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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 L<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> (I<not> 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
183handle). Note that only file handles pointing to things for which 200handle). Note that only file handles pointing to things for which
184non-blocking operation makes sense are allowed. This includes sockets, 201non-blocking operation makes sense are allowed. This includes sockets,
185most character devices, pipes, fifos and so on, but not for example files 202most character devices, pipes, fifos and so on, but not for example files
186or block devices. 203or block devices.
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 instrument to do that is called a "condition variable", so called
472because they represent a condition that must become true. 562because they represent a condition that must become true.
473 563
564Now is probably a good time to look at the examples further below.
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"
486Condition variables are similar to callbacks, except that you can 577Condition variables are similar to callbacks, except that you can
487optionally wait for them. They can also be called merge points - points 578optionally wait for them. They can also be called merge points - points
488in time where multiple outstanding events have been processed. And yet 579in time where multiple outstanding events have been processed. And yet
489another way to call them is transactions - each condition variable can be 580another way to call them is transactions - each condition variable can be
490used to represent a transaction, which finishes at some point and delivers 581used to represent a transaction, which finishes at some point and delivers
491a result. 582a result. And yet some people know them as "futures" - a promise to
583compute/deliver something that you can wait for.
492 584
493Condition variables are very useful to signal that something has finished, 585Condition variables are very useful to signal that something has finished,
494for example, if you write a module that does asynchronous http requests, 586for example, if you write a module that does asynchronous http requests,
495then a condition variable would be the ideal candidate to signal the 587then a condition variable would be the ideal candidate to signal the
496availability of results. The user can either act when the callback is 588availability of results. The user can either act when the callback is
517eventually calls C<< -> send >>, and the "consumer side", which waits 609eventually calls C<< -> send >>, and the "consumer side", which waits
518for the send to occur. 610for the send to occur.
519 611
520Example: wait for a timer. 612Example: wait for a timer.
521 613
522 # wait till the result is ready 614 # condition: "wait till the timer is fired"
523 my $result_ready = AnyEvent->condvar; 615 my $timer_fired = AnyEvent->condvar;
524 616
525 # do something such as adding a timer 617 # create the timer - we could wait for, say
526 # or socket watcher the calls $result_ready->send 618 # a handle becomign ready, or even an
527 # when the "result" is ready. 619 # AnyEvent::HTTP request to finish, but
528 # in this case, we simply use a timer: 620 # in this case, we simply use a timer:
529 my $w = AnyEvent->timer ( 621 my $w = AnyEvent->timer (
530 after => 1, 622 after => 1,
531 cb => sub { $result_ready->send }, 623 cb => sub { $timer_fired->send },
532 ); 624 );
533 625
534 # this "blocks" (while handling events) till the callback 626 # this "blocks" (while handling events) till the callback
535 # calls send 627 # calls ->send
536 $result_ready->recv; 628 $timer_fired->recv;
537 629
538Example: wait for a timer, but take advantage of the fact that 630Example: wait for a timer, but take advantage of the fact that condition
539condition variables are also code references. 631variables are also callable directly.
540 632
541 my $done = AnyEvent->condvar; 633 my $done = AnyEvent->condvar;
542 my $delay = AnyEvent->timer (after => 5, cb => $done); 634 my $delay = AnyEvent->timer (after => 5, cb => $done);
543 $done->recv; 635 $done->recv;
544 636
550 642
551 ... 643 ...
552 644
553 my @info = $couchdb->info->recv; 645 my @info = $couchdb->info->recv;
554 646
555And this is how you would just ste a callback to be called whenever the 647And this is how you would just set a callback to be called whenever the
556results are available: 648results are available:
557 649
558 $couchdb->info->cb (sub { 650 $couchdb->info->cb (sub {
559 my @info = $_[0]->recv; 651 my @info = $_[0]->recv;
560 }); 652 });
578immediately from within send. 670immediately from within send.
579 671
580Any arguments passed to the C<send> call will be returned by all 672Any arguments passed to the C<send> call will be returned by all
581future C<< ->recv >> calls. 673future C<< ->recv >> calls.
582 674
583Condition variables are overloaded so one can call them directly 675Condition variables are overloaded so one can call them directly (as if
584(as a code reference). Calling them directly is the same as calling 676they 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 677C<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).
591 678
592=item $cv->croak ($error) 679=item $cv->croak ($error)
593 680
594Similar to send, but causes all call's to C<< ->recv >> to invoke 681Similar to send, but causes all call's to C<< ->recv >> to invoke
595C<Carp::croak> with the given error message/object/scalar. 682C<Carp::croak> with the given error message/object/scalar.
596 683
597This can be used to signal any errors to the condition variable 684This can be used to signal any errors to the condition variable
598user/consumer. 685user/consumer. Doing it this way instead of calling C<croak> directly
686delays the error detetcion, but has the overwhelmign advantage that it
687diagnoses the error at the place where the result is expected, and not
688deep in some event clalback without connection to the actual code causing
689the problem.
599 690
600=item $cv->begin ([group callback]) 691=item $cv->begin ([group callback])
601 692
602=item $cv->end 693=item $cv->end
603 694
605one. For example, a function that pings many hosts in parallel might want 696one. For example, a function that pings many hosts in parallel might want
606to use a condition variable for the whole process. 697to use a condition variable for the whole process.
607 698
608Every call to C<< ->begin >> will increment a counter, and every call to 699Every 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 700C<< ->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 701>>, 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 702condvar as first argument. That callback is I<supposed> to call C<< ->send
612callback was set, C<send> will be called without any arguments. 703>>, but that is not required. If no group callback was set, C<send> will
704be called without any arguments.
613 705
614You can think of C<< $cv->send >> giving you an OR condition (one call 706You 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 707sends), 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). 708condition (all C<begin> calls must be C<end>'ed before the condvar sends).
617 709
644begung can potentially be zero: 736begung can potentially be zero:
645 737
646 my $cv = AnyEvent->condvar; 738 my $cv = AnyEvent->condvar;
647 739
648 my %result; 740 my %result;
649 $cv->begin (sub { $cv->send (\%result) }); 741 $cv->begin (sub { shift->send (\%result) });
650 742
651 for my $host (@list_of_hosts) { 743 for my $host (@list_of_hosts) {
652 $cv->begin; 744 $cv->begin;
653 ping_host_then_call_callback $host, sub { 745 ping_host_then_call_callback $host, sub {
654 $result{$host} = ...; 746 $result{$host} = ...;
699function will call C<croak>. 791function will call C<croak>.
700 792
701In list context, all parameters passed to C<send> will be returned, 793In list context, all parameters passed to C<send> will be returned,
702in scalar context only the first one will be returned. 794in scalar context only the first one will be returned.
703 795
796Note that doing a blocking wait in a callback is not supported by any
797event loop, that is, recursive invocation of a blocking C<< ->recv
798>> is not allowed, and the C<recv> call will C<croak> if such a
799condition is detected. This condition can be slightly loosened by using
800L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from
801any thread that doesn't run the event loop itself.
802
704Not all event models support a blocking wait - some die in that case 803Not 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 804(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 805using 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 806caller decide whether the call will block or not (for example, by coupling
708condition variables with some kind of request results and supporting 807condition variables with some kind of request results and supporting
709callbacks so the caller knows that getting the result will not block, 808callbacks so the caller knows that getting the result will not block,
710while still supporting blocking waits if the caller so desires). 809while still supporting blocking waits if the caller so desires).
711 810
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 811You can ensure that C<< -recv >> never blocks by setting a callback and
724only calling C<< ->recv >> from within that callback (or at a later 812only calling C<< ->recv >> from within that callback (or at a later
725time). This will work even when the event loop does not support blocking 813time). This will work even when the event loop does not support blocking
726waits otherwise. 814waits otherwise.
727 815
733=item $cb = $cv->cb ($cb->($cv)) 821=item $cb = $cv->cb ($cb->($cv))
734 822
735This is a mutator function that returns the callback set and optionally 823This is a mutator function that returns the callback set and optionally
736replaces it before doing so. 824replaces it before doing so.
737 825
738The callback will be called when the condition becomes "true", i.e. when 826The 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 827"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 828the only argument being the condition variable itself. Calling C<recv>
741is guaranteed not to block. 829inside the callback or at any later time is guaranteed not to block.
742 830
743=back 831=back
744 832
833=head1 SUPPORTED EVENT LOOPS/BACKENDS
834
835The available backend classes are (every class has its own manpage):
836
837=over 4
838
839=item Backends that are autoprobed when no other event loop can be found.
840
841EV is the preferred backend when no other event loop seems to be in
842use. If EV is not installed, then AnyEvent will fall back to its own
843pure-perl implementation, which is available everywhere as it comes with
844AnyEvent itself.
845
846 AnyEvent::Impl::EV based on EV (interface to libev, best choice).
847 AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
848
849=item Backends that are transparently being picked up when they are used.
850
851These will be used when they are currently loaded when the first watcher
852is created, in which case it is assumed that the application is using
853them. This means that AnyEvent will automatically pick the right backend
854when the main program loads an event module before anything starts to
855create watchers. Nothing special needs to be done by the main program.
856
857 AnyEvent::Impl::Event based on Event, very stable, few glitches.
858 AnyEvent::Impl::Glib based on Glib, slow but very stable.
859 AnyEvent::Impl::Tk based on Tk, very broken.
860 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
861 AnyEvent::Impl::POE based on POE, very slow, some limitations.
862 AnyEvent::Impl::Irssi used when running within irssi.
863
864=item Backends with special needs.
865
866Qt requires the Qt::Application to be instantiated first, but will
867otherwise be picked up automatically. As long as the main program
868instantiates the application before any AnyEvent watchers are created,
869everything should just work.
870
871 AnyEvent::Impl::Qt based on Qt.
872
873Support for IO::Async can only be partial, as it is too broken and
874architecturally limited to even support the AnyEvent API. It also
875is the only event loop that needs the loop to be set explicitly, so
876it can only be used by a main program knowing about AnyEvent. See
877L<AnyEvent::Impl::Async> for the gory details.
878
879 AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
880
881=item Event loops that are indirectly supported via other backends.
882
883Some event loops can be supported via other modules:
884
885There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
886
887B<WxWidgets> has no support for watching file handles. However, you can
888use WxWidgets through the POE adaptor, as POE has a Wx backend that simply
889polls 20 times per second, which was considered to be too horrible to even
890consider for AnyEvent.
891
892B<Prima> is not supported as nobody seems to be using it, but it has a POE
893backend, so it can be supported through POE.
894
895AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to
896load L<POE> when detecting them, in the hope that POE will pick them up,
897in which case everything will be automatic.
898
899=back
900
745=head1 GLOBAL VARIABLES AND FUNCTIONS 901=head1 GLOBAL VARIABLES AND FUNCTIONS
746 902
903These are not normally required to use AnyEvent, but can be useful to
904write AnyEvent extension modules.
905
747=over 4 906=over 4
748 907
749=item $AnyEvent::MODEL 908=item $AnyEvent::MODEL
750 909
751Contains C<undef> until the first watcher is being created. Then it 910Contains C<undef> until the first watcher is being created, before the
911backend has been autodetected.
912
752contains the event model that is being used, which is the name of the 913Afterwards it contains the event model that is being used, which is the
753Perl class implementing the model. This class is usually one of the 914name 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 915of 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>). 916case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
756 917will 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.
781 918
782=item AnyEvent::detect 919=item AnyEvent::detect
783 920
784Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model 921Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
785if necessary. You should only call this function right before you would 922if necessary. You should only call this function right before you would
786have created an AnyEvent watcher anyway, that is, as late as possible at 923have created an AnyEvent watcher anyway, that is, as late as possible at
787runtime. 924runtime, and not e.g. while initialising of your module.
925
926If you need to do some initialisation before AnyEvent watchers are
927created, use C<post_detect>.
788 928
789=item $guard = AnyEvent::post_detect { BLOCK } 929=item $guard = AnyEvent::post_detect { BLOCK }
790 930
791Arranges for the code block to be executed as soon as the event model is 931Arranges for the code block to be executed as soon as the event model is
792autodetected (or immediately if this has already happened). 932autodetected (or immediately if this has already happened).
793 933
934The block will be executed I<after> the actual backend has been detected
935(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
936created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
937other initialisations - see the sources of L<AnyEvent::Strict> or
938L<AnyEvent::AIO> to see how this is used.
939
940The most common usage is to create some global watchers, without forcing
941event module detection too early, for example, L<AnyEvent::AIO> creates
942and installs the global L<IO::AIO> watcher in a C<post_detect> block to
943avoid autodetecting the event module at load time.
944
794If called in scalar or list context, then it creates and returns an object 945If called in scalar or list context, then it creates and returns an object
795that automatically removes the callback again when it is destroyed. See 946that automatically removes the callback again when it is destroyed (or
947C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
796L<Coro::BDB> for a case where this is useful. 948a case where this is useful.
949
950Example: Create a watcher for the IO::AIO module and store it in
951C<$WATCHER>. Only do so after the event loop is initialised, though.
952
953 our WATCHER;
954
955 my $guard = AnyEvent::post_detect {
956 $WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
957 };
958
959 # the ||= is important in case post_detect immediately runs the block,
960 # as to not clobber the newly-created watcher. assigning both watcher and
961 # post_detect guard to the same variable has the advantage of users being
962 # able to just C<undef $WATCHER> if the watcher causes them grief.
963
964 $WATCHER ||= $guard;
797 965
798=item @AnyEvent::post_detect 966=item @AnyEvent::post_detect
799 967
800If there are any code references in this array (you can C<push> to it 968If there are any code references in this array (you can C<push> to it
801before or after loading AnyEvent), then they will called directly after 969before or after loading AnyEvent), then they will called directly after
802the event loop has been chosen. 970the event loop has been chosen.
803 971
804You should check C<$AnyEvent::MODEL> before adding to this array, though: 972You 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, 973if it is defined then the event loop has already been detected, and the
806and the array will be ignored. 974array will be ignored.
807 975
808Best use C<AnyEvent::post_detect { BLOCK }> instead. 976Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
977it, as it takes care of these details.
978
979This variable is mainly useful for modules that can do something useful
980when AnyEvent is used and thus want to know when it is initialised, but do
981not need to even load it by default. This array provides the means to hook
982into AnyEvent passively, without loading it.
983
984Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
985together, you could put this into Coro (this is the actual code used by
986Coro to accomplish this):
987
988 if (defined $AnyEvent::MODEL) {
989 # AnyEvent already initialised, so load Coro::AnyEvent
990 require Coro::AnyEvent;
991 } else {
992 # AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
993 # as soon as it is
994 push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
995 }
809 996
810=back 997=back
811 998
812=head1 WHAT TO DO IN A MODULE 999=head1 WHAT TO DO IN A MODULE
813 1000
868 1055
869 1056
870=head1 OTHER MODULES 1057=head1 OTHER MODULES
871 1058
872The following is a non-exhaustive list of additional modules that use 1059The following is a non-exhaustive list of additional modules that use
873AnyEvent and can therefore be mixed easily with other AnyEvent modules 1060AnyEvent 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 1061modules and other event loops in the same program. Some of the modules
875available via CPAN. 1062come with AnyEvent, most are available via CPAN.
876 1063
877=over 4 1064=over 4
878 1065
879=item L<AnyEvent::Util> 1066=item L<AnyEvent::Util>
880 1067
889 1076
890=item L<AnyEvent::Handle> 1077=item L<AnyEvent::Handle>
891 1078
892Provide read and write buffers, manages watchers for reads and writes, 1079Provide read and write buffers, manages watchers for reads and writes,
893supports raw and formatted I/O, I/O queued and fully transparent and 1080supports raw and formatted I/O, I/O queued and fully transparent and
894non-blocking SSL/TLS. 1081non-blocking SSL/TLS (via L<AnyEvent::TLS>.
895 1082
896=item L<AnyEvent::DNS> 1083=item L<AnyEvent::DNS>
897 1084
898Provides rich asynchronous DNS resolver capabilities. 1085Provides rich asynchronous DNS resolver capabilities.
899 1086
927 1114
928=item L<AnyEvent::GPSD> 1115=item L<AnyEvent::GPSD>
929 1116
930A non-blocking interface to gpsd, a daemon delivering GPS information. 1117A non-blocking interface to gpsd, a daemon delivering GPS information.
931 1118
1119=item L<AnyEvent::IRC>
1120
1121AnyEvent based IRC client module family (replacing the older Net::IRC3).
1122
1123=item L<AnyEvent::XMPP>
1124
1125AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1126Net::XMPP2>.
1127
932=item L<AnyEvent::IGS> 1128=item L<AnyEvent::IGS>
933 1129
934A non-blocking interface to the Internet Go Server protocol (used by 1130A non-blocking interface to the Internet Go Server protocol (used by
935L<App::IGS>). 1131L<App::IGS>).
936 1132
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> 1133=item L<Net::FCP>
946 1134
947AnyEvent-based implementation of the Freenet Client Protocol, birthplace 1135AnyEvent-based implementation of the Freenet Client Protocol, birthplace
948of AnyEvent. 1136of AnyEvent.
949 1137
953 1141
954=item L<Coro> 1142=item L<Coro>
955 1143
956Has special support for AnyEvent via L<Coro::AnyEvent>. 1144Has special support for AnyEvent via L<Coro::AnyEvent>.
957 1145
958=item L<IO::Lambda>
959
960The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
961
962=back 1146=back
963 1147
964=cut 1148=cut
965 1149
966package AnyEvent; 1150package AnyEvent;
967 1151
968no warnings; 1152# basically a tuned-down version of common::sense
969use strict qw(vars subs); 1153sub common_sense {
1154 # from common:.sense 1.0
1155 ${^WARNING_BITS} = "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x00";
1156 # use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1157 $^H |= 0x00000600;
1158}
970 1159
1160BEGIN { AnyEvent::common_sense }
1161
971use Carp; 1162use Carp ();
972 1163
973our $VERSION = 4.452; 1164our $VERSION = '5.26';
974our $MODEL; 1165our $MODEL;
975 1166
976our $AUTOLOAD; 1167our $AUTOLOAD;
977our @ISA; 1168our @ISA;
978 1169
979our @REGISTRY; 1170our @REGISTRY;
980 1171
981our $WIN32; 1172our $VERBOSE;
982 1173
983BEGIN { 1174BEGIN {
984 eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; 1175 require "AnyEvent/constants.pl";
1176
985 eval "sub TAINT(){ " . (${^TAINT}*1) . " }"; 1177 eval "sub TAINT (){" . (${^TAINT}*1) . "}";
986 1178
987 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} 1179 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
988 if ${^TAINT}; 1180 if ${^TAINT};
989}
990 1181
991our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; 1182 $VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
1183
1184}
1185
1186our $MAX_SIGNAL_LATENCY = 10;
992 1187
993our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred 1188our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
994 1189
995{ 1190{
996 my $idx; 1191 my $idx;
998 for reverse split /\s*,\s*/, 1193 for reverse split /\s*,\s*/,
999 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; 1194 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1000} 1195}
1001 1196
1002my @models = ( 1197my @models = (
1003 [EV:: => AnyEvent::Impl::EV::], 1198 [EV:: => AnyEvent::Impl::EV:: , 1],
1004 [Event:: => AnyEvent::Impl::Event::],
1005 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], 1199 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1006 # everything below here will not be autoprobed 1200 # everything below here will not (normally) be autoprobed
1007 # as the pureperl backend should work everywhere 1201 # as the pureperl backend should work everywhere
1008 # and is usually faster 1202 # and is usually faster
1203 [Event:: => AnyEvent::Impl::Event::, 1],
1204 [Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1205 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1206 [Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1009 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles 1207 [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 1208 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1013 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza 1209 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1014 [Wx:: => AnyEvent::Impl::POE::], 1210 [Wx:: => AnyEvent::Impl::POE::],
1015 [Prima:: => AnyEvent::Impl::POE::], 1211 [Prima:: => AnyEvent::Impl::POE::],
1016 # IO::Async is just too broken - we would need workaorunds for its 1212 # IO::Async is just too broken - we would need workarounds for its
1017 # byzantine signal and broken child handling, among others. 1213 # byzantine signal and broken child handling, among others.
1018 # IO::Async is rather hard to detect, as it doesn't have any 1214 # IO::Async is rather hard to detect, as it doesn't have any
1019 # obvious default class. 1215 # obvious default class.
1020# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program 1216 [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1021# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program 1217 [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1022# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program 1218 [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1219 [AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1023); 1220);
1024 1221
1025our %method = map +($_ => 1), 1222our %method = map +($_ => 1),
1026 qw(io timer time now now_update signal child idle condvar one_event DESTROY); 1223 qw(io timer time now now_update signal child idle condvar one_event DESTROY);
1027 1224
1028our @post_detect; 1225our @post_detect;
1029 1226
1030sub post_detect(&) { 1227sub post_detect(&) {
1031 my ($cb) = @_; 1228 my ($cb) = @_;
1032 1229
1033 if ($MODEL) {
1034 $cb->();
1035
1036 1
1037 } else {
1038 push @post_detect, $cb; 1230 push @post_detect, $cb;
1039 1231
1040 defined wantarray 1232 defined wantarray
1041 ? bless \$cb, "AnyEvent::Util::postdetect" 1233 ? bless \$cb, "AnyEvent::Util::postdetect"
1042 : () 1234 : ()
1043 }
1044} 1235}
1045 1236
1046sub AnyEvent::Util::postdetect::DESTROY { 1237sub AnyEvent::Util::postdetect::DESTROY {
1047 @post_detect = grep $_ != ${$_[0]}, @post_detect; 1238 @post_detect = grep $_ != ${$_[0]}, @post_detect;
1048} 1239}
1049 1240
1050sub detect() { 1241sub detect() {
1242 # free some memory
1243 *detect = sub () { $MODEL };
1244
1245 local $!; # for good measure
1246 local $SIG{__DIE__};
1247
1248 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1249 my $model = "AnyEvent::Impl::$1";
1250 if (eval "require $model") {
1251 $MODEL = $model;
1252 warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
1253 } else {
1254 warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1255 }
1256 }
1257
1258 # check for already loaded models
1051 unless ($MODEL) { 1259 unless ($MODEL) {
1052 no strict 'refs'; 1260 for (@REGISTRY, @models) {
1053 local $SIG{__DIE__}; 1261 my ($package, $model) = @$_;
1054 1262 if (${"$package\::VERSION"} > 0) {
1055 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1056 my $model = "AnyEvent::Impl::$1";
1057 if (eval "require $model") { 1263 if (eval "require $model") {
1058 $MODEL = $model; 1264 $MODEL = $model;
1059 warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1; 1265 warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1060 } else { 1266 last;
1061 warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose; 1267 }
1062 } 1268 }
1063 } 1269 }
1064 1270
1065 # check for already loaded models
1066 unless ($MODEL) { 1271 unless ($MODEL) {
1272 # try to autoload a model
1067 for (@REGISTRY, @models) { 1273 for (@REGISTRY, @models) {
1068 my ($package, $model) = @$_; 1274 my ($package, $model, $autoload) = @$_;
1275 if (
1276 $autoload
1277 and eval "require $package"
1069 if (${"$package\::VERSION"} > 0) { 1278 and ${"$package\::VERSION"} > 0
1070 if (eval "require $model") { 1279 and eval "require $model"
1280 ) {
1071 $MODEL = $model; 1281 $MODEL = $model;
1072 warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1; 1282 warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1073 last; 1283 last;
1074 }
1075 } 1284 }
1076 } 1285 }
1077 1286
1078 unless ($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 1287 $MODEL
1093 or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n"; 1288 or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";
1094 }
1095 } 1289 }
1096
1097 push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1098
1099 unshift @ISA, $MODEL;
1100
1101 require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1102
1103 (shift @post_detect)->() while @post_detect;
1104 } 1290 }
1291
1292 @models = (); # free probe data
1293
1294 push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1295 unshift @ISA, $MODEL;
1296
1297 # now nuke some methods that are overriden by the backend.
1298 # SUPER is not allowed.
1299 for (qw(time signal child idle)) {
1300 undef &{"AnyEvent::Base::$_"}
1301 if defined &{"$MODEL\::$_"};
1302 }
1303
1304 require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1305
1306 (shift @post_detect)->() while @post_detect;
1307
1308 *post_detect = sub(&) {
1309 shift->();
1310
1311 undef
1312 };
1105 1313
1106 $MODEL 1314 $MODEL
1107} 1315}
1108 1316
1109sub AUTOLOAD { 1317sub AUTOLOAD {
1110 (my $func = $AUTOLOAD) =~ s/.*://; 1318 (my $func = $AUTOLOAD) =~ s/.*://;
1111 1319
1112 $method{$func} 1320 $method{$func}
1113 or croak "$func: not a valid method for AnyEvent objects"; 1321 or Carp::croak "$func: not a valid AnyEvent class method";
1114 1322
1115 detect unless $MODEL; 1323 detect;
1116 1324
1117 my $class = shift; 1325 my $class = shift;
1118 $class->$func (@_); 1326 $class->$func (@_);
1119} 1327}
1120 1328
1123# allow only one watcher per fd, so we dup it to get a different one). 1331# allow only one watcher per fd, so we dup it to get a different one).
1124sub _dupfh($$;$$) { 1332sub _dupfh($$;$$) {
1125 my ($poll, $fh, $r, $w) = @_; 1333 my ($poll, $fh, $r, $w) = @_;
1126 1334
1127 # cygwin requires the fh mode to be matching, unix doesn't 1335 # cygwin requires the fh mode to be matching, unix doesn't
1128 my ($rw, $mode) = $poll eq "r" ? ($r, "<") 1336 my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1129 : $poll eq "w" ? ($w, ">")
1130 : Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
1131 1337
1132 open my $fh2, "$mode&" . fileno $fh 1338 open my $fh2, $mode, $fh
1133 or die "cannot dup() filehandle: $!,"; 1339 or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1134 1340
1135 # we assume CLOEXEC is already set by perl in all important cases 1341 # we assume CLOEXEC is already set by perl in all important cases
1136 1342
1137 ($fh2, $rw) 1343 ($fh2, $rw)
1138} 1344}
1139 1345
1346=head1 SIMPLIFIED AE API
1347
1348Starting with version 5.0, AnyEvent officially supports a second, much
1349simpler, API that is designed to reduce the calling, typing and memory
1350overhead by using function call syntax and a fixed number of parameters.
1351
1352See the L<AE> manpage for details.
1353
1354=cut
1355
1356package AE;
1357
1358our $VERSION = $AnyEvent::VERSION;
1359
1360# fall back to the main API by default - backends and AnyEvent::Base
1361# implementations can overwrite these.
1362
1363sub io($$$) {
1364 AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1365}
1366
1367sub timer($$$) {
1368 AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
1369}
1370
1371sub signal($$) {
1372 AnyEvent->signal (signal => $_[0], cb => $_[1])
1373}
1374
1375sub child($$) {
1376 AnyEvent->child (pid => $_[0], cb => $_[1])
1377}
1378
1379sub idle($) {
1380 AnyEvent->idle (cb => $_[0])
1381}
1382
1383sub cv(;&) {
1384 AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
1385}
1386
1387sub now() {
1388 AnyEvent->now
1389}
1390
1391sub now_update() {
1392 AnyEvent->now_update
1393}
1394
1395sub time() {
1396 AnyEvent->time
1397}
1398
1140package AnyEvent::Base; 1399package AnyEvent::Base;
1141 1400
1142# default implementations for many methods 1401# default implementations for many methods
1143 1402
1144BEGIN { 1403sub time {
1404 eval q{ # poor man's autoloading {}
1405 # probe for availability of Time::HiRes
1145 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { 1406 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1407 warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1146 *_time = \&Time::HiRes::time; 1408 *AE::time = \&Time::HiRes::time;
1147 # if (eval "use POSIX (); (POSIX::times())... 1409 # if (eval "use POSIX (); (POSIX::times())...
1148 } else { 1410 } else {
1411 warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1149 *_time = sub { time }; # epic fail 1412 *AE::time = sub (){ time }; # epic fail
1413 }
1414
1415 *time = sub { AE::time }; # different prototypes
1416 };
1417 die if $@;
1418
1419 &time
1420}
1421
1422*now = \&time;
1423
1424sub now_update { }
1425
1426# default implementation for ->condvar
1427
1428sub condvar {
1429 eval q{ # poor man's autoloading {}
1430 *condvar = sub {
1431 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1432 };
1433
1434 *AE::cv = sub (;&) {
1435 bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
1436 };
1437 };
1438 die if $@;
1439
1440 &condvar
1441}
1442
1443# default implementation for ->signal
1444
1445our $HAVE_ASYNC_INTERRUPT;
1446
1447sub _have_async_interrupt() {
1448 $HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
1449 && eval "use Async::Interrupt 1.02 (); 1")
1450 unless defined $HAVE_ASYNC_INTERRUPT;
1451
1452 $HAVE_ASYNC_INTERRUPT
1453}
1454
1455our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1456our (%SIG_ASY, %SIG_ASY_W);
1457our ($SIG_COUNT, $SIG_TW);
1458
1459# install a dummy wakeup watcher to reduce signal catching latency
1460# used by Impls
1461sub _sig_add() {
1462 unless ($SIG_COUNT++) {
1463 # try to align timer on a full-second boundary, if possible
1464 my $NOW = AE::now;
1465
1466 $SIG_TW = AE::timer
1467 $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1468 $MAX_SIGNAL_LATENCY,
1469 sub { } # just for the PERL_ASYNC_CHECK
1470 ;
1150 } 1471 }
1151} 1472}
1152 1473
1153sub time { _time } 1474sub _sig_del {
1154sub now { _time } 1475 undef $SIG_TW
1155sub now_update { } 1476 unless --$SIG_COUNT;
1156
1157# default implementation for ->condvar
1158
1159sub condvar {
1160 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1161} 1477}
1162 1478
1163# default implementation for ->signal 1479our $_sig_name_init; $_sig_name_init = sub {
1480 eval q{ # poor man's autoloading {}
1481 undef $_sig_name_init;
1164 1482
1165our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); 1483 if (_have_async_interrupt) {
1484 *sig2num = \&Async::Interrupt::sig2num;
1485 *sig2name = \&Async::Interrupt::sig2name;
1486 } else {
1487 require Config;
1166 1488
1167sub _signal_exec { 1489 my %signame2num;
1168 sysread $SIGPIPE_R, my $dummy, 4; 1490 @signame2num{ split ' ', $Config::Config{sig_name} }
1491 = split ' ', $Config::Config{sig_num};
1169 1492
1170 while (%SIG_EV) { 1493 my @signum2name;
1171 for (keys %SIG_EV) { 1494 @signum2name[values %signame2num] = keys %signame2num;
1172 delete $SIG_EV{$_}; 1495
1173 $_->() for values %{ $SIG_CB{$_} || {} }; 1496 *sig2num = sub($) {
1497 $_[0] > 0 ? shift : $signame2num{+shift}
1498 };
1499 *sig2name = sub ($) {
1500 $_[0] > 0 ? $signum2name[+shift] : shift
1501 };
1174 } 1502 }
1175 } 1503 };
1176} 1504 die if $@;
1505};
1506
1507sub sig2num ($) { &$_sig_name_init; &sig2num }
1508sub sig2name($) { &$_sig_name_init; &sig2name }
1177 1509
1178sub signal { 1510sub signal {
1179 my (undef, %arg) = @_; 1511 eval q{ # poor man's autoloading {}
1512 # probe for availability of Async::Interrupt
1513 if (_have_async_interrupt) {
1514 warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1180 1515
1181 unless ($SIGPIPE_R) { 1516 $SIGPIPE_R = new Async::Interrupt::EventPipe;
1182 require Fcntl; 1517 $SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1183 1518
1184 if (AnyEvent::WIN32) {
1185 require AnyEvent::Util;
1186
1187 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1188 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1189 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1190 } else { 1519 } else {
1520 warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1521
1522 if (AnyEvent::WIN32) {
1523 require AnyEvent::Util;
1524
1525 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1526 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1527 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1528 } else {
1191 pipe $SIGPIPE_R, $SIGPIPE_W; 1529 pipe $SIGPIPE_R, $SIGPIPE_W;
1192 fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R; 1530 fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
1193 fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case 1531 fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
1194 1532
1195 # not strictly required, as $^F is normally 2, but let's make sure... 1533 # not strictly required, as $^F is normally 2, but let's make sure...
1196 fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; 1534 fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1197 fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; 1535 fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1536 }
1537
1538 $SIGPIPE_R
1539 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1540
1541 $SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1198 } 1542 }
1199 1543
1200 $SIGPIPE_R 1544 *signal = $HAVE_ASYNC_INTERRUPT
1201 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; 1545 ? sub {
1546 my (undef, %arg) = @_;
1202 1547
1203 $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec); 1548 # async::interrupt
1204 }
1205
1206 my $signal = uc $arg{signal} 1549 my $signal = sig2num $arg{signal};
1207 or Carp::croak "required option 'signal' is missing";
1208
1209 $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; 1550 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1551
1552 $SIG_ASY{$signal} ||= new Async::Interrupt
1553 cb => sub { undef $SIG_EV{$signal} },
1554 signal => $signal,
1555 pipe => [$SIGPIPE_R->filenos],
1556 pipe_autodrain => 0,
1557 ;
1558
1559 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1560 }
1561 : sub {
1562 my (undef, %arg) = @_;
1563
1564 # pure perl
1565 my $signal = sig2name $arg{signal};
1566 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1567
1210 $SIG{$signal} ||= sub { 1568 $SIG{$signal} ||= sub {
1211 local $!; 1569 local $!;
1212 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; 1570 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1213 undef $SIG_EV{$signal}; 1571 undef $SIG_EV{$signal};
1572 };
1573
1574 # can't do signal processing without introducing races in pure perl,
1575 # so limit the signal latency.
1576 _sig_add;
1577
1578 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1579 }
1580 ;
1581
1582 *AnyEvent::Base::signal::DESTROY = sub {
1583 my ($signal, $cb) = @{$_[0]};
1584
1585 _sig_del;
1586
1587 delete $SIG_CB{$signal}{$cb};
1588
1589 $HAVE_ASYNC_INTERRUPT
1590 ? delete $SIG_ASY{$signal}
1591 : # delete doesn't work with older perls - they then
1592 # print weird messages, or just unconditionally exit
1593 # instead of getting the default action.
1594 undef $SIG{$signal}
1595 unless keys %{ $SIG_CB{$signal} };
1596 };
1597
1598 *_signal_exec = sub {
1599 $HAVE_ASYNC_INTERRUPT
1600 ? $SIGPIPE_R->drain
1601 : sysread $SIGPIPE_R, (my $dummy), 9;
1602
1603 while (%SIG_EV) {
1604 for (keys %SIG_EV) {
1605 delete $SIG_EV{$_};
1606 $_->() for values %{ $SIG_CB{$_} || {} };
1607 }
1608 }
1609 };
1214 }; 1610 };
1611 die if $@;
1215 1612
1216 bless [$signal, $arg{cb}], "AnyEvent::Base::signal" 1613 &signal
1217}
1218
1219sub AnyEvent::Base::signal::DESTROY {
1220 my ($signal, $cb) = @{$_[0]};
1221
1222 delete $SIG_CB{$signal}{$cb};
1223
1224 # delete doesn't work with older perls - they then
1225 # print weird messages, or just unconditionally exit
1226 # instead of getting the default action.
1227 undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1228} 1614}
1229 1615
1230# default implementation for ->child 1616# default implementation for ->child
1231 1617
1232our %PID_CB; 1618our %PID_CB;
1233our $CHLD_W; 1619our $CHLD_W;
1234our $CHLD_DELAY_W; 1620our $CHLD_DELAY_W;
1235our $WNOHANG; 1621our $WNOHANG;
1236 1622
1237sub _sigchld { 1623# used by many Impl's
1238 while (0 < (my $pid = waitpid -1, $WNOHANG)) { 1624sub _emit_childstatus($$) {
1625 my (undef, $rpid, $rstatus) = @_;
1626
1627 $_->($rpid, $rstatus)
1239 $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), 1628 for values %{ $PID_CB{$rpid} || {} },
1240 (values %{ $PID_CB{0} || {} }); 1629 values %{ $PID_CB{0} || {} };
1241 }
1242} 1630}
1243 1631
1244sub child { 1632sub child {
1633 eval q{ # poor man's autoloading {}
1634 *_sigchld = sub {
1635 my $pid;
1636
1637 AnyEvent->_emit_childstatus ($pid, $?)
1638 while ($pid = waitpid -1, $WNOHANG) > 0;
1639 };
1640
1641 *child = sub {
1245 my (undef, %arg) = @_; 1642 my (undef, %arg) = @_;
1246 1643
1247 defined (my $pid = $arg{pid} + 0) 1644 defined (my $pid = $arg{pid} + 0)
1248 or Carp::croak "required option 'pid' is missing"; 1645 or Carp::croak "required option 'pid' is missing";
1249 1646
1250 $PID_CB{$pid}{$arg{cb}} = $arg{cb}; 1647 $PID_CB{$pid}{$arg{cb}} = $arg{cb};
1251 1648
1649 # WNOHANG is almost cetrainly 1 everywhere
1650 $WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1651 ? 1
1252 $WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; 1652 : eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1253 1653
1254 unless ($CHLD_W) { 1654 unless ($CHLD_W) {
1255 $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); 1655 $CHLD_W = AE::signal CHLD => \&_sigchld;
1256 # child could be a zombie already, so make at least one round 1656 # child could be a zombie already, so make at least one round
1257 &_sigchld; 1657 &_sigchld;
1258 } 1658 }
1259 1659
1260 bless [$pid, $arg{cb}], "AnyEvent::Base::child" 1660 bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1261} 1661 };
1262 1662
1263sub AnyEvent::Base::child::DESTROY { 1663 *AnyEvent::Base::child::DESTROY = sub {
1264 my ($pid, $cb) = @{$_[0]}; 1664 my ($pid, $cb) = @{$_[0]};
1265 1665
1266 delete $PID_CB{$pid}{$cb}; 1666 delete $PID_CB{$pid}{$cb};
1267 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; 1667 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1268 1668
1269 undef $CHLD_W unless keys %PID_CB; 1669 undef $CHLD_W unless keys %PID_CB;
1670 };
1671 };
1672 die if $@;
1673
1674 &child
1270} 1675}
1271 1676
1272# idle emulation is done by simply using a timer, regardless 1677# idle emulation is done by simply using a timer, regardless
1273# of whether the process is idle or not, and not letting 1678# of whether the process is idle or not, and not letting
1274# the callback use more than 50% of the time. 1679# the callback use more than 50% of the time.
1275sub idle { 1680sub idle {
1681 eval q{ # poor man's autoloading {}
1682 *idle = sub {
1276 my (undef, %arg) = @_; 1683 my (undef, %arg) = @_;
1277 1684
1278 my ($cb, $w, $rcb) = $arg{cb}; 1685 my ($cb, $w, $rcb) = $arg{cb};
1279 1686
1280 $rcb = sub { 1687 $rcb = sub {
1281 if ($cb) { 1688 if ($cb) {
1282 $w = _time; 1689 $w = _time;
1283 &$cb; 1690 &$cb;
1284 $w = _time - $w; 1691 $w = _time - $w;
1285 1692
1286 # never use more then 50% of the time for the idle watcher, 1693 # never use more then 50% of the time for the idle watcher,
1287 # within some limits 1694 # within some limits
1288 $w = 0.0001 if $w < 0.0001; 1695 $w = 0.0001 if $w < 0.0001;
1289 $w = 5 if $w > 5; 1696 $w = 5 if $w > 5;
1290 1697
1291 $w = AnyEvent->timer (after => $w, cb => $rcb); 1698 $w = AE::timer $w, 0, $rcb;
1292 } else { 1699 } else {
1293 # clean up... 1700 # clean up...
1294 undef $w; 1701 undef $w;
1295 undef $rcb; 1702 undef $rcb;
1703 }
1704 };
1705
1706 $w = AE::timer 0.05, 0, $rcb;
1707
1708 bless \\$cb, "AnyEvent::Base::idle"
1296 } 1709 };
1710
1711 *AnyEvent::Base::idle::DESTROY = sub {
1712 undef $${$_[0]};
1713 };
1297 }; 1714 };
1715 die if $@;
1298 1716
1299 $w = AnyEvent->timer (after => 0.05, cb => $rcb); 1717 &idle
1300
1301 bless \\$cb, "AnyEvent::Base::idle"
1302}
1303
1304sub AnyEvent::Base::idle::DESTROY {
1305 undef $${$_[0]};
1306} 1718}
1307 1719
1308package AnyEvent::CondVar; 1720package AnyEvent::CondVar;
1309 1721
1310our @ISA = AnyEvent::CondVar::Base::; 1722our @ISA = AnyEvent::CondVar::Base::;
1311 1723
1312package AnyEvent::CondVar::Base; 1724package AnyEvent::CondVar::Base;
1313 1725
1314use overload 1726#use overload
1315 '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, 1727# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1316 fallback => 1; 1728# fallback => 1;
1729
1730# save 300+ kilobytes by dirtily hardcoding overloading
1731${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching.
1732*{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod."
1733*{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{}
1734${'AnyEvent::CondVar::Base::()'} = 1; # fallback
1735
1736our $WAITING;
1317 1737
1318sub _send { 1738sub _send {
1319 # nop 1739 # nop
1320} 1740}
1321 1741
1334sub ready { 1754sub ready {
1335 $_[0]{_ae_sent} 1755 $_[0]{_ae_sent}
1336} 1756}
1337 1757
1338sub _wait { 1758sub _wait {
1759 $WAITING
1760 and !$_[0]{_ae_sent}
1761 and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1762
1763 local $WAITING = 1;
1339 AnyEvent->one_event while !$_[0]{_ae_sent}; 1764 AnyEvent->one_event while !$_[0]{_ae_sent};
1340} 1765}
1341 1766
1342sub recv { 1767sub recv {
1343 $_[0]->_wait; 1768 $_[0]->_wait;
1345 Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak}; 1770 Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1346 wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0] 1771 wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1347} 1772}
1348 1773
1349sub cb { 1774sub cb {
1350 $_[0]{_ae_cb} = $_[1] if @_ > 1; 1775 my $cv = shift;
1776
1777 @_
1778 and $cv->{_ae_cb} = shift
1779 and $cv->{_ae_sent}
1780 and (delete $cv->{_ae_cb})->($cv);
1781
1351 $_[0]{_ae_cb} 1782 $cv->{_ae_cb}
1352} 1783}
1353 1784
1354sub begin { 1785sub begin {
1355 ++$_[0]{_ae_counter}; 1786 ++$_[0]{_ae_counter};
1356 $_[0]{_ae_end_cb} = $_[1] if @_ > 1; 1787 $_[0]{_ae_end_cb} = $_[1] if @_ > 1;
1405C<PERL_ANYEVENT_MODEL>. 1836C<PERL_ANYEVENT_MODEL>.
1406 1837
1407When set to C<2> or higher, cause AnyEvent to report to STDERR which event 1838When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1408model it chooses. 1839model it chooses.
1409 1840
1841When set to C<8> or higher, then AnyEvent will report extra information on
1842which optional modules it loads and how it implements certain features.
1843
1410=item C<PERL_ANYEVENT_STRICT> 1844=item C<PERL_ANYEVENT_STRICT>
1411 1845
1412AnyEvent does not do much argument checking by default, as thorough 1846AnyEvent does not do much argument checking by default, as thorough
1413argument checking is very costly. Setting this variable to a true value 1847argument checking is very costly. Setting this variable to a true value
1414will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly 1848will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1415check the arguments passed to most method calls. If it finds any problems, 1849check the arguments passed to most method calls. If it finds any problems,
1416it will croak. 1850it will croak.
1417 1851
1418In other words, enables "strict" mode. 1852In other words, enables "strict" mode.
1419 1853
1420Unlike C<use strict>, it is definitely recommended to keep it off in 1854Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>
1421production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while 1855>>, it is definitely recommended to keep it off in production. Keeping
1422developing programs can be very useful, however. 1856C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1857can be very useful, however.
1423 1858
1424=item C<PERL_ANYEVENT_MODEL> 1859=item C<PERL_ANYEVENT_MODEL>
1425 1860
1426This can be used to specify the event model to be used by AnyEvent, before 1861This can be used to specify the event model to be used by AnyEvent, before
1427auto detection and -probing kicks in. It must be a string consisting 1862auto detection and -probing kicks in. It must be a string consisting
1470 1905
1471=item C<PERL_ANYEVENT_MAX_FORKS> 1906=item C<PERL_ANYEVENT_MAX_FORKS>
1472 1907
1473The maximum number of child processes that C<AnyEvent::Util::fork_call> 1908The maximum number of child processes that C<AnyEvent::Util::fork_call>
1474will create in parallel. 1909will create in parallel.
1910
1911=item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS>
1912
1913The default value for the C<max_outstanding> parameter for the default DNS
1914resolver - this is the maximum number of parallel DNS requests that are
1915sent to the DNS server.
1916
1917=item C<PERL_ANYEVENT_RESOLV_CONF>
1918
1919The file to use instead of F</etc/resolv.conf> (or OS-specific
1920configuration) in the default resolver. When set to the empty string, no
1921default config will be used.
1922
1923=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1924
1925When neither C<ca_file> nor C<ca_path> was specified during
1926L<AnyEvent::TLS> context creation, and either of these environment
1927variables exist, they will be used to specify CA certificate locations
1928instead of a system-dependent default.
1929
1930=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1931
1932When these are set to C<1>, then the respective modules are not
1933loaded. Mostly good for testing AnyEvent itself.
1475 1934
1476=back 1935=back
1477 1936
1478=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE 1937=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1479 1938
1537 warn "read: $input\n"; # output what has been read 1996 warn "read: $input\n"; # output what has been read
1538 $cv->send if $input =~ /^q/i; # quit program if /^q/i 1997 $cv->send if $input =~ /^q/i; # quit program if /^q/i
1539 }, 1998 },
1540 ); 1999 );
1541 2000
1542 my $time_watcher; # can only be used once
1543
1544 sub new_timer {
1545 $timer = AnyEvent->timer (after => 1, cb => sub { 2001 my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1546 warn "timeout\n"; # print 'timeout' about every second 2002 warn "timeout\n"; # print 'timeout' at most every second
1547 &new_timer; # and restart the time
1548 }); 2003 });
1549 }
1550
1551 new_timer; # create first timer
1552 2004
1553 $cv->recv; # wait until user enters /^q/i 2005 $cv->recv; # wait until user enters /^q/i
1554 2006
1555=head1 REAL-WORLD EXAMPLE 2007=head1 REAL-WORLD EXAMPLE
1556 2008
1629 2081
1630The actual code goes further and collects all errors (C<die>s, exceptions) 2082The actual code goes further and collects all errors (C<die>s, exceptions)
1631that occurred during request processing. The C<result> method detects 2083that occurred during request processing. The C<result> method detects
1632whether an exception as thrown (it is stored inside the $txn object) 2084whether an exception as thrown (it is stored inside the $txn object)
1633and just throws the exception, which means connection errors and other 2085and just throws the exception, which means connection errors and other
1634problems get reported tot he code that tries to use the result, not in a 2086problems get reported to the code that tries to use the result, not in a
1635random callback. 2087random callback.
1636 2088
1637All of this enables the following usage styles: 2089All of this enables the following usage styles:
1638 2090
16391. Blocking: 20911. Blocking:
1687through AnyEvent. The benchmark creates a lot of timers (with a zero 2139through AnyEvent. The benchmark creates a lot of timers (with a zero
1688timeout) and I/O watchers (watching STDOUT, a pty, to become writable, 2140timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1689which it is), lets them fire exactly once and destroys them again. 2141which it is), lets them fire exactly once and destroys them again.
1690 2142
1691Source code for this benchmark is found as F<eg/bench> in the AnyEvent 2143Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1692distribution. 2144distribution. It uses the L<AE> interface, which makes a real difference
2145for the EV and Perl backends only.
1693 2146
1694=head3 Explanation of the columns 2147=head3 Explanation of the columns
1695 2148
1696I<watcher> is the number of event watchers created/destroyed. Since 2149I<watcher> is the number of event watchers created/destroyed. Since
1697different event models feature vastly different performances, each event 2150different event models feature vastly different performances, each event
1718watcher. 2171watcher.
1719 2172
1720=head3 Results 2173=head3 Results
1721 2174
1722 name watchers bytes create invoke destroy comment 2175 name watchers bytes create invoke destroy comment
1723 EV/EV 400000 224 0.47 0.35 0.27 EV native interface 2176 EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1724 EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers 2177 EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1725 CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal 2178 Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1726 Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation 2179 Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1727 Event/Event 16000 517 32.20 31.80 0.81 Event native interface 2180 Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1728 Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers 2181 Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
1729 IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll 2182 IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
1730 IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll 2183 IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1731 Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour 2184 Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1732 Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers 2185 Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1733 POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event 2186 POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1734 POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select 2187 POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1735 2188
1736=head3 Discussion 2189=head3 Discussion
1737 2190
1738The benchmark does I<not> measure scalability of the event loop very 2191The benchmark does I<not> measure scalability of the event loop very
1739well. For example, a select-based event loop (such as the pure perl one) 2192well. For example, a select-based event loop (such as the pure perl one)
1751benchmark machine, handling an event takes roughly 1600 CPU cycles with 2204benchmark machine, handling an event takes roughly 1600 CPU cycles with
1752EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU 2205EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1753cycles with POE. 2206cycles with POE.
1754 2207
1755C<EV> is the sole leader regarding speed and memory use, which are both 2208C<EV> is the sole leader regarding speed and memory use, which are both
1756maximal/minimal, respectively. Even when going through AnyEvent, it uses 2209maximal/minimal, respectively. When using the L<AE> API there is zero
2210overhead (when going through the AnyEvent API create is about 5-6 times
2211slower, with other times being equal, so still uses far less memory than
1757far less memory than any other event loop and is still faster than Event 2212any other event loop and is still faster than Event natively).
1758natively.
1759 2213
1760The pure perl implementation is hit in a few sweet spots (both the 2214The pure perl implementation is hit in a few sweet spots (both the
1761constant timeout and the use of a single fd hit optimisations in the perl 2215constant timeout and the use of a single fd hit optimisations in the perl
1762interpreter and the backend itself). Nevertheless this shows that it 2216interpreter and the backend itself). Nevertheless this shows that it
1763adds very little overhead in itself. Like any select-based backend its 2217adds very little overhead in itself. Like any select-based backend its
1837In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100 2291In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
1838(1%) are active. This mirrors the activity of large servers with many 2292(1%) are active. This mirrors the activity of large servers with many
1839connections, most of which are idle at any one point in time. 2293connections, most of which are idle at any one point in time.
1840 2294
1841Source code for this benchmark is found as F<eg/bench2> in the AnyEvent 2295Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
1842distribution. 2296distribution. It uses the L<AE> interface, which makes a real difference
2297for the EV and Perl backends only.
1843 2298
1844=head3 Explanation of the columns 2299=head3 Explanation of the columns
1845 2300
1846I<sockets> is the number of sockets, and twice the number of "servers" (as 2301I<sockets> is the number of sockets, and twice the number of "servers" (as
1847each server has a read and write socket end). 2302each server has a read and write socket end).
1855a new one that moves the timeout into the future. 2310a new one that moves the timeout into the future.
1856 2311
1857=head3 Results 2312=head3 Results
1858 2313
1859 name sockets create request 2314 name sockets create request
1860 EV 20000 69.01 11.16 2315 EV 20000 62.66 7.99
1861 Perl 20000 73.32 35.87 2316 Perl 20000 68.32 32.64
1862 IOAsync 20000 157.00 98.14 epoll 2317 IOAsync 20000 174.06 101.15 epoll
1863 IOAsync 20000 159.31 616.06 poll 2318 IOAsync 20000 174.67 610.84 poll
1864 Event 20000 212.62 257.32 2319 Event 20000 202.69 242.91
1865 Glib 20000 651.16 1896.30 2320 Glib 20000 557.01 1689.52
1866 POE 20000 349.67 12317.24 uses POE::Loop::Event 2321 POE 20000 341.54 12086.32 uses POE::Loop::Event
1867 2322
1868=head3 Discussion 2323=head3 Discussion
1869 2324
1870This benchmark I<does> measure scalability and overall performance of the 2325This benchmark I<does> measure scalability and overall performance of the
1871particular event loop. 2326particular event loop.
1997As you can see, the AnyEvent + EV combination even beats the 2452As you can see, the AnyEvent + EV combination even beats the
1998hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl 2453hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
1999backend easily beats IO::Lambda and POE. 2454backend easily beats IO::Lambda and POE.
2000 2455
2001And even the 100% non-blocking version written using the high-level (and 2456And even the 100% non-blocking version written using the high-level (and
2002slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a 2457slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2003large margin, even though it does all of DNS, tcp-connect and socket I/O 2458higher level ("unoptimised") abstractions by a large margin, even though
2004in a non-blocking way. 2459it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2005 2460
2006The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and 2461The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2007F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are 2462F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2008part of the IO::lambda distribution and were used without any changes. 2463part of the IO::Lambda distribution and were used without any changes.
2009 2464
2010 2465
2011=head1 SIGNALS 2466=head1 SIGNALS
2012 2467
2013AnyEvent currently installs handlers for these signals: 2468AnyEvent currently installs handlers for these signals:
2018 2473
2019A handler for C<SIGCHLD> is installed by AnyEvent's child watcher 2474A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
2020emulation for event loops that do not support them natively. Also, some 2475emulation for event loops that do not support them natively. Also, some
2021event loops install a similar handler. 2476event loops install a similar handler.
2022 2477
2023If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will 2478Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
2024reset it to default, to avoid losing child exit statuses. 2479AnyEvent will reset it to default, to avoid losing child exit statuses.
2025 2480
2026=item SIGPIPE 2481=item SIGPIPE
2027 2482
2028A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> 2483A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
2029when AnyEvent gets loaded. 2484when AnyEvent gets loaded.
2047 if $SIG{CHLD} eq 'IGNORE'; 2502 if $SIG{CHLD} eq 'IGNORE';
2048 2503
2049$SIG{PIPE} = sub { } 2504$SIG{PIPE} = sub { }
2050 unless defined $SIG{PIPE}; 2505 unless defined $SIG{PIPE};
2051 2506
2507=head1 RECOMMENDED/OPTIONAL MODULES
2508
2509One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2510it's built-in modules) are required to use it.
2511
2512That does not mean that AnyEvent won't take advantage of some additional
2513modules if they are installed.
2514
2515This section explains which additional modules will be used, and how they
2516affect AnyEvent's operation.
2517
2518=over 4
2519
2520=item L<Async::Interrupt>
2521
2522This slightly arcane module is used to implement fast signal handling: To
2523my knowledge, there is no way to do completely race-free and quick
2524signal handling in pure perl. To ensure that signals still get
2525delivered, AnyEvent will start an interval timer to wake up perl (and
2526catch the signals) with some delay (default is 10 seconds, look for
2527C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2528
2529If this module is available, then it will be used to implement signal
2530catching, which means that signals will not be delayed, and the event loop
2531will not be interrupted regularly, which is more efficient (and good for
2532battery life on laptops).
2533
2534This affects not just the pure-perl event loop, but also other event loops
2535that have no signal handling on their own (e.g. Glib, Tk, Qt).
2536
2537Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
2538and either employ their own workarounds (POE) or use AnyEvent's workaround
2539(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
2540does nothing for those backends.
2541
2542=item L<EV>
2543
2544This module isn't really "optional", as it is simply one of the backend
2545event loops that AnyEvent can use. However, it is simply the best event
2546loop available in terms of features, speed and stability: It supports
2547the AnyEvent API optimally, implements all the watcher types in XS, does
2548automatic timer adjustments even when no monotonic clock is available,
2549can take avdantage of advanced kernel interfaces such as C<epoll> and
2550C<kqueue>, and is the fastest backend I<by far>. You can even embed
2551L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2552
2553If you only use backends that rely on another event loop (e.g. C<Tk>),
2554then this module will do nothing for you.
2555
2556=item L<Guard>
2557
2558The guard module, when used, will be used to implement
2559C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2560lot less memory), but otherwise doesn't affect guard operation much. It is
2561purely used for performance.
2562
2563=item L<JSON> and L<JSON::XS>
2564
2565One of these modules is required when you want to read or write JSON data
2566via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2567advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2568
2569=item L<Net::SSLeay>
2570
2571Implementing TLS/SSL in Perl is certainly interesting, but not very
2572worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2573the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2574
2575=item L<Time::HiRes>
2576
2577This module is part of perl since release 5.008. It will be used when the
2578chosen event library does not come with a timing source on it's own. The
2579pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
2580try to use a monotonic clock for timing stability.
2581
2582=back
2583
2584
2052=head1 FORK 2585=head1 FORK
2053 2586
2054Most event libraries are not fork-safe. The ones who are usually are 2587Most event libraries are not fork-safe. The ones who are usually are
2055because they rely on inefficient but fork-safe C<select> or C<poll> 2588because they rely on inefficient but fork-safe C<select> or C<poll> calls
2056calls. Only L<EV> is fully fork-aware. 2589- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
2590are usually badly thought-out hacks that are incompatible with fork in
2591one way or another. Only L<EV> is fully fork-aware and ensures that you
2592continue event-processing in both parent and child (or both, if you know
2593what you are doing).
2594
2595This means that, in general, you cannot fork and do event processing in
2596the child if the event library was initialised before the fork (which
2597usually happens when the first AnyEvent watcher is created, or the library
2598is loaded).
2057 2599
2058If you have to fork, you must either do so I<before> creating your first 2600If you have to fork, you must either do so I<before> creating your first
2059watcher OR you must not use AnyEvent at all in the child. 2601watcher OR you must not use AnyEvent at all in the child OR you must do
2602something completely out of the scope of AnyEvent.
2603
2604The problem of doing event processing in the parent I<and> the child
2605is much more complicated: even for backends that I<are> fork-aware or
2606fork-safe, their behaviour is not usually what you want: fork clones all
2607watchers, that means all timers, I/O watchers etc. are active in both
2608parent and child, which is almost never what you want. USing C<exec>
2609to start worker children from some kind of manage rprocess is usually
2610preferred, because it is much easier and cleaner, at the expense of having
2611to have another binary.
2060 2612
2061 2613
2062=head1 SECURITY CONSIDERATIONS 2614=head1 SECURITY CONSIDERATIONS
2063 2615
2064AnyEvent can be forced to load any event model via 2616AnyEvent can be forced to load any event model via
2102L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. 2654L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2103 2655
2104Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, 2656Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2105L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, 2657L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2106L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, 2658L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2107L<AnyEvent::Impl::POE>. 2659L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
2108 2660
2109Non-blocking file handles, sockets, TCP clients and 2661Non-blocking file handles, sockets, TCP clients and
2110servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>. 2662servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2111 2663
2112Asynchronous DNS: L<AnyEvent::DNS>. 2664Asynchronous DNS: L<AnyEvent::DNS>.
2113 2665
2114Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>, 2666Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,
2667L<Coro::Event>,
2115 2668
2116Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. 2669Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,
2670L<AnyEvent::HTTP>.
2117 2671
2118 2672
2119=head1 AUTHOR 2673=head1 AUTHOR
2120 2674
2121 Marc Lehmann <schmorp@schmorp.de> 2675 Marc Lehmann <schmorp@schmorp.de>

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