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Revision 1.149 by root, Sat May 31 01:41:22 2008 UTC vs.
Revision 1.167 by root, Tue Jul 8 23:44:51 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
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
… …
305=back 303=back
306 304
307=head2 SIGNAL WATCHERS 305=head2 SIGNAL WATCHERS
308 306
309You can watch for signals using a signal watcher, C<signal> is the signal 307You can watch for signals using a signal watcher, C<signal> is the signal
310I<name> without any C<SIG> prefix, C<cb> is the Perl callback to 308I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
311be invoked whenever a signal occurs. 309callback to be invoked whenever a signal occurs.
312 310
313Although the callback might get passed parameters, their value and 311Although the callback might get passed parameters, their value and
314presence is undefined and you cannot rely on them. Portable AnyEvent 312presence is undefined and you cannot rely on them. Portable AnyEvent
315callbacks cannot use arguments passed to signal watcher callbacks. 313callbacks cannot use arguments passed to signal watcher callbacks.
316 314
… …
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
… …
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>
758
759A simple-to-use HTTP library that is capable of making a lot of concurrent
760HTTP requests.
761
757=item L<AnyEvent::HTTPD> 762=item L<AnyEvent::HTTPD>
758 763
759Provides a simple web application server framework. 764Provides a simple web application server framework.
760 765
761=item L<AnyEvent::FastPing> 766=item L<AnyEvent::FastPing>
762 767
763The 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>).
764 793
765=item L<Net::IRC3> 794=item L<Net::IRC3>
766 795
767AnyEvent based IRC client module family. 796AnyEvent based IRC client module family.
768 797
… …
781 810
782=item L<Coro> 811=item L<Coro>
783 812
784Has special support for AnyEvent via L<Coro::AnyEvent>. 813Has special support for AnyEvent via L<Coro::AnyEvent>.
785 814
786=item L<AnyEvent::AIO>, L<IO::AIO>
787
788Truly asynchronous I/O, should be in the toolbox of every event
789programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent
790together.
791
792=item L<AnyEvent::BDB>, L<BDB>
793
794Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses
795IO::AIO and AnyEvent together.
796
797=item L<IO::Lambda> 815=item L<IO::Lambda>
798 816
799The 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.
800 818
801=back 819=back
… …
807no warnings; 825no warnings;
808use strict; 826use strict;
809 827
810use Carp; 828use Carp;
811 829
812our $VERSION = 4.11; 830our $VERSION = 4.2;
813our $MODEL; 831our $MODEL;
814 832
815our $AUTOLOAD; 833our $AUTOLOAD;
816our @ISA; 834our @ISA;
817 835
… …
920 $MODEL 938 $MODEL
921 or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib."; 939 or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";
922 } 940 }
923 } 941 }
924 942
925 unshift @ISA, $MODEL;
926 push @{"$MODEL\::ISA"}, "AnyEvent::Base"; 943 push @{"$MODEL\::ISA"}, "AnyEvent::Base";
944
945 if ($ENV{PERL_ANYEVENT_STRICT}) {
946 unshift @AnyEvent::Base::Strict::ISA, $MODEL;
947 unshift @ISA, AnyEvent::Base::Strict::
948 } else {
949 unshift @ISA, $MODEL;
950 }
927 951
928 (shift @post_detect)->() while @post_detect; 952 (shift @post_detect)->() while @post_detect;
929 } 953 }
930 954
931 $MODEL 955 $MODEL
… …
979sub AnyEvent::Base::Signal::DESTROY { 1003sub AnyEvent::Base::Signal::DESTROY {
980 my ($signal, $cb) = @{$_[0]}; 1004 my ($signal, $cb) = @{$_[0]};
981 1005
982 delete $SIG_CB{$signal}{$cb}; 1006 delete $SIG_CB{$signal}{$cb};
983 1007
984 $SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} }; 1008 delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
985} 1009}
986 1010
987# default implementation for ->child 1011# default implementation for ->child
988 1012
989our %PID_CB; 1013our %PID_CB;
… …
1097 1121
1098# undocumented/compatibility with pre-3.4 1122# undocumented/compatibility with pre-3.4
1099*broadcast = \&send; 1123*broadcast = \&send;
1100*wait = \&_wait; 1124*wait = \&_wait;
1101 1125
1126package AnyEvent::Base::Strict;
1127
1128use Carp qw(croak);
1129
1130# supply checks for argument validity for many functions
1131
1132sub io {
1133 my $class = shift;
1134 my %arg = @_;
1135
1136 ref $arg{cb}
1137 or croak "AnyEvent->io called with illegal cb argument '$arg{cb}'";
1138 delete $arg{cb};
1139
1140 fileno $arg{fh}
1141 or croak "AnyEvent->io called with illegal fh argument '$arg{fh}'";
1142 delete $arg{fh};
1143
1144 $arg{poll} =~ /^[rw]$/
1145 or croak "AnyEvent->io called with illegal poll argument '$arg{poll}'";
1146 delete $arg{poll};
1147
1148 croak "AnyEvent->io called with unsupported parameter(s) " . join ", ", keys %arg
1149 if keys %arg;
1150
1151 $class->SUPER::io (@_)
1152}
1153
1154sub timer {
1155 my $class = shift;
1156 my %arg = @_;
1157
1158 ref $arg{cb}
1159 or croak "AnyEvent->timer called with illegal cb argument '$arg{cb}'";
1160 delete $arg{cb};
1161
1162 exists $arg{after}
1163 or croak "AnyEvent->timer called without mandatory 'after' parameter";
1164 delete $arg{after};
1165
1166 $arg{interval} > 0 || !$arg{interval}
1167 or croak "AnyEvent->timer called with illegal interval argument '$arg{interval}'";
1168 delete $arg{interval};
1169
1170 croak "AnyEvent->timer called with unsupported parameter(s) " . join ", ", keys %arg
1171 if keys %arg;
1172
1173 $class->SUPER::timer (@_)
1174}
1175
1176sub signal {
1177 my $class = shift;
1178 my %arg = @_;
1179
1180 ref $arg{cb}
1181 or croak "AnyEvent->signal called with illegal cb argument '$arg{cb}'";
1182 delete $arg{cb};
1183
1184 eval "require POSIX; defined &POSIX::SIG$arg{signal}"
1185 or croak "AnyEvent->signal called with illegal signal name '$arg{signal}'";
1186 delete $arg{signal};
1187
1188 croak "AnyEvent->signal called with unsupported parameter(s) " . join ", ", keys %arg
1189 if keys %arg;
1190
1191 $class->SUPER::signal (@_)
1192}
1193
1194sub child {
1195 my $class = shift;
1196 my %arg = @_;
1197
1198 ref $arg{cb}
1199 or croak "AnyEvent->signal called with illegal cb argument '$arg{cb}'";
1200 delete $arg{cb};
1201
1202 $arg{pid} =~ /^-?\d+$/
1203 or croak "AnyEvent->signal called with illegal pid value '$arg{pid}'";
1204 delete $arg{pid};
1205
1206 croak "AnyEvent->signal called with unsupported parameter(s) " . join ", ", keys %arg
1207 if keys %arg;
1208
1209 $class->SUPER::child (@_)
1210}
1211
1212sub condvar {
1213 my $class = shift;
1214 my %arg = @_;
1215
1216 !exists $arg{cb} or ref $arg{cb}
1217 or croak "AnyEvent->condvar called with illegal cb argument '$arg{cb}'";
1218 delete $arg{cb};
1219
1220 croak "AnyEvent->condvar called with unsupported parameter(s) " . join ", ", keys %arg
1221 if keys %arg;
1222
1223 $class->SUPER::condvar (@_)
1224}
1225
1226sub time {
1227 my $class = shift;
1228
1229 @_
1230 and croak "AnyEvent->time wrongly called with paramaters";
1231
1232 $class->SUPER::time (@_)
1233}
1234
1235sub now {
1236 my $class = shift;
1237
1238 @_
1239 and croak "AnyEvent->now wrongly called with paramaters";
1240
1241 $class->SUPER::now (@_)
1242}
1243
1102=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE 1244=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1103 1245
1104This is an advanced topic that you do not normally need to use AnyEvent in 1246This is an advanced topic that you do not normally need to use AnyEvent in
1105a module. This section is only of use to event loop authors who want to 1247a module. This section is only of use to event loop authors who want to
1106provide AnyEvent compatibility. 1248provide AnyEvent compatibility.
… …
1159C<PERL_ANYEVENT_MODEL>. 1301C<PERL_ANYEVENT_MODEL>.
1160 1302
1161When set to C<2> or higher, cause AnyEvent to report to STDERR which event 1303When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1162model it chooses. 1304model it chooses.
1163 1305
1306=item C<PERL_ANYEVENT_STRICT>
1307
1308AnyEvent does not do much argument checking by default, as thorough
1309argument checking is very costly. Setting this variable to a true value
1310will cause AnyEvent to thoroughly check the arguments passed to most
1311method calls and croaks if it finds any problems. In other words, enables
1312"strict" mode. Unlike C<use strict> it is definitely recommended ot keep
1313it off in production.
1314
1164=item C<PERL_ANYEVENT_MODEL> 1315=item C<PERL_ANYEVENT_MODEL>
1165 1316
1166This can be used to specify the event model to be used by AnyEvent, before 1317This can be used to specify the event model to be used by AnyEvent, before
1167auto detection and -probing kicks in. It must be a string consisting 1318auto detection and -probing kicks in. It must be a string consisting
1168entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended 1319entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
… …
1173This functionality might change in future versions. 1324This functionality might change in future versions.
1174 1325
1175For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you 1326For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
1176could start your program like this: 1327could start your program like this:
1177 1328
1178 PERL_ANYEVENT_MODEL=Perl perl ... 1329 PERL_ANYEVENT_MODEL=Perl perl ...
1179 1330
1180=item C<PERL_ANYEVENT_PROTOCOLS> 1331=item C<PERL_ANYEVENT_PROTOCOLS>
1181 1332
1182Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences 1333Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
1183for IPv4 or IPv6. The default is unspecified (and might change, or be the result 1334for IPv4 or IPv6. The default is unspecified (and might change, or be the result
… …
1658specified in the variable. 1809specified in the variable.
1659 1810
1660You can make AnyEvent completely ignore this variable by deleting it 1811You can make AnyEvent completely ignore this variable by deleting it
1661before the first watcher gets created, e.g. with a C<BEGIN> block: 1812before the first watcher gets created, e.g. with a C<BEGIN> block:
1662 1813
1663 BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } 1814 BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }
1664 1815
1665 use AnyEvent; 1816 use AnyEvent;
1666 1817
1667Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can 1818Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1668be used to probe what backend is used and gain other information (which is 1819be used to probe what backend is used and gain other information (which is
1669probably even less useful to an attacker than PERL_ANYEVENT_MODEL). 1820probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
1821$ENV{PERL_ANYEGENT_STRICT}.
1822
1823
1824=head1 BUGS
1825
1826Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
1827to work around. If you suffer from memleaks, first upgrade to Perl 5.10
1828and check wether the leaks still show up. (Perl 5.10.0 has other annoying
1829mamleaks, such as leaking on C<map> and C<grep> but it is usually not as
1830pronounced).
1670 1831
1671 1832
1672=head1 SEE ALSO 1833=head1 SEE ALSO
1673 1834
1674Utility functions: L<AnyEvent::Util>. 1835Utility functions: L<AnyEvent::Util>.
… …
1691Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. 1852Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.
1692 1853
1693 1854
1694=head1 AUTHOR 1855=head1 AUTHOR
1695 1856
1696 Marc Lehmann <schmorp@schmorp.de> 1857 Marc Lehmann <schmorp@schmorp.de>
1697 http://home.schmorp.de/ 1858 http://home.schmorp.de/
1698 1859
1699=cut 1860=cut
1700 1861
17011 18621
1702 1863

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