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Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.155 by root, Fri Jun 6 07:07:01 2008 UTC vs.
Revision 1.166 by root, Tue Jul 8 23:10:20 2008 UTC

152=head2 I/O WATCHERS 152=head2 I/O WATCHERS
153 153
154You can create an I/O watcher by calling the C<< AnyEvent->io >> method 154You can create an I/O watcher by calling the C<< AnyEvent->io >> method
155with the following mandatory key-value pairs as arguments: 155with the following mandatory key-value pairs as arguments:
156 156
157C<fh> the Perl I<file handle> (I<not> file descriptor) to watch 157C<fh> the Perl I<file handle> (I<not> file descriptor) to watch for events
158for events. C<poll> must be a string that is either C<r> or C<w>, 158(AnyEvent might or might not keep a reference to this file handle). C<poll>
159which creates a watcher waiting for "r"eadable or "w"ritable events, 159must be a string that is either C<r> or C<w>, which creates a watcher
160respectively. C<cb> is the callback to invoke each time the file handle 160waiting for "r"eadable or "w"ritable events, respectively. C<cb> is the
161becomes ready. 161callback to invoke each time the file handle becomes ready.
162 162
163Although the callback might get passed parameters, their value and 163Although the callback might get passed parameters, their value and
164presence is undefined and you cannot rely on them. Portable AnyEvent 164presence is undefined and you cannot rely on them. Portable AnyEvent
165callbacks cannot use arguments passed to I/O watcher callbacks. 165callbacks cannot use arguments passed to I/O watcher callbacks.
166 166
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
738=item L<AnyEvent::Util> 736=item L<AnyEvent::Util>
739 737
740Contains various utility functions that replace often-used but blocking 738Contains various utility functions that replace often-used but blocking
741functions such as C<inet_aton> by event-/callback-based versions. 739functions such as C<inet_aton> by event-/callback-based versions.
742 740
743=item L<AnyEvent::Handle>
744
745Provide read and write buffers and manages watchers for reads and writes.
746
747=item L<AnyEvent::Socket> 741=item L<AnyEvent::Socket>
748 742
749Provides various utility functions for (internet protocol) sockets, 743Provides various utility functions for (internet protocol) sockets,
750addresses and name resolution. Also functions to create non-blocking tcp 744addresses and name resolution. Also functions to create non-blocking tcp
751connections or tcp servers, with IPv6 and SRV record support and more. 745connections or tcp servers, with IPv6 and SRV record support and more.
752 746
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
753=item L<AnyEvent::DNS> 753=item L<AnyEvent::DNS>
754 754
755Provides rich asynchronous DNS resolver capabilities. 755Provides rich asynchronous DNS resolver capabilities.
756 756
757=item L<AnyEvent::HTTP> 757=item L<AnyEvent::HTTP>
765 765
766=item L<AnyEvent::FastPing> 766=item L<AnyEvent::FastPing>
767 767
768The fastest ping in the west. 768The fastest ping in the west.
769 769
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>).
793
770=item L<Net::IRC3> 794=item L<Net::IRC3>
771 795
772AnyEvent based IRC client module family. 796AnyEvent based IRC client module family.
773 797
774=item L<Net::XMPP2> 798=item L<Net::XMPP2>
786 810
787=item L<Coro> 811=item L<Coro>
788 812
789Has special support for AnyEvent via L<Coro::AnyEvent>. 813Has special support for AnyEvent via L<Coro::AnyEvent>.
790 814
791=item L<AnyEvent::AIO>, L<IO::AIO>
792
793Truly asynchronous I/O, should be in the toolbox of every event
794programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent
795together.
796
797=item L<AnyEvent::BDB>, L<BDB>
798
799Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses
800IO::AIO and AnyEvent together.
801
802=item L<IO::Lambda> 815=item L<IO::Lambda>
803 816
804The 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.
805 818
806=back 819=back
812no warnings; 825no warnings;
813use strict; 826use strict;
814 827
815use Carp; 828use Carp;
816 829
817our $VERSION = 4.14; 830our $VERSION = 4.2;
818our $MODEL; 831our $MODEL;
819 832
820our $AUTOLOAD; 833our $AUTOLOAD;
821our @ISA; 834our @ISA;
822 835
984sub AnyEvent::Base::Signal::DESTROY { 997sub AnyEvent::Base::Signal::DESTROY {
985 my ($signal, $cb) = @{$_[0]}; 998 my ($signal, $cb) = @{$_[0]};
986 999
987 delete $SIG_CB{$signal}{$cb}; 1000 delete $SIG_CB{$signal}{$cb};
988 1001
989 $SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} }; 1002 delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
990} 1003}
991 1004
992# default implementation for ->child 1005# default implementation for ->child
993 1006
994our %PID_CB; 1007our %PID_CB;
1672Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can 1685Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1673be 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
1674probably even less useful to an attacker than PERL_ANYEVENT_MODEL). 1687probably even less useful to an attacker than PERL_ANYEVENT_MODEL).
1675 1688
1676 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).
1697
1698
1677=head1 SEE ALSO 1699=head1 SEE ALSO
1678 1700
1679Utility functions: L<AnyEvent::Util>. 1701Utility functions: L<AnyEvent::Util>.
1680 1702
1681Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>, 1703Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,

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