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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 : 3;
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) { # also catches non-numeric levels(!)
1309 require AnyEvent::Log;
1310 # AnyEvent::Log overwrites this function
1311 goto &log;
1312 }
1313
1314 0 # not logged
1315}
1316
1317if (length $ENV{PERL_ANYEVENT_LOG}) {
1318 require AnyEvent::Log; # AnyEvent::Log does the thing for us
1319}
1320
1162my @models = ( 1321our @models = (
1163 [EV:: => AnyEvent::Impl::EV:: , 1], 1322 [EV:: => AnyEvent::Impl::EV:: , 1],
1164 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1], 1323 [AnyEvent::Loop:: => AnyEvent::Impl::Perl:: , 1],
1165 # everything below here will not (normally) be autoprobed 1324 # everything below here will not (normally) be autoprobed
1166 # as the pureperl backend should work everywhere 1325 # as the pure perl backend should work everywhere
1167 # and is usually faster 1326 # and is usually faster
1168 [Event:: => AnyEvent::Impl::Event::, 1], 1327 [Event:: => AnyEvent::Impl::Event::, 1],
1169 [Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers 1328 [Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1170 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy 1329 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1171 [Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package 1330 [Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1172 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles 1331 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1173 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program 1332 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1174 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza 1333 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1175 [Wx:: => AnyEvent::Impl::POE::], 1334 [Wx:: => AnyEvent::Impl::POE::],
1176 [Prima:: => AnyEvent::Impl::POE::], 1335 [Prima:: => AnyEvent::Impl::POE::],
1177 # IO::Async is just too broken - we would need workarounds for its 1336 [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1178 # byzantine signal and broken child handling, among others. 1337 [Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1179 # IO::Async is rather hard to detect, as it doesn't have any 1338 [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); 1339);
1186 1340
1187our %method = map +($_ => 1), 1341our @isa_hook;
1342
1343sub _isa_set {
1344 my @pkg = ("AnyEvent", (map $_->[0], grep defined, @isa_hook), $MODEL);
1345
1346 @{"$pkg[$_-1]::ISA"} = $pkg[$_]
1347 for 1 .. $#pkg;
1348
1349 grep $_ && $_->[1], @isa_hook
1350 and AE::_reset ();
1351}
1352
1353# used for hooking AnyEvent::Strict and AnyEvent::Debug::Wrap into the class hierarchy
1354sub _isa_hook($$;$) {
1355 my ($i, $pkg, $reset_ae) = @_;
1356
1357 $isa_hook[$i] = $pkg ? [$pkg, $reset_ae] : undef;
1358
1359 _isa_set;
1360}
1361
1362# all autoloaded methods reserve the complete glob, not just the method slot.
1363# due to bugs in perls method cache implementation.
1188 qw(io timer time now now_update signal child idle condvar one_event DESTROY); 1364our @methods = qw(io timer time now now_update signal child idle condvar);
1189 1365
1190our @post_detect;
1191
1192sub post_detect(&) { 1366sub detect() {
1193 my ($cb) = @_; 1367 return $MODEL if $MODEL; # some programs keep references to detect
1194 1368
1195 if ($MODEL) { 1369 local $!; # for good measure
1196 $cb->(); 1370 local $SIG{__DIE__}; # we use eval
1197 1371
1198 undef 1372 # free some memory
1373 *detect = sub () { $MODEL };
1374 # undef &func doesn't correctly update the method cache. grmbl.
1375 # so we delete the whole glob. grmbl.
1376 # otoh, perl doesn't let me undef an active usb, but it lets me free
1377 # a glob with an active sub. hrm. i hope it works, but perl is
1378 # usually buggy in this department. sigh.
1379 delete @{"AnyEvent::"}{@methods};
1380 undef @methods;
1381
1382 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) {
1383 my $model = $1;
1384 $model = "AnyEvent::Impl::$model" unless $model =~ s/::$//;
1385 if (eval "require $model") {
1386 AnyEvent::log 7 => "loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.";
1387 $MODEL = $model;
1199 } else { 1388 } else {
1200 push @post_detect, $cb; 1389 AnyEvent::log 5 => "unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
1201 1390 }
1202 defined wantarray
1203 ? bless \$cb, "AnyEvent::Util::postdetect"
1204 : ()
1205 } 1391 }
1206}
1207 1392
1208sub AnyEvent::Util::postdetect::DESTROY { 1393 # check for already loaded models
1209 @post_detect = grep $_ != ${$_[0]}, @post_detect;
1210}
1211
1212sub detect() {
1213 unless ($MODEL) { 1394 unless ($MODEL) {
1214 local $SIG{__DIE__}; 1395 for (@REGISTRY, @models) {
1215 1396 my ($package, $model) = @$_;
1216 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { 1397 if (${"$package\::VERSION"} > 0) {
1217 my $model = "AnyEvent::Impl::$1";
1218 if (eval "require $model") { 1398 if (eval "require $model") {
1399 AnyEvent::log 7 => "autodetected model '$model', using it.";
1219 $MODEL = $model; 1400 $MODEL = $model;
1220 warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2; 1401 last;
1221 } else { 1402 }
1222 warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1223 } 1403 }
1224 } 1404 }
1225 1405
1226 # check for already loaded models
1227 unless ($MODEL) { 1406 unless ($MODEL) {
1407 # try to autoload a model
1228 for (@REGISTRY, @models) { 1408 for (@REGISTRY, @models) {
1229 my ($package, $model) = @$_; 1409 my ($package, $model, $autoload) = @$_;
1410 if (
1411 $autoload
1412 and eval "require $package"
1230 if (${"$package\::VERSION"} > 0) { 1413 and ${"$package\::VERSION"} > 0
1231 if (eval "require $model") { 1414 and eval "require $model"
1415 ) {
1416 AnyEvent::log 7 => "autoloaded model '$model', using it.";
1232 $MODEL = $model; 1417 $MODEL = $model;
1233 warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1234 last; 1418 last;
1235 }
1236 } 1419 }
1237 } 1420 }
1238 1421
1239 unless ($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 1422 $MODEL
1256 or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n"; 1423 or die "AnyEvent: backend autodetection failed - did you properly install AnyEvent?";
1257 }
1258 } 1424 }
1259
1260 push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1261
1262 unshift @ISA, $MODEL;
1263
1264 require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1265
1266 (shift @post_detect)->() while @post_detect;
1267 } 1425 }
1268 1426
1427 # free memory only needed for probing
1428 undef @models;
1429 undef @REGISTRY;
1430
1431 push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1432
1433 # now nuke some methods that are overridden by the backend.
1434 # SUPER usage is not allowed in these.
1435 for (qw(time signal child idle)) {
1436 undef &{"AnyEvent::Base::$_"}
1437 if defined &{"$MODEL\::$_"};
1438 }
1439
1440 _isa_set;
1441
1442 # we're officially open!
1443
1444 if ($ENV{PERL_ANYEVENT_STRICT}) {
1445 require AnyEvent::Strict;
1446 }
1447
1448 if ($ENV{PERL_ANYEVENT_DEBUG_WRAP}) {
1449 require AnyEvent::Debug;
1450 AnyEvent::Debug::wrap ($ENV{PERL_ANYEVENT_DEBUG_WRAP});
1451 }
1452
1453 if (length $ENV{PERL_ANYEVENT_DEBUG_SHELL}) {
1454 require AnyEvent::Socket;
1455 require AnyEvent::Debug;
1456
1457 my $shell = $ENV{PERL_ANYEVENT_DEBUG_SHELL};
1458 $shell =~ s/\$\$/$$/g;
1459
1460 my ($host, $service) = AnyEvent::Socket::parse_hostport ($shell);
1461 $AnyEvent::Debug::SHELL = AnyEvent::Debug::shell ($host, $service);
1462 }
1463
1464 # now the anyevent environment is set up as the user told us to, so
1465 # call the actual user code - post detects
1466
1467 (shift @post_detect)->() while @post_detect;
1468 undef @post_detect;
1469
1470 *post_detect = sub(&) {
1471 shift->();
1472
1473 undef
1474 };
1475
1269 $MODEL 1476 $MODEL
1270} 1477}
1271 1478
1272sub AUTOLOAD { 1479for my $name (@methods) {
1273 (my $func = $AUTOLOAD) =~ s/.*://; 1480 *$name = sub {
1274 1481 detect;
1275 $method{$func} 1482 # we use goto because
1276 or Carp::croak "$func: not a valid method for AnyEvent objects"; 1483 # a) it makes the thunk more transparent
1277 1484 # b) it allows us to delete the thunk later
1278 detect unless $MODEL; 1485 goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
1279 1486 };
1280 my $class = shift;
1281 $class->$func (@_);
1282} 1487}
1283 1488
1284# utility function to dup a filehandle. this is used by many backends 1489# utility function to dup a filehandle. this is used by many backends
1285# to support binding more than one watcher per filehandle (they usually 1490# 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). 1491# allow only one watcher per fd, so we dup it to get a different one).
1300 1505
1301=head1 SIMPLIFIED AE API 1506=head1 SIMPLIFIED AE API
1302 1507
1303Starting with version 5.0, AnyEvent officially supports a second, much 1508Starting with version 5.0, AnyEvent officially supports a second, much
1304simpler, API that is designed to reduce the calling, typing and memory 1509simpler, API that is designed to reduce the calling, typing and memory
1305overhead. 1510overhead by using function call syntax and a fixed number of parameters.
1306 1511
1307See the L<AE> manpage for details. 1512See the L<AE> manpage for details.
1308 1513
1309=cut 1514=cut
1310 1515
1311package AE; 1516package AE;
1312 1517
1313our $VERSION = $AnyEvent::VERSION; 1518our $VERSION = $AnyEvent::VERSION;
1314 1519
1520sub _reset() {
1521 eval q{
1522 # fall back to the main API by default - backends and AnyEvent::Base
1523 # implementations can overwrite these.
1524
1315sub io($$$) { 1525 sub io($$$) {
1316 AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2]) 1526 AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1317} 1527 }
1318 1528
1319sub timer($$$) { 1529 sub timer($$$) {
1320 AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2]) 1530 AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
1321} 1531 }
1322 1532
1323sub signal($$) { 1533 sub signal($$) {
1324 AnyEvent->signal (signal => $_[0], cb => $_[1]) 1534 AnyEvent->signal (signal => $_[0], cb => $_[1])
1325} 1535 }
1326 1536
1327sub child($$) { 1537 sub child($$) {
1328 AnyEvent->child (pid => $_[0], cb => $_[1]) 1538 AnyEvent->child (pid => $_[0], cb => $_[1])
1329} 1539 }
1330 1540
1331sub idle($) { 1541 sub idle($) {
1332 AnyEvent->idle (cb => $_[0]) 1542 AnyEvent->idle (cb => $_[0]);
1333} 1543 }
1334 1544
1335sub cv(;&) { 1545 sub cv(;&) {
1336 AnyEvent->condvar (@_ ? (cb => $_[0]) : ()) 1546 AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
1337} 1547 }
1338 1548
1339sub now() { 1549 sub now() {
1340 AnyEvent->now 1550 AnyEvent->now
1341} 1551 }
1342 1552
1343sub now_update() { 1553 sub now_update() {
1344 AnyEvent->now_update 1554 AnyEvent->now_update
1345} 1555 }
1346 1556
1347sub time() { 1557 sub time() {
1348 AnyEvent->time 1558 AnyEvent->time
1559 }
1560
1561 *postpone = \&AnyEvent::postpone;
1562 *log = \&AnyEvent::log;
1563 };
1564 die if $@;
1349} 1565}
1566
1567BEGIN { _reset }
1350 1568
1351package AnyEvent::Base; 1569package AnyEvent::Base;
1352 1570
1353# default implementations for many methods 1571# default implementations for many methods
1354 1572
1355sub _time() { 1573sub time {
1574 eval q{ # poor man's autoloading {}
1356 # probe for availability of Time::HiRes 1575 # probe for availability of Time::HiRes
1357 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { 1576 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1358 warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8; 1577 *time = sub { Time::HiRes::time () };
1359 *_time = \&Time::HiRes::time; 1578 *AE::time = \& Time::HiRes::time ;
1579 *now = \&time;
1580 AnyEvent::log 8 => "AnyEvent: using Time::HiRes for sub-second timing accuracy.";
1360 # if (eval "use POSIX (); (POSIX::times())... 1581 # if (eval "use POSIX (); (POSIX::times())...
1361 } else { 1582 } else {
1583 *time = sub { CORE::time };
1584 *AE::time = sub (){ CORE::time };
1585 *now = \&time;
1362 warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE; 1586 AnyEvent::log 3 => "using built-in time(), WARNING, no sub-second resolution!";
1363 *_time = sub { time }; # epic fail 1587 }
1364 } 1588 };
1589 die if $@;
1365 1590
1366 &_time 1591 &time
1367} 1592}
1368 1593
1369sub time { _time } 1594*now = \&time;
1370sub now { _time }
1371sub now_update { } 1595sub now_update { }
1372 1596
1597sub _poll {
1598 Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
1599}
1600
1373# default implementation for ->condvar 1601# default implementation for ->condvar
1602# in fact, the default should not be overwritten
1374 1603
1375sub condvar { 1604sub condvar {
1605 eval q{ # poor man's autoloading {}
1606 *condvar = sub {
1376 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar" 1607 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1608 };
1609
1610 *AE::cv = sub (;&) {
1611 bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
1612 };
1613 };
1614 die if $@;
1615
1616 &condvar
1377} 1617}
1378 1618
1379# default implementation for ->signal 1619# default implementation for ->signal
1380 1620
1381our $HAVE_ASYNC_INTERRUPT; 1621our $HAVE_ASYNC_INTERRUPT;
1390 1630
1391our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); 1631our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1392our (%SIG_ASY, %SIG_ASY_W); 1632our (%SIG_ASY, %SIG_ASY_W);
1393our ($SIG_COUNT, $SIG_TW); 1633our ($SIG_COUNT, $SIG_TW);
1394 1634
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 1635# install a dummy wakeup watcher to reduce signal catching latency
1636# used by Impls
1409sub _sig_add() { 1637sub _sig_add() {
1410 unless ($SIG_COUNT++) { 1638 unless ($SIG_COUNT++) {
1411 # try to align timer on a full-second boundary, if possible 1639 # try to align timer on a full-second boundary, if possible
1412 my $NOW = AE::now; 1640 my $NOW = AE::now;
1413 1641
1423 undef $SIG_TW 1651 undef $SIG_TW
1424 unless --$SIG_COUNT; 1652 unless --$SIG_COUNT;
1425} 1653}
1426 1654
1427our $_sig_name_init; $_sig_name_init = sub { 1655our $_sig_name_init; $_sig_name_init = sub {
1428 eval q{ # poor man's autoloading 1656 eval q{ # poor man's autoloading {}
1429 undef $_sig_name_init; 1657 undef $_sig_name_init;
1430 1658
1431 if (_have_async_interrupt) { 1659 if (_have_async_interrupt) {
1432 *sig2num = \&Async::Interrupt::sig2num; 1660 *sig2num = \&Async::Interrupt::sig2num;
1433 *sig2name = \&Async::Interrupt::sig2name; 1661 *sig2name = \&Async::Interrupt::sig2name;
1457 1685
1458sub signal { 1686sub signal {
1459 eval q{ # poor man's autoloading {} 1687 eval q{ # poor man's autoloading {}
1460 # probe for availability of Async::Interrupt 1688 # probe for availability of Async::Interrupt
1461 if (_have_async_interrupt) { 1689 if (_have_async_interrupt) {
1462 warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8; 1690 AnyEvent::log 8 => "using Async::Interrupt for race-free signal handling.";
1463 1691
1464 $SIGPIPE_R = new Async::Interrupt::EventPipe; 1692 $SIGPIPE_R = new Async::Interrupt::EventPipe;
1465 $SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec; 1693 $SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1466 1694
1467 } else { 1695 } else {
1468 warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8; 1696 AnyEvent::log 8 => "using emulated perl signal handling with latency timer.";
1469
1470 require Fcntl;
1471 1697
1472 if (AnyEvent::WIN32) { 1698 if (AnyEvent::WIN32) {
1473 require AnyEvent::Util; 1699 require AnyEvent::Util;
1474 1700
1475 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe (); 1701 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1476 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R; 1702 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1477 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case 1703 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1478 } else { 1704 } else {
1479 pipe $SIGPIPE_R, $SIGPIPE_W; 1705 pipe $SIGPIPE_R, $SIGPIPE_W;
1480 fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R; 1706 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 1707 fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
1482 1708
1483 # not strictly required, as $^F is normally 2, but let's make sure... 1709 # not strictly required, as $^F is normally 2, but let's make sure...
1484 fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; 1710 fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1485 fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; 1711 fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1486 } 1712 }
1487 1713
1488 $SIGPIPE_R 1714 $SIGPIPE_R
1489 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; 1715 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1490 1716
1491 $SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec; 1717 $SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1492 } 1718 }
1493 1719
1494 *signal = sub { 1720 *signal = $HAVE_ASYNC_INTERRUPT
1721 ? sub {
1495 my (undef, %arg) = @_; 1722 my (undef, %arg) = @_;
1496 1723
1497 my $signal = uc $arg{signal}
1498 or Carp::croak "required option 'signal' is missing";
1499
1500 if ($HAVE_ASYNC_INTERRUPT) {
1501 # async::interrupt 1724 # async::interrupt
1502
1503 $signal = sig2num $signal; 1725 my $signal = sig2num $arg{signal};
1504 $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; 1726 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1505 1727
1506 $SIG_ASY{$signal} ||= new Async::Interrupt 1728 $SIG_ASY{$signal} ||= new Async::Interrupt
1507 cb => sub { undef $SIG_EV{$signal} }, 1729 cb => sub { undef $SIG_EV{$signal} },
1508 signal => $signal, 1730 signal => $signal,
1509 pipe => [$SIGPIPE_R->filenos], 1731 pipe => [$SIGPIPE_R->filenos],
1510 pipe_autodrain => 0, 1732 pipe_autodrain => 0,
1511 ; 1733 ;
1512 1734
1513 } else { 1735 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1736 }
1737 : sub {
1738 my (undef, %arg) = @_;
1739
1514 # pure perl 1740 # pure perl
1515
1516 # AE::Util has been loaded in signal
1517 $signal = sig2name $signal; 1741 my $signal = sig2name $arg{signal};
1518 $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; 1742 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1519 1743
1520 $SIG{$signal} ||= sub { 1744 $SIG{$signal} ||= sub {
1521 local $!; 1745 local $!;
1522 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; 1746 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1523 undef $SIG_EV{$signal}; 1747 undef $SIG_EV{$signal};
1524 }; 1748 };
1525 1749
1526 # can't do signal processing without introducing races in pure perl, 1750 # can't do signal processing without introducing races in pure perl,
1527 # so limit the signal latency. 1751 # so limit the signal latency.
1528 _sig_add; 1752 _sig_add;
1529 }
1530 1753
1531 bless [$signal, $arg{cb}], "AnyEvent::Base::signal" 1754 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1755 }
1532 }; 1756 ;
1533 1757
1534 *AnyEvent::Base::signal::DESTROY = sub { 1758 *AnyEvent::Base::signal::DESTROY = sub {
1535 my ($signal, $cb) = @{$_[0]}; 1759 my ($signal, $cb) = @{$_[0]};
1536 1760
1537 _sig_del; 1761 _sig_del;
1544 # print weird messages, or just unconditionally exit 1768 # print weird messages, or just unconditionally exit
1545 # instead of getting the default action. 1769 # instead of getting the default action.
1546 undef $SIG{$signal} 1770 undef $SIG{$signal}
1547 unless keys %{ $SIG_CB{$signal} }; 1771 unless keys %{ $SIG_CB{$signal} };
1548 }; 1772 };
1773
1774 *_signal_exec = sub {
1775 $HAVE_ASYNC_INTERRUPT
1776 ? $SIGPIPE_R->drain
1777 : sysread $SIGPIPE_R, (my $dummy), 9;
1778
1779 while (%SIG_EV) {
1780 for (keys %SIG_EV) {
1781 delete $SIG_EV{$_};
1782 &$_ for values %{ $SIG_CB{$_} || {} };
1783 }
1784 }
1785 };
1549 }; 1786 };
1550 die if $@; 1787 die if $@;
1788
1551 &signal 1789 &signal
1552} 1790}
1553 1791
1554# default implementation for ->child 1792# default implementation for ->child
1555 1793
1556our %PID_CB; 1794our %PID_CB;
1557our $CHLD_W; 1795our $CHLD_W;
1558our $CHLD_DELAY_W; 1796our $CHLD_DELAY_W;
1559our $WNOHANG;
1560 1797
1798# used by many Impl's
1561sub _emit_childstatus($$) { 1799sub _emit_childstatus($$) {
1562 my (undef, $rpid, $rstatus) = @_; 1800 my (undef, $rpid, $rstatus) = @_;
1563 1801
1564 $_->($rpid, $rstatus) 1802 $_->($rpid, $rstatus)
1565 for values %{ $PID_CB{$rpid} || {} }, 1803 for values %{ $PID_CB{$rpid} || {} },
1566 values %{ $PID_CB{0} || {} }; 1804 values %{ $PID_CB{0} || {} };
1567} 1805}
1568 1806
1569sub _sigchld {
1570 my $pid;
1571
1572 AnyEvent->_emit_childstatus ($pid, $?)
1573 while ($pid = waitpid -1, $WNOHANG) > 0;
1574}
1575
1576sub child { 1807sub child {
1808 eval q{ # poor man's autoloading {}
1809 *_sigchld = sub {
1810 my $pid;
1811
1812 AnyEvent->_emit_childstatus ($pid, $?)
1813 while ($pid = waitpid -1, WNOHANG) > 0;
1814 };
1815
1816 *child = sub {
1577 my (undef, %arg) = @_; 1817 my (undef, %arg) = @_;
1578 1818
1579 defined (my $pid = $arg{pid} + 0) 1819 my $pid = $arg{pid};
1580 or Carp::croak "required option 'pid' is missing"; 1820 my $cb = $arg{cb};
1581 1821
1582 $PID_CB{$pid}{$arg{cb}} = $arg{cb}; 1822 $PID_CB{$pid}{$cb+0} = $cb;
1583 1823
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) { 1824 unless ($CHLD_W) {
1590 $CHLD_W = AE::signal CHLD => \&_sigchld; 1825 $CHLD_W = AE::signal CHLD => \&_sigchld;
1591 # child could be a zombie already, so make at least one round 1826 # child could be a zombie already, so make at least one round
1592 &_sigchld; 1827 &_sigchld;
1593 } 1828 }
1594 1829
1595 bless [$pid, $arg{cb}], "AnyEvent::Base::child" 1830 bless [$pid, $cb+0], "AnyEvent::Base::child"
1596} 1831 };
1597 1832
1598sub AnyEvent::Base::child::DESTROY { 1833 *AnyEvent::Base::child::DESTROY = sub {
1599 my ($pid, $cb) = @{$_[0]}; 1834 my ($pid, $icb) = @{$_[0]};
1600 1835
1601 delete $PID_CB{$pid}{$cb}; 1836 delete $PID_CB{$pid}{$icb};
1602 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; 1837 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1603 1838
1604 undef $CHLD_W unless keys %PID_CB; 1839 undef $CHLD_W unless keys %PID_CB;
1840 };
1841 };
1842 die if $@;
1843
1844 &child
1605} 1845}
1606 1846
1607# idle emulation is done by simply using a timer, regardless 1847# idle emulation is done by simply using a timer, regardless
1608# of whether the process is idle or not, and not letting 1848# of whether the process is idle or not, and not letting
1609# the callback use more than 50% of the time. 1849# the callback use more than 50% of the time.
1610sub idle { 1850sub idle {
1851 eval q{ # poor man's autoloading {}
1852 *idle = sub {
1611 my (undef, %arg) = @_; 1853 my (undef, %arg) = @_;
1612 1854
1613 my ($cb, $w, $rcb) = $arg{cb}; 1855 my ($cb, $w, $rcb) = $arg{cb};
1614 1856
1615 $rcb = sub { 1857 $rcb = sub {
1616 if ($cb) { 1858 if ($cb) {
1617 $w = _time; 1859 $w = AE::time;
1618 &$cb; 1860 &$cb;
1619 $w = _time - $w; 1861 $w = AE::time - $w;
1620 1862
1621 # never use more then 50% of the time for the idle watcher, 1863 # never use more then 50% of the time for the idle watcher,
1622 # within some limits 1864 # within some limits
1623 $w = 0.0001 if $w < 0.0001; 1865 $w = 0.0001 if $w < 0.0001;
1624 $w = 5 if $w > 5; 1866 $w = 5 if $w > 5;
1625 1867
1626 $w = AE::timer $w, 0, $rcb; 1868 $w = AE::timer $w, 0, $rcb;
1627 } else { 1869 } else {
1628 # clean up... 1870 # clean up...
1629 undef $w; 1871 undef $w;
1630 undef $rcb; 1872 undef $rcb;
1873 }
1874 };
1875
1876 $w = AE::timer 0.05, 0, $rcb;
1877
1878 bless \\$cb, "AnyEvent::Base::idle"
1631 } 1879 };
1880
1881 *AnyEvent::Base::idle::DESTROY = sub {
1882 undef $${$_[0]};
1883 };
1632 }; 1884 };
1885 die if $@;
1633 1886
1634 $w = AE::timer 0.05, 0, $rcb; 1887 &idle
1635
1636 bless \\$cb, "AnyEvent::Base::idle"
1637}
1638
1639sub AnyEvent::Base::idle::DESTROY {
1640 undef $${$_[0]};
1641} 1888}
1642 1889
1643package AnyEvent::CondVar; 1890package AnyEvent::CondVar;
1644 1891
1645our @ISA = AnyEvent::CondVar::Base::; 1892our @ISA = AnyEvent::CondVar::Base::;
1893
1894# only to be used for subclassing
1895sub new {
1896 my $class = shift;
1897 bless AnyEvent->condvar (@_), $class
1898}
1646 1899
1647package AnyEvent::CondVar::Base; 1900package AnyEvent::CondVar::Base;
1648 1901
1649#use overload 1902#use overload
1650# '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, 1903# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1660 1913
1661sub _send { 1914sub _send {
1662 # nop 1915 # nop
1663} 1916}
1664 1917
1918sub _wait {
1919 AnyEvent->_poll until $_[0]{_ae_sent};
1920}
1921
1665sub send { 1922sub send {
1666 my $cv = shift; 1923 my $cv = shift;
1667 $cv->{_ae_sent} = [@_]; 1924 $cv->{_ae_sent} = [@_];
1668 (delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb}; 1925 (delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1669 $cv->_send; 1926 $cv->_send;
1676 1933
1677sub ready { 1934sub ready {
1678 $_[0]{_ae_sent} 1935 $_[0]{_ae_sent}
1679} 1936}
1680 1937
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 { 1938sub recv {
1939 unless ($_[0]{_ae_sent}) {
1940 $WAITING
1941 and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
1942
1943 local $WAITING = 1;
1691 $_[0]->_wait; 1944 $_[0]->_wait;
1945 }
1692 1946
1693 Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak}; 1947 $_[0]{_ae_croak}
1694 wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0] 1948 and Carp::croak $_[0]{_ae_croak};
1949
1950 wantarray
1951 ? @{ $_[0]{_ae_sent} }
1952 : $_[0]{_ae_sent}[0]
1695} 1953}
1696 1954
1697sub cb { 1955sub cb {
1698 my $cv = shift; 1956 my $cv = shift;
1699 1957
1715 &{ $_[0]{_ae_end_cb} || sub { $_[0]->send } }; 1973 &{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1716} 1974}
1717 1975
1718# undocumented/compatibility with pre-3.4 1976# undocumented/compatibility with pre-3.4
1719*broadcast = \&send; 1977*broadcast = \&send;
1720*wait = \&_wait; 1978*wait = \&recv;
1721 1979
1722=head1 ERROR AND EXCEPTION HANDLING 1980=head1 ERROR AND EXCEPTION HANDLING
1723 1981
1724In general, AnyEvent does not do any error handling - it relies on the 1982In 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 1983caller to do that if required. The L<AnyEvent::Strict> module (see also
1737$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and 1995$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
1738so on. 1996so on.
1739 1997
1740=head1 ENVIRONMENT VARIABLES 1998=head1 ENVIRONMENT VARIABLES
1741 1999
1742The following environment variables are used by this module or its 2000AnyEvent supports a number of environment variables that tune the
1743submodules. 2001runtime behaviour. They are usually evaluated when AnyEvent is
2002loaded, initialised, or a submodule that uses them is loaded. Many of
2003them also cause AnyEvent to load additional modules - for example,
2004C<PERL_ANYEVENT_DEBUG_WRAP> causes the L<AnyEvent::Debug> module to be
2005loaded.
1744 2006
1745Note that AnyEvent will remove I<all> environment variables starting with 2007All the environment variables documented here start with
1746C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is 2008C<PERL_ANYEVENT_>, which is what AnyEvent considers its own
1747enabled. 2009namespace. Other modules are encouraged (but by no means required) to use
2010C<PERL_ANYEVENT_SUBMODULE> if they have registered the AnyEvent::Submodule
2011namespace on CPAN, for any submodule. For example, L<AnyEvent::HTTP> could
2012be expected to use C<PERL_ANYEVENT_HTTP_PROXY> (it should not access env
2013variables starting with C<AE_>, see below).
2014
2015All variables can also be set via the C<AE_> prefix, that is, instead
2016of setting C<PERL_ANYEVENT_VERBOSE> you can also set C<AE_VERBOSE>. In
2017case there is a clash btween anyevent and another program that uses
2018C<AE_something> you can set the corresponding C<PERL_ANYEVENT_something>
2019variable to the empty string, as those variables take precedence.
2020
2021When AnyEvent is first loaded, it copies all C<AE_xxx> env variables
2022to their C<PERL_ANYEVENT_xxx> counterpart unless that variable already
2023exists. If taint mode is on, then AnyEvent will remove I<all> environment
2024variables starting with C<PERL_ANYEVENT_> from C<%ENV> (or replace them
2025with C<undef> or the empty string, if the corresaponding C<AE_> variable
2026is set).
2027
2028The exact algorithm is currently:
2029
2030 1. if taint mode enabled, delete all PERL_ANYEVENT_xyz variables from %ENV
2031 2. copy over AE_xyz to PERL_ANYEVENT_xyz unless the latter alraedy exists
2032 3. if taint mode enabled, set all PERL_ANYEVENT_xyz variables to undef.
2033
2034This ensures that child processes will not see the C<AE_> variables.
2035
2036The following environment variables are currently known to AnyEvent:
1748 2037
1749=over 4 2038=over 4
1750 2039
1751=item C<PERL_ANYEVENT_VERBOSE> 2040=item C<PERL_ANYEVENT_VERBOSE>
1752 2041
1753By default, AnyEvent will be completely silent except in fatal 2042By default, AnyEvent will only log messages with loglevel C<3>
1754conditions. You can set this environment variable to make AnyEvent more 2043(C<critical>) or higher (see L<AnyEvent::Log>). You can set this
2044environment variable to a numerical loglevel to make AnyEvent more (or
1755talkative. 2045less) talkative.
1756 2046
2047If you want to do more than just set the global logging level
2048you should have a look at C<PERL_ANYEVENT_LOG>, which allows much more
2049complex specifications.
2050
2051When set to C<0> (C<off>), then no messages whatsoever will be logged with
2052the default logging settings.
2053
1757When set to C<1> or higher, causes AnyEvent to warn about unexpected 2054When 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 2055unexpected conditions, such as not being able to load the event model
1759C<PERL_ANYEVENT_MODEL>. 2056specified by C<PERL_ANYEVENT_MODEL>, or a guard callback throwing an
2057exception - this is the minimum recommended level.
1760 2058
1761When set to C<2> or higher, cause AnyEvent to report to STDERR which event 2059When set to C<7> or higher (info), cause AnyEvent to report which event model it
1762model it chooses. 2060chooses.
1763 2061
1764When set to C<8> or higher, then AnyEvent will report extra information on 2062When 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. 2063which optional modules it loads and how it implements certain features.
2064
2065=item C<PERL_ANYEVENT_LOG>
2066
2067Accepts rather complex logging specifications. For example, you could log
2068all C<debug> messages of some module to stderr, warnings and above to
2069stderr, and errors and above to syslog, with:
2070
2071 PERL_ANYEVENT_LOG=Some::Module=debug,+log:filter=warn,+%syslog:%syslog=error,syslog
2072
2073For the rather extensive details, see L<AnyEvent::Log>.
2074
2075This variable is evaluated when AnyEvent (or L<AnyEvent::Log>) is loaded,
2076so will take effect even before AnyEvent has initialised itself.
2077
2078Note that specifying this environment variable causes the L<AnyEvent::Log>
2079module to be loaded, while C<PERL_ANYEVENT_VERBOSE> does not, so only
2080using the latter saves a few hundred kB of memory until the first message
2081is being logged.
1766 2082
1767=item C<PERL_ANYEVENT_STRICT> 2083=item C<PERL_ANYEVENT_STRICT>
1768 2084
1769AnyEvent does not do much argument checking by default, as thorough 2085AnyEvent does not do much argument checking by default, as thorough
1770argument checking is very costly. Setting this variable to a true value 2086argument checking is very costly. Setting this variable to a true value
1772check the arguments passed to most method calls. If it finds any problems, 2088check the arguments passed to most method calls. If it finds any problems,
1773it will croak. 2089it will croak.
1774 2090
1775In other words, enables "strict" mode. 2091In other words, enables "strict" mode.
1776 2092
1777Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense> 2093Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1778>>, it is definitely recommended to keep it off in production. Keeping 2094>>, it is definitely recommended to keep it off in production. Keeping
1779C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs 2095C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1780can be very useful, however. 2096can be very useful, however.
1781 2097
2098=item C<PERL_ANYEVENT_DEBUG_SHELL>
2099
2100If this env variable is set, then its contents will be interpreted by
2101C<AnyEvent::Socket::parse_hostport> (after replacing every occurance of
2102C<$$> by the process pid) and an C<AnyEvent::Debug::shell> is bound on
2103that port. The shell object is saved in C<$AnyEvent::Debug::SHELL>.
2104
2105This happens when the first watcher is created.
2106
2107For example, to bind a debug shell on a unix domain socket in
2108F<< /tmp/debug<pid>.sock >>, you could use this:
2109
2110 PERL_ANYEVENT_DEBUG_SHELL=/tmp/debug\$\$.sock perlprog
2111
2112Note that creating sockets in F</tmp> is very unsafe on multiuser
2113systems.
2114
2115=item C<PERL_ANYEVENT_DEBUG_WRAP>
2116
2117Can be set to C<0>, C<1> or C<2> and enables wrapping of all watchers for
2118debugging purposes. See C<AnyEvent::Debug::wrap> for details.
2119
1782=item C<PERL_ANYEVENT_MODEL> 2120=item C<PERL_ANYEVENT_MODEL>
1783 2121
1784This can be used to specify the event model to be used by AnyEvent, before 2122This 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 2123auto detection and -probing kicks in.
1786entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended 2124
2125It normally is a string consisting entirely of ASCII letters (e.g. C<EV>
2126or C<IOAsync>). The string C<AnyEvent::Impl::> gets prepended and the
1787and the resulting module name is loaded and if the load was successful, 2127resulting 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 2128event model backend. If it fails to load then AnyEvent will proceed with
1789auto detection and -probing. 2129auto detection and -probing.
1790 2130
1791This functionality might change in future versions. 2131If the string ends with C<::> instead (e.g. C<AnyEvent::Impl::EV::>) then
2132nothing gets prepended and the module name is used as-is (hint: C<::> at
2133the end of a string designates a module name and quotes it appropriately).
1792 2134
1793For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you 2135For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1794could start your program like this: 2136could start your program like this:
1795 2137
1796 PERL_ANYEVENT_MODEL=Perl perl ... 2138 PERL_ANYEVENT_MODEL=Perl perl ...
1797 2139
1798=item C<PERL_ANYEVENT_PROTOCOLS> 2140=item C<PERL_ANYEVENT_PROTOCOLS>
1814but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4> 2156but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1815- only support IPv4, never try to resolve or contact IPv6 2157- only support IPv4, never try to resolve or contact IPv6
1816addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or 2158addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1817IPv6, but prefer IPv6 over IPv4. 2159IPv6, but prefer IPv6 over IPv4.
1818 2160
2161=item C<PERL_ANYEVENT_HOSTS>
2162
2163This variable, if specified, overrides the F</etc/hosts> file used by
2164L<AnyEvent::Socket>C<::resolve_sockaddr>, i.e. hosts aliases will be read
2165from that file instead.
2166
1819=item C<PERL_ANYEVENT_EDNS0> 2167=item C<PERL_ANYEVENT_EDNS0>
1820 2168
1821Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension 2169Used 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 2170DNS. This extension is generally useful to reduce DNS traffic, especially
1823some (broken) firewalls drop such DNS packets, which is why it is off by 2171when DNSSEC is involved, but some (broken) firewalls drop such DNS
1824default. 2172packets, which is why it is off by default.
1825 2173
1826Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce 2174Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1827EDNS0 in its DNS requests. 2175EDNS0 in its DNS requests.
1828 2176
1829=item C<PERL_ANYEVENT_MAX_FORKS> 2177=item C<PERL_ANYEVENT_MAX_FORKS>
1837resolver - this is the maximum number of parallel DNS requests that are 2185resolver - this is the maximum number of parallel DNS requests that are
1838sent to the DNS server. 2186sent to the DNS server.
1839 2187
1840=item C<PERL_ANYEVENT_RESOLV_CONF> 2188=item C<PERL_ANYEVENT_RESOLV_CONF>
1841 2189
1842The file to use instead of F</etc/resolv.conf> (or OS-specific 2190The 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 2191F</etc/resolv.conf> (or the OS-specific configuration) in the default
1844default config will be used. 2192resolver, or the empty string to select the default configuration.
1845 2193
1846=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>. 2194=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1847 2195
1848When neither C<ca_file> nor C<ca_path> was specified during 2196When neither C<ca_file> nor C<ca_path> was specified during
1849L<AnyEvent::TLS> context creation, and either of these environment 2197L<AnyEvent::TLS> context creation, and either of these environment
1850variables exist, they will be used to specify CA certificate locations 2198variables are nonempty, they will be used to specify CA certificate
1851instead of a system-dependent default. 2199locations instead of a system-dependent default.
1852 2200
1853=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT> 2201=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1854 2202
1855When these are set to C<1>, then the respective modules are not 2203When these are set to C<1>, then the respective modules are not
1856loaded. Mostly good for testing AnyEvent itself. 2204loaded. Mostly good for testing AnyEvent itself.
2004 2352
2005The actual code goes further and collects all errors (C<die>s, exceptions) 2353The actual code goes further and collects all errors (C<die>s, exceptions)
2006that occurred during request processing. The C<result> method detects 2354that occurred during request processing. The C<result> method detects
2007whether an exception as thrown (it is stored inside the $txn object) 2355whether an exception as thrown (it is stored inside the $txn object)
2008and just throws the exception, which means connection errors and other 2356and 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 2357problems get reported to the code that tries to use the result, not in a
2010random callback. 2358random callback.
2011 2359
2012All of this enables the following usage styles: 2360All of this enables the following usage styles:
2013 2361
20141. Blocking: 23621. Blocking:
2188(even when used without AnyEvent), but most event loops have acceptable 2536(even when used without AnyEvent), but most event loops have acceptable
2189performance with or without AnyEvent. 2537performance with or without AnyEvent.
2190 2538
2191=item * The overhead AnyEvent adds is usually much smaller than the overhead of 2539=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 2540the actual event loop, only with extremely fast event loops such as EV
2193adds AnyEvent significant overhead. 2541does AnyEvent add significant overhead.
2194 2542
2195=item * You should avoid POE like the plague if you want performance or 2543=item * You should avoid POE like the plague if you want performance or
2196reasonable memory usage. 2544reasonable memory usage.
2197 2545
2198=back 2546=back
2428 unless defined $SIG{PIPE}; 2776 unless defined $SIG{PIPE};
2429 2777
2430=head1 RECOMMENDED/OPTIONAL MODULES 2778=head1 RECOMMENDED/OPTIONAL MODULES
2431 2779
2432One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and 2780One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2433it's built-in modules) are required to use it. 2781its built-in modules) are required to use it.
2434 2782
2435That does not mean that AnyEvent won't take advantage of some additional 2783That does not mean that AnyEvent won't take advantage of some additional
2436modules if they are installed. 2784modules if they are installed.
2437 2785
2438This section epxlains which additional modules will be used, and how they 2786This section explains which additional modules will be used, and how they
2439affect AnyEvent's operetion. 2787affect AnyEvent's operation.
2440 2788
2441=over 4 2789=over 4
2442 2790
2443=item L<Async::Interrupt> 2791=item L<Async::Interrupt>
2444 2792
2449catch the signals) with some delay (default is 10 seconds, look for 2797catch the signals) with some delay (default is 10 seconds, look for
2450C<$AnyEvent::MAX_SIGNAL_LATENCY>). 2798C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2451 2799
2452If this module is available, then it will be used to implement signal 2800If 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 2801catching, which means that signals will not be delayed, and the event loop
2454will not be interrupted regularly, which is more efficient (And good for 2802will not be interrupted regularly, which is more efficient (and good for
2455battery life on laptops). 2803battery life on laptops).
2456 2804
2457This affects not just the pure-perl event loop, but also other event loops 2805This 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). 2806that have no signal handling on their own (e.g. Glib, Tk, Qt).
2459 2807
2471automatic timer adjustments even when no monotonic clock is available, 2819automatic timer adjustments even when no monotonic clock is available,
2472can take avdantage of advanced kernel interfaces such as C<epoll> and 2820can 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 2821C<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>). 2822L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2475 2823
2824If you only use backends that rely on another event loop (e.g. C<Tk>),
2825then this module will do nothing for you.
2826
2476=item L<Guard> 2827=item L<Guard>
2477 2828
2478The guard module, when used, will be used to implement 2829The guard module, when used, will be used to implement
2479C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a 2830C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2480lot less memory), but otherwise doesn't affect guard operation much. It is 2831lot less memory), but otherwise doesn't affect guard operation much. It is
2481purely used for performance. 2832purely used for performance.
2482 2833
2483=item L<JSON> and L<JSON::XS> 2834=item L<JSON> and L<JSON::XS>
2484 2835
2485One of these modules is required when you want to read or write JSON data 2836One 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 2837via 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. 2838advantage 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 2839
2492=item L<Net::SSLeay> 2840=item L<Net::SSLeay>
2493 2841
2494Implementing TLS/SSL in Perl is certainly interesting, but not very 2842Implementing TLS/SSL in Perl is certainly interesting, but not very
2495worthwhile: If this module is installed, then L<AnyEvent::Handle> (with 2843worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2496the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL. 2844the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2497 2845
2498=item L<Time::HiRes> 2846=item L<Time::HiRes>
2499 2847
2500This module is part of perl since release 5.008. It will be used when the 2848This 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 2849chosen 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 2850pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2503try to use a monotonic clock for timing stability. 2851try to use a monotonic clock for timing stability.
2504 2852
2505=back 2853=back
2506 2854
2507 2855
2508=head1 FORK 2856=head1 FORK
2509 2857
2510Most event libraries are not fork-safe. The ones who are usually are 2858Most 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> 2859because they rely on inefficient but fork-safe C<select> or C<poll> calls
2512calls. Only L<EV> is fully fork-aware. 2860- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
2861are usually badly thought-out hacks that are incompatible with fork in
2862one way or another. Only L<EV> is fully fork-aware and ensures that you
2863continue event-processing in both parent and child (or both, if you know
2864what you are doing).
2865
2866This means that, in general, you cannot fork and do event processing in
2867the child if the event library was initialised before the fork (which
2868usually happens when the first AnyEvent watcher is created, or the library
2869is loaded).
2513 2870
2514If you have to fork, you must either do so I<before> creating your first 2871If 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 2872watcher OR you must not use AnyEvent at all in the child OR you must do
2516something completely out of the scope of AnyEvent. 2873something completely out of the scope of AnyEvent.
2874
2875The problem of doing event processing in the parent I<and> the child
2876is much more complicated: even for backends that I<are> fork-aware or
2877fork-safe, their behaviour is not usually what you want: fork clones all
2878watchers, that means all timers, I/O watchers etc. are active in both
2879parent and child, which is almost never what you want. USing C<exec>
2880to start worker children from some kind of manage rprocess is usually
2881preferred, because it is much easier and cleaner, at the expense of having
2882to have another binary.
2517 2883
2518 2884
2519=head1 SECURITY CONSIDERATIONS 2885=head1 SECURITY CONSIDERATIONS
2520 2886
2521AnyEvent can be forced to load any event model via 2887AnyEvent can be forced to load any event model via
2551pronounced). 2917pronounced).
2552 2918
2553 2919
2554=head1 SEE ALSO 2920=head1 SEE ALSO
2555 2921
2556Utility functions: L<AnyEvent::Util>. 2922Tutorial/Introduction: L<AnyEvent::Intro>.
2557 2923
2558Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>, 2924FAQ: L<AnyEvent::FAQ>.
2559L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. 2925
2926Utility functions: L<AnyEvent::Util> (misc. grab-bag), L<AnyEvent::Log>
2927(simply logging).
2928
2929Development/Debugging: L<AnyEvent::Strict> (stricter checking),
2930L<AnyEvent::Debug> (interactive shell, watcher tracing).
2931
2932Supported event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>,
2933L<Glib::EV>, L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>,
2934L<Qt>, L<POE>, L<FLTK>.
2560 2935
2561Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, 2936Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2562L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, 2937L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2563L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, 2938L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2564L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>. 2939L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>,
2940L<AnyEvent::Impl::FLTK>.
2565 2941
2566Non-blocking file handles, sockets, TCP clients and 2942Non-blocking handles, pipes, stream sockets, TCP clients and
2567servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>. 2943servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2568 2944
2569Asynchronous DNS: L<AnyEvent::DNS>. 2945Asynchronous DNS: L<AnyEvent::DNS>.
2570 2946
2571Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, 2947Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2572L<Coro::Event>,
2573 2948
2574Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>, 2949Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2575L<AnyEvent::HTTP>. 2950L<AnyEvent::HTTP>.
2576 2951
2577 2952
2578=head1 AUTHOR 2953=head1 AUTHOR
2579 2954

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