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15 # file handle or descriptor readable 15 # file handle or descriptor readable
16 my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... }); 16 my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
17 17
18 # one-shot or repeating timers 18 # one-shot or repeating timers
19 my $w = AnyEvent->timer (after => $seconds, cb => sub { ... }); 19 my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
20 my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ... 20 my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...);
21 21
22 print AnyEvent->now; # prints current event loop time 22 print AnyEvent->now; # prints current event loop time
23 print AnyEvent->time; # think Time::HiRes::time or simply CORE::time. 23 print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
24 24
25 # POSIX signal 25 # POSIX signal
46in a tutorial or some gentle introduction, have a look at the 46in a tutorial or some gentle introduction, have a look at the
47L<AnyEvent::Intro> manpage. 47L<AnyEvent::Intro> manpage.
48 48
49=head1 SUPPORT 49=head1 SUPPORT
50 50
51An FAQ document is available as L<AnyEvent::FAQ>.
52
51There is a mailinglist for discussing all things AnyEvent, and an IRC 53There also is a mailinglist for discussing all things AnyEvent, and an IRC
52channel, too. 54channel, too.
53 55
54See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software 56See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
55Repository>, at L<http://anyevent.schmorp.de>, for more info. 57Repository>, at L<http://anyevent.schmorp.de>, for more info.
56 58
76module 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
77model you use. 79model you use.
78 80
79For 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
80actually 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
81like 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
82cannot use anything else, as they are simply incompatible to everything 84cannot use anything else, as they are simply incompatible to everything
83that 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
84module 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.
85 87
86AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works 88AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
87fine. 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
88with 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
89your 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
90too. But if your module uses AnyEvent, it works transparently with all 92your module uses AnyEvent, it works transparently with all event models it
91event 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
92use 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,
93to AnyEvent, too, so it is future-proof). 95so it is future-proof).
94 96
95In 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
96model>, 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
97modules, 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
98follow. 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
99offering 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
100technically possible. 102technically possible.
101 103
102Of course, AnyEvent comes with a big (and fully optional!) toolbox 104Of course, AnyEvent comes with a big (and fully optional!) toolbox
103of useful functionality, such as an asynchronous DNS resolver, 100% 105of useful functionality, such as an asynchronous DNS resolver, 100%
109useful) 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
110model, you should I<not> use this module. 112model, you should I<not> use this module.
111 113
112=head1 DESCRIPTION 114=head1 DESCRIPTION
113 115
114L<AnyEvent> provides an identical interface to multiple event loops. This 116L<AnyEvent> provides a uniform interface to various event loops. This
115allows module authors to utilise an event loop without forcing module 117allows module authors to use event loop functionality without forcing
116users 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
117peacefully at any one time). 119than one event loop cannot coexist peacefully).
118 120
119The 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>
120module. 122module.
121 123
122During the first call of any watcher-creation method, the module tries 124During the first call of any watcher-creation method, the module tries
123to 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
124following modules is already loaded: L<EV>, 126following modules is already loaded: L<EV>, L<AnyEvent::Loop>,
125L<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
126L<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
127to 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
128adaptor should always succeed) in the order given. The first one that can 130available, the pure-perl L<AnyEvent::Loop> should always work, so
129be successfully loaded will be used. If, after this, still none could be 131the other two are not normally tried.
130found, AnyEvent will fall back to a pure-perl event loop, which is not
131very efficient, but should work everywhere.
132 132
133Because AnyEvent first checks for modules that are already loaded, loading 133Because AnyEvent first checks for modules that are already loaded, loading
134an event model explicitly before first using AnyEvent will likely make 134an event model explicitly before first using AnyEvent will likely make
135that model the default. For example: 135that model the default. For example:
136 136
142The 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
143starts using it, all bets are off - this case should be very rare though, 143starts using it, all bets are off - this case should be very rare though,
144as very few modules hardcode event loops without announcing this very 144as very few modules hardcode event loops without announcing this very
145loudly. 145loudly.
146 146
147The pure-perl implementation of AnyEvent is called 147The pure-perl implementation of AnyEvent is called C<AnyEvent::Loop>. Like
148C<AnyEvent::Impl::Perl>. Like other event modules you can load it 148other event modules you can load it explicitly and enjoy the high
149explicitly and enjoy the high availability of that event loop :) 149availability of that event loop :)
150 150
151=head1 WATCHERS 151=head1 WATCHERS
152 152
153AnyEvent 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
154stores 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
159callback when the event occurs (of course, only when the event model 159callback when the event occurs (of course, only when the event model
160is in control). 160is in control).
161 161
162Note that B<callbacks must not permanently change global variables> 162Note that B<callbacks must not permanently change global variables>
163potentially 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<<
164callbacks must not C<die> >>. The former is good programming practise in 164callbacks must not C<die> >>. The former is good programming practice in
165Perl and the latter stems from the fact that exception handling differs 165Perl and the latter stems from the fact that exception handling differs
166widely between event loops. 166widely between event loops.
167 167
168To 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
169variable 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
170to it). 170to it).
171 171
172All 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.
173 173
174Many watchers either are used with "recursion" (repeating timers for 174Many watchers either are used with "recursion" (repeating timers for
175example), or need to refer to their watcher object in other ways. 175example), or need to refer to their watcher object in other ways.
176 176
177An any way to achieve that is this pattern: 177One way to achieve that is this pattern:
178 178
179 my $w; $w = AnyEvent->type (arg => value ..., cb => sub { 179 my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
180 # you can use $w here, for example to undef it 180 # you can use $w here, for example to undef it
181 undef $w; 181 undef $w;
182 }); 182 });
214 214
215The 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.
216You 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
217underlying file descriptor. 217underlying file descriptor.
218 218
219Some event loops issue spurious readyness notifications, so you should 219Some event loops issue spurious readiness notifications, so you should
220always use non-blocking calls when reading/writing from/to your file 220always use non-blocking calls when reading/writing from/to your file
221handles. 221handles.
222 222
223Example: 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
224watcher. 224watcher.
248 248
249Although the callback might get passed parameters, their value and 249Although the callback might get passed parameters, their value and
250presence is undefined and you cannot rely on them. Portable AnyEvent 250presence is undefined and you cannot rely on them. Portable AnyEvent
251callbacks cannot use arguments passed to time watcher callbacks. 251callbacks cannot use arguments passed to time watcher callbacks.
252 252
253The callback will normally be invoked once only. If you specify another 253The callback will normally be invoked only once. If you specify another
254parameter, C<interval>, as a strictly positive number (> 0), then the 254parameter, C<interval>, as a strictly positive number (> 0), then the
255callback will be invoked regularly at that interval (in fractional 255callback will be invoked regularly at that interval (in fractional
256seconds) after the first invocation. If C<interval> is specified with a 256seconds) after the first invocation. If C<interval> is specified with a
257false value, then it is treated as if it were missing. 257false value, then it is treated as if it were not specified at all.
258 258
259The callback will be rescheduled before invoking the callback, but no 259The callback will be rescheduled before invoking the callback, but no
260attempt 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
261only approximate. 261only approximate.
262 262
263Example: fire an event after 7.7 seconds. 263Example: fire an event after 7.7 seconds.
264 264
265 my $w = AnyEvent->timer (after => 7.7, cb => sub { 265 my $w = AnyEvent->timer (after => 7.7, cb => sub {
283 283
284While 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
285use absolute time internally. This makes a difference when your clock 285use absolute time internally. This makes a difference when your clock
286"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
287the 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
288fire "after" a second might actually take six years to finally fire. 288fire "after a second" might actually take six years to finally fire.
289 289
290AnyEvent cannot compensate for this. The only event loop that is conscious 290AnyEvent cannot compensate for this. The only event loop that is conscious
291about 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
292on true relative time) and absolute (ev_periodic, based on wallclock time) 292on true relative time) and absolute (ev_periodic, based on wallclock time)
293timers. 293timers.
294 294
295AnyEvent always prefers relative timers, if available, matching the 295AnyEvent always prefers relative timers, if available, matching the
296AnyEvent API. 296AnyEvent API.
318I<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
319function to call when you want to know the current time.> 319function to call when you want to know the current time.>
320 320
321This function is also often faster then C<< AnyEvent->time >>, and 321This function is also often faster then C<< AnyEvent->time >>, and
322thus the preferred method if you want some timestamp (for example, 322thus the preferred method if you want some timestamp (for example,
323L<AnyEvent::Handle> uses this to update it's activity timeouts). 323L<AnyEvent::Handle> uses this to update its activity timeouts).
324 324
325The 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
326with your timing, you can skip it without bad conscience. 326with your timing; you can skip it without a bad conscience.
327 327
328For 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>
329and L<EV> and the following set-up: 329and L<EV> and the following set-up:
330 330
331The 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
332time=500 (assume no other callbacks delay processing). In your callback, 332time=500 (assume no other callbacks delay processing). In your callback,
333you 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
334second) 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
335after three seconds. 335after three seconds.
336 336
356difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into 356difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
357account. 357account.
358 358
359=item AnyEvent->now_update 359=item AnyEvent->now_update
360 360
361Some 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
362the current time for each loop iteration (see the discussion of L<< 362time for each loop iteration (see the discussion of L<< AnyEvent->now >>,
363AnyEvent->now >>, above). 363above).
364 364
365When 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
366this "current" time will differ substantially from the real time, which 366this "current" time will differ substantially from the real time, which
367might affect timers and time-outs. 367might affect timers and time-outs.
368 368
429=head3 Signal Races, Delays and Workarounds 429=head3 Signal Races, Delays and Workarounds
430 430
431Many 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
432callbacks 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
433do race-free signal handling in perl, requiring C libraries for 433do race-free signal handling in perl, requiring C libraries for
434this. 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,
435signals 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
436specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This 436specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
437variable can be changed only before the first signal watcher is created, 437variable can be changed only before the first signal watcher is created,
438and should be left alone otherwise. This variable determines how often 438and should be left alone otherwise. This variable determines how often
439AnyEvent 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
441saving. 441saving.
442 442
443All these problems can be avoided by installing the optional 443All these problems can be avoided by installing the optional
444L<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
445work 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>
446(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
447one-second latency). For those, you just have to suffer the delays. 447one-second latency). For those, you just have to suffer the delays.
448 448
449=head2 CHILD PROCESS WATCHERS 449=head2 CHILD PROCESS WATCHERS
450 450
451 $w = AnyEvent->child (pid => <process id>, cb => <callback>); 451 $w = AnyEvent->child (pid => <process id>, cb => <callback>);
452 452
453You 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.
454 454
455The 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,
456using 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
457croak). The watcher will be triggered only when the child process has 457croak). The watcher will be triggered only when the child process has
458finished and an exit status is available, not on any trace events 458finished and an exit status is available, not on any trace events
459(stopped/continued). 459(stopped/continued).
460 460
482thing 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
483watcher before you C<fork> the child (alternatively, you can call 483watcher before you C<fork> the child (alternatively, you can call
484C<AnyEvent::detect>). 484C<AnyEvent::detect>).
485 485
486As 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
487emulated 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
488mentioned in the description of signal watchers apply. 488problems mentioned in the description of signal watchers apply.
489 489
490Example: fork a process and wait for it 490Example: fork a process and wait for it
491 491
492 my $done = AnyEvent->condvar; 492 my $done = AnyEvent->condvar;
493 493
507 507
508=head2 IDLE WATCHERS 508=head2 IDLE WATCHERS
509 509
510 $w = AnyEvent->idle (cb => <callback>); 510 $w = AnyEvent->idle (cb => <callback>);
511 511
512Repeatedly invoke the callback after the process becomes idle, until 512This will repeatedly invoke the callback after the process becomes idle,
513either the watcher is destroyed or new events have been detected. 513until either the watcher is destroyed or new events have been detected.
514 514
515Idle 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
516is 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
517invoked only when there is "nothing better to do", which is usually 517invoked only when there is "nothing better to do", which is usually
518defined as "all outstanding events have been handled and no new events 518defined as "all outstanding events have been handled and no new events
588the signal fires. 588the signal fires.
589 589
590=item * Condition variables are like "Merge Points" - points in your program 590=item * Condition variables are like "Merge Points" - points in your program
591where you merge multiple independent results/control flows into one. 591where you merge multiple independent results/control flows into one.
592 592
593=item * Condition variables represent a transaction - function that start 593=item * Condition variables represent a transaction - functions that start
594some kind of transaction can return them, leaving the caller the choice 594some kind of transaction can return them, leaving the caller the choice
595between waiting in a blocking fashion, or setting a callback. 595between waiting in a blocking fashion, or setting a callback.
596 596
597=item * Condition variables represent future values, or promises to deliver 597=item * Condition variables represent future values, or promises to deliver
598some result, long before the result is available. 598some result, long before the result is available.
618 618
619Condition variables are represented by hash refs in perl, and the keys 619Condition variables are represented by hash refs in perl, and the keys
620used 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
621easy (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
622AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call 622AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call
623it's C<new> method in your own C<new> method. 623its C<new> method in your own C<new> method.
624 624
625There are two "sides" to a condition variable - the "producer side" which 625There are two "sides" to a condition variable - the "producer side" which
626eventually calls C<< -> send >>, and the "consumer side", which waits 626eventually calls C<< -> send >>, and the "consumer side", which waits
627for the send to occur. 627for the send to occur.
628 628
693they 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
694C<send>. 694C<send>.
695 695
696=item $cv->croak ($error) 696=item $cv->croak ($error)
697 697
698Similar to send, but causes all call's to C<< ->recv >> to invoke 698Similar to send, but causes all calls to C<< ->recv >> to invoke
699C<Carp::croak> with the given error message/object/scalar. 699C<Carp::croak> with the given error message/object/scalar.
700 700
701This can be used to signal any errors to the condition variable 701This can be used to signal any errors to the condition variable
702user/consumer. Doing it this way instead of calling C<croak> directly 702user/consumer. Doing it this way instead of calling C<croak> directly
703delays the error detetcion, but has the overwhelmign advantage that it 703delays the error detection, but has the overwhelming advantage that it
704diagnoses 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
705deep in some event clalback without connection to the actual code causing 705deep in some event callback with no connection to the actual code causing
706the problem. 706the problem.
707 707
708=item $cv->begin ([group callback]) 708=item $cv->begin ([group callback])
709 709
710=item $cv->end 710=item $cv->end
748one 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
749sending. 749sending.
750 750
751The ping example mentioned above is slightly more complicated, as the 751The ping example mentioned above is slightly more complicated, as the
752there 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
753begung can potentially be zero: 753begun can potentially be zero:
754 754
755 my $cv = AnyEvent->condvar; 755 my $cv = AnyEvent->condvar;
756 756
757 my %result; 757 my %result;
758 $cv->begin (sub { shift->send (\%result) }); 758 $cv->begin (sub { shift->send (\%result) });
779to 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
780C<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
781doesn't execute once). 781doesn't execute once).
782 782
783This is the general pattern when you "fan out" into multiple (but 783This is the general pattern when you "fan out" into multiple (but
784potentially 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
785the 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
786subrequest you start, call C<begin> and for each subrequest you finish, 786subrequest you start, call C<begin> and for each subrequest you finish,
787call C<end>. 787call C<end>.
788 788
789=back 789=back
796=over 4 796=over 4
797 797
798=item $cv->recv 798=item $cv->recv
799 799
800Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak 800Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
801>> methods have been called on c<$cv>, while servicing other watchers 801>> methods have been called on C<$cv>, while servicing other watchers
802normally. 802normally.
803 803
804You 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
805will return immediately. 805will return immediately.
806 806
823caller 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
824condition variables with some kind of request results and supporting 824condition variables with some kind of request results and supporting
825callbacks so the caller knows that getting the result will not block, 825callbacks so the caller knows that getting the result will not block,
826while still supporting blocking waits if the caller so desires). 826while still supporting blocking waits if the caller so desires).
827 827
828You 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
829only calling C<< ->recv >> from within that callback (or at a later 829only calling C<< ->recv >> from within that callback (or at a later
830time). 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
831waits otherwise. 831waits otherwise.
832 832
833=item $bool = $cv->ready 833=item $bool = $cv->ready
838=item $cb = $cv->cb ($cb->($cv)) 838=item $cb = $cv->cb ($cb->($cv))
839 839
840This is a mutator function that returns the callback set and optionally 840This is a mutator function that returns the callback set and optionally
841replaces it before doing so. 841replaces it before doing so.
842 842
843The callback will be called when the condition becomes (or already was) 843The callback will be called when the condition becomes "true", i.e. when
844"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
845the 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
846inside the callback or at any later time is guaranteed not to block. 847the callback or at any later time is guaranteed not to block.
847 848
848=back 849=back
849 850
850=head1 SUPPORTED EVENT LOOPS/BACKENDS 851=head1 SUPPORTED EVENT LOOPS/BACKENDS
851 852
859use. 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
860pure-perl implementation, which is available everywhere as it comes with 861pure-perl implementation, which is available everywhere as it comes with
861AnyEvent itself. 862AnyEvent itself.
862 863
863 AnyEvent::Impl::EV based on EV (interface to libev, best choice). 864 AnyEvent::Impl::EV based on EV (interface to libev, best choice).
864 AnyEvent::Impl::Perl pure-perl implementation, fast and portable. 865 AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
865 866
866=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.
867 868
868These 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
869is 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
870them. This means that AnyEvent will automatically pick the right backend 871them. This means that AnyEvent will automatically pick the right backend
871when the main program loads an event module before anything starts to 872when the main program loads an event module before anything starts to
872create watchers. Nothing special needs to be done by the main program. 873create watchers. Nothing special needs to be done by the main program.
873 874
875 AnyEvent::Impl::Glib based on Glib, slow but very stable. 876 AnyEvent::Impl::Glib based on Glib, slow but very stable.
876 AnyEvent::Impl::Tk based on Tk, very broken. 877 AnyEvent::Impl::Tk based on Tk, very broken.
877 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. 878 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
878 AnyEvent::Impl::POE based on POE, very slow, some limitations. 879 AnyEvent::Impl::POE based on POE, very slow, some limitations.
879 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.
880 884
881=item Backends with special needs. 885=item Backends with special needs.
882 886
883Qt requires the Qt::Application to be instantiated first, but will 887Qt requires the Qt::Application to be instantiated first, but will
884otherwise be picked up automatically. As long as the main program 888otherwise be picked up automatically. As long as the main program
885instantiates the application before any AnyEvent watchers are created, 889instantiates the application before any AnyEvent watchers are created,
886everything should just work. 890everything should just work.
887 891
888 AnyEvent::Impl::Qt based on Qt. 892 AnyEvent::Impl::Qt based on Qt.
889 893
890Support for IO::Async can only be partial, as it is too broken and
891architecturally limited to even support the AnyEvent API. It also
892is the only event loop that needs the loop to be set explicitly, so
893it can only be used by a main program knowing about AnyEvent. See
894L<AnyEvent::Impl::Async> for the gory details.
895
896 AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
897
898=item Event loops that are indirectly supported via other backends. 894=item Event loops that are indirectly supported via other backends.
899 895
900Some event loops can be supported via other modules: 896Some event loops can be supported via other modules:
901 897
902There is no direct support for WxWidgets (L<Wx>) or L<Prima>. 898There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
927Contains C<undef> until the first watcher is being created, before the 923Contains C<undef> until the first watcher is being created, before the
928backend has been autodetected. 924backend has been autodetected.
929 925
930Afterwards 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
931name 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
932of 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
933case 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
934will be C<urxvt::anyevent>). 930will be C<urxvt::anyevent>).
935 931
936=item AnyEvent::detect 932=item AnyEvent::detect
937 933
938Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model 934Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
939if necessary. You should only call this function right before you would 935if necessary. You should only call this function right before you would
940have 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
941runtime, and not e.g. while initialising of your module. 937runtime, and not e.g. during initialisation of your module.
942 938
943If you need to do some initialisation before AnyEvent watchers are 939If you need to do some initialisation before AnyEvent watchers are
944created, use C<post_detect>. 940created, use C<post_detect>.
945 941
946=item $guard = AnyEvent::post_detect { BLOCK } 942=item $guard = AnyEvent::post_detect { BLOCK }
947 943
948Arranges for the code block to be executed as soon as the event model is 944Arranges for the code block to be executed as soon as the event model is
949autodetected (or immediately if this has already happened). 945autodetected (or immediately if that has already happened).
950 946
951The block will be executed I<after> the actual backend has been detected 947The block will be executed I<after> the actual backend has been detected
952(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been 948(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
953created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do 949created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
954other initialisations - see the sources of L<AnyEvent::Strict> or 950other initialisations - see the sources of L<AnyEvent::Strict> or
963that automatically removes the callback again when it is destroyed (or 959that automatically removes the callback again when it is destroyed (or
964C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for 960C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
965a case where this is useful. 961a case where this is useful.
966 962
967Example: Create a watcher for the IO::AIO module and store it in 963Example: Create a watcher for the IO::AIO module and store it in
968C<$WATCHER>. Only do so after the event loop is initialised, though. 964C<$WATCHER>, but do so only do so after the event loop is initialised.
969 965
970 our WATCHER; 966 our WATCHER;
971 967
972 my $guard = AnyEvent::post_detect { 968 my $guard = AnyEvent::post_detect {
973 $WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb); 969 $WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
981 $WATCHER ||= $guard; 977 $WATCHER ||= $guard;
982 978
983=item @AnyEvent::post_detect 979=item @AnyEvent::post_detect
984 980
985If there are any code references in this array (you can C<push> to it 981If there are any code references in this array (you can C<push> to it
986before or after loading AnyEvent), then they will called directly after 982before or after loading AnyEvent), then they will be called directly
987the event loop has been chosen. 983after the event loop has been chosen.
988 984
989You should check C<$AnyEvent::MODEL> before adding to this array, though: 985You should check C<$AnyEvent::MODEL> before adding to this array, though:
990if it is defined then the event loop has already been detected, and the 986if it is defined then the event loop has already been detected, and the
991array will be ignored. 987array will be ignored.
992 988
1009 # AnyEvent not yet initialised, so make sure to load Coro::AnyEvent 1005 # AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
1010 # as soon as it is 1006 # as soon as it is
1011 push @AnyEvent::post_detect, sub { require Coro::AnyEvent }; 1007 push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
1012 } 1008 }
1013 1009
1010=item AnyEvent::postpone { BLOCK }
1011
1012Arranges for the block to be executed as soon as possible, but not before
1013the call itself returns. In practise, the block will be executed just
1014before the event loop polls for new events, or shortly afterwards.
1015
1016This function never returns anything (to make the C<return postpone { ...
1017}> idiom more useful.
1018
1019To understand the usefulness of this function, consider a function that
1020asynchronously does something for you and returns some transaction
1021object or guard to let you cancel the operation. For example,
1022C<AnyEvent::Socket::tcp_connect>:
1023
1024 # start a conenction attempt unless one is active
1025 $self->{connect_guard} ||= AnyEvent::Socket::tcp_connect "www.example.net", 80, sub {
1026 delete $self->{connect_guard};
1027 ...
1028 };
1029
1030Imagine that this function could instantly call the callback, for
1031example, because it detects an obvious error such as a negative port
1032number. Invoking the callback before the function returns causes problems
1033however: the callback will be called and will try to delete the guard
1034object. But since the function hasn't returned yet, there is nothing to
1035delete. When the function eventually returns it will assign the guard
1036object to C<< $self->{connect_guard} >>, where it will likely never be
1037deleted, so the program thinks it is still trying to connect.
1038
1039This is where C<AnyEvent::postpone> should be used. Instead of calling the
1040callback directly on error:
1041
1042 $cb->(undef), return # signal error to callback, BAD!
1043 if $some_error_condition;
1044
1045It should use C<postpone>:
1046
1047 AnyEvent::postpone { $cb->(undef) }, return # signal error to callback, later
1048 if $some_error_condition;
1049
1014=back 1050=back
1015 1051
1016=head1 WHAT TO DO IN A MODULE 1052=head1 WHAT TO DO IN A MODULE
1017 1053
1018As a module author, you should C<use AnyEvent> and call AnyEvent methods 1054As a module author, you should C<use AnyEvent> and call AnyEvent methods
1028because it will stall the whole program, and the whole point of using 1064because it will stall the whole program, and the whole point of using
1029events is to stay interactive. 1065events is to stay interactive.
1030 1066
1031It is fine, however, to call C<< ->recv >> when the user of your module 1067It is fine, however, to call C<< ->recv >> when the user of your module
1032requests it (i.e. if you create a http request object ad have a method 1068requests it (i.e. if you create a http request object ad have a method
1033called C<results> that returns the results, it should call C<< ->recv >> 1069called C<results> that returns the results, it may call C<< ->recv >>
1034freely, as the user of your module knows what she is doing. always). 1070freely, as the user of your module knows what she is doing. Always).
1035 1071
1036=head1 WHAT TO DO IN THE MAIN PROGRAM 1072=head1 WHAT TO DO IN THE MAIN PROGRAM
1037 1073
1038There will always be a single main program - the only place that should 1074There will always be a single main program - the only place that should
1039dictate which event model to use. 1075dictate which event model to use.
1040 1076
1041If it doesn't care, it can just "use AnyEvent" and use it itself, or not 1077If the program is not event-based, it need not do anything special, even
1042do anything special (it does not need to be event-based) and let AnyEvent 1078when it depends on a module that uses an AnyEvent. If the program itself
1043decide which implementation to chose if some module relies on it. 1079uses AnyEvent, but does not care which event loop is used, all it needs
1080to do is C<use AnyEvent>. In either case, AnyEvent will choose the best
1081available loop implementation.
1044 1082
1045If the main program relies on a specific event model - for example, in 1083If the main program relies on a specific event model - for example, in
1046Gtk2 programs you have to rely on the Glib module - you should load the 1084Gtk2 programs you have to rely on the Glib module - you should load the
1047event module before loading AnyEvent or any module that uses it: generally 1085event module before loading AnyEvent or any module that uses it: generally
1048speaking, you should load it as early as possible. The reason is that 1086speaking, you should load it as early as possible. The reason is that
1049modules might create watchers when they are loaded, and AnyEvent will 1087modules might create watchers when they are loaded, and AnyEvent will
1050decide on the event model to use as soon as it creates watchers, and it 1088decide on the event model to use as soon as it creates watchers, and it
1051might chose the wrong one unless you load the correct one yourself. 1089might choose the wrong one unless you load the correct one yourself.
1052 1090
1053You can chose to use a pure-perl implementation by loading the 1091You can chose to use a pure-perl implementation by loading the
1054C<AnyEvent::Impl::Perl> module, which gives you similar behaviour 1092C<AnyEvent::Loop> module, which gives you similar behaviour
1055everywhere, but letting AnyEvent chose the model is generally better. 1093everywhere, but letting AnyEvent chose the model is generally better.
1056 1094
1057=head2 MAINLOOP EMULATION 1095=head2 MAINLOOP EMULATION
1058 1096
1059Sometimes (often for short test scripts, or even standalone programs who 1097Sometimes (often for short test scripts, or even standalone programs who
1080 1118
1081=over 4 1119=over 4
1082 1120
1083=item L<AnyEvent::Util> 1121=item L<AnyEvent::Util>
1084 1122
1085Contains various utility functions that replace often-used but blocking 1123Contains various utility functions that replace often-used blocking
1086functions such as C<inet_aton> by event-/callback-based versions. 1124functions such as C<inet_aton> with event/callback-based versions.
1087 1125
1088=item L<AnyEvent::Socket> 1126=item L<AnyEvent::Socket>
1089 1127
1090Provides various utility functions for (internet protocol) sockets, 1128Provides various utility functions for (internet protocol) sockets,
1091addresses and name resolution. Also functions to create non-blocking tcp 1129addresses and name resolution. Also functions to create non-blocking tcp
1093 1131
1094=item L<AnyEvent::Handle> 1132=item L<AnyEvent::Handle>
1095 1133
1096Provide read and write buffers, manages watchers for reads and writes, 1134Provide read and write buffers, manages watchers for reads and writes,
1097supports raw and formatted I/O, I/O queued and fully transparent and 1135supports raw and formatted I/O, I/O queued and fully transparent and
1098non-blocking SSL/TLS (via L<AnyEvent::TLS>. 1136non-blocking SSL/TLS (via L<AnyEvent::TLS>).
1099 1137
1100=item L<AnyEvent::DNS> 1138=item L<AnyEvent::DNS>
1101 1139
1102Provides rich asynchronous DNS resolver capabilities. 1140Provides rich asynchronous DNS resolver capabilities.
1103 1141
1111 1149
1112Here be danger! 1150Here be danger!
1113 1151
1114As Pauli would put it, "Not only is it not right, it's not even wrong!" - 1152As Pauli would put it, "Not only is it not right, it's not even wrong!" -
1115there are so many things wrong with AnyEvent::Handle::UDP, most notably 1153there are so many things wrong with AnyEvent::Handle::UDP, most notably
1116it's use of a stream-based API with a protocol that isn't streamable, that 1154its use of a stream-based API with a protocol that isn't streamable, that
1117the only way to improve it is to delete it. 1155the only way to improve it is to delete it.
1118 1156
1119It features data corruption (but typically only under load) and general 1157It features data corruption (but typically only under load) and general
1120confusion. On top, the author is not only clueless about UDP but also 1158confusion. On top, the author is not only clueless about UDP but also
1121fact-resistant - some gems of his understanding: "connect doesn't work 1159fact-resistant - some gems of his understanding: "connect doesn't work
1125wrong with his module when it is explained to him. 1163wrong with his module when it is explained to him.
1126 1164
1127=item L<AnyEvent::DBI> 1165=item L<AnyEvent::DBI>
1128 1166
1129Executes L<DBI> requests asynchronously in a proxy process for you, 1167Executes L<DBI> requests asynchronously in a proxy process for you,
1130notifying you in an event-bnased way when the operation is finished. 1168notifying you in an event-based way when the operation is finished.
1131 1169
1132=item L<AnyEvent::AIO> 1170=item L<AnyEvent::AIO>
1133 1171
1134Truly asynchronous (as opposed to non-blocking) I/O, should be in the 1172Truly asynchronous (as opposed to non-blocking) I/O, should be in the
1135toolbox of every event programmer. AnyEvent::AIO transparently fuses 1173toolbox of every event programmer. AnyEvent::AIO transparently fuses
1154 1192
1155package AnyEvent; 1193package AnyEvent;
1156 1194
1157# basically a tuned-down version of common::sense 1195# basically a tuned-down version of common::sense
1158sub common_sense { 1196sub common_sense {
1159 # from common:.sense 1.0 1197 # from common:.sense 3.4
1160 ${^WARNING_BITS} = "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x00"; 1198 ${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
1161 # use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl) 1199 # use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1162 $^H |= 0x00000600; 1200 $^H |= 0x00000600;
1163} 1201}
1164 1202
1165BEGIN { AnyEvent::common_sense } 1203BEGIN { AnyEvent::common_sense }
1166 1204
1167use Carp (); 1205use Carp ();
1168 1206
1169our $VERSION = '5.271'; 1207our $VERSION = '5.34';
1170our $MODEL; 1208our $MODEL;
1171 1209
1172our $AUTOLOAD; 1210our $AUTOLOAD;
1173our @ISA; 1211our @ISA;
1174 1212
1199 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; 1237 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1200} 1238}
1201 1239
1202my @models = ( 1240my @models = (
1203 [EV:: => AnyEvent::Impl::EV:: , 1], 1241 [EV:: => AnyEvent::Impl::EV:: , 1],
1204 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1], 1242 [AnyEvent::Loop:: => AnyEvent::Impl::Perl:: , 1],
1205 # everything below here will not (normally) be autoprobed 1243 # everything below here will not (normally) be autoprobed
1206 # as the pureperl backend should work everywhere 1244 # as the pure perl backend should work everywhere
1207 # and is usually faster 1245 # and is usually faster
1208 [Event:: => AnyEvent::Impl::Event::, 1], 1246 [Event:: => AnyEvent::Impl::Event::, 1],
1209 [Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers 1247 [Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1210 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy 1248 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1211 [Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package 1249 [Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1212 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles 1250 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1213 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program 1251 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1214 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza 1252 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1215 [Wx:: => AnyEvent::Impl::POE::], 1253 [Wx:: => AnyEvent::Impl::POE::],
1216 [Prima:: => AnyEvent::Impl::POE::], 1254 [Prima:: => AnyEvent::Impl::POE::],
1217 # IO::Async is just too broken - we would need workarounds for its
1218 # byzantine signal and broken child handling, among others.
1219 # IO::Async is rather hard to detect, as it doesn't have any
1220 # obvious default class.
1221 [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1222 [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program 1255 [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::],
1223 [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program 1256 [Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1224 [AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program 1257 [FLTK:: => AnyEvent::Impl::FLTK::],
1225); 1258);
1226 1259
1227our %method = map +($_ => 1), 1260our %method = map +($_ => 1),
1228 qw(io timer time now now_update signal child idle condvar one_event DESTROY); 1261 qw(io timer time now now_update signal child idle condvar DESTROY);
1229 1262
1230our @post_detect; 1263our @post_detect;
1231 1264
1232sub post_detect(&) { 1265sub post_detect(&) {
1233 my ($cb) = @_; 1266 my ($cb) = @_;
1288 last; 1321 last;
1289 } 1322 }
1290 } 1323 }
1291 1324
1292 $MODEL 1325 $MODEL
1293 or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n"; 1326 or die "AnyEvent: backend autodetection failed - did you properly install AnyEvent?\n";
1294 } 1327 }
1295 } 1328 }
1296 1329
1297 @models = (); # free probe data 1330 @models = (); # free probe data
1298 1331
1299 push @{"$MODEL\::ISA"}, "AnyEvent::Base"; 1332 push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1300 unshift @ISA, $MODEL; 1333 unshift @ISA, $MODEL;
1301 1334
1302 # now nuke some methods that are overriden by the backend. 1335 # now nuke some methods that are overridden by the backend.
1303 # SUPER is not allowed. 1336 # SUPER is not allowed.
1304 for (qw(time signal child idle)) { 1337 for (qw(time signal child idle)) {
1305 undef &{"AnyEvent::Base::$_"} 1338 undef &{"AnyEvent::Base::$_"}
1306 if defined &{"$MODEL\::$_"}; 1339 if defined &{"$MODEL\::$_"};
1307 } 1340 }
1308 1341
1309 require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT}; 1342 if ($ENV{PERL_ANYEVENT_STRICT}) {
1343 eval { require AnyEvent::Strict };
1344 warn "AnyEvent: cannot load AnyEvent::Strict: $@"
1345 if $@ && $VERBOSE;
1346 }
1310 1347
1311 (shift @post_detect)->() while @post_detect; 1348 (shift @post_detect)->() while @post_detect;
1312 1349
1313 *post_detect = sub(&) { 1350 *post_detect = sub(&) {
1314 shift->(); 1351 shift->();
1327 1364
1328 detect; 1365 detect;
1329 1366
1330 my $class = shift; 1367 my $class = shift;
1331 $class->$func (@_); 1368 $class->$func (@_);
1369}
1370
1371our $POSTPONE_W;
1372our @POSTPONE;
1373
1374sub _postpone_exec {
1375 undef $POSTPONE_W;
1376 (pop @POSTPONE)->()
1377 while @POSTPONE;
1378}
1379
1380sub postpone(&) {
1381 push @POSTPONE, shift;
1382
1383 $POSTPONE_W ||= AE::timer (0, 0, \&_postpone_exec);
1384
1385 ()
1332} 1386}
1333 1387
1334# utility function to dup a filehandle. this is used by many backends 1388# utility function to dup a filehandle. this is used by many backends
1335# to support binding more than one watcher per filehandle (they usually 1389# to support binding more than one watcher per filehandle (they usually
1336# allow only one watcher per fd, so we dup it to get a different one). 1390# allow only one watcher per fd, so we dup it to get a different one).
1398} 1452}
1399 1453
1400sub time() { 1454sub time() {
1401 AnyEvent->time 1455 AnyEvent->time
1402} 1456}
1457
1458*postpone = \&AnyEvent::postpone;
1403 1459
1404package AnyEvent::Base; 1460package AnyEvent::Base;
1405 1461
1406# default implementations for many methods 1462# default implementations for many methods
1407 1463
1426 1482
1427*now = \&time; 1483*now = \&time;
1428 1484
1429sub now_update { } 1485sub now_update { }
1430 1486
1487sub _poll {
1488 Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
1489}
1490
1431# default implementation for ->condvar 1491# default implementation for ->condvar
1492# in fact, the default should not be overwritten
1432 1493
1433sub condvar { 1494sub condvar {
1434 eval q{ # poor man's autoloading {} 1495 eval q{ # poor man's autoloading {}
1435 *condvar = sub { 1496 *condvar = sub {
1436 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar" 1497 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1621# default implementation for ->child 1682# default implementation for ->child
1622 1683
1623our %PID_CB; 1684our %PID_CB;
1624our $CHLD_W; 1685our $CHLD_W;
1625our $CHLD_DELAY_W; 1686our $CHLD_DELAY_W;
1626our $WNOHANG;
1627 1687
1628# used by many Impl's 1688# used by many Impl's
1629sub _emit_childstatus($$) { 1689sub _emit_childstatus($$) {
1630 my (undef, $rpid, $rstatus) = @_; 1690 my (undef, $rpid, $rstatus) = @_;
1631 1691
1638 eval q{ # poor man's autoloading {} 1698 eval q{ # poor man's autoloading {}
1639 *_sigchld = sub { 1699 *_sigchld = sub {
1640 my $pid; 1700 my $pid;
1641 1701
1642 AnyEvent->_emit_childstatus ($pid, $?) 1702 AnyEvent->_emit_childstatus ($pid, $?)
1643 while ($pid = waitpid -1, $WNOHANG) > 0; 1703 while ($pid = waitpid -1, WNOHANG) > 0;
1644 }; 1704 };
1645 1705
1646 *child = sub { 1706 *child = sub {
1647 my (undef, %arg) = @_; 1707 my (undef, %arg) = @_;
1648 1708
1649 defined (my $pid = $arg{pid} + 0) 1709 my $pid = $arg{pid};
1650 or Carp::croak "required option 'pid' is missing"; 1710 my $cb = $arg{cb};
1651 1711
1652 $PID_CB{$pid}{$arg{cb}} = $arg{cb}; 1712 $PID_CB{$pid}{$cb+0} = $cb;
1653
1654 # WNOHANG is almost cetrainly 1 everywhere
1655 $WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1656 ? 1
1657 : eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1658 1713
1659 unless ($CHLD_W) { 1714 unless ($CHLD_W) {
1660 $CHLD_W = AE::signal CHLD => \&_sigchld; 1715 $CHLD_W = AE::signal CHLD => \&_sigchld;
1661 # child could be a zombie already, so make at least one round 1716 # child could be a zombie already, so make at least one round
1662 &_sigchld; 1717 &_sigchld;
1663 } 1718 }
1664 1719
1665 bless [$pid, $arg{cb}], "AnyEvent::Base::child" 1720 bless [$pid, $cb+0], "AnyEvent::Base::child"
1666 }; 1721 };
1667 1722
1668 *AnyEvent::Base::child::DESTROY = sub { 1723 *AnyEvent::Base::child::DESTROY = sub {
1669 my ($pid, $cb) = @{$_[0]}; 1724 my ($pid, $icb) = @{$_[0]};
1670 1725
1671 delete $PID_CB{$pid}{$cb}; 1726 delete $PID_CB{$pid}{$icb};
1672 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; 1727 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1673 1728
1674 undef $CHLD_W unless keys %PID_CB; 1729 undef $CHLD_W unless keys %PID_CB;
1675 }; 1730 };
1676 }; 1731 };
1724 1779
1725package AnyEvent::CondVar; 1780package AnyEvent::CondVar;
1726 1781
1727our @ISA = AnyEvent::CondVar::Base::; 1782our @ISA = AnyEvent::CondVar::Base::;
1728 1783
1784# only to be used for subclassing
1785sub new {
1786 my $class = shift;
1787 bless AnyEvent->condvar (@_), $class
1788}
1789
1729package AnyEvent::CondVar::Base; 1790package AnyEvent::CondVar::Base;
1730 1791
1731#use overload 1792#use overload
1732# '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, 1793# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1733# fallback => 1; 1794# fallback => 1;
1742 1803
1743sub _send { 1804sub _send {
1744 # nop 1805 # nop
1745} 1806}
1746 1807
1808sub _wait {
1809 AnyEvent->_poll until $_[0]{_ae_sent};
1810}
1811
1747sub send { 1812sub send {
1748 my $cv = shift; 1813 my $cv = shift;
1749 $cv->{_ae_sent} = [@_]; 1814 $cv->{_ae_sent} = [@_];
1750 (delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb}; 1815 (delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1751 $cv->_send; 1816 $cv->_send;
1758 1823
1759sub ready { 1824sub ready {
1760 $_[0]{_ae_sent} 1825 $_[0]{_ae_sent}
1761} 1826}
1762 1827
1763sub _wait {
1764 $WAITING
1765 and !$_[0]{_ae_sent}
1766 and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1767
1768 local $WAITING = 1;
1769 AnyEvent->one_event while !$_[0]{_ae_sent};
1770}
1771
1772sub recv { 1828sub recv {
1829 unless ($_[0]{_ae_sent}) {
1830 $WAITING
1831 and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
1832
1833 local $WAITING = 1;
1773 $_[0]->_wait; 1834 $_[0]->_wait;
1835 }
1774 1836
1775 Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak}; 1837 $_[0]{_ae_croak}
1776 wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0] 1838 and Carp::croak $_[0]{_ae_croak};
1839
1840 wantarray
1841 ? @{ $_[0]{_ae_sent} }
1842 : $_[0]{_ae_sent}[0]
1777} 1843}
1778 1844
1779sub cb { 1845sub cb {
1780 my $cv = shift; 1846 my $cv = shift;
1781 1847
1797 &{ $_[0]{_ae_end_cb} || sub { $_[0]->send } }; 1863 &{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1798} 1864}
1799 1865
1800# undocumented/compatibility with pre-3.4 1866# undocumented/compatibility with pre-3.4
1801*broadcast = \&send; 1867*broadcast = \&send;
1802*wait = \&_wait; 1868*wait = \&recv;
1803 1869
1804=head1 ERROR AND EXCEPTION HANDLING 1870=head1 ERROR AND EXCEPTION HANDLING
1805 1871
1806In general, AnyEvent does not do any error handling - it relies on the 1872In general, AnyEvent does not do any error handling - it relies on the
1807caller to do that if required. The L<AnyEvent::Strict> module (see also 1873caller to do that if required. The L<AnyEvent::Strict> module (see also
1854check the arguments passed to most method calls. If it finds any problems, 1920check the arguments passed to most method calls. If it finds any problems,
1855it will croak. 1921it will croak.
1856 1922
1857In other words, enables "strict" mode. 1923In other words, enables "strict" mode.
1858 1924
1859Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense> 1925Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1860>>, it is definitely recommended to keep it off in production. Keeping 1926>>, it is definitely recommended to keep it off in production. Keeping
1861C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs 1927C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1862can be very useful, however. 1928can be very useful, however.
1863 1929
1864=item C<PERL_ANYEVENT_MODEL> 1930=item C<PERL_ANYEVENT_MODEL>
1870used as event model. If it fails to load AnyEvent will proceed with 1936used as event model. If it fails to load AnyEvent will proceed with
1871auto detection and -probing. 1937auto detection and -probing.
1872 1938
1873This functionality might change in future versions. 1939This functionality might change in future versions.
1874 1940
1875For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you 1941For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1876could start your program like this: 1942could start your program like this:
1877 1943
1878 PERL_ANYEVENT_MODEL=Perl perl ... 1944 PERL_ANYEVENT_MODEL=Perl perl ...
1879 1945
1880=item C<PERL_ANYEVENT_PROTOCOLS> 1946=item C<PERL_ANYEVENT_PROTOCOLS>
2510 unless defined $SIG{PIPE}; 2576 unless defined $SIG{PIPE};
2511 2577
2512=head1 RECOMMENDED/OPTIONAL MODULES 2578=head1 RECOMMENDED/OPTIONAL MODULES
2513 2579
2514One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and 2580One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2515it's built-in modules) are required to use it. 2581its built-in modules) are required to use it.
2516 2582
2517That does not mean that AnyEvent won't take advantage of some additional 2583That does not mean that AnyEvent won't take advantage of some additional
2518modules if they are installed. 2584modules if they are installed.
2519 2585
2520This section explains which additional modules will be used, and how they 2586This section explains which additional modules will be used, and how they
2578the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL. 2644the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2579 2645
2580=item L<Time::HiRes> 2646=item L<Time::HiRes>
2581 2647
2582This module is part of perl since release 5.008. It will be used when the 2648This module is part of perl since release 5.008. It will be used when the
2583chosen event library does not come with a timing source on it's own. The 2649chosen event library does not come with a timing source of its own. The
2584pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to 2650pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2585try to use a monotonic clock for timing stability. 2651try to use a monotonic clock for timing stability.
2586 2652
2587=back 2653=back
2588 2654
2589 2655
2651pronounced). 2717pronounced).
2652 2718
2653 2719
2654=head1 SEE ALSO 2720=head1 SEE ALSO
2655 2721
2722Tutorial/Introduction: L<AnyEvent::Intro>.
2723
2724FAQ: L<AnyEvent::FAQ>.
2725
2656Utility functions: L<AnyEvent::Util>. 2726Utility functions: L<AnyEvent::Util>.
2657 2727
2658Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>, 2728Event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>, L<Glib::EV>,
2659L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. 2729L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2660 2730
2661Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, 2731Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2662L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, 2732L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2663L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, 2733L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2664L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>. 2734L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
2666Non-blocking file handles, sockets, TCP clients and 2736Non-blocking file handles, sockets, TCP clients and
2667servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>. 2737servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2668 2738
2669Asynchronous DNS: L<AnyEvent::DNS>. 2739Asynchronous DNS: L<AnyEvent::DNS>.
2670 2740
2671Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, 2741Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2672L<Coro::Event>,
2673 2742
2674Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>, 2743Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2675L<AnyEvent::HTTP>. 2744L<AnyEvent::HTTP>.
2676 2745
2677 2746
2678=head1 AUTHOR 2747=head1 AUTHOR
2679 2748

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