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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 1.164 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
… …
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 positive number, then the callback will be
199and Glib). 199invoked regularly at that interval (in fractional seconds) after the first
200invocation.
200 201
201Example: 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.
202 205
203 # fire an event after 7.7 seconds 206Example: fire an event after 7.7 seconds.
207
204 my $w = AnyEvent->timer (after => 7.7, cb => sub { 208 my $w = AnyEvent->timer (after => 7.7, cb => sub {
205 warn "timeout\n"; 209 warn "timeout\n";
206 }); 210 });
207 211
208 # to cancel the timer: 212 # to cancel the timer:
209 undef $w; 213 undef $w;
210 214
211Example 2:
212
213 # fire an event after 0.5 seconds, then roughly every second 215Example 2: fire an event after 0.5 seconds, then roughly every second.
214 my $w;
215 216
216 my $cb = sub {
217 # cancel the old timer while creating a new one
218 $w = AnyEvent->timer (after => 1, cb => $cb); 217 my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub {
218 warn "timeout\n";
219 }; 219 };
220
221 # start the "loop" by creating the first watcher
222 $w = AnyEvent->timer (after => 0.5, cb => $cb);
223 220
224=head3 TIMING ISSUES 221=head3 TIMING ISSUES
225 222
226There 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
227in 10 seconds") and based on wallclock time (absolute, "fire at 12 224in 10 seconds") and based on wallclock time (absolute, "fire at 12
… …
352AnyEvent 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
353C<fork> the child (alternatively, you can call C<AnyEvent::detect>). 350C<fork> the child (alternatively, you can call C<AnyEvent::detect>).
354 351
355Example: fork a process and wait for it 352Example: fork a process and wait for it
356 353
357 my $done = AnyEvent->condvar; 354 my $done = AnyEvent->condvar;
358 355
359 my $pid = fork or exit 5; 356 my $pid = fork or exit 5;
360 357
361 my $w = AnyEvent->child ( 358 my $w = AnyEvent->child (
362 pid => $pid, 359 pid => $pid,
363 cb => sub { 360 cb => sub {
364 my ($pid, $status) = @_; 361 my ($pid, $status) = @_;
365 warn "pid $pid exited with status $status"; 362 warn "pid $pid exited with status $status";
366 $done->send; 363 $done->send;
367 }, 364 },
368 ); 365 );
369 366
370 # do something else, then wait for process exit 367 # do something else, then wait for process exit
371 $done->recv; 368 $done->recv;
372 369
373=head2 CONDITION VARIABLES 370=head2 CONDITION VARIABLES
374 371
375If 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
376require you to run some blocking "loop", "run" or similar function that 373require you to run some blocking "loop", "run" or similar function that
… …
597 594
598This is a mutator function that returns the callback set and optionally 595This is a mutator function that returns the callback set and optionally
599replaces it before doing so. 596replaces it before doing so.
600 597
601The 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
602C<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
603or 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.
604 602
605=back 603=back
606 604
607=head1 GLOBAL VARIABLES AND FUNCTIONS 605=head1 GLOBAL VARIABLES AND FUNCTIONS
608 606
… …
737=item L<AnyEvent::Util> 735=item L<AnyEvent::Util>
738 736
739Contains various utility functions that replace often-used but blocking 737Contains various utility functions that replace often-used but blocking
740functions such as C<inet_aton> by event-/callback-based versions. 738functions such as C<inet_aton> by event-/callback-based versions.
741 739
742=item L<AnyEvent::Handle>
743
744Provide read and write buffers and manages watchers for reads and writes.
745
746=item L<AnyEvent::Socket> 740=item L<AnyEvent::Socket>
747 741
748Provides various utility functions for (internet protocol) sockets, 742Provides various utility functions for (internet protocol) sockets,
749addresses and name resolution. Also functions to create non-blocking tcp 743addresses and name resolution. Also functions to create non-blocking tcp
750connections or tcp servers, with IPv6 and SRV record support and more. 744connections or tcp servers, with IPv6 and SRV record support and more.
751 745
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
752=item L<AnyEvent::DNS> 752=item L<AnyEvent::DNS>
753 753
754Provides rich asynchronous DNS resolver capabilities. 754Provides rich asynchronous DNS resolver capabilities.
755 755
756=item L<AnyEvent::HTTP>
757
758A simple-to-use HTTP library that is capable of making a lot of concurrent
759HTTP requests.
760
756=item L<AnyEvent::HTTPD> 761=item L<AnyEvent::HTTPD>
757 762
758Provides a simple web application server framework. 763Provides a simple web application server framework.
759 764
760=item L<AnyEvent::FastPing> 765=item L<AnyEvent::FastPing>
761 766
762The 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>).
763 792
764=item L<Net::IRC3> 793=item L<Net::IRC3>
765 794
766AnyEvent based IRC client module family. 795AnyEvent based IRC client module family.
767 796
… …
780 809
781=item L<Coro> 810=item L<Coro>
782 811
783Has special support for AnyEvent via L<Coro::AnyEvent>. 812Has special support for AnyEvent via L<Coro::AnyEvent>.
784 813
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> 814=item L<IO::Lambda>
797 815
798The 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.
799 817
800=back 818=back
… …
806no warnings; 824no warnings;
807use strict; 825use strict;
808 826
809use Carp; 827use Carp;
810 828
811our $VERSION = 4.11; 829our $VERSION = 4.2;
812our $MODEL; 830our $MODEL;
813 831
814our $AUTOLOAD; 832our $AUTOLOAD;
815our @ISA; 833our @ISA;
816 834
… …
978sub AnyEvent::Base::Signal::DESTROY { 996sub AnyEvent::Base::Signal::DESTROY {
979 my ($signal, $cb) = @{$_[0]}; 997 my ($signal, $cb) = @{$_[0]};
980 998
981 delete $SIG_CB{$signal}{$cb}; 999 delete $SIG_CB{$signal}{$cb};
982 1000
983 $SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} }; 1001 delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
984} 1002}
985 1003
986# default implementation for ->child 1004# default implementation for ->child
987 1005
988our %PID_CB; 1006our %PID_CB;
… …
1172This functionality might change in future versions. 1190This functionality might change in future versions.
1173 1191
1174For 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
1175could start your program like this: 1193could start your program like this:
1176 1194
1177 PERL_ANYEVENT_MODEL=Perl perl ... 1195 PERL_ANYEVENT_MODEL=Perl perl ...
1178 1196
1179=item C<PERL_ANYEVENT_PROTOCOLS> 1197=item C<PERL_ANYEVENT_PROTOCOLS>
1180 1198
1181Used 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
1182for 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
… …
1657specified in the variable. 1675specified in the variable.
1658 1676
1659You can make AnyEvent completely ignore this variable by deleting it 1677You can make AnyEvent completely ignore this variable by deleting it
1660before 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:
1661 1679
1662 BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } 1680 BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }
1663 1681
1664 use AnyEvent; 1682 use AnyEvent;
1665 1683
1666Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can 1684Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1667be 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
1668probably 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).
1669 1696
1670 1697
1671=head1 SEE ALSO 1698=head1 SEE ALSO
1672 1699
1673Utility functions: L<AnyEvent::Util>. 1700Utility functions: L<AnyEvent::Util>.
… …
1690Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. 1717Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.
1691 1718
1692 1719
1693=head1 AUTHOR 1720=head1 AUTHOR
1694 1721
1695 Marc Lehmann <schmorp@schmorp.de> 1722 Marc Lehmann <schmorp@schmorp.de>
1696 http://home.schmorp.de/ 1723 http://home.schmorp.de/
1697 1724
1698=cut 1725=cut
1699 1726
17001 17271
1701 1728

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