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1=head1 NAME 1=head1 NAME
2 2
3AnyEvent - provide framework for multiple event loops 3AnyEvent - the DBI of event loop programming
4 4
5EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported 5EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt
6event loops. 6and POE are various supported event loops/environments.
7 7
8=head1 SYNOPSIS 8=head1 SYNOPSIS
9 9
10 use AnyEvent; 10 use AnyEvent;
11 11
12 # if you prefer function calls, look at the L<AE> manpage for
13 # an alternative API.
14
12 # file descriptor readable 15 # file handle or descriptor readable
13 my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... }); 16 my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
14 17
15 # one-shot or repeating timers 18 # one-shot or repeating timers
16 my $w = AnyEvent->timer (after => $seconds, cb => sub { ... }); 19 my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
17 my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ... 20 my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...
40=head1 INTRODUCTION/TUTORIAL 43=head1 INTRODUCTION/TUTORIAL
41 44
42This manpage is mainly a reference manual. If you are interested 45This manpage is mainly a reference manual. If you are interested
43in a tutorial or some gentle introduction, have a look at the 46in a tutorial or some gentle introduction, have a look at the
44L<AnyEvent::Intro> manpage. 47L<AnyEvent::Intro> manpage.
48
49=head1 SUPPORT
50
51There is a mailinglist for discussing all things AnyEvent, and an IRC
52channel, too.
53
54See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
55Repository>, at L<http://anyevent.schmorp.de>, for more info.
45 56
46=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT) 57=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
47 58
48Glib, POE, IO::Async, Event... CPAN offers event models by the dozen 59Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
49nowadays. So what is different about AnyEvent? 60nowadays. So what is different about AnyEvent?
173my variables are only visible after the statement in which they are 184my variables are only visible after the statement in which they are
174declared. 185declared.
175 186
176=head2 I/O WATCHERS 187=head2 I/O WATCHERS
177 188
189 $w = AnyEvent->io (
190 fh => <filehandle_or_fileno>,
191 poll => <"r" or "w">,
192 cb => <callback>,
193 );
194
178You can create an I/O watcher by calling the C<< AnyEvent->io >> method 195You can create an I/O watcher by calling the C<< AnyEvent->io >> method
179with the following mandatory key-value pairs as arguments: 196with the following mandatory key-value pairs as arguments:
180 197
181C<fh> is the Perl I<file handle> (I<not> file descriptor, see below) to 198C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch
182watch for events (AnyEvent might or might not keep a reference to this 199for events (AnyEvent might or might not keep a reference to this file
183file handle). Note that only file handles pointing to things for which 200handle). Note that only file handles pointing to things for which
184non-blocking operation makes sense are allowed. This includes sockets, 201non-blocking operation makes sense are allowed. This includes sockets,
185most character devices, pipes, fifos and so on, but not for example files 202most character devices, pipes, fifos and so on, but not for example files
186or block devices. 203or block devices.
187 204
188C<poll> must be a string that is either C<r> or C<w>, which creates a 205C<poll> must be a string that is either C<r> or C<w>, which creates a
209 chomp (my $input = <STDIN>); 226 chomp (my $input = <STDIN>);
210 warn "read: $input\n"; 227 warn "read: $input\n";
211 undef $w; 228 undef $w;
212 }); 229 });
213 230
214=head3 GETTING A FILE HANDLE FROM A FILE DESCRIPTOR
215
216It is not uncommon to only have a file descriptor, while AnyEvent requires
217a Perl file handle.
218
219There are basically two methods to convert a file descriptor into a file handle. If you own
220the file descriptor, you can open it with C<&=>, as in:
221
222 open my $fh, "<&=$fileno" or die "xxx: ยง!";
223
224This will "own" the file descriptor, meaning that when C<$fh> is
225destroyed, it will automatically close the C<$fileno>. Also, note that
226the open mode (read, write, read/write) must correspond with how the
227underlying file descriptor was opened.
228
229In many cases, taking over the file descriptor is now what you want, in
230which case the only alternative is to dup the file descriptor:
231
232 open my $fh, "<&$fileno" or die "xxx: $!";
233
234This has the advantage of not closing the file descriptor and the
235disadvantage of making a slow copy.
236
237=head2 TIME WATCHERS 231=head2 TIME WATCHERS
232
233 $w = AnyEvent->timer (after => <seconds>, cb => <callback>);
234
235 $w = AnyEvent->timer (
236 after => <fractional_seconds>,
237 interval => <fractional_seconds>,
238 cb => <callback>,
239 );
238 240
239You can create a time watcher by calling the C<< AnyEvent->timer >> 241You can create a time watcher by calling the C<< AnyEvent->timer >>
240method with the following mandatory arguments: 242method with the following mandatory arguments:
241 243
242C<after> specifies after how many seconds (fractional values are 244C<after> specifies after how many seconds (fractional values are
364might affect timers and time-outs. 366might affect timers and time-outs.
365 367
366When this is the case, you can call this method, which will update the 368When this is the case, you can call this method, which will update the
367event loop's idea of "current time". 369event loop's idea of "current time".
368 370
371A typical example would be a script in a web server (e.g. C<mod_perl>) -
372when mod_perl executes the script, then the event loop will have the wrong
373idea about the "current time" (being potentially far in the past, when the
374script ran the last time). In that case you should arrange a call to C<<
375AnyEvent->now_update >> each time the web server process wakes up again
376(e.g. at the start of your script, or in a handler).
377
369Note that updating the time I<might> cause some events to be handled. 378Note that updating the time I<might> cause some events to be handled.
370 379
371=back 380=back
372 381
373=head2 SIGNAL WATCHERS 382=head2 SIGNAL WATCHERS
383
384 $w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
374 385
375You can watch for signals using a signal watcher, C<signal> is the signal 386You can watch for signals using a signal watcher, C<signal> is the signal
376I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl 387I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
377callback to be invoked whenever a signal occurs. 388callback to be invoked whenever a signal occurs.
378 389
384invocation, and callback invocation will be synchronous. Synchronous means 395invocation, and callback invocation will be synchronous. Synchronous means
385that it might take a while until the signal gets handled by the process, 396that it might take a while until the signal gets handled by the process,
386but it is guaranteed not to interrupt any other callbacks. 397but it is guaranteed not to interrupt any other callbacks.
387 398
388The main advantage of using these watchers is that you can share a signal 399The main advantage of using these watchers is that you can share a signal
389between multiple watchers. 400between multiple watchers, and AnyEvent will ensure that signals will not
401interrupt your program at bad times.
390 402
391This watcher might use C<%SIG>, so programs overwriting those signals 403This watcher might use C<%SIG> (depending on the event loop used),
392directly will likely not work correctly. 404so programs overwriting those signals directly will likely not work
405correctly.
393 406
394Example: exit on SIGINT 407Example: exit on SIGINT
395 408
396 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 }); 409 my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
397 410
411=head3 Restart Behaviour
412
413While restart behaviour is up to the event loop implementation, most will
414not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
415pure perl implementation).
416
417=head3 Safe/Unsafe Signals
418
419Perl signals can be either "safe" (synchronous to opcode handling) or
420"unsafe" (asynchronous) - the former might get delayed indefinitely, the
421latter might corrupt your memory.
422
423AnyEvent signal handlers are, in addition, synchronous to the event loop,
424i.e. they will not interrupt your running perl program but will only be
425called as part of the normal event handling (just like timer, I/O etc.
426callbacks, too).
427
428=head3 Signal Races, Delays and Workarounds
429
430Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
431callbacks to signals in a generic way, which is a pity, as you cannot
432do race-free signal handling in perl, requiring C libraries for
433this. AnyEvent will try to do it's best, which means in some cases,
434signals will be delayed. The maximum time a signal might be delayed is
435specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
436variable can be changed only before the first signal watcher is created,
437and should be left alone otherwise. This variable determines how often
438AnyEvent polls for signals (in case a wake-up was missed). Higher values
439will cause fewer spurious wake-ups, which is better for power and CPU
440saving.
441
442All these problems can be avoided by installing the optional
443L<Async::Interrupt> module, which works with most event loops. It will not
444work with inherently broken event loops such as L<Event> or L<Event::Lib>
445(and not with L<POE> currently, as POE does it's own workaround with
446one-second latency). For those, you just have to suffer the delays.
447
398=head2 CHILD PROCESS WATCHERS 448=head2 CHILD PROCESS WATCHERS
399 449
450 $w = AnyEvent->child (pid => <process id>, cb => <callback>);
451
400You can also watch on a child process exit and catch its exit status. 452You can also watch on a child process exit and catch its exit status.
401 453
402The child process is specified by the C<pid> argument (if set to C<0>, it 454The child process is specified by the C<pid> argument (one some backends,
403watches for any child process exit). The watcher will triggered only when 455using C<0> watches for any child process exit, on others this will
404the child process has finished and an exit status is available, not on 456croak). The watcher will be triggered only when the child process has
405any trace events (stopped/continued). 457finished and an exit status is available, not on any trace events
458(stopped/continued).
406 459
407The callback will be called with the pid and exit status (as returned by 460The callback will be called with the pid and exit status (as returned by
408waitpid), so unlike other watcher types, you I<can> rely on child watcher 461waitpid), so unlike other watcher types, you I<can> rely on child watcher
409callback arguments. 462callback arguments.
410 463
426 479
427This means you cannot create a child watcher as the very first 480This means you cannot create a child watcher as the very first
428thing in an AnyEvent program, you I<have> to create at least one 481thing in an AnyEvent program, you I<have> to create at least one
429watcher before you C<fork> the child (alternatively, you can call 482watcher before you C<fork> the child (alternatively, you can call
430C<AnyEvent::detect>). 483C<AnyEvent::detect>).
484
485As most event loops do not support waiting for child events, they will be
486emulated by AnyEvent in most cases, in which the latency and race problems
487mentioned in the description of signal watchers apply.
431 488
432Example: fork a process and wait for it 489Example: fork a process and wait for it
433 490
434 my $done = AnyEvent->condvar; 491 my $done = AnyEvent->condvar;
435 492
447 # do something else, then wait for process exit 504 # do something else, then wait for process exit
448 $done->recv; 505 $done->recv;
449 506
450=head2 IDLE WATCHERS 507=head2 IDLE WATCHERS
451 508
452Sometimes there is a need to do something, but it is not so important 509 $w = AnyEvent->idle (cb => <callback>);
453to do it instantly, but only when there is nothing better to do. This
454"nothing better to do" is usually defined to be "no other events need
455attention by the event loop".
456 510
457Idle watchers ideally get invoked when the event loop has nothing 511Repeatedly invoke the callback after the process becomes idle, until
458better to do, just before it would block the process to wait for new 512either the watcher is destroyed or new events have been detected.
459events. Instead of blocking, the idle watcher is invoked.
460 513
461Most event loops unfortunately do not really support idle watchers (only 514Idle watchers are useful when there is a need to do something, but it
515is not so important (or wise) to do it instantly. The callback will be
516invoked only when there is "nothing better to do", which is usually
517defined as "all outstanding events have been handled and no new events
518have been detected". That means that idle watchers ideally get invoked
519when the event loop has just polled for new events but none have been
520detected. Instead of blocking to wait for more events, the idle watchers
521will be invoked.
522
523Unfortunately, most event loops do not really support idle watchers (only
462EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent 524EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
463will simply call the callback "from time to time". 525will simply call the callback "from time to time".
464 526
465Example: read lines from STDIN, but only process them when the 527Example: read lines from STDIN, but only process them when the
466program is otherwise idle: 528program is otherwise idle:
482 }); 544 });
483 }); 545 });
484 546
485=head2 CONDITION VARIABLES 547=head2 CONDITION VARIABLES
486 548
549 $cv = AnyEvent->condvar;
550
551 $cv->send (<list>);
552 my @res = $cv->recv;
553
487If you are familiar with some event loops you will know that all of them 554If you are familiar with some event loops you will know that all of them
488require you to run some blocking "loop", "run" or similar function that 555require you to run some blocking "loop", "run" or similar function that
489will actively watch for new events and call your callbacks. 556will actively watch for new events and call your callbacks.
490 557
491AnyEvent is different, it expects somebody else to run the event loop and 558AnyEvent is slightly different: it expects somebody else to run the event
492will only block when necessary (usually when told by the user). 559loop and will only block when necessary (usually when told by the user).
493 560
494The instrument to do that is called a "condition variable", so called 561The instrument to do that is called a "condition variable", so called
495because they represent a condition that must become true. 562because they represent a condition that must become true.
496 563
564Now is probably a good time to look at the examples further below.
565
497Condition variables can be created by calling the C<< AnyEvent->condvar 566Condition variables can be created by calling the C<< AnyEvent->condvar
498>> method, usually without arguments. The only argument pair allowed is 567>> method, usually without arguments. The only argument pair allowed is
499
500C<cb>, which specifies a callback to be called when the condition variable 568C<cb>, which specifies a callback to be called when the condition variable
501becomes true, with the condition variable as the first argument (but not 569becomes true, with the condition variable as the first argument (but not
502the results). 570the results).
503 571
504After creation, the condition variable is "false" until it becomes "true" 572After creation, the condition variable is "false" until it becomes "true"
509Condition variables are similar to callbacks, except that you can 577Condition variables are similar to callbacks, except that you can
510optionally wait for them. They can also be called merge points - points 578optionally wait for them. They can also be called merge points - points
511in time where multiple outstanding events have been processed. And yet 579in time where multiple outstanding events have been processed. And yet
512another way to call them is transactions - each condition variable can be 580another way to call them is transactions - each condition variable can be
513used to represent a transaction, which finishes at some point and delivers 581used to represent a transaction, which finishes at some point and delivers
514a result. 582a result. And yet some people know them as "futures" - a promise to
583compute/deliver something that you can wait for.
515 584
516Condition variables are very useful to signal that something has finished, 585Condition variables are very useful to signal that something has finished,
517for example, if you write a module that does asynchronous http requests, 586for example, if you write a module that does asynchronous http requests,
518then a condition variable would be the ideal candidate to signal the 587then a condition variable would be the ideal candidate to signal the
519availability of results. The user can either act when the callback is 588availability of results. The user can either act when the callback is
540eventually calls C<< -> send >>, and the "consumer side", which waits 609eventually calls C<< -> send >>, and the "consumer side", which waits
541for the send to occur. 610for the send to occur.
542 611
543Example: wait for a timer. 612Example: wait for a timer.
544 613
545 # wait till the result is ready 614 # condition: "wait till the timer is fired"
546 my $result_ready = AnyEvent->condvar; 615 my $timer_fired = AnyEvent->condvar;
547 616
548 # do something such as adding a timer 617 # create the timer - we could wait for, say
549 # or socket watcher the calls $result_ready->send 618 # a handle becomign ready, or even an
550 # when the "result" is ready. 619 # AnyEvent::HTTP request to finish, but
551 # in this case, we simply use a timer: 620 # in this case, we simply use a timer:
552 my $w = AnyEvent->timer ( 621 my $w = AnyEvent->timer (
553 after => 1, 622 after => 1,
554 cb => sub { $result_ready->send }, 623 cb => sub { $timer_fired->send },
555 ); 624 );
556 625
557 # this "blocks" (while handling events) till the callback 626 # this "blocks" (while handling events) till the callback
558 # calls send 627 # calls ->send
559 $result_ready->recv; 628 $timer_fired->recv;
560 629
561Example: wait for a timer, but take advantage of the fact that 630Example: wait for a timer, but take advantage of the fact that condition
562condition variables are also code references. 631variables are also callable directly.
563 632
564 my $done = AnyEvent->condvar; 633 my $done = AnyEvent->condvar;
565 my $delay = AnyEvent->timer (after => 5, cb => $done); 634 my $delay = AnyEvent->timer (after => 5, cb => $done);
566 $done->recv; 635 $done->recv;
567 636
573 642
574 ... 643 ...
575 644
576 my @info = $couchdb->info->recv; 645 my @info = $couchdb->info->recv;
577 646
578And this is how you would just ste a callback to be called whenever the 647And this is how you would just set a callback to be called whenever the
579results are available: 648results are available:
580 649
581 $couchdb->info->cb (sub { 650 $couchdb->info->cb (sub {
582 my @info = $_[0]->recv; 651 my @info = $_[0]->recv;
583 }); 652 });
601immediately from within send. 670immediately from within send.
602 671
603Any arguments passed to the C<send> call will be returned by all 672Any arguments passed to the C<send> call will be returned by all
604future C<< ->recv >> calls. 673future C<< ->recv >> calls.
605 674
606Condition variables are overloaded so one can call them directly 675Condition variables are overloaded so one can call them directly (as if
607(as a code reference). Calling them directly is the same as calling 676they were a code reference). Calling them directly is the same as calling
608C<send>. Note, however, that many C-based event loops do not handle 677C<send>.
609overloading, so as tempting as it may be, passing a condition variable
610instead of a callback does not work. Both the pure perl and EV loops
611support overloading, however, as well as all functions that use perl to
612invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
613example).
614 678
615=item $cv->croak ($error) 679=item $cv->croak ($error)
616 680
617Similar to send, but causes all call's to C<< ->recv >> to invoke 681Similar to send, but causes all call's to C<< ->recv >> to invoke
618C<Carp::croak> with the given error message/object/scalar. 682C<Carp::croak> with the given error message/object/scalar.
619 683
620This can be used to signal any errors to the condition variable 684This can be used to signal any errors to the condition variable
621user/consumer. 685user/consumer. Doing it this way instead of calling C<croak> directly
686delays the error detetcion, but has the overwhelmign advantage that it
687diagnoses the error at the place where the result is expected, and not
688deep in some event clalback without connection to the actual code causing
689the problem.
622 690
623=item $cv->begin ([group callback]) 691=item $cv->begin ([group callback])
624 692
625=item $cv->end 693=item $cv->end
626 694
628one. For example, a function that pings many hosts in parallel might want 696one. For example, a function that pings many hosts in parallel might want
629to use a condition variable for the whole process. 697to use a condition variable for the whole process.
630 698
631Every call to C<< ->begin >> will increment a counter, and every call to 699Every call to C<< ->begin >> will increment a counter, and every call to
632C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end 700C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
633>>, the (last) callback passed to C<begin> will be executed. That callback 701>>, the (last) callback passed to C<begin> will be executed, passing the
634is I<supposed> to call C<< ->send >>, but that is not required. If no 702condvar as first argument. That callback is I<supposed> to call C<< ->send
635callback was set, C<send> will be called without any arguments. 703>>, but that is not required. If no group callback was set, C<send> will
704be called without any arguments.
636 705
637You can think of C<< $cv->send >> giving you an OR condition (one call 706You can think of C<< $cv->send >> giving you an OR condition (one call
638sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND 707sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
639condition (all C<begin> calls must be C<end>'ed before the condvar sends). 708condition (all C<begin> calls must be C<end>'ed before the condvar sends).
640 709
667begung can potentially be zero: 736begung can potentially be zero:
668 737
669 my $cv = AnyEvent->condvar; 738 my $cv = AnyEvent->condvar;
670 739
671 my %result; 740 my %result;
672 $cv->begin (sub { $cv->send (\%result) }); 741 $cv->begin (sub { shift->send (\%result) });
673 742
674 for my $host (@list_of_hosts) { 743 for my $host (@list_of_hosts) {
675 $cv->begin; 744 $cv->begin;
676 ping_host_then_call_callback $host, sub { 745 ping_host_then_call_callback $host, sub {
677 $result{$host} = ...; 746 $result{$host} = ...;
722function will call C<croak>. 791function will call C<croak>.
723 792
724In list context, all parameters passed to C<send> will be returned, 793In list context, all parameters passed to C<send> will be returned,
725in scalar context only the first one will be returned. 794in scalar context only the first one will be returned.
726 795
796Note that doing a blocking wait in a callback is not supported by any
797event loop, that is, recursive invocation of a blocking C<< ->recv
798>> is not allowed, and the C<recv> call will C<croak> if such a
799condition is detected. This condition can be slightly loosened by using
800L<Coro::AnyEvent>, which allows you to do a blocking C<< ->recv >> from
801any thread that doesn't run the event loop itself.
802
727Not all event models support a blocking wait - some die in that case 803Not all event models support a blocking wait - some die in that case
728(programs might want to do that to stay interactive), so I<if you are 804(programs might want to do that to stay interactive), so I<if you are
729using this from a module, never require a blocking wait>, but let the 805using this from a module, never require a blocking wait>. Instead, let the
730caller decide whether the call will block or not (for example, by coupling 806caller decide whether the call will block or not (for example, by coupling
731condition variables with some kind of request results and supporting 807condition variables with some kind of request results and supporting
732callbacks so the caller knows that getting the result will not block, 808callbacks so the caller knows that getting the result will not block,
733while still supporting blocking waits if the caller so desires). 809while still supporting blocking waits if the caller so desires).
734 810
735Another reason I<never> to C<< ->recv >> in a module is that you cannot
736sensibly have two C<< ->recv >>'s in parallel, as that would require
737multiple interpreters or coroutines/threads, none of which C<AnyEvent>
738can supply.
739
740The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
741fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
742versions and also integrates coroutines into AnyEvent, making blocking
743C<< ->recv >> calls perfectly safe as long as they are done from another
744coroutine (one that doesn't run the event loop).
745
746You can ensure that C<< -recv >> never blocks by setting a callback and 811You can ensure that C<< -recv >> never blocks by setting a callback and
747only calling C<< ->recv >> from within that callback (or at a later 812only calling C<< ->recv >> from within that callback (or at a later
748time). This will work even when the event loop does not support blocking 813time). This will work even when the event loop does not support blocking
749waits otherwise. 814waits otherwise.
750 815
756=item $cb = $cv->cb ($cb->($cv)) 821=item $cb = $cv->cb ($cb->($cv))
757 822
758This is a mutator function that returns the callback set and optionally 823This is a mutator function that returns the callback set and optionally
759replaces it before doing so. 824replaces it before doing so.
760 825
761The callback will be called when the condition becomes "true", i.e. when 826The callback will be called when the condition becomes (or already was)
762C<send> or C<croak> are called, with the only argument being the condition 827"true", i.e. when C<send> or C<croak> are called (or were called), with
763variable itself. Calling C<recv> inside the callback or at any later time 828the only argument being the condition variable itself. Calling C<recv>
764is guaranteed not to block. 829inside the callback or at any later time is guaranteed not to block.
765 830
766=back 831=back
767 832
833=head1 SUPPORTED EVENT LOOPS/BACKENDS
834
835The available backend classes are (every class has its own manpage):
836
837=over 4
838
839=item Backends that are autoprobed when no other event loop can be found.
840
841EV is the preferred backend when no other event loop seems to be in
842use. If EV is not installed, then AnyEvent will fall back to its own
843pure-perl implementation, which is available everywhere as it comes with
844AnyEvent itself.
845
846 AnyEvent::Impl::EV based on EV (interface to libev, best choice).
847 AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
848
849=item Backends that are transparently being picked up when they are used.
850
851These will be used when they are currently loaded when the first watcher
852is created, in which case it is assumed that the application is using
853them. This means that AnyEvent will automatically pick the right backend
854when the main program loads an event module before anything starts to
855create watchers. Nothing special needs to be done by the main program.
856
857 AnyEvent::Impl::Event based on Event, very stable, few glitches.
858 AnyEvent::Impl::Glib based on Glib, slow but very stable.
859 AnyEvent::Impl::Tk based on Tk, very broken.
860 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
861 AnyEvent::Impl::POE based on POE, very slow, some limitations.
862 AnyEvent::Impl::Irssi used when running within irssi.
863
864=item Backends with special needs.
865
866Qt requires the Qt::Application to be instantiated first, but will
867otherwise be picked up automatically. As long as the main program
868instantiates the application before any AnyEvent watchers are created,
869everything should just work.
870
871 AnyEvent::Impl::Qt based on Qt.
872
873Support for IO::Async can only be partial, as it is too broken and
874architecturally limited to even support the AnyEvent API. It also
875is the only event loop that needs the loop to be set explicitly, so
876it can only be used by a main program knowing about AnyEvent. See
877L<AnyEvent::Impl::Async> for the gory details.
878
879 AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
880
881=item Event loops that are indirectly supported via other backends.
882
883Some event loops can be supported via other modules:
884
885There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
886
887B<WxWidgets> has no support for watching file handles. However, you can
888use WxWidgets through the POE adaptor, as POE has a Wx backend that simply
889polls 20 times per second, which was considered to be too horrible to even
890consider for AnyEvent.
891
892B<Prima> is not supported as nobody seems to be using it, but it has a POE
893backend, so it can be supported through POE.
894
895AnyEvent knows about both L<Prima> and L<Wx>, however, and will try to
896load L<POE> when detecting them, in the hope that POE will pick them up,
897in which case everything will be automatic.
898
899=back
900
768=head1 GLOBAL VARIABLES AND FUNCTIONS 901=head1 GLOBAL VARIABLES AND FUNCTIONS
769 902
903These are not normally required to use AnyEvent, but can be useful to
904write AnyEvent extension modules.
905
770=over 4 906=over 4
771 907
772=item $AnyEvent::MODEL 908=item $AnyEvent::MODEL
773 909
774Contains C<undef> until the first watcher is being created. Then it 910Contains C<undef> until the first watcher is being created, before the
911backend has been autodetected.
912
775contains the event model that is being used, which is the name of the 913Afterwards it contains the event model that is being used, which is the
776Perl class implementing the model. This class is usually one of the 914name of the Perl class implementing the model. This class is usually one
777C<AnyEvent::Impl:xxx> modules, but can be any other class in the case 915of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the
778AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>). 916case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
779 917will be C<urxvt::anyevent>).
780The known classes so far are:
781
782 AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
783 AnyEvent::Impl::Event based on Event, second best choice.
784 AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
785 AnyEvent::Impl::Glib based on Glib, third-best choice.
786 AnyEvent::Impl::Tk based on Tk, very bad choice.
787 AnyEvent::Impl::Qt based on Qt, cannot be autoprobed (see its docs).
788 AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
789 AnyEvent::Impl::POE based on POE, not generic enough for full support.
790
791 # warning, support for IO::Async is only partial, as it is too broken
792 # and limited toe ven support the AnyEvent API. See AnyEvent::Impl::Async.
793 AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed (see its docs).
794
795There is no support for WxWidgets, as WxWidgets has no support for
796watching file handles. However, you can use WxWidgets through the
797POE Adaptor, as POE has a Wx backend that simply polls 20 times per
798second, which was considered to be too horrible to even consider for
799AnyEvent. Likewise, other POE backends can be used by AnyEvent by using
800it's adaptor.
801
802AnyEvent knows about L<Prima> and L<Wx> and will try to use L<POE> when
803autodetecting them.
804 918
805=item AnyEvent::detect 919=item AnyEvent::detect
806 920
807Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model 921Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
808if necessary. You should only call this function right before you would 922if necessary. You should only call this function right before you would
809have created an AnyEvent watcher anyway, that is, as late as possible at 923have created an AnyEvent watcher anyway, that is, as late as possible at
810runtime. 924runtime, and not e.g. while initialising of your module.
925
926If you need to do some initialisation before AnyEvent watchers are
927created, use C<post_detect>.
811 928
812=item $guard = AnyEvent::post_detect { BLOCK } 929=item $guard = AnyEvent::post_detect { BLOCK }
813 930
814Arranges for the code block to be executed as soon as the event model is 931Arranges for the code block to be executed as soon as the event model is
815autodetected (or immediately if this has already happened). 932autodetected (or immediately if this has already happened).
816 933
934The block will be executed I<after> the actual backend has been detected
935(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
936created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
937other initialisations - see the sources of L<AnyEvent::Strict> or
938L<AnyEvent::AIO> to see how this is used.
939
940The most common usage is to create some global watchers, without forcing
941event module detection too early, for example, L<AnyEvent::AIO> creates
942and installs the global L<IO::AIO> watcher in a C<post_detect> block to
943avoid autodetecting the event module at load time.
944
817If called in scalar or list context, then it creates and returns an object 945If called in scalar or list context, then it creates and returns an object
818that automatically removes the callback again when it is destroyed. See 946that automatically removes the callback again when it is destroyed (or
947C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
819L<Coro::BDB> for a case where this is useful. 948a case where this is useful.
949
950Example: Create a watcher for the IO::AIO module and store it in
951C<$WATCHER>. Only do so after the event loop is initialised, though.
952
953 our WATCHER;
954
955 my $guard = AnyEvent::post_detect {
956 $WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
957 };
958
959 # the ||= is important in case post_detect immediately runs the block,
960 # as to not clobber the newly-created watcher. assigning both watcher and
961 # post_detect guard to the same variable has the advantage of users being
962 # able to just C<undef $WATCHER> if the watcher causes them grief.
963
964 $WATCHER ||= $guard;
820 965
821=item @AnyEvent::post_detect 966=item @AnyEvent::post_detect
822 967
823If there are any code references in this array (you can C<push> to it 968If there are any code references in this array (you can C<push> to it
824before or after loading AnyEvent), then they will called directly after 969before or after loading AnyEvent), then they will called directly after
825the event loop has been chosen. 970the event loop has been chosen.
826 971
827You should check C<$AnyEvent::MODEL> before adding to this array, though: 972You should check C<$AnyEvent::MODEL> before adding to this array, though:
828if it contains a true value then the event loop has already been detected, 973if it is defined then the event loop has already been detected, and the
829and the array will be ignored. 974array will be ignored.
830 975
831Best use C<AnyEvent::post_detect { BLOCK }> instead. 976Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
977it, as it takes care of these details.
978
979This variable is mainly useful for modules that can do something useful
980when AnyEvent is used and thus want to know when it is initialised, but do
981not need to even load it by default. This array provides the means to hook
982into AnyEvent passively, without loading it.
983
984Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
985together, you could put this into Coro (this is the actual code used by
986Coro to accomplish this):
987
988 if (defined $AnyEvent::MODEL) {
989 # AnyEvent already initialised, so load Coro::AnyEvent
990 require Coro::AnyEvent;
991 } else {
992 # AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
993 # as soon as it is
994 push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
995 }
832 996
833=back 997=back
834 998
835=head1 WHAT TO DO IN A MODULE 999=head1 WHAT TO DO IN A MODULE
836 1000
891 1055
892 1056
893=head1 OTHER MODULES 1057=head1 OTHER MODULES
894 1058
895The following is a non-exhaustive list of additional modules that use 1059The following is a non-exhaustive list of additional modules that use
896AnyEvent and can therefore be mixed easily with other AnyEvent modules 1060AnyEvent as a client and can therefore be mixed easily with other AnyEvent
897in the same program. Some of the modules come with AnyEvent, some are 1061modules and other event loops in the same program. Some of the modules
898available via CPAN. 1062come with AnyEvent, most are available via CPAN.
899 1063
900=over 4 1064=over 4
901 1065
902=item L<AnyEvent::Util> 1066=item L<AnyEvent::Util>
903 1067
912 1076
913=item L<AnyEvent::Handle> 1077=item L<AnyEvent::Handle>
914 1078
915Provide read and write buffers, manages watchers for reads and writes, 1079Provide read and write buffers, manages watchers for reads and writes,
916supports raw and formatted I/O, I/O queued and fully transparent and 1080supports raw and formatted I/O, I/O queued and fully transparent and
917non-blocking SSL/TLS. 1081non-blocking SSL/TLS (via L<AnyEvent::TLS>.
918 1082
919=item L<AnyEvent::DNS> 1083=item L<AnyEvent::DNS>
920 1084
921Provides rich asynchronous DNS resolver capabilities. 1085Provides rich asynchronous DNS resolver capabilities.
922 1086
950 1114
951=item L<AnyEvent::GPSD> 1115=item L<AnyEvent::GPSD>
952 1116
953A non-blocking interface to gpsd, a daemon delivering GPS information. 1117A non-blocking interface to gpsd, a daemon delivering GPS information.
954 1118
1119=item L<AnyEvent::IRC>
1120
1121AnyEvent based IRC client module family (replacing the older Net::IRC3).
1122
1123=item L<AnyEvent::XMPP>
1124
1125AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1126Net::XMPP2>.
1127
955=item L<AnyEvent::IGS> 1128=item L<AnyEvent::IGS>
956 1129
957A non-blocking interface to the Internet Go Server protocol (used by 1130A non-blocking interface to the Internet Go Server protocol (used by
958L<App::IGS>). 1131L<App::IGS>).
959 1132
960=item L<AnyEvent::IRC>
961
962AnyEvent based IRC client module family (replacing the older Net::IRC3).
963
964=item L<Net::XMPP2>
965
966AnyEvent based XMPP (Jabber protocol) module family.
967
968=item L<Net::FCP> 1133=item L<Net::FCP>
969 1134
970AnyEvent-based implementation of the Freenet Client Protocol, birthplace 1135AnyEvent-based implementation of the Freenet Client Protocol, birthplace
971of AnyEvent. 1136of AnyEvent.
972 1137
976 1141
977=item L<Coro> 1142=item L<Coro>
978 1143
979Has special support for AnyEvent via L<Coro::AnyEvent>. 1144Has special support for AnyEvent via L<Coro::AnyEvent>.
980 1145
981=item L<IO::Lambda>
982
983The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
984
985=back 1146=back
986 1147
987=cut 1148=cut
988 1149
989package AnyEvent; 1150package AnyEvent;
990 1151
991no warnings; 1152# basically a tuned-down version of common::sense
992use strict qw(vars subs); 1153sub common_sense {
1154 # from common:.sense 1.0
1155 ${^WARNING_BITS} = "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x00";
1156 # use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1157 $^H |= 0x00000600;
1158}
993 1159
1160BEGIN { AnyEvent::common_sense }
1161
994use Carp; 1162use Carp ();
995 1163
996our $VERSION = 4.8; 1164our $VERSION = '5.261';
997our $MODEL; 1165our $MODEL;
998 1166
999our $AUTOLOAD; 1167our $AUTOLOAD;
1000our @ISA; 1168our @ISA;
1001 1169
1002our @REGISTRY; 1170our @REGISTRY;
1003 1171
1004our $WIN32; 1172our $VERBOSE;
1005 1173
1006BEGIN { 1174BEGIN {
1007 eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }"; 1175 require "AnyEvent/constants.pl";
1176
1008 eval "sub TAINT(){ " . (${^TAINT}*1) . " }"; 1177 eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1009 1178
1010 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV} 1179 delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1011 if ${^TAINT}; 1180 if ${^TAINT};
1012}
1013 1181
1014our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1; 1182 $VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
1183
1184}
1185
1186our $MAX_SIGNAL_LATENCY = 10;
1015 1187
1016our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred 1188our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
1017 1189
1018{ 1190{
1019 my $idx; 1191 my $idx;
1021 for reverse split /\s*,\s*/, 1193 for reverse split /\s*,\s*/,
1022 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6"; 1194 $ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1023} 1195}
1024 1196
1025my @models = ( 1197my @models = (
1026 [EV:: => AnyEvent::Impl::EV::], 1198 [EV:: => AnyEvent::Impl::EV:: , 1],
1027 [Event:: => AnyEvent::Impl::Event::],
1028 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::], 1199 [AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1029 # everything below here will not be autoprobed 1200 # everything below here will not (normally) be autoprobed
1030 # as the pureperl backend should work everywhere 1201 # as the pureperl backend should work everywhere
1031 # and is usually faster 1202 # and is usually faster
1203 [Event:: => AnyEvent::Impl::Event::, 1],
1204 [Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1205 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1206 [Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1032 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles 1207 [Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1033 [Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
1034 [Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1035 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program 1208 [Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1036 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza 1209 [POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1037 [Wx:: => AnyEvent::Impl::POE::], 1210 [Wx:: => AnyEvent::Impl::POE::],
1038 [Prima:: => AnyEvent::Impl::POE::], 1211 [Prima:: => AnyEvent::Impl::POE::],
1039 # IO::Async is just too broken - we would need workaorunds for its 1212 # IO::Async is just too broken - we would need workarounds for its
1040 # byzantine signal and broken child handling, among others. 1213 # byzantine signal and broken child handling, among others.
1041 # IO::Async is rather hard to detect, as it doesn't have any 1214 # IO::Async is rather hard to detect, as it doesn't have any
1042 # obvious default class. 1215 # obvious default class.
1043# [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program 1216 [IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1044# [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program 1217 [IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1045# [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program 1218 [IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1219 [AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1046); 1220);
1047 1221
1048our %method = map +($_ => 1), 1222our %method = map +($_ => 1),
1049 qw(io timer time now now_update signal child idle condvar one_event DESTROY); 1223 qw(io timer time now now_update signal child idle condvar one_event DESTROY);
1050 1224
1051our @post_detect; 1225our @post_detect;
1052 1226
1053sub post_detect(&) { 1227sub post_detect(&) {
1054 my ($cb) = @_; 1228 my ($cb) = @_;
1055 1229
1056 if ($MODEL) {
1057 $cb->();
1058
1059 1
1060 } else {
1061 push @post_detect, $cb; 1230 push @post_detect, $cb;
1062 1231
1063 defined wantarray 1232 defined wantarray
1064 ? bless \$cb, "AnyEvent::Util::postdetect" 1233 ? bless \$cb, "AnyEvent::Util::postdetect"
1065 : () 1234 : ()
1066 }
1067} 1235}
1068 1236
1069sub AnyEvent::Util::postdetect::DESTROY { 1237sub AnyEvent::Util::postdetect::DESTROY {
1070 @post_detect = grep $_ != ${$_[0]}, @post_detect; 1238 @post_detect = grep $_ != ${$_[0]}, @post_detect;
1071} 1239}
1072 1240
1073sub detect() { 1241sub detect() {
1242 # free some memory
1243 *detect = sub () { $MODEL };
1244
1245 local $!; # for good measure
1246 local $SIG{__DIE__};
1247
1248 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1249 my $model = "AnyEvent::Impl::$1";
1250 if (eval "require $model") {
1251 $MODEL = $model;
1252 warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
1253 } else {
1254 warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1255 }
1256 }
1257
1258 # check for already loaded models
1074 unless ($MODEL) { 1259 unless ($MODEL) {
1075 no strict 'refs'; 1260 for (@REGISTRY, @models) {
1076 local $SIG{__DIE__}; 1261 my ($package, $model) = @$_;
1077 1262 if (${"$package\::VERSION"} > 0) {
1078 if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
1079 my $model = "AnyEvent::Impl::$1";
1080 if (eval "require $model") { 1263 if (eval "require $model") {
1081 $MODEL = $model; 1264 $MODEL = $model;
1082 warn "AnyEvent: loaded model '$model' (forced by \$PERL_ANYEVENT_MODEL), using it.\n" if $verbose > 1; 1265 warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1083 } else { 1266 last;
1084 warn "AnyEvent: unable to load model '$model' (from \$PERL_ANYEVENT_MODEL):\n$@" if $verbose; 1267 }
1085 } 1268 }
1086 } 1269 }
1087 1270
1088 # check for already loaded models
1089 unless ($MODEL) { 1271 unless ($MODEL) {
1272 # try to autoload a model
1090 for (@REGISTRY, @models) { 1273 for (@REGISTRY, @models) {
1091 my ($package, $model) = @$_; 1274 my ($package, $model, $autoload) = @$_;
1275 if (
1276 $autoload
1277 and eval "require $package"
1092 if (${"$package\::VERSION"} > 0) { 1278 and ${"$package\::VERSION"} > 0
1093 if (eval "require $model") { 1279 and eval "require $model"
1280 ) {
1094 $MODEL = $model; 1281 $MODEL = $model;
1095 warn "AnyEvent: autodetected model '$model', using it.\n" if $verbose > 1; 1282 warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1096 last; 1283 last;
1097 }
1098 } 1284 }
1099 } 1285 }
1100 1286
1101 unless ($MODEL) {
1102 # try to load a model
1103
1104 for (@REGISTRY, @models) {
1105 my ($package, $model) = @$_;
1106 if (eval "require $package"
1107 and ${"$package\::VERSION"} > 0
1108 and eval "require $model") {
1109 $MODEL = $model;
1110 warn "AnyEvent: autoprobed model '$model', using it.\n" if $verbose > 1;
1111 last;
1112 }
1113 }
1114
1115 $MODEL 1287 $MODEL
1116 or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n"; 1288 or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";
1117 }
1118 } 1289 }
1119
1120 push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1121
1122 unshift @ISA, $MODEL;
1123
1124 require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1125
1126 (shift @post_detect)->() while @post_detect;
1127 } 1290 }
1291
1292 @models = (); # free probe data
1293
1294 push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1295 unshift @ISA, $MODEL;
1296
1297 # now nuke some methods that are overriden by the backend.
1298 # SUPER is not allowed.
1299 for (qw(time signal child idle)) {
1300 undef &{"AnyEvent::Base::$_"}
1301 if defined &{"$MODEL\::$_"};
1302 }
1303
1304 require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1305
1306 (shift @post_detect)->() while @post_detect;
1307
1308 *post_detect = sub(&) {
1309 shift->();
1310
1311 undef
1312 };
1128 1313
1129 $MODEL 1314 $MODEL
1130} 1315}
1131 1316
1132sub AUTOLOAD { 1317sub AUTOLOAD {
1133 (my $func = $AUTOLOAD) =~ s/.*://; 1318 (my $func = $AUTOLOAD) =~ s/.*://;
1134 1319
1135 $method{$func} 1320 $method{$func}
1136 or croak "$func: not a valid method for AnyEvent objects"; 1321 or Carp::croak "$func: not a valid AnyEvent class method";
1137 1322
1138 detect unless $MODEL; 1323 detect;
1139 1324
1140 my $class = shift; 1325 my $class = shift;
1141 $class->$func (@_); 1326 $class->$func (@_);
1142} 1327}
1143 1328
1146# allow only one watcher per fd, so we dup it to get a different one). 1331# allow only one watcher per fd, so we dup it to get a different one).
1147sub _dupfh($$;$$) { 1332sub _dupfh($$;$$) {
1148 my ($poll, $fh, $r, $w) = @_; 1333 my ($poll, $fh, $r, $w) = @_;
1149 1334
1150 # cygwin requires the fh mode to be matching, unix doesn't 1335 # cygwin requires the fh mode to be matching, unix doesn't
1151 my ($rw, $mode) = $poll eq "r" ? ($r, "<") 1336 my ($rw, $mode) = $poll eq "r" ? ($r, "<&") : ($w, ">&");
1152 : $poll eq "w" ? ($w, ">")
1153 : Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
1154 1337
1155 open my $fh2, "$mode&" . fileno $fh 1338 open my $fh2, $mode, $fh
1156 or die "cannot dup() filehandle: $!,"; 1339 or die "AnyEvent->io: cannot dup() filehandle in mode '$poll': $!,";
1157 1340
1158 # we assume CLOEXEC is already set by perl in all important cases 1341 # we assume CLOEXEC is already set by perl in all important cases
1159 1342
1160 ($fh2, $rw) 1343 ($fh2, $rw)
1161} 1344}
1162 1345
1346=head1 SIMPLIFIED AE API
1347
1348Starting with version 5.0, AnyEvent officially supports a second, much
1349simpler, API that is designed to reduce the calling, typing and memory
1350overhead by using function call syntax and a fixed number of parameters.
1351
1352See the L<AE> manpage for details.
1353
1354=cut
1355
1356package AE;
1357
1358our $VERSION = $AnyEvent::VERSION;
1359
1360# fall back to the main API by default - backends and AnyEvent::Base
1361# implementations can overwrite these.
1362
1363sub io($$$) {
1364 AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1365}
1366
1367sub timer($$$) {
1368 AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
1369}
1370
1371sub signal($$) {
1372 AnyEvent->signal (signal => $_[0], cb => $_[1])
1373}
1374
1375sub child($$) {
1376 AnyEvent->child (pid => $_[0], cb => $_[1])
1377}
1378
1379sub idle($) {
1380 AnyEvent->idle (cb => $_[0])
1381}
1382
1383sub cv(;&) {
1384 AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
1385}
1386
1387sub now() {
1388 AnyEvent->now
1389}
1390
1391sub now_update() {
1392 AnyEvent->now_update
1393}
1394
1395sub time() {
1396 AnyEvent->time
1397}
1398
1163package AnyEvent::Base; 1399package AnyEvent::Base;
1164 1400
1165# default implementations for many methods 1401# default implementations for many methods
1166 1402
1167BEGIN { 1403sub time {
1404 eval q{ # poor man's autoloading {}
1405 # probe for availability of Time::HiRes
1168 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") { 1406 if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1407 warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1169 *_time = \&Time::HiRes::time; 1408 *AE::time = \&Time::HiRes::time;
1170 # if (eval "use POSIX (); (POSIX::times())... 1409 # if (eval "use POSIX (); (POSIX::times())...
1171 } else { 1410 } else {
1411 warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1172 *_time = sub { time }; # epic fail 1412 *AE::time = sub (){ time }; # epic fail
1413 }
1414
1415 *time = sub { AE::time }; # different prototypes
1416 };
1417 die if $@;
1418
1419 &time
1420}
1421
1422*now = \&time;
1423
1424sub now_update { }
1425
1426# default implementation for ->condvar
1427
1428sub condvar {
1429 eval q{ # poor man's autoloading {}
1430 *condvar = sub {
1431 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1432 };
1433
1434 *AE::cv = sub (;&) {
1435 bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
1436 };
1437 };
1438 die if $@;
1439
1440 &condvar
1441}
1442
1443# default implementation for ->signal
1444
1445our $HAVE_ASYNC_INTERRUPT;
1446
1447sub _have_async_interrupt() {
1448 $HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
1449 && eval "use Async::Interrupt 1.02 (); 1")
1450 unless defined $HAVE_ASYNC_INTERRUPT;
1451
1452 $HAVE_ASYNC_INTERRUPT
1453}
1454
1455our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1456our (%SIG_ASY, %SIG_ASY_W);
1457our ($SIG_COUNT, $SIG_TW);
1458
1459# install a dummy wakeup watcher to reduce signal catching latency
1460# used by Impls
1461sub _sig_add() {
1462 unless ($SIG_COUNT++) {
1463 # try to align timer on a full-second boundary, if possible
1464 my $NOW = AE::now;
1465
1466 $SIG_TW = AE::timer
1467 $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1468 $MAX_SIGNAL_LATENCY,
1469 sub { } # just for the PERL_ASYNC_CHECK
1470 ;
1173 } 1471 }
1174} 1472}
1175 1473
1176sub time { _time } 1474sub _sig_del {
1177sub now { _time } 1475 undef $SIG_TW
1178sub now_update { } 1476 unless --$SIG_COUNT;
1179
1180# default implementation for ->condvar
1181
1182sub condvar {
1183 bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
1184} 1477}
1185 1478
1186# default implementation for ->signal 1479our $_sig_name_init; $_sig_name_init = sub {
1480 eval q{ # poor man's autoloading {}
1481 undef $_sig_name_init;
1187 1482
1188our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO); 1483 if (_have_async_interrupt) {
1484 *sig2num = \&Async::Interrupt::sig2num;
1485 *sig2name = \&Async::Interrupt::sig2name;
1486 } else {
1487 require Config;
1189 1488
1190sub _signal_exec { 1489 my %signame2num;
1191 sysread $SIGPIPE_R, my $dummy, 4; 1490 @signame2num{ split ' ', $Config::Config{sig_name} }
1491 = split ' ', $Config::Config{sig_num};
1192 1492
1193 while (%SIG_EV) { 1493 my @signum2name;
1194 for (keys %SIG_EV) { 1494 @signum2name[values %signame2num] = keys %signame2num;
1195 delete $SIG_EV{$_}; 1495
1196 $_->() for values %{ $SIG_CB{$_} || {} }; 1496 *sig2num = sub($) {
1497 $_[0] > 0 ? shift : $signame2num{+shift}
1498 };
1499 *sig2name = sub ($) {
1500 $_[0] > 0 ? $signum2name[+shift] : shift
1501 };
1197 } 1502 }
1198 } 1503 };
1199} 1504 die if $@;
1505};
1506
1507sub sig2num ($) { &$_sig_name_init; &sig2num }
1508sub sig2name($) { &$_sig_name_init; &sig2name }
1200 1509
1201sub signal { 1510sub signal {
1202 my (undef, %arg) = @_; 1511 eval q{ # poor man's autoloading {}
1512 # probe for availability of Async::Interrupt
1513 if (_have_async_interrupt) {
1514 warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1203 1515
1204 unless ($SIGPIPE_R) { 1516 $SIGPIPE_R = new Async::Interrupt::EventPipe;
1205 require Fcntl; 1517 $SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1206 1518
1207 if (AnyEvent::WIN32) {
1208 require AnyEvent::Util;
1209
1210 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1211 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1212 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1213 } else { 1519 } else {
1520 warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1521
1522 if (AnyEvent::WIN32) {
1523 require AnyEvent::Util;
1524
1525 ($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1526 AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1527 AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1528 } else {
1214 pipe $SIGPIPE_R, $SIGPIPE_W; 1529 pipe $SIGPIPE_R, $SIGPIPE_W;
1215 fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R; 1530 fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
1216 fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case 1531 fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
1217 1532
1218 # not strictly required, as $^F is normally 2, but let's make sure... 1533 # not strictly required, as $^F is normally 2, but let's make sure...
1219 fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; 1534 fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1220 fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC; 1535 fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1536 }
1537
1538 $SIGPIPE_R
1539 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1540
1541 $SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1221 } 1542 }
1222 1543
1223 $SIGPIPE_R 1544 *signal = $HAVE_ASYNC_INTERRUPT
1224 or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n"; 1545 ? sub {
1546 my (undef, %arg) = @_;
1225 1547
1226 $SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec); 1548 # async::interrupt
1227 }
1228
1229 my $signal = uc $arg{signal} 1549 my $signal = sig2num $arg{signal};
1230 or Carp::croak "required option 'signal' is missing";
1231
1232 $SIG_CB{$signal}{$arg{cb}} = $arg{cb}; 1550 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1551
1552 $SIG_ASY{$signal} ||= new Async::Interrupt
1553 cb => sub { undef $SIG_EV{$signal} },
1554 signal => $signal,
1555 pipe => [$SIGPIPE_R->filenos],
1556 pipe_autodrain => 0,
1557 ;
1558
1559 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1560 }
1561 : sub {
1562 my (undef, %arg) = @_;
1563
1564 # pure perl
1565 my $signal = sig2name $arg{signal};
1566 $SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1567
1233 $SIG{$signal} ||= sub { 1568 $SIG{$signal} ||= sub {
1234 local $!; 1569 local $!;
1235 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV; 1570 syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1236 undef $SIG_EV{$signal}; 1571 undef $SIG_EV{$signal};
1572 };
1573
1574 # can't do signal processing without introducing races in pure perl,
1575 # so limit the signal latency.
1576 _sig_add;
1577
1578 bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
1579 }
1580 ;
1581
1582 *AnyEvent::Base::signal::DESTROY = sub {
1583 my ($signal, $cb) = @{$_[0]};
1584
1585 _sig_del;
1586
1587 delete $SIG_CB{$signal}{$cb};
1588
1589 $HAVE_ASYNC_INTERRUPT
1590 ? delete $SIG_ASY{$signal}
1591 : # delete doesn't work with older perls - they then
1592 # print weird messages, or just unconditionally exit
1593 # instead of getting the default action.
1594 undef $SIG{$signal}
1595 unless keys %{ $SIG_CB{$signal} };
1596 };
1597
1598 *_signal_exec = sub {
1599 $HAVE_ASYNC_INTERRUPT
1600 ? $SIGPIPE_R->drain
1601 : sysread $SIGPIPE_R, (my $dummy), 9;
1602
1603 while (%SIG_EV) {
1604 for (keys %SIG_EV) {
1605 delete $SIG_EV{$_};
1606 $_->() for values %{ $SIG_CB{$_} || {} };
1607 }
1608 }
1609 };
1237 }; 1610 };
1611 die if $@;
1238 1612
1239 bless [$signal, $arg{cb}], "AnyEvent::Base::signal" 1613 &signal
1240}
1241
1242sub AnyEvent::Base::signal::DESTROY {
1243 my ($signal, $cb) = @{$_[0]};
1244
1245 delete $SIG_CB{$signal}{$cb};
1246
1247 # delete doesn't work with older perls - they then
1248 # print weird messages, or just unconditionally exit
1249 # instead of getting the default action.
1250 undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
1251} 1614}
1252 1615
1253# default implementation for ->child 1616# default implementation for ->child
1254 1617
1255our %PID_CB; 1618our %PID_CB;
1256our $CHLD_W; 1619our $CHLD_W;
1257our $CHLD_DELAY_W; 1620our $CHLD_DELAY_W;
1258our $WNOHANG; 1621our $WNOHANG;
1259 1622
1260sub _sigchld { 1623# used by many Impl's
1261 while (0 < (my $pid = waitpid -1, $WNOHANG)) { 1624sub _emit_childstatus($$) {
1625 my (undef, $rpid, $rstatus) = @_;
1626
1627 $_->($rpid, $rstatus)
1262 $_->($pid, $?) for (values %{ $PID_CB{$pid} || {} }), 1628 for values %{ $PID_CB{$rpid} || {} },
1263 (values %{ $PID_CB{0} || {} }); 1629 values %{ $PID_CB{0} || {} };
1264 }
1265} 1630}
1266 1631
1267sub child { 1632sub child {
1633 eval q{ # poor man's autoloading {}
1634 *_sigchld = sub {
1635 my $pid;
1636
1637 AnyEvent->_emit_childstatus ($pid, $?)
1638 while ($pid = waitpid -1, $WNOHANG) > 0;
1639 };
1640
1641 *child = sub {
1268 my (undef, %arg) = @_; 1642 my (undef, %arg) = @_;
1269 1643
1270 defined (my $pid = $arg{pid} + 0) 1644 defined (my $pid = $arg{pid} + 0)
1271 or Carp::croak "required option 'pid' is missing"; 1645 or Carp::croak "required option 'pid' is missing";
1272 1646
1273 $PID_CB{$pid}{$arg{cb}} = $arg{cb}; 1647 $PID_CB{$pid}{$arg{cb}} = $arg{cb};
1274 1648
1649 # WNOHANG is almost cetrainly 1 everywhere
1650 $WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1651 ? 1
1275 $WNOHANG ||= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1; 1652 : eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1276 1653
1277 unless ($CHLD_W) { 1654 unless ($CHLD_W) {
1278 $CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld); 1655 $CHLD_W = AE::signal CHLD => \&_sigchld;
1279 # child could be a zombie already, so make at least one round 1656 # child could be a zombie already, so make at least one round
1280 &_sigchld; 1657 &_sigchld;
1281 } 1658 }
1282 1659
1283 bless [$pid, $arg{cb}], "AnyEvent::Base::child" 1660 bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1284} 1661 };
1285 1662
1286sub AnyEvent::Base::child::DESTROY { 1663 *AnyEvent::Base::child::DESTROY = sub {
1287 my ($pid, $cb) = @{$_[0]}; 1664 my ($pid, $cb) = @{$_[0]};
1288 1665
1289 delete $PID_CB{$pid}{$cb}; 1666 delete $PID_CB{$pid}{$cb};
1290 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} }; 1667 delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1291 1668
1292 undef $CHLD_W unless keys %PID_CB; 1669 undef $CHLD_W unless keys %PID_CB;
1670 };
1671 };
1672 die if $@;
1673
1674 &child
1293} 1675}
1294 1676
1295# idle emulation is done by simply using a timer, regardless 1677# idle emulation is done by simply using a timer, regardless
1296# of whether the process is idle or not, and not letting 1678# of whether the process is idle or not, and not letting
1297# the callback use more than 50% of the time. 1679# the callback use more than 50% of the time.
1298sub idle { 1680sub idle {
1681 eval q{ # poor man's autoloading {}
1682 *idle = sub {
1299 my (undef, %arg) = @_; 1683 my (undef, %arg) = @_;
1300 1684
1301 my ($cb, $w, $rcb) = $arg{cb}; 1685 my ($cb, $w, $rcb) = $arg{cb};
1302 1686
1303 $rcb = sub { 1687 $rcb = sub {
1304 if ($cb) { 1688 if ($cb) {
1305 $w = _time; 1689 $w = _time;
1306 &$cb; 1690 &$cb;
1307 $w = _time - $w; 1691 $w = _time - $w;
1308 1692
1309 # never use more then 50% of the time for the idle watcher, 1693 # never use more then 50% of the time for the idle watcher,
1310 # within some limits 1694 # within some limits
1311 $w = 0.0001 if $w < 0.0001; 1695 $w = 0.0001 if $w < 0.0001;
1312 $w = 5 if $w > 5; 1696 $w = 5 if $w > 5;
1313 1697
1314 $w = AnyEvent->timer (after => $w, cb => $rcb); 1698 $w = AE::timer $w, 0, $rcb;
1315 } else { 1699 } else {
1316 # clean up... 1700 # clean up...
1317 undef $w; 1701 undef $w;
1318 undef $rcb; 1702 undef $rcb;
1703 }
1704 };
1705
1706 $w = AE::timer 0.05, 0, $rcb;
1707
1708 bless \\$cb, "AnyEvent::Base::idle"
1319 } 1709 };
1710
1711 *AnyEvent::Base::idle::DESTROY = sub {
1712 undef $${$_[0]};
1713 };
1320 }; 1714 };
1715 die if $@;
1321 1716
1322 $w = AnyEvent->timer (after => 0.05, cb => $rcb); 1717 &idle
1323
1324 bless \\$cb, "AnyEvent::Base::idle"
1325}
1326
1327sub AnyEvent::Base::idle::DESTROY {
1328 undef $${$_[0]};
1329} 1718}
1330 1719
1331package AnyEvent::CondVar; 1720package AnyEvent::CondVar;
1332 1721
1333our @ISA = AnyEvent::CondVar::Base::; 1722our @ISA = AnyEvent::CondVar::Base::;
1334 1723
1335package AnyEvent::CondVar::Base; 1724package AnyEvent::CondVar::Base;
1336 1725
1337use overload 1726#use overload
1338 '&{}' => sub { my $self = shift; sub { $self->send (@_) } }, 1727# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1339 fallback => 1; 1728# fallback => 1;
1729
1730# save 300+ kilobytes by dirtily hardcoding overloading
1731${"AnyEvent::CondVar::Base::OVERLOAD"}{dummy}++; # Register with magic by touching.
1732*{'AnyEvent::CondVar::Base::()'} = sub { }; # "Make it findable via fetchmethod."
1733*{'AnyEvent::CondVar::Base::(&{}'} = sub { my $self = shift; sub { $self->send (@_) } }; # &{}
1734${'AnyEvent::CondVar::Base::()'} = 1; # fallback
1735
1736our $WAITING;
1340 1737
1341sub _send { 1738sub _send {
1342 # nop 1739 # nop
1343} 1740}
1344 1741
1357sub ready { 1754sub ready {
1358 $_[0]{_ae_sent} 1755 $_[0]{_ae_sent}
1359} 1756}
1360 1757
1361sub _wait { 1758sub _wait {
1759 $WAITING
1760 and !$_[0]{_ae_sent}
1761 and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1762
1763 local $WAITING = 1;
1362 AnyEvent->one_event while !$_[0]{_ae_sent}; 1764 AnyEvent->one_event while !$_[0]{_ae_sent};
1363} 1765}
1364 1766
1365sub recv { 1767sub recv {
1366 $_[0]->_wait; 1768 $_[0]->_wait;
1368 Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak}; 1770 Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1369 wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0] 1771 wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1370} 1772}
1371 1773
1372sub cb { 1774sub cb {
1373 $_[0]{_ae_cb} = $_[1] if @_ > 1; 1775 my $cv = shift;
1776
1777 @_
1778 and $cv->{_ae_cb} = shift
1779 and $cv->{_ae_sent}
1780 and (delete $cv->{_ae_cb})->($cv);
1781
1374 $_[0]{_ae_cb} 1782 $cv->{_ae_cb}
1375} 1783}
1376 1784
1377sub begin { 1785sub begin {
1378 ++$_[0]{_ae_counter}; 1786 ++$_[0]{_ae_counter};
1379 $_[0]{_ae_end_cb} = $_[1] if @_ > 1; 1787 $_[0]{_ae_end_cb} = $_[1] if @_ > 1;
1428C<PERL_ANYEVENT_MODEL>. 1836C<PERL_ANYEVENT_MODEL>.
1429 1837
1430When set to C<2> or higher, cause AnyEvent to report to STDERR which event 1838When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1431model it chooses. 1839model it chooses.
1432 1840
1841When set to C<8> or higher, then AnyEvent will report extra information on
1842which optional modules it loads and how it implements certain features.
1843
1433=item C<PERL_ANYEVENT_STRICT> 1844=item C<PERL_ANYEVENT_STRICT>
1434 1845
1435AnyEvent does not do much argument checking by default, as thorough 1846AnyEvent does not do much argument checking by default, as thorough
1436argument checking is very costly. Setting this variable to a true value 1847argument checking is very costly. Setting this variable to a true value
1437will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly 1848will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
1438check the arguments passed to most method calls. If it finds any problems, 1849check the arguments passed to most method calls. If it finds any problems,
1439it will croak. 1850it will croak.
1440 1851
1441In other words, enables "strict" mode. 1852In other words, enables "strict" mode.
1442 1853
1443Unlike C<use strict>, it is definitely recommended to keep it off in 1854Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>
1444production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while 1855>>, it is definitely recommended to keep it off in production. Keeping
1445developing programs can be very useful, however. 1856C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1857can be very useful, however.
1446 1858
1447=item C<PERL_ANYEVENT_MODEL> 1859=item C<PERL_ANYEVENT_MODEL>
1448 1860
1449This can be used to specify the event model to be used by AnyEvent, before 1861This can be used to specify the event model to be used by AnyEvent, before
1450auto detection and -probing kicks in. It must be a string consisting 1862auto detection and -probing kicks in. It must be a string consisting
1512 1924
1513When neither C<ca_file> nor C<ca_path> was specified during 1925When neither C<ca_file> nor C<ca_path> was specified during
1514L<AnyEvent::TLS> context creation, and either of these environment 1926L<AnyEvent::TLS> context creation, and either of these environment
1515variables exist, they will be used to specify CA certificate locations 1927variables exist, they will be used to specify CA certificate locations
1516instead of a system-dependent default. 1928instead of a system-dependent default.
1929
1930=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1931
1932When these are set to C<1>, then the respective modules are not
1933loaded. Mostly good for testing AnyEvent itself.
1517 1934
1518=back 1935=back
1519 1936
1520=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE 1937=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1521 1938
1579 warn "read: $input\n"; # output what has been read 1996 warn "read: $input\n"; # output what has been read
1580 $cv->send if $input =~ /^q/i; # quit program if /^q/i 1997 $cv->send if $input =~ /^q/i; # quit program if /^q/i
1581 }, 1998 },
1582 ); 1999 );
1583 2000
1584 my $time_watcher; # can only be used once
1585
1586 sub new_timer {
1587 $timer = AnyEvent->timer (after => 1, cb => sub { 2001 my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1588 warn "timeout\n"; # print 'timeout' about every second 2002 warn "timeout\n"; # print 'timeout' at most every second
1589 &new_timer; # and restart the time
1590 }); 2003 });
1591 }
1592
1593 new_timer; # create first timer
1594 2004
1595 $cv->recv; # wait until user enters /^q/i 2005 $cv->recv; # wait until user enters /^q/i
1596 2006
1597=head1 REAL-WORLD EXAMPLE 2007=head1 REAL-WORLD EXAMPLE
1598 2008
1671 2081
1672The actual code goes further and collects all errors (C<die>s, exceptions) 2082The actual code goes further and collects all errors (C<die>s, exceptions)
1673that occurred during request processing. The C<result> method detects 2083that occurred during request processing. The C<result> method detects
1674whether an exception as thrown (it is stored inside the $txn object) 2084whether an exception as thrown (it is stored inside the $txn object)
1675and just throws the exception, which means connection errors and other 2085and just throws the exception, which means connection errors and other
1676problems get reported tot he code that tries to use the result, not in a 2086problems get reported to the code that tries to use the result, not in a
1677random callback. 2087random callback.
1678 2088
1679All of this enables the following usage styles: 2089All of this enables the following usage styles:
1680 2090
16811. Blocking: 20911. Blocking:
1729through AnyEvent. The benchmark creates a lot of timers (with a zero 2139through AnyEvent. The benchmark creates a lot of timers (with a zero
1730timeout) and I/O watchers (watching STDOUT, a pty, to become writable, 2140timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1731which it is), lets them fire exactly once and destroys them again. 2141which it is), lets them fire exactly once and destroys them again.
1732 2142
1733Source code for this benchmark is found as F<eg/bench> in the AnyEvent 2143Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1734distribution. 2144distribution. It uses the L<AE> interface, which makes a real difference
2145for the EV and Perl backends only.
1735 2146
1736=head3 Explanation of the columns 2147=head3 Explanation of the columns
1737 2148
1738I<watcher> is the number of event watchers created/destroyed. Since 2149I<watcher> is the number of event watchers created/destroyed. Since
1739different event models feature vastly different performances, each event 2150different event models feature vastly different performances, each event
1760watcher. 2171watcher.
1761 2172
1762=head3 Results 2173=head3 Results
1763 2174
1764 name watchers bytes create invoke destroy comment 2175 name watchers bytes create invoke destroy comment
1765 EV/EV 400000 224 0.47 0.35 0.27 EV native interface 2176 EV/EV 100000 223 0.47 0.43 0.27 EV native interface
1766 EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers 2177 EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
1767 CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal 2178 Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
1768 Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation 2179 Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
1769 Event/Event 16000 517 32.20 31.80 0.81 Event native interface 2180 Event/Event 16000 516 31.16 31.84 0.82 Event native interface
1770 Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers 2181 Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
1771 IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll 2182 IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
1772 IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll 2183 IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
1773 Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour 2184 Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
1774 Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers 2185 Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
1775 POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event 2186 POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
1776 POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select 2187 POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
1777 2188
1778=head3 Discussion 2189=head3 Discussion
1779 2190
1780The benchmark does I<not> measure scalability of the event loop very 2191The benchmark does I<not> measure scalability of the event loop very
1781well. For example, a select-based event loop (such as the pure perl one) 2192well. For example, a select-based event loop (such as the pure perl one)
1793benchmark machine, handling an event takes roughly 1600 CPU cycles with 2204benchmark machine, handling an event takes roughly 1600 CPU cycles with
1794EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU 2205EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
1795cycles with POE. 2206cycles with POE.
1796 2207
1797C<EV> is the sole leader regarding speed and memory use, which are both 2208C<EV> is the sole leader regarding speed and memory use, which are both
1798maximal/minimal, respectively. Even when going through AnyEvent, it uses 2209maximal/minimal, respectively. When using the L<AE> API there is zero
2210overhead (when going through the AnyEvent API create is about 5-6 times
2211slower, with other times being equal, so still uses far less memory than
1799far less memory than any other event loop and is still faster than Event 2212any other event loop and is still faster than Event natively).
1800natively.
1801 2213
1802The pure perl implementation is hit in a few sweet spots (both the 2214The pure perl implementation is hit in a few sweet spots (both the
1803constant timeout and the use of a single fd hit optimisations in the perl 2215constant timeout and the use of a single fd hit optimisations in the perl
1804interpreter and the backend itself). Nevertheless this shows that it 2216interpreter and the backend itself). Nevertheless this shows that it
1805adds very little overhead in itself. Like any select-based backend its 2217adds very little overhead in itself. Like any select-based backend its
1879In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100 2291In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
1880(1%) are active. This mirrors the activity of large servers with many 2292(1%) are active. This mirrors the activity of large servers with many
1881connections, most of which are idle at any one point in time. 2293connections, most of which are idle at any one point in time.
1882 2294
1883Source code for this benchmark is found as F<eg/bench2> in the AnyEvent 2295Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
1884distribution. 2296distribution. It uses the L<AE> interface, which makes a real difference
2297for the EV and Perl backends only.
1885 2298
1886=head3 Explanation of the columns 2299=head3 Explanation of the columns
1887 2300
1888I<sockets> is the number of sockets, and twice the number of "servers" (as 2301I<sockets> is the number of sockets, and twice the number of "servers" (as
1889each server has a read and write socket end). 2302each server has a read and write socket end).
1897a new one that moves the timeout into the future. 2310a new one that moves the timeout into the future.
1898 2311
1899=head3 Results 2312=head3 Results
1900 2313
1901 name sockets create request 2314 name sockets create request
1902 EV 20000 69.01 11.16 2315 EV 20000 62.66 7.99
1903 Perl 20000 73.32 35.87 2316 Perl 20000 68.32 32.64
1904 IOAsync 20000 157.00 98.14 epoll 2317 IOAsync 20000 174.06 101.15 epoll
1905 IOAsync 20000 159.31 616.06 poll 2318 IOAsync 20000 174.67 610.84 poll
1906 Event 20000 212.62 257.32 2319 Event 20000 202.69 242.91
1907 Glib 20000 651.16 1896.30 2320 Glib 20000 557.01 1689.52
1908 POE 20000 349.67 12317.24 uses POE::Loop::Event 2321 POE 20000 341.54 12086.32 uses POE::Loop::Event
1909 2322
1910=head3 Discussion 2323=head3 Discussion
1911 2324
1912This benchmark I<does> measure scalability and overall performance of the 2325This benchmark I<does> measure scalability and overall performance of the
1913particular event loop. 2326particular event loop.
2039As you can see, the AnyEvent + EV combination even beats the 2452As you can see, the AnyEvent + EV combination even beats the
2040hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl 2453hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2041backend easily beats IO::Lambda and POE. 2454backend easily beats IO::Lambda and POE.
2042 2455
2043And even the 100% non-blocking version written using the high-level (and 2456And even the 100% non-blocking version written using the high-level (and
2044slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a 2457slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2045large margin, even though it does all of DNS, tcp-connect and socket I/O 2458higher level ("unoptimised") abstractions by a large margin, even though
2046in a non-blocking way. 2459it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2047 2460
2048The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and 2461The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2049F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are 2462F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2050part of the IO::lambda distribution and were used without any changes. 2463part of the IO::Lambda distribution and were used without any changes.
2051 2464
2052 2465
2053=head1 SIGNALS 2466=head1 SIGNALS
2054 2467
2055AnyEvent currently installs handlers for these signals: 2468AnyEvent currently installs handlers for these signals:
2060 2473
2061A handler for C<SIGCHLD> is installed by AnyEvent's child watcher 2474A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
2062emulation for event loops that do not support them natively. Also, some 2475emulation for event loops that do not support them natively. Also, some
2063event loops install a similar handler. 2476event loops install a similar handler.
2064 2477
2065If, when AnyEvent is loaded, SIGCHLD is set to IGNORE, then AnyEvent will 2478Additionally, when AnyEvent is loaded and SIGCHLD is set to IGNORE, then
2066reset it to default, to avoid losing child exit statuses. 2479AnyEvent will reset it to default, to avoid losing child exit statuses.
2067 2480
2068=item SIGPIPE 2481=item SIGPIPE
2069 2482
2070A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef> 2483A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
2071when AnyEvent gets loaded. 2484when AnyEvent gets loaded.
2089 if $SIG{CHLD} eq 'IGNORE'; 2502 if $SIG{CHLD} eq 'IGNORE';
2090 2503
2091$SIG{PIPE} = sub { } 2504$SIG{PIPE} = sub { }
2092 unless defined $SIG{PIPE}; 2505 unless defined $SIG{PIPE};
2093 2506
2507=head1 RECOMMENDED/OPTIONAL MODULES
2508
2509One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2510it's built-in modules) are required to use it.
2511
2512That does not mean that AnyEvent won't take advantage of some additional
2513modules if they are installed.
2514
2515This section explains which additional modules will be used, and how they
2516affect AnyEvent's operation.
2517
2518=over 4
2519
2520=item L<Async::Interrupt>
2521
2522This slightly arcane module is used to implement fast signal handling: To
2523my knowledge, there is no way to do completely race-free and quick
2524signal handling in pure perl. To ensure that signals still get
2525delivered, AnyEvent will start an interval timer to wake up perl (and
2526catch the signals) with some delay (default is 10 seconds, look for
2527C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2528
2529If this module is available, then it will be used to implement signal
2530catching, which means that signals will not be delayed, and the event loop
2531will not be interrupted regularly, which is more efficient (and good for
2532battery life on laptops).
2533
2534This affects not just the pure-perl event loop, but also other event loops
2535that have no signal handling on their own (e.g. Glib, Tk, Qt).
2536
2537Some event loops (POE, Event, Event::Lib) offer signal watchers natively,
2538and either employ their own workarounds (POE) or use AnyEvent's workaround
2539(using C<$AnyEvent::MAX_SIGNAL_LATENCY>). Installing L<Async::Interrupt>
2540does nothing for those backends.
2541
2542=item L<EV>
2543
2544This module isn't really "optional", as it is simply one of the backend
2545event loops that AnyEvent can use. However, it is simply the best event
2546loop available in terms of features, speed and stability: It supports
2547the AnyEvent API optimally, implements all the watcher types in XS, does
2548automatic timer adjustments even when no monotonic clock is available,
2549can take avdantage of advanced kernel interfaces such as C<epoll> and
2550C<kqueue>, and is the fastest backend I<by far>. You can even embed
2551L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2552
2553If you only use backends that rely on another event loop (e.g. C<Tk>),
2554then this module will do nothing for you.
2555
2556=item L<Guard>
2557
2558The guard module, when used, will be used to implement
2559C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2560lot less memory), but otherwise doesn't affect guard operation much. It is
2561purely used for performance.
2562
2563=item L<JSON> and L<JSON::XS>
2564
2565One of these modules is required when you want to read or write JSON data
2566via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2567advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2568
2569=item L<Net::SSLeay>
2570
2571Implementing TLS/SSL in Perl is certainly interesting, but not very
2572worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2573the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2574
2575=item L<Time::HiRes>
2576
2577This module is part of perl since release 5.008. It will be used when the
2578chosen event library does not come with a timing source on it's own. The
2579pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
2580try to use a monotonic clock for timing stability.
2581
2582=back
2583
2584
2094=head1 FORK 2585=head1 FORK
2095 2586
2096Most event libraries are not fork-safe. The ones who are usually are 2587Most event libraries are not fork-safe. The ones who are usually are
2097because they rely on inefficient but fork-safe C<select> or C<poll> 2588because they rely on inefficient but fork-safe C<select> or C<poll> calls
2098calls. Only L<EV> is fully fork-aware. 2589- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
2590are usually badly thought-out hacks that are incompatible with fork in
2591one way or another. Only L<EV> is fully fork-aware and ensures that you
2592continue event-processing in both parent and child (or both, if you know
2593what you are doing).
2594
2595This means that, in general, you cannot fork and do event processing in
2596the child if the event library was initialised before the fork (which
2597usually happens when the first AnyEvent watcher is created, or the library
2598is loaded).
2099 2599
2100If you have to fork, you must either do so I<before> creating your first 2600If you have to fork, you must either do so I<before> creating your first
2101watcher OR you must not use AnyEvent at all in the child. 2601watcher OR you must not use AnyEvent at all in the child OR you must do
2602something completely out of the scope of AnyEvent.
2603
2604The problem of doing event processing in the parent I<and> the child
2605is much more complicated: even for backends that I<are> fork-aware or
2606fork-safe, their behaviour is not usually what you want: fork clones all
2607watchers, that means all timers, I/O watchers etc. are active in both
2608parent and child, which is almost never what you want. USing C<exec>
2609to start worker children from some kind of manage rprocess is usually
2610preferred, because it is much easier and cleaner, at the expense of having
2611to have another binary.
2102 2612
2103 2613
2104=head1 SECURITY CONSIDERATIONS 2614=head1 SECURITY CONSIDERATIONS
2105 2615
2106AnyEvent can be forced to load any event model via 2616AnyEvent can be forced to load any event model via
2144L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. 2654L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2145 2655
2146Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>, 2656Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2147L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, 2657L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2148L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>, 2658L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2149L<AnyEvent::Impl::POE>. 2659L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
2150 2660
2151Non-blocking file handles, sockets, TCP clients and 2661Non-blocking file handles, sockets, TCP clients and
2152servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>. 2662servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2153 2663
2154Asynchronous DNS: L<AnyEvent::DNS>. 2664Asynchronous DNS: L<AnyEvent::DNS>.
2155 2665
2156Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>, 2666Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,
2667L<Coro::Event>,
2157 2668
2158Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>. 2669Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,
2670L<AnyEvent::HTTP>.
2159 2671
2160 2672
2161=head1 AUTHOR 2673=head1 AUTHOR
2162 2674
2163 Marc Lehmann <schmorp@schmorp.de> 2675 Marc Lehmann <schmorp@schmorp.de>

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