ViewVC Help
View File | Revision Log | Show Annotations | Download File
/cvs/AnyEvent/lib/AnyEvent/Handle.pm
(Generate patch)

Comparing AnyEvent/lib/AnyEvent/Handle.pm (file contents):
Revision 1.182 by root, Thu Sep 3 12:35:01 2009 UTC vs.
Revision 1.214 by root, Sun Jan 16 17:12:27 2011 UTC

1=head1 NAME 1=head1 NAME
2 2
3AnyEvent::Handle - non-blocking I/O on file handles via AnyEvent 3AnyEvent::Handle - non-blocking I/O on streaming handles via AnyEvent
4 4
5=head1 SYNOPSIS 5=head1 SYNOPSIS
6 6
7 use AnyEvent; 7 use AnyEvent;
8 use AnyEvent::Handle; 8 use AnyEvent::Handle;
… …
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 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
… …
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
36filehandles. 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
… …
60use AnyEvent (); BEGIN { AnyEvent::common_sense } 60use AnyEvent (); BEGIN { AnyEvent::common_sense }
61use AnyEvent::Util qw(WSAEWOULDBLOCK); 61use AnyEvent::Util qw(WSAEWOULDBLOCK);
62 62
63our $VERSION = $AnyEvent::VERSION; 63our $VERSION = $AnyEvent::VERSION;
64 64
65sub _load_func($) {
66 my $func = $_[0];
67
68 unless (defined &$func) {
69 my $pkg = $func;
70 do {
71 $pkg =~ s/::[^:]+$//
72 or return;
73 eval "require $pkg";
74 } until defined &$func;
75 }
76
77 \&$func
78}
79
80sub MAX_READ_SIZE() { 131072 }
81
65=head1 METHODS 82=head1 METHODS
66 83
67=over 4 84=over 4
68 85
69=item $handle = B<new> AnyEvent::TLS fh => $filehandle, key => value... 86=item $handle = B<new> AnyEvent::Handle fh => $filehandle, key => value...
70 87
71The constructor supports these arguments (all as C<< key => value >> pairs). 88The constructor supports these arguments (all as C<< key => value >> pairs).
72 89
73=over 4 90=over 4
74 91
… …
97=over 4 114=over 4
98 115
99=item on_prepare => $cb->($handle) 116=item on_prepare => $cb->($handle)
100 117
101This (rarely used) callback is called before a new connection is 118This (rarely used) callback is called before a new connection is
102attempted, 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
103prepare the file handle with parameters required for the actual connect 121file handle with parameters required for the actual connect (as opposed to
104(as opposed to settings that can be changed when the connection is already 122settings that can be changed when the connection is already established).
105established).
106 123
107The 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
108seconds (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
109timeout is to be used). 126default timeout is to be used).
110 127
111=item on_connect => $cb->($handle, $host, $port, $retry->()) 128=item on_connect => $cb->($handle, $host, $port, $retry->())
112 129
113This callback is called when a connection has been successfully established. 130This callback is called when a connection has been successfully established.
114 131
115The actual numeric host and port (the socket peername) are passed as 132The peer's numeric host and port (the socket peername) are passed as
116parameters, together with a retry callback. 133parameters, together with a retry callback.
117 134
118When, for some reason, the handle is not acceptable, then calling 135If, for some reason, the handle is not acceptable, calling C<$retry>
119C<$retry> will continue with the next conenction target (in case of 136will continue with the next connection target (in case of multi-homed
120multi-homed hosts or SRV records there can be multiple connection 137hosts or SRV records there can be multiple connection endpoints). At the
121endpoints). When it is called then the read and write queues, eof status, 138time it is called the read and write queues, eof status, tls status and
122tls status and similar properties of the handle are being reset. 139similar properties of the handle will have been reset.
123 140
124In most cases, ignoring the C<$retry> parameter is the way to go. 141In most cases, you should ignore the C<$retry> parameter.
125 142
126=item on_connect_error => $cb->($handle, $message) 143=item on_connect_error => $cb->($handle, $message)
127 144
128This callback is called when the conenction could not be 145This callback is called when the connection could not be
129established. C<$!> will contain the relevant error code, and C<$message> a 146established. C<$!> will contain the relevant error code, and C<$message> a
130message describing it (usually the same as C<"$!">). 147message describing it (usually the same as C<"$!">).
131 148
132If this callback isn't specified, then C<on_error> will be called with a 149If this callback isn't specified, then C<on_error> will be called with a
133fatal error instead. 150fatal error instead.
… …
136 153
137=item on_error => $cb->($handle, $fatal, $message) 154=item on_error => $cb->($handle, $fatal, $message)
138 155
139This is the error callback, which is called when, well, some error 156This is the error callback, which is called when, well, some error
140occured, such as not being able to resolve the hostname, failure to 157occured, such as not being able to resolve the hostname, failure to
141connect or a read error. 158connect, or a read error.
142 159
143Some errors are fatal (which is indicated by C<$fatal> being true). On 160Some errors are fatal (which is indicated by C<$fatal> being true). On
144fatal errors the handle object will be destroyed (by a call to C<< -> 161fatal errors the handle object will be destroyed (by a call to C<< ->
145destroy >>) after invoking the error callback (which means you are free to 162destroy >>) after invoking the error callback (which means you are free to
146examine the handle object). Examples of fatal errors are an EOF condition 163examine the handle object). Examples of fatal errors are an EOF condition
147with active (but unsatisifable) read watchers (C<EPIPE>) or I/O errors. In 164with active (but unsatisfiable) read watchers (C<EPIPE>) or I/O errors. In
148cases where the other side can close the connection at their will it is 165cases where the other side can close the connection at will, it is
149often easiest to not report C<EPIPE> errors in this callback. 166often easiest to not report C<EPIPE> errors in this callback.
150 167
151AnyEvent::Handle tries to find an appropriate error code for you to check 168AnyEvent::Handle tries to find an appropriate error code for you to check
152against, but in some cases (TLS errors), this does not work well. It is 169against, but in some cases (TLS errors), this does not work well. It is
153recommended to always output the C<$message> argument in human-readable 170recommended to always output the C<$message> argument in human-readable
154error messages (it's usually the same as C<"$!">). 171error messages (it's usually the same as C<"$!">).
155 172
156Non-fatal errors can be retried by simply returning, but it is recommended 173Non-fatal errors can be retried by returning, but it is recommended
157to simply ignore this parameter and instead abondon the handle object 174to simply ignore this parameter and instead abondon the handle object
158when this callback is invoked. Examples of non-fatal errors are timeouts 175when this callback is invoked. Examples of non-fatal errors are timeouts
159C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>). 176C<ETIMEDOUT>) or badly-formatted data (C<EBADMSG>).
160 177
161On callback entrance, the value of C<$!> contains the operating system 178On entry to the callback, the value of C<$!> contains the operating
162error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or 179system error code (or C<ENOSPC>, C<EPIPE>, C<ETIMEDOUT>, C<EBADMSG> or
163C<EPROTO>). 180C<EPROTO>).
164 181
165While 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
166you will not be notified of errors otherwise. The default simply calls 183you will not be notified of errors otherwise. The default just calls
167C<croak>. 184C<croak>.
168 185
169=item on_read => $cb->($handle) 186=item on_read => $cb->($handle)
170 187
171This sets the default read callback, which is called when data arrives 188This sets the default read callback, which is called when data arrives
… …
176To 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 >>
177method or access the C<< $handle->{rbuf} >> member directly. Note that you 194method or access the C<< $handle->{rbuf} >> member directly. Note that you
178must not enlarge or modify the read buffer, you can only remove data at 195must not enlarge or modify the read buffer, you can only remove data at
179the beginning from it. 196the beginning from it.
180 197
198You can also call C<< ->push_read (...) >> or any other function that
199modifies the read queue. Or do both. Or ...
200
181When an EOF condition is detected then AnyEvent::Handle will first try to 201When an EOF condition is detected, AnyEvent::Handle will first try to
182feed all the remaining data to the queued callbacks and C<on_read> before 202feed all the remaining data to the queued callbacks and C<on_read> before
183calling the C<on_eof> callback. If no progress can be made, then a fatal 203calling the C<on_eof> callback. If no progress can be made, then a fatal
184error will be raised (with C<$!> set to C<EPIPE>). 204error will be raised (with C<$!> set to C<EPIPE>).
185 205
186Note that, unlike requests in the read queue, an C<on_read> callback 206Note that, unlike requests in the read queue, an C<on_read> callback
… …
205set, then a fatal error will be raised with C<$!> set to <0>. 225set, then a fatal error will be raised with C<$!> set to <0>.
206 226
207=item on_drain => $cb->($handle) 227=item on_drain => $cb->($handle)
208 228
209This 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
210(or when the callback is set and the buffer is empty already). 230(or immediately if the buffer is empty already).
211 231
212To append to the write buffer, use the C<< ->push_write >> method. 232To append to the write buffer, use the C<< ->push_write >> method.
213 233
214This 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
215into 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
… …
227many seconds pass without a successful read or write on the underlying 247many seconds pass without a successful read or write on the underlying
228file 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
229will 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>
230error will be raised). 250error will be raised).
231 251
232There are three variants of the timeouts that work fully independent 252There are three variants of the timeouts that work independently
233of each other, for both read and write, just read, and just write: 253of each other, for both read and write, just read, and just write:
234C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks 254C<timeout>, C<rtimeout> and C<wtimeout>, with corresponding callbacks
235C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions 255C<on_timeout>, C<on_rtimeout> and C<on_wtimeout>, and reset functions
236C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>. 256C<timeout_reset>, C<rtimeout_reset>, and C<wtimeout_reset>.
237 257
238Note that timeout processing is also active when you currently do not have 258Note that timeout processing is active even when you do not have
239any outstanding read or write requests: If you plan to keep the connection 259any outstanding read or write requests: If you plan to keep the connection
240idle then you should disable the timout temporarily or ignore the timeout 260idle then you should disable the timeout temporarily or ignore the timeout
241in the C<on_timeout> callback, in which case AnyEvent::Handle will simply 261in the C<on_timeout> callback, in which case AnyEvent::Handle will simply
242restart the timeout. 262restart the timeout.
243 263
244Zero (the default) disables this timeout. 264Zero (the default) disables this timeout.
245 265
… …
259be configured to accept only so-and-so much data that it cannot act on 279be configured to accept only so-and-so much data that it cannot act on
260(for example, when expecting a line, an attacker could send an unlimited 280(for example, when expecting a line, an attacker could send an unlimited
261amount of data without a callback ever being called as long as the line 281amount of data without a callback ever being called as long as the line
262isn't finished). 282isn't finished).
263 283
284=item wbuf_max => <bytes>
285
286If defined, then a fatal error will be raised (with C<$!> set to C<ENOSPC>)
287when the write buffer ever (strictly) exceeds this size. This is useful to
288avoid some forms of denial-of-service attacks.
289
290Although the units of this parameter is bytes, this is the I<raw> number
291of bytes not yet accepted by the kernel. This can make a difference when
292you e.g. use TLS, as TLS typically makes your write data larger (but it
293can also make it smaller due to compression).
294
295As an example of when this limit is useful, take a chat server that sends
296chat messages to a client. If the client does not read those in a timely
297manner then the send buffer in the server would grow unbounded.
298
264=item autocork => <boolean> 299=item autocork => <boolean>
265 300
266When disabled (the default), then C<push_write> will try to immediately 301When disabled (the default), C<push_write> will try to immediately
267write the data to the handle, if possible. This avoids having to register 302write the data to the handle if possible. This avoids having to register
268a write watcher and wait for the next event loop iteration, but can 303a write watcher and wait for the next event loop iteration, but can
269be inefficient if you write multiple small chunks (on the wire, this 304be inefficient if you write multiple small chunks (on the wire, this
270disadvantage is usually avoided by your kernel's nagle algorithm, see 305disadvantage is usually avoided by your kernel's nagle algorithm, see
271C<no_delay>, but this option can save costly syscalls). 306C<no_delay>, but this option can save costly syscalls).
272 307
273When enabled, then writes will always be queued till the next event loop 308When enabled, writes will always be queued till the next event loop
274iteration. This is efficient when you do many small writes per iteration, 309iteration. This is efficient when you do many small writes per iteration,
275but less efficient when you do a single write only per iteration (or when 310but less efficient when you do a single write only per iteration (or when
276the write buffer often is full). It also increases write latency. 311the write buffer often is full). It also increases write latency.
277 312
278=item no_delay => <boolean> 313=item no_delay => <boolean>
… …
282the Nagle algorithm, and usually it is beneficial. 317the Nagle algorithm, and usually it is beneficial.
283 318
284In some situations you want as low a delay as possible, which can be 319In some situations you want as low a delay as possible, which can be
285accomplishd by setting this option to a true value. 320accomplishd by setting this option to a true value.
286 321
287The default is your opertaing system's default behaviour (most likely 322The default is your operating system's default behaviour (most likely
288enabled), this option explicitly enables or disables it, if possible. 323enabled). This option explicitly enables or disables it, if possible.
289 324
290=item keepalive => <boolean> 325=item keepalive => <boolean>
291 326
292Enables (default disable) the SO_KEEPALIVE option on the stream socket: 327Enables (default disable) the SO_KEEPALIVE option on the stream socket:
293normally, TCP connections have no time-out once established, so TCP 328normally, TCP connections have no time-out once established, so TCP
294conenctions, once established, can stay alive forever even when the other 329connections, once established, can stay alive forever even when the other
295side has long gone. TCP keepalives are a cheap way to take down long-lived 330side has long gone. TCP keepalives are a cheap way to take down long-lived
296TCP connections whent he other side becomes unreachable. While the default 331TCP connections when the other side becomes unreachable. While the default
297is OS-dependent, TCP keepalives usually kick in after around two hours, 332is OS-dependent, TCP keepalives usually kick in after around two hours,
298and, if the other side doesn't reply, take down the TCP connection some 10 333and, if the other side doesn't reply, take down the TCP connection some 10
299to 15 minutes later. 334to 15 minutes later.
300 335
301It is harmless to specify this option for file handles that do not support 336It is harmless to specify this option for file handles that do not support
… …
306 341
307BSD majorly fucked up the implementation of TCP urgent data. The result 342BSD majorly fucked up the implementation of TCP urgent data. The result
308is that almost no OS implements TCP according to the specs, and every OS 343is that almost no OS implements TCP according to the specs, and every OS
309implements it slightly differently. 344implements it slightly differently.
310 345
311If you want to handle TCP urgent data, then setting this flag gives you 346If you want to handle TCP urgent data, then setting this flag (the default
312the most portable way of getting urgent data, by putting it into the 347is enabled) gives you the most portable way of getting urgent data, by
313stream. 348putting it into the stream.
349
350Since BSD emulation of OOB data on top of TCP's urgent data can have
351security implications, AnyEvent::Handle sets this flag automatically
352unless explicitly specified. Note that setting this flag after
353establishing a connection I<may> be a bit too late (data loss could
354already have occured on BSD systems), but at least it will protect you
355from most attacks.
314 356
315=item read_size => <bytes> 357=item read_size => <bytes>
316 358
317The default read block size (the amount of bytes this module will 359The initial read block size, the number of bytes this module will try to
318try to read during each loop iteration, which affects memory 360read during each loop iteration. Each handle object will consume at least
319requirements). Default: C<8192>. 361this amount of memory for the read buffer as well, so when handling many
362connections requirements). See also C<max_read_size>. Default: C<2048>.
363
364=item max_read_size => <bytes>
365
366The maximum read buffer size used by the dynamic adjustment
367algorithm: Each time AnyEvent::Handle can read C<read_size> bytes in
368one go it will double C<read_size> up to the maximum given by this
369option. Default: C<131072> or C<read_size>, whichever is higher.
320 370
321=item low_water_mark => <bytes> 371=item low_water_mark => <bytes>
322 372
323Sets the amount of bytes (default: C<0>) that make up an "empty" write 373Sets the number of bytes (default: C<0>) that make up an "empty" write
324buffer: If the write reaches this size or gets even samller it is 374buffer: If the buffer reaches this size or gets even samller it is
325considered empty. 375considered empty.
326 376
327Sometimes it can be beneficial (for performance reasons) to add data to 377Sometimes it can be beneficial (for performance reasons) to add data to
328the write buffer before it is fully drained, but this is a rare case, as 378the write buffer before it is fully drained, but this is a rare case, as
329the operating system kernel usually buffers data as well, so the default 379the operating system kernel usually buffers data as well, so the default
330is good in almost all cases. 380is good in almost all cases.
331 381
332=item linger => <seconds> 382=item linger => <seconds>
333 383
334If non-zero (default: C<3600>), then the destructor of the 384If this is non-zero (default: C<3600>), the destructor of the
335AnyEvent::Handle object will check whether there is still outstanding 385AnyEvent::Handle object will check whether there is still outstanding
336write data and will install a watcher that will write this data to the 386write data and will install a watcher that will write this data to the
337socket. No errors will be reported (this mostly matches how the operating 387socket. No errors will be reported (this mostly matches how the operating
338system treats outstanding data at socket close time). 388system treats outstanding data at socket close time).
339 389
… …
346A string used to identify the remote site - usually the DNS hostname 396A string used to identify the remote site - usually the DNS hostname
347(I<not> IDN!) used to create the connection, rarely the IP address. 397(I<not> IDN!) used to create the connection, rarely the IP address.
348 398
349Apart from being useful in error messages, this string is also used in TLS 399Apart from being useful in error messages, this string is also used in TLS
350peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This 400peername verification (see C<verify_peername> in L<AnyEvent::TLS>). This
351verification will be skipped when C<peername> is not specified or 401verification will be skipped when C<peername> is not specified or is
352C<undef>. 402C<undef>.
353 403
354=item tls => "accept" | "connect" | Net::SSLeay::SSL object 404=item tls => "accept" | "connect" | Net::SSLeay::SSL object
355 405
356When this parameter is given, it enables TLS (SSL) mode, that means 406When this parameter is given, it enables TLS (SSL) mode, that means
357AnyEvent will start a TLS handshake as soon as the conenction has been 407AnyEvent will start a TLS handshake as soon as the connection has been
358established and will transparently encrypt/decrypt data afterwards. 408established and will transparently encrypt/decrypt data afterwards.
359 409
360All TLS protocol errors will be signalled as C<EPROTO>, with an 410All TLS protocol errors will be signalled as C<EPROTO>, with an
361appropriate error message. 411appropriate error message.
362 412
… …
382B<IMPORTANT:> since Net::SSLeay "objects" are really only integers, 432B<IMPORTANT:> since Net::SSLeay "objects" are really only integers,
383passing in the wrong integer will lead to certain crash. This most often 433passing in the wrong integer will lead to certain crash. This most often
384happens when one uses a stylish C<< tls => 1 >> and is surprised about the 434happens when one uses a stylish C<< tls => 1 >> and is surprised about the
385segmentation fault. 435segmentation fault.
386 436
387See the C<< ->starttls >> method for when need to start TLS negotiation later. 437Use the C<< ->starttls >> method if you need to start TLS negotiation later.
388 438
389=item tls_ctx => $anyevent_tls 439=item tls_ctx => $anyevent_tls
390 440
391Use the given C<AnyEvent::TLS> object to create the new TLS connection 441Use the given C<AnyEvent::TLS> object to create the new TLS connection
392(unless a connection object was specified directly). If this parameter is 442(unless a connection object was specified directly). If this
393missing, then AnyEvent::Handle will use C<AnyEvent::Handle::TLS_CTX>. 443parameter is missing (or C<undef>), then AnyEvent::Handle will use
444C<AnyEvent::Handle::TLS_CTX>.
394 445
395Instead of an object, you can also specify a hash reference with C<< key 446Instead of an object, you can also specify a hash reference with C<< key
396=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a 447=> value >> pairs. Those will be passed to L<AnyEvent::TLS> to create a
397new TLS context object. 448new TLS context object.
398 449
… …
407 458
408TLS handshake failures will not cause C<on_error> to be invoked when this 459TLS handshake failures will not cause C<on_error> to be invoked when this
409callback is in effect, instead, the error message will be passed to C<on_starttls>. 460callback is in effect, instead, the error message will be passed to C<on_starttls>.
410 461
411Without this callback, handshake failures lead to C<on_error> being 462Without this callback, handshake failures lead to C<on_error> being
412called, as normal. 463called as usual.
413 464
414Note that you cannot call C<starttls> right again in this callback. If you 465Note that you cannot just call C<starttls> again in this callback. If you
415need to do that, start an zero-second timer instead whose callback can 466need to do that, start an zero-second timer instead whose callback can
416then call C<< ->starttls >> again. 467then call C<< ->starttls >> again.
417 468
418=item on_stoptls => $cb->($handle) 469=item on_stoptls => $cb->($handle)
419 470
… …
466 AnyEvent::Socket::tcp_connect ( 517 AnyEvent::Socket::tcp_connect (
467 $self->{connect}[0], 518 $self->{connect}[0],
468 $self->{connect}[1], 519 $self->{connect}[1],
469 sub { 520 sub {
470 my ($fh, $host, $port, $retry) = @_; 521 my ($fh, $host, $port, $retry) = @_;
522
523 delete $self->{_connect}; # no longer needed
471 524
472 if ($fh) { 525 if ($fh) {
473 $self->{fh} = $fh; 526 $self->{fh} = $fh;
474 527
475 delete $self->{_skip_drain_rbuf}; 528 delete $self->{_skip_drain_rbuf};
… …
493 }, 546 },
494 sub { 547 sub {
495 local $self->{fh} = $_[0]; 548 local $self->{fh} = $_[0];
496 549
497 $self->{on_prepare} 550 $self->{on_prepare}
498 ? $self->{on_prepare}->($self) 551 ? $self->{on_prepare}->($self)
499 : () 552 : ()
500 } 553 }
501 ); 554 );
502 } 555 }
503 556
… …
509} 562}
510 563
511sub _start { 564sub _start {
512 my ($self) = @_; 565 my ($self) = @_;
513 566
567 # too many clueless people try to use udp and similar sockets
568 # with AnyEvent::Handle, do them a favour.
569 my $type = getsockopt $self->{fh}, Socket::SOL_SOCKET (), Socket::SO_TYPE ();
570 Carp::croak "AnyEvent::Handle: only stream sockets supported, anything else will NOT work!"
571 if Socket::SOCK_STREAM () != (unpack "I", $type) && defined $type;
572
514 AnyEvent::Util::fh_nonblocking $self->{fh}, 1; 573 AnyEvent::Util::fh_nonblocking $self->{fh}, 1;
515 574
516 $self->{_activity} = 575 $self->{_activity} =
517 $self->{_ractivity} = 576 $self->{_ractivity} =
518 $self->{_wactivity} = AE::now; 577 $self->{_wactivity} = AE::now;
519 578
579 $self->{read_size} ||= 2048;
580 $self->{max_read_size} = $self->{read_size}
581 if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
582
520 $self->timeout (delete $self->{timeout} ) if $self->{timeout}; 583 $self->timeout (delete $self->{timeout} ) if $self->{timeout};
521 $self->rtimeout (delete $self->{rtimeout} ) if $self->{rtimeout}; 584 $self->rtimeout (delete $self->{rtimeout} ) if $self->{rtimeout};
522 $self->wtimeout (delete $self->{wtimeout} ) if $self->{wtimeout}; 585 $self->wtimeout (delete $self->{wtimeout} ) if $self->{wtimeout};
523 586
524 $self->no_delay (delete $self->{no_delay} ) if exists $self->{no_delay}; 587 $self->no_delay (delete $self->{no_delay} ) if exists $self->{no_delay} && $self->{no_delay};
525 $self->keepalive (delete $self->{keepalive}) if exists $self->{keepalive}; 588 $self->keepalive (delete $self->{keepalive}) if exists $self->{keepalive} && $self->{keepalive};
589
526 $self->oobinline (delete $self->{oobinline}) if exists $self->{oobinline}; 590 $self->oobinline (exists $self->{oobinline} ? delete $self->{oobinline} : 1);
527 591
528 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx}) 592 $self->starttls (delete $self->{tls}, delete $self->{tls_ctx})
529 if $self->{tls}; 593 if $self->{tls};
530 594
531 $self->on_drain (delete $self->{on_drain}) if $self->{on_drain}; 595 $self->on_drain (delete $self->{on_drain} ) if $self->{on_drain};
532 596
533 $self->start_read 597 $self->start_read
534 if $self->{on_read} || @{ $self->{_queue} }; 598 if $self->{on_read} || @{ $self->{_queue} };
535 599
536 $self->_drain_wbuf; 600 $self->_drain_wbuf;
… …
543 $message ||= "$!"; 607 $message ||= "$!";
544 608
545 if ($self->{on_error}) { 609 if ($self->{on_error}) {
546 $self->{on_error}($self, $fatal, $message); 610 $self->{on_error}($self, $fatal, $message);
547 $self->destroy if $fatal; 611 $self->destroy if $fatal;
548 } elsif ($self->{fh}) { 612 } elsif ($self->{fh} || $self->{connect}) {
549 $self->destroy; 613 $self->destroy;
550 Carp::croak "AnyEvent::Handle uncaught error: $message"; 614 Carp::croak "AnyEvent::Handle uncaught error: $message";
551 } 615 }
552} 616}
553 617
… …
612=cut 676=cut
613 677
614sub no_delay { 678sub no_delay {
615 $_[0]{no_delay} = $_[1]; 679 $_[0]{no_delay} = $_[1];
616 680
617 eval {
618 local $SIG{__DIE__};
619 setsockopt $_[0]{fh}, Socket::IPPROTO_TCP (), Socket::TCP_NODELAY (), int $_[1] 681 setsockopt $_[0]{fh}, Socket::IPPROTO_TCP (), Socket::TCP_NODELAY (), int $_[1]
620 if $_[0]{fh}; 682 if $_[0]{fh};
621 };
622} 683}
623 684
624=item $handle->keepalive ($boolean) 685=item $handle->keepalive ($boolean)
625 686
626Enables or disables the C<keepalive> setting (see constructor argument of 687Enables or disables the C<keepalive> setting (see constructor argument of
… …
686 747
687Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument). 748Replace the current C<on_stoptls> callback (see the C<on_stoptls> constructor argument).
688 749
689=cut 750=cut
690 751
691sub on_starttls { 752sub on_stoptls {
692 $_[0]{on_stoptls} = $_[1]; 753 $_[0]{on_stoptls} = $_[1];
693} 754}
694 755
695=item $handle->rbuf_max ($max_octets) 756=item $handle->rbuf_max ($max_octets)
696 757
697Configures the C<rbuf_max> setting (C<undef> disables it). 758Configures the C<rbuf_max> setting (C<undef> disables it).
759
760=item $handle->wbuf_max ($max_octets)
761
762Configures the C<wbuf_max> setting (C<undef> disables it).
698 763
699=cut 764=cut
700 765
701sub rbuf_max { 766sub rbuf_max {
702 $_[0]{rbuf_max} = $_[1]; 767 $_[0]{rbuf_max} = $_[1];
768}
769
770sub rbuf_max {
771 $_[0]{wbuf_max} = $_[1];
703} 772}
704 773
705############################################################################# 774#############################################################################
706 775
707=item $handle->timeout ($seconds) 776=item $handle->timeout ($seconds)
… …
735 $_[0]{$on_timeout} = $_[1]; 804 $_[0]{$on_timeout} = $_[1];
736 }; 805 };
737 806
738 *$timeout = sub { 807 *$timeout = sub {
739 my ($self, $new_value) = @_; 808 my ($self, $new_value) = @_;
809
810 $new_value >= 0
811 or Carp::croak "AnyEvent::Handle->$timeout called with negative timeout ($new_value), caught";
740 812
741 $self->{$timeout} = $new_value; 813 $self->{$timeout} = $new_value;
742 delete $self->{$tw}; &$cb; 814 delete $self->{$tw}; &$cb;
743 }; 815 };
744 816
… …
808=item $handle->on_drain ($cb) 880=item $handle->on_drain ($cb)
809 881
810Sets the C<on_drain> callback or clears it (see the description of 882Sets the C<on_drain> callback or clears it (see the description of
811C<on_drain> in the constructor). 883C<on_drain> in the constructor).
812 884
885This method may invoke callbacks (and therefore the handle might be
886destroyed after it returns).
887
813=cut 888=cut
814 889
815sub on_drain { 890sub on_drain {
816 my ($self, $cb) = @_; 891 my ($self, $cb) = @_;
817 892
… …
821 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf}); 896 if $cb && $self->{low_water_mark} >= (length $self->{wbuf}) + (length $self->{_tls_wbuf});
822} 897}
823 898
824=item $handle->push_write ($data) 899=item $handle->push_write ($data)
825 900
826Queues the given scalar to be written. You can push as much data as you 901Queues the given scalar to be written. You can push as much data as
827want (only limited by the available memory), as C<AnyEvent::Handle> 902you want (only limited by the available memory and C<wbuf_max>), as
828buffers it independently of the kernel. 903C<AnyEvent::Handle> buffers it independently of the kernel.
904
905This method may invoke callbacks (and therefore the handle might be
906destroyed after it returns).
829 907
830=cut 908=cut
831 909
832sub _drain_wbuf { 910sub _drain_wbuf {
833 my ($self) = @_; 911 my ($self) = @_;
… …
858 $cb->() unless $self->{autocork}; 936 $cb->() unless $self->{autocork};
859 937
860 # if still data left in wbuf, we need to poll 938 # if still data left in wbuf, we need to poll
861 $self->{_ww} = AE::io $self->{fh}, 1, $cb 939 $self->{_ww} = AE::io $self->{fh}, 1, $cb
862 if length $self->{wbuf}; 940 if length $self->{wbuf};
941
942 if (
943 defined $self->{wbuf_max}
944 && $self->{wbuf_max} < length $self->{wbuf}
945 ) {
946 $self->_error (Errno::ENOSPC, 1), return;
947 }
863 }; 948 };
864} 949}
865 950
866our %WH; 951our %WH;
867 952
953# deprecated
868sub register_write_type($$) { 954sub register_write_type($$) {
869 $WH{$_[0]} = $_[1]; 955 $WH{$_[0]} = $_[1];
870} 956}
871 957
872sub push_write { 958sub push_write {
873 my $self = shift; 959 my $self = shift;
874 960
875 if (@_ > 1) { 961 if (@_ > 1) {
876 my $type = shift; 962 my $type = shift;
877 963
964 @_ = ($WH{$type} ||= _load_func "$type\::anyevent_write_type"
878 @_ = ($WH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_write") 965 or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_write")
879 ->($self, @_); 966 ->($self, @_);
880 } 967 }
881 968
969 # we downgrade here to avoid hard-to-track-down bugs,
970 # and diagnose the problem earlier and better.
971
882 if ($self->{tls}) { 972 if ($self->{tls}) {
883 $self->{_tls_wbuf} .= $_[0]; 973 utf8::downgrade $self->{_tls_wbuf} .= $_[0];
884 &_dotls ($self) if $self->{fh}; 974 &_dotls ($self) if $self->{fh};
885 } else { 975 } else {
886 $self->{wbuf} .= $_[0]; 976 utf8::downgrade $self->{wbuf} .= $_[0];
887 $self->_drain_wbuf if $self->{fh}; 977 $self->_drain_wbuf if $self->{fh};
888 } 978 }
889} 979}
890 980
891=item $handle->push_write (type => @args) 981=item $handle->push_write (type => @args)
892 982
893Instead of formatting your data yourself, you can also let this module do 983Instead of formatting your data yourself, you can also let this module
894the job by specifying a type and type-specific arguments. 984do the job by specifying a type and type-specific arguments. You
985can also specify the (fully qualified) name of a package, in which
986case AnyEvent tries to load the package and then expects to find the
987C<anyevent_write_type> function inside (see "custom write types", below).
895 988
896Predefined types are (if you have ideas for additional types, feel free to 989Predefined types are (if you have ideas for additional types, feel free to
897drop by and tell us): 990drop by and tell us):
898 991
899=over 4 992=over 4
… …
994before it was actually written. One way to do that is to replace your 1087before it was actually written. One way to do that is to replace your
995C<on_drain> handler by a callback that shuts down the socket (and set 1088C<on_drain> handler by a callback that shuts down the socket (and set
996C<low_water_mark> to C<0>). This method is a shorthand for just that, and 1089C<low_water_mark> to C<0>). This method is a shorthand for just that, and
997replaces the C<on_drain> callback with: 1090replaces the C<on_drain> callback with:
998 1091
999 sub { shutdown $_[0]{fh}, 1 } # for push_shutdown 1092 sub { shutdown $_[0]{fh}, 1 }
1000 1093
1001This simply shuts down the write side and signals an EOF condition to the 1094This simply shuts down the write side and signals an EOF condition to the
1002the peer. 1095the peer.
1003 1096
1004You can rely on the normal read queue and C<on_eof> handling 1097You can rely on the normal read queue and C<on_eof> handling
1005afterwards. This is the cleanest way to close a connection. 1098afterwards. This is the cleanest way to close a connection.
1006 1099
1100This method may invoke callbacks (and therefore the handle might be
1101destroyed after it returns).
1102
1007=cut 1103=cut
1008 1104
1009sub push_shutdown { 1105sub push_shutdown {
1010 my ($self) = @_; 1106 my ($self) = @_;
1011 1107
1012 delete $self->{low_water_mark}; 1108 delete $self->{low_water_mark};
1013 $self->on_drain (sub { shutdown $_[0]{fh}, 1 }); 1109 $self->on_drain (sub { shutdown $_[0]{fh}, 1 });
1014} 1110}
1015 1111
1016=item AnyEvent::Handle::register_write_type type => $coderef->($handle, @args) 1112=item custom write types - Package::anyevent_write_type $handle, @args
1017 1113
1018This function (not method) lets you add your own types to C<push_write>. 1114Instead of one of the predefined types, you can also specify the name of
1115a package. AnyEvent will try to load the package and then expects to find
1116a function named C<anyevent_write_type> inside. If it isn't found, it
1117progressively tries to load the parent package until it either finds the
1118function (good) or runs out of packages (bad).
1119
1019Whenever the given C<type> is used, C<push_write> will invoke the code 1120Whenever the given C<type> is used, C<push_write> will the function with
1020reference with the handle object and the remaining arguments. 1121the handle object and the remaining arguments.
1021 1122
1022The code reference is supposed to return a single octet string that will 1123The function is supposed to return a single octet string that will be
1023be appended to the write buffer. 1124appended to the write buffer, so you cna mentally treat this function as a
1125"arguments to on-the-wire-format" converter.
1024 1126
1025Note that this is a function, and all types registered this way will be 1127Example: implement a custom write type C<join> that joins the remaining
1026global, so try to use unique names. 1128arguments using the first one.
1129
1130 $handle->push_write (My::Type => " ", 1,2,3);
1131
1132 # uses the following package, which can be defined in the "My::Type" or in
1133 # the "My" modules to be auto-loaded, or just about anywhere when the
1134 # My::Type::anyevent_write_type is defined before invoking it.
1135
1136 package My::Type;
1137
1138 sub anyevent_write_type {
1139 my ($handle, $delim, @args) = @_;
1140
1141 join $delim, @args
1142 }
1027 1143
1028=cut 1144=cut
1029 1145
1030############################################################################# 1146#############################################################################
1031 1147
… …
1040ways, the "simple" way, using only C<on_read> and the "complex" way, using 1156ways, the "simple" way, using only C<on_read> and the "complex" way, using
1041a queue. 1157a queue.
1042 1158
1043In the simple case, you just install an C<on_read> callback and whenever 1159In the simple case, you just install an C<on_read> callback and whenever
1044new data arrives, it will be called. You can then remove some data (if 1160new data arrives, it will be called. You can then remove some data (if
1045enough is there) from the read buffer (C<< $handle->rbuf >>). Or you cna 1161enough is there) from the read buffer (C<< $handle->rbuf >>). Or you can
1046leave the data there if you want to accumulate more (e.g. when only a 1162leave the data there if you want to accumulate more (e.g. when only a
1047partial message has been received so far). 1163partial message has been received so far), or change the read queue with
1164e.g. C<push_read>.
1048 1165
1049In the more complex case, you want to queue multiple callbacks. In this 1166In the more complex case, you want to queue multiple callbacks. In this
1050case, AnyEvent::Handle will call the first queued callback each time new 1167case, AnyEvent::Handle will call the first queued callback each time new
1051data arrives (also the first time it is queued) and removes it when it has 1168data arrives (also the first time it is queued) and remove it when it has
1052done its job (see C<push_read>, below). 1169done its job (see C<push_read>, below).
1053 1170
1054This way you can, for example, push three line-reads, followed by reading 1171This way you can, for example, push three line-reads, followed by reading
1055a chunk of data, and AnyEvent::Handle will execute them in order. 1172a chunk of data, and AnyEvent::Handle will execute them in order.
1056 1173
… …
1187 1304
1188This replaces the currently set C<on_read> callback, or clears it (when 1305This replaces the currently set C<on_read> callback, or clears it (when
1189the new callback is C<undef>). See the description of C<on_read> in the 1306the new callback is C<undef>). See the description of C<on_read> in the
1190constructor. 1307constructor.
1191 1308
1309This method may invoke callbacks (and therefore the handle might be
1310destroyed after it returns).
1311
1192=cut 1312=cut
1193 1313
1194sub on_read { 1314sub on_read {
1195 my ($self, $cb) = @_; 1315 my ($self, $cb) = @_;
1196 1316
… …
1198 $self->_drain_rbuf if $cb; 1318 $self->_drain_rbuf if $cb;
1199} 1319}
1200 1320
1201=item $handle->rbuf 1321=item $handle->rbuf
1202 1322
1203Returns the read buffer (as a modifiable lvalue). 1323Returns the read buffer (as a modifiable lvalue). You can also access the
1324read buffer directly as the C<< ->{rbuf} >> member, if you want (this is
1325much faster, and no less clean).
1204 1326
1205You can access the read buffer directly as the C<< ->{rbuf} >> 1327The only operation allowed on the read buffer (apart from looking at it)
1206member, if you want. However, the only operation allowed on the 1328is removing data from its beginning. Otherwise modifying or appending to
1207read buffer (apart from looking at it) is removing data from its 1329it is not allowed and will lead to hard-to-track-down bugs.
1208beginning. Otherwise modifying or appending to it is not allowed and will
1209lead to hard-to-track-down bugs.
1210 1330
1211NOTE: The read buffer should only be used or modified if the C<on_read>, 1331NOTE: The read buffer should only be used or modified in the C<on_read>
1212C<push_read> or C<unshift_read> methods are used. The other read methods 1332callback or when C<push_read> or C<unshift_read> are used with a single
1213automatically manage the read buffer. 1333callback (i.e. untyped). Typed C<push_read> and C<unshift_read> methods
1334will manage the read buffer on their own.
1214 1335
1215=cut 1336=cut
1216 1337
1217sub rbuf : lvalue { 1338sub rbuf : lvalue {
1218 $_[0]{rbuf} 1339 $_[0]{rbuf}
… …
1235 1356
1236If enough data was available, then the callback must remove all data it is 1357If enough data was available, then the callback must remove all data it is
1237interested in (which can be none at all) and return a true value. After returning 1358interested in (which can be none at all) and return a true value. After returning
1238true, it will be removed from the queue. 1359true, it will be removed from the queue.
1239 1360
1361These methods may invoke callbacks (and therefore the handle might be
1362destroyed after it returns).
1363
1240=cut 1364=cut
1241 1365
1242our %RH; 1366our %RH;
1243 1367
1244sub register_read_type($$) { 1368sub register_read_type($$) {
… …
1250 my $cb = pop; 1374 my $cb = pop;
1251 1375
1252 if (@_) { 1376 if (@_) {
1253 my $type = shift; 1377 my $type = shift;
1254 1378
1379 $cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
1255 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::push_read") 1380 or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::push_read")
1256 ->($self, $cb, @_); 1381 ->($self, $cb, @_);
1257 } 1382 }
1258 1383
1259 push @{ $self->{_queue} }, $cb; 1384 push @{ $self->{_queue} }, $cb;
1260 $self->_drain_rbuf; 1385 $self->_drain_rbuf;
… …
1265 my $cb = pop; 1390 my $cb = pop;
1266 1391
1267 if (@_) { 1392 if (@_) {
1268 my $type = shift; 1393 my $type = shift;
1269 1394
1395 $cb = ($RH{$type} ||= _load_func "$type\::anyevent_read_type"
1270 $cb = ($RH{$type} or Carp::croak "unsupported type passed to AnyEvent::Handle::unshift_read") 1396 or Carp::croak "unsupported/unloadable type '$type' passed to AnyEvent::Handle::unshift_read")
1271 ->($self, $cb, @_); 1397 ->($self, $cb, @_);
1272 } 1398 }
1273 1399
1274 unshift @{ $self->{_queue} }, $cb; 1400 unshift @{ $self->{_queue} }, $cb;
1275 $self->_drain_rbuf; 1401 $self->_drain_rbuf;
… …
1279 1405
1280=item $handle->unshift_read (type => @args, $cb) 1406=item $handle->unshift_read (type => @args, $cb)
1281 1407
1282Instead of providing a callback that parses the data itself you can chose 1408Instead of providing a callback that parses the data itself you can chose
1283between a number of predefined parsing formats, for chunks of data, lines 1409between a number of predefined parsing formats, for chunks of data, lines
1284etc. 1410etc. You can also specify the (fully qualified) name of a package, in
1411which case AnyEvent tries to load the package and then expects to find the
1412C<anyevent_read_type> function inside (see "custom read types", below).
1285 1413
1286Predefined types are (if you have ideas for additional types, feel free to 1414Predefined types are (if you have ideas for additional types, feel free to
1287drop by and tell us): 1415drop by and tell us):
1288 1416
1289=over 4 1417=over 4
… …
1381the receive buffer when neither C<$accept> nor C<$reject> match, 1509the receive buffer when neither C<$accept> nor C<$reject> match,
1382and everything preceding and including the match will be accepted 1510and everything preceding and including the match will be accepted
1383unconditionally. This is useful to skip large amounts of data that you 1511unconditionally. This is useful to skip large amounts of data that you
1384know cannot be matched, so that the C<$accept> or C<$reject> regex do not 1512know cannot be matched, so that the C<$accept> or C<$reject> regex do not
1385have to start matching from the beginning. This is purely an optimisation 1513have to start matching from the beginning. This is purely an optimisation
1386and is usually worth only when you expect more than a few kilobytes. 1514and is usually worth it only when you expect more than a few kilobytes.
1387 1515
1388Example: expect a http header, which ends at C<\015\012\015\012>. Since we 1516Example: expect a http header, which ends at C<\015\012\015\012>. Since we
1389expect the header to be very large (it isn't in practise, but...), we use 1517expect the header to be very large (it isn't in practice, but...), we use
1390a skip regex to skip initial portions. The skip regex is tricky in that 1518a skip regex to skip initial portions. The skip regex is tricky in that
1391it only accepts something not ending in either \015 or \012, as these are 1519it only accepts something not ending in either \015 or \012, as these are
1392required for the accept regex. 1520required for the accept regex.
1393 1521
1394 $handle->push_read (regex => 1522 $handle->push_read (regex =>
… …
1608 } 1736 }
1609}; 1737};
1610 1738
1611=back 1739=back
1612 1740
1613=item AnyEvent::Handle::register_read_type type => $coderef->($handle, $cb, @args) 1741=item custom read types - Package::anyevent_read_type $handle, $cb, @args
1614 1742
1615This function (not method) lets you add your own types to C<push_read>. 1743Instead of one of the predefined types, you can also specify the name
1744of a package. AnyEvent will try to load the package and then expects to
1745find a function named C<anyevent_read_type> inside. If it isn't found, it
1746progressively tries to load the parent package until it either finds the
1747function (good) or runs out of packages (bad).
1616 1748
1617Whenever the given C<type> is used, C<push_read> will invoke the code 1749Whenever this type is used, C<push_read> will invoke the function with the
1618reference with the handle object, the callback and the remaining 1750handle object, the original callback and the remaining arguments.
1619arguments.
1620 1751
1621The code reference is supposed to return a callback (usually a closure) 1752The function is supposed to return a callback (usually a closure) that
1622that works as a plain read callback (see C<< ->push_read ($cb) >>). 1753works as a plain read callback (see C<< ->push_read ($cb) >>), so you can
1754mentally treat the function as a "configurable read type to read callback"
1755converter.
1623 1756
1624It should invoke the passed callback when it is done reading (remember to 1757It should invoke the original callback when it is done reading (remember
1625pass C<$handle> as first argument as all other callbacks do that). 1758to pass C<$handle> as first argument as all other callbacks do that,
1759although there is no strict requirement on this).
1626 1760
1627Note that this is a function, and all types registered this way will be
1628global, so try to use unique names.
1629
1630For examples, see the source of this module (F<perldoc -m AnyEvent::Handle>, 1761For examples, see the source of this module (F<perldoc -m
1631search for C<register_read_type>)). 1762AnyEvent::Handle>, search for C<register_read_type>)).
1632 1763
1633=item $handle->stop_read 1764=item $handle->stop_read
1634 1765
1635=item $handle->start_read 1766=item $handle->start_read
1636 1767
… …
1642Note that AnyEvent::Handle will automatically C<start_read> for you when 1773Note that AnyEvent::Handle will automatically C<start_read> for you when
1643you change the C<on_read> callback or push/unshift a read callback, and it 1774you change the C<on_read> callback or push/unshift a read callback, and it
1644will automatically C<stop_read> for you when neither C<on_read> is set nor 1775will automatically C<stop_read> for you when neither C<on_read> is set nor
1645there are any read requests in the queue. 1776there are any read requests in the queue.
1646 1777
1647These methods will have no effect when in TLS mode (as TLS doesn't support 1778In older versions of this module (<= 5.3), these methods had no effect,
1648half-duplex connections). 1779as TLS does not support half-duplex connections. In current versions they
1780work as expected, as this behaviour is required to avoid certain resource
1781attacks, where the program would be forced to read (and buffer) arbitrary
1782amounts of data before being able to send some data. The drawback is that
1783some readings of the the SSL/TLS specifications basically require this
1784attack to be working, as SSL/TLS implementations might stall sending data
1785during a rehandshake.
1786
1787As a guideline, during the initial handshake, you should not stop reading,
1788and as a client, it might cause problems, depending on your applciation.
1649 1789
1650=cut 1790=cut
1651 1791
1652sub stop_read { 1792sub stop_read {
1653 my ($self) = @_; 1793 my ($self) = @_;
1654 1794
1655 delete $self->{_rw} unless $self->{tls}; 1795 delete $self->{_rw};
1656} 1796}
1657 1797
1658sub start_read { 1798sub start_read {
1659 my ($self) = @_; 1799 my ($self) = @_;
1660 1800
1661 unless ($self->{_rw} || $self->{_eof}) { 1801 unless ($self->{_rw} || $self->{_eof} || !$self->{fh}) {
1662 Scalar::Util::weaken $self; 1802 Scalar::Util::weaken $self;
1663 1803
1664 $self->{_rw} = AE::io $self->{fh}, 0, sub { 1804 $self->{_rw} = AE::io $self->{fh}, 0, sub {
1665 my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf}); 1805 my $rbuf = \($self->{tls} ? my $buf : $self->{rbuf});
1666 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size} || 8192, length $$rbuf; 1806 my $len = sysread $self->{fh}, $$rbuf, $self->{read_size}, length $$rbuf;
1667 1807
1668 if ($len > 0) { 1808 if ($len > 0) {
1669 $self->{_activity} = $self->{_ractivity} = AE::now; 1809 $self->{_activity} = $self->{_ractivity} = AE::now;
1670 1810
1671 if ($self->{tls}) { 1811 if ($self->{tls}) {
1672 Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf); 1812 Net::SSLeay::BIO_write ($self->{_rbio}, $$rbuf);
1673 1813
1674 &_dotls ($self); 1814 &_dotls ($self);
1675 } else { 1815 } else {
1676 $self->_drain_rbuf; 1816 $self->_drain_rbuf;
1817 }
1818
1819 if ($len == $self->{read_size}) {
1820 $self->{read_size} *= 2;
1821 $self->{read_size} = $self->{max_read_size} || MAX_READ_SIZE
1822 if $self->{read_size} > ($self->{max_read_size} || MAX_READ_SIZE);
1677 } 1823 }
1678 1824
1679 } elsif (defined $len) { 1825 } elsif (defined $len) {
1680 delete $self->{_rw}; 1826 delete $self->{_rw};
1681 $self->{_eof} = 1; 1827 $self->{_eof} = 1;
… …
1759 && ($tmp != $ERROR_SYSCALL || $!); 1905 && ($tmp != $ERROR_SYSCALL || $!);
1760 1906
1761 while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) { 1907 while (length ($tmp = Net::SSLeay::BIO_read ($self->{_wbio}))) {
1762 $self->{wbuf} .= $tmp; 1908 $self->{wbuf} .= $tmp;
1763 $self->_drain_wbuf; 1909 $self->_drain_wbuf;
1910 $self->{tls} or return; # tls session might have gone away in callback
1764 } 1911 }
1765 1912
1766 $self->{_on_starttls} 1913 $self->{_on_starttls}
1767 and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK () 1914 and Net::SSLeay::state ($self->{tls}) == Net::SSLeay::ST_OK ()
1768 and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established"); 1915 and (delete $self->{_on_starttls})->($self, 1, "TLS/SSL connection established");
… …
1790context in C<< $handle->{tls_ctx} >> after this call and can be used or 1937context in C<< $handle->{tls_ctx} >> after this call and can be used or
1791changed to your liking. Note that the handshake might have already started 1938changed to your liking. Note that the handshake might have already started
1792when this function returns. 1939when this function returns.
1793 1940
1794Due to bugs in OpenSSL, it might or might not be possible to do multiple 1941Due to bugs in OpenSSL, it might or might not be possible to do multiple
1795handshakes on the same stream. Best do not attempt to use the stream after 1942handshakes on the same stream. It is best to not attempt to use the
1796stopping TLS. 1943stream after stopping TLS.
1944
1945This method may invoke callbacks (and therefore the handle might be
1946destroyed after it returns).
1797 1947
1798=cut 1948=cut
1799 1949
1800our %TLS_CACHE; #TODO not yet documented, should we? 1950our %TLS_CACHE; #TODO not yet documented, should we?
1801 1951
… …
1867 2017
1868=item $handle->stoptls 2018=item $handle->stoptls
1869 2019
1870Shuts down the SSL connection - this makes a proper EOF handshake by 2020Shuts down the SSL connection - this makes a proper EOF handshake by
1871sending a close notify to the other side, but since OpenSSL doesn't 2021sending a close notify to the other side, but since OpenSSL doesn't
1872support non-blocking shut downs, it is not guarenteed that you can re-use 2022support non-blocking shut downs, it is not guaranteed that you can re-use
1873the stream afterwards. 2023the stream afterwards.
2024
2025This method may invoke callbacks (and therefore the handle might be
2026destroyed after it returns).
1874 2027
1875=cut 2028=cut
1876 2029
1877sub stoptls { 2030sub stoptls {
1878 my ($self) = @_; 2031 my ($self) = @_;
1879 2032
1880 if ($self->{tls}) { 2033 if ($self->{tls} && $self->{fh}) {
1881 Net::SSLeay::shutdown ($self->{tls}); 2034 Net::SSLeay::shutdown ($self->{tls});
1882 2035
1883 &_dotls; 2036 &_dotls;
1884 2037
1885# # we don't give a shit. no, we do, but we can't. no...#d# 2038# # we don't give a shit. no, we do, but we can't. no...#d#
… …
1915 push @linger, AE::io $fh, 1, sub { 2068 push @linger, AE::io $fh, 1, sub {
1916 my $len = syswrite $fh, $wbuf, length $wbuf; 2069 my $len = syswrite $fh, $wbuf, length $wbuf;
1917 2070
1918 if ($len > 0) { 2071 if ($len > 0) {
1919 substr $wbuf, 0, $len, ""; 2072 substr $wbuf, 0, $len, "";
1920 } else { 2073 } elsif (defined $len || ($! != EAGAIN && $! != EINTR && $! != WSAEWOULDBLOCK)) {
1921 @linger = (); # end 2074 @linger = (); # end
1922 } 2075 }
1923 }; 2076 };
1924 push @linger, AE::timer $linger, 0, sub { 2077 push @linger, AE::timer $linger, 0, sub {
1925 @linger = (); 2078 @linger = ();
… …
1962 2115
1963sub AnyEvent::Handle::destroyed::AUTOLOAD { 2116sub AnyEvent::Handle::destroyed::AUTOLOAD {
1964 #nop 2117 #nop
1965} 2118}
1966 2119
2120=item $handle->destroyed
2121
2122Returns false as long as the handle hasn't been destroyed by a call to C<<
2123->destroy >>, true otherwise.
2124
2125Can be useful to decide whether the handle is still valid after some
2126callback possibly destroyed the handle. For example, C<< ->push_write >>,
2127C<< ->starttls >> and other methods can call user callbacks, which in turn
2128can destroy the handle, so work can be avoided by checking sometimes:
2129
2130 $hdl->starttls ("accept");
2131 return if $hdl->destroyed;
2132 $hdl->push_write (...
2133
2134Note that the call to C<push_write> will silently be ignored if the handle
2135has been destroyed, so often you can just ignore the possibility of the
2136handle being destroyed.
2137
2138=cut
2139
2140sub destroyed { 0 }
2141sub AnyEvent::Handle::destroyed::destroyed { 1 }
2142
1967=item AnyEvent::Handle::TLS_CTX 2143=item AnyEvent::Handle::TLS_CTX
1968 2144
1969This function creates and returns the AnyEvent::TLS object used by default 2145This function creates and returns the AnyEvent::TLS object used by default
1970for TLS mode. 2146for TLS mode.
1971 2147
… …
1998 2174
1999It is only safe to "forget" the reference inside EOF or error callbacks, 2175It is only safe to "forget" the reference inside EOF or error callbacks,
2000from within all other callbacks, you need to explicitly call the C<< 2176from within all other callbacks, you need to explicitly call the C<<
2001->destroy >> method. 2177->destroy >> method.
2002 2178
2179=item Why is my C<on_eof> callback never called?
2180
2181Probably because your C<on_error> callback is being called instead: When
2182you have outstanding requests in your read queue, then an EOF is
2183considered an error as you clearly expected some data.
2184
2185To avoid this, make sure you have an empty read queue whenever your handle
2186is supposed to be "idle" (i.e. connection closes are O.K.). You cna set
2187an C<on_read> handler that simply pushes the first read requests in the
2188queue.
2189
2190See also the next question, which explains this in a bit more detail.
2191
2192=item How can I serve requests in a loop?
2193
2194Most protocols consist of some setup phase (authentication for example)
2195followed by a request handling phase, where the server waits for requests
2196and handles them, in a loop.
2197
2198There are two important variants: The first (traditional, better) variant
2199handles requests until the server gets some QUIT command, causing it to
2200close the connection first (highly desirable for a busy TCP server). A
2201client dropping the connection is an error, which means this variant can
2202detect an unexpected detection close.
2203
2204To handle this case, always make sure you have a on-empty read queue, by
2205pushing the "read request start" handler on it:
2206
2207 # we assume a request starts with a single line
2208 my @start_request; @start_request = (line => sub {
2209 my ($hdl, $line) = @_;
2210
2211 ... handle request
2212
2213 # push next request read, possibly from a nested callback
2214 $hdl->push_read (@start_request);
2215 });
2216
2217 # auth done, now go into request handling loop
2218 # now push the first @start_request
2219 $hdl->push_read (@start_request);
2220
2221By always having an outstanding C<push_read>, the handle always expects
2222some data and raises the C<EPIPE> error when the connction is dropped
2223unexpectedly.
2224
2225The second variant is a protocol where the client can drop the connection
2226at any time. For TCP, this means that the server machine may run out of
2227sockets easier, and in general, it means you cnanot distinguish a protocl
2228failure/client crash from a normal connection close. Nevertheless, these
2229kinds of protocols are common (and sometimes even the best solution to the
2230problem).
2231
2232Having an outstanding read request at all times is possible if you ignore
2233C<EPIPE> errors, but this doesn't help with when the client drops the
2234connection during a request, which would still be an error.
2235
2236A better solution is to push the initial request read in an C<on_read>
2237callback. This avoids an error, as when the server doesn't expect data
2238(i.e. is idly waiting for the next request, an EOF will not raise an
2239error, but simply result in an C<on_eof> callback. It is also a bit slower
2240and simpler:
2241
2242 # auth done, now go into request handling loop
2243 $hdl->on_read (sub {
2244 my ($hdl) = @_;
2245
2246 # called each time we receive data but the read queue is empty
2247 # simply start read the request
2248
2249 $hdl->push_read (line => sub {
2250 my ($hdl, $line) = @_;
2251
2252 ... handle request
2253
2254 # do nothing special when the request has been handled, just
2255 # let the request queue go empty.
2256 });
2257 });
2258
2003=item I get different callback invocations in TLS mode/Why can't I pause 2259=item I get different callback invocations in TLS mode/Why can't I pause
2004reading? 2260reading?
2005 2261
2006Unlike, say, TCP, TLS connections do not consist of two independent 2262Unlike, say, TCP, TLS connections do not consist of two independent
2007communication channels, one for each direction. Or put differently. The 2263communication channels, one for each direction. Or put differently, the
2008read and write directions are not independent of each other: you cannot 2264read and write directions are not independent of each other: you cannot
2009write data unless you are also prepared to read, and vice versa. 2265write data unless you are also prepared to read, and vice versa.
2010 2266
2011This can mean than, in TLS mode, you might get C<on_error> or C<on_eof> 2267This means that, in TLS mode, you might get C<on_error> or C<on_eof>
2012callback invocations when you are not expecting any read data - the reason 2268callback invocations when you are not expecting any read data - the reason
2013is that AnyEvent::Handle always reads in TLS mode. 2269is that AnyEvent::Handle always reads in TLS mode.
2014 2270
2015During the connection, you have to make sure that you always have a 2271During the connection, you have to make sure that you always have a
2016non-empty read-queue, or an C<on_read> watcher. At the end of the 2272non-empty read-queue, or an C<on_read> watcher. At the end of the
… …
2030 my $data = delete $_[0]{rbuf}; 2286 my $data = delete $_[0]{rbuf};
2031 }); 2287 });
2032 2288
2033The reason to use C<on_error> is that TCP connections, due to latencies 2289The reason to use C<on_error> is that TCP connections, due to latencies
2034and packets loss, might get closed quite violently with an error, when in 2290and packets loss, might get closed quite violently with an error, when in
2035fact, all data has been received. 2291fact all data has been received.
2036 2292
2037It is usually better to use acknowledgements when transferring data, 2293It is usually better to use acknowledgements when transferring data,
2038to make sure the other side hasn't just died and you got the data 2294to make sure the other side hasn't just died and you got the data
2039intact. This is also one reason why so many internet protocols have an 2295intact. This is also one reason why so many internet protocols have an
2040explicit QUIT command. 2296explicit QUIT command.
… …
2057consider using C<< ->push_shutdown >> instead. 2313consider using C<< ->push_shutdown >> instead.
2058 2314
2059=item I want to contact a TLS/SSL server, I don't care about security. 2315=item I want to contact a TLS/SSL server, I don't care about security.
2060 2316
2061If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS, 2317If your TLS server is a pure TLS server (e.g. HTTPS) that only speaks TLS,
2062simply connect to it and then create the AnyEvent::Handle with the C<tls> 2318connect to it and then create the AnyEvent::Handle with the C<tls>
2063parameter: 2319parameter:
2064 2320
2065 tcp_connect $host, $port, sub { 2321 tcp_connect $host, $port, sub {
2066 my ($fh) = @_; 2322 my ($fh) = @_;
2067 2323
… …
2167 2423
2168=item * all members not documented here and not prefixed with an underscore 2424=item * all members not documented here and not prefixed with an underscore
2169are free to use in subclasses. 2425are free to use in subclasses.
2170 2426
2171Of course, new versions of AnyEvent::Handle may introduce more "public" 2427Of course, new versions of AnyEvent::Handle may introduce more "public"
2172member variables, but thats just life, at least it is documented. 2428member variables, but that's just life. At least it is documented.
2173 2429
2174=back 2430=back
2175 2431
2176=head1 AUTHOR 2432=head1 AUTHOR
2177 2433

Diff Legend

– Removed lines
+ Added lines
< Changed lines
> Changed lines