",") { 1591 if ($_[1] eq ",") {
1531 $cb->($_[0], $string); 1592 $cb->($_[0], $string);
1532 } else { 1593 } else {
1533 $self->_error (Errno::EBADMSG); 1594 $_[0]->_error (Errno::EBADMSG);
1534 } 1595 }
1535 }); 1596 });
1536 }); 1597 });
1537 1598
1538 1 1599 1
… …
1611 1672
1612 my $data; 1673 my $data;
1613 my $rbuf = \$self->{rbuf}; 1674 my $rbuf = \$self->{rbuf};
1614 1675
1615 sub { 1676 sub {
1616 my $ref = eval { $json->incr_parse ($self->{rbuf}) }; 1677 my $ref = eval { $json->incr_parse ($_[0]{rbuf}) };
1617 1678
1618 if ($ref) { 1679 if ($ref) {
1619 $self->{rbuf} = $json->incr_text; 1680 $_[0]{rbuf} = $json->incr_text;
1620 $json->incr_text = ""; 1681 $json->incr_text = "";
1621 $cb->($self, $ref); 1682 $cb->($_[0], $ref);
1622 1683
1623 1 1684 1
1624 } elsif ($@) { 1685 } elsif ($@) {
1625 # error case 1686 # error case
1626 $json->incr_skip; 1687 $json->incr_skip;
1627 1688
1628 $self->{rbuf} = $json->incr_text; 1689 $_[0]{rbuf} = $json->incr_text;
1629 $json->incr_text = ""; 1690 $json->incr_text = "";
1630 1691
1631 $self->_error (Errno::EBADMSG); 1692 $_[0]->_error (Errno::EBADMSG);
1632 1693
1633 () 1694 ()
1634 } else { 1695 } else {
1635 $self->{rbuf} = ""; 1696 $_[0]{rbuf} = "";
1636 1697
1637 () 1698 ()
1638 } 1699 }
1639 } 1700 }
1640}; 1701};
… …
1673 # read remaining chunk 1734 # read remaining chunk
1674 $_[0]->unshift_read (chunk => $len, sub { 1735 $_[0]->unshift_read (chunk => $len, sub {
1675 if (my $ref = eval { Storable::thaw ($_[1]) }) { 1736 if (my $ref = eval { Storable::thaw ($_[1]) }) {
1676 $cb->($_[0], $ref); 1737 $cb->($_[0], $ref);
1677 } else { 1738 } else {
1678 $self->_error (Errno::EBADMSG); 1739 $_[0]->_error (Errno::EBADMSG);
1679 } 1740 }
1680 }); 1741 });
1681 } 1742 }
1682 1743
1683 1 1744 1
… …
1721Note that AnyEvent::Handle will automatically C<start_read> for you when 1782Note that AnyEvent::Handle will automatically C<start_read> for you when
1722you change the C<on_read> callback or push/unshift a read callback, and it 1783you change the C<on_read> callback or push/unshift a read callback, and it
1723will automatically C<stop_read> for you when neither C<on_read> is set nor 1784will automatically C<stop_read> for you when neither C<on_read> is set nor
1724there are any read requests in the queue. 1785there are any read requests in the queue.
1725 1786
1726These methods will have no effect when in TLS mode (as TLS doesn't support 1787In older versions of this module (<= 5.3), these methods had no effect,
1727half-duplex connections). 1788as TLS does not support half-duplex connections. In current versions they
1789work as expected, as this behaviour is required to avoid certain resource
1790attacks, where the program would be forced to read (and buffer) arbitrary
1791amounts of data before being able to send some data. The drawback is that
1792some readings of the the SSL/TLS specifications basically require this
1793attack to be working, as SSL/TLS implementations might stall sending data
1794during a rehandshake.
1795
1796As a guideline, during the initial handshake, you should not stop reading,
1797and as a client, it might cause problems, depending on your applciation.
1728 1798
1729=cut 1799=cut
1730 1800
1731sub stop_read { 1801sub stop_read {
1732 my ($self) = @_; 1802 my ($self) = @_;
1733 1803
1734 delete $self->{_rw} unless $self->{tls}; 1804 delete $self->{_rw};
1735} 1805}
1736 1806
1737sub start_read { 1807sub start_read {
1738 my ($self) = @_; 1808 my ($self) = @_;
1739 1809
1740 unless ($self->{_rw} || $self->{_eof} || !$self->{fh}) { 1810 unless ($self->{_rw} || $self->{_eof} || !$self->{fh}) {
1741 Scalar::Util::weaken $self; 1811 Scalar::Util::weaken $self;
1742 1812
1743 $self->{_rw} = AE::io $self->{fh}, 0, sub { 1813 $self->{_rw} = AE::io $self->{fh}, 0, sub {
1744 my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf}); 1814 my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
1745 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf; 1815 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size}, length $$rbuf;
1746 1816
1747 if ($len > 0) { 1817 if ($len > 0) {
1748 $self->{_activity} = $self->{_ractivity} = AE::now; 1818 $self->{_activity} = $self->{_ractivity} = AE::now;
1749 1819
1750 if ($self->{tls}) { 1820 if ($self->{tls}) {
1751 Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf); 1821 Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
1752 1822
1753 &_dotls ($self); 1823 &_dotls ($self);
1754 } else { 1824 } else {
1755 $self->_drain_rbuf; 1825 $self->_drain_rbuf;
1826 }
1827
1828 if ($len == $self->{read_size}) {
1829 $self->{read_size} *= 2;
1830 $self->{read_size} = $self->{max_read_size} || MAX_READ_SIZE
1831 if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
1756 } 1832 }
1757 1833
1758 } elsif (defined $len) { 1834 } elsif (defined $len) {
1759 delete $self->{_rw}; 1835 delete $self->{_rw};
1760 $self->{_eof} = 1; 1836 $self->{_eof} = 1;
… …
1870context in C<< $handle->{tls_ctx} >> after this call and can be used or 1946context in C<< $handle->{tls_ctx} >> after this call and can be used or
1871changed to your liking. Note that the handshake might have already started 1947changed to your liking. Note that the handshake might have already started
1872when this function returns. 1948when this function returns.
1873 1949
1874Due to bugs in OpenSSL, it might or might not be possible to do multiple 1950Due to bugs in OpenSSL, it might or might not be possible to do multiple
1875handshakes on the same stream. Best do not attempt to use the stream after 1951handshakes on the same stream. It is best to not attempt to use the
1876stopping TLS. 1952stream after stopping TLS.
1877 1953
1878This method may invoke callbacks (and therefore the handle might be 1954This method may invoke callbacks (and therefore the handle might be
1879destroyed after it returns). 1955destroyed after it returns).
1880 1956
1881=cut 1957=cut
… …
1935 Net::SSLeay::CTX_set_mode ($tls, 1|2); 2011 Net::SSLeay::CTX_set_mode ($tls, 1|2);
1936 2012
1937 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 2013 $self->{_rbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1938 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ()); 2014 $self->{_wbio} = Net::SSLeay::BIO_new (Net::SSLeay::BIO_s_mem ());
1939 2015
1940 Net::SSLeay::BIO_write ($self->{_rbio}, delete $self->{rbuf}); 2016 Net::SSLeay::BIO_write ($self->{_rbio}, $self->{rbuf});
2017 $self->{rbuf} = "";
1941 2018
1942 Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio}); 2019 Net::SSLeay::set_bio ($tls, $self->{_rbio}, $self->{_wbio});
1943 2020
1944 $self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) } 2021 $self->{_on_starttls} = sub { $_[0]{on_starttls}(@_) }
1945 if $self->{on_starttls}; 2022 if $self->{on_starttls};
… …
1983 if $self->{tls} > 0; 2060 if $self->{tls} > 0;
1984 2061
1985 delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)}; 2062 delete @$self{qw(_rbio _wbio _tls_wbuf _on_starttls)};
1986} 2063}
1987 2064
2065=item $handle->resettls
2066
2067This rarely-used method simply resets and TLS state on the handle, usually
2068causing data loss.
2069
2070One case where it may be useful is when you want to skip over the data in
2071the stream but you are not interested in interpreting it, so data loss is
2072no concern.
2073
2074=cut
2075
2076*resettls = \&_freetls;
2077
1988sub DESTROY { 2078sub DESTROY {
1989 my ($self) = @_; 2079 my ($self) = @_;
1990 2080
1991 &_freetls; 2081 &_freetls;
1992 2082
… …
2001 push @linger, AE::io $fh, 1, sub { 2091 push @linger, AE::io $fh, 1, sub {
2002 my $len = syswrite $fh, $wbuf, length $wbuf; 2092 my $len = syswrite $fh, $wbuf, length $wbuf;
2003 2093
2004 if ($len > 0) { 2094 if ($len > 0) {
2005 substr $wbuf, 0, $len, ""; 2095 substr $wbuf, 0, $len, "";
2006 } else { 2096 } elsif (defined $len || ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK)) {
2007 @linger = (); # end 2097 @linger = (); # end
2008 } 2098 }
2009 }; 2099 };
2010 push @linger, AE::timer $linger, 0, sub { 2100 push @linger, AE::timer $linger, 0, sub {
2011 @linger = (); 2101 @linger = ();
… …
2107 2197
2108It is only safe to "forget" the reference inside EOF or error callbacks, 2198It is only safe to "forget" the reference inside EOF or error callbacks,
2109from within all other callbacks, you need to explicitly call the C<< 2199from within all other callbacks, you need to explicitly call the C<<
2110->destroy >> method. 2200->destroy >> method.
2111 2201
2202=item Why is my C<on_eof> callback never called?
2203
2204Probably because your C<on_error> callback is being called instead: When
2205you have outstanding requests in your read queue, then an EOF is
2206considered an error as you clearly expected some data.
2207
2208To avoid this, make sure you have an empty read queue whenever your handle
2209is supposed to be "idle" (i.e. connection closes are O.K.). You cna set
2210an C<on_read> handler that simply pushes the first read requests in the
2211queue.
2212
2213See also the next question, which explains this in a bit more detail.
2214
2215=item How can I serve requests in a loop?
2216
2217Most protocols consist of some setup phase (authentication for example)
2218followed by a request handling phase, where the server waits for requests
2219and handles them, in a loop.
2220
2221There are two important variants: The first (traditional, better) variant
2222handles requests until the server gets some QUIT command, causing it to
2223close the connection first (highly desirable for a busy TCP server). A
2224client dropping the connection is an error, which means this variant can
2225detect an unexpected detection close.
2226
2227To handle this case, always make sure you have a on-empty read queue, by
2228pushing the "read request start" handler on it:
2229
2230 # we assume a request starts with a single line
2231 my @start_request; @start_request = (line => sub {
2232 my ($hdl, $line) = @_;
2233
2234 ... handle request
2235
2236 # push next request read, possibly from a nested callback
2237 $hdl->push_read (@start_request);
2238 });
2239
2240 # auth done, now go into request handling loop
2241 # now push the first @start_request
2242 $hdl->push_read (@start_request);
2243
2244By always having an outstanding C<push_read>, the handle always expects
2245some data and raises the C<EPIPE> error when the connction is dropped
2246unexpectedly.
2247
2248The second variant is a protocol where the client can drop the connection
2249at any time. For TCP, this means that the server machine may run out of
2250sockets easier, and in general, it means you cnanot distinguish a protocl
2251failure/client crash from a normal connection close. Nevertheless, these
2252kinds of protocols are common (and sometimes even the best solution to the
2253problem).
2254
2255Having an outstanding read request at all times is possible if you ignore
2256C<EPIPE> errors, but this doesn't help with when the client drops the
2257connection during a request, which would still be an error.
2258
2259A better solution is to push the initial request read in an C<on_read>
2260callback. This avoids an error, as when the server doesn't expect data
2261(i.e. is idly waiting for the next request, an EOF will not raise an
2262error, but simply result in an C<on_eof> callback. It is also a bit slower
2263and simpler:
2264
2265 # auth done, now go into request handling loop
2266 $hdl->on_read (sub {
2267 my ($hdl) = @_;
2268
2269 # called each time we receive data but the read queue is empty
2270 # simply start read the request
2271
2272 $hdl->push_read (line => sub {
2273 my ($hdl, $line) = @_;
2274
2275 ... handle request
2276
2277 # do nothing special when the request has been handled, just
2278 # let the request queue go empty.
2279 });
2280 });
2281
2112=item I get different callback invocations in TLS mode/Why can't I pause 2282=item I get different callback invocations in TLS mode/Why can't I pause
2113reading? 2283reading?
2114 2284
2115Unlike, say, TCP, TLS connections do not consist of two independent 2285Unlike, say, TCP, TLS connections do not consist of two independent
2116communication channels, one for each direction. Or put differently. The 2286communication channels, one for each direction. Or put differently, the
2117read and write directions are not independent of each other: you cannot 2287read and write directions are not independent of each other: you cannot
2118write data unless you are also prepared to read, and vice versa. 2288write data unless you are also prepared to read, and vice versa.
2119 2289
2120This can mean than, in TLS mode, you might get C<on_error> or C<on_eof> 2290This means that, in TLS mode, you might get C<on_error> or C<on_eof>
2121callback invocations when you are not expecting any read data - the reason 2291callback invocations when you are not expecting any read data - the reason
2122is that AnyEvent::Handle always reads in TLS mode. 2292is that AnyEvent::Handle always reads in TLS mode.
2123 2293
2124During the connection, you have to make sure that you always have a 2294During the connection, you have to make sure that you always have a
2125non-empty read-queue, or an C<on_read> watcher. At the end of the 2295non-empty read-queue, or an C<on_read> watcher. At the end of the
… …
2137 $handle->on_eof (undef); 2307 $handle->on_eof (undef);
2138 $handle->on_error (sub { 2308 $handle->on_error (sub {
2139 my $data = delete $_[0]{rbuf}; 2309 my $data = delete $_[0]{rbuf};
2140 }); 2310 });
2141 2311
2312Note that this example removes the C<rbuf> member from the handle object,
2313which is not normally allowed by the API. It is expressly permitted in
2314this case only, as the handle object needs to be destroyed afterwards.
2315
2142The reason to use C<on_error> is that TCP connections, due to latencies 2316The reason to use C<on_error> is that TCP connections, due to latencies
2143and packets loss, might get closed quite violently with an error, when in 2317and packets loss, might get closed quite violently with an error, when in
2144fact, all data has been received. 2318fact all data has been received.
2145 2319
2146It is usually better to use acknowledgements when transferring data, 2320It is usually better to use acknowledgements when transferring data,
2147to make sure the other side hasn't just died and you got the data 2321to make sure the other side hasn't just died and you got the data
2148intact. This is also one reason why so many internet protocols have an 2322intact. This is also one reason why so many internet protocols have an
2149explicit QUIT command. 2323explicit QUIT command.
… …
2156C<low_water_mark> this will be called precisely when all data has been 2330C<low_water_mark> this will be called precisely when all data has been
2157written to the socket: 2331written to the socket:
2158 2332
2159 $handle->push_write (...); 2333 $handle->push_write (...);
2160 $handle->on_drain (sub { 2334 $handle->on_drain (sub {
2161 warn "all data submitted to the kernel\n"; 2335 AE::log debug => "all data submitted to the kernel\n";
2162 undef $handle; 2336 undef $handle;
2163 }); 2337 });
2164 2338
2165If you just want to queue some data and then signal EOF to the other side, 2339If you just want to queue some data and then signal EOF to the other side,
2166consider using C<< ->push_shutdown >> instead. 2340consider using C<< ->push_shutdown >> instead.
2167 2341
2168=item I want to contact a TLS/SSL server, I don't care about security. 2342=item I want to contact a TLS/SSL server, I don't care about security.
2169 2343
2170If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS, 2344If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
2171simply connect to it and then create the AnyEvent::Handle with the C<tls> 2345connect to it and then create the AnyEvent::Handle with the C<tls>
2172parameter: 2346parameter:
2173 2347
2174 tcp_connect $host, $port, sub { 2348 tcp_connect $host, $port, sub {
2175 my ($fh) = @_; 2349 my ($fh) = @_;
2176 2350
… …
2276 2450
2277=item * all members not documented here and not prefixed with an underscore 2451=item * all members not documented here and not prefixed with an underscore
2278are free to use in subclasses. 2452are free to use in subclasses.
2279 2453
2280Of course, new versions of AnyEvent::Handle may introduce more "public" 2454Of course, new versions of AnyEvent::Handle may introduce more "public"
2281member variables, but thats just life, at least it is documented. 2455member variables, but that's just life. At least it is documented.
2282 2456
2283=back 2457=back
2284 2458
2285=head1 AUTHOR 2459=head1 AUTHOR
2286 2460

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