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1NAME 1NAME
2 AnyEvent - the DBI of event loop programming 2 AnyEvent - the DBI of event loop programming
3 3
4 EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, 4 EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async,
5 Qt and POE are various supported event loops/environments. 5 Qt, FLTK and POE are various supported event loops/environments.
6 6
7SYNOPSIS 7SYNOPSIS
8 use AnyEvent; 8 use AnyEvent;
9 9
10 # if you prefer function calls, look at the AE manpage for 10 # if you prefer function calls, look at the AE manpage for
13 # file handle or descriptor readable 13 # file handle or descriptor readable
14 my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... }); 14 my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
15 15
16 # one-shot or repeating timers 16 # one-shot or repeating timers
17 my $w = AnyEvent->timer (after => $seconds, cb => sub { ... }); 17 my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
18 my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ... 18 my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...);
19 19
20 print AnyEvent->now; # prints current event loop time 20 print AnyEvent->now; # prints current event loop time
21 print AnyEvent->time; # think Time::HiRes::time or simply CORE::time. 21 print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
22 22
23 # POSIX signal 23 # POSIX signal
42 This manpage is mainly a reference manual. If you are interested in a 42 This manpage is mainly a reference manual. If you are interested in a
43 tutorial or some gentle introduction, have a look at the AnyEvent::Intro 43 tutorial or some gentle introduction, have a look at the AnyEvent::Intro
44 manpage. 44 manpage.
45 45
46SUPPORT 46SUPPORT
47 An FAQ document is available as AnyEvent::FAQ.
48
47 There is a mailinglist for discussing all things AnyEvent, and an IRC 49 There also is a mailinglist for discussing all things AnyEvent, and an
48 channel, too. 50 IRC channel, too.
49 51
50 See the AnyEvent project page at the Schmorpforge Ta-Sa Software 52 See the AnyEvent project page at the Schmorpforge Ta-Sa Software
51 Repository, at <http://anyevent.schmorp.de>, for more info. 53 Repository, at <http://anyevent.schmorp.de>, for more info.
52 54
53WHY YOU SHOULD USE THIS MODULE (OR NOT) 55WHY YOU SHOULD USE THIS MODULE (OR NOT)
71 module users into the same thing by forcing them to use the same event 73 module users into the same thing by forcing them to use the same event
72 model you use. 74 model you use.
73 75
74 For modules like POE or IO::Async (which is a total misnomer as it is 76 For modules like POE or IO::Async (which is a total misnomer as it is
75 actually doing all I/O *synchronously*...), using them in your module is 77 actually doing all I/O *synchronously*...), using them in your module is
76 like joining a cult: After you joined, you are dependent on them and you 78 like joining a cult: After you join, you are dependent on them and you
77 cannot use anything else, as they are simply incompatible to everything 79 cannot use anything else, as they are simply incompatible to everything
78 that isn't them. What's worse, all the potential users of your module 80 that isn't them. What's worse, all the potential users of your module
79 are *also* forced to use the same event loop you use. 81 are *also* forced to use the same event loop you use.
80 82
81 AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works 83 AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
82 fine. AnyEvent + Tk works fine etc. etc. but none of these work together 84 fine. AnyEvent + Tk works fine etc. etc. but none of these work together
83 with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if your 85 with the rest: POE + EV? No go. Tk + Event? No go. Again: if your module
84 module uses one of those, every user of your module has to use it, too. 86 uses one of those, every user of your module has to use it, too. But if
85 But if your module uses AnyEvent, it works transparently with all event 87 your module uses AnyEvent, it works transparently with all event models
86 models it supports (including stuff like IO::Async, as long as those use 88 it supports (including stuff like IO::Async, as long as those use one of
87 one of the supported event loops. It is trivial to add new event loops 89 the supported event loops. It is easy to add new event loops to
88 to AnyEvent, too, so it is future-proof). 90 AnyEvent, too, so it is future-proof).
89 91
90 In addition to being free of having to use *the one and only true event 92 In addition to being free of having to use *the one and only true event
91 model*, AnyEvent also is free of bloat and policy: with POE or similar 93 model*, AnyEvent also is free of bloat and policy: with POE or similar
92 modules, you get an enormous amount of code and strict rules you have to 94 modules, you get an enormous amount of code and strict rules you have to
93 follow. AnyEvent, on the other hand, is lean and up to the point, by 95 follow. AnyEvent, on the other hand, is lean and to the point, by only
94 only offering the functionality that is necessary, in as thin as a 96 offering the functionality that is necessary, in as thin as a wrapper as
95 wrapper as technically possible. 97 technically possible.
96 98
97 Of course, AnyEvent comes with a big (and fully optional!) toolbox of 99 Of course, AnyEvent comes with a big (and fully optional!) toolbox of
98 useful functionality, such as an asynchronous DNS resolver, 100% 100 useful functionality, such as an asynchronous DNS resolver, 100%
99 non-blocking connects (even with TLS/SSL, IPv6 and on broken platforms 101 non-blocking connects (even with TLS/SSL, IPv6 and on broken platforms
100 such as Windows) and lots of real-world knowledge and workarounds for 102 such as Windows) and lots of real-world knowledge and workarounds for
103 Now, if you *do want* lots of policy (this can arguably be somewhat 105 Now, if you *do want* lots of policy (this can arguably be somewhat
104 useful) and you want to force your users to use the one and only event 106 useful) and you want to force your users to use the one and only event
105 model, you should *not* use this module. 107 model, you should *not* use this module.
106 108
107DESCRIPTION 109DESCRIPTION
108 AnyEvent provides an identical interface to multiple event loops. This 110 AnyEvent provides a uniform interface to various event loops. This
109 allows module authors to utilise an event loop without forcing module 111 allows module authors to use event loop functionality without forcing
110 users to use the same event loop (as only a single event loop can 112 module users to use a specific event loop implementation (since more
111 coexist peacefully at any one time). 113 than one event loop cannot coexist peacefully).
112 114
113 The interface itself is vaguely similar, but not identical to the Event 115 The interface itself is vaguely similar, but not identical to the Event
114 module. 116 module.
115 117
116 During the first call of any watcher-creation method, the module tries 118 During the first call of any watcher-creation method, the module tries
117 to detect the currently loaded event loop by probing whether one of the 119 to detect the currently loaded event loop by probing whether one of the
118 following modules is already loaded: EV, Event, Glib, 120 following modules is already loaded: EV, AnyEvent::Loop, Event, Glib,
119 AnyEvent::Impl::Perl, Tk, Event::Lib, Qt, POE. The first one found is 121 Tk, Event::Lib, Qt, POE. The first one found is used. If none are
120 used. If none are found, the module tries to load these modules 122 detected, the module tries to load the first four modules in the order
121 (excluding Tk, Event::Lib, Qt and POE as the pure perl adaptor should 123 given; but note that if EV is not available, the pure-perl
122 always succeed) in the order given. The first one that can be 124 AnyEvent::Loop should always work, so the other two are not normally
123 successfully loaded will be used. If, after this, still none could be 125 tried.
124 found, AnyEvent will fall back to a pure-perl event loop, which is not
125 very efficient, but should work everywhere.
126 126
127 Because AnyEvent first checks for modules that are already loaded, 127 Because AnyEvent first checks for modules that are already loaded,
128 loading an event model explicitly before first using AnyEvent will 128 loading an event model explicitly before first using AnyEvent will
129 likely make that model the default. For example: 129 likely make that model the default. For example:
130 130
132 use AnyEvent; 132 use AnyEvent;
133 133
134 # .. AnyEvent will likely default to Tk 134 # .. AnyEvent will likely default to Tk
135 135
136 The *likely* means that, if any module loads another event model and 136 The *likely* means that, if any module loads another event model and
137 starts using it, all bets are off. Maybe you should tell their authors 137 starts using it, all bets are off - this case should be very rare
138 to use AnyEvent so their modules work together with others seamlessly... 138 though, as very few modules hardcode event loops without announcing this
139 very loudly.
139 140
140 The pure-perl implementation of AnyEvent is called 141 The pure-perl implementation of AnyEvent is called "AnyEvent::Loop".
141 "AnyEvent::Impl::Perl". Like other event modules you can load it 142 Like other event modules you can load it explicitly and enjoy the high
142 explicitly and enjoy the high availability of that event loop :) 143 availability of that event loop :)
143 144
144WATCHERS 145WATCHERS
145 AnyEvent has the central concept of a *watcher*, which is an object that 146 AnyEvent has the central concept of a *watcher*, which is an object that
146 stores relevant data for each kind of event you are waiting for, such as 147 stores relevant data for each kind of event you are waiting for, such as
147 the callback to call, the file handle to watch, etc. 148 the callback to call, the file handle to watch, etc.
151 callback when the event occurs (of course, only when the event model is 152 callback when the event occurs (of course, only when the event model is
152 in control). 153 in control).
153 154
154 Note that callbacks must not permanently change global variables 155 Note that callbacks must not permanently change global variables
155 potentially in use by the event loop (such as $_ or $[) and that 156 potentially in use by the event loop (such as $_ or $[) and that
156 callbacks must not "die". The former is good programming practise in 157 callbacks must not "die". The former is good programming practice in
157 Perl and the latter stems from the fact that exception handling differs 158 Perl and the latter stems from the fact that exception handling differs
158 widely between event loops. 159 widely between event loops.
159 160
160 To disable the watcher you have to destroy it (e.g. by setting the 161 To disable a watcher you have to destroy it (e.g. by setting the
161 variable you store it in to "undef" or otherwise deleting all references 162 variable you store it in to "undef" or otherwise deleting all references
162 to it). 163 to it).
163 164
164 All watchers are created by calling a method on the "AnyEvent" class. 165 All watchers are created by calling a method on the "AnyEvent" class.
165 166
166 Many watchers either are used with "recursion" (repeating timers for 167 Many watchers either are used with "recursion" (repeating timers for
167 example), or need to refer to their watcher object in other ways. 168 example), or need to refer to their watcher object in other ways.
168 169
169 An any way to achieve that is this pattern: 170 One way to achieve that is this pattern:
170 171
171 my $w; $w = AnyEvent->type (arg => value ..., cb => sub { 172 my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
172 # you can use $w here, for example to undef it 173 # you can use $w here, for example to undef it
173 undef $w; 174 undef $w;
174 }); 175 });
205 206
206 The I/O watcher might use the underlying file descriptor or a copy of 207 The I/O watcher might use the underlying file descriptor or a copy of
207 it. You must not close a file handle as long as any watcher is active on 208 it. You must not close a file handle as long as any watcher is active on
208 the underlying file descriptor. 209 the underlying file descriptor.
209 210
210 Some event loops issue spurious readyness notifications, so you should 211 Some event loops issue spurious readiness notifications, so you should
211 always use non-blocking calls when reading/writing from/to your file 212 always use non-blocking calls when reading/writing from/to your file
212 handles. 213 handles.
213 214
214 Example: wait for readability of STDIN, then read a line and disable the 215 Example: wait for readability of STDIN, then read a line and disable the
215 watcher. 216 watcher.
238 239
239 Although the callback might get passed parameters, their value and 240 Although the callback might get passed parameters, their value and
240 presence is undefined and you cannot rely on them. Portable AnyEvent 241 presence is undefined and you cannot rely on them. Portable AnyEvent
241 callbacks cannot use arguments passed to time watcher callbacks. 242 callbacks cannot use arguments passed to time watcher callbacks.
242 243
243 The callback will normally be invoked once only. If you specify another 244 The callback will normally be invoked only once. If you specify another
244 parameter, "interval", as a strictly positive number (> 0), then the 245 parameter, "interval", as a strictly positive number (> 0), then the
245 callback will be invoked regularly at that interval (in fractional 246 callback will be invoked regularly at that interval (in fractional
246 seconds) after the first invocation. If "interval" is specified with a 247 seconds) after the first invocation. If "interval" is specified with a
247 false value, then it is treated as if it were missing. 248 false value, then it is treated as if it were not specified at all.
248 249
249 The callback will be rescheduled before invoking the callback, but no 250 The callback will be rescheduled before invoking the callback, but no
250 attempt is done to avoid timer drift in most backends, so the interval 251 attempt is made to avoid timer drift in most backends, so the interval
251 is only approximate. 252 is only approximate.
252 253
253 Example: fire an event after 7.7 seconds. 254 Example: fire an event after 7.7 seconds.
254 255
255 my $w = AnyEvent->timer (after => 7.7, cb => sub { 256 my $w = AnyEvent->timer (after => 7.7, cb => sub {
261 262
262 Example 2: fire an event after 0.5 seconds, then roughly every second. 263 Example 2: fire an event after 0.5 seconds, then roughly every second.
263 264
264 my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub { 265 my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub {
265 warn "timeout\n"; 266 warn "timeout\n";
266 }; 267 });
267 268
268 TIMING ISSUES 269 TIMING ISSUES
269 There are two ways to handle timers: based on real time (relative, "fire 270 There are two ways to handle timers: based on real time (relative, "fire
270 in 10 seconds") and based on wallclock time (absolute, "fire at 12 271 in 10 seconds") and based on wallclock time (absolute, "fire at 12
271 o'clock"). 272 o'clock").
272 273
273 While most event loops expect timers to specified in a relative way, 274 While most event loops expect timers to specified in a relative way,
274 they use absolute time internally. This makes a difference when your 275 they use absolute time internally. This makes a difference when your
275 clock "jumps", for example, when ntp decides to set your clock backwards 276 clock "jumps", for example, when ntp decides to set your clock backwards
276 from the wrong date of 2014-01-01 to 2008-01-01, a watcher that is 277 from the wrong date of 2014-01-01 to 2008-01-01, a watcher that is
277 supposed to fire "after" a second might actually take six years to 278 supposed to fire "after a second" might actually take six years to
278 finally fire. 279 finally fire.
279 280
280 AnyEvent cannot compensate for this. The only event loop that is 281 AnyEvent cannot compensate for this. The only event loop that is
281 conscious about these issues is EV, which offers both relative 282 conscious of these issues is EV, which offers both relative (ev_timer,
282 (ev_timer, based on true relative time) and absolute (ev_periodic, based 283 based on true relative time) and absolute (ev_periodic, based on
283 on wallclock time) timers. 284 wallclock time) timers.
284 285
285 AnyEvent always prefers relative timers, if available, matching the 286 AnyEvent always prefers relative timers, if available, matching the
286 AnyEvent API. 287 AnyEvent API.
287 288
288 AnyEvent has two additional methods that return the "current time": 289 AnyEvent has two additional methods that return the "current time":
307 *In almost all cases (in all cases if you don't care), this is the 308 *In almost all cases (in all cases if you don't care), this is the
308 function to call when you want to know the current time.* 309 function to call when you want to know the current time.*
309 310
310 This function is also often faster then "AnyEvent->time", and thus 311 This function is also often faster then "AnyEvent->time", and thus
311 the preferred method if you want some timestamp (for example, 312 the preferred method if you want some timestamp (for example,
312 AnyEvent::Handle uses this to update it's activity timeouts). 313 AnyEvent::Handle uses this to update its activity timeouts).
313 314
314 The rest of this section is only of relevance if you try to be very 315 The rest of this section is only of relevance if you try to be very
315 exact with your timing, you can skip it without bad conscience. 316 exact with your timing; you can skip it without a bad conscience.
316 317
317 For a practical example of when these times differ, consider 318 For a practical example of when these times differ, consider
318 Event::Lib and EV and the following set-up: 319 Event::Lib and EV and the following set-up:
319 320
320 The event loop is running and has just invoked one of your callback 321 The event loop is running and has just invoked one of your callbacks
321 at time=500 (assume no other callbacks delay processing). In your 322 at time=500 (assume no other callbacks delay processing). In your
322 callback, you wait a second by executing "sleep 1" (blocking the 323 callback, you wait a second by executing "sleep 1" (blocking the
323 process for a second) and then (at time=501) you create a relative 324 process for a second) and then (at time=501) you create a relative
324 timer that fires after three seconds. 325 timer that fires after three seconds.
325 326
346 can get whatever behaviour you want with any event loop, by taking 347 can get whatever behaviour you want with any event loop, by taking
347 the difference between "AnyEvent->time" and "AnyEvent->now" into 348 the difference between "AnyEvent->time" and "AnyEvent->now" into
348 account. 349 account.
349 350
350 AnyEvent->now_update 351 AnyEvent->now_update
351 Some event loops (such as EV or AnyEvent::Impl::Perl) cache the 352 Some event loops (such as EV or AnyEvent::Loop) cache the current
352 current time for each loop iteration (see the discussion of 353 time for each loop iteration (see the discussion of AnyEvent->now,
353 AnyEvent->now, above). 354 above).
354 355
355 When a callback runs for a long time (or when the process sleeps), 356 When a callback runs for a long time (or when the process sleeps),
356 then this "current" time will differ substantially from the real 357 then this "current" time will differ substantially from the real
357 time, which might affect timers and time-outs. 358 time, which might affect timers and time-outs.
358 359
402 will not restart syscalls (that includes Async::Interrupt and AnyEvent's 403 will not restart syscalls (that includes Async::Interrupt and AnyEvent's
403 pure perl implementation). 404 pure perl implementation).
404 405
405 Safe/Unsafe Signals 406 Safe/Unsafe Signals
406 Perl signals can be either "safe" (synchronous to opcode handling) or 407 Perl signals can be either "safe" (synchronous to opcode handling) or
407 "unsafe" (asynchronous) - the former might get delayed indefinitely, the 408 "unsafe" (asynchronous) - the former might delay signal delivery
408 latter might corrupt your memory. 409 indefinitely, the latter might corrupt your memory.
409 410
410 AnyEvent signal handlers are, in addition, synchronous to the event 411 AnyEvent signal handlers are, in addition, synchronous to the event
411 loop, i.e. they will not interrupt your running perl program but will 412 loop, i.e. they will not interrupt your running perl program but will
412 only be called as part of the normal event handling (just like timer, 413 only be called as part of the normal event handling (just like timer,
413 I/O etc. callbacks, too). 414 I/O etc. callbacks, too).
414 415
415 Signal Races, Delays and Workarounds 416 Signal Races, Delays and Workarounds
416 Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching 417 Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
417 callbacks to signals in a generic way, which is a pity, as you cannot do 418 callbacks to signals in a generic way, which is a pity, as you cannot do
418 race-free signal handling in perl, requiring C libraries for this. 419 race-free signal handling in perl, requiring C libraries for this.
419 AnyEvent will try to do it's best, which means in some cases, signals 420 AnyEvent will try to do its best, which means in some cases, signals
420 will be delayed. The maximum time a signal might be delayed is specified 421 will be delayed. The maximum time a signal might be delayed is 10
421 in $AnyEvent::MAX_SIGNAL_LATENCY (default: 10 seconds). This variable 422 seconds by default, but can be overriden via
422 can be changed only before the first signal watcher is created, and 423 $ENV{PERL_ANYEVENT_MAX_SIGNAL_LATENCY} or $AnyEvent::MAX_SIGNAL_LATENCY
423 should be left alone otherwise. This variable determines how often 424 - see the "ENVIRONMENT VARIABLES" section for details.
424 AnyEvent polls for signals (in case a wake-up was missed). Higher values
425 will cause fewer spurious wake-ups, which is better for power and CPU
426 saving.
427 425
428 All these problems can be avoided by installing the optional 426 All these problems can be avoided by installing the optional
429 Async::Interrupt module, which works with most event loops. It will not 427 Async::Interrupt module, which works with most event loops. It will not
430 work with inherently broken event loops such as Event or Event::Lib (and 428 work with inherently broken event loops such as Event or Event::Lib (and
431 not with POE currently, as POE does it's own workaround with one-second
432 latency). For those, you just have to suffer the delays. 429 not with POE currently). For those, you just have to suffer the delays.
433 430
434 CHILD PROCESS WATCHERS 431 CHILD PROCESS WATCHERS
435 $w = AnyEvent->child (pid => <process id>, cb => <callback>); 432 $w = AnyEvent->child (pid => <process id>, cb => <callback>);
436 433
437 You can also watch on a child process exit and catch its exit status. 434 You can also watch for a child process exit and catch its exit status.
438 435
439 The child process is specified by the "pid" argument (one some backends, 436 The child process is specified by the "pid" argument (on some backends,
440 using 0 watches for any child process exit, on others this will croak). 437 using 0 watches for any child process exit, on others this will croak).
441 The watcher will be triggered only when the child process has finished 438 The watcher will be triggered only when the child process has finished
442 and an exit status is available, not on any trace events 439 and an exit status is available, not on any trace events
443 (stopped/continued). 440 (stopped/continued).
444 441
465 This means you cannot create a child watcher as the very first thing in 462 This means you cannot create a child watcher as the very first thing in
466 an AnyEvent program, you *have* to create at least one watcher before 463 an AnyEvent program, you *have* to create at least one watcher before
467 you "fork" the child (alternatively, you can call "AnyEvent::detect"). 464 you "fork" the child (alternatively, you can call "AnyEvent::detect").
468 465
469 As most event loops do not support waiting for child events, they will 466 As most event loops do not support waiting for child events, they will
470 be emulated by AnyEvent in most cases, in which the latency and race 467 be emulated by AnyEvent in most cases, in which case the latency and
471 problems mentioned in the description of signal watchers apply. 468 race problems mentioned in the description of signal watchers apply.
472 469
473 Example: fork a process and wait for it 470 Example: fork a process and wait for it
474 471
475 my $done = AnyEvent->condvar; 472 my $done = AnyEvent->condvar;
476 473
489 $done->recv; 486 $done->recv;
490 487
491 IDLE WATCHERS 488 IDLE WATCHERS
492 $w = AnyEvent->idle (cb => <callback>); 489 $w = AnyEvent->idle (cb => <callback>);
493 490
494 Repeatedly invoke the callback after the process becomes idle, until 491 This will repeatedly invoke the callback after the process becomes idle,
495 either the watcher is destroyed or new events have been detected. 492 until either the watcher is destroyed or new events have been detected.
496 493
497 Idle watchers are useful when there is a need to do something, but it is 494 Idle watchers are useful when there is a need to do something, but it is
498 not so important (or wise) to do it instantly. The callback will be 495 not so important (or wise) to do it instantly. The callback will be
499 invoked only when there is "nothing better to do", which is usually 496 invoked only when there is "nothing better to do", which is usually
500 defined as "all outstanding events have been handled and no new events 497 defined as "all outstanding events have been handled and no new events
570 called when the signal fires. 567 called when the signal fires.
571 568
572 * Condition variables are like "Merge Points" - points in your program 569 * Condition variables are like "Merge Points" - points in your program
573 where you merge multiple independent results/control flows into one. 570 where you merge multiple independent results/control flows into one.
574 571
575 * Condition variables represent a transaction - function that start 572 * Condition variables represent a transaction - functions that start
576 some kind of transaction can return them, leaving the caller the 573 some kind of transaction can return them, leaving the caller the
577 choice between waiting in a blocking fashion, or setting a callback. 574 choice between waiting in a blocking fashion, or setting a callback.
578 575
579 * Condition variables represent future values, or promises to deliver 576 * Condition variables represent future values, or promises to deliver
580 some result, long before the result is available. 577 some result, long before the result is available.
598 595
599 Condition variables are represented by hash refs in perl, and the keys 596 Condition variables are represented by hash refs in perl, and the keys
600 used by AnyEvent itself are all named "_ae_XXX" to make subclassing easy 597 used by AnyEvent itself are all named "_ae_XXX" to make subclassing easy
601 (it is often useful to build your own transaction class on top of 598 (it is often useful to build your own transaction class on top of
602 AnyEvent). To subclass, use "AnyEvent::CondVar" as base class and call 599 AnyEvent). To subclass, use "AnyEvent::CondVar" as base class and call
603 it's "new" method in your own "new" method. 600 its "new" method in your own "new" method.
604 601
605 There are two "sides" to a condition variable - the "producer side" 602 There are two "sides" to a condition variable - the "producer side"
606 which eventually calls "-> send", and the "consumer side", which waits 603 which eventually calls "-> send", and the "consumer side", which waits
607 for the send to occur. 604 for the send to occur.
608 605
668 Condition variables are overloaded so one can call them directly (as 665 Condition variables are overloaded so one can call them directly (as
669 if they were a code reference). Calling them directly is the same as 666 if they were a code reference). Calling them directly is the same as
670 calling "send". 667 calling "send".
671 668
672 $cv->croak ($error) 669 $cv->croak ($error)
673 Similar to send, but causes all call's to "->recv" to invoke 670 Similar to send, but causes all calls to "->recv" to invoke
674 "Carp::croak" with the given error message/object/scalar. 671 "Carp::croak" with the given error message/object/scalar.
675 672
676 This can be used to signal any errors to the condition variable 673 This can be used to signal any errors to the condition variable
677 user/consumer. Doing it this way instead of calling "croak" directly 674 user/consumer. Doing it this way instead of calling "croak" directly
678 delays the error detetcion, but has the overwhelmign advantage that 675 delays the error detection, but has the overwhelming advantage that
679 it diagnoses the error at the place where the result is expected, 676 it diagnoses the error at the place where the result is expected,
680 and not deep in some event clalback without connection to the actual 677 and not deep in some event callback with no connection to the actual
681 code causing the problem. 678 code causing the problem.
682 679
683 $cv->begin ([group callback]) 680 $cv->begin ([group callback])
684 $cv->end 681 $cv->end
685 These two methods can be used to combine many transactions/events 682 These two methods can be used to combine many transactions/events
722 there is one call to "begin", so the condvar waits for all calls to 719 there is one call to "begin", so the condvar waits for all calls to
723 "end" before sending. 720 "end" before sending.
724 721
725 The ping example mentioned above is slightly more complicated, as 722 The ping example mentioned above is slightly more complicated, as
726 the there are results to be passwd back, and the number of tasks 723 the there are results to be passwd back, and the number of tasks
727 that are begung can potentially be zero: 724 that are begun can potentially be zero:
728 725
729 my $cv = AnyEvent->condvar; 726 my $cv = AnyEvent->condvar;
730 727
731 my %result; 728 my %result;
732 $cv->begin (sub { shift->send (\%result) }); 729 $cv->begin (sub { shift->send (\%result) });
739 }; 736 };
740 } 737 }
741 738
742 $cv->end; 739 $cv->end;
743 740
741 ...
742
743 my $results = $cv->recv;
744
744 This code fragment supposedly pings a number of hosts and calls 745 This code fragment supposedly pings a number of hosts and calls
745 "send" after results for all then have have been gathered - in any 746 "send" after results for all then have have been gathered - in any
746 order. To achieve this, the code issues a call to "begin" when it 747 order. To achieve this, the code issues a call to "begin" when it
747 starts each ping request and calls "end" when it has received some 748 starts each ping request and calls "end" when it has received some
748 result for it. Since "begin" and "end" only maintain a counter, the 749 result for it. Since "begin" and "end" only maintain a counter, the
753 callback to be called once the counter reaches 0, and second, it 754 callback to be called once the counter reaches 0, and second, it
754 ensures that "send" is called even when "no" hosts are being pinged 755 ensures that "send" is called even when "no" hosts are being pinged
755 (the loop doesn't execute once). 756 (the loop doesn't execute once).
756 757
757 This is the general pattern when you "fan out" into multiple (but 758 This is the general pattern when you "fan out" into multiple (but
758 potentially none) subrequests: use an outer "begin"/"end" pair to 759 potentially zero) subrequests: use an outer "begin"/"end" pair to
759 set the callback and ensure "end" is called at least once, and then, 760 set the callback and ensure "end" is called at least once, and then,
760 for each subrequest you start, call "begin" and for each subrequest 761 for each subrequest you start, call "begin" and for each subrequest
761 you finish, call "end". 762 you finish, call "end".
762 763
763 METHODS FOR CONSUMERS 764 METHODS FOR CONSUMERS
764 These methods should only be used by the consuming side, i.e. the code 765 These methods should only be used by the consuming side, i.e. the code
765 awaits the condition. 766 awaits the condition.
766 767
767 $cv->recv 768 $cv->recv
768 Wait (blocking if necessary) until the "->send" or "->croak" methods 769 Wait (blocking if necessary) until the "->send" or "->croak" methods
769 have been called on c<$cv>, while servicing other watchers normally. 770 have been called on $cv, while servicing other watchers normally.
770 771
771 You can only wait once on a condition - additional calls are valid 772 You can only wait once on a condition - additional calls are valid
772 but will return immediately. 773 but will return immediately.
773 774
774 If an error condition has been set by calling "->croak", then this 775 If an error condition has been set by calling "->croak", then this
777 In list context, all parameters passed to "send" will be returned, 778 In list context, all parameters passed to "send" will be returned,
778 in scalar context only the first one will be returned. 779 in scalar context only the first one will be returned.
779 780
780 Note that doing a blocking wait in a callback is not supported by 781 Note that doing a blocking wait in a callback is not supported by
781 any event loop, that is, recursive invocation of a blocking "->recv" 782 any event loop, that is, recursive invocation of a blocking "->recv"
782 is not allowed, and the "recv" call will "croak" if such a condition 783 is not allowed and the "recv" call will "croak" if such a condition
783 is detected. This condition can be slightly loosened by using 784 is detected. This requirement can be dropped by relying on
784 Coro::AnyEvent, which allows you to do a blocking "->recv" from any 785 Coro::AnyEvent , which allows you to do a blocking "->recv" from any
785 thread that doesn't run the event loop itself. 786 thread that doesn't run the event loop itself. Coro::AnyEvent is
787 loaded automatically when Coro is used with AnyEvent, so code does
788 not need to do anything special to take advantage of that: any code
789 that would normally block your program because it calls "recv", be
790 executed in an "async" thread instead without blocking other
791 threads.
786 792
787 Not all event models support a blocking wait - some die in that case 793 Not all event models support a blocking wait - some die in that case
788 (programs might want to do that to stay interactive), so *if you are 794 (programs might want to do that to stay interactive), so *if you are
789 using this from a module, never require a blocking wait*. Instead, 795 using this from a module, never require a blocking wait*. Instead,
790 let the caller decide whether the call will block or not (for 796 let the caller decide whether the call will block or not (for
791 example, by coupling condition variables with some kind of request 797 example, by coupling condition variables with some kind of request
792 results and supporting callbacks so the caller knows that getting 798 results and supporting callbacks so the caller knows that getting
793 the result will not block, while still supporting blocking waits if 799 the result will not block, while still supporting blocking waits if
794 the caller so desires). 800 the caller so desires).
795 801
796 You can ensure that "-recv" never blocks by setting a callback and 802 You can ensure that "->recv" never blocks by setting a callback and
797 only calling "->recv" from within that callback (or at a later 803 only calling "->recv" from within that callback (or at a later
798 time). This will work even when the event loop does not support 804 time). This will work even when the event loop does not support
799 blocking waits otherwise. 805 blocking waits otherwise.
800 806
801 $bool = $cv->ready 807 $bool = $cv->ready
804 810
805 $cb = $cv->cb ($cb->($cv)) 811 $cb = $cv->cb ($cb->($cv))
806 This is a mutator function that returns the callback set and 812 This is a mutator function that returns the callback set and
807 optionally replaces it before doing so. 813 optionally replaces it before doing so.
808 814
809 The callback will be called when the condition becomes (or already 815 The callback will be called when the condition becomes "true", i.e.
810 was) "true", i.e. when "send" or "croak" are called (or were 816 when "send" or "croak" are called, with the only argument being the
811 called), with the only argument being the condition variable itself. 817 condition variable itself. If the condition is already true, the
812 Calling "recv" inside the callback or at any later time is 818 callback is called immediately when it is set. Calling "recv" inside
813 guaranteed not to block. 819 the callback or at any later time is guaranteed not to block.
814 820
815SUPPORTED EVENT LOOPS/BACKENDS 821SUPPORTED EVENT LOOPS/BACKENDS
816 The available backend classes are (every class has its own manpage): 822 The available backend classes are (every class has its own manpage):
817 823
818 Backends that are autoprobed when no other event loop can be found. 824 Backends that are autoprobed when no other event loop can be found.
820 use. If EV is not installed, then AnyEvent will fall back to its own 826 use. If EV is not installed, then AnyEvent will fall back to its own
821 pure-perl implementation, which is available everywhere as it comes 827 pure-perl implementation, which is available everywhere as it comes
822 with AnyEvent itself. 828 with AnyEvent itself.
823 829
824 AnyEvent::Impl::EV based on EV (interface to libev, best choice). 830 AnyEvent::Impl::EV based on EV (interface to libev, best choice).
825 AnyEvent::Impl::Perl pure-perl implementation, fast and portable. 831 AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
826 832
827 Backends that are transparently being picked up when they are used. 833 Backends that are transparently being picked up when they are used.
828 These will be used when they are currently loaded when the first 834 These will be used if they are already loaded when the first watcher
829 watcher is created, in which case it is assumed that the application 835 is created, in which case it is assumed that the application is
830 is using them. This means that AnyEvent will automatically pick the 836 using them. This means that AnyEvent will automatically pick the
831 right backend when the main program loads an event module before 837 right backend when the main program loads an event module before
832 anything starts to create watchers. Nothing special needs to be done 838 anything starts to create watchers. Nothing special needs to be done
833 by the main program. 839 by the main program.
834 840
835 AnyEvent::Impl::Event based on Event, very stable, few glitches. 841 AnyEvent::Impl::Event based on Event, very stable, few glitches.
836 AnyEvent::Impl::Glib based on Glib, slow but very stable. 842 AnyEvent::Impl::Glib based on Glib, slow but very stable.
837 AnyEvent::Impl::Tk based on Tk, very broken. 843 AnyEvent::Impl::Tk based on Tk, very broken.
838 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. 844 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
839 AnyEvent::Impl::POE based on POE, very slow, some limitations. 845 AnyEvent::Impl::POE based on POE, very slow, some limitations.
840 AnyEvent::Impl::Irssi used when running within irssi. 846 AnyEvent::Impl::Irssi used when running within irssi.
847 AnyEvent::Impl::IOAsync based on IO::Async.
848 AnyEvent::Impl::Cocoa based on Cocoa::EventLoop.
849 AnyEvent::Impl::FLTK based on FLTK (fltk 2 binding).
841 850
842 Backends with special needs. 851 Backends with special needs.
843 Qt requires the Qt::Application to be instantiated first, but will 852 Qt requires the Qt::Application to be instantiated first, but will
844 otherwise be picked up automatically. As long as the main program 853 otherwise be picked up automatically. As long as the main program
845 instantiates the application before any AnyEvent watchers are 854 instantiates the application before any AnyEvent watchers are
846 created, everything should just work. 855 created, everything should just work.
847 856
848 AnyEvent::Impl::Qt based on Qt. 857 AnyEvent::Impl::Qt based on Qt.
849 858
850 Support for IO::Async can only be partial, as it is too broken and
851 architecturally limited to even support the AnyEvent API. It also is
852 the only event loop that needs the loop to be set explicitly, so it
853 can only be used by a main program knowing about AnyEvent. See
854 AnyEvent::Impl::Async for the gory details.
855
856 AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
857
858 Event loops that are indirectly supported via other backends. 859 Event loops that are indirectly supported via other backends.
859 Some event loops can be supported via other modules: 860 Some event loops can be supported via other modules:
860 861
861 There is no direct support for WxWidgets (Wx) or Prima. 862 There is no direct support for WxWidgets (Wx) or Prima.
862 863
880 Contains "undef" until the first watcher is being created, before 881 Contains "undef" until the first watcher is being created, before
881 the backend has been autodetected. 882 the backend has been autodetected.
882 883
883 Afterwards it contains the event model that is being used, which is 884 Afterwards it contains the event model that is being used, which is
884 the name of the Perl class implementing the model. This class is 885 the name of the Perl class implementing the model. This class is
885 usually one of the "AnyEvent::Impl:xxx" modules, but can be any 886 usually one of the "AnyEvent::Impl::xxx" modules, but can be any
886 other class in the case AnyEvent has been extended at runtime (e.g. 887 other class in the case AnyEvent has been extended at runtime (e.g.
887 in *rxvt-unicode* it will be "urxvt::anyevent"). 888 in *rxvt-unicode* it will be "urxvt::anyevent").
888 889
889 AnyEvent::detect 890 AnyEvent::detect
890 Returns $AnyEvent::MODEL, forcing autodetection of the event model 891 Returns $AnyEvent::MODEL, forcing autodetection of the event model
891 if necessary. You should only call this function right before you 892 if necessary. You should only call this function right before you
892 would have created an AnyEvent watcher anyway, that is, as late as 893 would have created an AnyEvent watcher anyway, that is, as late as
893 possible at runtime, and not e.g. while initialising of your module. 894 possible at runtime, and not e.g. during initialisation of your
895 module.
896
897 The effect of calling this function is as if a watcher had been
898 created (specifically, actions that happen "when the first watcher
899 is created" happen when calling detetc as well).
894 900
895 If you need to do some initialisation before AnyEvent watchers are 901 If you need to do some initialisation before AnyEvent watchers are
896 created, use "post_detect". 902 created, use "post_detect".
897 903
898 $guard = AnyEvent::post_detect { BLOCK } 904 $guard = AnyEvent::post_detect { BLOCK }
899 Arranges for the code block to be executed as soon as the event 905 Arranges for the code block to be executed as soon as the event
900 model is autodetected (or immediately if this has already happened). 906 model is autodetected (or immediately if that has already happened).
901 907
902 The block will be executed *after* the actual backend has been 908 The block will be executed *after* the actual backend has been
903 detected ($AnyEvent::MODEL is set), but *before* any watchers have 909 detected ($AnyEvent::MODEL is set), but *before* any watchers have
904 been created, so it is possible to e.g. patch @AnyEvent::ISA or do 910 been created, so it is possible to e.g. patch @AnyEvent::ISA or do
905 other initialisations - see the sources of AnyEvent::Strict or 911 other initialisations - see the sources of AnyEvent::Strict or
914 object that automatically removes the callback again when it is 920 object that automatically removes the callback again when it is
915 destroyed (or "undef" when the hook was immediately executed). See 921 destroyed (or "undef" when the hook was immediately executed). See
916 AnyEvent::AIO for a case where this is useful. 922 AnyEvent::AIO for a case where this is useful.
917 923
918 Example: Create a watcher for the IO::AIO module and store it in 924 Example: Create a watcher for the IO::AIO module and store it in
919 $WATCHER. Only do so after the event loop is initialised, though. 925 $WATCHER, but do so only do so after the event loop is initialised.
920 926
921 our WATCHER; 927 our WATCHER;
922 928
923 my $guard = AnyEvent::post_detect { 929 my $guard = AnyEvent::post_detect {
924 $WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb); 930 $WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
931 937
932 $WATCHER ||= $guard; 938 $WATCHER ||= $guard;
933 939
934 @AnyEvent::post_detect 940 @AnyEvent::post_detect
935 If there are any code references in this array (you can "push" to it 941 If there are any code references in this array (you can "push" to it
936 before or after loading AnyEvent), then they will called directly 942 before or after loading AnyEvent), then they will be called directly
937 after the event loop has been chosen. 943 after the event loop has been chosen.
938 944
939 You should check $AnyEvent::MODEL before adding to this array, 945 You should check $AnyEvent::MODEL before adding to this array,
940 though: if it is defined then the event loop has already been 946 though: if it is defined then the event loop has already been
941 detected, and the array will be ignored. 947 detected, and the array will be ignored.
960 # AnyEvent not yet initialised, so make sure to load Coro::AnyEvent 966 # AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
961 # as soon as it is 967 # as soon as it is
962 push @AnyEvent::post_detect, sub { require Coro::AnyEvent }; 968 push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
963 } 969 }
964 970
971 AnyEvent::postpone { BLOCK }
972 Arranges for the block to be executed as soon as possible, but not
973 before the call itself returns. In practise, the block will be
974 executed just before the event loop polls for new events, or shortly
975 afterwards.
976
977 This function never returns anything (to make the "return postpone {
978 ... }" idiom more useful.
979
980 To understand the usefulness of this function, consider a function
981 that asynchronously does something for you and returns some
982 transaction object or guard to let you cancel the operation. For
983 example, "AnyEvent::Socket::tcp_connect":
984
985 # start a conenction attempt unless one is active
986 $self->{connect_guard} ||= AnyEvent::Socket::tcp_connect "www.example.net", 80, sub {
987 delete $self->{connect_guard};
988 ...
989 };
990
991 Imagine that this function could instantly call the callback, for
992 example, because it detects an obvious error such as a negative port
993 number. Invoking the callback before the function returns causes
994 problems however: the callback will be called and will try to delete
995 the guard object. But since the function hasn't returned yet, there
996 is nothing to delete. When the function eventually returns it will
997 assign the guard object to "$self->{connect_guard}", where it will
998 likely never be deleted, so the program thinks it is still trying to
999 connect.
1000
1001 This is where "AnyEvent::postpone" should be used. Instead of
1002 calling the callback directly on error:
1003
1004 $cb->(undef), return # signal error to callback, BAD!
1005 if $some_error_condition;
1006
1007 It should use "postpone":
1008
1009 AnyEvent::postpone { $cb->(undef) }, return # signal error to callback, later
1010 if $some_error_condition;
1011
1012 AnyEvent::log $level, $msg[, @args]
1013 Log the given $msg at the given $level.
1014
1015 If AnyEvent::Log is not loaded then this function makes a simple
1016 test to see whether the message will be logged. If the test succeeds
1017 it will load AnyEvent::Log and call "AnyEvent::Log::log" -
1018 consequently, look at the AnyEvent::Log documentation for details.
1019
1020 If the test fails it will simply return. Right now this happens when
1021 a numerical loglevel is used and it is larger than the level
1022 specified via $ENV{PERL_ANYEVENT_VERBOSE}.
1023
1024 If you want to sprinkle loads of logging calls around your code,
1025 consider creating a logger callback with the "AnyEvent::Log::logger"
1026 function, which can reduce typing, codesize and can reduce the
1027 logging overhead enourmously.
1028
965WHAT TO DO IN A MODULE 1029WHAT TO DO IN A MODULE
966 As a module author, you should "use AnyEvent" and call AnyEvent methods 1030 As a module author, you should "use AnyEvent" and call AnyEvent methods
967 freely, but you should not load a specific event module or rely on it. 1031 freely, but you should not load a specific event module or rely on it.
968 1032
969 Be careful when you create watchers in the module body - AnyEvent will 1033 Be careful when you create watchers in the module body - AnyEvent will
976 stall the whole program, and the whole point of using events is to stay 1040 stall the whole program, and the whole point of using events is to stay
977 interactive. 1041 interactive.
978 1042
979 It is fine, however, to call "->recv" when the user of your module 1043 It is fine, however, to call "->recv" when the user of your module
980 requests it (i.e. if you create a http request object ad have a method 1044 requests it (i.e. if you create a http request object ad have a method
981 called "results" that returns the results, it should call "->recv" 1045 called "results" that returns the results, it may call "->recv" freely,
982 freely, as the user of your module knows what she is doing. always). 1046 as the user of your module knows what she is doing. Always).
983 1047
984WHAT TO DO IN THE MAIN PROGRAM 1048WHAT TO DO IN THE MAIN PROGRAM
985 There will always be a single main program - the only place that should 1049 There will always be a single main program - the only place that should
986 dictate which event model to use. 1050 dictate which event model to use.
987 1051
988 If it doesn't care, it can just "use AnyEvent" and use it itself, or not 1052 If the program is not event-based, it need not do anything special, even
989 do anything special (it does not need to be event-based) and let 1053 when it depends on a module that uses an AnyEvent. If the program itself
990 AnyEvent decide which implementation to chose if some module relies on 1054 uses AnyEvent, but does not care which event loop is used, all it needs
991 it. 1055 to do is "use AnyEvent". In either case, AnyEvent will choose the best
1056 available loop implementation.
992 1057
993 If the main program relies on a specific event model - for example, in 1058 If the main program relies on a specific event model - for example, in
994 Gtk2 programs you have to rely on the Glib module - you should load the 1059 Gtk2 programs you have to rely on the Glib module - you should load the
995 event module before loading AnyEvent or any module that uses it: 1060 event module before loading AnyEvent or any module that uses it:
996 generally speaking, you should load it as early as possible. The reason 1061 generally speaking, you should load it as early as possible. The reason
997 is that modules might create watchers when they are loaded, and AnyEvent 1062 is that modules might create watchers when they are loaded, and AnyEvent
998 will decide on the event model to use as soon as it creates watchers, 1063 will decide on the event model to use as soon as it creates watchers,
999 and it might chose the wrong one unless you load the correct one 1064 and it might choose the wrong one unless you load the correct one
1000 yourself. 1065 yourself.
1001 1066
1002 You can chose to use a pure-perl implementation by loading the 1067 You can chose to use a pure-perl implementation by loading the
1003 "AnyEvent::Impl::Perl" module, which gives you similar behaviour 1068 "AnyEvent::Loop" module, which gives you similar behaviour everywhere,
1004 everywhere, but letting AnyEvent chose the model is generally better. 1069 but letting AnyEvent chose the model is generally better.
1005 1070
1006 MAINLOOP EMULATION 1071 MAINLOOP EMULATION
1007 Sometimes (often for short test scripts, or even standalone programs who 1072 Sometimes (often for short test scripts, or even standalone programs who
1008 only want to use AnyEvent), you do not want to run a specific event 1073 only want to use AnyEvent), you do not want to run a specific event
1009 loop. 1074 loop.
1021 1086
1022OTHER MODULES 1087OTHER MODULES
1023 The following is a non-exhaustive list of additional modules that use 1088 The following is a non-exhaustive list of additional modules that use
1024 AnyEvent as a client and can therefore be mixed easily with other 1089 AnyEvent as a client and can therefore be mixed easily with other
1025 AnyEvent modules and other event loops in the same program. Some of the 1090 AnyEvent modules and other event loops in the same program. Some of the
1026 modules come as part of AnyEvent, the others are available via CPAN. 1091 modules come as part of AnyEvent, the others are available via CPAN (see
1092 <http://search.cpan.org/search?m=module&q=anyevent%3A%3A*> for a longer
1093 non-exhaustive list), and the list is heavily biased towards modules of
1094 the AnyEvent author himself :)
1027 1095
1028 AnyEvent::Util 1096 AnyEvent::Util (part of the AnyEvent distribution)
1029 Contains various utility functions that replace often-used but 1097 Contains various utility functions that replace often-used blocking
1030 blocking functions such as "inet_aton" by event-/callback-based 1098 functions such as "inet_aton" with event/callback-based versions.
1031 versions.
1032 1099
1033 AnyEvent::Socket 1100 AnyEvent::Socket (part of the AnyEvent distribution)
1034 Provides various utility functions for (internet protocol) sockets, 1101 Provides various utility functions for (internet protocol) sockets,
1035 addresses and name resolution. Also functions to create non-blocking 1102 addresses and name resolution. Also functions to create non-blocking
1036 tcp connections or tcp servers, with IPv6 and SRV record support and 1103 tcp connections or tcp servers, with IPv6 and SRV record support and
1037 more. 1104 more.
1038 1105
1039 AnyEvent::Handle 1106 AnyEvent::Handle (part of the AnyEvent distribution)
1040 Provide read and write buffers, manages watchers for reads and 1107 Provide read and write buffers, manages watchers for reads and
1041 writes, supports raw and formatted I/O, I/O queued and fully 1108 writes, supports raw and formatted I/O, I/O queued and fully
1042 transparent and non-blocking SSL/TLS (via AnyEvent::TLS. 1109 transparent and non-blocking SSL/TLS (via AnyEvent::TLS).
1043 1110
1044 AnyEvent::DNS 1111 AnyEvent::DNS (part of the AnyEvent distribution)
1045 Provides rich asynchronous DNS resolver capabilities. 1112 Provides rich asynchronous DNS resolver capabilities.
1046 1113
1047 AnyEvent::HTTP, AnyEvent::IRC, AnyEvent::XMPP, AnyEvent::GPSD, 1114 AnyEvent::HTTP, AnyEvent::IRC, AnyEvent::XMPP, AnyEvent::GPSD,
1048 AnyEvent::IGS, AnyEvent::FCP 1115 AnyEvent::IGS, AnyEvent::FCP
1049 Implement event-based interfaces to the protocols of the same name 1116 Implement event-based interfaces to the protocols of the same name
1050 (for the curious, IGS is the International Go Server and FCP is the 1117 (for the curious, IGS is the International Go Server and FCP is the
1051 Freenet Client Protocol). 1118 Freenet Client Protocol).
1052 1119
1053 AnyEvent::Handle::UDP 1120 AnyEvent::AIO (part of the AnyEvent distribution)
1054 Here be danger!
1055
1056 As Pauli would put it, "Not only is it not right, it's not even
1057 wrong!" - there are so many things wrong with AnyEvent::Handle::UDP,
1058 most notably it's use of a stream-based API with a protocol that
1059 isn't streamable, that the only way to improve it is to delete it.
1060
1061 It features data corruption (but typically only under load) and
1062 general confusion. On top, the author is not only clueless about UDP
1063 but also fact-resistant - some gems of his understanding: "connect
1064 doesn't work with UDP", "UDP packets are not IP packets", "UDP only
1065 has datagrams, not packets", "I don't need to implement proper error
1066 checking as UDP doesn't support error checking" and so on - he
1067 doesn't even understand what's wrong with his module when it is
1068 explained to him.
1069
1070 AnyEvent::DBI
1071 Executes DBI requests asynchronously in a proxy process for you,
1072 notifying you in an event-bnased way when the operation is finished.
1073
1074 AnyEvent::AIO
1075 Truly asynchronous (as opposed to non-blocking) I/O, should be in 1121 Truly asynchronous (as opposed to non-blocking) I/O, should be in
1076 the toolbox of every event programmer. AnyEvent::AIO transparently 1122 the toolbox of every event programmer. AnyEvent::AIO transparently
1077 fuses IO::AIO and AnyEvent together, giving AnyEvent access to 1123 fuses IO::AIO and AnyEvent together, giving AnyEvent access to
1078 event-based file I/O, and much more. 1124 event-based file I/O, and much more.
1079 1125
1126 AnyEvent::Filesys::Notify
1127 AnyEvent is good for non-blocking stuff, but it can't detect file or
1128 path changes (e.g. "watch this directory for new files", "watch this
1129 file for changes"). The AnyEvent::Filesys::Notify module promises to
1130 do just that in a portbale fashion, supporting inotify on GNU/Linux
1131 and some weird, without doubt broken, stuff on OS X to monitor
1132 files. It can fall back to blocking scans at regular intervals
1133 transparently on other platforms, so it's about as portable as it
1134 gets.
1135
1136 (I haven't used it myself, but I haven't heard anybody complaining
1137 about it yet).
1138
1139 AnyEvent::DBI
1140 Executes DBI requests asynchronously in a proxy process for you,
1141 notifying you in an event-based way when the operation is finished.
1142
1080 AnyEvent::HTTPD 1143 AnyEvent::HTTPD
1081 A simple embedded webserver. 1144 A simple embedded webserver.
1082 1145
1083 AnyEvent::FastPing 1146 AnyEvent::FastPing
1084 The fastest ping in the west. 1147 The fastest ping in the west.
1085 1148
1086 Coro 1149 Coro
1087 Has special support for AnyEvent via Coro::AnyEvent. 1150 Has special support for AnyEvent via Coro::AnyEvent, which allows
1151 you to simply invert the flow control - don't call us, we will call
1152 you:
1153
1154 async {
1155 Coro::AnyEvent::sleep 5; # creates a 5s timer and waits for it
1156 print "5 seconds later!\n";
1157
1158 Coro::AnyEvent::readable *STDIN; # uses an I/O watcher
1159 my $line = <STDIN>; # works for ttys
1160
1161 AnyEvent::HTTP::http_get "url", Coro::rouse_cb;
1162 my ($body, $hdr) = Coro::rouse_wait;
1163 };
1088 1164
1089SIMPLIFIED AE API 1165SIMPLIFIED AE API
1090 Starting with version 5.0, AnyEvent officially supports a second, much 1166 Starting with version 5.0, AnyEvent officially supports a second, much
1091 simpler, API that is designed to reduce the calling, typing and memory 1167 simpler, API that is designed to reduce the calling, typing and memory
1092 overhead by using function call syntax and a fixed number of parameters. 1168 overhead by using function call syntax and a fixed number of parameters.
1108 The pure perl event loop simply re-throws the exception (usually within 1184 The pure perl event loop simply re-throws the exception (usually within
1109 "condvar->recv"), the Event and EV modules call "$Event/EV::DIED->()", 1185 "condvar->recv"), the Event and EV modules call "$Event/EV::DIED->()",
1110 Glib uses "install_exception_handler" and so on. 1186 Glib uses "install_exception_handler" and so on.
1111 1187
1112ENVIRONMENT VARIABLES 1188ENVIRONMENT VARIABLES
1113 The following environment variables are used by this module or its 1189 AnyEvent supports a number of environment variables that tune the
1114 submodules. 1190 runtime behaviour. They are usually evaluated when AnyEvent is loaded,
1191 initialised, or a submodule that uses them is loaded. Many of them also
1192 cause AnyEvent to load additional modules - for example,
1193 "PERL_ANYEVENT_DEBUG_WRAP" causes the AnyEvent::Debug module to be
1194 loaded.
1115 1195
1116 Note that AnyEvent will remove *all* environment variables starting with 1196 All the environment variables documented here start with
1117 "PERL_ANYEVENT_" from %ENV when it is loaded while taint mode is 1197 "PERL_ANYEVENT_", which is what AnyEvent considers its own namespace.
1118 enabled. 1198 Other modules are encouraged (but by no means required) to use
1199 "PERL_ANYEVENT_SUBMODULE" if they have registered the
1200 AnyEvent::Submodule namespace on CPAN, for any submodule. For example,
1201 AnyEvent::HTTP could be expected to use "PERL_ANYEVENT_HTTP_PROXY" (it
1202 should not access env variables starting with "AE_", see below).
1203
1204 All variables can also be set via the "AE_" prefix, that is, instead of
1205 setting "PERL_ANYEVENT_VERBOSE" you can also set "AE_VERBOSE". In case
1206 there is a clash btween anyevent and another program that uses
1207 "AE_something" you can set the corresponding "PERL_ANYEVENT_something"
1208 variable to the empty string, as those variables take precedence.
1209
1210 When AnyEvent is first loaded, it copies all "AE_xxx" env variables to
1211 their "PERL_ANYEVENT_xxx" counterpart unless that variable already
1212 exists. If taint mode is on, then AnyEvent will remove *all* environment
1213 variables starting with "PERL_ANYEVENT_" from %ENV (or replace them with
1214 "undef" or the empty string, if the corresaponding "AE_" variable is
1215 set).
1216
1217 The exact algorithm is currently:
1218
1219 1. if taint mode enabled, delete all PERL_ANYEVENT_xyz variables from %ENV
1220 2. copy over AE_xyz to PERL_ANYEVENT_xyz unless the latter alraedy exists
1221 3. if taint mode enabled, set all PERL_ANYEVENT_xyz variables to undef.
1222
1223 This ensures that child processes will not see the "AE_" variables.
1224
1225 The following environment variables are currently known to AnyEvent:
1119 1226
1120 "PERL_ANYEVENT_VERBOSE" 1227 "PERL_ANYEVENT_VERBOSE"
1121 By default, AnyEvent will be completely silent except in fatal 1228 By default, AnyEvent will log messages with loglevel 4 ("error") or
1122 conditions. You can set this environment variable to make AnyEvent 1229 higher (see AnyEvent::Log). You can set this environment variable to
1123 more talkative. 1230 a numerical loglevel to make AnyEvent more (or less) talkative.
1124 1231
1232 If you want to do more than just set the global logging level you
1233 should have a look at "PERL_ANYEVENT_LOG", which allows much more
1234 complex specifications.
1235
1236 When set to 0 ("off"), then no messages whatsoever will be logged
1237 with everything else at defaults.
1238
1125 When set to 1 or higher, causes AnyEvent to warn about unexpected 1239 When set to 5 or higher ("warn"), AnyEvent warns about unexpected
1126 conditions, such as not being able to load the event model specified 1240 conditions, such as not being able to load the event model specified
1127 by "PERL_ANYEVENT_MODEL". 1241 by "PERL_ANYEVENT_MODEL", or a guard callback throwing an exception
1242 - this is the minimum recommended level for use during development.
1128 1243
1129 When set to 2 or higher, cause AnyEvent to report to STDERR which 1244 When set to 7 or higher (info), AnyEvent reports which event model
1130 event model it chooses. 1245 it chooses.
1131 1246
1132 When set to 8 or higher, then AnyEvent will report extra information 1247 When set to 8 or higher (debug), then AnyEvent will report extra
1133 on which optional modules it loads and how it implements certain 1248 information on which optional modules it loads and how it implements
1134 features. 1249 certain features.
1250
1251 "PERL_ANYEVENT_LOG"
1252 Accepts rather complex logging specifications. For example, you
1253 could log all "debug" messages of some module to stderr, warnings
1254 and above to stderr, and errors and above to syslog, with:
1255
1256 PERL_ANYEVENT_LOG=Some::Module=debug,+log:filter=warn,+%syslog:%syslog=error,syslog
1257
1258 For the rather extensive details, see AnyEvent::Log.
1259
1260 This variable is evaluated when AnyEvent (or AnyEvent::Log) is
1261 loaded, so will take effect even before AnyEvent has initialised
1262 itself.
1263
1264 Note that specifying this environment variable causes the
1265 AnyEvent::Log module to be loaded, while "PERL_ANYEVENT_VERBOSE"
1266 does not, so only using the latter saves a few hundred kB of memory
1267 unless a module explicitly needs the extra features of
1268 AnyEvent::Log.
1135 1269
1136 "PERL_ANYEVENT_STRICT" 1270 "PERL_ANYEVENT_STRICT"
1137 AnyEvent does not do much argument checking by default, as thorough 1271 AnyEvent does not do much argument checking by default, as thorough
1138 argument checking is very costly. Setting this variable to a true 1272 argument checking is very costly. Setting this variable to a true
1139 value will cause AnyEvent to load "AnyEvent::Strict" and then to 1273 value will cause AnyEvent to load "AnyEvent::Strict" and then to
1140 thoroughly check the arguments passed to most method calls. If it 1274 thoroughly check the arguments passed to most method calls. If it
1141 finds any problems, it will croak. 1275 finds any problems, it will croak.
1142 1276
1143 In other words, enables "strict" mode. 1277 In other words, enables "strict" mode.
1144 1278
1145 Unlike "use strict" (or it's modern cousin, "use common::sense", it 1279 Unlike "use strict" (or its modern cousin, "use common::sense", it
1146 is definitely recommended to keep it off in production. Keeping 1280 is definitely recommended to keep it off in production. Keeping
1147 "PERL_ANYEVENT_STRICT=1" in your environment while developing 1281 "PERL_ANYEVENT_STRICT=1" in your environment while developing
1148 programs can be very useful, however. 1282 programs can be very useful, however.
1149 1283
1284 "PERL_ANYEVENT_DEBUG_SHELL"
1285 If this env variable is nonempty, then its contents will be
1286 interpreted by "AnyEvent::Socket::parse_hostport" and
1287 "AnyEvent::Debug::shell" (after replacing every occurance of $$ by
1288 the process pid). The shell object is saved in
1289 $AnyEvent::Debug::SHELL.
1290
1291 This happens when the first watcher is created.
1292
1293 For example, to bind a debug shell on a unix domain socket in
1294 /tmp/debug<pid>.sock, you could use this:
1295
1296 PERL_ANYEVENT_DEBUG_SHELL=/tmp/debug\$\$.sock perlprog
1297 # connect with e.g.: socat readline /tmp/debug123.sock
1298
1299 Or to bind to tcp port 4545 on localhost:
1300
1301 PERL_ANYEVENT_DEBUG_SHELL=127.0.0.1:4545 perlprog
1302 # connect with e.g.: telnet localhost 4545
1303
1304 Note that creating sockets in /tmp or on localhost is very unsafe on
1305 multiuser systems.
1306
1307 "PERL_ANYEVENT_DEBUG_WRAP"
1308 Can be set to 0, 1 or 2 and enables wrapping of all watchers for
1309 debugging purposes. See "AnyEvent::Debug::wrap" for details.
1310
1150 "PERL_ANYEVENT_MODEL" 1311 "PERL_ANYEVENT_MODEL"
1151 This can be used to specify the event model to be used by AnyEvent, 1312 This can be used to specify the event model to be used by AnyEvent,
1152 before auto detection and -probing kicks in. It must be a string 1313 before auto detection and -probing kicks in.
1153 consisting entirely of ASCII letters. The string "AnyEvent::Impl::" 1314
1154 gets prepended and the resulting module name is loaded and if the 1315 It normally is a string consisting entirely of ASCII letters (e.g.
1155 load was successful, used as event model. If it fails to load 1316 "EV" or "IOAsync"). The string "AnyEvent::Impl::" gets prepended and
1317 the resulting module name is loaded and - if the load was successful
1318 - used as event model backend. If it fails to load then AnyEvent
1156 AnyEvent will proceed with auto detection and -probing. 1319 will proceed with auto detection and -probing.
1157 1320
1158 This functionality might change in future versions. 1321 If the string ends with "::" instead (e.g. "AnyEvent::Impl::EV::")
1322 then nothing gets prepended and the module name is used as-is (hint:
1323 "::" at the end of a string designates a module name and quotes it
1324 appropriately).
1159 1325
1160 For example, to force the pure perl model (AnyEvent::Impl::Perl) you 1326 For example, to force the pure perl model (AnyEvent::Loop::Perl) you
1161 could start your program like this: 1327 could start your program like this:
1162 1328
1163 PERL_ANYEVENT_MODEL=Perl perl ... 1329 PERL_ANYEVENT_MODEL=Perl perl ...
1330
1331 "PERL_ANYEVENT_IO_MODEL"
1332 The current file I/O model - see AnyEvent::IO for more info.
1333
1334 At the moment, only "Perl" (small, pure-perl, synchronous) and
1335 "IOAIO" (truly asynchronous) are supported. The default is "IOAIO"
1336 if AnyEvent::AIO can be loaded, otherwise it is "Perl".
1164 1337
1165 "PERL_ANYEVENT_PROTOCOLS" 1338 "PERL_ANYEVENT_PROTOCOLS"
1166 Used by both AnyEvent::DNS and AnyEvent::Socket to determine 1339 Used by both AnyEvent::DNS and AnyEvent::Socket to determine
1167 preferences for IPv4 or IPv6. The default is unspecified (and might 1340 preferences for IPv4 or IPv6. The default is unspecified (and might
1168 change, or be the result of auto probing). 1341 change, or be the result of auto probing).
1182 "PERL_ANYEVENT_PROTOCOLS=ipv4" - only support IPv4, never try to 1355 "PERL_ANYEVENT_PROTOCOLS=ipv4" - only support IPv4, never try to
1183 resolve or contact IPv6 addresses. 1356 resolve or contact IPv6 addresses.
1184 "PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4" support either IPv4 or IPv6, but 1357 "PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4" support either IPv4 or IPv6, but
1185 prefer IPv6 over IPv4. 1358 prefer IPv6 over IPv4.
1186 1359
1360 "PERL_ANYEVENT_HOSTS"
1361 This variable, if specified, overrides the /etc/hosts file used by
1362 AnyEvent::Socket"::resolve_sockaddr", i.e. hosts aliases will be
1363 read from that file instead.
1364
1187 "PERL_ANYEVENT_EDNS0" 1365 "PERL_ANYEVENT_EDNS0"
1188 Used by AnyEvent::DNS to decide whether to use the EDNS0 extension 1366 Used by AnyEvent::DNS to decide whether to use the EDNS0 extension
1189 for DNS. This extension is generally useful to reduce DNS traffic, 1367 for DNS. This extension is generally useful to reduce DNS traffic,
1190 but some (broken) firewalls drop such DNS packets, which is why it 1368 especially when DNSSEC is involved, but some (broken) firewalls drop
1191 is off by default. 1369 such DNS packets, which is why it is off by default.
1192 1370
1193 Setting this variable to 1 will cause AnyEvent::DNS to announce 1371 Setting this variable to 1 will cause AnyEvent::DNS to announce
1194 EDNS0 in its DNS requests. 1372 EDNS0 in its DNS requests.
1195 1373
1196 "PERL_ANYEVENT_MAX_FORKS" 1374 "PERL_ANYEVENT_MAX_FORKS"
1200 "PERL_ANYEVENT_MAX_OUTSTANDING_DNS" 1378 "PERL_ANYEVENT_MAX_OUTSTANDING_DNS"
1201 The default value for the "max_outstanding" parameter for the 1379 The default value for the "max_outstanding" parameter for the
1202 default DNS resolver - this is the maximum number of parallel DNS 1380 default DNS resolver - this is the maximum number of parallel DNS
1203 requests that are sent to the DNS server. 1381 requests that are sent to the DNS server.
1204 1382
1383 "PERL_ANYEVENT_MAX_SIGNAL_LATENCY"
1384 Perl has inherently racy signal handling (you can basically choose
1385 between losing signals and memory corruption) - pure perl event
1386 loops (including "AnyEvent::Loop", when "Async::Interrupt" isn't
1387 available) therefore have to poll regularly to avoid losing signals.
1388
1389 Some event loops are racy, but don't poll regularly, and some event
1390 loops are written in C but are still racy. For those event loops,
1391 AnyEvent installs a timer that regularly wakes up the event loop.
1392
1393 By default, the interval for this timer is 10 seconds, but you can
1394 override this delay with this environment variable (or by setting
1395 the $AnyEvent::MAX_SIGNAL_LATENCY variable before creating signal
1396 watchers).
1397
1398 Lower values increase CPU (and energy) usage, higher values can
1399 introduce long delays when reaping children or waiting for signals.
1400
1401 The AnyEvent::Async module, if available, will be used to avoid this
1402 polling (with most event loops).
1403
1205 "PERL_ANYEVENT_RESOLV_CONF" 1404 "PERL_ANYEVENT_RESOLV_CONF"
1206 The file to use instead of /etc/resolv.conf (or OS-specific 1405 The absolute path to a resolv.conf-style file to use instead of
1207 configuration) in the default resolver. When set to the empty 1406 /etc/resolv.conf (or the OS-specific configuration) in the default
1208 string, no default config will be used. 1407 resolver, or the empty string to select the default configuration.
1209 1408
1210 "PERL_ANYEVENT_CA_FILE", "PERL_ANYEVENT_CA_PATH". 1409 "PERL_ANYEVENT_CA_FILE", "PERL_ANYEVENT_CA_PATH".
1211 When neither "ca_file" nor "ca_path" was specified during 1410 When neither "ca_file" nor "ca_path" was specified during
1212 AnyEvent::TLS context creation, and either of these environment 1411 AnyEvent::TLS context creation, and either of these environment
1213 variables exist, they will be used to specify CA certificate 1412 variables are nonempty, they will be used to specify CA certificate
1214 locations instead of a system-dependent default. 1413 locations instead of a system-dependent default.
1215 1414
1216 "PERL_ANYEVENT_AVOID_GUARD" and "PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT" 1415 "PERL_ANYEVENT_AVOID_GUARD" and "PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT"
1217 When these are set to 1, then the respective modules are not loaded. 1416 When these are set to 1, then the respective modules are not loaded.
1218 Mostly good for testing AnyEvent itself. 1417 Mostly good for testing AnyEvent itself.
1538 when used without AnyEvent), but most event loops have acceptable 1737 when used without AnyEvent), but most event loops have acceptable
1539 performance with or without AnyEvent. 1738 performance with or without AnyEvent.
1540 1739
1541 * The overhead AnyEvent adds is usually much smaller than the overhead 1740 * The overhead AnyEvent adds is usually much smaller than the overhead
1542 of the actual event loop, only with extremely fast event loops such 1741 of the actual event loop, only with extremely fast event loops such
1543 as EV adds AnyEvent significant overhead. 1742 as EV does AnyEvent add significant overhead.
1544 1743
1545 * You should avoid POE like the plague if you want performance or 1744 * You should avoid POE like the plague if you want performance or
1546 reasonable memory usage. 1745 reasonable memory usage.
1547 1746
1548 BENCHMARKING THE LARGE SERVER CASE 1747 BENCHMARKING THE LARGE SERVER CASE
1746 1945
1747 Feel free to install your own handler, or reset it to defaults. 1946 Feel free to install your own handler, or reset it to defaults.
1748 1947
1749RECOMMENDED/OPTIONAL MODULES 1948RECOMMENDED/OPTIONAL MODULES
1750 One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and 1949 One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
1751 it's built-in modules) are required to use it. 1950 its built-in modules) are required to use it.
1752 1951
1753 That does not mean that AnyEvent won't take advantage of some additional 1952 That does not mean that AnyEvent won't take advantage of some additional
1754 modules if they are installed. 1953 modules if they are installed.
1755 1954
1756 This section explains which additional modules will be used, and how 1955 This section explains which additional modules will be used, and how
1807 worthwhile: If this module is installed, then AnyEvent::Handle (with 2006 worthwhile: If this module is installed, then AnyEvent::Handle (with
1808 the help of AnyEvent::TLS), gains the ability to do TLS/SSL. 2007 the help of AnyEvent::TLS), gains the ability to do TLS/SSL.
1809 2008
1810 Time::HiRes 2009 Time::HiRes
1811 This module is part of perl since release 5.008. It will be used 2010 This module is part of perl since release 5.008. It will be used
1812 when the chosen event library does not come with a timing source on 2011 when the chosen event library does not come with a timing source of
1813 it's own. The pure-perl event loop (AnyEvent::Impl::Perl) will 2012 its own. The pure-perl event loop (AnyEvent::Loop) will additionally
1814 additionally use it to try to use a monotonic clock for timing 2013 load it to try to use a monotonic clock for timing stability.
1815 stability. 2014
2015 AnyEvent::AIO (and IO::AIO)
2016 The default implementation of AnyEvent::IO is to do I/O
2017 synchronously, stopping programs while they access the disk, which
2018 is fine for a lot of programs.
2019
2020 Installing AnyEvent::AIO (and its IO::AIO dependency) makes it
2021 switch to a true asynchronous implementation, so event processing
2022 can continue even while waiting for disk I/O.
1816 2023
1817FORK 2024FORK
1818 Most event libraries are not fork-safe. The ones who are usually are 2025 Most event libraries are not fork-safe. The ones who are usually are
1819 because they rely on inefficient but fork-safe "select" or "poll" calls 2026 because they rely on inefficient but fork-safe "select" or "poll" calls
1820 - higher performance APIs such as BSD's kqueue or the dreaded Linux 2027 - higher performance APIs such as BSD's kqueue or the dreaded Linux
1871 5.10 and check wether the leaks still show up. (Perl 5.10.0 has other 2078 5.10 and check wether the leaks still show up. (Perl 5.10.0 has other
1872 annoying memleaks, such as leaking on "map" and "grep" but it is usually 2079 annoying memleaks, such as leaking on "map" and "grep" but it is usually
1873 not as pronounced). 2080 not as pronounced).
1874 2081
1875SEE ALSO 2082SEE ALSO
1876 Utility functions: AnyEvent::Util. 2083 Tutorial/Introduction: AnyEvent::Intro.
1877 2084
1878 Event modules: EV, EV::Glib, Glib::EV, Event, Glib::Event, Glib, Tk, 2085 FAQ: AnyEvent::FAQ.
1879 Event::Lib, Qt, POE. 2086
2087 Utility functions: AnyEvent::Util (misc. grab-bag), AnyEvent::Log
2088 (simply logging).
2089
2090 Development/Debugging: AnyEvent::Strict (stricter checking),
2091 AnyEvent::Debug (interactive shell, watcher tracing).
2092
2093 Supported event modules: AnyEvent::Loop, EV, EV::Glib, Glib::EV, Event,
2094 Glib::Event, Glib, Tk, Event::Lib, Qt, POE, FLTK.
1880 2095
1881 Implementations: AnyEvent::Impl::EV, AnyEvent::Impl::Event, 2096 Implementations: AnyEvent::Impl::EV, AnyEvent::Impl::Event,
1882 AnyEvent::Impl::Glib, AnyEvent::Impl::Tk, AnyEvent::Impl::Perl, 2097 AnyEvent::Impl::Glib, AnyEvent::Impl::Tk, AnyEvent::Impl::Perl,
1883 AnyEvent::Impl::EventLib, AnyEvent::Impl::Qt, AnyEvent::Impl::POE, 2098 AnyEvent::Impl::EventLib, AnyEvent::Impl::Qt, AnyEvent::Impl::POE,
1884 AnyEvent::Impl::IOAsync, Anyevent::Impl::Irssi. 2099 AnyEvent::Impl::IOAsync, Anyevent::Impl::Irssi, AnyEvent::Impl::FLTK.
1885 2100
1886 Non-blocking file handles, sockets, TCP clients and servers: 2101 Non-blocking handles, pipes, stream sockets, TCP clients and servers:
1887 AnyEvent::Handle, AnyEvent::Socket, AnyEvent::TLS. 2102 AnyEvent::Handle, AnyEvent::Socket, AnyEvent::TLS.
1888 2103
2104 Asynchronous File I/O: AnyEvent::IO.
2105
1889 Asynchronous DNS: AnyEvent::DNS. 2106 Asynchronous DNS: AnyEvent::DNS.
1890 2107
1891 Coroutine support: Coro, Coro::AnyEvent, Coro::EV, Coro::Event, 2108 Thread support: Coro, Coro::AnyEvent, Coro::EV, Coro::Event.
1892 2109
1893 Nontrivial usage examples: AnyEvent::GPSD, AnyEvent::XMPP, 2110 Nontrivial usage examples: AnyEvent::GPSD, AnyEvent::IRC,
1894 AnyEvent::HTTP. 2111 AnyEvent::HTTP.
1895 2112
1896AUTHOR 2113AUTHOR
1897 Marc Lehmann <schmorp@schmorp.de> 2114 Marc Lehmann <schmorp@schmorp.de>
1898 http://home.schmorp.de/ 2115 http://anyevent.schmorp.de
1899 2116

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