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Revision 1.137 by root, Mon May 26 03:27:52 2008 UTC vs.
Revision 1.158 by root, Fri Jun 6 15:35:30 2008 UTC

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
… …
17 }); 17 });
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
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.
22 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?
… …
48isn't itself. What's worse, all the potential users of your module are 54isn't itself. What's worse, all the potential users of your module are
49I<also> forced to use the same event loop you use. 55I<also> forced to use the same event loop you use.
50 56
51AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works 57AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
52fine. AnyEvent + Tk works fine etc. etc. but none of these work together 58fine. 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 59with 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, 60your 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 61too. But if your module uses AnyEvent, it works transparently with all
56event models it supports (including stuff like POE and IO::Async, as long 62event models it supports (including stuff like POE and IO::Async, as long
57as those use one of the supported event loops. It is trivial to add new 63as those use one of the supported event loops. It is trivial to add new
58event loops to AnyEvent, too, so it is future-proof). 64event loops to AnyEvent, too, so it is future-proof).
… …
62modules, you get an enormous amount of code and strict rules you have to 68modules, 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 69follow. 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 70offering the functionality that is necessary, in as thin as a wrapper as
65technically possible. 71technically possible.
66 72
73Of course, AnyEvent comes with a big (and fully optional!) toolbox
74of useful functionality, such as an asynchronous DNS resolver, 100%
75non-blocking connects (even with TLS/SSL, IPv6 and on broken platforms
76such as Windows) and lots of real-world knowledge and workarounds for
77platform bugs and differences.
78
67Of course, if you want lots of policy (this can arguably be somewhat 79Now, 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 80useful) and you want to force your users to use the one and only event
69model, you should I<not> use this module. 81model, you should I<not> use this module.
70 82
71=head1 DESCRIPTION 83=head1 DESCRIPTION
72 84
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102starts using it, all bets are off. Maybe you should tell their authors to 114starts using it, all bets are off. Maybe you should tell their authors to
103use AnyEvent so their modules work together with others seamlessly... 115use AnyEvent so their modules work together with others seamlessly...
104 116
105The pure-perl implementation of AnyEvent is called 117The pure-perl implementation of AnyEvent is called
106C<AnyEvent::Impl::Perl>. Like other event modules you can load it 118C<AnyEvent::Impl::Perl>. Like other event modules you can load it
107explicitly. 119explicitly and enjoy the high availability of that event loop :)
108 120
109=head1 WATCHERS 121=head1 WATCHERS
110 122
111AnyEvent has the central concept of a I<watcher>, which is an object that 123AnyEvent 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 124stores relevant data for each kind of event you are waiting for, such as
… …
126Many watchers either are used with "recursion" (repeating timers for 138Many watchers either are used with "recursion" (repeating timers for
127example), or need to refer to their watcher object in other ways. 139example), or need to refer to their watcher object in other ways.
128 140
129An any way to achieve that is this pattern: 141An any way to achieve that is this pattern:
130 142
131 my $w; $w = AnyEvent->type (arg => value ..., cb => sub { 143 my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
132 # you can use $w here, for example to undef it 144 # you can use $w here, for example to undef it
133 undef $w; 145 undef $w;
134 }); 146 });
135 147
136Note that C<my $w; $w => combination. This is necessary because in Perl, 148Note that C<my $w; $w => combination. This is necessary because in Perl,
137my variables are only visible after the statement in which they are 149my variables are only visible after the statement in which they are
138declared. 150declared.
139 151
… …
227timers. 239timers.
228 240
229AnyEvent always prefers relative timers, if available, matching the 241AnyEvent always prefers relative timers, if available, matching the
230AnyEvent API. 242AnyEvent API.
231 243
244AnyEvent has two additional methods that return the "current time":
245
246=over 4
247
248=item AnyEvent->time
249
250This returns the "current wallclock time" as a fractional number of
251seconds since the Epoch (the same thing as C<time> or C<Time::HiRes::time>
252return, and the result is guaranteed to be compatible with those).
253
254It progresses independently of any event loop processing, i.e. each call
255will check the system clock, which usually gets updated frequently.
256
257=item AnyEvent->now
258
259This also returns the "current wallclock time", but unlike C<time>, above,
260this value might change only once per event loop iteration, depending on
261the event loop (most return the same time as C<time>, above). This is the
262time that AnyEvent's timers get scheduled against.
263
264I<In almost all cases (in all cases if you don't care), this is the
265function to call when you want to know the current time.>
266
267This function is also often faster then C<< AnyEvent->time >>, and
268thus the preferred method if you want some timestamp (for example,
269L<AnyEvent::Handle> uses this to update it's activity timeouts).
270
271The rest of this section is only of relevance if you try to be very exact
272with your timing, you can skip it without bad conscience.
273
274For a practical example of when these times differ, consider L<Event::Lib>
275and L<EV> and the following set-up:
276
277The event loop is running and has just invoked one of your callback at
278time=500 (assume no other callbacks delay processing). In your callback,
279you wait a second by executing C<sleep 1> (blocking the process for a
280second) and then (at time=501) you create a relative timer that fires
281after three seconds.
282
283With L<Event::Lib>, C<< AnyEvent->time >> and C<< AnyEvent->now >> will
284both return C<501>, because that is the current time, and the timer will
285be scheduled to fire at time=504 (C<501> + C<3>).
286
287With L<EV>, C<< AnyEvent->time >> returns C<501> (as that is the current
288time), but C<< AnyEvent->now >> returns C<500>, as that is the time the
289last event processing phase started. With L<EV>, your timer gets scheduled
290to run at time=503 (C<500> + C<3>).
291
292In one sense, L<Event::Lib> is more exact, as it uses the current time
293regardless of any delays introduced by event processing. However, most
294callbacks do not expect large delays in processing, so this causes a
295higher drift (and a lot more system calls to get the current time).
296
297In another sense, L<EV> is more exact, as your timer will be scheduled at
298the same time, regardless of how long event processing actually took.
299
300In either case, if you care (and in most cases, you don't), then you
301can get whatever behaviour you want with any event loop, by taking the
302difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
303account.
304
305=back
306
232=head2 SIGNAL WATCHERS 307=head2 SIGNAL WATCHERS
233 308
234You can watch for signals using a signal watcher, C<signal> is the signal 309You 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 310I<name> without any C<SIG> prefix, C<cb> is the Perl callback to
236be invoked whenever a signal occurs. 311be invoked whenever a signal occurs.
… …
277AnyEvent program, you I<have> to create at least one watcher before you 352AnyEvent program, you I<have> to create at least one watcher before you
278C<fork> the child (alternatively, you can call C<AnyEvent::detect>). 353C<fork> the child (alternatively, you can call C<AnyEvent::detect>).
279 354
280Example: fork a process and wait for it 355Example: fork a process and wait for it
281 356
282 my $done = AnyEvent->condvar; 357 my $done = AnyEvent->condvar;
283 358
284 my $pid = fork or exit 5; 359 my $pid = fork or exit 5;
285 360
286 my $w = AnyEvent->child ( 361 my $w = AnyEvent->child (
287 pid => $pid, 362 pid => $pid,
288 cb => sub { 363 cb => sub {
289 my ($pid, $status) = @_; 364 my ($pid, $status) = @_;
290 warn "pid $pid exited with status $status"; 365 warn "pid $pid exited with status $status";
291 $done->send; 366 $done->send;
292 }, 367 },
293 ); 368 );
294 369
295 # do something else, then wait for process exit 370 # do something else, then wait for process exit
296 $done->recv; 371 $done->recv;
297 372
298=head2 CONDITION VARIABLES 373=head2 CONDITION VARIABLES
299 374
300If you are familiar with some event loops you will know that all of them 375If 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 376require you to run some blocking "loop", "run" or similar function that
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522 597
523This is a mutator function that returns the callback set and optionally 598This is a mutator function that returns the callback set and optionally
524replaces it before doing so. 599replaces it before doing so.
525 600
526The callback will be called when the condition becomes "true", i.e. when 601The callback will be called when the condition becomes "true", i.e. when
527C<send> or C<croak> are called. Calling C<recv> inside the callback 602C<send> or C<croak> are called, with the only argument being the condition
528or at any later time is guaranteed not to block. 603variable itself. Calling C<recv> inside the callback or at any later time
604is guaranteed not to block.
529 605
530=back 606=back
531 607
532=head1 GLOBAL VARIABLES AND FUNCTIONS 608=head1 GLOBAL VARIABLES AND FUNCTIONS
533 609
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676 752
677=item L<AnyEvent::DNS> 753=item L<AnyEvent::DNS>
678 754
679Provides rich asynchronous DNS resolver capabilities. 755Provides rich asynchronous DNS resolver capabilities.
680 756
757=item L<AnyEvent::HTTP>
758
759A simple-to-use HTTP library that is capable of making a lot of concurrent
760HTTP requests.
761
681=item L<AnyEvent::HTTPD> 762=item L<AnyEvent::HTTPD>
682 763
683Provides a simple web application server framework. 764Provides a simple web application server framework.
684 765
685=item L<AnyEvent::FastPing> 766=item L<AnyEvent::FastPing>
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731no warnings; 812no warnings;
732use strict; 813use strict;
733 814
734use Carp; 815use Carp;
735 816
736our $VERSION = '4.03'; 817our $VERSION = 4.151;
737our $MODEL; 818our $MODEL;
738 819
739our $AUTOLOAD; 820our $AUTOLOAD;
740our @ISA; 821our @ISA;
741 822
742our @REGISTRY; 823our @REGISTRY;
824
825our $WIN32;
826
827BEGIN {
828 my $win32 = ! ! ($^O =~ /mswin32/i);
829 eval "sub WIN32(){ $win32 }";
830}
743 831
744our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; 832our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;
745 833
746our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred 834our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
747 835
… …
766 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza 854 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
767 [Wx:: => AnyEvent::Impl::POE::], 855 [Wx:: => AnyEvent::Impl::POE::],
768 [Prima:: => AnyEvent::Impl::POE::], 856 [Prima:: => AnyEvent::Impl::POE::],
769); 857);
770 858
771our %method = map +($_ => 1), qw(io timer signal child condvar one_event DESTROY); 859our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY);
772 860
773our @post_detect; 861our @post_detect;
774 862
775sub post_detect(&) { 863sub post_detect(&) {
776 my ($cb) = @_; 864 my ($cb) = @_;
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860 $class->$func (@_); 948 $class->$func (@_);
861} 949}
862 950
863package AnyEvent::Base; 951package AnyEvent::Base;
864 952
953# default implementation for now and time
954
955use Time::HiRes ();
956
957sub time { Time::HiRes::time }
958sub now { Time::HiRes::time }
959
865# default implementation for ->condvar 960# default implementation for ->condvar
866 961
867sub condvar { 962sub condvar {
868 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar:: 963 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::
869} 964}
… …
1083This functionality might change in future versions. 1178This functionality might change in future versions.
1084 1179
1085For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you 1180For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
1086could start your program like this: 1181could start your program like this:
1087 1182
1088 PERL_ANYEVENT_MODEL=Perl perl ... 1183 PERL_ANYEVENT_MODEL=Perl perl ...
1089 1184
1090=item C<PERL_ANYEVENT_PROTOCOLS> 1185=item C<PERL_ANYEVENT_PROTOCOLS>
1091 1186
1092Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences 1187Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
1093for IPv4 or IPv6. The default is unspecified (and might change, or be the result 1188for IPv4 or IPv6. The default is unspecified (and might change, or be the result
… …
1115some (broken) firewalls drop such DNS packets, which is why it is off by 1210some (broken) firewalls drop such DNS packets, which is why it is off by
1116default. 1211default.
1117 1212
1118Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce 1213Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1119EDNS0 in its DNS requests. 1214EDNS0 in its DNS requests.
1215
1216=item C<PERL_ANYEVENT_MAX_FORKS>
1217
1218The maximum number of child processes that C<AnyEvent::Util::fork_call>
1219will create in parallel.
1120 1220
1121=back 1221=back
1122 1222
1123=head1 EXAMPLE PROGRAM 1223=head1 EXAMPLE PROGRAM
1124 1224
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1563specified in the variable. 1663specified in the variable.
1564 1664
1565You can make AnyEvent completely ignore this variable by deleting it 1665You can make AnyEvent completely ignore this variable by deleting it
1566before the first watcher gets created, e.g. with a C<BEGIN> block: 1666before the first watcher gets created, e.g. with a C<BEGIN> block:
1567 1667
1568 BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } 1668 BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }
1569 1669
1570 use AnyEvent; 1670 use AnyEvent;
1571 1671
1572Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can 1672Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1573be used to probe what backend is used and gain other information (which is 1673be used to probe what backend is used and gain other information (which is
1574probably even less useful to an attacker than PERL_ANYEVENT_MODEL). 1674probably even less useful to an attacker than PERL_ANYEVENT_MODEL).
1675
1676
1677=head1 BUGS
1678
1679Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
1680to work around. If you suffer from memleaks, first upgrade to Perl 5.10
1681and check wether the leaks still show up. (Perl 5.10.0 has other annoying
1682mamleaks, such as leaking on C<map> and C<grep> but it is usually not as
1683pronounced).
1575 1684
1576 1685
1577=head1 SEE ALSO 1686=head1 SEE ALSO
1578 1687
1579Utility functions: L<AnyEvent::Util>. 1688Utility functions: L<AnyEvent::Util>.
… …
1596Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. 1705Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.
1597 1706
1598 1707
1599=head1 AUTHOR 1708=head1 AUTHOR
1600 1709
1601 Marc Lehmann <schmorp@schmorp.de> 1710 Marc Lehmann <schmorp@schmorp.de>
1602 http://home.schmorp.de/ 1711 http://home.schmorp.de/
1603 1712
1604=cut 1713=cut
1605 1714
16061 17151
1607 1716

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