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1=head1 => NAME 1=head1 NAME
2 2
3AnyEvent - provide framework for multiple event loops 3AnyEvent - provide framework for multiple event loops
4 4
5EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops 5EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops
6 6
18 18
19 my $w = AnyEvent->condvar; # stores whether a condition was flagged 19 my $w = AnyEvent->condvar; # stores whether a condition was flagged
20 $w->send; # wake up current and all future recv's 20 $w->send; # wake up current and all future recv's
21 $w->recv; # enters "main loop" till $condvar gets ->send 21 $w->recv; # enters "main loop" till $condvar gets ->send
22 22
23=head1 INTRODUCTION/TUTORIAL
24
25This manpage is mainly a reference manual. If you are interested
26in a tutorial or some gentle introduction, have a look at the
27L<AnyEvent::Intro> manpage.
28
23=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT) 29=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
24 30
25Glib, POE, IO::Async, Event... CPAN offers event models by the dozen 31Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
26nowadays. So what is different about AnyEvent? 32nowadays. So what is different about AnyEvent?
27 33
28Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of 34Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of
29policy> and AnyEvent is I<small and efficient>. 35policy> and AnyEvent is I<small and efficient>.
30 36
31First and foremost, I<AnyEvent is not an event model> itself, it only 37First and foremost, I<AnyEvent is not an event model> itself, it only
32interfaces to whatever event model the main program happens to use in a 38interfaces to whatever event model the main program happens to use, in a
33pragmatic way. For event models and certain classes of immortals alike, 39pragmatic way. For event models and certain classes of immortals alike,
34the statement "there can only be one" is a bitter reality: In general, 40the statement "there can only be one" is a bitter reality: In general,
35only one event loop can be active at the same time in a process. AnyEvent 41only one event loop can be active at the same time in a process. AnyEvent
36helps hiding the differences between those event loops. 42cannot change this, but it can hide the differences between those event
43loops.
37 44
38The goal of AnyEvent is to offer module authors the ability to do event 45The goal of AnyEvent is to offer module authors the ability to do event
39programming (waiting for I/O or timer events) without subscribing to a 46programming (waiting for I/O or timer events) without subscribing to a
40religion, a way of living, and most importantly: without forcing your 47religion, a way of living, and most importantly: without forcing your
41module users into the same thing by forcing them to use the same event 48module users into the same thing by forcing them to use the same event
42model you use. 49model you use.
43 50
44For modules like POE or IO::Async (which is a total misnomer as it is 51For modules like POE or IO::Async (which is a total misnomer as it is
45actually doing all I/O I<synchronously>...), using them in your module is 52actually doing all I/O I<synchronously>...), using them in your module is
46like joining a cult: After you joined, you are dependent on them and you 53like joining a cult: After you joined, you are dependent on them and you
47cannot use anything else, as it is simply incompatible to everything that 54cannot use anything else, as they are simply incompatible to everything
48isn't itself. What's worse, all the potential users of your module are 55that isn't them. What's worse, all the potential users of your
49I<also> forced to use the same event loop you use. 56module are I<also> forced to use the same event loop you use.
50 57
51AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works 58AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
52fine. AnyEvent + Tk works fine etc. etc. but none of these work together 59fine. AnyEvent + Tk works fine etc. etc. but none of these work together
53with the rest: POE + IO::Async? no go. Tk + Event? no go. Again: if 60with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if
54your module uses one of those, every user of your module has to use it, 61your module uses one of those, every user of your module has to use it,
55too. But if your module uses AnyEvent, it works transparently with all 62too. But if your module uses AnyEvent, it works transparently with all
56event models it supports (including stuff like POE and IO::Async, as long 63event models it supports (including stuff like IO::Async, as long as those
57as those use one of the supported event loops. It is trivial to add new 64use one of the supported event loops. It is trivial to add new event loops
58event loops to AnyEvent, too, so it is future-proof). 65to AnyEvent, too, so it is future-proof).
59 66
60In addition to being free of having to use I<the one and only true event 67In addition to being free of having to use I<the one and only true event
61model>, AnyEvent also is free of bloat and policy: with POE or similar 68model>, AnyEvent also is free of bloat and policy: with POE or similar
62modules, you get an enormous amount of code and strict rules you have to 69modules, you get an enormous amount of code and strict rules you have to
63follow. AnyEvent, on the other hand, is lean and up to the point, by only 70follow. AnyEvent, on the other hand, is lean and up to the point, by only
64offering the functionality that is necessary, in as thin as a wrapper as 71offering the functionality that is necessary, in as thin as a wrapper as
65technically possible. 72technically possible.
66 73
74Of course, AnyEvent comes with a big (and fully optional!) toolbox
75of useful functionality, such as an asynchronous DNS resolver, 100%
76non-blocking connects (even with TLS/SSL, IPv6 and on broken platforms
77such as Windows) and lots of real-world knowledge and workarounds for
78platform bugs and differences.
79
67Of course, if you want lots of policy (this can arguably be somewhat 80Now, if you I<do want> lots of policy (this can arguably be somewhat
68useful) and you want to force your users to use the one and only event 81useful) and you want to force your users to use the one and only event
69model, you should I<not> use this module. 82model, you should I<not> use this module.
70 83
71=head1 DESCRIPTION 84=head1 DESCRIPTION
72 85
102starts using it, all bets are off. Maybe you should tell their authors to 115starts using it, all bets are off. Maybe you should tell their authors to
103use AnyEvent so their modules work together with others seamlessly... 116use AnyEvent so their modules work together with others seamlessly...
104 117
105The pure-perl implementation of AnyEvent is called 118The pure-perl implementation of AnyEvent is called
106C<AnyEvent::Impl::Perl>. Like other event modules you can load it 119C<AnyEvent::Impl::Perl>. Like other event modules you can load it
107explicitly. 120explicitly and enjoy the high availability of that event loop :)
108 121
109=head1 WATCHERS 122=head1 WATCHERS
110 123
111AnyEvent has the central concept of a I<watcher>, which is an object that 124AnyEvent has the central concept of a I<watcher>, which is an object that
112stores relevant data for each kind of event you are waiting for, such as 125stores relevant data for each kind of event you are waiting for, such as
126Many watchers either are used with "recursion" (repeating timers for 139Many watchers either are used with "recursion" (repeating timers for
127example), or need to refer to their watcher object in other ways. 140example), or need to refer to their watcher object in other ways.
128 141
129An any way to achieve that is this pattern: 142An any way to achieve that is this pattern:
130 143
131 my $w; $w = AnyEvent->type (arg => value ..., cb => sub { 144 my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
132 # you can use $w here, for example to undef it 145 # you can use $w here, for example to undef it
133 undef $w; 146 undef $w;
134 }); 147 });
135 148
136Note that C<my $w; $w => combination. This is necessary because in Perl, 149Note that C<my $w; $w => combination. This is necessary because in Perl,
137my variables are only visible after the statement in which they are 150my variables are only visible after the statement in which they are
138declared. 151declared.
139 152
140=head2 I/O WATCHERS 153=head2 I/O WATCHERS
141 154
142You can create an I/O watcher by calling the C<< AnyEvent->io >> method 155You can create an I/O watcher by calling the C<< AnyEvent->io >> method
143with the following mandatory key-value pairs as arguments: 156with the following mandatory key-value pairs as arguments:
144 157
145C<fh> the Perl I<file handle> (I<not> file descriptor) to watch 158C<fh> the Perl I<file handle> (I<not> file descriptor) to watch for events
146for events. C<poll> must be a string that is either C<r> or C<w>, 159(AnyEvent might or might not keep a reference to this file handle). C<poll>
147which creates a watcher waiting for "r"eadable or "w"ritable events, 160must be a string that is either C<r> or C<w>, which creates a watcher
148respectively. C<cb> is the callback to invoke each time the file handle 161waiting for "r"eadable or "w"ritable events, respectively. C<cb> is the
149becomes ready. 162callback to invoke each time the file handle becomes ready.
150 163
151Although the callback might get passed parameters, their value and 164Although the callback might get passed parameters, their value and
152presence is undefined and you cannot rely on them. Portable AnyEvent 165presence is undefined and you cannot rely on them. Portable AnyEvent
153callbacks cannot use arguments passed to I/O watcher callbacks. 166callbacks cannot use arguments passed to I/O watcher callbacks.
154 167
158 171
159Some event loops issue spurious readyness notifications, so you should 172Some event loops issue spurious readyness notifications, so you should
160always use non-blocking calls when reading/writing from/to your file 173always use non-blocking calls when reading/writing from/to your file
161handles. 174handles.
162 175
163Example:
164
165 # wait for readability of STDIN, then read a line and disable the watcher 176Example: wait for readability of STDIN, then read a line and disable the
177watcher.
178
166 my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { 179 my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {
167 chomp (my $input = <STDIN>); 180 chomp (my $input = <STDIN>);
168 warn "read: $input\n"; 181 warn "read: $input\n";
169 undef $w; 182 undef $w;
170 }); 183 });
180 193
181Although the callback might get passed parameters, their value and 194Although the callback might get passed parameters, their value and
182presence is undefined and you cannot rely on them. Portable AnyEvent 195presence is undefined and you cannot rely on them. Portable AnyEvent
183callbacks cannot use arguments passed to time watcher callbacks. 196callbacks cannot use arguments passed to time watcher callbacks.
184 197
185The timer callback will be invoked at most once: if you want a repeating 198The callback will normally be invoked once only. If you specify another
186timer you have to create a new watcher (this is a limitation by both Tk 199parameter, C<interval>, as a strictly positive number (> 0), then the
187and Glib). 200callback will be invoked regularly at that interval (in fractional
201seconds) after the first invocation. If C<interval> is specified with a
202false value, then it is treated as if it were missing.
188 203
189Example: 204The callback will be rescheduled before invoking the callback, but no
205attempt is done to avoid timer drift in most backends, so the interval is
206only approximate.
190 207
191 # fire an event after 7.7 seconds 208Example: fire an event after 7.7 seconds.
209
192 my $w = AnyEvent->timer (after => 7.7, cb => sub { 210 my $w = AnyEvent->timer (after => 7.7, cb => sub {
193 warn "timeout\n"; 211 warn "timeout\n";
194 }); 212 });
195 213
196 # to cancel the timer: 214 # to cancel the timer:
197 undef $w; 215 undef $w;
198 216
199Example 2:
200
201 # fire an event after 0.5 seconds, then roughly every second 217Example 2: fire an event after 0.5 seconds, then roughly every second.
202 my $w;
203 218
204 my $cb = sub {
205 # cancel the old timer while creating a new one
206 $w = AnyEvent->timer (after => 1, cb => $cb); 219 my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub {
220 warn "timeout\n";
207 }; 221 };
208
209 # start the "loop" by creating the first watcher
210 $w = AnyEvent->timer (after => 0.5, cb => $cb);
211 222
212=head3 TIMING ISSUES 223=head3 TIMING ISSUES
213 224
214There are two ways to handle timers: based on real time (relative, "fire 225There are two ways to handle timers: based on real time (relative, "fire
215in 10 seconds") and based on wallclock time (absolute, "fire at 12 226in 10 seconds") and based on wallclock time (absolute, "fire at 12
227timers. 238timers.
228 239
229AnyEvent always prefers relative timers, if available, matching the 240AnyEvent always prefers relative timers, if available, matching the
230AnyEvent API. 241AnyEvent API.
231 242
243AnyEvent has two additional methods that return the "current time":
244
245=over 4
246
247=item AnyEvent->time
248
249This returns the "current wallclock time" as a fractional number of
250seconds since the Epoch (the same thing as C<time> or C<Time::HiRes::time>
251return, and the result is guaranteed to be compatible with those).
252
253It progresses independently of any event loop processing, i.e. each call
254will check the system clock, which usually gets updated frequently.
255
256=item AnyEvent->now
257
258This also returns the "current wallclock time", but unlike C<time>, above,
259this value might change only once per event loop iteration, depending on
260the event loop (most return the same time as C<time>, above). This is the
261time that AnyEvent's timers get scheduled against.
262
263I<In almost all cases (in all cases if you don't care), this is the
264function to call when you want to know the current time.>
265
266This function is also often faster then C<< AnyEvent->time >>, and
267thus the preferred method if you want some timestamp (for example,
268L<AnyEvent::Handle> uses this to update it's activity timeouts).
269
270The rest of this section is only of relevance if you try to be very exact
271with your timing, you can skip it without bad conscience.
272
273For a practical example of when these times differ, consider L<Event::Lib>
274and L<EV> and the following set-up:
275
276The event loop is running and has just invoked one of your callback at
277time=500 (assume no other callbacks delay processing). In your callback,
278you wait a second by executing C<sleep 1> (blocking the process for a
279second) and then (at time=501) you create a relative timer that fires
280after three seconds.
281
282With L<Event::Lib>, C<< AnyEvent->time >> and C<< AnyEvent->now >> will
283both return C<501>, because that is the current time, and the timer will
284be scheduled to fire at time=504 (C<501> + C<3>).
285
286With L<EV>, C<< AnyEvent->time >> returns C<501> (as that is the current
287time), but C<< AnyEvent->now >> returns C<500>, as that is the time the
288last event processing phase started. With L<EV>, your timer gets scheduled
289to run at time=503 (C<500> + C<3>).
290
291In one sense, L<Event::Lib> is more exact, as it uses the current time
292regardless of any delays introduced by event processing. However, most
293callbacks do not expect large delays in processing, so this causes a
294higher drift (and a lot more system calls to get the current time).
295
296In another sense, L<EV> is more exact, as your timer will be scheduled at
297the same time, regardless of how long event processing actually took.
298
299In either case, if you care (and in most cases, you don't), then you
300can get whatever behaviour you want with any event loop, by taking the
301difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
302account.
303
304=back
305
232=head2 SIGNAL WATCHERS 306=head2 SIGNAL WATCHERS
233 307
234You can watch for signals using a signal watcher, C<signal> is the signal 308You can watch for signals using a signal watcher, C<signal> is the signal
235I<name> without any C<SIG> prefix, C<cb> is the Perl callback to 309I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
236be invoked whenever a signal occurs. 310callback to be invoked whenever a signal occurs.
237 311
238Although the callback might get passed parameters, their value and 312Although the callback might get passed parameters, their value and
239presence is undefined and you cannot rely on them. Portable AnyEvent 313presence is undefined and you cannot rely on them. Portable AnyEvent
240callbacks cannot use arguments passed to signal watcher callbacks. 314callbacks cannot use arguments passed to signal watcher callbacks.
241 315
277AnyEvent program, you I<have> to create at least one watcher before you 351AnyEvent program, you I<have> to create at least one watcher before you
278C<fork> the child (alternatively, you can call C<AnyEvent::detect>). 352C<fork> the child (alternatively, you can call C<AnyEvent::detect>).
279 353
280Example: fork a process and wait for it 354Example: fork a process and wait for it
281 355
282 my $done = AnyEvent->condvar; 356 my $done = AnyEvent->condvar;
283 357
284 my $pid = fork or exit 5; 358 my $pid = fork or exit 5;
285 359
286 my $w = AnyEvent->child ( 360 my $w = AnyEvent->child (
287 pid => $pid, 361 pid => $pid,
288 cb => sub { 362 cb => sub {
289 my ($pid, $status) = @_; 363 my ($pid, $status) = @_;
290 warn "pid $pid exited with status $status"; 364 warn "pid $pid exited with status $status";
291 $done->send; 365 $done->send;
292 }, 366 },
293 ); 367 );
294 368
295 # do something else, then wait for process exit 369 # do something else, then wait for process exit
296 $done->recv; 370 $done->recv;
297 371
298=head2 CONDITION VARIABLES 372=head2 CONDITION VARIABLES
299 373
300If you are familiar with some event loops you will know that all of them 374If you are familiar with some event loops you will know that all of them
301require you to run some blocking "loop", "run" or similar function that 375require you to run some blocking "loop", "run" or similar function that
312C<cb>, which specifies a callback to be called when the condition variable 386C<cb>, which specifies a callback to be called when the condition variable
313becomes true. 387becomes true.
314 388
315After creation, the condition variable is "false" until it becomes "true" 389After creation, the condition variable is "false" until it becomes "true"
316by calling the C<send> method (or calling the condition variable as if it 390by calling the C<send> method (or calling the condition variable as if it
317were a callback). 391were a callback, read about the caveats in the description for the C<<
392->send >> method).
318 393
319Condition variables are similar to callbacks, except that you can 394Condition variables are similar to callbacks, except that you can
320optionally wait for them. They can also be called merge points - points 395optionally wait for them. They can also be called merge points - points
321in time where multiple outstanding events have been processed. And yet 396in time where multiple outstanding events have been processed. And yet
322another way to call them is transactions - each condition variable can be 397another way to call them is transactions - each condition variable can be
394immediately from within send. 469immediately from within send.
395 470
396Any arguments passed to the C<send> call will be returned by all 471Any arguments passed to the C<send> call will be returned by all
397future C<< ->recv >> calls. 472future C<< ->recv >> calls.
398 473
399Condition variables are overloaded so one can call them directly (as a 474Condition variables are overloaded so one can call them directly
400code reference). Calling them directly is the same as calling C<send>. 475(as a code reference). Calling them directly is the same as calling
476C<send>. Note, however, that many C-based event loops do not handle
477overloading, so as tempting as it may be, passing a condition variable
478instead of a callback does not work. Both the pure perl and EV loops
479support overloading, however, as well as all functions that use perl to
480invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
481example).
401 482
402=item $cv->croak ($error) 483=item $cv->croak ($error)
403 484
404Similar to send, but causes all call's to C<< ->recv >> to invoke 485Similar to send, but causes all call's to C<< ->recv >> to invoke
405C<Carp::croak> with the given error message/object/scalar. 486C<Carp::croak> with the given error message/object/scalar.
515 596
516This is a mutator function that returns the callback set and optionally 597This is a mutator function that returns the callback set and optionally
517replaces it before doing so. 598replaces it before doing so.
518 599
519The callback will be called when the condition becomes "true", i.e. when 600The callback will be called when the condition becomes "true", i.e. when
520C<send> or C<croak> are called. Calling C<recv> inside the callback 601C<send> or C<croak> are called, with the only argument being the condition
521or at any later time is guaranteed not to block. 602variable itself. Calling C<recv> inside the callback or at any later time
603is guaranteed not to block.
522 604
523=back 605=back
524 606
525=head1 GLOBAL VARIABLES AND FUNCTIONS 607=head1 GLOBAL VARIABLES AND FUNCTIONS
526 608
612 694
613If it doesn't care, it can just "use AnyEvent" and use it itself, or not 695If it doesn't care, it can just "use AnyEvent" and use it itself, or not
614do anything special (it does not need to be event-based) and let AnyEvent 696do anything special (it does not need to be event-based) and let AnyEvent
615decide which implementation to chose if some module relies on it. 697decide which implementation to chose if some module relies on it.
616 698
617If the main program relies on a specific event model. For example, in 699If the main program relies on a specific event model - for example, in
618Gtk2 programs you have to rely on the Glib module. You should load the 700Gtk2 programs you have to rely on the Glib module - you should load the
619event module before loading AnyEvent or any module that uses it: generally 701event module before loading AnyEvent or any module that uses it: generally
620speaking, you should load it as early as possible. The reason is that 702speaking, you should load it as early as possible. The reason is that
621modules might create watchers when they are loaded, and AnyEvent will 703modules might create watchers when they are loaded, and AnyEvent will
622decide on the event model to use as soon as it creates watchers, and it 704decide on the event model to use as soon as it creates watchers, and it
623might chose the wrong one unless you load the correct one yourself. 705might chose the wrong one unless you load the correct one yourself.
624 706
625You can chose to use a rather inefficient pure-perl implementation by 707You can chose to use a pure-perl implementation by loading the
626loading the C<AnyEvent::Impl::Perl> module, which gives you similar 708C<AnyEvent::Impl::Perl> module, which gives you similar behaviour
627behaviour everywhere, but letting AnyEvent chose is generally better. 709everywhere, but letting AnyEvent chose the model is generally better.
710
711=head2 MAINLOOP EMULATION
712
713Sometimes (often for short test scripts, or even standalone programs who
714only want to use AnyEvent), you do not want to run a specific event loop.
715
716In that case, you can use a condition variable like this:
717
718 AnyEvent->condvar->recv;
719
720This has the effect of entering the event loop and looping forever.
721
722Note that usually your program has some exit condition, in which case
723it is better to use the "traditional" approach of storing a condition
724variable somewhere, waiting for it, and sending it when the program should
725exit cleanly.
726
628 727
629=head1 OTHER MODULES 728=head1 OTHER MODULES
630 729
631The following is a non-exhaustive list of additional modules that use 730The following is a non-exhaustive list of additional modules that use
632AnyEvent and can therefore be mixed easily with other AnyEvent modules 731AnyEvent and can therefore be mixed easily with other AnyEvent modules
638=item L<AnyEvent::Util> 737=item L<AnyEvent::Util>
639 738
640Contains various utility functions that replace often-used but blocking 739Contains various utility functions that replace often-used but blocking
641functions such as C<inet_aton> by event-/callback-based versions. 740functions such as C<inet_aton> by event-/callback-based versions.
642 741
643=item L<AnyEvent::Handle>
644
645Provide read and write buffers and manages watchers for reads and writes.
646
647=item L<AnyEvent::Socket> 742=item L<AnyEvent::Socket>
648 743
649Provides various utility functions for (internet protocol) sockets, 744Provides various utility functions for (internet protocol) sockets,
650addresses and name resolution. Also functions to create non-blocking tcp 745addresses and name resolution. Also functions to create non-blocking tcp
651connections or tcp servers, with IPv6 and SRV record support and more. 746connections or tcp servers, with IPv6 and SRV record support and more.
652 747
748=item L<AnyEvent::Handle>
749
750Provide read and write buffers, manages watchers for reads and writes,
751supports raw and formatted I/O, I/O queued and fully transparent and
752non-blocking SSL/TLS.
753
754=item L<AnyEvent::DNS>
755
756Provides rich asynchronous DNS resolver capabilities.
757
758=item L<AnyEvent::HTTP>
759
760A simple-to-use HTTP library that is capable of making a lot of concurrent
761HTTP requests.
762
653=item L<AnyEvent::HTTPD> 763=item L<AnyEvent::HTTPD>
654 764
655Provides a simple web application server framework. 765Provides a simple web application server framework.
656 766
657=item L<AnyEvent::DNS>
658
659Provides rich asynchronous DNS resolver capabilities.
660
661=item L<AnyEvent::FastPing> 767=item L<AnyEvent::FastPing>
662 768
663The fastest ping in the west. 769The fastest ping in the west.
770
771=item L<AnyEvent::DBI>
772
773Executes L<DBI> requests asynchronously in a proxy process.
774
775=item L<AnyEvent::AIO>
776
777Truly asynchronous I/O, should be in the toolbox of every event
778programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
779together.
780
781=item L<AnyEvent::BDB>
782
783Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
784L<BDB> and AnyEvent together.
785
786=item L<AnyEvent::GPSD>
787
788A non-blocking interface to gpsd, a daemon delivering GPS information.
789
790=item L<AnyEvent::IGS>
791
792A non-blocking interface to the Internet Go Server protocol (used by
793L<App::IGS>).
664 794
665=item L<Net::IRC3> 795=item L<Net::IRC3>
666 796
667AnyEvent based IRC client module family. 797AnyEvent based IRC client module family.
668 798
681 811
682=item L<Coro> 812=item L<Coro>
683 813
684Has special support for AnyEvent via L<Coro::AnyEvent>. 814Has special support for AnyEvent via L<Coro::AnyEvent>.
685 815
686=item L<AnyEvent::AIO>, L<IO::AIO>
687
688Truly asynchronous I/O, should be in the toolbox of every event
689programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent
690together.
691
692=item L<AnyEvent::BDB>, L<BDB>
693
694Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses
695IO::AIO and AnyEvent together.
696
697=item L<IO::Lambda> 816=item L<IO::Lambda>
698 817
699The lambda approach to I/O - don't ask, look there. Can use AnyEvent. 818The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
700 819
701=back 820=back
707no warnings; 826no warnings;
708use strict; 827use strict;
709 828
710use Carp; 829use Carp;
711 830
712our $VERSION = '4.0'; 831our $VERSION = 4.22;
713our $MODEL; 832our $MODEL;
714 833
715our $AUTOLOAD; 834our $AUTOLOAD;
716our @ISA; 835our @ISA;
717 836
837our @REGISTRY;
838
839our $WIN32;
840
841BEGIN {
842 my $win32 = ! ! ($^O =~ /mswin32/i);
843 eval "sub WIN32(){ $win32 }";
844}
845
718our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; 846our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;
719 847
720our @REGISTRY; 848our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
721
722our %PROTOCOL; # (ipv4|ipv6) => (1|2)
723 849
724{ 850{
725 my $idx; 851 my $idx;
726 $PROTOCOL{$_} = ++$idx 852 $PROTOCOL{$_} = ++$idx
853 for reverse split /\s*,\s*/,
727 for split /\s*,\s*/, $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; 854 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
728} 855}
729 856
730my @models = ( 857my @models = (
731 [EV:: => AnyEvent::Impl::EV::], 858 [EV:: => AnyEvent::Impl::EV::],
732 [Event:: => AnyEvent::Impl::Event::], 859 [Event:: => AnyEvent::Impl::Event::],
733 [Tk:: => AnyEvent::Impl::Tk::],
734 [Wx:: => AnyEvent::Impl::POE::],
735 [Prima:: => AnyEvent::Impl::POE::],
736 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], 860 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
737 # everything below here will not be autoprobed as the pureperl backend should work everywhere 861 # everything below here will not be autoprobed
738 [Glib:: => AnyEvent::Impl::Glib::], 862 # as the pureperl backend should work everywhere
863 # and is usually faster
864 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
865 [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
739 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy 866 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
740 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program 867 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program
741 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza 868 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
869 [Wx:: => AnyEvent::Impl::POE::],
870 [Prima:: => AnyEvent::Impl::POE::],
742); 871);
743 872
744our %method = map +($_ => 1), qw(io timer signal child condvar one_event DESTROY); 873our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY);
745 874
746our @post_detect; 875our @post_detect;
747 876
748sub post_detect(&) { 877sub post_detect(&) {
749 my ($cb) = @_; 878 my ($cb) = @_;
766} 895}
767 896
768sub detect() { 897sub detect() {
769 unless ($MODEL) { 898 unless ($MODEL) {
770 no strict 'refs'; 899 no strict 'refs';
900 local $SIG{__DIE__};
771 901
772 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { 902 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
773 my $model = "AnyEvent::Impl::$1"; 903 my $model = "AnyEvent::Impl::$1";
774 if (eval "require $model") { 904 if (eval "require $model") {
775 $MODEL = $model; 905 $MODEL = $model;
809 $MODEL 939 $MODEL
810 or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib."; 940 or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";
811 } 941 }
812 } 942 }
813 943
944 push @{"$MODEL\::ISA"}, "AnyEvent::Base";
945
814 unshift @ISA, $MODEL; 946 unshift @ISA, $MODEL;
815 push @{"$MODEL\::ISA"}, "AnyEvent::Base"; 947
948 require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
816 949
817 (shift @post_detect)->() while @post_detect; 950 (shift @post_detect)->() while @post_detect;
818 } 951 }
819 952
820 $MODEL 953 $MODEL
830 963
831 my $class = shift; 964 my $class = shift;
832 $class->$func (@_); 965 $class->$func (@_);
833} 966}
834 967
968# utility function to dup a filehandle. this is used by many backends
969# to support binding more than one watcher per filehandle (they usually
970# allow only one watcher per fd, so we dup it to get a different one).
971sub _dupfh($$$$) {
972 my ($poll, $fh, $r, $w) = @_;
973
974 require Fcntl;
975
976 # cygwin requires the fh mode to be matching, unix doesn't
977 my ($rw, $mode) = $poll eq "r" ? ($r, "<")
978 : $poll eq "w" ? ($w, ">")
979 : Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
980
981 open my $fh2, "$mode&" . fileno $fh
982 or die "cannot dup() filehandle: $!";
983
984 # we assume CLOEXEC is already set by perl in all important cases
985
986 ($fh2, $rw)
987}
988
835package AnyEvent::Base; 989package AnyEvent::Base;
990
991# default implementation for now and time
992
993use Time::HiRes ();
994
995sub time { Time::HiRes::time }
996sub now { Time::HiRes::time }
836 997
837# default implementation for ->condvar 998# default implementation for ->condvar
838 999
839sub condvar { 1000sub condvar {
840 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar:: 1001 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::
861sub AnyEvent::Base::Signal::DESTROY { 1022sub AnyEvent::Base::Signal::DESTROY {
862 my ($signal, $cb) = @{$_[0]}; 1023 my ($signal, $cb) = @{$_[0]};
863 1024
864 delete $SIG_CB{$signal}{$cb}; 1025 delete $SIG_CB{$signal}{$cb};
865 1026
866 $SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} }; 1027 delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
867} 1028}
868 1029
869# default implementation for ->child 1030# default implementation for ->child
870 1031
871our %PID_CB; 1032our %PID_CB;
898 or Carp::croak "required option 'pid' is missing"; 1059 or Carp::croak "required option 'pid' is missing";
899 1060
900 $PID_CB{$pid}{$arg{cb}} = $arg{cb}; 1061 $PID_CB{$pid}{$arg{cb}} = $arg{cb};
901 1062
902 unless ($WNOHANG) { 1063 unless ($WNOHANG) {
903 $WNOHANG = eval { require POSIX; &POSIX::WNOHANG } || 1; 1064 $WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
904 } 1065 }
905 1066
906 unless ($CHLD_W) { 1067 unless ($CHLD_W) {
907 $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); 1068 $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
908 # child could be a zombie already, so make at least one round 1069 # child could be a zombie already, so make at least one round
1041C<PERL_ANYEVENT_MODEL>. 1202C<PERL_ANYEVENT_MODEL>.
1042 1203
1043When set to C<2> or higher, cause AnyEvent to report to STDERR which event 1204When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1044model it chooses. 1205model it chooses.
1045 1206
1207=item C<PERL_ANYEVENT_STRICT>
1208
1209AnyEvent does not do much argument checking by default, as thorough
1210argument checking is very costly. Setting this variable to a true value
1211will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1212check the arguments passed to most method calls. If it finds any problems
1213it will croak.
1214
1215In other words, enables "strict" mode.
1216
1217Unlike C<use strict> it is definitely recommended ot keep it off in
1218production.
1219
1046=item C<PERL_ANYEVENT_MODEL> 1220=item C<PERL_ANYEVENT_MODEL>
1047 1221
1048This can be used to specify the event model to be used by AnyEvent, before 1222This can be used to specify the event model to be used by AnyEvent, before
1049auto detection and -probing kicks in. It must be a string consisting 1223auto detection and -probing kicks in. It must be a string consisting
1050entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended 1224entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
1055This functionality might change in future versions. 1229This functionality might change in future versions.
1056 1230
1057For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you 1231For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
1058could start your program like this: 1232could start your program like this:
1059 1233
1060 PERL_ANYEVENT_MODEL=Perl perl ... 1234 PERL_ANYEVENT_MODEL=Perl perl ...
1061 1235
1062=item C<PERL_ANYEVENT_PROTOCOLS> 1236=item C<PERL_ANYEVENT_PROTOCOLS>
1063 1237
1064Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences 1238Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
1065for IPv4 or IPv6. The default is unspecified (and might change, or be the result 1239for IPv4 or IPv6. The default is unspecified (and might change, or be the result
1087some (broken) firewalls drop such DNS packets, which is why it is off by 1261some (broken) firewalls drop such DNS packets, which is why it is off by
1088default. 1262default.
1089 1263
1090Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce 1264Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1091EDNS0 in its DNS requests. 1265EDNS0 in its DNS requests.
1266
1267=item C<PERL_ANYEVENT_MAX_FORKS>
1268
1269The maximum number of child processes that C<AnyEvent::Util::fork_call>
1270will create in parallel.
1092 1271
1093=back 1272=back
1094 1273
1095=head1 EXAMPLE PROGRAM 1274=head1 EXAMPLE PROGRAM
1096 1275
1535specified in the variable. 1714specified in the variable.
1536 1715
1537You can make AnyEvent completely ignore this variable by deleting it 1716You can make AnyEvent completely ignore this variable by deleting it
1538before the first watcher gets created, e.g. with a C<BEGIN> block: 1717before the first watcher gets created, e.g. with a C<BEGIN> block:
1539 1718
1540 BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } 1719 BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }
1541 1720
1542 use AnyEvent; 1721 use AnyEvent;
1543 1722
1544Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can 1723Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1545be used to probe what backend is used and gain other information (which is 1724be used to probe what backend is used and gain other information (which is
1546probably even less useful to an attacker than PERL_ANYEVENT_MODEL). 1725probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
1726$ENV{PERL_ANYEGENT_STRICT}.
1727
1728
1729=head1 BUGS
1730
1731Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
1732to work around. If you suffer from memleaks, first upgrade to Perl 5.10
1733and check wether the leaks still show up. (Perl 5.10.0 has other annoying
1734mamleaks, such as leaking on C<map> and C<grep> but it is usually not as
1735pronounced).
1547 1736
1548 1737
1549=head1 SEE ALSO 1738=head1 SEE ALSO
1550 1739
1551Utility functions: L<AnyEvent::Util>. 1740Utility functions: L<AnyEvent::Util>.
1568Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. 1757Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.
1569 1758
1570 1759
1571=head1 AUTHOR 1760=head1 AUTHOR
1572 1761
1573 Marc Lehmann <schmorp@schmorp.de> 1762 Marc Lehmann <schmorp@schmorp.de>
1574 http://home.schmorp.de/ 1763 http://home.schmorp.de/
1575 1764
1576=cut 1765=cut
1577 1766
15781 17671
1579 1768

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