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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.127 by root, Sat May 24 01:15:19 2008 UTC vs.
Revision 1.168 by root, Tue Jul 8 23:53:37 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, 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
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->send; # wake up current and all future recv's
21	$w->recv; # enters "main loop" till $condvar gets ->send	21	$w->recv; # enters "main loop" till $condvar gets ->send
22		22
		23	=head1 INTRODUCTION/TUTORIAL
		24
		25	This manpage is mainly a reference manual. If you are interested
		26	in a tutorial or some gentle introduction, have a look at the
		27	L<AnyEvent::Intro> manpage.
		28
23	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)	29	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
24		30
25	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen	31	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
26	nowadays. So what is different about AnyEvent?	32	nowadays. So what is different about AnyEvent?
27		33
28	Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of	34	Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of
29	policy> and AnyEvent is I<small and efficient>.	35	policy> and AnyEvent is I<small and efficient>.
30		36
31	First and foremost, I<AnyEvent is not an event model> itself, it only	37	First and foremost, I<AnyEvent is not an event model> itself, it only
32	interfaces to whatever event model the main program happens to use in a	38	interfaces to whatever event model the main program happens to use, in a
33	pragmatic way. For event models and certain classes of immortals alike,	39	pragmatic way. For event models and certain classes of immortals alike,
34	the statement "there can only be one" is a bitter reality: In general,	40	the statement "there can only be one" is a bitter reality: In general,
35	only one event loop can be active at the same time in a process. AnyEvent	41	only one event loop can be active at the same time in a process. AnyEvent
36	helps hiding the differences between those event loops.	42	cannot change this, but it can hide the differences between those event
		43	loops.
37		44
38	The goal of AnyEvent is to offer module authors the ability to do event	45	The goal of AnyEvent is to offer module authors the ability to do event
39	programming (waiting for I/O or timer events) without subscribing to a	46	programming (waiting for I/O or timer events) without subscribing to a
40	religion, a way of living, and most importantly: without forcing your	47	religion, a way of living, and most importantly: without forcing your
41	module users into the same thing by forcing them to use the same event	48	module users into the same thing by forcing them to use the same event
42	model you use.	49	model you use.
43		50
44	For modules like POE or IO::Async (which is a total misnomer as it is	51	For modules like POE or IO::Async (which is a total misnomer as it is
45	actually doing all I/O I<synchronously>...), using them in your module is	52	actually doing all I/O I<synchronously>...), using them in your module is
46	like joining a cult: After you joined, you are dependent on them and you	53	like joining a cult: After you joined, you are dependent on them and you
47	cannot use anything else, as it is simply incompatible to everything that	54	cannot use anything else, as they are simply incompatible to everything
48	isn't itself. What's worse, all the potential users of your module are	55	that isn't them. What's worse, all the potential users of your
49	I<also> forced to use the same event loop you use.	56	module are I<also> forced to use the same event loop you use.
50		57
51	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	58	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
52	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	59	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	60	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,	61	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	62	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	63	event models it supports (including stuff like IO::Async, as long as those
57	as those use one of the supported event loops. It is trivial to add new	64	use one of the supported event loops. It is trivial to add new event loops
58	event loops to AnyEvent, too, so it is future-proof).	65	to AnyEvent, too, so it is future-proof).
59		66
60	In addition to being free of having to use I<the one and only true event	67	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	68	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	69	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	70	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	71	offering the functionality that is necessary, in as thin as a wrapper as
65	technically possible.	72	technically possible.
66		73
		74	Of course, AnyEvent comes with a big (and fully optional!) toolbox
		75	of useful functionality, such as an asynchronous DNS resolver, 100%
		76	non-blocking connects (even with TLS/SSL, IPv6 and on broken platforms
		77	such as Windows) and lots of real-world knowledge and workarounds for
		78	platform bugs and differences.
		79
67	Of course, if you want lots of policy (this can arguably be somewhat	80	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	81	useful) and you want to force your users to use the one and only event
69	model, you should I<not> use this module.	82	model, you should I<not> use this module.
70		83
71	=head1 DESCRIPTION	84	=head1 DESCRIPTION
72		85
…		…
102	starts using it, all bets are off. Maybe you should tell their authors to	115	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...	116	use AnyEvent so their modules work together with others seamlessly...
104		117
105	The pure-perl implementation of AnyEvent is called	118	The pure-perl implementation of AnyEvent is called
106	C<AnyEvent::Impl::Perl>. Like other event modules you can load it	119	C<AnyEvent::Impl::Perl>. Like other event modules you can load it
107	explicitly.	120	explicitly and enjoy the high availability of that event loop :)
108		121
109	=head1 WATCHERS	122	=head1 WATCHERS
110		123
111	AnyEvent has the central concept of a I<watcher>, which is an object that	124	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	125	stores relevant data for each kind of event you are waiting for, such as
113	the callback to call, the filehandle to watch, etc.	126	the callback to call, the file handle to watch, etc.
114		127
115	These watchers are normal Perl objects with normal Perl lifetime. After	128	These watchers are normal Perl objects with normal Perl lifetime. After
116	creating a watcher it will immediately "watch" for events and invoke the	129	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	130	callback when the event occurs (of course, only when the event model
118	is in control).	131	is in control).
…		…
126	Many watchers either are used with "recursion" (repeating timers for	139	Many watchers either are used with "recursion" (repeating timers for
127	example), or need to refer to their watcher object in other ways.	140	example), or need to refer to their watcher object in other ways.
128		141
129	An any way to achieve that is this pattern:	142	An any way to achieve that is this pattern:
130		143
131	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	144	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
132	# you can use $w here, for example to undef it	145	# you can use $w here, for example to undef it
133	undef $w;	146	undef $w;
134	});	147	});
135		148
136	Note that C<my $w; $w => combination. This is necessary because in Perl,	149	Note that C<my $w; $w => combination. This is necessary because in Perl,
137	my variables are only visible after the statement in which they are	150	my variables are only visible after the statement in which they are
138	declared.	151	declared.
139		152
140	=head2 I/O WATCHERS	153	=head2 I/O WATCHERS
141		154
142	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	155	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
143	with the following mandatory key-value pairs as arguments:	156	with the following mandatory key-value pairs as arguments:
144		157
145	C<fh> the Perl I<file handle> (I<not> file descriptor) to watch	158	C<fh> the Perl I<file handle> (I<not> file descriptor) to watch for events
146	for events. C<poll> must be a string that is either C<r> or C<w>,	159	(AnyEvent might or might not keep a reference to this file handle). C<poll>
147	which creates a watcher waiting for "r"eadable or "w"ritable events,	160	must be a string that is either C<r> or C<w>, which creates a watcher
148	respectively. C<cb> is the callback to invoke each time the file handle	161	waiting for "r"eadable or "w"ritable events, respectively. C<cb> is the
149	becomes ready.	162	callback to invoke each time the file handle becomes ready.
150		163
151	Although the callback might get passed parameters, their value and	164	Although the callback might get passed parameters, their value and
152	presence is undefined and you cannot rely on them. Portable AnyEvent	165	presence is undefined and you cannot rely on them. Portable AnyEvent
153	callbacks cannot use arguments passed to I/O watcher callbacks.	166	callbacks cannot use arguments passed to I/O watcher callbacks.
154		167
…		…
158		171
159	Some event loops issue spurious readyness notifications, so you should	172	Some event loops issue spurious readyness notifications, so you should
160	always use non-blocking calls when reading/writing from/to your file	173	always use non-blocking calls when reading/writing from/to your file
161	handles.	174	handles.
162		175
163	Example:
164
165	# wait for readability of STDIN, then read a line and disable the watcher	176	Example: wait for readability of STDIN, then read a line and disable the
		177	watcher.
		178
166	my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {	179	my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {
167	chomp (my $input = <STDIN>);	180	chomp (my $input = <STDIN>);
168	warn "read: $input\n";	181	warn "read: $input\n";
169	undef $w;	182	undef $w;
170	});	183	});
…		…
180		193
181	Although the callback might get passed parameters, their value and	194	Although the callback might get passed parameters, their value and
182	presence is undefined and you cannot rely on them. Portable AnyEvent	195	presence is undefined and you cannot rely on them. Portable AnyEvent
183	callbacks cannot use arguments passed to time watcher callbacks.	196	callbacks cannot use arguments passed to time watcher callbacks.
184		197
185	The timer callback will be invoked at most once: if you want a repeating	198	The callback will normally be invoked once only. If you specify another
186	timer you have to create a new watcher (this is a limitation by both Tk	199	parameter, C<interval>, as a strictly positive number (> 0), then the
187	and Glib).	200	callback will be invoked regularly at that interval (in fractional
		201	seconds) after the first invocation. If C<interval> is specified with a
		202	false value, then it is treated as if it were missing.
188		203
189	Example:	204	The callback will be rescheduled before invoking the callback, but no
		205	attempt is done to avoid timer drift in most backends, so the interval is
		206	only approximate.
190		207
191	# fire an event after 7.7 seconds	208	Example: fire an event after 7.7 seconds.
		209
192	my $w = AnyEvent->timer (after => 7.7, cb => sub {	210	my $w = AnyEvent->timer (after => 7.7, cb => sub {
193	warn "timeout\n";	211	warn "timeout\n";
194	});	212	});
195		213
196	# to cancel the timer:	214	# to cancel the timer:
197	undef $w;	215	undef $w;
198		216
199	Example 2:
200
201	# fire an event after 0.5 seconds, then roughly every second	217	Example 2: fire an event after 0.5 seconds, then roughly every second.
202	my $w;
203		218
204	my $cb = sub {
205	# cancel the old timer while creating a new one
206	$w = AnyEvent->timer (after => 1, cb => $cb);	219	my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub {
		220	warn "timeout\n";
207	};	221	};
208
209	# start the "loop" by creating the first watcher
210	$w = AnyEvent->timer (after => 0.5, cb => $cb);
211		222
212	=head3 TIMING ISSUES	223	=head3 TIMING ISSUES
213		224
214	There are two ways to handle timers: based on real time (relative, "fire	225	There are two ways to handle timers: based on real time (relative, "fire
215	in 10 seconds") and based on wallclock time (absolute, "fire at 12	226	in 10 seconds") and based on wallclock time (absolute, "fire at 12
…		…
227	timers.	238	timers.
228		239
229	AnyEvent always prefers relative timers, if available, matching the	240	AnyEvent always prefers relative timers, if available, matching the
230	AnyEvent API.	241	AnyEvent API.
231		242
		243	AnyEvent has two additional methods that return the "current time":
		244
		245	=over 4
		246
		247	=item AnyEvent->time
		248
		249	This returns the "current wallclock time" as a fractional number of
		250	seconds since the Epoch (the same thing as C<time> or C<Time::HiRes::time>
		251	return, and the result is guaranteed to be compatible with those).
		252
		253	It progresses independently of any event loop processing, i.e. each call
		254	will check the system clock, which usually gets updated frequently.
		255
		256	=item AnyEvent->now
		257
		258	This also returns the "current wallclock time", but unlike C<time>, above,
		259	this value might change only once per event loop iteration, depending on
		260	the event loop (most return the same time as C<time>, above). This is the
		261	time that AnyEvent's timers get scheduled against.
		262
		263	I<In almost all cases (in all cases if you don't care), this is the
		264	function to call when you want to know the current time.>
		265
		266	This function is also often faster then C<< AnyEvent->time >>, and
		267	thus the preferred method if you want some timestamp (for example,
		268	L<AnyEvent::Handle> uses this to update it's activity timeouts).
		269
		270	The rest of this section is only of relevance if you try to be very exact
		271	with your timing, you can skip it without bad conscience.
		272
		273	For a practical example of when these times differ, consider L<Event::Lib>
		274	and L<EV> and the following set-up:
		275
		276	The event loop is running and has just invoked one of your callback at
		277	time=500 (assume no other callbacks delay processing). In your callback,
		278	you wait a second by executing C<sleep 1> (blocking the process for a
		279	second) and then (at time=501) you create a relative timer that fires
		280	after three seconds.
		281
		282	With L<Event::Lib>, C<< AnyEvent->time >> and C<< AnyEvent->now >> will
		283	both return C<501>, because that is the current time, and the timer will
		284	be scheduled to fire at time=504 (C<501> + C<3>).
		285
		286	With L<EV>, C<< AnyEvent->time >> returns C<501> (as that is the current
		287	time), but C<< AnyEvent->now >> returns C<500>, as that is the time the
		288	last event processing phase started. With L<EV>, your timer gets scheduled
		289	to run at time=503 (C<500> + C<3>).
		290
		291	In one sense, L<Event::Lib> is more exact, as it uses the current time
		292	regardless of any delays introduced by event processing. However, most
		293	callbacks do not expect large delays in processing, so this causes a
		294	higher drift (and a lot more system calls to get the current time).
		295
		296	In another sense, L<EV> is more exact, as your timer will be scheduled at
		297	the same time, regardless of how long event processing actually took.
		298
		299	In either case, if you care (and in most cases, you don't), then you
		300	can get whatever behaviour you want with any event loop, by taking the
		301	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
		302	account.
		303
		304	=back
		305
232	=head2 SIGNAL WATCHERS	306	=head2 SIGNAL WATCHERS
233		307
234	You can watch for signals using a signal watcher, C<signal> is the signal	308	You can watch for signals using a signal watcher, C<signal> is the signal
235	I<name> without any C<SIG> prefix, C<cb> is the Perl callback to	309	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
236	be invoked whenever a signal occurs.	310	callback to be invoked whenever a signal occurs.
237		311
238	Although the callback might get passed parameters, their value and	312	Although the callback might get passed parameters, their value and
239	presence is undefined and you cannot rely on them. Portable AnyEvent	313	presence is undefined and you cannot rely on them. Portable AnyEvent
240	callbacks cannot use arguments passed to signal watcher callbacks.	314	callbacks cannot use arguments passed to signal watcher callbacks.
241		315
242	Multiple signal occurances can be clumped together into one callback	316	Multiple signal occurrences can be clumped together into one callback
243	invocation, and callback invocation will be synchronous. synchronous means	317	invocation, and callback invocation will be synchronous. Synchronous means
244	that it might take a while until the signal gets handled by the process,	318	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.	319	but it is guaranteed not to interrupt any other callbacks.
246		320
247	The main advantage of using these watchers is that you can share a signal	321	The main advantage of using these watchers is that you can share a signal
248	between multiple watchers.	322	between multiple watchers.
249		323
250	This watcher might use C<%SIG>, so programs overwriting those signals	324	This watcher might use C<%SIG>, so programs overwriting those signals
…		…
277	AnyEvent program, you I<have> to create at least one watcher before you	351	AnyEvent program, you I<have> to create at least one watcher before you
278	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).	352	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).
279		353
280	Example: fork a process and wait for it	354	Example: fork a process and wait for it
281		355
282	my $done = AnyEvent->condvar;	356	my $done = AnyEvent->condvar;
283		357
284	my $pid = fork or exit 5;	358	my $pid = fork or exit 5;
285		359
286	my $w = AnyEvent->child (	360	my $w = AnyEvent->child (
287	pid => $pid,	361	pid => $pid,
288	cb => sub {	362	cb => sub {
289	my ($pid, $status) = @_;	363	my ($pid, $status) = @_;
290	warn "pid $pid exited with status $status";	364	warn "pid $pid exited with status $status";
291	$done->send;	365	$done->send;
292	},	366	},
293	);	367	);
294		368
295	# do something else, then wait for process exit	369	# do something else, then wait for process exit
296	$done->recv;	370	$done->recv;
297		371
298	=head2 CONDITION VARIABLES	372	=head2 CONDITION VARIABLES
299		373
300	If you are familiar with some event loops you will know that all of them	374	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	375	require you to run some blocking "loop", "run" or similar function that
…		…
310	Condition variables can be created by calling the C<< AnyEvent->condvar	384	Condition variables can be created by calling the C<< AnyEvent->condvar
311	>> method, usually without arguments. The only argument pair allowed is	385	>> method, usually without arguments. The only argument pair allowed is
312	C<cb>, which specifies a callback to be called when the condition variable	386	C<cb>, which specifies a callback to be called when the condition variable
313	becomes true.	387	becomes true.
314		388
315	After creation, the conditon variable is "false" until it becomes "true"	389	After creation, the condition variable is "false" until it becomes "true"
316	by calling the C<send> method.	390	by calling the C<send> method (or calling the condition variable as if it
		391	were a callback, read about the caveats in the description for the C<<
		392	->send >> method).
317		393
318	Condition variables are similar to callbacks, except that you can	394	Condition variables are similar to callbacks, except that you can
319	optionally wait for them. They can also be called merge points - points	395	optionally wait for them. They can also be called merge points - points
320	in time where multiple outstandign events have been processed. And yet	396	in time where multiple outstanding events have been processed. And yet
321	another way to call them is transations - each condition variable can be	397	another way to call them is transactions - each condition variable can be
322	used to represent a transaction, which finishes at some point and delivers	398	used to represent a transaction, which finishes at some point and delivers
323	a result.	399	a result.
324		400
325	Condition variables are very useful to signal that something has finished,	401	Condition variables are very useful to signal that something has finished,
326	for example, if you write a module that does asynchronous http requests,	402	for example, if you write a module that does asynchronous http requests,
…		…
332	you can block your main program until an event occurs - for example, you	408	you can block your main program until an event occurs - for example, you
333	could C<< ->recv >> in your main program until the user clicks the Quit	409	could C<< ->recv >> in your main program until the user clicks the Quit
334	button of your app, which would C<< ->send >> the "quit" event.	410	button of your app, which would C<< ->send >> the "quit" event.
335		411
336	Note that condition variables recurse into the event loop - if you have	412	Note that condition variables recurse into the event loop - if you have
337	two pieces of code that call C<< ->recv >> in a round-robbin fashion, you	413	two pieces of code that call C<< ->recv >> in a round-robin fashion, you
338	lose. Therefore, condition variables are good to export to your caller, but	414	lose. Therefore, condition variables are good to export to your caller, but
339	you should avoid making a blocking wait yourself, at least in callbacks,	415	you should avoid making a blocking wait yourself, at least in callbacks,
340	as this asks for trouble.	416	as this asks for trouble.
341		417
342	Condition variables are represented by hash refs in perl, and the keys	418	Condition variables are represented by hash refs in perl, and the keys
…		…
347		423
348	There are two "sides" to a condition variable - the "producer side" which	424	There are two "sides" to a condition variable - the "producer side" which
349	eventually calls C<< -> send >>, and the "consumer side", which waits	425	eventually calls C<< -> send >>, and the "consumer side", which waits
350	for the send to occur.	426	for the send to occur.
351		427
352	Example:	428	Example: wait for a timer.
353		429
354	# wait till the result is ready	430	# wait till the result is ready
355	my $result_ready = AnyEvent->condvar;	431	my $result_ready = AnyEvent->condvar;
356		432
357	# do something such as adding a timer	433	# do something such as adding a timer
…		…
365		441
366	# this "blocks" (while handling events) till the callback	442	# this "blocks" (while handling events) till the callback
367	# calls send	443	# calls send
368	$result_ready->recv;	444	$result_ready->recv;
369		445
		446	Example: wait for a timer, but take advantage of the fact that
		447	condition variables are also code references.
		448
		449	my $done = AnyEvent->condvar;
		450	my $delay = AnyEvent->timer (after => 5, cb => $done);
		451	$done->recv;
		452
370	=head3 METHODS FOR PRODUCERS	453	=head3 METHODS FOR PRODUCERS
371		454
372	These methods should only be used by the producing side, i.e. the	455	These methods should only be used by the producing side, i.e. the
373	code/module that eventually sends the signal. Note that it is also	456	code/module that eventually sends the signal. Note that it is also
374	the producer side which creates the condvar in most cases, but it isn't	457	the producer side which creates the condvar in most cases, but it isn't
…		…
385	If a callback has been set on the condition variable, it is called	468	If a callback has been set on the condition variable, it is called
386	immediately from within send.	469	immediately from within send.
387		470
388	Any arguments passed to the C<send> call will be returned by all	471	Any arguments passed to the C<send> call will be returned by all
389	future C<< ->recv >> calls.	472	future C<< ->recv >> calls.
		473
		474	Condition variables are overloaded so one can call them directly
		475	(as a code reference). Calling them directly is the same as calling
		476	C<send>. Note, however, that many C-based event loops do not handle
		477	overloading, so as tempting as it may be, passing a condition variable
		478	instead of a callback does not work. Both the pure perl and EV loops
		479	support overloading, however, as well as all functions that use perl to
		480	invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
		481	example).
390		482
391	=item $cv->croak ($error)	483	=item $cv->croak ($error)
392		484
393	Similar to send, but causes all call's to C<< ->recv >> to invoke	485	Similar to send, but causes all call's to C<< ->recv >> to invoke
394	C<Carp::croak> with the given error message/object/scalar.	486	C<Carp::croak> with the given error message/object/scalar.
…		…
443	doesn't execute once).	535	doesn't execute once).
444		536
445	This is the general pattern when you "fan out" into multiple subrequests:	537	This is the general pattern when you "fan out" into multiple subrequests:
446	use an outer C<begin>/C<end> pair to set the callback and ensure C<end>	538	use an outer C<begin>/C<end> pair to set the callback and ensure C<end>
447	is called at least once, and then, for each subrequest you start, call	539	is called at least once, and then, for each subrequest you start, call
448	C<begin> and for eahc subrequest you finish, call C<end>.	540	C<begin> and for each subrequest you finish, call C<end>.
449		541
450	=back	542	=back
451		543
452	=head3 METHODS FOR CONSUMERS	544	=head3 METHODS FOR CONSUMERS
453		545
…		…
475	(programs might want to do that to stay interactive), so I<if you are	567	(programs might want to do that to stay interactive), so I<if you are
476	using this from a module, never require a blocking wait>, but let the	568	using this from a module, never require a blocking wait>, but let the
477	caller decide whether the call will block or not (for example, by coupling	569	caller decide whether the call will block or not (for example, by coupling
478	condition variables with some kind of request results and supporting	570	condition variables with some kind of request results and supporting
479	callbacks so the caller knows that getting the result will not block,	571	callbacks so the caller knows that getting the result will not block,
480	while still suppporting blocking waits if the caller so desires).	572	while still supporting blocking waits if the caller so desires).
481		573
482	Another reason I<never> to C<< ->recv >> in a module is that you cannot	574	Another reason I<never> to C<< ->recv >> in a module is that you cannot
483	sensibly have two C<< ->recv >>'s in parallel, as that would require	575	sensibly have two C<< ->recv >>'s in parallel, as that would require
484	multiple interpreters or coroutines/threads, none of which C<AnyEvent>	576	multiple interpreters or coroutines/threads, none of which C<AnyEvent>
485	can supply.	577	can supply.
…		…
504		596
505	This is a mutator function that returns the callback set and optionally	597	This is a mutator function that returns the callback set and optionally
506	replaces it before doing so.	598	replaces it before doing so.
507		599
508	The callback will be called when the condition becomes "true", i.e. when	600	The callback will be called when the condition becomes "true", i.e. when
509	C<send> or C<croak> are called. Calling C<recv> inside the callback	601	C<send> or C<croak> are called, with the only argument being the condition
510	or at any later time is guaranteed not to block.	602	variable itself. Calling C<recv> inside the callback or at any later time
		603	is guaranteed not to block.
511		604
512	=back	605	=back
513		606
514	=head1 GLOBAL VARIABLES AND FUNCTIONS	607	=head1 GLOBAL VARIABLES AND FUNCTIONS
515		608
…		…
601		694
602	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	695	If it doesn't care, it can just "use AnyEvent" and use it itself, or not
603	do anything special (it does not need to be event-based) and let AnyEvent	696	do anything special (it does not need to be event-based) and let AnyEvent
604	decide which implementation to chose if some module relies on it.	697	decide which implementation to chose if some module relies on it.
605		698
606	If the main program relies on a specific event model. For example, in	699	If the main program relies on a specific event model - for example, in
607	Gtk2 programs you have to rely on the Glib module. You should load the	700	Gtk2 programs you have to rely on the Glib module - you should load the
608	event module before loading AnyEvent or any module that uses it: generally	701	event module before loading AnyEvent or any module that uses it: generally
609	speaking, you should load it as early as possible. The reason is that	702	speaking, you should load it as early as possible. The reason is that
610	modules might create watchers when they are loaded, and AnyEvent will	703	modules might create watchers when they are loaded, and AnyEvent will
611	decide on the event model to use as soon as it creates watchers, and it	704	decide on the event model to use as soon as it creates watchers, and it
612	might chose the wrong one unless you load the correct one yourself.	705	might chose the wrong one unless you load the correct one yourself.
613		706
614	You can chose to use a rather inefficient pure-perl implementation by	707	You can chose to use a pure-perl implementation by loading the
615	loading the C<AnyEvent::Impl::Perl> module, which gives you similar	708	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour
616	behaviour everywhere, but letting AnyEvent chose is generally better.	709	everywhere, but letting AnyEvent chose the model is generally better.
		710
		711	=head2 MAINLOOP EMULATION
		712
		713	Sometimes (often for short test scripts, or even standalone programs who
		714	only want to use AnyEvent), you do not want to run a specific event loop.
		715
		716	In that case, you can use a condition variable like this:
		717
		718	AnyEvent->condvar->recv;
		719
		720	This has the effect of entering the event loop and looping forever.
		721
		722	Note that usually your program has some exit condition, in which case
		723	it is better to use the "traditional" approach of storing a condition
		724	variable somewhere, waiting for it, and sending it when the program should
		725	exit cleanly.
		726
617		727
618	=head1 OTHER MODULES	728	=head1 OTHER MODULES
619		729
620	The following is a non-exhaustive list of additional modules that use	730	The following is a non-exhaustive list of additional modules that use
621	AnyEvent and can therefore be mixed easily with other AnyEvent modules	731	AnyEvent and can therefore be mixed easily with other AnyEvent modules
…		…
627	=item L<AnyEvent::Util>	737	=item L<AnyEvent::Util>
628		738
629	Contains various utility functions that replace often-used but blocking	739	Contains various utility functions that replace often-used but blocking
630	functions such as C<inet_aton> by event-/callback-based versions.	740	functions such as C<inet_aton> by event-/callback-based versions.
631		741
632	=item L<AnyEvent::Handle>
633
634	Provide read and write buffers and manages watchers for reads and writes.
635
636	=item L<AnyEvent::Socket>	742	=item L<AnyEvent::Socket>
637		743
638	Provides various utility functions for (internet protocol) sockets,	744	Provides various utility functions for (internet protocol) sockets,
639	addresses and name resolution. Also functions to create non-blocking tcp	745	addresses and name resolution. Also functions to create non-blocking tcp
640	connections or tcp servers, with IPv6 and SRV record support and more.	746	connections or tcp servers, with IPv6 and SRV record support and more.
641		747
		748	=item L<AnyEvent::Handle>
		749
		750	Provide read and write buffers, manages watchers for reads and writes,
		751	supports raw and formatted I/O, I/O queued and fully transparent and
		752	non-blocking SSL/TLS.
		753
		754	=item L<AnyEvent::DNS>
		755
		756	Provides rich asynchronous DNS resolver capabilities.
		757
		758	=item L<AnyEvent::HTTP>
		759
		760	A simple-to-use HTTP library that is capable of making a lot of concurrent
		761	HTTP requests.
		762
642	=item L<AnyEvent::HTTPD>	763	=item L<AnyEvent::HTTPD>
643		764
644	Provides a simple web application server framework.	765	Provides a simple web application server framework.
645		766
646	=item L<AnyEvent::DNS>
647
648	Provides rich asynchronous DNS resolver capabilities.
649
650	=item L<AnyEvent::FastPing>	767	=item L<AnyEvent::FastPing>
651		768
652	The fastest ping in the west.	769	The fastest ping in the west.
		770
		771	=item L<AnyEvent::DBI>
		772
		773	Executes L<DBI> requests asynchronously in a proxy process.
		774
		775	=item L<AnyEvent::AIO>
		776
		777	Truly asynchronous I/O, should be in the toolbox of every event
		778	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
		779	together.
		780
		781	=item L<AnyEvent::BDB>
		782
		783	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
		784	L<BDB> and AnyEvent together.
		785
		786	=item L<AnyEvent::GPSD>
		787
		788	A non-blocking interface to gpsd, a daemon delivering GPS information.
		789
		790	=item L<AnyEvent::IGS>
		791
		792	A non-blocking interface to the Internet Go Server protocol (used by
		793	L<App::IGS>).
653		794
654	=item L<Net::IRC3>	795	=item L<Net::IRC3>
655		796
656	AnyEvent based IRC client module family.	797	AnyEvent based IRC client module family.
657		798
…		…
670		811
671	=item L<Coro>	812	=item L<Coro>
672		813
673	Has special support for AnyEvent via L<Coro::AnyEvent>.	814	Has special support for AnyEvent via L<Coro::AnyEvent>.
674		815
675	=item L<AnyEvent::AIO>, L<IO::AIO>
676
677	Truly asynchronous I/O, should be in the toolbox of every event
678	programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent
679	together.
680
681	=item L<AnyEvent::BDB>, L<BDB>
682
683	Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses
684	IO::AIO and AnyEvent together.
685
686	=item L<IO::Lambda>	816	=item L<IO::Lambda>
687		817
688	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.	818	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
689		819
690	=back	820	=back
…		…
696	no warnings;	826	no warnings;
697	use strict;	827	use strict;
698		828
699	use Carp;	829	use Carp;
700		830
701	our $VERSION = '3.6';	831	our $VERSION = 4.2;
702	our $MODEL;	832	our $MODEL;
703		833
704	our $AUTOLOAD;	834	our $AUTOLOAD;
705	our @ISA;	835	our @ISA;
706		836
		837	our @REGISTRY;
		838
		839	our $WIN32;
		840
		841	BEGIN {
		842	my $win32 = ! ! ($^O =~ /mswin32/i);
		843	eval "sub WIN32(){ $win32 }";
		844	}
		845
707	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	846	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;
708		847
709	our @REGISTRY;	848	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred
710
711	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2)
712		849
713	{	850	{
714	my $idx;	851	my $idx;
715	$PROTOCOL{$_} = ++$idx	852	$PROTOCOL{$_} = ++$idx
		853	for reverse split /\s,\s/,
716	for split /\s,\s/, $ENV{PERL_ANYEVENT_PROTOCOLS} \|\| "ipv4,ipv6";	854	$ENV{PERL_ANYEVENT_PROTOCOLS} \|\| "ipv4,ipv6";
717	}	855	}
718		856
719	my @models = (	857	my @models = (
720	[EV:: => AnyEvent::Impl::EV::],	858	[EV:: => AnyEvent::Impl::EV::],
721	[Event:: => AnyEvent::Impl::Event::],	859	[Event:: => AnyEvent::Impl::Event::],
722	[Tk:: => AnyEvent::Impl::Tk::],
723	[Wx:: => AnyEvent::Impl::POE::],
724	[Prima:: => AnyEvent::Impl::POE::],
725	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	860	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
726	# everything below here will not be autoprobed as the pureperl backend should work everywhere	861	# everything below here will not be autoprobed
727	[Glib:: => AnyEvent::Impl::Glib::],	862	# as the pureperl backend should work everywhere
		863	# and is usually faster
		864	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
		865	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
728	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	866	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
729	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	867	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
730	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	868	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
		869	[Wx:: => AnyEvent::Impl::POE::],
		870	[Prima:: => AnyEvent::Impl::POE::],
731	);	871	);
732		872
733	our %method = map +($_ => 1), qw(io timer signal child condvar one_event DESTROY);	873	our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY);
734		874
735	our @post_detect;	875	our @post_detect;
736		876
737	sub post_detect(&) {	877	sub post_detect(&) {
738	my ($cb) = @_;	878	my ($cb) = @_;
…		…
755	}	895	}
756		896
757	sub detect() {	897	sub detect() {
758	unless ($MODEL) {	898	unless ($MODEL) {
759	no strict 'refs';	899	no strict 'refs';
		900	local $SIG{__DIE__};
760		901
761	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	902	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
762	my $model = "AnyEvent::Impl::$1";	903	my $model = "AnyEvent::Impl::$1";
763	if (eval "require $model") {	904	if (eval "require $model") {
764	$MODEL = $model;	905	$MODEL = $model;
…		…
798	$MODEL	939	$MODEL
799	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";	940	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";
800	}	941	}
801	}	942	}
802		943
		944	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		945
803	unshift @ISA, $MODEL;	946	unshift @ISA, $MODEL;
804	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	947
		948	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
805		949
806	(shift @post_detect)->() while @post_detect;	950	(shift @post_detect)->() while @post_detect;
807	}	951	}
808		952
809	$MODEL	953	$MODEL
…		…
820	my $class = shift;	964	my $class = shift;
821	$class->$func (@_);	965	$class->$func (@_);
822	}	966	}
823		967
824	package AnyEvent::Base;	968	package AnyEvent::Base;
		969
		970	# default implementation for now and time
		971
		972	use Time::HiRes ();
		973
		974	sub time { Time::HiRes::time }
		975	sub now { Time::HiRes::time }
825		976
826	# default implementation for ->condvar	977	# default implementation for ->condvar
827		978
828	sub condvar {	979	sub condvar {
829	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::	980	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::
…		…
850	sub AnyEvent::Base::Signal::DESTROY {	1001	sub AnyEvent::Base::Signal::DESTROY {
851	my ($signal, $cb) = @{$_[0]};	1002	my ($signal, $cb) = @{$_[0]};
852		1003
853	delete $SIG_CB{$signal}{$cb};	1004	delete $SIG_CB{$signal}{$cb};
854		1005
855	$SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} };	1006	delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
856	}	1007	}
857		1008
858	# default implementation for ->child	1009	# default implementation for ->child
859		1010
860	our %PID_CB;	1011	our %PID_CB;
…		…
887	or Carp::croak "required option 'pid' is missing";	1038	or Carp::croak "required option 'pid' is missing";
888		1039
889	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1040	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
890		1041
891	unless ($WNOHANG) {	1042	unless ($WNOHANG) {
892	$WNOHANG = eval { require POSIX; &POSIX::WNOHANG } \|\| 1;	1043	$WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;
893	}	1044	}
894		1045
895	unless ($CHLD_W) {	1046	unless ($CHLD_W) {
896	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1047	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
897	# child could be a zombie already, so make at least one round	1048	# child could be a zombie already, so make at least one round
…		…
913	package AnyEvent::CondVar;	1064	package AnyEvent::CondVar;
914		1065
915	our @ISA = AnyEvent::CondVar::Base::;	1066	our @ISA = AnyEvent::CondVar::Base::;
916		1067
917	package AnyEvent::CondVar::Base;	1068	package AnyEvent::CondVar::Base;
		1069
		1070	use overload
		1071	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },
		1072	fallback => 1;
918		1073
919	sub _send {	1074	sub _send {
920	# nop	1075	# nop
921	}	1076	}
922		1077
…		…
1026	C<PERL_ANYEVENT_MODEL>.	1181	C<PERL_ANYEVENT_MODEL>.
1027		1182
1028	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	1183	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1029	model it chooses.	1184	model it chooses.
1030		1185
		1186	=item C<PERL_ANYEVENT_STRICT>
		1187
		1188	AnyEvent does not do much argument checking by default, as thorough
		1189	argument checking is very costly. Setting this variable to a true value
		1190	will cause AnyEvent to thoroughly check the arguments passed to most
		1191	method calls and croaks if it finds any problems. In other words, enables
		1192	"strict" mode. Unlike C<use strict> it is definitely recommended ot keep
		1193	it off in production.
		1194
1031	=item C<PERL_ANYEVENT_MODEL>	1195	=item C<PERL_ANYEVENT_MODEL>
1032		1196
1033	This can be used to specify the event model to be used by AnyEvent, before	1197	This can be used to specify the event model to be used by AnyEvent, before
1034	autodetection and -probing kicks in. It must be a string consisting	1198	auto detection and -probing kicks in. It must be a string consisting
1035	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	1199	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
1036	and the resulting module name is loaded and if the load was successful,	1200	and the resulting module name is loaded and if the load was successful,
1037	used as event model. If it fails to load AnyEvent will proceed with	1201	used as event model. If it fails to load AnyEvent will proceed with
1038	autodetection and -probing.	1202	auto detection and -probing.
1039		1203
1040	This functionality might change in future versions.	1204	This functionality might change in future versions.
1041		1205
1042	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	1206	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
1043	could start your program like this:	1207	could start your program like this:
1044		1208
1045	PERL_ANYEVENT_MODEL=Perl perl ...	1209	PERL_ANYEVENT_MODEL=Perl perl ...
1046		1210
1047	=item C<PERL_ANYEVENT_PROTOCOLS>	1211	=item C<PERL_ANYEVENT_PROTOCOLS>
1048		1212
1049	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences	1213	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
1050	for IPv4 or IPv6. The default is unspecified (and might change, or be the result	1214	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
1051	of autoprobing).	1215	of auto probing).
1052		1216
1053	Must be set to a comma-separated list of protocols or address families,	1217	Must be set to a comma-separated list of protocols or address families,
1054	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be	1218	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
1055	used, and preference will be given to protocols mentioned earlier in the	1219	used, and preference will be given to protocols mentioned earlier in the
1056	list.	1220	list.
…		…
1060	small, as the program has to handle connection errors already-	1224	small, as the program has to handle connection errors already-
1061		1225
1062	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,	1226	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
1063	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>	1227	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1064	- only support IPv4, never try to resolve or contact IPv6	1228	- only support IPv4, never try to resolve or contact IPv6
1065	addressses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or	1229	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1066	IPv6, but prefer IPv6 over IPv4.	1230	IPv6, but prefer IPv6 over IPv4.
1067		1231
1068	=item C<PERL_ANYEVENT_EDNS0>	1232	=item C<PERL_ANYEVENT_EDNS0>
1069		1233
1070	Used by L<AnyEvent::DNS> to decide wether to use the EDNS0 extension	1234	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
1071	for DNS. This extension is generally useful to reduce DNS traffic, but	1235	for DNS. This extension is generally useful to reduce DNS traffic, but
1072	some (broken) firewalls drop such DNS packets, which is why it is off by	1236	some (broken) firewalls drop such DNS packets, which is why it is off by
1073	default.	1237	default.
1074		1238
1075	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce	1239	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1076	EDNS0 in its DNS requests.	1240	EDNS0 in its DNS requests.
		1241
		1242	=item C<PERL_ANYEVENT_MAX_FORKS>
		1243
		1244	The maximum number of child processes that C<AnyEvent::Util::fork_call>
		1245	will create in parallel.
1077		1246
1078	=back	1247	=back
1079		1248
1080	=head1 EXAMPLE PROGRAM	1249	=head1 EXAMPLE PROGRAM
1081		1250
…		…
1167	syswrite $txn->{fh}, $txn->{request}	1336	syswrite $txn->{fh}, $txn->{request}
1168	or die "connection or write error";	1337	or die "connection or write error";
1169	$txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r });	1338	$txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r });
1170		1339
1171	Again, C<fh_ready_r> waits till all data has arrived, and then stores the	1340	Again, C<fh_ready_r> waits till all data has arrived, and then stores the
1172	result and signals any possible waiters that the request ahs finished:	1341	result and signals any possible waiters that the request has finished:
1173		1342
1174	sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf};	1343	sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf};
1175		1344
1176	if (end-of-file or data complete) {	1345	if (end-of-file or data complete) {
1177	$txn->{result} = $txn->{buf};	1346	$txn->{result} = $txn->{buf};
…		…
1185		1354
1186	$txn->{finished}->recv;	1355	$txn->{finished}->recv;
1187	return $txn->{result};	1356	return $txn->{result};
1188		1357
1189	The actual code goes further and collects all errors (C<die>s, exceptions)	1358	The actual code goes further and collects all errors (C<die>s, exceptions)
1190	that occured during request processing. The C<result> method detects	1359	that occurred during request processing. The C<result> method detects
1191	whether an exception as thrown (it is stored inside the $txn object)	1360	whether an exception as thrown (it is stored inside the $txn object)
1192	and just throws the exception, which means connection errors and other	1361	and just throws the exception, which means connection errors and other
1193	problems get reported tot he code that tries to use the result, not in a	1362	problems get reported tot he code that tries to use the result, not in a
1194	random callback.	1363	random callback.
1195		1364
…		…
1241	of various event loops I prepared some benchmarks.	1410	of various event loops I prepared some benchmarks.
1242		1411
1243	=head2 BENCHMARKING ANYEVENT OVERHEAD	1412	=head2 BENCHMARKING ANYEVENT OVERHEAD
1244		1413
1245	Here is a benchmark of various supported event models used natively and	1414	Here is a benchmark of various supported event models used natively and
1246	through anyevent. The benchmark creates a lot of timers (with a zero	1415	through AnyEvent. The benchmark creates a lot of timers (with a zero
1247	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	1416	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1248	which it is), lets them fire exactly once and destroys them again.	1417	which it is), lets them fire exactly once and destroys them again.
1249		1418
1250	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	1419	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1251	distribution.	1420	distribution.
…		…
1374		1543
1375	=back	1544	=back
1376		1545
1377	=head2 BENCHMARKING THE LARGE SERVER CASE	1546	=head2 BENCHMARKING THE LARGE SERVER CASE
1378		1547
1379	This benchmark atcually benchmarks the event loop itself. It works by	1548	This benchmark actually benchmarks the event loop itself. It works by
1380	creating a number of "servers": each server consists of a socketpair, a	1549	creating a number of "servers": each server consists of a socket pair, a
1381	timeout watcher that gets reset on activity (but never fires), and an I/O	1550	timeout watcher that gets reset on activity (but never fires), and an I/O
1382	watcher waiting for input on one side of the socket. Each time the socket	1551	watcher waiting for input on one side of the socket. Each time the socket
1383	watcher reads a byte it will write that byte to a random other "server".	1552	watcher reads a byte it will write that byte to a random other "server".
1384		1553
1385	The effect is that there will be a lot of I/O watchers, only part of which	1554	The effect is that there will be a lot of I/O watchers, only part of which
1386	are active at any one point (so there is a constant number of active	1555	are active at any one point (so there is a constant number of active
1387	fds for each loop iterstaion, but which fds these are is random). The	1556	fds for each loop iteration, but which fds these are is random). The
1388	timeout is reset each time something is read because that reflects how	1557	timeout is reset each time something is read because that reflects how
1389	most timeouts work (and puts extra pressure on the event loops).	1558	most timeouts work (and puts extra pressure on the event loops).
1390		1559
1391	In this benchmark, we use 10000 socketpairs (20000 sockets), of which 100	1560	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
1392	(1%) are active. This mirrors the activity of large servers with many	1561	(1%) are active. This mirrors the activity of large servers with many
1393	connections, most of which are idle at any one point in time.	1562	connections, most of which are idle at any one point in time.
1394		1563
1395	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	1564	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
1396	distribution.	1565	distribution.
…		…
1398	=head3 Explanation of the columns	1567	=head3 Explanation of the columns
1399		1568
1400	I<sockets> is the number of sockets, and twice the number of "servers" (as	1569	I<sockets> is the number of sockets, and twice the number of "servers" (as
1401	each server has a read and write socket end).	1570	each server has a read and write socket end).
1402		1571
1403	I<create> is the time it takes to create a socketpair (which is	1572	I<create> is the time it takes to create a socket pair (which is
1404	nontrivial) and two watchers: an I/O watcher and a timeout watcher.	1573	nontrivial) and two watchers: an I/O watcher and a timeout watcher.
1405		1574
1406	I<request>, the most important value, is the time it takes to handle a	1575	I<request>, the most important value, is the time it takes to handle a
1407	single "request", that is, reading the token from the pipe and forwarding	1576	single "request", that is, reading the token from the pipe and forwarding
1408	it to another server. This includes deleting the old timeout and creating	1577	it to another server. This includes deleting the old timeout and creating
…		…
1481	speed most when you have lots of watchers, not when you only have a few of	1650	speed most when you have lots of watchers, not when you only have a few of
1482	them).	1651	them).
1483		1652
1484	EV is again fastest.	1653	EV is again fastest.
1485		1654
1486	Perl again comes second. It is noticably faster than the C-based event	1655	Perl again comes second. It is noticeably faster than the C-based event
1487	loops Event and Glib, although the difference is too small to really	1656	loops Event and Glib, although the difference is too small to really
1488	matter.	1657	matter.
1489		1658
1490	POE also performs much better in this case, but is is still far behind the	1659	POE also performs much better in this case, but is is still far behind the
1491	others.	1660	others.
…		…
1520	specified in the variable.	1689	specified in the variable.
1521		1690
1522	You can make AnyEvent completely ignore this variable by deleting it	1691	You can make AnyEvent completely ignore this variable by deleting it
1523	before the first watcher gets created, e.g. with a C<BEGIN> block:	1692	before the first watcher gets created, e.g. with a C<BEGIN> block:
1524		1693
1525	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }	1694	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }
1526		1695
1527	use AnyEvent;	1696	use AnyEvent;
1528		1697
1529	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can	1698	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1530	be used to probe what backend is used and gain other information (which is	1699	be used to probe what backend is used and gain other information (which is
1531	probably even less useful to an attacker than PERL_ANYEVENT_MODEL).	1700	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
		1701	$ENV{PERL_ANYEGENT_STRICT}.
		1702
		1703
		1704	=head1 BUGS
		1705
		1706	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
		1707	to work around. If you suffer from memleaks, first upgrade to Perl 5.10
		1708	and check wether the leaks still show up. (Perl 5.10.0 has other annoying
		1709	mamleaks, such as leaking on C<map> and C<grep> but it is usually not as
		1710	pronounced).
1532		1711
1533		1712
1534	=head1 SEE ALSO	1713	=head1 SEE ALSO
1535		1714
1536	Utility functions: L<AnyEvent::Util>.	1715	Utility functions: L<AnyEvent::Util>.
…		…
1553	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.	1732	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.
1554		1733
1555		1734
1556	=head1 AUTHOR	1735	=head1 AUTHOR
1557		1736
1558	Marc Lehmann <schmorp@schmorp.de>	1737	Marc Lehmann <schmorp@schmorp.de>
1559	http://home.schmorp.de/	1738	http://home.schmorp.de/
1560		1739
1561	=cut	1740	=cut
1562		1741
1563	1	1742	1
1564		1743

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.127 by root, Sat May 24 01:15:19 2008 UTC vs. Revision 1.168 by root, Tue Jul 8 23:53:37 2008 UTC

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Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.127 by root, Sat May 24 01:15:19 2008 UTC vs.
Revision 1.168 by root, Tue Jul 8 23:53:37 2008 UTC