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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?
173my variables are only visible after the statement in which they are 184my variables are only visible after the statement in which they are
174declared. 185declared.
175 186
176=head2 I/O WATCHERS 187=head2 I/O WATCHERS
177 188
189 $w = AnyEvent->io (
190 fh => <filehandle_or_fileno>,
191 poll => <"r" or "w">,
192 cb => <callback>,
193 );
194
178You can create an I/O watcher by calling the C<< AnyEvent->io >> method 195You can create an I/O watcher by calling the C<< AnyEvent->io >> method
179with the following mandatory key-value pairs as arguments: 196with the following mandatory key-value pairs as arguments:
180 197
181C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch 198C<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 199for events (AnyEvent might or might not keep a reference to this file
211 undef $w; 228 undef $w;
212 }); 229 });
213 230
214=head2 TIME WATCHERS 231=head2 TIME WATCHERS
215 232
233 $w = AnyEvent->timer (after => <seconds>, cb => <callback>);
234
235 $w = AnyEvent->timer (
236 after => <fractional_seconds>,
237 interval => <fractional_seconds>,
238 cb => <callback>,
239 );
240
216You can create a time watcher by calling the C<< AnyEvent->timer >> 241You can create a time watcher by calling the C<< AnyEvent->timer >>
217method with the following mandatory arguments: 242method with the following mandatory arguments:
218 243
219C<after> specifies after how many seconds (fractional values are 244C<after> specifies after how many seconds (fractional values are
220supported) the callback should be invoked. C<cb> is the callback to invoke 245supported) the callback should be invoked. C<cb> is the callback to invoke
341might affect timers and time-outs. 366might affect timers and time-outs.
342 367
343When this is the case, you can call this method, which will update the 368When this is the case, you can call this method, which will update the
344event loop's idea of "current time". 369event loop's idea of "current time".
345 370
371A typical example would be a script in a web server (e.g. C<mod_perl>) -
372when mod_perl executes the script, then the event loop will have the wrong
373idea about the "current time" (being potentially far in the past, when the
374script ran the last time). In that case you should arrange a call to C<<
375AnyEvent->now_update >> each time the web server process wakes up again
376(e.g. at the start of your script, or in a handler).
377
346Note that updating the time I<might> cause some events to be handled. 378Note that updating the time I<might> cause some events to be handled.
347 379
348=back 380=back
349 381
350=head2 SIGNAL WATCHERS 382=head2 SIGNAL WATCHERS
383
384 $w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
351 385
352You can watch for signals using a signal watcher, C<signal> is the signal 386You 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 387I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
354callback to be invoked whenever a signal occurs. 388callback to be invoked whenever a signal occurs.
355 389
361invocation, and callback invocation will be synchronous. Synchronous means 395invocation, and callback invocation will be synchronous. Synchronous means
362that it might take a while until the signal gets handled by the process, 396that it might take a while until the signal gets handled by the process,
363but it is guaranteed not to interrupt any other callbacks. 397but it is guaranteed not to interrupt any other callbacks.
364 398
365The main advantage of using these watchers is that you can share a signal 399The main advantage of using these watchers is that you can share a signal
366between multiple watchers. 400between multiple watchers, and AnyEvent will ensure that signals will not
401interrupt your program at bad times.
367 402
368This watcher might use C<%SIG>, so programs overwriting those signals 403This watcher might use C<%SIG> (depending on the event loop used),
369directly will likely not work correctly. 404so programs overwriting those signals directly will likely not work
405correctly.
370 406
371Example: exit on SIGINT 407Example: exit on SIGINT
372 408
373 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); 409 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
374 410
411=head3 Restart Behaviour
412
413While restart behaviour is up to the event loop implementation, most will
414not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
415pure perl implementation).
416
417=head3 Safe/Unsafe Signals
418
419Perl signals can be either "safe" (synchronous to opcode handling) or
420"unsafe" (asynchronous) - the former might get delayed indefinitely, the
421latter might corrupt your memory.
422
423AnyEvent signal handlers are, in addition, synchronous to the event loop,
424i.e. they will not interrupt your running perl program but will only be
425called as part of the normal event handling (just like timer, I/O etc.
426callbacks, too).
427
428=head3 Signal Races, Delays and Workarounds
429
430Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
431callbacks to signals in a generic way, which is a pity, as you cannot
432do race-free signal handling in perl, requiring C libraries for
433this. AnyEvent will try to do it's best, which means in some cases,
434signals will be delayed. The maximum time a signal might be delayed is
435specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
436variable can be changed only before the first signal watcher is created,
437and should be left alone otherwise. This variable determines how often
438AnyEvent polls for signals (in case a wake-up was missed). Higher values
439will cause fewer spurious wake-ups, which is better for power and CPU
440saving.
441
442All these problems can be avoided by installing the optional
443L<Async::Interrupt> module, which works with most event loops. It will not
444work with inherently broken event loops such as L<Event> or L<Event::Lib>
445(and not with L<POE> currently, as POE does it's own workaround with
446one-second latency). For those, you just have to suffer the delays.
447
375=head2 CHILD PROCESS WATCHERS 448=head2 CHILD PROCESS WATCHERS
376 449
450 $w = AnyEvent->child (pid => <process id>, cb => <callback>);
451
377You can also watch on a child process exit and catch its exit status. 452You can also watch on a child process exit and catch its exit status.
378 453
379The child process is specified by the C<pid> argument (if set to C<0>, it 454The child process is specified by the C<pid> argument (one some backends,
380watches for any child process exit). The watcher will triggered only when 455using 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 456croak). The watcher will be triggered only when the child process has
382any trace events (stopped/continued). 457finished and an exit status is available, not on any trace events
458(stopped/continued).
383 459
384The callback will be called with the pid and exit status (as returned by 460The 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 461waitpid), so unlike other watcher types, you I<can> rely on child watcher
386callback arguments. 462callback arguments.
387 463
403 479
404This means you cannot create a child watcher as the very first 480This means you cannot create a child watcher as the very first
405thing in an AnyEvent program, you I<have> to create at least one 481thing in an AnyEvent program, you I<have> to create at least one
406watcher before you C<fork> the child (alternatively, you can call 482watcher before you C<fork> the child (alternatively, you can call
407C<AnyEvent::detect>). 483C<AnyEvent::detect>).
484
485As most event loops do not support waiting for child events, they will be
486emulated by AnyEvent in most cases, in which the latency and race problems
487mentioned in the description of signal watchers apply.
408 488
409Example: fork a process and wait for it 489Example: fork a process and wait for it
410 490
411 my $done = AnyEvent->condvar; 491 my $done = AnyEvent->condvar;
412 492
424 # do something else, then wait for process exit 504 # do something else, then wait for process exit
425 $done->recv; 505 $done->recv;
426 506
427=head2 IDLE WATCHERS 507=head2 IDLE WATCHERS
428 508
429Sometimes there is a need to do something, but it is not so important 509 $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".
433 510
434Idle watchers ideally get invoked when the event loop has nothing 511Repeatedly invoke the callback after the process becomes idle, until
435better to do, just before it would block the process to wait for new 512either the watcher is destroyed or new events have been detected.
436events. Instead of blocking, the idle watcher is invoked.
437 513
438Most event loops unfortunately do not really support idle watchers (only 514Idle watchers are useful when there is a need to do something, but it
515is not so important (or wise) to do it instantly. The callback will be
516invoked only when there is "nothing better to do", which is usually
517defined as "all outstanding events have been handled and no new events
518have been detected". That means that idle watchers ideally get invoked
519when the event loop has just polled for new events but none have been
520detected. Instead of blocking to wait for more events, the idle watchers
521will be invoked.
522
523Unfortunately, most event loops do not really support idle watchers (only
439EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent 524EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
440will simply call the callback "from time to time". 525will simply call the callback "from time to time".
441 526
442Example: read lines from STDIN, but only process them when the 527Example: read lines from STDIN, but only process them when the
443program is otherwise idle: 528program is otherwise idle:
459 }); 544 });
460 }); 545 });
461 546
462=head2 CONDITION VARIABLES 547=head2 CONDITION VARIABLES
463 548
549 $cv = AnyEvent->condvar;
550
551 $cv->send (<list>);
552 my @res = $cv->recv;
553
464If you are familiar with some event loops you will know that all of them 554If 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 555require you to run some blocking "loop", "run" or similar function that
466will actively watch for new events and call your callbacks. 556will actively watch for new events and call your callbacks.
467 557
468AnyEvent is different, it expects somebody else to run the event loop and 558AnyEvent is slightly different: it expects somebody else to run the event
469will only block when necessary (usually when told by the user). 559loop and will only block when necessary (usually when told by the user).
470 560
471The instrument to do that is called a "condition variable", so called 561The tool to do that is called a "condition variable", so called because
472because they represent a condition that must become true. 562they represent a condition that must become true.
563
564Now is probably a good time to look at the examples further below.
473 565
474Condition variables can be created by calling the C<< AnyEvent->condvar 566Condition variables can be created by calling the C<< AnyEvent->condvar
475>> method, usually without arguments. The only argument pair allowed is 567>> method, usually without arguments. The only argument pair allowed is
476
477C<cb>, which specifies a callback to be called when the condition variable 568C<cb>, which specifies a callback to be called when the condition variable
478becomes true, with the condition variable as the first argument (but not 569becomes true, with the condition variable as the first argument (but not
479the results). 570the results).
480 571
481After creation, the condition variable is "false" until it becomes "true" 572After creation, the condition variable is "false" until it becomes "true"
482by calling the C<send> method (or calling the condition variable as if it 573by 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<< 574were a callback, read about the caveats in the description for the C<<
484->send >> method). 575->send >> method).
485 576
486Condition variables are similar to callbacks, except that you can 577Since 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 578some 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 579
489another way to call them is transactions - each condition variable can be 580=over 4
490used to represent a transaction, which finishes at some point and delivers 581
491a result. 582=item * Condition variables are like callbacks - you can call them (and pass them instead
583of callbacks). Unlike callbacks however, you can also wait for them to be called.
584
585=item * Condition variables are signals - one side can emit or send them,
586the other side can wait for them, or install a handler that is called when
587the signal fires.
588
589=item * Condition variables are like "Merge Points" - points in your program
590where you merge multiple independent results/control flows into one.
591
592=item * Condition variables represent a transaction - function that start
593some kind of transaction can return them, leaving the caller the choice
594between waiting in a blocking fashion, or setting a callback.
595
596=item * Condition variables represent future values, or promises to deliver
597some result, long before the result is available.
598
599=back
492 600
493Condition variables are very useful to signal that something has finished, 601Condition variables are very useful to signal that something has finished,
494for example, if you write a module that does asynchronous http requests, 602for example, if you write a module that does asynchronous http requests,
495then a condition variable would be the ideal candidate to signal the 603then a condition variable would be the ideal candidate to signal the
496availability of results. The user can either act when the callback is 604availability of results. The user can either act when the callback is
517eventually calls C<< -> send >>, and the "consumer side", which waits 625eventually calls C<< -> send >>, and the "consumer side", which waits
518for the send to occur. 626for the send to occur.
519 627
520Example: wait for a timer. 628Example: wait for a timer.
521 629
522 # wait till the result is ready 630 # condition: "wait till the timer is fired"
523 my $result_ready = AnyEvent->condvar; 631 my $timer_fired = AnyEvent->condvar;
524 632
525 # do something such as adding a timer 633 # create the timer - we could wait for, say
526 # or socket watcher the calls $result_ready->send 634 # a handle becomign ready, or even an
527 # when the "result" is ready. 635 # AnyEvent::HTTP request to finish, but
528 # in this case, we simply use a timer: 636 # in this case, we simply use a timer:
529 my $w = AnyEvent->timer ( 637 my $w = AnyEvent->timer (
530 after => 1, 638 after => 1,
531 cb => sub { $result_ready->send }, 639 cb => sub { $timer_fired->send },
532 ); 640 );
533 641
534 # this "blocks" (while handling events) till the callback 642 # this "blocks" (while handling events) till the callback
535 # calls send 643 # calls ->send
536 $result_ready->recv; 644 $timer_fired->recv;
537 645
538Example: wait for a timer, but take advantage of the fact that 646Example: wait for a timer, but take advantage of the fact that condition
539condition variables are also code references. 647variables are also callable directly.
540 648
541 my $done = AnyEvent->condvar; 649 my $done = AnyEvent->condvar;
542 my $delay = AnyEvent->timer (after => 5, cb => $done); 650 my $delay = AnyEvent->timer (after => 5, cb => $done);
543 $done->recv; 651 $done->recv;
544 652
550 658
551 ... 659 ...
552 660
553 my @info = $couchdb->info->recv; 661 my @info = $couchdb->info->recv;
554 662
555And this is how you would just ste a callback to be called whenever the 663And this is how you would just set a callback to be called whenever the
556results are available: 664results are available:
557 665
558 $couchdb->info->cb (sub { 666 $couchdb->info->cb (sub {
559 my @info = $_[0]->recv; 667 my @info = $_[0]->recv;
560 }); 668 });
578immediately from within send. 686immediately from within send.
579 687
580Any arguments passed to the C<send> call will be returned by all 688Any arguments passed to the C<send> call will be returned by all
581future C<< ->recv >> calls. 689future C<< ->recv >> calls.
582 690
583Condition variables are overloaded so one can call them directly 691Condition variables are overloaded so one can call them directly (as if
584(as a code reference). Calling them directly is the same as calling 692they 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 693C<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).
591 694
592=item $cv->croak ($error) 695=item $cv->croak ($error)
593 696
594Similar to send, but causes all call's to C<< ->recv >> to invoke 697Similar to send, but causes all call's to C<< ->recv >> to invoke
595C<Carp::croak> with the given error message/object/scalar. 698C<Carp::croak> with the given error message/object/scalar.
596 699
597This can be used to signal any errors to the condition variable 700This can be used to signal any errors to the condition variable
598user/consumer. 701user/consumer. Doing it this way instead of calling C<croak> directly
702delays the error detetcion, but has the overwhelmign advantage that it
703diagnoses the error at the place where the result is expected, and not
704deep in some event clalback without connection to the actual code causing
705the problem.
599 706
600=item $cv->begin ([group callback]) 707=item $cv->begin ([group callback])
601 708
602=item $cv->end 709=item $cv->end
603 710
605one. For example, a function that pings many hosts in parallel might want 712one. For example, a function that pings many hosts in parallel might want
606to use a condition variable for the whole process. 713to use a condition variable for the whole process.
607 714
608Every call to C<< ->begin >> will increment a counter, and every call to 715Every 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 716C<< ->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 717>>, 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 718condvar as first argument. That callback is I<supposed> to call C<< ->send
612callback was set, C<send> will be called without any arguments. 719>>, but that is not required. If no group callback was set, C<send> will
720be called without any arguments.
613 721
614You can think of C<< $cv->send >> giving you an OR condition (one call 722You 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 723sends), 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). 724condition (all C<begin> calls must be C<end>'ed before the condvar sends).
617 725
644begung can potentially be zero: 752begung can potentially be zero:
645 753
646 my $cv = AnyEvent->condvar; 754 my $cv = AnyEvent->condvar;
647 755
648 my %result; 756 my %result;
649 $cv->begin (sub { $cv->send (\%result) }); 757 $cv->begin (sub { shift->send (\%result) });
650 758
651 for my $host (@list_of_hosts) { 759 for my $host (@list_of_hosts) {
652 $cv->begin; 760 $cv->begin;
653 ping_host_then_call_callback $host, sub { 761 ping_host_then_call_callback $host, sub {
654 $result{$host} = ...; 762 $result{$host} = ...;
699function will call C<croak>. 807function will call C<croak>.
700 808
701In list context, all parameters passed to C<send> will be returned, 809In list context, all parameters passed to C<send> will be returned,
702in scalar context only the first one will be returned. 810in scalar context only the first one will be returned.
703 811
812Note that doing a blocking wait in a callback is not supported by any
813event loop, that is, recursive invocation of a blocking C<< ->recv
814>> is not allowed, and the C<recv> call will C<croak> if such a
815condition is detected. This condition can be slightly loosened by using
816L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from
817any thread that doesn't run the event loop itself.
818
704Not all event models support a blocking wait - some die in that case 819Not 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 820(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 821using 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 822caller decide whether the call will block or not (for example, by coupling
708condition variables with some kind of request results and supporting 823condition variables with some kind of request results and supporting
709callbacks so the caller knows that getting the result will not block, 824callbacks so the caller knows that getting the result will not block,
710while still supporting blocking waits if the caller so desires). 825while still supporting blocking waits if the caller so desires).
711 826
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 827You can ensure that C<< -recv >> never blocks by setting a callback and
724only calling C<< ->recv >> from within that callback (or at a later 828only calling C<< ->recv >> from within that callback (or at a later
725time). This will work even when the event loop does not support blocking 829time). This will work even when the event loop does not support blocking
726waits otherwise. 830waits otherwise.
727 831
733=item $cb = $cv->cb ($cb->($cv)) 837=item $cb = $cv->cb ($cb->($cv))
734 838
735This is a mutator function that returns the callback set and optionally 839This is a mutator function that returns the callback set and optionally
736replaces it before doing so. 840replaces it before doing so.
737 841
738The callback will be called when the condition becomes "true", i.e. when 842The 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 843"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 844the only argument being the condition variable itself. Calling C<recv>
741is guaranteed not to block. 845inside the callback or at any later time is guaranteed not to block.
742 846
743=back 847=back
744 848
849=head1 SUPPORTED EVENT LOOPS/BACKENDS
850
851The available backend classes are (every class has its own manpage):
852
853=over 4
854
855=item Backends that are autoprobed when no other event loop can be found.
856
857EV is the preferred backend when no other event loop seems to be in
858use. If EV is not installed, then AnyEvent will fall back to its own
859pure-perl implementation, which is available everywhere as it comes with
860AnyEvent itself.
861
862 AnyEvent::Impl::EV based on EV (interface to libev, best choice).
863 AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
864
865=item Backends that are transparently being picked up when they are used.
866
867These will be used when they are currently loaded when the first watcher
868is created, in which case it is assumed that the application is using
869them. This means that AnyEvent will automatically pick the right backend
870when the main program loads an event module before anything starts to
871create watchers. Nothing special needs to be done by the main program.
872
873 AnyEvent::Impl::Event based on Event, very stable, few glitches.
874 AnyEvent::Impl::Glib based on Glib, slow but very stable.
875 AnyEvent::Impl::Tk based on Tk, very broken.
876 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
877 AnyEvent::Impl::POE based on POE, very slow, some limitations.
878 AnyEvent::Impl::Irssi used when running within irssi.
879
880=item Backends with special needs.
881
882Qt requires the Qt::Application to be instantiated first, but will
883otherwise be picked up automatically. As long as the main program
884instantiates the application before any AnyEvent watchers are created,
885everything should just work.
886
887 AnyEvent::Impl::Qt based on Qt.
888
889Support for IO::Async can only be partial, as it is too broken and
890architecturally limited to even support the AnyEvent API. It also
891is the only event loop that needs the loop to be set explicitly, so
892it can only be used by a main program knowing about AnyEvent. See
893L<AnyEvent::Impl::Async> for the gory details.
894
895 AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
896
897=item Event loops that are indirectly supported via other backends.
898
899Some event loops can be supported via other modules:
900
901There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
902
903B<WxWidgets> has no support for watching file handles. However, you can
904use WxWidgets through the POE adaptor, as POE has a Wx backend that simply
905polls 20 times per second, which was considered to be too horrible to even
906consider for AnyEvent.
907
908B<Prima> is not supported as nobody seems to be using it, but it has a POE
909backend, so it can be supported through POE.
910
911AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to
912load L<POE> when detecting them, in the hope that POE will pick them up,
913in which case everything will be automatic.
914
915=back
916
745=head1 GLOBAL VARIABLES AND FUNCTIONS 917=head1 GLOBAL VARIABLES AND FUNCTIONS
746 918
919These are not normally required to use AnyEvent, but can be useful to
920write AnyEvent extension modules.
921
747=over 4 922=over 4
748 923
749=item $AnyEvent::MODEL 924=item $AnyEvent::MODEL
750 925
751Contains C<undef> until the first watcher is being created. Then it 926Contains C<undef> until the first watcher is being created, before the
927backend has been autodetected.
928
752contains the event model that is being used, which is the name of the 929Afterwards it contains the event model that is being used, which is the
753Perl class implementing the model. This class is usually one of the 930name of the Perl class implementing the model. This class is usually one
754C<AnyEvent::Impl:xxx> modules, but can be any other class in the case 931of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the
755AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>). 932case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
756 933will be C<urxvt::anyevent>).
757The known classes so far are:
758
759 AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
760 AnyEvent::Impl::Event based on Event, second best choice.
761 AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
762 AnyEvent::Impl::Glib based on Glib, third-best choice.
763 AnyEvent::Impl::Tk based on Tk, very bad choice.
764 AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
765 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
766 AnyEvent::Impl::POE based on POE, not generic enough for full support.
767
768 # warning, support for IO::Async is only partial, as it is too broken
769 # and limited toe ven support the AnyEvent API. See AnyEvent::Impl::Async.
770 AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed (see its docs).
771
772There is no support for WxWidgets, as WxWidgets has no support for
773watching file handles. However, you can use WxWidgets through the
774POE Adaptor, as POE has a Wx backend that simply polls 20 times per
775second, which was considered to be too horrible to even consider for
776AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
777it's adaptor.
778
779AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
780autodetecting them.
781 934
782=item AnyEvent::detect 935=item AnyEvent::detect
783 936
784Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model 937Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
785if necessary. You should only call this function right before you would 938if necessary. You should only call this function right before you would
786have created an AnyEvent watcher anyway, that is, as late as possible at 939have created an AnyEvent watcher anyway, that is, as late as possible at
787runtime. 940runtime, and not e.g. while initialising of your module.
941
942If you need to do some initialisation before AnyEvent watchers are
943created, use C<post_detect>.
788 944
789=item $guard = AnyEvent::post_detect { BLOCK } 945=item $guard = AnyEvent::post_detect { BLOCK }
790 946
791Arranges for the code block to be executed as soon as the event model is 947Arranges for the code block to be executed as soon as the event model is
792autodetected (or immediately if this has already happened). 948autodetected (or immediately if this has already happened).
793 949
950The block will be executed I<after> the actual backend has been detected
951(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
952created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
953other initialisations - see the sources of L<AnyEvent::Strict> or
954L<AnyEvent::AIO> to see how this is used.
955
956The most common usage is to create some global watchers, without forcing
957event module detection too early, for example, L<AnyEvent::AIO> creates
958and installs the global L<IO::AIO> watcher in a C<post_detect> block to
959avoid autodetecting the event module at load time.
960
794If called in scalar or list context, then it creates and returns an object 961If called in scalar or list context, then it creates and returns an object
795that automatically removes the callback again when it is destroyed. See 962that automatically removes the callback again when it is destroyed (or
963C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
796L<Coro::BDB> for a case where this is useful. 964a case where this is useful.
965
966Example: Create a watcher for the IO::AIO module and store it in
967C<$WATCHER>. Only do so after the event loop is initialised, though.
968
969 our WATCHER;
970
971 my $guard = AnyEvent::post_detect {
972 $WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
973 };
974
975 # the ||= is important in case post_detect immediately runs the block,
976 # as to not clobber the newly-created watcher. assigning both watcher and
977 # post_detect guard to the same variable has the advantage of users being
978 # able to just C<undef $WATCHER> if the watcher causes them grief.
979
980 $WATCHER ||= $guard;
797 981
798=item @AnyEvent::post_detect 982=item @AnyEvent::post_detect
799 983
800If there are any code references in this array (you can C<push> to it 984If there are any code references in this array (you can C<push> to it
801before or after loading AnyEvent), then they will called directly after 985before or after loading AnyEvent), then they will called directly after
802the event loop has been chosen. 986the event loop has been chosen.
803 987
804You should check C<$AnyEvent::MODEL> before adding to this array, though: 988You should check C<$AnyEvent::MODEL> before adding to this array, though:
805if it contains a true value then the event loop has already been detected, 989if it is defined then the event loop has already been detected, and the
806and the array will be ignored. 990array will be ignored.
807 991
808Best use C<AnyEvent::post_detect { BLOCK }> instead. 992Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
993it, as it takes care of these details.
994
995This variable is mainly useful for modules that can do something useful
996when AnyEvent is used and thus want to know when it is initialised, but do
997not need to even load it by default. This array provides the means to hook
998into AnyEvent passively, without loading it.
999
1000Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
1001together, you could put this into Coro (this is the actual code used by
1002Coro to accomplish this):
1003
1004 if (defined $AnyEvent::MODEL) {
1005 # AnyEvent already initialised, so load Coro::AnyEvent
1006 require Coro::AnyEvent;
1007 } else {
1008 # AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
1009 # as soon as it is
1010 push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
1011 }
809 1012
810=back 1013=back
811 1014
812=head1 WHAT TO DO IN A MODULE 1015=head1 WHAT TO DO IN A MODULE
813 1016
868 1071
869 1072
870=head1 OTHER MODULES 1073=head1 OTHER MODULES
871 1074
872The following is a non-exhaustive list of additional modules that use 1075The following is a non-exhaustive list of additional modules that use
873AnyEvent and can therefore be mixed easily with other AnyEvent modules 1076AnyEvent as a client and can therefore be mixed easily with other AnyEvent
874in the same program. Some of the modules come with AnyEvent, some are 1077modules and other event loops in the same program. Some of the modules
875available via CPAN. 1078come as part of AnyEvent, the others are available via CPAN.
876 1079
877=over 4 1080=over 4
878 1081
879=item L<AnyEvent::Util> 1082=item L<AnyEvent::Util>
880 1083
889 1092
890=item L<AnyEvent::Handle> 1093=item L<AnyEvent::Handle>
891 1094
892Provide read and write buffers, manages watchers for reads and writes, 1095Provide read and write buffers, manages watchers for reads and writes,
893supports raw and formatted I/O, I/O queued and fully transparent and 1096supports raw and formatted I/O, I/O queued and fully transparent and
894non-blocking SSL/TLS. 1097non-blocking SSL/TLS (via L<AnyEvent::TLS>.
895 1098
896=item L<AnyEvent::DNS> 1099=item L<AnyEvent::DNS>
897 1100
898Provides rich asynchronous DNS resolver capabilities. 1101Provides rich asynchronous DNS resolver capabilities.
899 1102
1103=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
1104
1105Implement event-based interfaces to the protocols of the same name (for
1106the curious, IGS is the International Go Server and FCP is the Freenet
1107Client Protocol).
1108
1109=item L<AnyEvent::Handle::UDP>
1110
1111Here be danger!
1112
1113As Pauli would put it, "Not only is it not right, it's not even wrong!" -
1114there are so many things wrong with AnyEvent::Handle::UDP, most notably
1115it's use of a stream-based API with a protocol that isn't streamable, that
1116the only way to improve it is to delete it.
1117
1118It features data corruption (but typically only under load) and general
1119confusion. On top, the author is not only clueless about UDP but also
1120fact-resistant - some gems of his understanding: "connect doesn't work
1121with UDP", "UDP packets are not IP packets", "UDP only has datagrams, not
1122packets", "I don't need to implement proper error checking as UDP doesn't
1123support error checking" and so on - he doesn't even understand what's
1124wrong with his module when it is explained to him.
1125
900=item L<AnyEvent::HTTP> 1126=item L<AnyEvent::DBI>
901 1127
902A simple-to-use HTTP library that is capable of making a lot of concurrent 1128Executes L<DBI> requests asynchronously in a proxy process for you,
903HTTP requests. 1129notifying you in an event-bnased way when the operation is finished.
1130
1131=item L<AnyEvent::AIO>
1132
1133Truly asynchronous (as opposed to non-blocking) I/O, should be in the
1134toolbox of every event programmer. AnyEvent::AIO transparently fuses
1135L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
1136file I/O, and much more.
904 1137
905=item L<AnyEvent::HTTPD> 1138=item L<AnyEvent::HTTPD>
906 1139
907Provides a simple web application server framework. 1140A simple embedded webserver.
908 1141
909=item L<AnyEvent::FastPing> 1142=item L<AnyEvent::FastPing>
910 1143
911The fastest ping in the west. 1144The fastest ping in the west.
912 1145
913=item L<AnyEvent::DBI>
914
915Executes L<DBI> requests asynchronously in a proxy process.
916
917=item L<AnyEvent::AIO>
918
919Truly asynchronous I/O, should be in the toolbox of every event
920programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
921together.
922
923=item L<AnyEvent::BDB>
924
925Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
926L<BDB> and AnyEvent together.
927
928=item L<AnyEvent::GPSD>
929
930A non-blocking interface to gpsd, a daemon delivering GPS information.
931
932=item L<AnyEvent::IGS>
933
934A non-blocking interface to the Internet Go Server protocol (used by
935L<App::IGS>).
936
937=item L<AnyEvent::IRC>
938
939AnyEvent based IRC client module family (replacing the older Net::IRC3).
940
941=item L<Net::XMPP2>
942
943AnyEvent based XMPP (Jabber protocol) module family.
944
945=item L<Net::FCP>
946
947AnyEvent-based implementation of the Freenet Client Protocol, birthplace
948of AnyEvent.
949
950=item L<Event::ExecFlow>
951
952High level API for event-based execution flow control.
953
954=item L<Coro> 1146=item L<Coro>
955 1147
956Has special support for AnyEvent via L<Coro::AnyEvent>. 1148Has special support for AnyEvent via L<Coro::AnyEvent>.
957 1149
958=item L<IO::Lambda>
959
960The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
961
962=back 1150=back
963 1151
964=cut 1152=cut
965 1153
966package AnyEvent; 1154package AnyEvent;
967 1155
968no warnings; 1156# basically a tuned-down version of common::sense
969use strict qw(vars subs); 1157sub common_sense {
1158 # from common:.sense 1.0
1159 ${^WARNING_BITS} = "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x00";
1160 # use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1161 $^H |= 0x00000600;
1162}
970 1163
1164BEGIN { AnyEvent::common_sense }
1165
971use Carp; 1166use Carp ();
972 1167
973our $VERSION = 4.8; 1168our $VERSION = '5.27';
974our $MODEL; 1169our $MODEL;
975 1170
976our $AUTOLOAD; 1171our $AUTOLOAD;
977our @ISA; 1172our @ISA;
978 1173
979our @REGISTRY; 1174our @REGISTRY;
980 1175
981our $WIN32; 1176our $VERBOSE;
982 1177
983BEGIN { 1178BEGIN {
984 eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; 1179 require "AnyEvent/constants.pl";
1180
985 eval "sub TAINT(){ " . (${^TAINT}*1) . " }"; 1181 eval "sub TAINT (){" . (${^TAINT}*1) . "}";
986 1182
987 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} 1183 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
988 if ${^TAINT}; 1184 if ${^TAINT};
989}
990 1185
991our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; 1186 $VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
1187
1188}
1189
1190our $MAX_SIGNAL_LATENCY = 10;
992 1191
993our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred 1192our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
994 1193
995{ 1194{
996 my $idx; 1195 my $idx;
998 for reverse split /\s*,\s*/, 1197 for reverse split /\s*,\s*/,
999 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; 1198 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1000} 1199}
1001 1200
1002my @models = ( 1201my @models = (
1003 [EV:: => AnyEvent::Impl::EV::], 1202 [EV:: => AnyEvent::Impl::EV:: , 1],
1004 [Event:: => AnyEvent::Impl::Event::],
1005 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], 1203 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1006 # everything below here will not be autoprobed 1204 # everything below here will not (normally) be autoprobed
1007 # as the pureperl backend should work everywhere 1205 # as the pureperl backend should work everywhere
1008 # and is usually faster 1206 # and is usually faster
1207 [Event:: => AnyEvent::Impl::Event::, 1],
1208 [Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1209 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1210 [Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1009 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles 1211 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1010 [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
1011 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1012 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program 1212 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1013 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza 1213 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1014 [Wx:: => AnyEvent::Impl::POE::], 1214 [Wx:: => AnyEvent::Impl::POE::],
1015 [Prima:: => AnyEvent::Impl::POE::], 1215 [Prima:: => AnyEvent::Impl::POE::],
1016 # IO::Async is just too broken - we would need workaorunds for its 1216 # IO::Async is just too broken - we would need workarounds for its
1017 # byzantine signal and broken child handling, among others. 1217 # byzantine signal and broken child handling, among others.
1018 # IO::Async is rather hard to detect, as it doesn't have any 1218 # IO::Async is rather hard to detect, as it doesn't have any
1019 # obvious default class. 1219 # obvious default class.
1020# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program 1220 [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1021# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program 1221 [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1022# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program 1222 [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1223 [AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1023); 1224);
1024 1225
1025our %method = map +($_ => 1), 1226our %method = map +($_ => 1),
1026 qw(io timer time now now_update signal child idle condvar one_event DESTROY); 1227 qw(io timer time now now_update signal child idle condvar one_event DESTROY);
1027 1228
1028our @post_detect; 1229our @post_detect;
1029 1230
1030sub post_detect(&) { 1231sub post_detect(&) {
1031 my ($cb) = @_; 1232 my ($cb) = @_;
1032 1233
1033 if ($MODEL) {
1034 $cb->();
1035
1036 1
1037 } else {
1038 push @post_detect, $cb; 1234 push @post_detect, $cb;
1039 1235
1040 defined wantarray 1236 defined wantarray
1041 ? bless \$cb, "AnyEvent::Util::postdetect" 1237 ? bless \$cb, "AnyEvent::Util::postdetect"
1042 : () 1238 : ()
1043 }
1044} 1239}
1045 1240
1046sub AnyEvent::Util::postdetect::DESTROY { 1241sub AnyEvent::Util::postdetect::DESTROY {
1047 @post_detect = grep $_ != ${$_[0]}, @post_detect; 1242 @post_detect = grep $_ != ${$_[0]}, @post_detect;
1048} 1243}
1049 1244
1050sub detect() { 1245sub detect() {
1246 # free some memory
1247 *detect = sub () { $MODEL };
1248
1249 local $!; # for good measure
1250 local $SIG{__DIE__};
1251
1252 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1253 my $model = "AnyEvent::Impl::$1";
1254 if (eval "require $model") {
1255 $MODEL = $model;
1256 warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
1257 } else {
1258 warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1259 }
1260 }
1261
1262 # check for already loaded models
1051 unless ($MODEL) { 1263 unless ($MODEL) {
1052 no strict 'refs'; 1264 for (@REGISTRY, @models) {
1053 local $SIG{__DIE__}; 1265 my ($package, $model) = @$_;
1054 1266 if (${"$package\::VERSION"} > 0) {
1055 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1056 my $model = "AnyEvent::Impl::$1";
1057 if (eval "require $model") { 1267 if (eval "require $model") {
1058 $MODEL = $model; 1268 $MODEL = $model;
1059 warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1; 1269 warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1060 } else { 1270 last;
1061 warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose; 1271 }
1062 } 1272 }
1063 } 1273 }
1064 1274
1065 # check for already loaded models
1066 unless ($MODEL) { 1275 unless ($MODEL) {
1276 # try to autoload a model
1067 for (@REGISTRY, @models) { 1277 for (@REGISTRY, @models) {
1068 my ($package, $model) = @$_; 1278 my ($package, $model, $autoload) = @$_;
1279 if (
1280 $autoload
1281 and eval "require $package"
1069 if (${"$package\::VERSION"} > 0) { 1282 and ${"$package\::VERSION"} > 0
1070 if (eval "require $model") { 1283 and eval "require $model"
1284 ) {
1071 $MODEL = $model; 1285 $MODEL = $model;
1072 warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1; 1286 warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1073 last; 1287 last;
1074 }
1075 } 1288 }
1076 } 1289 }
1077 1290
1078 unless ($MODEL) {
1079 # try to load a model
1080
1081 for (@REGISTRY, @models) {
1082 my ($package, $model) = @$_;
1083 if (eval "require $package"
1084 and ${"$package\::VERSION"} > 0
1085 and eval "require $model") {
1086 $MODEL = $model;
1087 warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1;
1088 last;
1089 }
1090 }
1091
1092 $MODEL 1291 $MODEL
1093 or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n"; 1292 or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";
1094 }
1095 } 1293 }
1096
1097 push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1098
1099 unshift @ISA, $MODEL;
1100
1101 require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1102
1103 (shift @post_detect)->() while @post_detect;
1104 } 1294 }
1295
1296 @models = (); # free probe data
1297
1298 push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1299 unshift @ISA, $MODEL;
1300
1301 # now nuke some methods that are overriden by the backend.
1302 # SUPER is not allowed.
1303 for (qw(time signal child idle)) {
1304 undef &{"AnyEvent::Base::$_"}
1305 if defined &{"$MODEL\::$_"};
1306 }
1307
1308 require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1309
1310 (shift @post_detect)->() while @post_detect;
1311
1312 *post_detect = sub(&) {
1313 shift->();
1314
1315 undef
1316 };
1105 1317
1106 $MODEL 1318 $MODEL
1107} 1319}
1108 1320
1109sub AUTOLOAD { 1321sub AUTOLOAD {
1110 (my $func = $AUTOLOAD) =~ s/.*://; 1322 (my $func = $AUTOLOAD) =~ s/.*://;
1111 1323
1112 $method{$func} 1324 $method{$func}
1113 or croak "$func: not a valid method for AnyEvent objects"; 1325 or Carp::croak "$func: not a valid AnyEvent class method";
1114 1326
1115 detect unless $MODEL; 1327 detect;
1116 1328
1117 my $class = shift; 1329 my $class = shift;
1118 $class->$func (@_); 1330 $class->$func (@_);
1119} 1331}
1120 1332
1123# allow only one watcher per fd, so we dup it to get a different one). 1335# allow only one watcher per fd, so we dup it to get a different one).
1124sub _dupfh($$;$$) { 1336sub _dupfh($$;$$) {
1125 my ($poll, $fh, $r, $w) = @_; 1337 my ($poll, $fh, $r, $w) = @_;
1126 1338
1127 # cygwin requires the fh mode to be matching, unix doesn't 1339 # cygwin requires the fh mode to be matching, unix doesn't
1128 my ($rw, $mode) = $poll eq "r" ? ($r, "<") : ($w, ">"); 1340 my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1129 1341
1130 open my $fh2, "$mode&", $fh 1342 open my $fh2, $mode, $fh
1131 or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,"; 1343 or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1132 1344
1133 # we assume CLOEXEC is already set by perl in all important cases 1345 # we assume CLOEXEC is already set by perl in all important cases
1134 1346
1135 ($fh2, $rw) 1347 ($fh2, $rw)
1136} 1348}
1137 1349
1350=head1 SIMPLIFIED AE API
1351
1352Starting with version 5.0, AnyEvent officially supports a second, much
1353simpler, API that is designed to reduce the calling, typing and memory
1354overhead by using function call syntax and a fixed number of parameters.
1355
1356See the L<AE> manpage for details.
1357
1358=cut
1359
1360package AE;
1361
1362our $VERSION = $AnyEvent::VERSION;
1363
1364# fall back to the main API by default - backends and AnyEvent::Base
1365# implementations can overwrite these.
1366
1367sub io($$$) {
1368 AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1369}
1370
1371sub timer($$$) {
1372 AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
1373}
1374
1375sub signal($$) {
1376 AnyEvent->signal (signal => $_[0], cb => $_[1])
1377}
1378
1379sub child($$) {
1380 AnyEvent->child (pid => $_[0], cb => $_[1])
1381}
1382
1383sub idle($) {
1384 AnyEvent->idle (cb => $_[0])
1385}
1386
1387sub cv(;&) {
1388 AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
1389}
1390
1391sub now() {
1392 AnyEvent->now
1393}
1394
1395sub now_update() {
1396 AnyEvent->now_update
1397}
1398
1399sub time() {
1400 AnyEvent->time
1401}
1402
1138package AnyEvent::Base; 1403package AnyEvent::Base;
1139 1404
1140# default implementations for many methods 1405# default implementations for many methods
1141 1406
1142BEGIN { 1407sub time {
1408 eval q{ # poor man's autoloading {}
1409 # probe for availability of Time::HiRes
1143 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { 1410 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1411 warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1144 *_time = \&Time::HiRes::time; 1412 *AE::time = \&Time::HiRes::time;
1145 # if (eval "use POSIX (); (POSIX::times())... 1413 # if (eval "use POSIX (); (POSIX::times())...
1146 } else { 1414 } else {
1415 warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1147 *_time = sub { time }; # epic fail 1416 *AE::time = sub (){ time }; # epic fail
1417 }
1418
1419 *time = sub { AE::time }; # different prototypes
1420 };
1421 die if $@;
1422
1423 &time
1424}
1425
1426*now = \&time;
1427
1428sub now_update { }
1429
1430# default implementation for ->condvar
1431
1432sub condvar {
1433 eval q{ # poor man's autoloading {}
1434 *condvar = sub {
1435 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1436 };
1437
1438 *AE::cv = sub (;&) {
1439 bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
1440 };
1441 };
1442 die if $@;
1443
1444 &condvar
1445}
1446
1447# default implementation for ->signal
1448
1449our $HAVE_ASYNC_INTERRUPT;
1450
1451sub _have_async_interrupt() {
1452 $HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
1453 && eval "use Async::Interrupt 1.02 (); 1")
1454 unless defined $HAVE_ASYNC_INTERRUPT;
1455
1456 $HAVE_ASYNC_INTERRUPT
1457}
1458
1459our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1460our (%SIG_ASY, %SIG_ASY_W);
1461our ($SIG_COUNT, $SIG_TW);
1462
1463# install a dummy wakeup watcher to reduce signal catching latency
1464# used by Impls
1465sub _sig_add() {
1466 unless ($SIG_COUNT++) {
1467 # try to align timer on a full-second boundary, if possible
1468 my $NOW = AE::now;
1469
1470 $SIG_TW = AE::timer
1471 $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1472 $MAX_SIGNAL_LATENCY,
1473 sub { } # just for the PERL_ASYNC_CHECK
1474 ;
1148 } 1475 }
1149} 1476}
1150 1477
1151sub time { _time } 1478sub _sig_del {
1152sub now { _time } 1479 undef $SIG_TW
1153sub now_update { } 1480 unless --$SIG_COUNT;
1154
1155# default implementation for ->condvar
1156
1157sub condvar {
1158 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1159} 1481}
1160 1482
1161# default implementation for ->signal 1483our $_sig_name_init; $_sig_name_init = sub {
1484 eval q{ # poor man's autoloading {}
1485 undef $_sig_name_init;
1162 1486
1163our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); 1487 if (_have_async_interrupt) {
1488 *sig2num = \&Async::Interrupt::sig2num;
1489 *sig2name = \&Async::Interrupt::sig2name;
1490 } else {
1491 require Config;
1164 1492
1165sub _signal_exec { 1493 my %signame2num;
1166 sysread $SIGPIPE_R, my $dummy, 4; 1494 @signame2num{ split ' ', $Config::Config{sig_name} }
1495 = split ' ', $Config::Config{sig_num};
1167 1496
1168 while (%SIG_EV) { 1497 my @signum2name;
1169 for (keys %SIG_EV) { 1498 @signum2name[values %signame2num] = keys %signame2num;
1170 delete $SIG_EV{$_}; 1499
1171 $_->() for values %{ $SIG_CB{$_} || {} }; 1500 *sig2num = sub($) {
1501 $_[0] > 0 ? shift : $signame2num{+shift}
1502 };
1503 *sig2name = sub ($) {
1504 $_[0] > 0 ? $signum2name[+shift] : shift
1505 };
1172 } 1506 }
1173 } 1507 };
1174} 1508 die if $@;
1509};
1510
1511sub sig2num ($) { &$_sig_name_init; &sig2num }
1512sub sig2name($) { &$_sig_name_init; &sig2name }
1175 1513
1176sub signal { 1514sub signal {
1177 my (undef, %arg) = @_; 1515 eval q{ # poor man's autoloading {}
1516 # probe for availability of Async::Interrupt
1517 if (_have_async_interrupt) {
1518 warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1178 1519
1179 unless ($SIGPIPE_R) { 1520 $SIGPIPE_R = new Async::Interrupt::EventPipe;
1180 require Fcntl; 1521 $SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1181 1522
1182 if (AnyEvent::WIN32) {
1183 require AnyEvent::Util;
1184
1185 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1186 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1187 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1188 } else { 1523 } else {
1524 warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1525
1526 if (AnyEvent::WIN32) {
1527 require AnyEvent::Util;
1528
1529 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1530 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1531 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1532 } else {
1189 pipe $SIGPIPE_R, $SIGPIPE_W; 1533 pipe $SIGPIPE_R, $SIGPIPE_W;
1190 fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R; 1534 fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
1191 fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case 1535 fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
1192 1536
1193 # not strictly required, as $^F is normally 2, but let's make sure... 1537 # not strictly required, as $^F is normally 2, but let's make sure...
1194 fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; 1538 fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1195 fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; 1539 fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1540 }
1541
1542 $SIGPIPE_R
1543 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1544
1545 $SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1196 } 1546 }
1197 1547
1198 $SIGPIPE_R 1548 *signal = $HAVE_ASYNC_INTERRUPT
1199 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; 1549 ? sub {
1550 my (undef, %arg) = @_;
1200 1551
1201 $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec); 1552 # async::interrupt
1202 }
1203
1204 my $signal = uc $arg{signal} 1553 my $signal = sig2num $arg{signal};
1205 or Carp::croak "required option 'signal' is missing";
1206
1207 $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; 1554 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1555
1556 $SIG_ASY{$signal} ||= new Async::Interrupt
1557 cb => sub { undef $SIG_EV{$signal} },
1558 signal => $signal,
1559 pipe => [$SIGPIPE_R->filenos],
1560 pipe_autodrain => 0,
1561 ;
1562
1563 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1564 }
1565 : sub {
1566 my (undef, %arg) = @_;
1567
1568 # pure perl
1569 my $signal = sig2name $arg{signal};
1570 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1571
1208 $SIG{$signal} ||= sub { 1572 $SIG{$signal} ||= sub {
1209 local $!; 1573 local $!;
1210 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; 1574 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1211 undef $SIG_EV{$signal}; 1575 undef $SIG_EV{$signal};
1576 };
1577
1578 # can't do signal processing without introducing races in pure perl,
1579 # so limit the signal latency.
1580 _sig_add;
1581
1582 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1583 }
1584 ;
1585
1586 *AnyEvent::Base::signal::DESTROY = sub {
1587 my ($signal, $cb) = @{$_[0]};
1588
1589 _sig_del;
1590
1591 delete $SIG_CB{$signal}{$cb};
1592
1593 $HAVE_ASYNC_INTERRUPT
1594 ? delete $SIG_ASY{$signal}
1595 : # delete doesn't work with older perls - they then
1596 # print weird messages, or just unconditionally exit
1597 # instead of getting the default action.
1598 undef $SIG{$signal}
1599 unless keys %{ $SIG_CB{$signal} };
1600 };
1601
1602 *_signal_exec = sub {
1603 $HAVE_ASYNC_INTERRUPT
1604 ? $SIGPIPE_R->drain
1605 : sysread $SIGPIPE_R, (my $dummy), 9;
1606
1607 while (%SIG_EV) {
1608 for (keys %SIG_EV) {
1609 delete $SIG_EV{$_};
1610 $_->() for values %{ $SIG_CB{$_} || {} };
1611 }
1612 }
1613 };
1212 }; 1614 };
1615 die if $@;
1213 1616
1214 bless [$signal, $arg{cb}], "AnyEvent::Base::signal" 1617 &signal
1215}
1216
1217sub AnyEvent::Base::signal::DESTROY {
1218 my ($signal, $cb) = @{$_[0]};
1219
1220 delete $SIG_CB{$signal}{$cb};
1221
1222 # delete doesn't work with older perls - they then
1223 # print weird messages, or just unconditionally exit
1224 # instead of getting the default action.
1225 undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1226} 1618}
1227 1619
1228# default implementation for ->child 1620# default implementation for ->child
1229 1621
1230our %PID_CB; 1622our %PID_CB;
1231our $CHLD_W; 1623our $CHLD_W;
1232our $CHLD_DELAY_W; 1624our $CHLD_DELAY_W;
1233our $WNOHANG; 1625our $WNOHANG;
1234 1626
1235sub _sigchld { 1627# used by many Impl's
1236 while (0 < (my $pid = waitpid -1, $WNOHANG)) { 1628sub _emit_childstatus($$) {
1629 my (undef, $rpid, $rstatus) = @_;
1630
1631 $_->($rpid, $rstatus)
1237 $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), 1632 for values %{ $PID_CB{$rpid} || {} },
1238 (values %{ $PID_CB{0} || {} }); 1633 values %{ $PID_CB{0} || {} };
1239 }
1240} 1634}
1241 1635
1242sub child { 1636sub child {
1637 eval q{ # poor man's autoloading {}
1638 *_sigchld = sub {
1639 my $pid;
1640
1641 AnyEvent->_emit_childstatus ($pid, $?)
1642 while ($pid = waitpid -1, $WNOHANG) > 0;
1643 };
1644
1645 *child = sub {
1243 my (undef, %arg) = @_; 1646 my (undef, %arg) = @_;
1244 1647
1245 defined (my $pid = $arg{pid} + 0) 1648 defined (my $pid = $arg{pid} + 0)
1246 or Carp::croak "required option 'pid' is missing"; 1649 or Carp::croak "required option 'pid' is missing";
1247 1650
1248 $PID_CB{$pid}{$arg{cb}} = $arg{cb}; 1651 $PID_CB{$pid}{$arg{cb}} = $arg{cb};
1249 1652
1653 # WNOHANG is almost cetrainly 1 everywhere
1654 $WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1655 ? 1
1250 $WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; 1656 : eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1251 1657
1252 unless ($CHLD_W) { 1658 unless ($CHLD_W) {
1253 $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); 1659 $CHLD_W = AE::signal CHLD => \&_sigchld;
1254 # child could be a zombie already, so make at least one round 1660 # child could be a zombie already, so make at least one round
1255 &_sigchld; 1661 &_sigchld;
1256 } 1662 }
1257 1663
1258 bless [$pid, $arg{cb}], "AnyEvent::Base::child" 1664 bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1259} 1665 };
1260 1666
1261sub AnyEvent::Base::child::DESTROY { 1667 *AnyEvent::Base::child::DESTROY = sub {
1262 my ($pid, $cb) = @{$_[0]}; 1668 my ($pid, $cb) = @{$_[0]};
1263 1669
1264 delete $PID_CB{$pid}{$cb}; 1670 delete $PID_CB{$pid}{$cb};
1265 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; 1671 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1266 1672
1267 undef $CHLD_W unless keys %PID_CB; 1673 undef $CHLD_W unless keys %PID_CB;
1674 };
1675 };
1676 die if $@;
1677
1678 &child
1268} 1679}
1269 1680
1270# idle emulation is done by simply using a timer, regardless 1681# idle emulation is done by simply using a timer, regardless
1271# of whether the process is idle or not, and not letting 1682# of whether the process is idle or not, and not letting
1272# the callback use more than 50% of the time. 1683# the callback use more than 50% of the time.
1273sub idle { 1684sub idle {
1685 eval q{ # poor man's autoloading {}
1686 *idle = sub {
1274 my (undef, %arg) = @_; 1687 my (undef, %arg) = @_;
1275 1688
1276 my ($cb, $w, $rcb) = $arg{cb}; 1689 my ($cb, $w, $rcb) = $arg{cb};
1277 1690
1278 $rcb = sub { 1691 $rcb = sub {
1279 if ($cb) { 1692 if ($cb) {
1280 $w = _time; 1693 $w = _time;
1281 &$cb; 1694 &$cb;
1282 $w = _time - $w; 1695 $w = _time - $w;
1283 1696
1284 # never use more then 50% of the time for the idle watcher, 1697 # never use more then 50% of the time for the idle watcher,
1285 # within some limits 1698 # within some limits
1286 $w = 0.0001 if $w < 0.0001; 1699 $w = 0.0001 if $w < 0.0001;
1287 $w = 5 if $w > 5; 1700 $w = 5 if $w > 5;
1288 1701
1289 $w = AnyEvent->timer (after => $w, cb => $rcb); 1702 $w = AE::timer $w, 0, $rcb;
1290 } else { 1703 } else {
1291 # clean up... 1704 # clean up...
1292 undef $w; 1705 undef $w;
1293 undef $rcb; 1706 undef $rcb;
1707 }
1708 };
1709
1710 $w = AE::timer 0.05, 0, $rcb;
1711
1712 bless \\$cb, "AnyEvent::Base::idle"
1294 } 1713 };
1714
1715 *AnyEvent::Base::idle::DESTROY = sub {
1716 undef $${$_[0]};
1717 };
1295 }; 1718 };
1719 die if $@;
1296 1720
1297 $w = AnyEvent->timer (after => 0.05, cb => $rcb); 1721 &idle
1298
1299 bless \\$cb, "AnyEvent::Base::idle"
1300}
1301
1302sub AnyEvent::Base::idle::DESTROY {
1303 undef $${$_[0]};
1304} 1722}
1305 1723
1306package AnyEvent::CondVar; 1724package AnyEvent::CondVar;
1307 1725
1308our @ISA = AnyEvent::CondVar::Base::; 1726our @ISA = AnyEvent::CondVar::Base::;
1309 1727
1310package AnyEvent::CondVar::Base; 1728package AnyEvent::CondVar::Base;
1311 1729
1312use overload 1730#use overload
1313 '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, 1731# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1314 fallback => 1; 1732# fallback => 1;
1733
1734# save 300+ kilobytes by dirtily hardcoding overloading
1735${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching.
1736*{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod."
1737*{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{}
1738${'AnyEvent::CondVar::Base::()'} = 1; # fallback
1739
1740our $WAITING;
1315 1741
1316sub _send { 1742sub _send {
1317 # nop 1743 # nop
1318} 1744}
1319 1745
1332sub ready { 1758sub ready {
1333 $_[0]{_ae_sent} 1759 $_[0]{_ae_sent}
1334} 1760}
1335 1761
1336sub _wait { 1762sub _wait {
1763 $WAITING
1764 and !$_[0]{_ae_sent}
1765 and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1766
1767 local $WAITING = 1;
1337 AnyEvent->one_event while !$_[0]{_ae_sent}; 1768 AnyEvent->one_event while !$_[0]{_ae_sent};
1338} 1769}
1339 1770
1340sub recv { 1771sub recv {
1341 $_[0]->_wait; 1772 $_[0]->_wait;
1343 Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak}; 1774 Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1344 wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0] 1775 wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1345} 1776}
1346 1777
1347sub cb { 1778sub cb {
1348 $_[0]{_ae_cb} = $_[1] if @_ > 1; 1779 my $cv = shift;
1780
1781 @_
1782 and $cv->{_ae_cb} = shift
1783 and $cv->{_ae_sent}
1784 and (delete $cv->{_ae_cb})->($cv);
1785
1349 $_[0]{_ae_cb} 1786 $cv->{_ae_cb}
1350} 1787}
1351 1788
1352sub begin { 1789sub begin {
1353 ++$_[0]{_ae_counter}; 1790 ++$_[0]{_ae_counter};
1354 $_[0]{_ae_end_cb} = $_[1] if @_ > 1; 1791 $_[0]{_ae_end_cb} = $_[1] if @_ > 1;
1403C<PERL_ANYEVENT_MODEL>. 1840C<PERL_ANYEVENT_MODEL>.
1404 1841
1405When set to C<2> or higher, cause AnyEvent to report to STDERR which event 1842When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1406model it chooses. 1843model it chooses.
1407 1844
1845When set to C<8> or higher, then AnyEvent will report extra information on
1846which optional modules it loads and how it implements certain features.
1847
1408=item C<PERL_ANYEVENT_STRICT> 1848=item C<PERL_ANYEVENT_STRICT>
1409 1849
1410AnyEvent does not do much argument checking by default, as thorough 1850AnyEvent does not do much argument checking by default, as thorough
1411argument checking is very costly. Setting this variable to a true value 1851argument checking is very costly. Setting this variable to a true value
1412will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly 1852will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1413check the arguments passed to most method calls. If it finds any problems, 1853check the arguments passed to most method calls. If it finds any problems,
1414it will croak. 1854it will croak.
1415 1855
1416In other words, enables "strict" mode. 1856In other words, enables "strict" mode.
1417 1857
1418Unlike C<use strict>, it is definitely recommended to keep it off in 1858Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>
1419production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while 1859>>, it is definitely recommended to keep it off in production. Keeping
1420developing programs can be very useful, however. 1860C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1861can be very useful, however.
1421 1862
1422=item C<PERL_ANYEVENT_MODEL> 1863=item C<PERL_ANYEVENT_MODEL>
1423 1864
1424This can be used to specify the event model to be used by AnyEvent, before 1865This can be used to specify the event model to be used by AnyEvent, before
1425auto detection and -probing kicks in. It must be a string consisting 1866auto detection and -probing kicks in. It must be a string consisting
1487 1928
1488When neither C<ca_file> nor C<ca_path> was specified during 1929When neither C<ca_file> nor C<ca_path> was specified during
1489L<AnyEvent::TLS> context creation, and either of these environment 1930L<AnyEvent::TLS> context creation, and either of these environment
1490variables exist, they will be used to specify CA certificate locations 1931variables exist, they will be used to specify CA certificate locations
1491instead of a system-dependent default. 1932instead of a system-dependent default.
1933
1934=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1935
1936When these are set to C<1>, then the respective modules are not
1937loaded. Mostly good for testing AnyEvent itself.
1492 1938
1493=back 1939=back
1494 1940
1495=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE 1941=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1496 1942
1554 warn "read: $input\n"; # output what has been read 2000 warn "read: $input\n"; # output what has been read
1555 $cv->send if $input =~ /^q/i; # quit program if /^q/i 2001 $cv->send if $input =~ /^q/i; # quit program if /^q/i
1556 }, 2002 },
1557 ); 2003 );
1558 2004
1559 my $time_watcher; # can only be used once
1560
1561 sub new_timer {
1562 $timer = AnyEvent->timer (after => 1, cb => sub { 2005 my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1563 warn "timeout\n"; # print 'timeout' about every second 2006 warn "timeout\n"; # print 'timeout' at most every second
1564 &new_timer; # and restart the time
1565 }); 2007 });
1566 }
1567
1568 new_timer; # create first timer
1569 2008
1570 $cv->recv; # wait until user enters /^q/i 2009 $cv->recv; # wait until user enters /^q/i
1571 2010
1572=head1 REAL-WORLD EXAMPLE 2011=head1 REAL-WORLD EXAMPLE
1573 2012
1646 2085
1647The actual code goes further and collects all errors (C<die>s, exceptions) 2086The actual code goes further and collects all errors (C<die>s, exceptions)
1648that occurred during request processing. The C<result> method detects 2087that occurred during request processing. The C<result> method detects
1649whether an exception as thrown (it is stored inside the $txn object) 2088whether an exception as thrown (it is stored inside the $txn object)
1650and just throws the exception, which means connection errors and other 2089and just throws the exception, which means connection errors and other
1651problems get reported tot he code that tries to use the result, not in a 2090problems get reported to the code that tries to use the result, not in a
1652random callback. 2091random callback.
1653 2092
1654All of this enables the following usage styles: 2093All of this enables the following usage styles:
1655 2094
16561. Blocking: 20951. Blocking:
1704through AnyEvent. The benchmark creates a lot of timers (with a zero 2143through AnyEvent. The benchmark creates a lot of timers (with a zero
1705timeout) and I/O watchers (watching STDOUT, a pty, to become writable, 2144timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1706which it is), lets them fire exactly once and destroys them again. 2145which it is), lets them fire exactly once and destroys them again.
1707 2146
1708Source code for this benchmark is found as F<eg/bench> in the AnyEvent 2147Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1709distribution. 2148distribution. It uses the L<AE> interface, which makes a real difference
2149for the EV and Perl backends only.
1710 2150
1711=head3 Explanation of the columns 2151=head3 Explanation of the columns
1712 2152
1713I<watcher> is the number of event watchers created/destroyed. Since 2153I<watcher> is the number of event watchers created/destroyed. Since
1714different event models feature vastly different performances, each event 2154different event models feature vastly different performances, each event
1735watcher. 2175watcher.
1736 2176
1737=head3 Results 2177=head3 Results
1738 2178
1739 name watchers bytes create invoke destroy comment 2179 name watchers bytes create invoke destroy comment
1740 EV/EV 400000 224 0.47 0.35 0.27 EV native interface 2180 EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1741 EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers 2181 EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1742 CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal 2182 Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1743 Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation 2183 Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1744 Event/Event 16000 517 32.20 31.80 0.81 Event native interface 2184 Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1745 Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers 2185 Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
1746 IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll 2186 IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
1747 IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll 2187 IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1748 Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour 2188 Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1749 Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers 2189 Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1750 POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event 2190 POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1751 POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select 2191 POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1752 2192
1753=head3 Discussion 2193=head3 Discussion
1754 2194
1755The benchmark does I<not> measure scalability of the event loop very 2195The benchmark does I<not> measure scalability of the event loop very
1756well. For example, a select-based event loop (such as the pure perl one) 2196well. For example, a select-based event loop (such as the pure perl one)
1768benchmark machine, handling an event takes roughly 1600 CPU cycles with 2208benchmark machine, handling an event takes roughly 1600 CPU cycles with
1769EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU 2209EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1770cycles with POE. 2210cycles with POE.
1771 2211
1772C<EV> is the sole leader regarding speed and memory use, which are both 2212C<EV> is the sole leader regarding speed and memory use, which are both
1773maximal/minimal, respectively. Even when going through AnyEvent, it uses 2213maximal/minimal, respectively. When using the L<AE> API there is zero
2214overhead (when going through the AnyEvent API create is about 5-6 times
2215slower, with other times being equal, so still uses far less memory than
1774far less memory than any other event loop and is still faster than Event 2216any other event loop and is still faster than Event natively).
1775natively.
1776 2217
1777The pure perl implementation is hit in a few sweet spots (both the 2218The pure perl implementation is hit in a few sweet spots (both the
1778constant timeout and the use of a single fd hit optimisations in the perl 2219constant timeout and the use of a single fd hit optimisations in the perl
1779interpreter and the backend itself). Nevertheless this shows that it 2220interpreter and the backend itself). Nevertheless this shows that it
1780adds very little overhead in itself. Like any select-based backend its 2221adds very little overhead in itself. Like any select-based backend its
1854In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100 2295In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
1855(1%) are active. This mirrors the activity of large servers with many 2296(1%) are active. This mirrors the activity of large servers with many
1856connections, most of which are idle at any one point in time. 2297connections, most of which are idle at any one point in time.
1857 2298
1858Source code for this benchmark is found as F<eg/bench2> in the AnyEvent 2299Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
1859distribution. 2300distribution. It uses the L<AE> interface, which makes a real difference
2301for the EV and Perl backends only.
1860 2302
1861=head3 Explanation of the columns 2303=head3 Explanation of the columns
1862 2304
1863I<sockets> is the number of sockets, and twice the number of "servers" (as 2305I<sockets> is the number of sockets, and twice the number of "servers" (as
1864each server has a read and write socket end). 2306each server has a read and write socket end).
1872a new one that moves the timeout into the future. 2314a new one that moves the timeout into the future.
1873 2315
1874=head3 Results 2316=head3 Results
1875 2317
1876 name sockets create request 2318 name sockets create request
1877 EV 20000 69.01 11.16 2319 EV 20000 62.66 7.99
1878 Perl 20000 73.32 35.87 2320 Perl 20000 68.32 32.64
1879 IOAsync 20000 157.00 98.14 epoll 2321 IOAsync 20000 174.06 101.15 epoll
1880 IOAsync 20000 159.31 616.06 poll 2322 IOAsync 20000 174.67 610.84 poll
1881 Event 20000 212.62 257.32 2323 Event 20000 202.69 242.91
1882 Glib 20000 651.16 1896.30 2324 Glib 20000 557.01 1689.52
1883 POE 20000 349.67 12317.24 uses POE::Loop::Event 2325 POE 20000 341.54 12086.32 uses POE::Loop::Event
1884 2326
1885=head3 Discussion 2327=head3 Discussion
1886 2328
1887This benchmark I<does> measure scalability and overall performance of the 2329This benchmark I<does> measure scalability and overall performance of the
1888particular event loop. 2330particular event loop.
2014As you can see, the AnyEvent + EV combination even beats the 2456As you can see, the AnyEvent + EV combination even beats the
2015hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl 2457hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2016backend easily beats IO::Lambda and POE. 2458backend easily beats IO::Lambda and POE.
2017 2459
2018And even the 100% non-blocking version written using the high-level (and 2460And even the 100% non-blocking version written using the high-level (and
2019slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a 2461slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2020large margin, even though it does all of DNS, tcp-connect and socket I/O 2462higher level ("unoptimised") abstractions by a large margin, even though
2021in a non-blocking way. 2463it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2022 2464
2023The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and 2465The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2024F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are 2466F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2025part of the IO::lambda distribution and were used without any changes. 2467part of the IO::Lambda distribution and were used without any changes.
2026 2468
2027 2469
2028=head1 SIGNALS 2470=head1 SIGNALS
2029 2471
2030AnyEvent currently installs handlers for these signals: 2472AnyEvent currently installs handlers for these signals:
2035 2477
2036A handler for C<SIGCHLD> is installed by AnyEvent's child watcher 2478A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
2037emulation for event loops that do not support them natively. Also, some 2479emulation for event loops that do not support them natively. Also, some
2038event loops install a similar handler. 2480event loops install a similar handler.
2039 2481
2040If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will 2482Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
2041reset it to default, to avoid losing child exit statuses. 2483AnyEvent will reset it to default, to avoid losing child exit statuses.
2042 2484
2043=item SIGPIPE 2485=item SIGPIPE
2044 2486
2045A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> 2487A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
2046when AnyEvent gets loaded. 2488when AnyEvent gets loaded.
2064 if $SIG{CHLD} eq 'IGNORE'; 2506 if $SIG{CHLD} eq 'IGNORE';
2065 2507
2066$SIG{PIPE} = sub { } 2508$SIG{PIPE} = sub { }
2067 unless defined $SIG{PIPE}; 2509 unless defined $SIG{PIPE};
2068 2510
2511=head1 RECOMMENDED/OPTIONAL MODULES
2512
2513One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2514it's built-in modules) are required to use it.
2515
2516That does not mean that AnyEvent won't take advantage of some additional
2517modules if they are installed.
2518
2519This section explains which additional modules will be used, and how they
2520affect AnyEvent's operation.
2521
2522=over 4
2523
2524=item L<Async::Interrupt>
2525
2526This slightly arcane module is used to implement fast signal handling: To
2527my knowledge, there is no way to do completely race-free and quick
2528signal handling in pure perl. To ensure that signals still get
2529delivered, AnyEvent will start an interval timer to wake up perl (and
2530catch the signals) with some delay (default is 10 seconds, look for
2531C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2532
2533If this module is available, then it will be used to implement signal
2534catching, which means that signals will not be delayed, and the event loop
2535will not be interrupted regularly, which is more efficient (and good for
2536battery life on laptops).
2537
2538This affects not just the pure-perl event loop, but also other event loops
2539that have no signal handling on their own (e.g. Glib, Tk, Qt).
2540
2541Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
2542and either employ their own workarounds (POE) or use AnyEvent's workaround
2543(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
2544does nothing for those backends.
2545
2546=item L<EV>
2547
2548This module isn't really "optional", as it is simply one of the backend
2549event loops that AnyEvent can use. However, it is simply the best event
2550loop available in terms of features, speed and stability: It supports
2551the AnyEvent API optimally, implements all the watcher types in XS, does
2552automatic timer adjustments even when no monotonic clock is available,
2553can take avdantage of advanced kernel interfaces such as C<epoll> and
2554C<kqueue>, and is the fastest backend I<by far>. You can even embed
2555L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2556
2557If you only use backends that rely on another event loop (e.g. C<Tk>),
2558then this module will do nothing for you.
2559
2560=item L<Guard>
2561
2562The guard module, when used, will be used to implement
2563C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2564lot less memory), but otherwise doesn't affect guard operation much. It is
2565purely used for performance.
2566
2567=item L<JSON> and L<JSON::XS>
2568
2569One of these modules is required when you want to read or write JSON data
2570via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2571advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2572
2573=item L<Net::SSLeay>
2574
2575Implementing TLS/SSL in Perl is certainly interesting, but not very
2576worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2577the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2578
2579=item L<Time::HiRes>
2580
2581This module is part of perl since release 5.008. It will be used when the
2582chosen event library does not come with a timing source on it's own. The
2583pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
2584try to use a monotonic clock for timing stability.
2585
2586=back
2587
2588
2069=head1 FORK 2589=head1 FORK
2070 2590
2071Most event libraries are not fork-safe. The ones who are usually are 2591Most event libraries are not fork-safe. The ones who are usually are
2072because they rely on inefficient but fork-safe C<select> or C<poll> 2592because they rely on inefficient but fork-safe C<select> or C<poll> calls
2073calls. Only L<EV> is fully fork-aware. 2593- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
2594are usually badly thought-out hacks that are incompatible with fork in
2595one way or another. Only L<EV> is fully fork-aware and ensures that you
2596continue event-processing in both parent and child (or both, if you know
2597what you are doing).
2598
2599This means that, in general, you cannot fork and do event processing in
2600the child if the event library was initialised before the fork (which
2601usually happens when the first AnyEvent watcher is created, or the library
2602is loaded).
2074 2603
2075If you have to fork, you must either do so I<before> creating your first 2604If you have to fork, you must either do so I<before> creating your first
2076watcher OR you must not use AnyEvent at all in the child. 2605watcher OR you must not use AnyEvent at all in the child OR you must do
2606something completely out of the scope of AnyEvent.
2607
2608The problem of doing event processing in the parent I<and> the child
2609is much more complicated: even for backends that I<are> fork-aware or
2610fork-safe, their behaviour is not usually what you want: fork clones all
2611watchers, that means all timers, I/O watchers etc. are active in both
2612parent and child, which is almost never what you want. USing C<exec>
2613to start worker children from some kind of manage rprocess is usually
2614preferred, because it is much easier and cleaner, at the expense of having
2615to have another binary.
2077 2616
2078 2617
2079=head1 SECURITY CONSIDERATIONS 2618=head1 SECURITY CONSIDERATIONS
2080 2619
2081AnyEvent can be forced to load any event model via 2620AnyEvent can be forced to load any event model via
2119L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. 2658L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2120 2659
2121Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, 2660Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2122L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, 2661L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2123L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, 2662L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2124L<AnyEvent::Impl::POE>. 2663L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
2125 2664
2126Non-blocking file handles, sockets, TCP clients and 2665Non-blocking file handles, sockets, TCP clients and
2127servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>. 2666servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2128 2667
2129Asynchronous DNS: L<AnyEvent::DNS>. 2668Asynchronous DNS: L<AnyEvent::DNS>.
2130 2669
2131Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>, 2670Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,
2671L<Coro::Event>,
2132 2672
2133Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. 2673Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,
2674L<AnyEvent::HTTP>.
2134 2675
2135 2676
2136=head1 AUTHOR 2677=head1 AUTHOR
2137 2678
2138 Marc Lehmann <schmorp@schmorp.de> 2679 Marc Lehmann <schmorp@schmorp.de>

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