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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, POE - various supported event loops 5EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt
6and POE are various supported event loops/environments.
6 7
7=head1 SYNOPSIS 8=head1 SYNOPSIS
8 9
9 use AnyEvent; 10 use AnyEvent;
10 11
12 # file descriptor readable
11 my $w = AnyEvent->io (fh => $fh, poll => "r|w", cb => sub { ... }); 13 my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
12 14
15 # one-shot or repeating timers
13 my $w = AnyEvent->timer (after => $seconds, cb => sub { ... }); 16 my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
14 my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ... 17 my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...
15 18
16 print AnyEvent->now; # prints current event loop time 19 print AnyEvent->now; # prints current event loop time
17 print AnyEvent->time; # think Time::HiRes::time or simply CORE::time. 20 print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
18 21
22 # POSIX signal
19 my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... }); 23 my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... });
20 24
25 # child process exit
21 my $w = AnyEvent->child (pid => $pid, cb => sub { 26 my $w = AnyEvent->child (pid => $pid, cb => sub {
22 my ($pid, $status) = @_; 27 my ($pid, $status) = @_;
23 ... 28 ...
24 }); 29 });
30
31 # called when event loop idle (if applicable)
32 my $w = AnyEvent->idle (cb => sub { ... });
25 33
26 my $w = AnyEvent->condvar; # stores whether a condition was flagged 34 my $w = AnyEvent->condvar; # stores whether a condition was flagged
27 $w->send; # wake up current and all future recv's 35 $w->send; # wake up current and all future recv's
28 $w->recv; # enters "main loop" till $condvar gets ->send 36 $w->recv; # enters "main loop" till $condvar gets ->send
29 # use a condvar in callback mode: 37 # use a condvar in callback mode:
32=head1 INTRODUCTION/TUTORIAL 40=head1 INTRODUCTION/TUTORIAL
33 41
34This manpage is mainly a reference manual. If you are interested 42This manpage is mainly a reference manual. If you are interested
35in a tutorial or some gentle introduction, have a look at the 43in a tutorial or some gentle introduction, have a look at the
36L<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.
37 53
38=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT) 54=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
39 55
40Glib, POE, IO::Async, Event... CPAN offers event models by the dozen 56Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
41nowadays. So what is different about AnyEvent? 57nowadays. So what is different about AnyEvent?
165my variables are only visible after the statement in which they are 181my variables are only visible after the statement in which they are
166declared. 182declared.
167 183
168=head2 I/O WATCHERS 184=head2 I/O WATCHERS
169 185
186 $w = AnyEvent->io (
187 fh => <filehandle_or_fileno>,
188 poll => <"r" or "w">,
189 cb => <callback>,
190 );
191
170You 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
171with the following mandatory key-value pairs as arguments: 193with the following mandatory key-value pairs as arguments:
172 194
173C<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
174for 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
175handle). Note that only file handles pointing to things for which 197handle). Note that only file handles pointing to things for which
176non-blocking operation makes sense are allowed. This includes sockets, 198non-blocking operation makes sense are allowed. This includes sockets,
177most 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
178or block devices. 200or block devices.
203 undef $w; 225 undef $w;
204 }); 226 });
205 227
206=head2 TIME WATCHERS 228=head2 TIME WATCHERS
207 229
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
208You can create a time watcher by calling the C<< AnyEvent->timer >> 238You can create a time watcher by calling the C<< AnyEvent->timer >>
209method with the following mandatory arguments: 239method with the following mandatory arguments:
210 240
211C<after> specifies after how many seconds (fractional values are 241C<after> specifies after how many seconds (fractional values are
212supported) 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
333might affect timers and time-outs. 363might affect timers and time-outs.
334 364
335When 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
336event loop's idea of "current time". 366event loop's idea of "current time".
337 367
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
338Note 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.
339 376
340=back 377=back
341 378
342=head2 SIGNAL WATCHERS 379=head2 SIGNAL WATCHERS
380
381 $w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
343 382
344You 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
345I<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
346callback to be invoked whenever a signal occurs. 385callback to be invoked whenever a signal occurs.
347 386
353invocation, and callback invocation will be synchronous. Synchronous means 392invocation, and callback invocation will be synchronous. Synchronous means
354that 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,
355but it is guaranteed not to interrupt any other callbacks. 394but it is guaranteed not to interrupt any other callbacks.
356 395
357The 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
358between multiple watchers. 397between multiple watchers, and AnyEvent will ensure that signals will not
398interrupt your program at bad times.
359 399
360This watcher might use C<%SIG>, so programs overwriting those signals 400This watcher might use C<%SIG> (depending on the event loop used),
361directly will likely not work correctly. 401so programs overwriting those signals directly will likely not work
402correctly.
362 403
363Example: exit on SIGINT 404Example: exit on SIGINT
364 405
365 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); 406 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
366 407
408=head3 Signal Races, Delays and Workarounds
409
410Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
411callbacks to signals in a generic way, which is a pity, as you cannot
412do race-free signal handling in perl, requiring C libraries for
413this. AnyEvent will try to do it's best, which means in some cases,
414signals will be delayed. The maximum time a signal might be delayed is
415specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
416variable can be changed only before the first signal watcher is created,
417and should be left alone otherwise. This variable determines how often
418AnyEvent polls for signals (in case a wake-up was missed). Higher values
419will cause fewer spurious wake-ups, which is better for power and CPU
420saving.
421
422All these problems can be avoided by installing the optional
423L<Async::Interrupt> module, which works with most event loops. It will not
424work with inherently broken event loops such as L<Event> or L<Event::Lib>
425(and not with L<POE> currently, as POE does it's own workaround with
426one-second latency). For those, you just have to suffer the delays.
427
367=head2 CHILD PROCESS WATCHERS 428=head2 CHILD PROCESS WATCHERS
368 429
430 $w = AnyEvent->child (pid => <process id>, cb => <callback>);
431
369You can also watch on a child process exit and catch its exit status. 432You can also watch on a child process exit and catch its exit status.
370 433
371The child process is specified by the C<pid> argument (if set to C<0>, it 434The child process is specified by the C<pid> argument (one some backends,
372watches for any child process exit). The watcher will triggered only when 435using C<0> watches for any child process exit, on others this will
373the child process has finished and an exit status is available, not on 436croak). The watcher will be triggered only when the child process has
374any trace events (stopped/continued). 437finished and an exit status is available, not on any trace events
438(stopped/continued).
375 439
376The callback will be called with the pid and exit status (as returned by 440The callback will be called with the pid and exit status (as returned by
377waitpid), so unlike other watcher types, you I<can> rely on child watcher 441waitpid), so unlike other watcher types, you I<can> rely on child watcher
378callback arguments. 442callback arguments.
379 443
384 448
385There is a slight catch to child watchers, however: you usually start them 449There is a slight catch to child watchers, however: you usually start them
386I<after> the child process was created, and this means the process could 450I<after> the child process was created, and this means the process could
387have exited already (and no SIGCHLD will be sent anymore). 451have exited already (and no SIGCHLD will be sent anymore).
388 452
389Not all event models handle this correctly (POE doesn't), but even for 453Not all event models handle this correctly (neither POE nor IO::Async do,
454see their AnyEvent::Impl manpages for details), but even for event models
390event models that I<do> handle this correctly, they usually need to be 455that I<do> handle this correctly, they usually need to be loaded before
391loaded before the process exits (i.e. before you fork in the first place). 456the process exits (i.e. before you fork in the first place). AnyEvent's
457pure perl event loop handles all cases correctly regardless of when you
458start the watcher.
392 459
393This means you cannot create a child watcher as the very first thing in an 460This means you cannot create a child watcher as the very first
394AnyEvent program, you I<have> to create at least one watcher before you 461thing in an AnyEvent program, you I<have> to create at least one
395C<fork> the child (alternatively, you can call C<AnyEvent::detect>). 462watcher before you C<fork> the child (alternatively, you can call
463C<AnyEvent::detect>).
464
465As most event loops do not support waiting for child events, they will be
466emulated by AnyEvent in most cases, in which the latency and race problems
467mentioned in the description of signal watchers apply.
396 468
397Example: fork a process and wait for it 469Example: fork a process and wait for it
398 470
399 my $done = AnyEvent->condvar; 471 my $done = AnyEvent->condvar;
400 472
410 ); 482 );
411 483
412 # do something else, then wait for process exit 484 # do something else, then wait for process exit
413 $done->recv; 485 $done->recv;
414 486
487=head2 IDLE WATCHERS
488
489 $w = AnyEvent->idle (cb => <callback>);
490
491Sometimes there is a need to do something, but it is not so important
492to do it instantly, but only when there is nothing better to do. This
493"nothing better to do" is usually defined to be "no other events need
494attention by the event loop".
495
496Idle watchers ideally get invoked when the event loop has nothing
497better to do, just before it would block the process to wait for new
498events. Instead of blocking, the idle watcher is invoked.
499
500Most event loops unfortunately do not really support idle watchers (only
501EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
502will simply call the callback "from time to time".
503
504Example: read lines from STDIN, but only process them when the
505program is otherwise idle:
506
507 my @lines; # read data
508 my $idle_w;
509 my $io_w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {
510 push @lines, scalar <STDIN>;
511
512 # start an idle watcher, if not already done
513 $idle_w ||= AnyEvent->idle (cb => sub {
514 # handle only one line, when there are lines left
515 if (my $line = shift @lines) {
516 print "handled when idle: $line";
517 } else {
518 # otherwise disable the idle watcher again
519 undef $idle_w;
520 }
521 });
522 });
523
415=head2 CONDITION VARIABLES 524=head2 CONDITION VARIABLES
525
526 $cv = AnyEvent->condvar;
527
528 $cv->send (<list>);
529 my @res = $cv->recv;
416 530
417If you are familiar with some event loops you will know that all of them 531If you are familiar with some event loops you will know that all of them
418require you to run some blocking "loop", "run" or similar function that 532require you to run some blocking "loop", "run" or similar function that
419will actively watch for new events and call your callbacks. 533will actively watch for new events and call your callbacks.
420 534
421AnyEvent is different, it expects somebody else to run the event loop and 535AnyEvent is slightly different: it expects somebody else to run the event
422will only block when necessary (usually when told by the user). 536loop and will only block when necessary (usually when told by the user).
423 537
424The instrument to do that is called a "condition variable", so called 538The instrument to do that is called a "condition variable", so called
425because they represent a condition that must become true. 539because they represent a condition that must become true.
426 540
541Now is probably a good time to look at the examples further below.
542
427Condition variables can be created by calling the C<< AnyEvent->condvar 543Condition variables can be created by calling the C<< AnyEvent->condvar
428>> method, usually without arguments. The only argument pair allowed is 544>> method, usually without arguments. The only argument pair allowed is
429
430C<cb>, which specifies a callback to be called when the condition variable 545C<cb>, which specifies a callback to be called when the condition variable
431becomes true, with the condition variable as the first argument (but not 546becomes true, with the condition variable as the first argument (but not
432the results). 547the results).
433 548
434After creation, the condition variable is "false" until it becomes "true" 549After creation, the condition variable is "false" until it becomes "true"
439Condition variables are similar to callbacks, except that you can 554Condition variables are similar to callbacks, except that you can
440optionally wait for them. They can also be called merge points - points 555optionally wait for them. They can also be called merge points - points
441in time where multiple outstanding events have been processed. And yet 556in time where multiple outstanding events have been processed. And yet
442another way to call them is transactions - each condition variable can be 557another way to call them is transactions - each condition variable can be
443used to represent a transaction, which finishes at some point and delivers 558used to represent a transaction, which finishes at some point and delivers
444a result. 559a result. And yet some people know them as "futures" - a promise to
560compute/deliver something that you can wait for.
445 561
446Condition variables are very useful to signal that something has finished, 562Condition variables are very useful to signal that something has finished,
447for example, if you write a module that does asynchronous http requests, 563for example, if you write a module that does asynchronous http requests,
448then a condition variable would be the ideal candidate to signal the 564then a condition variable would be the ideal candidate to signal the
449availability of results. The user can either act when the callback is 565availability of results. The user can either act when the callback is
483 after => 1, 599 after => 1,
484 cb => sub { $result_ready->send }, 600 cb => sub { $result_ready->send },
485 ); 601 );
486 602
487 # this "blocks" (while handling events) till the callback 603 # this "blocks" (while handling events) till the callback
488 # calls send 604 # calls ->send
489 $result_ready->recv; 605 $result_ready->recv;
490 606
491Example: wait for a timer, but take advantage of the fact that 607Example: wait for a timer, but take advantage of the fact that condition
492condition variables are also code references. 608variables are also callable directly.
493 609
494 my $done = AnyEvent->condvar; 610 my $done = AnyEvent->condvar;
495 my $delay = AnyEvent->timer (after => 5, cb => $done); 611 my $delay = AnyEvent->timer (after => 5, cb => $done);
496 $done->recv; 612 $done->recv;
497 613
503 619
504 ... 620 ...
505 621
506 my @info = $couchdb->info->recv; 622 my @info = $couchdb->info->recv;
507 623
508And this is how you would just ste a callback to be called whenever the 624And this is how you would just set a callback to be called whenever the
509results are available: 625results are available:
510 626
511 $couchdb->info->cb (sub { 627 $couchdb->info->cb (sub {
512 my @info = $_[0]->recv; 628 my @info = $_[0]->recv;
513 }); 629 });
531immediately from within send. 647immediately from within send.
532 648
533Any arguments passed to the C<send> call will be returned by all 649Any arguments passed to the C<send> call will be returned by all
534future C<< ->recv >> calls. 650future C<< ->recv >> calls.
535 651
536Condition variables are overloaded so one can call them directly 652Condition variables are overloaded so one can call them directly (as if
537(as a code reference). Calling them directly is the same as calling 653they were a code reference). Calling them directly is the same as calling
538C<send>. Note, however, that many C-based event loops do not handle 654C<send>.
539overloading, so as tempting as it may be, passing a condition variable
540instead of a callback does not work. Both the pure perl and EV loops
541support overloading, however, as well as all functions that use perl to
542invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
543example).
544 655
545=item $cv->croak ($error) 656=item $cv->croak ($error)
546 657
547Similar to send, but causes all call's to C<< ->recv >> to invoke 658Similar to send, but causes all call's to C<< ->recv >> to invoke
548C<Carp::croak> with the given error message/object/scalar. 659C<Carp::croak> with the given error message/object/scalar.
549 660
550This can be used to signal any errors to the condition variable 661This can be used to signal any errors to the condition variable
551user/consumer. 662user/consumer. Doing it this way instead of calling C<croak> directly
663delays the error detetcion, but has the overwhelmign advantage that it
664diagnoses the error at the place where the result is expected, and not
665deep in some event clalback without connection to the actual code causing
666the problem.
552 667
553=item $cv->begin ([group callback]) 668=item $cv->begin ([group callback])
554 669
555=item $cv->end 670=item $cv->end
556
557These two methods are EXPERIMENTAL and MIGHT CHANGE.
558 671
559These two methods can be used to combine many transactions/events into 672These two methods can be used to combine many transactions/events into
560one. For example, a function that pings many hosts in parallel might want 673one. For example, a function that pings many hosts in parallel might want
561to use a condition variable for the whole process. 674to use a condition variable for the whole process.
562 675
563Every call to C<< ->begin >> will increment a counter, and every call to 676Every call to C<< ->begin >> will increment a counter, and every call to
564C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end 677C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
565>>, the (last) callback passed to C<begin> will be executed. That callback 678>>, the (last) callback passed to C<begin> will be executed, passing the
566is I<supposed> to call C<< ->send >>, but that is not required. If no 679condvar as first argument. That callback is I<supposed> to call C<< ->send
567callback was set, C<send> will be called without any arguments. 680>>, but that is not required. If no group callback was set, C<send> will
681be called without any arguments.
568 682
569Let's clarify this with the ping example: 683You can think of C<< $cv->send >> giving you an OR condition (one call
684sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
685condition (all C<begin> calls must be C<end>'ed before the condvar sends).
686
687Let's start with a simple example: you have two I/O watchers (for example,
688STDOUT and STDERR for a program), and you want to wait for both streams to
689close before activating a condvar:
570 690
571 my $cv = AnyEvent->condvar; 691 my $cv = AnyEvent->condvar;
572 692
693 $cv->begin; # first watcher
694 my $w1 = AnyEvent->io (fh => $fh1, cb => sub {
695 defined sysread $fh1, my $buf, 4096
696 or $cv->end;
697 });
698
699 $cv->begin; # second watcher
700 my $w2 = AnyEvent->io (fh => $fh2, cb => sub {
701 defined sysread $fh2, my $buf, 4096
702 or $cv->end;
703 });
704
705 $cv->recv;
706
707This works because for every event source (EOF on file handle), there is
708one call to C<begin>, so the condvar waits for all calls to C<end> before
709sending.
710
711The ping example mentioned above is slightly more complicated, as the
712there are results to be passwd back, and the number of tasks that are
713begung can potentially be zero:
714
715 my $cv = AnyEvent->condvar;
716
573 my %result; 717 my %result;
574 $cv->begin (sub { $cv->send (\%result) }); 718 $cv->begin (sub { shift->send (\%result) });
575 719
576 for my $host (@list_of_hosts) { 720 for my $host (@list_of_hosts) {
577 $cv->begin; 721 $cv->begin;
578 ping_host_then_call_callback $host, sub { 722 ping_host_then_call_callback $host, sub {
579 $result{$host} = ...; 723 $result{$host} = ...;
594loop, which serves two important purposes: first, it sets the callback 738loop, which serves two important purposes: first, it sets the callback
595to be called once the counter reaches C<0>, and second, it ensures that 739to be called once the counter reaches C<0>, and second, it ensures that
596C<send> is called even when C<no> hosts are being pinged (the loop 740C<send> is called even when C<no> hosts are being pinged (the loop
597doesn't execute once). 741doesn't execute once).
598 742
599This is the general pattern when you "fan out" into multiple subrequests: 743This is the general pattern when you "fan out" into multiple (but
600use an outer C<begin>/C<end> pair to set the callback and ensure C<end> 744potentially none) subrequests: use an outer C<begin>/C<end> pair to set
601is called at least once, and then, for each subrequest you start, call 745the callback and ensure C<end> is called at least once, and then, for each
602C<begin> and for each subrequest you finish, call C<end>. 746subrequest you start, call C<begin> and for each subrequest you finish,
747call C<end>.
603 748
604=back 749=back
605 750
606=head3 METHODS FOR CONSUMERS 751=head3 METHODS FOR CONSUMERS
607 752
623function will call C<croak>. 768function will call C<croak>.
624 769
625In list context, all parameters passed to C<send> will be returned, 770In list context, all parameters passed to C<send> will be returned,
626in scalar context only the first one will be returned. 771in scalar context only the first one will be returned.
627 772
773Note that doing a blocking wait in a callback is not supported by any
774event loop, that is, recursive invocation of a blocking C<< ->recv
775>> is not allowed, and the C<recv> call will C<croak> if such a
776condition is detected. This condition can be slightly loosened by using
777L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from
778any thread that doesn't run the event loop itself.
779
628Not all event models support a blocking wait - some die in that case 780Not all event models support a blocking wait - some die in that case
629(programs might want to do that to stay interactive), so I<if you are 781(programs might want to do that to stay interactive), so I<if you are
630using this from a module, never require a blocking wait>, but let the 782using this from a module, never require a blocking wait>. Instead, let the
631caller decide whether the call will block or not (for example, by coupling 783caller decide whether the call will block or not (for example, by coupling
632condition variables with some kind of request results and supporting 784condition variables with some kind of request results and supporting
633callbacks so the caller knows that getting the result will not block, 785callbacks so the caller knows that getting the result will not block,
634while still supporting blocking waits if the caller so desires). 786while still supporting blocking waits if the caller so desires).
635 787
636Another reason I<never> to C<< ->recv >> in a module is that you cannot
637sensibly have two C<< ->recv >>'s in parallel, as that would require
638multiple interpreters or coroutines/threads, none of which C<AnyEvent>
639can supply.
640
641The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
642fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
643versions and also integrates coroutines into AnyEvent, making blocking
644C<< ->recv >> calls perfectly safe as long as they are done from another
645coroutine (one that doesn't run the event loop).
646
647You can ensure that C<< -recv >> never blocks by setting a callback and 788You can ensure that C<< -recv >> never blocks by setting a callback and
648only calling C<< ->recv >> from within that callback (or at a later 789only calling C<< ->recv >> from within that callback (or at a later
649time). This will work even when the event loop does not support blocking 790time). This will work even when the event loop does not support blocking
650waits otherwise. 791waits otherwise.
651 792
657=item $cb = $cv->cb ($cb->($cv)) 798=item $cb = $cv->cb ($cb->($cv))
658 799
659This is a mutator function that returns the callback set and optionally 800This is a mutator function that returns the callback set and optionally
660replaces it before doing so. 801replaces it before doing so.
661 802
662The callback will be called when the condition becomes "true", i.e. when 803The callback will be called when the condition becomes (or already was)
663C<send> or C<croak> are called, with the only argument being the condition 804"true", i.e. when C<send> or C<croak> are called (or were called), with
664variable itself. Calling C<recv> inside the callback or at any later time 805the only argument being the condition variable itself. Calling C<recv>
665is guaranteed not to block. 806inside the callback or at any later time is guaranteed not to block.
666 807
667=back 808=back
668 809
810=head1 SUPPORTED EVENT LOOPS/BACKENDS
811
812The available backend classes are (every class has its own manpage):
813
814=over 4
815
816=item Backends that are autoprobed when no other event loop can be found.
817
818EV is the preferred backend when no other event loop seems to be in
819use. If EV is not installed, then AnyEvent will fall back to its own
820pure-perl implementation, which is available everywhere as it comes with
821AnyEvent itself.
822
823 AnyEvent::Impl::EV based on EV (interface to libev, best choice).
824 AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
825
826=item Backends that are transparently being picked up when they are used.
827
828These will be used when they are currently loaded when the first watcher
829is created, in which case it is assumed that the application is using
830them. This means that AnyEvent will automatically pick the right backend
831when the main program loads an event module before anything starts to
832create watchers. Nothing special needs to be done by the main program.
833
834 AnyEvent::Impl::Event based on Event, very stable, few glitches.
835 AnyEvent::Impl::Glib based on Glib, slow but very stable.
836 AnyEvent::Impl::Tk based on Tk, very broken.
837 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
838 AnyEvent::Impl::POE based on POE, very slow, some limitations.
839 AnyEvent::Impl::Irssi used when running within irssi.
840
841=item Backends with special needs.
842
843Qt requires the Qt::Application to be instantiated first, but will
844otherwise be picked up automatically. As long as the main program
845instantiates the application before any AnyEvent watchers are created,
846everything should just work.
847
848 AnyEvent::Impl::Qt based on Qt.
849
850Support for IO::Async can only be partial, as it is too broken and
851architecturally limited to even support the AnyEvent API. It also
852is the only event loop that needs the loop to be set explicitly, so
853it can only be used by a main program knowing about AnyEvent. See
854L<AnyEvent::Impl::Async> for the gory details.
855
856 AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
857
858=item Event loops that are indirectly supported via other backends.
859
860Some event loops can be supported via other modules:
861
862There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
863
864B<WxWidgets> has no support for watching file handles. However, you can
865use WxWidgets through the POE adaptor, as POE has a Wx backend that simply
866polls 20 times per second, which was considered to be too horrible to even
867consider for AnyEvent.
868
869B<Prima> is not supported as nobody seems to be using it, but it has a POE
870backend, so it can be supported through POE.
871
872AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to
873load L<POE> when detecting them, in the hope that POE will pick them up,
874in which case everything will be automatic.
875
876=back
877
669=head1 GLOBAL VARIABLES AND FUNCTIONS 878=head1 GLOBAL VARIABLES AND FUNCTIONS
670 879
880These are not normally required to use AnyEvent, but can be useful to
881write AnyEvent extension modules.
882
671=over 4 883=over 4
672 884
673=item $AnyEvent::MODEL 885=item $AnyEvent::MODEL
674 886
675Contains C<undef> until the first watcher is being created. Then it 887Contains C<undef> until the first watcher is being created, before the
888backend has been autodetected.
889
676contains the event model that is being used, which is the name of the 890Afterwards it contains the event model that is being used, which is the
677Perl class implementing the model. This class is usually one of the 891name of the Perl class implementing the model. This class is usually one
678C<AnyEvent::Impl:xxx> modules, but can be any other class in the case 892of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the
679AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>). 893case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
680 894will be C<urxvt::anyevent>).
681The known classes so far are:
682
683 AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
684 AnyEvent::Impl::Event based on Event, second best choice.
685 AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
686 AnyEvent::Impl::Glib based on Glib, third-best choice.
687 AnyEvent::Impl::Tk based on Tk, very bad choice.
688 AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
689 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
690 AnyEvent::Impl::POE based on POE, not generic enough for full support.
691
692There is no support for WxWidgets, as WxWidgets has no support for
693watching file handles. However, you can use WxWidgets through the
694POE Adaptor, as POE has a Wx backend that simply polls 20 times per
695second, which was considered to be too horrible to even consider for
696AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
697it's adaptor.
698
699AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
700autodetecting them.
701 895
702=item AnyEvent::detect 896=item AnyEvent::detect
703 897
704Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model 898Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
705if necessary. You should only call this function right before you would 899if necessary. You should only call this function right before you would
706have created an AnyEvent watcher anyway, that is, as late as possible at 900have created an AnyEvent watcher anyway, that is, as late as possible at
707runtime. 901runtime, and not e.g. while initialising of your module.
902
903If you need to do some initialisation before AnyEvent watchers are
904created, use C<post_detect>.
708 905
709=item $guard = AnyEvent::post_detect { BLOCK } 906=item $guard = AnyEvent::post_detect { BLOCK }
710 907
711Arranges for the code block to be executed as soon as the event model is 908Arranges for the code block to be executed as soon as the event model is
712autodetected (or immediately if this has already happened). 909autodetected (or immediately if this has already happened).
713 910
911The block will be executed I<after> the actual backend has been detected
912(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
913created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
914other initialisations - see the sources of L<AnyEvent::Strict> or
915L<AnyEvent::AIO> to see how this is used.
916
917The most common usage is to create some global watchers, without forcing
918event module detection too early, for example, L<AnyEvent::AIO> creates
919and installs the global L<IO::AIO> watcher in a C<post_detect> block to
920avoid autodetecting the event module at load time.
921
714If called in scalar or list context, then it creates and returns an object 922If called in scalar or list context, then it creates and returns an object
715that automatically removes the callback again when it is destroyed. See 923that automatically removes the callback again when it is destroyed (or
924C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
716L<Coro::BDB> for a case where this is useful. 925a case where this is useful.
926
927Example: Create a watcher for the IO::AIO module and store it in
928C<$WATCHER>. Only do so after the event loop is initialised, though.
929
930 our WATCHER;
931
932 my $guard = AnyEvent::post_detect {
933 $WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
934 };
935
936 # the ||= is important in case post_detect immediately runs the block,
937 # as to not clobber the newly-created watcher. assigning both watcher and
938 # post_detect guard to the same variable has the advantage of users being
939 # able to just C<undef $WATCHER> if the watcher causes them grief.
940
941 $WATCHER ||= $guard;
717 942
718=item @AnyEvent::post_detect 943=item @AnyEvent::post_detect
719 944
720If there are any code references in this array (you can C<push> to it 945If there are any code references in this array (you can C<push> to it
721before or after loading AnyEvent), then they will called directly after 946before or after loading AnyEvent), then they will called directly after
722the event loop has been chosen. 947the event loop has been chosen.
723 948
724You should check C<$AnyEvent::MODEL> before adding to this array, though: 949You should check C<$AnyEvent::MODEL> before adding to this array, though:
725if it contains a true value then the event loop has already been detected, 950if it is defined then the event loop has already been detected, and the
726and the array will be ignored. 951array will be ignored.
727 952
728Best use C<AnyEvent::post_detect { BLOCK }> instead. 953Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
954it,as it takes care of these details.
955
956This variable is mainly useful for modules that can do something useful
957when AnyEvent is used and thus want to know when it is initialised, but do
958not need to even load it by default. This array provides the means to hook
959into AnyEvent passively, without loading it.
729 960
730=back 961=back
731 962
732=head1 WHAT TO DO IN A MODULE 963=head1 WHAT TO DO IN A MODULE
733 964
788 1019
789 1020
790=head1 OTHER MODULES 1021=head1 OTHER MODULES
791 1022
792The following is a non-exhaustive list of additional modules that use 1023The following is a non-exhaustive list of additional modules that use
793AnyEvent and can therefore be mixed easily with other AnyEvent modules 1024AnyEvent as a client and can therefore be mixed easily with other AnyEvent
794in the same program. Some of the modules come with AnyEvent, some are 1025modules and other event loops in the same program. Some of the modules
795available via CPAN. 1026come with AnyEvent, most are available via CPAN.
796 1027
797=over 4 1028=over 4
798 1029
799=item L<AnyEvent::Util> 1030=item L<AnyEvent::Util>
800 1031
809 1040
810=item L<AnyEvent::Handle> 1041=item L<AnyEvent::Handle>
811 1042
812Provide read and write buffers, manages watchers for reads and writes, 1043Provide read and write buffers, manages watchers for reads and writes,
813supports raw and formatted I/O, I/O queued and fully transparent and 1044supports raw and formatted I/O, I/O queued and fully transparent and
814non-blocking SSL/TLS. 1045non-blocking SSL/TLS (via L<AnyEvent::TLS>.
815 1046
816=item L<AnyEvent::DNS> 1047=item L<AnyEvent::DNS>
817 1048
818Provides rich asynchronous DNS resolver capabilities. 1049Provides rich asynchronous DNS resolver capabilities.
819 1050
847 1078
848=item L<AnyEvent::GPSD> 1079=item L<AnyEvent::GPSD>
849 1080
850A non-blocking interface to gpsd, a daemon delivering GPS information. 1081A non-blocking interface to gpsd, a daemon delivering GPS information.
851 1082
1083=item L<AnyEvent::IRC>
1084
1085AnyEvent based IRC client module family (replacing the older Net::IRC3).
1086
1087=item L<AnyEvent::XMPP>
1088
1089AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1090Net::XMPP2>.
1091
852=item L<AnyEvent::IGS> 1092=item L<AnyEvent::IGS>
853 1093
854A non-blocking interface to the Internet Go Server protocol (used by 1094A non-blocking interface to the Internet Go Server protocol (used by
855L<App::IGS>). 1095L<App::IGS>).
856 1096
857=item L<AnyEvent::IRC>
858
859AnyEvent based IRC client module family (replacing the older Net::IRC3).
860
861=item L<Net::XMPP2>
862
863AnyEvent based XMPP (Jabber protocol) module family.
864
865=item L<Net::FCP> 1097=item L<Net::FCP>
866 1098
867AnyEvent-based implementation of the Freenet Client Protocol, birthplace 1099AnyEvent-based implementation of the Freenet Client Protocol, birthplace
868of AnyEvent. 1100of AnyEvent.
869 1101
873 1105
874=item L<Coro> 1106=item L<Coro>
875 1107
876Has special support for AnyEvent via L<Coro::AnyEvent>. 1108Has special support for AnyEvent via L<Coro::AnyEvent>.
877 1109
878=item L<IO::Lambda>
879
880The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
881
882=back 1110=back
883 1111
884=cut 1112=cut
885 1113
886package AnyEvent; 1114package AnyEvent;
887 1115
888no warnings; 1116# basically a tuned-down version of common::sense
1117sub common_sense {
1118 # from common:.sense 1.0
1119 ${^WARNING_BITS} = "\xfc\x3f\xf3\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x03";
889use strict qw(vars subs); 1120 # use strict vars subs
1121 $^H |= 0x00000600;
1122}
890 1123
1124BEGIN { AnyEvent::common_sense }
1125
891use Carp; 1126use Carp ();
892 1127
893our $VERSION = 4.351; 1128our $VERSION = '5.202';
894our $MODEL; 1129our $MODEL;
895 1130
896our $AUTOLOAD; 1131our $AUTOLOAD;
897our @ISA; 1132our @ISA;
898 1133
899our @REGISTRY; 1134our @REGISTRY;
900 1135
901our $WIN32; 1136our $WIN32;
902 1137
1138our $VERBOSE;
1139
903BEGIN { 1140BEGIN {
904 my $win32 = ! ! ($^O =~ /mswin32/i); 1141 eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
905 eval "sub WIN32(){ $win32 }"; 1142 eval "sub TAINT(){ " . (${^TAINT}*1) . " }";
906}
907 1143
1144 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1145 if ${^TAINT};
1146
908our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; 1147 $VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
1148
1149}
1150
1151our $MAX_SIGNAL_LATENCY = 10;
909 1152
910our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred 1153our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
911 1154
912{ 1155{
913 my $idx; 1156 my $idx;
915 for reverse split /\s*,\s*/, 1158 for reverse split /\s*,\s*/,
916 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; 1159 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
917} 1160}
918 1161
919my @models = ( 1162my @models = (
920 [EV:: => AnyEvent::Impl::EV::], 1163 [EV:: => AnyEvent::Impl::EV:: , 1],
921 [Event:: => AnyEvent::Impl::Event::],
922 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], 1164 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
923 # everything below here will not be autoprobed 1165 # everything below here will not (normally) be autoprobed
924 # as the pureperl backend should work everywhere 1166 # as the pureperl backend should work everywhere
925 # and is usually faster 1167 # and is usually faster
1168 [Event:: => AnyEvent::Impl::Event::, 1],
1169 [Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1170 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1171 [Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
926 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles 1172 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
927 [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
928 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
929 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program 1173 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program
930 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza 1174 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
931 [Wx:: => AnyEvent::Impl::POE::], 1175 [Wx:: => AnyEvent::Impl::POE::],
932 [Prima:: => AnyEvent::Impl::POE::], 1176 [Prima:: => AnyEvent::Impl::POE::],
1177 # IO::Async is just too broken - we would need workarounds for its
1178 # byzantine signal and broken child handling, among others.
1179 # IO::Async is rather hard to detect, as it doesn't have any
1180 # obvious default class.
1181 [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1182 [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1183 [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1184 [AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
933); 1185);
934 1186
935our %method = map +($_ => 1), 1187our %method = map +($_ => 1),
936 qw(io timer time now now_update signal child condvar one_event DESTROY); 1188 qw(io timer time now now_update signal child idle condvar one_event DESTROY);
937 1189
938our @post_detect; 1190our @post_detect;
939 1191
940sub post_detect(&) { 1192sub post_detect(&) {
941 my ($cb) = @_; 1193 my ($cb) = @_;
942 1194
943 if ($MODEL) { 1195 if ($MODEL) {
944 $cb->(); 1196 $cb->();
945 1197
946 1 1198 undef
947 } else { 1199 } else {
948 push @post_detect, $cb; 1200 push @post_detect, $cb;
949 1201
950 defined wantarray 1202 defined wantarray
951 ? bless \$cb, "AnyEvent::Util::PostDetect" 1203 ? bless \$cb, "AnyEvent::Util::postdetect"
952 : () 1204 : ()
953 } 1205 }
954} 1206}
955 1207
956sub AnyEvent::Util::PostDetect::DESTROY { 1208sub AnyEvent::Util::postdetect::DESTROY {
957 @post_detect = grep $_ != ${$_[0]}, @post_detect; 1209 @post_detect = grep $_ != ${$_[0]}, @post_detect;
958} 1210}
959 1211
960sub detect() { 1212sub detect() {
961 unless ($MODEL) { 1213 unless ($MODEL) {
962 no strict 'refs';
963 local $SIG{__DIE__}; 1214 local $SIG{__DIE__};
964 1215
965 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) { 1216 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
966 my $model = "AnyEvent::Impl::$1"; 1217 my $model = "AnyEvent::Impl::$1";
967 if (eval "require $model") { 1218 if (eval "require $model") {
968 $MODEL = $model; 1219 $MODEL = $model;
969 warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1; 1220 warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
970 } else { 1221 } else {
971 warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose; 1222 warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
972 } 1223 }
973 } 1224 }
974 1225
975 # check for already loaded models 1226 # check for already loaded models
976 unless ($MODEL) { 1227 unless ($MODEL) {
977 for (@REGISTRY, @models) { 1228 for (@REGISTRY, @models) {
978 my ($package, $model) = @$_; 1229 my ($package, $model) = @$_;
979 if (${"$package\::VERSION"} > 0) { 1230 if (${"$package\::VERSION"} > 0) {
980 if (eval "require $model") { 1231 if (eval "require $model") {
981 $MODEL = $model; 1232 $MODEL = $model;
982 warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1; 1233 warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
983 last; 1234 last;
984 } 1235 }
985 } 1236 }
986 } 1237 }
987 1238
988 unless ($MODEL) { 1239 unless ($MODEL) {
989 # try to load a model 1240 # try to autoload a model
990
991 for (@REGISTRY, @models) { 1241 for (@REGISTRY, @models) {
992 my ($package, $model) = @$_; 1242 my ($package, $model, $autoload) = @$_;
1243 if (
1244 $autoload
993 if (eval "require $package" 1245 and eval "require $package"
994 and ${"$package\::VERSION"} > 0 1246 and ${"$package\::VERSION"} > 0
995 and eval "require $model") { 1247 and eval "require $model"
1248 ) {
996 $MODEL = $model; 1249 $MODEL = $model;
997 warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1; 1250 warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
998 last; 1251 last;
999 } 1252 }
1000 } 1253 }
1001 1254
1002 $MODEL 1255 $MODEL
1018 1271
1019sub AUTOLOAD { 1272sub AUTOLOAD {
1020 (my $func = $AUTOLOAD) =~ s/.*://; 1273 (my $func = $AUTOLOAD) =~ s/.*://;
1021 1274
1022 $method{$func} 1275 $method{$func}
1023 or croak "$func: not a valid method for AnyEvent objects"; 1276 or Carp::croak "$func: not a valid method for AnyEvent objects";
1024 1277
1025 detect unless $MODEL; 1278 detect unless $MODEL;
1026 1279
1027 my $class = shift; 1280 my $class = shift;
1028 $class->$func (@_); 1281 $class->$func (@_);
1029} 1282}
1030 1283
1031# utility function to dup a filehandle. this is used by many backends 1284# utility function to dup a filehandle. this is used by many backends
1032# to support binding more than one watcher per filehandle (they usually 1285# to support binding more than one watcher per filehandle (they usually
1033# allow only one watcher per fd, so we dup it to get a different one). 1286# allow only one watcher per fd, so we dup it to get a different one).
1034sub _dupfh($$$$) { 1287sub _dupfh($$;$$) {
1035 my ($poll, $fh, $r, $w) = @_; 1288 my ($poll, $fh, $r, $w) = @_;
1036 1289
1037 # cygwin requires the fh mode to be matching, unix doesn't 1290 # cygwin requires the fh mode to be matching, unix doesn't
1038 my ($rw, $mode) = $poll eq "r" ? ($r, "<") 1291 my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1039 : $poll eq "w" ? ($w, ">")
1040 : Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
1041 1292
1042 open my $fh2, "$mode&" . fileno $fh 1293 open my $fh2, $mode, $fh
1043 or die "cannot dup() filehandle: $!,"; 1294 or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1044 1295
1045 # we assume CLOEXEC is already set by perl in all important cases 1296 # we assume CLOEXEC is already set by perl in all important cases
1046 1297
1047 ($fh2, $rw) 1298 ($fh2, $rw)
1048} 1299}
1049 1300
1301=head1 SIMPLIFIED AE API
1302
1303Starting with version 5.0, AnyEvent officially supports a second, much
1304simpler, API that is designed to reduce the calling, typing and memory
1305overhead.
1306
1307See the L<AE> manpage for details.
1308
1309=cut
1310
1311package AE;
1312
1313our $VERSION = $AnyEvent::VERSION;
1314
1315sub io($$$) {
1316 AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1317}
1318
1319sub timer($$$) {
1320 AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
1321}
1322
1323sub signal($$) {
1324 AnyEvent->signal (signal => $_[0], cb => $_[1])
1325}
1326
1327sub child($$) {
1328 AnyEvent->child (pid => $_[0], cb => $_[1])
1329}
1330
1331sub idle($) {
1332 AnyEvent->idle (cb => $_[0])
1333}
1334
1335sub cv(;&) {
1336 AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
1337}
1338
1339sub now() {
1340 AnyEvent->now
1341}
1342
1343sub now_update() {
1344 AnyEvent->now_update
1345}
1346
1347sub time() {
1348 AnyEvent->time
1349}
1350
1050package AnyEvent::Base; 1351package AnyEvent::Base;
1051 1352
1052# default implementations for many methods 1353# default implementations for many methods
1053 1354
1054BEGIN { 1355sub _time() {
1356 # probe for availability of Time::HiRes
1055 if (eval "use Time::HiRes (); time (); 1") { 1357 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1358 warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1056 *_time = \&Time::HiRes::time; 1359 *_time = \&Time::HiRes::time;
1057 # if (eval "use POSIX (); (POSIX::times())... 1360 # if (eval "use POSIX (); (POSIX::times())...
1058 } else { 1361 } else {
1362 warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1059 *_time = sub { time }; # epic fail 1363 *_time = sub { time }; # epic fail
1060 } 1364 }
1365
1366 &_time
1061} 1367}
1062 1368
1063sub time { _time } 1369sub time { _time }
1064sub now { _time } 1370sub now { _time }
1065sub now_update { } 1371sub now_update { }
1066 1372
1067# default implementation for ->condvar 1373# default implementation for ->condvar
1068 1374
1069sub condvar { 1375sub condvar {
1070 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar:: 1376 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1071} 1377}
1072 1378
1073# default implementation for ->signal 1379# default implementation for ->signal
1074 1380
1381our $HAVE_ASYNC_INTERRUPT;
1382
1383sub _have_async_interrupt() {
1384 $HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
1385 && eval "use Async::Interrupt 1.02 (); 1")
1386 unless defined $HAVE_ASYNC_INTERRUPT;
1387
1388 $HAVE_ASYNC_INTERRUPT
1389}
1390
1075our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); 1391our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1392our (%SIG_ASY, %SIG_ASY_W);
1393our ($SIG_COUNT, $SIG_TW);
1076 1394
1077sub _signal_exec { 1395sub _signal_exec {
1396 $HAVE_ASYNC_INTERRUPT
1397 ? $SIGPIPE_R->drain
1078 sysread $SIGPIPE_R, my $dummy, 4; 1398 : sysread $SIGPIPE_R, (my $dummy), 9;
1079 1399
1080 while (%SIG_EV) { 1400 while (%SIG_EV) {
1081 for (keys %SIG_EV) { 1401 for (keys %SIG_EV) {
1082 delete $SIG_EV{$_}; 1402 delete $SIG_EV{$_};
1083 $_->() for values %{ $SIG_CB{$_} || {} }; 1403 $_->() for values %{ $SIG_CB{$_} || {} };
1084 } 1404 }
1085 } 1405 }
1086} 1406}
1087 1407
1408# install a dummy wakeup watcher to reduce signal catching latency
1409sub _sig_add() {
1410 unless ($SIG_COUNT++) {
1411 # try to align timer on a full-second boundary, if possible
1412 my $NOW = AE::now;
1413
1414 $SIG_TW = AE::timer
1415 $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1416 $MAX_SIGNAL_LATENCY,
1417 sub { } # just for the PERL_ASYNC_CHECK
1418 ;
1419 }
1420}
1421
1422sub _sig_del {
1423 undef $SIG_TW
1424 unless --$SIG_COUNT;
1425}
1426
1427our $_sig_name_init; $_sig_name_init = sub {
1428 eval q{ # poor man's autoloading
1429 undef $_sig_name_init;
1430
1431 if (_have_async_interrupt) {
1432 *sig2num = \&Async::Interrupt::sig2num;
1433 *sig2name = \&Async::Interrupt::sig2name;
1434 } else {
1435 require Config;
1436
1437 my %signame2num;
1438 @signame2num{ split ' ', $Config::Config{sig_name} }
1439 = split ' ', $Config::Config{sig_num};
1440
1441 my @signum2name;
1442 @signum2name[values %signame2num] = keys %signame2num;
1443
1444 *sig2num = sub($) {
1445 $_[0] > 0 ? shift : $signame2num{+shift}
1446 };
1447 *sig2name = sub ($) {
1448 $_[0] > 0 ? $signum2name[+shift] : shift
1449 };
1450 }
1451 };
1452 die if $@;
1453};
1454
1455sub sig2num ($) { &$_sig_name_init; &sig2num }
1456sub sig2name($) { &$_sig_name_init; &sig2name }
1457
1088sub signal { 1458sub signal {
1089 my (undef, %arg) = @_; 1459 eval q{ # poor man's autoloading {}
1460 # probe for availability of Async::Interrupt
1461 if (_have_async_interrupt) {
1462 warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1090 1463
1091 unless ($SIGPIPE_R) { 1464 $SIGPIPE_R = new Async::Interrupt::EventPipe;
1092 require Fcntl; 1465 $SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1093 1466
1094 if (AnyEvent::WIN32) {
1095 require AnyEvent::Util;
1096
1097 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1098 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1099 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1100 } else { 1467 } else {
1468 warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1469
1470 require Fcntl;
1471
1472 if (AnyEvent::WIN32) {
1473 require AnyEvent::Util;
1474
1475 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1476 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1477 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1478 } else {
1101 pipe $SIGPIPE_R, $SIGPIPE_W; 1479 pipe $SIGPIPE_R, $SIGPIPE_W;
1102 fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R; 1480 fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1103 fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case 1481 fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
1482
1483 # not strictly required, as $^F is normally 2, but let's make sure...
1484 fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1485 fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1486 }
1487
1488 $SIGPIPE_R
1489 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1490
1491 $SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1104 } 1492 }
1105 1493
1106 $SIGPIPE_R 1494 *signal = sub {
1107 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; 1495 my (undef, %arg) = @_;
1108 1496
1109 # not strictly required, as $^F is normally 2, but let's make sure...
1110 fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1111 fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1112
1113 $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1114 }
1115
1116 my $signal = uc $arg{signal} 1497 my $signal = uc $arg{signal}
1117 or Carp::croak "required option 'signal' is missing"; 1498 or Carp::croak "required option 'signal' is missing";
1118 1499
1500 if ($HAVE_ASYNC_INTERRUPT) {
1501 # async::interrupt
1502
1503 $signal = sig2num $signal;
1119 $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; 1504 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1505
1506 $SIG_ASY{$signal} ||= new Async::Interrupt
1507 cb => sub { undef $SIG_EV{$signal} },
1508 signal => $signal,
1509 pipe => [$SIGPIPE_R->filenos],
1510 pipe_autodrain => 0,
1511 ;
1512
1513 } else {
1514 # pure perl
1515
1516 # AE::Util has been loaded in signal
1517 $signal = sig2name $signal;
1518 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1519
1120 $SIG{$signal} ||= sub { 1520 $SIG{$signal} ||= sub {
1121 local $!; 1521 local $!;
1122 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; 1522 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1123 undef $SIG_EV{$signal}; 1523 undef $SIG_EV{$signal};
1524 };
1525
1526 # can't do signal processing without introducing races in pure perl,
1527 # so limit the signal latency.
1528 _sig_add;
1529 }
1530
1531 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1532 };
1533
1534 *AnyEvent::Base::signal::DESTROY = sub {
1535 my ($signal, $cb) = @{$_[0]};
1536
1537 _sig_del;
1538
1539 delete $SIG_CB{$signal}{$cb};
1540
1541 $HAVE_ASYNC_INTERRUPT
1542 ? delete $SIG_ASY{$signal}
1543 : # delete doesn't work with older perls - they then
1544 # print weird messages, or just unconditionally exit
1545 # instead of getting the default action.
1546 undef $SIG{$signal}
1547 unless keys %{ $SIG_CB{$signal} };
1548 };
1124 }; 1549 };
1125 1550 die if $@;
1126 bless [$signal, $arg{cb}], "AnyEvent::Base::Signal" 1551 &signal
1127}
1128
1129sub AnyEvent::Base::Signal::DESTROY {
1130 my ($signal, $cb) = @{$_[0]};
1131
1132 delete $SIG_CB{$signal}{$cb};
1133
1134 delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1135} 1552}
1136 1553
1137# default implementation for ->child 1554# default implementation for ->child
1138 1555
1139our %PID_CB; 1556our %PID_CB;
1140our $CHLD_W; 1557our $CHLD_W;
1141our $CHLD_DELAY_W; 1558our $CHLD_DELAY_W;
1142our $PID_IDLE;
1143our $WNOHANG; 1559our $WNOHANG;
1144 1560
1145sub _child_wait { 1561sub _emit_childstatus($$) {
1146 while (0 < (my $pid = waitpid -1, $WNOHANG)) { 1562 my (undef, $rpid, $rstatus) = @_;
1563
1564 $_->($rpid, $rstatus)
1147 $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), 1565 for values %{ $PID_CB{$rpid} || {} },
1148 (values %{ $PID_CB{0} || {} }); 1566 values %{ $PID_CB{0} || {} };
1149 }
1150
1151 undef $PID_IDLE;
1152} 1567}
1153 1568
1154sub _sigchld { 1569sub _sigchld {
1155 # make sure we deliver these changes "synchronous" with the event loop. 1570 my $pid;
1156 $CHLD_DELAY_W ||= AnyEvent->timer (after => 0, cb => sub { 1571
1157 undef $CHLD_DELAY_W; 1572 AnyEvent->_emit_childstatus ($pid, $?)
1158 &_child_wait; 1573 while ($pid = waitpid -1, $WNOHANG) > 0;
1159 });
1160} 1574}
1161 1575
1162sub child { 1576sub child {
1163 my (undef, %arg) = @_; 1577 my (undef, %arg) = @_;
1164 1578
1165 defined (my $pid = $arg{pid} + 0) 1579 defined (my $pid = $arg{pid} + 0)
1166 or Carp::croak "required option 'pid' is missing"; 1580 or Carp::croak "required option 'pid' is missing";
1167 1581
1168 $PID_CB{$pid}{$arg{cb}} = $arg{cb}; 1582 $PID_CB{$pid}{$arg{cb}} = $arg{cb};
1169 1583
1170 unless ($WNOHANG) { 1584 # WNOHANG is almost cetrainly 1 everywhere
1585 $WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1586 ? 1
1171 $WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; 1587 : eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1172 }
1173 1588
1174 unless ($CHLD_W) { 1589 unless ($CHLD_W) {
1175 $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); 1590 $CHLD_W = AE::signal CHLD => \&_sigchld;
1176 # child could be a zombie already, so make at least one round 1591 # child could be a zombie already, so make at least one round
1177 &_sigchld; 1592 &_sigchld;
1178 } 1593 }
1179 1594
1180 bless [$pid, $arg{cb}], "AnyEvent::Base::Child" 1595 bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1181} 1596}
1182 1597
1183sub AnyEvent::Base::Child::DESTROY { 1598sub AnyEvent::Base::child::DESTROY {
1184 my ($pid, $cb) = @{$_[0]}; 1599 my ($pid, $cb) = @{$_[0]};
1185 1600
1186 delete $PID_CB{$pid}{$cb}; 1601 delete $PID_CB{$pid}{$cb};
1187 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; 1602 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1188 1603
1189 undef $CHLD_W unless keys %PID_CB; 1604 undef $CHLD_W unless keys %PID_CB;
1190} 1605}
1191 1606
1607# idle emulation is done by simply using a timer, regardless
1608# of whether the process is idle or not, and not letting
1609# the callback use more than 50% of the time.
1610sub idle {
1611 my (undef, %arg) = @_;
1612
1613 my ($cb, $w, $rcb) = $arg{cb};
1614
1615 $rcb = sub {
1616 if ($cb) {
1617 $w = _time;
1618 &$cb;
1619 $w = _time - $w;
1620
1621 # never use more then 50% of the time for the idle watcher,
1622 # within some limits
1623 $w = 0.0001 if $w < 0.0001;
1624 $w = 5 if $w > 5;
1625
1626 $w = AE::timer $w, 0, $rcb;
1627 } else {
1628 # clean up...
1629 undef $w;
1630 undef $rcb;
1631 }
1632 };
1633
1634 $w = AE::timer 0.05, 0, $rcb;
1635
1636 bless \\$cb, "AnyEvent::Base::idle"
1637}
1638
1639sub AnyEvent::Base::idle::DESTROY {
1640 undef $${$_[0]};
1641}
1642
1192package AnyEvent::CondVar; 1643package AnyEvent::CondVar;
1193 1644
1194our @ISA = AnyEvent::CondVar::Base::; 1645our @ISA = AnyEvent::CondVar::Base::;
1195 1646
1196package AnyEvent::CondVar::Base; 1647package AnyEvent::CondVar::Base;
1197 1648
1198use overload 1649#use overload
1199 '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, 1650# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1200 fallback => 1; 1651# fallback => 1;
1652
1653# save 300+ kilobytes by dirtily hardcoding overloading
1654${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching.
1655*{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod."
1656*{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{}
1657${'AnyEvent::CondVar::Base::()'} = 1; # fallback
1658
1659our $WAITING;
1201 1660
1202sub _send { 1661sub _send {
1203 # nop 1662 # nop
1204} 1663}
1205 1664
1218sub ready { 1677sub ready {
1219 $_[0]{_ae_sent} 1678 $_[0]{_ae_sent}
1220} 1679}
1221 1680
1222sub _wait { 1681sub _wait {
1682 $WAITING
1683 and !$_[0]{_ae_sent}
1684 and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1685
1686 local $WAITING = 1;
1223 AnyEvent->one_event while !$_[0]{_ae_sent}; 1687 AnyEvent->one_event while !$_[0]{_ae_sent};
1224} 1688}
1225 1689
1226sub recv { 1690sub recv {
1227 $_[0]->_wait; 1691 $_[0]->_wait;
1229 Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak}; 1693 Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1230 wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0] 1694 wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1231} 1695}
1232 1696
1233sub cb { 1697sub cb {
1234 $_[0]{_ae_cb} = $_[1] if @_ > 1; 1698 my $cv = shift;
1699
1700 @_
1701 and $cv->{_ae_cb} = shift
1702 and $cv->{_ae_sent}
1703 and (delete $cv->{_ae_cb})->($cv);
1704
1235 $_[0]{_ae_cb} 1705 $cv->{_ae_cb}
1236} 1706}
1237 1707
1238sub begin { 1708sub begin {
1239 ++$_[0]{_ae_counter}; 1709 ++$_[0]{_ae_counter};
1240 $_[0]{_ae_end_cb} = $_[1] if @_ > 1; 1710 $_[0]{_ae_end_cb} = $_[1] if @_ > 1;
1268so on. 1738so on.
1269 1739
1270=head1 ENVIRONMENT VARIABLES 1740=head1 ENVIRONMENT VARIABLES
1271 1741
1272The following environment variables are used by this module or its 1742The following environment variables are used by this module or its
1273submodules: 1743submodules.
1744
1745Note that AnyEvent will remove I<all> environment variables starting with
1746C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is
1747enabled.
1274 1748
1275=over 4 1749=over 4
1276 1750
1277=item C<PERL_ANYEVENT_VERBOSE> 1751=item C<PERL_ANYEVENT_VERBOSE>
1278 1752
1285C<PERL_ANYEVENT_MODEL>. 1759C<PERL_ANYEVENT_MODEL>.
1286 1760
1287When set to C<2> or higher, cause AnyEvent to report to STDERR which event 1761When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1288model it chooses. 1762model it chooses.
1289 1763
1764When set to C<8> or higher, then AnyEvent will report extra information on
1765which optional modules it loads and how it implements certain features.
1766
1290=item C<PERL_ANYEVENT_STRICT> 1767=item C<PERL_ANYEVENT_STRICT>
1291 1768
1292AnyEvent does not do much argument checking by default, as thorough 1769AnyEvent does not do much argument checking by default, as thorough
1293argument checking is very costly. Setting this variable to a true value 1770argument checking is very costly. Setting this variable to a true value
1294will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly 1771will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1295check the arguments passed to most method calls. If it finds any problems 1772check the arguments passed to most method calls. If it finds any problems,
1296it will croak. 1773it will croak.
1297 1774
1298In other words, enables "strict" mode. 1775In other words, enables "strict" mode.
1299 1776
1300Unlike C<use strict>, it is definitely recommended ot keep it off in 1777Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>
1301production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while 1778>>, it is definitely recommended to keep it off in production. Keeping
1302developing programs can be very useful, however. 1779C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1780can be very useful, however.
1303 1781
1304=item C<PERL_ANYEVENT_MODEL> 1782=item C<PERL_ANYEVENT_MODEL>
1305 1783
1306This can be used to specify the event model to be used by AnyEvent, before 1784This can be used to specify the event model to be used by AnyEvent, before
1307auto detection and -probing kicks in. It must be a string consisting 1785auto detection and -probing kicks in. It must be a string consisting
1350 1828
1351=item C<PERL_ANYEVENT_MAX_FORKS> 1829=item C<PERL_ANYEVENT_MAX_FORKS>
1352 1830
1353The maximum number of child processes that C<AnyEvent::Util::fork_call> 1831The maximum number of child processes that C<AnyEvent::Util::fork_call>
1354will create in parallel. 1832will create in parallel.
1833
1834=item C<PERL_ANYEVENT_MAX_OUTSTANDING_DNS>
1835
1836The default value for the C<max_outstanding> parameter for the default DNS
1837resolver - this is the maximum number of parallel DNS requests that are
1838sent to the DNS server.
1839
1840=item C<PERL_ANYEVENT_RESOLV_CONF>
1841
1842The file to use instead of F</etc/resolv.conf> (or OS-specific
1843configuration) in the default resolver. When set to the empty string, no
1844default config will be used.
1845
1846=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1847
1848When neither C<ca_file> nor C<ca_path> was specified during
1849L<AnyEvent::TLS> context creation, and either of these environment
1850variables exist, they will be used to specify CA certificate locations
1851instead of a system-dependent default.
1852
1853=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1854
1855When these are set to C<1>, then the respective modules are not
1856loaded. Mostly good for testing AnyEvent itself.
1355 1857
1356=back 1858=back
1357 1859
1358=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE 1860=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1359 1861
1417 warn "read: $input\n"; # output what has been read 1919 warn "read: $input\n"; # output what has been read
1418 $cv->send if $input =~ /^q/i; # quit program if /^q/i 1920 $cv->send if $input =~ /^q/i; # quit program if /^q/i
1419 }, 1921 },
1420 ); 1922 );
1421 1923
1422 my $time_watcher; # can only be used once
1423
1424 sub new_timer {
1425 $timer = AnyEvent->timer (after => 1, cb => sub { 1924 my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1426 warn "timeout\n"; # print 'timeout' about every second 1925 warn "timeout\n"; # print 'timeout' at most every second
1427 &new_timer; # and restart the time
1428 }); 1926 });
1429 }
1430
1431 new_timer; # create first timer
1432 1927
1433 $cv->recv; # wait until user enters /^q/i 1928 $cv->recv; # wait until user enters /^q/i
1434 1929
1435=head1 REAL-WORLD EXAMPLE 1930=head1 REAL-WORLD EXAMPLE
1436 1931
1567through AnyEvent. The benchmark creates a lot of timers (with a zero 2062through AnyEvent. The benchmark creates a lot of timers (with a zero
1568timeout) and I/O watchers (watching STDOUT, a pty, to become writable, 2063timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1569which it is), lets them fire exactly once and destroys them again. 2064which it is), lets them fire exactly once and destroys them again.
1570 2065
1571Source code for this benchmark is found as F<eg/bench> in the AnyEvent 2066Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1572distribution. 2067distribution. It uses the L<AE> interface, which makes a real difference
2068for the EV and Perl backends only.
1573 2069
1574=head3 Explanation of the columns 2070=head3 Explanation of the columns
1575 2071
1576I<watcher> is the number of event watchers created/destroyed. Since 2072I<watcher> is the number of event watchers created/destroyed. Since
1577different event models feature vastly different performances, each event 2073different event models feature vastly different performances, each event
1598watcher. 2094watcher.
1599 2095
1600=head3 Results 2096=head3 Results
1601 2097
1602 name watchers bytes create invoke destroy comment 2098 name watchers bytes create invoke destroy comment
1603 EV/EV 400000 224 0.47 0.35 0.27 EV native interface 2099 EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1604 EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers 2100 EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1605 CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal 2101 Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1606 Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation 2102 Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1607 Event/Event 16000 517 32.20 31.80 0.81 Event native interface 2103 Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1608 Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers 2104 Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
2105 IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
2106 IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1609 Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour 2107 Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1610 Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers 2108 Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1611 POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event 2109 POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1612 POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select 2110 POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1613 2111
1614=head3 Discussion 2112=head3 Discussion
1615 2113
1616The benchmark does I<not> measure scalability of the event loop very 2114The benchmark does I<not> measure scalability of the event loop very
1617well. For example, a select-based event loop (such as the pure perl one) 2115well. For example, a select-based event loop (such as the pure perl one)
1629benchmark machine, handling an event takes roughly 1600 CPU cycles with 2127benchmark machine, handling an event takes roughly 1600 CPU cycles with
1630EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU 2128EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1631cycles with POE. 2129cycles with POE.
1632 2130
1633C<EV> is the sole leader regarding speed and memory use, which are both 2131C<EV> is the sole leader regarding speed and memory use, which are both
1634maximal/minimal, respectively. Even when going through AnyEvent, it uses 2132maximal/minimal, respectively. When using the L<AE> API there is zero
2133overhead (when going through the AnyEvent API create is about 5-6 times
2134slower, with other times being equal, so still uses far less memory than
1635far less memory than any other event loop and is still faster than Event 2135any other event loop and is still faster than Event natively).
1636natively.
1637 2136
1638The pure perl implementation is hit in a few sweet spots (both the 2137The pure perl implementation is hit in a few sweet spots (both the
1639constant timeout and the use of a single fd hit optimisations in the perl 2138constant timeout and the use of a single fd hit optimisations in the perl
1640interpreter and the backend itself). Nevertheless this shows that it 2139interpreter and the backend itself). Nevertheless this shows that it
1641adds very little overhead in itself. Like any select-based backend its 2140adds very little overhead in itself. Like any select-based backend its
1642performance becomes really bad with lots of file descriptors (and few of 2141performance becomes really bad with lots of file descriptors (and few of
1643them active), of course, but this was not subject of this benchmark. 2142them active), of course, but this was not subject of this benchmark.
1644 2143
1645The C<Event> module has a relatively high setup and callback invocation 2144The C<Event> module has a relatively high setup and callback invocation
1646cost, but overall scores in on the third place. 2145cost, but overall scores in on the third place.
2146
2147C<IO::Async> performs admirably well, about on par with C<Event>, even
2148when using its pure perl backend.
1647 2149
1648C<Glib>'s memory usage is quite a bit higher, but it features a 2150C<Glib>'s memory usage is quite a bit higher, but it features a
1649faster callback invocation and overall ends up in the same class as 2151faster callback invocation and overall ends up in the same class as
1650C<Event>. However, Glib scales extremely badly, doubling the number of 2152C<Event>. However, Glib scales extremely badly, doubling the number of
1651watchers increases the processing time by more than a factor of four, 2153watchers increases the processing time by more than a factor of four,
1712In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100 2214In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
1713(1%) are active. This mirrors the activity of large servers with many 2215(1%) are active. This mirrors the activity of large servers with many
1714connections, most of which are idle at any one point in time. 2216connections, most of which are idle at any one point in time.
1715 2217
1716Source code for this benchmark is found as F<eg/bench2> in the AnyEvent 2218Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
1717distribution. 2219distribution. It uses the L<AE> interface, which makes a real difference
2220for the EV and Perl backends only.
1718 2221
1719=head3 Explanation of the columns 2222=head3 Explanation of the columns
1720 2223
1721I<sockets> is the number of sockets, and twice the number of "servers" (as 2224I<sockets> is the number of sockets, and twice the number of "servers" (as
1722each server has a read and write socket end). 2225each server has a read and write socket end).
1729it to another server. This includes deleting the old timeout and creating 2232it to another server. This includes deleting the old timeout and creating
1730a new one that moves the timeout into the future. 2233a new one that moves the timeout into the future.
1731 2234
1732=head3 Results 2235=head3 Results
1733 2236
1734 name sockets create request 2237 name sockets create request
1735 EV 20000 69.01 11.16 2238 EV 20000 62.66 7.99
1736 Perl 20000 73.32 35.87 2239 Perl 20000 68.32 32.64
1737 Event 20000 212.62 257.32 2240 IOAsync 20000 174.06 101.15 epoll
1738 Glib 20000 651.16 1896.30 2241 IOAsync 20000 174.67 610.84 poll
2242 Event 20000 202.69 242.91
2243 Glib 20000 557.01 1689.52
1739 POE 20000 349.67 12317.24 uses POE::Loop::Event 2244 POE 20000 341.54 12086.32 uses POE::Loop::Event
1740 2245
1741=head3 Discussion 2246=head3 Discussion
1742 2247
1743This benchmark I<does> measure scalability and overall performance of the 2248This benchmark I<does> measure scalability and overall performance of the
1744particular event loop. 2249particular event loop.
1746EV is again fastest. Since it is using epoll on my system, the setup time 2251EV is again fastest. Since it is using epoll on my system, the setup time
1747is relatively high, though. 2252is relatively high, though.
1748 2253
1749Perl surprisingly comes second. It is much faster than the C-based event 2254Perl surprisingly comes second. It is much faster than the C-based event
1750loops Event and Glib. 2255loops Event and Glib.
2256
2257IO::Async performs very well when using its epoll backend, and still quite
2258good compared to Glib when using its pure perl backend.
1751 2259
1752Event suffers from high setup time as well (look at its code and you will 2260Event suffers from high setup time as well (look at its code and you will
1753understand why). Callback invocation also has a high overhead compared to 2261understand why). Callback invocation also has a high overhead compared to
1754the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event 2262the C<< $_->() for .. >>-style loop that the Perl event loop uses. Event
1755uses select or poll in basically all documented configurations. 2263uses select or poll in basically all documented configurations.
1818=item * C-based event loops perform very well with small number of 2326=item * C-based event loops perform very well with small number of
1819watchers, as the management overhead dominates. 2327watchers, as the management overhead dominates.
1820 2328
1821=back 2329=back
1822 2330
2331=head2 THE IO::Lambda BENCHMARK
2332
2333Recently I was told about the benchmark in the IO::Lambda manpage, which
2334could be misinterpreted to make AnyEvent look bad. In fact, the benchmark
2335simply compares IO::Lambda with POE, and IO::Lambda looks better (which
2336shouldn't come as a surprise to anybody). As such, the benchmark is
2337fine, and mostly shows that the AnyEvent backend from IO::Lambda isn't
2338very optimal. But how would AnyEvent compare when used without the extra
2339baggage? To explore this, I wrote the equivalent benchmark for AnyEvent.
2340
2341The benchmark itself creates an echo-server, and then, for 500 times,
2342connects to the echo server, sends a line, waits for the reply, and then
2343creates the next connection. This is a rather bad benchmark, as it doesn't
2344test the efficiency of the framework or much non-blocking I/O, but it is a
2345benchmark nevertheless.
2346
2347 name runtime
2348 Lambda/select 0.330 sec
2349 + optimized 0.122 sec
2350 Lambda/AnyEvent 0.327 sec
2351 + optimized 0.138 sec
2352 Raw sockets/select 0.077 sec
2353 POE/select, components 0.662 sec
2354 POE/select, raw sockets 0.226 sec
2355 POE/select, optimized 0.404 sec
2356
2357 AnyEvent/select/nb 0.085 sec
2358 AnyEvent/EV/nb 0.068 sec
2359 +state machine 0.134 sec
2360
2361The benchmark is also a bit unfair (my fault): the IO::Lambda/POE
2362benchmarks actually make blocking connects and use 100% blocking I/O,
2363defeating the purpose of an event-based solution. All of the newly
2364written AnyEvent benchmarks use 100% non-blocking connects (using
2365AnyEvent::Socket::tcp_connect and the asynchronous pure perl DNS
2366resolver), so AnyEvent is at a disadvantage here, as non-blocking connects
2367generally require a lot more bookkeeping and event handling than blocking
2368connects (which involve a single syscall only).
2369
2370The last AnyEvent benchmark additionally uses L<AnyEvent::Handle>, which
2371offers similar expressive power as POE and IO::Lambda, using conventional
2372Perl syntax. This means that both the echo server and the client are 100%
2373non-blocking, further placing it at a disadvantage.
2374
2375As you can see, the AnyEvent + EV combination even beats the
2376hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2377backend easily beats IO::Lambda and POE.
2378
2379And even the 100% non-blocking version written using the high-level (and
2380slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2381higher level ("unoptimised") abstractions by a large margin, even though
2382it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2383
2384The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2385F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2386part of the IO::Lambda distribution and were used without any changes.
2387
1823 2388
1824=head1 SIGNALS 2389=head1 SIGNALS
1825 2390
1826AnyEvent currently installs handlers for these signals: 2391AnyEvent currently installs handlers for these signals:
1827 2392
1830=item SIGCHLD 2395=item SIGCHLD
1831 2396
1832A handler for C<SIGCHLD> is installed by AnyEvent's child watcher 2397A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
1833emulation for event loops that do not support them natively. Also, some 2398emulation for event loops that do not support them natively. Also, some
1834event loops install a similar handler. 2399event loops install a similar handler.
2400
2401Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
2402AnyEvent will reset it to default, to avoid losing child exit statuses.
1835 2403
1836=item SIGPIPE 2404=item SIGPIPE
1837 2405
1838A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> 2406A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
1839when AnyEvent gets loaded. 2407when AnyEvent gets loaded.
1851 2419
1852=back 2420=back
1853 2421
1854=cut 2422=cut
1855 2423
2424undef $SIG{CHLD}
2425 if $SIG{CHLD} eq 'IGNORE';
2426
1856$SIG{PIPE} = sub { } 2427$SIG{PIPE} = sub { }
1857 unless defined $SIG{PIPE}; 2428 unless defined $SIG{PIPE};
2429
2430=head1 RECOMMENDED/OPTIONAL MODULES
2431
2432One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2433it's built-in modules) are required to use it.
2434
2435That does not mean that AnyEvent won't take advantage of some additional
2436modules if they are installed.
2437
2438This section epxlains which additional modules will be used, and how they
2439affect AnyEvent's operetion.
2440
2441=over 4
2442
2443=item L<Async::Interrupt>
2444
2445This slightly arcane module is used to implement fast signal handling: To
2446my knowledge, there is no way to do completely race-free and quick
2447signal handling in pure perl. To ensure that signals still get
2448delivered, AnyEvent will start an interval timer to wake up perl (and
2449catch the signals) with some delay (default is 10 seconds, look for
2450C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2451
2452If this module is available, then it will be used to implement signal
2453catching, which means that signals will not be delayed, and the event loop
2454will not be interrupted regularly, which is more efficient (And good for
2455battery life on laptops).
2456
2457This affects not just the pure-perl event loop, but also other event loops
2458that have no signal handling on their own (e.g. Glib, Tk, Qt).
2459
2460Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
2461and either employ their own workarounds (POE) or use AnyEvent's workaround
2462(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
2463does nothing for those backends.
2464
2465=item L<EV>
2466
2467This module isn't really "optional", as it is simply one of the backend
2468event loops that AnyEvent can use. However, it is simply the best event
2469loop available in terms of features, speed and stability: It supports
2470the AnyEvent API optimally, implements all the watcher types in XS, does
2471automatic timer adjustments even when no monotonic clock is available,
2472can take avdantage of advanced kernel interfaces such as C<epoll> and
2473C<kqueue>, and is the fastest backend I<by far>. You can even embed
2474L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2475
2476=item L<Guard>
2477
2478The guard module, when used, will be used to implement
2479C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2480lot less memory), but otherwise doesn't affect guard operation much. It is
2481purely used for performance.
2482
2483=item L<JSON> and L<JSON::XS>
2484
2485One of these modules is required when you want to read or write JSON data
2486via L<AnyEvent::Handle>. It is also written in pure-perl, but can take
2487advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2488
2489In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2490installed.
2491
2492=item L<Net::SSLeay>
2493
2494Implementing TLS/SSL in Perl is certainly interesting, but not very
2495worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2496the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2497
2498=item L<Time::HiRes>
2499
2500This module is part of perl since release 5.008. It will be used when the
2501chosen event library does not come with a timing source on it's own. The
2502pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
2503try to use a monotonic clock for timing stability.
2504
2505=back
1858 2506
1859 2507
1860=head1 FORK 2508=head1 FORK
1861 2509
1862Most event libraries are not fork-safe. The ones who are usually are 2510Most event libraries are not fork-safe. The ones who are usually are
1863because they rely on inefficient but fork-safe C<select> or C<poll> 2511because they rely on inefficient but fork-safe C<select> or C<poll>
1864calls. Only L<EV> is fully fork-aware. 2512calls. Only L<EV> is fully fork-aware.
1865 2513
1866If you have to fork, you must either do so I<before> creating your first 2514If you have to fork, you must either do so I<before> creating your first
1867watcher OR you must not use AnyEvent at all in the child. 2515watcher OR you must not use AnyEvent at all in the child OR you must do
2516something completely out of the scope of AnyEvent.
1868 2517
1869 2518
1870=head1 SECURITY CONSIDERATIONS 2519=head1 SECURITY CONSIDERATIONS
1871 2520
1872AnyEvent can be forced to load any event model via 2521AnyEvent can be forced to load any event model via
1884 use AnyEvent; 2533 use AnyEvent;
1885 2534
1886Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can 2535Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1887be used to probe what backend is used and gain other information (which is 2536be used to probe what backend is used and gain other information (which is
1888probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and 2537probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
1889$ENV{PERL_ANYEGENT_STRICT}. 2538$ENV{PERL_ANYEVENT_STRICT}.
2539
2540Note that AnyEvent will remove I<all> environment variables starting with
2541C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is
2542enabled.
1890 2543
1891 2544
1892=head1 BUGS 2545=head1 BUGS
1893 2546
1894Perl 5.8 has numerous memleaks that sometimes hit this module and are hard 2547Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
1906L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. 2559L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
1907 2560
1908Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, 2561Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
1909L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, 2562L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
1910L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, 2563L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
1911L<AnyEvent::Impl::POE>. 2564L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
1912 2565
1913Non-blocking file handles, sockets, TCP clients and 2566Non-blocking file handles, sockets, TCP clients and
1914servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>. 2567servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
1915 2568
1916Asynchronous DNS: L<AnyEvent::DNS>. 2569Asynchronous DNS: L<AnyEvent::DNS>.
1917 2570
1918Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>, 2571Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,
2572L<Coro::Event>,
1919 2573
1920Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. 2574Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,
2575L<AnyEvent::HTTP>.
1921 2576
1922 2577
1923=head1 AUTHOR 2578=head1 AUTHOR
1924 2579
1925 Marc Lehmann <schmorp@schmorp.de> 2580 Marc Lehmann <schmorp@schmorp.de>

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