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Revision 1.311 by root, Wed Feb 10 13:33:44 2010 UTC vs.
Revision 1.330 by root, Tue Aug 31 00:59:55 2010 UTC

7 7
8=head1 SYNOPSIS 8=head1 SYNOPSIS
9 9
10 use AnyEvent; 10 use AnyEvent;
11 11
12 # if you prefer function calls, look at the AE manpage for
13 # an alternative API.
14
12 # file descriptor readable 15 # file handle or descriptor readable
13 my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... }); 16 my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
14 17
15 # one-shot or repeating timers 18 # one-shot or repeating timers
16 my $w = AnyEvent->timer (after => $seconds, cb => sub { ... }); 19 my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
17 my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ... 20 my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...);
18 21
19 print AnyEvent->now; # prints current event loop time 22 print AnyEvent->now; # prints current event loop time
20 print AnyEvent->time; # think Time::HiRes::time or simply CORE::time. 23 print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
21 24
22 # POSIX signal 25 # POSIX signal
73module users into the same thing by forcing them to use the same event 76module users into the same thing by forcing them to use the same event
74model you use. 77model you use.
75 78
76For modules like POE or IO::Async (which is a total misnomer as it is 79For 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 80actually 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 81like joining a cult: After you join, you are dependent on them and you
79cannot use anything else, as they are simply incompatible to everything 82cannot use anything else, as they are simply incompatible to everything
80that isn't them. What's worse, all the potential users of your 83that 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. 84module are I<also> forced to use the same event loop you use.
82 85
83AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works 86AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
84fine. AnyEvent + Tk works fine etc. etc. but none of these work together 87fine. 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 88with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if
86your module uses one of those, every user of your module has to use it, 89your module uses one of those, every user of your module has to use it,
87too. But if your module uses AnyEvent, it works transparently with all 90too. But if your module uses AnyEvent, it works transparently with all
88event models it supports (including stuff like IO::Async, as long as those 91event models it supports (including stuff like IO::Async, as long as those
89use one of the supported event loops. It is trivial to add new event loops 92use one of the supported event loops. It is easy to add new event loops
90to AnyEvent, too, so it is future-proof). 93to AnyEvent, too, so it is future-proof).
91 94
92In addition to being free of having to use I<the one and only true event 95In 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 96model>, 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 97modules, 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 98follow. 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 99offering the functionality that is necessary, in as thin as a wrapper as
97technically possible. 100technically possible.
98 101
99Of course, AnyEvent comes with a big (and fully optional!) toolbox 102Of course, AnyEvent comes with a big (and fully optional!) toolbox
100of useful functionality, such as an asynchronous DNS resolver, 100% 103of useful functionality, such as an asynchronous DNS resolver, 100%
106useful) and you want to force your users to use the one and only event 109useful) and you want to force your users to use the one and only event
107model, you should I<not> use this module. 110model, you should I<not> use this module.
108 111
109=head1 DESCRIPTION 112=head1 DESCRIPTION
110 113
111L<AnyEvent> provides an identical interface to multiple event loops. This 114L<AnyEvent> provides a uniform interface to various event loops. This
112allows module authors to utilise an event loop without forcing module 115allows module authors to use event loop functionality without forcing
113users to use the same event loop (as only a single event loop can coexist 116module users to use a specific event loop implementation (since more
114peacefully at any one time). 117than one event loop cannot coexist peacefully).
115 118
116The interface itself is vaguely similar, but not identical to the L<Event> 119The interface itself is vaguely similar, but not identical to the L<Event>
117module. 120module.
118 121
119During the first call of any watcher-creation method, the module tries 122During the first call of any watcher-creation method, the module tries
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
144C<AnyEvent::Impl::Perl>. Like other event modules you can load it 148C<AnyEvent::Impl::Perl>. Like other event modules you can load it
145explicitly and enjoy the high availability of that event loop :) 149explicitly and enjoy the high availability of that event loop :)
146 150
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
425=head3 Signal Races, Delays and Workarounds 429=head3 Signal Races, Delays and Workarounds
426 430
427Many 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
428callbacks 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
429do race-free signal handling in perl, requiring C libraries for 433do race-free signal handling in perl, requiring C libraries for
430this. 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,
431signals 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
432specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This 436specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
433variable can be changed only before the first signal watcher is created, 437variable can be changed only before the first signal watcher is created,
434and should be left alone otherwise. This variable determines how often 438and should be left alone otherwise. This variable determines how often
435AnyEvent 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
437saving. 441saving.
438 442
439All these problems can be avoided by installing the optional 443All these problems can be avoided by installing the optional
440L<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
441work 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>
442(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
443one-second latency). For those, you just have to suffer the delays. 447one-second latency). For those, you just have to suffer the delays.
444 448
445=head2 CHILD PROCESS WATCHERS 449=head2 CHILD PROCESS WATCHERS
446 450
447 $w = AnyEvent->child (pid => <process id>, cb => <callback>); 451 $w = AnyEvent->child (pid => <process id>, cb => <callback>);
448 452
449You 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.
450 454
451The 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,
452using 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
453croak). The watcher will be triggered only when the child process has 457croak). The watcher will be triggered only when the child process has
454finished and an exit status is available, not on any trace events 458finished and an exit status is available, not on any trace events
455(stopped/continued). 459(stopped/continued).
456 460
503 507
504=head2 IDLE WATCHERS 508=head2 IDLE WATCHERS
505 509
506 $w = AnyEvent->idle (cb => <callback>); 510 $w = AnyEvent->idle (cb => <callback>);
507 511
508Repeatedly invoke the callback after the process becomes idle, until 512This will repeatedly invoke the callback after the process becomes idle,
509either the watcher is destroyed or new events have been detected. 513until either the watcher is destroyed or new events have been detected.
510 514
511Idle watchers are useful when there is a need to do something, but it 515Idle watchers are useful when there is a need to do something, but it
512is not so important (or wise) to do it instantly. The callback will be 516is not so important (or wise) to do it instantly. The callback will be
513invoked only when there is "nothing better to do", which is usually 517invoked only when there is "nothing better to do", which is usually
514defined as "all outstanding events have been handled and no new events 518defined as "all outstanding events have been handled and no new events
553will actively watch for new events and call your callbacks. 557will actively watch for new events and call your callbacks.
554 558
555AnyEvent is slightly different: it expects somebody else to run the event 559AnyEvent is slightly different: it expects somebody else to run the event
556loop 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).
557 561
558The instrument to do that is called a "condition variable", so called 562The tool to do that is called a "condition variable", so called because
559because they represent a condition that must become true. 563they represent a condition that must become true.
560 564
561Now 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.
562 566
563Condition variables can be created by calling the C<< AnyEvent->condvar 567Condition variables can be created by calling the C<< AnyEvent->condvar
564>> method, usually without arguments. The only argument pair allowed is 568>> method, usually without arguments. The only argument pair allowed is
569After creation, the condition variable is "false" until it becomes "true" 573After creation, the condition variable is "false" until it becomes "true"
570by 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
571were 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<<
572->send >> method). 576->send >> method).
573 577
574Condition variables are similar to callbacks, except that you can 578Since condition variables are the most complex part of the AnyEvent API, here are
575optionally 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:
576in time where multiple outstanding events have been processed. And yet 580
577another way to call them is transactions - each condition variable can be 581=over 4
578used to represent a transaction, which finishes at some point and delivers 582
579a 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
580compute/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
581 601
582Condition variables are very useful to signal that something has finished, 602Condition variables are very useful to signal that something has finished,
583for example, if you write a module that does asynchronous http requests, 603for example, if you write a module that does asynchronous http requests,
584then a condition variable would be the ideal candidate to signal the 604then a condition variable would be the ideal candidate to signal the
585availability of results. The user can either act when the callback is 605availability of results. The user can either act when the callback is
598 618
599Condition variables are represented by hash refs in perl, and the keys 619Condition variables are represented by hash refs in perl, and the keys
600used 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
601easy (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
602AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call 622AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call
603it's C<new> method in your own C<new> method. 623its C<new> method in your own C<new> method.
604 624
605There are two "sides" to a condition variable - the "producer side" which 625There are two "sides" to a condition variable - the "producer side" which
606eventually calls C<< -> send >>, and the "consumer side", which waits 626eventually calls C<< -> send >>, and the "consumer side", which waits
607for the send to occur. 627for the send to occur.
608 628
609Example: wait for a timer. 629Example: wait for a timer.
610 630
611 # wait till the result is ready 631 # condition: "wait till the timer is fired"
612 my $result_ready = AnyEvent->condvar; 632 my $timer_fired = AnyEvent->condvar;
613 633
614 # do something such as adding a timer 634 # create the timer - we could wait for, say
615 # or socket watcher the calls $result_ready->send 635 # a handle becomign ready, or even an
616 # when the "result" is ready. 636 # AnyEvent::HTTP request to finish, but
617 # in this case, we simply use a timer: 637 # in this case, we simply use a timer:
618 my $w = AnyEvent->timer ( 638 my $w = AnyEvent->timer (
619 after => 1, 639 after => 1,
620 cb => sub { $result_ready->send }, 640 cb => sub { $timer_fired->send },
621 ); 641 );
622 642
623 # this "blocks" (while handling events) till the callback 643 # this "blocks" (while handling events) till the callback
624 # calls ->send 644 # calls ->send
625 $result_ready->recv; 645 $timer_fired->recv;
626 646
627Example: 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
628variables are also callable directly. 648variables are also callable directly.
629 649
630 my $done = AnyEvent->condvar; 650 my $done = AnyEvent->condvar;
673they 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
674C<send>. 694C<send>.
675 695
676=item $cv->croak ($error) 696=item $cv->croak ($error)
677 697
678Similar to send, but causes all call's to C<< ->recv >> to invoke 698Similar to send, but causes all calls to C<< ->recv >> to invoke
679C<Carp::croak> with the given error message/object/scalar. 699C<Carp::croak> with the given error message/object/scalar.
680 700
681This can be used to signal any errors to the condition variable 701This can be used to signal any errors to the condition variable
682user/consumer. Doing it this way instead of calling C<croak> directly 702user/consumer. Doing it this way instead of calling C<croak> directly
683delays the error detetcion, but has the overwhelmign advantage that it 703delays the error detection, but has the overwhelming advantage that it
684diagnoses 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
685deep in some event clalback without connection to the actual code causing 705deep in some event callback with no connection to the actual code causing
686the problem. 706the problem.
687 707
688=item $cv->begin ([group callback]) 708=item $cv->begin ([group callback])
689 709
690=item $cv->end 710=item $cv->end
728one 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
729sending. 749sending.
730 750
731The ping example mentioned above is slightly more complicated, as the 751The ping example mentioned above is slightly more complicated, as the
732there 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
733begung can potentially be zero: 753begun can potentially be zero:
734 754
735 my $cv = AnyEvent->condvar; 755 my $cv = AnyEvent->condvar;
736 756
737 my %result; 757 my %result;
738 $cv->begin (sub { shift->send (\%result) }); 758 $cv->begin (sub { shift->send (\%result) });
759to 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
760C<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
761doesn't execute once). 781doesn't execute once).
762 782
763This is the general pattern when you "fan out" into multiple (but 783This is the general pattern when you "fan out" into multiple (but
764potentially 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
765the 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
766subrequest you start, call C<begin> and for each subrequest you finish, 786subrequest you start, call C<begin> and for each subrequest you finish,
767call C<end>. 787call C<end>.
768 788
769=back 789=back
776=over 4 796=over 4
777 797
778=item $cv->recv 798=item $cv->recv
779 799
780Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak 800Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
781>> methods have been called on c<$cv>, while servicing other watchers 801>> methods have been called on C<$cv>, while servicing other watchers
782normally. 802normally.
783 803
784You 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
785will return immediately. 805will return immediately.
786 806
803caller 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
804condition variables with some kind of request results and supporting 824condition variables with some kind of request results and supporting
805callbacks so the caller knows that getting the result will not block, 825callbacks so the caller knows that getting the result will not block,
806while still supporting blocking waits if the caller so desires). 826while still supporting blocking waits if the caller so desires).
807 827
808You 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
809only calling C<< ->recv >> from within that callback (or at a later 829only calling C<< ->recv >> from within that callback (or at a later
810time). 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
811waits otherwise. 831waits otherwise.
812 832
813=item $bool = $cv->ready 833=item $bool = $cv->ready
818=item $cb = $cv->cb ($cb->($cv)) 838=item $cb = $cv->cb ($cb->($cv))
819 839
820This is a mutator function that returns the callback set and optionally 840This is a mutator function that returns the callback set and optionally
821replaces it before doing so. 841replaces it before doing so.
822 842
823The callback will be called when the condition becomes (or already was) 843The callback will be called when the condition becomes "true", i.e. when
824"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
825the 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
826inside the callback or at any later time is guaranteed not to block. 847the callback or at any later time is guaranteed not to block.
827 848
828=back 849=back
829 850
830=head1 SUPPORTED EVENT LOOPS/BACKENDS 851=head1 SUPPORTED EVENT LOOPS/BACKENDS
831 852
843 AnyEvent::Impl::EV based on EV (interface to libev, best choice). 864 AnyEvent::Impl::EV based on EV (interface to libev, best choice).
844 AnyEvent::Impl::Perl pure-perl implementation, fast and portable. 865 AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
845 866
846=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.
847 868
848These 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
849is 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
850them. This means that AnyEvent will automatically pick the right backend 871them. This means that AnyEvent will automatically pick the right backend
851when the main program loads an event module before anything starts to 872when the main program loads an event module before anything starts to
852create watchers. Nothing special needs to be done by the main program. 873create watchers. Nothing special needs to be done by the main program.
853 874
869 890
870Support for IO::Async can only be partial, as it is too broken and 891Support for IO::Async can only be partial, as it is too broken and
871architecturally limited to even support the AnyEvent API. It also 892architecturally limited to even support the AnyEvent API. It also
872is the only event loop that needs the loop to be set explicitly, so 893is the only event loop that needs the loop to be set explicitly, so
873it can only be used by a main program knowing about AnyEvent. See 894it can only be used by a main program knowing about AnyEvent. See
874L<AnyEvent::Impl::Async> for the gory details. 895L<AnyEvent::Impl::IOAsync> for the gory details.
875 896
876 AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed. 897 AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
877 898
878=item Event loops that are indirectly supported via other backends. 899=item Event loops that are indirectly supported via other backends.
879 900
907Contains C<undef> until the first watcher is being created, before the 928Contains C<undef> until the first watcher is being created, before the
908backend has been autodetected. 929backend has been autodetected.
909 930
910Afterwards it contains the event model that is being used, which is the 931Afterwards it contains the event model that is being used, which is the
911name of the Perl class implementing the model. This class is usually one 932name of the Perl class implementing the model. This class is usually one
912of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the 933of the C<AnyEvent::Impl::xxx> modules, but can be any other class in the
913case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it 934case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
914will be C<urxvt::anyevent>). 935will be C<urxvt::anyevent>).
915 936
916=item AnyEvent::detect 937=item AnyEvent::detect
917 938
918Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model 939Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
919if necessary. You should only call this function right before you would 940if necessary. You should only call this function right before you would
920have created an AnyEvent watcher anyway, that is, as late as possible at 941have created an AnyEvent watcher anyway, that is, as late as possible at
921runtime, and not e.g. while initialising of your module. 942runtime, and not e.g. during initialisation of your module.
922 943
923If you need to do some initialisation before AnyEvent watchers are 944If you need to do some initialisation before AnyEvent watchers are
924created, use C<post_detect>. 945created, use C<post_detect>.
925 946
926=item $guard = AnyEvent::post_detect { BLOCK } 947=item $guard = AnyEvent::post_detect { BLOCK }
927 948
928Arranges for the code block to be executed as soon as the event model is 949Arranges for the code block to be executed as soon as the event model is
929autodetected (or immediately if this has already happened). 950autodetected (or immediately if that has already happened).
930 951
931The block will be executed I<after> the actual backend has been detected 952The block will be executed I<after> the actual backend has been detected
932(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been 953(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
933created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do 954created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
934other initialisations - see the sources of L<AnyEvent::Strict> or 955other initialisations - see the sources of L<AnyEvent::Strict> or
943that automatically removes the callback again when it is destroyed (or 964that automatically removes the callback again when it is destroyed (or
944C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for 965C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
945a case where this is useful. 966a case where this is useful.
946 967
947Example: Create a watcher for the IO::AIO module and store it in 968Example: Create a watcher for the IO::AIO module and store it in
948C<$WATCHER>. Only do so after the event loop is initialised, though. 969C<$WATCHER>, but do so only do so after the event loop is initialised.
949 970
950 our WATCHER; 971 our WATCHER;
951 972
952 my $guard = AnyEvent::post_detect { 973 my $guard = AnyEvent::post_detect {
953 $WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb); 974 $WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
961 $WATCHER ||= $guard; 982 $WATCHER ||= $guard;
962 983
963=item @AnyEvent::post_detect 984=item @AnyEvent::post_detect
964 985
965If there are any code references in this array (you can C<push> to it 986If there are any code references in this array (you can C<push> to it
966before or after loading AnyEvent), then they will called directly after 987before or after loading AnyEvent), then they will be called directly
967the event loop has been chosen. 988after the event loop has been chosen.
968 989
969You should check C<$AnyEvent::MODEL> before adding to this array, though: 990You should check C<$AnyEvent::MODEL> before adding to this array, though:
970if it is defined then the event loop has already been detected, and the 991if it is defined then the event loop has already been detected, and the
971array will be ignored. 992array will be ignored.
972 993
1008because it will stall the whole program, and the whole point of using 1029because it will stall the whole program, and the whole point of using
1009events is to stay interactive. 1030events is to stay interactive.
1010 1031
1011It is fine, however, to call C<< ->recv >> when the user of your module 1032It is fine, however, to call C<< ->recv >> when the user of your module
1012requests it (i.e. if you create a http request object ad have a method 1033requests it (i.e. if you create a http request object ad have a method
1013called C<results> that returns the results, it should call C<< ->recv >> 1034called C<results> that returns the results, it may call C<< ->recv >>
1014freely, as the user of your module knows what she is doing. always). 1035freely, as the user of your module knows what she is doing. Always).
1015 1036
1016=head1 WHAT TO DO IN THE MAIN PROGRAM 1037=head1 WHAT TO DO IN THE MAIN PROGRAM
1017 1038
1018There will always be a single main program - the only place that should 1039There will always be a single main program - the only place that should
1019dictate which event model to use. 1040dictate which event model to use.
1020 1041
1021If it doesn't care, it can just "use AnyEvent" and use it itself, or not 1042If the program is not event-based, it need not do anything special, even
1022do anything special (it does not need to be event-based) and let AnyEvent 1043when it depends on a module that uses an AnyEvent. If the program itself
1023decide which implementation to chose if some module relies on it. 1044uses AnyEvent, but does not care which event loop is used, all it needs
1045to do is C<use AnyEvent>. In either case, AnyEvent will choose the best
1046available loop implementation.
1024 1047
1025If the main program relies on a specific event model - for example, in 1048If the main program relies on a specific event model - for example, in
1026Gtk2 programs you have to rely on the Glib module - you should load the 1049Gtk2 programs you have to rely on the Glib module - you should load the
1027event module before loading AnyEvent or any module that uses it: generally 1050event module before loading AnyEvent or any module that uses it: generally
1028speaking, you should load it as early as possible. The reason is that 1051speaking, you should load it as early as possible. The reason is that
1029modules might create watchers when they are loaded, and AnyEvent will 1052modules might create watchers when they are loaded, and AnyEvent will
1030decide on the event model to use as soon as it creates watchers, and it 1053decide on the event model to use as soon as it creates watchers, and it
1031might chose the wrong one unless you load the correct one yourself. 1054might choose the wrong one unless you load the correct one yourself.
1032 1055
1033You can chose to use a pure-perl implementation by loading the 1056You can chose to use a pure-perl implementation by loading the
1034C<AnyEvent::Impl::Perl> module, which gives you similar behaviour 1057C<AnyEvent::Impl::Perl> module, which gives you similar behaviour
1035everywhere, but letting AnyEvent chose the model is generally better. 1058everywhere, but letting AnyEvent chose the model is generally better.
1036 1059
1054=head1 OTHER MODULES 1077=head1 OTHER MODULES
1055 1078
1056The following is a non-exhaustive list of additional modules that use 1079The following is a non-exhaustive list of additional modules that use
1057AnyEvent as a client and can therefore be mixed easily with other AnyEvent 1080AnyEvent as a client and can therefore be mixed easily with other AnyEvent
1058modules and other event loops in the same program. Some of the modules 1081modules and other event loops in the same program. Some of the modules
1059come with AnyEvent, most are available via CPAN. 1082come as part of AnyEvent, the others are available via CPAN.
1060 1083
1061=over 4 1084=over 4
1062 1085
1063=item L<AnyEvent::Util> 1086=item L<AnyEvent::Util>
1064 1087
1065Contains various utility functions that replace often-used but blocking 1088Contains various utility functions that replace often-used blocking
1066functions such as C<inet_aton> by event-/callback-based versions. 1089functions such as C<inet_aton> with event/callback-based versions.
1067 1090
1068=item L<AnyEvent::Socket> 1091=item L<AnyEvent::Socket>
1069 1092
1070Provides various utility functions for (internet protocol) sockets, 1093Provides various utility functions for (internet protocol) sockets,
1071addresses and name resolution. Also functions to create non-blocking tcp 1094addresses and name resolution. Also functions to create non-blocking tcp
1073 1096
1074=item L<AnyEvent::Handle> 1097=item L<AnyEvent::Handle>
1075 1098
1076Provide read and write buffers, manages watchers for reads and writes, 1099Provide read and write buffers, manages watchers for reads and writes,
1077supports raw and formatted I/O, I/O queued and fully transparent and 1100supports raw and formatted I/O, I/O queued and fully transparent and
1078non-blocking SSL/TLS (via L<AnyEvent::TLS>. 1101non-blocking SSL/TLS (via L<AnyEvent::TLS>).
1079 1102
1080=item L<AnyEvent::DNS> 1103=item L<AnyEvent::DNS>
1081 1104
1082Provides rich asynchronous DNS resolver capabilities. 1105Provides rich asynchronous DNS resolver capabilities.
1083 1106
1107=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
1108
1109Implement event-based interfaces to the protocols of the same name (for
1110the curious, IGS is the International Go Server and FCP is the Freenet
1111Client Protocol).
1112
1113=item L<AnyEvent::Handle::UDP>
1114
1115Here be danger!
1116
1117As Pauli would put it, "Not only is it not right, it's not even wrong!" -
1118there are so many things wrong with AnyEvent::Handle::UDP, most notably
1119its use of a stream-based API with a protocol that isn't streamable, that
1120the only way to improve it is to delete it.
1121
1122It features data corruption (but typically only under load) and general
1123confusion. On top, the author is not only clueless about UDP but also
1124fact-resistant - some gems of his understanding: "connect doesn't work
1125with UDP", "UDP packets are not IP packets", "UDP only has datagrams, not
1126packets", "I don't need to implement proper error checking as UDP doesn't
1127support error checking" and so on - he doesn't even understand what's
1128wrong with his module when it is explained to him.
1129
1084=item L<AnyEvent::HTTP> 1130=item L<AnyEvent::DBI>
1085 1131
1086A simple-to-use HTTP library that is capable of making a lot of concurrent 1132Executes L<DBI> requests asynchronously in a proxy process for you,
1087HTTP requests. 1133notifying you in an event-based way when the operation is finished.
1134
1135=item L<AnyEvent::AIO>
1136
1137Truly asynchronous (as opposed to non-blocking) I/O, should be in the
1138toolbox of every event programmer. AnyEvent::AIO transparently fuses
1139L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
1140file I/O, and much more.
1088 1141
1089=item L<AnyEvent::HTTPD> 1142=item L<AnyEvent::HTTPD>
1090 1143
1091Provides a simple web application server framework. 1144A simple embedded webserver.
1092 1145
1093=item L<AnyEvent::FastPing> 1146=item L<AnyEvent::FastPing>
1094 1147
1095The fastest ping in the west. 1148The fastest ping in the west.
1096
1097=item L<AnyEvent::DBI>
1098
1099Executes L<DBI> requests asynchronously in a proxy process.
1100
1101=item L<AnyEvent::AIO>
1102
1103Truly asynchronous I/O, should be in the toolbox of every event
1104programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1105together.
1106
1107=item L<AnyEvent::BDB>
1108
1109Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1110L<BDB> and AnyEvent together.
1111
1112=item L<AnyEvent::GPSD>
1113
1114A non-blocking interface to gpsd, a daemon delivering GPS information.
1115
1116=item L<AnyEvent::IRC>
1117
1118AnyEvent based IRC client module family (replacing the older Net::IRC3).
1119
1120=item L<AnyEvent::XMPP>
1121
1122AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1123Net::XMPP2>.
1124
1125=item L<AnyEvent::IGS>
1126
1127A non-blocking interface to the Internet Go Server protocol (used by
1128L<App::IGS>).
1129
1130=item L<Net::FCP>
1131
1132AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1133of AnyEvent.
1134
1135=item L<Event::ExecFlow>
1136
1137High level API for event-based execution flow control.
1138 1149
1139=item L<Coro> 1150=item L<Coro>
1140 1151
1141Has special support for AnyEvent via L<Coro::AnyEvent>. 1152Has special support for AnyEvent via L<Coro::AnyEvent>.
1142 1153
1156 1167
1157BEGIN { AnyEvent::common_sense } 1168BEGIN { AnyEvent::common_sense }
1158 1169
1159use Carp (); 1170use Carp ();
1160 1171
1161our $VERSION = '5.24'; 1172our $VERSION = '5.271';
1162our $MODEL; 1173our $MODEL;
1163 1174
1164our $AUTOLOAD; 1175our $AUTOLOAD;
1165our @ISA; 1176our @ISA;
1166 1177
1167our @REGISTRY; 1178our @REGISTRY;
1168 1179
1169our $VERBOSE; 1180our $VERBOSE;
1170 1181
1171BEGIN { 1182BEGIN {
1172 eval "sub CYGWIN(){" . (($^O =~ /cygwin/i) *1) . "}"; 1183 require "AnyEvent/constants.pl";
1173 eval "sub WIN32 (){" . (($^O =~ /mswin32/i)*1) . "}"; 1184
1174 eval "sub TAINT (){" . (${^TAINT} *1) . "}"; 1185 eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1175 1186
1176 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} 1187 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1177 if ${^TAINT}; 1188 if ${^TAINT};
1178 1189
1179 $VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1; 1190 $VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
1222our @post_detect; 1233our @post_detect;
1223 1234
1224sub post_detect(&) { 1235sub post_detect(&) {
1225 my ($cb) = @_; 1236 my ($cb) = @_;
1226 1237
1227 if ($MODEL) {
1228 $cb->();
1229
1230 undef
1231 } else {
1232 push @post_detect, $cb; 1238 push @post_detect, $cb;
1233 1239
1234 defined wantarray 1240 defined wantarray
1235 ? bless \$cb, "AnyEvent::Util::postdetect" 1241 ? bless \$cb, "AnyEvent::Util::postdetect"
1236 : () 1242 : ()
1237 }
1238} 1243}
1239 1244
1240sub AnyEvent::Util::postdetect::DESTROY { 1245sub AnyEvent::Util::postdetect::DESTROY {
1241 @post_detect = grep $_ != ${$_[0]}, @post_detect; 1246 @post_detect = grep $_ != ${$_[0]}, @post_detect;
1242} 1247}
1243 1248
1244sub detect() { 1249sub detect() {
1250 # free some memory
1251 *detect = sub () { $MODEL };
1252
1253 local $!; # for good measure
1254 local $SIG{__DIE__};
1255
1256 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1257 my $model = "AnyEvent::Impl::$1";
1258 if (eval "require $model") {
1259 $MODEL = $model;
1260 warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
1261 } else {
1262 warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1263 }
1264 }
1265
1266 # check for already loaded models
1245 unless ($MODEL) { 1267 unless ($MODEL) {
1246 local $SIG{__DIE__}; 1268 for (@REGISTRY, @models) {
1247 1269 my ($package, $model) = @$_;
1248 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { 1270 if (${"$package\::VERSION"} > 0) {
1249 my $model = "AnyEvent::Impl::$1";
1250 if (eval "require $model") { 1271 if (eval "require $model") {
1251 $MODEL = $model; 1272 $MODEL = $model;
1252 warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2; 1273 warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1253 } else { 1274 last;
1254 warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE; 1275 }
1255 } 1276 }
1256 } 1277 }
1257 1278
1258 # check for already loaded models
1259 unless ($MODEL) { 1279 unless ($MODEL) {
1280 # try to autoload a model
1260 for (@REGISTRY, @models) { 1281 for (@REGISTRY, @models) {
1261 my ($package, $model) = @$_; 1282 my ($package, $model, $autoload) = @$_;
1283 if (
1284 $autoload
1285 and eval "require $package"
1262 if (${"$package\::VERSION"} > 0) { 1286 and ${"$package\::VERSION"} > 0
1263 if (eval "require $model") { 1287 and eval "require $model"
1288 ) {
1264 $MODEL = $model; 1289 $MODEL = $model;
1265 warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2; 1290 warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1266 last; 1291 last;
1267 }
1268 } 1292 }
1269 } 1293 }
1270 1294
1271 unless ($MODEL) {
1272 # try to autoload a model
1273 for (@REGISTRY, @models) {
1274 my ($package, $model, $autoload) = @$_;
1275 if (
1276 $autoload
1277 and eval "require $package"
1278 and ${"$package\::VERSION"} > 0
1279 and eval "require $model"
1280 ) {
1281 $MODEL = $model;
1282 warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1283 last;
1284 }
1285 }
1286
1287 $MODEL 1295 $MODEL
1288 or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n"; 1296 or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";
1289 }
1290 } 1297 }
1291
1292 push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1293
1294 unshift @ISA, $MODEL;
1295
1296 require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1297
1298 (shift @post_detect)->() while @post_detect;
1299 } 1298 }
1299
1300 @models = (); # free probe data
1301
1302 push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1303 unshift @ISA, $MODEL;
1304
1305 # now nuke some methods that are overriden by the backend.
1306 # SUPER is not allowed.
1307 for (qw(time signal child idle)) {
1308 undef &{"AnyEvent::Base::$_"}
1309 if defined &{"$MODEL\::$_"};
1310 }
1311
1312 require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1313
1314 (shift @post_detect)->() while @post_detect;
1315
1316 *post_detect = sub(&) {
1317 shift->();
1318
1319 undef
1320 };
1300 1321
1301 $MODEL 1322 $MODEL
1302} 1323}
1303 1324
1304sub AUTOLOAD { 1325sub AUTOLOAD {
1305 (my $func = $AUTOLOAD) =~ s/.*://; 1326 (my $func = $AUTOLOAD) =~ s/.*://;
1306 1327
1307 $method{$func} 1328 $method{$func}
1308 or Carp::croak "$func: not a valid method for AnyEvent objects"; 1329 or Carp::croak "$func: not a valid AnyEvent class method";
1309 1330
1310 detect unless $MODEL; 1331 detect;
1311 1332
1312 my $class = shift; 1333 my $class = shift;
1313 $class->$func (@_); 1334 $class->$func (@_);
1314} 1335}
1315 1336
1332 1353
1333=head1 SIMPLIFIED AE API 1354=head1 SIMPLIFIED AE API
1334 1355
1335Starting with version 5.0, AnyEvent officially supports a second, much 1356Starting with version 5.0, AnyEvent officially supports a second, much
1336simpler, API that is designed to reduce the calling, typing and memory 1357simpler, API that is designed to reduce the calling, typing and memory
1337overhead. 1358overhead by using function call syntax and a fixed number of parameters.
1338 1359
1339See the L<AE> manpage for details. 1360See the L<AE> manpage for details.
1340 1361
1341=cut 1362=cut
1342 1363
1343package AE; 1364package AE;
1344 1365
1345our $VERSION = $AnyEvent::VERSION; 1366our $VERSION = $AnyEvent::VERSION;
1367
1368# fall back to the main API by default - backends and AnyEvent::Base
1369# implementations can overwrite these.
1346 1370
1347sub io($$$) { 1371sub io($$$) {
1348 AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2]) 1372 AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1349} 1373}
1350 1374
1382 1406
1383package AnyEvent::Base; 1407package AnyEvent::Base;
1384 1408
1385# default implementations for many methods 1409# default implementations for many methods
1386 1410
1387sub _time() { 1411sub time {
1412 eval q{ # poor man's autoloading {}
1388 # probe for availability of Time::HiRes 1413 # probe for availability of Time::HiRes
1389 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { 1414 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1390 warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8; 1415 warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1391 *_time = \&Time::HiRes::time; 1416 *AE::time = \&Time::HiRes::time;
1392 # if (eval "use POSIX (); (POSIX::times())... 1417 # if (eval "use POSIX (); (POSIX::times())...
1393 } else { 1418 } else {
1394 warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE; 1419 warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1395 *_time = sub (){ time }; # epic fail 1420 *AE::time = sub (){ time }; # epic fail
1421 }
1422
1423 *time = sub { AE::time }; # different prototypes
1396 } 1424 };
1425 die if $@;
1397 1426
1398 &_time 1427 &time
1399} 1428}
1400 1429
1401sub time { _time } 1430*now = \&time;
1402sub now { _time } 1431
1403sub now_update { } 1432sub now_update { }
1404 1433
1405# default implementation for ->condvar 1434# default implementation for ->condvar
1406 1435
1407sub condvar { 1436sub condvar {
1437 eval q{ # poor man's autoloading {}
1438 *condvar = sub {
1408 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar" 1439 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1440 };
1441
1442 *AE::cv = sub (;&) {
1443 bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
1444 };
1445 };
1446 die if $@;
1447
1448 &condvar
1409} 1449}
1410 1450
1411# default implementation for ->signal 1451# default implementation for ->signal
1412 1452
1413our $HAVE_ASYNC_INTERRUPT; 1453our $HAVE_ASYNC_INTERRUPT;
1422 1462
1423our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); 1463our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1424our (%SIG_ASY, %SIG_ASY_W); 1464our (%SIG_ASY, %SIG_ASY_W);
1425our ($SIG_COUNT, $SIG_TW); 1465our ($SIG_COUNT, $SIG_TW);
1426 1466
1427sub _signal_exec {
1428 $HAVE_ASYNC_INTERRUPT
1429 ? $SIGPIPE_R->drain
1430 : sysread $SIGPIPE_R, (my $dummy), 9;
1431
1432 while (%SIG_EV) {
1433 for (keys %SIG_EV) {
1434 delete $SIG_EV{$_};
1435 $_->() for values %{ $SIG_CB{$_} || {} };
1436 }
1437 }
1438}
1439
1440# install a dummy wakeup watcher to reduce signal catching latency 1467# install a dummy wakeup watcher to reduce signal catching latency
1468# used by Impls
1441sub _sig_add() { 1469sub _sig_add() {
1442 unless ($SIG_COUNT++) { 1470 unless ($SIG_COUNT++) {
1443 # try to align timer on a full-second boundary, if possible 1471 # try to align timer on a full-second boundary, if possible
1444 my $NOW = AE::now; 1472 my $NOW = AE::now;
1445 1473
1455 undef $SIG_TW 1483 undef $SIG_TW
1456 unless --$SIG_COUNT; 1484 unless --$SIG_COUNT;
1457} 1485}
1458 1486
1459our $_sig_name_init; $_sig_name_init = sub { 1487our $_sig_name_init; $_sig_name_init = sub {
1460 eval q{ # poor man's autoloading 1488 eval q{ # poor man's autoloading {}
1461 undef $_sig_name_init; 1489 undef $_sig_name_init;
1462 1490
1463 if (_have_async_interrupt) { 1491 if (_have_async_interrupt) {
1464 *sig2num = \&Async::Interrupt::sig2num; 1492 *sig2num = \&Async::Interrupt::sig2num;
1465 *sig2name = \&Async::Interrupt::sig2name; 1493 *sig2name = \&Async::Interrupt::sig2name;
1497 $SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec; 1525 $SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1498 1526
1499 } else { 1527 } else {
1500 warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8; 1528 warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1501 1529
1502 require Fcntl;
1503
1504 if (AnyEvent::WIN32) { 1530 if (AnyEvent::WIN32) {
1505 require AnyEvent::Util; 1531 require AnyEvent::Util;
1506 1532
1507 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe (); 1533 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1508 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R; 1534 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1509 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case 1535 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1510 } else { 1536 } else {
1511 pipe $SIGPIPE_R, $SIGPIPE_W; 1537 pipe $SIGPIPE_R, $SIGPIPE_W;
1512 fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R; 1538 fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
1513 fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case 1539 fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
1514 1540
1515 # not strictly required, as $^F is normally 2, but let's make sure... 1541 # not strictly required, as $^F is normally 2, but let's make sure...
1516 fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; 1542 fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1517 fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; 1543 fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1518 } 1544 }
1519 1545
1520 $SIGPIPE_R 1546 $SIGPIPE_R
1521 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; 1547 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1522 1548
1523 $SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec; 1549 $SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1524 } 1550 }
1525 1551
1526 *signal = sub { 1552 *signal = $HAVE_ASYNC_INTERRUPT
1553 ? sub {
1527 my (undef, %arg) = @_; 1554 my (undef, %arg) = @_;
1528 1555
1529 my $signal = uc $arg{signal}
1530 or Carp::croak "required option 'signal' is missing";
1531
1532 if ($HAVE_ASYNC_INTERRUPT) {
1533 # async::interrupt 1556 # async::interrupt
1534
1535 $signal = sig2num $signal; 1557 my $signal = sig2num $arg{signal};
1536 $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; 1558 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1537 1559
1538 $SIG_ASY{$signal} ||= new Async::Interrupt 1560 $SIG_ASY{$signal} ||= new Async::Interrupt
1539 cb => sub { undef $SIG_EV{$signal} }, 1561 cb => sub { undef $SIG_EV{$signal} },
1540 signal => $signal, 1562 signal => $signal,
1541 pipe => [$SIGPIPE_R->filenos], 1563 pipe => [$SIGPIPE_R->filenos],
1542 pipe_autodrain => 0, 1564 pipe_autodrain => 0,
1543 ; 1565 ;
1544 1566
1545 } else { 1567 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1568 }
1569 : sub {
1570 my (undef, %arg) = @_;
1571
1546 # pure perl 1572 # pure perl
1547
1548 # AE::Util has been loaded in signal
1549 $signal = sig2name $signal; 1573 my $signal = sig2name $arg{signal};
1550 $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; 1574 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1551 1575
1552 $SIG{$signal} ||= sub { 1576 $SIG{$signal} ||= sub {
1553 local $!; 1577 local $!;
1554 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; 1578 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1555 undef $SIG_EV{$signal}; 1579 undef $SIG_EV{$signal};
1556 }; 1580 };
1557 1581
1558 # can't do signal processing without introducing races in pure perl, 1582 # can't do signal processing without introducing races in pure perl,
1559 # so limit the signal latency. 1583 # so limit the signal latency.
1560 _sig_add; 1584 _sig_add;
1561 }
1562 1585
1563 bless [$signal, $arg{cb}], "AnyEvent::Base::signal" 1586 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1587 }
1564 }; 1588 ;
1565 1589
1566 *AnyEvent::Base::signal::DESTROY = sub { 1590 *AnyEvent::Base::signal::DESTROY = sub {
1567 my ($signal, $cb) = @{$_[0]}; 1591 my ($signal, $cb) = @{$_[0]};
1568 1592
1569 _sig_del; 1593 _sig_del;
1576 # print weird messages, or just unconditionally exit 1600 # print weird messages, or just unconditionally exit
1577 # instead of getting the default action. 1601 # instead of getting the default action.
1578 undef $SIG{$signal} 1602 undef $SIG{$signal}
1579 unless keys %{ $SIG_CB{$signal} }; 1603 unless keys %{ $SIG_CB{$signal} };
1580 }; 1604 };
1605
1606 *_signal_exec = sub {
1607 $HAVE_ASYNC_INTERRUPT
1608 ? $SIGPIPE_R->drain
1609 : sysread $SIGPIPE_R, (my $dummy), 9;
1610
1611 while (%SIG_EV) {
1612 for (keys %SIG_EV) {
1613 delete $SIG_EV{$_};
1614 $_->() for values %{ $SIG_CB{$_} || {} };
1615 }
1616 }
1617 };
1581 }; 1618 };
1582 die if $@; 1619 die if $@;
1620
1583 &signal 1621 &signal
1584} 1622}
1585 1623
1586# default implementation for ->child 1624# default implementation for ->child
1587 1625
1588our %PID_CB; 1626our %PID_CB;
1589our $CHLD_W; 1627our $CHLD_W;
1590our $CHLD_DELAY_W; 1628our $CHLD_DELAY_W;
1591our $WNOHANG; 1629our $WNOHANG;
1592 1630
1631# used by many Impl's
1593sub _emit_childstatus($$) { 1632sub _emit_childstatus($$) {
1594 my (undef, $rpid, $rstatus) = @_; 1633 my (undef, $rpid, $rstatus) = @_;
1595 1634
1596 $_->($rpid, $rstatus) 1635 $_->($rpid, $rstatus)
1597 for values %{ $PID_CB{$rpid} || {} }, 1636 for values %{ $PID_CB{$rpid} || {} },
1598 values %{ $PID_CB{0} || {} }; 1637 values %{ $PID_CB{0} || {} };
1599} 1638}
1600 1639
1601sub _sigchld {
1602 my $pid;
1603
1604 AnyEvent->_emit_childstatus ($pid, $?)
1605 while ($pid = waitpid -1, $WNOHANG) > 0;
1606}
1607
1608sub child { 1640sub child {
1641 eval q{ # poor man's autoloading {}
1642 *_sigchld = sub {
1643 my $pid;
1644
1645 AnyEvent->_emit_childstatus ($pid, $?)
1646 while ($pid = waitpid -1, $WNOHANG) > 0;
1647 };
1648
1649 *child = sub {
1609 my (undef, %arg) = @_; 1650 my (undef, %arg) = @_;
1610 1651
1611 defined (my $pid = $arg{pid} + 0) 1652 defined (my $pid = $arg{pid} + 0)
1612 or Carp::croak "required option 'pid' is missing"; 1653 or Carp::croak "required option 'pid' is missing";
1613 1654
1614 $PID_CB{$pid}{$arg{cb}} = $arg{cb}; 1655 $PID_CB{$pid}{$arg{cb}} = $arg{cb};
1615 1656
1616 # WNOHANG is almost cetrainly 1 everywhere 1657 # WNOHANG is almost cetrainly 1 everywhere
1617 $WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/ 1658 $WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1618 ? 1 1659 ? 1
1619 : eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; 1660 : eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1620 1661
1621 unless ($CHLD_W) { 1662 unless ($CHLD_W) {
1622 $CHLD_W = AE::signal CHLD => \&_sigchld; 1663 $CHLD_W = AE::signal CHLD => \&_sigchld;
1623 # child could be a zombie already, so make at least one round 1664 # child could be a zombie already, so make at least one round
1624 &_sigchld; 1665 &_sigchld;
1625 } 1666 }
1626 1667
1627 bless [$pid, $arg{cb}], "AnyEvent::Base::child" 1668 bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1628} 1669 };
1629 1670
1630sub AnyEvent::Base::child::DESTROY { 1671 *AnyEvent::Base::child::DESTROY = sub {
1631 my ($pid, $cb) = @{$_[0]}; 1672 my ($pid, $cb) = @{$_[0]};
1632 1673
1633 delete $PID_CB{$pid}{$cb}; 1674 delete $PID_CB{$pid}{$cb};
1634 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; 1675 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1635 1676
1636 undef $CHLD_W unless keys %PID_CB; 1677 undef $CHLD_W unless keys %PID_CB;
1678 };
1679 };
1680 die if $@;
1681
1682 &child
1637} 1683}
1638 1684
1639# idle emulation is done by simply using a timer, regardless 1685# idle emulation is done by simply using a timer, regardless
1640# of whether the process is idle or not, and not letting 1686# of whether the process is idle or not, and not letting
1641# the callback use more than 50% of the time. 1687# the callback use more than 50% of the time.
1642sub idle { 1688sub idle {
1689 eval q{ # poor man's autoloading {}
1690 *idle = sub {
1643 my (undef, %arg) = @_; 1691 my (undef, %arg) = @_;
1644 1692
1645 my ($cb, $w, $rcb) = $arg{cb}; 1693 my ($cb, $w, $rcb) = $arg{cb};
1646 1694
1647 $rcb = sub { 1695 $rcb = sub {
1648 if ($cb) { 1696 if ($cb) {
1649 $w = _time; 1697 $w = _time;
1650 &$cb; 1698 &$cb;
1651 $w = _time - $w; 1699 $w = _time - $w;
1652 1700
1653 # never use more then 50% of the time for the idle watcher, 1701 # never use more then 50% of the time for the idle watcher,
1654 # within some limits 1702 # within some limits
1655 $w = 0.0001 if $w < 0.0001; 1703 $w = 0.0001 if $w < 0.0001;
1656 $w = 5 if $w > 5; 1704 $w = 5 if $w > 5;
1657 1705
1658 $w = AE::timer $w, 0, $rcb; 1706 $w = AE::timer $w, 0, $rcb;
1659 } else { 1707 } else {
1660 # clean up... 1708 # clean up...
1661 undef $w; 1709 undef $w;
1662 undef $rcb; 1710 undef $rcb;
1711 }
1712 };
1713
1714 $w = AE::timer 0.05, 0, $rcb;
1715
1716 bless \\$cb, "AnyEvent::Base::idle"
1663 } 1717 };
1718
1719 *AnyEvent::Base::idle::DESTROY = sub {
1720 undef $${$_[0]};
1721 };
1664 }; 1722 };
1723 die if $@;
1665 1724
1666 $w = AE::timer 0.05, 0, $rcb; 1725 &idle
1667
1668 bless \\$cb, "AnyEvent::Base::idle"
1669}
1670
1671sub AnyEvent::Base::idle::DESTROY {
1672 undef $${$_[0]};
1673} 1726}
1674 1727
1675package AnyEvent::CondVar; 1728package AnyEvent::CondVar;
1676 1729
1677our @ISA = AnyEvent::CondVar::Base::; 1730our @ISA = AnyEvent::CondVar::Base::;
1804check the arguments passed to most method calls. If it finds any problems, 1857check the arguments passed to most method calls. If it finds any problems,
1805it will croak. 1858it will croak.
1806 1859
1807In other words, enables "strict" mode. 1860In other words, enables "strict" mode.
1808 1861
1809Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense> 1862Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1810>>, it is definitely recommended to keep it off in production. Keeping 1863>>, it is definitely recommended to keep it off in production. Keeping
1811C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs 1864C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1812can be very useful, however. 1865can be very useful, however.
1813 1866
1814=item C<PERL_ANYEVENT_MODEL> 1867=item C<PERL_ANYEVENT_MODEL>
2036 2089
2037The actual code goes further and collects all errors (C<die>s, exceptions) 2090The actual code goes further and collects all errors (C<die>s, exceptions)
2038that occurred during request processing. The C<result> method detects 2091that occurred during request processing. The C<result> method detects
2039whether an exception as thrown (it is stored inside the $txn object) 2092whether an exception as thrown (it is stored inside the $txn object)
2040and just throws the exception, which means connection errors and other 2093and just throws the exception, which means connection errors and other
2041problems get reported tot he code that tries to use the result, not in a 2094problems get reported to the code that tries to use the result, not in a
2042random callback. 2095random callback.
2043 2096
2044All of this enables the following usage styles: 2097All of this enables the following usage styles:
2045 2098
20461. Blocking: 20991. Blocking:
2460 unless defined $SIG{PIPE}; 2513 unless defined $SIG{PIPE};
2461 2514
2462=head1 RECOMMENDED/OPTIONAL MODULES 2515=head1 RECOMMENDED/OPTIONAL MODULES
2463 2516
2464One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and 2517One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2465it's built-in modules) are required to use it. 2518its built-in modules) are required to use it.
2466 2519
2467That does not mean that AnyEvent won't take advantage of some additional 2520That does not mean that AnyEvent won't take advantage of some additional
2468modules if they are installed. 2521modules if they are installed.
2469 2522
2470This section explains which additional modules will be used, and how they 2523This section explains which additional modules will be used, and how they
2503automatic timer adjustments even when no monotonic clock is available, 2556automatic timer adjustments even when no monotonic clock is available,
2504can take avdantage of advanced kernel interfaces such as C<epoll> and 2557can take avdantage of advanced kernel interfaces such as C<epoll> and
2505C<kqueue>, and is the fastest backend I<by far>. You can even embed 2558C<kqueue>, and is the fastest backend I<by far>. You can even embed
2506L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>). 2559L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2507 2560
2561If you only use backends that rely on another event loop (e.g. C<Tk>),
2562then this module will do nothing for you.
2563
2508=item L<Guard> 2564=item L<Guard>
2509 2565
2510The guard module, when used, will be used to implement 2566The guard module, when used, will be used to implement
2511C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a 2567C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2512lot less memory), but otherwise doesn't affect guard operation much. It is 2568lot less memory), but otherwise doesn't affect guard operation much. It is
2513purely used for performance. 2569purely used for performance.
2514 2570
2515=item L<JSON> and L<JSON::XS> 2571=item L<JSON> and L<JSON::XS>
2516 2572
2517One of these modules is required when you want to read or write JSON data 2573One of these modules is required when you want to read or write JSON data
2518via L<AnyEvent::Handle>. It is also written in pure-perl, but can take 2574via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2519advantage of the ultra-high-speed L<JSON::XS> module when it is installed. 2575advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2520
2521In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2522installed.
2523 2576
2524=item L<Net::SSLeay> 2577=item L<Net::SSLeay>
2525 2578
2526Implementing TLS/SSL in Perl is certainly interesting, but not very 2579Implementing TLS/SSL in Perl is certainly interesting, but not very
2527worthwhile: If this module is installed, then L<AnyEvent::Handle> (with 2580worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2528the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL. 2581the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2529 2582
2530=item L<Time::HiRes> 2583=item L<Time::HiRes>
2531 2584
2532This module is part of perl since release 5.008. It will be used when the 2585This module is part of perl since release 5.008. It will be used when the
2533chosen event library does not come with a timing source on it's own. The 2586chosen event library does not come with a timing source of its own. The
2534pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to 2587pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
2535try to use a monotonic clock for timing stability. 2588try to use a monotonic clock for timing stability.
2536 2589
2537=back 2590=back
2538 2591

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