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Revision 1.148 by root, Sat May 31 00:40:16 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
… …
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
… …
919 $MODEL 938 $MODEL
920 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.";
921 } 940 }
922 } 941 }
923 942
924 unshift @ISA, $MODEL;
925 push @{"$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 }
926 951
927 (shift @post_detect)->() while @post_detect; 952 (shift @post_detect)->() while @post_detect;
928 } 953 }
929 954
930 $MODEL 955 $MODEL
… …
978sub AnyEvent::Base::Signal::DESTROY { 1003sub AnyEvent::Base::Signal::DESTROY {
979 my ($signal, $cb) = @{$_[0]}; 1004 my ($signal, $cb) = @{$_[0]};
980 1005
981 delete $SIG_CB{$signal}{$cb}; 1006 delete $SIG_CB{$signal}{$cb};
982 1007
983 $SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} }; 1008 delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
984} 1009}
985 1010
986# default implementation for ->child 1011# default implementation for ->child
987 1012
988our %PID_CB; 1013our %PID_CB;
… …
1096 1121
1097# undocumented/compatibility with pre-3.4 1122# undocumented/compatibility with pre-3.4
1098*broadcast = \&send; 1123*broadcast = \&send;
1099*wait = \&_wait; 1124*wait = \&_wait;
1100 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
1101=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE 1244=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1102 1245
1103This 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
1104a 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
1105provide AnyEvent compatibility. 1248provide AnyEvent compatibility.
… …
1158C<PERL_ANYEVENT_MODEL>. 1301C<PERL_ANYEVENT_MODEL>.
1159 1302
1160When 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
1161model it chooses. 1304model it chooses.
1162 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
1163=item C<PERL_ANYEVENT_MODEL> 1315=item C<PERL_ANYEVENT_MODEL>
1164 1316
1165This 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
1166auto detection and -probing kicks in. It must be a string consisting 1318auto detection and -probing kicks in. It must be a string consisting
1167entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended 1319entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
… …
1172This functionality might change in future versions. 1324This functionality might change in future versions.
1173 1325
1174For 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
1175could start your program like this: 1327could start your program like this:
1176 1328
1177 PERL_ANYEVENT_MODEL=Perl perl ... 1329 PERL_ANYEVENT_MODEL=Perl perl ...
1178 1330
1179=item C<PERL_ANYEVENT_PROTOCOLS> 1331=item C<PERL_ANYEVENT_PROTOCOLS>
1180 1332
1181Used 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
1182for 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
… …
1657specified in the variable. 1809specified in the variable.
1658 1810
1659You can make AnyEvent completely ignore this variable by deleting it 1811You can make AnyEvent completely ignore this variable by deleting it
1660before 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:
1661 1813
1662 BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} } 1814 BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }
1663 1815
1664 use AnyEvent; 1816 use AnyEvent;
1665 1817
1666Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can 1818Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1667be used to probe what backend is used and gain other information (which is 1819be used to probe what backend is used and gain other information (which is
1668probably even less useful to an attacker than PERL_ANYEVENT_MODEL). 1820probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
1821$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).
1669 1831
1670 1832
1671=head1 SEE ALSO 1833=head1 SEE ALSO
1672 1834
1673Utility functions: L<AnyEvent::Util>. 1835Utility functions: L<AnyEvent::Util>.
… …
1690Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. 1852Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.
1691 1853
1692 1854
1693=head1 AUTHOR 1855=head1 AUTHOR
1694 1856
1695 Marc Lehmann <schmorp@schmorp.de> 1857 Marc Lehmann <schmorp@schmorp.de>
1696 http://home.schmorp.de/ 1858 http://home.schmorp.de/
1697 1859
1698=cut 1860=cut
1699 1861
17001 18621
1701 1863

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