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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
12 # if you prefer function calls, look at the AE manpage for
13 # an alternative API.
14
12 # file descriptor readable 15 # file handle or descriptor readable
13 my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... }); 16 my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
14 17
15 # one-shot or repeating timers 18 # one-shot or repeating timers
16 my $w = AnyEvent->timer (after => $seconds, cb => sub { ... }); 19 my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
17 my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ... 20 my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...
40=head1 INTRODUCTION/TUTORIAL 43=head1 INTRODUCTION/TUTORIAL
41 44
42This manpage is mainly a reference manual. If you are interested 45This manpage is mainly a reference manual. If you are interested
43in a tutorial or some gentle introduction, have a look at the 46in a tutorial or some gentle introduction, have a look at the
44L<AnyEvent::Intro> manpage. 47L<AnyEvent::Intro> manpage.
48
49=head1 SUPPORT
50
51There is a mailinglist for discussing all things AnyEvent, and an IRC
52channel, too.
53
54See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
55Repository>, at L<http://anyevent.schmorp.de>, for more info.
45 56
46=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT) 57=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
47 58
48Glib, POE, IO::Async, Event... CPAN offers event models by the dozen 59Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
49nowadays. So what is different about AnyEvent? 60nowadays. So what is different about AnyEvent?
127 use AnyEvent; 138 use AnyEvent;
128 139
129 # .. AnyEvent will likely default to Tk 140 # .. AnyEvent will likely default to Tk
130 141
131The I<likely> means that, if any module loads another event model and 142The I<likely> means that, if any module loads another event model and
132starts using it, all bets are off. Maybe you should tell their authors to 143starts using it, all bets are off - this case should be very rare though,
133use AnyEvent so their modules work together with others seamlessly... 144as very few modules hardcode event loops without announcing this very
145loudly.
134 146
135The pure-perl implementation of AnyEvent is called 147The pure-perl implementation of AnyEvent is called
136C<AnyEvent::Impl::Perl>. Like other event modules you can load it 148C<AnyEvent::Impl::Perl>. Like other event modules you can load it
137explicitly and enjoy the high availability of that event loop :) 149explicitly and enjoy the high availability of that event loop :)
138 150
172Note that C<my $w; $w => combination. This is necessary because in Perl, 184Note that C<my $w; $w => combination. This is necessary because in Perl,
173my variables are only visible after the statement in which they are 185my variables are only visible after the statement in which they are
174declared. 186declared.
175 187
176=head2 I/O WATCHERS 188=head2 I/O WATCHERS
189
190 $w = AnyEvent->io (
191 fh => <filehandle_or_fileno>,
192 poll => <"r" or "w">,
193 cb => <callback>,
194 );
177 195
178You can create an I/O watcher by calling the C<< AnyEvent->io >> method 196You can create an I/O watcher by calling the C<< AnyEvent->io >> method
179with the following mandatory key-value pairs as arguments: 197with the following mandatory key-value pairs as arguments:
180 198
181C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch 199C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch
211 undef $w; 229 undef $w;
212 }); 230 });
213 231
214=head2 TIME WATCHERS 232=head2 TIME WATCHERS
215 233
234 $w = AnyEvent->timer (after => <seconds>, cb => <callback>);
235
236 $w = AnyEvent->timer (
237 after => <fractional_seconds>,
238 interval => <fractional_seconds>,
239 cb => <callback>,
240 );
241
216You can create a time watcher by calling the C<< AnyEvent->timer >> 242You can create a time watcher by calling the C<< AnyEvent->timer >>
217method with the following mandatory arguments: 243method with the following mandatory arguments:
218 244
219C<after> specifies after how many seconds (fractional values are 245C<after> specifies after how many seconds (fractional values are
220supported) the callback should be invoked. C<cb> is the callback to invoke 246supported) the callback should be invoked. C<cb> is the callback to invoke
341might affect timers and time-outs. 367might affect timers and time-outs.
342 368
343When this is the case, you can call this method, which will update the 369When this is the case, you can call this method, which will update the
344event loop's idea of "current time". 370event loop's idea of "current time".
345 371
372A typical example would be a script in a web server (e.g. C<mod_perl>) -
373when mod_perl executes the script, then the event loop will have the wrong
374idea about the "current time" (being potentially far in the past, when the
375script ran the last time). In that case you should arrange a call to C<<
376AnyEvent->now_update >> each time the web server process wakes up again
377(e.g. at the start of your script, or in a handler).
378
346Note that updating the time I<might> cause some events to be handled. 379Note that updating the time I<might> cause some events to be handled.
347 380
348=back 381=back
349 382
350=head2 SIGNAL WATCHERS 383=head2 SIGNAL WATCHERS
384
385 $w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
351 386
352You can watch for signals using a signal watcher, C<signal> is the signal 387You 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 388I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
354callback to be invoked whenever a signal occurs. 389callback to be invoked whenever a signal occurs.
355 390
361invocation, and callback invocation will be synchronous. Synchronous means 396invocation, and callback invocation will be synchronous. Synchronous means
362that it might take a while until the signal gets handled by the process, 397that it might take a while until the signal gets handled by the process,
363but it is guaranteed not to interrupt any other callbacks. 398but it is guaranteed not to interrupt any other callbacks.
364 399
365The main advantage of using these watchers is that you can share a signal 400The main advantage of using these watchers is that you can share a signal
366between multiple watchers. 401between multiple watchers, and AnyEvent will ensure that signals will not
402interrupt your program at bad times.
367 403
368This watcher might use C<%SIG>, so programs overwriting those signals 404This watcher might use C<%SIG> (depending on the event loop used),
369directly will likely not work correctly. 405so programs overwriting those signals directly will likely not work
406correctly.
370 407
371Example: exit on SIGINT 408Example: exit on SIGINT
372 409
373 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); 410 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
374 411
412=head3 Restart Behaviour
413
414While restart behaviour is up to the event loop implementation, most will
415not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
416pure perl implementation).
417
418=head3 Safe/Unsafe Signals
419
420Perl signals can be either "safe" (synchronous to opcode handling) or
421"unsafe" (asynchronous) - the former might get delayed indefinitely, the
422latter might corrupt your memory.
423
424AnyEvent signal handlers are, in addition, synchronous to the event loop,
425i.e. they will not interrupt your running perl program but will only be
426called as part of the normal event handling (just like timer, I/O etc.
427callbacks, too).
428
429=head3 Signal Races, Delays and Workarounds
430
431Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
432callbacks to signals in a generic way, which is a pity, as you cannot
433do race-free signal handling in perl, requiring C libraries for
434this. AnyEvent will try to do it's best, which means in some cases,
435signals will be delayed. The maximum time a signal might be delayed is
436specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
437variable can be changed only before the first signal watcher is created,
438and should be left alone otherwise. This variable determines how often
439AnyEvent polls for signals (in case a wake-up was missed). Higher values
440will cause fewer spurious wake-ups, which is better for power and CPU
441saving.
442
443All these problems can be avoided by installing the optional
444L<Async::Interrupt> module, which works with most event loops. It will not
445work with inherently broken event loops such as L<Event> or L<Event::Lib>
446(and not with L<POE> currently, as POE does it's own workaround with
447one-second latency). For those, you just have to suffer the delays.
448
375=head2 CHILD PROCESS WATCHERS 449=head2 CHILD PROCESS WATCHERS
376 450
451 $w = AnyEvent->child (pid => <process id>, cb => <callback>);
452
377You can also watch on a child process exit and catch its exit status. 453You can also watch on a child process exit and catch its exit status.
378 454
379The child process is specified by the C<pid> argument (if set to C<0>, it 455The child process is specified by the C<pid> argument (one some backends,
380watches for any child process exit). The watcher will triggered only when 456using C<0> watches for any child process exit, on others this will
381the child process has finished and an exit status is available, not on 457croak). The watcher will be triggered only when the child process has
382any trace events (stopped/continued). 458finished and an exit status is available, not on any trace events
459(stopped/continued).
383 460
384The callback will be called with the pid and exit status (as returned by 461The callback will be called with the pid and exit status (as returned by
385waitpid), so unlike other watcher types, you I<can> rely on child watcher 462waitpid), so unlike other watcher types, you I<can> rely on child watcher
386callback arguments. 463callback arguments.
387 464
403 480
404This means you cannot create a child watcher as the very first 481This means you cannot create a child watcher as the very first
405thing in an AnyEvent program, you I<have> to create at least one 482thing in an AnyEvent program, you I<have> to create at least one
406watcher before you C<fork> the child (alternatively, you can call 483watcher before you C<fork> the child (alternatively, you can call
407C<AnyEvent::detect>). 484C<AnyEvent::detect>).
485
486As most event loops do not support waiting for child events, they will be
487emulated by AnyEvent in most cases, in which the latency and race problems
488mentioned in the description of signal watchers apply.
408 489
409Example: fork a process and wait for it 490Example: fork a process and wait for it
410 491
411 my $done = AnyEvent->condvar; 492 my $done = AnyEvent->condvar;
412 493
424 # do something else, then wait for process exit 505 # do something else, then wait for process exit
425 $done->recv; 506 $done->recv;
426 507
427=head2 IDLE WATCHERS 508=head2 IDLE WATCHERS
428 509
429Sometimes there is a need to do something, but it is not so important 510 $w = AnyEvent->idle (cb => <callback>);
430to do it instantly, but only when there is nothing better to do. This
431"nothing better to do" is usually defined to be "no other events need
432attention by the event loop".
433 511
434Idle watchers ideally get invoked when the event loop has nothing 512Repeatedly invoke the callback after the process becomes idle, until
435better to do, just before it would block the process to wait for new 513either the watcher is destroyed or new events have been detected.
436events. Instead of blocking, the idle watcher is invoked.
437 514
438Most event loops unfortunately do not really support idle watchers (only 515Idle watchers are useful when there is a need to do something, but it
516is not so important (or wise) to do it instantly. The callback will be
517invoked only when there is "nothing better to do", which is usually
518defined as "all outstanding events have been handled and no new events
519have been detected". That means that idle watchers ideally get invoked
520when the event loop has just polled for new events but none have been
521detected. Instead of blocking to wait for more events, the idle watchers
522will be invoked.
523
524Unfortunately, most event loops do not really support idle watchers (only
439EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent 525EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
440will simply call the callback "from time to time". 526will simply call the callback "from time to time".
441 527
442Example: read lines from STDIN, but only process them when the 528Example: read lines from STDIN, but only process them when the
443program is otherwise idle: 529program is otherwise idle:
459 }); 545 });
460 }); 546 });
461 547
462=head2 CONDITION VARIABLES 548=head2 CONDITION VARIABLES
463 549
550 $cv = AnyEvent->condvar;
551
552 $cv->send (<list>);
553 my @res = $cv->recv;
554
464If you are familiar with some event loops you will know that all of them 555If you are familiar with some event loops you will know that all of them
465require you to run some blocking "loop", "run" or similar function that 556require you to run some blocking "loop", "run" or similar function that
466will actively watch for new events and call your callbacks. 557will actively watch for new events and call your callbacks.
467 558
468AnyEvent is different, it expects somebody else to run the event loop and 559AnyEvent is slightly different: it expects somebody else to run the event
469will only block when necessary (usually when told by the user). 560loop and will only block when necessary (usually when told by the user).
470 561
471The instrument to do that is called a "condition variable", so called 562The tool to do that is called a "condition variable", so called because
472because they represent a condition that must become true. 563they represent a condition that must become true.
564
565Now is probably a good time to look at the examples further below.
473 566
474Condition variables can be created by calling the C<< AnyEvent->condvar 567Condition variables can be created by calling the C<< AnyEvent->condvar
475>> method, usually without arguments. The only argument pair allowed is 568>> method, usually without arguments. The only argument pair allowed is
476
477C<cb>, which specifies a callback to be called when the condition variable 569C<cb>, which specifies a callback to be called when the condition variable
478becomes true, with the condition variable as the first argument (but not 570becomes true, with the condition variable as the first argument (but not
479the results). 571the results).
480 572
481After creation, the condition variable is "false" until it becomes "true" 573After creation, the condition variable is "false" until it becomes "true"
482by calling the C<send> method (or calling the condition variable as if it 574by calling the C<send> method (or calling the condition variable as if it
483were a callback, read about the caveats in the description for the C<< 575were a callback, read about the caveats in the description for the C<<
484->send >> method). 576->send >> method).
485 577
486Condition variables are similar to callbacks, except that you can 578Since condition variables are the most complex part of the AnyEvent API, here are
487optionally wait for them. They can also be called merge points - points 579some different mental models of what they are - pick the ones you can connect to:
488in time where multiple outstanding events have been processed. And yet 580
489another way to call them is transactions - each condition variable can be 581=over 4
490used to represent a transaction, which finishes at some point and delivers 582
491a result. 583=item * Condition variables are like callbacks - you can call them (and pass them instead
584of callbacks). Unlike callbacks however, you can also wait for them to be called.
585
586=item * Condition variables are signals - one side can emit or send them,
587the other side can wait for them, or install a handler that is called when
588the signal fires.
589
590=item * Condition variables are like "Merge Points" - points in your program
591where you merge multiple independent results/control flows into one.
592
593=item * Condition variables represent a transaction - function that start
594some kind of transaction can return them, leaving the caller the choice
595between waiting in a blocking fashion, or setting a callback.
596
597=item * Condition variables represent future values, or promises to deliver
598some result, long before the result is available.
599
600=back
492 601
493Condition variables are very useful to signal that something has finished, 602Condition variables are very useful to signal that something has finished,
494for example, if you write a module that does asynchronous http requests, 603for example, if you write a module that does asynchronous http requests,
495then a condition variable would be the ideal candidate to signal the 604then a condition variable would be the ideal candidate to signal the
496availability of results. The user can either act when the callback is 605availability of results. The user can either act when the callback is
517eventually calls C<< -> send >>, and the "consumer side", which waits 626eventually calls C<< -> send >>, and the "consumer side", which waits
518for the send to occur. 627for the send to occur.
519 628
520Example: wait for a timer. 629Example: wait for a timer.
521 630
522 # wait till the result is ready 631 # condition: "wait till the timer is fired"
523 my $result_ready = AnyEvent->condvar; 632 my $timer_fired = AnyEvent->condvar;
524 633
525 # do something such as adding a timer 634 # create the timer - we could wait for, say
526 # or socket watcher the calls $result_ready->send 635 # a handle becomign ready, or even an
527 # when the "result" is ready. 636 # AnyEvent::HTTP request to finish, but
528 # in this case, we simply use a timer: 637 # in this case, we simply use a timer:
529 my $w = AnyEvent->timer ( 638 my $w = AnyEvent->timer (
530 after => 1, 639 after => 1,
531 cb => sub { $result_ready->send }, 640 cb => sub { $timer_fired->send },
532 ); 641 );
533 642
534 # this "blocks" (while handling events) till the callback 643 # this "blocks" (while handling events) till the callback
535 # calls send 644 # calls ->send
536 $result_ready->recv; 645 $timer_fired->recv;
537 646
538Example: wait for a timer, but take advantage of the fact that 647Example: wait for a timer, but take advantage of the fact that condition
539condition variables are also code references. 648variables are also callable directly.
540 649
541 my $done = AnyEvent->condvar; 650 my $done = AnyEvent->condvar;
542 my $delay = AnyEvent->timer (after => 5, cb => $done); 651 my $delay = AnyEvent->timer (after => 5, cb => $done);
543 $done->recv; 652 $done->recv;
544 653
550 659
551 ... 660 ...
552 661
553 my @info = $couchdb->info->recv; 662 my @info = $couchdb->info->recv;
554 663
555And this is how you would just ste a callback to be called whenever the 664And this is how you would just set a callback to be called whenever the
556results are available: 665results are available:
557 666
558 $couchdb->info->cb (sub { 667 $couchdb->info->cb (sub {
559 my @info = $_[0]->recv; 668 my @info = $_[0]->recv;
560 }); 669 });
578immediately from within send. 687immediately from within send.
579 688
580Any arguments passed to the C<send> call will be returned by all 689Any arguments passed to the C<send> call will be returned by all
581future C<< ->recv >> calls. 690future C<< ->recv >> calls.
582 691
583Condition variables are overloaded so one can call them directly 692Condition variables are overloaded so one can call them directly (as if
584(as a code reference). Calling them directly is the same as calling 693they were a code reference). Calling them directly is the same as calling
585C<send>. Note, however, that many C-based event loops do not handle 694C<send>.
586overloading, so as tempting as it may be, passing a condition variable
587instead of a callback does not work. Both the pure perl and EV loops
588support overloading, however, as well as all functions that use perl to
589invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
590example).
591 695
592=item $cv->croak ($error) 696=item $cv->croak ($error)
593 697
594Similar to send, but causes all call's to C<< ->recv >> to invoke 698Similar to send, but causes all call's to C<< ->recv >> to invoke
595C<Carp::croak> with the given error message/object/scalar. 699C<Carp::croak> with the given error message/object/scalar.
596 700
597This can be used to signal any errors to the condition variable 701This can be used to signal any errors to the condition variable
598user/consumer. 702user/consumer. Doing it this way instead of calling C<croak> directly
703delays the error detetcion, but has the overwhelmign advantage that it
704diagnoses the error at the place where the result is expected, and not
705deep in some event clalback without connection to the actual code causing
706the problem.
599 707
600=item $cv->begin ([group callback]) 708=item $cv->begin ([group callback])
601 709
602=item $cv->end 710=item $cv->end
603 711
605one. For example, a function that pings many hosts in parallel might want 713one. For example, a function that pings many hosts in parallel might want
606to use a condition variable for the whole process. 714to use a condition variable for the whole process.
607 715
608Every call to C<< ->begin >> will increment a counter, and every call to 716Every call to C<< ->begin >> will increment a counter, and every call to
609C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end 717C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
610>>, the (last) callback passed to C<begin> will be executed. That callback 718>>, the (last) callback passed to C<begin> will be executed, passing the
611is I<supposed> to call C<< ->send >>, but that is not required. If no 719condvar as first argument. That callback is I<supposed> to call C<< ->send
612callback was set, C<send> will be called without any arguments. 720>>, but that is not required. If no group callback was set, C<send> will
721be called without any arguments.
613 722
614You can think of C<< $cv->send >> giving you an OR condition (one call 723You can think of C<< $cv->send >> giving you an OR condition (one call
615sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND 724sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
616condition (all C<begin> calls must be C<end>'ed before the condvar sends). 725condition (all C<begin> calls must be C<end>'ed before the condvar sends).
617 726
644begung can potentially be zero: 753begung can potentially be zero:
645 754
646 my $cv = AnyEvent->condvar; 755 my $cv = AnyEvent->condvar;
647 756
648 my %result; 757 my %result;
649 $cv->begin (sub { $cv->send (\%result) }); 758 $cv->begin (sub { shift->send (\%result) });
650 759
651 for my $host (@list_of_hosts) { 760 for my $host (@list_of_hosts) {
652 $cv->begin; 761 $cv->begin;
653 ping_host_then_call_callback $host, sub { 762 ping_host_then_call_callback $host, sub {
654 $result{$host} = ...; 763 $result{$host} = ...;
699function will call C<croak>. 808function will call C<croak>.
700 809
701In list context, all parameters passed to C<send> will be returned, 810In list context, all parameters passed to C<send> will be returned,
702in scalar context only the first one will be returned. 811in scalar context only the first one will be returned.
703 812
813Note that doing a blocking wait in a callback is not supported by any
814event loop, that is, recursive invocation of a blocking C<< ->recv
815>> is not allowed, and the C<recv> call will C<croak> if such a
816condition is detected. This condition can be slightly loosened by using
817L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from
818any thread that doesn't run the event loop itself.
819
704Not all event models support a blocking wait - some die in that case 820Not all event models support a blocking wait - some die in that case
705(programs might want to do that to stay interactive), so I<if you are 821(programs might want to do that to stay interactive), so I<if you are
706using this from a module, never require a blocking wait>, but let the 822using this from a module, never require a blocking wait>. Instead, let the
707caller decide whether the call will block or not (for example, by coupling 823caller decide whether the call will block or not (for example, by coupling
708condition variables with some kind of request results and supporting 824condition variables with some kind of request results and supporting
709callbacks so the caller knows that getting the result will not block, 825callbacks so the caller knows that getting the result will not block,
710while still supporting blocking waits if the caller so desires). 826while still supporting blocking waits if the caller so desires).
711 827
712Another reason I<never> to C<< ->recv >> in a module is that you cannot
713sensibly have two C<< ->recv >>'s in parallel, as that would require
714multiple interpreters or coroutines/threads, none of which C<AnyEvent>
715can supply.
716
717The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
718fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
719versions and also integrates coroutines into AnyEvent, making blocking
720C<< ->recv >> calls perfectly safe as long as they are done from another
721coroutine (one that doesn't run the event loop).
722
723You can ensure that C<< -recv >> never blocks by setting a callback and 828You can ensure that C<< -recv >> never blocks by setting a callback and
724only calling C<< ->recv >> from within that callback (or at a later 829only calling C<< ->recv >> from within that callback (or at a later
725time). This will work even when the event loop does not support blocking 830time). This will work even when the event loop does not support blocking
726waits otherwise. 831waits otherwise.
727 832
733=item $cb = $cv->cb ($cb->($cv)) 838=item $cb = $cv->cb ($cb->($cv))
734 839
735This is a mutator function that returns the callback set and optionally 840This is a mutator function that returns the callback set and optionally
736replaces it before doing so. 841replaces it before doing so.
737 842
738The callback will be called when the condition becomes "true", i.e. when 843The callback will be called when the condition becomes (or already was)
739C<send> or C<croak> are called, with the only argument being the condition 844"true", i.e. when C<send> or C<croak> are called (or were called), with
740variable itself. Calling C<recv> inside the callback or at any later time 845the only argument being the condition variable itself. Calling C<recv>
741is guaranteed not to block. 846inside the callback or at any later time is guaranteed not to block.
742 847
743=back 848=back
744 849
745=head1 SUPPORTED EVENT LOOPS/BACKENDS 850=head1 SUPPORTED EVENT LOOPS/BACKENDS
746 851
749=over 4 854=over 4
750 855
751=item Backends that are autoprobed when no other event loop can be found. 856=item Backends that are autoprobed when no other event loop can be found.
752 857
753EV is the preferred backend when no other event loop seems to be in 858EV is the preferred backend when no other event loop seems to be in
754use. If EV is not installed, then AnyEvent will try Event, and, failing 859use. If EV is not installed, then AnyEvent will fall back to its own
755that, will fall back to its own pure-perl implementation, which is 860pure-perl implementation, which is available everywhere as it comes with
756available everywhere as it comes with AnyEvent itself. 861AnyEvent itself.
757 862
758 AnyEvent::Impl::EV based on EV (interface to libev, best choice). 863 AnyEvent::Impl::EV based on EV (interface to libev, best choice).
759 AnyEvent::Impl::Event based on Event, very stable, few glitches.
760 AnyEvent::Impl::Perl pure-perl implementation, fast and portable. 864 AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
761 865
762=item Backends that are transparently being picked up when they are used. 866=item Backends that are transparently being picked up when they are used.
763 867
764These will be used when they are currently loaded when the first watcher 868These will be used when they are currently loaded when the first watcher
765is created, in which case it is assumed that the application is using 869is created, in which case it is assumed that the application is using
766them. This means that AnyEvent will automatically pick the right backend 870them. This means that AnyEvent will automatically pick the right backend
767when the main program loads an event module before anything starts to 871when the main program loads an event module before anything starts to
768create watchers. Nothing special needs to be done by the main program. 872create watchers. Nothing special needs to be done by the main program.
769 873
874 AnyEvent::Impl::Event based on Event, very stable, few glitches.
770 AnyEvent::Impl::Glib based on Glib, slow but very stable. 875 AnyEvent::Impl::Glib based on Glib, slow but very stable.
771 AnyEvent::Impl::Tk based on Tk, very broken. 876 AnyEvent::Impl::Tk based on Tk, very broken.
772 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse. 877 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
773 AnyEvent::Impl::POE based on POE, very slow, some limitations. 878 AnyEvent::Impl::POE based on POE, very slow, some limitations.
879 AnyEvent::Impl::Irssi used when running within irssi.
774 880
775=item Backends with special needs. 881=item Backends with special needs.
776 882
777Qt requires the Qt::Application to be instantiated first, but will 883Qt requires the Qt::Application to be instantiated first, but will
778otherwise be picked up automatically. As long as the main program 884otherwise be picked up automatically. As long as the main program
809 915
810=back 916=back
811 917
812=head1 GLOBAL VARIABLES AND FUNCTIONS 918=head1 GLOBAL VARIABLES AND FUNCTIONS
813 919
920These are not normally required to use AnyEvent, but can be useful to
921write AnyEvent extension modules.
922
814=over 4 923=over 4
815 924
816=item $AnyEvent::MODEL 925=item $AnyEvent::MODEL
817 926
818Contains C<undef> until the first watcher is being created. Then it 927Contains C<undef> until the first watcher is being created, before the
928backend has been autodetected.
929
819contains the event model that is being used, which is the name of the 930Afterwards it contains the event model that is being used, which is the
820Perl class implementing the model. This class is usually one of the 931name of the Perl class implementing the model. This class is usually one
821C<AnyEvent::Impl:xxx> modules, but can be any other class in the case 932of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the
822AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>). 933case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
934will be C<urxvt::anyevent>).
823 935
824=item AnyEvent::detect 936=item AnyEvent::detect
825 937
826Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model 938Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
827if necessary. You should only call this function right before you would 939if necessary. You should only call this function right before you would
828have created an AnyEvent watcher anyway, that is, as late as possible at 940have created an AnyEvent watcher anyway, that is, as late as possible at
829runtime. 941runtime, and not e.g. while initialising of your module.
942
943If you need to do some initialisation before AnyEvent watchers are
944created, use C<post_detect>.
830 945
831=item $guard = AnyEvent::post_detect { BLOCK } 946=item $guard = AnyEvent::post_detect { BLOCK }
832 947
833Arranges for the code block to be executed as soon as the event model is 948Arranges for the code block to be executed as soon as the event model is
834autodetected (or immediately if this has already happened). 949autodetected (or immediately if this has already happened).
835 950
951The block will be executed I<after> the actual backend has been detected
952(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
953created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
954other initialisations - see the sources of L<AnyEvent::Strict> or
955L<AnyEvent::AIO> to see how this is used.
956
957The most common usage is to create some global watchers, without forcing
958event module detection too early, for example, L<AnyEvent::AIO> creates
959and installs the global L<IO::AIO> watcher in a C<post_detect> block to
960avoid autodetecting the event module at load time.
961
836If called in scalar or list context, then it creates and returns an object 962If called in scalar or list context, then it creates and returns an object
837that automatically removes the callback again when it is destroyed. See 963that automatically removes the callback again when it is destroyed (or
964C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
838L<Coro::BDB> for a case where this is useful. 965a case where this is useful.
966
967Example: Create a watcher for the IO::AIO module and store it in
968C<$WATCHER>. Only do so after the event loop is initialised, though.
969
970 our WATCHER;
971
972 my $guard = AnyEvent::post_detect {
973 $WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
974 };
975
976 # the ||= is important in case post_detect immediately runs the block,
977 # as to not clobber the newly-created watcher. assigning both watcher and
978 # post_detect guard to the same variable has the advantage of users being
979 # able to just C<undef $WATCHER> if the watcher causes them grief.
980
981 $WATCHER ||= $guard;
839 982
840=item @AnyEvent::post_detect 983=item @AnyEvent::post_detect
841 984
842If there are any code references in this array (you can C<push> to it 985If there are any code references in this array (you can C<push> to it
843before or after loading AnyEvent), then they will called directly after 986before or after loading AnyEvent), then they will called directly after
844the event loop has been chosen. 987the event loop has been chosen.
845 988
846You should check C<$AnyEvent::MODEL> before adding to this array, though: 989You should check C<$AnyEvent::MODEL> before adding to this array, though:
847if it contains a true value then the event loop has already been detected, 990if it is defined then the event loop has already been detected, and the
848and the array will be ignored. 991array will be ignored.
849 992
850Best use C<AnyEvent::post_detect { BLOCK }> instead. 993Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
994it, as it takes care of these details.
995
996This variable is mainly useful for modules that can do something useful
997when AnyEvent is used and thus want to know when it is initialised, but do
998not need to even load it by default. This array provides the means to hook
999into AnyEvent passively, without loading it.
1000
1001Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
1002together, you could put this into Coro (this is the actual code used by
1003Coro to accomplish this):
1004
1005 if (defined $AnyEvent::MODEL) {
1006 # AnyEvent already initialised, so load Coro::AnyEvent
1007 require Coro::AnyEvent;
1008 } else {
1009 # AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
1010 # as soon as it is
1011 push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
1012 }
851 1013
852=back 1014=back
853 1015
854=head1 WHAT TO DO IN A MODULE 1016=head1 WHAT TO DO IN A MODULE
855 1017
912=head1 OTHER MODULES 1074=head1 OTHER MODULES
913 1075
914The following is a non-exhaustive list of additional modules that use 1076The following is a non-exhaustive list of additional modules that use
915AnyEvent as a client and can therefore be mixed easily with other AnyEvent 1077AnyEvent as a client and can therefore be mixed easily with other AnyEvent
916modules and other event loops in the same program. Some of the modules 1078modules and other event loops in the same program. Some of the modules
917come with AnyEvent, most are available via CPAN. 1079come as part of AnyEvent, the others are available via CPAN.
918 1080
919=over 4 1081=over 4
920 1082
921=item L<AnyEvent::Util> 1083=item L<AnyEvent::Util>
922 1084
937 1099
938=item L<AnyEvent::DNS> 1100=item L<AnyEvent::DNS>
939 1101
940Provides rich asynchronous DNS resolver capabilities. 1102Provides rich asynchronous DNS resolver capabilities.
941 1103
1104=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
1105
1106Implement event-based interfaces to the protocols of the same name (for
1107the curious, IGS is the International Go Server and FCP is the Freenet
1108Client Protocol).
1109
1110=item L<AnyEvent::Handle::UDP>
1111
1112Here be danger!
1113
1114As Pauli would put it, "Not only is it not right, it's not even wrong!" -
1115there are so many things wrong with AnyEvent::Handle::UDP, most notably
1116it's use of a stream-based API with a protocol that isn't streamable, that
1117the only way to improve it is to delete it.
1118
1119It features data corruption (but typically only under load) and general
1120confusion. On top, the author is not only clueless about UDP but also
1121fact-resistant - some gems of his understanding: "connect doesn't work
1122with UDP", "UDP packets are not IP packets", "UDP only has datagrams, not
1123packets", "I don't need to implement proper error checking as UDP doesn't
1124support error checking" and so on - he doesn't even understand what's
1125wrong with his module when it is explained to him.
1126
942=item L<AnyEvent::HTTP> 1127=item L<AnyEvent::DBI>
943 1128
944A simple-to-use HTTP library that is capable of making a lot of concurrent 1129Executes L<DBI> requests asynchronously in a proxy process for you,
945HTTP requests. 1130notifying you in an event-bnased way when the operation is finished.
1131
1132=item L<AnyEvent::AIO>
1133
1134Truly asynchronous (as opposed to non-blocking) I/O, should be in the
1135toolbox of every event programmer. AnyEvent::AIO transparently fuses
1136L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
1137file I/O, and much more.
946 1138
947=item L<AnyEvent::HTTPD> 1139=item L<AnyEvent::HTTPD>
948 1140
949Provides a simple web application server framework. 1141A simple embedded webserver.
950 1142
951=item L<AnyEvent::FastPing> 1143=item L<AnyEvent::FastPing>
952 1144
953The fastest ping in the west. 1145The fastest ping in the west.
954 1146
955=item L<AnyEvent::DBI>
956
957Executes L<DBI> requests asynchronously in a proxy process.
958
959=item L<AnyEvent::AIO>
960
961Truly asynchronous I/O, should be in the toolbox of every event
962programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
963together.
964
965=item L<AnyEvent::BDB>
966
967Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
968L<BDB> and AnyEvent together.
969
970=item L<AnyEvent::GPSD>
971
972A non-blocking interface to gpsd, a daemon delivering GPS information.
973
974=item L<AnyEvent::IRC>
975
976AnyEvent based IRC client module family (replacing the older Net::IRC3).
977
978=item L<AnyEvent::XMPP>
979
980AnyEvent based XMPP (Jabber protocol) module family (replacing the older
981Net::XMPP2>.
982
983=item L<AnyEvent::IGS>
984
985A non-blocking interface to the Internet Go Server protocol (used by
986L<App::IGS>).
987
988=item L<Net::FCP>
989
990AnyEvent-based implementation of the Freenet Client Protocol, birthplace
991of AnyEvent.
992
993=item L<Event::ExecFlow>
994
995High level API for event-based execution flow control.
996
997=item L<Coro> 1147=item L<Coro>
998 1148
999Has special support for AnyEvent via L<Coro::AnyEvent>. 1149Has special support for AnyEvent via L<Coro::AnyEvent>.
1000 1150
1001=back 1151=back
1002 1152
1003=cut 1153=cut
1004 1154
1005package AnyEvent; 1155package AnyEvent;
1006 1156
1007no warnings; 1157# basically a tuned-down version of common::sense
1008use strict qw(vars subs); 1158sub common_sense {
1159 # from common:.sense 1.0
1160 ${^WARNING_BITS} = "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x00";
1161 # use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1162 $^H |= 0x00000600;
1163}
1009 1164
1165BEGIN { AnyEvent::common_sense }
1166
1010use Carp; 1167use Carp ();
1011 1168
1012our $VERSION = 4.801; 1169our $VERSION = '5.271';
1013our $MODEL; 1170our $MODEL;
1014 1171
1015our $AUTOLOAD; 1172our $AUTOLOAD;
1016our @ISA; 1173our @ISA;
1017 1174
1018our @REGISTRY; 1175our @REGISTRY;
1019 1176
1020our $WIN32; 1177our $VERBOSE;
1021 1178
1022BEGIN { 1179BEGIN {
1023 eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; 1180 require "AnyEvent/constants.pl";
1181
1024 eval "sub TAINT(){ " . (${^TAINT}*1) . " }"; 1182 eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1025 1183
1026 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} 1184 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1027 if ${^TAINT}; 1185 if ${^TAINT};
1028}
1029 1186
1030our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; 1187 $VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
1188
1189}
1190
1191our $MAX_SIGNAL_LATENCY = 10;
1031 1192
1032our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred 1193our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
1033 1194
1034{ 1195{
1035 my $idx; 1196 my $idx;
1037 for reverse split /\s*,\s*/, 1198 for reverse split /\s*,\s*/,
1038 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; 1199 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1039} 1200}
1040 1201
1041my @models = ( 1202my @models = (
1042 [EV:: => AnyEvent::Impl::EV::], 1203 [EV:: => AnyEvent::Impl::EV:: , 1],
1043 [Event:: => AnyEvent::Impl::Event::],
1044 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], 1204 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1045 # everything below here will not be autoprobed 1205 # everything below here will not (normally) be autoprobed
1046 # as the pureperl backend should work everywhere 1206 # as the pureperl backend should work everywhere
1047 # and is usually faster 1207 # and is usually faster
1208 [Event:: => AnyEvent::Impl::Event::, 1],
1048 [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers 1209 [Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1049 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy 1210 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1211 [Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1050 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles 1212 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1213 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1051 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza 1214 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1052 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1053 [Wx:: => AnyEvent::Impl::POE::], 1215 [Wx:: => AnyEvent::Impl::POE::],
1054 [Prima:: => AnyEvent::Impl::POE::], 1216 [Prima:: => AnyEvent::Impl::POE::],
1055 # IO::Async is just too broken - we would need workarounds for its 1217 # IO::Async is just too broken - we would need workarounds for its
1056 # byzantine signal and broken child handling, among others. 1218 # byzantine signal and broken child handling, among others.
1057 # IO::Async is rather hard to detect, as it doesn't have any 1219 # IO::Async is rather hard to detect, as it doesn't have any
1058 # obvious default class. 1220 # obvious default class.
1059# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program 1221 [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1060# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program 1222 [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1061# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program 1223 [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1224 [AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1062); 1225);
1063 1226
1064our %method = map +($_ => 1), 1227our %method = map +($_ => 1),
1065 qw(io timer time now now_update signal child idle condvar one_event DESTROY); 1228 qw(io timer time now now_update signal child idle condvar one_event DESTROY);
1066 1229
1067our @post_detect; 1230our @post_detect;
1068 1231
1069sub post_detect(&) { 1232sub post_detect(&) {
1070 my ($cb) = @_; 1233 my ($cb) = @_;
1071 1234
1072 if ($MODEL) {
1073 $cb->();
1074
1075 1
1076 } else {
1077 push @post_detect, $cb; 1235 push @post_detect, $cb;
1078 1236
1079 defined wantarray 1237 defined wantarray
1080 ? bless \$cb, "AnyEvent::Util::postdetect" 1238 ? bless \$cb, "AnyEvent::Util::postdetect"
1081 : () 1239 : ()
1082 }
1083} 1240}
1084 1241
1085sub AnyEvent::Util::postdetect::DESTROY { 1242sub AnyEvent::Util::postdetect::DESTROY {
1086 @post_detect = grep $_ != ${$_[0]}, @post_detect; 1243 @post_detect = grep $_ != ${$_[0]}, @post_detect;
1087} 1244}
1088 1245
1089sub detect() { 1246sub detect() {
1247 # free some memory
1248 *detect = sub () { $MODEL };
1249
1250 local $!; # for good measure
1251 local $SIG{__DIE__};
1252
1253 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1254 my $model = "AnyEvent::Impl::$1";
1255 if (eval "require $model") {
1256 $MODEL = $model;
1257 warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
1258 } else {
1259 warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1260 }
1261 }
1262
1263 # check for already loaded models
1090 unless ($MODEL) { 1264 unless ($MODEL) {
1091 no strict 'refs'; 1265 for (@REGISTRY, @models) {
1092 local $SIG{__DIE__}; 1266 my ($package, $model) = @$_;
1093 1267 if (${"$package\::VERSION"} > 0) {
1094 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1095 my $model = "AnyEvent::Impl::$1";
1096 if (eval "require $model") { 1268 if (eval "require $model") {
1097 $MODEL = $model; 1269 $MODEL = $model;
1098 warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1; 1270 warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1099 } else { 1271 last;
1100 warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose; 1272 }
1101 } 1273 }
1102 } 1274 }
1103 1275
1104 # check for already loaded models
1105 unless ($MODEL) { 1276 unless ($MODEL) {
1277 # try to autoload a model
1106 for (@REGISTRY, @models) { 1278 for (@REGISTRY, @models) {
1107 my ($package, $model) = @$_; 1279 my ($package, $model, $autoload) = @$_;
1280 if (
1281 $autoload
1282 and eval "require $package"
1108 if (${"$package\::VERSION"} > 0) { 1283 and ${"$package\::VERSION"} > 0
1109 if (eval "require $model") { 1284 and eval "require $model"
1285 ) {
1110 $MODEL = $model; 1286 $MODEL = $model;
1111 warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1; 1287 warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1112 last; 1288 last;
1113 }
1114 } 1289 }
1115 } 1290 }
1116 1291
1117 unless ($MODEL) {
1118 # try to load a model
1119
1120 for (@REGISTRY, @models) {
1121 my ($package, $model) = @$_;
1122 if (eval "require $package"
1123 and ${"$package\::VERSION"} > 0
1124 and eval "require $model") {
1125 $MODEL = $model;
1126 warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1;
1127 last;
1128 }
1129 }
1130
1131 $MODEL 1292 $MODEL
1132 or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n"; 1293 or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";
1133 }
1134 } 1294 }
1135
1136 push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1137
1138 unshift @ISA, $MODEL;
1139
1140 require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1141
1142 (shift @post_detect)->() while @post_detect;
1143 } 1295 }
1296
1297 @models = (); # free probe data
1298
1299 push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1300 unshift @ISA, $MODEL;
1301
1302 # now nuke some methods that are overriden by the backend.
1303 # SUPER is not allowed.
1304 for (qw(time signal child idle)) {
1305 undef &{"AnyEvent::Base::$_"}
1306 if defined &{"$MODEL\::$_"};
1307 }
1308
1309 require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1310
1311 (shift @post_detect)->() while @post_detect;
1312
1313 *post_detect = sub(&) {
1314 shift->();
1315
1316 undef
1317 };
1144 1318
1145 $MODEL 1319 $MODEL
1146} 1320}
1147 1321
1148sub AUTOLOAD { 1322sub AUTOLOAD {
1149 (my $func = $AUTOLOAD) =~ s/.*://; 1323 (my $func = $AUTOLOAD) =~ s/.*://;
1150 1324
1151 $method{$func} 1325 $method{$func}
1152 or croak "$func: not a valid method for AnyEvent objects"; 1326 or Carp::croak "$func: not a valid AnyEvent class method";
1153 1327
1154 detect unless $MODEL; 1328 detect;
1155 1329
1156 my $class = shift; 1330 my $class = shift;
1157 $class->$func (@_); 1331 $class->$func (@_);
1158} 1332}
1159 1333
1162# allow only one watcher per fd, so we dup it to get a different one). 1336# allow only one watcher per fd, so we dup it to get a different one).
1163sub _dupfh($$;$$) { 1337sub _dupfh($$;$$) {
1164 my ($poll, $fh, $r, $w) = @_; 1338 my ($poll, $fh, $r, $w) = @_;
1165 1339
1166 # cygwin requires the fh mode to be matching, unix doesn't 1340 # cygwin requires the fh mode to be matching, unix doesn't
1167 my ($rw, $mode) = $poll eq "r" ? ($r, "<") : ($w, ">"); 1341 my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1168 1342
1169 open my $fh2, "$mode&", $fh 1343 open my $fh2, $mode, $fh
1170 or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,"; 1344 or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1171 1345
1172 # we assume CLOEXEC is already set by perl in all important cases 1346 # we assume CLOEXEC is already set by perl in all important cases
1173 1347
1174 ($fh2, $rw) 1348 ($fh2, $rw)
1175} 1349}
1176 1350
1351=head1 SIMPLIFIED AE API
1352
1353Starting with version 5.0, AnyEvent officially supports a second, much
1354simpler, API that is designed to reduce the calling, typing and memory
1355overhead by using function call syntax and a fixed number of parameters.
1356
1357See the L<AE> manpage for details.
1358
1359=cut
1360
1361package AE;
1362
1363our $VERSION = $AnyEvent::VERSION;
1364
1365# fall back to the main API by default - backends and AnyEvent::Base
1366# implementations can overwrite these.
1367
1368sub io($$$) {
1369 AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1370}
1371
1372sub timer($$$) {
1373 AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
1374}
1375
1376sub signal($$) {
1377 AnyEvent->signal (signal => $_[0], cb => $_[1])
1378}
1379
1380sub child($$) {
1381 AnyEvent->child (pid => $_[0], cb => $_[1])
1382}
1383
1384sub idle($) {
1385 AnyEvent->idle (cb => $_[0])
1386}
1387
1388sub cv(;&) {
1389 AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
1390}
1391
1392sub now() {
1393 AnyEvent->now
1394}
1395
1396sub now_update() {
1397 AnyEvent->now_update
1398}
1399
1400sub time() {
1401 AnyEvent->time
1402}
1403
1177package AnyEvent::Base; 1404package AnyEvent::Base;
1178 1405
1179# default implementations for many methods 1406# default implementations for many methods
1180 1407
1181BEGIN { 1408sub time {
1409 eval q{ # poor man's autoloading {}
1410 # probe for availability of Time::HiRes
1182 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { 1411 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1412 warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1183 *_time = \&Time::HiRes::time; 1413 *AE::time = \&Time::HiRes::time;
1184 # if (eval "use POSIX (); (POSIX::times())... 1414 # if (eval "use POSIX (); (POSIX::times())...
1185 } else { 1415 } else {
1416 warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1186 *_time = sub { time }; # epic fail 1417 *AE::time = sub (){ time }; # epic fail
1418 }
1419
1420 *time = sub { AE::time }; # different prototypes
1421 };
1422 die if $@;
1423
1424 &time
1425}
1426
1427*now = \&time;
1428
1429sub now_update { }
1430
1431# default implementation for ->condvar
1432
1433sub condvar {
1434 eval q{ # poor man's autoloading {}
1435 *condvar = sub {
1436 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1437 };
1438
1439 *AE::cv = sub (;&) {
1440 bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
1441 };
1442 };
1443 die if $@;
1444
1445 &condvar
1446}
1447
1448# default implementation for ->signal
1449
1450our $HAVE_ASYNC_INTERRUPT;
1451
1452sub _have_async_interrupt() {
1453 $HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
1454 && eval "use Async::Interrupt 1.02 (); 1")
1455 unless defined $HAVE_ASYNC_INTERRUPT;
1456
1457 $HAVE_ASYNC_INTERRUPT
1458}
1459
1460our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1461our (%SIG_ASY, %SIG_ASY_W);
1462our ($SIG_COUNT, $SIG_TW);
1463
1464# install a dummy wakeup watcher to reduce signal catching latency
1465# used by Impls
1466sub _sig_add() {
1467 unless ($SIG_COUNT++) {
1468 # try to align timer on a full-second boundary, if possible
1469 my $NOW = AE::now;
1470
1471 $SIG_TW = AE::timer
1472 $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1473 $MAX_SIGNAL_LATENCY,
1474 sub { } # just for the PERL_ASYNC_CHECK
1475 ;
1187 } 1476 }
1188} 1477}
1189 1478
1190sub time { _time } 1479sub _sig_del {
1191sub now { _time } 1480 undef $SIG_TW
1192sub now_update { } 1481 unless --$SIG_COUNT;
1193
1194# default implementation for ->condvar
1195
1196sub condvar {
1197 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1198} 1482}
1199 1483
1200# default implementation for ->signal 1484our $_sig_name_init; $_sig_name_init = sub {
1485 eval q{ # poor man's autoloading {}
1486 undef $_sig_name_init;
1201 1487
1202our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); 1488 if (_have_async_interrupt) {
1489 *sig2num = \&Async::Interrupt::sig2num;
1490 *sig2name = \&Async::Interrupt::sig2name;
1491 } else {
1492 require Config;
1203 1493
1204sub _signal_exec { 1494 my %signame2num;
1205 sysread $SIGPIPE_R, my $dummy, 4; 1495 @signame2num{ split ' ', $Config::Config{sig_name} }
1496 = split ' ', $Config::Config{sig_num};
1206 1497
1207 while (%SIG_EV) { 1498 my @signum2name;
1208 for (keys %SIG_EV) { 1499 @signum2name[values %signame2num] = keys %signame2num;
1209 delete $SIG_EV{$_}; 1500
1210 $_->() for values %{ $SIG_CB{$_} || {} }; 1501 *sig2num = sub($) {
1502 $_[0] > 0 ? shift : $signame2num{+shift}
1503 };
1504 *sig2name = sub ($) {
1505 $_[0] > 0 ? $signum2name[+shift] : shift
1506 };
1211 } 1507 }
1212 } 1508 };
1213} 1509 die if $@;
1510};
1511
1512sub sig2num ($) { &$_sig_name_init; &sig2num }
1513sub sig2name($) { &$_sig_name_init; &sig2name }
1214 1514
1215sub signal { 1515sub signal {
1216 my (undef, %arg) = @_; 1516 eval q{ # poor man's autoloading {}
1517 # probe for availability of Async::Interrupt
1518 if (_have_async_interrupt) {
1519 warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1217 1520
1218 unless ($SIGPIPE_R) { 1521 $SIGPIPE_R = new Async::Interrupt::EventPipe;
1219 require Fcntl; 1522 $SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1220 1523
1221 if (AnyEvent::WIN32) {
1222 require AnyEvent::Util;
1223
1224 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1225 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1226 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1227 } else { 1524 } else {
1525 warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1526
1527 if (AnyEvent::WIN32) {
1528 require AnyEvent::Util;
1529
1530 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1531 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1532 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1533 } else {
1228 pipe $SIGPIPE_R, $SIGPIPE_W; 1534 pipe $SIGPIPE_R, $SIGPIPE_W;
1229 fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R; 1535 fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
1230 fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case 1536 fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
1231 1537
1232 # not strictly required, as $^F is normally 2, but let's make sure... 1538 # not strictly required, as $^F is normally 2, but let's make sure...
1233 fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; 1539 fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1234 fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; 1540 fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1541 }
1542
1543 $SIGPIPE_R
1544 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1545
1546 $SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1235 } 1547 }
1236 1548
1237 $SIGPIPE_R 1549 *signal = $HAVE_ASYNC_INTERRUPT
1238 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; 1550 ? sub {
1551 my (undef, %arg) = @_;
1239 1552
1240 $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec); 1553 # async::interrupt
1241 }
1242
1243 my $signal = uc $arg{signal} 1554 my $signal = sig2num $arg{signal};
1244 or Carp::croak "required option 'signal' is missing";
1245
1246 $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; 1555 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1556
1557 $SIG_ASY{$signal} ||= new Async::Interrupt
1558 cb => sub { undef $SIG_EV{$signal} },
1559 signal => $signal,
1560 pipe => [$SIGPIPE_R->filenos],
1561 pipe_autodrain => 0,
1562 ;
1563
1564 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1565 }
1566 : sub {
1567 my (undef, %arg) = @_;
1568
1569 # pure perl
1570 my $signal = sig2name $arg{signal};
1571 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1572
1247 $SIG{$signal} ||= sub { 1573 $SIG{$signal} ||= sub {
1248 local $!; 1574 local $!;
1249 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; 1575 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1250 undef $SIG_EV{$signal}; 1576 undef $SIG_EV{$signal};
1577 };
1578
1579 # can't do signal processing without introducing races in pure perl,
1580 # so limit the signal latency.
1581 _sig_add;
1582
1583 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1584 }
1585 ;
1586
1587 *AnyEvent::Base::signal::DESTROY = sub {
1588 my ($signal, $cb) = @{$_[0]};
1589
1590 _sig_del;
1591
1592 delete $SIG_CB{$signal}{$cb};
1593
1594 $HAVE_ASYNC_INTERRUPT
1595 ? delete $SIG_ASY{$signal}
1596 : # delete doesn't work with older perls - they then
1597 # print weird messages, or just unconditionally exit
1598 # instead of getting the default action.
1599 undef $SIG{$signal}
1600 unless keys %{ $SIG_CB{$signal} };
1601 };
1602
1603 *_signal_exec = sub {
1604 $HAVE_ASYNC_INTERRUPT
1605 ? $SIGPIPE_R->drain
1606 : sysread $SIGPIPE_R, (my $dummy), 9;
1607
1608 while (%SIG_EV) {
1609 for (keys %SIG_EV) {
1610 delete $SIG_EV{$_};
1611 $_->() for values %{ $SIG_CB{$_} || {} };
1612 }
1613 }
1614 };
1251 }; 1615 };
1616 die if $@;
1252 1617
1253 bless [$signal, $arg{cb}], "AnyEvent::Base::signal" 1618 &signal
1254}
1255
1256sub AnyEvent::Base::signal::DESTROY {
1257 my ($signal, $cb) = @{$_[0]};
1258
1259 delete $SIG_CB{$signal}{$cb};
1260
1261 # delete doesn't work with older perls - they then
1262 # print weird messages, or just unconditionally exit
1263 # instead of getting the default action.
1264 undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1265} 1619}
1266 1620
1267# default implementation for ->child 1621# default implementation for ->child
1268 1622
1269our %PID_CB; 1623our %PID_CB;
1270our $CHLD_W; 1624our $CHLD_W;
1271our $CHLD_DELAY_W; 1625our $CHLD_DELAY_W;
1272our $WNOHANG; 1626our $WNOHANG;
1273 1627
1274sub _sigchld { 1628# used by many Impl's
1275 while (0 < (my $pid = waitpid -1, $WNOHANG)) { 1629sub _emit_childstatus($$) {
1630 my (undef, $rpid, $rstatus) = @_;
1631
1632 $_->($rpid, $rstatus)
1276 $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), 1633 for values %{ $PID_CB{$rpid} || {} },
1277 (values %{ $PID_CB{0} || {} }); 1634 values %{ $PID_CB{0} || {} };
1278 }
1279} 1635}
1280 1636
1281sub child { 1637sub child {
1638 eval q{ # poor man's autoloading {}
1639 *_sigchld = sub {
1640 my $pid;
1641
1642 AnyEvent->_emit_childstatus ($pid, $?)
1643 while ($pid = waitpid -1, $WNOHANG) > 0;
1644 };
1645
1646 *child = sub {
1282 my (undef, %arg) = @_; 1647 my (undef, %arg) = @_;
1283 1648
1284 defined (my $pid = $arg{pid} + 0) 1649 defined (my $pid = $arg{pid} + 0)
1285 or Carp::croak "required option 'pid' is missing"; 1650 or Carp::croak "required option 'pid' is missing";
1286 1651
1287 $PID_CB{$pid}{$arg{cb}} = $arg{cb}; 1652 $PID_CB{$pid}{$arg{cb}} = $arg{cb};
1288 1653
1654 # WNOHANG is almost cetrainly 1 everywhere
1655 $WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1656 ? 1
1289 $WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; 1657 : eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1290 1658
1291 unless ($CHLD_W) { 1659 unless ($CHLD_W) {
1292 $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); 1660 $CHLD_W = AE::signal CHLD => \&_sigchld;
1293 # child could be a zombie already, so make at least one round 1661 # child could be a zombie already, so make at least one round
1294 &_sigchld; 1662 &_sigchld;
1295 } 1663 }
1296 1664
1297 bless [$pid, $arg{cb}], "AnyEvent::Base::child" 1665 bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1298} 1666 };
1299 1667
1300sub AnyEvent::Base::child::DESTROY { 1668 *AnyEvent::Base::child::DESTROY = sub {
1301 my ($pid, $cb) = @{$_[0]}; 1669 my ($pid, $cb) = @{$_[0]};
1302 1670
1303 delete $PID_CB{$pid}{$cb}; 1671 delete $PID_CB{$pid}{$cb};
1304 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; 1672 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1305 1673
1306 undef $CHLD_W unless keys %PID_CB; 1674 undef $CHLD_W unless keys %PID_CB;
1675 };
1676 };
1677 die if $@;
1678
1679 &child
1307} 1680}
1308 1681
1309# idle emulation is done by simply using a timer, regardless 1682# idle emulation is done by simply using a timer, regardless
1310# of whether the process is idle or not, and not letting 1683# of whether the process is idle or not, and not letting
1311# the callback use more than 50% of the time. 1684# the callback use more than 50% of the time.
1312sub idle { 1685sub idle {
1686 eval q{ # poor man's autoloading {}
1687 *idle = sub {
1313 my (undef, %arg) = @_; 1688 my (undef, %arg) = @_;
1314 1689
1315 my ($cb, $w, $rcb) = $arg{cb}; 1690 my ($cb, $w, $rcb) = $arg{cb};
1316 1691
1317 $rcb = sub { 1692 $rcb = sub {
1318 if ($cb) { 1693 if ($cb) {
1319 $w = _time; 1694 $w = _time;
1320 &$cb; 1695 &$cb;
1321 $w = _time - $w; 1696 $w = _time - $w;
1322 1697
1323 # never use more then 50% of the time for the idle watcher, 1698 # never use more then 50% of the time for the idle watcher,
1324 # within some limits 1699 # within some limits
1325 $w = 0.0001 if $w < 0.0001; 1700 $w = 0.0001 if $w < 0.0001;
1326 $w = 5 if $w > 5; 1701 $w = 5 if $w > 5;
1327 1702
1328 $w = AnyEvent->timer (after => $w, cb => $rcb); 1703 $w = AE::timer $w, 0, $rcb;
1329 } else { 1704 } else {
1330 # clean up... 1705 # clean up...
1331 undef $w; 1706 undef $w;
1332 undef $rcb; 1707 undef $rcb;
1708 }
1709 };
1710
1711 $w = AE::timer 0.05, 0, $rcb;
1712
1713 bless \\$cb, "AnyEvent::Base::idle"
1333 } 1714 };
1715
1716 *AnyEvent::Base::idle::DESTROY = sub {
1717 undef $${$_[0]};
1718 };
1334 }; 1719 };
1720 die if $@;
1335 1721
1336 $w = AnyEvent->timer (after => 0.05, cb => $rcb); 1722 &idle
1337
1338 bless \\$cb, "AnyEvent::Base::idle"
1339}
1340
1341sub AnyEvent::Base::idle::DESTROY {
1342 undef $${$_[0]};
1343} 1723}
1344 1724
1345package AnyEvent::CondVar; 1725package AnyEvent::CondVar;
1346 1726
1347our @ISA = AnyEvent::CondVar::Base::; 1727our @ISA = AnyEvent::CondVar::Base::;
1348 1728
1349package AnyEvent::CondVar::Base; 1729package AnyEvent::CondVar::Base;
1350 1730
1351use overload 1731#use overload
1352 '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, 1732# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1353 fallback => 1; 1733# fallback => 1;
1734
1735# save 300+ kilobytes by dirtily hardcoding overloading
1736${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching.
1737*{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod."
1738*{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{}
1739${'AnyEvent::CondVar::Base::()'} = 1; # fallback
1740
1741our $WAITING;
1354 1742
1355sub _send { 1743sub _send {
1356 # nop 1744 # nop
1357} 1745}
1358 1746
1371sub ready { 1759sub ready {
1372 $_[0]{_ae_sent} 1760 $_[0]{_ae_sent}
1373} 1761}
1374 1762
1375sub _wait { 1763sub _wait {
1764 $WAITING
1765 and !$_[0]{_ae_sent}
1766 and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1767
1768 local $WAITING = 1;
1376 AnyEvent->one_event while !$_[0]{_ae_sent}; 1769 AnyEvent->one_event while !$_[0]{_ae_sent};
1377} 1770}
1378 1771
1379sub recv { 1772sub recv {
1380 $_[0]->_wait; 1773 $_[0]->_wait;
1382 Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak}; 1775 Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1383 wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0] 1776 wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1384} 1777}
1385 1778
1386sub cb { 1779sub cb {
1387 $_[0]{_ae_cb} = $_[1] if @_ > 1; 1780 my $cv = shift;
1781
1782 @_
1783 and $cv->{_ae_cb} = shift
1784 and $cv->{_ae_sent}
1785 and (delete $cv->{_ae_cb})->($cv);
1786
1388 $_[0]{_ae_cb} 1787 $cv->{_ae_cb}
1389} 1788}
1390 1789
1391sub begin { 1790sub begin {
1392 ++$_[0]{_ae_counter}; 1791 ++$_[0]{_ae_counter};
1393 $_[0]{_ae_end_cb} = $_[1] if @_ > 1; 1792 $_[0]{_ae_end_cb} = $_[1] if @_ > 1;
1442C<PERL_ANYEVENT_MODEL>. 1841C<PERL_ANYEVENT_MODEL>.
1443 1842
1444When set to C<2> or higher, cause AnyEvent to report to STDERR which event 1843When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1445model it chooses. 1844model it chooses.
1446 1845
1846When set to C<8> or higher, then AnyEvent will report extra information on
1847which optional modules it loads and how it implements certain features.
1848
1447=item C<PERL_ANYEVENT_STRICT> 1849=item C<PERL_ANYEVENT_STRICT>
1448 1850
1449AnyEvent does not do much argument checking by default, as thorough 1851AnyEvent does not do much argument checking by default, as thorough
1450argument checking is very costly. Setting this variable to a true value 1852argument checking is very costly. Setting this variable to a true value
1451will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly 1853will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1452check the arguments passed to most method calls. If it finds any problems, 1854check the arguments passed to most method calls. If it finds any problems,
1453it will croak. 1855it will croak.
1454 1856
1455In other words, enables "strict" mode. 1857In other words, enables "strict" mode.
1456 1858
1457Unlike C<use strict>, it is definitely recommended to keep it off in 1859Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>
1458production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while 1860>>, it is definitely recommended to keep it off in production. Keeping
1459developing programs can be very useful, however. 1861C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1862can be very useful, however.
1460 1863
1461=item C<PERL_ANYEVENT_MODEL> 1864=item C<PERL_ANYEVENT_MODEL>
1462 1865
1463This can be used to specify the event model to be used by AnyEvent, before 1866This can be used to specify the event model to be used by AnyEvent, before
1464auto detection and -probing kicks in. It must be a string consisting 1867auto detection and -probing kicks in. It must be a string consisting
1526 1929
1527When neither C<ca_file> nor C<ca_path> was specified during 1930When neither C<ca_file> nor C<ca_path> was specified during
1528L<AnyEvent::TLS> context creation, and either of these environment 1931L<AnyEvent::TLS> context creation, and either of these environment
1529variables exist, they will be used to specify CA certificate locations 1932variables exist, they will be used to specify CA certificate locations
1530instead of a system-dependent default. 1933instead of a system-dependent default.
1934
1935=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1936
1937When these are set to C<1>, then the respective modules are not
1938loaded. Mostly good for testing AnyEvent itself.
1531 1939
1532=back 1940=back
1533 1941
1534=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE 1942=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1535 1943
1593 warn "read: $input\n"; # output what has been read 2001 warn "read: $input\n"; # output what has been read
1594 $cv->send if $input =~ /^q/i; # quit program if /^q/i 2002 $cv->send if $input =~ /^q/i; # quit program if /^q/i
1595 }, 2003 },
1596 ); 2004 );
1597 2005
1598 my $time_watcher; # can only be used once
1599
1600 sub new_timer {
1601 $timer = AnyEvent->timer (after => 1, cb => sub { 2006 my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1602 warn "timeout\n"; # print 'timeout' about every second 2007 warn "timeout\n"; # print 'timeout' at most every second
1603 &new_timer; # and restart the time
1604 }); 2008 });
1605 }
1606
1607 new_timer; # create first timer
1608 2009
1609 $cv->recv; # wait until user enters /^q/i 2010 $cv->recv; # wait until user enters /^q/i
1610 2011
1611=head1 REAL-WORLD EXAMPLE 2012=head1 REAL-WORLD EXAMPLE
1612 2013
1685 2086
1686The actual code goes further and collects all errors (C<die>s, exceptions) 2087The actual code goes further and collects all errors (C<die>s, exceptions)
1687that occurred during request processing. The C<result> method detects 2088that occurred during request processing. The C<result> method detects
1688whether an exception as thrown (it is stored inside the $txn object) 2089whether an exception as thrown (it is stored inside the $txn object)
1689and just throws the exception, which means connection errors and other 2090and just throws the exception, which means connection errors and other
1690problems get reported tot he code that tries to use the result, not in a 2091problems get reported to the code that tries to use the result, not in a
1691random callback. 2092random callback.
1692 2093
1693All of this enables the following usage styles: 2094All of this enables the following usage styles:
1694 2095
16951. Blocking: 20961. Blocking:
1743through AnyEvent. The benchmark creates a lot of timers (with a zero 2144through AnyEvent. The benchmark creates a lot of timers (with a zero
1744timeout) and I/O watchers (watching STDOUT, a pty, to become writable, 2145timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1745which it is), lets them fire exactly once and destroys them again. 2146which it is), lets them fire exactly once and destroys them again.
1746 2147
1747Source code for this benchmark is found as F<eg/bench> in the AnyEvent 2148Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1748distribution. 2149distribution. It uses the L<AE> interface, which makes a real difference
2150for the EV and Perl backends only.
1749 2151
1750=head3 Explanation of the columns 2152=head3 Explanation of the columns
1751 2153
1752I<watcher> is the number of event watchers created/destroyed. Since 2154I<watcher> is the number of event watchers created/destroyed. Since
1753different event models feature vastly different performances, each event 2155different event models feature vastly different performances, each event
1774watcher. 2176watcher.
1775 2177
1776=head3 Results 2178=head3 Results
1777 2179
1778 name watchers bytes create invoke destroy comment 2180 name watchers bytes create invoke destroy comment
1779 EV/EV 400000 224 0.47 0.35 0.27 EV native interface 2181 EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1780 EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers 2182 EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1781 CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal 2183 Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1782 Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation 2184 Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1783 Event/Event 16000 517 32.20 31.80 0.81 Event native interface 2185 Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1784 Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers 2186 Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
1785 IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll 2187 IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
1786 IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll 2188 IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1787 Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour 2189 Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1788 Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers 2190 Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1789 POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event 2191 POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1790 POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select 2192 POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1791 2193
1792=head3 Discussion 2194=head3 Discussion
1793 2195
1794The benchmark does I<not> measure scalability of the event loop very 2196The benchmark does I<not> measure scalability of the event loop very
1795well. For example, a select-based event loop (such as the pure perl one) 2197well. For example, a select-based event loop (such as the pure perl one)
1807benchmark machine, handling an event takes roughly 1600 CPU cycles with 2209benchmark machine, handling an event takes roughly 1600 CPU cycles with
1808EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU 2210EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1809cycles with POE. 2211cycles with POE.
1810 2212
1811C<EV> is the sole leader regarding speed and memory use, which are both 2213C<EV> is the sole leader regarding speed and memory use, which are both
1812maximal/minimal, respectively. Even when going through AnyEvent, it uses 2214maximal/minimal, respectively. When using the L<AE> API there is zero
2215overhead (when going through the AnyEvent API create is about 5-6 times
2216slower, with other times being equal, so still uses far less memory than
1813far less memory than any other event loop and is still faster than Event 2217any other event loop and is still faster than Event natively).
1814natively.
1815 2218
1816The pure perl implementation is hit in a few sweet spots (both the 2219The pure perl implementation is hit in a few sweet spots (both the
1817constant timeout and the use of a single fd hit optimisations in the perl 2220constant timeout and the use of a single fd hit optimisations in the perl
1818interpreter and the backend itself). Nevertheless this shows that it 2221interpreter and the backend itself). Nevertheless this shows that it
1819adds very little overhead in itself. Like any select-based backend its 2222adds very little overhead in itself. Like any select-based backend its
1893In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100 2296In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
1894(1%) are active. This mirrors the activity of large servers with many 2297(1%) are active. This mirrors the activity of large servers with many
1895connections, most of which are idle at any one point in time. 2298connections, most of which are idle at any one point in time.
1896 2299
1897Source code for this benchmark is found as F<eg/bench2> in the AnyEvent 2300Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
1898distribution. 2301distribution. It uses the L<AE> interface, which makes a real difference
2302for the EV and Perl backends only.
1899 2303
1900=head3 Explanation of the columns 2304=head3 Explanation of the columns
1901 2305
1902I<sockets> is the number of sockets, and twice the number of "servers" (as 2306I<sockets> is the number of sockets, and twice the number of "servers" (as
1903each server has a read and write socket end). 2307each server has a read and write socket end).
1911a new one that moves the timeout into the future. 2315a new one that moves the timeout into the future.
1912 2316
1913=head3 Results 2317=head3 Results
1914 2318
1915 name sockets create request 2319 name sockets create request
1916 EV 20000 69.01 11.16 2320 EV 20000 62.66 7.99
1917 Perl 20000 73.32 35.87 2321 Perl 20000 68.32 32.64
1918 IOAsync 20000 157.00 98.14 epoll 2322 IOAsync 20000 174.06 101.15 epoll
1919 IOAsync 20000 159.31 616.06 poll 2323 IOAsync 20000 174.67 610.84 poll
1920 Event 20000 212.62 257.32 2324 Event 20000 202.69 242.91
1921 Glib 20000 651.16 1896.30 2325 Glib 20000 557.01 1689.52
1922 POE 20000 349.67 12317.24 uses POE::Loop::Event 2326 POE 20000 341.54 12086.32 uses POE::Loop::Event
1923 2327
1924=head3 Discussion 2328=head3 Discussion
1925 2329
1926This benchmark I<does> measure scalability and overall performance of the 2330This benchmark I<does> measure scalability and overall performance of the
1927particular event loop. 2331particular event loop.
2053As you can see, the AnyEvent + EV combination even beats the 2457As you can see, the AnyEvent + EV combination even beats the
2054hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl 2458hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2055backend easily beats IO::Lambda and POE. 2459backend easily beats IO::Lambda and POE.
2056 2460
2057And even the 100% non-blocking version written using the high-level (and 2461And even the 100% non-blocking version written using the high-level (and
2058slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a 2462slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2059large margin, even though it does all of DNS, tcp-connect and socket I/O 2463higher level ("unoptimised") abstractions by a large margin, even though
2060in a non-blocking way. 2464it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2061 2465
2062The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and 2466The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2063F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are 2467F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2064part of the IO::lambda distribution and were used without any changes. 2468part of the IO::Lambda distribution and were used without any changes.
2065 2469
2066 2470
2067=head1 SIGNALS 2471=head1 SIGNALS
2068 2472
2069AnyEvent currently installs handlers for these signals: 2473AnyEvent currently installs handlers for these signals:
2074 2478
2075A handler for C<SIGCHLD> is installed by AnyEvent's child watcher 2479A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
2076emulation for event loops that do not support them natively. Also, some 2480emulation for event loops that do not support them natively. Also, some
2077event loops install a similar handler. 2481event loops install a similar handler.
2078 2482
2079If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will 2483Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
2080reset it to default, to avoid losing child exit statuses. 2484AnyEvent will reset it to default, to avoid losing child exit statuses.
2081 2485
2082=item SIGPIPE 2486=item SIGPIPE
2083 2487
2084A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> 2488A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
2085when AnyEvent gets loaded. 2489when AnyEvent gets loaded.
2103 if $SIG{CHLD} eq 'IGNORE'; 2507 if $SIG{CHLD} eq 'IGNORE';
2104 2508
2105$SIG{PIPE} = sub { } 2509$SIG{PIPE} = sub { }
2106 unless defined $SIG{PIPE}; 2510 unless defined $SIG{PIPE};
2107 2511
2512=head1 RECOMMENDED/OPTIONAL MODULES
2513
2514One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2515it's built-in modules) are required to use it.
2516
2517That does not mean that AnyEvent won't take advantage of some additional
2518modules if they are installed.
2519
2520This section explains which additional modules will be used, and how they
2521affect AnyEvent's operation.
2522
2523=over 4
2524
2525=item L<Async::Interrupt>
2526
2527This slightly arcane module is used to implement fast signal handling: To
2528my knowledge, there is no way to do completely race-free and quick
2529signal handling in pure perl. To ensure that signals still get
2530delivered, AnyEvent will start an interval timer to wake up perl (and
2531catch the signals) with some delay (default is 10 seconds, look for
2532C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2533
2534If this module is available, then it will be used to implement signal
2535catching, which means that signals will not be delayed, and the event loop
2536will not be interrupted regularly, which is more efficient (and good for
2537battery life on laptops).
2538
2539This affects not just the pure-perl event loop, but also other event loops
2540that have no signal handling on their own (e.g. Glib, Tk, Qt).
2541
2542Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
2543and either employ their own workarounds (POE) or use AnyEvent's workaround
2544(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
2545does nothing for those backends.
2546
2547=item L<EV>
2548
2549This module isn't really "optional", as it is simply one of the backend
2550event loops that AnyEvent can use. However, it is simply the best event
2551loop available in terms of features, speed and stability: It supports
2552the AnyEvent API optimally, implements all the watcher types in XS, does
2553automatic timer adjustments even when no monotonic clock is available,
2554can take avdantage of advanced kernel interfaces such as C<epoll> and
2555C<kqueue>, and is the fastest backend I<by far>. You can even embed
2556L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2557
2558If you only use backends that rely on another event loop (e.g. C<Tk>),
2559then this module will do nothing for you.
2560
2561=item L<Guard>
2562
2563The guard module, when used, will be used to implement
2564C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2565lot less memory), but otherwise doesn't affect guard operation much. It is
2566purely used for performance.
2567
2568=item L<JSON> and L<JSON::XS>
2569
2570One of these modules is required when you want to read or write JSON data
2571via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2572advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2573
2574=item L<Net::SSLeay>
2575
2576Implementing TLS/SSL in Perl is certainly interesting, but not very
2577worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2578the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2579
2580=item L<Time::HiRes>
2581
2582This module is part of perl since release 5.008. It will be used when the
2583chosen event library does not come with a timing source on it's own. The
2584pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
2585try to use a monotonic clock for timing stability.
2586
2587=back
2588
2589
2108=head1 FORK 2590=head1 FORK
2109 2591
2110Most event libraries are not fork-safe. The ones who are usually are 2592Most event libraries are not fork-safe. The ones who are usually are
2111because they rely on inefficient but fork-safe C<select> or C<poll> 2593because they rely on inefficient but fork-safe C<select> or C<poll> calls
2112calls. Only L<EV> is fully fork-aware. 2594- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
2595are usually badly thought-out hacks that are incompatible with fork in
2596one way or another. Only L<EV> is fully fork-aware and ensures that you
2597continue event-processing in both parent and child (or both, if you know
2598what you are doing).
2599
2600This means that, in general, you cannot fork and do event processing in
2601the child if the event library was initialised before the fork (which
2602usually happens when the first AnyEvent watcher is created, or the library
2603is loaded).
2113 2604
2114If you have to fork, you must either do so I<before> creating your first 2605If you have to fork, you must either do so I<before> creating your first
2115watcher OR you must not use AnyEvent at all in the child. 2606watcher OR you must not use AnyEvent at all in the child OR you must do
2607something completely out of the scope of AnyEvent.
2608
2609The problem of doing event processing in the parent I<and> the child
2610is much more complicated: even for backends that I<are> fork-aware or
2611fork-safe, their behaviour is not usually what you want: fork clones all
2612watchers, that means all timers, I/O watchers etc. are active in both
2613parent and child, which is almost never what you want. USing C<exec>
2614to start worker children from some kind of manage rprocess is usually
2615preferred, because it is much easier and cleaner, at the expense of having
2616to have another binary.
2116 2617
2117 2618
2118=head1 SECURITY CONSIDERATIONS 2619=head1 SECURITY CONSIDERATIONS
2119 2620
2120AnyEvent can be forced to load any event model via 2621AnyEvent can be forced to load any event model via
2158L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. 2659L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2159 2660
2160Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, 2661Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2161L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, 2662L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2162L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, 2663L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2163L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>. 2664L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
2164 2665
2165Non-blocking file handles, sockets, TCP clients and 2666Non-blocking file handles, sockets, TCP clients and
2166servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>. 2667servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2167 2668
2168Asynchronous DNS: L<AnyEvent::DNS>. 2669Asynchronous DNS: L<AnyEvent::DNS>.

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