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1=head1 NAME 1=head1 NAME
2 2
3AnyEvent - provide framework for multiple event loops 3AnyEvent - the DBI of event loop programming
4 4
5EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported 5EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt
6event loops. 6and POE are various supported event loops/environments.
7 7
8=head1 SYNOPSIS 8=head1 SYNOPSIS
9 9
10 use AnyEvent; 10 use AnyEvent;
11 11
40=head1 INTRODUCTION/TUTORIAL 40=head1 INTRODUCTION/TUTORIAL
41 41
42This manpage is mainly a reference manual. If you are interested 42This manpage is mainly a reference manual. If you are interested
43in a tutorial or some gentle introduction, have a look at the 43in a tutorial or some gentle introduction, have a look at the
44L<AnyEvent::Intro> manpage. 44L<AnyEvent::Intro> manpage.
45
46=head1 SUPPORT
47
48There is a mailinglist for discussing all things AnyEvent, and an IRC
49channel, too.
50
51See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
52Repository>, at L<http://anyevent.schmorp.de>, for more info.
45 53
46=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT) 54=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
47 55
48Glib, POE, IO::Async, Event... CPAN offers event models by the dozen 56Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
49nowadays. So what is different about AnyEvent? 57nowadays. So what is different about AnyEvent?
173my variables are only visible after the statement in which they are 181my variables are only visible after the statement in which they are
174declared. 182declared.
175 183
176=head2 I/O WATCHERS 184=head2 I/O WATCHERS
177 185
186 $w = AnyEvent->io (
187 fh => <filehandle_or_fileno>,
188 poll => <"r" or "w">,
189 cb => <callback>,
190 );
191
178You can create an I/O watcher by calling the C<< AnyEvent->io >> method 192You can create an I/O watcher by calling the C<< AnyEvent->io >> method
179with the following mandatory key-value pairs as arguments: 193with the following mandatory key-value pairs as arguments:
180 194
181C<fh> is the Perl I<file handle> (I<not> file descriptor) to watch 195C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch
182for events (AnyEvent might or might not keep a reference to this file 196for events (AnyEvent might or might not keep a reference to this file
183handle). Note that only file handles pointing to things for which 197handle). Note that only file handles pointing to things for which
184non-blocking operation makes sense are allowed. This includes sockets, 198non-blocking operation makes sense are allowed. This includes sockets,
185most character devices, pipes, fifos and so on, but not for example files 199most character devices, pipes, fifos and so on, but not for example files
186or block devices. 200or block devices.
211 undef $w; 225 undef $w;
212 }); 226 });
213 227
214=head2 TIME WATCHERS 228=head2 TIME WATCHERS
215 229
230 $w = AnyEvent->timer (after => <seconds>, cb => <callback>);
231
232 $w = AnyEvent->timer (
233 after => <fractional_seconds>,
234 interval => <fractional_seconds>,
235 cb => <callback>,
236 );
237
216You can create a time watcher by calling the C<< AnyEvent->timer >> 238You can create a time watcher by calling the C<< AnyEvent->timer >>
217method with the following mandatory arguments: 239method with the following mandatory arguments:
218 240
219C<after> specifies after how many seconds (fractional values are 241C<after> specifies after how many seconds (fractional values are
220supported) the callback should be invoked. C<cb> is the callback to invoke 242supported) the callback should be invoked. C<cb> is the callback to invoke
341might affect timers and time-outs. 363might affect timers and time-outs.
342 364
343When this is the case, you can call this method, which will update the 365When this is the case, you can call this method, which will update the
344event loop's idea of "current time". 366event loop's idea of "current time".
345 367
368A typical example would be a script in a web server (e.g. C<mod_perl>) -
369when mod_perl executes the script, then the event loop will have the wrong
370idea about the "current time" (being potentially far in the past, when the
371script ran the last time). In that case you should arrange a call to C<<
372AnyEvent->now_update >> each time the web server process wakes up again
373(e.g. at the start of your script, or in a handler).
374
346Note that updating the time I<might> cause some events to be handled. 375Note that updating the time I<might> cause some events to be handled.
347 376
348=back 377=back
349 378
350=head2 SIGNAL WATCHERS 379=head2 SIGNAL WATCHERS
380
381 $w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
351 382
352You can watch for signals using a signal watcher, C<signal> is the signal 383You can watch for signals using a signal watcher, C<signal> is the signal
353I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl 384I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
354callback to be invoked whenever a signal occurs. 385callback to be invoked whenever a signal occurs.
355 386
361invocation, and callback invocation will be synchronous. Synchronous means 392invocation, and callback invocation will be synchronous. Synchronous means
362that it might take a while until the signal gets handled by the process, 393that it might take a while until the signal gets handled by the process,
363but it is guaranteed not to interrupt any other callbacks. 394but it is guaranteed not to interrupt any other callbacks.
364 395
365The main advantage of using these watchers is that you can share a signal 396The main advantage of using these watchers is that you can share a signal
366between multiple watchers. 397between multiple watchers, and AnyEvent will ensure that signals will not
398interrupt your program at bad times.
367 399
368This watcher might use C<%SIG>, so programs overwriting those signals 400This watcher might use C<%SIG> (depending on the event loop used),
369directly will likely not work correctly. 401so programs overwriting those signals directly will likely not work
402correctly.
370 403
371Example: exit on SIGINT 404Example: exit on SIGINT
372 405
373 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); 406 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
374 407
408=head3 Restart Behaviour
409
410While restart behaviour is up to the event loop implementation, most will
411not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
412pure perl implementation).
413
414=head3 Safe/Unsafe Signals
415
416Perl signals can be either "safe" (synchronous to opcode handling) or
417"unsafe" (asynchronous) - the former might get delayed indefinitely, the
418latter might corrupt your memory.
419
420AnyEvent signal handlers are, in addition, synchronous to the event loop,
421i.e. they will not interrupt your running perl program but will only be
422called as part of the normal event handling (just like timer, I/O etc.
423callbacks, too).
424
425=head3 Signal Races, Delays and Workarounds
426
427Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
428callbacks to signals in a generic way, which is a pity, as you cannot
429do race-free signal handling in perl, requiring C libraries for
430this. AnyEvent will try to do it's best, which means in some cases,
431signals will be delayed. The maximum time a signal might be delayed is
432specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
433variable can be changed only before the first signal watcher is created,
434and should be left alone otherwise. This variable determines how often
435AnyEvent polls for signals (in case a wake-up was missed). Higher values
436will cause fewer spurious wake-ups, which is better for power and CPU
437saving.
438
439All these problems can be avoided by installing the optional
440L<Async::Interrupt> module, which works with most event loops. It will not
441work with inherently broken event loops such as L<Event> or L<Event::Lib>
442(and not with L<POE> currently, as POE does it's own workaround with
443one-second latency). For those, you just have to suffer the delays.
444
375=head2 CHILD PROCESS WATCHERS 445=head2 CHILD PROCESS WATCHERS
376 446
447 $w = AnyEvent->child (pid => <process id>, cb => <callback>);
448
377You can also watch on a child process exit and catch its exit status. 449You can also watch on a child process exit and catch its exit status.
378 450
379The child process is specified by the C<pid> argument (if set to C<0>, it 451The child process is specified by the C<pid> argument (one some backends,
380watches for any child process exit). The watcher will triggered only when 452using 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 453croak). The watcher will be triggered only when the child process has
382any trace events (stopped/continued). 454finished and an exit status is available, not on any trace events
455(stopped/continued).
383 456
384The callback will be called with the pid and exit status (as returned by 457The callback will be called with the pid and exit status (as returned by
385waitpid), so unlike other watcher types, you I<can> rely on child watcher 458waitpid), so unlike other watcher types, you I<can> rely on child watcher
386callback arguments. 459callback arguments.
387 460
403 476
404This means you cannot create a child watcher as the very first 477This means you cannot create a child watcher as the very first
405thing in an AnyEvent program, you I<have> to create at least one 478thing in an AnyEvent program, you I<have> to create at least one
406watcher before you C<fork> the child (alternatively, you can call 479watcher before you C<fork> the child (alternatively, you can call
407C<AnyEvent::detect>). 480C<AnyEvent::detect>).
481
482As most event loops do not support waiting for child events, they will be
483emulated by AnyEvent in most cases, in which the latency and race problems
484mentioned in the description of signal watchers apply.
408 485
409Example: fork a process and wait for it 486Example: fork a process and wait for it
410 487
411 my $done = AnyEvent->condvar; 488 my $done = AnyEvent->condvar;
412 489
424 # do something else, then wait for process exit 501 # do something else, then wait for process exit
425 $done->recv; 502 $done->recv;
426 503
427=head2 IDLE WATCHERS 504=head2 IDLE WATCHERS
428 505
429Sometimes there is a need to do something, but it is not so important 506 $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".
433 507
434Idle watchers ideally get invoked when the event loop has nothing 508Repeatedly invoke the callback after the process becomes idle, until
435better to do, just before it would block the process to wait for new 509either the watcher is destroyed or new events have been detected.
436events. Instead of blocking, the idle watcher is invoked.
437 510
438Most event loops unfortunately do not really support idle watchers (only 511Idle watchers are useful when there is a need to do something, but it
512is not so important (or wise) to do it instantly. The callback will be
513invoked only when there is "nothing better to do", which is usually
514defined as "all outstanding events have been handled and no new events
515have been detected". That means that idle watchers ideally get invoked
516when the event loop has just polled for new events but none have been
517detected. Instead of blocking to wait for more events, the idle watchers
518will be invoked.
519
520Unfortunately, most event loops do not really support idle watchers (only
439EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent 521EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
440will simply call the callback "from time to time". 522will simply call the callback "from time to time".
441 523
442Example: read lines from STDIN, but only process them when the 524Example: read lines from STDIN, but only process them when the
443program is otherwise idle: 525program is otherwise idle:
459 }); 541 });
460 }); 542 });
461 543
462=head2 CONDITION VARIABLES 544=head2 CONDITION VARIABLES
463 545
546 $cv = AnyEvent->condvar;
547
548 $cv->send (<list>);
549 my @res = $cv->recv;
550
464If you are familiar with some event loops you will know that all of them 551If you are familiar with some event loops you will know that all of them
465require you to run some blocking "loop", "run" or similar function that 552require you to run some blocking "loop", "run" or similar function that
466will actively watch for new events and call your callbacks. 553will actively watch for new events and call your callbacks.
467 554
468AnyEvent is different, it expects somebody else to run the event loop and 555AnyEvent is slightly different: it expects somebody else to run the event
469will only block when necessary (usually when told by the user). 556loop and will only block when necessary (usually when told by the user).
470 557
471The instrument to do that is called a "condition variable", so called 558The instrument to do that is called a "condition variable", so called
472because they represent a condition that must become true. 559because they represent a condition that must become true.
473 560
561Now is probably a good time to look at the examples further below.
562
474Condition variables can be created by calling the C<< AnyEvent->condvar 563Condition variables can be created by calling the C<< AnyEvent->condvar
475>> method, usually without arguments. The only argument pair allowed is 564>> method, usually without arguments. The only argument pair allowed is
476
477C<cb>, which specifies a callback to be called when the condition variable 565C<cb>, which specifies a callback to be called when the condition variable
478becomes true, with the condition variable as the first argument (but not 566becomes true, with the condition variable as the first argument (but not
479the results). 567the results).
480 568
481After creation, the condition variable is "false" until it becomes "true" 569After creation, the condition variable is "false" until it becomes "true"
486Condition variables are similar to callbacks, except that you can 574Condition variables are similar to callbacks, except that you can
487optionally wait for them. They can also be called merge points - points 575optionally wait for them. They can also be called merge points - points
488in time where multiple outstanding events have been processed. And yet 576in time where multiple outstanding events have been processed. And yet
489another way to call them is transactions - each condition variable can be 577another way to call them is transactions - each condition variable can be
490used to represent a transaction, which finishes at some point and delivers 578used to represent a transaction, which finishes at some point and delivers
491a result. 579a result. And yet some people know them as "futures" - a promise to
580compute/deliver something that you can wait for.
492 581
493Condition variables are very useful to signal that something has finished, 582Condition variables are very useful to signal that something has finished,
494for example, if you write a module that does asynchronous http requests, 583for example, if you write a module that does asynchronous http requests,
495then a condition variable would be the ideal candidate to signal the 584then a condition variable would be the ideal candidate to signal the
496availability of results. The user can either act when the callback is 585availability of results. The user can either act when the callback is
530 after => 1, 619 after => 1,
531 cb => sub { $result_ready->send }, 620 cb => sub { $result_ready->send },
532 ); 621 );
533 622
534 # this "blocks" (while handling events) till the callback 623 # this "blocks" (while handling events) till the callback
535 # calls send 624 # calls ->send
536 $result_ready->recv; 625 $result_ready->recv;
537 626
538Example: wait for a timer, but take advantage of the fact that 627Example: wait for a timer, but take advantage of the fact that condition
539condition variables are also code references. 628variables are also callable directly.
540 629
541 my $done = AnyEvent->condvar; 630 my $done = AnyEvent->condvar;
542 my $delay = AnyEvent->timer (after => 5, cb => $done); 631 my $delay = AnyEvent->timer (after => 5, cb => $done);
543 $done->recv; 632 $done->recv;
544 633
550 639
551 ... 640 ...
552 641
553 my @info = $couchdb->info->recv; 642 my @info = $couchdb->info->recv;
554 643
555And this is how you would just ste a callback to be called whenever the 644And this is how you would just set a callback to be called whenever the
556results are available: 645results are available:
557 646
558 $couchdb->info->cb (sub { 647 $couchdb->info->cb (sub {
559 my @info = $_[0]->recv; 648 my @info = $_[0]->recv;
560 }); 649 });
578immediately from within send. 667immediately from within send.
579 668
580Any arguments passed to the C<send> call will be returned by all 669Any arguments passed to the C<send> call will be returned by all
581future C<< ->recv >> calls. 670future C<< ->recv >> calls.
582 671
583Condition variables are overloaded so one can call them directly 672Condition variables are overloaded so one can call them directly (as if
584(as a code reference). Calling them directly is the same as calling 673they 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 674C<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).
591 675
592=item $cv->croak ($error) 676=item $cv->croak ($error)
593 677
594Similar to send, but causes all call's to C<< ->recv >> to invoke 678Similar to send, but causes all call's to C<< ->recv >> to invoke
595C<Carp::croak> with the given error message/object/scalar. 679C<Carp::croak> with the given error message/object/scalar.
596 680
597This can be used to signal any errors to the condition variable 681This can be used to signal any errors to the condition variable
598user/consumer. 682user/consumer. Doing it this way instead of calling C<croak> directly
683delays the error detetcion, but has the overwhelmign advantage that it
684diagnoses the error at the place where the result is expected, and not
685deep in some event clalback without connection to the actual code causing
686the problem.
599 687
600=item $cv->begin ([group callback]) 688=item $cv->begin ([group callback])
601 689
602=item $cv->end 690=item $cv->end
603
604These two methods are EXPERIMENTAL and MIGHT CHANGE.
605 691
606These two methods can be used to combine many transactions/events into 692These two methods can be used to combine many transactions/events into
607one. For example, a function that pings many hosts in parallel might want 693one. For example, a function that pings many hosts in parallel might want
608to use a condition variable for the whole process. 694to use a condition variable for the whole process.
609 695
610Every call to C<< ->begin >> will increment a counter, and every call to 696Every call to C<< ->begin >> will increment a counter, and every call to
611C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end 697C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
612>>, the (last) callback passed to C<begin> will be executed. That callback 698>>, the (last) callback passed to C<begin> will be executed, passing the
613is I<supposed> to call C<< ->send >>, but that is not required. If no 699condvar as first argument. That callback is I<supposed> to call C<< ->send
614callback was set, C<send> will be called without any arguments. 700>>, but that is not required. If no group callback was set, C<send> will
701be called without any arguments.
615 702
616Let's clarify this with the ping example: 703You can think of C<< $cv->send >> giving you an OR condition (one call
704sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
705condition (all C<begin> calls must be C<end>'ed before the condvar sends).
706
707Let's start with a simple example: you have two I/O watchers (for example,
708STDOUT and STDERR for a program), and you want to wait for both streams to
709close before activating a condvar:
617 710
618 my $cv = AnyEvent->condvar; 711 my $cv = AnyEvent->condvar;
619 712
713 $cv->begin; # first watcher
714 my $w1 = AnyEvent->io (fh => $fh1, cb => sub {
715 defined sysread $fh1, my $buf, 4096
716 or $cv->end;
717 });
718
719 $cv->begin; # second watcher
720 my $w2 = AnyEvent->io (fh => $fh2, cb => sub {
721 defined sysread $fh2, my $buf, 4096
722 or $cv->end;
723 });
724
725 $cv->recv;
726
727This works because for every event source (EOF on file handle), there is
728one call to C<begin>, so the condvar waits for all calls to C<end> before
729sending.
730
731The ping example mentioned above is slightly more complicated, as the
732there are results to be passwd back, and the number of tasks that are
733begung can potentially be zero:
734
735 my $cv = AnyEvent->condvar;
736
620 my %result; 737 my %result;
621 $cv->begin (sub { $cv->send (\%result) }); 738 $cv->begin (sub { shift->send (\%result) });
622 739
623 for my $host (@list_of_hosts) { 740 for my $host (@list_of_hosts) {
624 $cv->begin; 741 $cv->begin;
625 ping_host_then_call_callback $host, sub { 742 ping_host_then_call_callback $host, sub {
626 $result{$host} = ...; 743 $result{$host} = ...;
641loop, which serves two important purposes: first, it sets the callback 758loop, which serves two important purposes: first, it sets the callback
642to be called once the counter reaches C<0>, and second, it ensures that 759to be called once the counter reaches C<0>, and second, it ensures that
643C<send> is called even when C<no> hosts are being pinged (the loop 760C<send> is called even when C<no> hosts are being pinged (the loop
644doesn't execute once). 761doesn't execute once).
645 762
646This is the general pattern when you "fan out" into multiple subrequests: 763This is the general pattern when you "fan out" into multiple (but
647use an outer C<begin>/C<end> pair to set the callback and ensure C<end> 764potentially none) subrequests: use an outer C<begin>/C<end> pair to set
648is called at least once, and then, for each subrequest you start, call 765the callback and ensure C<end> is called at least once, and then, for each
649C<begin> and for each subrequest you finish, call C<end>. 766subrequest you start, call C<begin> and for each subrequest you finish,
767call C<end>.
650 768
651=back 769=back
652 770
653=head3 METHODS FOR CONSUMERS 771=head3 METHODS FOR CONSUMERS
654 772
670function will call C<croak>. 788function will call C<croak>.
671 789
672In list context, all parameters passed to C<send> will be returned, 790In list context, all parameters passed to C<send> will be returned,
673in scalar context only the first one will be returned. 791in scalar context only the first one will be returned.
674 792
793Note that doing a blocking wait in a callback is not supported by any
794event loop, that is, recursive invocation of a blocking C<< ->recv
795>> is not allowed, and the C<recv> call will C<croak> if such a
796condition is detected. This condition can be slightly loosened by using
797L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from
798any thread that doesn't run the event loop itself.
799
675Not all event models support a blocking wait - some die in that case 800Not all event models support a blocking wait - some die in that case
676(programs might want to do that to stay interactive), so I<if you are 801(programs might want to do that to stay interactive), so I<if you are
677using this from a module, never require a blocking wait>, but let the 802using this from a module, never require a blocking wait>. Instead, let the
678caller decide whether the call will block or not (for example, by coupling 803caller decide whether the call will block or not (for example, by coupling
679condition variables with some kind of request results and supporting 804condition variables with some kind of request results and supporting
680callbacks so the caller knows that getting the result will not block, 805callbacks so the caller knows that getting the result will not block,
681while still supporting blocking waits if the caller so desires). 806while still supporting blocking waits if the caller so desires).
682 807
683Another reason I<never> to C<< ->recv >> in a module is that you cannot
684sensibly have two C<< ->recv >>'s in parallel, as that would require
685multiple interpreters or coroutines/threads, none of which C<AnyEvent>
686can supply.
687
688The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
689fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
690versions and also integrates coroutines into AnyEvent, making blocking
691C<< ->recv >> calls perfectly safe as long as they are done from another
692coroutine (one that doesn't run the event loop).
693
694You can ensure that C<< -recv >> never blocks by setting a callback and 808You can ensure that C<< -recv >> never blocks by setting a callback and
695only calling C<< ->recv >> from within that callback (or at a later 809only calling C<< ->recv >> from within that callback (or at a later
696time). This will work even when the event loop does not support blocking 810time). This will work even when the event loop does not support blocking
697waits otherwise. 811waits otherwise.
698 812
704=item $cb = $cv->cb ($cb->($cv)) 818=item $cb = $cv->cb ($cb->($cv))
705 819
706This is a mutator function that returns the callback set and optionally 820This is a mutator function that returns the callback set and optionally
707replaces it before doing so. 821replaces it before doing so.
708 822
709The callback will be called when the condition becomes "true", i.e. when 823The callback will be called when the condition becomes (or already was)
710C<send> or C<croak> are called, with the only argument being the condition 824"true", i.e. when C<send> or C<croak> are called (or were called), with
711variable itself. Calling C<recv> inside the callback or at any later time 825the only argument being the condition variable itself. Calling C<recv>
712is guaranteed not to block. 826inside the callback or at any later time is guaranteed not to block.
713 827
714=back 828=back
715 829
830=head1 SUPPORTED EVENT LOOPS/BACKENDS
831
832The available backend classes are (every class has its own manpage):
833
834=over 4
835
836=item Backends that are autoprobed when no other event loop can be found.
837
838EV is the preferred backend when no other event loop seems to be in
839use. If EV is not installed, then AnyEvent will fall back to its own
840pure-perl implementation, which is available everywhere as it comes with
841AnyEvent itself.
842
843 AnyEvent::Impl::EV based on EV (interface to libev, best choice).
844 AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
845
846=item Backends that are transparently being picked up when they are used.
847
848These will be used when they are currently loaded when the first watcher
849is created, in which case it is assumed that the application is using
850them. This means that AnyEvent will automatically pick the right backend
851when the main program loads an event module before anything starts to
852create watchers. Nothing special needs to be done by the main program.
853
854 AnyEvent::Impl::Event based on Event, very stable, few glitches.
855 AnyEvent::Impl::Glib based on Glib, slow but very stable.
856 AnyEvent::Impl::Tk based on Tk, very broken.
857 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
858 AnyEvent::Impl::POE based on POE, very slow, some limitations.
859 AnyEvent::Impl::Irssi used when running within irssi.
860
861=item Backends with special needs.
862
863Qt requires the Qt::Application to be instantiated first, but will
864otherwise be picked up automatically. As long as the main program
865instantiates the application before any AnyEvent watchers are created,
866everything should just work.
867
868 AnyEvent::Impl::Qt based on Qt.
869
870Support for IO::Async can only be partial, as it is too broken and
871architecturally limited to even support the AnyEvent API. It also
872is the only event loop that needs the loop to be set explicitly, so
873it can only be used by a main program knowing about AnyEvent. See
874L<AnyEvent::Impl::Async> for the gory details.
875
876 AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
877
878=item Event loops that are indirectly supported via other backends.
879
880Some event loops can be supported via other modules:
881
882There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
883
884B<WxWidgets> has no support for watching file handles. However, you can
885use WxWidgets through the POE adaptor, as POE has a Wx backend that simply
886polls 20 times per second, which was considered to be too horrible to even
887consider for AnyEvent.
888
889B<Prima> is not supported as nobody seems to be using it, but it has a POE
890backend, so it can be supported through POE.
891
892AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to
893load L<POE> when detecting them, in the hope that POE will pick them up,
894in which case everything will be automatic.
895
896=back
897
716=head1 GLOBAL VARIABLES AND FUNCTIONS 898=head1 GLOBAL VARIABLES AND FUNCTIONS
717 899
900These are not normally required to use AnyEvent, but can be useful to
901write AnyEvent extension modules.
902
718=over 4 903=over 4
719 904
720=item $AnyEvent::MODEL 905=item $AnyEvent::MODEL
721 906
722Contains C<undef> until the first watcher is being created. Then it 907Contains C<undef> until the first watcher is being created, before the
908backend has been autodetected.
909
723contains the event model that is being used, which is the name of the 910Afterwards it contains the event model that is being used, which is the
724Perl class implementing the model. This class is usually one of the 911name of the Perl class implementing the model. This class is usually one
725C<AnyEvent::Impl:xxx> modules, but can be any other class in the case 912of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the
726AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>). 913case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
727 914will be C<urxvt::anyevent>).
728The known classes so far are:
729
730 AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
731 AnyEvent::Impl::Event based on Event, second best choice.
732 AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
733 AnyEvent::Impl::Glib based on Glib, third-best choice.
734 AnyEvent::Impl::Tk based on Tk, very bad choice.
735 AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
736 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
737 AnyEvent::Impl::POE based on POE, not generic enough for full support.
738
739 # warning, support for IO::Async is only partial, as it is too broken
740 # and limited toe ven support the AnyEvent API. See AnyEvent::Impl::Async.
741 AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed (see its docs).
742
743There is no support for WxWidgets, as WxWidgets has no support for
744watching file handles. However, you can use WxWidgets through the
745POE Adaptor, as POE has a Wx backend that simply polls 20 times per
746second, which was considered to be too horrible to even consider for
747AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
748it's adaptor.
749
750AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
751autodetecting them.
752 915
753=item AnyEvent::detect 916=item AnyEvent::detect
754 917
755Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model 918Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
756if necessary. You should only call this function right before you would 919if necessary. You should only call this function right before you would
757have created an AnyEvent watcher anyway, that is, as late as possible at 920have created an AnyEvent watcher anyway, that is, as late as possible at
758runtime. 921runtime, and not e.g. while initialising of your module.
922
923If you need to do some initialisation before AnyEvent watchers are
924created, use C<post_detect>.
759 925
760=item $guard = AnyEvent::post_detect { BLOCK } 926=item $guard = AnyEvent::post_detect { BLOCK }
761 927
762Arranges for the code block to be executed as soon as the event model is 928Arranges for the code block to be executed as soon as the event model is
763autodetected (or immediately if this has already happened). 929autodetected (or immediately if this has already happened).
764 930
931The block will be executed I<after> the actual backend has been detected
932(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
933created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
934other initialisations - see the sources of L<AnyEvent::Strict> or
935L<AnyEvent::AIO> to see how this is used.
936
937The most common usage is to create some global watchers, without forcing
938event module detection too early, for example, L<AnyEvent::AIO> creates
939and installs the global L<IO::AIO> watcher in a C<post_detect> block to
940avoid autodetecting the event module at load time.
941
765If called in scalar or list context, then it creates and returns an object 942If called in scalar or list context, then it creates and returns an object
766that automatically removes the callback again when it is destroyed. See 943that automatically removes the callback again when it is destroyed (or
944C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
767L<Coro::BDB> for a case where this is useful. 945a case where this is useful.
946
947Example: Create a watcher for the IO::AIO module and store it in
948C<$WATCHER>. Only do so after the event loop is initialised, though.
949
950 our WATCHER;
951
952 my $guard = AnyEvent::post_detect {
953 $WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
954 };
955
956 # the ||= is important in case post_detect immediately runs the block,
957 # as to not clobber the newly-created watcher. assigning both watcher and
958 # post_detect guard to the same variable has the advantage of users being
959 # able to just C<undef $WATCHER> if the watcher causes them grief.
960
961 $WATCHER ||= $guard;
768 962
769=item @AnyEvent::post_detect 963=item @AnyEvent::post_detect
770 964
771If there are any code references in this array (you can C<push> to it 965If there are any code references in this array (you can C<push> to it
772before or after loading AnyEvent), then they will called directly after 966before or after loading AnyEvent), then they will called directly after
773the event loop has been chosen. 967the event loop has been chosen.
774 968
775You should check C<$AnyEvent::MODEL> before adding to this array, though: 969You should check C<$AnyEvent::MODEL> before adding to this array, though:
776if it contains a true value then the event loop has already been detected, 970if it is defined then the event loop has already been detected, and the
777and the array will be ignored. 971array will be ignored.
778 972
779Best use C<AnyEvent::post_detect { BLOCK }> instead. 973Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
974it, as it takes care of these details.
975
976This variable is mainly useful for modules that can do something useful
977when AnyEvent is used and thus want to know when it is initialised, but do
978not need to even load it by default. This array provides the means to hook
979into AnyEvent passively, without loading it.
980
981Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
982together, you could put this into Coro (this is the actual code used by
983Coro to accomplish this):
984
985 if (defined $AnyEvent::MODEL) {
986 # AnyEvent already initialised, so load Coro::AnyEvent
987 require Coro::AnyEvent;
988 } else {
989 # AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
990 # as soon as it is
991 push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
992 }
780 993
781=back 994=back
782 995
783=head1 WHAT TO DO IN A MODULE 996=head1 WHAT TO DO IN A MODULE
784 997
839 1052
840 1053
841=head1 OTHER MODULES 1054=head1 OTHER MODULES
842 1055
843The following is a non-exhaustive list of additional modules that use 1056The following is a non-exhaustive list of additional modules that use
844AnyEvent and can therefore be mixed easily with other AnyEvent modules 1057AnyEvent as a client and can therefore be mixed easily with other AnyEvent
845in the same program. Some of the modules come with AnyEvent, some are 1058modules and other event loops in the same program. Some of the modules
846available via CPAN. 1059come with AnyEvent, most are available via CPAN.
847 1060
848=over 4 1061=over 4
849 1062
850=item L<AnyEvent::Util> 1063=item L<AnyEvent::Util>
851 1064
860 1073
861=item L<AnyEvent::Handle> 1074=item L<AnyEvent::Handle>
862 1075
863Provide read and write buffers, manages watchers for reads and writes, 1076Provide read and write buffers, manages watchers for reads and writes,
864supports raw and formatted I/O, I/O queued and fully transparent and 1077supports raw and formatted I/O, I/O queued and fully transparent and
865non-blocking SSL/TLS. 1078non-blocking SSL/TLS (via L<AnyEvent::TLS>.
866 1079
867=item L<AnyEvent::DNS> 1080=item L<AnyEvent::DNS>
868 1081
869Provides rich asynchronous DNS resolver capabilities. 1082Provides rich asynchronous DNS resolver capabilities.
870 1083
898 1111
899=item L<AnyEvent::GPSD> 1112=item L<AnyEvent::GPSD>
900 1113
901A non-blocking interface to gpsd, a daemon delivering GPS information. 1114A non-blocking interface to gpsd, a daemon delivering GPS information.
902 1115
1116=item L<AnyEvent::IRC>
1117
1118AnyEvent based IRC client module family (replacing the older Net::IRC3).
1119
1120=item L<AnyEvent::XMPP>
1121
1122AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1123Net::XMPP2>.
1124
903=item L<AnyEvent::IGS> 1125=item L<AnyEvent::IGS>
904 1126
905A non-blocking interface to the Internet Go Server protocol (used by 1127A non-blocking interface to the Internet Go Server protocol (used by
906L<App::IGS>). 1128L<App::IGS>).
907 1129
908=item L<AnyEvent::IRC>
909
910AnyEvent based IRC client module family (replacing the older Net::IRC3).
911
912=item L<Net::XMPP2>
913
914AnyEvent based XMPP (Jabber protocol) module family.
915
916=item L<Net::FCP> 1130=item L<Net::FCP>
917 1131
918AnyEvent-based implementation of the Freenet Client Protocol, birthplace 1132AnyEvent-based implementation of the Freenet Client Protocol, birthplace
919of AnyEvent. 1133of AnyEvent.
920 1134
924 1138
925=item L<Coro> 1139=item L<Coro>
926 1140
927Has special support for AnyEvent via L<Coro::AnyEvent>. 1141Has special support for AnyEvent via L<Coro::AnyEvent>.
928 1142
929=item L<IO::Lambda>
930
931The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
932
933=back 1143=back
934 1144
935=cut 1145=cut
936 1146
937package AnyEvent; 1147package AnyEvent;
938 1148
939no warnings; 1149# basically a tuned-down version of common::sense
940use strict qw(vars subs); 1150sub common_sense {
1151 # from common:.sense 1.0
1152 ${^WARNING_BITS} = "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x00";
1153 # use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1154 $^H |= 0x00000600;
1155}
941 1156
1157BEGIN { AnyEvent::common_sense }
1158
942use Carp; 1159use Carp ();
943 1160
944our $VERSION = 4.412; 1161our $VERSION = '5.24';
945our $MODEL; 1162our $MODEL;
946 1163
947our $AUTOLOAD; 1164our $AUTOLOAD;
948our @ISA; 1165our @ISA;
949 1166
950our @REGISTRY; 1167our @REGISTRY;
951 1168
952our $WIN32; 1169our $VERBOSE;
953 1170
954BEGIN { 1171BEGIN {
955 eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; 1172 require "AnyEvent/constants.pl";
1173
956 eval "sub TAINT(){ " . (${^TAINT}*1) . " }"; 1174 eval "sub TAINT (){" . (${^TAINT} *1) . "}";
957 1175
958 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} 1176 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
959 if ${^TAINT}; 1177 if ${^TAINT};
960}
961 1178
962our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; 1179 $VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
1180
1181}
1182
1183our $MAX_SIGNAL_LATENCY = 10;
963 1184
964our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred 1185our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
965 1186
966{ 1187{
967 my $idx; 1188 my $idx;
969 for reverse split /\s*,\s*/, 1190 for reverse split /\s*,\s*/,
970 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; 1191 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
971} 1192}
972 1193
973my @models = ( 1194my @models = (
974 [EV:: => AnyEvent::Impl::EV::], 1195 [EV:: => AnyEvent::Impl::EV:: , 1],
975 [Event:: => AnyEvent::Impl::Event::],
976 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], 1196 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
977 # everything below here will not be autoprobed 1197 # everything below here will not (normally) be autoprobed
978 # as the pureperl backend should work everywhere 1198 # as the pureperl backend should work everywhere
979 # and is usually faster 1199 # and is usually faster
1200 [Event:: => AnyEvent::Impl::Event::, 1],
1201 [Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1202 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1203 [Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
980 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles 1204 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
981 [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
982 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
983 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program 1205 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program
984 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza 1206 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
985 [Wx:: => AnyEvent::Impl::POE::], 1207 [Wx:: => AnyEvent::Impl::POE::],
986 [Prima:: => AnyEvent::Impl::POE::], 1208 [Prima:: => AnyEvent::Impl::POE::],
987 # IO::Async is just too broken - we would need workaorunds for its 1209 # IO::Async is just too broken - we would need workarounds for its
988 # byzantine signal and broken child handling, among others. 1210 # byzantine signal and broken child handling, among others.
989 # IO::Async is rather hard to detect, as it doesn't have any 1211 # IO::Async is rather hard to detect, as it doesn't have any
990 # obvious default class. 1212 # obvious default class.
991# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program 1213 [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
992# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program 1214 [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
993# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program 1215 [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1216 [AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
994); 1217);
995 1218
996our %method = map +($_ => 1), 1219our %method = map +($_ => 1),
997 qw(io timer time now now_update signal child idle condvar one_event DESTROY); 1220 qw(io timer time now now_update signal child idle condvar one_event DESTROY);
998 1221
1002 my ($cb) = @_; 1225 my ($cb) = @_;
1003 1226
1004 if ($MODEL) { 1227 if ($MODEL) {
1005 $cb->(); 1228 $cb->();
1006 1229
1007 1 1230 undef
1008 } else { 1231 } else {
1009 push @post_detect, $cb; 1232 push @post_detect, $cb;
1010 1233
1011 defined wantarray 1234 defined wantarray
1012 ? bless \$cb, "AnyEvent::Util::postdetect" 1235 ? bless \$cb, "AnyEvent::Util::postdetect"
1017sub AnyEvent::Util::postdetect::DESTROY { 1240sub AnyEvent::Util::postdetect::DESTROY {
1018 @post_detect = grep $_ != ${$_[0]}, @post_detect; 1241 @post_detect = grep $_ != ${$_[0]}, @post_detect;
1019} 1242}
1020 1243
1021sub detect() { 1244sub detect() {
1245 # free some memory
1246 *detect = sub () { $MODEL };
1247
1248 local $!; # for good measure
1249 local $SIG{__DIE__};
1250
1251 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1252 my $model = "AnyEvent::Impl::$1";
1253 if (eval "require $model") {
1254 $MODEL = $model;
1255 warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
1256 } else {
1257 warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1258 }
1259 }
1260
1261 # check for already loaded models
1022 unless ($MODEL) { 1262 unless ($MODEL) {
1023 no strict 'refs'; 1263 for (@REGISTRY, @models) {
1024 local $SIG{__DIE__}; 1264 my ($package, $model) = @$_;
1025 1265 if (${"$package\::VERSION"} > 0) {
1026 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1027 my $model = "AnyEvent::Impl::$1";
1028 if (eval "require $model") { 1266 if (eval "require $model") {
1029 $MODEL = $model; 1267 $MODEL = $model;
1030 warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1; 1268 warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1031 } else { 1269 last;
1032 warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose; 1270 }
1033 } 1271 }
1034 } 1272 }
1035 1273
1036 # check for already loaded models
1037 unless ($MODEL) { 1274 unless ($MODEL) {
1275 # try to autoload a model
1038 for (@REGISTRY, @models) { 1276 for (@REGISTRY, @models) {
1039 my ($package, $model) = @$_; 1277 my ($package, $model, $autoload) = @$_;
1278 if (
1279 $autoload
1280 and eval "require $package"
1040 if (${"$package\::VERSION"} > 0) { 1281 and ${"$package\::VERSION"} > 0
1041 if (eval "require $model") { 1282 and eval "require $model"
1283 ) {
1042 $MODEL = $model; 1284 $MODEL = $model;
1043 warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1; 1285 warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1044 last; 1286 last;
1045 }
1046 } 1287 }
1047 } 1288 }
1048 1289
1049 unless ($MODEL) {
1050 # try to load a model
1051
1052 for (@REGISTRY, @models) {
1053 my ($package, $model) = @$_;
1054 if (eval "require $package"
1055 and ${"$package\::VERSION"} > 0
1056 and eval "require $model") {
1057 $MODEL = $model;
1058 warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1;
1059 last;
1060 }
1061 }
1062
1063 $MODEL 1290 $MODEL
1064 or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n"; 1291 or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";
1065 }
1066 } 1292 }
1067
1068 push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1069
1070 unshift @ISA, $MODEL;
1071
1072 require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1073
1074 (shift @post_detect)->() while @post_detect;
1075 } 1293 }
1294
1295 @models = (); # free probe data
1296
1297 push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1298 unshift @ISA, $MODEL;
1299
1300 require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1301
1302 (shift @post_detect)->() while @post_detect;
1076 1303
1077 $MODEL 1304 $MODEL
1078} 1305}
1079 1306
1080sub AUTOLOAD { 1307sub AUTOLOAD {
1081 (my $func = $AUTOLOAD) =~ s/.*://; 1308 (my $func = $AUTOLOAD) =~ s/.*://;
1082 1309
1083 $method{$func} 1310 $method{$func}
1084 or croak "$func: not a valid method for AnyEvent objects"; 1311 or Carp::croak "$func: not a valid AnyEvent class method";
1085 1312
1086 detect unless $MODEL; 1313 detect;
1087 1314
1088 my $class = shift; 1315 my $class = shift;
1089 $class->$func (@_); 1316 $class->$func (@_);
1090} 1317}
1091 1318
1094# allow only one watcher per fd, so we dup it to get a different one). 1321# allow only one watcher per fd, so we dup it to get a different one).
1095sub _dupfh($$;$$) { 1322sub _dupfh($$;$$) {
1096 my ($poll, $fh, $r, $w) = @_; 1323 my ($poll, $fh, $r, $w) = @_;
1097 1324
1098 # cygwin requires the fh mode to be matching, unix doesn't 1325 # cygwin requires the fh mode to be matching, unix doesn't
1099 my ($rw, $mode) = $poll eq "r" ? ($r, "<") 1326 my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1100 : $poll eq "w" ? ($w, ">")
1101 : Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
1102 1327
1103 open my $fh2, "$mode&" . fileno $fh 1328 open my $fh2, $mode, $fh
1104 or die "cannot dup() filehandle: $!,"; 1329 or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1105 1330
1106 # we assume CLOEXEC is already set by perl in all important cases 1331 # we assume CLOEXEC is already set by perl in all important cases
1107 1332
1108 ($fh2, $rw) 1333 ($fh2, $rw)
1109} 1334}
1110 1335
1336=head1 SIMPLIFIED AE API
1337
1338Starting with version 5.0, AnyEvent officially supports a second, much
1339simpler, API that is designed to reduce the calling, typing and memory
1340overhead.
1341
1342See the L<AE> manpage for details.
1343
1344=cut
1345
1346package AE;
1347
1348our $VERSION = $AnyEvent::VERSION;
1349
1350sub io($$$) {
1351 AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1352}
1353
1354sub timer($$$) {
1355 AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
1356}
1357
1358sub signal($$) {
1359 AnyEvent->signal (signal => $_[0], cb => $_[1])
1360}
1361
1362sub child($$) {
1363 AnyEvent->child (pid => $_[0], cb => $_[1])
1364}
1365
1366sub idle($) {
1367 AnyEvent->idle (cb => $_[0])
1368}
1369
1370sub cv(;&) {
1371 AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
1372}
1373
1374sub now() {
1375 AnyEvent->now
1376}
1377
1378sub now_update() {
1379 AnyEvent->now_update
1380}
1381
1382sub time() {
1383 AnyEvent->time
1384}
1385
1111package AnyEvent::Base; 1386package AnyEvent::Base;
1112 1387
1113# default implementations for many methods 1388# default implementations for many methods
1114 1389
1115BEGIN { 1390sub _time() {
1391 eval q{ # poor man's autoloading
1392 # probe for availability of Time::HiRes
1116 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { 1393 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1394 warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1117 *_time = \&Time::HiRes::time; 1395 *_time = \&Time::HiRes::time;
1118 # if (eval "use POSIX (); (POSIX::times())... 1396 # if (eval "use POSIX (); (POSIX::times())...
1119 } else { 1397 } else {
1398 warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1120 *_time = sub { time }; # epic fail 1399 *_time = sub (){ time }; # epic fail
1400 }
1121 } 1401 };
1402 die if $@;
1403
1404 &_time
1122} 1405}
1123 1406
1124sub time { _time } 1407sub time { _time }
1125sub now { _time } 1408sub now { _time }
1126sub now_update { } 1409sub now_update { }
1131 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar" 1414 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1132} 1415}
1133 1416
1134# default implementation for ->signal 1417# default implementation for ->signal
1135 1418
1419our $HAVE_ASYNC_INTERRUPT;
1420
1421sub _have_async_interrupt() {
1422 $HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
1423 && eval "use Async::Interrupt 1.02 (); 1")
1424 unless defined $HAVE_ASYNC_INTERRUPT;
1425
1426 $HAVE_ASYNC_INTERRUPT
1427}
1428
1136our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); 1429our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1430our (%SIG_ASY, %SIG_ASY_W);
1431our ($SIG_COUNT, $SIG_TW);
1137 1432
1138sub _signal_exec { 1433# install a dummy wakeup watcher to reduce signal catching latency
1139 sysread $SIGPIPE_R, my $dummy, 4; 1434# used by Impls
1435sub _sig_add() {
1436 unless ($SIG_COUNT++) {
1437 # try to align timer on a full-second boundary, if possible
1438 my $NOW = AE::now;
1140 1439
1141 while (%SIG_EV) { 1440 $SIG_TW = AE::timer
1142 for (keys %SIG_EV) { 1441 $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1143 delete $SIG_EV{$_}; 1442 $MAX_SIGNAL_LATENCY,
1144 $_->() for values %{ $SIG_CB{$_} || {} }; 1443 sub { } # just for the PERL_ASYNC_CHECK
1444 ;
1445 }
1446}
1447
1448sub _sig_del {
1449 undef $SIG_TW
1450 unless --$SIG_COUNT;
1451}
1452
1453our $_sig_name_init; $_sig_name_init = sub {
1454 eval q{ # poor man's autoloading
1455 undef $_sig_name_init;
1456
1457 if (_have_async_interrupt) {
1458 *sig2num = \&Async::Interrupt::sig2num;
1459 *sig2name = \&Async::Interrupt::sig2name;
1460 } else {
1461 require Config;
1462
1463 my %signame2num;
1464 @signame2num{ split ' ', $Config::Config{sig_name} }
1465 = split ' ', $Config::Config{sig_num};
1466
1467 my @signum2name;
1468 @signum2name[values %signame2num] = keys %signame2num;
1469
1470 *sig2num = sub($) {
1471 $_[0] > 0 ? shift : $signame2num{+shift}
1472 };
1473 *sig2name = sub ($) {
1474 $_[0] > 0 ? $signum2name[+shift] : shift
1475 };
1145 } 1476 }
1146 } 1477 };
1147} 1478 die if $@;
1479};
1480
1481sub sig2num ($) { &$_sig_name_init; &sig2num }
1482sub sig2name($) { &$_sig_name_init; &sig2name }
1148 1483
1149sub signal { 1484sub signal {
1150 my (undef, %arg) = @_; 1485 eval q{ # poor man's autoloading {}
1486 # probe for availability of Async::Interrupt
1487 if (_have_async_interrupt) {
1488 warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1151 1489
1152 unless ($SIGPIPE_R) { 1490 $SIGPIPE_R = new Async::Interrupt::EventPipe;
1153 require Fcntl; 1491 $SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1154 1492
1155 if (AnyEvent::WIN32) {
1156 require AnyEvent::Util;
1157
1158 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1159 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1160 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1161 } else { 1493 } else {
1494 warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1495
1496 if (AnyEvent::WIN32) {
1497 require AnyEvent::Util;
1498
1499 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1500 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1501 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1502 } else {
1162 pipe $SIGPIPE_R, $SIGPIPE_W; 1503 pipe $SIGPIPE_R, $SIGPIPE_W;
1163 fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R; 1504 fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
1164 fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case 1505 fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
1165 1506
1166 # not strictly required, as $^F is normally 2, but let's make sure... 1507 # not strictly required, as $^F is normally 2, but let's make sure...
1167 fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; 1508 fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1168 fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; 1509 fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1510 }
1511
1512 $SIGPIPE_R
1513 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1514
1515 $SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1169 } 1516 }
1170 1517
1171 $SIGPIPE_R 1518 *signal = sub {
1172 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; 1519 my (undef, %arg) = @_;
1173 1520
1174 $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1175 }
1176
1177 my $signal = uc $arg{signal} 1521 my $signal = uc $arg{signal}
1178 or Carp::croak "required option 'signal' is missing"; 1522 or Carp::croak "required option 'signal' is missing";
1179 1523
1524 if ($HAVE_ASYNC_INTERRUPT) {
1525 # async::interrupt
1526
1527 $signal = sig2num $signal;
1180 $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; 1528 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1529
1530 $SIG_ASY{$signal} ||= new Async::Interrupt
1531 cb => sub { undef $SIG_EV{$signal} },
1532 signal => $signal,
1533 pipe => [$SIGPIPE_R->filenos],
1534 pipe_autodrain => 0,
1535 ;
1536
1537 } else {
1538 # pure perl
1539
1540 # AE::Util has been loaded in signal
1541 $signal = sig2name $signal;
1542 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1543
1181 $SIG{$signal} ||= sub { 1544 $SIG{$signal} ||= sub {
1182 local $!; 1545 local $!;
1183 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; 1546 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1184 undef $SIG_EV{$signal}; 1547 undef $SIG_EV{$signal};
1548 };
1549
1550 # can't do signal processing without introducing races in pure perl,
1551 # so limit the signal latency.
1552 _sig_add;
1553 }
1554
1555 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1556 };
1557
1558 *AnyEvent::Base::signal::DESTROY = sub {
1559 my ($signal, $cb) = @{$_[0]};
1560
1561 _sig_del;
1562
1563 delete $SIG_CB{$signal}{$cb};
1564
1565 $HAVE_ASYNC_INTERRUPT
1566 ? delete $SIG_ASY{$signal}
1567 : # delete doesn't work with older perls - they then
1568 # print weird messages, or just unconditionally exit
1569 # instead of getting the default action.
1570 undef $SIG{$signal}
1571 unless keys %{ $SIG_CB{$signal} };
1572 };
1573
1574 *_signal_exec = sub {
1575 $HAVE_ASYNC_INTERRUPT
1576 ? $SIGPIPE_R->drain
1577 : sysread $SIGPIPE_R, (my $dummy), 9;
1578
1579 while (%SIG_EV) {
1580 for (keys %SIG_EV) {
1581 delete $SIG_EV{$_};
1582 $_->() for values %{ $SIG_CB{$_} || {} };
1583 }
1584 }
1585 };
1185 }; 1586 };
1587 die if $@;
1186 1588
1187 bless [$signal, $arg{cb}], "AnyEvent::Base::signal" 1589 &signal
1188}
1189
1190sub AnyEvent::Base::signal::DESTROY {
1191 my ($signal, $cb) = @{$_[0]};
1192
1193 delete $SIG_CB{$signal}{$cb};
1194
1195 # delete doesn't work with older perls - they then
1196 # print weird messages, or just unconditionally exit
1197 # instead of getting the default action.
1198 undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1199} 1590}
1200 1591
1201# default implementation for ->child 1592# default implementation for ->child
1202 1593
1203our %PID_CB; 1594our %PID_CB;
1204our $CHLD_W; 1595our $CHLD_W;
1205our $CHLD_DELAY_W; 1596our $CHLD_DELAY_W;
1206our $WNOHANG; 1597our $WNOHANG;
1207 1598
1208sub _sigchld { 1599# used by many Impl's
1209 while (0 < (my $pid = waitpid -1, $WNOHANG)) { 1600sub _emit_childstatus($$) {
1601 my (undef, $rpid, $rstatus) = @_;
1602
1603 $_->($rpid, $rstatus)
1210 $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), 1604 for values %{ $PID_CB{$rpid} || {} },
1211 (values %{ $PID_CB{0} || {} }); 1605 values %{ $PID_CB{0} || {} };
1212 }
1213} 1606}
1214 1607
1215sub child { 1608sub child {
1609 eval q{ # poor man's autoloading {}
1610 *_sigchld = sub {
1611 my $pid;
1612
1613 AnyEvent->_emit_childstatus ($pid, $?)
1614 while ($pid = waitpid -1, $WNOHANG) > 0;
1615 };
1616
1617 *child = sub {
1216 my (undef, %arg) = @_; 1618 my (undef, %arg) = @_;
1217 1619
1218 defined (my $pid = $arg{pid} + 0) 1620 defined (my $pid = $arg{pid} + 0)
1219 or Carp::croak "required option 'pid' is missing"; 1621 or Carp::croak "required option 'pid' is missing";
1220 1622
1221 $PID_CB{$pid}{$arg{cb}} = $arg{cb}; 1623 $PID_CB{$pid}{$arg{cb}} = $arg{cb};
1222 1624
1625 # WNOHANG is almost cetrainly 1 everywhere
1626 $WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1627 ? 1
1223 $WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; 1628 : eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1224 1629
1225 unless ($CHLD_W) { 1630 unless ($CHLD_W) {
1226 $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); 1631 $CHLD_W = AE::signal CHLD => \&_sigchld;
1227 # child could be a zombie already, so make at least one round 1632 # child could be a zombie already, so make at least one round
1228 &_sigchld; 1633 &_sigchld;
1229 } 1634 }
1230 1635
1231 bless [$pid, $arg{cb}], "AnyEvent::Base::child" 1636 bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1232} 1637 };
1233 1638
1234sub AnyEvent::Base::child::DESTROY { 1639 *AnyEvent::Base::child::DESTROY = sub {
1235 my ($pid, $cb) = @{$_[0]}; 1640 my ($pid, $cb) = @{$_[0]};
1236 1641
1237 delete $PID_CB{$pid}{$cb}; 1642 delete $PID_CB{$pid}{$cb};
1238 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; 1643 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1239 1644
1240 undef $CHLD_W unless keys %PID_CB; 1645 undef $CHLD_W unless keys %PID_CB;
1646 };
1647 };
1648 die if $@;
1649
1650 &child
1241} 1651}
1242 1652
1243# idle emulation is done by simply using a timer, regardless 1653# idle emulation is done by simply using a timer, regardless
1244# of whether the process is idle or not, and not letting 1654# of whether the process is idle or not, and not letting
1245# the callback use more than 50% of the time. 1655# the callback use more than 50% of the time.
1246sub idle { 1656sub idle {
1657 eval q{ # poor man's autoloading {}
1658 *idle = sub {
1247 my (undef, %arg) = @_; 1659 my (undef, %arg) = @_;
1248 1660
1249 my ($cb, $w, $rcb) = $arg{cb}; 1661 my ($cb, $w, $rcb) = $arg{cb};
1250 1662
1251 $rcb = sub { 1663 $rcb = sub {
1252 if ($cb) { 1664 if ($cb) {
1253 $w = _time; 1665 $w = _time;
1254 &$cb; 1666 &$cb;
1255 $w = _time - $w; 1667 $w = _time - $w;
1256 1668
1257 # never use more then 50% of the time for the idle watcher, 1669 # never use more then 50% of the time for the idle watcher,
1258 # within some limits 1670 # within some limits
1259 $w = 0.0001 if $w < 0.0001; 1671 $w = 0.0001 if $w < 0.0001;
1260 $w = 5 if $w > 5; 1672 $w = 5 if $w > 5;
1261 1673
1262 $w = AnyEvent->timer (after => $w, cb => $rcb); 1674 $w = AE::timer $w, 0, $rcb;
1263 } else { 1675 } else {
1264 # clean up... 1676 # clean up...
1265 undef $w; 1677 undef $w;
1266 undef $rcb; 1678 undef $rcb;
1679 }
1680 };
1681
1682 $w = AE::timer 0.05, 0, $rcb;
1683
1684 bless \\$cb, "AnyEvent::Base::idle"
1267 } 1685 };
1686
1687 *AnyEvent::Base::idle::DESTROY = sub {
1688 undef $${$_[0]};
1689 };
1268 }; 1690 };
1691 die if $@;
1269 1692
1270 $w = AnyEvent->timer (after => 0.05, cb => $rcb); 1693 &idle
1271
1272 bless \\$cb, "AnyEvent::Base::idle"
1273}
1274
1275sub AnyEvent::Base::idle::DESTROY {
1276 undef $${$_[0]};
1277} 1694}
1278 1695
1279package AnyEvent::CondVar; 1696package AnyEvent::CondVar;
1280 1697
1281our @ISA = AnyEvent::CondVar::Base::; 1698our @ISA = AnyEvent::CondVar::Base::;
1282 1699
1283package AnyEvent::CondVar::Base; 1700package AnyEvent::CondVar::Base;
1284 1701
1285use overload 1702#use overload
1286 '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, 1703# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1287 fallback => 1; 1704# fallback => 1;
1705
1706# save 300+ kilobytes by dirtily hardcoding overloading
1707${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching.
1708*{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod."
1709*{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{}
1710${'AnyEvent::CondVar::Base::()'} = 1; # fallback
1711
1712our $WAITING;
1288 1713
1289sub _send { 1714sub _send {
1290 # nop 1715 # nop
1291} 1716}
1292 1717
1305sub ready { 1730sub ready {
1306 $_[0]{_ae_sent} 1731 $_[0]{_ae_sent}
1307} 1732}
1308 1733
1309sub _wait { 1734sub _wait {
1735 $WAITING
1736 and !$_[0]{_ae_sent}
1737 and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1738
1739 local $WAITING = 1;
1310 AnyEvent->one_event while !$_[0]{_ae_sent}; 1740 AnyEvent->one_event while !$_[0]{_ae_sent};
1311} 1741}
1312 1742
1313sub recv { 1743sub recv {
1314 $_[0]->_wait; 1744 $_[0]->_wait;
1316 Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak}; 1746 Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1317 wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0] 1747 wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1318} 1748}
1319 1749
1320sub cb { 1750sub cb {
1321 $_[0]{_ae_cb} = $_[1] if @_ > 1; 1751 my $cv = shift;
1752
1753 @_
1754 and $cv->{_ae_cb} = shift
1755 and $cv->{_ae_sent}
1756 and (delete $cv->{_ae_cb})->($cv);
1757
1322 $_[0]{_ae_cb} 1758 $cv->{_ae_cb}
1323} 1759}
1324 1760
1325sub begin { 1761sub begin {
1326 ++$_[0]{_ae_counter}; 1762 ++$_[0]{_ae_counter};
1327 $_[0]{_ae_end_cb} = $_[1] if @_ > 1; 1763 $_[0]{_ae_end_cb} = $_[1] if @_ > 1;
1376C<PERL_ANYEVENT_MODEL>. 1812C<PERL_ANYEVENT_MODEL>.
1377 1813
1378When set to C<2> or higher, cause AnyEvent to report to STDERR which event 1814When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1379model it chooses. 1815model it chooses.
1380 1816
1817When set to C<8> or higher, then AnyEvent will report extra information on
1818which optional modules it loads and how it implements certain features.
1819
1381=item C<PERL_ANYEVENT_STRICT> 1820=item C<PERL_ANYEVENT_STRICT>
1382 1821
1383AnyEvent does not do much argument checking by default, as thorough 1822AnyEvent does not do much argument checking by default, as thorough
1384argument checking is very costly. Setting this variable to a true value 1823argument checking is very costly. Setting this variable to a true value
1385will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly 1824will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1386check the arguments passed to most method calls. If it finds any problems, 1825check the arguments passed to most method calls. If it finds any problems,
1387it will croak. 1826it will croak.
1388 1827
1389In other words, enables "strict" mode. 1828In other words, enables "strict" mode.
1390 1829
1391Unlike C<use strict>, it is definitely recommended to keep it off in 1830Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>
1392production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while 1831>>, it is definitely recommended to keep it off in production. Keeping
1393developing programs can be very useful, however. 1832C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1833can be very useful, however.
1394 1834
1395=item C<PERL_ANYEVENT_MODEL> 1835=item C<PERL_ANYEVENT_MODEL>
1396 1836
1397This can be used to specify the event model to be used by AnyEvent, before 1837This can be used to specify the event model to be used by AnyEvent, before
1398auto detection and -probing kicks in. It must be a string consisting 1838auto detection and -probing kicks in. It must be a string consisting
1441 1881
1442=item C<PERL_ANYEVENT_MAX_FORKS> 1882=item C<PERL_ANYEVENT_MAX_FORKS>
1443 1883
1444The maximum number of child processes that C<AnyEvent::Util::fork_call> 1884The maximum number of child processes that C<AnyEvent::Util::fork_call>
1445will create in parallel. 1885will create in parallel.
1886
1887=item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS>
1888
1889The default value for the C<max_outstanding> parameter for the default DNS
1890resolver - this is the maximum number of parallel DNS requests that are
1891sent to the DNS server.
1892
1893=item C<PERL_ANYEVENT_RESOLV_CONF>
1894
1895The file to use instead of F</etc/resolv.conf> (or OS-specific
1896configuration) in the default resolver. When set to the empty string, no
1897default config will be used.
1898
1899=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1900
1901When neither C<ca_file> nor C<ca_path> was specified during
1902L<AnyEvent::TLS> context creation, and either of these environment
1903variables exist, they will be used to specify CA certificate locations
1904instead of a system-dependent default.
1905
1906=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1907
1908When these are set to C<1>, then the respective modules are not
1909loaded. Mostly good for testing AnyEvent itself.
1446 1910
1447=back 1911=back
1448 1912
1449=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE 1913=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1450 1914
1508 warn "read: $input\n"; # output what has been read 1972 warn "read: $input\n"; # output what has been read
1509 $cv->send if $input =~ /^q/i; # quit program if /^q/i 1973 $cv->send if $input =~ /^q/i; # quit program if /^q/i
1510 }, 1974 },
1511 ); 1975 );
1512 1976
1513 my $time_watcher; # can only be used once
1514
1515 sub new_timer {
1516 $timer = AnyEvent->timer (after => 1, cb => sub { 1977 my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1517 warn "timeout\n"; # print 'timeout' about every second 1978 warn "timeout\n"; # print 'timeout' at most every second
1518 &new_timer; # and restart the time
1519 }); 1979 });
1520 }
1521
1522 new_timer; # create first timer
1523 1980
1524 $cv->recv; # wait until user enters /^q/i 1981 $cv->recv; # wait until user enters /^q/i
1525 1982
1526=head1 REAL-WORLD EXAMPLE 1983=head1 REAL-WORLD EXAMPLE
1527 1984
1658through AnyEvent. The benchmark creates a lot of timers (with a zero 2115through AnyEvent. The benchmark creates a lot of timers (with a zero
1659timeout) and I/O watchers (watching STDOUT, a pty, to become writable, 2116timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1660which it is), lets them fire exactly once and destroys them again. 2117which it is), lets them fire exactly once and destroys them again.
1661 2118
1662Source code for this benchmark is found as F<eg/bench> in the AnyEvent 2119Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1663distribution. 2120distribution. It uses the L<AE> interface, which makes a real difference
2121for the EV and Perl backends only.
1664 2122
1665=head3 Explanation of the columns 2123=head3 Explanation of the columns
1666 2124
1667I<watcher> is the number of event watchers created/destroyed. Since 2125I<watcher> is the number of event watchers created/destroyed. Since
1668different event models feature vastly different performances, each event 2126different event models feature vastly different performances, each event
1689watcher. 2147watcher.
1690 2148
1691=head3 Results 2149=head3 Results
1692 2150
1693 name watchers bytes create invoke destroy comment 2151 name watchers bytes create invoke destroy comment
1694 EV/EV 400000 224 0.47 0.35 0.27 EV native interface 2152 EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1695 EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers 2153 EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1696 CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal 2154 Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1697 Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation 2155 Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1698 Event/Event 16000 517 32.20 31.80 0.81 Event native interface 2156 Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1699 Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers 2157 Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
2158 IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
2159 IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1700 Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour 2160 Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1701 Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers 2161 Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1702 POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event 2162 POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1703 POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select 2163 POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1704 2164
1705=head3 Discussion 2165=head3 Discussion
1706 2166
1707The benchmark does I<not> measure scalability of the event loop very 2167The benchmark does I<not> measure scalability of the event loop very
1708well. For example, a select-based event loop (such as the pure perl one) 2168well. For example, a select-based event loop (such as the pure perl one)
1720benchmark machine, handling an event takes roughly 1600 CPU cycles with 2180benchmark machine, handling an event takes roughly 1600 CPU cycles with
1721EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU 2181EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1722cycles with POE. 2182cycles with POE.
1723 2183
1724C<EV> is the sole leader regarding speed and memory use, which are both 2184C<EV> is the sole leader regarding speed and memory use, which are both
1725maximal/minimal, respectively. Even when going through AnyEvent, it uses 2185maximal/minimal, respectively. When using the L<AE> API there is zero
2186overhead (when going through the AnyEvent API create is about 5-6 times
2187slower, with other times being equal, so still uses far less memory than
1726far less memory than any other event loop and is still faster than Event 2188any other event loop and is still faster than Event natively).
1727natively.
1728 2189
1729The pure perl implementation is hit in a few sweet spots (both the 2190The pure perl implementation is hit in a few sweet spots (both the
1730constant timeout and the use of a single fd hit optimisations in the perl 2191constant timeout and the use of a single fd hit optimisations in the perl
1731interpreter and the backend itself). Nevertheless this shows that it 2192interpreter and the backend itself). Nevertheless this shows that it
1732adds very little overhead in itself. Like any select-based backend its 2193adds very little overhead in itself. Like any select-based backend its
1733performance becomes really bad with lots of file descriptors (and few of 2194performance becomes really bad with lots of file descriptors (and few of
1734them active), of course, but this was not subject of this benchmark. 2195them active), of course, but this was not subject of this benchmark.
1735 2196
1736The C<Event> module has a relatively high setup and callback invocation 2197The C<Event> module has a relatively high setup and callback invocation
1737cost, but overall scores in on the third place. 2198cost, but overall scores in on the third place.
2199
2200C<IO::Async> performs admirably well, about on par with C<Event>, even
2201when using its pure perl backend.
1738 2202
1739C<Glib>'s memory usage is quite a bit higher, but it features a 2203C<Glib>'s memory usage is quite a bit higher, but it features a
1740faster callback invocation and overall ends up in the same class as 2204faster callback invocation and overall ends up in the same class as
1741C<Event>. However, Glib scales extremely badly, doubling the number of 2205C<Event>. However, Glib scales extremely badly, doubling the number of
1742watchers increases the processing time by more than a factor of four, 2206watchers increases the processing time by more than a factor of four,
1803In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100 2267In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
1804(1%) are active. This mirrors the activity of large servers with many 2268(1%) are active. This mirrors the activity of large servers with many
1805connections, most of which are idle at any one point in time. 2269connections, most of which are idle at any one point in time.
1806 2270
1807Source code for this benchmark is found as F<eg/bench2> in the AnyEvent 2271Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
1808distribution. 2272distribution. It uses the L<AE> interface, which makes a real difference
2273for the EV and Perl backends only.
1809 2274
1810=head3 Explanation of the columns 2275=head3 Explanation of the columns
1811 2276
1812I<sockets> is the number of sockets, and twice the number of "servers" (as 2277I<sockets> is the number of sockets, and twice the number of "servers" (as
1813each server has a read and write socket end). 2278each server has a read and write socket end).
1820it to another server. This includes deleting the old timeout and creating 2285it to another server. This includes deleting the old timeout and creating
1821a new one that moves the timeout into the future. 2286a new one that moves the timeout into the future.
1822 2287
1823=head3 Results 2288=head3 Results
1824 2289
1825 name sockets create request 2290 name sockets create request
1826 EV 20000 69.01 11.16 2291 EV 20000 62.66 7.99
1827 Perl 20000 73.32 35.87 2292 Perl 20000 68.32 32.64
1828 Event 20000 212.62 257.32 2293 IOAsync 20000 174.06 101.15 epoll
1829 Glib 20000 651.16 1896.30 2294 IOAsync 20000 174.67 610.84 poll
2295 Event 20000 202.69 242.91
2296 Glib 20000 557.01 1689.52
1830 POE 20000 349.67 12317.24 uses POE::Loop::Event 2297 POE 20000 341.54 12086.32 uses POE::Loop::Event
1831 2298
1832=head3 Discussion 2299=head3 Discussion
1833 2300
1834This benchmark I<does> measure scalability and overall performance of the 2301This benchmark I<does> measure scalability and overall performance of the
1835particular event loop. 2302particular event loop.
1837EV is again fastest. Since it is using epoll on my system, the setup time 2304EV is again fastest. Since it is using epoll on my system, the setup time
1838is relatively high, though. 2305is relatively high, though.
1839 2306
1840Perl surprisingly comes second. It is much faster than the C-based event 2307Perl surprisingly comes second. It is much faster than the C-based event
1841loops Event and Glib. 2308loops Event and Glib.
2309
2310IO::Async performs very well when using its epoll backend, and still quite
2311good compared to Glib when using its pure perl backend.
1842 2312
1843Event suffers from high setup time as well (look at its code and you will 2313Event suffers from high setup time as well (look at its code and you will
1844understand why). Callback invocation also has a high overhead compared to 2314understand why). Callback invocation also has a high overhead compared to
1845the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event 2315the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event
1846uses select or poll in basically all documented configurations. 2316uses select or poll in basically all documented configurations.
1958As you can see, the AnyEvent + EV combination even beats the 2428As you can see, the AnyEvent + EV combination even beats the
1959hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl 2429hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
1960backend easily beats IO::Lambda and POE. 2430backend easily beats IO::Lambda and POE.
1961 2431
1962And even the 100% non-blocking version written using the high-level (and 2432And even the 100% non-blocking version written using the high-level (and
1963slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a 2433slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
1964large margin, even though it does all of DNS, tcp-connect and socket I/O 2434higher level ("unoptimised") abstractions by a large margin, even though
1965in a non-blocking way. 2435it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
1966 2436
1967The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and 2437The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
1968F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are 2438F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
1969part of the IO::lambda distribution and were used without any changes. 2439part of the IO::Lambda distribution and were used without any changes.
1970 2440
1971 2441
1972=head1 SIGNALS 2442=head1 SIGNALS
1973 2443
1974AnyEvent currently installs handlers for these signals: 2444AnyEvent currently installs handlers for these signals:
1979 2449
1980A handler for C<SIGCHLD> is installed by AnyEvent's child watcher 2450A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
1981emulation for event loops that do not support them natively. Also, some 2451emulation for event loops that do not support them natively. Also, some
1982event loops install a similar handler. 2452event loops install a similar handler.
1983 2453
1984If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will 2454Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
1985reset it to default, to avoid losing child exit statuses. 2455AnyEvent will reset it to default, to avoid losing child exit statuses.
1986 2456
1987=item SIGPIPE 2457=item SIGPIPE
1988 2458
1989A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> 2459A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
1990when AnyEvent gets loaded. 2460when AnyEvent gets loaded.
2008 if $SIG{CHLD} eq 'IGNORE'; 2478 if $SIG{CHLD} eq 'IGNORE';
2009 2479
2010$SIG{PIPE} = sub { } 2480$SIG{PIPE} = sub { }
2011 unless defined $SIG{PIPE}; 2481 unless defined $SIG{PIPE};
2012 2482
2483=head1 RECOMMENDED/OPTIONAL MODULES
2484
2485One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2486it's built-in modules) are required to use it.
2487
2488That does not mean that AnyEvent won't take advantage of some additional
2489modules if they are installed.
2490
2491This section explains which additional modules will be used, and how they
2492affect AnyEvent's operation.
2493
2494=over 4
2495
2496=item L<Async::Interrupt>
2497
2498This slightly arcane module is used to implement fast signal handling: To
2499my knowledge, there is no way to do completely race-free and quick
2500signal handling in pure perl. To ensure that signals still get
2501delivered, AnyEvent will start an interval timer to wake up perl (and
2502catch the signals) with some delay (default is 10 seconds, look for
2503C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2504
2505If this module is available, then it will be used to implement signal
2506catching, which means that signals will not be delayed, and the event loop
2507will not be interrupted regularly, which is more efficient (and good for
2508battery life on laptops).
2509
2510This affects not just the pure-perl event loop, but also other event loops
2511that have no signal handling on their own (e.g. Glib, Tk, Qt).
2512
2513Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
2514and either employ their own workarounds (POE) or use AnyEvent's workaround
2515(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
2516does nothing for those backends.
2517
2518=item L<EV>
2519
2520This module isn't really "optional", as it is simply one of the backend
2521event loops that AnyEvent can use. However, it is simply the best event
2522loop available in terms of features, speed and stability: It supports
2523the AnyEvent API optimally, implements all the watcher types in XS, does
2524automatic timer adjustments even when no monotonic clock is available,
2525can take avdantage of advanced kernel interfaces such as C<epoll> and
2526C<kqueue>, and is the fastest backend I<by far>. You can even embed
2527L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2528
2529=item L<Guard>
2530
2531The guard module, when used, will be used to implement
2532C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2533lot less memory), but otherwise doesn't affect guard operation much. It is
2534purely used for performance.
2535
2536=item L<JSON> and L<JSON::XS>
2537
2538One of these modules is required when you want to read or write JSON data
2539via L<AnyEvent::Handle>. It is also written in pure-perl, but can take
2540advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2541
2542In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2543installed.
2544
2545=item L<Net::SSLeay>
2546
2547Implementing TLS/SSL in Perl is certainly interesting, but not very
2548worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2549the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2550
2551=item L<Time::HiRes>
2552
2553This module is part of perl since release 5.008. It will be used when the
2554chosen event library does not come with a timing source on it's own. The
2555pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
2556try to use a monotonic clock for timing stability.
2557
2558=back
2559
2560
2013=head1 FORK 2561=head1 FORK
2014 2562
2015Most event libraries are not fork-safe. The ones who are usually are 2563Most event libraries are not fork-safe. The ones who are usually are
2016because they rely on inefficient but fork-safe C<select> or C<poll> 2564because they rely on inefficient but fork-safe C<select> or C<poll> calls
2017calls. Only L<EV> is fully fork-aware. 2565- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
2566are usually badly thought-out hacks that are incompatible with fork in
2567one way or another. Only L<EV> is fully fork-aware and ensures that you
2568continue event-processing in both parent and child (or both, if you know
2569what you are doing).
2570
2571This means that, in general, you cannot fork and do event processing in
2572the child if the event library was initialised before the fork (which
2573usually happens when the first AnyEvent watcher is created, or the library
2574is loaded).
2018 2575
2019If you have to fork, you must either do so I<before> creating your first 2576If you have to fork, you must either do so I<before> creating your first
2020watcher OR you must not use AnyEvent at all in the child. 2577watcher OR you must not use AnyEvent at all in the child OR you must do
2578something completely out of the scope of AnyEvent.
2579
2580The problem of doing event processing in the parent I<and> the child
2581is much more complicated: even for backends that I<are> fork-aware or
2582fork-safe, their behaviour is not usually what you want: fork clones all
2583watchers, that means all timers, I/O watchers etc. are active in both
2584parent and child, which is almost never what you want. USing C<exec>
2585to start worker children from some kind of manage rprocess is usually
2586preferred, because it is much easier and cleaner, at the expense of having
2587to have another binary.
2021 2588
2022 2589
2023=head1 SECURITY CONSIDERATIONS 2590=head1 SECURITY CONSIDERATIONS
2024 2591
2025AnyEvent can be forced to load any event model via 2592AnyEvent can be forced to load any event model via
2063L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. 2630L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2064 2631
2065Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, 2632Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2066L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, 2633L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2067L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, 2634L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2068L<AnyEvent::Impl::POE>. 2635L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
2069 2636
2070Non-blocking file handles, sockets, TCP clients and 2637Non-blocking file handles, sockets, TCP clients and
2071servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>. 2638servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2072 2639
2073Asynchronous DNS: L<AnyEvent::DNS>. 2640Asynchronous DNS: L<AnyEvent::DNS>.
2074 2641
2075Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>, 2642Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,
2643L<Coro::Event>,
2076 2644
2077Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. 2645Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,
2646L<AnyEvent::HTTP>.
2078 2647
2079 2648
2080=head1 AUTHOR 2649=head1 AUTHOR
2081 2650
2082 Marc Lehmann <schmorp@schmorp.de> 2651 Marc Lehmann <schmorp@schmorp.de>

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