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Revision 1.357 by root, Sat Aug 13 02:20:29 2011 UTC

7 7
8=head1 SYNOPSIS 8=head1 SYNOPSIS
9 9
10 use AnyEvent; 10 use AnyEvent;
11 11
12 # if you prefer function calls, look at the AE manpage for
13 # an alternative API.
14
12 # file descriptor readable 15 # file handle or descriptor readable
13 my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... }); 16 my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
14 17
15 # one-shot or repeating timers 18 # one-shot or repeating timers
16 my $w = AnyEvent->timer (after => $seconds, cb => sub { ... }); 19 my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
17 my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ... 20 my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...);
18 21
19 print AnyEvent->now; # prints current event loop time 22 print AnyEvent->now; # prints current event loop time
20 print AnyEvent->time; # think Time::HiRes::time or simply CORE::time. 23 print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
21 24
22 # POSIX signal 25 # POSIX signal
43in a tutorial or some gentle introduction, have a look at the 46in a tutorial or some gentle introduction, have a look at the
44L<AnyEvent::Intro> manpage. 47L<AnyEvent::Intro> manpage.
45 48
46=head1 SUPPORT 49=head1 SUPPORT
47 50
51An FAQ document is available as L<AnyEvent::FAQ>.
52
48There is a mailinglist for discussing all things AnyEvent, and an IRC 53There also is a mailinglist for discussing all things AnyEvent, and an IRC
49channel, too. 54channel, too.
50 55
51See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software 56See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
52Repository>, at L<http://anyevent.schmorp.de>, for more info. 57Repository>, at L<http://anyevent.schmorp.de>, for more info.
53 58
73module users into the same thing by forcing them to use the same event 78module users into the same thing by forcing them to use the same event
74model you use. 79model you use.
75 80
76For modules like POE or IO::Async (which is a total misnomer as it is 81For modules like POE or IO::Async (which is a total misnomer as it is
77actually doing all I/O I<synchronously>...), using them in your module is 82actually doing all I/O I<synchronously>...), using them in your module is
78like joining a cult: After you joined, you are dependent on them and you 83like joining a cult: After you join, you are dependent on them and you
79cannot use anything else, as they are simply incompatible to everything 84cannot use anything else, as they are simply incompatible to everything
80that isn't them. What's worse, all the potential users of your 85that isn't them. What's worse, all the potential users of your
81module are I<also> forced to use the same event loop you use. 86module are I<also> forced to use the same event loop you use.
82 87
83AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works 88AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
84fine. AnyEvent + Tk works fine etc. etc. but none of these work together 89fine. AnyEvent + Tk works fine etc. etc. but none of these work together
85with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if 90with the rest: POE + EV? No go. Tk + Event? No go. Again: if your module
86your module uses one of those, every user of your module has to use it, 91uses one of those, every user of your module has to use it, too. But if
87too. But if your module uses AnyEvent, it works transparently with all 92your module uses AnyEvent, it works transparently with all event models it
88event models it supports (including stuff like IO::Async, as long as those 93supports (including stuff like IO::Async, as long as those use one of the
89use one of the supported event loops. It is trivial to add new event loops 94supported event loops. It is easy to add new event loops to AnyEvent, too,
90to AnyEvent, too, so it is future-proof). 95so it is future-proof).
91 96
92In addition to being free of having to use I<the one and only true event 97In addition to being free of having to use I<the one and only true event
93model>, AnyEvent also is free of bloat and policy: with POE or similar 98model>, AnyEvent also is free of bloat and policy: with POE or similar
94modules, you get an enormous amount of code and strict rules you have to 99modules, you get an enormous amount of code and strict rules you have to
95follow. AnyEvent, on the other hand, is lean and up to the point, by only 100follow. AnyEvent, on the other hand, is lean and to the point, by only
96offering the functionality that is necessary, in as thin as a wrapper as 101offering the functionality that is necessary, in as thin as a wrapper as
97technically possible. 102technically possible.
98 103
99Of course, AnyEvent comes with a big (and fully optional!) toolbox 104Of course, AnyEvent comes with a big (and fully optional!) toolbox
100of useful functionality, such as an asynchronous DNS resolver, 100% 105of useful functionality, such as an asynchronous DNS resolver, 100%
106useful) and you want to force your users to use the one and only event 111useful) and you want to force your users to use the one and only event
107model, you should I<not> use this module. 112model, you should I<not> use this module.
108 113
109=head1 DESCRIPTION 114=head1 DESCRIPTION
110 115
111L<AnyEvent> provides an identical interface to multiple event loops. This 116L<AnyEvent> provides a uniform interface to various event loops. This
112allows module authors to utilise an event loop without forcing module 117allows module authors to use event loop functionality without forcing
113users to use the same event loop (as only a single event loop can coexist 118module users to use a specific event loop implementation (since more
114peacefully at any one time). 119than one event loop cannot coexist peacefully).
115 120
116The interface itself is vaguely similar, but not identical to the L<Event> 121The interface itself is vaguely similar, but not identical to the L<Event>
117module. 122module.
118 123
119During the first call of any watcher-creation method, the module tries 124During the first call of any watcher-creation method, the module tries
120to detect the currently loaded event loop by probing whether one of the 125to detect the currently loaded event loop by probing whether one of the
121following modules is already loaded: L<EV>, 126following modules is already loaded: L<EV>, L<AnyEvent::Loop>,
122L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>, 127L<Event>, L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. The first one
123L<POE>. The first one found is used. If none are found, the module tries 128found is used. If none are detected, the module tries to load the first
124to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl 129four modules in the order given; but note that if L<EV> is not
125adaptor should always succeed) in the order given. The first one that can 130available, the pure-perl L<AnyEvent::Loop> should always work, so
126be successfully loaded will be used. If, after this, still none could be 131the other two are not normally tried.
127found, AnyEvent will fall back to a pure-perl event loop, which is not
128very efficient, but should work everywhere.
129 132
130Because AnyEvent first checks for modules that are already loaded, loading 133Because AnyEvent first checks for modules that are already loaded, loading
131an event model explicitly before first using AnyEvent will likely make 134an event model explicitly before first using AnyEvent will likely make
132that model the default. For example: 135that model the default. For example:
133 136
135 use AnyEvent; 138 use AnyEvent;
136 139
137 # .. AnyEvent will likely default to Tk 140 # .. AnyEvent will likely default to Tk
138 141
139The I<likely> means that, if any module loads another event model and 142The I<likely> means that, if any module loads another event model and
140starts using it, all bets are off. Maybe you should tell their authors to 143starts using it, all bets are off - this case should be very rare though,
141use AnyEvent so their modules work together with others seamlessly... 144as very few modules hardcode event loops without announcing this very
145loudly.
142 146
143The pure-perl implementation of AnyEvent is called 147The pure-perl implementation of AnyEvent is called C<AnyEvent::Loop>. Like
144C<AnyEvent::Impl::Perl>. Like other event modules you can load it 148other event modules you can load it explicitly and enjoy the high
145explicitly and enjoy the high availability of that event loop :) 149availability of that event loop :)
146 150
147=head1 WATCHERS 151=head1 WATCHERS
148 152
149AnyEvent has the central concept of a I<watcher>, which is an object that 153AnyEvent has the central concept of a I<watcher>, which is an object that
150stores relevant data for each kind of event you are waiting for, such as 154stores relevant data for each kind of event you are waiting for, such as
155callback when the event occurs (of course, only when the event model 159callback when the event occurs (of course, only when the event model
156is in control). 160is in control).
157 161
158Note that B<callbacks must not permanently change global variables> 162Note that B<callbacks must not permanently change global variables>
159potentially in use by the event loop (such as C<$_> or C<$[>) and that B<< 163potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<
160callbacks must not C<die> >>. The former is good programming practise in 164callbacks must not C<die> >>. The former is good programming practice in
161Perl and the latter stems from the fact that exception handling differs 165Perl and the latter stems from the fact that exception handling differs
162widely between event loops. 166widely between event loops.
163 167
164To disable the watcher you have to destroy it (e.g. by setting the 168To disable a watcher you have to destroy it (e.g. by setting the
165variable you store it in to C<undef> or otherwise deleting all references 169variable you store it in to C<undef> or otherwise deleting all references
166to it). 170to it).
167 171
168All watchers are created by calling a method on the C<AnyEvent> class. 172All watchers are created by calling a method on the C<AnyEvent> class.
169 173
170Many watchers either are used with "recursion" (repeating timers for 174Many watchers either are used with "recursion" (repeating timers for
171example), or need to refer to their watcher object in other ways. 175example), or need to refer to their watcher object in other ways.
172 176
173An any way to achieve that is this pattern: 177One way to achieve that is this pattern:
174 178
175 my $w; $w = AnyEvent->type (arg => value ..., cb => sub { 179 my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
176 # you can use $w here, for example to undef it 180 # you can use $w here, for example to undef it
177 undef $w; 181 undef $w;
178 }); 182 });
210 214
211The I/O watcher might use the underlying file descriptor or a copy of it. 215The I/O watcher might use the underlying file descriptor or a copy of it.
212You must not close a file handle as long as any watcher is active on the 216You must not close a file handle as long as any watcher is active on the
213underlying file descriptor. 217underlying file descriptor.
214 218
215Some event loops issue spurious readyness notifications, so you should 219Some event loops issue spurious readiness notifications, so you should
216always use non-blocking calls when reading/writing from/to your file 220always use non-blocking calls when reading/writing from/to your file
217handles. 221handles.
218 222
219Example: wait for readability of STDIN, then read a line and disable the 223Example: wait for readability of STDIN, then read a line and disable the
220watcher. 224watcher.
244 248
245Although the callback might get passed parameters, their value and 249Although the callback might get passed parameters, their value and
246presence is undefined and you cannot rely on them. Portable AnyEvent 250presence is undefined and you cannot rely on them. Portable AnyEvent
247callbacks cannot use arguments passed to time watcher callbacks. 251callbacks cannot use arguments passed to time watcher callbacks.
248 252
249The callback will normally be invoked once only. If you specify another 253The callback will normally be invoked only once. If you specify another
250parameter, C<interval>, as a strictly positive number (> 0), then the 254parameter, C<interval>, as a strictly positive number (> 0), then the
251callback will be invoked regularly at that interval (in fractional 255callback will be invoked regularly at that interval (in fractional
252seconds) after the first invocation. If C<interval> is specified with a 256seconds) after the first invocation. If C<interval> is specified with a
253false value, then it is treated as if it were missing. 257false value, then it is treated as if it were not specified at all.
254 258
255The callback will be rescheduled before invoking the callback, but no 259The callback will be rescheduled before invoking the callback, but no
256attempt is done to avoid timer drift in most backends, so the interval is 260attempt is made to avoid timer drift in most backends, so the interval is
257only approximate. 261only approximate.
258 262
259Example: fire an event after 7.7 seconds. 263Example: fire an event after 7.7 seconds.
260 264
261 my $w = AnyEvent->timer (after => 7.7, cb => sub { 265 my $w = AnyEvent->timer (after => 7.7, cb => sub {
279 283
280While most event loops expect timers to specified in a relative way, they 284While most event loops expect timers to specified in a relative way, they
281use absolute time internally. This makes a difference when your clock 285use absolute time internally. This makes a difference when your clock
282"jumps", for example, when ntp decides to set your clock backwards from 286"jumps", for example, when ntp decides to set your clock backwards from
283the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to 287the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to
284fire "after" a second might actually take six years to finally fire. 288fire "after a second" might actually take six years to finally fire.
285 289
286AnyEvent cannot compensate for this. The only event loop that is conscious 290AnyEvent cannot compensate for this. The only event loop that is conscious
287about these issues is L<EV>, which offers both relative (ev_timer, based 291of these issues is L<EV>, which offers both relative (ev_timer, based
288on true relative time) and absolute (ev_periodic, based on wallclock time) 292on true relative time) and absolute (ev_periodic, based on wallclock time)
289timers. 293timers.
290 294
291AnyEvent always prefers relative timers, if available, matching the 295AnyEvent always prefers relative timers, if available, matching the
292AnyEvent API. 296AnyEvent API.
314I<In almost all cases (in all cases if you don't care), this is the 318I<In almost all cases (in all cases if you don't care), this is the
315function to call when you want to know the current time.> 319function to call when you want to know the current time.>
316 320
317This function is also often faster then C<< AnyEvent->time >>, and 321This function is also often faster then C<< AnyEvent->time >>, and
318thus the preferred method if you want some timestamp (for example, 322thus the preferred method if you want some timestamp (for example,
319L<AnyEvent::Handle> uses this to update it's activity timeouts). 323L<AnyEvent::Handle> uses this to update its activity timeouts).
320 324
321The rest of this section is only of relevance if you try to be very exact 325The rest of this section is only of relevance if you try to be very exact
322with your timing, you can skip it without bad conscience. 326with your timing; you can skip it without a bad conscience.
323 327
324For a practical example of when these times differ, consider L<Event::Lib> 328For a practical example of when these times differ, consider L<Event::Lib>
325and L<EV> and the following set-up: 329and L<EV> and the following set-up:
326 330
327The event loop is running and has just invoked one of your callback at 331The event loop is running and has just invoked one of your callbacks at
328time=500 (assume no other callbacks delay processing). In your callback, 332time=500 (assume no other callbacks delay processing). In your callback,
329you wait a second by executing C<sleep 1> (blocking the process for a 333you wait a second by executing C<sleep 1> (blocking the process for a
330second) and then (at time=501) you create a relative timer that fires 334second) and then (at time=501) you create a relative timer that fires
331after three seconds. 335after three seconds.
332 336
352difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into 356difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
353account. 357account.
354 358
355=item AnyEvent->now_update 359=item AnyEvent->now_update
356 360
357Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache 361Some event loops (such as L<EV> or L<AnyEvent::Loop>) cache the current
358the current time for each loop iteration (see the discussion of L<< 362time for each loop iteration (see the discussion of L<< AnyEvent->now >>,
359AnyEvent->now >>, above). 363above).
360 364
361When a callback runs for a long time (or when the process sleeps), then 365When a callback runs for a long time (or when the process sleeps), then
362this "current" time will differ substantially from the real time, which 366this "current" time will differ substantially from the real time, which
363might affect timers and time-outs. 367might affect timers and time-outs.
364 368
403 407
404Example: exit on SIGINT 408Example: exit on SIGINT
405 409
406 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); 410 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
407 411
412=head3 Restart Behaviour
413
414While restart behaviour is up to the event loop implementation, most will
415not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
416pure perl implementation).
417
418=head3 Safe/Unsafe Signals
419
420Perl signals can be either "safe" (synchronous to opcode handling) or
421"unsafe" (asynchronous) - the former might get delayed indefinitely, the
422latter might corrupt your memory.
423
424AnyEvent signal handlers are, in addition, synchronous to the event loop,
425i.e. they will not interrupt your running perl program but will only be
426called as part of the normal event handling (just like timer, I/O etc.
427callbacks, too).
428
408=head3 Signal Races, Delays and Workarounds 429=head3 Signal Races, Delays and Workarounds
409 430
410Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching 431Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
411callbacks to signals in a generic way, which is a pity, as you cannot 432callbacks to signals in a generic way, which is a pity, as you cannot
412do race-free signal handling in perl, requiring C libraries for 433do race-free signal handling in perl, requiring C libraries for
413this. AnyEvent will try to do it's best, which means in some cases, 434this. AnyEvent will try to do its best, which means in some cases,
414signals will be delayed. The maximum time a signal might be delayed is 435signals will be delayed. The maximum time a signal might be delayed is
415specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This 436specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
416variable can be changed only before the first signal watcher is created, 437variable can be changed only before the first signal watcher is created,
417and should be left alone otherwise. This variable determines how often 438and should be left alone otherwise. This variable determines how often
418AnyEvent polls for signals (in case a wake-up was missed). Higher values 439AnyEvent polls for signals (in case a wake-up was missed). Higher values
420saving. 441saving.
421 442
422All these problems can be avoided by installing the optional 443All these problems can be avoided by installing the optional
423L<Async::Interrupt> module, which works with most event loops. It will not 444L<Async::Interrupt> module, which works with most event loops. It will not
424work with inherently broken event loops such as L<Event> or L<Event::Lib> 445work with inherently broken event loops such as L<Event> or L<Event::Lib>
425(and not with L<POE> currently, as POE does it's own workaround with 446(and not with L<POE> currently, as POE does its own workaround with
426one-second latency). For those, you just have to suffer the delays. 447one-second latency). For those, you just have to suffer the delays.
427 448
428=head2 CHILD PROCESS WATCHERS 449=head2 CHILD PROCESS WATCHERS
429 450
430 $w = AnyEvent->child (pid => <process id>, cb => <callback>); 451 $w = AnyEvent->child (pid => <process id>, cb => <callback>);
431 452
432You can also watch on a child process exit and catch its exit status. 453You can also watch for a child process exit and catch its exit status.
433 454
434The child process is specified by the C<pid> argument (one some backends, 455The child process is specified by the C<pid> argument (on some backends,
435using C<0> watches for any child process exit, on others this will 456using C<0> watches for any child process exit, on others this will
436croak). The watcher will be triggered only when the child process has 457croak). The watcher will be triggered only when the child process has
437finished and an exit status is available, not on any trace events 458finished and an exit status is available, not on any trace events
438(stopped/continued). 459(stopped/continued).
439 460
461thing in an AnyEvent program, you I<have> to create at least one 482thing in an AnyEvent program, you I<have> to create at least one
462watcher before you C<fork> the child (alternatively, you can call 483watcher before you C<fork> the child (alternatively, you can call
463C<AnyEvent::detect>). 484C<AnyEvent::detect>).
464 485
465As most event loops do not support waiting for child events, they will be 486As most event loops do not support waiting for child events, they will be
466emulated by AnyEvent in most cases, in which the latency and race problems 487emulated by AnyEvent in most cases, in which case the latency and race
467mentioned in the description of signal watchers apply. 488problems mentioned in the description of signal watchers apply.
468 489
469Example: fork a process and wait for it 490Example: fork a process and wait for it
470 491
471 my $done = AnyEvent->condvar; 492 my $done = AnyEvent->condvar;
472 493
486 507
487=head2 IDLE WATCHERS 508=head2 IDLE WATCHERS
488 509
489 $w = AnyEvent->idle (cb => <callback>); 510 $w = AnyEvent->idle (cb => <callback>);
490 511
491Sometimes there is a need to do something, but it is not so important 512This will repeatedly invoke the callback after the process becomes idle,
492to do it instantly, but only when there is nothing better to do. This 513until either the watcher is destroyed or new events have been detected.
493"nothing better to do" is usually defined to be "no other events need
494attention by the event loop".
495 514
496Idle watchers ideally get invoked when the event loop has nothing 515Idle watchers are useful when there is a need to do something, but it
497better to do, just before it would block the process to wait for new 516is not so important (or wise) to do it instantly. The callback will be
498events. Instead of blocking, the idle watcher is invoked. 517invoked only when there is "nothing better to do", which is usually
518defined as "all outstanding events have been handled and no new events
519have been detected". That means that idle watchers ideally get invoked
520when the event loop has just polled for new events but none have been
521detected. Instead of blocking to wait for more events, the idle watchers
522will be invoked.
499 523
500Most event loops unfortunately do not really support idle watchers (only 524Unfortunately, most event loops do not really support idle watchers (only
501EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent 525EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
502will simply call the callback "from time to time". 526will simply call the callback "from time to time".
503 527
504Example: read lines from STDIN, but only process them when the 528Example: read lines from STDIN, but only process them when the
505program is otherwise idle: 529program is otherwise idle:
533will actively watch for new events and call your callbacks. 557will actively watch for new events and call your callbacks.
534 558
535AnyEvent is slightly different: it expects somebody else to run the event 559AnyEvent is slightly different: it expects somebody else to run the event
536loop and will only block when necessary (usually when told by the user). 560loop and will only block when necessary (usually when told by the user).
537 561
538The instrument to do that is called a "condition variable", so called 562The tool to do that is called a "condition variable", so called because
539because they represent a condition that must become true. 563they represent a condition that must become true.
540 564
541Now is probably a good time to look at the examples further below. 565Now is probably a good time to look at the examples further below.
542 566
543Condition variables can be created by calling the C<< AnyEvent->condvar 567Condition variables can be created by calling the C<< AnyEvent->condvar
544>> method, usually without arguments. The only argument pair allowed is 568>> method, usually without arguments. The only argument pair allowed is
549After creation, the condition variable is "false" until it becomes "true" 573After creation, the condition variable is "false" until it becomes "true"
550by calling the C<send> method (or calling the condition variable as if it 574by calling the C<send> method (or calling the condition variable as if it
551were a callback, read about the caveats in the description for the C<< 575were a callback, read about the caveats in the description for the C<<
552->send >> method). 576->send >> method).
553 577
554Condition variables are similar to callbacks, except that you can 578Since condition variables are the most complex part of the AnyEvent API, here are
555optionally wait for them. They can also be called merge points - points 579some different mental models of what they are - pick the ones you can connect to:
556in time where multiple outstanding events have been processed. And yet 580
557another way to call them is transactions - each condition variable can be 581=over 4
558used to represent a transaction, which finishes at some point and delivers 582
559a result. And yet some people know them as "futures" - a promise to 583=item * Condition variables are like callbacks - you can call them (and pass them instead
560compute/deliver something that you can wait for. 584of callbacks). Unlike callbacks however, you can also wait for them to be called.
585
586=item * Condition variables are signals - one side can emit or send them,
587the other side can wait for them, or install a handler that is called when
588the signal fires.
589
590=item * Condition variables are like "Merge Points" - points in your program
591where you merge multiple independent results/control flows into one.
592
593=item * Condition variables represent a transaction - functions that start
594some kind of transaction can return them, leaving the caller the choice
595between waiting in a blocking fashion, or setting a callback.
596
597=item * Condition variables represent future values, or promises to deliver
598some result, long before the result is available.
599
600=back
561 601
562Condition variables are very useful to signal that something has finished, 602Condition variables are very useful to signal that something has finished,
563for example, if you write a module that does asynchronous http requests, 603for example, if you write a module that does asynchronous http requests,
564then a condition variable would be the ideal candidate to signal the 604then a condition variable would be the ideal candidate to signal the
565availability of results. The user can either act when the callback is 605availability of results. The user can either act when the callback is
578 618
579Condition variables are represented by hash refs in perl, and the keys 619Condition variables are represented by hash refs in perl, and the keys
580used by AnyEvent itself are all named C<_ae_XXX> to make subclassing 620used by AnyEvent itself are all named C<_ae_XXX> to make subclassing
581easy (it is often useful to build your own transaction class on top of 621easy (it is often useful to build your own transaction class on top of
582AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call 622AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call
583it's C<new> method in your own C<new> method. 623its C<new> method in your own C<new> method.
584 624
585There are two "sides" to a condition variable - the "producer side" which 625There are two "sides" to a condition variable - the "producer side" which
586eventually calls C<< -> send >>, and the "consumer side", which waits 626eventually calls C<< -> send >>, and the "consumer side", which waits
587for the send to occur. 627for the send to occur.
588 628
589Example: wait for a timer. 629Example: wait for a timer.
590 630
591 # wait till the result is ready 631 # condition: "wait till the timer is fired"
592 my $result_ready = AnyEvent->condvar; 632 my $timer_fired = AnyEvent->condvar;
593 633
594 # do something such as adding a timer 634 # create the timer - we could wait for, say
595 # or socket watcher the calls $result_ready->send 635 # a handle becomign ready, or even an
596 # when the "result" is ready. 636 # AnyEvent::HTTP request to finish, but
597 # in this case, we simply use a timer: 637 # in this case, we simply use a timer:
598 my $w = AnyEvent->timer ( 638 my $w = AnyEvent->timer (
599 after => 1, 639 after => 1,
600 cb => sub { $result_ready->send }, 640 cb => sub { $timer_fired->send },
601 ); 641 );
602 642
603 # this "blocks" (while handling events) till the callback 643 # this "blocks" (while handling events) till the callback
604 # calls ->send 644 # calls ->send
605 $result_ready->recv; 645 $timer_fired->recv;
606 646
607Example: wait for a timer, but take advantage of the fact that condition 647Example: wait for a timer, but take advantage of the fact that condition
608variables are also callable directly. 648variables are also callable directly.
609 649
610 my $done = AnyEvent->condvar; 650 my $done = AnyEvent->condvar;
653they were a code reference). Calling them directly is the same as calling 693they were a code reference). Calling them directly is the same as calling
654C<send>. 694C<send>.
655 695
656=item $cv->croak ($error) 696=item $cv->croak ($error)
657 697
658Similar to send, but causes all call's to C<< ->recv >> to invoke 698Similar to send, but causes all calls to C<< ->recv >> to invoke
659C<Carp::croak> with the given error message/object/scalar. 699C<Carp::croak> with the given error message/object/scalar.
660 700
661This can be used to signal any errors to the condition variable 701This can be used to signal any errors to the condition variable
662user/consumer. Doing it this way instead of calling C<croak> directly 702user/consumer. Doing it this way instead of calling C<croak> directly
663delays the error detetcion, but has the overwhelmign advantage that it 703delays the error detection, but has the overwhelming advantage that it
664diagnoses the error at the place where the result is expected, and not 704diagnoses the error at the place where the result is expected, and not
665deep in some event clalback without connection to the actual code causing 705deep in some event callback with no connection to the actual code causing
666the problem. 706the problem.
667 707
668=item $cv->begin ([group callback]) 708=item $cv->begin ([group callback])
669 709
670=item $cv->end 710=item $cv->end
708one call to C<begin>, so the condvar waits for all calls to C<end> before 748one call to C<begin>, so the condvar waits for all calls to C<end> before
709sending. 749sending.
710 750
711The ping example mentioned above is slightly more complicated, as the 751The ping example mentioned above is slightly more complicated, as the
712there are results to be passwd back, and the number of tasks that are 752there are results to be passwd back, and the number of tasks that are
713begung can potentially be zero: 753begun can potentially be zero:
714 754
715 my $cv = AnyEvent->condvar; 755 my $cv = AnyEvent->condvar;
716 756
717 my %result; 757 my %result;
718 $cv->begin (sub { shift->send (\%result) }); 758 $cv->begin (sub { shift->send (\%result) });
739to be called once the counter reaches C<0>, and second, it ensures that 779to be called once the counter reaches C<0>, and second, it ensures that
740C<send> is called even when C<no> hosts are being pinged (the loop 780C<send> is called even when C<no> hosts are being pinged (the loop
741doesn't execute once). 781doesn't execute once).
742 782
743This is the general pattern when you "fan out" into multiple (but 783This is the general pattern when you "fan out" into multiple (but
744potentially none) subrequests: use an outer C<begin>/C<end> pair to set 784potentially zero) subrequests: use an outer C<begin>/C<end> pair to set
745the callback and ensure C<end> is called at least once, and then, for each 785the callback and ensure C<end> is called at least once, and then, for each
746subrequest you start, call C<begin> and for each subrequest you finish, 786subrequest you start, call C<begin> and for each subrequest you finish,
747call C<end>. 787call C<end>.
748 788
749=back 789=back
756=over 4 796=over 4
757 797
758=item $cv->recv 798=item $cv->recv
759 799
760Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak 800Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
761>> methods have been called on c<$cv>, while servicing other watchers 801>> methods have been called on C<$cv>, while servicing other watchers
762normally. 802normally.
763 803
764You can only wait once on a condition - additional calls are valid but 804You can only wait once on a condition - additional calls are valid but
765will return immediately. 805will return immediately.
766 806
783caller decide whether the call will block or not (for example, by coupling 823caller decide whether the call will block or not (for example, by coupling
784condition variables with some kind of request results and supporting 824condition variables with some kind of request results and supporting
785callbacks so the caller knows that getting the result will not block, 825callbacks so the caller knows that getting the result will not block,
786while still supporting blocking waits if the caller so desires). 826while still supporting blocking waits if the caller so desires).
787 827
788You can ensure that C<< -recv >> never blocks by setting a callback and 828You can ensure that C<< ->recv >> never blocks by setting a callback and
789only calling C<< ->recv >> from within that callback (or at a later 829only calling C<< ->recv >> from within that callback (or at a later
790time). This will work even when the event loop does not support blocking 830time). This will work even when the event loop does not support blocking
791waits otherwise. 831waits otherwise.
792 832
793=item $bool = $cv->ready 833=item $bool = $cv->ready
798=item $cb = $cv->cb ($cb->($cv)) 838=item $cb = $cv->cb ($cb->($cv))
799 839
800This is a mutator function that returns the callback set and optionally 840This is a mutator function that returns the callback set and optionally
801replaces it before doing so. 841replaces it before doing so.
802 842
803The callback will be called when the condition becomes (or already was) 843The callback will be called when the condition becomes "true", i.e. when
804"true", i.e. when C<send> or C<croak> are called (or were called), with 844C<send> or C<croak> are called, with the only argument being the
805the only argument being the condition variable itself. Calling C<recv> 845condition variable itself. If the condition is already true, the
846callback is called immediately when it is set. Calling C<recv> inside
806inside the callback or at any later time is guaranteed not to block. 847the callback or at any later time is guaranteed not to block.
807 848
808=back 849=back
809 850
810=head1 SUPPORTED EVENT LOOPS/BACKENDS 851=head1 SUPPORTED EVENT LOOPS/BACKENDS
811 852
819use. If EV is not installed, then AnyEvent will fall back to its own 860use. If EV is not installed, then AnyEvent will fall back to its own
820pure-perl implementation, which is available everywhere as it comes with 861pure-perl implementation, which is available everywhere as it comes with
821AnyEvent itself. 862AnyEvent itself.
822 863
823 AnyEvent::Impl::EV based on EV (interface to libev, best choice). 864 AnyEvent::Impl::EV based on EV (interface to libev, best choice).
824 AnyEvent::Impl::Perl pure-perl implementation, fast and portable. 865 AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
825 866
826=item Backends that are transparently being picked up when they are used. 867=item Backends that are transparently being picked up when they are used.
827 868
828These will be used when they are currently loaded when the first watcher 869These will be used if they are already loaded when the first watcher
829is created, in which case it is assumed that the application is using 870is created, in which case it is assumed that the application is using
830them. This means that AnyEvent will automatically pick the right backend 871them. This means that AnyEvent will automatically pick the right backend
831when the main program loads an event module before anything starts to 872when the main program loads an event module before anything starts to
832create watchers. Nothing special needs to be done by the main program. 873create watchers. Nothing special needs to be done by the main program.
833 874
835 AnyEvent::Impl::Glib based on Glib, slow but very stable. 876 AnyEvent::Impl::Glib based on Glib, slow but very stable.
836 AnyEvent::Impl::Tk based on Tk, very broken. 877 AnyEvent::Impl::Tk based on Tk, very broken.
837 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. 878 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
838 AnyEvent::Impl::POE based on POE, very slow, some limitations. 879 AnyEvent::Impl::POE based on POE, very slow, some limitations.
839 AnyEvent::Impl::Irssi used when running within irssi. 880 AnyEvent::Impl::Irssi used when running within irssi.
881 AnyEvent::Impl::IOAsync based on IO::Async.
882 AnyEvent::Impl::Cocoa based on Cocoa::EventLoop.
883 AnyEvent::Impl::FLTK2 based on FLTK (fltk 2 binding).
840 884
841=item Backends with special needs. 885=item Backends with special needs.
842 886
843Qt requires the Qt::Application to be instantiated first, but will 887Qt requires the Qt::Application to be instantiated first, but will
844otherwise be picked up automatically. As long as the main program 888otherwise be picked up automatically. As long as the main program
845instantiates the application before any AnyEvent watchers are created, 889instantiates the application before any AnyEvent watchers are created,
846everything should just work. 890everything should just work.
847 891
848 AnyEvent::Impl::Qt based on Qt. 892 AnyEvent::Impl::Qt based on Qt.
849 893
850Support for IO::Async can only be partial, as it is too broken and
851architecturally limited to even support the AnyEvent API. It also
852is the only event loop that needs the loop to be set explicitly, so
853it can only be used by a main program knowing about AnyEvent. See
854L<AnyEvent::Impl::Async> for the gory details.
855
856 AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
857
858=item Event loops that are indirectly supported via other backends. 894=item Event loops that are indirectly supported via other backends.
859 895
860Some event loops can be supported via other modules: 896Some event loops can be supported via other modules:
861 897
862There is no direct support for WxWidgets (L<Wx>) or L<Prima>. 898There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
887Contains C<undef> until the first watcher is being created, before the 923Contains C<undef> until the first watcher is being created, before the
888backend has been autodetected. 924backend has been autodetected.
889 925
890Afterwards it contains the event model that is being used, which is the 926Afterwards it contains the event model that is being used, which is the
891name of the Perl class implementing the model. This class is usually one 927name of the Perl class implementing the model. This class is usually one
892of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the 928of the C<AnyEvent::Impl::xxx> modules, but can be any other class in the
893case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it 929case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
894will be C<urxvt::anyevent>). 930will be C<urxvt::anyevent>).
895 931
896=item AnyEvent::detect 932=item AnyEvent::detect
897 933
898Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model 934Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
899if necessary. You should only call this function right before you would 935if necessary. You should only call this function right before you would
900have created an AnyEvent watcher anyway, that is, as late as possible at 936have created an AnyEvent watcher anyway, that is, as late as possible at
901runtime, and not e.g. while initialising of your module. 937runtime, and not e.g. during initialisation of your module.
902 938
903If you need to do some initialisation before AnyEvent watchers are 939If you need to do some initialisation before AnyEvent watchers are
904created, use C<post_detect>. 940created, use C<post_detect>.
905 941
906=item $guard = AnyEvent::post_detect { BLOCK } 942=item $guard = AnyEvent::post_detect { BLOCK }
907 943
908Arranges for the code block to be executed as soon as the event model is 944Arranges for the code block to be executed as soon as the event model is
909autodetected (or immediately if this has already happened). 945autodetected (or immediately if that has already happened).
910 946
911The block will be executed I<after> the actual backend has been detected 947The block will be executed I<after> the actual backend has been detected
912(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been 948(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
913created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do 949created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
914other initialisations - see the sources of L<AnyEvent::Strict> or 950other initialisations - see the sources of L<AnyEvent::Strict> or
923that automatically removes the callback again when it is destroyed (or 959that automatically removes the callback again when it is destroyed (or
924C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for 960C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
925a case where this is useful. 961a case where this is useful.
926 962
927Example: Create a watcher for the IO::AIO module and store it in 963Example: Create a watcher for the IO::AIO module and store it in
928C<$WATCHER>. Only do so after the event loop is initialised, though. 964C<$WATCHER>, but do so only do so after the event loop is initialised.
929 965
930 our WATCHER; 966 our WATCHER;
931 967
932 my $guard = AnyEvent::post_detect { 968 my $guard = AnyEvent::post_detect {
933 $WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb); 969 $WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
941 $WATCHER ||= $guard; 977 $WATCHER ||= $guard;
942 978
943=item @AnyEvent::post_detect 979=item @AnyEvent::post_detect
944 980
945If there are any code references in this array (you can C<push> to it 981If there are any code references in this array (you can C<push> to it
946before or after loading AnyEvent), then they will called directly after 982before or after loading AnyEvent), then they will be called directly
947the event loop has been chosen. 983after the event loop has been chosen.
948 984
949You should check C<$AnyEvent::MODEL> before adding to this array, though: 985You should check C<$AnyEvent::MODEL> before adding to this array, though:
950if it is defined then the event loop has already been detected, and the 986if it is defined then the event loop has already been detected, and the
951array will be ignored. 987array will be ignored.
952 988
953Best use C<AnyEvent::post_detect { BLOCK }> when your application allows 989Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
954it,as it takes care of these details. 990it, as it takes care of these details.
955 991
956This variable is mainly useful for modules that can do something useful 992This variable is mainly useful for modules that can do something useful
957when AnyEvent is used and thus want to know when it is initialised, but do 993when AnyEvent is used and thus want to know when it is initialised, but do
958not need to even load it by default. This array provides the means to hook 994not need to even load it by default. This array provides the means to hook
959into AnyEvent passively, without loading it. 995into AnyEvent passively, without loading it.
960 996
997Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
998together, you could put this into Coro (this is the actual code used by
999Coro to accomplish this):
1000
1001 if (defined $AnyEvent::MODEL) {
1002 # AnyEvent already initialised, so load Coro::AnyEvent
1003 require Coro::AnyEvent;
1004 } else {
1005 # AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
1006 # as soon as it is
1007 push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
1008 }
1009
1010=item AnyEvent::postpone { BLOCK }
1011
1012Arranges for the block to be executed as soon as possible, but not before
1013the call itself returns. In practise, the block will be executed just
1014before the event loop polls for new events, or shortly afterwards.
1015
1016This function never returns anything (to make the C<return postpone { ...
1017}> idiom more useful.
1018
1019To understand the usefulness of this function, consider a function that
1020asynchronously does something for you and returns some transaction
1021object or guard to let you cancel the operation. For example,
1022C<AnyEvent::Socket::tcp_connect>:
1023
1024 # start a conenction attempt unless one is active
1025 $self->{connect_guard} ||= AnyEvent::Socket::tcp_connect "www.example.net", 80, sub {
1026 delete $self->{connect_guard};
1027 ...
1028 };
1029
1030Imagine that this function could instantly call the callback, for
1031example, because it detects an obvious error such as a negative port
1032number. Invoking the callback before the function returns causes problems
1033however: the callback will be called and will try to delete the guard
1034object. But since the function hasn't returned yet, there is nothing to
1035delete. When the function eventually returns it will assign the guard
1036object to C<< $self->{connect_guard} >>, where it will likely never be
1037deleted, so the program thinks it is still trying to connect.
1038
1039This is where C<AnyEvent::postpone> should be used. Instead of calling the
1040callback directly on error:
1041
1042 $cb->(undef), return # signal error to callback, BAD!
1043 if $some_error_condition;
1044
1045It should use C<postpone>:
1046
1047 AnyEvent::postpone { $cb->(undef) }, return # signal error to callback, later
1048 if $some_error_condition;
1049
961=back 1050=back
962 1051
963=head1 WHAT TO DO IN A MODULE 1052=head1 WHAT TO DO IN A MODULE
964 1053
965As a module author, you should C<use AnyEvent> and call AnyEvent methods 1054As a module author, you should C<use AnyEvent> and call AnyEvent methods
975because it will stall the whole program, and the whole point of using 1064because it will stall the whole program, and the whole point of using
976events is to stay interactive. 1065events is to stay interactive.
977 1066
978It is fine, however, to call C<< ->recv >> when the user of your module 1067It is fine, however, to call C<< ->recv >> when the user of your module
979requests it (i.e. if you create a http request object ad have a method 1068requests it (i.e. if you create a http request object ad have a method
980called C<results> that returns the results, it should call C<< ->recv >> 1069called C<results> that returns the results, it may call C<< ->recv >>
981freely, as the user of your module knows what she is doing. always). 1070freely, as the user of your module knows what she is doing. Always).
982 1071
983=head1 WHAT TO DO IN THE MAIN PROGRAM 1072=head1 WHAT TO DO IN THE MAIN PROGRAM
984 1073
985There will always be a single main program - the only place that should 1074There will always be a single main program - the only place that should
986dictate which event model to use. 1075dictate which event model to use.
987 1076
988If it doesn't care, it can just "use AnyEvent" and use it itself, or not 1077If the program is not event-based, it need not do anything special, even
989do anything special (it does not need to be event-based) and let AnyEvent 1078when it depends on a module that uses an AnyEvent. If the program itself
990decide which implementation to chose if some module relies on it. 1079uses AnyEvent, but does not care which event loop is used, all it needs
1080to do is C<use AnyEvent>. In either case, AnyEvent will choose the best
1081available loop implementation.
991 1082
992If the main program relies on a specific event model - for example, in 1083If the main program relies on a specific event model - for example, in
993Gtk2 programs you have to rely on the Glib module - you should load the 1084Gtk2 programs you have to rely on the Glib module - you should load the
994event module before loading AnyEvent or any module that uses it: generally 1085event module before loading AnyEvent or any module that uses it: generally
995speaking, you should load it as early as possible. The reason is that 1086speaking, you should load it as early as possible. The reason is that
996modules might create watchers when they are loaded, and AnyEvent will 1087modules might create watchers when they are loaded, and AnyEvent will
997decide on the event model to use as soon as it creates watchers, and it 1088decide on the event model to use as soon as it creates watchers, and it
998might chose the wrong one unless you load the correct one yourself. 1089might choose the wrong one unless you load the correct one yourself.
999 1090
1000You can chose to use a pure-perl implementation by loading the 1091You can chose to use a pure-perl implementation by loading the
1001C<AnyEvent::Impl::Perl> module, which gives you similar behaviour 1092C<AnyEvent::Loop> module, which gives you similar behaviour
1002everywhere, but letting AnyEvent chose the model is generally better. 1093everywhere, but letting AnyEvent chose the model is generally better.
1003 1094
1004=head2 MAINLOOP EMULATION 1095=head2 MAINLOOP EMULATION
1005 1096
1006Sometimes (often for short test scripts, or even standalone programs who 1097Sometimes (often for short test scripts, or even standalone programs who
1021=head1 OTHER MODULES 1112=head1 OTHER MODULES
1022 1113
1023The following is a non-exhaustive list of additional modules that use 1114The following is a non-exhaustive list of additional modules that use
1024AnyEvent as a client and can therefore be mixed easily with other AnyEvent 1115AnyEvent as a client and can therefore be mixed easily with other AnyEvent
1025modules and other event loops in the same program. Some of the modules 1116modules and other event loops in the same program. Some of the modules
1026come with AnyEvent, most are available via CPAN. 1117come as part of AnyEvent, the others are available via CPAN.
1027 1118
1028=over 4 1119=over 4
1029 1120
1030=item L<AnyEvent::Util> 1121=item L<AnyEvent::Util>
1031 1122
1032Contains various utility functions that replace often-used but blocking 1123Contains various utility functions that replace often-used blocking
1033functions such as C<inet_aton> by event-/callback-based versions. 1124functions such as C<inet_aton> with event/callback-based versions.
1034 1125
1035=item L<AnyEvent::Socket> 1126=item L<AnyEvent::Socket>
1036 1127
1037Provides various utility functions for (internet protocol) sockets, 1128Provides various utility functions for (internet protocol) sockets,
1038addresses and name resolution. Also functions to create non-blocking tcp 1129addresses and name resolution. Also functions to create non-blocking tcp
1040 1131
1041=item L<AnyEvent::Handle> 1132=item L<AnyEvent::Handle>
1042 1133
1043Provide read and write buffers, manages watchers for reads and writes, 1134Provide read and write buffers, manages watchers for reads and writes,
1044supports raw and formatted I/O, I/O queued and fully transparent and 1135supports raw and formatted I/O, I/O queued and fully transparent and
1045non-blocking SSL/TLS (via L<AnyEvent::TLS>. 1136non-blocking SSL/TLS (via L<AnyEvent::TLS>).
1046 1137
1047=item L<AnyEvent::DNS> 1138=item L<AnyEvent::DNS>
1048 1139
1049Provides rich asynchronous DNS resolver capabilities. 1140Provides rich asynchronous DNS resolver capabilities.
1050 1141
1142=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
1143
1144Implement event-based interfaces to the protocols of the same name (for
1145the curious, IGS is the International Go Server and FCP is the Freenet
1146Client Protocol).
1147
1148=item L<AnyEvent::Handle::UDP>
1149
1150Here be danger!
1151
1152As Pauli would put it, "Not only is it not right, it's not even wrong!" -
1153there are so many things wrong with AnyEvent::Handle::UDP, most notably
1154its use of a stream-based API with a protocol that isn't streamable, that
1155the only way to improve it is to delete it.
1156
1157It features data corruption (but typically only under load) and general
1158confusion. On top, the author is not only clueless about UDP but also
1159fact-resistant - some gems of his understanding: "connect doesn't work
1160with UDP", "UDP packets are not IP packets", "UDP only has datagrams, not
1161packets", "I don't need to implement proper error checking as UDP doesn't
1162support error checking" and so on - he doesn't even understand what's
1163wrong with his module when it is explained to him.
1164
1051=item L<AnyEvent::HTTP> 1165=item L<AnyEvent::DBI>
1052 1166
1053A simple-to-use HTTP library that is capable of making a lot of concurrent 1167Executes L<DBI> requests asynchronously in a proxy process for you,
1054HTTP requests. 1168notifying you in an event-based way when the operation is finished.
1169
1170=item L<AnyEvent::AIO>
1171
1172Truly asynchronous (as opposed to non-blocking) I/O, should be in the
1173toolbox of every event programmer. AnyEvent::AIO transparently fuses
1174L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
1175file I/O, and much more.
1055 1176
1056=item L<AnyEvent::HTTPD> 1177=item L<AnyEvent::HTTPD>
1057 1178
1058Provides a simple web application server framework. 1179A simple embedded webserver.
1059 1180
1060=item L<AnyEvent::FastPing> 1181=item L<AnyEvent::FastPing>
1061 1182
1062The fastest ping in the west. 1183The fastest ping in the west.
1063
1064=item L<AnyEvent::DBI>
1065
1066Executes L<DBI> requests asynchronously in a proxy process.
1067
1068=item L<AnyEvent::AIO>
1069
1070Truly asynchronous I/O, should be in the toolbox of every event
1071programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1072together.
1073
1074=item L<AnyEvent::BDB>
1075
1076Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1077L<BDB> and AnyEvent together.
1078
1079=item L<AnyEvent::GPSD>
1080
1081A non-blocking interface to gpsd, a daemon delivering GPS information.
1082
1083=item L<AnyEvent::IRC>
1084
1085AnyEvent based IRC client module family (replacing the older Net::IRC3).
1086
1087=item L<AnyEvent::XMPP>
1088
1089AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1090Net::XMPP2>.
1091
1092=item L<AnyEvent::IGS>
1093
1094A non-blocking interface to the Internet Go Server protocol (used by
1095L<App::IGS>).
1096
1097=item L<Net::FCP>
1098
1099AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1100of AnyEvent.
1101
1102=item L<Event::ExecFlow>
1103
1104High level API for event-based execution flow control.
1105 1184
1106=item L<Coro> 1185=item L<Coro>
1107 1186
1108Has special support for AnyEvent via L<Coro::AnyEvent>. 1187Has special support for AnyEvent via L<Coro::AnyEvent>.
1109 1188
1113 1192
1114package AnyEvent; 1193package AnyEvent;
1115 1194
1116# basically a tuned-down version of common::sense 1195# basically a tuned-down version of common::sense
1117sub common_sense { 1196sub common_sense {
1118 # from common:.sense 1.0 1197 # from common:.sense 3.4
1119 ${^WARNING_BITS} = "\xfc\x3f\xf3\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x03"; 1198 ${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
1120 # use strict vars subs 1199 # use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1121 $^H |= 0x00000600; 1200 $^H |= 0x00000600;
1122} 1201}
1123 1202
1124BEGIN { AnyEvent::common_sense } 1203BEGIN { AnyEvent::common_sense }
1125 1204
1126use Carp (); 1205use Carp ();
1127 1206
1128our $VERSION = '5.202'; 1207our $VERSION = '5.34';
1129our $MODEL; 1208our $MODEL;
1130 1209
1131our $AUTOLOAD;
1132our @ISA; 1210our @ISA;
1133 1211
1134our @REGISTRY; 1212our @REGISTRY;
1135 1213
1136our $WIN32;
1137
1138our $VERBOSE; 1214our $VERBOSE;
1139 1215
1140BEGIN { 1216BEGIN {
1141 eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; 1217 require "AnyEvent/constants.pl";
1218
1142 eval "sub TAINT(){ " . (${^TAINT}*1) . " }"; 1219 eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1143 1220
1144 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} 1221 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1145 if ${^TAINT}; 1222 if ${^TAINT};
1146 1223
1147 $VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1; 1224 $VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
1157 $PROTOCOL{$_} = ++$idx 1234 $PROTOCOL{$_} = ++$idx
1158 for reverse split /\s*,\s*/, 1235 for reverse split /\s*,\s*/,
1159 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; 1236 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1160} 1237}
1161 1238
1239our @post_detect;
1240
1241sub post_detect(&) {
1242 my ($cb) = @_;
1243
1244 push @post_detect, $cb;
1245
1246 defined wantarray
1247 ? bless \$cb, "AnyEvent::Util::postdetect"
1248 : ()
1249}
1250
1251sub AnyEvent::Util::postdetect::DESTROY {
1252 @post_detect = grep $_ != ${$_[0]}, @post_detect;
1253}
1254
1255our $POSTPONE_W;
1256our @POSTPONE;
1257
1258sub _postpone_exec {
1259 undef $POSTPONE_W;
1260
1261 &{ shift @POSTPONE }
1262 while @POSTPONE;
1263}
1264
1265sub postpone(&) {
1266 push @POSTPONE, shift;
1267
1268 $POSTPONE_W ||= AE::timer (0, 0, \&_postpone_exec);
1269
1270 ()
1271}
1272
1162my @models = ( 1273our @models = (
1163 [EV:: => AnyEvent::Impl::EV:: , 1], 1274 [EV:: => AnyEvent::Impl::EV:: , 1],
1164 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1], 1275 [AnyEvent::Loop:: => AnyEvent::Impl::Perl:: , 1],
1165 # everything below here will not (normally) be autoprobed 1276 # everything below here will not (normally) be autoprobed
1166 # as the pureperl backend should work everywhere 1277 # as the pure perl backend should work everywhere
1167 # and is usually faster 1278 # and is usually faster
1168 [Event:: => AnyEvent::Impl::Event::, 1], 1279 [Event:: => AnyEvent::Impl::Event::, 1],
1169 [Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers 1280 [Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1170 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy 1281 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1171 [Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package 1282 [Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1172 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles 1283 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1173 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program 1284 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1174 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza 1285 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1175 [Wx:: => AnyEvent::Impl::POE::], 1286 [Wx:: => AnyEvent::Impl::POE::],
1176 [Prima:: => AnyEvent::Impl::POE::], 1287 [Prima:: => AnyEvent::Impl::POE::],
1177 # IO::Async is just too broken - we would need workarounds for its 1288 [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1178 # byzantine signal and broken child handling, among others. 1289 [Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1179 # IO::Async is rather hard to detect, as it doesn't have any 1290 [FLTK:: => AnyEvent::Impl::FLTK2::],
1180 # obvious default class.
1181 [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1182 [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1183 [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1184 [AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1185); 1291);
1186 1292
1187our %method = map +($_ => 1), 1293# all autoloaded methods reserve the complete glob, not just the method slot.
1294# due to bugs in perls method cache implementation.
1188 qw(io timer time now now_update signal child idle condvar one_event DESTROY); 1295our @methods = qw(io timer time now now_update signal child idle condvar);
1189 1296
1190our @post_detect;
1191
1192sub post_detect(&) { 1297sub detect() {
1193 my ($cb) = @_; 1298 local $!; # for good measure
1299 local $SIG{__DIE__}; # we use eval
1194 1300
1195 if ($MODEL) { 1301 # free some memory
1196 $cb->(); 1302 *detect = sub () { $MODEL };
1303 # undef &func doesn't correctly update the method cache. grmbl.
1304 # so we delete the whole glob. grmbl.
1305 # otoh, perl doesn't let me undef an active usb, but it lets me free
1306 # a glob with an active sub. hrm. i hope it works, but perl is
1307 # usually buggy in this department. sigh.
1308 delete @{"AnyEvent::"}{@methods};
1309 undef @methods;
1197 1310
1198 undef 1311 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) {
1312 my $model = $1;
1313 $model = "AnyEvent::Impl::$model" unless $model =~ s/::$//;
1314 if (eval "require $model") {
1315 $MODEL = $model;
1316 warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
1199 } else { 1317 } else {
1200 push @post_detect, $cb; 1318 warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1201 1319 }
1202 defined wantarray
1203 ? bless \$cb, "AnyEvent::Util::postdetect"
1204 : ()
1205 } 1320 }
1206}
1207 1321
1208sub AnyEvent::Util::postdetect::DESTROY { 1322 # check for already loaded models
1209 @post_detect = grep $_ != ${$_[0]}, @post_detect;
1210}
1211
1212sub detect() {
1213 unless ($MODEL) { 1323 unless ($MODEL) {
1214 local $SIG{__DIE__}; 1324 for (@REGISTRY, @models) {
1215 1325 my ($package, $model) = @$_;
1216 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { 1326 if (${"$package\::VERSION"} > 0) {
1217 my $model = "AnyEvent::Impl::$1";
1218 if (eval "require $model") { 1327 if (eval "require $model") {
1219 $MODEL = $model; 1328 $MODEL = $model;
1220 warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2; 1329 warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1221 } else { 1330 last;
1222 warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE; 1331 }
1223 } 1332 }
1224 } 1333 }
1225 1334
1226 # check for already loaded models
1227 unless ($MODEL) { 1335 unless ($MODEL) {
1336 # try to autoload a model
1228 for (@REGISTRY, @models) { 1337 for (@REGISTRY, @models) {
1229 my ($package, $model) = @$_; 1338 my ($package, $model, $autoload) = @$_;
1339 if (
1340 $autoload
1341 and eval "require $package"
1230 if (${"$package\::VERSION"} > 0) { 1342 and ${"$package\::VERSION"} > 0
1231 if (eval "require $model") { 1343 and eval "require $model"
1344 ) {
1232 $MODEL = $model; 1345 $MODEL = $model;
1233 warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2; 1346 warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1234 last; 1347 last;
1235 }
1236 } 1348 }
1237 } 1349 }
1238 1350
1239 unless ($MODEL) {
1240 # try to autoload a model
1241 for (@REGISTRY, @models) {
1242 my ($package, $model, $autoload) = @$_;
1243 if (
1244 $autoload
1245 and eval "require $package"
1246 and ${"$package\::VERSION"} > 0
1247 and eval "require $model"
1248 ) {
1249 $MODEL = $model;
1250 warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1251 last;
1252 }
1253 }
1254
1255 $MODEL 1351 $MODEL
1256 or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n"; 1352 or die "AnyEvent: backend autodetection failed - did you properly install AnyEvent?\n";
1257 }
1258 } 1353 }
1259
1260 push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1261
1262 unshift @ISA, $MODEL;
1263
1264 require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1265
1266 (shift @post_detect)->() while @post_detect;
1267 } 1354 }
1268 1355
1356 # free memory only needed for probing
1357 undef @models;
1358 undef @REGISTRY;
1359
1360 push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1361 unshift @ISA, $MODEL;
1362
1363 # now nuke some methods that are overridden by the backend.
1364 # SUPER usage is not allowed in these.
1365 for (qw(time signal child idle)) {
1366 undef &{"AnyEvent::Base::$_"}
1367 if defined &{"$MODEL\::$_"};
1368 }
1369
1370 if ($ENV{PERL_ANYEVENT_STRICT}) {
1371 require AnyEvent::Strict;
1372 }
1373
1374 if ($ENV{PERL_ANYEVENT_DEBUG_WRAP}) {
1375 require AnyEvent::Debug;
1376 AnyEvent::Debug::wrap ($ENV{PERL_ANYEVENT_DEBUG_WRAP});
1377 }
1378
1379 if (exists $ENV{PERL_ANYEVENT_DEBUG_SHELL}) {
1380 require AnyEvent::Debug;
1381 #d#
1382 }
1383
1384 (shift @post_detect)->() while @post_detect;
1385 undef @post_detect;
1386
1387 *post_detect = sub(&) {
1388 shift->();
1389
1390 undef
1391 };
1392
1269 $MODEL 1393 $MODEL
1270} 1394}
1271 1395
1272sub AUTOLOAD { 1396for my $name (@methods) {
1273 (my $func = $AUTOLOAD) =~ s/.*://; 1397 *$name = sub {
1274 1398 detect;
1275 $method{$func} 1399 # we use goto because
1276 or Carp::croak "$func: not a valid method for AnyEvent objects"; 1400 # a) it makes the thunk more transparent
1277 1401 # b) it allows us to delete the thunk later
1278 detect unless $MODEL; 1402 goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
1279 1403 };
1280 my $class = shift;
1281 $class->$func (@_);
1282} 1404}
1283 1405
1284# utility function to dup a filehandle. this is used by many backends 1406# utility function to dup a filehandle. this is used by many backends
1285# to support binding more than one watcher per filehandle (they usually 1407# to support binding more than one watcher per filehandle (they usually
1286# allow only one watcher per fd, so we dup it to get a different one). 1408# allow only one watcher per fd, so we dup it to get a different one).
1300 1422
1301=head1 SIMPLIFIED AE API 1423=head1 SIMPLIFIED AE API
1302 1424
1303Starting with version 5.0, AnyEvent officially supports a second, much 1425Starting with version 5.0, AnyEvent officially supports a second, much
1304simpler, API that is designed to reduce the calling, typing and memory 1426simpler, API that is designed to reduce the calling, typing and memory
1305overhead. 1427overhead by using function call syntax and a fixed number of parameters.
1306 1428
1307See the L<AE> manpage for details. 1429See the L<AE> manpage for details.
1308 1430
1309=cut 1431=cut
1310 1432
1311package AE; 1433package AE;
1312 1434
1313our $VERSION = $AnyEvent::VERSION; 1435our $VERSION = $AnyEvent::VERSION;
1314 1436
1437sub _reset() {
1438 eval q{
1439 # fall back to the main API by default - backends and AnyEvent::Base
1440 # implementations can overwrite these.
1441
1315sub io($$$) { 1442 sub io($$$) {
1316 AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2]) 1443 AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1317} 1444 }
1318 1445
1319sub timer($$$) { 1446 sub timer($$$) {
1320 AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2]) 1447 AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
1321} 1448 }
1322 1449
1323sub signal($$) { 1450 sub signal($$) {
1324 AnyEvent->signal (signal => $_[0], cb => $_[1]) 1451 AnyEvent->signal (signal => $_[0], cb => $_[1])
1325} 1452 }
1326 1453
1327sub child($$) { 1454 sub child($$) {
1328 AnyEvent->child (pid => $_[0], cb => $_[1]) 1455 AnyEvent->child (pid => $_[0], cb => $_[1])
1329} 1456 }
1330 1457
1331sub idle($) { 1458 sub idle($) {
1332 AnyEvent->idle (cb => $_[0]) 1459 AnyEvent->idle (cb => $_[0]);
1333} 1460 }
1334 1461
1335sub cv(;&) { 1462 sub cv(;&) {
1336 AnyEvent->condvar (@_ ? (cb => $_[0]) : ()) 1463 AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
1337} 1464 }
1338 1465
1339sub now() { 1466 sub now() {
1340 AnyEvent->now 1467 AnyEvent->now
1341} 1468 }
1342 1469
1343sub now_update() { 1470 sub now_update() {
1344 AnyEvent->now_update 1471 AnyEvent->now_update
1345} 1472 }
1346 1473
1347sub time() { 1474 sub time() {
1348 AnyEvent->time 1475 AnyEvent->time
1476 }
1477
1478 *postpone = \&AnyEvent::postpone;
1479 };
1480 die if $@;
1349} 1481}
1482
1483BEGIN { _reset }
1350 1484
1351package AnyEvent::Base; 1485package AnyEvent::Base;
1352 1486
1353# default implementations for many methods 1487# default implementations for many methods
1354 1488
1355sub _time() { 1489sub time {
1490 eval q{ # poor man's autoloading {}
1356 # probe for availability of Time::HiRes 1491 # probe for availability of Time::HiRes
1357 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { 1492 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1358 warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8; 1493 warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1359 *_time = \&Time::HiRes::time; 1494 *AE::time = \&Time::HiRes::time;
1360 # if (eval "use POSIX (); (POSIX::times())... 1495 # if (eval "use POSIX (); (POSIX::times())...
1361 } else { 1496 } else {
1362 warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE; 1497 warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1363 *_time = sub { time }; # epic fail 1498 *AE::time = sub (){ time }; # epic fail
1499 }
1500
1501 *time = sub { AE::time }; # different prototypes
1364 } 1502 };
1503 die if $@;
1365 1504
1366 &_time 1505 &time
1367} 1506}
1368 1507
1369sub time { _time } 1508*now = \&time;
1370sub now { _time } 1509
1371sub now_update { } 1510sub now_update { }
1372 1511
1512sub _poll {
1513 Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
1514}
1515
1373# default implementation for ->condvar 1516# default implementation for ->condvar
1517# in fact, the default should not be overwritten
1374 1518
1375sub condvar { 1519sub condvar {
1520 eval q{ # poor man's autoloading {}
1521 *condvar = sub {
1376 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar" 1522 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1523 };
1524
1525 *AE::cv = sub (;&) {
1526 bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
1527 };
1528 };
1529 die if $@;
1530
1531 &condvar
1377} 1532}
1378 1533
1379# default implementation for ->signal 1534# default implementation for ->signal
1380 1535
1381our $HAVE_ASYNC_INTERRUPT; 1536our $HAVE_ASYNC_INTERRUPT;
1390 1545
1391our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); 1546our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1392our (%SIG_ASY, %SIG_ASY_W); 1547our (%SIG_ASY, %SIG_ASY_W);
1393our ($SIG_COUNT, $SIG_TW); 1548our ($SIG_COUNT, $SIG_TW);
1394 1549
1395sub _signal_exec {
1396 $HAVE_ASYNC_INTERRUPT
1397 ? $SIGPIPE_R->drain
1398 : sysread $SIGPIPE_R, (my $dummy), 9;
1399
1400 while (%SIG_EV) {
1401 for (keys %SIG_EV) {
1402 delete $SIG_EV{$_};
1403 $_->() for values %{ $SIG_CB{$_} || {} };
1404 }
1405 }
1406}
1407
1408# install a dummy wakeup watcher to reduce signal catching latency 1550# install a dummy wakeup watcher to reduce signal catching latency
1551# used by Impls
1409sub _sig_add() { 1552sub _sig_add() {
1410 unless ($SIG_COUNT++) { 1553 unless ($SIG_COUNT++) {
1411 # try to align timer on a full-second boundary, if possible 1554 # try to align timer on a full-second boundary, if possible
1412 my $NOW = AE::now; 1555 my $NOW = AE::now;
1413 1556
1423 undef $SIG_TW 1566 undef $SIG_TW
1424 unless --$SIG_COUNT; 1567 unless --$SIG_COUNT;
1425} 1568}
1426 1569
1427our $_sig_name_init; $_sig_name_init = sub { 1570our $_sig_name_init; $_sig_name_init = sub {
1428 eval q{ # poor man's autoloading 1571 eval q{ # poor man's autoloading {}
1429 undef $_sig_name_init; 1572 undef $_sig_name_init;
1430 1573
1431 if (_have_async_interrupt) { 1574 if (_have_async_interrupt) {
1432 *sig2num = \&Async::Interrupt::sig2num; 1575 *sig2num = \&Async::Interrupt::sig2num;
1433 *sig2name = \&Async::Interrupt::sig2name; 1576 *sig2name = \&Async::Interrupt::sig2name;
1465 $SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec; 1608 $SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1466 1609
1467 } else { 1610 } else {
1468 warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8; 1611 warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1469 1612
1470 require Fcntl;
1471
1472 if (AnyEvent::WIN32) { 1613 if (AnyEvent::WIN32) {
1473 require AnyEvent::Util; 1614 require AnyEvent::Util;
1474 1615
1475 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe (); 1616 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1476 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R; 1617 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1477 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case 1618 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1478 } else { 1619 } else {
1479 pipe $SIGPIPE_R, $SIGPIPE_W; 1620 pipe $SIGPIPE_R, $SIGPIPE_W;
1480 fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R; 1621 fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
1481 fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case 1622 fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
1482 1623
1483 # not strictly required, as $^F is normally 2, but let's make sure... 1624 # not strictly required, as $^F is normally 2, but let's make sure...
1484 fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; 1625 fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1485 fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; 1626 fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1486 } 1627 }
1487 1628
1488 $SIGPIPE_R 1629 $SIGPIPE_R
1489 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; 1630 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1490 1631
1491 $SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec; 1632 $SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1492 } 1633 }
1493 1634
1494 *signal = sub { 1635 *signal = $HAVE_ASYNC_INTERRUPT
1636 ? sub {
1495 my (undef, %arg) = @_; 1637 my (undef, %arg) = @_;
1496 1638
1497 my $signal = uc $arg{signal}
1498 or Carp::croak "required option 'signal' is missing";
1499
1500 if ($HAVE_ASYNC_INTERRUPT) {
1501 # async::interrupt 1639 # async::interrupt
1502
1503 $signal = sig2num $signal; 1640 my $signal = sig2num $arg{signal};
1504 $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; 1641 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1505 1642
1506 $SIG_ASY{$signal} ||= new Async::Interrupt 1643 $SIG_ASY{$signal} ||= new Async::Interrupt
1507 cb => sub { undef $SIG_EV{$signal} }, 1644 cb => sub { undef $SIG_EV{$signal} },
1508 signal => $signal, 1645 signal => $signal,
1509 pipe => [$SIGPIPE_R->filenos], 1646 pipe => [$SIGPIPE_R->filenos],
1510 pipe_autodrain => 0, 1647 pipe_autodrain => 0,
1511 ; 1648 ;
1512 1649
1513 } else { 1650 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1651 }
1652 : sub {
1653 my (undef, %arg) = @_;
1654
1514 # pure perl 1655 # pure perl
1515
1516 # AE::Util has been loaded in signal
1517 $signal = sig2name $signal; 1656 my $signal = sig2name $arg{signal};
1518 $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; 1657 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1519 1658
1520 $SIG{$signal} ||= sub { 1659 $SIG{$signal} ||= sub {
1521 local $!; 1660 local $!;
1522 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; 1661 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1523 undef $SIG_EV{$signal}; 1662 undef $SIG_EV{$signal};
1524 }; 1663 };
1525 1664
1526 # can't do signal processing without introducing races in pure perl, 1665 # can't do signal processing without introducing races in pure perl,
1527 # so limit the signal latency. 1666 # so limit the signal latency.
1528 _sig_add; 1667 _sig_add;
1529 }
1530 1668
1531 bless [$signal, $arg{cb}], "AnyEvent::Base::signal" 1669 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1670 }
1532 }; 1671 ;
1533 1672
1534 *AnyEvent::Base::signal::DESTROY = sub { 1673 *AnyEvent::Base::signal::DESTROY = sub {
1535 my ($signal, $cb) = @{$_[0]}; 1674 my ($signal, $cb) = @{$_[0]};
1536 1675
1537 _sig_del; 1676 _sig_del;
1544 # print weird messages, or just unconditionally exit 1683 # print weird messages, or just unconditionally exit
1545 # instead of getting the default action. 1684 # instead of getting the default action.
1546 undef $SIG{$signal} 1685 undef $SIG{$signal}
1547 unless keys %{ $SIG_CB{$signal} }; 1686 unless keys %{ $SIG_CB{$signal} };
1548 }; 1687 };
1688
1689 *_signal_exec = sub {
1690 $HAVE_ASYNC_INTERRUPT
1691 ? $SIGPIPE_R->drain
1692 : sysread $SIGPIPE_R, (my $dummy), 9;
1693
1694 while (%SIG_EV) {
1695 for (keys %SIG_EV) {
1696 delete $SIG_EV{$_};
1697 &$_ for values %{ $SIG_CB{$_} || {} };
1698 }
1699 }
1700 };
1549 }; 1701 };
1550 die if $@; 1702 die if $@;
1703
1551 &signal 1704 &signal
1552} 1705}
1553 1706
1554# default implementation for ->child 1707# default implementation for ->child
1555 1708
1556our %PID_CB; 1709our %PID_CB;
1557our $CHLD_W; 1710our $CHLD_W;
1558our $CHLD_DELAY_W; 1711our $CHLD_DELAY_W;
1559our $WNOHANG;
1560 1712
1713# used by many Impl's
1561sub _emit_childstatus($$) { 1714sub _emit_childstatus($$) {
1562 my (undef, $rpid, $rstatus) = @_; 1715 my (undef, $rpid, $rstatus) = @_;
1563 1716
1564 $_->($rpid, $rstatus) 1717 $_->($rpid, $rstatus)
1565 for values %{ $PID_CB{$rpid} || {} }, 1718 for values %{ $PID_CB{$rpid} || {} },
1566 values %{ $PID_CB{0} || {} }; 1719 values %{ $PID_CB{0} || {} };
1567} 1720}
1568 1721
1569sub _sigchld {
1570 my $pid;
1571
1572 AnyEvent->_emit_childstatus ($pid, $?)
1573 while ($pid = waitpid -1, $WNOHANG) > 0;
1574}
1575
1576sub child { 1722sub child {
1723 eval q{ # poor man's autoloading {}
1724 *_sigchld = sub {
1725 my $pid;
1726
1727 AnyEvent->_emit_childstatus ($pid, $?)
1728 while ($pid = waitpid -1, WNOHANG) > 0;
1729 };
1730
1731 *child = sub {
1577 my (undef, %arg) = @_; 1732 my (undef, %arg) = @_;
1578 1733
1579 defined (my $pid = $arg{pid} + 0) 1734 my $pid = $arg{pid};
1580 or Carp::croak "required option 'pid' is missing"; 1735 my $cb = $arg{cb};
1581 1736
1582 $PID_CB{$pid}{$arg{cb}} = $arg{cb}; 1737 $PID_CB{$pid}{$cb+0} = $cb;
1583 1738
1584 # WNOHANG is almost cetrainly 1 everywhere
1585 $WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1586 ? 1
1587 : eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1588
1589 unless ($CHLD_W) { 1739 unless ($CHLD_W) {
1590 $CHLD_W = AE::signal CHLD => \&_sigchld; 1740 $CHLD_W = AE::signal CHLD => \&_sigchld;
1591 # child could be a zombie already, so make at least one round 1741 # child could be a zombie already, so make at least one round
1592 &_sigchld; 1742 &_sigchld;
1593 } 1743 }
1594 1744
1595 bless [$pid, $arg{cb}], "AnyEvent::Base::child" 1745 bless [$pid, $cb+0], "AnyEvent::Base::child"
1596} 1746 };
1597 1747
1598sub AnyEvent::Base::child::DESTROY { 1748 *AnyEvent::Base::child::DESTROY = sub {
1599 my ($pid, $cb) = @{$_[0]}; 1749 my ($pid, $icb) = @{$_[0]};
1600 1750
1601 delete $PID_CB{$pid}{$cb}; 1751 delete $PID_CB{$pid}{$icb};
1602 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; 1752 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1603 1753
1604 undef $CHLD_W unless keys %PID_CB; 1754 undef $CHLD_W unless keys %PID_CB;
1755 };
1756 };
1757 die if $@;
1758
1759 &child
1605} 1760}
1606 1761
1607# idle emulation is done by simply using a timer, regardless 1762# idle emulation is done by simply using a timer, regardless
1608# of whether the process is idle or not, and not letting 1763# of whether the process is idle or not, and not letting
1609# the callback use more than 50% of the time. 1764# the callback use more than 50% of the time.
1610sub idle { 1765sub idle {
1766 eval q{ # poor man's autoloading {}
1767 *idle = sub {
1611 my (undef, %arg) = @_; 1768 my (undef, %arg) = @_;
1612 1769
1613 my ($cb, $w, $rcb) = $arg{cb}; 1770 my ($cb, $w, $rcb) = $arg{cb};
1614 1771
1615 $rcb = sub { 1772 $rcb = sub {
1616 if ($cb) { 1773 if ($cb) {
1617 $w = _time; 1774 $w = AE::time;
1618 &$cb; 1775 &$cb;
1619 $w = _time - $w; 1776 $w = AE::time - $w;
1620 1777
1621 # never use more then 50% of the time for the idle watcher, 1778 # never use more then 50% of the time for the idle watcher,
1622 # within some limits 1779 # within some limits
1623 $w = 0.0001 if $w < 0.0001; 1780 $w = 0.0001 if $w < 0.0001;
1624 $w = 5 if $w > 5; 1781 $w = 5 if $w > 5;
1625 1782
1626 $w = AE::timer $w, 0, $rcb; 1783 $w = AE::timer $w, 0, $rcb;
1627 } else { 1784 } else {
1628 # clean up... 1785 # clean up...
1629 undef $w; 1786 undef $w;
1630 undef $rcb; 1787 undef $rcb;
1788 }
1789 };
1790
1791 $w = AE::timer 0.05, 0, $rcb;
1792
1793 bless \\$cb, "AnyEvent::Base::idle"
1631 } 1794 };
1795
1796 *AnyEvent::Base::idle::DESTROY = sub {
1797 undef $${$_[0]};
1798 };
1632 }; 1799 };
1800 die if $@;
1633 1801
1634 $w = AE::timer 0.05, 0, $rcb; 1802 &idle
1635
1636 bless \\$cb, "AnyEvent::Base::idle"
1637}
1638
1639sub AnyEvent::Base::idle::DESTROY {
1640 undef $${$_[0]};
1641} 1803}
1642 1804
1643package AnyEvent::CondVar; 1805package AnyEvent::CondVar;
1644 1806
1645our @ISA = AnyEvent::CondVar::Base::; 1807our @ISA = AnyEvent::CondVar::Base::;
1808
1809# only to be used for subclassing
1810sub new {
1811 my $class = shift;
1812 bless AnyEvent->condvar (@_), $class
1813}
1646 1814
1647package AnyEvent::CondVar::Base; 1815package AnyEvent::CondVar::Base;
1648 1816
1649#use overload 1817#use overload
1650# '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, 1818# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1660 1828
1661sub _send { 1829sub _send {
1662 # nop 1830 # nop
1663} 1831}
1664 1832
1833sub _wait {
1834 AnyEvent->_poll until $_[0]{_ae_sent};
1835}
1836
1665sub send { 1837sub send {
1666 my $cv = shift; 1838 my $cv = shift;
1667 $cv->{_ae_sent} = [@_]; 1839 $cv->{_ae_sent} = [@_];
1668 (delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb}; 1840 (delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1669 $cv->_send; 1841 $cv->_send;
1676 1848
1677sub ready { 1849sub ready {
1678 $_[0]{_ae_sent} 1850 $_[0]{_ae_sent}
1679} 1851}
1680 1852
1681sub _wait {
1682 $WAITING
1683 and !$_[0]{_ae_sent}
1684 and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1685
1686 local $WAITING = 1;
1687 AnyEvent->one_event while !$_[0]{_ae_sent};
1688}
1689
1690sub recv { 1853sub recv {
1854 unless ($_[0]{_ae_sent}) {
1855 $WAITING
1856 and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
1857
1858 local $WAITING = 1;
1691 $_[0]->_wait; 1859 $_[0]->_wait;
1860 }
1692 1861
1693 Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak}; 1862 $_[0]{_ae_croak}
1694 wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0] 1863 and Carp::croak $_[0]{_ae_croak};
1864
1865 wantarray
1866 ? @{ $_[0]{_ae_sent} }
1867 : $_[0]{_ae_sent}[0]
1695} 1868}
1696 1869
1697sub cb { 1870sub cb {
1698 my $cv = shift; 1871 my $cv = shift;
1699 1872
1715 &{ $_[0]{_ae_end_cb} || sub { $_[0]->send } }; 1888 &{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1716} 1889}
1717 1890
1718# undocumented/compatibility with pre-3.4 1891# undocumented/compatibility with pre-3.4
1719*broadcast = \&send; 1892*broadcast = \&send;
1720*wait = \&_wait; 1893*wait = \&recv;
1721 1894
1722=head1 ERROR AND EXCEPTION HANDLING 1895=head1 ERROR AND EXCEPTION HANDLING
1723 1896
1724In general, AnyEvent does not do any error handling - it relies on the 1897In general, AnyEvent does not do any error handling - it relies on the
1725caller to do that if required. The L<AnyEvent::Strict> module (see also 1898caller to do that if required. The L<AnyEvent::Strict> module (see also
1772check the arguments passed to most method calls. If it finds any problems, 1945check the arguments passed to most method calls. If it finds any problems,
1773it will croak. 1946it will croak.
1774 1947
1775In other words, enables "strict" mode. 1948In other words, enables "strict" mode.
1776 1949
1777Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense> 1950Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1778>>, it is definitely recommended to keep it off in production. Keeping 1951>>, it is definitely recommended to keep it off in production. Keeping
1779C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs 1952C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1780can be very useful, however. 1953can be very useful, however.
1781 1954
1782=item C<PERL_ANYEVENT_MODEL> 1955=item C<PERL_ANYEVENT_MODEL>
1783 1956
1784This can be used to specify the event model to be used by AnyEvent, before 1957This can be used to specify the event model to be used by AnyEvent, before
1785auto detection and -probing kicks in. It must be a string consisting 1958auto detection and -probing kicks in.
1786entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended 1959
1960It normally is a string consisting entirely of ASCII letters (e.g. C<EV>
1961or C<IOAsync>). The string C<AnyEvent::Impl::> gets prepended and the
1787and the resulting module name is loaded and if the load was successful, 1962resulting module name is loaded and - if the load was successful - used as
1788used as event model. If it fails to load AnyEvent will proceed with 1963event model backend. If it fails to load then AnyEvent will proceed with
1789auto detection and -probing. 1964auto detection and -probing.
1790 1965
1791This functionality might change in future versions. 1966If the string ends with C<::> instead (e.g. C<AnyEvent::Impl::EV::>) then
1967nothing gets prepended and the module name is used as-is (hint: C<::> at
1968the end of a string designates a module name and quotes it appropriately).
1792 1969
1793For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you 1970For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1794could start your program like this: 1971could start your program like this:
1795 1972
1796 PERL_ANYEVENT_MODEL=Perl perl ... 1973 PERL_ANYEVENT_MODEL=Perl perl ...
1797 1974
1798=item C<PERL_ANYEVENT_PROTOCOLS> 1975=item C<PERL_ANYEVENT_PROTOCOLS>
2004 2181
2005The actual code goes further and collects all errors (C<die>s, exceptions) 2182The actual code goes further and collects all errors (C<die>s, exceptions)
2006that occurred during request processing. The C<result> method detects 2183that occurred during request processing. The C<result> method detects
2007whether an exception as thrown (it is stored inside the $txn object) 2184whether an exception as thrown (it is stored inside the $txn object)
2008and just throws the exception, which means connection errors and other 2185and just throws the exception, which means connection errors and other
2009problems get reported tot he code that tries to use the result, not in a 2186problems get reported to the code that tries to use the result, not in a
2010random callback. 2187random callback.
2011 2188
2012All of this enables the following usage styles: 2189All of this enables the following usage styles:
2013 2190
20141. Blocking: 21911. Blocking:
2428 unless defined $SIG{PIPE}; 2605 unless defined $SIG{PIPE};
2429 2606
2430=head1 RECOMMENDED/OPTIONAL MODULES 2607=head1 RECOMMENDED/OPTIONAL MODULES
2431 2608
2432One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and 2609One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2433it's built-in modules) are required to use it. 2610its built-in modules) are required to use it.
2434 2611
2435That does not mean that AnyEvent won't take advantage of some additional 2612That does not mean that AnyEvent won't take advantage of some additional
2436modules if they are installed. 2613modules if they are installed.
2437 2614
2438This section epxlains which additional modules will be used, and how they 2615This section explains which additional modules will be used, and how they
2439affect AnyEvent's operetion. 2616affect AnyEvent's operation.
2440 2617
2441=over 4 2618=over 4
2442 2619
2443=item L<Async::Interrupt> 2620=item L<Async::Interrupt>
2444 2621
2449catch the signals) with some delay (default is 10 seconds, look for 2626catch the signals) with some delay (default is 10 seconds, look for
2450C<$AnyEvent::MAX_SIGNAL_LATENCY>). 2627C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2451 2628
2452If this module is available, then it will be used to implement signal 2629If this module is available, then it will be used to implement signal
2453catching, which means that signals will not be delayed, and the event loop 2630catching, which means that signals will not be delayed, and the event loop
2454will not be interrupted regularly, which is more efficient (And good for 2631will not be interrupted regularly, which is more efficient (and good for
2455battery life on laptops). 2632battery life on laptops).
2456 2633
2457This affects not just the pure-perl event loop, but also other event loops 2634This affects not just the pure-perl event loop, but also other event loops
2458that have no signal handling on their own (e.g. Glib, Tk, Qt). 2635that have no signal handling on their own (e.g. Glib, Tk, Qt).
2459 2636
2471automatic timer adjustments even when no monotonic clock is available, 2648automatic timer adjustments even when no monotonic clock is available,
2472can take avdantage of advanced kernel interfaces such as C<epoll> and 2649can take avdantage of advanced kernel interfaces such as C<epoll> and
2473C<kqueue>, and is the fastest backend I<by far>. You can even embed 2650C<kqueue>, and is the fastest backend I<by far>. You can even embed
2474L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>). 2651L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2475 2652
2653If you only use backends that rely on another event loop (e.g. C<Tk>),
2654then this module will do nothing for you.
2655
2476=item L<Guard> 2656=item L<Guard>
2477 2657
2478The guard module, when used, will be used to implement 2658The guard module, when used, will be used to implement
2479C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a 2659C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2480lot less memory), but otherwise doesn't affect guard operation much. It is 2660lot less memory), but otherwise doesn't affect guard operation much. It is
2481purely used for performance. 2661purely used for performance.
2482 2662
2483=item L<JSON> and L<JSON::XS> 2663=item L<JSON> and L<JSON::XS>
2484 2664
2485One of these modules is required when you want to read or write JSON data 2665One of these modules is required when you want to read or write JSON data
2486via L<AnyEvent::Handle>. It is also written in pure-perl, but can take 2666via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2487advantage of the ultra-high-speed L<JSON::XS> module when it is installed. 2667advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2488
2489In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2490installed.
2491 2668
2492=item L<Net::SSLeay> 2669=item L<Net::SSLeay>
2493 2670
2494Implementing TLS/SSL in Perl is certainly interesting, but not very 2671Implementing TLS/SSL in Perl is certainly interesting, but not very
2495worthwhile: If this module is installed, then L<AnyEvent::Handle> (with 2672worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2496the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL. 2673the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2497 2674
2498=item L<Time::HiRes> 2675=item L<Time::HiRes>
2499 2676
2500This module is part of perl since release 5.008. It will be used when the 2677This module is part of perl since release 5.008. It will be used when the
2501chosen event library does not come with a timing source on it's own. The 2678chosen event library does not come with a timing source of its own. The
2502pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to 2679pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2503try to use a monotonic clock for timing stability. 2680try to use a monotonic clock for timing stability.
2504 2681
2505=back 2682=back
2506 2683
2507 2684
2508=head1 FORK 2685=head1 FORK
2509 2686
2510Most event libraries are not fork-safe. The ones who are usually are 2687Most event libraries are not fork-safe. The ones who are usually are
2511because they rely on inefficient but fork-safe C<select> or C<poll> 2688because they rely on inefficient but fork-safe C<select> or C<poll> calls
2512calls. Only L<EV> is fully fork-aware. 2689- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
2690are usually badly thought-out hacks that are incompatible with fork in
2691one way or another. Only L<EV> is fully fork-aware and ensures that you
2692continue event-processing in both parent and child (or both, if you know
2693what you are doing).
2694
2695This means that, in general, you cannot fork and do event processing in
2696the child if the event library was initialised before the fork (which
2697usually happens when the first AnyEvent watcher is created, or the library
2698is loaded).
2513 2699
2514If you have to fork, you must either do so I<before> creating your first 2700If you have to fork, you must either do so I<before> creating your first
2515watcher OR you must not use AnyEvent at all in the child OR you must do 2701watcher OR you must not use AnyEvent at all in the child OR you must do
2516something completely out of the scope of AnyEvent. 2702something completely out of the scope of AnyEvent.
2703
2704The problem of doing event processing in the parent I<and> the child
2705is much more complicated: even for backends that I<are> fork-aware or
2706fork-safe, their behaviour is not usually what you want: fork clones all
2707watchers, that means all timers, I/O watchers etc. are active in both
2708parent and child, which is almost never what you want. USing C<exec>
2709to start worker children from some kind of manage rprocess is usually
2710preferred, because it is much easier and cleaner, at the expense of having
2711to have another binary.
2517 2712
2518 2713
2519=head1 SECURITY CONSIDERATIONS 2714=head1 SECURITY CONSIDERATIONS
2520 2715
2521AnyEvent can be forced to load any event model via 2716AnyEvent can be forced to load any event model via
2551pronounced). 2746pronounced).
2552 2747
2553 2748
2554=head1 SEE ALSO 2749=head1 SEE ALSO
2555 2750
2751Tutorial/Introduction: L<AnyEvent::Intro>.
2752
2753FAQ: L<AnyEvent::FAQ>.
2754
2556Utility functions: L<AnyEvent::Util>. 2755Utility functions: L<AnyEvent::Util>.
2557 2756
2558Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>, 2757Event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>, L<Glib::EV>,
2559L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. 2758L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2560 2759
2561Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, 2760Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2562L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, 2761L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2563L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, 2762L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2564L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>. 2763L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
2566Non-blocking file handles, sockets, TCP clients and 2765Non-blocking file handles, sockets, TCP clients and
2567servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>. 2766servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2568 2767
2569Asynchronous DNS: L<AnyEvent::DNS>. 2768Asynchronous DNS: L<AnyEvent::DNS>.
2570 2769
2571Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, 2770Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2572L<Coro::Event>,
2573 2771
2574Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>, 2772Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2575L<AnyEvent::HTTP>. 2773L<AnyEvent::HTTP>.
2576 2774
2577 2775
2578=head1 AUTHOR 2776=head1 AUTHOR
2579 2777

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