… | |
… | |
5 | loops |
5 | loops |
6 | |
6 | |
7 | SYNOPSIS |
7 | SYNOPSIS |
8 | use AnyEvent; |
8 | use AnyEvent; |
9 | |
9 | |
10 | my $w = AnyEvent->io (fh => $fh, poll => "r|w", cb => sub { |
10 | my $w = AnyEvent->io (fh => $fh, poll => "r|w", cb => sub { ... }); |
11 | ... |
|
|
12 | }); |
|
|
13 | |
11 | |
14 | my $w = AnyEvent->timer (after => $seconds, cb => sub { |
12 | my $w = AnyEvent->timer (after => $seconds, cb => sub { ... }); |
|
|
13 | my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ... |
|
|
14 | |
|
|
15 | print AnyEvent->now; # prints current event loop time |
|
|
16 | print AnyEvent->time; # think Time::HiRes::time or simply CORE::time. |
|
|
17 | |
|
|
18 | my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... }); |
|
|
19 | |
|
|
20 | my $w = AnyEvent->child (pid => $pid, cb => sub { |
|
|
21 | my ($pid, $status) = @_; |
15 | ... |
22 | ... |
16 | }); |
23 | }); |
17 | |
24 | |
18 | my $w = AnyEvent->condvar; # stores whether a condition was flagged |
25 | my $w = AnyEvent->condvar; # stores whether a condition was flagged |
19 | $w->send; # wake up current and all future recv's |
26 | $w->send; # wake up current and all future recv's |
20 | $w->recv; # enters "main loop" till $condvar gets ->send |
27 | $w->recv; # enters "main loop" till $condvar gets ->send |
|
|
28 | # use a condvar in callback mode: |
|
|
29 | $w->cb (sub { $_[0]->recv }); |
21 | |
30 | |
22 | INTRODUCTION/TUTORIAL |
31 | INTRODUCTION/TUTORIAL |
23 | This manpage is mainly a reference manual. If you are interested in a |
32 | This manpage is mainly a reference manual. If you are interested in a |
24 | tutorial or some gentle introduction, have a look at the AnyEvent::Intro |
33 | tutorial or some gentle introduction, have a look at the AnyEvent::Intro |
25 | manpage. |
34 | manpage. |
… | |
… | |
30 | |
39 | |
31 | Executive Summary: AnyEvent is *compatible*, AnyEvent is *free of |
40 | Executive Summary: AnyEvent is *compatible*, AnyEvent is *free of |
32 | policy* and AnyEvent is *small and efficient*. |
41 | policy* and AnyEvent is *small and efficient*. |
33 | |
42 | |
34 | First and foremost, *AnyEvent is not an event model* itself, it only |
43 | First and foremost, *AnyEvent is not an event model* itself, it only |
35 | interfaces to whatever event model the main program happens to use in a |
44 | interfaces to whatever event model the main program happens to use, in a |
36 | pragmatic way. For event models and certain classes of immortals alike, |
45 | pragmatic way. For event models and certain classes of immortals alike, |
37 | the statement "there can only be one" is a bitter reality: In general, |
46 | the statement "there can only be one" is a bitter reality: In general, |
38 | only one event loop can be active at the same time in a process. |
47 | only one event loop can be active at the same time in a process. |
39 | AnyEvent helps hiding the differences between those event loops. |
48 | AnyEvent cannot change this, but it can hide the differences between |
|
|
49 | those event loops. |
40 | |
50 | |
41 | The goal of AnyEvent is to offer module authors the ability to do event |
51 | The goal of AnyEvent is to offer module authors the ability to do event |
42 | programming (waiting for I/O or timer events) without subscribing to a |
52 | programming (waiting for I/O or timer events) without subscribing to a |
43 | religion, a way of living, and most importantly: without forcing your |
53 | religion, a way of living, and most importantly: without forcing your |
44 | module users into the same thing by forcing them to use the same event |
54 | module users into the same thing by forcing them to use the same event |
45 | model you use. |
55 | model you use. |
46 | |
56 | |
47 | For modules like POE or IO::Async (which is a total misnomer as it is |
57 | For modules like POE or IO::Async (which is a total misnomer as it is |
48 | actually doing all I/O *synchronously*...), using them in your module is |
58 | actually doing all I/O *synchronously*...), using them in your module is |
49 | like joining a cult: After you joined, you are dependent on them and you |
59 | like joining a cult: After you joined, you are dependent on them and you |
50 | cannot use anything else, as it is simply incompatible to everything |
60 | cannot use anything else, as they are simply incompatible to everything |
51 | that isn't itself. What's worse, all the potential users of your module |
61 | that isn't them. What's worse, all the potential users of your module |
52 | are *also* forced to use the same event loop you use. |
62 | are *also* forced to use the same event loop you use. |
53 | |
63 | |
54 | AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works |
64 | AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works |
55 | fine. AnyEvent + Tk works fine etc. etc. but none of these work together |
65 | fine. AnyEvent + Tk works fine etc. etc. but none of these work together |
56 | with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if your |
66 | with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if your |
57 | module uses one of those, every user of your module has to use it, too. |
67 | module uses one of those, every user of your module has to use it, too. |
58 | But if your module uses AnyEvent, it works transparently with all event |
68 | But if your module uses AnyEvent, it works transparently with all event |
59 | models it supports (including stuff like POE and IO::Async, as long as |
69 | models it supports (including stuff like IO::Async, as long as those use |
60 | those use one of the supported event loops. It is trivial to add new |
70 | one of the supported event loops. It is trivial to add new event loops |
61 | event loops to AnyEvent, too, so it is future-proof). |
71 | to AnyEvent, too, so it is future-proof). |
62 | |
72 | |
63 | In addition to being free of having to use *the one and only true event |
73 | In addition to being free of having to use *the one and only true event |
64 | model*, AnyEvent also is free of bloat and policy: with POE or similar |
74 | model*, AnyEvent also is free of bloat and policy: with POE or similar |
65 | modules, you get an enormous amount of code and strict rules you have to |
75 | modules, you get an enormous amount of code and strict rules you have to |
66 | follow. AnyEvent, on the other hand, is lean and up to the point, by |
76 | follow. AnyEvent, on the other hand, is lean and up to the point, by |
… | |
… | |
146 | |
156 | |
147 | I/O WATCHERS |
157 | I/O WATCHERS |
148 | You can create an I/O watcher by calling the "AnyEvent->io" method with |
158 | You can create an I/O watcher by calling the "AnyEvent->io" method with |
149 | the following mandatory key-value pairs as arguments: |
159 | the following mandatory key-value pairs as arguments: |
150 | |
160 | |
151 | "fh" the Perl *file handle* (*not* file descriptor) to watch for events. |
161 | "fh" the Perl *file handle* (*not* file descriptor) to watch for events |
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|
162 | (AnyEvent might or might not keep a reference to this file handle). |
152 | "poll" must be a string that is either "r" or "w", which creates a |
163 | "poll" must be a string that is either "r" or "w", which creates a |
153 | watcher waiting for "r"eadable or "w"ritable events, respectively. "cb" |
164 | watcher waiting for "r"eadable or "w"ritable events, respectively. "cb" |
154 | is the callback to invoke each time the file handle becomes ready. |
165 | is the callback to invoke each time the file handle becomes ready. |
155 | |
166 | |
156 | Although the callback might get passed parameters, their value and |
167 | Although the callback might get passed parameters, their value and |
… | |
… | |
163 | |
174 | |
164 | Some event loops issue spurious readyness notifications, so you should |
175 | Some event loops issue spurious readyness notifications, so you should |
165 | always use non-blocking calls when reading/writing from/to your file |
176 | always use non-blocking calls when reading/writing from/to your file |
166 | handles. |
177 | handles. |
167 | |
178 | |
168 | Example: |
|
|
169 | |
|
|
170 | # wait for readability of STDIN, then read a line and disable the watcher |
179 | Example: wait for readability of STDIN, then read a line and disable the |
|
|
180 | watcher. |
|
|
181 | |
171 | my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
182 | my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { |
172 | chomp (my $input = <STDIN>); |
183 | chomp (my $input = <STDIN>); |
173 | warn "read: $input\n"; |
184 | warn "read: $input\n"; |
174 | undef $w; |
185 | undef $w; |
175 | }); |
186 | }); |
… | |
… | |
184 | |
195 | |
185 | Although the callback might get passed parameters, their value and |
196 | Although the callback might get passed parameters, their value and |
186 | presence is undefined and you cannot rely on them. Portable AnyEvent |
197 | presence is undefined and you cannot rely on them. Portable AnyEvent |
187 | callbacks cannot use arguments passed to time watcher callbacks. |
198 | callbacks cannot use arguments passed to time watcher callbacks. |
188 | |
199 | |
189 | The timer callback will be invoked at most once: if you want a repeating |
200 | The callback will normally be invoked once only. If you specify another |
190 | timer you have to create a new watcher (this is a limitation by both Tk |
201 | parameter, "interval", as a strictly positive number (> 0), then the |
191 | and Glib). |
202 | callback will be invoked regularly at that interval (in fractional |
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|
203 | seconds) after the first invocation. If "interval" is specified with a |
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|
204 | false value, then it is treated as if it were missing. |
192 | |
205 | |
193 | Example: |
206 | The callback will be rescheduled before invoking the callback, but no |
|
|
207 | attempt is done to avoid timer drift in most backends, so the interval |
|
|
208 | is only approximate. |
194 | |
209 | |
195 | # fire an event after 7.7 seconds |
210 | Example: fire an event after 7.7 seconds. |
|
|
211 | |
196 | my $w = AnyEvent->timer (after => 7.7, cb => sub { |
212 | my $w = AnyEvent->timer (after => 7.7, cb => sub { |
197 | warn "timeout\n"; |
213 | warn "timeout\n"; |
198 | }); |
214 | }); |
199 | |
215 | |
200 | # to cancel the timer: |
216 | # to cancel the timer: |
201 | undef $w; |
217 | undef $w; |
202 | |
218 | |
203 | Example 2: |
|
|
204 | |
|
|
205 | # fire an event after 0.5 seconds, then roughly every second |
219 | Example 2: fire an event after 0.5 seconds, then roughly every second. |
206 | my $w; |
|
|
207 | |
220 | |
208 | my $cb = sub { |
|
|
209 | # cancel the old timer while creating a new one |
|
|
210 | $w = AnyEvent->timer (after => 1, cb => $cb); |
221 | my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub { |
|
|
222 | warn "timeout\n"; |
211 | }; |
223 | }; |
212 | |
|
|
213 | # start the "loop" by creating the first watcher |
|
|
214 | $w = AnyEvent->timer (after => 0.5, cb => $cb); |
|
|
215 | |
224 | |
216 | TIMING ISSUES |
225 | TIMING ISSUES |
217 | There are two ways to handle timers: based on real time (relative, "fire |
226 | There are two ways to handle timers: based on real time (relative, "fire |
218 | in 10 seconds") and based on wallclock time (absolute, "fire at 12 |
227 | in 10 seconds") and based on wallclock time (absolute, "fire at 12 |
219 | o'clock"). |
228 | o'clock"). |
… | |
… | |
295 | the difference between "AnyEvent->time" and "AnyEvent->now" into |
304 | the difference between "AnyEvent->time" and "AnyEvent->now" into |
296 | account. |
305 | account. |
297 | |
306 | |
298 | SIGNAL WATCHERS |
307 | SIGNAL WATCHERS |
299 | You can watch for signals using a signal watcher, "signal" is the signal |
308 | You can watch for signals using a signal watcher, "signal" is the signal |
300 | *name* without any "SIG" prefix, "cb" is the Perl callback to be invoked |
309 | *name* in uppercase and without any "SIG" prefix, "cb" is the Perl |
301 | whenever a signal occurs. |
310 | callback to be invoked whenever a signal occurs. |
302 | |
311 | |
303 | Although the callback might get passed parameters, their value and |
312 | Although the callback might get passed parameters, their value and |
304 | presence is undefined and you cannot rely on them. Portable AnyEvent |
313 | presence is undefined and you cannot rely on them. Portable AnyEvent |
305 | callbacks cannot use arguments passed to signal watcher callbacks. |
314 | callbacks cannot use arguments passed to signal watcher callbacks. |
306 | |
315 | |
… | |
… | |
371 | The instrument to do that is called a "condition variable", so called |
380 | The instrument to do that is called a "condition variable", so called |
372 | because they represent a condition that must become true. |
381 | because they represent a condition that must become true. |
373 | |
382 | |
374 | Condition variables can be created by calling the "AnyEvent->condvar" |
383 | Condition variables can be created by calling the "AnyEvent->condvar" |
375 | method, usually without arguments. The only argument pair allowed is |
384 | method, usually without arguments. The only argument pair allowed is |
|
|
385 | |
376 | "cb", which specifies a callback to be called when the condition |
386 | "cb", which specifies a callback to be called when the condition |
377 | variable becomes true. |
387 | variable becomes true, with the condition variable as the first argument |
|
|
388 | (but not the results). |
378 | |
389 | |
379 | After creation, the condition variable is "false" until it becomes |
390 | After creation, the condition variable is "false" until it becomes |
380 | "true" by calling the "send" method (or calling the condition variable |
391 | "true" by calling the "send" method (or calling the condition variable |
381 | as if it were a callback, read about the caveats in the description for |
392 | as if it were a callback, read about the caveats in the description for |
382 | the "->send" method). |
393 | the "->send" method). |
… | |
… | |
438 | |
449 | |
439 | my $done = AnyEvent->condvar; |
450 | my $done = AnyEvent->condvar; |
440 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
451 | my $delay = AnyEvent->timer (after => 5, cb => $done); |
441 | $done->recv; |
452 | $done->recv; |
442 | |
453 | |
|
|
454 | Example: Imagine an API that returns a condvar and doesn't support |
|
|
455 | callbacks. This is how you make a synchronous call, for example from the |
|
|
456 | main program: |
|
|
457 | |
|
|
458 | use AnyEvent::CouchDB; |
|
|
459 | |
|
|
460 | ... |
|
|
461 | |
|
|
462 | my @info = $couchdb->info->recv; |
|
|
463 | |
|
|
464 | And this is how you would just ste a callback to be called whenever the |
|
|
465 | results are available: |
|
|
466 | |
|
|
467 | $couchdb->info->cb (sub { |
|
|
468 | my @info = $_[0]->recv; |
|
|
469 | }); |
|
|
470 | |
443 | METHODS FOR PRODUCERS |
471 | METHODS FOR PRODUCERS |
444 | These methods should only be used by the producing side, i.e. the |
472 | These methods should only be used by the producing side, i.e. the |
445 | code/module that eventually sends the signal. Note that it is also the |
473 | code/module that eventually sends the signal. Note that it is also the |
446 | producer side which creates the condvar in most cases, but it isn't |
474 | producer side which creates the condvar in most cases, but it isn't |
447 | uncommon for the consumer to create it as well. |
475 | uncommon for the consumer to create it as well. |
… | |
… | |
567 | |
595 | |
568 | $bool = $cv->ready |
596 | $bool = $cv->ready |
569 | Returns true when the condition is "true", i.e. whether "send" or |
597 | Returns true when the condition is "true", i.e. whether "send" or |
570 | "croak" have been called. |
598 | "croak" have been called. |
571 | |
599 | |
572 | $cb = $cv->cb ([new callback]) |
600 | $cb = $cv->cb ($cb->($cv)) |
573 | This is a mutator function that returns the callback set and |
601 | This is a mutator function that returns the callback set and |
574 | optionally replaces it before doing so. |
602 | optionally replaces it before doing so. |
575 | |
603 | |
576 | The callback will be called when the condition becomes "true", i.e. |
604 | The callback will be called when the condition becomes "true", i.e. |
577 | when "send" or "croak" are called, with the only argument being the |
605 | when "send" or "croak" are called, with the only argument being the |
… | |
… | |
698 | AnyEvent::Util |
726 | AnyEvent::Util |
699 | Contains various utility functions that replace often-used but |
727 | Contains various utility functions that replace often-used but |
700 | blocking functions such as "inet_aton" by event-/callback-based |
728 | blocking functions such as "inet_aton" by event-/callback-based |
701 | versions. |
729 | versions. |
702 | |
730 | |
703 | AnyEvent::Handle |
|
|
704 | Provide read and write buffers and manages watchers for reads and |
|
|
705 | writes. |
|
|
706 | |
|
|
707 | AnyEvent::Socket |
731 | AnyEvent::Socket |
708 | Provides various utility functions for (internet protocol) sockets, |
732 | Provides various utility functions for (internet protocol) sockets, |
709 | addresses and name resolution. Also functions to create non-blocking |
733 | addresses and name resolution. Also functions to create non-blocking |
710 | tcp connections or tcp servers, with IPv6 and SRV record support and |
734 | tcp connections or tcp servers, with IPv6 and SRV record support and |
711 | more. |
735 | more. |
712 | |
736 | |
|
|
737 | AnyEvent::Handle |
|
|
738 | Provide read and write buffers, manages watchers for reads and |
|
|
739 | writes, supports raw and formatted I/O, I/O queued and fully |
|
|
740 | transparent and non-blocking SSL/TLS. |
|
|
741 | |
713 | AnyEvent::DNS |
742 | AnyEvent::DNS |
714 | Provides rich asynchronous DNS resolver capabilities. |
743 | Provides rich asynchronous DNS resolver capabilities. |
715 | |
744 | |
716 | AnyEvent::HTTP |
745 | AnyEvent::HTTP |
717 | A simple-to-use HTTP library that is capable of making a lot of |
746 | A simple-to-use HTTP library that is capable of making a lot of |
… | |
… | |
721 | Provides a simple web application server framework. |
750 | Provides a simple web application server framework. |
722 | |
751 | |
723 | AnyEvent::FastPing |
752 | AnyEvent::FastPing |
724 | The fastest ping in the west. |
753 | The fastest ping in the west. |
725 | |
754 | |
|
|
755 | AnyEvent::DBI |
|
|
756 | Executes DBI requests asynchronously in a proxy process. |
|
|
757 | |
|
|
758 | AnyEvent::AIO |
|
|
759 | Truly asynchronous I/O, should be in the toolbox of every event |
|
|
760 | programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent |
|
|
761 | together. |
|
|
762 | |
|
|
763 | AnyEvent::BDB |
|
|
764 | Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently |
|
|
765 | fuses BDB and AnyEvent together. |
|
|
766 | |
|
|
767 | AnyEvent::GPSD |
|
|
768 | A non-blocking interface to gpsd, a daemon delivering GPS |
|
|
769 | information. |
|
|
770 | |
|
|
771 | AnyEvent::IGS |
|
|
772 | A non-blocking interface to the Internet Go Server protocol (used by |
|
|
773 | App::IGS). |
|
|
774 | |
726 | Net::IRC3 |
775 | Net::IRC3 |
727 | AnyEvent based IRC client module family. |
776 | AnyEvent based IRC client module family. |
728 | |
777 | |
729 | Net::XMPP2 |
778 | Net::XMPP2 |
730 | AnyEvent based XMPP (Jabber protocol) module family. |
779 | AnyEvent based XMPP (Jabber protocol) module family. |
… | |
… | |
736 | Event::ExecFlow |
785 | Event::ExecFlow |
737 | High level API for event-based execution flow control. |
786 | High level API for event-based execution flow control. |
738 | |
787 | |
739 | Coro |
788 | Coro |
740 | Has special support for AnyEvent via Coro::AnyEvent. |
789 | Has special support for AnyEvent via Coro::AnyEvent. |
741 | |
|
|
742 | AnyEvent::AIO, IO::AIO |
|
|
743 | Truly asynchronous I/O, should be in the toolbox of every event |
|
|
744 | programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent |
|
|
745 | together. |
|
|
746 | |
|
|
747 | AnyEvent::BDB, BDB |
|
|
748 | Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently |
|
|
749 | fuses IO::AIO and AnyEvent together. |
|
|
750 | |
790 | |
751 | IO::Lambda |
791 | IO::Lambda |
752 | The lambda approach to I/O - don't ask, look there. Can use |
792 | The lambda approach to I/O - don't ask, look there. Can use |
753 | AnyEvent. |
793 | AnyEvent. |
754 | |
794 | |
… | |
… | |
807 | conditions, such as not being able to load the event model specified |
847 | conditions, such as not being able to load the event model specified |
808 | by "PERL_ANYEVENT_MODEL". |
848 | by "PERL_ANYEVENT_MODEL". |
809 | |
849 | |
810 | When set to 2 or higher, cause AnyEvent to report to STDERR which |
850 | When set to 2 or higher, cause AnyEvent to report to STDERR which |
811 | event model it chooses. |
851 | event model it chooses. |
|
|
852 | |
|
|
853 | "PERL_ANYEVENT_STRICT" |
|
|
854 | AnyEvent does not do much argument checking by default, as thorough |
|
|
855 | argument checking is very costly. Setting this variable to a true |
|
|
856 | value will cause AnyEvent to load "AnyEvent::Strict" and then to |
|
|
857 | thoroughly check the arguments passed to most method calls. If it |
|
|
858 | finds any problems it will croak. |
|
|
859 | |
|
|
860 | In other words, enables "strict" mode. |
|
|
861 | |
|
|
862 | Unlike "use strict" it is definitely recommended ot keep it off in |
|
|
863 | production. |
812 | |
864 | |
813 | "PERL_ANYEVENT_MODEL" |
865 | "PERL_ANYEVENT_MODEL" |
814 | This can be used to specify the event model to be used by AnyEvent, |
866 | This can be used to specify the event model to be used by AnyEvent, |
815 | before auto detection and -probing kicks in. It must be a string |
867 | before auto detection and -probing kicks in. It must be a string |
816 | consisting entirely of ASCII letters. The string "AnyEvent::Impl::" |
868 | consisting entirely of ASCII letters. The string "AnyEvent::Impl::" |
… | |
… | |
1278 | |
1330 | |
1279 | use AnyEvent; |
1331 | use AnyEvent; |
1280 | |
1332 | |
1281 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
1333 | Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can |
1282 | be used to probe what backend is used and gain other information (which |
1334 | be used to probe what backend is used and gain other information (which |
1283 | is probably even less useful to an attacker than PERL_ANYEVENT_MODEL). |
1335 | is probably even less useful to an attacker than PERL_ANYEVENT_MODEL), |
|
|
1336 | and $ENV{PERL_ANYEGENT_STRICT}. |
1284 | |
1337 | |
1285 | BUGS |
1338 | BUGS |
1286 | Perl 5.8 has numerous memleaks that sometimes hit this module and are |
1339 | Perl 5.8 has numerous memleaks that sometimes hit this module and are |
1287 | hard to work around. If you suffer from memleaks, first upgrade to Perl |
1340 | hard to work around. If you suffer from memleaks, first upgrade to Perl |
1288 | 5.10 and check wether the leaks still show up. (Perl 5.10.0 has other |
1341 | 5.10 and check wether the leaks still show up. (Perl 5.10.0 has other |