[ViewVC] Diff of: cvs/AnyEvent/lib/AnyEvent.pm

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.105 by root, Thu May 1 12:35:54 2008 UTC vs.
Revision 1.125 by root, Fri May 23 23:37:13 2008 UTC

…		…
1	=head1 NAME	1	=head1 => NAME
2		2
3	AnyEvent - provide framework for multiple event loops	3	AnyEvent - provide framework for multiple event loops
4		4
5	EV, Event, Coro::EV, Coro::Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops	5	EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops
6		6
7	=head1 SYNOPSIS	7	=head1 SYNOPSIS
8		8
9	use AnyEvent;	9	use AnyEvent;
10		10
15	my $w = AnyEvent->timer (after => $seconds, cb => sub {	15	my $w = AnyEvent->timer (after => $seconds, cb => sub {
16	...	16	...
17	});	17	});
18		18
19	my $w = AnyEvent->condvar; # stores whether a condition was flagged	19	my $w = AnyEvent->condvar; # stores whether a condition was flagged
		20	$w->send; # wake up current and all future recv's
20	$w->wait; # enters "main loop" till $condvar gets ->broadcast	21	$w->recv; # enters "main loop" till $condvar gets ->send
21	$w->broadcast; # wake up current and all future wait's
22		22
23	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)	23	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
24		24
25	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen	25	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
26	nowadays. So what is different about AnyEvent?	26	nowadays. So what is different about AnyEvent?
…		…
78	The interface itself is vaguely similar, but not identical to the L<Event>	78	The interface itself is vaguely similar, but not identical to the L<Event>
79	module.	79	module.
80		80
81	During the first call of any watcher-creation method, the module tries	81	During the first call of any watcher-creation method, the module tries
82	to detect the currently loaded event loop by probing whether one of the	82	to detect the currently loaded event loop by probing whether one of the
83	following modules is already loaded: L<Coro::EV>, L<Coro::Event>, L<EV>,	83	following modules is already loaded: L<EV>,
84	L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>,	84	L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>,
85	L<POE>. The first one found is used. If none are found, the module tries	85	L<POE>. The first one found is used. If none are found, the module tries
86	to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl	86	to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl
87	adaptor should always succeed) in the order given. The first one that can	87	adaptor should always succeed) in the order given. The first one that can
88	be successfully loaded will be used. If, after this, still none could be	88	be successfully loaded will be used. If, after this, still none could be
…		…
279		279
280	Example: fork a process and wait for it	280	Example: fork a process and wait for it
281		281
282	my $done = AnyEvent->condvar;	282	my $done = AnyEvent->condvar;
283		283
284	AnyEvent::detect; # force event module to be initialised
285
286	my $pid = fork or exit 5;	284	my $pid = fork or exit 5;
287		285
288	my $w = AnyEvent->child (	286	my $w = AnyEvent->child (
289	pid => $pid,	287	pid => $pid,
290	cb => sub {	288	cb => sub {
291	my ($pid, $status) = @_;	289	my ($pid, $status) = @_;
292	warn "pid $pid exited with status $status";	290	warn "pid $pid exited with status $status";
293	$done->broadcast;	291	$done->send;
294	},	292	},
295	);	293	);
296		294
297	# do something else, then wait for process exit	295	# do something else, then wait for process exit
298	$done->wait;	296	$done->recv;
299		297
300	=head2 CONDITION VARIABLES	298	=head2 CONDITION VARIABLES
301		299
302	If you are familiar with some event loops you will know that all of them	300	If you are familiar with some event loops you will know that all of them
303	require you to run some blocking "loop", "run" or similar function that	301	require you to run some blocking "loop", "run" or similar function that
…		…
313	>> method, usually without arguments. The only argument pair allowed is	311	>> method, usually without arguments. The only argument pair allowed is
314	C<cb>, which specifies a callback to be called when the condition variable	312	C<cb>, which specifies a callback to be called when the condition variable
315	becomes true.	313	becomes true.
316		314
317	After creation, the conditon variable is "false" until it becomes "true"	315	After creation, the conditon variable is "false" until it becomes "true"
318	by calling the C<broadcast> method.	316	by calling the C<send> method.
319		317
320	Condition variables are similar to callbacks, except that you can	318	Condition variables are similar to callbacks, except that you can
321	optionally wait for them. They can also be called merge points - points	319	optionally wait for them. They can also be called merge points - points
322	in time where multiple outstandign events have been processed. And yet	320	in time where multiple outstandign events have been processed. And yet
323	another way to call them is transations - each condition variable can be	321	another way to call them is transations - each condition variable can be
…		…
326		324
327	Condition variables are very useful to signal that something has finished,	325	Condition variables are very useful to signal that something has finished,
328	for example, if you write a module that does asynchronous http requests,	326	for example, if you write a module that does asynchronous http requests,
329	then a condition variable would be the ideal candidate to signal the	327	then a condition variable would be the ideal candidate to signal the
330	availability of results. The user can either act when the callback is	328	availability of results. The user can either act when the callback is
331	called or can synchronously C<< ->wait >> for the results.	329	called or can synchronously C<< ->recv >> for the results.
332		330
333	You can also use them to simulate traditional event loops - for example,	331	You can also use them to simulate traditional event loops - for example,
334	you can block your main program until an event occurs - for example, you	332	you can block your main program until an event occurs - for example, you
335	could C<< ->wait >> in your main program until the user clicks the Quit	333	could C<< ->recv >> in your main program until the user clicks the Quit
336	button of your app, which would C<< ->broadcast >> the "quit" event.	334	button of your app, which would C<< ->send >> the "quit" event.
337		335
338	Note that condition variables recurse into the event loop - if you have	336	Note that condition variables recurse into the event loop - if you have
339	two pieces of code that call C<< ->wait >> in a round-robbin fashion, you	337	two pieces of code that call C<< ->recv >> in a round-robbin fashion, you
340	lose. Therefore, condition variables are good to export to your caller, but	338	lose. Therefore, condition variables are good to export to your caller, but
341	you should avoid making a blocking wait yourself, at least in callbacks,	339	you should avoid making a blocking wait yourself, at least in callbacks,
342	as this asks for trouble.	340	as this asks for trouble.
343		341
344	Condition variables are represented by hash refs in perl, and the keys	342	Condition variables are represented by hash refs in perl, and the keys
…		…
346	easy (it is often useful to build your own transaction class on top of	344	easy (it is often useful to build your own transaction class on top of
347	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call	345	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call
348	it's C<new> method in your own C<new> method.	346	it's C<new> method in your own C<new> method.
349		347
350	There are two "sides" to a condition variable - the "producer side" which	348	There are two "sides" to a condition variable - the "producer side" which
351	eventually calls C<< -> broadcast >>, and the "consumer side", which waits	349	eventually calls C<< -> send >>, and the "consumer side", which waits
352	for the broadcast to occur.	350	for the send to occur.
353		351
354	Example:	352	Example:
355		353
356	# wait till the result is ready	354	# wait till the result is ready
357	my $result_ready = AnyEvent->condvar;	355	my $result_ready = AnyEvent->condvar;
358		356
359	# do something such as adding a timer	357	# do something such as adding a timer
360	# or socket watcher the calls $result_ready->broadcast	358	# or socket watcher the calls $result_ready->send
361	# when the "result" is ready.	359	# when the "result" is ready.
362	# in this case, we simply use a timer:	360	# in this case, we simply use a timer:
363	my $w = AnyEvent->timer (	361	my $w = AnyEvent->timer (
364	after => 1,	362	after => 1,
365	cb => sub { $result_ready->broadcast },	363	cb => sub { $result_ready->send },
366	);	364	);
367		365
368	# this "blocks" (while handling events) till the callback	366	# this "blocks" (while handling events) till the callback
369	# calls broadcast	367	# calls send
370	$result_ready->wait;	368	$result_ready->recv;
371		369
372	=head3 METHODS FOR PRODUCERS	370	=head3 METHODS FOR PRODUCERS
373		371
374	These methods should only be used by the producing side, i.e. the	372	These methods should only be used by the producing side, i.e. the
375	code/module that eventually broadcasts the signal. Note that it is also	373	code/module that eventually sends the signal. Note that it is also
376	the producer side which creates the condvar in most cases, but it isn't	374	the producer side which creates the condvar in most cases, but it isn't
377	uncommon for the consumer to create it as well.	375	uncommon for the consumer to create it as well.
378		376
379	=over 4	377	=over 4
380		378
381	=item $cv->broadcast (...)	379	=item $cv->send (...)
382		380
383	Flag the condition as ready - a running C<< ->wait >> and all further	381	Flag the condition as ready - a running C<< ->recv >> and all further
384	calls to C<wait> will (eventually) return after this method has been	382	calls to C<recv> will (eventually) return after this method has been
385	called. If nobody is waiting the broadcast will be remembered.	383	called. If nobody is waiting the send will be remembered.
386		384
387	If a callback has been set on the condition variable, it is called	385	If a callback has been set on the condition variable, it is called
388	immediately from within broadcast.	386	immediately from within send.
389		387
390	Any arguments passed to the C<broadcast> call will be returned by all	388	Any arguments passed to the C<send> call will be returned by all
391	future C<< ->wait >> calls.	389	future C<< ->recv >> calls.
392		390
393	=item $cv->croak ($error)	391	=item $cv->croak ($error)
394		392
395	Similar to broadcast, but causes all call's wait C<< ->wait >> to invoke	393	Similar to send, but causes all call's to C<< ->recv >> to invoke
396	C<Carp::croak> with the given error message/object/scalar.	394	C<Carp::croak> with the given error message/object/scalar.
397		395
398	This can be used to signal any errors to the condition variable	396	This can be used to signal any errors to the condition variable
399	user/consumer.	397	user/consumer.
400		398
401	=item $cv->begin ([group callback])	399	=item $cv->begin ([group callback])
402		400
403	=item $cv->end	401	=item $cv->end
		402
		403	These two methods are EXPERIMENTAL and MIGHT CHANGE.
404		404
405	These two methods can be used to combine many transactions/events into	405	These two methods can be used to combine many transactions/events into
406	one. For example, a function that pings many hosts in parallel might want	406	one. For example, a function that pings many hosts in parallel might want
407	to use a condition variable for the whole process.	407	to use a condition variable for the whole process.
408		408
409	Every call to C<< ->begin >> will increment a counter, and every call to	409	Every call to C<< ->begin >> will increment a counter, and every call to
410	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	410	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
411	>>, the (last) callback passed to C<begin> will be executed. That callback	411	>>, the (last) callback passed to C<begin> will be executed. That callback
412	is I<supposed> to call C<< ->broadcast >>, but that is not required. If no	412	is I<supposed> to call C<< ->send >>, but that is not required. If no
413	callback was set, C<broadcast> will be called without any arguments.	413	callback was set, C<send> will be called without any arguments.
414		414
415	Let's clarify this with the ping example:	415	Let's clarify this with the ping example:
416		416
417	my $cv = AnyEvent->condvar;	417	my $cv = AnyEvent->condvar;
418		418
419	my %result;	419	my %result;
420	$cv->begin (sub { $cv->broadcast (\%result) });	420	$cv->begin (sub { $cv->send (\%result) });
421		421
422	for my $host (@list_of_hosts) {	422	for my $host (@list_of_hosts) {
423	$cv->begin;	423	$cv->begin;
424	ping_host_then_call_callback $host, sub {	424	ping_host_then_call_callback $host, sub {
425	$result{$host} = ...;	425	$result{$host} = ...;
…		…
428	}	428	}
429		429
430	$cv->end;	430	$cv->end;
431		431
432	This code fragment supposedly pings a number of hosts and calls	432	This code fragment supposedly pings a number of hosts and calls
433	C<broadcast> after results for all then have have been gathered - in any	433	C<send> after results for all then have have been gathered - in any
434	order. To achieve this, the code issues a call to C<begin> when it starts	434	order. To achieve this, the code issues a call to C<begin> when it starts
435	each ping request and calls C<end> when it has received some result for	435	each ping request and calls C<end> when it has received some result for
436	it. Since C<begin> and C<end> only maintain a counter, the order in which	436	it. Since C<begin> and C<end> only maintain a counter, the order in which
437	results arrive is not relevant.	437	results arrive is not relevant.
438		438
439	There is an additional bracketing call to C<begin> and C<end> outside the	439	There is an additional bracketing call to C<begin> and C<end> outside the
440	loop, which serves two important purposes: first, it sets the callback	440	loop, which serves two important purposes: first, it sets the callback
441	to be called once the counter reaches C<0>, and second, it ensures that	441	to be called once the counter reaches C<0>, and second, it ensures that
442	broadcast is called even when C<no> hosts are being pinged (the loop	442	C<send> is called even when C<no> hosts are being pinged (the loop
443	doesn't execute once).	443	doesn't execute once).
444		444
445	This is the general pattern when you "fan out" into multiple subrequests:	445	This is the general pattern when you "fan out" into multiple subrequests:
446	use an outer C<begin>/C<end> pair to set the callback and ensure C<end>	446	use an outer C<begin>/C<end> pair to set the callback and ensure C<end>
447	is called at least once, and then, for each subrequest you start, call	447	is called at least once, and then, for each subrequest you start, call
…		…
452	=head3 METHODS FOR CONSUMERS	452	=head3 METHODS FOR CONSUMERS
453		453
454	These methods should only be used by the consuming side, i.e. the	454	These methods should only be used by the consuming side, i.e. the
455	code awaits the condition.	455	code awaits the condition.
456		456
457	=item $cv->wait	457	=over 4
458		458
		459	=item $cv->recv
		460
459	Wait (blocking if necessary) until the C<< ->broadcast >> or C<< ->croak	461	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
460	>> methods have been called on c<$cv>, while servicing other watchers	462	>> methods have been called on c<$cv>, while servicing other watchers
461	normally.	463	normally.
462		464
463	You can only wait once on a condition - additional calls are valid but	465	You can only wait once on a condition - additional calls are valid but
464	will return immediately.	466	will return immediately.
465		467
466	If an error condition has been set by calling C<< ->croak >>, then this	468	If an error condition has been set by calling C<< ->croak >>, then this
467	function will call C<croak>.	469	function will call C<croak>.
468		470
469	In list context, all parameters passed to C<broadcast> will be returned,	471	In list context, all parameters passed to C<send> will be returned,
470	in scalar context only the first one will be returned.	472	in scalar context only the first one will be returned.
471		473
472	Not all event models support a blocking wait - some die in that case	474	Not all event models support a blocking wait - some die in that case
473	(programs might want to do that to stay interactive), so I<if you are	475	(programs might want to do that to stay interactive), so I<if you are
474	using this from a module, never require a blocking wait>, but let the	476	using this from a module, never require a blocking wait>, but let the
475	caller decide whether the call will block or not (for example, by coupling	477	caller decide whether the call will block or not (for example, by coupling
476	condition variables with some kind of request results and supporting	478	condition variables with some kind of request results and supporting
477	callbacks so the caller knows that getting the result will not block,	479	callbacks so the caller knows that getting the result will not block,
478	while still suppporting blocking waits if the caller so desires).	480	while still suppporting blocking waits if the caller so desires).
479		481
480	Another reason I<never> to C<< ->wait >> in a module is that you cannot	482	Another reason I<never> to C<< ->recv >> in a module is that you cannot
481	sensibly have two C<< ->wait >>'s in parallel, as that would require	483	sensibly have two C<< ->recv >>'s in parallel, as that would require
482	multiple interpreters or coroutines/threads, none of which C<AnyEvent>	484	multiple interpreters or coroutines/threads, none of which C<AnyEvent>
483	can supply (the coroutine-aware backends L<AnyEvent::Impl::CoroEV> and	485	can supply.
484	L<AnyEvent::Impl::CoroEvent> explicitly support concurrent C<< ->wait >>'s
485	from different coroutines, however).
486		486
		487	The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
		488	fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
		489	versions and also integrates coroutines into AnyEvent, making blocking
		490	C<< ->recv >> calls perfectly safe as long as they are done from another
		491	coroutine (one that doesn't run the event loop).
		492
487	You can ensure that C<< -wait >> never blocks by setting a callback and	493	You can ensure that C<< -recv >> never blocks by setting a callback and
488	only calling C<< ->wait >> from within that callback (or at a later	494	only calling C<< ->recv >> from within that callback (or at a later
489	time). This will work even when the event loop does not support blocking	495	time). This will work even when the event loop does not support blocking
490	waits otherwise.	496	waits otherwise.
		497
		498	=item $bool = $cv->ready
		499
		500	Returns true when the condition is "true", i.e. whether C<send> or
		501	C<croak> have been called.
		502
		503	=item $cb = $cv->cb ([new callback])
		504
		505	This is a mutator function that returns the callback set and optionally
		506	replaces it before doing so.
		507
		508	The callback will be called when the condition becomes "true", i.e. when
		509	C<send> or C<croak> are called. Calling C<recv> inside the callback
		510	or at any later time is guaranteed not to block.
491		511
492	=back	512	=back
493		513
494	=head1 GLOBAL VARIABLES AND FUNCTIONS	514	=head1 GLOBAL VARIABLES AND FUNCTIONS
495		515
…		…
503	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	523	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case
504	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	524	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).
505		525
506	The known classes so far are:	526	The known classes so far are:
507		527
508	AnyEvent::Impl::CoroEV based on Coro::EV, best choice.
509	AnyEvent::Impl::CoroEvent based on Coro::Event, second best choice.
510	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).	528	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
511	AnyEvent::Impl::Event based on Event, second best choice.	529	AnyEvent::Impl::Event based on Event, second best choice.
512	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	530	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
513	AnyEvent::Impl::Glib based on Glib, third-best choice.	531	AnyEvent::Impl::Glib based on Glib, third-best choice.
514	AnyEvent::Impl::Tk based on Tk, very bad choice.	532	AnyEvent::Impl::Tk based on Tk, very bad choice.
…		…
531	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	549	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
532	if necessary. You should only call this function right before you would	550	if necessary. You should only call this function right before you would
533	have created an AnyEvent watcher anyway, that is, as late as possible at	551	have created an AnyEvent watcher anyway, that is, as late as possible at
534	runtime.	552	runtime.
535		553
		554	=item $guard = AnyEvent::post_detect { BLOCK }
		555
		556	Arranges for the code block to be executed as soon as the event model is
		557	autodetected (or immediately if this has already happened).
		558
		559	If called in scalar or list context, then it creates and returns an object
		560	that automatically removes the callback again when it is destroyed. See
		561	L<Coro::BDB> for a case where this is useful.
		562
		563	=item @AnyEvent::post_detect
		564
		565	If there are any code references in this array (you can C<push> to it
		566	before or after loading AnyEvent), then they will called directly after
		567	the event loop has been chosen.
		568
		569	You should check C<$AnyEvent::MODEL> before adding to this array, though:
		570	if it contains a true value then the event loop has already been detected,
		571	and the array will be ignored.
		572
		573	Best use C<AnyEvent::post_detect { BLOCK }> instead.
		574
536	=back	575	=back
537		576
538	=head1 WHAT TO DO IN A MODULE	577	=head1 WHAT TO DO IN A MODULE
539		578
540	As a module author, you should C<use AnyEvent> and call AnyEvent methods	579	As a module author, you should C<use AnyEvent> and call AnyEvent methods
…		…
543	Be careful when you create watchers in the module body - AnyEvent will	582	Be careful when you create watchers in the module body - AnyEvent will
544	decide which event module to use as soon as the first method is called, so	583	decide which event module to use as soon as the first method is called, so
545	by calling AnyEvent in your module body you force the user of your module	584	by calling AnyEvent in your module body you force the user of your module
546	to load the event module first.	585	to load the event module first.
547		586
548	Never call C<< ->wait >> on a condition variable unless you I<know> that	587	Never call C<< ->recv >> on a condition variable unless you I<know> that
549	the C<< ->broadcast >> method has been called on it already. This is	588	the C<< ->send >> method has been called on it already. This is
550	because it will stall the whole program, and the whole point of using	589	because it will stall the whole program, and the whole point of using
551	events is to stay interactive.	590	events is to stay interactive.
552		591
553	It is fine, however, to call C<< ->wait >> when the user of your module	592	It is fine, however, to call C<< ->recv >> when the user of your module
554	requests it (i.e. if you create a http request object ad have a method	593	requests it (i.e. if you create a http request object ad have a method
555	called C<results> that returns the results, it should call C<< ->wait >>	594	called C<results> that returns the results, it should call C<< ->recv >>
556	freely, as the user of your module knows what she is doing. always).	595	freely, as the user of your module knows what she is doing. always).
557		596
558	=head1 WHAT TO DO IN THE MAIN PROGRAM	597	=head1 WHAT TO DO IN THE MAIN PROGRAM
559		598
560	There will always be a single main program - the only place that should	599	There will always be a single main program - the only place that should
…		…
594		633
595	Provide read and write buffers and manages watchers for reads and writes.	634	Provide read and write buffers and manages watchers for reads and writes.
596		635
597	=item L<AnyEvent::Socket>	636	=item L<AnyEvent::Socket>
598		637
599	Provides a means to do non-blocking connects, accepts etc.	638	Provides various utility functions for (internet protocol) sockets,
		639	addresses and name resolution. Also functions to create non-blocking tcp
		640	connections or tcp servers, with IPv6 and SRV record support and more.
600		641
601	=item L<AnyEvent::HTTPD>	642	=item L<AnyEvent::HTTPD>
602		643
603	Provides a simple web application server framework.	644	Provides a simple web application server framework.
604		645
605	=item L<AnyEvent::DNS>	646	=item L<AnyEvent::DNS>
606		647
607	Provides asynchronous DNS resolver capabilities, beyond what	648	Provides rich asynchronous DNS resolver capabilities.
608	L<AnyEvent::Util> offers.
609		649
610	=item L<AnyEvent::FastPing>	650	=item L<AnyEvent::FastPing>
611		651
612	The fastest ping in the west.	652	The fastest ping in the west.
613		653
…		…
628		668
629	High level API for event-based execution flow control.	669	High level API for event-based execution flow control.
630		670
631	=item L<Coro>	671	=item L<Coro>
632		672
633	Has special support for AnyEvent.	673	Has special support for AnyEvent via L<Coro::AnyEvent>.
		674
		675	=item L<AnyEvent::AIO>, L<IO::AIO>
		676
		677	Truly asynchronous I/O, should be in the toolbox of every event
		678	programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent
		679	together.
		680
		681	=item L<AnyEvent::BDB>, L<BDB>
		682
		683	Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses
		684	IO::AIO and AnyEvent together.
634		685
635	=item L<IO::Lambda>	686	=item L<IO::Lambda>
636		687
637	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.	688	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
638
639	=item L<IO::AIO>
640
641	Truly asynchronous I/O, should be in the toolbox of every event
642	programmer. Can be trivially made to use AnyEvent.
643
644	=item L<BDB>
645
646	Truly asynchronous Berkeley DB access. Can be trivially made to use
647	AnyEvent.
648		689
649	=back	690	=back
650		691
651	=cut	692	=cut
652		693
…		…
655	no warnings;	696	no warnings;
656	use strict;	697	use strict;
657		698
658	use Carp;	699	use Carp;
659		700
660	our $VERSION = '3.3';	701	our $VERSION = '3.6';
661	our $MODEL;	702	our $MODEL;
662		703
663	our $AUTOLOAD;	704	our $AUTOLOAD;
664	our @ISA;	705	our @ISA;
665		706
666	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	707	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;
667		708
668	our @REGISTRY;	709	our @REGISTRY;
669		710
670	my @models = (	711	my @models = (
671	[Coro::EV:: => AnyEvent::Impl::CoroEV::],
672	[Coro::Event:: => AnyEvent::Impl::CoroEvent::],
673	[EV:: => AnyEvent::Impl::EV::],	712	[EV:: => AnyEvent::Impl::EV::],
674	[Event:: => AnyEvent::Impl::Event::],	713	[Event:: => AnyEvent::Impl::Event::],
675	[Tk:: => AnyEvent::Impl::Tk::],	714	[Tk:: => AnyEvent::Impl::Tk::],
676	[Wx:: => AnyEvent::Impl::POE::],	715	[Wx:: => AnyEvent::Impl::POE::],
677	[Prima:: => AnyEvent::Impl::POE::],	716	[Prima:: => AnyEvent::Impl::POE::],
…		…
681	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	720	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
682	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	721	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
683	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	722	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
684	);	723	);
685		724
686	our %method = map +($_ => 1), qw(io timer signal child condvar broadcast wait one_event DESTROY);	725	our %method = map +($_ => 1), qw(io timer signal child condvar one_event DESTROY);
		726
		727	our @post_detect;
		728
		729	sub post_detect(&) {
		730	my ($cb) = @_;
		731
		732	if ($MODEL) {
		733	$cb->();
		734
		735	1
		736	} else {
		737	push @post_detect, $cb;
		738
		739	defined wantarray
		740	? bless \$cb, "AnyEvent::Util::PostDetect"
		741	: ()
		742	}
		743	}
		744
		745	sub AnyEvent::Util::PostDetect::DESTROY {
		746	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		747	}
687		748
688	sub detect() {	749	sub detect() {
689	unless ($MODEL) {	750	unless ($MODEL) {
690	no strict 'refs';	751	no strict 'refs';
691		752
…		…
725	last;	786	last;
726	}	787	}
727	}	788	}
728		789
729	$MODEL	790	$MODEL
730	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV (or Coro+EV), Event (or Coro+Event) or Glib.";	791	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";
731	}	792	}
732	}	793	}
733		794
734	unshift @ISA, $MODEL;	795	unshift @ISA, $MODEL;
735	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	796	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		797
		798	(shift @post_detect)->() while @post_detect;
736	}	799	}
737		800
738	$MODEL	801	$MODEL
739	}	802	}
740		803
…		…
750	$class->$func (@_);	813	$class->$func (@_);
751	}	814	}
752		815
753	package AnyEvent::Base;	816	package AnyEvent::Base;
754		817
755	# default implementation for ->condvar, ->wait, ->broadcast	818	# default implementation for ->condvar
756		819
757	sub condvar {	820	sub condvar {
758	bless \my $flag, "AnyEvent::Base::CondVar"	821	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::
759	}
760
761	sub AnyEvent::Base::CondVar::broadcast {
762	${$_[0]}++;
763	}
764
765	sub AnyEvent::Base::CondVar::wait {
766	AnyEvent->one_event while !${$_[0]};
767	}	822	}
768		823
769	# default implementation for ->signal	824	# default implementation for ->signal
770		825
771	our %SIG_CB;	826	our %SIG_CB;
…		…
845	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	900	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
846		901
847	undef $CHLD_W unless keys %PID_CB;	902	undef $CHLD_W unless keys %PID_CB;
848	}	903	}
849		904
		905	package AnyEvent::CondVar;
		906
		907	our @ISA = AnyEvent::CondVar::Base::;
		908
		909	package AnyEvent::CondVar::Base;
		910
		911	sub _send {
		912	# nop
		913	}
		914
		915	sub send {
		916	my $cv = shift;
		917	$cv->{_ae_sent} = [@_];
		918	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
		919	$cv->_send;
		920	}
		921
		922	sub croak {
		923	$_[0]{_ae_croak} = $_[1];
		924	$_[0]->send;
		925	}
		926
		927	sub ready {
		928	$_[0]{_ae_sent}
		929	}
		930
		931	sub _wait {
		932	AnyEvent->one_event while !$_[0]{_ae_sent};
		933	}
		934
		935	sub recv {
		936	$_[0]->_wait;
		937
		938	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
		939	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
		940	}
		941
		942	sub cb {
		943	$_[0]{_ae_cb} = $_[1] if @_ > 1;
		944	$_[0]{_ae_cb}
		945	}
		946
		947	sub begin {
		948	++$_[0]{_ae_counter};
		949	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
		950	}
		951
		952	sub end {
		953	return if --$_[0]{_ae_counter};
		954	&{ $_[0]{_ae_end_cb} \|\| sub { $_[0]->send } };
		955	}
		956
		957	# undocumented/compatibility with pre-3.4
		958	*broadcast = \&send;
		959	*wait = \&_wait;
		960
850	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	961	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
851		962
852	This is an advanced topic that you do not normally need to use AnyEvent in	963	This is an advanced topic that you do not normally need to use AnyEvent in
853	a module. This section is only of use to event loop authors who want to	964	a module. This section is only of use to event loop authors who want to
854	provide AnyEvent compatibility.	965	provide AnyEvent compatibility.
…		…
922		1033
923	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	1034	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
924	could start your program like this:	1035	could start your program like this:
925		1036
926	PERL_ANYEVENT_MODEL=Perl perl ...	1037	PERL_ANYEVENT_MODEL=Perl perl ...
		1038
		1039	=item C<PERL_ANYEVENT_PROTOCOLS>
		1040
		1041	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
		1042	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
		1043	of autoprobing).
		1044
		1045	Must be set to a comma-separated list of protocols or address families,
		1046	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
		1047	used, and preference will be given to protocols mentioned earlier in the
		1048	list.
		1049
		1050	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
		1051	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
		1052	- only support IPv4, never try to resolve or contact IPv6
		1053	addressses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
		1054	IPv6, but prefer IPv6 over IPv4.
927		1055
928	=back	1056	=back
929		1057
930	=head1 EXAMPLE PROGRAM	1058	=head1 EXAMPLE PROGRAM
931		1059
…		…
942	poll => 'r',	1070	poll => 'r',
943	cb => sub {	1071	cb => sub {
944	warn "io event <$_[0]>\n"; # will always output <r>	1072	warn "io event <$_[0]>\n"; # will always output <r>
945	chomp (my $input = <STDIN>); # read a line	1073	chomp (my $input = <STDIN>); # read a line
946	warn "read: $input\n"; # output what has been read	1074	warn "read: $input\n"; # output what has been read
947	$cv->broadcast if $input =~ /^q/i; # quit program if /^q/i	1075	$cv->send if $input =~ /^q/i; # quit program if /^q/i
948	},	1076	},
949	);	1077	);
950		1078
951	my $time_watcher; # can only be used once	1079	my $time_watcher; # can only be used once
952		1080
…		…
957	});	1085	});
958	}	1086	}
959		1087
960	new_timer; # create first timer	1088	new_timer; # create first timer
961		1089
962	$cv->wait; # wait until user enters /^q/i	1090	$cv->recv; # wait until user enters /^q/i
963		1091
964	=head1 REAL-WORLD EXAMPLE	1092	=head1 REAL-WORLD EXAMPLE
965		1093
966	Consider the L<Net::FCP> module. It features (among others) the following	1094	Consider the L<Net::FCP> module. It features (among others) the following
967	API calls, which are to freenet what HTTP GET requests are to http:	1095	API calls, which are to freenet what HTTP GET requests are to http:
…		…
1023		1151
1024	sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf};	1152	sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf};
1025		1153
1026	if (end-of-file or data complete) {	1154	if (end-of-file or data complete) {
1027	$txn->{result} = $txn->{buf};	1155	$txn->{result} = $txn->{buf};
1028	$txn->{finished}->broadcast;	1156	$txn->{finished}->send;
1029	$txb->{cb}->($txn) of $txn->{cb}; # also call callback	1157	$txb->{cb}->($txn) of $txn->{cb}; # also call callback
1030	}	1158	}
1031		1159
1032	The C<result> method, finally, just waits for the finished signal (if the	1160	The C<result> method, finally, just waits for the finished signal (if the
1033	request was already finished, it doesn't wait, of course, and returns the	1161	request was already finished, it doesn't wait, of course, and returns the
1034	data:	1162	data:
1035		1163
1036	$txn->{finished}->wait;	1164	$txn->{finished}->recv;
1037	return $txn->{result};	1165	return $txn->{result};
1038		1166
1039	The actual code goes further and collects all errors (C<die>s, exceptions)	1167	The actual code goes further and collects all errors (C<die>s, exceptions)
1040	that occured during request processing. The C<result> method detects	1168	that occured during request processing. The C<result> method detects
1041	whether an exception as thrown (it is stored inside the $txn object)	1169	whether an exception as thrown (it is stored inside the $txn object)
…		…
1076		1204
1077	my $quit = AnyEvent->condvar;	1205	my $quit = AnyEvent->condvar;
1078		1206
1079	$fcp->txn_client_get ($url)->cb (sub {	1207	$fcp->txn_client_get ($url)->cb (sub {
1080	...	1208	...
1081	$quit->broadcast;	1209	$quit->send;
1082	});	1210	});
1083		1211
1084	$quit->wait;	1212	$quit->recv;
1085		1213
1086		1214
1087	=head1 BENCHMARKS	1215	=head1 BENCHMARKS
1088		1216
1089	To give you an idea of the performance and overheads that AnyEvent adds	1217	To give you an idea of the performance and overheads that AnyEvent adds
…		…
1118	all watchers, to avoid adding memory overhead. That means closure creation	1246	all watchers, to avoid adding memory overhead. That means closure creation
1119	and memory usage is not included in the figures.	1247	and memory usage is not included in the figures.
1120		1248
1121	I<invoke> is the time, in microseconds, used to invoke a simple	1249	I<invoke> is the time, in microseconds, used to invoke a simple
1122	callback. The callback simply counts down a Perl variable and after it was	1250	callback. The callback simply counts down a Perl variable and after it was
1123	invoked "watcher" times, it would C<< ->broadcast >> a condvar once to	1251	invoked "watcher" times, it would C<< ->send >> a condvar once to
1124	signal the end of this phase.	1252	signal the end of this phase.
1125		1253
1126	I<destroy> is the time, in microseconds, that it takes to destroy a single	1254	I<destroy> is the time, in microseconds, that it takes to destroy a single
1127	watcher.	1255	watcher.
1128		1256
…		…
1374		1502
1375	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }	1503	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }
1376		1504
1377	use AnyEvent;	1505	use AnyEvent;
1378		1506
		1507	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
		1508	be used to probe what backend is used and gain other information (which is
		1509	probably even less useful to an attacker than PERL_ANYEVENT_MODEL).
		1510
1379		1511
1380	=head1 SEE ALSO	1512	=head1 SEE ALSO
1381		1513
1382	Event modules: L<Coro::EV>, L<EV>, L<EV::Glib>, L<Glib::EV>,	1514	Utility functions: L<AnyEvent::Util>.
1383	L<Coro::Event>, L<Event>, L<Glib::Event>, L<Glib>, L<Coro>, L<Tk>,	1515
		1516	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,
1384	L<Event::Lib>, L<Qt>, L<POE>.	1517	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
1385		1518
1386	Implementations: L<AnyEvent::Impl::CoroEV>, L<AnyEvent::Impl::EV>,	1519	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
1387	L<AnyEvent::Impl::CoroEvent>, L<AnyEvent::Impl::Event>, L<AnyEvent::Impl::Glib>,	1520	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
1388	L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, L<AnyEvent::Impl::EventLib>,	1521	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
1389	L<AnyEvent::Impl::Qt>, L<AnyEvent::Impl::POE>.	1522	L<AnyEvent::Impl::POE>.
1390		1523
		1524	Non-blocking file handles, sockets, TCP clients and
		1525	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.
		1526
		1527	Asynchronous DNS: L<AnyEvent::DNS>.
		1528
		1529	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>,
		1530
1391	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>.	1531	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.
1392		1532
1393		1533
1394	=head1 AUTHOR	1534	=head1 AUTHOR
1395		1535
1396	Marc Lehmann <schmorp@schmorp.de>	1536	Marc Lehmann <schmorp@schmorp.de>

Diff Legend

-–
+Removed lines
-+
+Added lines
-<
+Changed lines
->
+Changed lines

Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.105 by root, Thu May 1 12:35:54 2008 UTC vs. Revision 1.125 by root, Fri May 23 23:37:13 2008 UTC

Diff Legend

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.105 by root, Thu May 1 12:35:54 2008 UTC vs.
Revision 1.125 by root, Fri May 23 23:37:13 2008 UTC