[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 1.138 by root, Mon May 26 05:09:53 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?
…		…
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, if you want lots of policy (this can arguably be somewhat	67	Of course, if you want lots of policy (this can arguably be somewhat
…		…
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
…		…
108		108
109	=head1 WATCHERS	109	=head1 WATCHERS
110		110
111	AnyEvent has the central concept of a I<watcher>, which is an object that	111	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	112	stores relevant data for each kind of event you are waiting for, such as
113	the callback to call, the filehandle to watch, etc.	113	the callback to call, the file handle to watch, etc.
114		114
115	These watchers are normal Perl objects with normal Perl lifetime. After	115	These watchers are normal Perl objects with normal Perl lifetime. After
116	creating a watcher it will immediately "watch" for events and invoke the	116	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	117	callback when the event occurs (of course, only when the event model
118	is in control).	118	is in control).
…		…
237		237
238	Although the callback might get passed parameters, their value and	238	Although the callback might get passed parameters, their value and
239	presence is undefined and you cannot rely on them. Portable AnyEvent	239	presence is undefined and you cannot rely on them. Portable AnyEvent
240	callbacks cannot use arguments passed to signal watcher callbacks.	240	callbacks cannot use arguments passed to signal watcher callbacks.
241		241
242	Multiple signal occurances can be clumped together into one callback	242	Multiple signal occurrences can be clumped together into one callback
243	invocation, and callback invocation will be synchronous. synchronous means	243	invocation, and callback invocation will be synchronous. Synchronous means
244	that it might take a while until the signal gets handled by the process,	244	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.	245	but it is guaranteed not to interrupt any other callbacks.
246		246
247	The main advantage of using these watchers is that you can share a signal	247	The main advantage of using these watchers is that you can share a signal
248	between multiple watchers.	248	between multiple watchers.
249		249
250	This watcher might use C<%SIG>, so programs overwriting those signals	250	This watcher might use C<%SIG>, so programs overwriting those signals
…		…
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
		300	If you are familiar with some event loops you will know that all of them
		301	require you to run some blocking "loop", "run" or similar function that
		302	will actively watch for new events and call your callbacks.
		303
		304	AnyEvent is different, it expects somebody else to run the event loop and
		305	will only block when necessary (usually when told by the user).
		306
		307	The instrument to do that is called a "condition variable", so called
		308	because they represent a condition that must become true.
		309
302	Condition variables can be created by calling the C<< AnyEvent->condvar >>	310	Condition variables can be created by calling the C<< AnyEvent->condvar
303	method without any arguments.	311	>> method, usually without arguments. The only argument pair allowed is
		312	C<cb>, which specifies a callback to be called when the condition variable
		313	becomes true.
304		314
305	A condition variable waits for a condition - precisely that the C<<	315	After creation, the condition variable is "false" until it becomes "true"
306	->broadcast >> method has been called.	316	by calling the C<send> method (or calling the condition variable as if it
		317	were a callback, read about the caveats in the description for the C<<
		318	->send >> method).
307		319
308	They are very useful to signal that a condition has been fulfilled, for	320	Condition variables are similar to callbacks, except that you can
		321	optionally wait for them. They can also be called merge points - points
		322	in time where multiple outstanding events have been processed. And yet
		323	another way to call them is transactions - each condition variable can be
		324	used to represent a transaction, which finishes at some point and delivers
		325	a result.
		326
		327	Condition variables are very useful to signal that something has finished,
309	example, if you write a module that does asynchronous http requests,	328	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	329	then a condition variable would be the ideal candidate to signal the
311	availability of results.	330	availability of results. The user can either act when the callback is
		331	called or can synchronously C<< ->recv >> for the results.
312		332
313	You can also use condition variables to block your main program until	333	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	334	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<<	335	could C<< ->recv >> in your main program until the user clicks the Quit
316	->broadcast >> the "quit" event.	336	button of your app, which would C<< ->send >> the "quit" event.
317		337
318	Note that condition variables recurse into the event loop - if you have	338	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	339	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	340	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,	341	you should avoid making a blocking wait yourself, at least in callbacks,
322	as this asks for trouble.	342	as this asks for trouble.
323		343
324	This object has two methods:	344	Condition variables are represented by hash refs in perl, and the keys
		345	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing
		346	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
		348	it's C<new> method in your own C<new> method.
		349
		350	There are two "sides" to a condition variable - the "producer side" which
		351	eventually calls C<< -> send >>, and the "consumer side", which waits
		352	for the send to occur.
		353
		354	Example: wait for a timer.
		355
		356	# wait till the result is ready
		357	my $result_ready = AnyEvent->condvar;
		358
		359	# do something such as adding a timer
		360	# or socket watcher the calls $result_ready->send
		361	# when the "result" is ready.
		362	# in this case, we simply use a timer:
		363	my $w = AnyEvent->timer (
		364	after => 1,
		365	cb => sub { $result_ready->send },
		366	);
		367
		368	# this "blocks" (while handling events) till the callback
		369	# calls send
		370	$result_ready->recv;
		371
		372	Example: wait for a timer, but take advantage of the fact that
		373	condition variables are also code references.
		374
		375	my $done = AnyEvent->condvar;
		376	my $delay = AnyEvent->timer (after => 5, cb => $done);
		377	$done->recv;
		378
		379	=head3 METHODS FOR PRODUCERS
		380
		381	These methods should only be used by the producing side, i.e. the
		382	code/module that eventually sends the signal. Note that it is also
		383	the producer side which creates the condvar in most cases, but it isn't
		384	uncommon for the consumer to create it as well.
325		385
326	=over 4	386	=over 4
327		387
		388	=item $cv->send (...)
		389
		390	Flag the condition as ready - a running C<< ->recv >> and all further
		391	calls to C<recv> will (eventually) return after this method has been
		392	called. If nobody is waiting the send will be remembered.
		393
		394	If a callback has been set on the condition variable, it is called
		395	immediately from within send.
		396
		397	Any arguments passed to the C<send> call will be returned by all
		398	future C<< ->recv >> calls.
		399
		400	Condition variables are overloaded so one can call them directly
		401	(as a code reference). Calling them directly is the same as calling
		402	C<send>. Note, however, that many C-based event loops do not handle
		403	overloading, so as tempting as it may be, passing a condition variable
		404	instead of a callback does not work. Both the pure perl and EV loops
		405	support overloading, however, as well as all functions that use perl to
		406	invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
		407	example).
		408
		409	=item $cv->croak ($error)
		410
		411	Similar to send, but causes all call's to C<< ->recv >> to invoke
		412	C<Carp::croak> with the given error message/object/scalar.
		413
		414	This can be used to signal any errors to the condition variable
		415	user/consumer.
		416
		417	=item $cv->begin ([group callback])
		418
328	=item $cv->wait	419	=item $cv->end
329		420
330	Wait (blocking if necessary) until the C<< ->broadcast >> method has been	421	These two methods are EXPERIMENTAL and MIGHT CHANGE.
		422
		423	These two methods can be used to combine many transactions/events into
		424	one. For example, a function that pings many hosts in parallel might want
		425	to use a condition variable for the whole process.
		426
		427	Every call to C<< ->begin >> will increment a counter, and every call to
		428	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
		429	>>, the (last) callback passed to C<begin> will be executed. That callback
		430	is I<supposed> to call C<< ->send >>, but that is not required. If no
		431	callback was set, C<send> will be called without any arguments.
		432
		433	Let's clarify this with the ping example:
		434
		435	my $cv = AnyEvent->condvar;
		436
		437	my %result;
		438	$cv->begin (sub { $cv->send (\%result) });
		439
		440	for my $host (@list_of_hosts) {
		441	$cv->begin;
		442	ping_host_then_call_callback $host, sub {
		443	$result{$host} = ...;
		444	$cv->end;
		445	};
		446	}
		447
		448	$cv->end;
		449
		450	This code fragment supposedly pings a number of hosts and calls
		451	C<send> after results for all then have have been gathered - in any
		452	order. To achieve this, the code issues a call to C<begin> when it starts
		453	each ping request and calls C<end> when it has received some result for
		454	it. Since C<begin> and C<end> only maintain a counter, the order in which
		455	results arrive is not relevant.
		456
		457	There is an additional bracketing call to C<begin> and C<end> outside the
		458	loop, which serves two important purposes: first, it sets the callback
		459	to be called once the counter reaches C<0>, and second, it ensures that
		460	C<send> is called even when C<no> hosts are being pinged (the loop
		461	doesn't execute once).
		462
		463	This is the general pattern when you "fan out" into multiple subrequests:
		464	use an outer C<begin>/C<end> pair to set the callback and ensure C<end>
		465	is called at least once, and then, for each subrequest you start, call
		466	C<begin> and for each subrequest you finish, call C<end>.
		467
		468	=back
		469
		470	=head3 METHODS FOR CONSUMERS
		471
		472	These methods should only be used by the consuming side, i.e. the
		473	code awaits the condition.
		474
		475	=over 4
		476
		477	=item $cv->recv
		478
		479	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
331	called on c<$cv>, while servicing other watchers normally.	480	>> methods have been called on c<$cv>, while servicing other watchers
		481	normally.
332		482
333	You can only wait once on a condition - additional calls will return	483	You can only wait once on a condition - additional calls are valid but
334	immediately.	484	will return immediately.
		485
		486	If an error condition has been set by calling C<< ->croak >>, then this
		487	function will call C<croak>.
		488
		489	In list context, all parameters passed to C<send> will be returned,
		490	in scalar context only the first one will be returned.
335		491
336	Not all event models support a blocking wait - some die in that case	492	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	493	(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	494	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	495	caller decide whether the call will block or not (for example, by coupling
340	condition variables with some kind of request results and supporting	496	condition variables with some kind of request results and supporting
341	callbacks so the caller knows that getting the result will not block,	497	callbacks so the caller knows that getting the result will not block,
342	while still suppporting blocking waits if the caller so desires).	498	while still supporting blocking waits if the caller so desires).
343		499
344	Another reason I<never> to C<< ->wait >> in a module is that you cannot	500	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	501	sensibly have two C<< ->recv >>'s in parallel, as that would require
346	multiple interpreters or coroutines/threads, none of which C<AnyEvent>	502	multiple interpreters or coroutines/threads, none of which C<AnyEvent>
347	can supply (the coroutine-aware backends L<AnyEvent::Impl::CoroEV> and	503	can supply.
348	L<AnyEvent::Impl::CoroEvent> explicitly support concurrent C<< ->wait >>'s
349	from different coroutines, however).
350		504
351	=item $cv->broadcast	505	The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
		506	fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
		507	versions and also integrates coroutines into AnyEvent, making blocking
		508	C<< ->recv >> calls perfectly safe as long as they are done from another
		509	coroutine (one that doesn't run the event loop).
352		510
353	Flag the condition as ready - a running C<< ->wait >> and all further	511	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	512	only calling C<< ->recv >> from within that callback (or at a later
355	called. If nobody is waiting the broadcast will be remembered..	513	time). This will work even when the event loop does not support blocking
		514	waits otherwise.
		515
		516	=item $bool = $cv->ready
		517
		518	Returns true when the condition is "true", i.e. whether C<send> or
		519	C<croak> have been called.
		520
		521	=item $cb = $cv->cb ([new callback])
		522
		523	This is a mutator function that returns the callback set and optionally
		524	replaces it before doing so.
		525
		526	The callback will be called when the condition becomes "true", i.e. when
		527	C<send> or C<croak> are called. Calling C<recv> inside the callback
		528	or at any later time is guaranteed not to block.
356		529
357	=back	530	=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	$result_ready->wait;
376		531
377	=head1 GLOBAL VARIABLES AND FUNCTIONS	532	=head1 GLOBAL VARIABLES AND FUNCTIONS
378		533
379	=over 4	534	=over 4
380		535
…		…
386	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	541	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case
387	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	542	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).
388		543
389	The known classes so far are:	544	The known classes so far are:
390		545
391	AnyEvent::Impl::CoroEV based on Coro::EV, best choice.
392	AnyEvent::Impl::CoroEvent based on Coro::Event, second best choice.
393	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).	546	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
394	AnyEvent::Impl::Event based on Event, second best choice.	547	AnyEvent::Impl::Event based on Event, second best choice.
395	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	548	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
396	AnyEvent::Impl::Glib based on Glib, third-best choice.	549	AnyEvent::Impl::Glib based on Glib, third-best choice.
397	AnyEvent::Impl::Tk based on Tk, very bad choice.	550	AnyEvent::Impl::Tk based on Tk, very bad choice.
…		…
414	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	567	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
415	if necessary. You should only call this function right before you would	568	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	569	have created an AnyEvent watcher anyway, that is, as late as possible at
417	runtime.	570	runtime.
418		571
		572	=item $guard = AnyEvent::post_detect { BLOCK }
		573
		574	Arranges for the code block to be executed as soon as the event model is
		575	autodetected (or immediately if this has already happened).
		576
		577	If called in scalar or list context, then it creates and returns an object
		578	that automatically removes the callback again when it is destroyed. See
		579	L<Coro::BDB> for a case where this is useful.
		580
		581	=item @AnyEvent::post_detect
		582
		583	If there are any code references in this array (you can C<push> to it
		584	before or after loading AnyEvent), then they will called directly after
		585	the event loop has been chosen.
		586
		587	You should check C<$AnyEvent::MODEL> before adding to this array, though:
		588	if it contains a true value then the event loop has already been detected,
		589	and the array will be ignored.
		590
		591	Best use C<AnyEvent::post_detect { BLOCK }> instead.
		592
419	=back	593	=back
420		594
421	=head1 WHAT TO DO IN A MODULE	595	=head1 WHAT TO DO IN A MODULE
422		596
423	As a module author, you should C<use AnyEvent> and call AnyEvent methods	597	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	600	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	601	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	602	by calling AnyEvent in your module body you force the user of your module
429	to load the event module first.	603	to load the event module first.
430		604
431	Never call C<< ->wait >> on a condition variable unless you I<know> that	605	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	606	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	607	because it will stall the whole program, and the whole point of using
434	events is to stay interactive.	608	events is to stay interactive.
435		609
436	It is fine, however, to call C<< ->wait >> when the user of your module	610	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	611	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 >>	612	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).	613	freely, as the user of your module knows what she is doing. always).
440		614
441	=head1 WHAT TO DO IN THE MAIN PROGRAM	615	=head1 WHAT TO DO IN THE MAIN PROGRAM
442		616
443	There will always be a single main program - the only place that should	617	There will always be a single main program - the only place that should
…		…
445		619
446	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	620	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	621	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.	622	decide which implementation to chose if some module relies on it.
449		623
450	If the main program relies on a specific event model. For example, in	624	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	625	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	626	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	627	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	628	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	629	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.	630	might chose the wrong one unless you load the correct one yourself.
457		631
458	You can chose to use a rather inefficient pure-perl implementation by	632	You can chose to use a pure-perl implementation by loading the
459	loading the C<AnyEvent::Impl::Perl> module, which gives you similar	633	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour
460	behaviour everywhere, but letting AnyEvent chose is generally better.	634	everywhere, but letting AnyEvent chose the model is generally better.
		635
		636	=head2 MAINLOOP EMULATION
		637
		638	Sometimes (often for short test scripts, or even standalone programs who
		639	only want to use AnyEvent), you do not want to run a specific event loop.
		640
		641	In that case, you can use a condition variable like this:
		642
		643	AnyEvent->condvar->recv;
		644
		645	This has the effect of entering the event loop and looping forever.
		646
		647	Note that usually your program has some exit condition, in which case
		648	it is better to use the "traditional" approach of storing a condition
		649	variable somewhere, waiting for it, and sending it when the program should
		650	exit cleanly.
		651
461		652
462	=head1 OTHER MODULES	653	=head1 OTHER MODULES
463		654
464	The following is a non-exhaustive list of additional modules that use	655	The following is a non-exhaustive list of additional modules that use
465	AnyEvent and can therefore be mixed easily with other AnyEvent modules	656	AnyEvent and can therefore be mixed easily with other AnyEvent modules
…		…
477		668
478	Provide read and write buffers and manages watchers for reads and writes.	669	Provide read and write buffers and manages watchers for reads and writes.
479		670
480	=item L<AnyEvent::Socket>	671	=item L<AnyEvent::Socket>
481		672
482	Provides a means to do non-blocking connects, accepts etc.	673	Provides various utility functions for (internet protocol) sockets,
		674	addresses and name resolution. Also functions to create non-blocking tcp
		675	connections or tcp servers, with IPv6 and SRV record support and more.
		676
		677	=item L<AnyEvent::DNS>
		678
		679	Provides rich asynchronous DNS resolver capabilities.
483		680
484	=item L<AnyEvent::HTTPD>	681	=item L<AnyEvent::HTTPD>
485		682
486	Provides a simple web application server framework.	683	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		684
493	=item L<AnyEvent::FastPing>	685	=item L<AnyEvent::FastPing>
494		686
495	The fastest ping in the west.	687	The fastest ping in the west.
496		688
…		…
511		703
512	High level API for event-based execution flow control.	704	High level API for event-based execution flow control.
513		705
514	=item L<Coro>	706	=item L<Coro>
515		707
516	Has special support for AnyEvent.	708	Has special support for AnyEvent via L<Coro::AnyEvent>.
		709
		710	=item L<AnyEvent::AIO>, L<IO::AIO>
		711
		712	Truly asynchronous I/O, should be in the toolbox of every event
		713	programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent
		714	together.
		715
		716	=item L<AnyEvent::BDB>, L<BDB>
		717
		718	Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses
		719	IO::AIO and AnyEvent together.
517		720
518	=item L<IO::Lambda>	721	=item L<IO::Lambda>
519		722
520	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.	723	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		724
532	=back	725	=back
533		726
534	=cut	727	=cut
535		728
…		…
538	no warnings;	731	no warnings;
539	use strict;	732	use strict;
540		733
541	use Carp;	734	use Carp;
542		735
543	our $VERSION = '3.3';	736	our $VERSION = '4.03';
544	our $MODEL;	737	our $MODEL;
545		738
546	our $AUTOLOAD;	739	our $AUTOLOAD;
547	our @ISA;	740	our @ISA;
548		741
		742	our @REGISTRY;
		743
		744	our $WIN32;
		745
		746	BEGIN {
		747	my $win32 = ! ! ($^O =~ /mswin32/i);
		748	eval "sub WIN32(){ $win32 }";
		749	}
		750
549	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	751	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;
550		752
551	our @REGISTRY;	753	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred
		754
		755	{
		756	my $idx;
		757	$PROTOCOL{$_} = ++$idx
		758	for reverse split /\s,\s/,
		759	$ENV{PERL_ANYEVENT_PROTOCOLS} \|\| "ipv4,ipv6";
		760	}
		761
		762	sub import {
		763	shift;
		764	return unless @_;
		765
		766	my $pkg = caller;
		767
		768	no strict 'refs';
		769
		770	for (@_) {
		771	{"$pkg\::WIN32"} = WIN32 if $_ eq "WIN32";
		772	}
		773	}
552		774
553	my @models = (	775	my @models = (
554	[Coro::EV:: => AnyEvent::Impl::CoroEV::],
555	[Coro::Event:: => AnyEvent::Impl::CoroEvent::],
556	[EV:: => AnyEvent::Impl::EV::],	776	[EV:: => AnyEvent::Impl::EV::],
557	[Event:: => AnyEvent::Impl::Event::],	777	[Event:: => AnyEvent::Impl::Event::],
558	[Tk:: => AnyEvent::Impl::Tk::],
559	[Wx:: => AnyEvent::Impl::POE::],
560	[Prima:: => AnyEvent::Impl::POE::],
561	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	778	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
562	# everything below here will not be autoprobed as the pureperl backend should work everywhere	779	# everything below here will not be autoprobed
563	[Glib:: => AnyEvent::Impl::Glib::],	780	# as the pureperl backend should work everywhere
		781	# and is usually faster
		782	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
		783	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
564	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	784	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
565	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	785	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
566	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	786	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
		787	[Wx:: => AnyEvent::Impl::POE::],
		788	[Prima:: => AnyEvent::Impl::POE::],
567	);	789	);
568		790
569	our %method = map +($_ => 1), qw(io timer signal child condvar broadcast wait one_event DESTROY);	791	our %method = map +($_ => 1), qw(io timer signal child condvar one_event DESTROY);
		792
		793	our @post_detect;
		794
		795	sub post_detect(&) {
		796	my ($cb) = @_;
		797
		798	if ($MODEL) {
		799	$cb->();
		800
		801	1
		802	} else {
		803	push @post_detect, $cb;
		804
		805	defined wantarray
		806	? bless \$cb, "AnyEvent::Util::PostDetect"
		807	: ()
		808	}
		809	}
		810
		811	sub AnyEvent::Util::PostDetect::DESTROY {
		812	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		813	}
570		814
571	sub detect() {	815	sub detect() {
572	unless ($MODEL) {	816	unless ($MODEL) {
573	no strict 'refs';	817	no strict 'refs';
		818	local $SIG{__DIE__};
574		819
575	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	820	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
576	my $model = "AnyEvent::Impl::$1";	821	my $model = "AnyEvent::Impl::$1";
577	if (eval "require $model") {	822	if (eval "require $model") {
578	$MODEL = $model;	823	$MODEL = $model;
…		…
608	last;	853	last;
609	}	854	}
610	}	855	}
611		856
612	$MODEL	857	$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.";	858	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";
614	}	859	}
615	}	860	}
616		861
617	unshift @ISA, $MODEL;	862	unshift @ISA, $MODEL;
618	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	863	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		864
		865	(shift @post_detect)->() while @post_detect;
619	}	866	}
620		867
621	$MODEL	868	$MODEL
622	}	869	}
623		870
…		…
633	$class->$func (@_);	880	$class->$func (@_);
634	}	881	}
635		882
636	package AnyEvent::Base;	883	package AnyEvent::Base;
637		884
638	# default implementation for ->condvar, ->wait, ->broadcast	885	# default implementation for ->condvar
639		886
640	sub condvar {	887	sub condvar {
641	bless \my $flag, "AnyEvent::Base::CondVar"	888	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	}	889	}
651		890
652	# default implementation for ->signal	891	# default implementation for ->signal
653		892
654	our %SIG_CB;	893	our %SIG_CB;
…		…
707	or Carp::croak "required option 'pid' is missing";	946	or Carp::croak "required option 'pid' is missing";
708		947
709	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	948	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
710		949
711	unless ($WNOHANG) {	950	unless ($WNOHANG) {
712	$WNOHANG = eval { require POSIX; &POSIX::WNOHANG } \|\| 1;	951	$WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;
713	}	952	}
714		953
715	unless ($CHLD_W) {	954	unless ($CHLD_W) {
716	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	955	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
717	# child could be a zombie already, so make at least one round	956	# child could be a zombie already, so make at least one round
…		…
727	delete $PID_CB{$pid}{$cb};	966	delete $PID_CB{$pid}{$cb};
728	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	967	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
729		968
730	undef $CHLD_W unless keys %PID_CB;	969	undef $CHLD_W unless keys %PID_CB;
731	}	970	}
		971
		972	package AnyEvent::CondVar;
		973
		974	our @ISA = AnyEvent::CondVar::Base::;
		975
		976	package AnyEvent::CondVar::Base;
		977
		978	use overload
		979	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },
		980	fallback => 1;
		981
		982	sub _send {
		983	# nop
		984	}
		985
		986	sub send {
		987	my $cv = shift;
		988	$cv->{_ae_sent} = [@_];
		989	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
		990	$cv->_send;
		991	}
		992
		993	sub croak {
		994	$_[0]{_ae_croak} = $_[1];
		995	$_[0]->send;
		996	}
		997
		998	sub ready {
		999	$_[0]{_ae_sent}
		1000	}
		1001
		1002	sub _wait {
		1003	AnyEvent->one_event while !$_[0]{_ae_sent};
		1004	}
		1005
		1006	sub recv {
		1007	$_[0]->_wait;
		1008
		1009	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
		1010	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
		1011	}
		1012
		1013	sub cb {
		1014	$_[0]{_ae_cb} = $_[1] if @_ > 1;
		1015	$_[0]{_ae_cb}
		1016	}
		1017
		1018	sub begin {
		1019	++$_[0]{_ae_counter};
		1020	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
		1021	}
		1022
		1023	sub end {
		1024	return if --$_[0]{_ae_counter};
		1025	&{ $_[0]{_ae_end_cb} \|\| sub { $_[0]->send } };
		1026	}
		1027
		1028	# undocumented/compatibility with pre-3.4
		1029	*broadcast = \&send;
		1030	*wait = \&_wait;
732		1031
733	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1032	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
734		1033
735	This is an advanced topic that you do not normally need to use AnyEvent in	1034	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	1035	a module. This section is only of use to event loop authors who want to
…		…
793	model it chooses.	1092	model it chooses.
794		1093
795	=item C<PERL_ANYEVENT_MODEL>	1094	=item C<PERL_ANYEVENT_MODEL>
796		1095
797	This can be used to specify the event model to be used by AnyEvent, before	1096	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	1097	auto detection and -probing kicks in. It must be a string consisting
799	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	1098	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,	1099	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	1100	used as event model. If it fails to load AnyEvent will proceed with
802	autodetection and -probing.	1101	auto detection and -probing.
803		1102
804	This functionality might change in future versions.	1103	This functionality might change in future versions.
805		1104
806	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	1105	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
807	could start your program like this:	1106	could start your program like this:
808		1107
809	PERL_ANYEVENT_MODEL=Perl perl ...	1108	PERL_ANYEVENT_MODEL=Perl perl ...
		1109
		1110	=item C<PERL_ANYEVENT_PROTOCOLS>
		1111
		1112	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
		1113	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
		1114	of auto probing).
		1115
		1116	Must be set to a comma-separated list of protocols or address families,
		1117	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
		1118	used, and preference will be given to protocols mentioned earlier in the
		1119	list.
		1120
		1121	This variable can effectively be used for denial-of-service attacks
		1122	against local programs (e.g. when setuid), although the impact is likely
		1123	small, as the program has to handle connection errors already-
		1124
		1125	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
		1126	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
		1127	- only support IPv4, never try to resolve or contact IPv6
		1128	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
		1129	IPv6, but prefer IPv6 over IPv4.
		1130
		1131	=item C<PERL_ANYEVENT_EDNS0>
		1132
		1133	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
		1134	for DNS. This extension is generally useful to reduce DNS traffic, but
		1135	some (broken) firewalls drop such DNS packets, which is why it is off by
		1136	default.
		1137
		1138	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
		1139	EDNS0 in its DNS requests.
810		1140
811	=back	1141	=back
812		1142
813	=head1 EXAMPLE PROGRAM	1143	=head1 EXAMPLE PROGRAM
814		1144
…		…
825	poll => 'r',	1155	poll => 'r',
826	cb => sub {	1156	cb => sub {
827	warn "io event <$_[0]>\n"; # will always output <r>	1157	warn "io event <$_[0]>\n"; # will always output <r>
828	chomp (my $input = <STDIN>); # read a line	1158	chomp (my $input = <STDIN>); # read a line
829	warn "read: $input\n"; # output what has been read	1159	warn "read: $input\n"; # output what has been read
830	$cv->broadcast if $input =~ /^q/i; # quit program if /^q/i	1160	$cv->send if $input =~ /^q/i; # quit program if /^q/i
831	},	1161	},
832	);	1162	);
833		1163
834	my $time_watcher; # can only be used once	1164	my $time_watcher; # can only be used once
835		1165
…		…
840	});	1170	});
841	}	1171	}
842		1172
843	new_timer; # create first timer	1173	new_timer; # create first timer
844		1174
845	$cv->wait; # wait until user enters /^q/i	1175	$cv->recv; # wait until user enters /^q/i
846		1176
847	=head1 REAL-WORLD EXAMPLE	1177	=head1 REAL-WORLD EXAMPLE
848		1178
849	Consider the L<Net::FCP> module. It features (among others) the following	1179	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:	1180	API calls, which are to freenet what HTTP GET requests are to http:
…		…
900	syswrite $txn->{fh}, $txn->{request}	1230	syswrite $txn->{fh}, $txn->{request}
901	or die "connection or write error";	1231	or die "connection or write error";
902	$txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r });	1232	$txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r });
903		1233
904	Again, C<fh_ready_r> waits till all data has arrived, and then stores the	1234	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:	1235	result and signals any possible waiters that the request has finished:
906		1236
907	sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf};	1237	sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf};
908		1238
909	if (end-of-file or data complete) {	1239	if (end-of-file or data complete) {
910	$txn->{result} = $txn->{buf};	1240	$txn->{result} = $txn->{buf};
911	$txn->{finished}->broadcast;	1241	$txn->{finished}->send;
912	$txb->{cb}->($txn) of $txn->{cb}; # also call callback	1242	$txb->{cb}->($txn) of $txn->{cb}; # also call callback
913	}	1243	}
914		1244
915	The C<result> method, finally, just waits for the finished signal (if the	1245	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	1246	request was already finished, it doesn't wait, of course, and returns the
917	data:	1247	data:
918		1248
919	$txn->{finished}->wait;	1249	$txn->{finished}->recv;
920	return $txn->{result};	1250	return $txn->{result};
921		1251
922	The actual code goes further and collects all errors (C<die>s, exceptions)	1252	The actual code goes further and collects all errors (C<die>s, exceptions)
923	that occured during request processing. The C<result> method detects	1253	that occurred during request processing. The C<result> method detects
924	whether an exception as thrown (it is stored inside the $txn object)	1254	whether an exception as thrown (it is stored inside the $txn object)
925	and just throws the exception, which means connection errors and other	1255	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	1256	problems get reported tot he code that tries to use the result, not in a
927	random callback.	1257	random callback.
928		1258
…		…
959		1289
960	my $quit = AnyEvent->condvar;	1290	my $quit = AnyEvent->condvar;
961		1291
962	$fcp->txn_client_get ($url)->cb (sub {	1292	$fcp->txn_client_get ($url)->cb (sub {
963	...	1293	...
964	$quit->broadcast;	1294	$quit->send;
965	});	1295	});
966		1296
967	$quit->wait;	1297	$quit->recv;
968		1298
969		1299
970	=head1 BENCHMARKS	1300	=head1 BENCHMARKS
971		1301
972	To give you an idea of the performance and overheads that AnyEvent adds	1302	To give you an idea of the performance and overheads that AnyEvent adds
…		…
974	of various event loops I prepared some benchmarks.	1304	of various event loops I prepared some benchmarks.
975		1305
976	=head2 BENCHMARKING ANYEVENT OVERHEAD	1306	=head2 BENCHMARKING ANYEVENT OVERHEAD
977		1307
978	Here is a benchmark of various supported event models used natively and	1308	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	1309	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,	1310	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.	1311	which it is), lets them fire exactly once and destroys them again.
982		1312
983	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	1313	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
984	distribution.	1314	distribution.
…		…
1001	all watchers, to avoid adding memory overhead. That means closure creation	1331	all watchers, to avoid adding memory overhead. That means closure creation
1002	and memory usage is not included in the figures.	1332	and memory usage is not included in the figures.
1003		1333
1004	I<invoke> is the time, in microseconds, used to invoke a simple	1334	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	1335	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	1336	invoked "watcher" times, it would C<< ->send >> a condvar once to
1007	signal the end of this phase.	1337	signal the end of this phase.
1008		1338
1009	I<destroy> is the time, in microseconds, that it takes to destroy a single	1339	I<destroy> is the time, in microseconds, that it takes to destroy a single
1010	watcher.	1340	watcher.
1011		1341
…		…
1107		1437
1108	=back	1438	=back
1109		1439
1110	=head2 BENCHMARKING THE LARGE SERVER CASE	1440	=head2 BENCHMARKING THE LARGE SERVER CASE
1111		1441
1112	This benchmark atcually benchmarks the event loop itself. It works by	1442	This benchmark actually benchmarks the event loop itself. It works by
1113	creating a number of "servers": each server consists of a socketpair, a	1443	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	1444	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	1445	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".	1446	watcher reads a byte it will write that byte to a random other "server".
1117		1447
1118	The effect is that there will be a lot of I/O watchers, only part of which	1448	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	1449	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	1450	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	1451	timeout is reset each time something is read because that reflects how
1122	most timeouts work (and puts extra pressure on the event loops).	1452	most timeouts work (and puts extra pressure on the event loops).
1123		1453
1124	In this benchmark, we use 10000 socketpairs (20000 sockets), of which 100	1454	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	1455	(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.	1456	connections, most of which are idle at any one point in time.
1127		1457
1128	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	1458	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
1129	distribution.	1459	distribution.
…		…
1131	=head3 Explanation of the columns	1461	=head3 Explanation of the columns
1132		1462
1133	I<sockets> is the number of sockets, and twice the number of "servers" (as	1463	I<sockets> is the number of sockets, and twice the number of "servers" (as
1134	each server has a read and write socket end).	1464	each server has a read and write socket end).
1135		1465
1136	I<create> is the time it takes to create a socketpair (which is	1466	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.	1467	nontrivial) and two watchers: an I/O watcher and a timeout watcher.
1138		1468
1139	I<request>, the most important value, is the time it takes to handle a	1469	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	1470	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	1471	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	1544	speed most when you have lots of watchers, not when you only have a few of
1215	them).	1545	them).
1216		1546
1217	EV is again fastest.	1547	EV is again fastest.
1218		1548
1219	Perl again comes second. It is noticably faster than the C-based event	1549	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	1550	loops Event and Glib, although the difference is too small to really
1221	matter.	1551	matter.
1222		1552
1223	POE also performs much better in this case, but is is still far behind the	1553	POE also performs much better in this case, but is is still far behind the
1224	others.	1554	others.
…		…
1257		1587
1258	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }	1588	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }
1259		1589
1260	use AnyEvent;	1590	use AnyEvent;
1261		1591
		1592	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
		1593	be used to probe what backend is used and gain other information (which is
		1594	probably even less useful to an attacker than PERL_ANYEVENT_MODEL).
		1595
1262		1596
1263	=head1 SEE ALSO	1597	=head1 SEE ALSO
1264		1598
1265	Event modules: L<Coro::EV>, L<EV>, L<EV::Glib>, L<Glib::EV>,	1599	Utility functions: L<AnyEvent::Util>.
1266	L<Coro::Event>, L<Event>, L<Glib::Event>, L<Glib>, L<Coro>, L<Tk>,	1600
		1601	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,
1267	L<Event::Lib>, L<Qt>, L<POE>.	1602	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
1268		1603
1269	Implementations: L<AnyEvent::Impl::CoroEV>, L<AnyEvent::Impl::EV>,	1604	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
1270	L<AnyEvent::Impl::CoroEvent>, L<AnyEvent::Impl::Event>, L<AnyEvent::Impl::Glib>,	1605	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>,	1606	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
1272	L<AnyEvent::Impl::Qt>, L<AnyEvent::Impl::POE>.	1607	L<AnyEvent::Impl::POE>.
1273		1608
		1609	Non-blocking file handles, sockets, TCP clients and
		1610	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.
		1611
		1612	Asynchronous DNS: L<AnyEvent::DNS>.
		1613
		1614	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>,
		1615
1274	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>.	1616	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.
1275		1617
1276		1618
1277	=head1 AUTHOR	1619	=head1 AUTHOR
1278		1620
1279	Marc Lehmann <schmorp@schmorp.de>	1621	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 1.138 by root, Mon May 26 05:09:53 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 1.138 by root, Mon May 26 05:09:53 2008 UTC