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1=head1 NAME 1=head1 NAME
2 2
3AnyEvent - provide framework for multiple event loops 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
40=head1 INTRODUCTION/TUTORIAL 40=head1 INTRODUCTION/TUTORIAL
41 41
42This manpage is mainly a reference manual. If you are interested 42This manpage is mainly a reference manual. If you are interested
43in a tutorial or some gentle introduction, have a look at the 43in a tutorial or some gentle introduction, have a look at the
44L<AnyEvent::Intro> manpage. 44L<AnyEvent::Intro> manpage.
45
46=head1 SUPPORT
47
48There is a mailinglist for discussing all things AnyEvent, and an IRC
49channel, too.
50
51See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
52Repository>, at L<http://anyevent.schmorp.de>, for more info.
45 53
46=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT) 54=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
47 55
48Glib, POE, IO::Async, Event... CPAN offers event models by the dozen 56Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
49nowadays. So what is different about AnyEvent? 57nowadays. So what is different about AnyEvent?
173my variables are only visible after the statement in which they are 181my variables are only visible after the statement in which they are
174declared. 182declared.
175 183
176=head2 I/O WATCHERS 184=head2 I/O WATCHERS
177 185
186 $w = AnyEvent->io (
187 fh => <filehandle_or_fileno>,
188 poll => <"r" or "w">,
189 cb => <callback>,
190 );
191
178You 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
179with the following mandatory key-value pairs as arguments: 193with the following mandatory key-value pairs as arguments:
180 194
181C<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
182for 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
211 undef $w; 225 undef $w;
212 }); 226 });
213 227
214=head2 TIME WATCHERS 228=head2 TIME WATCHERS
215 229
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
216You can create a time watcher by calling the C<< AnyEvent->timer >> 238You can create a time watcher by calling the C<< AnyEvent->timer >>
217method with the following mandatory arguments: 239method with the following mandatory arguments:
218 240
219C<after> specifies after how many seconds (fractional values are 241C<after> specifies after how many seconds (fractional values are
220supported) 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
341might affect timers and time-outs. 363might affect timers and time-outs.
342 364
343When 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
344event loop's idea of "current time". 366event loop's idea of "current time".
345 367
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
346Note 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.
347 376
348=back 377=back
349 378
350=head2 SIGNAL WATCHERS 379=head2 SIGNAL WATCHERS
380
381 $w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
351 382
352You 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
353I<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
354callback to be invoked whenever a signal occurs. 385callback to be invoked whenever a signal occurs.
355 386
368 399
369This watcher might use C<%SIG> (depending on the event loop used), 400This watcher might use C<%SIG> (depending on the event loop used),
370so programs overwriting those signals directly will likely not work 401so programs overwriting those signals directly will likely not work
371correctly. 402correctly.
372 403
404Example: exit on SIGINT
405
406 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
407
408=head3 Restart Behaviour
409
410While restart behaviour is up to the event loop implementation, most will
411not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
412pure perl implementation).
413
414=head3 Safe/Unsafe Signals
415
416Perl signals can be either "safe" (synchronous to opcode handling) or
417"unsafe" (asynchronous) - the former might get delayed indefinitely, the
418latter might corrupt your memory.
419
420AnyEvent signal handlers are, in addition, synchronous to the event loop,
421i.e. they will not interrupt your running perl program but will only be
422called as part of the normal event handling (just like timer, I/O etc.
423callbacks, too).
424
425=head3 Signal Races, Delays and Workarounds
426
373Also note that many event loops (e.g. Glib, Tk, Qt, IO::Async) do not 427Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
374support attaching callbacks to signals, which is a pity, as you cannot do 428callbacks to signals in a generic way, which is a pity, as you cannot
375race-free signal handling in perl. AnyEvent will try to do it's best, but 429do race-free signal handling in perl, requiring C libraries for
430this. AnyEvent will try to do it's best, which means in some cases,
376in some cases, signals will be delayed. The maximum time a signal might 431signals will be delayed. The maximum time a signal might be delayed is
377be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 432specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
378seconds). This variable can be changed only before the first signal 433variable can be changed only before the first signal watcher is created,
379watcher 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
380will 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
381saving. All these problems can be avoided by installing the optional 439All these problems can be avoided by installing the optional
382L<Async::Interrupt> module. 440L<Async::Interrupt> module, which works with most event loops. It will not
383 441work with inherently broken event loops such as L<Event> or L<Event::Lib>
384Example: exit on SIGINT 442(and not with L<POE> currently, as POE does it's own workaround with
385 443one-second latency). For those, you just have to suffer the delays.
386 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
387 444
388=head2 CHILD PROCESS WATCHERS 445=head2 CHILD PROCESS WATCHERS
389 446
447 $w = AnyEvent->child (pid => <process id>, cb => <callback>);
448
390You 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.
391 450
392The 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,
393watches for any child process exit). The watcher will triggered only when 452using C<0> watches for any child process exit, on others this will
394the child process has finished and an exit status is available, not on 453croak). The watcher will be triggered only when the child process has
395any trace events (stopped/continued). 454finished and an exit status is available, not on any trace events
455(stopped/continued).
396 456
397The 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
398waitpid), 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
399callback arguments. 459callback arguments.
400 460
441 # do something else, then wait for process exit 501 # do something else, then wait for process exit
442 $done->recv; 502 $done->recv;
443 503
444=head2 IDLE WATCHERS 504=head2 IDLE WATCHERS
445 505
506 $w = AnyEvent->idle (cb => <callback>);
507
446Sometimes there is a need to do something, but it is not so important 508Sometimes there is a need to do something, but it is not so important
447to do it instantly, but only when there is nothing better to do. This 509to do it instantly, but only when there is nothing better to do. This
448"nothing better to do" is usually defined to be "no other events need 510"nothing better to do" is usually defined to be "no other events need
449attention by the event loop". 511attention by the event loop".
450 512
476 }); 538 });
477 }); 539 });
478 540
479=head2 CONDITION VARIABLES 541=head2 CONDITION VARIABLES
480 542
543 $cv = AnyEvent->condvar;
544
545 $cv->send (<list>);
546 my @res = $cv->recv;
547
481If you are familiar with some event loops you will know that all of them 548If you are familiar with some event loops you will know that all of them
482require you to run some blocking "loop", "run" or similar function that 549require you to run some blocking "loop", "run" or similar function that
483will actively watch for new events and call your callbacks. 550will actively watch for new events and call your callbacks.
484 551
485AnyEvent is slightly different: it expects somebody else to run the event 552AnyEvent is slightly different: it expects somebody else to run the event
504Condition variables are similar to callbacks, except that you can 571Condition variables are similar to callbacks, except that you can
505optionally wait for them. They can also be called merge points - points 572optionally wait for them. They can also be called merge points - points
506in time where multiple outstanding events have been processed. And yet 573in time where multiple outstanding events have been processed. And yet
507another way to call them is transactions - each condition variable can be 574another way to call them is transactions - each condition variable can be
508used to represent a transaction, which finishes at some point and delivers 575used to represent a transaction, which finishes at some point and delivers
509a result. 576a result. And yet some people know them as "futures" - a promise to
577compute/deliver something that you can wait for.
510 578
511Condition variables are very useful to signal that something has finished, 579Condition variables are very useful to signal that something has finished,
512for example, if you write a module that does asynchronous http requests, 580for example, if you write a module that does asynchronous http requests,
513then a condition variable would be the ideal candidate to signal the 581then a condition variable would be the ideal candidate to signal the
514availability of results. The user can either act when the callback is 582availability of results. The user can either act when the callback is
548 after => 1, 616 after => 1,
549 cb => sub { $result_ready->send }, 617 cb => sub { $result_ready->send },
550 ); 618 );
551 619
552 # this "blocks" (while handling events) till the callback 620 # this "blocks" (while handling events) till the callback
553 # calls -<send 621 # calls ->send
554 $result_ready->recv; 622 $result_ready->recv;
555 623
556Example: wait for a timer, but take advantage of the fact that condition 624Example: wait for a timer, but take advantage of the fact that condition
557variables are also callable directly. 625variables are also callable directly.
558 626
622one. For example, a function that pings many hosts in parallel might want 690one. For example, a function that pings many hosts in parallel might want
623to use a condition variable for the whole process. 691to use a condition variable for the whole process.
624 692
625Every call to C<< ->begin >> will increment a counter, and every call to 693Every call to C<< ->begin >> will increment a counter, and every call to
626C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end 694C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
627>>, the (last) callback passed to C<begin> will be executed. That callback 695>>, the (last) callback passed to C<begin> will be executed, passing the
628is I<supposed> to call C<< ->send >>, but that is not required. If no 696condvar as first argument. That callback is I<supposed> to call C<< ->send
629callback was set, C<send> will be called without any arguments. 697>>, but that is not required. If no group callback was set, C<send> will
698be called without any arguments.
630 699
631You can think of C<< $cv->send >> giving you an OR condition (one call 700You can think of C<< $cv->send >> giving you an OR condition (one call
632sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND 701sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
633condition (all C<begin> calls must be C<end>'ed before the condvar sends). 702condition (all C<begin> calls must be C<end>'ed before the condvar sends).
634 703
661begung can potentially be zero: 730begung can potentially be zero:
662 731
663 my $cv = AnyEvent->condvar; 732 my $cv = AnyEvent->condvar;
664 733
665 my %result; 734 my %result;
666 $cv->begin (sub { $cv->send (\%result) }); 735 $cv->begin (sub { shift->send (\%result) });
667 736
668 for my $host (@list_of_hosts) { 737 for my $host (@list_of_hosts) {
669 $cv->begin; 738 $cv->begin;
670 ping_host_then_call_callback $host, sub { 739 ping_host_then_call_callback $host, sub {
671 $result{$host} = ...; 740 $result{$host} = ...;
746=item $cb = $cv->cb ($cb->($cv)) 815=item $cb = $cv->cb ($cb->($cv))
747 816
748This is a mutator function that returns the callback set and optionally 817This is a mutator function that returns the callback set and optionally
749replaces it before doing so. 818replaces it before doing so.
750 819
751The callback will be called when the condition becomes "true", i.e. when 820The callback will be called when the condition becomes (or already was)
752C<send> or C<croak> are called, with the only argument being the condition 821"true", i.e. when C<send> or C<croak> are called (or were called), with
753variable itself. Calling C<recv> inside the callback or at any later time 822the only argument being the condition variable itself. Calling C<recv>
754is guaranteed not to block. 823inside the callback or at any later time is guaranteed not to block.
755 824
756=back 825=back
757 826
758=head1 SUPPORTED EVENT LOOPS/BACKENDS 827=head1 SUPPORTED EVENT LOOPS/BACKENDS
759 828
762=over 4 831=over 4
763 832
764=item Backends that are autoprobed when no other event loop can be found. 833=item Backends that are autoprobed when no other event loop can be found.
765 834
766EV is the preferred backend when no other event loop seems to be in 835EV is the preferred backend when no other event loop seems to be in
767use. If EV is not installed, then AnyEvent will try Event, and, failing 836use. If EV is not installed, then AnyEvent will fall back to its own
768that, will fall back to its own pure-perl implementation, which is 837pure-perl implementation, which is available everywhere as it comes with
769available everywhere as it comes with AnyEvent itself. 838AnyEvent itself.
770 839
771 AnyEvent::Impl::EV based on EV (interface to libev, best choice). 840 AnyEvent::Impl::EV based on EV (interface to libev, best choice).
772 AnyEvent::Impl::Event based on Event, very stable, few glitches.
773 AnyEvent::Impl::Perl pure-perl implementation, fast and portable. 841 AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
774 842
775=item Backends that are transparently being picked up when they are used. 843=item Backends that are transparently being picked up when they are used.
776 844
777These will be used when they are currently loaded when the first watcher 845These will be used when they are currently loaded when the first watcher
778is created, in which case it is assumed that the application is using 846is created, in which case it is assumed that the application is using
779them. This means that AnyEvent will automatically pick the right backend 847them. This means that AnyEvent will automatically pick the right backend
780when the main program loads an event module before anything starts to 848when the main program loads an event module before anything starts to
781create watchers. Nothing special needs to be done by the main program. 849create watchers. Nothing special needs to be done by the main program.
782 850
851 AnyEvent::Impl::Event based on Event, very stable, few glitches.
783 AnyEvent::Impl::Glib based on Glib, slow but very stable. 852 AnyEvent::Impl::Glib based on Glib, slow but very stable.
784 AnyEvent::Impl::Tk based on Tk, very broken. 853 AnyEvent::Impl::Tk based on Tk, very broken.
785 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. 854 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
786 AnyEvent::Impl::POE based on POE, very slow, some limitations. 855 AnyEvent::Impl::POE based on POE, very slow, some limitations.
856 AnyEvent::Impl::Irssi used when running within irssi.
787 857
788=item Backends with special needs. 858=item Backends with special needs.
789 859
790Qt requires the Qt::Application to be instantiated first, but will 860Qt requires the Qt::Application to be instantiated first, but will
791otherwise be picked up automatically. As long as the main program 861otherwise be picked up automatically. As long as the main program
865event module detection too early, for example, L<AnyEvent::AIO> creates 935event module detection too early, for example, L<AnyEvent::AIO> creates
866and installs the global L<IO::AIO> watcher in a C<post_detect> block to 936and installs the global L<IO::AIO> watcher in a C<post_detect> block to
867avoid autodetecting the event module at load time. 937avoid autodetecting the event module at load time.
868 938
869If called in scalar or list context, then it creates and returns an object 939If called in scalar or list context, then it creates and returns an object
870that automatically removes the callback again when it is destroyed. See 940that automatically removes the callback again when it is destroyed (or
941C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
871L<Coro::BDB> for a case where this is useful. 942a case where this is useful.
943
944Example: Create a watcher for the IO::AIO module and store it in
945C<$WATCHER>. Only do so after the event loop is initialised, though.
946
947 our WATCHER;
948
949 my $guard = AnyEvent::post_detect {
950 $WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
951 };
952
953 # the ||= is important in case post_detect immediately runs the block,
954 # as to not clobber the newly-created watcher. assigning both watcher and
955 # post_detect guard to the same variable has the advantage of users being
956 # able to just C<undef $WATCHER> if the watcher causes them grief.
957
958 $WATCHER ||= $guard;
872 959
873=item @AnyEvent::post_detect 960=item @AnyEvent::post_detect
874 961
875If there are any code references in this array (you can C<push> to it 962If there are any code references in this array (you can C<push> to it
876before or after loading AnyEvent), then they will called directly after 963before or after loading AnyEvent), then they will called directly after
879You should check C<$AnyEvent::MODEL> before adding to this array, though: 966You should check C<$AnyEvent::MODEL> before adding to this array, though:
880if it is defined then the event loop has already been detected, and the 967if it is defined then the event loop has already been detected, and the
881array will be ignored. 968array will be ignored.
882 969
883Best use C<AnyEvent::post_detect { BLOCK }> when your application allows 970Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
884it,as it takes care of these details. 971it, as it takes care of these details.
885 972
886This variable is mainly useful for modules that can do something useful 973This variable is mainly useful for modules that can do something useful
887when AnyEvent is used and thus want to know when it is initialised, but do 974when AnyEvent is used and thus want to know when it is initialised, but do
888not need to even load it by default. This array provides the means to hook 975not need to even load it by default. This array provides the means to hook
889into AnyEvent passively, without loading it. 976into AnyEvent passively, without loading it.
977
978Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
979together, you could put this into Coro (this is the actual code used by
980Coro to accomplish this):
981
982 if (defined $AnyEvent::MODEL) {
983 # AnyEvent already initialised, so load Coro::AnyEvent
984 require Coro::AnyEvent;
985 } else {
986 # AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
987 # as soon as it is
988 push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
989 }
890 990
891=back 991=back
892 992
893=head1 WHAT TO DO IN A MODULE 993=head1 WHAT TO DO IN A MODULE
894 994
1043 1143
1044package AnyEvent; 1144package AnyEvent;
1045 1145
1046# basically a tuned-down version of common::sense 1146# basically a tuned-down version of common::sense
1047sub common_sense { 1147sub common_sense {
1048 # no warnings 1148 # from common:.sense 1.0
1049 ${^WARNING_BITS} ^= ${^WARNING_BITS}; 1149 ${^WARNING_BITS} = "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x00";
1050 # use strict vars subs 1150 # use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1051 $^H |= 0x00000600; 1151 $^H |= 0x00000600;
1052} 1152}
1053 1153
1054BEGIN { AnyEvent::common_sense } 1154BEGIN { AnyEvent::common_sense }
1055 1155
1056use Carp (); 1156use Carp ();
1057 1157
1058our $VERSION = 4.85; 1158our $VERSION = '5.23';
1059our $MODEL; 1159our $MODEL;
1060 1160
1061our $AUTOLOAD; 1161our $AUTOLOAD;
1062our @ISA; 1162our @ISA;
1063 1163
1064our @REGISTRY; 1164our @REGISTRY;
1065
1066our $WIN32;
1067 1165
1068our $VERBOSE; 1166our $VERBOSE;
1069 1167
1070BEGIN { 1168BEGIN {
1071 eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; 1169 eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
1088 for reverse split /\s*,\s*/, 1186 for reverse split /\s*,\s*/,
1089 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; 1187 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1090} 1188}
1091 1189
1092my @models = ( 1190my @models = (
1093 [EV:: => AnyEvent::Impl::EV::], 1191 [EV:: => AnyEvent::Impl::EV:: , 1],
1094 [Event:: => AnyEvent::Impl::Event::],
1095 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], 1192 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1096 # everything below here will not be autoprobed 1193 # everything below here will not (normally) be autoprobed
1097 # as the pureperl backend should work everywhere 1194 # as the pureperl backend should work everywhere
1098 # and is usually faster 1195 # and is usually faster
1196 [Event:: => AnyEvent::Impl::Event::, 1],
1099 [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers 1197 [Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1100 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy 1198 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1199 [Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1101 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles 1200 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1102 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program 1201 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1103 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza 1202 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1104 [Wx:: => AnyEvent::Impl::POE::], 1203 [Wx:: => AnyEvent::Impl::POE::],
1105 [Prima:: => AnyEvent::Impl::POE::], 1204 [Prima:: => AnyEvent::Impl::POE::],
1106 # IO::Async is just too broken - we would need workarounds for its 1205 # IO::Async is just too broken - we would need workarounds for its
1107 # byzantine signal and broken child handling, among others. 1206 # byzantine signal and broken child handling, among others.
1108 # IO::Async is rather hard to detect, as it doesn't have any 1207 # IO::Async is rather hard to detect, as it doesn't have any
1109 # obvious default class. 1208 # obvious default class.
1110# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program 1209 [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1111# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program 1210 [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1112# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program 1211 [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1212 [AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1113); 1213);
1114 1214
1115our %method = map +($_ => 1), 1215our %method = map +($_ => 1),
1116 qw(io timer time now now_update signal child idle condvar one_event DESTROY); 1216 qw(io timer time now now_update signal child idle condvar one_event DESTROY);
1117 1217
1121 my ($cb) = @_; 1221 my ($cb) = @_;
1122 1222
1123 if ($MODEL) { 1223 if ($MODEL) {
1124 $cb->(); 1224 $cb->();
1125 1225
1126 1 1226 undef
1127 } else { 1227 } else {
1128 push @post_detect, $cb; 1228 push @post_detect, $cb;
1129 1229
1130 defined wantarray 1230 defined wantarray
1131 ? bless \$cb, "AnyEvent::Util::postdetect" 1231 ? bless \$cb, "AnyEvent::Util::postdetect"
1163 } 1263 }
1164 } 1264 }
1165 } 1265 }
1166 1266
1167 unless ($MODEL) { 1267 unless ($MODEL) {
1168 # try to load a model 1268 # try to autoload a model
1169
1170 for (@REGISTRY, @models) { 1269 for (@REGISTRY, @models) {
1171 my ($package, $model) = @$_; 1270 my ($package, $model, $autoload) = @$_;
1271 if (
1272 $autoload
1172 if (eval "require $package" 1273 and eval "require $package"
1173 and ${"$package\::VERSION"} > 0 1274 and ${"$package\::VERSION"} > 0
1174 and eval "require $model") { 1275 and eval "require $model"
1276 ) {
1175 $MODEL = $model; 1277 $MODEL = $model;
1176 warn "AnyEvent: autoprobed model '$model', using it.\n" if $VERBOSE >= 2; 1278 warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1177 last; 1279 last;
1178 } 1280 }
1179 } 1281 }
1180 1282
1181 $MODEL 1283 $MODEL
1222 # we assume CLOEXEC is already set by perl in all important cases 1324 # we assume CLOEXEC is already set by perl in all important cases
1223 1325
1224 ($fh2, $rw) 1326 ($fh2, $rw)
1225} 1327}
1226 1328
1329=head1 SIMPLIFIED AE API
1330
1331Starting with version 5.0, AnyEvent officially supports a second, much
1332simpler, API that is designed to reduce the calling, typing and memory
1333overhead.
1334
1335See the L<AE> manpage for details.
1336
1337=cut
1338
1339package AE;
1340
1341our $VERSION = $AnyEvent::VERSION;
1342
1343sub io($$$) {
1344 AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1345}
1346
1347sub timer($$$) {
1348 AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
1349}
1350
1351sub signal($$) {
1352 AnyEvent->signal (signal => $_[0], cb => $_[1])
1353}
1354
1355sub child($$) {
1356 AnyEvent->child (pid => $_[0], cb => $_[1])
1357}
1358
1359sub idle($) {
1360 AnyEvent->idle (cb => $_[0])
1361}
1362
1363sub cv(;&) {
1364 AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
1365}
1366
1367sub now() {
1368 AnyEvent->now
1369}
1370
1371sub now_update() {
1372 AnyEvent->now_update
1373}
1374
1375sub time() {
1376 AnyEvent->time
1377}
1378
1227package AnyEvent::Base; 1379package AnyEvent::Base;
1228 1380
1229# default implementations for many methods 1381# default implementations for many methods
1230 1382
1231sub _time { 1383sub _time() {
1232 # probe for availability of Time::HiRes 1384 # probe for availability of Time::HiRes
1233 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { 1385 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1234 warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8; 1386 warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1235 *_time = \&Time::HiRes::time; 1387 *_time = \&Time::HiRes::time;
1236 # if (eval "use POSIX (); (POSIX::times())... 1388 # if (eval "use POSIX (); (POSIX::times())...
1253} 1405}
1254 1406
1255# default implementation for ->signal 1407# default implementation for ->signal
1256 1408
1257our $HAVE_ASYNC_INTERRUPT; 1409our $HAVE_ASYNC_INTERRUPT;
1410
1411sub _have_async_interrupt() {
1412 $HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
1413 && eval "use Async::Interrupt 1.02 (); 1")
1414 unless defined $HAVE_ASYNC_INTERRUPT;
1415
1416 $HAVE_ASYNC_INTERRUPT
1417}
1418
1258our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); 1419our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1259our (%SIG_ASY, %SIG_ASY_W); 1420our (%SIG_ASY, %SIG_ASY_W);
1260our ($SIG_COUNT, $SIG_TW); 1421our ($SIG_COUNT, $SIG_TW);
1261 1422
1262sub _signal_exec { 1423sub _signal_exec {
1263 $HAVE_ASYNC_INTERRUPT 1424 $HAVE_ASYNC_INTERRUPT
1264 ? $SIGPIPE_R->drain 1425 ? $SIGPIPE_R->drain
1265 : sysread $SIGPIPE_R, my $dummy, 9; 1426 : sysread $SIGPIPE_R, (my $dummy), 9;
1266 1427
1267 while (%SIG_EV) { 1428 while (%SIG_EV) {
1268 for (keys %SIG_EV) { 1429 for (keys %SIG_EV) {
1269 delete $SIG_EV{$_}; 1430 delete $SIG_EV{$_};
1270 $_->() for values %{ $SIG_CB{$_} || {} }; 1431 $_->() for values %{ $SIG_CB{$_} || {} };
1271 } 1432 }
1272 } 1433 }
1273} 1434}
1274 1435
1436# install a dummy wakeup watcher to reduce signal catching latency
1275sub _signal { 1437sub _sig_add() {
1276 my (undef, %arg) = @_; 1438 unless ($SIG_COUNT++) {
1439 # try to align timer on a full-second boundary, if possible
1440 my $NOW = AE::now;
1277 1441
1278 my $signal = uc $arg{signal} 1442 $SIG_TW = AE::timer
1279 or Carp::croak "required option 'signal' is missing"; 1443 $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1280 1444 $MAX_SIGNAL_LATENCY,
1281 $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; 1445 sub { } # just for the PERL_ASYNC_CHECK
1282
1283 if ($HAVE_ASYNC_INTERRUPT) {
1284 # async::interrupt
1285
1286 $SIG_ASY{$signal} ||= do {
1287 my $asy = new Async::Interrupt
1288 cb => sub { undef $SIG_EV{$signal} },
1289 signal => $signal,
1290 pipe => [$SIGPIPE_R->filenos],
1291 ;
1292 $asy->pipe_autodrain (0);
1293
1294 $asy
1295 }; 1446 ;
1296
1297 } else {
1298 # pure perl
1299
1300 $SIG{$signal} ||= sub {
1301 local $!;
1302 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1303 undef $SIG_EV{$signal};
1304 };
1305
1306 # can't do signal processing without introducing races in pure perl,
1307 # so limit the signal latency.
1308 ++$SIG_COUNT;
1309 $SIG_TW ||= AnyEvent->timer (
1310 after => $MAX_SIGNAL_LATENCY,
1311 interval => $MAX_SIGNAL_LATENCY,
1312 cb => sub { }, # just for the PERL_ASYNC_CHECK
1313 );
1314 } 1447 }
1315
1316 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1317} 1448}
1318 1449
1319sub signal { 1450sub _sig_del {
1320 # probe for availability of Async::Interrupt
1321 if (!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT} && eval "use Async::Interrupt 0.6 (); 1") {
1322 warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1323
1324 $HAVE_ASYNC_INTERRUPT = 1;
1325 $SIGPIPE_R = new Async::Interrupt::EventPipe;
1326 $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec);
1327
1328 } else {
1329 warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1330
1331 require Fcntl;
1332
1333 if (AnyEvent::WIN32) {
1334 require AnyEvent::Util;
1335
1336 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1337 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1338 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1339 } else {
1340 pipe $SIGPIPE_R, $SIGPIPE_W;
1341 fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1342 fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
1343
1344 # not strictly required, as $^F is normally 2, but let's make sure...
1345 fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1346 fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1347 }
1348
1349 $SIGPIPE_R
1350 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1351
1352 $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1353 }
1354
1355 *signal = \&_signal;
1356 &signal
1357}
1358
1359sub AnyEvent::Base::signal::DESTROY {
1360 my ($signal, $cb) = @{$_[0]};
1361
1362 undef $SIG_TW 1451 undef $SIG_TW
1363 unless --$SIG_COUNT; 1452 unless --$SIG_COUNT;
1453}
1364 1454
1455our $_sig_name_init; $_sig_name_init = sub {
1456 eval q{ # poor man's autoloading
1457 undef $_sig_name_init;
1458
1459 if (_have_async_interrupt) {
1460 *sig2num = \&Async::Interrupt::sig2num;
1461 *sig2name = \&Async::Interrupt::sig2name;
1462 } else {
1463 require Config;
1464
1465 my %signame2num;
1466 @signame2num{ split ' ', $Config::Config{sig_name} }
1467 = split ' ', $Config::Config{sig_num};
1468
1469 my @signum2name;
1470 @signum2name[values %signame2num] = keys %signame2num;
1471
1472 *sig2num = sub($) {
1473 $_[0] > 0 ? shift : $signame2num{+shift}
1474 };
1475 *sig2name = sub ($) {
1476 $_[0] > 0 ? $signum2name[+shift] : shift
1477 };
1478 }
1479 };
1480 die if $@;
1481};
1482
1483sub sig2num ($) { &$_sig_name_init; &sig2num }
1484sub sig2name($) { &$_sig_name_init; &sig2name }
1485
1486sub signal {
1487 eval q{ # poor man's autoloading {}
1488 # probe for availability of Async::Interrupt
1489 if (_have_async_interrupt) {
1490 warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1491
1492 $SIGPIPE_R = new Async::Interrupt::EventPipe;
1493 $SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1494
1495 } else {
1496 warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1497
1498 require Fcntl;
1499
1500 if (AnyEvent::WIN32) {
1501 require AnyEvent::Util;
1502
1503 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1504 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1505 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1506 } else {
1507 pipe $SIGPIPE_R, $SIGPIPE_W;
1508 fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1509 fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
1510
1511 # not strictly required, as $^F is normally 2, but let's make sure...
1512 fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1513 fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1514 }
1515
1516 $SIGPIPE_R
1517 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1518
1519 $SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1520 }
1521
1522 *signal = sub {
1523 my (undef, %arg) = @_;
1524
1525 my $signal = uc $arg{signal}
1526 or Carp::croak "required option 'signal' is missing";
1527
1528 if ($HAVE_ASYNC_INTERRUPT) {
1529 # async::interrupt
1530
1531 $signal = sig2num $signal;
1532 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1533
1534 $SIG_ASY{$signal} ||= new Async::Interrupt
1535 cb => sub { undef $SIG_EV{$signal} },
1536 signal => $signal,
1537 pipe => [$SIGPIPE_R->filenos],
1538 pipe_autodrain => 0,
1539 ;
1540
1541 } else {
1542 # pure perl
1543
1544 # AE::Util has been loaded in signal
1545 $signal = sig2name $signal;
1546 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1547
1548 $SIG{$signal} ||= sub {
1549 local $!;
1550 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1551 undef $SIG_EV{$signal};
1552 };
1553
1554 # can't do signal processing without introducing races in pure perl,
1555 # so limit the signal latency.
1556 _sig_add;
1557 }
1558
1559 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1560 };
1561
1562 *AnyEvent::Base::signal::DESTROY = sub {
1563 my ($signal, $cb) = @{$_[0]};
1564
1565 _sig_del;
1566
1365 delete $SIG_CB{$signal}{$cb}; 1567 delete $SIG_CB{$signal}{$cb};
1366 1568
1367 $HAVE_ASYNC_INTERRUPT 1569 $HAVE_ASYNC_INTERRUPT
1368 ? delete $SIG_ASY{$signal} 1570 ? delete $SIG_ASY{$signal}
1369 : # delete doesn't work with older perls - they then 1571 : # delete doesn't work with older perls - they then
1370 # print weird messages, or just unconditionally exit 1572 # print weird messages, or just unconditionally exit
1371 # instead of getting the default action. 1573 # instead of getting the default action.
1372 undef $SIG{$signal} 1574 undef $SIG{$signal}
1373 unless keys %{ $SIG_CB{$signal} }; 1575 unless keys %{ $SIG_CB{$signal} };
1576 };
1577 };
1578 die if $@;
1579 &signal
1374} 1580}
1375 1581
1376# default implementation for ->child 1582# default implementation for ->child
1377 1583
1378our %PID_CB; 1584our %PID_CB;
1379our $CHLD_W; 1585our $CHLD_W;
1380our $CHLD_DELAY_W; 1586our $CHLD_DELAY_W;
1381our $WNOHANG; 1587our $WNOHANG;
1382 1588
1589sub _emit_childstatus($$) {
1590 my (undef, $rpid, $rstatus) = @_;
1591
1592 $_->($rpid, $rstatus)
1593 for values %{ $PID_CB{$rpid} || {} },
1594 values %{ $PID_CB{0} || {} };
1595}
1596
1383sub _sigchld { 1597sub _sigchld {
1598 my $pid;
1599
1600 AnyEvent->_emit_childstatus ($pid, $?)
1384 while (0 < (my $pid = waitpid -1, $WNOHANG)) { 1601 while ($pid = waitpid -1, $WNOHANG) > 0;
1385 $_->($pid, $?)
1386 for values %{ $PID_CB{$pid} || {} },
1387 values %{ $PID_CB{0} || {} };
1388 }
1389} 1602}
1390 1603
1391sub child { 1604sub child {
1392 my (undef, %arg) = @_; 1605 my (undef, %arg) = @_;
1393 1606
1400 $WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/ 1613 $WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1401 ? 1 1614 ? 1
1402 : eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; 1615 : eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1403 1616
1404 unless ($CHLD_W) { 1617 unless ($CHLD_W) {
1405 $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); 1618 $CHLD_W = AE::signal CHLD => \&_sigchld;
1406 # child could be a zombie already, so make at least one round 1619 # child could be a zombie already, so make at least one round
1407 &_sigchld; 1620 &_sigchld;
1408 } 1621 }
1409 1622
1410 bless [$pid, $arg{cb}], "AnyEvent::Base::child" 1623 bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1436 # never use more then 50% of the time for the idle watcher, 1649 # never use more then 50% of the time for the idle watcher,
1437 # within some limits 1650 # within some limits
1438 $w = 0.0001 if $w < 0.0001; 1651 $w = 0.0001 if $w < 0.0001;
1439 $w = 5 if $w > 5; 1652 $w = 5 if $w > 5;
1440 1653
1441 $w = AnyEvent->timer (after => $w, cb => $rcb); 1654 $w = AE::timer $w, 0, $rcb;
1442 } else { 1655 } else {
1443 # clean up... 1656 # clean up...
1444 undef $w; 1657 undef $w;
1445 undef $rcb; 1658 undef $rcb;
1446 } 1659 }
1447 }; 1660 };
1448 1661
1449 $w = AnyEvent->timer (after => 0.05, cb => $rcb); 1662 $w = AE::timer 0.05, 0, $rcb;
1450 1663
1451 bless \\$cb, "AnyEvent::Base::idle" 1664 bless \\$cb, "AnyEvent::Base::idle"
1452} 1665}
1453 1666
1454sub AnyEvent::Base::idle::DESTROY { 1667sub AnyEvent::Base::idle::DESTROY {
1508 Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak}; 1721 Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1509 wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0] 1722 wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1510} 1723}
1511 1724
1512sub cb { 1725sub cb {
1513 $_[0]{_ae_cb} = $_[1] if @_ > 1; 1726 my $cv = shift;
1727
1728 @_
1729 and $cv->{_ae_cb} = shift
1730 and $cv->{_ae_sent}
1731 and (delete $cv->{_ae_cb})->($cv);
1732
1514 $_[0]{_ae_cb} 1733 $cv->{_ae_cb}
1515} 1734}
1516 1735
1517sub begin { 1736sub begin {
1518 ++$_[0]{_ae_counter}; 1737 ++$_[0]{_ae_counter};
1519 $_[0]{_ae_end_cb} = $_[1] if @_ > 1; 1738 $_[0]{_ae_end_cb} = $_[1] if @_ > 1;
1728 warn "read: $input\n"; # output what has been read 1947 warn "read: $input\n"; # output what has been read
1729 $cv->send if $input =~ /^q/i; # quit program if /^q/i 1948 $cv->send if $input =~ /^q/i; # quit program if /^q/i
1730 }, 1949 },
1731 ); 1950 );
1732 1951
1733 my $time_watcher; # can only be used once
1734
1735 sub new_timer {
1736 $timer = AnyEvent->timer (after => 1, cb => sub { 1952 my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1737 warn "timeout\n"; # print 'timeout' about every second 1953 warn "timeout\n"; # print 'timeout' at most every second
1738 &new_timer; # and restart the time
1739 }); 1954 });
1740 }
1741
1742 new_timer; # create first timer
1743 1955
1744 $cv->recv; # wait until user enters /^q/i 1956 $cv->recv; # wait until user enters /^q/i
1745 1957
1746=head1 REAL-WORLD EXAMPLE 1958=head1 REAL-WORLD EXAMPLE
1747 1959
1878through AnyEvent. The benchmark creates a lot of timers (with a zero 2090through AnyEvent. The benchmark creates a lot of timers (with a zero
1879timeout) and I/O watchers (watching STDOUT, a pty, to become writable, 2091timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1880which it is), lets them fire exactly once and destroys them again. 2092which it is), lets them fire exactly once and destroys them again.
1881 2093
1882Source code for this benchmark is found as F<eg/bench> in the AnyEvent 2094Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1883distribution. 2095distribution. It uses the L<AE> interface, which makes a real difference
2096for the EV and Perl backends only.
1884 2097
1885=head3 Explanation of the columns 2098=head3 Explanation of the columns
1886 2099
1887I<watcher> is the number of event watchers created/destroyed. Since 2100I<watcher> is the number of event watchers created/destroyed. Since
1888different event models feature vastly different performances, each event 2101different event models feature vastly different performances, each event
1909watcher. 2122watcher.
1910 2123
1911=head3 Results 2124=head3 Results
1912 2125
1913 name watchers bytes create invoke destroy comment 2126 name watchers bytes create invoke destroy comment
1914 EV/EV 400000 224 0.47 0.35 0.27 EV native interface 2127 EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1915 EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers 2128 EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1916 CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal 2129 Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1917 Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation 2130 Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1918 Event/Event 16000 517 32.20 31.80 0.81 Event native interface 2131 Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1919 Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers 2132 Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
1920 IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll 2133 IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
1921 IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll 2134 IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1922 Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour 2135 Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1923 Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers 2136 Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1924 POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event 2137 POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1925 POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select 2138 POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1926 2139
1927=head3 Discussion 2140=head3 Discussion
1928 2141
1929The benchmark does I<not> measure scalability of the event loop very 2142The benchmark does I<not> measure scalability of the event loop very
1930well. For example, a select-based event loop (such as the pure perl one) 2143well. For example, a select-based event loop (such as the pure perl one)
1942benchmark machine, handling an event takes roughly 1600 CPU cycles with 2155benchmark machine, handling an event takes roughly 1600 CPU cycles with
1943EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU 2156EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1944cycles with POE. 2157cycles with POE.
1945 2158
1946C<EV> is the sole leader regarding speed and memory use, which are both 2159C<EV> is the sole leader regarding speed and memory use, which are both
1947maximal/minimal, respectively. Even when going through AnyEvent, it uses 2160maximal/minimal, respectively. When using the L<AE> API there is zero
2161overhead (when going through the AnyEvent API create is about 5-6 times
2162slower, with other times being equal, so still uses far less memory than
1948far less memory than any other event loop and is still faster than Event 2163any other event loop and is still faster than Event natively).
1949natively.
1950 2164
1951The pure perl implementation is hit in a few sweet spots (both the 2165The pure perl implementation is hit in a few sweet spots (both the
1952constant timeout and the use of a single fd hit optimisations in the perl 2166constant timeout and the use of a single fd hit optimisations in the perl
1953interpreter and the backend itself). Nevertheless this shows that it 2167interpreter and the backend itself). Nevertheless this shows that it
1954adds very little overhead in itself. Like any select-based backend its 2168adds very little overhead in itself. Like any select-based backend its
2028In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100 2242In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
2029(1%) are active. This mirrors the activity of large servers with many 2243(1%) are active. This mirrors the activity of large servers with many
2030connections, most of which are idle at any one point in time. 2244connections, most of which are idle at any one point in time.
2031 2245
2032Source code for this benchmark is found as F<eg/bench2> in the AnyEvent 2246Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
2033distribution. 2247distribution. It uses the L<AE> interface, which makes a real difference
2248for the EV and Perl backends only.
2034 2249
2035=head3 Explanation of the columns 2250=head3 Explanation of the columns
2036 2251
2037I<sockets> is the number of sockets, and twice the number of "servers" (as 2252I<sockets> is the number of sockets, and twice the number of "servers" (as
2038each server has a read and write socket end). 2253each server has a read and write socket end).
2046a new one that moves the timeout into the future. 2261a new one that moves the timeout into the future.
2047 2262
2048=head3 Results 2263=head3 Results
2049 2264
2050 name sockets create request 2265 name sockets create request
2051 EV 20000 69.01 11.16 2266 EV 20000 62.66 7.99
2052 Perl 20000 73.32 35.87 2267 Perl 20000 68.32 32.64
2053 IOAsync 20000 157.00 98.14 epoll 2268 IOAsync 20000 174.06 101.15 epoll
2054 IOAsync 20000 159.31 616.06 poll 2269 IOAsync 20000 174.67 610.84 poll
2055 Event 20000 212.62 257.32 2270 Event 20000 202.69 242.91
2056 Glib 20000 651.16 1896.30 2271 Glib 20000 557.01 1689.52
2057 POE 20000 349.67 12317.24 uses POE::Loop::Event 2272 POE 20000 341.54 12086.32 uses POE::Loop::Event
2058 2273
2059=head3 Discussion 2274=head3 Discussion
2060 2275
2061This benchmark I<does> measure scalability and overall performance of the 2276This benchmark I<does> measure scalability and overall performance of the
2062particular event loop. 2277particular event loop.
2188As you can see, the AnyEvent + EV combination even beats the 2403As you can see, the AnyEvent + EV combination even beats the
2189hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl 2404hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2190backend easily beats IO::Lambda and POE. 2405backend easily beats IO::Lambda and POE.
2191 2406
2192And even the 100% non-blocking version written using the high-level (and 2407And even the 100% non-blocking version written using the high-level (and
2193slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a 2408slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2194large margin, even though it does all of DNS, tcp-connect and socket I/O 2409higher level ("unoptimised") abstractions by a large margin, even though
2195in a non-blocking way. 2410it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2196 2411
2197The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and 2412The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2198F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are 2413F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2199part of the IO::lambda distribution and were used without any changes. 2414part of the IO::Lambda distribution and were used without any changes.
2200 2415
2201 2416
2202=head1 SIGNALS 2417=head1 SIGNALS
2203 2418
2204AnyEvent currently installs handlers for these signals: 2419AnyEvent currently installs handlers for these signals:
2246it's built-in modules) are required to use it. 2461it's built-in modules) are required to use it.
2247 2462
2248That does not mean that AnyEvent won't take advantage of some additional 2463That does not mean that AnyEvent won't take advantage of some additional
2249modules if they are installed. 2464modules if they are installed.
2250 2465
2251This section epxlains which additional modules will be used, and how they 2466This section explains which additional modules will be used, and how they
2252affect AnyEvent's operetion. 2467affect AnyEvent's operation.
2253 2468
2254=over 4 2469=over 4
2255 2470
2256=item L<Async::Interrupt> 2471=item L<Async::Interrupt>
2257 2472
2258This slightly arcane module is used to implement fast signal handling: To 2473This slightly arcane module is used to implement fast signal handling: To
2259my knowledge, there is no way to do completely race-free and quick 2474my knowledge, there is no way to do completely race-free and quick
2260signal handling in pure perl. To ensure that signals still get 2475signal handling in pure perl. To ensure that signals still get
2261delivered, AnyEvent will start an interval timer to wake up perl (and 2476delivered, AnyEvent will start an interval timer to wake up perl (and
2262catch the signals) with soemd elay (default is 10 seconds, look for 2477catch the signals) with some delay (default is 10 seconds, look for
2263C<$AnyEvent::MAX_SIGNAL_LATENCY>). 2478C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2264 2479
2265If this module is available, then it will be used to implement signal 2480If this module is available, then it will be used to implement signal
2266catching, which means that signals will not be delayed, and the event loop 2481catching, which means that signals will not be delayed, and the event loop
2267will not be interrupted regularly, which is more efficient (And good for 2482will not be interrupted regularly, which is more efficient (and good for
2268battery life on laptops). 2483battery life on laptops).
2269 2484
2270This affects not just the pure-perl event loop, but also other event loops 2485This affects not just the pure-perl event loop, but also other event loops
2271that have no signal handling on their own (e.g. Glib, Tk, Qt). 2486that have no signal handling on their own (e.g. Glib, Tk, Qt).
2487
2488Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
2489and either employ their own workarounds (POE) or use AnyEvent's workaround
2490(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
2491does nothing for those backends.
2272 2492
2273=item L<EV> 2493=item L<EV>
2274 2494
2275This module isn't really "optional", as it is simply one of the backend 2495This module isn't really "optional", as it is simply one of the backend
2276event loops that AnyEvent can use. However, it is simply the best event 2496event loops that AnyEvent can use. However, it is simply the best event
2288lot less memory), but otherwise doesn't affect guard operation much. It is 2508lot less memory), but otherwise doesn't affect guard operation much. It is
2289purely used for performance. 2509purely used for performance.
2290 2510
2291=item L<JSON> and L<JSON::XS> 2511=item L<JSON> and L<JSON::XS>
2292 2512
2293This module is required when you want to read or write JSON data via 2513One of these modules is required when you want to read or write JSON data
2294L<AnyEvent::Handle>. It is also written in pure-perl, but can take 2514via L<AnyEvent::Handle>. It is also written in pure-perl, but can take
2295advantage of the ulta-high-speed L<JSON::XS> module when it is installed. 2515advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2296 2516
2297In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is 2517In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2298installed. 2518installed.
2299 2519
2300=item L<Net::SSLeay> 2520=item L<Net::SSLeay>
2314 2534
2315 2535
2316=head1 FORK 2536=head1 FORK
2317 2537
2318Most event libraries are not fork-safe. The ones who are usually are 2538Most event libraries are not fork-safe. The ones who are usually are
2319because they rely on inefficient but fork-safe C<select> or C<poll> 2539because they rely on inefficient but fork-safe C<select> or C<poll> calls
2320calls. Only L<EV> is fully fork-aware. 2540- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
2541are usually badly thought-out hacks that are incompatible with fork in
2542one way or another. Only L<EV> is fully fork-aware and ensures that you
2543continue event-processing in both parent and child (or both, if you know
2544what you are doing).
2545
2546This means that, in general, you cannot fork and do event processing in
2547the child if the event library was initialised before the fork (which
2548usually happens when the first AnyEvent watcher is created, or the library
2549is loaded).
2321 2550
2322If you have to fork, you must either do so I<before> creating your first 2551If you have to fork, you must either do so I<before> creating your first
2323watcher OR you must not use AnyEvent at all in the child OR you must do 2552watcher OR you must not use AnyEvent at all in the child OR you must do
2324something completely out of the scope of AnyEvent. 2553something completely out of the scope of AnyEvent.
2554
2555The problem of doing event processing in the parent I<and> the child
2556is much more complicated: even for backends that I<are> fork-aware or
2557fork-safe, their behaviour is not usually what you want: fork clones all
2558watchers, that means all timers, I/O watchers etc. are active in both
2559parent and child, which is almost never what you want. USing C<exec>
2560to start worker children from some kind of manage rprocess is usually
2561preferred, because it is much easier and cleaner, at the expense of having
2562to have another binary.
2325 2563
2326 2564
2327=head1 SECURITY CONSIDERATIONS 2565=head1 SECURITY CONSIDERATIONS
2328 2566
2329AnyEvent can be forced to load any event model via 2567AnyEvent can be forced to load any event model via
2367L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. 2605L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2368 2606
2369Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, 2607Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2370L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, 2608L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2371L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, 2609L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2372L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>. 2610L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
2373 2611
2374Non-blocking file handles, sockets, TCP clients and 2612Non-blocking file handles, sockets, TCP clients and
2375servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>. 2613servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2376 2614
2377Asynchronous DNS: L<AnyEvent::DNS>. 2615Asynchronous DNS: L<AnyEvent::DNS>.

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