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Revision 1.253 by root, Tue Jul 21 06:00:47 2009 UTC vs.
Revision 1.309 by root, Sat Dec 26 08:59:35 2009 UTC

1=head1 NAME 1=head1 NAME
2 2
3AnyEvent - events independent of event loop implementation 3AnyEvent - the DBI of event loop programming
4 4
5EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported 5EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt
6event loops. 6and POE are various supported event loops/environments.
7 7
8=head1 SYNOPSIS 8=head1 SYNOPSIS
9 9
10 use AnyEvent; 10 use AnyEvent;
11 11
47 47
48There is a mailinglist for discussing all things AnyEvent, and an IRC 48There is a mailinglist for discussing all things AnyEvent, and an IRC
49channel, too. 49channel, too.
50 50
51See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software 51See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
52Respository>, at L<http://anyevent.schmorp.de>, for more info. 52Repository>, at L<http://anyevent.schmorp.de>, for more info.
53 53
54=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT) 54=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
55 55
56Glib, POE, IO::Async, Event... CPAN offers event models by the dozen 56Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
57nowadays. So what is different about AnyEvent? 57nowadays. So what is different about AnyEvent?
181my variables are only visible after the statement in which they are 181my variables are only visible after the statement in which they are
182declared. 182declared.
183 183
184=head2 I/O WATCHERS 184=head2 I/O WATCHERS
185 185
186 $w = AnyEvent->io (
187 fh => <filehandle_or_fileno>,
188 poll => <"r" or "w">,
189 cb => <callback>,
190 );
191
186You can create an I/O watcher by calling the C<< AnyEvent->io >> method 192You can create an I/O watcher by calling the C<< AnyEvent->io >> method
187with the following mandatory key-value pairs as arguments: 193with the following mandatory key-value pairs as arguments:
188 194
189C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch 195C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch
190for events (AnyEvent might or might not keep a reference to this file 196for events (AnyEvent might or might not keep a reference to this file
219 undef $w; 225 undef $w;
220 }); 226 });
221 227
222=head2 TIME WATCHERS 228=head2 TIME WATCHERS
223 229
230 $w = AnyEvent->timer (after => <seconds>, cb => <callback>);
231
232 $w = AnyEvent->timer (
233 after => <fractional_seconds>,
234 interval => <fractional_seconds>,
235 cb => <callback>,
236 );
237
224You can create a time watcher by calling the C<< AnyEvent->timer >> 238You can create a time watcher by calling the C<< AnyEvent->timer >>
225method with the following mandatory arguments: 239method with the following mandatory arguments:
226 240
227C<after> specifies after how many seconds (fractional values are 241C<after> specifies after how many seconds (fractional values are
228supported) the callback should be invoked. C<cb> is the callback to invoke 242supported) the callback should be invoked. C<cb> is the callback to invoke
349might affect timers and time-outs. 363might affect timers and time-outs.
350 364
351When this is the case, you can call this method, which will update the 365When this is the case, you can call this method, which will update the
352event loop's idea of "current time". 366event loop's idea of "current time".
353 367
368A typical example would be a script in a web server (e.g. C<mod_perl>) -
369when mod_perl executes the script, then the event loop will have the wrong
370idea about the "current time" (being potentially far in the past, when the
371script ran the last time). In that case you should arrange a call to C<<
372AnyEvent->now_update >> each time the web server process wakes up again
373(e.g. at the start of your script, or in a handler).
374
354Note that updating the time I<might> cause some events to be handled. 375Note that updating the time I<might> cause some events to be handled.
355 376
356=back 377=back
357 378
358=head2 SIGNAL WATCHERS 379=head2 SIGNAL WATCHERS
380
381 $w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
359 382
360You can watch for signals using a signal watcher, C<signal> is the signal 383You can watch for signals using a signal watcher, C<signal> is the signal
361I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl 384I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
362callback to be invoked whenever a signal occurs. 385callback to be invoked whenever a signal occurs.
363 386
380 403
381Example: exit on SIGINT 404Example: exit on SIGINT
382 405
383 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); 406 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
384 407
408=head3 Restart Behaviour
409
410While restart behaviour is up to the event loop implementation, most will
411not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
412pure perl implementation).
413
414=head3 Safe/Unsafe Signals
415
416Perl signals can be either "safe" (synchronous to opcode handling) or
417"unsafe" (asynchronous) - the former might get delayed indefinitely, the
418latter might corrupt your memory.
419
420AnyEvent signal handlers are, in addition, synchronous to the event loop,
421i.e. they will not interrupt your running perl program but will only be
422called as part of the normal event handling (just like timer, I/O etc.
423callbacks, too).
424
385=head3 Signal Races, Delays and Workarounds 425=head3 Signal Races, Delays and Workarounds
386 426
387Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching 427Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
388callbacks to signals in a generic way, which is a pity, as you cannot do 428callbacks to signals in a generic way, which is a pity, as you cannot
389race-free signal handling in perl. AnyEvent will try to do it's best, but 429do race-free signal handling in perl, requiring C libraries for
430this. AnyEvent will try to do it's best, which means in some cases,
390in some cases, signals will be delayed. The maximum time a signal might 431signals will be delayed. The maximum time a signal might be delayed is
391be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 432specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
392seconds). This variable can be changed only before the first signal 433variable can be changed only before the first signal watcher is created,
393watcher is created, and should be left alone otherwise. Higher values 434and should be left alone otherwise. This variable determines how often
435AnyEvent polls for signals (in case a wake-up was missed). Higher values
394will cause fewer spurious wake-ups, which is better for power and CPU 436will cause fewer spurious wake-ups, which is better for power and CPU
437saving.
438
395saving. All these problems can be avoided by installing the optional 439All these problems can be avoided by installing the optional
396L<Async::Interrupt> module. This will not work with inherently broken 440L<Async::Interrupt> module, which works with most event loops. It will not
397event loops such as L<Event> or L<Event::Lib> (and not with L<POE> 441work with inherently broken event loops such as L<Event> or L<Event::Lib>
398currently, as POE does it's own workaround with one-second latency). With 442(and not with L<POE> currently, as POE does it's own workaround with
399those, you just have to suffer the delays. 443one-second latency). For those, you just have to suffer the delays.
400 444
401=head2 CHILD PROCESS WATCHERS 445=head2 CHILD PROCESS WATCHERS
402 446
447 $w = AnyEvent->child (pid => <process id>, cb => <callback>);
448
403You can also watch on a child process exit and catch its exit status. 449You can also watch on a child process exit and catch its exit status.
404 450
405The child process is specified by the C<pid> argument (if set to C<0>, it 451The child process is specified by the C<pid> argument (one some backends,
406watches for any child process exit). The watcher will triggered only when 452using C<0> watches for any child process exit, on others this will
407the child process has finished and an exit status is available, not on 453croak). The watcher will be triggered only when the child process has
408any trace events (stopped/continued). 454finished and an exit status is available, not on any trace events
455(stopped/continued).
409 456
410The callback will be called with the pid and exit status (as returned by 457The callback will be called with the pid and exit status (as returned by
411waitpid), so unlike other watcher types, you I<can> rely on child watcher 458waitpid), so unlike other watcher types, you I<can> rely on child watcher
412callback arguments. 459callback arguments.
413 460
454 # do something else, then wait for process exit 501 # do something else, then wait for process exit
455 $done->recv; 502 $done->recv;
456 503
457=head2 IDLE WATCHERS 504=head2 IDLE WATCHERS
458 505
459Sometimes there is a need to do something, but it is not so important 506 $w = AnyEvent->idle (cb => <callback>);
460to do it instantly, but only when there is nothing better to do. This
461"nothing better to do" is usually defined to be "no other events need
462attention by the event loop".
463 507
464Idle watchers ideally get invoked when the event loop has nothing 508Repeatedly invoke the callback after the process becomes idle, until
465better to do, just before it would block the process to wait for new 509either the watcher is destroyed or new events have been detected.
466events. Instead of blocking, the idle watcher is invoked.
467 510
468Most event loops unfortunately do not really support idle watchers (only 511Idle watchers are useful when there is a need to do something, but it
512is not so important (or wise) to do it instantly. The callback will be
513invoked only when there is "nothing better to do", which is usually
514defined as "all outstanding events have been handled and no new events
515have been detected". That means that idle watchers ideally get invoked
516when the event loop has just polled for new events but none have been
517detected. Instead of blocking to wait for more events, the idle watchers
518will be invoked.
519
520Unfortunately, most event loops do not really support idle watchers (only
469EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent 521EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
470will simply call the callback "from time to time". 522will simply call the callback "from time to time".
471 523
472Example: read lines from STDIN, but only process them when the 524Example: read lines from STDIN, but only process them when the
473program is otherwise idle: 525program is otherwise idle:
489 }); 541 });
490 }); 542 });
491 543
492=head2 CONDITION VARIABLES 544=head2 CONDITION VARIABLES
493 545
546 $cv = AnyEvent->condvar;
547
548 $cv->send (<list>);
549 my @res = $cv->recv;
550
494If you are familiar with some event loops you will know that all of them 551If you are familiar with some event loops you will know that all of them
495require you to run some blocking "loop", "run" or similar function that 552require you to run some blocking "loop", "run" or similar function that
496will actively watch for new events and call your callbacks. 553will actively watch for new events and call your callbacks.
497 554
498AnyEvent is slightly different: it expects somebody else to run the event 555AnyEvent is slightly different: it expects somebody else to run the event
562 after => 1, 619 after => 1,
563 cb => sub { $result_ready->send }, 620 cb => sub { $result_ready->send },
564 ); 621 );
565 622
566 # this "blocks" (while handling events) till the callback 623 # this "blocks" (while handling events) till the callback
567 # calls -<send 624 # calls ->send
568 $result_ready->recv; 625 $result_ready->recv;
569 626
570Example: wait for a timer, but take advantage of the fact that condition 627Example: wait for a timer, but take advantage of the fact that condition
571variables are also callable directly. 628variables are also callable directly.
572 629
636one. For example, a function that pings many hosts in parallel might want 693one. For example, a function that pings many hosts in parallel might want
637to use a condition variable for the whole process. 694to use a condition variable for the whole process.
638 695
639Every call to C<< ->begin >> will increment a counter, and every call to 696Every call to C<< ->begin >> will increment a counter, and every call to
640C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end 697C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
641>>, the (last) callback passed to C<begin> will be executed. That callback 698>>, the (last) callback passed to C<begin> will be executed, passing the
642is I<supposed> to call C<< ->send >>, but that is not required. If no 699condvar as first argument. That callback is I<supposed> to call C<< ->send
643callback was set, C<send> will be called without any arguments. 700>>, but that is not required. If no group callback was set, C<send> will
701be called without any arguments.
644 702
645You can think of C<< $cv->send >> giving you an OR condition (one call 703You can think of C<< $cv->send >> giving you an OR condition (one call
646sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND 704sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
647condition (all C<begin> calls must be C<end>'ed before the condvar sends). 705condition (all C<begin> calls must be C<end>'ed before the condvar sends).
648 706
675begung can potentially be zero: 733begung can potentially be zero:
676 734
677 my $cv = AnyEvent->condvar; 735 my $cv = AnyEvent->condvar;
678 736
679 my %result; 737 my %result;
680 $cv->begin (sub { $cv->send (\%result) }); 738 $cv->begin (sub { shift->send (\%result) });
681 739
682 for my $host (@list_of_hosts) { 740 for my $host (@list_of_hosts) {
683 $cv->begin; 741 $cv->begin;
684 ping_host_then_call_callback $host, sub { 742 ping_host_then_call_callback $host, sub {
685 $result{$host} = ...; 743 $result{$host} = ...;
760=item $cb = $cv->cb ($cb->($cv)) 818=item $cb = $cv->cb ($cb->($cv))
761 819
762This is a mutator function that returns the callback set and optionally 820This is a mutator function that returns the callback set and optionally
763replaces it before doing so. 821replaces it before doing so.
764 822
765The callback will be called when the condition becomes "true", i.e. when 823The callback will be called when the condition becomes (or already was)
766C<send> or C<croak> are called, with the only argument being the condition 824"true", i.e. when C<send> or C<croak> are called (or were called), with
767variable itself. Calling C<recv> inside the callback or at any later time 825the only argument being the condition variable itself. Calling C<recv>
768is guaranteed not to block. 826inside the callback or at any later time is guaranteed not to block.
769 827
770=back 828=back
771 829
772=head1 SUPPORTED EVENT LOOPS/BACKENDS 830=head1 SUPPORTED EVENT LOOPS/BACKENDS
773 831
776=over 4 834=over 4
777 835
778=item Backends that are autoprobed when no other event loop can be found. 836=item Backends that are autoprobed when no other event loop can be found.
779 837
780EV is the preferred backend when no other event loop seems to be in 838EV is the preferred backend when no other event loop seems to be in
781use. If EV is not installed, then AnyEvent will try Event, and, failing 839use. If EV is not installed, then AnyEvent will fall back to its own
782that, will fall back to its own pure-perl implementation, which is 840pure-perl implementation, which is available everywhere as it comes with
783available everywhere as it comes with AnyEvent itself. 841AnyEvent itself.
784 842
785 AnyEvent::Impl::EV based on EV (interface to libev, best choice). 843 AnyEvent::Impl::EV based on EV (interface to libev, best choice).
786 AnyEvent::Impl::Event based on Event, very stable, few glitches.
787 AnyEvent::Impl::Perl pure-perl implementation, fast and portable. 844 AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
788 845
789=item Backends that are transparently being picked up when they are used. 846=item Backends that are transparently being picked up when they are used.
790 847
791These will be used when they are currently loaded when the first watcher 848These will be used when they are currently loaded when the first watcher
792is created, in which case it is assumed that the application is using 849is created, in which case it is assumed that the application is using
793them. This means that AnyEvent will automatically pick the right backend 850them. This means that AnyEvent will automatically pick the right backend
794when the main program loads an event module before anything starts to 851when the main program loads an event module before anything starts to
795create watchers. Nothing special needs to be done by the main program. 852create watchers. Nothing special needs to be done by the main program.
796 853
854 AnyEvent::Impl::Event based on Event, very stable, few glitches.
797 AnyEvent::Impl::Glib based on Glib, slow but very stable. 855 AnyEvent::Impl::Glib based on Glib, slow but very stable.
798 AnyEvent::Impl::Tk based on Tk, very broken. 856 AnyEvent::Impl::Tk based on Tk, very broken.
799 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. 857 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
800 AnyEvent::Impl::POE based on POE, very slow, some limitations. 858 AnyEvent::Impl::POE based on POE, very slow, some limitations.
859 AnyEvent::Impl::Irssi used when running within irssi.
801 860
802=item Backends with special needs. 861=item Backends with special needs.
803 862
804Qt requires the Qt::Application to be instantiated first, but will 863Qt requires the Qt::Application to be instantiated first, but will
805otherwise be picked up automatically. As long as the main program 864otherwise be picked up automatically. As long as the main program
910You should check C<$AnyEvent::MODEL> before adding to this array, though: 969You should check C<$AnyEvent::MODEL> before adding to this array, though:
911if it is defined then the event loop has already been detected, and the 970if it is defined then the event loop has already been detected, and the
912array will be ignored. 971array will be ignored.
913 972
914Best use C<AnyEvent::post_detect { BLOCK }> when your application allows 973Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
915it,as it takes care of these details. 974it, as it takes care of these details.
916 975
917This variable is mainly useful for modules that can do something useful 976This variable is mainly useful for modules that can do something useful
918when AnyEvent is used and thus want to know when it is initialised, but do 977when AnyEvent is used and thus want to know when it is initialised, but do
919not need to even load it by default. This array provides the means to hook 978not need to even load it by default. This array provides the means to hook
920into AnyEvent passively, without loading it. 979into AnyEvent passively, without loading it.
980
981Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
982together, you could put this into Coro (this is the actual code used by
983Coro to accomplish this):
984
985 if (defined $AnyEvent::MODEL) {
986 # AnyEvent already initialised, so load Coro::AnyEvent
987 require Coro::AnyEvent;
988 } else {
989 # AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
990 # as soon as it is
991 push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
992 }
921 993
922=back 994=back
923 995
924=head1 WHAT TO DO IN A MODULE 996=head1 WHAT TO DO IN A MODULE
925 997
1074 1146
1075package AnyEvent; 1147package AnyEvent;
1076 1148
1077# basically a tuned-down version of common::sense 1149# basically a tuned-down version of common::sense
1078sub common_sense { 1150sub common_sense {
1079 # no warnings 1151 # from common:.sense 1.0
1080 ${^WARNING_BITS} ^= ${^WARNING_BITS}; 1152 ${^WARNING_BITS} = "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x00";
1081 # use strict vars subs 1153 # use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1082 $^H |= 0x00000600; 1154 $^H |= 0x00000600;
1083} 1155}
1084 1156
1085BEGIN { AnyEvent::common_sense } 1157BEGIN { AnyEvent::common_sense }
1086 1158
1087use Carp (); 1159use Carp ();
1088 1160
1089our $VERSION = 4.86; 1161our $VERSION = '5.23';
1090our $MODEL; 1162our $MODEL;
1091 1163
1092our $AUTOLOAD; 1164our $AUTOLOAD;
1093our @ISA; 1165our @ISA;
1094 1166
1095our @REGISTRY; 1167our @REGISTRY;
1096
1097our $WIN32;
1098 1168
1099our $VERBOSE; 1169our $VERBOSE;
1100 1170
1101BEGIN { 1171BEGIN {
1102 eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; 1172 eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
1119 for reverse split /\s*,\s*/, 1189 for reverse split /\s*,\s*/,
1120 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; 1190 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1121} 1191}
1122 1192
1123my @models = ( 1193my @models = (
1124 [EV:: => AnyEvent::Impl::EV::], 1194 [EV:: => AnyEvent::Impl::EV:: , 1],
1125 [Event:: => AnyEvent::Impl::Event::],
1126 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], 1195 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1127 # everything below here will not be autoprobed 1196 # everything below here will not (normally) be autoprobed
1128 # as the pureperl backend should work everywhere 1197 # as the pureperl backend should work everywhere
1129 # and is usually faster 1198 # and is usually faster
1199 [Event:: => AnyEvent::Impl::Event::, 1],
1130 [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers 1200 [Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1131 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy 1201 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1202 [Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1132 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles 1203 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1133 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program 1204 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1134 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza 1205 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1135 [Wx:: => AnyEvent::Impl::POE::], 1206 [Wx:: => AnyEvent::Impl::POE::],
1136 [Prima:: => AnyEvent::Impl::POE::], 1207 [Prima:: => AnyEvent::Impl::POE::],
1137 # IO::Async is just too broken - we would need workarounds for its 1208 # IO::Async is just too broken - we would need workarounds for its
1138 # byzantine signal and broken child handling, among others. 1209 # byzantine signal and broken child handling, among others.
1139 # IO::Async is rather hard to detect, as it doesn't have any 1210 # IO::Async is rather hard to detect, as it doesn't have any
1140 # obvious default class. 1211 # obvious default class.
1141# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program 1212 [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1142# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program 1213 [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1143# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program 1214 [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1215 [AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1144); 1216);
1145 1217
1146our %method = map +($_ => 1), 1218our %method = map +($_ => 1),
1147 qw(io timer time now now_update signal child idle condvar one_event DESTROY); 1219 qw(io timer time now now_update signal child idle condvar one_event DESTROY);
1148 1220
1194 } 1266 }
1195 } 1267 }
1196 } 1268 }
1197 1269
1198 unless ($MODEL) { 1270 unless ($MODEL) {
1199 # try to load a model 1271 # try to autoload a model
1200
1201 for (@REGISTRY, @models) { 1272 for (@REGISTRY, @models) {
1202 my ($package, $model) = @$_; 1273 my ($package, $model, $autoload) = @$_;
1274 if (
1275 $autoload
1203 if (eval "require $package" 1276 and eval "require $package"
1204 and ${"$package\::VERSION"} > 0 1277 and ${"$package\::VERSION"} > 0
1205 and eval "require $model") { 1278 and eval "require $model"
1279 ) {
1206 $MODEL = $model; 1280 $MODEL = $model;
1207 warn "AnyEvent: autoprobed model '$model', using it.\n" if $VERBOSE >= 2; 1281 warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1208 last; 1282 last;
1209 } 1283 }
1210 } 1284 }
1211 1285
1212 $MODEL 1286 $MODEL
1253 # we assume CLOEXEC is already set by perl in all important cases 1327 # we assume CLOEXEC is already set by perl in all important cases
1254 1328
1255 ($fh2, $rw) 1329 ($fh2, $rw)
1256} 1330}
1257 1331
1332=head1 SIMPLIFIED AE API
1333
1334Starting with version 5.0, AnyEvent officially supports a second, much
1335simpler, API that is designed to reduce the calling, typing and memory
1336overhead.
1337
1338See the L<AE> manpage for details.
1339
1340=cut
1341
1342package AE;
1343
1344our $VERSION = $AnyEvent::VERSION;
1345
1346sub io($$$) {
1347 AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1348}
1349
1350sub timer($$$) {
1351 AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
1352}
1353
1354sub signal($$) {
1355 AnyEvent->signal (signal => $_[0], cb => $_[1])
1356}
1357
1358sub child($$) {
1359 AnyEvent->child (pid => $_[0], cb => $_[1])
1360}
1361
1362sub idle($) {
1363 AnyEvent->idle (cb => $_[0])
1364}
1365
1366sub cv(;&) {
1367 AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
1368}
1369
1370sub now() {
1371 AnyEvent->now
1372}
1373
1374sub now_update() {
1375 AnyEvent->now_update
1376}
1377
1378sub time() {
1379 AnyEvent->time
1380}
1381
1258package AnyEvent::Base; 1382package AnyEvent::Base;
1259 1383
1260# default implementations for many methods 1384# default implementations for many methods
1261 1385
1262sub _time { 1386sub _time() {
1263 # probe for availability of Time::HiRes 1387 # probe for availability of Time::HiRes
1264 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { 1388 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1265 warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8; 1389 warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1266 *_time = \&Time::HiRes::time; 1390 *_time = \&Time::HiRes::time;
1267 # if (eval "use POSIX (); (POSIX::times())... 1391 # if (eval "use POSIX (); (POSIX::times())...
1284} 1408}
1285 1409
1286# default implementation for ->signal 1410# default implementation for ->signal
1287 1411
1288our $HAVE_ASYNC_INTERRUPT; 1412our $HAVE_ASYNC_INTERRUPT;
1413
1414sub _have_async_interrupt() {
1415 $HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
1416 && eval "use Async::Interrupt 1.02 (); 1")
1417 unless defined $HAVE_ASYNC_INTERRUPT;
1418
1419 $HAVE_ASYNC_INTERRUPT
1420}
1421
1289our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); 1422our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1290our (%SIG_ASY, %SIG_ASY_W); 1423our (%SIG_ASY, %SIG_ASY_W);
1291our ($SIG_COUNT, $SIG_TW); 1424our ($SIG_COUNT, $SIG_TW);
1292 1425
1293sub _signal_exec { 1426sub _signal_exec {
1294 $HAVE_ASYNC_INTERRUPT 1427 $HAVE_ASYNC_INTERRUPT
1295 ? $SIGPIPE_R->drain 1428 ? $SIGPIPE_R->drain
1296 : sysread $SIGPIPE_R, my $dummy, 9; 1429 : sysread $SIGPIPE_R, (my $dummy), 9;
1297 1430
1298 while (%SIG_EV) { 1431 while (%SIG_EV) {
1299 for (keys %SIG_EV) { 1432 for (keys %SIG_EV) {
1300 delete $SIG_EV{$_}; 1433 delete $SIG_EV{$_};
1301 $_->() for values %{ $SIG_CB{$_} || {} }; 1434 $_->() for values %{ $SIG_CB{$_} || {} };
1302 } 1435 }
1303 } 1436 }
1304} 1437}
1305 1438
1306# install a dumym wakeupw atcher to reduce signal catching latency 1439# install a dummy wakeup watcher to reduce signal catching latency
1307sub _sig_add() { 1440sub _sig_add() {
1308 unless ($SIG_COUNT++) { 1441 unless ($SIG_COUNT++) {
1309 # try to align timer on a full-second boundary, if possible 1442 # try to align timer on a full-second boundary, if possible
1310 my $NOW = AnyEvent->now; 1443 my $NOW = AE::now;
1311 1444
1312 $SIG_TW = AnyEvent->timer ( 1445 $SIG_TW = AE::timer
1313 after => $MAX_SIGNAL_LATENCY - ($NOW - int $NOW), 1446 $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1314 interval => $MAX_SIGNAL_LATENCY, 1447 $MAX_SIGNAL_LATENCY,
1315 cb => sub { }, # just for the PERL_ASYNC_CHECK 1448 sub { } # just for the PERL_ASYNC_CHECK
1316 ); 1449 ;
1317 } 1450 }
1318} 1451}
1319 1452
1320sub _sig_del { 1453sub _sig_del {
1321 undef $SIG_TW 1454 undef $SIG_TW
1322 unless --$SIG_COUNT; 1455 unless --$SIG_COUNT;
1323} 1456}
1324 1457
1458our $_sig_name_init; $_sig_name_init = sub {
1459 eval q{ # poor man's autoloading
1460 undef $_sig_name_init;
1461
1462 if (_have_async_interrupt) {
1463 *sig2num = \&Async::Interrupt::sig2num;
1464 *sig2name = \&Async::Interrupt::sig2name;
1465 } else {
1466 require Config;
1467
1468 my %signame2num;
1469 @signame2num{ split ' ', $Config::Config{sig_name} }
1470 = split ' ', $Config::Config{sig_num};
1471
1472 my @signum2name;
1473 @signum2name[values %signame2num] = keys %signame2num;
1474
1475 *sig2num = sub($) {
1476 $_[0] > 0 ? shift : $signame2num{+shift}
1477 };
1478 *sig2name = sub ($) {
1479 $_[0] > 0 ? $signum2name[+shift] : shift
1480 };
1481 }
1482 };
1483 die if $@;
1484};
1485
1486sub sig2num ($) { &$_sig_name_init; &sig2num }
1487sub sig2name($) { &$_sig_name_init; &sig2name }
1488
1325sub _signal { 1489sub signal {
1490 eval q{ # poor man's autoloading {}
1491 # probe for availability of Async::Interrupt
1492 if (_have_async_interrupt) {
1493 warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1494
1495 $SIGPIPE_R = new Async::Interrupt::EventPipe;
1496 $SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1497
1498 } else {
1499 warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1500
1501 require Fcntl;
1502
1503 if (AnyEvent::WIN32) {
1504 require AnyEvent::Util;
1505
1506 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1507 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1508 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1509 } else {
1510 pipe $SIGPIPE_R, $SIGPIPE_W;
1511 fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1512 fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
1513
1514 # not strictly required, as $^F is normally 2, but let's make sure...
1515 fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1516 fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1517 }
1518
1519 $SIGPIPE_R
1520 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1521
1522 $SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1523 }
1524
1525 *signal = sub {
1326 my (undef, %arg) = @_; 1526 my (undef, %arg) = @_;
1327 1527
1328 my $signal = uc $arg{signal} 1528 my $signal = uc $arg{signal}
1329 or Carp::croak "required option 'signal' is missing"; 1529 or Carp::croak "required option 'signal' is missing";
1330 1530
1331 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1332
1333 if ($HAVE_ASYNC_INTERRUPT) { 1531 if ($HAVE_ASYNC_INTERRUPT) {
1334 # async::interrupt 1532 # async::interrupt
1335 1533
1336 $SIG_ASY{$signal} ||= do { 1534 $signal = sig2num $signal;
1337 my $asy = new Async::Interrupt 1535 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1536
1537 $SIG_ASY{$signal} ||= new Async::Interrupt
1338 cb => sub { undef $SIG_EV{$signal} }, 1538 cb => sub { undef $SIG_EV{$signal} },
1339 signal => $signal, 1539 signal => $signal,
1340 pipe => [$SIGPIPE_R->filenos], 1540 pipe => [$SIGPIPE_R->filenos],
1541 pipe_autodrain => 0,
1542 ;
1543
1544 } else {
1545 # pure perl
1546
1547 # AE::Util has been loaded in signal
1548 $signal = sig2name $signal;
1549 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1550
1551 $SIG{$signal} ||= sub {
1552 local $!;
1553 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1554 undef $SIG_EV{$signal};
1555 };
1556
1557 # can't do signal processing without introducing races in pure perl,
1558 # so limit the signal latency.
1559 _sig_add;
1341 ; 1560 }
1342 $asy->pipe_autodrain (0);
1343 1561
1344 $asy 1562 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1345 }; 1563 };
1346 1564
1347 } else { 1565 *AnyEvent::Base::signal::DESTROY = sub {
1348 # pure perl 1566 my ($signal, $cb) = @{$_[0]};
1349 1567
1350 $SIG{$signal} ||= sub { 1568 _sig_del;
1351 local $!; 1569
1352 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; 1570 delete $SIG_CB{$signal}{$cb};
1571
1572 $HAVE_ASYNC_INTERRUPT
1573 ? delete $SIG_ASY{$signal}
1574 : # delete doesn't work with older perls - they then
1575 # print weird messages, or just unconditionally exit
1576 # instead of getting the default action.
1353 undef $SIG_EV{$signal}; 1577 undef $SIG{$signal}
1578 unless keys %{ $SIG_CB{$signal} };
1354 }; 1579 };
1355
1356 # can't do signal processing without introducing races in pure perl,
1357 # so limit the signal latency.
1358 _sig_add;
1359 } 1580 };
1360 1581 die if $@;
1361 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1362}
1363
1364sub signal {
1365 # probe for availability of Async::Interrupt
1366 if (!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} && eval "use Async::Interrupt 0.6 (); 1") {
1367 warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1368
1369 $HAVE_ASYNC_INTERRUPT = 1;
1370 $SIGPIPE_R = new Async::Interrupt::EventPipe;
1371 $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec);
1372
1373 } else {
1374 warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1375
1376 require Fcntl;
1377
1378 if (AnyEvent::WIN32) {
1379 require AnyEvent::Util;
1380
1381 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1382 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1383 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1384 } else {
1385 pipe $SIGPIPE_R, $SIGPIPE_W;
1386 fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1387 fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
1388
1389 # not strictly required, as $^F is normally 2, but let's make sure...
1390 fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1391 fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1392 }
1393
1394 $SIGPIPE_R
1395 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1396
1397 $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1398 }
1399
1400 *signal = \&_signal;
1401 &signal 1582 &signal
1402}
1403
1404sub AnyEvent::Base::signal::DESTROY {
1405 my ($signal, $cb) = @{$_[0]};
1406
1407 _sig_del;
1408
1409 delete $SIG_CB{$signal}{$cb};
1410
1411 $HAVE_ASYNC_INTERRUPT
1412 ? delete $SIG_ASY{$signal}
1413 : # delete doesn't work with older perls - they then
1414 # print weird messages, or just unconditionally exit
1415 # instead of getting the default action.
1416 undef $SIG{$signal}
1417 unless keys %{ $SIG_CB{$signal} };
1418} 1583}
1419 1584
1420# default implementation for ->child 1585# default implementation for ->child
1421 1586
1422our %PID_CB; 1587our %PID_CB;
1423our $CHLD_W; 1588our $CHLD_W;
1424our $CHLD_DELAY_W; 1589our $CHLD_DELAY_W;
1425our $WNOHANG; 1590our $WNOHANG;
1426 1591
1592sub _emit_childstatus($$) {
1593 my (undef, $rpid, $rstatus) = @_;
1594
1595 $_->($rpid, $rstatus)
1596 for values %{ $PID_CB{$rpid} || {} },
1597 values %{ $PID_CB{0} || {} };
1598}
1599
1427sub _sigchld { 1600sub _sigchld {
1601 my $pid;
1602
1603 AnyEvent->_emit_childstatus ($pid, $?)
1428 while (0 < (my $pid = waitpid -1, $WNOHANG)) { 1604 while ($pid = waitpid -1, $WNOHANG) > 0;
1429 $_->($pid, $?)
1430 for values %{ $PID_CB{$pid} || {} },
1431 values %{ $PID_CB{0} || {} };
1432 }
1433} 1605}
1434 1606
1435sub child { 1607sub child {
1436 my (undef, %arg) = @_; 1608 my (undef, %arg) = @_;
1437 1609
1444 $WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/ 1616 $WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1445 ? 1 1617 ? 1
1446 : eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; 1618 : eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1447 1619
1448 unless ($CHLD_W) { 1620 unless ($CHLD_W) {
1449 $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); 1621 $CHLD_W = AE::signal CHLD => \&_sigchld;
1450 # child could be a zombie already, so make at least one round 1622 # child could be a zombie already, so make at least one round
1451 &_sigchld; 1623 &_sigchld;
1452 } 1624 }
1453 1625
1454 bless [$pid, $arg{cb}], "AnyEvent::Base::child" 1626 bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1480 # never use more then 50% of the time for the idle watcher, 1652 # never use more then 50% of the time for the idle watcher,
1481 # within some limits 1653 # within some limits
1482 $w = 0.0001 if $w < 0.0001; 1654 $w = 0.0001 if $w < 0.0001;
1483 $w = 5 if $w > 5; 1655 $w = 5 if $w > 5;
1484 1656
1485 $w = AnyEvent->timer (after => $w, cb => $rcb); 1657 $w = AE::timer $w, 0, $rcb;
1486 } else { 1658 } else {
1487 # clean up... 1659 # clean up...
1488 undef $w; 1660 undef $w;
1489 undef $rcb; 1661 undef $rcb;
1490 } 1662 }
1491 }; 1663 };
1492 1664
1493 $w = AnyEvent->timer (after => 0.05, cb => $rcb); 1665 $w = AE::timer 0.05, 0, $rcb;
1494 1666
1495 bless \\$cb, "AnyEvent::Base::idle" 1667 bless \\$cb, "AnyEvent::Base::idle"
1496} 1668}
1497 1669
1498sub AnyEvent::Base::idle::DESTROY { 1670sub AnyEvent::Base::idle::DESTROY {
1552 Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak}; 1724 Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1553 wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0] 1725 wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1554} 1726}
1555 1727
1556sub cb { 1728sub cb {
1557 $_[0]{_ae_cb} = $_[1] if @_ > 1; 1729 my $cv = shift;
1730
1731 @_
1732 and $cv->{_ae_cb} = shift
1733 and $cv->{_ae_sent}
1734 and (delete $cv->{_ae_cb})->($cv);
1735
1558 $_[0]{_ae_cb} 1736 $cv->{_ae_cb}
1559} 1737}
1560 1738
1561sub begin { 1739sub begin {
1562 ++$_[0]{_ae_counter}; 1740 ++$_[0]{_ae_counter};
1563 $_[0]{_ae_end_cb} = $_[1] if @_ > 1; 1741 $_[0]{_ae_end_cb} = $_[1] if @_ > 1;
1772 warn "read: $input\n"; # output what has been read 1950 warn "read: $input\n"; # output what has been read
1773 $cv->send if $input =~ /^q/i; # quit program if /^q/i 1951 $cv->send if $input =~ /^q/i; # quit program if /^q/i
1774 }, 1952 },
1775 ); 1953 );
1776 1954
1777 my $time_watcher; # can only be used once
1778
1779 sub new_timer {
1780 $timer = AnyEvent->timer (after => 1, cb => sub { 1955 my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1781 warn "timeout\n"; # print 'timeout' about every second 1956 warn "timeout\n"; # print 'timeout' at most every second
1782 &new_timer; # and restart the time
1783 }); 1957 });
1784 }
1785
1786 new_timer; # create first timer
1787 1958
1788 $cv->recv; # wait until user enters /^q/i 1959 $cv->recv; # wait until user enters /^q/i
1789 1960
1790=head1 REAL-WORLD EXAMPLE 1961=head1 REAL-WORLD EXAMPLE
1791 1962
1922through AnyEvent. The benchmark creates a lot of timers (with a zero 2093through AnyEvent. The benchmark creates a lot of timers (with a zero
1923timeout) and I/O watchers (watching STDOUT, a pty, to become writable, 2094timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1924which it is), lets them fire exactly once and destroys them again. 2095which it is), lets them fire exactly once and destroys them again.
1925 2096
1926Source code for this benchmark is found as F<eg/bench> in the AnyEvent 2097Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1927distribution. 2098distribution. It uses the L<AE> interface, which makes a real difference
2099for the EV and Perl backends only.
1928 2100
1929=head3 Explanation of the columns 2101=head3 Explanation of the columns
1930 2102
1931I<watcher> is the number of event watchers created/destroyed. Since 2103I<watcher> is the number of event watchers created/destroyed. Since
1932different event models feature vastly different performances, each event 2104different event models feature vastly different performances, each event
1953watcher. 2125watcher.
1954 2126
1955=head3 Results 2127=head3 Results
1956 2128
1957 name watchers bytes create invoke destroy comment 2129 name watchers bytes create invoke destroy comment
1958 EV/EV 400000 224 0.47 0.35 0.27 EV native interface 2130 EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1959 EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers 2131 EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1960 CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal 2132 Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1961 Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation 2133 Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1962 Event/Event 16000 517 32.20 31.80 0.81 Event native interface 2134 Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1963 Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers 2135 Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
1964 IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll 2136 IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
1965 IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll 2137 IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1966 Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour 2138 Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1967 Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers 2139 Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1968 POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event 2140 POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1969 POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select 2141 POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1970 2142
1971=head3 Discussion 2143=head3 Discussion
1972 2144
1973The benchmark does I<not> measure scalability of the event loop very 2145The benchmark does I<not> measure scalability of the event loop very
1974well. For example, a select-based event loop (such as the pure perl one) 2146well. For example, a select-based event loop (such as the pure perl one)
1986benchmark machine, handling an event takes roughly 1600 CPU cycles with 2158benchmark machine, handling an event takes roughly 1600 CPU cycles with
1987EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU 2159EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1988cycles with POE. 2160cycles with POE.
1989 2161
1990C<EV> is the sole leader regarding speed and memory use, which are both 2162C<EV> is the sole leader regarding speed and memory use, which are both
1991maximal/minimal, respectively. Even when going through AnyEvent, it uses 2163maximal/minimal, respectively. When using the L<AE> API there is zero
2164overhead (when going through the AnyEvent API create is about 5-6 times
2165slower, with other times being equal, so still uses far less memory than
1992far less memory than any other event loop and is still faster than Event 2166any other event loop and is still faster than Event natively).
1993natively.
1994 2167
1995The pure perl implementation is hit in a few sweet spots (both the 2168The pure perl implementation is hit in a few sweet spots (both the
1996constant timeout and the use of a single fd hit optimisations in the perl 2169constant timeout and the use of a single fd hit optimisations in the perl
1997interpreter and the backend itself). Nevertheless this shows that it 2170interpreter and the backend itself). Nevertheless this shows that it
1998adds very little overhead in itself. Like any select-based backend its 2171adds very little overhead in itself. Like any select-based backend its
2072In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100 2245In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
2073(1%) are active. This mirrors the activity of large servers with many 2246(1%) are active. This mirrors the activity of large servers with many
2074connections, most of which are idle at any one point in time. 2247connections, most of which are idle at any one point in time.
2075 2248
2076Source code for this benchmark is found as F<eg/bench2> in the AnyEvent 2249Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
2077distribution. 2250distribution. It uses the L<AE> interface, which makes a real difference
2251for the EV and Perl backends only.
2078 2252
2079=head3 Explanation of the columns 2253=head3 Explanation of the columns
2080 2254
2081I<sockets> is the number of sockets, and twice the number of "servers" (as 2255I<sockets> is the number of sockets, and twice the number of "servers" (as
2082each server has a read and write socket end). 2256each server has a read and write socket end).
2090a new one that moves the timeout into the future. 2264a new one that moves the timeout into the future.
2091 2265
2092=head3 Results 2266=head3 Results
2093 2267
2094 name sockets create request 2268 name sockets create request
2095 EV 20000 69.01 11.16 2269 EV 20000 62.66 7.99
2096 Perl 20000 73.32 35.87 2270 Perl 20000 68.32 32.64
2097 IOAsync 20000 157.00 98.14 epoll 2271 IOAsync 20000 174.06 101.15 epoll
2098 IOAsync 20000 159.31 616.06 poll 2272 IOAsync 20000 174.67 610.84 poll
2099 Event 20000 212.62 257.32 2273 Event 20000 202.69 242.91
2100 Glib 20000 651.16 1896.30 2274 Glib 20000 557.01 1689.52
2101 POE 20000 349.67 12317.24 uses POE::Loop::Event 2275 POE 20000 341.54 12086.32 uses POE::Loop::Event
2102 2276
2103=head3 Discussion 2277=head3 Discussion
2104 2278
2105This benchmark I<does> measure scalability and overall performance of the 2279This benchmark I<does> measure scalability and overall performance of the
2106particular event loop. 2280particular event loop.
2232As you can see, the AnyEvent + EV combination even beats the 2406As you can see, the AnyEvent + EV combination even beats the
2233hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl 2407hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2234backend easily beats IO::Lambda and POE. 2408backend easily beats IO::Lambda and POE.
2235 2409
2236And even the 100% non-blocking version written using the high-level (and 2410And even the 100% non-blocking version written using the high-level (and
2237slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a 2411slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2238large margin, even though it does all of DNS, tcp-connect and socket I/O 2412higher level ("unoptimised") abstractions by a large margin, even though
2239in a non-blocking way. 2413it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2240 2414
2241The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and 2415The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2242F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are 2416F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2243part of the IO::lambda distribution and were used without any changes. 2417part of the IO::Lambda distribution and were used without any changes.
2244 2418
2245 2419
2246=head1 SIGNALS 2420=head1 SIGNALS
2247 2421
2248AnyEvent currently installs handlers for these signals: 2422AnyEvent currently installs handlers for these signals:
2290it's built-in modules) are required to use it. 2464it's built-in modules) are required to use it.
2291 2465
2292That does not mean that AnyEvent won't take advantage of some additional 2466That does not mean that AnyEvent won't take advantage of some additional
2293modules if they are installed. 2467modules if they are installed.
2294 2468
2295This section epxlains which additional modules will be used, and how they 2469This section explains which additional modules will be used, and how they
2296affect AnyEvent's operetion. 2470affect AnyEvent's operation.
2297 2471
2298=over 4 2472=over 4
2299 2473
2300=item L<Async::Interrupt> 2474=item L<Async::Interrupt>
2301 2475
2306catch the signals) with some delay (default is 10 seconds, look for 2480catch the signals) with some delay (default is 10 seconds, look for
2307C<$AnyEvent::MAX_SIGNAL_LATENCY>). 2481C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2308 2482
2309If this module is available, then it will be used to implement signal 2483If this module is available, then it will be used to implement signal
2310catching, which means that signals will not be delayed, and the event loop 2484catching, which means that signals will not be delayed, and the event loop
2311will not be interrupted regularly, which is more efficient (And good for 2485will not be interrupted regularly, which is more efficient (and good for
2312battery life on laptops). 2486battery life on laptops).
2313 2487
2314This affects not just the pure-perl event loop, but also other event loops 2488This affects not just the pure-perl event loop, but also other event loops
2315that have no signal handling on their own (e.g. Glib, Tk, Qt). 2489that have no signal handling on their own (e.g. Glib, Tk, Qt).
2316 2490
2337lot less memory), but otherwise doesn't affect guard operation much. It is 2511lot less memory), but otherwise doesn't affect guard operation much. It is
2338purely used for performance. 2512purely used for performance.
2339 2513
2340=item L<JSON> and L<JSON::XS> 2514=item L<JSON> and L<JSON::XS>
2341 2515
2342This module is required when you want to read or write JSON data via 2516One of these modules is required when you want to read or write JSON data
2343L<AnyEvent::Handle>. It is also written in pure-perl, but can take 2517via L<AnyEvent::Handle>. It is also written in pure-perl, but can take
2344advantage of the ultra-high-speed L<JSON::XS> module when it is installed. 2518advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2345 2519
2346In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is 2520In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2347installed. 2521installed.
2348 2522
2363 2537
2364 2538
2365=head1 FORK 2539=head1 FORK
2366 2540
2367Most event libraries are not fork-safe. The ones who are usually are 2541Most event libraries are not fork-safe. The ones who are usually are
2368because they rely on inefficient but fork-safe C<select> or C<poll> 2542because they rely on inefficient but fork-safe C<select> or C<poll> calls
2369calls. Only L<EV> is fully fork-aware. 2543- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
2544are usually badly thought-out hacks that are incompatible with fork in
2545one way or another. Only L<EV> is fully fork-aware and ensures that you
2546continue event-processing in both parent and child (or both, if you know
2547what you are doing).
2548
2549This means that, in general, you cannot fork and do event processing in
2550the child if the event library was initialised before the fork (which
2551usually happens when the first AnyEvent watcher is created, or the library
2552is loaded).
2370 2553
2371If you have to fork, you must either do so I<before> creating your first 2554If you have to fork, you must either do so I<before> creating your first
2372watcher OR you must not use AnyEvent at all in the child OR you must do 2555watcher OR you must not use AnyEvent at all in the child OR you must do
2373something completely out of the scope of AnyEvent. 2556something completely out of the scope of AnyEvent.
2557
2558The problem of doing event processing in the parent I<and> the child
2559is much more complicated: even for backends that I<are> fork-aware or
2560fork-safe, their behaviour is not usually what you want: fork clones all
2561watchers, that means all timers, I/O watchers etc. are active in both
2562parent and child, which is almost never what you want. USing C<exec>
2563to start worker children from some kind of manage rprocess is usually
2564preferred, because it is much easier and cleaner, at the expense of having
2565to have another binary.
2374 2566
2375 2567
2376=head1 SECURITY CONSIDERATIONS 2568=head1 SECURITY CONSIDERATIONS
2377 2569
2378AnyEvent can be forced to load any event model via 2570AnyEvent can be forced to load any event model via
2416L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. 2608L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2417 2609
2418Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, 2610Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2419L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, 2611L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2420L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, 2612L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2421L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>. 2613L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
2422 2614
2423Non-blocking file handles, sockets, TCP clients and 2615Non-blocking file handles, sockets, TCP clients and
2424servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>. 2616servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2425 2617
2426Asynchronous DNS: L<AnyEvent::DNS>. 2618Asynchronous DNS: L<AnyEvent::DNS>.

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