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Revision 1.145 by root, Thu May 29 03:45:37 2008 UTC vs.
Revision 1.164 by root, Tue Jul 8 19:50:25 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?
… …
132Many watchers either are used with "recursion" (repeating timers for 138Many watchers either are used with "recursion" (repeating timers for
133example), or need to refer to their watcher object in other ways. 139example), or need to refer to their watcher object in other ways.
134 140
135An any way to achieve that is this pattern: 141An any way to achieve that is this pattern:
136 142
137 my $w; $w = AnyEvent->type (arg => value ..., cb => sub { 143 my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
138 # you can use $w here, for example to undef it 144 # you can use $w here, for example to undef it
139 undef $w; 145 undef $w;
140 }); 146 });
141 147
142Note 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,
143my variables are only visible after the statement in which they are 149my variables are only visible after the statement in which they are
144declared. 150declared.
145 151
… …
164 170
165Some event loops issue spurious readyness notifications, so you should 171Some event loops issue spurious readyness notifications, so you should
166always use non-blocking calls when reading/writing from/to your file 172always use non-blocking calls when reading/writing from/to your file
167handles. 173handles.
168 174
169Example:
170
171 # wait for readability of STDIN, then read a line and disable the watcher 175Example: wait for readability of STDIN, then read a line and disable the
176watcher.
177
172 my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { 178 my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {
173 chomp (my $input = <STDIN>); 179 chomp (my $input = <STDIN>);
174 warn "read: $input\n"; 180 warn "read: $input\n";
175 undef $w; 181 undef $w;
176 }); 182 });
… …
186 192
187Although the callback might get passed parameters, their value and 193Although the callback might get passed parameters, their value and
188presence is undefined and you cannot rely on them. Portable AnyEvent 194presence is undefined and you cannot rely on them. Portable AnyEvent
189callbacks cannot use arguments passed to time watcher callbacks. 195callbacks cannot use arguments passed to time watcher callbacks.
190 196
191The timer callback will be invoked at most once: if you want a repeating 197The callback will normally be invoked once only. If you specify another
192timer you have to create a new watcher (this is a limitation by both Tk 198parameter, C<interval>, as a positive number, then the callback will be
193and Glib). 199invoked regularly at that interval (in fractional seconds) after the first
200invocation.
194 201
195Example: 202The callback will be rescheduled before invoking the callback, but no
203attempt is done to avoid timer drift in most backends, so the interval is
204only approximate.
196 205
197 # fire an event after 7.7 seconds 206Example: fire an event after 7.7 seconds.
207
198 my $w = AnyEvent->timer (after => 7.7, cb => sub { 208 my $w = AnyEvent->timer (after => 7.7, cb => sub {
199 warn "timeout\n"; 209 warn "timeout\n";
200 }); 210 });
201 211
202 # to cancel the timer: 212 # to cancel the timer:
203 undef $w; 213 undef $w;
204 214
205Example 2:
206
207 # fire an event after 0.5 seconds, then roughly every second 215Example 2: fire an event after 0.5 seconds, then roughly every second.
208 my $w;
209 216
210 my $cb = sub {
211 # cancel the old timer while creating a new one
212 $w = AnyEvent->timer (after => 1, cb => $cb); 217 my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub {
218 warn "timeout\n";
213 }; 219 };
214
215 # start the "loop" by creating the first watcher
216 $w = AnyEvent->timer (after => 0.5, cb => $cb);
217 220
218=head3 TIMING ISSUES 221=head3 TIMING ISSUES
219 222
220There are two ways to handle timers: based on real time (relative, "fire 223There are two ways to handle timers: based on real time (relative, "fire
221in 10 seconds") and based on wallclock time (absolute, "fire at 12 224in 10 seconds") and based on wallclock time (absolute, "fire at 12
… …
346AnyEvent program, you I<have> to create at least one watcher before you 349AnyEvent program, you I<have> to create at least one watcher before you
347C<fork> the child (alternatively, you can call C<AnyEvent::detect>). 350C<fork> the child (alternatively, you can call C<AnyEvent::detect>).
348 351
349Example: fork a process and wait for it 352Example: fork a process and wait for it
350 353
351 my $done = AnyEvent->condvar; 354 my $done = AnyEvent->condvar;
352 355
353 my $pid = fork or exit 5; 356 my $pid = fork or exit 5;
354 357
355 my $w = AnyEvent->child ( 358 my $w = AnyEvent->child (
356 pid => $pid, 359 pid => $pid,
357 cb => sub { 360 cb => sub {
358 my ($pid, $status) = @_; 361 my ($pid, $status) = @_;
359 warn "pid $pid exited with status $status"; 362 warn "pid $pid exited with status $status";
360 $done->send; 363 $done->send;
361 }, 364 },
362 ); 365 );
363 366
364 # do something else, then wait for process exit 367 # do something else, then wait for process exit
365 $done->recv; 368 $done->recv;
366 369
367=head2 CONDITION VARIABLES 370=head2 CONDITION VARIABLES
368 371
369If you are familiar with some event loops you will know that all of them 372If you are familiar with some event loops you will know that all of them
370require you to run some blocking "loop", "run" or similar function that 373require you to run some blocking "loop", "run" or similar function that
… …
591 594
592This is a mutator function that returns the callback set and optionally 595This is a mutator function that returns the callback set and optionally
593replaces it before doing so. 596replaces it before doing so.
594 597
595The callback will be called when the condition becomes "true", i.e. when 598The callback will be called when the condition becomes "true", i.e. when
596C<send> or C<croak> are called. Calling C<recv> inside the callback 599C<send> or C<croak> are called, with the only argument being the condition
597or at any later time is guaranteed not to block. 600variable itself. Calling C<recv> inside the callback or at any later time
601is guaranteed not to block.
598 602
599=back 603=back
600 604
601=head1 GLOBAL VARIABLES AND FUNCTIONS 605=head1 GLOBAL VARIABLES AND FUNCTIONS
602 606
… …
731=item L<AnyEvent::Util> 735=item L<AnyEvent::Util>
732 736
733Contains various utility functions that replace often-used but blocking 737Contains various utility functions that replace often-used but blocking
734functions such as C<inet_aton> by event-/callback-based versions. 738functions such as C<inet_aton> by event-/callback-based versions.
735 739
736=item L<AnyEvent::Handle>
737
738Provide read and write buffers and manages watchers for reads and writes.
739
740=item L<AnyEvent::Socket> 740=item L<AnyEvent::Socket>
741 741
742Provides various utility functions for (internet protocol) sockets, 742Provides various utility functions for (internet protocol) sockets,
743addresses and name resolution. Also functions to create non-blocking tcp 743addresses and name resolution. Also functions to create non-blocking tcp
744connections or tcp servers, with IPv6 and SRV record support and more. 744connections or tcp servers, with IPv6 and SRV record support and more.
745 745
746=item L<AnyEvent::Handle>
747
748Provide read and write buffers, manages watchers for reads and writes,
749supports raw and formatted I/O, I/O queued and fully transparent and
750non-blocking SSL/TLS.
751
746=item L<AnyEvent::DNS> 752=item L<AnyEvent::DNS>
747 753
748Provides rich asynchronous DNS resolver capabilities. 754Provides rich asynchronous DNS resolver capabilities.
749 755
756=item L<AnyEvent::HTTP>
757
758A simple-to-use HTTP library that is capable of making a lot of concurrent
759HTTP requests.
760
750=item L<AnyEvent::HTTPD> 761=item L<AnyEvent::HTTPD>
751 762
752Provides a simple web application server framework. 763Provides a simple web application server framework.
753 764
754=item L<AnyEvent::FastPing> 765=item L<AnyEvent::FastPing>
755 766
756The fastest ping in the west. 767The fastest ping in the west.
768
769=item L<AnyEvent::DBI>
770
771Executes L<DBI> requests asynchronously in a proxy process.
772
773=item L<AnyEvent::AIO>
774
775Truly asynchronous I/O, should be in the toolbox of every event
776programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
777together.
778
779=item L<AnyEvent::BDB>
780
781Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
782L<BDB> and AnyEvent together.
783
784=item L<AnyEvent::GPSD>
785
786A non-blocking interface to gpsd, a daemon delivering GPS information.
787
788=item L<AnyEvent::IGS>
789
790A non-blocking interface to the Internet Go Server protocol (used by
791L<App::IGS>).
757 792
758=item L<Net::IRC3> 793=item L<Net::IRC3>
759 794
760AnyEvent based IRC client module family. 795AnyEvent based IRC client module family.
761 796
… …
774 809
775=item L<Coro> 810=item L<Coro>
776 811
777Has special support for AnyEvent via L<Coro::AnyEvent>. 812Has special support for AnyEvent via L<Coro::AnyEvent>.
778 813
779=item L<AnyEvent::AIO>, L<IO::AIO>
780
781Truly asynchronous I/O, should be in the toolbox of every event
782programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent
783together.
784
785=item L<AnyEvent::BDB>, L<BDB>
786
787Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses
788IO::AIO and AnyEvent together.
789
790=item L<IO::Lambda> 814=item L<IO::Lambda>
791 815
792The lambda approach to I/O - don't ask, look there. Can use AnyEvent. 816The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
793 817
794=back 818=back
… …
800no warnings; 824no warnings;
801use strict; 825use strict;
802 826
803use Carp; 827use Carp;
804 828
805our $VERSION = '4.1'; 829our $VERSION = 4.2;
806our $MODEL; 830our $MODEL;
807 831
808our $AUTOLOAD; 832our $AUTOLOAD;
809our @ISA; 833our @ISA;
810 834
… …
972sub AnyEvent::Base::Signal::DESTROY { 996sub AnyEvent::Base::Signal::DESTROY {
973 my ($signal, $cb) = @{$_[0]}; 997 my ($signal, $cb) = @{$_[0]};
974 998
975 delete $SIG_CB{$signal}{$cb}; 999 delete $SIG_CB{$signal}{$cb};
976 1000
977 $SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} }; 1001 delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
978} 1002}
979 1003
980# default implementation for ->child 1004# default implementation for ->child
981 1005
982our %PID_CB; 1006our %PID_CB;
… …
1166This functionality might change in future versions. 1190This functionality might change in future versions.
1167 1191
1168For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you 1192For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
1169could start your program like this: 1193could start your program like this:
1170 1194
1171 PERL_ANYEVENT_MODEL=Perl perl ... 1195 PERL_ANYEVENT_MODEL=Perl perl ...
1172 1196
1173=item C<PERL_ANYEVENT_PROTOCOLS> 1197=item C<PERL_ANYEVENT_PROTOCOLS>
1174 1198
1175Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences 1199Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
1176for IPv4 or IPv6. The default is unspecified (and might change, or be the result 1200for IPv4 or IPv6. The default is unspecified (and might change, or be the result
… …
1651specified in the variable. 1675specified in the variable.
1652 1676
1653You can make AnyEvent completely ignore this variable by deleting it 1677You can make AnyEvent completely ignore this variable by deleting it
1654before the first watcher gets created, e.g. with a C<BEGIN> block: 1678before the first watcher gets created, e.g. with a C<BEGIN> block:
1655 1679
1656 BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } 1680 BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }
1657 1681
1658 use AnyEvent; 1682 use AnyEvent;
1659 1683
1660Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can 1684Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1661be used to probe what backend is used and gain other information (which is 1685be used to probe what backend is used and gain other information (which is
1662probably even less useful to an attacker than PERL_ANYEVENT_MODEL). 1686probably even less useful to an attacker than PERL_ANYEVENT_MODEL).
1687
1688
1689=head1 BUGS
1690
1691Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
1692to work around. If you suffer from memleaks, first upgrade to Perl 5.10
1693and check wether the leaks still show up. (Perl 5.10.0 has other annoying
1694mamleaks, such as leaking on C<map> and C<grep> but it is usually not as
1695pronounced).
1663 1696
1664 1697
1665=head1 SEE ALSO 1698=head1 SEE ALSO
1666 1699
1667Utility functions: L<AnyEvent::Util>. 1700Utility functions: L<AnyEvent::Util>.
… …
1684Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. 1717Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.
1685 1718
1686 1719
1687=head1 AUTHOR 1720=head1 AUTHOR
1688 1721
1689 Marc Lehmann <schmorp@schmorp.de> 1722 Marc Lehmann <schmorp@schmorp.de>
1690 http://home.schmorp.de/ 1723 http://home.schmorp.de/
1691 1724
1692=cut 1725=cut
1693 1726
16941 17271
1695 1728

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