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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.104 by root, Wed Apr 30 11:40:22 2008 UTC vs.
Revision 1.142 by root, Tue May 27 02:34:30 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?
…		…
48	isn't itself. What's worse, all the potential users of your module are	48	isn't itself. What's worse, all the potential users of your module are
49	I<also> forced to use the same event loop you use.	49	I<also> forced to use the same event loop you use.
50		50
51	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	51	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
52	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	52	fine. AnyEvent + Tk works fine etc. etc. but none of these work together
53	with the rest: POE + IO::Async? no go. Tk + Event? no go. Again: if	53	with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if
54	your module uses one of those, every user of your module has to use it,	54	your module uses one of those, every user of your module has to use it,
55	too. But if your module uses AnyEvent, it works transparently with all	55	too. But if your module uses AnyEvent, it works transparently with all
56	event models it supports (including stuff like POE and IO::Async, as long	56	event models it supports (including stuff like POE and IO::Async, as long
57	as those use one of the supported event loops. It is trivial to add new	57	as those use one of the supported event loops. It is trivial to add new
58	event loops to AnyEvent, too, so it is future-proof).	58	event loops to AnyEvent, too, so it is future-proof).
59		59
60	In addition to being free of having to use I<the one and only true event	60	In addition to being free of having to use I<the one and only true event
61	model>, AnyEvent also is free of bloat and policy: with POE or similar	61	model>, AnyEvent also is free of bloat and policy: with POE or similar
62	modules, you get an enourmous amount of code and strict rules you have to	62	modules, you get an enormous amount of code and strict rules you have to
63	follow. AnyEvent, on the other hand, is lean and up to the point, by only	63	follow. AnyEvent, on the other hand, is lean and up to the point, by only
64	offering the functionality that is necessary, in as thin as a wrapper as	64	offering the functionality that is necessary, in as thin as a wrapper as
65	technically possible.	65	technically possible.
66		66
		67	Of course, AnyEvent comes with a big (and fully optional!) toolbox
		68	of useful functionality, such as an asynchronous DNS resolver, 100%
		69	non-blocking connects (even with TLS/SSL, IPv6 and on broken platforms
		70	such as Windows) and lots of real-world knowledge and workarounds for
		71	platform bugs and differences.
		72
67	Of course, if you want lots of policy (this can arguably be somewhat	73	Now, if you I<do want> lots of policy (this can arguably be somewhat
68	useful) and you want to force your users to use the one and only event	74	useful) and you want to force your users to use the one and only event
69	model, you should I<not> use this module.	75	model, you should I<not> use this module.
70		76
71	=head1 DESCRIPTION	77	=head1 DESCRIPTION
72		78
…		…
78	The interface itself is vaguely similar, but not identical to the L<Event>	84	The interface itself is vaguely similar, but not identical to the L<Event>
79	module.	85	module.
80		86
81	During the first call of any watcher-creation method, the module tries	87	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	88	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>,	89	following modules is already loaded: L<EV>,
84	L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>,	90	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	91	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	92	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	93	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	94	be successfully loaded will be used. If, after this, still none could be
…		…
102	starts using it, all bets are off. Maybe you should tell their authors to	108	starts using it, all bets are off. Maybe you should tell their authors to
103	use AnyEvent so their modules work together with others seamlessly...	109	use AnyEvent so their modules work together with others seamlessly...
104		110
105	The pure-perl implementation of AnyEvent is called	111	The pure-perl implementation of AnyEvent is called
106	C<AnyEvent::Impl::Perl>. Like other event modules you can load it	112	C<AnyEvent::Impl::Perl>. Like other event modules you can load it
107	explicitly.	113	explicitly and enjoy the high availability of that event loop :)
108		114
109	=head1 WATCHERS	115	=head1 WATCHERS
110		116
111	AnyEvent has the central concept of a I<watcher>, which is an object that	117	AnyEvent has the central concept of a I<watcher>, which is an object that
112	stores relevant data for each kind of event you are waiting for, such as	118	stores relevant data for each kind of event you are waiting for, such as
113	the callback to call, the filehandle to watch, etc.	119	the callback to call, the file handle to watch, etc.
114		120
115	These watchers are normal Perl objects with normal Perl lifetime. After	121	These watchers are normal Perl objects with normal Perl lifetime. After
116	creating a watcher it will immediately "watch" for events and invoke the	122	creating a watcher it will immediately "watch" for events and invoke the
117	callback when the event occurs (of course, only when the event model	123	callback when the event occurs (of course, only when the event model
118	is in control).	124	is in control).
…		…
237		243
238	Although the callback might get passed parameters, their value and	244	Although the callback might get passed parameters, their value and
239	presence is undefined and you cannot rely on them. Portable AnyEvent	245	presence is undefined and you cannot rely on them. Portable AnyEvent
240	callbacks cannot use arguments passed to signal watcher callbacks.	246	callbacks cannot use arguments passed to signal watcher callbacks.
241		247
242	Multiple signal occurances can be clumped together into one callback	248	Multiple signal occurrences can be clumped together into one callback
243	invocation, and callback invocation will be synchronous. synchronous means	249	invocation, and callback invocation will be synchronous. Synchronous means
244	that it might take a while until the signal gets handled by the process,	250	that it might take a while until the signal gets handled by the process,
245	but it is guarenteed not to interrupt any other callbacks.	251	but it is guaranteed not to interrupt any other callbacks.
246		252
247	The main advantage of using these watchers is that you can share a signal	253	The main advantage of using these watchers is that you can share a signal
248	between multiple watchers.	254	between multiple watchers.
249		255
250	This watcher might use C<%SIG>, so programs overwriting those signals	256	This watcher might use C<%SIG>, so programs overwriting those signals
…		…
279		285
280	Example: fork a process and wait for it	286	Example: fork a process and wait for it
281		287
282	my $done = AnyEvent->condvar;	288	my $done = AnyEvent->condvar;
283		289
284	AnyEvent::detect; # force event module to be initialised
285
286	my $pid = fork or exit 5;	290	my $pid = fork or exit 5;
287		291
288	my $w = AnyEvent->child (	292	my $w = AnyEvent->child (
289	pid => $pid,	293	pid => $pid,
290	cb => sub {	294	cb => sub {
291	my ($pid, $status) = @_;	295	my ($pid, $status) = @_;
292	warn "pid $pid exited with status $status";	296	warn "pid $pid exited with status $status";
293	$done->broadcast;	297	$done->send;
294	},	298	},
295	);	299	);
296		300
297	# do something else, then wait for process exit	301	# do something else, then wait for process exit
298	$done->wait;	302	$done->recv;
299		303
300	=head2 CONDITION VARIABLES	304	=head2 CONDITION VARIABLES
301		305
		306	If you are familiar with some event loops you will know that all of them
		307	require you to run some blocking "loop", "run" or similar function that
		308	will actively watch for new events and call your callbacks.
		309
		310	AnyEvent is different, it expects somebody else to run the event loop and
		311	will only block when necessary (usually when told by the user).
		312
		313	The instrument to do that is called a "condition variable", so called
		314	because they represent a condition that must become true.
		315
302	Condition variables can be created by calling the C<< AnyEvent->condvar >>	316	Condition variables can be created by calling the C<< AnyEvent->condvar
303	method without any arguments.	317	>> method, usually without arguments. The only argument pair allowed is
		318	C<cb>, which specifies a callback to be called when the condition variable
		319	becomes true.
304		320
305	A condition variable waits for a condition - precisely that the C<<	321	After creation, the condition variable is "false" until it becomes "true"
306	->broadcast >> method has been called.	322	by calling the C<send> method (or calling the condition variable as if it
		323	were a callback, read about the caveats in the description for the C<<
		324	->send >> method).
307		325
308	They are very useful to signal that a condition has been fulfilled, for	326	Condition variables are similar to callbacks, except that you can
		327	optionally wait for them. They can also be called merge points - points
		328	in time where multiple outstanding events have been processed. And yet
		329	another way to call them is transactions - each condition variable can be
		330	used to represent a transaction, which finishes at some point and delivers
		331	a result.
		332
		333	Condition variables are very useful to signal that something has finished,
309	example, if you write a module that does asynchronous http requests,	334	for example, if you write a module that does asynchronous http requests,
310	then a condition variable would be the ideal candidate to signal the	335	then a condition variable would be the ideal candidate to signal the
311	availability of results.	336	availability of results. The user can either act when the callback is
		337	called or can synchronously C<< ->recv >> for the results.
312		338
313	You can also use condition variables to block your main program until	339	You can also use them to simulate traditional event loops - for example,
314	an event occurs - for example, you could C<< ->wait >> in your main	340	you can block your main program until an event occurs - for example, you
315	program until the user clicks the Quit button in your app, which would C<<	341	could C<< ->recv >> in your main program until the user clicks the Quit
316	->broadcast >> the "quit" event.	342	button of your app, which would C<< ->send >> the "quit" event.
317		343
318	Note that condition variables recurse into the event loop - if you have	344	Note that condition variables recurse into the event loop - if you have
319	two pirces of code that call C<< ->wait >> in a round-robbin fashion, you	345	two pieces of code that call C<< ->recv >> in a round-robin fashion, you
320	lose. Therefore, condition variables are good to export to your caller, but	346	lose. Therefore, condition variables are good to export to your caller, but
321	you should avoid making a blocking wait yourself, at least in callbacks,	347	you should avoid making a blocking wait yourself, at least in callbacks,
322	as this asks for trouble.	348	as this asks for trouble.
323		349
324	This object has two methods:	350	Condition variables are represented by hash refs in perl, and the keys
		351	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing
		352	easy (it is often useful to build your own transaction class on top of
		353	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call
		354	it's C<new> method in your own C<new> method.
		355
		356	There are two "sides" to a condition variable - the "producer side" which
		357	eventually calls C<< -> send >>, and the "consumer side", which waits
		358	for the send to occur.
		359
		360	Example: wait for a timer.
		361
		362	# wait till the result is ready
		363	my $result_ready = AnyEvent->condvar;
		364
		365	# do something such as adding a timer
		366	# or socket watcher the calls $result_ready->send
		367	# when the "result" is ready.
		368	# in this case, we simply use a timer:
		369	my $w = AnyEvent->timer (
		370	after => 1,
		371	cb => sub { $result_ready->send },
		372	);
		373
		374	# this "blocks" (while handling events) till the callback
		375	# calls send
		376	$result_ready->recv;
		377
		378	Example: wait for a timer, but take advantage of the fact that
		379	condition variables are also code references.
		380
		381	my $done = AnyEvent->condvar;
		382	my $delay = AnyEvent->timer (after => 5, cb => $done);
		383	$done->recv;
		384
		385	=head3 METHODS FOR PRODUCERS
		386
		387	These methods should only be used by the producing side, i.e. the
		388	code/module that eventually sends the signal. Note that it is also
		389	the producer side which creates the condvar in most cases, but it isn't
		390	uncommon for the consumer to create it as well.
325		391
326	=over 4	392	=over 4
327		393
		394	=item $cv->send (...)
		395
		396	Flag the condition as ready - a running C<< ->recv >> and all further
		397	calls to C<recv> will (eventually) return after this method has been
		398	called. If nobody is waiting the send will be remembered.
		399
		400	If a callback has been set on the condition variable, it is called
		401	immediately from within send.
		402
		403	Any arguments passed to the C<send> call will be returned by all
		404	future C<< ->recv >> calls.
		405
		406	Condition variables are overloaded so one can call them directly
		407	(as a code reference). Calling them directly is the same as calling
		408	C<send>. Note, however, that many C-based event loops do not handle
		409	overloading, so as tempting as it may be, passing a condition variable
		410	instead of a callback does not work. Both the pure perl and EV loops
		411	support overloading, however, as well as all functions that use perl to
		412	invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
		413	example).
		414
		415	=item $cv->croak ($error)
		416
		417	Similar to send, but causes all call's to C<< ->recv >> to invoke
		418	C<Carp::croak> with the given error message/object/scalar.
		419
		420	This can be used to signal any errors to the condition variable
		421	user/consumer.
		422
		423	=item $cv->begin ([group callback])
		424
328	=item $cv->wait	425	=item $cv->end
329		426
330	Wait (blocking if necessary) until the C<< ->broadcast >> method has been	427	These two methods are EXPERIMENTAL and MIGHT CHANGE.
		428
		429	These two methods can be used to combine many transactions/events into
		430	one. For example, a function that pings many hosts in parallel might want
		431	to use a condition variable for the whole process.
		432
		433	Every call to C<< ->begin >> will increment a counter, and every call to
		434	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
		435	>>, the (last) callback passed to C<begin> will be executed. That callback
		436	is I<supposed> to call C<< ->send >>, but that is not required. If no
		437	callback was set, C<send> will be called without any arguments.
		438
		439	Let's clarify this with the ping example:
		440
		441	my $cv = AnyEvent->condvar;
		442
		443	my %result;
		444	$cv->begin (sub { $cv->send (\%result) });
		445
		446	for my $host (@list_of_hosts) {
		447	$cv->begin;
		448	ping_host_then_call_callback $host, sub {
		449	$result{$host} = ...;
		450	$cv->end;
		451	};
		452	}
		453
		454	$cv->end;
		455
		456	This code fragment supposedly pings a number of hosts and calls
		457	C<send> after results for all then have have been gathered - in any
		458	order. To achieve this, the code issues a call to C<begin> when it starts
		459	each ping request and calls C<end> when it has received some result for
		460	it. Since C<begin> and C<end> only maintain a counter, the order in which
		461	results arrive is not relevant.
		462
		463	There is an additional bracketing call to C<begin> and C<end> outside the
		464	loop, which serves two important purposes: first, it sets the callback
		465	to be called once the counter reaches C<0>, and second, it ensures that
		466	C<send> is called even when C<no> hosts are being pinged (the loop
		467	doesn't execute once).
		468
		469	This is the general pattern when you "fan out" into multiple subrequests:
		470	use an outer C<begin>/C<end> pair to set the callback and ensure C<end>
		471	is called at least once, and then, for each subrequest you start, call
		472	C<begin> and for each subrequest you finish, call C<end>.
		473
		474	=back
		475
		476	=head3 METHODS FOR CONSUMERS
		477
		478	These methods should only be used by the consuming side, i.e. the
		479	code awaits the condition.
		480
		481	=over 4
		482
		483	=item $cv->recv
		484
		485	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
331	called on c<$cv>, while servicing other watchers normally.	486	>> methods have been called on c<$cv>, while servicing other watchers
		487	normally.
332		488
333	You can only wait once on a condition - additional calls will return	489	You can only wait once on a condition - additional calls are valid but
334	immediately.	490	will return immediately.
		491
		492	If an error condition has been set by calling C<< ->croak >>, then this
		493	function will call C<croak>.
		494
		495	In list context, all parameters passed to C<send> will be returned,
		496	in scalar context only the first one will be returned.
335		497
336	Not all event models support a blocking wait - some die in that case	498	Not all event models support a blocking wait - some die in that case
337	(programs might want to do that to stay interactive), so I<if you are	499	(programs might want to do that to stay interactive), so I<if you are
338	using this from a module, never require a blocking wait>, but let the	500	using this from a module, never require a blocking wait>, but let the
339	caller decide whether the call will block or not (for example, by coupling	501	caller decide whether the call will block or not (for example, by coupling
340	condition variables with some kind of request results and supporting	502	condition variables with some kind of request results and supporting
341	callbacks so the caller knows that getting the result will not block,	503	callbacks so the caller knows that getting the result will not block,
342	while still suppporting blocking waits if the caller so desires).	504	while still supporting blocking waits if the caller so desires).
343		505
344	Another reason I<never> to C<< ->wait >> in a module is that you cannot	506	Another reason I<never> to C<< ->recv >> in a module is that you cannot
345	sensibly have two C<< ->wait >>'s in parallel, as that would require	507	sensibly have two C<< ->recv >>'s in parallel, as that would require
346	multiple interpreters or coroutines/threads, none of which C<AnyEvent>	508	multiple interpreters or coroutines/threads, none of which C<AnyEvent>
347	can supply (the coroutine-aware backends L<AnyEvent::Impl::CoroEV> and	509	can supply.
348	L<AnyEvent::Impl::CoroEvent> explicitly support concurrent C<< ->wait >>'s
349	from different coroutines, however).
350		510
351	=item $cv->broadcast	511	The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
		512	fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
		513	versions and also integrates coroutines into AnyEvent, making blocking
		514	C<< ->recv >> calls perfectly safe as long as they are done from another
		515	coroutine (one that doesn't run the event loop).
352		516
353	Flag the condition as ready - a running C<< ->wait >> and all further	517	You can ensure that C<< -recv >> never blocks by setting a callback and
354	calls to C<wait> will (eventually) return after this method has been	518	only calling C<< ->recv >> from within that callback (or at a later
355	called. If nobody is waiting the broadcast will be remembered..	519	time). This will work even when the event loop does not support blocking
		520	waits otherwise.
		521
		522	=item $bool = $cv->ready
		523
		524	Returns true when the condition is "true", i.e. whether C<send> or
		525	C<croak> have been called.
		526
		527	=item $cb = $cv->cb ([new callback])
		528
		529	This is a mutator function that returns the callback set and optionally
		530	replaces it before doing so.
		531
		532	The callback will be called when the condition becomes "true", i.e. when
		533	C<send> or C<croak> are called. Calling C<recv> inside the callback
		534	or at any later time is guaranteed not to block.
356		535
357	=back	536	=back
358
359	Example:
360
361	# wait till the result is ready
362	my $result_ready = AnyEvent->condvar;
363
364	# do something such as adding a timer
365	# or socket watcher the calls $result_ready->broadcast
366	# when the "result" is ready.
367	# in this case, we simply use a timer:
368	my $w = AnyEvent->timer (
369	after => 1,
370	cb => sub { $result_ready->broadcast },
371	);
372
373	# this "blocks" (while handling events) till the watcher
374	# calls broadcast
375	$result_ready->wait;
376		537
377	=head1 GLOBAL VARIABLES AND FUNCTIONS	538	=head1 GLOBAL VARIABLES AND FUNCTIONS
378		539
379	=over 4	540	=over 4
380		541
…		…
386	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	547	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case
387	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	548	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).
388		549
389	The known classes so far are:	550	The known classes so far are:
390		551
391	AnyEvent::Impl::CoroEV based on Coro::EV, best choice.
392	AnyEvent::Impl::CoroEvent based on Coro::Event, second best choice.
393	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).	552	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
394	AnyEvent::Impl::Event based on Event, second best choice.	553	AnyEvent::Impl::Event based on Event, second best choice.
395	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	554	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
396	AnyEvent::Impl::Glib based on Glib, third-best choice.	555	AnyEvent::Impl::Glib based on Glib, third-best choice.
397	AnyEvent::Impl::Tk based on Tk, very bad choice.	556	AnyEvent::Impl::Tk based on Tk, very bad choice.
…		…
414	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	573	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
415	if necessary. You should only call this function right before you would	574	if necessary. You should only call this function right before you would
416	have created an AnyEvent watcher anyway, that is, as late as possible at	575	have created an AnyEvent watcher anyway, that is, as late as possible at
417	runtime.	576	runtime.
418		577
		578	=item $guard = AnyEvent::post_detect { BLOCK }
		579
		580	Arranges for the code block to be executed as soon as the event model is
		581	autodetected (or immediately if this has already happened).
		582
		583	If called in scalar or list context, then it creates and returns an object
		584	that automatically removes the callback again when it is destroyed. See
		585	L<Coro::BDB> for a case where this is useful.
		586
		587	=item @AnyEvent::post_detect
		588
		589	If there are any code references in this array (you can C<push> to it
		590	before or after loading AnyEvent), then they will called directly after
		591	the event loop has been chosen.
		592
		593	You should check C<$AnyEvent::MODEL> before adding to this array, though:
		594	if it contains a true value then the event loop has already been detected,
		595	and the array will be ignored.
		596
		597	Best use C<AnyEvent::post_detect { BLOCK }> instead.
		598
419	=back	599	=back
420		600
421	=head1 WHAT TO DO IN A MODULE	601	=head1 WHAT TO DO IN A MODULE
422		602
423	As a module author, you should C<use AnyEvent> and call AnyEvent methods	603	As a module author, you should C<use AnyEvent> and call AnyEvent methods
…		…
426	Be careful when you create watchers in the module body - AnyEvent will	606	Be careful when you create watchers in the module body - AnyEvent will
427	decide which event module to use as soon as the first method is called, so	607	decide which event module to use as soon as the first method is called, so
428	by calling AnyEvent in your module body you force the user of your module	608	by calling AnyEvent in your module body you force the user of your module
429	to load the event module first.	609	to load the event module first.
430		610
431	Never call C<< ->wait >> on a condition variable unless you I<know> that	611	Never call C<< ->recv >> on a condition variable unless you I<know> that
432	the C<< ->broadcast >> method has been called on it already. This is	612	the C<< ->send >> method has been called on it already. This is
433	because it will stall the whole program, and the whole point of using	613	because it will stall the whole program, and the whole point of using
434	events is to stay interactive.	614	events is to stay interactive.
435		615
436	It is fine, however, to call C<< ->wait >> when the user of your module	616	It is fine, however, to call C<< ->recv >> when the user of your module
437	requests it (i.e. if you create a http request object ad have a method	617	requests it (i.e. if you create a http request object ad have a method
438	called C<results> that returns the results, it should call C<< ->wait >>	618	called C<results> that returns the results, it should call C<< ->recv >>
439	freely, as the user of your module knows what she is doing. always).	619	freely, as the user of your module knows what she is doing. always).
440		620
441	=head1 WHAT TO DO IN THE MAIN PROGRAM	621	=head1 WHAT TO DO IN THE MAIN PROGRAM
442		622
443	There will always be a single main program - the only place that should	623	There will always be a single main program - the only place that should
…		…
445		625
446	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	626	If it doesn't care, it can just "use AnyEvent" and use it itself, or not
447	do anything special (it does not need to be event-based) and let AnyEvent	627	do anything special (it does not need to be event-based) and let AnyEvent
448	decide which implementation to chose if some module relies on it.	628	decide which implementation to chose if some module relies on it.
449		629
450	If the main program relies on a specific event model. For example, in	630	If the main program relies on a specific event model - for example, in
451	Gtk2 programs you have to rely on the Glib module. You should load the	631	Gtk2 programs you have to rely on the Glib module - you should load the
452	event module before loading AnyEvent or any module that uses it: generally	632	event module before loading AnyEvent or any module that uses it: generally
453	speaking, you should load it as early as possible. The reason is that	633	speaking, you should load it as early as possible. The reason is that
454	modules might create watchers when they are loaded, and AnyEvent will	634	modules might create watchers when they are loaded, and AnyEvent will
455	decide on the event model to use as soon as it creates watchers, and it	635	decide on the event model to use as soon as it creates watchers, and it
456	might chose the wrong one unless you load the correct one yourself.	636	might chose the wrong one unless you load the correct one yourself.
457		637
458	You can chose to use a rather inefficient pure-perl implementation by	638	You can chose to use a pure-perl implementation by loading the
459	loading the C<AnyEvent::Impl::Perl> module, which gives you similar	639	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour
460	behaviour everywhere, but letting AnyEvent chose is generally better.	640	everywhere, but letting AnyEvent chose the model is generally better.
		641
		642	=head2 MAINLOOP EMULATION
		643
		644	Sometimes (often for short test scripts, or even standalone programs who
		645	only want to use AnyEvent), you do not want to run a specific event loop.
		646
		647	In that case, you can use a condition variable like this:
		648
		649	AnyEvent->condvar->recv;
		650
		651	This has the effect of entering the event loop and looping forever.
		652
		653	Note that usually your program has some exit condition, in which case
		654	it is better to use the "traditional" approach of storing a condition
		655	variable somewhere, waiting for it, and sending it when the program should
		656	exit cleanly.
		657
461		658
462	=head1 OTHER MODULES	659	=head1 OTHER MODULES
463		660
464	The following is a non-exhaustive list of additional modules that use	661	The following is a non-exhaustive list of additional modules that use
465	AnyEvent and can therefore be mixed easily with other AnyEvent modules	662	AnyEvent and can therefore be mixed easily with other AnyEvent modules
…		…
477		674
478	Provide read and write buffers and manages watchers for reads and writes.	675	Provide read and write buffers and manages watchers for reads and writes.
479		676
480	=item L<AnyEvent::Socket>	677	=item L<AnyEvent::Socket>
481		678
482	Provides a means to do non-blocking connects, accepts etc.	679	Provides various utility functions for (internet protocol) sockets,
		680	addresses and name resolution. Also functions to create non-blocking tcp
		681	connections or tcp servers, with IPv6 and SRV record support and more.
		682
		683	=item L<AnyEvent::DNS>
		684
		685	Provides rich asynchronous DNS resolver capabilities.
483		686
484	=item L<AnyEvent::HTTPD>	687	=item L<AnyEvent::HTTPD>
485		688
486	Provides a simple web application server framework.	689	Provides a simple web application server framework.
487
488	=item L<AnyEvent::DNS>
489
490	Provides asynchronous DNS resolver capabilities, beyond what
491	L<AnyEvent::Util> offers.
492		690
493	=item L<AnyEvent::FastPing>	691	=item L<AnyEvent::FastPing>
494		692
495	The fastest ping in the west.	693	The fastest ping in the west.
496		694
…		…
511		709
512	High level API for event-based execution flow control.	710	High level API for event-based execution flow control.
513		711
514	=item L<Coro>	712	=item L<Coro>
515		713
516	Has special support for AnyEvent.	714	Has special support for AnyEvent via L<Coro::AnyEvent>.
		715
		716	=item L<AnyEvent::AIO>, L<IO::AIO>
		717
		718	Truly asynchronous I/O, should be in the toolbox of every event
		719	programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent
		720	together.
		721
		722	=item L<AnyEvent::BDB>, L<BDB>
		723
		724	Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses
		725	IO::AIO and AnyEvent together.
517		726
518	=item L<IO::Lambda>	727	=item L<IO::Lambda>
519		728
520	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.	729	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
521
522	=item L<IO::AIO>
523
524	Truly asynchronous I/O, should be in the toolbox of every event
525	programmer. Can be trivially made to use AnyEvent.
526
527	=item L<BDB>
528
529	Truly asynchronous Berkeley DB access. Can be trivially made to use
530	AnyEvent.
531		730
532	=back	731	=back
533		732
534	=cut	733	=cut
535		734
…		…
538	no warnings;	737	no warnings;
539	use strict;	738	use strict;
540		739
541	use Carp;	740	use Carp;
542		741
543	our $VERSION = '3.3';	742	our $VERSION = '4.05';
544	our $MODEL;	743	our $MODEL;
545		744
546	our $AUTOLOAD;	745	our $AUTOLOAD;
547	our @ISA;	746	our @ISA;
548		747
		748	our @REGISTRY;
		749
		750	our $WIN32;
		751
		752	BEGIN {
		753	my $win32 = ! ! ($^O =~ /mswin32/i);
		754	eval "sub WIN32(){ $win32 }";
		755	}
		756
549	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	757	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;
550		758
551	our @REGISTRY;	759	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred
		760
		761	{
		762	my $idx;
		763	$PROTOCOL{$_} = ++$idx
		764	for reverse split /\s,\s/,
		765	$ENV{PERL_ANYEVENT_PROTOCOLS} \|\| "ipv4,ipv6";
		766	}
552		767
553	my @models = (	768	my @models = (
554	[Coro::EV:: => AnyEvent::Impl::CoroEV::],
555	[Coro::Event:: => AnyEvent::Impl::CoroEvent::],
556	[EV:: => AnyEvent::Impl::EV::],	769	[EV:: => AnyEvent::Impl::EV::],
557	[Event:: => AnyEvent::Impl::Event::],	770	[Event:: => AnyEvent::Impl::Event::],
558	[Tk:: => AnyEvent::Impl::Tk::],
559	[Wx:: => AnyEvent::Impl::POE::],
560	[Prima:: => AnyEvent::Impl::POE::],
561	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	771	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
562	# everything below here will not be autoprobed as the pureperl backend should work everywhere	772	# everything below here will not be autoprobed
563	[Glib:: => AnyEvent::Impl::Glib::],	773	# as the pureperl backend should work everywhere
		774	# and is usually faster
		775	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
		776	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
564	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	777	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
565	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	778	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
566	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	779	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
		780	[Wx:: => AnyEvent::Impl::POE::],
		781	[Prima:: => AnyEvent::Impl::POE::],
567	);	782	);
568		783
569	our %method = map +($_ => 1), qw(io timer signal child condvar broadcast wait one_event DESTROY);	784	our %method = map +($_ => 1), qw(io timer signal child condvar one_event DESTROY);
		785
		786	our @post_detect;
		787
		788	sub post_detect(&) {
		789	my ($cb) = @_;
		790
		791	if ($MODEL) {
		792	$cb->();
		793
		794	1
		795	} else {
		796	push @post_detect, $cb;
		797
		798	defined wantarray
		799	? bless \$cb, "AnyEvent::Util::PostDetect"
		800	: ()
		801	}
		802	}
		803
		804	sub AnyEvent::Util::PostDetect::DESTROY {
		805	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		806	}
570		807
571	sub detect() {	808	sub detect() {
572	unless ($MODEL) {	809	unless ($MODEL) {
573	no strict 'refs';	810	no strict 'refs';
		811	local $SIG{__DIE__};
574		812
575	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	813	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
576	my $model = "AnyEvent::Impl::$1";	814	my $model = "AnyEvent::Impl::$1";
577	if (eval "require $model") {	815	if (eval "require $model") {
578	$MODEL = $model;	816	$MODEL = $model;
…		…
608	last;	846	last;
609	}	847	}
610	}	848	}
611		849
612	$MODEL	850	$MODEL
613	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.";	851	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";
614	}	852	}
615	}	853	}
616		854
617	unshift @ISA, $MODEL;	855	unshift @ISA, $MODEL;
618	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	856	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		857
		858	(shift @post_detect)->() while @post_detect;
619	}	859	}
620		860
621	$MODEL	861	$MODEL
622	}	862	}
623		863
…		…
633	$class->$func (@_);	873	$class->$func (@_);
634	}	874	}
635		875
636	package AnyEvent::Base;	876	package AnyEvent::Base;
637		877
638	# default implementation for ->condvar, ->wait, ->broadcast	878	# default implementation for ->condvar
639		879
640	sub condvar {	880	sub condvar {
641	bless \my $flag, "AnyEvent::Base::CondVar"	881	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::
642	}
643
644	sub AnyEvent::Base::CondVar::broadcast {
645	${$_[0]}++;
646	}
647
648	sub AnyEvent::Base::CondVar::wait {
649	AnyEvent->one_event while !${$_[0]};
650	}	882	}
651		883
652	# default implementation for ->signal	884	# default implementation for ->signal
653		885
654	our %SIG_CB;	886	our %SIG_CB;
…		…
707	or Carp::croak "required option 'pid' is missing";	939	or Carp::croak "required option 'pid' is missing";
708		940
709	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	941	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
710		942
711	unless ($WNOHANG) {	943	unless ($WNOHANG) {
712	$WNOHANG = eval { require POSIX; &POSIX::WNOHANG } \|\| 1;	944	$WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;
713	}	945	}
714		946
715	unless ($CHLD_W) {	947	unless ($CHLD_W) {
716	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	948	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
717	# child could be a zombie already, so make at least one round	949	# child could be a zombie already, so make at least one round
…		…
727	delete $PID_CB{$pid}{$cb};	959	delete $PID_CB{$pid}{$cb};
728	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	960	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
729		961
730	undef $CHLD_W unless keys %PID_CB;	962	undef $CHLD_W unless keys %PID_CB;
731	}	963	}
		964
		965	package AnyEvent::CondVar;
		966
		967	our @ISA = AnyEvent::CondVar::Base::;
		968
		969	package AnyEvent::CondVar::Base;
		970
		971	use overload
		972	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },
		973	fallback => 1;
		974
		975	sub _send {
		976	# nop
		977	}
		978
		979	sub send {
		980	my $cv = shift;
		981	$cv->{_ae_sent} = [@_];
		982	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
		983	$cv->_send;
		984	}
		985
		986	sub croak {
		987	$_[0]{_ae_croak} = $_[1];
		988	$_[0]->send;
		989	}
		990
		991	sub ready {
		992	$_[0]{_ae_sent}
		993	}
		994
		995	sub _wait {
		996	AnyEvent->one_event while !$_[0]{_ae_sent};
		997	}
		998
		999	sub recv {
		1000	$_[0]->_wait;
		1001
		1002	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
		1003	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
		1004	}
		1005
		1006	sub cb {
		1007	$_[0]{_ae_cb} = $_[1] if @_ > 1;
		1008	$_[0]{_ae_cb}
		1009	}
		1010
		1011	sub begin {
		1012	++$_[0]{_ae_counter};
		1013	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
		1014	}
		1015
		1016	sub end {
		1017	return if --$_[0]{_ae_counter};
		1018	&{ $_[0]{_ae_end_cb} \|\| sub { $_[0]->send } };
		1019	}
		1020
		1021	# undocumented/compatibility with pre-3.4
		1022	*broadcast = \&send;
		1023	*wait = \&_wait;
732		1024
733	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1025	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
734		1026
735	This is an advanced topic that you do not normally need to use AnyEvent in	1027	This is an advanced topic that you do not normally need to use AnyEvent in
736	a module. This section is only of use to event loop authors who want to	1028	a module. This section is only of use to event loop authors who want to
…		…
793	model it chooses.	1085	model it chooses.
794		1086
795	=item C<PERL_ANYEVENT_MODEL>	1087	=item C<PERL_ANYEVENT_MODEL>
796		1088
797	This can be used to specify the event model to be used by AnyEvent, before	1089	This can be used to specify the event model to be used by AnyEvent, before
798	autodetection and -probing kicks in. It must be a string consisting	1090	auto detection and -probing kicks in. It must be a string consisting
799	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	1091	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
800	and the resulting module name is loaded and if the load was successful,	1092	and the resulting module name is loaded and if the load was successful,
801	used as event model. If it fails to load AnyEvent will proceed with	1093	used as event model. If it fails to load AnyEvent will proceed with
802	autodetection and -probing.	1094	auto detection and -probing.
803		1095
804	This functionality might change in future versions.	1096	This functionality might change in future versions.
805		1097
806	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	1098	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
807	could start your program like this:	1099	could start your program like this:
808		1100
809	PERL_ANYEVENT_MODEL=Perl perl ...	1101	PERL_ANYEVENT_MODEL=Perl perl ...
		1102
		1103	=item C<PERL_ANYEVENT_PROTOCOLS>
		1104
		1105	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
		1106	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
		1107	of auto probing).
		1108
		1109	Must be set to a comma-separated list of protocols or address families,
		1110	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
		1111	used, and preference will be given to protocols mentioned earlier in the
		1112	list.
		1113
		1114	This variable can effectively be used for denial-of-service attacks
		1115	against local programs (e.g. when setuid), although the impact is likely
		1116	small, as the program has to handle connection errors already-
		1117
		1118	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
		1119	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
		1120	- only support IPv4, never try to resolve or contact IPv6
		1121	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
		1122	IPv6, but prefer IPv6 over IPv4.
		1123
		1124	=item C<PERL_ANYEVENT_EDNS0>
		1125
		1126	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
		1127	for DNS. This extension is generally useful to reduce DNS traffic, but
		1128	some (broken) firewalls drop such DNS packets, which is why it is off by
		1129	default.
		1130
		1131	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
		1132	EDNS0 in its DNS requests.
		1133
		1134	=item C<PERL_ANYEVENT_MAX_FORKS>
		1135
		1136	The maximum number of child processes that C<AnyEvent::Util::fork_call>
		1137	will create in parallel.
810		1138
811	=back	1139	=back
812		1140
813	=head1 EXAMPLE PROGRAM	1141	=head1 EXAMPLE PROGRAM
814		1142
…		…
825	poll => 'r',	1153	poll => 'r',
826	cb => sub {	1154	cb => sub {
827	warn "io event <$_[0]>\n"; # will always output <r>	1155	warn "io event <$_[0]>\n"; # will always output <r>
828	chomp (my $input = <STDIN>); # read a line	1156	chomp (my $input = <STDIN>); # read a line
829	warn "read: $input\n"; # output what has been read	1157	warn "read: $input\n"; # output what has been read
830	$cv->broadcast if $input =~ /^q/i; # quit program if /^q/i	1158	$cv->send if $input =~ /^q/i; # quit program if /^q/i
831	},	1159	},
832	);	1160	);
833		1161
834	my $time_watcher; # can only be used once	1162	my $time_watcher; # can only be used once
835		1163
…		…
840	});	1168	});
841	}	1169	}
842		1170
843	new_timer; # create first timer	1171	new_timer; # create first timer
844		1172
845	$cv->wait; # wait until user enters /^q/i	1173	$cv->recv; # wait until user enters /^q/i
846		1174
847	=head1 REAL-WORLD EXAMPLE	1175	=head1 REAL-WORLD EXAMPLE
848		1176
849	Consider the L<Net::FCP> module. It features (among others) the following	1177	Consider the L<Net::FCP> module. It features (among others) the following
850	API calls, which are to freenet what HTTP GET requests are to http:	1178	API calls, which are to freenet what HTTP GET requests are to http:
…		…
900	syswrite $txn->{fh}, $txn->{request}	1228	syswrite $txn->{fh}, $txn->{request}
901	or die "connection or write error";	1229	or die "connection or write error";
902	$txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r });	1230	$txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r });
903		1231
904	Again, C<fh_ready_r> waits till all data has arrived, and then stores the	1232	Again, C<fh_ready_r> waits till all data has arrived, and then stores the
905	result and signals any possible waiters that the request ahs finished:	1233	result and signals any possible waiters that the request has finished:
906		1234
907	sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf};	1235	sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf};
908		1236
909	if (end-of-file or data complete) {	1237	if (end-of-file or data complete) {
910	$txn->{result} = $txn->{buf};	1238	$txn->{result} = $txn->{buf};
911	$txn->{finished}->broadcast;	1239	$txn->{finished}->send;
912	$txb->{cb}->($txn) of $txn->{cb}; # also call callback	1240	$txb->{cb}->($txn) of $txn->{cb}; # also call callback
913	}	1241	}
914		1242
915	The C<result> method, finally, just waits for the finished signal (if the	1243	The C<result> method, finally, just waits for the finished signal (if the
916	request was already finished, it doesn't wait, of course, and returns the	1244	request was already finished, it doesn't wait, of course, and returns the
917	data:	1245	data:
918		1246
919	$txn->{finished}->wait;	1247	$txn->{finished}->recv;
920	return $txn->{result};	1248	return $txn->{result};
921		1249
922	The actual code goes further and collects all errors (C<die>s, exceptions)	1250	The actual code goes further and collects all errors (C<die>s, exceptions)
923	that occured during request processing. The C<result> method detects	1251	that occurred during request processing. The C<result> method detects
924	whether an exception as thrown (it is stored inside the $txn object)	1252	whether an exception as thrown (it is stored inside the $txn object)
925	and just throws the exception, which means connection errors and other	1253	and just throws the exception, which means connection errors and other
926	problems get reported tot he code that tries to use the result, not in a	1254	problems get reported tot he code that tries to use the result, not in a
927	random callback.	1255	random callback.
928		1256
…		…
959		1287
960	my $quit = AnyEvent->condvar;	1288	my $quit = AnyEvent->condvar;
961		1289
962	$fcp->txn_client_get ($url)->cb (sub {	1290	$fcp->txn_client_get ($url)->cb (sub {
963	...	1291	...
964	$quit->broadcast;	1292	$quit->send;
965	});	1293	});
966		1294
967	$quit->wait;	1295	$quit->recv;
968		1296
969		1297
970	=head1 BENCHMARKS	1298	=head1 BENCHMARKS
971		1299
972	To give you an idea of the performance and overheads that AnyEvent adds	1300	To give you an idea of the performance and overheads that AnyEvent adds
…		…
974	of various event loops I prepared some benchmarks.	1302	of various event loops I prepared some benchmarks.
975		1303
976	=head2 BENCHMARKING ANYEVENT OVERHEAD	1304	=head2 BENCHMARKING ANYEVENT OVERHEAD
977		1305
978	Here is a benchmark of various supported event models used natively and	1306	Here is a benchmark of various supported event models used natively and
979	through anyevent. The benchmark creates a lot of timers (with a zero	1307	through AnyEvent. The benchmark creates a lot of timers (with a zero
980	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	1308	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
981	which it is), lets them fire exactly once and destroys them again.	1309	which it is), lets them fire exactly once and destroys them again.
982		1310
983	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	1311	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
984	distribution.	1312	distribution.
…		…
1001	all watchers, to avoid adding memory overhead. That means closure creation	1329	all watchers, to avoid adding memory overhead. That means closure creation
1002	and memory usage is not included in the figures.	1330	and memory usage is not included in the figures.
1003		1331
1004	I<invoke> is the time, in microseconds, used to invoke a simple	1332	I<invoke> is the time, in microseconds, used to invoke a simple
1005	callback. The callback simply counts down a Perl variable and after it was	1333	callback. The callback simply counts down a Perl variable and after it was
1006	invoked "watcher" times, it would C<< ->broadcast >> a condvar once to	1334	invoked "watcher" times, it would C<< ->send >> a condvar once to
1007	signal the end of this phase.	1335	signal the end of this phase.
1008		1336
1009	I<destroy> is the time, in microseconds, that it takes to destroy a single	1337	I<destroy> is the time, in microseconds, that it takes to destroy a single
1010	watcher.	1338	watcher.
1011		1339
…		…
1107		1435
1108	=back	1436	=back
1109		1437
1110	=head2 BENCHMARKING THE LARGE SERVER CASE	1438	=head2 BENCHMARKING THE LARGE SERVER CASE
1111		1439
1112	This benchmark atcually benchmarks the event loop itself. It works by	1440	This benchmark actually benchmarks the event loop itself. It works by
1113	creating a number of "servers": each server consists of a socketpair, a	1441	creating a number of "servers": each server consists of a socket pair, a
1114	timeout watcher that gets reset on activity (but never fires), and an I/O	1442	timeout watcher that gets reset on activity (but never fires), and an I/O
1115	watcher waiting for input on one side of the socket. Each time the socket	1443	watcher waiting for input on one side of the socket. Each time the socket
1116	watcher reads a byte it will write that byte to a random other "server".	1444	watcher reads a byte it will write that byte to a random other "server".
1117		1445
1118	The effect is that there will be a lot of I/O watchers, only part of which	1446	The effect is that there will be a lot of I/O watchers, only part of which
1119	are active at any one point (so there is a constant number of active	1447	are active at any one point (so there is a constant number of active
1120	fds for each loop iterstaion, but which fds these are is random). The	1448	fds for each loop iteration, but which fds these are is random). The
1121	timeout is reset each time something is read because that reflects how	1449	timeout is reset each time something is read because that reflects how
1122	most timeouts work (and puts extra pressure on the event loops).	1450	most timeouts work (and puts extra pressure on the event loops).
1123		1451
1124	In this benchmark, we use 10000 socketpairs (20000 sockets), of which 100	1452	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
1125	(1%) are active. This mirrors the activity of large servers with many	1453	(1%) are active. This mirrors the activity of large servers with many
1126	connections, most of which are idle at any one point in time.	1454	connections, most of which are idle at any one point in time.
1127		1455
1128	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	1456	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
1129	distribution.	1457	distribution.
…		…
1131	=head3 Explanation of the columns	1459	=head3 Explanation of the columns
1132		1460
1133	I<sockets> is the number of sockets, and twice the number of "servers" (as	1461	I<sockets> is the number of sockets, and twice the number of "servers" (as
1134	each server has a read and write socket end).	1462	each server has a read and write socket end).
1135		1463
1136	I<create> is the time it takes to create a socketpair (which is	1464	I<create> is the time it takes to create a socket pair (which is
1137	nontrivial) and two watchers: an I/O watcher and a timeout watcher.	1465	nontrivial) and two watchers: an I/O watcher and a timeout watcher.
1138		1466
1139	I<request>, the most important value, is the time it takes to handle a	1467	I<request>, the most important value, is the time it takes to handle a
1140	single "request", that is, reading the token from the pipe and forwarding	1468	single "request", that is, reading the token from the pipe and forwarding
1141	it to another server. This includes deleting the old timeout and creating	1469	it to another server. This includes deleting the old timeout and creating
…		…
1214	speed most when you have lots of watchers, not when you only have a few of	1542	speed most when you have lots of watchers, not when you only have a few of
1215	them).	1543	them).
1216		1544
1217	EV is again fastest.	1545	EV is again fastest.
1218		1546
1219	Perl again comes second. It is noticably faster than the C-based event	1547	Perl again comes second. It is noticeably faster than the C-based event
1220	loops Event and Glib, although the difference is too small to really	1548	loops Event and Glib, although the difference is too small to really
1221	matter.	1549	matter.
1222		1550
1223	POE also performs much better in this case, but is is still far behind the	1551	POE also performs much better in this case, but is is still far behind the
1224	others.	1552	others.
…		…
1257		1585
1258	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }	1586	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }
1259		1587
1260	use AnyEvent;	1588	use AnyEvent;
1261		1589
		1590	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
		1591	be used to probe what backend is used and gain other information (which is
		1592	probably even less useful to an attacker than PERL_ANYEVENT_MODEL).
		1593
1262		1594
1263	=head1 SEE ALSO	1595	=head1 SEE ALSO
1264		1596
1265	Event modules: L<Coro::EV>, L<EV>, L<EV::Glib>, L<Glib::EV>,	1597	Utility functions: L<AnyEvent::Util>.
1266	L<Coro::Event>, L<Event>, L<Glib::Event>, L<Glib>, L<Coro>, L<Tk>,	1598
		1599	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,
1267	L<Event::Lib>, L<Qt>, L<POE>.	1600	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
1268		1601
1269	Implementations: L<AnyEvent::Impl::CoroEV>, L<AnyEvent::Impl::EV>,	1602	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
1270	L<AnyEvent::Impl::CoroEvent>, L<AnyEvent::Impl::Event>, L<AnyEvent::Impl::Glib>,	1603	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
1271	L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, L<AnyEvent::Impl::EventLib>,	1604	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
1272	L<AnyEvent::Impl::Qt>, L<AnyEvent::Impl::POE>.	1605	L<AnyEvent::Impl::POE>.
1273		1606
		1607	Non-blocking file handles, sockets, TCP clients and
		1608	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.
		1609
		1610	Asynchronous DNS: L<AnyEvent::DNS>.
		1611
		1612	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>,
		1613
1274	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>.	1614	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.
1275		1615
1276		1616
1277	=head1 AUTHOR	1617	=head1 AUTHOR
1278		1618
1279	Marc Lehmann <schmorp@schmorp.de>	1619	Marc Lehmann <schmorp@schmorp.de>

Diff Legend

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

Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.104 by root, Wed Apr 30 11:40:22 2008 UTC vs. Revision 1.142 by root, Tue May 27 02:34:30 2008 UTC

Diff Legend

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.104 by root, Wed Apr 30 11:40:22 2008 UTC vs.
Revision 1.142 by root, Tue May 27 02:34:30 2008 UTC