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Revision 1.366 by root, Wed Aug 17 02:02:38 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
365When this is the case, you can call this method, which will update the 369When this is the case, you can call this method, which will update the
366event loop's idea of "current time". 370event loop's idea of "current time".
371
372A typical example would be a script in a web server (e.g. C<mod_perl>) -
373when mod_perl executes the script, then the event loop will have the wrong
374idea about the "current time" (being potentially far in the past, when the
375script ran the last time). In that case you should arrange a call to C<<
376AnyEvent->now_update >> each time the web server process wakes up again
377(e.g. at the start of your script, or in a handler).
367 378
368Note that updating the time I<might> cause some events to be handled. 379Note that updating the time I<might> cause some events to be handled.
369 380
370=back 381=back
371 382
396 407
397Example: exit on SIGINT 408Example: exit on SIGINT
398 409
399 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); 410 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
400 411
412=head3 Restart Behaviour
413
414While restart behaviour is up to the event loop implementation, most will
415not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
416pure perl implementation).
417
418=head3 Safe/Unsafe Signals
419
420Perl signals can be either "safe" (synchronous to opcode handling) or
421"unsafe" (asynchronous) - the former might get delayed indefinitely, the
422latter might corrupt your memory.
423
424AnyEvent signal handlers are, in addition, synchronous to the event loop,
425i.e. they will not interrupt your running perl program but will only be
426called as part of the normal event handling (just like timer, I/O etc.
427callbacks, too).
428
401=head3 Signal Races, Delays and Workarounds 429=head3 Signal Races, Delays and Workarounds
402 430
403Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching 431Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
404callbacks to signals in a generic way, which is a pity, as you cannot 432callbacks to signals in a generic way, which is a pity, as you cannot
405do race-free signal handling in perl, requiring C libraries for 433do race-free signal handling in perl, requiring C libraries for
406this. AnyEvent will try to do it's best, which means in some cases, 434this. AnyEvent will try to do its best, which means in some cases,
407signals will be delayed. The maximum time a signal might be delayed is 435signals will be delayed. The maximum time a signal might be delayed is
408specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This 436specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
409variable can be changed only before the first signal watcher is created, 437variable can be changed only before the first signal watcher is created,
410and should be left alone otherwise. This variable determines how often 438and should be left alone otherwise. This variable determines how often
411AnyEvent 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
413saving. 441saving.
414 442
415All these problems can be avoided by installing the optional 443All these problems can be avoided by installing the optional
416L<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
417work 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>
418(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
419one-second latency). For those, you just have to suffer the delays. 447one-second latency). For those, you just have to suffer the delays.
420 448
421=head2 CHILD PROCESS WATCHERS 449=head2 CHILD PROCESS WATCHERS
422 450
423 $w = AnyEvent->child (pid => <process id>, cb => <callback>); 451 $w = AnyEvent->child (pid => <process id>, cb => <callback>);
424 452
425You 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.
426 454
427The 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,
428using 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
429croak). The watcher will be triggered only when the child process has 457croak). The watcher will be triggered only when the child process has
430finished and an exit status is available, not on any trace events 458finished and an exit status is available, not on any trace events
431(stopped/continued). 459(stopped/continued).
432 460
454thing 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
455watcher before you C<fork> the child (alternatively, you can call 483watcher before you C<fork> the child (alternatively, you can call
456C<AnyEvent::detect>). 484C<AnyEvent::detect>).
457 485
458As 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
459emulated 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
460mentioned in the description of signal watchers apply. 488problems mentioned in the description of signal watchers apply.
461 489
462Example: fork a process and wait for it 490Example: fork a process and wait for it
463 491
464 my $done = AnyEvent->condvar; 492 my $done = AnyEvent->condvar;
465 493
479 507
480=head2 IDLE WATCHERS 508=head2 IDLE WATCHERS
481 509
482 $w = AnyEvent->idle (cb => <callback>); 510 $w = AnyEvent->idle (cb => <callback>);
483 511
484Sometimes there is a need to do something, but it is not so important 512This will repeatedly invoke the callback after the process becomes idle,
485to 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.
486"nothing better to do" is usually defined to be "no other events need
487attention by the event loop".
488 514
489Idle watchers ideally get invoked when the event loop has nothing 515Idle watchers are useful when there is a need to do something, but it
490better 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
491events. 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.
492 523
493Most event loops unfortunately do not really support idle watchers (only 524Unfortunately, most event loops do not really support idle watchers (only
494EV, 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
495will simply call the callback "from time to time". 526will simply call the callback "from time to time".
496 527
497Example: read lines from STDIN, but only process them when the 528Example: read lines from STDIN, but only process them when the
498program is otherwise idle: 529program is otherwise idle:
526will actively watch for new events and call your callbacks. 557will actively watch for new events and call your callbacks.
527 558
528AnyEvent is slightly different: it expects somebody else to run the event 559AnyEvent is slightly different: it expects somebody else to run the event
529loop 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).
530 561
531The instrument to do that is called a "condition variable", so called 562The tool to do that is called a "condition variable", so called because
532because they represent a condition that must become true. 563they represent a condition that must become true.
533 564
534Now 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.
535 566
536Condition variables can be created by calling the C<< AnyEvent->condvar 567Condition variables can be created by calling the C<< AnyEvent->condvar
537>> method, usually without arguments. The only argument pair allowed is 568>> method, usually without arguments. The only argument pair allowed is
542After creation, the condition variable is "false" until it becomes "true" 573After creation, the condition variable is "false" until it becomes "true"
543by 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
544were 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<<
545->send >> method). 576->send >> method).
546 577
547Condition variables are similar to callbacks, except that you can 578Since condition variables are the most complex part of the AnyEvent API, here are
548optionally 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:
549in time where multiple outstanding events have been processed. And yet 580
550another way to call them is transactions - each condition variable can be 581=over 4
551used to represent a transaction, which finishes at some point and delivers 582
552a 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
553compute/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
554 601
555Condition variables are very useful to signal that something has finished, 602Condition variables are very useful to signal that something has finished,
556for example, if you write a module that does asynchronous http requests, 603for example, if you write a module that does asynchronous http requests,
557then a condition variable would be the ideal candidate to signal the 604then a condition variable would be the ideal candidate to signal the
558availability of results. The user can either act when the callback is 605availability of results. The user can either act when the callback is
571 618
572Condition variables are represented by hash refs in perl, and the keys 619Condition variables are represented by hash refs in perl, and the keys
573used 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
574easy (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
575AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call 622AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call
576it's C<new> method in your own C<new> method. 623its C<new> method in your own C<new> method.
577 624
578There are two "sides" to a condition variable - the "producer side" which 625There are two "sides" to a condition variable - the "producer side" which
579eventually calls C<< -> send >>, and the "consumer side", which waits 626eventually calls C<< -> send >>, and the "consumer side", which waits
580for the send to occur. 627for the send to occur.
581 628
582Example: wait for a timer. 629Example: wait for a timer.
583 630
584 # wait till the result is ready 631 # condition: "wait till the timer is fired"
585 my $result_ready = AnyEvent->condvar; 632 my $timer_fired = AnyEvent->condvar;
586 633
587 # do something such as adding a timer 634 # create the timer - we could wait for, say
588 # or socket watcher the calls $result_ready->send 635 # a handle becomign ready, or even an
589 # when the "result" is ready. 636 # AnyEvent::HTTP request to finish, but
590 # in this case, we simply use a timer: 637 # in this case, we simply use a timer:
591 my $w = AnyEvent->timer ( 638 my $w = AnyEvent->timer (
592 after => 1, 639 after => 1,
593 cb => sub { $result_ready->send }, 640 cb => sub { $timer_fired->send },
594 ); 641 );
595 642
596 # this "blocks" (while handling events) till the callback 643 # this "blocks" (while handling events) till the callback
597 # calls -<send 644 # calls ->send
598 $result_ready->recv; 645 $timer_fired->recv;
599 646
600Example: 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
601variables are also callable directly. 648variables are also callable directly.
602 649
603 my $done = AnyEvent->condvar; 650 my $done = AnyEvent->condvar;
646they 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
647C<send>. 694C<send>.
648 695
649=item $cv->croak ($error) 696=item $cv->croak ($error)
650 697
651Similar to send, but causes all call's to C<< ->recv >> to invoke 698Similar to send, but causes all calls to C<< ->recv >> to invoke
652C<Carp::croak> with the given error message/object/scalar. 699C<Carp::croak> with the given error message/object/scalar.
653 700
654This can be used to signal any errors to the condition variable 701This can be used to signal any errors to the condition variable
655user/consumer. Doing it this way instead of calling C<croak> directly 702user/consumer. Doing it this way instead of calling C<croak> directly
656delays the error detetcion, but has the overwhelmign advantage that it 703delays the error detection, but has the overwhelming advantage that it
657diagnoses 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
658deep in some event clalback without connection to the actual code causing 705deep in some event callback with no connection to the actual code causing
659the problem. 706the problem.
660 707
661=item $cv->begin ([group callback]) 708=item $cv->begin ([group callback])
662 709
663=item $cv->end 710=item $cv->end
666one. For example, a function that pings many hosts in parallel might want 713one. For example, a function that pings many hosts in parallel might want
667to use a condition variable for the whole process. 714to use a condition variable for the whole process.
668 715
669Every call to C<< ->begin >> will increment a counter, and every call to 716Every call to C<< ->begin >> will increment a counter, and every call to
670C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end 717C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
671>>, the (last) callback passed to C<begin> will be executed. That callback 718>>, the (last) callback passed to C<begin> will be executed, passing the
672is I<supposed> to call C<< ->send >>, but that is not required. If no 719condvar as first argument. That callback is I<supposed> to call C<< ->send
673callback was set, C<send> will be called without any arguments. 720>>, but that is not required. If no group callback was set, C<send> will
721be called without any arguments.
674 722
675You can think of C<< $cv->send >> giving you an OR condition (one call 723You can think of C<< $cv->send >> giving you an OR condition (one call
676sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND 724sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
677condition (all C<begin> calls must be C<end>'ed before the condvar sends). 725condition (all C<begin> calls must be C<end>'ed before the condvar sends).
678 726
700one 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
701sending. 749sending.
702 750
703The ping example mentioned above is slightly more complicated, as the 751The ping example mentioned above is slightly more complicated, as the
704there 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
705begung can potentially be zero: 753begun can potentially be zero:
706 754
707 my $cv = AnyEvent->condvar; 755 my $cv = AnyEvent->condvar;
708 756
709 my %result; 757 my %result;
710 $cv->begin (sub { $cv->send (\%result) }); 758 $cv->begin (sub { shift->send (\%result) });
711 759
712 for my $host (@list_of_hosts) { 760 for my $host (@list_of_hosts) {
713 $cv->begin; 761 $cv->begin;
714 ping_host_then_call_callback $host, sub { 762 ping_host_then_call_callback $host, sub {
715 $result{$host} = ...; 763 $result{$host} = ...;
731to 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
732C<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
733doesn't execute once). 781doesn't execute once).
734 782
735This is the general pattern when you "fan out" into multiple (but 783This is the general pattern when you "fan out" into multiple (but
736potentially 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
737the 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
738subrequest you start, call C<begin> and for each subrequest you finish, 786subrequest you start, call C<begin> and for each subrequest you finish,
739call C<end>. 787call C<end>.
740 788
741=back 789=back
748=over 4 796=over 4
749 797
750=item $cv->recv 798=item $cv->recv
751 799
752Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak 800Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
753>> methods have been called on c<$cv>, while servicing other watchers 801>> methods have been called on C<$cv>, while servicing other watchers
754normally. 802normally.
755 803
756You 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
757will return immediately. 805will return immediately.
758 806
775caller 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
776condition variables with some kind of request results and supporting 824condition variables with some kind of request results and supporting
777callbacks so the caller knows that getting the result will not block, 825callbacks so the caller knows that getting the result will not block,
778while still supporting blocking waits if the caller so desires). 826while still supporting blocking waits if the caller so desires).
779 827
780You 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
781only calling C<< ->recv >> from within that callback (or at a later 829only calling C<< ->recv >> from within that callback (or at a later
782time). 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
783waits otherwise. 831waits otherwise.
784 832
785=item $bool = $cv->ready 833=item $bool = $cv->ready
790=item $cb = $cv->cb ($cb->($cv)) 838=item $cb = $cv->cb ($cb->($cv))
791 839
792This is a mutator function that returns the callback set and optionally 840This is a mutator function that returns the callback set and optionally
793replaces it before doing so. 841replaces it before doing so.
794 842
795The callback will be called when the condition becomes (or already was) 843The callback will be called when the condition becomes "true", i.e. when
796"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
797the 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
798inside the callback or at any later time is guaranteed not to block. 847the callback or at any later time is guaranteed not to block.
799 848
800=back 849=back
801 850
802=head1 SUPPORTED EVENT LOOPS/BACKENDS 851=head1 SUPPORTED EVENT LOOPS/BACKENDS
803 852
811use. 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
812pure-perl implementation, which is available everywhere as it comes with 861pure-perl implementation, which is available everywhere as it comes with
813AnyEvent itself. 862AnyEvent itself.
814 863
815 AnyEvent::Impl::EV based on EV (interface to libev, best choice). 864 AnyEvent::Impl::EV based on EV (interface to libev, best choice).
816 AnyEvent::Impl::Perl pure-perl implementation, fast and portable. 865 AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
817 866
818=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.
819 868
820These 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
821is 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
822them. This means that AnyEvent will automatically pick the right backend 871them. This means that AnyEvent will automatically pick the right backend
823when the main program loads an event module before anything starts to 872when the main program loads an event module before anything starts to
824create watchers. Nothing special needs to be done by the main program. 873create watchers. Nothing special needs to be done by the main program.
825 874
827 AnyEvent::Impl::Glib based on Glib, slow but very stable. 876 AnyEvent::Impl::Glib based on Glib, slow but very stable.
828 AnyEvent::Impl::Tk based on Tk, very broken. 877 AnyEvent::Impl::Tk based on Tk, very broken.
829 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. 878 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
830 AnyEvent::Impl::POE based on POE, very slow, some limitations. 879 AnyEvent::Impl::POE based on POE, very slow, some limitations.
831 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).
832 884
833=item Backends with special needs. 885=item Backends with special needs.
834 886
835Qt requires the Qt::Application to be instantiated first, but will 887Qt requires the Qt::Application to be instantiated first, but will
836otherwise be picked up automatically. As long as the main program 888otherwise be picked up automatically. As long as the main program
837instantiates the application before any AnyEvent watchers are created, 889instantiates the application before any AnyEvent watchers are created,
838everything should just work. 890everything should just work.
839 891
840 AnyEvent::Impl::Qt based on Qt. 892 AnyEvent::Impl::Qt based on Qt.
841 893
842Support for IO::Async can only be partial, as it is too broken and
843architecturally limited to even support the AnyEvent API. It also
844is the only event loop that needs the loop to be set explicitly, so
845it can only be used by a main program knowing about AnyEvent. See
846L<AnyEvent::Impl::Async> for the gory details.
847
848 AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
849
850=item Event loops that are indirectly supported via other backends. 894=item Event loops that are indirectly supported via other backends.
851 895
852Some event loops can be supported via other modules: 896Some event loops can be supported via other modules:
853 897
854There is no direct support for WxWidgets (L<Wx>) or L<Prima>. 898There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
879Contains C<undef> until the first watcher is being created, before the 923Contains C<undef> until the first watcher is being created, before the
880backend has been autodetected. 924backend has been autodetected.
881 925
882Afterwards 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
883name 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
884of 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
885case 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
886will be C<urxvt::anyevent>). 930will be C<urxvt::anyevent>).
887 931
888=item AnyEvent::detect 932=item AnyEvent::detect
889 933
890Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model 934Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
891if necessary. You should only call this function right before you would 935if necessary. You should only call this function right before you would
892have 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
893runtime, and not e.g. while initialising of your module. 937runtime, and not e.g. during initialisation of your module.
938
939The effect of calling this function is as if a watcher had been created
940(specifically, actions that happen "when the first watcher is created"
941happen when calling detetc as well).
894 942
895If you need to do some initialisation before AnyEvent watchers are 943If you need to do some initialisation before AnyEvent watchers are
896created, use C<post_detect>. 944created, use C<post_detect>.
897 945
898=item $guard = AnyEvent::post_detect { BLOCK } 946=item $guard = AnyEvent::post_detect { BLOCK }
899 947
900Arranges for the code block to be executed as soon as the event model is 948Arranges for the code block to be executed as soon as the event model is
901autodetected (or immediately if this has already happened). 949autodetected (or immediately if that has already happened).
902 950
903The block will be executed I<after> the actual backend has been detected 951The block will be executed I<after> the actual backend has been detected
904(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been 952(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
905created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do 953created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
906other initialisations - see the sources of L<AnyEvent::Strict> or 954other initialisations - see the sources of L<AnyEvent::Strict> or
915that automatically removes the callback again when it is destroyed (or 963that automatically removes the callback again when it is destroyed (or
916C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for 964C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
917a case where this is useful. 965a case where this is useful.
918 966
919Example: Create a watcher for the IO::AIO module and store it in 967Example: Create a watcher for the IO::AIO module and store it in
920C<$WATCHER>. Only do so after the event loop is initialised, though. 968C<$WATCHER>, but do so only do so after the event loop is initialised.
921 969
922 our WATCHER; 970 our WATCHER;
923 971
924 my $guard = AnyEvent::post_detect { 972 my $guard = AnyEvent::post_detect {
925 $WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb); 973 $WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
933 $WATCHER ||= $guard; 981 $WATCHER ||= $guard;
934 982
935=item @AnyEvent::post_detect 983=item @AnyEvent::post_detect
936 984
937If there are any code references in this array (you can C<push> to it 985If there are any code references in this array (you can C<push> to it
938before or after loading AnyEvent), then they will called directly after 986before or after loading AnyEvent), then they will be called directly
939the event loop has been chosen. 987after the event loop has been chosen.
940 988
941You should check C<$AnyEvent::MODEL> before adding to this array, though: 989You should check C<$AnyEvent::MODEL> before adding to this array, though:
942if it is defined then the event loop has already been detected, and the 990if it is defined then the event loop has already been detected, and the
943array will be ignored. 991array will be ignored.
944 992
945Best use C<AnyEvent::post_detect { BLOCK }> when your application allows 993Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
946it,as it takes care of these details. 994it, as it takes care of these details.
947 995
948This variable is mainly useful for modules that can do something useful 996This variable is mainly useful for modules that can do something useful
949when AnyEvent is used and thus want to know when it is initialised, but do 997when AnyEvent is used and thus want to know when it is initialised, but do
950not need to even load it by default. This array provides the means to hook 998not need to even load it by default. This array provides the means to hook
951into AnyEvent passively, without loading it. 999into AnyEvent passively, without loading it.
952 1000
1001Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
1002together, you could put this into Coro (this is the actual code used by
1003Coro to accomplish this):
1004
1005 if (defined $AnyEvent::MODEL) {
1006 # AnyEvent already initialised, so load Coro::AnyEvent
1007 require Coro::AnyEvent;
1008 } else {
1009 # AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
1010 # as soon as it is
1011 push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
1012 }
1013
1014=item AnyEvent::postpone { BLOCK }
1015
1016Arranges for the block to be executed as soon as possible, but not before
1017the call itself returns. In practise, the block will be executed just
1018before the event loop polls for new events, or shortly afterwards.
1019
1020This function never returns anything (to make the C<return postpone { ...
1021}> idiom more useful.
1022
1023To understand the usefulness of this function, consider a function that
1024asynchronously does something for you and returns some transaction
1025object or guard to let you cancel the operation. For example,
1026C<AnyEvent::Socket::tcp_connect>:
1027
1028 # start a conenction attempt unless one is active
1029 $self->{connect_guard} ||= AnyEvent::Socket::tcp_connect "www.example.net", 80, sub {
1030 delete $self->{connect_guard};
1031 ...
1032 };
1033
1034Imagine that this function could instantly call the callback, for
1035example, because it detects an obvious error such as a negative port
1036number. Invoking the callback before the function returns causes problems
1037however: the callback will be called and will try to delete the guard
1038object. But since the function hasn't returned yet, there is nothing to
1039delete. When the function eventually returns it will assign the guard
1040object to C<< $self->{connect_guard} >>, where it will likely never be
1041deleted, so the program thinks it is still trying to connect.
1042
1043This is where C<AnyEvent::postpone> should be used. Instead of calling the
1044callback directly on error:
1045
1046 $cb->(undef), return # signal error to callback, BAD!
1047 if $some_error_condition;
1048
1049It should use C<postpone>:
1050
1051 AnyEvent::postpone { $cb->(undef) }, return # signal error to callback, later
1052 if $some_error_condition;
1053
1054=item AnyEvent::log $level, $msg[, @args]
1055
1056Log the given C<$msg> at the given C<$level>.
1057
1058Loads AnyEvent::Log on first use and calls C<AnyEvent::Log::log> -
1059consequently, look at the L<AnyEvent::Log> documentation for details.
1060
953=back 1061=back
954 1062
955=head1 WHAT TO DO IN A MODULE 1063=head1 WHAT TO DO IN A MODULE
956 1064
957As a module author, you should C<use AnyEvent> and call AnyEvent methods 1065As a module author, you should C<use AnyEvent> and call AnyEvent methods
967because it will stall the whole program, and the whole point of using 1075because it will stall the whole program, and the whole point of using
968events is to stay interactive. 1076events is to stay interactive.
969 1077
970It is fine, however, to call C<< ->recv >> when the user of your module 1078It is fine, however, to call C<< ->recv >> when the user of your module
971requests it (i.e. if you create a http request object ad have a method 1079requests it (i.e. if you create a http request object ad have a method
972called C<results> that returns the results, it should call C<< ->recv >> 1080called C<results> that returns the results, it may call C<< ->recv >>
973freely, as the user of your module knows what she is doing. always). 1081freely, as the user of your module knows what she is doing. Always).
974 1082
975=head1 WHAT TO DO IN THE MAIN PROGRAM 1083=head1 WHAT TO DO IN THE MAIN PROGRAM
976 1084
977There will always be a single main program - the only place that should 1085There will always be a single main program - the only place that should
978dictate which event model to use. 1086dictate which event model to use.
979 1087
980If it doesn't care, it can just "use AnyEvent" and use it itself, or not 1088If the program is not event-based, it need not do anything special, even
981do anything special (it does not need to be event-based) and let AnyEvent 1089when it depends on a module that uses an AnyEvent. If the program itself
982decide which implementation to chose if some module relies on it. 1090uses AnyEvent, but does not care which event loop is used, all it needs
1091to do is C<use AnyEvent>. In either case, AnyEvent will choose the best
1092available loop implementation.
983 1093
984If the main program relies on a specific event model - for example, in 1094If the main program relies on a specific event model - for example, in
985Gtk2 programs you have to rely on the Glib module - you should load the 1095Gtk2 programs you have to rely on the Glib module - you should load the
986event module before loading AnyEvent or any module that uses it: generally 1096event module before loading AnyEvent or any module that uses it: generally
987speaking, you should load it as early as possible. The reason is that 1097speaking, you should load it as early as possible. The reason is that
988modules might create watchers when they are loaded, and AnyEvent will 1098modules might create watchers when they are loaded, and AnyEvent will
989decide on the event model to use as soon as it creates watchers, and it 1099decide on the event model to use as soon as it creates watchers, and it
990might chose the wrong one unless you load the correct one yourself. 1100might choose the wrong one unless you load the correct one yourself.
991 1101
992You can chose to use a pure-perl implementation by loading the 1102You can chose to use a pure-perl implementation by loading the
993C<AnyEvent::Impl::Perl> module, which gives you similar behaviour 1103C<AnyEvent::Loop> module, which gives you similar behaviour
994everywhere, but letting AnyEvent chose the model is generally better. 1104everywhere, but letting AnyEvent chose the model is generally better.
995 1105
996=head2 MAINLOOP EMULATION 1106=head2 MAINLOOP EMULATION
997 1107
998Sometimes (often for short test scripts, or even standalone programs who 1108Sometimes (often for short test scripts, or even standalone programs who
1013=head1 OTHER MODULES 1123=head1 OTHER MODULES
1014 1124
1015The following is a non-exhaustive list of additional modules that use 1125The following is a non-exhaustive list of additional modules that use
1016AnyEvent as a client and can therefore be mixed easily with other AnyEvent 1126AnyEvent as a client and can therefore be mixed easily with other AnyEvent
1017modules and other event loops in the same program. Some of the modules 1127modules and other event loops in the same program. Some of the modules
1018come with AnyEvent, most are available via CPAN. 1128come as part of AnyEvent, the others are available via CPAN.
1019 1129
1020=over 4 1130=over 4
1021 1131
1022=item L<AnyEvent::Util> 1132=item L<AnyEvent::Util>
1023 1133
1024Contains various utility functions that replace often-used but blocking 1134Contains various utility functions that replace often-used blocking
1025functions such as C<inet_aton> by event-/callback-based versions. 1135functions such as C<inet_aton> with event/callback-based versions.
1026 1136
1027=item L<AnyEvent::Socket> 1137=item L<AnyEvent::Socket>
1028 1138
1029Provides various utility functions for (internet protocol) sockets, 1139Provides various utility functions for (internet protocol) sockets,
1030addresses and name resolution. Also functions to create non-blocking tcp 1140addresses and name resolution. Also functions to create non-blocking tcp
1032 1142
1033=item L<AnyEvent::Handle> 1143=item L<AnyEvent::Handle>
1034 1144
1035Provide read and write buffers, manages watchers for reads and writes, 1145Provide read and write buffers, manages watchers for reads and writes,
1036supports raw and formatted I/O, I/O queued and fully transparent and 1146supports raw and formatted I/O, I/O queued and fully transparent and
1037non-blocking SSL/TLS (via L<AnyEvent::TLS>. 1147non-blocking SSL/TLS (via L<AnyEvent::TLS>).
1038 1148
1039=item L<AnyEvent::DNS> 1149=item L<AnyEvent::DNS>
1040 1150
1041Provides rich asynchronous DNS resolver capabilities. 1151Provides rich asynchronous DNS resolver capabilities.
1042 1152
1153=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
1154
1155Implement event-based interfaces to the protocols of the same name (for
1156the curious, IGS is the International Go Server and FCP is the Freenet
1157Client Protocol).
1158
1159=item L<AnyEvent::Handle::UDP>
1160
1161Here be danger!
1162
1163As Pauli would put it, "Not only is it not right, it's not even wrong!" -
1164there are so many things wrong with AnyEvent::Handle::UDP, most notably
1165its use of a stream-based API with a protocol that isn't streamable, that
1166the only way to improve it is to delete it.
1167
1168It features data corruption (but typically only under load) and general
1169confusion. On top, the author is not only clueless about UDP but also
1170fact-resistant - some gems of his understanding: "connect doesn't work
1171with UDP", "UDP packets are not IP packets", "UDP only has datagrams, not
1172packets", "I don't need to implement proper error checking as UDP doesn't
1173support error checking" and so on - he doesn't even understand what's
1174wrong with his module when it is explained to him.
1175
1043=item L<AnyEvent::HTTP> 1176=item L<AnyEvent::DBI>
1044 1177
1045A simple-to-use HTTP library that is capable of making a lot of concurrent 1178Executes L<DBI> requests asynchronously in a proxy process for you,
1046HTTP requests. 1179notifying you in an event-based way when the operation is finished.
1180
1181=item L<AnyEvent::AIO>
1182
1183Truly asynchronous (as opposed to non-blocking) I/O, should be in the
1184toolbox of every event programmer. AnyEvent::AIO transparently fuses
1185L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
1186file I/O, and much more.
1047 1187
1048=item L<AnyEvent::HTTPD> 1188=item L<AnyEvent::HTTPD>
1049 1189
1050Provides a simple web application server framework. 1190A simple embedded webserver.
1051 1191
1052=item L<AnyEvent::FastPing> 1192=item L<AnyEvent::FastPing>
1053 1193
1054The fastest ping in the west. 1194The fastest ping in the west.
1055
1056=item L<AnyEvent::DBI>
1057
1058Executes L<DBI> requests asynchronously in a proxy process.
1059
1060=item L<AnyEvent::AIO>
1061
1062Truly asynchronous I/O, should be in the toolbox of every event
1063programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1064together.
1065
1066=item L<AnyEvent::BDB>
1067
1068Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1069L<BDB> and AnyEvent together.
1070
1071=item L<AnyEvent::GPSD>
1072
1073A non-blocking interface to gpsd, a daemon delivering GPS information.
1074
1075=item L<AnyEvent::IRC>
1076
1077AnyEvent based IRC client module family (replacing the older Net::IRC3).
1078
1079=item L<AnyEvent::XMPP>
1080
1081AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1082Net::XMPP2>.
1083
1084=item L<AnyEvent::IGS>
1085
1086A non-blocking interface to the Internet Go Server protocol (used by
1087L<App::IGS>).
1088
1089=item L<Net::FCP>
1090
1091AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1092of AnyEvent.
1093
1094=item L<Event::ExecFlow>
1095
1096High level API for event-based execution flow control.
1097 1195
1098=item L<Coro> 1196=item L<Coro>
1099 1197
1100Has special support for AnyEvent via L<Coro::AnyEvent>. 1198Has special support for AnyEvent via L<Coro::AnyEvent>.
1101 1199
1105 1203
1106package AnyEvent; 1204package AnyEvent;
1107 1205
1108# basically a tuned-down version of common::sense 1206# basically a tuned-down version of common::sense
1109sub common_sense { 1207sub common_sense {
1110 # no warnings 1208 # from common:.sense 3.4
1111 ${^WARNING_BITS} ^= ${^WARNING_BITS}; 1209 ${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
1112 # use strict vars subs 1210 # use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1113 $^H |= 0x00000600; 1211 $^H |= 0x00000600;
1114} 1212}
1115 1213
1116BEGIN { AnyEvent::common_sense } 1214BEGIN { AnyEvent::common_sense }
1117 1215
1118use Carp (); 1216use Carp ();
1119 1217
1120our $VERSION = '5.0'; 1218our $VERSION = '6.01';
1121our $MODEL; 1219our $MODEL;
1122 1220
1123our $AUTOLOAD;
1124our @ISA; 1221our @ISA;
1125 1222
1126our @REGISTRY; 1223our @REGISTRY;
1127 1224
1128our $WIN32;
1129
1130our $VERBOSE; 1225our $VERBOSE;
1131 1226
1132BEGIN { 1227BEGIN {
1133 eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; 1228 require "AnyEvent/constants.pl";
1229
1134 eval "sub TAINT(){ " . (${^TAINT}*1) . " }"; 1230 eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1135 1231
1136 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} 1232 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1137 if ${^TAINT}; 1233 if ${^TAINT};
1138 1234
1139 $VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1; 1235 $VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
1140
1141} 1236}
1142 1237
1143our $MAX_SIGNAL_LATENCY = 10; 1238our $MAX_SIGNAL_LATENCY = 10;
1144 1239
1145our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred 1240our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
1149 $PROTOCOL{$_} = ++$idx 1244 $PROTOCOL{$_} = ++$idx
1150 for reverse split /\s*,\s*/, 1245 for reverse split /\s*,\s*/,
1151 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; 1246 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1152} 1247}
1153 1248
1249our @post_detect;
1250
1251sub post_detect(&) {
1252 my ($cb) = @_;
1253
1254 push @post_detect, $cb;
1255
1256 defined wantarray
1257 ? bless \$cb, "AnyEvent::Util::postdetect"
1258 : ()
1259}
1260
1261sub AnyEvent::Util::postdetect::DESTROY {
1262 @post_detect = grep $_ != ${$_[0]}, @post_detect;
1263}
1264
1265our $POSTPONE_W;
1266our @POSTPONE;
1267
1268sub _postpone_exec {
1269 undef $POSTPONE_W;
1270
1271 &{ shift @POSTPONE }
1272 while @POSTPONE;
1273}
1274
1275sub postpone(&) {
1276 push @POSTPONE, shift;
1277
1278 $POSTPONE_W ||= AE::timer (0, 0, \&_postpone_exec);
1279
1280 ()
1281}
1282
1283sub log($$;@) {
1284 require AnyEvent::Log;
1285 # AnyEvent::Log overwrites this function
1286 goto &log;
1287}
1288
1154my @models = ( 1289our @models = (
1155 [EV:: => AnyEvent::Impl::EV:: , 1], 1290 [EV:: => AnyEvent::Impl::EV:: , 1],
1156 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1], 1291 [AnyEvent::Loop:: => AnyEvent::Impl::Perl:: , 1],
1157 # everything below here will not (normally) be autoprobed 1292 # everything below here will not (normally) be autoprobed
1158 # as the pureperl backend should work everywhere 1293 # as the pure perl backend should work everywhere
1159 # and is usually faster 1294 # and is usually faster
1160 [Event:: => AnyEvent::Impl::Event::, 1], 1295 [Event:: => AnyEvent::Impl::Event::, 1],
1161 [Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers 1296 [Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1162 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy 1297 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1163 [Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package 1298 [Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1164 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles 1299 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1165 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program 1300 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1166 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza 1301 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1167 [Wx:: => AnyEvent::Impl::POE::], 1302 [Wx:: => AnyEvent::Impl::POE::],
1168 [Prima:: => AnyEvent::Impl::POE::], 1303 [Prima:: => AnyEvent::Impl::POE::],
1169 # IO::Async is just too broken - we would need workarounds for its 1304 [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1170 # byzantine signal and broken child handling, among others. 1305 [Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1171 # IO::Async is rather hard to detect, as it doesn't have any 1306 [FLTK:: => AnyEvent::Impl::FLTK2::],
1172 # obvious default class.
1173 [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1174 [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1175 [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1176 [AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1177); 1307);
1178 1308
1179our %method = map +($_ => 1), 1309our @isa_hook;
1310
1311sub _isa_set {
1312 my @pkg = ("AnyEvent", (map $_->[0], grep defined, @isa_hook), $MODEL);
1313
1314 @{"$pkg[$_-1]::ISA"} = $pkg[$_]
1315 for 1 .. $#pkg;
1316
1317 grep $_ && $_->[1], @isa_hook
1318 and AE::_reset ();
1319}
1320
1321# used for hooking AnyEvent::Strict and AnyEvent::Debug::Wrap into the class hierarchy
1322sub _isa_hook($$;$) {
1323 my ($i, $pkg, $reset_ae) = @_;
1324
1325 $isa_hook[$i] = $pkg ? [$pkg, $reset_ae] : undef;
1326
1327 _isa_set;
1328}
1329
1330# all autoloaded methods reserve the complete glob, not just the method slot.
1331# due to bugs in perls method cache implementation.
1180 qw(io timer time now now_update signal child idle condvar one_event DESTROY); 1332our @methods = qw(io timer time now now_update signal child idle condvar);
1181 1333
1182our @post_detect;
1183
1184sub post_detect(&) { 1334sub detect() {
1185 my ($cb) = @_; 1335 return $MODEL if $MODEL; # some programs keep references to detect
1186 1336
1187 if ($MODEL) { 1337 local $!; # for good measure
1188 $cb->(); 1338 local $SIG{__DIE__}; # we use eval
1189 1339
1190 undef 1340 # free some memory
1341 *detect = sub () { $MODEL };
1342 # undef &func doesn't correctly update the method cache. grmbl.
1343 # so we delete the whole glob. grmbl.
1344 # otoh, perl doesn't let me undef an active usb, but it lets me free
1345 # a glob with an active sub. hrm. i hope it works, but perl is
1346 # usually buggy in this department. sigh.
1347 delete @{"AnyEvent::"}{@methods};
1348 undef @methods;
1349
1350 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) {
1351 my $model = $1;
1352 $model = "AnyEvent::Impl::$model" unless $model =~ s/::$//;
1353 if (eval "require $model") {
1354 $MODEL = $model;
1355 AnyEvent::log 7 => "loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it."
1356 if $VERBOSE >= 7;
1191 } else { 1357 } else {
1192 push @post_detect, $cb; 1358 AnyEvent::log warn => "unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
1193 1359 }
1194 defined wantarray
1195 ? bless \$cb, "AnyEvent::Util::postdetect"
1196 : ()
1197 } 1360 }
1198}
1199 1361
1200sub AnyEvent::Util::postdetect::DESTROY { 1362 # check for already loaded models
1201 @post_detect = grep $_ != ${$_[0]}, @post_detect;
1202}
1203
1204sub detect() {
1205 unless ($MODEL) { 1363 unless ($MODEL) {
1206 local $SIG{__DIE__}; 1364 for (@REGISTRY, @models) {
1207 1365 my ($package, $model) = @$_;
1208 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { 1366 if (${"$package\::VERSION"} > 0) {
1209 my $model = "AnyEvent::Impl::$1";
1210 if (eval "require $model") { 1367 if (eval "require $model") {
1211 $MODEL = $model; 1368 $MODEL = $model;
1212 warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2; 1369 AnyEvent::log 7 => "autodetected model '$model', using it."
1213 } else { 1370 if $VERBOSE >= 7;
1214 warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE; 1371 last;
1372 }
1215 } 1373 }
1216 } 1374 }
1217 1375
1218 # check for already loaded models
1219 unless ($MODEL) { 1376 unless ($MODEL) {
1377 # try to autoload a model
1220 for (@REGISTRY, @models) { 1378 for (@REGISTRY, @models) {
1221 my ($package, $model) = @$_; 1379 my ($package, $model, $autoload) = @$_;
1380 if (
1381 $autoload
1382 and eval "require $package"
1222 if (${"$package\::VERSION"} > 0) { 1383 and ${"$package\::VERSION"} > 0
1223 if (eval "require $model") { 1384 and eval "require $model"
1385 ) {
1224 $MODEL = $model; 1386 $MODEL = $model;
1225 warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2; 1387 AnyEvent::log 7 => "autoloaded model '$model', using it."
1388 if $VERBOSE >= 7;
1226 last; 1389 last;
1227 }
1228 } 1390 }
1229 } 1391 }
1230 1392
1231 unless ($MODEL) {
1232 # try to autoload a model
1233 for (@REGISTRY, @models) {
1234 my ($package, $model, $autoload) = @$_;
1235 if (
1236 $autoload
1237 and eval "require $package"
1238 and ${"$package\::VERSION"} > 0
1239 and eval "require $model"
1240 ) {
1241 $MODEL = $model;
1242 warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1243 last;
1244 }
1245 }
1246
1247 $MODEL 1393 $MODEL
1248 or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n"; 1394 or die "AnyEvent: backend autodetection failed - did you properly install AnyEvent?";
1249 }
1250 } 1395 }
1251
1252 push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1253
1254 unshift @ISA, $MODEL;
1255
1256 require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1257
1258 (shift @post_detect)->() while @post_detect;
1259 } 1396 }
1260 1397
1398 # free memory only needed for probing
1399 undef @models;
1400 undef @REGISTRY;
1401
1402 push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1403
1404 # now nuke some methods that are overridden by the backend.
1405 # SUPER usage is not allowed in these.
1406 for (qw(time signal child idle)) {
1407 undef &{"AnyEvent::Base::$_"}
1408 if defined &{"$MODEL\::$_"};
1409 }
1410
1411 _isa_set;
1412
1413 if ($ENV{PERL_ANYEVENT_STRICT}) {
1414 require AnyEvent::Strict;
1415 }
1416
1417 if ($ENV{PERL_ANYEVENT_DEBUG_WRAP}) {
1418 require AnyEvent::Debug;
1419 AnyEvent::Debug::wrap ($ENV{PERL_ANYEVENT_DEBUG_WRAP});
1420 }
1421
1422 if (length $ENV{PERL_ANYEVENT_DEBUG_SHELL}) {
1423 require AnyEvent::Socket;
1424 require AnyEvent::Debug;
1425
1426 my $shell = $ENV{PERL_ANYEVENT_DEBUG_SHELL};
1427 $shell =~ s/\$\$/$$/g;
1428
1429 my ($host, $service) = AnyEvent::Socket::parse_hostport ($shell);
1430 $AnyEvent::Debug::SHELL = AnyEvent::Debug::shell ($host, $service);
1431 }
1432
1433 (shift @post_detect)->() while @post_detect;
1434 undef @post_detect;
1435
1436 *post_detect = sub(&) {
1437 shift->();
1438
1439 undef
1440 };
1441
1261 $MODEL 1442 $MODEL
1262} 1443}
1263 1444
1264sub AUTOLOAD { 1445for my $name (@methods) {
1265 (my $func = $AUTOLOAD) =~ s/.*://; 1446 *$name = sub {
1266 1447 detect;
1267 $method{$func} 1448 # we use goto because
1268 or Carp::croak "$func: not a valid method for AnyEvent objects"; 1449 # a) it makes the thunk more transparent
1269 1450 # b) it allows us to delete the thunk later
1270 detect unless $MODEL; 1451 goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
1271 1452 };
1272 my $class = shift;
1273 $class->$func (@_);
1274} 1453}
1275 1454
1276# utility function to dup a filehandle. this is used by many backends 1455# utility function to dup a filehandle. this is used by many backends
1277# to support binding more than one watcher per filehandle (they usually 1456# to support binding more than one watcher per filehandle (they usually
1278# allow only one watcher per fd, so we dup it to get a different one). 1457# allow only one watcher per fd, so we dup it to get a different one).
1292 1471
1293=head1 SIMPLIFIED AE API 1472=head1 SIMPLIFIED AE API
1294 1473
1295Starting with version 5.0, AnyEvent officially supports a second, much 1474Starting with version 5.0, AnyEvent officially supports a second, much
1296simpler, API that is designed to reduce the calling, typing and memory 1475simpler, API that is designed to reduce the calling, typing and memory
1297overhead. 1476overhead by using function call syntax and a fixed number of parameters.
1298 1477
1299See the L<AE> manpage for details. 1478See the L<AE> manpage for details.
1300 1479
1301=cut 1480=cut
1302 1481
1303package AE; 1482package AE;
1304 1483
1305our $VERSION = $AnyEvent::VERSION; 1484our $VERSION = $AnyEvent::VERSION;
1306 1485
1486sub _reset() {
1487 eval q{
1488 # fall back to the main API by default - backends and AnyEvent::Base
1489 # implementations can overwrite these.
1490
1307sub io($$$) { 1491 sub io($$$) {
1308 AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2]) 1492 AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1309} 1493 }
1310 1494
1311sub timer($$$) { 1495 sub timer($$$) {
1312 AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2]) 1496 AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
1313} 1497 }
1314 1498
1315sub signal($$) { 1499 sub signal($$) {
1316 AnyEvent->signal (signal => $_[0], cb => $_[1]) 1500 AnyEvent->signal (signal => $_[0], cb => $_[1])
1317} 1501 }
1318 1502
1319sub child($$) { 1503 sub child($$) {
1320 AnyEvent->child (pid => $_[0], cb => $_[1]) 1504 AnyEvent->child (pid => $_[0], cb => $_[1])
1321} 1505 }
1322 1506
1323sub idle($) { 1507 sub idle($) {
1324 AnyEvent->idle (cb => $_[0]) 1508 AnyEvent->idle (cb => $_[0]);
1325} 1509 }
1326 1510
1327sub cv(;&) { 1511 sub cv(;&) {
1328 AnyEvent->condvar (@_ ? (cb => $_[0]) : ()) 1512 AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
1329} 1513 }
1330 1514
1331sub now() { 1515 sub now() {
1332 AnyEvent->now 1516 AnyEvent->now
1333} 1517 }
1334 1518
1335sub now_update() { 1519 sub now_update() {
1336 AnyEvent->now_update 1520 AnyEvent->now_update
1337} 1521 }
1338 1522
1339sub time() { 1523 sub time() {
1340 AnyEvent->time 1524 AnyEvent->time
1525 }
1526
1527 *postpone = \&AnyEvent::postpone;
1528 *log = \&AnyEvent::log;
1529 };
1530 die if $@;
1341} 1531}
1532
1533BEGIN { _reset }
1342 1534
1343package AnyEvent::Base; 1535package AnyEvent::Base;
1344 1536
1345# default implementations for many methods 1537# default implementations for many methods
1346 1538
1347sub _time { 1539sub time {
1540 eval q{ # poor man's autoloading {}
1348 # probe for availability of Time::HiRes 1541 # probe for availability of Time::HiRes
1349 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { 1542 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1350 warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8; 1543 AnyEvent::log 8 => "AnyEvent: using Time::HiRes for sub-second timing accuracy."
1544 if $AnyEvent::VERBOSE >= 8;
1545 *time = sub { Time::HiRes::time () };
1351 *_time = \&Time::HiRes::time; 1546 *AE::time = \& Time::HiRes::time ;
1352 # if (eval "use POSIX (); (POSIX::times())... 1547 # if (eval "use POSIX (); (POSIX::times())...
1353 } else { 1548 } else {
1354 warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE; 1549 AnyEvent::log critical => "using built-in time(), WARNING, no sub-second resolution!";
1355 *_time = sub { time }; # epic fail 1550 *time = sub { CORE::time };
1551 *AE::time = sub (){ CORE::time };
1552 }
1553
1554 *now = \&time;
1356 } 1555 };
1556 die if $@;
1357 1557
1358 &_time 1558 &time
1359} 1559}
1360 1560
1361sub time { _time } 1561*now = \&time;
1362sub now { _time }
1363sub now_update { } 1562sub now_update { }
1364 1563
1564sub _poll {
1565 Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
1566}
1567
1365# default implementation for ->condvar 1568# default implementation for ->condvar
1569# in fact, the default should not be overwritten
1366 1570
1367sub condvar { 1571sub condvar {
1572 eval q{ # poor man's autoloading {}
1573 *condvar = sub {
1368 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar" 1574 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1575 };
1576
1577 *AE::cv = sub (;&) {
1578 bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
1579 };
1580 };
1581 die if $@;
1582
1583 &condvar
1369} 1584}
1370 1585
1371# default implementation for ->signal 1586# default implementation for ->signal
1372 1587
1373our $HAVE_ASYNC_INTERRUPT; 1588our $HAVE_ASYNC_INTERRUPT;
1374 1589
1375sub _have_async_interrupt() { 1590sub _have_async_interrupt() {
1376 $HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} 1591 $HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
1377 && eval "use Async::Interrupt 1.0 (); 1") 1592 && eval "use Async::Interrupt 1.02 (); 1")
1378 unless defined $HAVE_ASYNC_INTERRUPT; 1593 unless defined $HAVE_ASYNC_INTERRUPT;
1379 1594
1380 $HAVE_ASYNC_INTERRUPT 1595 $HAVE_ASYNC_INTERRUPT
1381} 1596}
1382 1597
1383our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); 1598our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1384our (%SIG_ASY, %SIG_ASY_W); 1599our (%SIG_ASY, %SIG_ASY_W);
1385our ($SIG_COUNT, $SIG_TW); 1600our ($SIG_COUNT, $SIG_TW);
1386 1601
1387sub _signal_exec {
1388 $HAVE_ASYNC_INTERRUPT
1389 ? $SIGPIPE_R->drain
1390 : sysread $SIGPIPE_R, my $dummy, 9;
1391
1392 while (%SIG_EV) {
1393 for (keys %SIG_EV) {
1394 delete $SIG_EV{$_};
1395 $_->() for values %{ $SIG_CB{$_} || {} };
1396 }
1397 }
1398}
1399
1400# install a dummy wakeup watcher to reduce signal catching latency 1602# install a dummy wakeup watcher to reduce signal catching latency
1603# used by Impls
1401sub _sig_add() { 1604sub _sig_add() {
1402 unless ($SIG_COUNT++) { 1605 unless ($SIG_COUNT++) {
1403 # try to align timer on a full-second boundary, if possible 1606 # try to align timer on a full-second boundary, if possible
1404 my $NOW = AE::now; 1607 my $NOW = AE::now;
1405 1608
1415 undef $SIG_TW 1618 undef $SIG_TW
1416 unless --$SIG_COUNT; 1619 unless --$SIG_COUNT;
1417} 1620}
1418 1621
1419our $_sig_name_init; $_sig_name_init = sub { 1622our $_sig_name_init; $_sig_name_init = sub {
1420 eval q{ # poor man's autoloading 1623 eval q{ # poor man's autoloading {}
1421 undef $_sig_name_init; 1624 undef $_sig_name_init;
1422 1625
1423 if (_have_async_interrupt) { 1626 if (_have_async_interrupt) {
1424 *sig2num = \&Async::Interrupt::sig2num; 1627 *sig2num = \&Async::Interrupt::sig2num;
1425 *sig2name = \&Async::Interrupt::sig2name; 1628 *sig2name = \&Async::Interrupt::sig2name;
1449 1652
1450sub signal { 1653sub signal {
1451 eval q{ # poor man's autoloading {} 1654 eval q{ # poor man's autoloading {}
1452 # probe for availability of Async::Interrupt 1655 # probe for availability of Async::Interrupt
1453 if (_have_async_interrupt) { 1656 if (_have_async_interrupt) {
1454 warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8; 1657 AnyEvent::log 8 => "using Async::Interrupt for race-free signal handling."
1658 if $AnyEvent::VERBOSE >= 8;
1455 1659
1456 $SIGPIPE_R = new Async::Interrupt::EventPipe; 1660 $SIGPIPE_R = new Async::Interrupt::EventPipe;
1457 $SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec; 1661 $SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1458 1662
1459 } else { 1663 } else {
1460 warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8; 1664 AnyEvent::log 8 => "using emulated perl signal handling with latency timer."
1461 1665 if $AnyEvent::VERBOSE >= 8;
1462 require Fcntl;
1463 1666
1464 if (AnyEvent::WIN32) { 1667 if (AnyEvent::WIN32) {
1465 require AnyEvent::Util; 1668 require AnyEvent::Util;
1466 1669
1467 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe (); 1670 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1468 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R; 1671 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1469 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case 1672 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1470 } else { 1673 } else {
1471 pipe $SIGPIPE_R, $SIGPIPE_W; 1674 pipe $SIGPIPE_R, $SIGPIPE_W;
1472 fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R; 1675 fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
1473 fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case 1676 fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
1474 1677
1475 # not strictly required, as $^F is normally 2, but let's make sure... 1678 # not strictly required, as $^F is normally 2, but let's make sure...
1476 fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; 1679 fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1477 fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; 1680 fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1478 } 1681 }
1479 1682
1480 $SIGPIPE_R 1683 $SIGPIPE_R
1481 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; 1684 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1482 1685
1483 $SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec; 1686 $SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1484 } 1687 }
1485 1688
1486 *signal = sub { 1689 *signal = $HAVE_ASYNC_INTERRUPT
1690 ? sub {
1487 my (undef, %arg) = @_; 1691 my (undef, %arg) = @_;
1488 1692
1489 my $signal = uc $arg{signal}
1490 or Carp::croak "required option 'signal' is missing";
1491
1492 if ($HAVE_ASYNC_INTERRUPT) {
1493 # async::interrupt 1693 # async::interrupt
1494
1495 $signal = sig2num $signal; 1694 my $signal = sig2num $arg{signal};
1496 $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; 1695 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1497 1696
1498 $SIG_ASY{$signal} ||= new Async::Interrupt 1697 $SIG_ASY{$signal} ||= new Async::Interrupt
1499 cb => sub { undef $SIG_EV{$signal} }, 1698 cb => sub { undef $SIG_EV{$signal} },
1500 signal => $signal, 1699 signal => $signal,
1501 pipe => [$SIGPIPE_R->filenos], 1700 pipe => [$SIGPIPE_R->filenos],
1502 pipe_autodrain => 0, 1701 pipe_autodrain => 0,
1503 ; 1702 ;
1504 1703
1505 } else { 1704 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1705 }
1706 : sub {
1707 my (undef, %arg) = @_;
1708
1506 # pure perl 1709 # pure perl
1507
1508 # AE::Util has been loaded in signal
1509 $signal = sig2name $signal; 1710 my $signal = sig2name $arg{signal};
1510 $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; 1711 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1511 1712
1512 $SIG{$signal} ||= sub { 1713 $SIG{$signal} ||= sub {
1513 local $!; 1714 local $!;
1514 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; 1715 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1515 undef $SIG_EV{$signal}; 1716 undef $SIG_EV{$signal};
1516 }; 1717 };
1517 1718
1518 # can't do signal processing without introducing races in pure perl, 1719 # can't do signal processing without introducing races in pure perl,
1519 # so limit the signal latency. 1720 # so limit the signal latency.
1520 _sig_add; 1721 _sig_add;
1521 }
1522 1722
1523 bless [$signal, $arg{cb}], "AnyEvent::Base::signal" 1723 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1724 }
1524 }; 1725 ;
1525 1726
1526 *AnyEvent::Base::signal::DESTROY = sub { 1727 *AnyEvent::Base::signal::DESTROY = sub {
1527 my ($signal, $cb) = @{$_[0]}; 1728 my ($signal, $cb) = @{$_[0]};
1528 1729
1529 _sig_del; 1730 _sig_del;
1536 # print weird messages, or just unconditionally exit 1737 # print weird messages, or just unconditionally exit
1537 # instead of getting the default action. 1738 # instead of getting the default action.
1538 undef $SIG{$signal} 1739 undef $SIG{$signal}
1539 unless keys %{ $SIG_CB{$signal} }; 1740 unless keys %{ $SIG_CB{$signal} };
1540 }; 1741 };
1742
1743 *_signal_exec = sub {
1744 $HAVE_ASYNC_INTERRUPT
1745 ? $SIGPIPE_R->drain
1746 : sysread $SIGPIPE_R, (my $dummy), 9;
1747
1748 while (%SIG_EV) {
1749 for (keys %SIG_EV) {
1750 delete $SIG_EV{$_};
1751 &$_ for values %{ $SIG_CB{$_} || {} };
1752 }
1753 }
1754 };
1541 }; 1755 };
1542 die if $@; 1756 die if $@;
1757
1543 &signal 1758 &signal
1544} 1759}
1545 1760
1546# default implementation for ->child 1761# default implementation for ->child
1547 1762
1548our %PID_CB; 1763our %PID_CB;
1549our $CHLD_W; 1764our $CHLD_W;
1550our $CHLD_DELAY_W; 1765our $CHLD_DELAY_W;
1551our $WNOHANG;
1552 1766
1767# used by many Impl's
1553sub _emit_childstatus($$) { 1768sub _emit_childstatus($$) {
1554 my (undef, $rpid, $rstatus) = @_; 1769 my (undef, $rpid, $rstatus) = @_;
1555 1770
1556 $_->($rpid, $rstatus) 1771 $_->($rpid, $rstatus)
1557 for values %{ $PID_CB{$rpid} || {} }, 1772 for values %{ $PID_CB{$rpid} || {} },
1558 values %{ $PID_CB{0} || {} }; 1773 values %{ $PID_CB{0} || {} };
1559} 1774}
1560 1775
1561sub _sigchld {
1562 my $pid;
1563
1564 AnyEvent->_emit_childstatus ($pid, $?)
1565 while ($pid = waitpid -1, $WNOHANG) > 0;
1566}
1567
1568sub child { 1776sub child {
1777 eval q{ # poor man's autoloading {}
1778 *_sigchld = sub {
1779 my $pid;
1780
1781 AnyEvent->_emit_childstatus ($pid, $?)
1782 while ($pid = waitpid -1, WNOHANG) > 0;
1783 };
1784
1785 *child = sub {
1569 my (undef, %arg) = @_; 1786 my (undef, %arg) = @_;
1570 1787
1571 defined (my $pid = $arg{pid} + 0) 1788 my $pid = $arg{pid};
1572 or Carp::croak "required option 'pid' is missing"; 1789 my $cb = $arg{cb};
1573 1790
1574 $PID_CB{$pid}{$arg{cb}} = $arg{cb}; 1791 $PID_CB{$pid}{$cb+0} = $cb;
1575 1792
1576 # WNOHANG is almost cetrainly 1 everywhere
1577 $WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1578 ? 1
1579 : eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1580
1581 unless ($CHLD_W) { 1793 unless ($CHLD_W) {
1582 $CHLD_W = AE::signal CHLD => \&_sigchld; 1794 $CHLD_W = AE::signal CHLD => \&_sigchld;
1583 # child could be a zombie already, so make at least one round 1795 # child could be a zombie already, so make at least one round
1584 &_sigchld; 1796 &_sigchld;
1585 } 1797 }
1586 1798
1587 bless [$pid, $arg{cb}], "AnyEvent::Base::child" 1799 bless [$pid, $cb+0], "AnyEvent::Base::child"
1588} 1800 };
1589 1801
1590sub AnyEvent::Base::child::DESTROY { 1802 *AnyEvent::Base::child::DESTROY = sub {
1591 my ($pid, $cb) = @{$_[0]}; 1803 my ($pid, $icb) = @{$_[0]};
1592 1804
1593 delete $PID_CB{$pid}{$cb}; 1805 delete $PID_CB{$pid}{$icb};
1594 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; 1806 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1595 1807
1596 undef $CHLD_W unless keys %PID_CB; 1808 undef $CHLD_W unless keys %PID_CB;
1809 };
1810 };
1811 die if $@;
1812
1813 &child
1597} 1814}
1598 1815
1599# idle emulation is done by simply using a timer, regardless 1816# idle emulation is done by simply using a timer, regardless
1600# of whether the process is idle or not, and not letting 1817# of whether the process is idle or not, and not letting
1601# the callback use more than 50% of the time. 1818# the callback use more than 50% of the time.
1602sub idle { 1819sub idle {
1820 eval q{ # poor man's autoloading {}
1821 *idle = sub {
1603 my (undef, %arg) = @_; 1822 my (undef, %arg) = @_;
1604 1823
1605 my ($cb, $w, $rcb) = $arg{cb}; 1824 my ($cb, $w, $rcb) = $arg{cb};
1606 1825
1607 $rcb = sub { 1826 $rcb = sub {
1608 if ($cb) { 1827 if ($cb) {
1609 $w = _time; 1828 $w = AE::time;
1610 &$cb; 1829 &$cb;
1611 $w = _time - $w; 1830 $w = AE::time - $w;
1612 1831
1613 # never use more then 50% of the time for the idle watcher, 1832 # never use more then 50% of the time for the idle watcher,
1614 # within some limits 1833 # within some limits
1615 $w = 0.0001 if $w < 0.0001; 1834 $w = 0.0001 if $w < 0.0001;
1616 $w = 5 if $w > 5; 1835 $w = 5 if $w > 5;
1617 1836
1618 $w = AE::timer $w, 0, $rcb; 1837 $w = AE::timer $w, 0, $rcb;
1619 } else { 1838 } else {
1620 # clean up... 1839 # clean up...
1621 undef $w; 1840 undef $w;
1622 undef $rcb; 1841 undef $rcb;
1842 }
1843 };
1844
1845 $w = AE::timer 0.05, 0, $rcb;
1846
1847 bless \\$cb, "AnyEvent::Base::idle"
1623 } 1848 };
1849
1850 *AnyEvent::Base::idle::DESTROY = sub {
1851 undef $${$_[0]};
1852 };
1624 }; 1853 };
1854 die if $@;
1625 1855
1626 $w = AE::timer 0.05, 0, $rcb; 1856 &idle
1627
1628 bless \\$cb, "AnyEvent::Base::idle"
1629}
1630
1631sub AnyEvent::Base::idle::DESTROY {
1632 undef $${$_[0]};
1633} 1857}
1634 1858
1635package AnyEvent::CondVar; 1859package AnyEvent::CondVar;
1636 1860
1637our @ISA = AnyEvent::CondVar::Base::; 1861our @ISA = AnyEvent::CondVar::Base::;
1862
1863# only to be used for subclassing
1864sub new {
1865 my $class = shift;
1866 bless AnyEvent->condvar (@_), $class
1867}
1638 1868
1639package AnyEvent::CondVar::Base; 1869package AnyEvent::CondVar::Base;
1640 1870
1641#use overload 1871#use overload
1642# '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, 1872# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1652 1882
1653sub _send { 1883sub _send {
1654 # nop 1884 # nop
1655} 1885}
1656 1886
1887sub _wait {
1888 AnyEvent->_poll until $_[0]{_ae_sent};
1889}
1890
1657sub send { 1891sub send {
1658 my $cv = shift; 1892 my $cv = shift;
1659 $cv->{_ae_sent} = [@_]; 1893 $cv->{_ae_sent} = [@_];
1660 (delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb}; 1894 (delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1661 $cv->_send; 1895 $cv->_send;
1668 1902
1669sub ready { 1903sub ready {
1670 $_[0]{_ae_sent} 1904 $_[0]{_ae_sent}
1671} 1905}
1672 1906
1673sub _wait {
1674 $WAITING
1675 and !$_[0]{_ae_sent}
1676 and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1677
1678 local $WAITING = 1;
1679 AnyEvent->one_event while !$_[0]{_ae_sent};
1680}
1681
1682sub recv { 1907sub recv {
1908 unless ($_[0]{_ae_sent}) {
1909 $WAITING
1910 and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
1911
1912 local $WAITING = 1;
1683 $_[0]->_wait; 1913 $_[0]->_wait;
1914 }
1684 1915
1685 Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak}; 1916 $_[0]{_ae_croak}
1686 wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0] 1917 and Carp::croak $_[0]{_ae_croak};
1918
1919 wantarray
1920 ? @{ $_[0]{_ae_sent} }
1921 : $_[0]{_ae_sent}[0]
1687} 1922}
1688 1923
1689sub cb { 1924sub cb {
1690 my $cv = shift; 1925 my $cv = shift;
1691 1926
1707 &{ $_[0]{_ae_end_cb} || sub { $_[0]->send } }; 1942 &{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1708} 1943}
1709 1944
1710# undocumented/compatibility with pre-3.4 1945# undocumented/compatibility with pre-3.4
1711*broadcast = \&send; 1946*broadcast = \&send;
1712*wait = \&_wait; 1947*wait = \&recv;
1713 1948
1714=head1 ERROR AND EXCEPTION HANDLING 1949=head1 ERROR AND EXCEPTION HANDLING
1715 1950
1716In general, AnyEvent does not do any error handling - it relies on the 1951In general, AnyEvent does not do any error handling - it relies on the
1717caller to do that if required. The L<AnyEvent::Strict> module (see also 1952caller to do that if required. The L<AnyEvent::Strict> module (see also
1744 1979
1745By default, AnyEvent will be completely silent except in fatal 1980By default, AnyEvent will be completely silent except in fatal
1746conditions. You can set this environment variable to make AnyEvent more 1981conditions. You can set this environment variable to make AnyEvent more
1747talkative. 1982talkative.
1748 1983
1749When set to C<1> or higher, causes AnyEvent to warn about unexpected 1984When set to C<5> or higher, causes AnyEvent to warn about unexpected
1750conditions, such as not being able to load the event model specified by 1985conditions, such as not being able to load the event model specified by
1751C<PERL_ANYEVENT_MODEL>. 1986C<PERL_ANYEVENT_MODEL>.
1752 1987
1753When set to C<2> or higher, cause AnyEvent to report to STDERR which event 1988When set to C<7> or higher, cause AnyEvent to report to STDERR which event
1754model it chooses. 1989model it chooses.
1755 1990
1756When set to C<8> or higher, then AnyEvent will report extra information on 1991When set to C<8> or higher, then AnyEvent will report extra information on
1757which optional modules it loads and how it implements certain features. 1992which optional modules it loads and how it implements certain features.
1758 1993
1764check the arguments passed to most method calls. If it finds any problems, 1999check the arguments passed to most method calls. If it finds any problems,
1765it will croak. 2000it will croak.
1766 2001
1767In other words, enables "strict" mode. 2002In other words, enables "strict" mode.
1768 2003
1769Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense> 2004Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1770>>, it is definitely recommended to keep it off in production. Keeping 2005>>, it is definitely recommended to keep it off in production. Keeping
1771C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs 2006C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1772can be very useful, however. 2007can be very useful, however.
1773 2008
2009=item C<PERL_ANYEVENT_DEBUG_SHELL>
2010
2011If this env variable is set, then its contents will be interpreted by
2012C<AnyEvent::Socket::parse_hostport> (after replacing every occurance of
2013C<$$> by the process pid) and an C<AnyEvent::Debug::shell> is bound on
2014that port. The shell object is saved in C<$AnyEvent::Debug::SHELL>.
2015
2016This takes place when the first watcher is created.
2017
2018For example, to bind a debug shell on a unix domain socket in
2019F<< /tmp/debug<pid>.sock >>, you could use this:
2020
2021 PERL_ANYEVENT_DEBUG_SHELL=/tmp/debug\$\$.sock perlprog
2022
2023Note that creating sockets in F</tmp> is very unsafe on multiuser
2024systems.
2025
2026=item C<PERL_ANYEVENT_DEBUG_WRAP>
2027
2028Can be set to C<0>, C<1> or C<2> and enables wrapping of all watchers for
2029debugging purposes. See C<AnyEvent::Debug::wrap> for details.
2030
1774=item C<PERL_ANYEVENT_MODEL> 2031=item C<PERL_ANYEVENT_MODEL>
1775 2032
1776This can be used to specify the event model to be used by AnyEvent, before 2033This can be used to specify the event model to be used by AnyEvent, before
1777auto detection and -probing kicks in. It must be a string consisting 2034auto detection and -probing kicks in.
1778entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended 2035
2036It normally is a string consisting entirely of ASCII letters (e.g. C<EV>
2037or C<IOAsync>). The string C<AnyEvent::Impl::> gets prepended and the
1779and the resulting module name is loaded and if the load was successful, 2038resulting module name is loaded and - if the load was successful - used as
1780used as event model. If it fails to load AnyEvent will proceed with 2039event model backend. If it fails to load then AnyEvent will proceed with
1781auto detection and -probing. 2040auto detection and -probing.
1782 2041
1783This functionality might change in future versions. 2042If the string ends with C<::> instead (e.g. C<AnyEvent::Impl::EV::>) then
2043nothing gets prepended and the module name is used as-is (hint: C<::> at
2044the end of a string designates a module name and quotes it appropriately).
1784 2045
1785For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you 2046For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1786could start your program like this: 2047could start your program like this:
1787 2048
1788 PERL_ANYEVENT_MODEL=Perl perl ... 2049 PERL_ANYEVENT_MODEL=Perl perl ...
1789 2050
1790=item C<PERL_ANYEVENT_PROTOCOLS> 2051=item C<PERL_ANYEVENT_PROTOCOLS>
1911 warn "read: $input\n"; # output what has been read 2172 warn "read: $input\n"; # output what has been read
1912 $cv->send if $input =~ /^q/i; # quit program if /^q/i 2173 $cv->send if $input =~ /^q/i; # quit program if /^q/i
1913 }, 2174 },
1914 ); 2175 );
1915 2176
1916 my $time_watcher; # can only be used once
1917
1918 sub new_timer {
1919 $timer = AnyEvent->timer (after => 1, cb => sub { 2177 my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1920 warn "timeout\n"; # print 'timeout' about every second 2178 warn "timeout\n"; # print 'timeout' at most every second
1921 &new_timer; # and restart the time
1922 }); 2179 });
1923 }
1924
1925 new_timer; # create first timer
1926 2180
1927 $cv->recv; # wait until user enters /^q/i 2181 $cv->recv; # wait until user enters /^q/i
1928 2182
1929=head1 REAL-WORLD EXAMPLE 2183=head1 REAL-WORLD EXAMPLE
1930 2184
2003 2257
2004The actual code goes further and collects all errors (C<die>s, exceptions) 2258The actual code goes further and collects all errors (C<die>s, exceptions)
2005that occurred during request processing. The C<result> method detects 2259that occurred during request processing. The C<result> method detects
2006whether an exception as thrown (it is stored inside the $txn object) 2260whether an exception as thrown (it is stored inside the $txn object)
2007and just throws the exception, which means connection errors and other 2261and just throws the exception, which means connection errors and other
2008problems get reported tot he code that tries to use the result, not in a 2262problems get reported to the code that tries to use the result, not in a
2009random callback. 2263random callback.
2010 2264
2011All of this enables the following usage styles: 2265All of this enables the following usage styles:
2012 2266
20131. Blocking: 22671. Blocking:
2187(even when used without AnyEvent), but most event loops have acceptable 2441(even when used without AnyEvent), but most event loops have acceptable
2188performance with or without AnyEvent. 2442performance with or without AnyEvent.
2189 2443
2190=item * The overhead AnyEvent adds is usually much smaller than the overhead of 2444=item * The overhead AnyEvent adds is usually much smaller than the overhead of
2191the actual event loop, only with extremely fast event loops such as EV 2445the actual event loop, only with extremely fast event loops such as EV
2192adds AnyEvent significant overhead. 2446does AnyEvent add significant overhead.
2193 2447
2194=item * You should avoid POE like the plague if you want performance or 2448=item * You should avoid POE like the plague if you want performance or
2195reasonable memory usage. 2449reasonable memory usage.
2196 2450
2197=back 2451=back
2374As you can see, the AnyEvent + EV combination even beats the 2628As you can see, the AnyEvent + EV combination even beats the
2375hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl 2629hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2376backend easily beats IO::Lambda and POE. 2630backend easily beats IO::Lambda and POE.
2377 2631
2378And even the 100% non-blocking version written using the high-level (and 2632And even the 100% non-blocking version written using the high-level (and
2379slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a 2633slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2380large margin, even though it does all of DNS, tcp-connect and socket I/O 2634higher level ("unoptimised") abstractions by a large margin, even though
2381in a non-blocking way. 2635it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2382 2636
2383The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and 2637The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2384F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are 2638F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2385part of the IO::lambda distribution and were used without any changes. 2639part of the IO::Lambda distribution and were used without any changes.
2386 2640
2387 2641
2388=head1 SIGNALS 2642=head1 SIGNALS
2389 2643
2390AnyEvent currently installs handlers for these signals: 2644AnyEvent currently installs handlers for these signals:
2427 unless defined $SIG{PIPE}; 2681 unless defined $SIG{PIPE};
2428 2682
2429=head1 RECOMMENDED/OPTIONAL MODULES 2683=head1 RECOMMENDED/OPTIONAL MODULES
2430 2684
2431One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and 2685One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2432it's built-in modules) are required to use it. 2686its built-in modules) are required to use it.
2433 2687
2434That does not mean that AnyEvent won't take advantage of some additional 2688That does not mean that AnyEvent won't take advantage of some additional
2435modules if they are installed. 2689modules if they are installed.
2436 2690
2437This section epxlains which additional modules will be used, and how they 2691This section explains which additional modules will be used, and how they
2438affect AnyEvent's operetion. 2692affect AnyEvent's operation.
2439 2693
2440=over 4 2694=over 4
2441 2695
2442=item L<Async::Interrupt> 2696=item L<Async::Interrupt>
2443 2697
2448catch the signals) with some delay (default is 10 seconds, look for 2702catch the signals) with some delay (default is 10 seconds, look for
2449C<$AnyEvent::MAX_SIGNAL_LATENCY>). 2703C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2450 2704
2451If this module is available, then it will be used to implement signal 2705If this module is available, then it will be used to implement signal
2452catching, which means that signals will not be delayed, and the event loop 2706catching, which means that signals will not be delayed, and the event loop
2453will not be interrupted regularly, which is more efficient (And good for 2707will not be interrupted regularly, which is more efficient (and good for
2454battery life on laptops). 2708battery life on laptops).
2455 2709
2456This affects not just the pure-perl event loop, but also other event loops 2710This affects not just the pure-perl event loop, but also other event loops
2457that have no signal handling on their own (e.g. Glib, Tk, Qt). 2711that have no signal handling on their own (e.g. Glib, Tk, Qt).
2458 2712
2470automatic timer adjustments even when no monotonic clock is available, 2724automatic timer adjustments even when no monotonic clock is available,
2471can take avdantage of advanced kernel interfaces such as C<epoll> and 2725can take avdantage of advanced kernel interfaces such as C<epoll> and
2472C<kqueue>, and is the fastest backend I<by far>. You can even embed 2726C<kqueue>, and is the fastest backend I<by far>. You can even embed
2473L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>). 2727L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2474 2728
2729If you only use backends that rely on another event loop (e.g. C<Tk>),
2730then this module will do nothing for you.
2731
2475=item L<Guard> 2732=item L<Guard>
2476 2733
2477The guard module, when used, will be used to implement 2734The guard module, when used, will be used to implement
2478C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a 2735C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2479lot less memory), but otherwise doesn't affect guard operation much. It is 2736lot less memory), but otherwise doesn't affect guard operation much. It is
2480purely used for performance. 2737purely used for performance.
2481 2738
2482=item L<JSON> and L<JSON::XS> 2739=item L<JSON> and L<JSON::XS>
2483 2740
2484This module is required when you want to read or write JSON data via 2741One of these modules is required when you want to read or write JSON data
2485L<AnyEvent::Handle>. It is also written in pure-perl, but can take 2742via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2486advantage of the ultra-high-speed L<JSON::XS> module when it is installed. 2743advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2487
2488In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2489installed.
2490 2744
2491=item L<Net::SSLeay> 2745=item L<Net::SSLeay>
2492 2746
2493Implementing TLS/SSL in Perl is certainly interesting, but not very 2747Implementing TLS/SSL in Perl is certainly interesting, but not very
2494worthwhile: If this module is installed, then L<AnyEvent::Handle> (with 2748worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2495the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL. 2749the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2496 2750
2497=item L<Time::HiRes> 2751=item L<Time::HiRes>
2498 2752
2499This module is part of perl since release 5.008. It will be used when the 2753This module is part of perl since release 5.008. It will be used when the
2500chosen event library does not come with a timing source on it's own. The 2754chosen event library does not come with a timing source of its own. The
2501pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to 2755pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2502try to use a monotonic clock for timing stability. 2756try to use a monotonic clock for timing stability.
2503 2757
2504=back 2758=back
2505 2759
2506 2760
2507=head1 FORK 2761=head1 FORK
2508 2762
2509Most event libraries are not fork-safe. The ones who are usually are 2763Most event libraries are not fork-safe. The ones who are usually are
2510because they rely on inefficient but fork-safe C<select> or C<poll> 2764because they rely on inefficient but fork-safe C<select> or C<poll> calls
2511calls. Only L<EV> is fully fork-aware. 2765- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
2766are usually badly thought-out hacks that are incompatible with fork in
2767one way or another. Only L<EV> is fully fork-aware and ensures that you
2768continue event-processing in both parent and child (or both, if you know
2769what you are doing).
2770
2771This means that, in general, you cannot fork and do event processing in
2772the child if the event library was initialised before the fork (which
2773usually happens when the first AnyEvent watcher is created, or the library
2774is loaded).
2512 2775
2513If you have to fork, you must either do so I<before> creating your first 2776If you have to fork, you must either do so I<before> creating your first
2514watcher OR you must not use AnyEvent at all in the child OR you must do 2777watcher OR you must not use AnyEvent at all in the child OR you must do
2515something completely out of the scope of AnyEvent. 2778something completely out of the scope of AnyEvent.
2779
2780The problem of doing event processing in the parent I<and> the child
2781is much more complicated: even for backends that I<are> fork-aware or
2782fork-safe, their behaviour is not usually what you want: fork clones all
2783watchers, that means all timers, I/O watchers etc. are active in both
2784parent and child, which is almost never what you want. USing C<exec>
2785to start worker children from some kind of manage rprocess is usually
2786preferred, because it is much easier and cleaner, at the expense of having
2787to have another binary.
2516 2788
2517 2789
2518=head1 SECURITY CONSIDERATIONS 2790=head1 SECURITY CONSIDERATIONS
2519 2791
2520AnyEvent can be forced to load any event model via 2792AnyEvent can be forced to load any event model via
2550pronounced). 2822pronounced).
2551 2823
2552 2824
2553=head1 SEE ALSO 2825=head1 SEE ALSO
2554 2826
2555Utility functions: L<AnyEvent::Util>. 2827Tutorial/Introduction: L<AnyEvent::Intro>.
2556 2828
2557Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>, 2829FAQ: L<AnyEvent::FAQ>.
2558L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. 2830
2831Utility functions: L<AnyEvent::Util> (misc. grab-bag), L<AnyEvent::Log>
2832(simply logging).
2833
2834Development/Debugging: L<AnyEvent::Strict> (stricter checking),
2835L<AnyEvent::Debug> (interactive shell, watcher tracing).
2836
2837Supported event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>,
2838L<Glib::EV>, L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>,
2839L<Qt>, L<POE>, L<FLTK>.
2559 2840
2560Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, 2841Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2561L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, 2842L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2562L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, 2843L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2563L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>. 2844L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>,
2845L<AnyEvent::Impl::FLTK>.
2564 2846
2565Non-blocking file handles, sockets, TCP clients and 2847Non-blocking handles, pipes, stream sockets, TCP clients and
2566servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>. 2848servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2567 2849
2568Asynchronous DNS: L<AnyEvent::DNS>. 2850Asynchronous DNS: L<AnyEvent::DNS>.
2569 2851
2570Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, 2852Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2571L<Coro::Event>,
2572 2853
2573Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>, 2854Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2574L<AnyEvent::HTTP>. 2855L<AnyEvent::HTTP>.
2575 2856
2576 2857
2577=head1 AUTHOR 2858=head1 AUTHOR
2578 2859

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