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1=head1 NAME 1=head1 NAME
2 2
3AnyEvent - the DBI of event loop programming 3AnyEvent - the DBI of event loop programming
4 4
5EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt 5EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt,
6and POE are various supported event loops/environments. 6FLTK and POE are various supported event loops/environments.
7 7
8=head1 SYNOPSIS 8=head1 SYNOPSIS
9 9
10 use AnyEvent; 10 use AnyEvent;
11 11
12 # if you prefer function calls, look at the AE manpage for
13 # an alternative API.
14
12 # file descriptor readable 15 # file handle or descriptor readable
13 my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... }); 16 my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
14 17
15 # one-shot or repeating timers 18 # one-shot or repeating timers
16 my $w = AnyEvent->timer (after => $seconds, cb => sub { ... }); 19 my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
17 my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ... 20 my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...);
18 21
19 print AnyEvent->now; # prints current event loop time 22 print AnyEvent->now; # prints current event loop time
20 print AnyEvent->time; # think Time::HiRes::time or simply CORE::time. 23 print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
21 24
22 # POSIX signal 25 # POSIX signal
43in a tutorial or some gentle introduction, have a look at the 46in a tutorial or some gentle introduction, have a look at the
44L<AnyEvent::Intro> manpage. 47L<AnyEvent::Intro> manpage.
45 48
46=head1 SUPPORT 49=head1 SUPPORT
47 50
51An FAQ document is available as L<AnyEvent::FAQ>.
52
48There is a mailinglist for discussing all things AnyEvent, and an IRC 53There also is a mailinglist for discussing all things AnyEvent, and an IRC
49channel, too. 54channel, too.
50 55
51See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software 56See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
52Repository>, at L<http://anyevent.schmorp.de>, for more info. 57Repository>, at L<http://anyevent.schmorp.de>, for more info.
53 58
73module users into the same thing by forcing them to use the same event 78module users into the same thing by forcing them to use the same event
74model you use. 79model you use.
75 80
76For modules like POE or IO::Async (which is a total misnomer as it is 81For modules like POE or IO::Async (which is a total misnomer as it is
77actually doing all I/O I<synchronously>...), using them in your module is 82actually doing all I/O I<synchronously>...), using them in your module is
78like joining a cult: After you joined, you are dependent on them and you 83like joining a cult: After you join, you are dependent on them and you
79cannot use anything else, as they are simply incompatible to everything 84cannot use anything else, as they are simply incompatible to everything
80that isn't them. What's worse, all the potential users of your 85that isn't them. What's worse, all the potential users of your
81module are I<also> forced to use the same event loop you use. 86module are I<also> forced to use the same event loop you use.
82 87
83AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works 88AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
84fine. AnyEvent + Tk works fine etc. etc. but none of these work together 89fine. AnyEvent + Tk works fine etc. etc. but none of these work together
85with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if 90with the rest: POE + EV? No go. Tk + Event? No go. Again: if your module
86your module uses one of those, every user of your module has to use it, 91uses one of those, every user of your module has to use it, too. But if
87too. But if your module uses AnyEvent, it works transparently with all 92your module uses AnyEvent, it works transparently with all event models it
88event models it supports (including stuff like IO::Async, as long as those 93supports (including stuff like IO::Async, as long as those use one of the
89use one of the supported event loops. It is trivial to add new event loops 94supported event loops. It is easy to add new event loops to AnyEvent, too,
90to AnyEvent, too, so it is future-proof). 95so it is future-proof).
91 96
92In addition to being free of having to use I<the one and only true event 97In addition to being free of having to use I<the one and only true event
93model>, AnyEvent also is free of bloat and policy: with POE or similar 98model>, AnyEvent also is free of bloat and policy: with POE or similar
94modules, you get an enormous amount of code and strict rules you have to 99modules, you get an enormous amount of code and strict rules you have to
95follow. AnyEvent, on the other hand, is lean and up to the point, by only 100follow. AnyEvent, on the other hand, is lean and to the point, by only
96offering the functionality that is necessary, in as thin as a wrapper as 101offering the functionality that is necessary, in as thin as a wrapper as
97technically possible. 102technically possible.
98 103
99Of course, AnyEvent comes with a big (and fully optional!) toolbox 104Of course, AnyEvent comes with a big (and fully optional!) toolbox
100of useful functionality, such as an asynchronous DNS resolver, 100% 105of useful functionality, such as an asynchronous DNS resolver, 100%
106useful) and you want to force your users to use the one and only event 111useful) and you want to force your users to use the one and only event
107model, you should I<not> use this module. 112model, you should I<not> use this module.
108 113
109=head1 DESCRIPTION 114=head1 DESCRIPTION
110 115
111L<AnyEvent> provides an identical interface to multiple event loops. This 116L<AnyEvent> provides a uniform interface to various event loops. This
112allows module authors to utilise an event loop without forcing module 117allows module authors to use event loop functionality without forcing
113users to use the same event loop (as only a single event loop can coexist 118module users to use a specific event loop implementation (since more
114peacefully at any one time). 119than one event loop cannot coexist peacefully).
115 120
116The interface itself is vaguely similar, but not identical to the L<Event> 121The interface itself is vaguely similar, but not identical to the L<Event>
117module. 122module.
118 123
119During the first call of any watcher-creation method, the module tries 124During the first call of any watcher-creation method, the module tries
120to detect the currently loaded event loop by probing whether one of the 125to detect the currently loaded event loop by probing whether one of the
121following modules is already loaded: L<EV>, 126following modules is already loaded: L<EV>, L<AnyEvent::Loop>,
122L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>, 127L<Event>, L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. The first one
123L<POE>. The first one found is used. If none are found, the module tries 128found is used. If none are detected, the module tries to load the first
124to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl 129four modules in the order given; but note that if L<EV> is not
125adaptor should always succeed) in the order given. The first one that can 130available, the pure-perl L<AnyEvent::Loop> should always work, so
126be successfully loaded will be used. If, after this, still none could be 131the other two are not normally tried.
127found, AnyEvent will fall back to a pure-perl event loop, which is not
128very efficient, but should work everywhere.
129 132
130Because AnyEvent first checks for modules that are already loaded, loading 133Because AnyEvent first checks for modules that are already loaded, loading
131an event model explicitly before first using AnyEvent will likely make 134an event model explicitly before first using AnyEvent will likely make
132that model the default. For example: 135that model the default. For example:
133 136
135 use AnyEvent; 138 use AnyEvent;
136 139
137 # .. AnyEvent will likely default to Tk 140 # .. AnyEvent will likely default to Tk
138 141
139The I<likely> means that, if any module loads another event model and 142The I<likely> means that, if any module loads another event model and
140starts using it, all bets are off. Maybe you should tell their authors to 143starts using it, all bets are off - this case should be very rare though,
141use AnyEvent so their modules work together with others seamlessly... 144as very few modules hardcode event loops without announcing this very
145loudly.
142 146
143The pure-perl implementation of AnyEvent is called 147The pure-perl implementation of AnyEvent is called C<AnyEvent::Loop>. Like
144C<AnyEvent::Impl::Perl>. Like other event modules you can load it 148other event modules you can load it explicitly and enjoy the high
145explicitly and enjoy the high availability of that event loop :) 149availability of that event loop :)
146 150
147=head1 WATCHERS 151=head1 WATCHERS
148 152
149AnyEvent has the central concept of a I<watcher>, which is an object that 153AnyEvent has the central concept of a I<watcher>, which is an object that
150stores relevant data for each kind of event you are waiting for, such as 154stores relevant data for each kind of event you are waiting for, such as
155callback when the event occurs (of course, only when the event model 159callback when the event occurs (of course, only when the event model
156is in control). 160is in control).
157 161
158Note that B<callbacks must not permanently change global variables> 162Note that B<callbacks must not permanently change global variables>
159potentially in use by the event loop (such as C<$_> or C<$[>) and that B<< 163potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<
160callbacks must not C<die> >>. The former is good programming practise in 164callbacks must not C<die> >>. The former is good programming practice in
161Perl and the latter stems from the fact that exception handling differs 165Perl and the latter stems from the fact that exception handling differs
162widely between event loops. 166widely between event loops.
163 167
164To disable the watcher you have to destroy it (e.g. by setting the 168To disable a watcher you have to destroy it (e.g. by setting the
165variable you store it in to C<undef> or otherwise deleting all references 169variable you store it in to C<undef> or otherwise deleting all references
166to it). 170to it).
167 171
168All watchers are created by calling a method on the C<AnyEvent> class. 172All watchers are created by calling a method on the C<AnyEvent> class.
169 173
170Many watchers either are used with "recursion" (repeating timers for 174Many watchers either are used with "recursion" (repeating timers for
171example), or need to refer to their watcher object in other ways. 175example), or need to refer to their watcher object in other ways.
172 176
173An any way to achieve that is this pattern: 177One way to achieve that is this pattern:
174 178
175 my $w; $w = AnyEvent->type (arg => value ..., cb => sub { 179 my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
176 # you can use $w here, for example to undef it 180 # you can use $w here, for example to undef it
177 undef $w; 181 undef $w;
178 }); 182 });
210 214
211The I/O watcher might use the underlying file descriptor or a copy of it. 215The I/O watcher might use the underlying file descriptor or a copy of it.
212You must not close a file handle as long as any watcher is active on the 216You must not close a file handle as long as any watcher is active on the
213underlying file descriptor. 217underlying file descriptor.
214 218
215Some event loops issue spurious readyness notifications, so you should 219Some event loops issue spurious readiness notifications, so you should
216always use non-blocking calls when reading/writing from/to your file 220always use non-blocking calls when reading/writing from/to your file
217handles. 221handles.
218 222
219Example: wait for readability of STDIN, then read a line and disable the 223Example: wait for readability of STDIN, then read a line and disable the
220watcher. 224watcher.
244 248
245Although the callback might get passed parameters, their value and 249Although the callback might get passed parameters, their value and
246presence is undefined and you cannot rely on them. Portable AnyEvent 250presence is undefined and you cannot rely on them. Portable AnyEvent
247callbacks cannot use arguments passed to time watcher callbacks. 251callbacks cannot use arguments passed to time watcher callbacks.
248 252
249The callback will normally be invoked once only. If you specify another 253The callback will normally be invoked only once. If you specify another
250parameter, C<interval>, as a strictly positive number (> 0), then the 254parameter, C<interval>, as a strictly positive number (> 0), then the
251callback will be invoked regularly at that interval (in fractional 255callback will be invoked regularly at that interval (in fractional
252seconds) after the first invocation. If C<interval> is specified with a 256seconds) after the first invocation. If C<interval> is specified with a
253false value, then it is treated as if it were missing. 257false value, then it is treated as if it were not specified at all.
254 258
255The callback will be rescheduled before invoking the callback, but no 259The callback will be rescheduled before invoking the callback, but no
256attempt is done to avoid timer drift in most backends, so the interval is 260attempt is made to avoid timer drift in most backends, so the interval is
257only approximate. 261only approximate.
258 262
259Example: fire an event after 7.7 seconds. 263Example: fire an event after 7.7 seconds.
260 264
261 my $w = AnyEvent->timer (after => 7.7, cb => sub { 265 my $w = AnyEvent->timer (after => 7.7, cb => sub {
279 283
280While most event loops expect timers to specified in a relative way, they 284While most event loops expect timers to specified in a relative way, they
281use absolute time internally. This makes a difference when your clock 285use absolute time internally. This makes a difference when your clock
282"jumps", for example, when ntp decides to set your clock backwards from 286"jumps", for example, when ntp decides to set your clock backwards from
283the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to 287the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to
284fire "after" a second might actually take six years to finally fire. 288fire "after a second" might actually take six years to finally fire.
285 289
286AnyEvent cannot compensate for this. The only event loop that is conscious 290AnyEvent cannot compensate for this. The only event loop that is conscious
287about these issues is L<EV>, which offers both relative (ev_timer, based 291of these issues is L<EV>, which offers both relative (ev_timer, based
288on true relative time) and absolute (ev_periodic, based on wallclock time) 292on true relative time) and absolute (ev_periodic, based on wallclock time)
289timers. 293timers.
290 294
291AnyEvent always prefers relative timers, if available, matching the 295AnyEvent always prefers relative timers, if available, matching the
292AnyEvent API. 296AnyEvent API.
314I<In almost all cases (in all cases if you don't care), this is the 318I<In almost all cases (in all cases if you don't care), this is the
315function to call when you want to know the current time.> 319function to call when you want to know the current time.>
316 320
317This function is also often faster then C<< AnyEvent->time >>, and 321This function is also often faster then C<< AnyEvent->time >>, and
318thus the preferred method if you want some timestamp (for example, 322thus the preferred method if you want some timestamp (for example,
319L<AnyEvent::Handle> uses this to update it's activity timeouts). 323L<AnyEvent::Handle> uses this to update its activity timeouts).
320 324
321The rest of this section is only of relevance if you try to be very exact 325The rest of this section is only of relevance if you try to be very exact
322with your timing, you can skip it without bad conscience. 326with your timing; you can skip it without a bad conscience.
323 327
324For a practical example of when these times differ, consider L<Event::Lib> 328For a practical example of when these times differ, consider L<Event::Lib>
325and L<EV> and the following set-up: 329and L<EV> and the following set-up:
326 330
327The event loop is running and has just invoked one of your callback at 331The event loop is running and has just invoked one of your callbacks at
328time=500 (assume no other callbacks delay processing). In your callback, 332time=500 (assume no other callbacks delay processing). In your callback,
329you wait a second by executing C<sleep 1> (blocking the process for a 333you wait a second by executing C<sleep 1> (blocking the process for a
330second) and then (at time=501) you create a relative timer that fires 334second) and then (at time=501) you create a relative timer that fires
331after three seconds. 335after three seconds.
332 336
352difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into 356difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
353account. 357account.
354 358
355=item AnyEvent->now_update 359=item AnyEvent->now_update
356 360
357Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache 361Some event loops (such as L<EV> or L<AnyEvent::Loop>) cache the current
358the current time for each loop iteration (see the discussion of L<< 362time for each loop iteration (see the discussion of L<< AnyEvent->now >>,
359AnyEvent->now >>, above). 363above).
360 364
361When a callback runs for a long time (or when the process sleeps), then 365When a callback runs for a long time (or when the process sleeps), then
362this "current" time will differ substantially from the real time, which 366this "current" time will differ substantially from the real time, which
363might affect timers and time-outs. 367might affect timers and time-outs.
364 368
403 407
404Example: exit on SIGINT 408Example: exit on SIGINT
405 409
406 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); 410 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
407 411
412=head3 Restart Behaviour
413
414While restart behaviour is up to the event loop implementation, most will
415not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
416pure perl implementation).
417
418=head3 Safe/Unsafe Signals
419
420Perl signals can be either "safe" (synchronous to opcode handling) or
421"unsafe" (asynchronous) - the former might get delayed indefinitely, the
422latter might corrupt your memory.
423
424AnyEvent signal handlers are, in addition, synchronous to the event loop,
425i.e. they will not interrupt your running perl program but will only be
426called as part of the normal event handling (just like timer, I/O etc.
427callbacks, too).
428
408=head3 Signal Races, Delays and Workarounds 429=head3 Signal Races, Delays and Workarounds
409 430
410Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching 431Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
411callbacks to signals in a generic way, which is a pity, as you cannot 432callbacks to signals in a generic way, which is a pity, as you cannot
412do race-free signal handling in perl, requiring C libraries for 433do race-free signal handling in perl, requiring C libraries for
413this. AnyEvent will try to do it's best, which means in some cases, 434this. AnyEvent will try to do its best, which means in some cases,
414signals will be delayed. The maximum time a signal might be delayed is 435signals will be delayed. The maximum time a signal might be delayed is
415specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This 436specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
416variable can be changed only before the first signal watcher is created, 437variable can be changed only before the first signal watcher is created,
417and should be left alone otherwise. This variable determines how often 438and should be left alone otherwise. This variable determines how often
418AnyEvent polls for signals (in case a wake-up was missed). Higher values 439AnyEvent polls for signals (in case a wake-up was missed). Higher values
420saving. 441saving.
421 442
422All these problems can be avoided by installing the optional 443All these problems can be avoided by installing the optional
423L<Async::Interrupt> module, which works with most event loops. It will not 444L<Async::Interrupt> module, which works with most event loops. It will not
424work with inherently broken event loops such as L<Event> or L<Event::Lib> 445work with inherently broken event loops such as L<Event> or L<Event::Lib>
425(and not with L<POE> currently, as POE does it's own workaround with 446(and not with L<POE> currently, as POE does its own workaround with
426one-second latency). For those, you just have to suffer the delays. 447one-second latency). For those, you just have to suffer the delays.
427 448
428=head2 CHILD PROCESS WATCHERS 449=head2 CHILD PROCESS WATCHERS
429 450
430 $w = AnyEvent->child (pid => <process id>, cb => <callback>); 451 $w = AnyEvent->child (pid => <process id>, cb => <callback>);
431 452
432You can also watch on a child process exit and catch its exit status. 453You can also watch for a child process exit and catch its exit status.
433 454
434The child process is specified by the C<pid> argument (one some backends, 455The child process is specified by the C<pid> argument (on some backends,
435using C<0> watches for any child process exit, on others this will 456using C<0> watches for any child process exit, on others this will
436croak). The watcher will be triggered only when the child process has 457croak). The watcher will be triggered only when the child process has
437finished and an exit status is available, not on any trace events 458finished and an exit status is available, not on any trace events
438(stopped/continued). 459(stopped/continued).
439 460
461thing in an AnyEvent program, you I<have> to create at least one 482thing in an AnyEvent program, you I<have> to create at least one
462watcher before you C<fork> the child (alternatively, you can call 483watcher before you C<fork> the child (alternatively, you can call
463C<AnyEvent::detect>). 484C<AnyEvent::detect>).
464 485
465As most event loops do not support waiting for child events, they will be 486As most event loops do not support waiting for child events, they will be
466emulated by AnyEvent in most cases, in which the latency and race problems 487emulated by AnyEvent in most cases, in which case the latency and race
467mentioned in the description of signal watchers apply. 488problems mentioned in the description of signal watchers apply.
468 489
469Example: fork a process and wait for it 490Example: fork a process and wait for it
470 491
471 my $done = AnyEvent->condvar; 492 my $done = AnyEvent->condvar;
472 493
486 507
487=head2 IDLE WATCHERS 508=head2 IDLE WATCHERS
488 509
489 $w = AnyEvent->idle (cb => <callback>); 510 $w = AnyEvent->idle (cb => <callback>);
490 511
491Sometimes there is a need to do something, but it is not so important 512This will repeatedly invoke the callback after the process becomes idle,
492to do it instantly, but only when there is nothing better to do. This 513until either the watcher is destroyed or new events have been detected.
493"nothing better to do" is usually defined to be "no other events need
494attention by the event loop".
495 514
496Idle watchers ideally get invoked when the event loop has nothing 515Idle watchers are useful when there is a need to do something, but it
497better to do, just before it would block the process to wait for new 516is not so important (or wise) to do it instantly. The callback will be
498events. Instead of blocking, the idle watcher is invoked. 517invoked only when there is "nothing better to do", which is usually
518defined as "all outstanding events have been handled and no new events
519have been detected". That means that idle watchers ideally get invoked
520when the event loop has just polled for new events but none have been
521detected. Instead of blocking to wait for more events, the idle watchers
522will be invoked.
499 523
500Most event loops unfortunately do not really support idle watchers (only 524Unfortunately, most event loops do not really support idle watchers (only
501EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent 525EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
502will simply call the callback "from time to time". 526will simply call the callback "from time to time".
503 527
504Example: read lines from STDIN, but only process them when the 528Example: read lines from STDIN, but only process them when the
505program is otherwise idle: 529program is otherwise idle:
533will actively watch for new events and call your callbacks. 557will actively watch for new events and call your callbacks.
534 558
535AnyEvent is slightly different: it expects somebody else to run the event 559AnyEvent is slightly different: it expects somebody else to run the event
536loop and will only block when necessary (usually when told by the user). 560loop and will only block when necessary (usually when told by the user).
537 561
538The instrument to do that is called a "condition variable", so called 562The tool to do that is called a "condition variable", so called because
539because they represent a condition that must become true. 563they represent a condition that must become true.
540 564
541Now is probably a good time to look at the examples further below. 565Now is probably a good time to look at the examples further below.
542 566
543Condition variables can be created by calling the C<< AnyEvent->condvar 567Condition variables can be created by calling the C<< AnyEvent->condvar
544>> method, usually without arguments. The only argument pair allowed is 568>> method, usually without arguments. The only argument pair allowed is
549After creation, the condition variable is "false" until it becomes "true" 573After creation, the condition variable is "false" until it becomes "true"
550by calling the C<send> method (or calling the condition variable as if it 574by calling the C<send> method (or calling the condition variable as if it
551were a callback, read about the caveats in the description for the C<< 575were a callback, read about the caveats in the description for the C<<
552->send >> method). 576->send >> method).
553 577
554Condition variables are similar to callbacks, except that you can 578Since condition variables are the most complex part of the AnyEvent API, here are
555optionally wait for them. They can also be called merge points - points 579some different mental models of what they are - pick the ones you can connect to:
556in time where multiple outstanding events have been processed. And yet 580
557another way to call them is transactions - each condition variable can be 581=over 4
558used to represent a transaction, which finishes at some point and delivers 582
559a result. And yet some people know them as "futures" - a promise to 583=item * Condition variables are like callbacks - you can call them (and pass them instead
560compute/deliver something that you can wait for. 584of callbacks). Unlike callbacks however, you can also wait for them to be called.
585
586=item * Condition variables are signals - one side can emit or send them,
587the other side can wait for them, or install a handler that is called when
588the signal fires.
589
590=item * Condition variables are like "Merge Points" - points in your program
591where you merge multiple independent results/control flows into one.
592
593=item * Condition variables represent a transaction - functions that start
594some kind of transaction can return them, leaving the caller the choice
595between waiting in a blocking fashion, or setting a callback.
596
597=item * Condition variables represent future values, or promises to deliver
598some result, long before the result is available.
599
600=back
561 601
562Condition variables are very useful to signal that something has finished, 602Condition variables are very useful to signal that something has finished,
563for example, if you write a module that does asynchronous http requests, 603for example, if you write a module that does asynchronous http requests,
564then a condition variable would be the ideal candidate to signal the 604then a condition variable would be the ideal candidate to signal the
565availability of results. The user can either act when the callback is 605availability of results. The user can either act when the callback is
578 618
579Condition variables are represented by hash refs in perl, and the keys 619Condition variables are represented by hash refs in perl, and the keys
580used by AnyEvent itself are all named C<_ae_XXX> to make subclassing 620used by AnyEvent itself are all named C<_ae_XXX> to make subclassing
581easy (it is often useful to build your own transaction class on top of 621easy (it is often useful to build your own transaction class on top of
582AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call 622AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call
583it's C<new> method in your own C<new> method. 623its C<new> method in your own C<new> method.
584 624
585There are two "sides" to a condition variable - the "producer side" which 625There are two "sides" to a condition variable - the "producer side" which
586eventually calls C<< -> send >>, and the "consumer side", which waits 626eventually calls C<< -> send >>, and the "consumer side", which waits
587for the send to occur. 627for the send to occur.
588 628
589Example: wait for a timer. 629Example: wait for a timer.
590 630
591 # wait till the result is ready 631 # condition: "wait till the timer is fired"
592 my $result_ready = AnyEvent->condvar; 632 my $timer_fired = AnyEvent->condvar;
593 633
594 # do something such as adding a timer 634 # create the timer - we could wait for, say
595 # or socket watcher the calls $result_ready->send 635 # a handle becomign ready, or even an
596 # when the "result" is ready. 636 # AnyEvent::HTTP request to finish, but
597 # in this case, we simply use a timer: 637 # in this case, we simply use a timer:
598 my $w = AnyEvent->timer ( 638 my $w = AnyEvent->timer (
599 after => 1, 639 after => 1,
600 cb => sub { $result_ready->send }, 640 cb => sub { $timer_fired->send },
601 ); 641 );
602 642
603 # this "blocks" (while handling events) till the callback 643 # this "blocks" (while handling events) till the callback
604 # calls ->send 644 # calls ->send
605 $result_ready->recv; 645 $timer_fired->recv;
606 646
607Example: wait for a timer, but take advantage of the fact that condition 647Example: wait for a timer, but take advantage of the fact that condition
608variables are also callable directly. 648variables are also callable directly.
609 649
610 my $done = AnyEvent->condvar; 650 my $done = AnyEvent->condvar;
653they were a code reference). Calling them directly is the same as calling 693they were a code reference). Calling them directly is the same as calling
654C<send>. 694C<send>.
655 695
656=item $cv->croak ($error) 696=item $cv->croak ($error)
657 697
658Similar to send, but causes all call's to C<< ->recv >> to invoke 698Similar to send, but causes all calls to C<< ->recv >> to invoke
659C<Carp::croak> with the given error message/object/scalar. 699C<Carp::croak> with the given error message/object/scalar.
660 700
661This can be used to signal any errors to the condition variable 701This can be used to signal any errors to the condition variable
662user/consumer. Doing it this way instead of calling C<croak> directly 702user/consumer. Doing it this way instead of calling C<croak> directly
663delays the error detetcion, but has the overwhelmign advantage that it 703delays the error detection, but has the overwhelming advantage that it
664diagnoses the error at the place where the result is expected, and not 704diagnoses the error at the place where the result is expected, and not
665deep in some event clalback without connection to the actual code causing 705deep in some event callback with no connection to the actual code causing
666the problem. 706the problem.
667 707
668=item $cv->begin ([group callback]) 708=item $cv->begin ([group callback])
669 709
670=item $cv->end 710=item $cv->end
708one call to C<begin>, so the condvar waits for all calls to C<end> before 748one call to C<begin>, so the condvar waits for all calls to C<end> before
709sending. 749sending.
710 750
711The ping example mentioned above is slightly more complicated, as the 751The ping example mentioned above is slightly more complicated, as the
712there are results to be passwd back, and the number of tasks that are 752there are results to be passwd back, and the number of tasks that are
713begung can potentially be zero: 753begun can potentially be zero:
714 754
715 my $cv = AnyEvent->condvar; 755 my $cv = AnyEvent->condvar;
716 756
717 my %result; 757 my %result;
718 $cv->begin (sub { shift->send (\%result) }); 758 $cv->begin (sub { shift->send (\%result) });
739to be called once the counter reaches C<0>, and second, it ensures that 779to be called once the counter reaches C<0>, and second, it ensures that
740C<send> is called even when C<no> hosts are being pinged (the loop 780C<send> is called even when C<no> hosts are being pinged (the loop
741doesn't execute once). 781doesn't execute once).
742 782
743This is the general pattern when you "fan out" into multiple (but 783This is the general pattern when you "fan out" into multiple (but
744potentially none) subrequests: use an outer C<begin>/C<end> pair to set 784potentially zero) subrequests: use an outer C<begin>/C<end> pair to set
745the callback and ensure C<end> is called at least once, and then, for each 785the callback and ensure C<end> is called at least once, and then, for each
746subrequest you start, call C<begin> and for each subrequest you finish, 786subrequest you start, call C<begin> and for each subrequest you finish,
747call C<end>. 787call C<end>.
748 788
749=back 789=back
756=over 4 796=over 4
757 797
758=item $cv->recv 798=item $cv->recv
759 799
760Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak 800Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
761>> methods have been called on c<$cv>, while servicing other watchers 801>> methods have been called on C<$cv>, while servicing other watchers
762normally. 802normally.
763 803
764You can only wait once on a condition - additional calls are valid but 804You can only wait once on a condition - additional calls are valid but
765will return immediately. 805will return immediately.
766 806
783caller decide whether the call will block or not (for example, by coupling 823caller decide whether the call will block or not (for example, by coupling
784condition variables with some kind of request results and supporting 824condition variables with some kind of request results and supporting
785callbacks so the caller knows that getting the result will not block, 825callbacks so the caller knows that getting the result will not block,
786while still supporting blocking waits if the caller so desires). 826while still supporting blocking waits if the caller so desires).
787 827
788You can ensure that C<< -recv >> never blocks by setting a callback and 828You can ensure that C<< ->recv >> never blocks by setting a callback and
789only calling C<< ->recv >> from within that callback (or at a later 829only calling C<< ->recv >> from within that callback (or at a later
790time). This will work even when the event loop does not support blocking 830time). This will work even when the event loop does not support blocking
791waits otherwise. 831waits otherwise.
792 832
793=item $bool = $cv->ready 833=item $bool = $cv->ready
798=item $cb = $cv->cb ($cb->($cv)) 838=item $cb = $cv->cb ($cb->($cv))
799 839
800This is a mutator function that returns the callback set and optionally 840This is a mutator function that returns the callback set and optionally
801replaces it before doing so. 841replaces it before doing so.
802 842
803The callback will be called when the condition becomes (or already was) 843The callback will be called when the condition becomes "true", i.e. when
804"true", i.e. when C<send> or C<croak> are called (or were called), with 844C<send> or C<croak> are called, with the only argument being the
805the only argument being the condition variable itself. Calling C<recv> 845condition variable itself. If the condition is already true, the
846callback is called immediately when it is set. Calling C<recv> inside
806inside the callback or at any later time is guaranteed not to block. 847the callback or at any later time is guaranteed not to block.
807 848
808=back 849=back
809 850
810=head1 SUPPORTED EVENT LOOPS/BACKENDS 851=head1 SUPPORTED EVENT LOOPS/BACKENDS
811 852
819use. If EV is not installed, then AnyEvent will fall back to its own 860use. If EV is not installed, then AnyEvent will fall back to its own
820pure-perl implementation, which is available everywhere as it comes with 861pure-perl implementation, which is available everywhere as it comes with
821AnyEvent itself. 862AnyEvent itself.
822 863
823 AnyEvent::Impl::EV based on EV (interface to libev, best choice). 864 AnyEvent::Impl::EV based on EV (interface to libev, best choice).
824 AnyEvent::Impl::Perl pure-perl implementation, fast and portable. 865 AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
825 866
826=item Backends that are transparently being picked up when they are used. 867=item Backends that are transparently being picked up when they are used.
827 868
828These will be used when they are currently loaded when the first watcher 869These will be used if they are already loaded when the first watcher
829is created, in which case it is assumed that the application is using 870is created, in which case it is assumed that the application is using
830them. This means that AnyEvent will automatically pick the right backend 871them. This means that AnyEvent will automatically pick the right backend
831when the main program loads an event module before anything starts to 872when the main program loads an event module before anything starts to
832create watchers. Nothing special needs to be done by the main program. 873create watchers. Nothing special needs to be done by the main program.
833 874
835 AnyEvent::Impl::Glib based on Glib, slow but very stable. 876 AnyEvent::Impl::Glib based on Glib, slow but very stable.
836 AnyEvent::Impl::Tk based on Tk, very broken. 877 AnyEvent::Impl::Tk based on Tk, very broken.
837 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. 878 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
838 AnyEvent::Impl::POE based on POE, very slow, some limitations. 879 AnyEvent::Impl::POE based on POE, very slow, some limitations.
839 AnyEvent::Impl::Irssi used when running within irssi. 880 AnyEvent::Impl::Irssi used when running within irssi.
881 AnyEvent::Impl::IOAsync based on IO::Async.
882 AnyEvent::Impl::Cocoa based on Cocoa::EventLoop.
883 AnyEvent::Impl::FLTK based on FLTK (fltk 2 binding).
840 884
841=item Backends with special needs. 885=item Backends with special needs.
842 886
843Qt requires the Qt::Application to be instantiated first, but will 887Qt requires the Qt::Application to be instantiated first, but will
844otherwise be picked up automatically. As long as the main program 888otherwise be picked up automatically. As long as the main program
845instantiates the application before any AnyEvent watchers are created, 889instantiates the application before any AnyEvent watchers are created,
846everything should just work. 890everything should just work.
847 891
848 AnyEvent::Impl::Qt based on Qt. 892 AnyEvent::Impl::Qt based on Qt.
849 893
850Support for IO::Async can only be partial, as it is too broken and
851architecturally limited to even support the AnyEvent API. It also
852is the only event loop that needs the loop to be set explicitly, so
853it can only be used by a main program knowing about AnyEvent. See
854L<AnyEvent::Impl::Async> for the gory details.
855
856 AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
857
858=item Event loops that are indirectly supported via other backends. 894=item Event loops that are indirectly supported via other backends.
859 895
860Some event loops can be supported via other modules: 896Some event loops can be supported via other modules:
861 897
862There is no direct support for WxWidgets (L<Wx>) or L<Prima>. 898There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
887Contains C<undef> until the first watcher is being created, before the 923Contains C<undef> until the first watcher is being created, before the
888backend has been autodetected. 924backend has been autodetected.
889 925
890Afterwards it contains the event model that is being used, which is the 926Afterwards it contains the event model that is being used, which is the
891name of the Perl class implementing the model. This class is usually one 927name of the Perl class implementing the model. This class is usually one
892of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the 928of the C<AnyEvent::Impl::xxx> modules, but can be any other class in the
893case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it 929case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
894will be C<urxvt::anyevent>). 930will be C<urxvt::anyevent>).
895 931
896=item AnyEvent::detect 932=item AnyEvent::detect
897 933
898Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model 934Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
899if necessary. You should only call this function right before you would 935if necessary. You should only call this function right before you would
900have created an AnyEvent watcher anyway, that is, as late as possible at 936have created an AnyEvent watcher anyway, that is, as late as possible at
901runtime, and not e.g. while initialising of your module. 937runtime, and not e.g. during initialisation of your module.
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).
902 942
903If you need to do some initialisation before AnyEvent watchers are 943If you need to do some initialisation before AnyEvent watchers are
904created, use C<post_detect>. 944created, use C<post_detect>.
905 945
906=item $guard = AnyEvent::post_detect { BLOCK } 946=item $guard = AnyEvent::post_detect { BLOCK }
907 947
908Arranges for the code block to be executed as soon as the event model is 948Arranges for the code block to be executed as soon as the event model is
909autodetected (or immediately if this has already happened). 949autodetected (or immediately if that has already happened).
910 950
911The block will be executed I<after> the actual backend has been detected 951The block will be executed I<after> the actual backend has been detected
912(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been 952(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
913created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do 953created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
914other initialisations - see the sources of L<AnyEvent::Strict> or 954other initialisations - see the sources of L<AnyEvent::Strict> or
923that automatically removes the callback again when it is destroyed (or 963that automatically removes the callback again when it is destroyed (or
924C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for 964C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
925a case where this is useful. 965a case where this is useful.
926 966
927Example: Create a watcher for the IO::AIO module and store it in 967Example: Create a watcher for the IO::AIO module and store it in
928C<$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.
929 969
930 our WATCHER; 970 our WATCHER;
931 971
932 my $guard = AnyEvent::post_detect { 972 my $guard = AnyEvent::post_detect {
933 $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);
941 $WATCHER ||= $guard; 981 $WATCHER ||= $guard;
942 982
943=item @AnyEvent::post_detect 983=item @AnyEvent::post_detect
944 984
945If there are any code references in this array (you can C<push> to it 985If there are any code references in this array (you can C<push> to it
946before or after loading AnyEvent), then they will called directly after 986before or after loading AnyEvent), then they will be called directly
947the event loop has been chosen. 987after the event loop has been chosen.
948 988
949You should check C<$AnyEvent::MODEL> before adding to this array, though: 989You should check C<$AnyEvent::MODEL> before adding to this array, though:
950if it is defined then the event loop has already been detected, and the 990if it is defined then the event loop has already been detected, and the
951array will be ignored. 991array will be ignored.
952 992
953Best use C<AnyEvent::post_detect { BLOCK }> when your application allows 993Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
954it,as it takes care of these details. 994it, as it takes care of these details.
955 995
956This variable is mainly useful for modules that can do something useful 996This variable is mainly useful for modules that can do something useful
957when AnyEvent is used and thus want to know when it is initialised, but do 997when AnyEvent is used and thus want to know when it is initialised, but do
958not need to even load it by default. This array provides the means to hook 998not need to even load it by default. This array provides the means to hook
959into AnyEvent passively, without loading it. 999into AnyEvent passively, without loading it.
960 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<$level>.
1057
1058If L<AnyEvent::Log> is not loaded then this function makes a simple test
1059to see whether the message will be logged. If the test succeeds it will
1060load AnyEvent::Log and call C<AnyEvent::Log::log> - consequently, look at
1061the L<AnyEvent::Log> documentation for details.
1062
1063If the test fails it will simply return. Right now this happens when a
1064numerical loglevel is used and it is larger than the level specified via
1065C<$ENV{PERL_ANYEVENT_VERBOSE}>.
1066
1067If you want to sprinkle loads of logging calls around your code, consider
1068creating a logger callback with the C<AnyEvent::Log::logger> function,
1069which can reduce typing, codesize and can reduce the logging overhead
1070enourmously.
1071
961=back 1072=back
962 1073
963=head1 WHAT TO DO IN A MODULE 1074=head1 WHAT TO DO IN A MODULE
964 1075
965As a module author, you should C<use AnyEvent> and call AnyEvent methods 1076As a module author, you should C<use AnyEvent> and call AnyEvent methods
975because it will stall the whole program, and the whole point of using 1086because it will stall the whole program, and the whole point of using
976events is to stay interactive. 1087events is to stay interactive.
977 1088
978It is fine, however, to call C<< ->recv >> when the user of your module 1089It is fine, however, to call C<< ->recv >> when the user of your module
979requests it (i.e. if you create a http request object ad have a method 1090requests it (i.e. if you create a http request object ad have a method
980called C<results> that returns the results, it should call C<< ->recv >> 1091called C<results> that returns the results, it may call C<< ->recv >>
981freely, as the user of your module knows what she is doing. always). 1092freely, as the user of your module knows what she is doing. Always).
982 1093
983=head1 WHAT TO DO IN THE MAIN PROGRAM 1094=head1 WHAT TO DO IN THE MAIN PROGRAM
984 1095
985There will always be a single main program - the only place that should 1096There will always be a single main program - the only place that should
986dictate which event model to use. 1097dictate which event model to use.
987 1098
988If it doesn't care, it can just "use AnyEvent" and use it itself, or not 1099If the program is not event-based, it need not do anything special, even
989do anything special (it does not need to be event-based) and let AnyEvent 1100when it depends on a module that uses an AnyEvent. If the program itself
990decide which implementation to chose if some module relies on it. 1101uses AnyEvent, but does not care which event loop is used, all it needs
1102to do is C<use AnyEvent>. In either case, AnyEvent will choose the best
1103available loop implementation.
991 1104
992If the main program relies on a specific event model - for example, in 1105If the main program relies on a specific event model - for example, in
993Gtk2 programs you have to rely on the Glib module - you should load the 1106Gtk2 programs you have to rely on the Glib module - you should load the
994event module before loading AnyEvent or any module that uses it: generally 1107event module before loading AnyEvent or any module that uses it: generally
995speaking, you should load it as early as possible. The reason is that 1108speaking, you should load it as early as possible. The reason is that
996modules might create watchers when they are loaded, and AnyEvent will 1109modules might create watchers when they are loaded, and AnyEvent will
997decide on the event model to use as soon as it creates watchers, and it 1110decide on the event model to use as soon as it creates watchers, and it
998might chose the wrong one unless you load the correct one yourself. 1111might choose the wrong one unless you load the correct one yourself.
999 1112
1000You can chose to use a pure-perl implementation by loading the 1113You can chose to use a pure-perl implementation by loading the
1001C<AnyEvent::Impl::Perl> module, which gives you similar behaviour 1114C<AnyEvent::Loop> module, which gives you similar behaviour
1002everywhere, but letting AnyEvent chose the model is generally better. 1115everywhere, but letting AnyEvent chose the model is generally better.
1003 1116
1004=head2 MAINLOOP EMULATION 1117=head2 MAINLOOP EMULATION
1005 1118
1006Sometimes (often for short test scripts, or even standalone programs who 1119Sometimes (often for short test scripts, or even standalone programs who
1019 1132
1020 1133
1021=head1 OTHER MODULES 1134=head1 OTHER MODULES
1022 1135
1023The following is a non-exhaustive list of additional modules that use 1136The following is a non-exhaustive list of additional modules that use
1024AnyEvent as a client and can therefore be mixed easily with other AnyEvent 1137AnyEvent as a client and can therefore be mixed easily with other
1025modules and other event loops in the same program. Some of the modules 1138AnyEvent modules and other event loops in the same program. Some of the
1026come with AnyEvent, most are available via CPAN. 1139modules come as part of AnyEvent, the others are available via CPAN (see
1140L<http://search.cpan.org/search?m=module&q=anyevent%3A%3A*> for
1141a longer non-exhaustive list), and the list is heavily biased towards
1142modules of the AnyEvent author himself :)
1027 1143
1028=over 4 1144=over 4
1029 1145
1030=item L<AnyEvent::Util> 1146=item L<AnyEvent::Util>
1031 1147
1032Contains various utility functions that replace often-used but blocking 1148Contains various utility functions that replace often-used blocking
1033functions such as C<inet_aton> by event-/callback-based versions. 1149functions such as C<inet_aton> with event/callback-based versions.
1034 1150
1035=item L<AnyEvent::Socket> 1151=item L<AnyEvent::Socket>
1036 1152
1037Provides various utility functions for (internet protocol) sockets, 1153Provides various utility functions for (internet protocol) sockets,
1038addresses and name resolution. Also functions to create non-blocking tcp 1154addresses and name resolution. Also functions to create non-blocking tcp
1040 1156
1041=item L<AnyEvent::Handle> 1157=item L<AnyEvent::Handle>
1042 1158
1043Provide read and write buffers, manages watchers for reads and writes, 1159Provide read and write buffers, manages watchers for reads and writes,
1044supports raw and formatted I/O, I/O queued and fully transparent and 1160supports raw and formatted I/O, I/O queued and fully transparent and
1045non-blocking SSL/TLS (via L<AnyEvent::TLS>. 1161non-blocking SSL/TLS (via L<AnyEvent::TLS>).
1046 1162
1047=item L<AnyEvent::DNS> 1163=item L<AnyEvent::DNS>
1048 1164
1049Provides rich asynchronous DNS resolver capabilities. 1165Provides rich asynchronous DNS resolver capabilities.
1050 1166
1167=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
1168
1169Implement event-based interfaces to the protocols of the same name (for
1170the curious, IGS is the International Go Server and FCP is the Freenet
1171Client Protocol).
1172
1051=item L<AnyEvent::HTTP> 1173=item L<AnyEvent::AIO>
1052 1174
1053A simple-to-use HTTP library that is capable of making a lot of concurrent 1175Truly asynchronous (as opposed to non-blocking) I/O, should be in the
1054HTTP requests. 1176toolbox of every event programmer. AnyEvent::AIO transparently fuses
1177L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
1178file I/O, and much more.
1179
1180=item L<AnyEvent::Filesys::Notify>
1181
1182AnyEvent is good for non-blocking stuff, but it can't detect file or
1183path changes (e.g. "watch this directory for new files", "watch this
1184file for changes"). The L<AnyEvent::Filesys::Notify> module promises to
1185do just that in a portbale fashion, supporting inotify on GNU/Linux and
1186some weird, without doubt broken, stuff on OS X to monitor files. It can
1187fall back to blocking scans at regular intervals transparently on other
1188platforms, so it's about as portable as it gets.
1189
1190(I haven't used it myself, but I haven't heard anybody complaining about
1191it yet).
1192
1193=item L<AnyEvent::DBI>
1194
1195Executes L<DBI> requests asynchronously in a proxy process for you,
1196notifying you in an event-based way when the operation is finished.
1055 1197
1056=item L<AnyEvent::HTTPD> 1198=item L<AnyEvent::HTTPD>
1057 1199
1058Provides a simple web application server framework. 1200A simple embedded webserver.
1059 1201
1060=item L<AnyEvent::FastPing> 1202=item L<AnyEvent::FastPing>
1061 1203
1062The fastest ping in the west. 1204The fastest ping in the west.
1063 1205
1064=item L<AnyEvent::DBI>
1065
1066Executes L<DBI> requests asynchronously in a proxy process.
1067
1068=item L<AnyEvent::AIO>
1069
1070Truly asynchronous I/O, should be in the toolbox of every event
1071programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1072together.
1073
1074=item L<AnyEvent::BDB>
1075
1076Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1077L<BDB> and AnyEvent together.
1078
1079=item L<AnyEvent::GPSD>
1080
1081A non-blocking interface to gpsd, a daemon delivering GPS information.
1082
1083=item L<AnyEvent::IRC>
1084
1085AnyEvent based IRC client module family (replacing the older Net::IRC3).
1086
1087=item L<AnyEvent::XMPP>
1088
1089AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1090Net::XMPP2>.
1091
1092=item L<AnyEvent::IGS>
1093
1094A non-blocking interface to the Internet Go Server protocol (used by
1095L<App::IGS>).
1096
1097=item L<Net::FCP>
1098
1099AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1100of AnyEvent.
1101
1102=item L<Event::ExecFlow>
1103
1104High level API for event-based execution flow control.
1105
1106=item L<Coro> 1206=item L<Coro>
1107 1207
1108Has special support for AnyEvent via L<Coro::AnyEvent>. 1208Has special support for AnyEvent via L<Coro::AnyEvent>, which allows you
1209to simply invert the flow control - don't call us, we will call you:
1210
1211 async {
1212 Coro::AnyEvent::sleep 5; # creates a 5s timer and waits for it
1213 print "5 seconds later!\n";
1214
1215 Coro::AnyEvent::readable *STDIN; # uses an I/O watcher
1216 my $line = <STDIN>; # works for ttys
1217
1218 AnyEvent::HTTP::http_get "url", Coro::rouse_cb;
1219 my ($body, $hdr) = Coro::rouse_wait;
1220 };
1109 1221
1110=back 1222=back
1111 1223
1112=cut 1224=cut
1113 1225
1114package AnyEvent; 1226package AnyEvent;
1115 1227
1116# basically a tuned-down version of common::sense 1228# basically a tuned-down version of common::sense
1117sub common_sense { 1229sub common_sense {
1118 # from common:.sense 1.0 1230 # from common:.sense 3.4
1119 ${^WARNING_BITS} = "\xfc\x3f\xf3\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x03"; 1231 ${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
1120 # use strict vars subs 1232 # use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1121 $^H |= 0x00000600; 1233 $^H |= 0x00000600;
1122} 1234}
1123 1235
1124BEGIN { AnyEvent::common_sense } 1236BEGIN { AnyEvent::common_sense }
1125 1237
1126use Carp (); 1238use Carp ();
1127 1239
1128our $VERSION = '5.202'; 1240our $VERSION = '6.02';
1129our $MODEL; 1241our $MODEL;
1130
1131our $AUTOLOAD;
1132our @ISA; 1242our @ISA;
1133
1134our @REGISTRY; 1243our @REGISTRY;
1135
1136our $WIN32;
1137
1138our $VERBOSE; 1244our $VERBOSE;
1245our $MAX_SIGNAL_LATENCY = 10;
1246our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
1139 1247
1140BEGIN { 1248BEGIN {
1141 eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; 1249 require "AnyEvent/constants.pl";
1250
1142 eval "sub TAINT(){ " . (${^TAINT}*1) . " }"; 1251 eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1143 1252
1144 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} 1253 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1145 if ${^TAINT}; 1254 if ${^TAINT};
1146 1255
1147 $VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1; 1256 $ENV{"PERL_ANYEVENT_$_"} = $ENV{"AE_$_"}
1257 for grep s/^AE_// && !exists $ENV{"PERL_ANYEVENT_$_"}, keys %ENV;
1148 1258
1149} 1259 @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} = ()
1260 if ${^TAINT};
1150 1261
1151our $MAX_SIGNAL_LATENCY = 10; 1262 # $ENV{PERL_ANYEVENT_xxx} now valid
1152 1263
1153our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred 1264 $VERBOSE = length $ENV{PERL_ANYEVENT_VERBOSE} ? $ENV{PERL_ANYEVENT_VERBOSE}*1 : 4;
1154 1265
1155{
1156 my $idx; 1266 my $idx;
1157 $PROTOCOL{$_} = ++$idx 1267 $PROTOCOL{$_} = ++$idx
1158 for reverse split /\s*,\s*/, 1268 for reverse split /\s*,\s*/,
1159 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; 1269 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1160} 1270}
1161 1271
1272our @post_detect;
1273
1274sub post_detect(&) {
1275 my ($cb) = @_;
1276
1277 push @post_detect, $cb;
1278
1279 defined wantarray
1280 ? bless \$cb, "AnyEvent::Util::postdetect"
1281 : ()
1282}
1283
1284sub AnyEvent::Util::postdetect::DESTROY {
1285 @post_detect = grep $_ != ${$_[0]}, @post_detect;
1286}
1287
1288our $POSTPONE_W;
1289our @POSTPONE;
1290
1291sub _postpone_exec {
1292 undef $POSTPONE_W;
1293
1294 &{ shift @POSTPONE }
1295 while @POSTPONE;
1296}
1297
1298sub postpone(&) {
1299 push @POSTPONE, shift;
1300
1301 $POSTPONE_W ||= AE::timer (0, 0, \&_postpone_exec);
1302
1303 ()
1304}
1305
1306sub log($$;@) {
1307 # only load the big bloated module when we actually are about to log something
1308 if ($_[0] <= ($VERBOSE || 1)) { # also catches non-numeric levels(!) and fatal
1309 require AnyEvent::Log; # among other things, sets $VERBOSE to 9
1310 # AnyEvent::Log overwrites this function
1311 goto &log;
1312 }
1313
1314 0 # not logged
1315}
1316
1317sub logger($;$) {
1318 package AnyEvent::Log;
1319
1320 my ($level, $renabled) = @_;
1321
1322 $$renabled = $level <= $VERBOSE;
1323
1324 my $pkg = (caller)[0];
1325
1326 my $logger = [$pkg, $level, $renabled];
1327
1328 our %LOGGER;
1329 $LOGGER{$logger+0} = $logger;
1330
1331 require AnyEvent::Util;
1332 my $guard = AnyEvent::Util::guard (sub {
1333 # "clean up"
1334 delete $LOGGER{$logger+0};
1335 });
1336
1337 sub {
1338 return 0 unless $$renabled;
1339
1340 $guard if 0; # keep guard alive, but don't cause runtime overhead
1341 require AnyEvent::Log unless $AnyEvent::Log::VERSION;
1342 package AnyEvent::Log;
1343 _log ($logger->[0], $level, @_) # logger->[0] has been converted at load time
1344 }
1345}
1346
1347if (length $ENV{PERL_ANYEVENT_LOG}) {
1348 require AnyEvent::Log; # AnyEvent::Log does the thing for us
1349}
1350
1162my @models = ( 1351our @models = (
1163 [EV:: => AnyEvent::Impl::EV:: , 1], 1352 [EV:: => AnyEvent::Impl::EV:: , 1],
1164 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1], 1353 [AnyEvent::Loop:: => AnyEvent::Impl::Perl:: , 1],
1165 # everything below here will not (normally) be autoprobed 1354 # everything below here will not (normally) be autoprobed
1166 # as the pureperl backend should work everywhere 1355 # as the pure perl backend should work everywhere
1167 # and is usually faster 1356 # and is usually faster
1168 [Event:: => AnyEvent::Impl::Event::, 1], 1357 [Event:: => AnyEvent::Impl::Event::, 1],
1169 [Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers 1358 [Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1170 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy 1359 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1171 [Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package 1360 [Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1172 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles 1361 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1173 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program 1362 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1174 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza 1363 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1175 [Wx:: => AnyEvent::Impl::POE::], 1364 [Wx:: => AnyEvent::Impl::POE::],
1176 [Prima:: => AnyEvent::Impl::POE::], 1365 [Prima:: => AnyEvent::Impl::POE::],
1177 # IO::Async is just too broken - we would need workarounds for its 1366 [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1178 # byzantine signal and broken child handling, among others. 1367 [Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1179 # IO::Async is rather hard to detect, as it doesn't have any 1368 [FLTK:: => AnyEvent::Impl::FLTK::],
1180 # obvious default class.
1181 [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1182 [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1183 [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1184 [AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1185); 1369);
1186 1370
1187our %method = map +($_ => 1), 1371our @isa_hook;
1372
1373sub _isa_set {
1374 my @pkg = ("AnyEvent", (map $_->[0], grep defined, @isa_hook), $MODEL);
1375
1376 @{"$pkg[$_-1]::ISA"} = $pkg[$_]
1377 for 1 .. $#pkg;
1378
1379 grep $_ && $_->[1], @isa_hook
1380 and AE::_reset ();
1381}
1382
1383# used for hooking AnyEvent::Strict and AnyEvent::Debug::Wrap into the class hierarchy
1384sub _isa_hook($$;$) {
1385 my ($i, $pkg, $reset_ae) = @_;
1386
1387 $isa_hook[$i] = $pkg ? [$pkg, $reset_ae] : undef;
1388
1389 _isa_set;
1390}
1391
1392# all autoloaded methods reserve the complete glob, not just the method slot.
1393# due to bugs in perls method cache implementation.
1188 qw(io timer time now now_update signal child idle condvar one_event DESTROY); 1394our @methods = qw(io timer time now now_update signal child idle condvar);
1189 1395
1190our @post_detect;
1191
1192sub post_detect(&) { 1396sub detect() {
1193 my ($cb) = @_; 1397 return $MODEL if $MODEL; # some programs keep references to detect
1194 1398
1195 if ($MODEL) { 1399 local $!; # for good measure
1196 $cb->(); 1400 local $SIG{__DIE__}; # we use eval
1197 1401
1198 undef 1402 # free some memory
1403 *detect = sub () { $MODEL };
1404 # undef &func doesn't correctly update the method cache. grmbl.
1405 # so we delete the whole glob. grmbl.
1406 # otoh, perl doesn't let me undef an active usb, but it lets me free
1407 # a glob with an active sub. hrm. i hope it works, but perl is
1408 # usually buggy in this department. sigh.
1409 delete @{"AnyEvent::"}{@methods};
1410 undef @methods;
1411
1412 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) {
1413 my $model = $1;
1414 $model = "AnyEvent::Impl::$model" unless $model =~ s/::$//;
1415 if (eval "require $model") {
1416 AnyEvent::log 7 => "loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.";
1417 $MODEL = $model;
1199 } else { 1418 } else {
1200 push @post_detect, $cb; 1419 AnyEvent::log 4 => "unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
1201 1420 }
1202 defined wantarray
1203 ? bless \$cb, "AnyEvent::Util::postdetect"
1204 : ()
1205 } 1421 }
1206}
1207 1422
1208sub AnyEvent::Util::postdetect::DESTROY { 1423 # check for already loaded models
1209 @post_detect = grep $_ != ${$_[0]}, @post_detect;
1210}
1211
1212sub detect() {
1213 unless ($MODEL) { 1424 unless ($MODEL) {
1214 local $SIG{__DIE__}; 1425 for (@REGISTRY, @models) {
1215 1426 my ($package, $model) = @$_;
1216 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { 1427 if (${"$package\::VERSION"} > 0) {
1217 my $model = "AnyEvent::Impl::$1";
1218 if (eval "require $model") { 1428 if (eval "require $model") {
1429 AnyEvent::log 7 => "autodetected model '$model', using it.";
1219 $MODEL = $model; 1430 $MODEL = $model;
1220 warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2; 1431 last;
1221 } else { 1432 }
1222 warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1223 } 1433 }
1224 } 1434 }
1225 1435
1226 # check for already loaded models
1227 unless ($MODEL) { 1436 unless ($MODEL) {
1437 # try to autoload a model
1228 for (@REGISTRY, @models) { 1438 for (@REGISTRY, @models) {
1229 my ($package, $model) = @$_; 1439 my ($package, $model, $autoload) = @$_;
1440 if (
1441 $autoload
1442 and eval "require $package"
1230 if (${"$package\::VERSION"} > 0) { 1443 and ${"$package\::VERSION"} > 0
1231 if (eval "require $model") { 1444 and eval "require $model"
1445 ) {
1446 AnyEvent::log 7 => "autoloaded model '$model', using it.";
1232 $MODEL = $model; 1447 $MODEL = $model;
1233 warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1234 last; 1448 last;
1235 }
1236 } 1449 }
1237 } 1450 }
1238 1451
1239 unless ($MODEL) {
1240 # try to autoload a model
1241 for (@REGISTRY, @models) {
1242 my ($package, $model, $autoload) = @$_;
1243 if (
1244 $autoload
1245 and eval "require $package"
1246 and ${"$package\::VERSION"} > 0
1247 and eval "require $model"
1248 ) {
1249 $MODEL = $model;
1250 warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1251 last;
1252 }
1253 }
1254
1255 $MODEL 1452 $MODEL
1256 or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n"; 1453 or AnyEvent::log fatal => "AnyEvent: backend autodetection failed - did you properly install AnyEvent?";
1257 }
1258 } 1454 }
1259
1260 push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1261
1262 unshift @ISA, $MODEL;
1263
1264 require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1265
1266 (shift @post_detect)->() while @post_detect;
1267 } 1455 }
1268 1456
1457 # free memory only needed for probing
1458 undef @models;
1459 undef @REGISTRY;
1460
1461 push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1462
1463 # now nuke some methods that are overridden by the backend.
1464 # SUPER usage is not allowed in these.
1465 for (qw(time signal child idle)) {
1466 undef &{"AnyEvent::Base::$_"}
1467 if defined &{"$MODEL\::$_"};
1468 }
1469
1470 _isa_set;
1471
1472 # we're officially open!
1473
1474 if ($ENV{PERL_ANYEVENT_STRICT}) {
1475 require AnyEvent::Strict;
1476 }
1477
1478 if ($ENV{PERL_ANYEVENT_DEBUG_WRAP}) {
1479 require AnyEvent::Debug;
1480 AnyEvent::Debug::wrap ($ENV{PERL_ANYEVENT_DEBUG_WRAP});
1481 }
1482
1483 if (length $ENV{PERL_ANYEVENT_DEBUG_SHELL}) {
1484 require AnyEvent::Socket;
1485 require AnyEvent::Debug;
1486
1487 my $shell = $ENV{PERL_ANYEVENT_DEBUG_SHELL};
1488 $shell =~ s/\$\$/$$/g;
1489
1490 my ($host, $service) = AnyEvent::Socket::parse_hostport ($shell);
1491 $AnyEvent::Debug::SHELL = AnyEvent::Debug::shell ($host, $service);
1492 }
1493
1494 # now the anyevent environment is set up as the user told us to, so
1495 # call the actual user code - post detects
1496
1497 (shift @post_detect)->() while @post_detect;
1498 undef @post_detect;
1499
1500 *post_detect = sub(&) {
1501 shift->();
1502
1503 undef
1504 };
1505
1269 $MODEL 1506 $MODEL
1270} 1507}
1271 1508
1272sub AUTOLOAD { 1509for my $name (@methods) {
1273 (my $func = $AUTOLOAD) =~ s/.*://; 1510 *$name = sub {
1274 1511 detect;
1275 $method{$func} 1512 # we use goto because
1276 or Carp::croak "$func: not a valid method for AnyEvent objects"; 1513 # a) it makes the thunk more transparent
1277 1514 # b) it allows us to delete the thunk later
1278 detect unless $MODEL; 1515 goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
1279 1516 };
1280 my $class = shift;
1281 $class->$func (@_);
1282} 1517}
1283 1518
1284# utility function to dup a filehandle. this is used by many backends 1519# utility function to dup a filehandle. this is used by many backends
1285# to support binding more than one watcher per filehandle (they usually 1520# to support binding more than one watcher per filehandle (they usually
1286# allow only one watcher per fd, so we dup it to get a different one). 1521# allow only one watcher per fd, so we dup it to get a different one).
1300 1535
1301=head1 SIMPLIFIED AE API 1536=head1 SIMPLIFIED AE API
1302 1537
1303Starting with version 5.0, AnyEvent officially supports a second, much 1538Starting with version 5.0, AnyEvent officially supports a second, much
1304simpler, API that is designed to reduce the calling, typing and memory 1539simpler, API that is designed to reduce the calling, typing and memory
1305overhead. 1540overhead by using function call syntax and a fixed number of parameters.
1306 1541
1307See the L<AE> manpage for details. 1542See the L<AE> manpage for details.
1308 1543
1309=cut 1544=cut
1310 1545
1311package AE; 1546package AE;
1312 1547
1313our $VERSION = $AnyEvent::VERSION; 1548our $VERSION = $AnyEvent::VERSION;
1314 1549
1550sub _reset() {
1551 eval q{
1552 # fall back to the main API by default - backends and AnyEvent::Base
1553 # implementations can overwrite these.
1554
1315sub io($$$) { 1555 sub io($$$) {
1316 AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2]) 1556 AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1317} 1557 }
1318 1558
1319sub timer($$$) { 1559 sub timer($$$) {
1320 AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2]) 1560 AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
1321} 1561 }
1322 1562
1323sub signal($$) { 1563 sub signal($$) {
1324 AnyEvent->signal (signal => $_[0], cb => $_[1]) 1564 AnyEvent->signal (signal => $_[0], cb => $_[1])
1325} 1565 }
1326 1566
1327sub child($$) { 1567 sub child($$) {
1328 AnyEvent->child (pid => $_[0], cb => $_[1]) 1568 AnyEvent->child (pid => $_[0], cb => $_[1])
1329} 1569 }
1330 1570
1331sub idle($) { 1571 sub idle($) {
1332 AnyEvent->idle (cb => $_[0]) 1572 AnyEvent->idle (cb => $_[0]);
1333} 1573 }
1334 1574
1335sub cv(;&) { 1575 sub cv(;&) {
1336 AnyEvent->condvar (@_ ? (cb => $_[0]) : ()) 1576 AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
1337} 1577 }
1338 1578
1339sub now() { 1579 sub now() {
1340 AnyEvent->now 1580 AnyEvent->now
1341} 1581 }
1342 1582
1343sub now_update() { 1583 sub now_update() {
1344 AnyEvent->now_update 1584 AnyEvent->now_update
1345} 1585 }
1346 1586
1347sub time() { 1587 sub time() {
1348 AnyEvent->time 1588 AnyEvent->time
1589 }
1590
1591 *postpone = \&AnyEvent::postpone;
1592 *log = \&AnyEvent::log;
1593 };
1594 die if $@;
1349} 1595}
1596
1597BEGIN { _reset }
1350 1598
1351package AnyEvent::Base; 1599package AnyEvent::Base;
1352 1600
1353# default implementations for many methods 1601# default implementations for many methods
1354 1602
1355sub _time() { 1603sub time {
1604 eval q{ # poor man's autoloading {}
1356 # probe for availability of Time::HiRes 1605 # probe for availability of Time::HiRes
1357 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { 1606 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1358 warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8; 1607 *time = sub { Time::HiRes::time () };
1359 *_time = \&Time::HiRes::time; 1608 *AE::time = \& Time::HiRes::time ;
1609 *now = \&time;
1610 AnyEvent::log 8 => "AnyEvent: using Time::HiRes for sub-second timing accuracy.";
1360 # if (eval "use POSIX (); (POSIX::times())... 1611 # if (eval "use POSIX (); (POSIX::times())...
1361 } else { 1612 } else {
1613 *time = sub { CORE::time };
1614 *AE::time = sub (){ CORE::time };
1615 *now = \&time;
1362 warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE; 1616 AnyEvent::log 3 => "using built-in time(), WARNING, no sub-second resolution!";
1363 *_time = sub { time }; # epic fail 1617 }
1364 } 1618 };
1619 die if $@;
1365 1620
1366 &_time 1621 &time
1367} 1622}
1368 1623
1369sub time { _time } 1624*now = \&time;
1370sub now { _time }
1371sub now_update { } 1625sub now_update { }
1372 1626
1627sub _poll {
1628 Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
1629}
1630
1373# default implementation for ->condvar 1631# default implementation for ->condvar
1632# in fact, the default should not be overwritten
1374 1633
1375sub condvar { 1634sub condvar {
1635 eval q{ # poor man's autoloading {}
1636 *condvar = sub {
1376 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar" 1637 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1638 };
1639
1640 *AE::cv = sub (;&) {
1641 bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
1642 };
1643 };
1644 die if $@;
1645
1646 &condvar
1377} 1647}
1378 1648
1379# default implementation for ->signal 1649# default implementation for ->signal
1380 1650
1381our $HAVE_ASYNC_INTERRUPT; 1651our $HAVE_ASYNC_INTERRUPT;
1390 1660
1391our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); 1661our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1392our (%SIG_ASY, %SIG_ASY_W); 1662our (%SIG_ASY, %SIG_ASY_W);
1393our ($SIG_COUNT, $SIG_TW); 1663our ($SIG_COUNT, $SIG_TW);
1394 1664
1395sub _signal_exec {
1396 $HAVE_ASYNC_INTERRUPT
1397 ? $SIGPIPE_R->drain
1398 : sysread $SIGPIPE_R, (my $dummy), 9;
1399
1400 while (%SIG_EV) {
1401 for (keys %SIG_EV) {
1402 delete $SIG_EV{$_};
1403 $_->() for values %{ $SIG_CB{$_} || {} };
1404 }
1405 }
1406}
1407
1408# install a dummy wakeup watcher to reduce signal catching latency 1665# install a dummy wakeup watcher to reduce signal catching latency
1666# used by Impls
1409sub _sig_add() { 1667sub _sig_add() {
1410 unless ($SIG_COUNT++) { 1668 unless ($SIG_COUNT++) {
1411 # try to align timer on a full-second boundary, if possible 1669 # try to align timer on a full-second boundary, if possible
1412 my $NOW = AE::now; 1670 my $NOW = AE::now;
1413 1671
1423 undef $SIG_TW 1681 undef $SIG_TW
1424 unless --$SIG_COUNT; 1682 unless --$SIG_COUNT;
1425} 1683}
1426 1684
1427our $_sig_name_init; $_sig_name_init = sub { 1685our $_sig_name_init; $_sig_name_init = sub {
1428 eval q{ # poor man's autoloading 1686 eval q{ # poor man's autoloading {}
1429 undef $_sig_name_init; 1687 undef $_sig_name_init;
1430 1688
1431 if (_have_async_interrupt) { 1689 if (_have_async_interrupt) {
1432 *sig2num = \&Async::Interrupt::sig2num; 1690 *sig2num = \&Async::Interrupt::sig2num;
1433 *sig2name = \&Async::Interrupt::sig2name; 1691 *sig2name = \&Async::Interrupt::sig2name;
1457 1715
1458sub signal { 1716sub signal {
1459 eval q{ # poor man's autoloading {} 1717 eval q{ # poor man's autoloading {}
1460 # probe for availability of Async::Interrupt 1718 # probe for availability of Async::Interrupt
1461 if (_have_async_interrupt) { 1719 if (_have_async_interrupt) {
1462 warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8; 1720 AnyEvent::log 8 => "using Async::Interrupt for race-free signal handling.";
1463 1721
1464 $SIGPIPE_R = new Async::Interrupt::EventPipe; 1722 $SIGPIPE_R = new Async::Interrupt::EventPipe;
1465 $SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec; 1723 $SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1466 1724
1467 } else { 1725 } else {
1468 warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8; 1726 AnyEvent::log 8 => "using emulated perl signal handling with latency timer.";
1469
1470 require Fcntl;
1471 1727
1472 if (AnyEvent::WIN32) { 1728 if (AnyEvent::WIN32) {
1473 require AnyEvent::Util; 1729 require AnyEvent::Util;
1474 1730
1475 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe (); 1731 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1476 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R; 1732 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1477 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case 1733 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1478 } else { 1734 } else {
1479 pipe $SIGPIPE_R, $SIGPIPE_W; 1735 pipe $SIGPIPE_R, $SIGPIPE_W;
1480 fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R; 1736 fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
1481 fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case 1737 fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
1482 1738
1483 # not strictly required, as $^F is normally 2, but let's make sure... 1739 # not strictly required, as $^F is normally 2, but let's make sure...
1484 fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; 1740 fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1485 fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; 1741 fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1486 } 1742 }
1487 1743
1488 $SIGPIPE_R 1744 $SIGPIPE_R
1489 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; 1745 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1490 1746
1491 $SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec; 1747 $SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1492 } 1748 }
1493 1749
1494 *signal = sub { 1750 *signal = $HAVE_ASYNC_INTERRUPT
1751 ? sub {
1495 my (undef, %arg) = @_; 1752 my (undef, %arg) = @_;
1496 1753
1497 my $signal = uc $arg{signal}
1498 or Carp::croak "required option 'signal' is missing";
1499
1500 if ($HAVE_ASYNC_INTERRUPT) {
1501 # async::interrupt 1754 # async::interrupt
1502
1503 $signal = sig2num $signal; 1755 my $signal = sig2num $arg{signal};
1504 $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; 1756 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1505 1757
1506 $SIG_ASY{$signal} ||= new Async::Interrupt 1758 $SIG_ASY{$signal} ||= new Async::Interrupt
1507 cb => sub { undef $SIG_EV{$signal} }, 1759 cb => sub { undef $SIG_EV{$signal} },
1508 signal => $signal, 1760 signal => $signal,
1509 pipe => [$SIGPIPE_R->filenos], 1761 pipe => [$SIGPIPE_R->filenos],
1510 pipe_autodrain => 0, 1762 pipe_autodrain => 0,
1511 ; 1763 ;
1512 1764
1513 } else { 1765 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1766 }
1767 : sub {
1768 my (undef, %arg) = @_;
1769
1514 # pure perl 1770 # pure perl
1515
1516 # AE::Util has been loaded in signal
1517 $signal = sig2name $signal; 1771 my $signal = sig2name $arg{signal};
1518 $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; 1772 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1519 1773
1520 $SIG{$signal} ||= sub { 1774 $SIG{$signal} ||= sub {
1521 local $!; 1775 local $!;
1522 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; 1776 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1523 undef $SIG_EV{$signal}; 1777 undef $SIG_EV{$signal};
1524 }; 1778 };
1525 1779
1526 # can't do signal processing without introducing races in pure perl, 1780 # can't do signal processing without introducing races in pure perl,
1527 # so limit the signal latency. 1781 # so limit the signal latency.
1528 _sig_add; 1782 _sig_add;
1529 }
1530 1783
1531 bless [$signal, $arg{cb}], "AnyEvent::Base::signal" 1784 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1785 }
1532 }; 1786 ;
1533 1787
1534 *AnyEvent::Base::signal::DESTROY = sub { 1788 *AnyEvent::Base::signal::DESTROY = sub {
1535 my ($signal, $cb) = @{$_[0]}; 1789 my ($signal, $cb) = @{$_[0]};
1536 1790
1537 _sig_del; 1791 _sig_del;
1544 # print weird messages, or just unconditionally exit 1798 # print weird messages, or just unconditionally exit
1545 # instead of getting the default action. 1799 # instead of getting the default action.
1546 undef $SIG{$signal} 1800 undef $SIG{$signal}
1547 unless keys %{ $SIG_CB{$signal} }; 1801 unless keys %{ $SIG_CB{$signal} };
1548 }; 1802 };
1803
1804 *_signal_exec = sub {
1805 $HAVE_ASYNC_INTERRUPT
1806 ? $SIGPIPE_R->drain
1807 : sysread $SIGPIPE_R, (my $dummy), 9;
1808
1809 while (%SIG_EV) {
1810 for (keys %SIG_EV) {
1811 delete $SIG_EV{$_};
1812 &$_ for values %{ $SIG_CB{$_} || {} };
1813 }
1814 }
1815 };
1549 }; 1816 };
1550 die if $@; 1817 die if $@;
1818
1551 &signal 1819 &signal
1552} 1820}
1553 1821
1554# default implementation for ->child 1822# default implementation for ->child
1555 1823
1556our %PID_CB; 1824our %PID_CB;
1557our $CHLD_W; 1825our $CHLD_W;
1558our $CHLD_DELAY_W; 1826our $CHLD_DELAY_W;
1559our $WNOHANG;
1560 1827
1828# used by many Impl's
1561sub _emit_childstatus($$) { 1829sub _emit_childstatus($$) {
1562 my (undef, $rpid, $rstatus) = @_; 1830 my (undef, $rpid, $rstatus) = @_;
1563 1831
1564 $_->($rpid, $rstatus) 1832 $_->($rpid, $rstatus)
1565 for values %{ $PID_CB{$rpid} || {} }, 1833 for values %{ $PID_CB{$rpid} || {} },
1566 values %{ $PID_CB{0} || {} }; 1834 values %{ $PID_CB{0} || {} };
1567} 1835}
1568 1836
1569sub _sigchld {
1570 my $pid;
1571
1572 AnyEvent->_emit_childstatus ($pid, $?)
1573 while ($pid = waitpid -1, $WNOHANG) > 0;
1574}
1575
1576sub child { 1837sub child {
1838 eval q{ # poor man's autoloading {}
1839 *_sigchld = sub {
1840 my $pid;
1841
1842 AnyEvent->_emit_childstatus ($pid, $?)
1843 while ($pid = waitpid -1, WNOHANG) > 0;
1844 };
1845
1846 *child = sub {
1577 my (undef, %arg) = @_; 1847 my (undef, %arg) = @_;
1578 1848
1579 defined (my $pid = $arg{pid} + 0) 1849 my $pid = $arg{pid};
1580 or Carp::croak "required option 'pid' is missing"; 1850 my $cb = $arg{cb};
1581 1851
1582 $PID_CB{$pid}{$arg{cb}} = $arg{cb}; 1852 $PID_CB{$pid}{$cb+0} = $cb;
1583 1853
1584 # WNOHANG is almost cetrainly 1 everywhere
1585 $WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1586 ? 1
1587 : eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1588
1589 unless ($CHLD_W) { 1854 unless ($CHLD_W) {
1590 $CHLD_W = AE::signal CHLD => \&_sigchld; 1855 $CHLD_W = AE::signal CHLD => \&_sigchld;
1591 # child could be a zombie already, so make at least one round 1856 # child could be a zombie already, so make at least one round
1592 &_sigchld; 1857 &_sigchld;
1593 } 1858 }
1594 1859
1595 bless [$pid, $arg{cb}], "AnyEvent::Base::child" 1860 bless [$pid, $cb+0], "AnyEvent::Base::child"
1596} 1861 };
1597 1862
1598sub AnyEvent::Base::child::DESTROY { 1863 *AnyEvent::Base::child::DESTROY = sub {
1599 my ($pid, $cb) = @{$_[0]}; 1864 my ($pid, $icb) = @{$_[0]};
1600 1865
1601 delete $PID_CB{$pid}{$cb}; 1866 delete $PID_CB{$pid}{$icb};
1602 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; 1867 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1603 1868
1604 undef $CHLD_W unless keys %PID_CB; 1869 undef $CHLD_W unless keys %PID_CB;
1870 };
1871 };
1872 die if $@;
1873
1874 &child
1605} 1875}
1606 1876
1607# idle emulation is done by simply using a timer, regardless 1877# idle emulation is done by simply using a timer, regardless
1608# of whether the process is idle or not, and not letting 1878# of whether the process is idle or not, and not letting
1609# the callback use more than 50% of the time. 1879# the callback use more than 50% of the time.
1610sub idle { 1880sub idle {
1881 eval q{ # poor man's autoloading {}
1882 *idle = sub {
1611 my (undef, %arg) = @_; 1883 my (undef, %arg) = @_;
1612 1884
1613 my ($cb, $w, $rcb) = $arg{cb}; 1885 my ($cb, $w, $rcb) = $arg{cb};
1614 1886
1615 $rcb = sub { 1887 $rcb = sub {
1616 if ($cb) { 1888 if ($cb) {
1617 $w = _time; 1889 $w = AE::time;
1618 &$cb; 1890 &$cb;
1619 $w = _time - $w; 1891 $w = AE::time - $w;
1620 1892
1621 # never use more then 50% of the time for the idle watcher, 1893 # never use more then 50% of the time for the idle watcher,
1622 # within some limits 1894 # within some limits
1623 $w = 0.0001 if $w < 0.0001; 1895 $w = 0.0001 if $w < 0.0001;
1624 $w = 5 if $w > 5; 1896 $w = 5 if $w > 5;
1625 1897
1626 $w = AE::timer $w, 0, $rcb; 1898 $w = AE::timer $w, 0, $rcb;
1627 } else { 1899 } else {
1628 # clean up... 1900 # clean up...
1629 undef $w; 1901 undef $w;
1630 undef $rcb; 1902 undef $rcb;
1903 }
1904 };
1905
1906 $w = AE::timer 0.05, 0, $rcb;
1907
1908 bless \\$cb, "AnyEvent::Base::idle"
1631 } 1909 };
1910
1911 *AnyEvent::Base::idle::DESTROY = sub {
1912 undef $${$_[0]};
1913 };
1632 }; 1914 };
1915 die if $@;
1633 1916
1634 $w = AE::timer 0.05, 0, $rcb; 1917 &idle
1635
1636 bless \\$cb, "AnyEvent::Base::idle"
1637}
1638
1639sub AnyEvent::Base::idle::DESTROY {
1640 undef $${$_[0]};
1641} 1918}
1642 1919
1643package AnyEvent::CondVar; 1920package AnyEvent::CondVar;
1644 1921
1645our @ISA = AnyEvent::CondVar::Base::; 1922our @ISA = AnyEvent::CondVar::Base::;
1923
1924# only to be used for subclassing
1925sub new {
1926 my $class = shift;
1927 bless AnyEvent->condvar (@_), $class
1928}
1646 1929
1647package AnyEvent::CondVar::Base; 1930package AnyEvent::CondVar::Base;
1648 1931
1649#use overload 1932#use overload
1650# '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, 1933# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1660 1943
1661sub _send { 1944sub _send {
1662 # nop 1945 # nop
1663} 1946}
1664 1947
1948sub _wait {
1949 AnyEvent->_poll until $_[0]{_ae_sent};
1950}
1951
1665sub send { 1952sub send {
1666 my $cv = shift; 1953 my $cv = shift;
1667 $cv->{_ae_sent} = [@_]; 1954 $cv->{_ae_sent} = [@_];
1668 (delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb}; 1955 (delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1669 $cv->_send; 1956 $cv->_send;
1676 1963
1677sub ready { 1964sub ready {
1678 $_[0]{_ae_sent} 1965 $_[0]{_ae_sent}
1679} 1966}
1680 1967
1681sub _wait {
1682 $WAITING
1683 and !$_[0]{_ae_sent}
1684 and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1685
1686 local $WAITING = 1;
1687 AnyEvent->one_event while !$_[0]{_ae_sent};
1688}
1689
1690sub recv { 1968sub recv {
1969 unless ($_[0]{_ae_sent}) {
1970 $WAITING
1971 and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
1972
1973 local $WAITING = 1;
1691 $_[0]->_wait; 1974 $_[0]->_wait;
1975 }
1692 1976
1693 Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak}; 1977 $_[0]{_ae_croak}
1694 wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0] 1978 and Carp::croak $_[0]{_ae_croak};
1979
1980 wantarray
1981 ? @{ $_[0]{_ae_sent} }
1982 : $_[0]{_ae_sent}[0]
1695} 1983}
1696 1984
1697sub cb { 1985sub cb {
1698 my $cv = shift; 1986 my $cv = shift;
1699 1987
1715 &{ $_[0]{_ae_end_cb} || sub { $_[0]->send } }; 2003 &{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1716} 2004}
1717 2005
1718# undocumented/compatibility with pre-3.4 2006# undocumented/compatibility with pre-3.4
1719*broadcast = \&send; 2007*broadcast = \&send;
1720*wait = \&_wait; 2008*wait = \&recv;
1721 2009
1722=head1 ERROR AND EXCEPTION HANDLING 2010=head1 ERROR AND EXCEPTION HANDLING
1723 2011
1724In general, AnyEvent does not do any error handling - it relies on the 2012In general, AnyEvent does not do any error handling - it relies on the
1725caller to do that if required. The L<AnyEvent::Strict> module (see also 2013caller to do that if required. The L<AnyEvent::Strict> module (see also
1737$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and 2025$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
1738so on. 2026so on.
1739 2027
1740=head1 ENVIRONMENT VARIABLES 2028=head1 ENVIRONMENT VARIABLES
1741 2029
1742The following environment variables are used by this module or its 2030AnyEvent supports a number of environment variables that tune the
1743submodules. 2031runtime behaviour. They are usually evaluated when AnyEvent is
2032loaded, initialised, or a submodule that uses them is loaded. Many of
2033them also cause AnyEvent to load additional modules - for example,
2034C<PERL_ANYEVENT_DEBUG_WRAP> causes the L<AnyEvent::Debug> module to be
2035loaded.
1744 2036
1745Note that AnyEvent will remove I<all> environment variables starting with 2037All the environment variables documented here start with
1746C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is 2038C<PERL_ANYEVENT_>, which is what AnyEvent considers its own
1747enabled. 2039namespace. Other modules are encouraged (but by no means required) to use
2040C<PERL_ANYEVENT_SUBMODULE> if they have registered the AnyEvent::Submodule
2041namespace on CPAN, for any submodule. For example, L<AnyEvent::HTTP> could
2042be expected to use C<PERL_ANYEVENT_HTTP_PROXY> (it should not access env
2043variables starting with C<AE_>, see below).
2044
2045All variables can also be set via the C<AE_> prefix, that is, instead
2046of setting C<PERL_ANYEVENT_VERBOSE> you can also set C<AE_VERBOSE>. In
2047case there is a clash btween anyevent and another program that uses
2048C<AE_something> you can set the corresponding C<PERL_ANYEVENT_something>
2049variable to the empty string, as those variables take precedence.
2050
2051When AnyEvent is first loaded, it copies all C<AE_xxx> env variables
2052to their C<PERL_ANYEVENT_xxx> counterpart unless that variable already
2053exists. If taint mode is on, then AnyEvent will remove I<all> environment
2054variables starting with C<PERL_ANYEVENT_> from C<%ENV> (or replace them
2055with C<undef> or the empty string, if the corresaponding C<AE_> variable
2056is set).
2057
2058The exact algorithm is currently:
2059
2060 1. if taint mode enabled, delete all PERL_ANYEVENT_xyz variables from %ENV
2061 2. copy over AE_xyz to PERL_ANYEVENT_xyz unless the latter alraedy exists
2062 3. if taint mode enabled, set all PERL_ANYEVENT_xyz variables to undef.
2063
2064This ensures that child processes will not see the C<AE_> variables.
2065
2066The following environment variables are currently known to AnyEvent:
1748 2067
1749=over 4 2068=over 4
1750 2069
1751=item C<PERL_ANYEVENT_VERBOSE> 2070=item C<PERL_ANYEVENT_VERBOSE>
1752 2071
1753By default, AnyEvent will be completely silent except in fatal 2072By default, AnyEvent will only log messages with loglevel C<3>
1754conditions. You can set this environment variable to make AnyEvent more 2073(C<critical>) or higher (see L<AnyEvent::Log>). You can set this
2074environment variable to a numerical loglevel to make AnyEvent more (or
1755talkative. 2075less) talkative.
1756 2076
2077If you want to do more than just set the global logging level
2078you should have a look at C<PERL_ANYEVENT_LOG>, which allows much more
2079complex specifications.
2080
2081When set to C<0> (C<off>), then no messages whatsoever will be logged with
2082the default logging settings.
2083
1757When set to C<1> or higher, causes AnyEvent to warn about unexpected 2084When set to C<5> or higher (C<warn>), causes AnyEvent to warn about
1758conditions, such as not being able to load the event model specified by 2085unexpected conditions, such as not being able to load the event model
1759C<PERL_ANYEVENT_MODEL>. 2086specified by C<PERL_ANYEVENT_MODEL>, or a guard callback throwing an
2087exception - this is the minimum recommended level.
1760 2088
1761When set to C<2> or higher, cause AnyEvent to report to STDERR which event 2089When set to C<7> or higher (info), cause AnyEvent to report which event model it
1762model it chooses. 2090chooses.
1763 2091
1764When set to C<8> or higher, then AnyEvent will report extra information on 2092When set to C<8> or higher (debug), then AnyEvent will report extra information on
1765which optional modules it loads and how it implements certain features. 2093which optional modules it loads and how it implements certain features.
2094
2095=item C<PERL_ANYEVENT_LOG>
2096
2097Accepts rather complex logging specifications. For example, you could log
2098all C<debug> messages of some module to stderr, warnings and above to
2099stderr, and errors and above to syslog, with:
2100
2101 PERL_ANYEVENT_LOG=Some::Module=debug,+log:filter=warn,+%syslog:%syslog=error,syslog
2102
2103For the rather extensive details, see L<AnyEvent::Log>.
2104
2105This variable is evaluated when AnyEvent (or L<AnyEvent::Log>) is loaded,
2106so will take effect even before AnyEvent has initialised itself.
2107
2108Note that specifying this environment variable causes the L<AnyEvent::Log>
2109module to be loaded, while C<PERL_ANYEVENT_VERBOSE> does not, so only
2110using the latter saves a few hundred kB of memory until the first message
2111is being logged.
1766 2112
1767=item C<PERL_ANYEVENT_STRICT> 2113=item C<PERL_ANYEVENT_STRICT>
1768 2114
1769AnyEvent does not do much argument checking by default, as thorough 2115AnyEvent does not do much argument checking by default, as thorough
1770argument checking is very costly. Setting this variable to a true value 2116argument checking is very costly. Setting this variable to a true value
1772check the arguments passed to most method calls. If it finds any problems, 2118check the arguments passed to most method calls. If it finds any problems,
1773it will croak. 2119it will croak.
1774 2120
1775In other words, enables "strict" mode. 2121In other words, enables "strict" mode.
1776 2122
1777Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense> 2123Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1778>>, it is definitely recommended to keep it off in production. Keeping 2124>>, it is definitely recommended to keep it off in production. Keeping
1779C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs 2125C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1780can be very useful, however. 2126can be very useful, however.
1781 2127
2128=item C<PERL_ANYEVENT_DEBUG_SHELL>
2129
2130If this env variable is nonempty, then its contents will be interpreted by
2131C<AnyEvent::Socket::parse_hostport> and C<AnyEvent::Debug::shell> (after
2132replacing every occurance of C<$$> by the process pid). The shell object
2133is saved in C<$AnyEvent::Debug::SHELL>.
2134
2135This happens when the first watcher is created.
2136
2137For example, to bind a debug shell on a unix domain socket in
2138F<< /tmp/debug<pid>.sock >>, you could use this:
2139
2140 PERL_ANYEVENT_DEBUG_SHELL=/tmp/debug\$\$.sock perlprog
2141 # connect with e.g.: socat readline /tmp/debug123.sock
2142
2143Or to bind to tcp port 4545 on localhost:
2144
2145 PERL_ANYEVENT_DEBUG_SHELL=127.0.0.1:4545 perlprog
2146 # connect with e.g.: telnet localhost 4545
2147
2148Note that creating sockets in F</tmp> or on localhost is very unsafe on
2149multiuser systems.
2150
2151=item C<PERL_ANYEVENT_DEBUG_WRAP>
2152
2153Can be set to C<0>, C<1> or C<2> and enables wrapping of all watchers for
2154debugging purposes. See C<AnyEvent::Debug::wrap> for details.
2155
1782=item C<PERL_ANYEVENT_MODEL> 2156=item C<PERL_ANYEVENT_MODEL>
1783 2157
1784This can be used to specify the event model to be used by AnyEvent, before 2158This can be used to specify the event model to be used by AnyEvent, before
1785auto detection and -probing kicks in. It must be a string consisting 2159auto detection and -probing kicks in.
1786entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended 2160
2161It normally is a string consisting entirely of ASCII letters (e.g. C<EV>
2162or C<IOAsync>). The string C<AnyEvent::Impl::> gets prepended and the
1787and the resulting module name is loaded and if the load was successful, 2163resulting module name is loaded and - if the load was successful - used as
1788used as event model. If it fails to load AnyEvent will proceed with 2164event model backend. If it fails to load then AnyEvent will proceed with
1789auto detection and -probing. 2165auto detection and -probing.
1790 2166
1791This functionality might change in future versions. 2167If the string ends with C<::> instead (e.g. C<AnyEvent::Impl::EV::>) then
2168nothing gets prepended and the module name is used as-is (hint: C<::> at
2169the end of a string designates a module name and quotes it appropriately).
1792 2170
1793For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you 2171For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1794could start your program like this: 2172could start your program like this:
1795 2173
1796 PERL_ANYEVENT_MODEL=Perl perl ... 2174 PERL_ANYEVENT_MODEL=Perl perl ...
1797 2175
1798=item C<PERL_ANYEVENT_PROTOCOLS> 2176=item C<PERL_ANYEVENT_PROTOCOLS>
1814but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> 2192but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1815- only support IPv4, never try to resolve or contact IPv6 2193- only support IPv4, never try to resolve or contact IPv6
1816addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or 2194addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1817IPv6, but prefer IPv6 over IPv4. 2195IPv6, but prefer IPv6 over IPv4.
1818 2196
2197=item C<PERL_ANYEVENT_HOSTS>
2198
2199This variable, if specified, overrides the F</etc/hosts> file used by
2200L<AnyEvent::Socket>C<::resolve_sockaddr>, i.e. hosts aliases will be read
2201from that file instead.
2202
1819=item C<PERL_ANYEVENT_EDNS0> 2203=item C<PERL_ANYEVENT_EDNS0>
1820 2204
1821Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension 2205Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension for
1822for DNS. This extension is generally useful to reduce DNS traffic, but 2206DNS. This extension is generally useful to reduce DNS traffic, especially
1823some (broken) firewalls drop such DNS packets, which is why it is off by 2207when DNSSEC is involved, but some (broken) firewalls drop such DNS
1824default. 2208packets, which is why it is off by default.
1825 2209
1826Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce 2210Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1827EDNS0 in its DNS requests. 2211EDNS0 in its DNS requests.
1828 2212
1829=item C<PERL_ANYEVENT_MAX_FORKS> 2213=item C<PERL_ANYEVENT_MAX_FORKS>
1837resolver - this is the maximum number of parallel DNS requests that are 2221resolver - this is the maximum number of parallel DNS requests that are
1838sent to the DNS server. 2222sent to the DNS server.
1839 2223
1840=item C<PERL_ANYEVENT_RESOLV_CONF> 2224=item C<PERL_ANYEVENT_RESOLV_CONF>
1841 2225
1842The file to use instead of F</etc/resolv.conf> (or OS-specific 2226The absolute path to a F<resolv.conf>-style file to use instead of
1843configuration) in the default resolver. When set to the empty string, no 2227F</etc/resolv.conf> (or the OS-specific configuration) in the default
1844default config will be used. 2228resolver, or the empty string to select the default configuration.
1845 2229
1846=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>. 2230=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1847 2231
1848When neither C<ca_file> nor C<ca_path> was specified during 2232When neither C<ca_file> nor C<ca_path> was specified during
1849L<AnyEvent::TLS> context creation, and either of these environment 2233L<AnyEvent::TLS> context creation, and either of these environment
1850variables exist, they will be used to specify CA certificate locations 2234variables are nonempty, they will be used to specify CA certificate
1851instead of a system-dependent default. 2235locations instead of a system-dependent default.
1852 2236
1853=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT> 2237=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1854 2238
1855When these are set to C<1>, then the respective modules are not 2239When these are set to C<1>, then the respective modules are not
1856loaded. Mostly good for testing AnyEvent itself. 2240loaded. Mostly good for testing AnyEvent itself.
2004 2388
2005The actual code goes further and collects all errors (C<die>s, exceptions) 2389The actual code goes further and collects all errors (C<die>s, exceptions)
2006that occurred during request processing. The C<result> method detects 2390that occurred during request processing. The C<result> method detects
2007whether an exception as thrown (it is stored inside the $txn object) 2391whether an exception as thrown (it is stored inside the $txn object)
2008and just throws the exception, which means connection errors and other 2392and just throws the exception, which means connection errors and other
2009problems get reported tot he code that tries to use the result, not in a 2393problems get reported to the code that tries to use the result, not in a
2010random callback. 2394random callback.
2011 2395
2012All of this enables the following usage styles: 2396All of this enables the following usage styles:
2013 2397
20141. Blocking: 23981. Blocking:
2188(even when used without AnyEvent), but most event loops have acceptable 2572(even when used without AnyEvent), but most event loops have acceptable
2189performance with or without AnyEvent. 2573performance with or without AnyEvent.
2190 2574
2191=item * The overhead AnyEvent adds is usually much smaller than the overhead of 2575=item * The overhead AnyEvent adds is usually much smaller than the overhead of
2192the actual event loop, only with extremely fast event loops such as EV 2576the actual event loop, only with extremely fast event loops such as EV
2193adds AnyEvent significant overhead. 2577does AnyEvent add significant overhead.
2194 2578
2195=item * You should avoid POE like the plague if you want performance or 2579=item * You should avoid POE like the plague if you want performance or
2196reasonable memory usage. 2580reasonable memory usage.
2197 2581
2198=back 2582=back
2428 unless defined $SIG{PIPE}; 2812 unless defined $SIG{PIPE};
2429 2813
2430=head1 RECOMMENDED/OPTIONAL MODULES 2814=head1 RECOMMENDED/OPTIONAL MODULES
2431 2815
2432One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and 2816One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2433it's built-in modules) are required to use it. 2817its built-in modules) are required to use it.
2434 2818
2435That does not mean that AnyEvent won't take advantage of some additional 2819That does not mean that AnyEvent won't take advantage of some additional
2436modules if they are installed. 2820modules if they are installed.
2437 2821
2438This section epxlains which additional modules will be used, and how they 2822This section explains which additional modules will be used, and how they
2439affect AnyEvent's operetion. 2823affect AnyEvent's operation.
2440 2824
2441=over 4 2825=over 4
2442 2826
2443=item L<Async::Interrupt> 2827=item L<Async::Interrupt>
2444 2828
2449catch the signals) with some delay (default is 10 seconds, look for 2833catch the signals) with some delay (default is 10 seconds, look for
2450C<$AnyEvent::MAX_SIGNAL_LATENCY>). 2834C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2451 2835
2452If this module is available, then it will be used to implement signal 2836If this module is available, then it will be used to implement signal
2453catching, which means that signals will not be delayed, and the event loop 2837catching, which means that signals will not be delayed, and the event loop
2454will not be interrupted regularly, which is more efficient (And good for 2838will not be interrupted regularly, which is more efficient (and good for
2455battery life on laptops). 2839battery life on laptops).
2456 2840
2457This affects not just the pure-perl event loop, but also other event loops 2841This affects not just the pure-perl event loop, but also other event loops
2458that have no signal handling on their own (e.g. Glib, Tk, Qt). 2842that have no signal handling on their own (e.g. Glib, Tk, Qt).
2459 2843
2471automatic timer adjustments even when no monotonic clock is available, 2855automatic timer adjustments even when no monotonic clock is available,
2472can take avdantage of advanced kernel interfaces such as C<epoll> and 2856can take avdantage of advanced kernel interfaces such as C<epoll> and
2473C<kqueue>, and is the fastest backend I<by far>. You can even embed 2857C<kqueue>, and is the fastest backend I<by far>. You can even embed
2474L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>). 2858L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2475 2859
2860If you only use backends that rely on another event loop (e.g. C<Tk>),
2861then this module will do nothing for you.
2862
2476=item L<Guard> 2863=item L<Guard>
2477 2864
2478The guard module, when used, will be used to implement 2865The guard module, when used, will be used to implement
2479C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a 2866C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2480lot less memory), but otherwise doesn't affect guard operation much. It is 2867lot less memory), but otherwise doesn't affect guard operation much. It is
2481purely used for performance. 2868purely used for performance.
2482 2869
2483=item L<JSON> and L<JSON::XS> 2870=item L<JSON> and L<JSON::XS>
2484 2871
2485One of these modules is required when you want to read or write JSON data 2872One of these modules is required when you want to read or write JSON data
2486via L<AnyEvent::Handle>. It is also written in pure-perl, but can take 2873via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2487advantage of the ultra-high-speed L<JSON::XS> module when it is installed. 2874advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2488
2489In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2490installed.
2491 2875
2492=item L<Net::SSLeay> 2876=item L<Net::SSLeay>
2493 2877
2494Implementing TLS/SSL in Perl is certainly interesting, but not very 2878Implementing TLS/SSL in Perl is certainly interesting, but not very
2495worthwhile: If this module is installed, then L<AnyEvent::Handle> (with 2879worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2496the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL. 2880the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2497 2881
2498=item L<Time::HiRes> 2882=item L<Time::HiRes>
2499 2883
2500This module is part of perl since release 5.008. It will be used when the 2884This module is part of perl since release 5.008. It will be used when the
2501chosen event library does not come with a timing source on it's own. The 2885chosen event library does not come with a timing source of its own. The
2502pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to 2886pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2503try to use a monotonic clock for timing stability. 2887try to use a monotonic clock for timing stability.
2504 2888
2505=back 2889=back
2506 2890
2507 2891
2508=head1 FORK 2892=head1 FORK
2509 2893
2510Most event libraries are not fork-safe. The ones who are usually are 2894Most event libraries are not fork-safe. The ones who are usually are
2511because they rely on inefficient but fork-safe C<select> or C<poll> 2895because they rely on inefficient but fork-safe C<select> or C<poll> calls
2512calls. Only L<EV> is fully fork-aware. 2896- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
2897are usually badly thought-out hacks that are incompatible with fork in
2898one way or another. Only L<EV> is fully fork-aware and ensures that you
2899continue event-processing in both parent and child (or both, if you know
2900what you are doing).
2901
2902This means that, in general, you cannot fork and do event processing in
2903the child if the event library was initialised before the fork (which
2904usually happens when the first AnyEvent watcher is created, or the library
2905is loaded).
2513 2906
2514If you have to fork, you must either do so I<before> creating your first 2907If you have to fork, you must either do so I<before> creating your first
2515watcher OR you must not use AnyEvent at all in the child OR you must do 2908watcher OR you must not use AnyEvent at all in the child OR you must do
2516something completely out of the scope of AnyEvent. 2909something completely out of the scope of AnyEvent.
2910
2911The problem of doing event processing in the parent I<and> the child
2912is much more complicated: even for backends that I<are> fork-aware or
2913fork-safe, their behaviour is not usually what you want: fork clones all
2914watchers, that means all timers, I/O watchers etc. are active in both
2915parent and child, which is almost never what you want. USing C<exec>
2916to start worker children from some kind of manage rprocess is usually
2917preferred, because it is much easier and cleaner, at the expense of having
2918to have another binary.
2517 2919
2518 2920
2519=head1 SECURITY CONSIDERATIONS 2921=head1 SECURITY CONSIDERATIONS
2520 2922
2521AnyEvent can be forced to load any event model via 2923AnyEvent can be forced to load any event model via
2551pronounced). 2953pronounced).
2552 2954
2553 2955
2554=head1 SEE ALSO 2956=head1 SEE ALSO
2555 2957
2556Utility functions: L<AnyEvent::Util>. 2958Tutorial/Introduction: L<AnyEvent::Intro>.
2557 2959
2558Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>, 2960FAQ: L<AnyEvent::FAQ>.
2559L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. 2961
2962Utility functions: L<AnyEvent::Util> (misc. grab-bag), L<AnyEvent::Log>
2963(simply logging).
2964
2965Development/Debugging: L<AnyEvent::Strict> (stricter checking),
2966L<AnyEvent::Debug> (interactive shell, watcher tracing).
2967
2968Supported event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>,
2969L<Glib::EV>, L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>,
2970L<Qt>, L<POE>, L<FLTK>.
2560 2971
2561Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, 2972Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2562L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, 2973L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2563L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, 2974L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2564L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>. 2975L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>,
2976L<AnyEvent::Impl::FLTK>.
2565 2977
2566Non-blocking file handles, sockets, TCP clients and 2978Non-blocking handles, pipes, stream sockets, TCP clients and
2567servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>. 2979servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2568 2980
2569Asynchronous DNS: L<AnyEvent::DNS>. 2981Asynchronous DNS: L<AnyEvent::DNS>.
2570 2982
2571Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, 2983Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2572L<Coro::Event>,
2573 2984
2574Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>, 2985Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2575L<AnyEvent::HTTP>. 2986L<AnyEvent::HTTP>.
2576 2987
2577 2988
2578=head1 AUTHOR 2989=head1 AUTHOR
2579 2990

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