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Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.148 by root, Sat May 31 00:40:16 2008 UTC vs.
Revision 1.165 by root, Tue Jul 8 23:07:26 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
… …
138Many watchers either are used with "recursion" (repeating timers for 138Many watchers either are used with "recursion" (repeating timers for
139example), or need to refer to their watcher object in other ways. 139example), or need to refer to their watcher object in other ways.
140 140
141An any way to achieve that is this pattern: 141An any way to achieve that is this pattern:
142 142
143 my $w; $w = AnyEvent->type (arg => value ..., cb => sub { 143 my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
144 # you can use $w here, for example to undef it 144 # you can use $w here, for example to undef it
145 undef $w; 145 undef $w;
146 }); 146 });
147 147
148Note 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,
149my variables are only visible after the statement in which they are 149my variables are only visible after the statement in which they are
150declared. 150declared.
151 151
… …
170 170
171Some event loops issue spurious readyness notifications, so you should 171Some event loops issue spurious readyness notifications, so you should
172always use non-blocking calls when reading/writing from/to your file 172always use non-blocking calls when reading/writing from/to your file
173handles. 173handles.
174 174
175Example:
176
177 # 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
178 my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub { 178 my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {
179 chomp (my $input = <STDIN>); 179 chomp (my $input = <STDIN>);
180 warn "read: $input\n"; 180 warn "read: $input\n";
181 undef $w; 181 undef $w;
182 }); 182 });
… …
192 192
193Although the callback might get passed parameters, their value and 193Although the callback might get passed parameters, their value and
194presence is undefined and you cannot rely on them. Portable AnyEvent 194presence is undefined and you cannot rely on them. Portable AnyEvent
195callbacks cannot use arguments passed to time watcher callbacks. 195callbacks cannot use arguments passed to time watcher callbacks.
196 196
197The 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
198timer you have to create a new watcher (this is a limitation by both Tk 198parameter, C<interval>, as a strictly positive number (> 0), then the
199and Glib). 199callback will be invoked regularly at that interval (in fractional
200seconds) after the first invocation. If C<interval> is specified with a
201false value, then it is treated as if it were missing.
200 202
201Example: 203The callback will be rescheduled before invoking the callback, but no
204attempt is done to avoid timer drift in most backends, so the interval is
205only approximate.
202 206
203 # fire an event after 7.7 seconds 207Example: fire an event after 7.7 seconds.
208
204 my $w = AnyEvent->timer (after => 7.7, cb => sub { 209 my $w = AnyEvent->timer (after => 7.7, cb => sub {
205 warn "timeout\n"; 210 warn "timeout\n";
206 }); 211 });
207 212
208 # to cancel the timer: 213 # to cancel the timer:
209 undef $w; 214 undef $w;
210 215
211Example 2:
212
213 # fire an event after 0.5 seconds, then roughly every second 216Example 2: fire an event after 0.5 seconds, then roughly every second.
214 my $w;
215 217
216 my $cb = sub {
217 # cancel the old timer while creating a new one
218 $w = AnyEvent->timer (after => 1, cb => $cb); 218 my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub {
219 warn "timeout\n";
219 }; 220 };
220
221 # start the "loop" by creating the first watcher
222 $w = AnyEvent->timer (after => 0.5, cb => $cb);
223 221
224=head3 TIMING ISSUES 222=head3 TIMING ISSUES
225 223
226There are two ways to handle timers: based on real time (relative, "fire 224There are two ways to handle timers: based on real time (relative, "fire
227in 10 seconds") and based on wallclock time (absolute, "fire at 12 225in 10 seconds") and based on wallclock time (absolute, "fire at 12
… …
352AnyEvent program, you I<have> to create at least one watcher before you 350AnyEvent program, you I<have> to create at least one watcher before you
353C<fork> the child (alternatively, you can call C<AnyEvent::detect>). 351C<fork> the child (alternatively, you can call C<AnyEvent::detect>).
354 352
355Example: fork a process and wait for it 353Example: fork a process and wait for it
356 354
357 my $done = AnyEvent->condvar; 355 my $done = AnyEvent->condvar;
358 356
359 my $pid = fork or exit 5; 357 my $pid = fork or exit 5;
360 358
361 my $w = AnyEvent->child ( 359 my $w = AnyEvent->child (
362 pid => $pid, 360 pid => $pid,
363 cb => sub { 361 cb => sub {
364 my ($pid, $status) = @_; 362 my ($pid, $status) = @_;
365 warn "pid $pid exited with status $status"; 363 warn "pid $pid exited with status $status";
366 $done->send; 364 $done->send;
367 }, 365 },
368 ); 366 );
369 367
370 # do something else, then wait for process exit 368 # do something else, then wait for process exit
371 $done->recv; 369 $done->recv;
372 370
373=head2 CONDITION VARIABLES 371=head2 CONDITION VARIABLES
374 372
375If you are familiar with some event loops you will know that all of them 373If you are familiar with some event loops you will know that all of them
376require you to run some blocking "loop", "run" or similar function that 374require you to run some blocking "loop", "run" or similar function that
… …
597 595
598This is a mutator function that returns the callback set and optionally 596This is a mutator function that returns the callback set and optionally
599replaces it before doing so. 597replaces it before doing so.
600 598
601The callback will be called when the condition becomes "true", i.e. when 599The callback will be called when the condition becomes "true", i.e. when
602C<send> or C<croak> are called. Calling C<recv> inside the callback 600C<send> or C<croak> are called, with the only argument being the condition
603or at any later time is guaranteed not to block. 601variable itself. Calling C<recv> inside the callback or at any later time
602is guaranteed not to block.
604 603
605=back 604=back
606 605
607=head1 GLOBAL VARIABLES AND FUNCTIONS 606=head1 GLOBAL VARIABLES AND FUNCTIONS
608 607
… …
737=item L<AnyEvent::Util> 736=item L<AnyEvent::Util>
738 737
739Contains various utility functions that replace often-used but blocking 738Contains various utility functions that replace often-used but blocking
740functions such as C<inet_aton> by event-/callback-based versions. 739functions such as C<inet_aton> by event-/callback-based versions.
741 740
742=item L<AnyEvent::Handle>
743
744Provide read and write buffers and manages watchers for reads and writes.
745
746=item L<AnyEvent::Socket> 741=item L<AnyEvent::Socket>
747 742
748Provides various utility functions for (internet protocol) sockets, 743Provides various utility functions for (internet protocol) sockets,
749addresses and name resolution. Also functions to create non-blocking tcp 744addresses and name resolution. Also functions to create non-blocking tcp
750connections or tcp servers, with IPv6 and SRV record support and more. 745connections or tcp servers, with IPv6 and SRV record support and more.
751 746
747=item L<AnyEvent::Handle>
748
749Provide read and write buffers, manages watchers for reads and writes,
750supports raw and formatted I/O, I/O queued and fully transparent and
751non-blocking SSL/TLS.
752
752=item L<AnyEvent::DNS> 753=item L<AnyEvent::DNS>
753 754
754Provides rich asynchronous DNS resolver capabilities. 755Provides rich asynchronous DNS resolver capabilities.
755 756
757=item L<AnyEvent::HTTP>
758
759A simple-to-use HTTP library that is capable of making a lot of concurrent
760HTTP requests.
761
756=item L<AnyEvent::HTTPD> 762=item L<AnyEvent::HTTPD>
757 763
758Provides a simple web application server framework. 764Provides a simple web application server framework.
759 765
760=item L<AnyEvent::FastPing> 766=item L<AnyEvent::FastPing>
761 767
762The fastest ping in the west. 768The fastest ping in the west.
769
770=item L<AnyEvent::DBI>
771
772Executes L<DBI> requests asynchronously in a proxy process.
773
774=item L<AnyEvent::AIO>
775
776Truly asynchronous I/O, should be in the toolbox of every event
777programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
778together.
779
780=item L<AnyEvent::BDB>
781
782Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
783L<BDB> and AnyEvent together.
784
785=item L<AnyEvent::GPSD>
786
787A non-blocking interface to gpsd, a daemon delivering GPS information.
788
789=item L<AnyEvent::IGS>
790
791A non-blocking interface to the Internet Go Server protocol (used by
792L<App::IGS>).
763 793
764=item L<Net::IRC3> 794=item L<Net::IRC3>
765 795
766AnyEvent based IRC client module family. 796AnyEvent based IRC client module family.
767 797
… …
780 810
781=item L<Coro> 811=item L<Coro>
782 812
783Has special support for AnyEvent via L<Coro::AnyEvent>. 813Has special support for AnyEvent via L<Coro::AnyEvent>.
784 814
785=item L<AnyEvent::AIO>, L<IO::AIO>
786
787Truly asynchronous I/O, should be in the toolbox of every event
788programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent
789together.
790
791=item L<AnyEvent::BDB>, L<BDB>
792
793Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses
794IO::AIO and AnyEvent together.
795
796=item L<IO::Lambda> 815=item L<IO::Lambda>
797 816
798The lambda approach to I/O - don't ask, look there. Can use AnyEvent. 817The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
799 818
800=back 819=back
… …
806no warnings; 825no warnings;
807use strict; 826use strict;
808 827
809use Carp; 828use Carp;
810 829
811our $VERSION = 4.11; 830our $VERSION = 4.2;
812our $MODEL; 831our $MODEL;
813 832
814our $AUTOLOAD; 833our $AUTOLOAD;
815our @ISA; 834our @ISA;
816 835
… …
978sub AnyEvent::Base::Signal::DESTROY { 997sub AnyEvent::Base::Signal::DESTROY {
979 my ($signal, $cb) = @{$_[0]}; 998 my ($signal, $cb) = @{$_[0]};
980 999
981 delete $SIG_CB{$signal}{$cb}; 1000 delete $SIG_CB{$signal}{$cb};
982 1001
983 $SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} }; 1002 delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
984} 1003}
985 1004
986# default implementation for ->child 1005# default implementation for ->child
987 1006
988our %PID_CB; 1007our %PID_CB;
… …
1172This functionality might change in future versions. 1191This functionality might change in future versions.
1173 1192
1174For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you 1193For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
1175could start your program like this: 1194could start your program like this:
1176 1195
1177 PERL_ANYEVENT_MODEL=Perl perl ... 1196 PERL_ANYEVENT_MODEL=Perl perl ...
1178 1197
1179=item C<PERL_ANYEVENT_PROTOCOLS> 1198=item C<PERL_ANYEVENT_PROTOCOLS>
1180 1199
1181Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences 1200Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
1182for IPv4 or IPv6. The default is unspecified (and might change, or be the result 1201for IPv4 or IPv6. The default is unspecified (and might change, or be the result
… …
1657specified in the variable. 1676specified in the variable.
1658 1677
1659You can make AnyEvent completely ignore this variable by deleting it 1678You can make AnyEvent completely ignore this variable by deleting it
1660before the first watcher gets created, e.g. with a C<BEGIN> block: 1679before the first watcher gets created, e.g. with a C<BEGIN> block:
1661 1680
1662 BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } 1681 BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }
1663 1682
1664 use AnyEvent; 1683 use AnyEvent;
1665 1684
1666Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can 1685Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1667be used to probe what backend is used and gain other information (which is 1686be used to probe what backend is used and gain other information (which is
1668probably even less useful to an attacker than PERL_ANYEVENT_MODEL). 1687probably even less useful to an attacker than PERL_ANYEVENT_MODEL).
1688
1689
1690=head1 BUGS
1691
1692Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
1693to work around. If you suffer from memleaks, first upgrade to Perl 5.10
1694and check wether the leaks still show up. (Perl 5.10.0 has other annoying
1695mamleaks, such as leaking on C<map> and C<grep> but it is usually not as
1696pronounced).
1669 1697
1670 1698
1671=head1 SEE ALSO 1699=head1 SEE ALSO
1672 1700
1673Utility functions: L<AnyEvent::Util>. 1701Utility functions: L<AnyEvent::Util>.
… …
1690Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. 1718Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.
1691 1719
1692 1720
1693=head1 AUTHOR 1721=head1 AUTHOR
1694 1722
1695 Marc Lehmann <schmorp@schmorp.de> 1723 Marc Lehmann <schmorp@schmorp.de>
1696 http://home.schmorp.de/ 1724 http://home.schmorp.de/
1697 1725
1698=cut 1726=cut
1699 1727
17001 17281
1701 1729

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