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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.105 by root, Thu May 1 12:35:54 2008 UTC vs.
Revision 1.164 by root, Tue Jul 8 19:50:25 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
		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.
22		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?
…		…
48	isn't itself. What's worse, all the potential users of your module are	54	isn't itself. What's worse, all the potential users of your module are
49	I<also> forced to use the same event loop you use.	55	I<also> forced to use the same event loop you use.
50		56
51	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	57	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
52	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	58	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	59	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,	60	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	61	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	62	event models it supports (including stuff like POE and IO::Async, as long
57	as those use one of the supported event loops. It is trivial to add new	63	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).	64	event loops to AnyEvent, too, so it is future-proof).
59		65
60	In addition to being free of having to use I<the one and only true event	66	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	67	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	68	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	69	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	70	offering the functionality that is necessary, in as thin as a wrapper as
65	technically possible.	71	technically possible.
66		72
		73	Of course, AnyEvent comes with a big (and fully optional!) toolbox
		74	of useful functionality, such as an asynchronous DNS resolver, 100%
		75	non-blocking connects (even with TLS/SSL, IPv6 and on broken platforms
		76	such as Windows) and lots of real-world knowledge and workarounds for
		77	platform bugs and differences.
		78
67	Of course, if you want lots of policy (this can arguably be somewhat	79	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	80	useful) and you want to force your users to use the one and only event
69	model, you should I<not> use this module.	81	model, you should I<not> use this module.
70		82
71	=head1 DESCRIPTION	83	=head1 DESCRIPTION
72		84
…		…
78	The interface itself is vaguely similar, but not identical to the L<Event>	90	The interface itself is vaguely similar, but not identical to the L<Event>
79	module.	91	module.
80		92
81	During the first call of any watcher-creation method, the module tries	93	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	94	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>,	95	following modules is already loaded: L<EV>,
84	L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>,	96	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	97	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	98	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	99	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	100	be successfully loaded will be used. If, after this, still none could be
…		…
102	starts using it, all bets are off. Maybe you should tell their authors to	114	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...	115	use AnyEvent so their modules work together with others seamlessly...
104		116
105	The pure-perl implementation of AnyEvent is called	117	The pure-perl implementation of AnyEvent is called
106	C<AnyEvent::Impl::Perl>. Like other event modules you can load it	118	C<AnyEvent::Impl::Perl>. Like other event modules you can load it
107	explicitly.	119	explicitly and enjoy the high availability of that event loop :)
108		120
109	=head1 WATCHERS	121	=head1 WATCHERS
110		122
111	AnyEvent has the central concept of a I<watcher>, which is an object that	123	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	124	stores relevant data for each kind of event you are waiting for, such as
113	the callback to call, the filehandle to watch, etc.	125	the callback to call, the file handle to watch, etc.
114		126
115	These watchers are normal Perl objects with normal Perl lifetime. After	127	These watchers are normal Perl objects with normal Perl lifetime. After
116	creating a watcher it will immediately "watch" for events and invoke the	128	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	129	callback when the event occurs (of course, only when the event model
118	is in control).	130	is in control).
…		…
126	Many watchers either are used with "recursion" (repeating timers for	138	Many watchers either are used with "recursion" (repeating timers for
127	example), or need to refer to their watcher object in other ways.	139	example), or need to refer to their watcher object in other ways.
128		140
129	An any way to achieve that is this pattern:	141	An any way to achieve that is this pattern:
130		142
131	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	143	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
132	# you can use $w here, for example to undef it	144	# you can use $w here, for example to undef it
133	undef $w;	145	undef $w;
134	});	146	});
135		147
136	Note that C<my $w; $w => combination. This is necessary because in Perl,	148	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	149	my variables are only visible after the statement in which they are
138	declared.	150	declared.
139		151
…		…
158		170
159	Some event loops issue spurious readyness notifications, so you should	171	Some event loops issue spurious readyness notifications, so you should
160	always use non-blocking calls when reading/writing from/to your file	172	always use non-blocking calls when reading/writing from/to your file
161	handles.	173	handles.
162		174
163	Example:
164
165	# wait for readability of STDIN, then read a line and disable the watcher	175	Example: wait for readability of STDIN, then read a line and disable the
		176	watcher.
		177
166	my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {	178	my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {
167	chomp (my $input = <STDIN>);	179	chomp (my $input = <STDIN>);
168	warn "read: $input\n";	180	warn "read: $input\n";
169	undef $w;	181	undef $w;
170	});	182	});
…		…
180		192
181	Although the callback might get passed parameters, their value and	193	Although the callback might get passed parameters, their value and
182	presence is undefined and you cannot rely on them. Portable AnyEvent	194	presence is undefined and you cannot rely on them. Portable AnyEvent
183	callbacks cannot use arguments passed to time watcher callbacks.	195	callbacks cannot use arguments passed to time watcher callbacks.
184		196
185	The timer callback will be invoked at most once: if you want a repeating	197	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	198	parameter, C<interval>, as a positive number, then the callback will be
187	and Glib).	199	invoked regularly at that interval (in fractional seconds) after the first
		200	invocation.
188		201
189	Example:	202	The callback will be rescheduled before invoking the callback, but no
		203	attempt is done to avoid timer drift in most backends, so the interval is
		204	only approximate.
190		205
191	# fire an event after 7.7 seconds	206	Example: fire an event after 7.7 seconds.
		207
192	my $w = AnyEvent->timer (after => 7.7, cb => sub {	208	my $w = AnyEvent->timer (after => 7.7, cb => sub {
193	warn "timeout\n";	209	warn "timeout\n";
194	});	210	});
195		211
196	# to cancel the timer:	212	# to cancel the timer:
197	undef $w;	213	undef $w;
198		214
199	Example 2:
200
201	# fire an event after 0.5 seconds, then roughly every second	215	Example 2: fire an event after 0.5 seconds, then roughly every second.
202	my $w;
203		216
204	my $cb = sub {
205	# cancel the old timer while creating a new one
206	$w = AnyEvent->timer (after => 1, cb => $cb);	217	my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub {
		218	warn "timeout\n";
207	};	219	};
208
209	# start the "loop" by creating the first watcher
210	$w = AnyEvent->timer (after => 0.5, cb => $cb);
211		220
212	=head3 TIMING ISSUES	221	=head3 TIMING ISSUES
213		222
214	There are two ways to handle timers: based on real time (relative, "fire	223	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	224	in 10 seconds") and based on wallclock time (absolute, "fire at 12
…		…
227	timers.	236	timers.
228		237
229	AnyEvent always prefers relative timers, if available, matching the	238	AnyEvent always prefers relative timers, if available, matching the
230	AnyEvent API.	239	AnyEvent API.
231		240
		241	AnyEvent has two additional methods that return the "current time":
		242
		243	=over 4
		244
		245	=item AnyEvent->time
		246
		247	This returns the "current wallclock time" as a fractional number of
		248	seconds since the Epoch (the same thing as C<time> or C<Time::HiRes::time>
		249	return, and the result is guaranteed to be compatible with those).
		250
		251	It progresses independently of any event loop processing, i.e. each call
		252	will check the system clock, which usually gets updated frequently.
		253
		254	=item AnyEvent->now
		255
		256	This also returns the "current wallclock time", but unlike C<time>, above,
		257	this value might change only once per event loop iteration, depending on
		258	the event loop (most return the same time as C<time>, above). This is the
		259	time that AnyEvent's timers get scheduled against.
		260
		261	I<In almost all cases (in all cases if you don't care), this is the
		262	function to call when you want to know the current time.>
		263
		264	This function is also often faster then C<< AnyEvent->time >>, and
		265	thus the preferred method if you want some timestamp (for example,
		266	L<AnyEvent::Handle> uses this to update it's activity timeouts).
		267
		268	The rest of this section is only of relevance if you try to be very exact
		269	with your timing, you can skip it without bad conscience.
		270
		271	For a practical example of when these times differ, consider L<Event::Lib>
		272	and L<EV> and the following set-up:
		273
		274	The event loop is running and has just invoked one of your callback at
		275	time=500 (assume no other callbacks delay processing). In your callback,
		276	you wait a second by executing C<sleep 1> (blocking the process for a
		277	second) and then (at time=501) you create a relative timer that fires
		278	after three seconds.
		279
		280	With L<Event::Lib>, C<< AnyEvent->time >> and C<< AnyEvent->now >> will
		281	both return C<501>, because that is the current time, and the timer will
		282	be scheduled to fire at time=504 (C<501> + C<3>).
		283
		284	With L<EV>, C<< AnyEvent->time >> returns C<501> (as that is the current
		285	time), but C<< AnyEvent->now >> returns C<500>, as that is the time the
		286	last event processing phase started. With L<EV>, your timer gets scheduled
		287	to run at time=503 (C<500> + C<3>).
		288
		289	In one sense, L<Event::Lib> is more exact, as it uses the current time
		290	regardless of any delays introduced by event processing. However, most
		291	callbacks do not expect large delays in processing, so this causes a
		292	higher drift (and a lot more system calls to get the current time).
		293
		294	In another sense, L<EV> is more exact, as your timer will be scheduled at
		295	the same time, regardless of how long event processing actually took.
		296
		297	In either case, if you care (and in most cases, you don't), then you
		298	can get whatever behaviour you want with any event loop, by taking the
		299	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
		300	account.
		301
		302	=back
		303
232	=head2 SIGNAL WATCHERS	304	=head2 SIGNAL WATCHERS
233		305
234	You can watch for signals using a signal watcher, C<signal> is the signal	306	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	307	I<name> without any C<SIG> prefix, C<cb> is the Perl callback to
236	be invoked whenever a signal occurs.	308	be invoked whenever a signal occurs.
237		309
238	Although the callback might get passed parameters, their value and	310	Although the callback might get passed parameters, their value and
239	presence is undefined and you cannot rely on them. Portable AnyEvent	311	presence is undefined and you cannot rely on them. Portable AnyEvent
240	callbacks cannot use arguments passed to signal watcher callbacks.	312	callbacks cannot use arguments passed to signal watcher callbacks.
241		313
242	Multiple signal occurances can be clumped together into one callback	314	Multiple signal occurrences can be clumped together into one callback
243	invocation, and callback invocation will be synchronous. synchronous means	315	invocation, and callback invocation will be synchronous. Synchronous means
244	that it might take a while until the signal gets handled by the process,	316	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.	317	but it is guaranteed not to interrupt any other callbacks.
246		318
247	The main advantage of using these watchers is that you can share a signal	319	The main advantage of using these watchers is that you can share a signal
248	between multiple watchers.	320	between multiple watchers.
249		321
250	This watcher might use C<%SIG>, so programs overwriting those signals	322	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	349	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>).	350	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).
279		351
280	Example: fork a process and wait for it	352	Example: fork a process and wait for it
281		353
282	my $done = AnyEvent->condvar;	354	my $done = AnyEvent->condvar;
283		355
284	AnyEvent::detect; # force event module to be initialised
285
286	my $pid = fork or exit 5;	356	my $pid = fork or exit 5;
287		357
288	my $w = AnyEvent->child (	358	my $w = AnyEvent->child (
289	pid => $pid,	359	pid => $pid,
290	cb => sub {	360	cb => sub {
291	my ($pid, $status) = @_;	361	my ($pid, $status) = @_;
292	warn "pid $pid exited with status $status";	362	warn "pid $pid exited with status $status";
293	$done->broadcast;	363	$done->send;
294	},	364	},
295	);	365	);
296		366
297	# do something else, then wait for process exit	367	# do something else, then wait for process exit
298	$done->wait;	368	$done->recv;
299		369
300	=head2 CONDITION VARIABLES	370	=head2 CONDITION VARIABLES
301		371
302	If you are familiar with some event loops you will know that all of them	372	If you are familiar with some event loops you will know that all of them
303	require you to run some blocking "loop", "run" or similar function that	373	require you to run some blocking "loop", "run" or similar function that
…		…
312	Condition variables can be created by calling the C<< AnyEvent->condvar	382	Condition variables can be created by calling the C<< AnyEvent->condvar
313	>> method, usually without arguments. The only argument pair allowed is	383	>> method, usually without arguments. The only argument pair allowed is
314	C<cb>, which specifies a callback to be called when the condition variable	384	C<cb>, which specifies a callback to be called when the condition variable
315	becomes true.	385	becomes true.
316		386
317	After creation, the conditon variable is "false" until it becomes "true"	387	After creation, the condition variable is "false" until it becomes "true"
318	by calling the C<broadcast> method.	388	by calling the C<send> method (or calling the condition variable as if it
		389	were a callback, read about the caveats in the description for the C<<
		390	->send >> method).
319		391
320	Condition variables are similar to callbacks, except that you can	392	Condition variables are similar to callbacks, except that you can
321	optionally wait for them. They can also be called merge points - points	393	optionally wait for them. They can also be called merge points - points
322	in time where multiple outstandign events have been processed. And yet	394	in time where multiple outstanding events have been processed. And yet
323	another way to call them is transations - each condition variable can be	395	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	396	used to represent a transaction, which finishes at some point and delivers
325	a result.	397	a result.
326		398
327	Condition variables are very useful to signal that something has finished,	399	Condition variables are very useful to signal that something has finished,
328	for example, if you write a module that does asynchronous http requests,	400	for example, if you write a module that does asynchronous http requests,
329	then a condition variable would be the ideal candidate to signal the	401	then a condition variable would be the ideal candidate to signal the
330	availability of results. The user can either act when the callback is	402	availability of results. The user can either act when the callback is
331	called or can synchronously C<< ->wait >> for the results.	403	called or can synchronously C<< ->recv >> for the results.
332		404
333	You can also use them to simulate traditional event loops - for example,	405	You can also use them to simulate traditional event loops - for example,
334	you can block your main program until an event occurs - for example, you	406	you can block your main program until an event occurs - for example, you
335	could C<< ->wait >> in your main program until the user clicks the Quit	407	could C<< ->recv >> in your main program until the user clicks the Quit
336	button of your app, which would C<< ->broadcast >> the "quit" event.	408	button of your app, which would C<< ->send >> the "quit" event.
337		409
338	Note that condition variables recurse into the event loop - if you have	410	Note that condition variables recurse into the event loop - if you have
339	two pieces of code that call C<< ->wait >> in a round-robbin fashion, you	411	two pieces of code that call C<< ->recv >> in a round-robin fashion, you
340	lose. Therefore, condition variables are good to export to your caller, but	412	lose. Therefore, condition variables are good to export to your caller, but
341	you should avoid making a blocking wait yourself, at least in callbacks,	413	you should avoid making a blocking wait yourself, at least in callbacks,
342	as this asks for trouble.	414	as this asks for trouble.
343		415
344	Condition variables are represented by hash refs in perl, and the keys	416	Condition variables are represented by hash refs in perl, and the keys
…		…
346	easy (it is often useful to build your own transaction class on top of	418	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	419	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call
348	it's C<new> method in your own C<new> method.	420	it's C<new> method in your own C<new> method.
349		421
350	There are two "sides" to a condition variable - the "producer side" which	422	There are two "sides" to a condition variable - the "producer side" which
351	eventually calls C<< -> broadcast >>, and the "consumer side", which waits	423	eventually calls C<< -> send >>, and the "consumer side", which waits
352	for the broadcast to occur.	424	for the send to occur.
353		425
354	Example:	426	Example: wait for a timer.
355		427
356	# wait till the result is ready	428	# wait till the result is ready
357	my $result_ready = AnyEvent->condvar;	429	my $result_ready = AnyEvent->condvar;
358		430
359	# do something such as adding a timer	431	# do something such as adding a timer
360	# or socket watcher the calls $result_ready->broadcast	432	# or socket watcher the calls $result_ready->send
361	# when the "result" is ready.	433	# when the "result" is ready.
362	# in this case, we simply use a timer:	434	# in this case, we simply use a timer:
363	my $w = AnyEvent->timer (	435	my $w = AnyEvent->timer (
364	after => 1,	436	after => 1,
365	cb => sub { $result_ready->broadcast },	437	cb => sub { $result_ready->send },
366	);	438	);
367		439
368	# this "blocks" (while handling events) till the callback	440	# this "blocks" (while handling events) till the callback
369	# calls broadcast	441	# calls send
370	$result_ready->wait;	442	$result_ready->recv;
		443
		444	Example: wait for a timer, but take advantage of the fact that
		445	condition variables are also code references.
		446
		447	my $done = AnyEvent->condvar;
		448	my $delay = AnyEvent->timer (after => 5, cb => $done);
		449	$done->recv;
371		450
372	=head3 METHODS FOR PRODUCERS	451	=head3 METHODS FOR PRODUCERS
373		452
374	These methods should only be used by the producing side, i.e. the	453	These methods should only be used by the producing side, i.e. the
375	code/module that eventually broadcasts the signal. Note that it is also	454	code/module that eventually sends the signal. Note that it is also
376	the producer side which creates the condvar in most cases, but it isn't	455	the producer side which creates the condvar in most cases, but it isn't
377	uncommon for the consumer to create it as well.	456	uncommon for the consumer to create it as well.
378		457
379	=over 4	458	=over 4
380		459
381	=item $cv->broadcast (...)	460	=item $cv->send (...)
382		461
383	Flag the condition as ready - a running C<< ->wait >> and all further	462	Flag the condition as ready - a running C<< ->recv >> and all further
384	calls to C<wait> will (eventually) return after this method has been	463	calls to C<recv> will (eventually) return after this method has been
385	called. If nobody is waiting the broadcast will be remembered.	464	called. If nobody is waiting the send will be remembered.
386		465
387	If a callback has been set on the condition variable, it is called	466	If a callback has been set on the condition variable, it is called
388	immediately from within broadcast.	467	immediately from within send.
389		468
390	Any arguments passed to the C<broadcast> call will be returned by all	469	Any arguments passed to the C<send> call will be returned by all
391	future C<< ->wait >> calls.	470	future C<< ->recv >> calls.
		471
		472	Condition variables are overloaded so one can call them directly
		473	(as a code reference). Calling them directly is the same as calling
		474	C<send>. Note, however, that many C-based event loops do not handle
		475	overloading, so as tempting as it may be, passing a condition variable
		476	instead of a callback does not work. Both the pure perl and EV loops
		477	support overloading, however, as well as all functions that use perl to
		478	invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
		479	example).
392		480
393	=item $cv->croak ($error)	481	=item $cv->croak ($error)
394		482
395	Similar to broadcast, but causes all call's wait C<< ->wait >> to invoke	483	Similar to send, but causes all call's to C<< ->recv >> to invoke
396	C<Carp::croak> with the given error message/object/scalar.	484	C<Carp::croak> with the given error message/object/scalar.
397		485
398	This can be used to signal any errors to the condition variable	486	This can be used to signal any errors to the condition variable
399	user/consumer.	487	user/consumer.
400		488
401	=item $cv->begin ([group callback])	489	=item $cv->begin ([group callback])
402		490
403	=item $cv->end	491	=item $cv->end
		492
		493	These two methods are EXPERIMENTAL and MIGHT CHANGE.
404		494
405	These two methods can be used to combine many transactions/events into	495	These two methods can be used to combine many transactions/events into
406	one. For example, a function that pings many hosts in parallel might want	496	one. For example, a function that pings many hosts in parallel might want
407	to use a condition variable for the whole process.	497	to use a condition variable for the whole process.
408		498
409	Every call to C<< ->begin >> will increment a counter, and every call to	499	Every call to C<< ->begin >> will increment a counter, and every call to
410	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	500	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
411	>>, the (last) callback passed to C<begin> will be executed. That callback	501	>>, the (last) callback passed to C<begin> will be executed. That callback
412	is I<supposed> to call C<< ->broadcast >>, but that is not required. If no	502	is I<supposed> to call C<< ->send >>, but that is not required. If no
413	callback was set, C<broadcast> will be called without any arguments.	503	callback was set, C<send> will be called without any arguments.
414		504
415	Let's clarify this with the ping example:	505	Let's clarify this with the ping example:
416		506
417	my $cv = AnyEvent->condvar;	507	my $cv = AnyEvent->condvar;
418		508
419	my %result;	509	my %result;
420	$cv->begin (sub { $cv->broadcast (\%result) });	510	$cv->begin (sub { $cv->send (\%result) });
421		511
422	for my $host (@list_of_hosts) {	512	for my $host (@list_of_hosts) {
423	$cv->begin;	513	$cv->begin;
424	ping_host_then_call_callback $host, sub {	514	ping_host_then_call_callback $host, sub {
425	$result{$host} = ...;	515	$result{$host} = ...;
…		…
428	}	518	}
429		519
430	$cv->end;	520	$cv->end;
431		521
432	This code fragment supposedly pings a number of hosts and calls	522	This code fragment supposedly pings a number of hosts and calls
433	C<broadcast> after results for all then have have been gathered - in any	523	C<send> after results for all then have have been gathered - in any
434	order. To achieve this, the code issues a call to C<begin> when it starts	524	order. To achieve this, the code issues a call to C<begin> when it starts
435	each ping request and calls C<end> when it has received some result for	525	each ping request and calls C<end> when it has received some result for
436	it. Since C<begin> and C<end> only maintain a counter, the order in which	526	it. Since C<begin> and C<end> only maintain a counter, the order in which
437	results arrive is not relevant.	527	results arrive is not relevant.
438		528
439	There is an additional bracketing call to C<begin> and C<end> outside the	529	There is an additional bracketing call to C<begin> and C<end> outside the
440	loop, which serves two important purposes: first, it sets the callback	530	loop, which serves two important purposes: first, it sets the callback
441	to be called once the counter reaches C<0>, and second, it ensures that	531	to be called once the counter reaches C<0>, and second, it ensures that
442	broadcast is called even when C<no> hosts are being pinged (the loop	532	C<send> is called even when C<no> hosts are being pinged (the loop
443	doesn't execute once).	533	doesn't execute once).
444		534
445	This is the general pattern when you "fan out" into multiple subrequests:	535	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>	536	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	537	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>.	538	C<begin> and for each subrequest you finish, call C<end>.
449		539
450	=back	540	=back
451		541
452	=head3 METHODS FOR CONSUMERS	542	=head3 METHODS FOR CONSUMERS
453		543
454	These methods should only be used by the consuming side, i.e. the	544	These methods should only be used by the consuming side, i.e. the
455	code awaits the condition.	545	code awaits the condition.
456		546
457	=item $cv->wait	547	=over 4
458		548
		549	=item $cv->recv
		550
459	Wait (blocking if necessary) until the C<< ->broadcast >> or C<< ->croak	551	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
460	>> methods have been called on c<$cv>, while servicing other watchers	552	>> methods have been called on c<$cv>, while servicing other watchers
461	normally.	553	normally.
462		554
463	You can only wait once on a condition - additional calls are valid but	555	You can only wait once on a condition - additional calls are valid but
464	will return immediately.	556	will return immediately.
465		557
466	If an error condition has been set by calling C<< ->croak >>, then this	558	If an error condition has been set by calling C<< ->croak >>, then this
467	function will call C<croak>.	559	function will call C<croak>.
468		560
469	In list context, all parameters passed to C<broadcast> will be returned,	561	In list context, all parameters passed to C<send> will be returned,
470	in scalar context only the first one will be returned.	562	in scalar context only the first one will be returned.
471		563
472	Not all event models support a blocking wait - some die in that case	564	Not all event models support a blocking wait - some die in that case
473	(programs might want to do that to stay interactive), so I<if you are	565	(programs might want to do that to stay interactive), so I<if you are
474	using this from a module, never require a blocking wait>, but let the	566	using this from a module, never require a blocking wait>, but let the
475	caller decide whether the call will block or not (for example, by coupling	567	caller decide whether the call will block or not (for example, by coupling
476	condition variables with some kind of request results and supporting	568	condition variables with some kind of request results and supporting
477	callbacks so the caller knows that getting the result will not block,	569	callbacks so the caller knows that getting the result will not block,
478	while still suppporting blocking waits if the caller so desires).	570	while still supporting blocking waits if the caller so desires).
479		571
480	Another reason I<never> to C<< ->wait >> in a module is that you cannot	572	Another reason I<never> to C<< ->recv >> in a module is that you cannot
481	sensibly have two C<< ->wait >>'s in parallel, as that would require	573	sensibly have two C<< ->recv >>'s in parallel, as that would require
482	multiple interpreters or coroutines/threads, none of which C<AnyEvent>	574	multiple interpreters or coroutines/threads, none of which C<AnyEvent>
483	can supply (the coroutine-aware backends L<AnyEvent::Impl::CoroEV> and	575	can supply.
484	L<AnyEvent::Impl::CoroEvent> explicitly support concurrent C<< ->wait >>'s
485	from different coroutines, however).
486		576
		577	The L<Coro> module, however, I<can> and I<does> supply coroutines and, in
		578	fact, L<Coro::AnyEvent> replaces AnyEvent's condvars by coroutine-safe
		579	versions and also integrates coroutines into AnyEvent, making blocking
		580	C<< ->recv >> calls perfectly safe as long as they are done from another
		581	coroutine (one that doesn't run the event loop).
		582
487	You can ensure that C<< -wait >> never blocks by setting a callback and	583	You can ensure that C<< -recv >> never blocks by setting a callback and
488	only calling C<< ->wait >> from within that callback (or at a later	584	only calling C<< ->recv >> from within that callback (or at a later
489	time). This will work even when the event loop does not support blocking	585	time). This will work even when the event loop does not support blocking
490	waits otherwise.	586	waits otherwise.
		587
		588	=item $bool = $cv->ready
		589
		590	Returns true when the condition is "true", i.e. whether C<send> or
		591	C<croak> have been called.
		592
		593	=item $cb = $cv->cb ([new callback])
		594
		595	This is a mutator function that returns the callback set and optionally
		596	replaces it before doing so.
		597
		598	The callback will be called when the condition becomes "true", i.e. when
		599	C<send> or C<croak> are called, with the only argument being the condition
		600	variable itself. Calling C<recv> inside the callback or at any later time
		601	is guaranteed not to block.
491		602
492	=back	603	=back
493		604
494	=head1 GLOBAL VARIABLES AND FUNCTIONS	605	=head1 GLOBAL VARIABLES AND FUNCTIONS
495		606
…		…
503	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case	614	C<AnyEvent::Impl:xxx> modules, but can be any other class in the case
504	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).	615	AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode>).
505		616
506	The known classes so far are:	617	The known classes so far are:
507		618
508	AnyEvent::Impl::CoroEV based on Coro::EV, best choice.
509	AnyEvent::Impl::CoroEvent based on Coro::Event, second best choice.
510	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).	619	AnyEvent::Impl::EV based on EV (an interface to libev, best choice).
511	AnyEvent::Impl::Event based on Event, second best choice.	620	AnyEvent::Impl::Event based on Event, second best choice.
512	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	621	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
513	AnyEvent::Impl::Glib based on Glib, third-best choice.	622	AnyEvent::Impl::Glib based on Glib, third-best choice.
514	AnyEvent::Impl::Tk based on Tk, very bad choice.	623	AnyEvent::Impl::Tk based on Tk, very bad choice.
…		…
531	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	640	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
532	if necessary. You should only call this function right before you would	641	if necessary. You should only call this function right before you would
533	have created an AnyEvent watcher anyway, that is, as late as possible at	642	have created an AnyEvent watcher anyway, that is, as late as possible at
534	runtime.	643	runtime.
535		644
		645	=item $guard = AnyEvent::post_detect { BLOCK }
		646
		647	Arranges for the code block to be executed as soon as the event model is
		648	autodetected (or immediately if this has already happened).
		649
		650	If called in scalar or list context, then it creates and returns an object
		651	that automatically removes the callback again when it is destroyed. See
		652	L<Coro::BDB> for a case where this is useful.
		653
		654	=item @AnyEvent::post_detect
		655
		656	If there are any code references in this array (you can C<push> to it
		657	before or after loading AnyEvent), then they will called directly after
		658	the event loop has been chosen.
		659
		660	You should check C<$AnyEvent::MODEL> before adding to this array, though:
		661	if it contains a true value then the event loop has already been detected,
		662	and the array will be ignored.
		663
		664	Best use C<AnyEvent::post_detect { BLOCK }> instead.
		665
536	=back	666	=back
537		667
538	=head1 WHAT TO DO IN A MODULE	668	=head1 WHAT TO DO IN A MODULE
539		669
540	As a module author, you should C<use AnyEvent> and call AnyEvent methods	670	As a module author, you should C<use AnyEvent> and call AnyEvent methods
…		…
543	Be careful when you create watchers in the module body - AnyEvent will	673	Be careful when you create watchers in the module body - AnyEvent will
544	decide which event module to use as soon as the first method is called, so	674	decide which event module to use as soon as the first method is called, so
545	by calling AnyEvent in your module body you force the user of your module	675	by calling AnyEvent in your module body you force the user of your module
546	to load the event module first.	676	to load the event module first.
547		677
548	Never call C<< ->wait >> on a condition variable unless you I<know> that	678	Never call C<< ->recv >> on a condition variable unless you I<know> that
549	the C<< ->broadcast >> method has been called on it already. This is	679	the C<< ->send >> method has been called on it already. This is
550	because it will stall the whole program, and the whole point of using	680	because it will stall the whole program, and the whole point of using
551	events is to stay interactive.	681	events is to stay interactive.
552		682
553	It is fine, however, to call C<< ->wait >> when the user of your module	683	It is fine, however, to call C<< ->recv >> when the user of your module
554	requests it (i.e. if you create a http request object ad have a method	684	requests it (i.e. if you create a http request object ad have a method
555	called C<results> that returns the results, it should call C<< ->wait >>	685	called C<results> that returns the results, it should call C<< ->recv >>
556	freely, as the user of your module knows what she is doing. always).	686	freely, as the user of your module knows what she is doing. always).
557		687
558	=head1 WHAT TO DO IN THE MAIN PROGRAM	688	=head1 WHAT TO DO IN THE MAIN PROGRAM
559		689
560	There will always be a single main program - the only place that should	690	There will always be a single main program - the only place that should
…		…
562		692
563	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	693	If it doesn't care, it can just "use AnyEvent" and use it itself, or not
564	do anything special (it does not need to be event-based) and let AnyEvent	694	do anything special (it does not need to be event-based) and let AnyEvent
565	decide which implementation to chose if some module relies on it.	695	decide which implementation to chose if some module relies on it.
566		696
567	If the main program relies on a specific event model. For example, in	697	If the main program relies on a specific event model - for example, in
568	Gtk2 programs you have to rely on the Glib module. You should load the	698	Gtk2 programs you have to rely on the Glib module - you should load the
569	event module before loading AnyEvent or any module that uses it: generally	699	event module before loading AnyEvent or any module that uses it: generally
570	speaking, you should load it as early as possible. The reason is that	700	speaking, you should load it as early as possible. The reason is that
571	modules might create watchers when they are loaded, and AnyEvent will	701	modules might create watchers when they are loaded, and AnyEvent will
572	decide on the event model to use as soon as it creates watchers, and it	702	decide on the event model to use as soon as it creates watchers, and it
573	might chose the wrong one unless you load the correct one yourself.	703	might chose the wrong one unless you load the correct one yourself.
574		704
575	You can chose to use a rather inefficient pure-perl implementation by	705	You can chose to use a pure-perl implementation by loading the
576	loading the C<AnyEvent::Impl::Perl> module, which gives you similar	706	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour
577	behaviour everywhere, but letting AnyEvent chose is generally better.	707	everywhere, but letting AnyEvent chose the model is generally better.
		708
		709	=head2 MAINLOOP EMULATION
		710
		711	Sometimes (often for short test scripts, or even standalone programs who
		712	only want to use AnyEvent), you do not want to run a specific event loop.
		713
		714	In that case, you can use a condition variable like this:
		715
		716	AnyEvent->condvar->recv;
		717
		718	This has the effect of entering the event loop and looping forever.
		719
		720	Note that usually your program has some exit condition, in which case
		721	it is better to use the "traditional" approach of storing a condition
		722	variable somewhere, waiting for it, and sending it when the program should
		723	exit cleanly.
		724
578		725
579	=head1 OTHER MODULES	726	=head1 OTHER MODULES
580		727
581	The following is a non-exhaustive list of additional modules that use	728	The following is a non-exhaustive list of additional modules that use
582	AnyEvent and can therefore be mixed easily with other AnyEvent modules	729	AnyEvent and can therefore be mixed easily with other AnyEvent modules
…		…
588	=item L<AnyEvent::Util>	735	=item L<AnyEvent::Util>
589		736
590	Contains various utility functions that replace often-used but blocking	737	Contains various utility functions that replace often-used but blocking
591	functions such as C<inet_aton> by event-/callback-based versions.	738	functions such as C<inet_aton> by event-/callback-based versions.
592		739
		740	=item L<AnyEvent::Socket>
		741
		742	Provides various utility functions for (internet protocol) sockets,
		743	addresses and name resolution. Also functions to create non-blocking tcp
		744	connections or tcp servers, with IPv6 and SRV record support and more.
		745
593	=item L<AnyEvent::Handle>	746	=item L<AnyEvent::Handle>
594		747
595	Provide read and write buffers and manages watchers for reads and writes.	748	Provide read and write buffers, manages watchers for reads and writes,
		749	supports raw and formatted I/O, I/O queued and fully transparent and
		750	non-blocking SSL/TLS.
596		751
597	=item L<AnyEvent::Socket>	752	=item L<AnyEvent::DNS>
598		753
599	Provides a means to do non-blocking connects, accepts etc.	754	Provides rich asynchronous DNS resolver capabilities.
		755
		756	=item L<AnyEvent::HTTP>
		757
		758	A simple-to-use HTTP library that is capable of making a lot of concurrent
		759	HTTP requests.
600		760
601	=item L<AnyEvent::HTTPD>	761	=item L<AnyEvent::HTTPD>
602		762
603	Provides a simple web application server framework.	763	Provides a simple web application server framework.
604		764
605	=item L<AnyEvent::DNS>
606
607	Provides asynchronous DNS resolver capabilities, beyond what
608	L<AnyEvent::Util> offers.
609
610	=item L<AnyEvent::FastPing>	765	=item L<AnyEvent::FastPing>
611		766
612	The fastest ping in the west.	767	The fastest ping in the west.
		768
		769	=item L<AnyEvent::DBI>
		770
		771	Executes L<DBI> requests asynchronously in a proxy process.
		772
		773	=item L<AnyEvent::AIO>
		774
		775	Truly asynchronous I/O, should be in the toolbox of every event
		776	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
		777	together.
		778
		779	=item L<AnyEvent::BDB>
		780
		781	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
		782	L<BDB> and AnyEvent together.
		783
		784	=item L<AnyEvent::GPSD>
		785
		786	A non-blocking interface to gpsd, a daemon delivering GPS information.
		787
		788	=item L<AnyEvent::IGS>
		789
		790	A non-blocking interface to the Internet Go Server protocol (used by
		791	L<App::IGS>).
613		792
614	=item L<Net::IRC3>	793	=item L<Net::IRC3>
615		794
616	AnyEvent based IRC client module family.	795	AnyEvent based IRC client module family.
617		796
…		…
628		807
629	High level API for event-based execution flow control.	808	High level API for event-based execution flow control.
630		809
631	=item L<Coro>	810	=item L<Coro>
632		811
633	Has special support for AnyEvent.	812	Has special support for AnyEvent via L<Coro::AnyEvent>.
634		813
635	=item L<IO::Lambda>	814	=item L<IO::Lambda>
636		815
637	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.	816	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
638
639	=item L<IO::AIO>
640
641	Truly asynchronous I/O, should be in the toolbox of every event
642	programmer. Can be trivially made to use AnyEvent.
643
644	=item L<BDB>
645
646	Truly asynchronous Berkeley DB access. Can be trivially made to use
647	AnyEvent.
648		817
649	=back	818	=back
650		819
651	=cut	820	=cut
652		821
…		…
655	no warnings;	824	no warnings;
656	use strict;	825	use strict;
657		826
658	use Carp;	827	use Carp;
659		828
660	our $VERSION = '3.3';	829	our $VERSION = 4.2;
661	our $MODEL;	830	our $MODEL;
662		831
663	our $AUTOLOAD;	832	our $AUTOLOAD;
664	our @ISA;	833	our @ISA;
665		834
		835	our @REGISTRY;
		836
		837	our $WIN32;
		838
		839	BEGIN {
		840	my $win32 = ! ! ($^O =~ /mswin32/i);
		841	eval "sub WIN32(){ $win32 }";
		842	}
		843
666	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	844	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;
667		845
668	our @REGISTRY;	846	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred
		847
		848	{
		849	my $idx;
		850	$PROTOCOL{$_} = ++$idx
		851	for reverse split /\s,\s/,
		852	$ENV{PERL_ANYEVENT_PROTOCOLS} \|\| "ipv4,ipv6";
		853	}
669		854
670	my @models = (	855	my @models = (
671	[Coro::EV:: => AnyEvent::Impl::CoroEV::],
672	[Coro::Event:: => AnyEvent::Impl::CoroEvent::],
673	[EV:: => AnyEvent::Impl::EV::],	856	[EV:: => AnyEvent::Impl::EV::],
674	[Event:: => AnyEvent::Impl::Event::],	857	[Event:: => AnyEvent::Impl::Event::],
675	[Tk:: => AnyEvent::Impl::Tk::],
676	[Wx:: => AnyEvent::Impl::POE::],
677	[Prima:: => AnyEvent::Impl::POE::],
678	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	858	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
679	# everything below here will not be autoprobed as the pureperl backend should work everywhere	859	# everything below here will not be autoprobed
680	[Glib:: => AnyEvent::Impl::Glib::],	860	# as the pureperl backend should work everywhere
		861	# and is usually faster
		862	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
		863	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
681	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	864	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
682	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	865	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
683	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	866	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
		867	[Wx:: => AnyEvent::Impl::POE::],
		868	[Prima:: => AnyEvent::Impl::POE::],
684	);	869	);
685		870
686	our %method = map +($_ => 1), qw(io timer signal child condvar broadcast wait one_event DESTROY);	871	our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY);
		872
		873	our @post_detect;
		874
		875	sub post_detect(&) {
		876	my ($cb) = @_;
		877
		878	if ($MODEL) {
		879	$cb->();
		880
		881	1
		882	} else {
		883	push @post_detect, $cb;
		884
		885	defined wantarray
		886	? bless \$cb, "AnyEvent::Util::PostDetect"
		887	: ()
		888	}
		889	}
		890
		891	sub AnyEvent::Util::PostDetect::DESTROY {
		892	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		893	}
687		894
688	sub detect() {	895	sub detect() {
689	unless ($MODEL) {	896	unless ($MODEL) {
690	no strict 'refs';	897	no strict 'refs';
		898	local $SIG{__DIE__};
691		899
692	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	900	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
693	my $model = "AnyEvent::Impl::$1";	901	my $model = "AnyEvent::Impl::$1";
694	if (eval "require $model") {	902	if (eval "require $model") {
695	$MODEL = $model;	903	$MODEL = $model;
…		…
725	last;	933	last;
726	}	934	}
727	}	935	}
728		936
729	$MODEL	937	$MODEL
730	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV (or Coro+EV), Event (or Coro+Event) or Glib.";	938	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";
731	}	939	}
732	}	940	}
733		941
734	unshift @ISA, $MODEL;	942	unshift @ISA, $MODEL;
735	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	943	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		944
		945	(shift @post_detect)->() while @post_detect;
736	}	946	}
737		947
738	$MODEL	948	$MODEL
739	}	949	}
740		950
…		…
750	$class->$func (@_);	960	$class->$func (@_);
751	}	961	}
752		962
753	package AnyEvent::Base;	963	package AnyEvent::Base;
754		964
		965	# default implementation for now and time
		966
		967	use Time::HiRes ();
		968
		969	sub time { Time::HiRes::time }
		970	sub now { Time::HiRes::time }
		971
755	# default implementation for ->condvar, ->wait, ->broadcast	972	# default implementation for ->condvar
756		973
757	sub condvar {	974	sub condvar {
758	bless \my $flag, "AnyEvent::Base::CondVar"	975	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::
759	}
760
761	sub AnyEvent::Base::CondVar::broadcast {
762	${$_[0]}++;
763	}
764
765	sub AnyEvent::Base::CondVar::wait {
766	AnyEvent->one_event while !${$_[0]};
767	}	976	}
768		977
769	# default implementation for ->signal	978	# default implementation for ->signal
770		979
771	our %SIG_CB;	980	our %SIG_CB;
…		…
787	sub AnyEvent::Base::Signal::DESTROY {	996	sub AnyEvent::Base::Signal::DESTROY {
788	my ($signal, $cb) = @{$_[0]};	997	my ($signal, $cb) = @{$_[0]};
789		998
790	delete $SIG_CB{$signal}{$cb};	999	delete $SIG_CB{$signal}{$cb};
791		1000
792	$SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} };	1001	delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
793	}	1002	}
794		1003
795	# default implementation for ->child	1004	# default implementation for ->child
796		1005
797	our %PID_CB;	1006	our %PID_CB;
…		…
824	or Carp::croak "required option 'pid' is missing";	1033	or Carp::croak "required option 'pid' is missing";
825		1034
826	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1035	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
827		1036
828	unless ($WNOHANG) {	1037	unless ($WNOHANG) {
829	$WNOHANG = eval { require POSIX; &POSIX::WNOHANG } \|\| 1;	1038	$WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;
830	}	1039	}
831		1040
832	unless ($CHLD_W) {	1041	unless ($CHLD_W) {
833	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1042	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
834	# child could be a zombie already, so make at least one round	1043	# child could be a zombie already, so make at least one round
…		…
844	delete $PID_CB{$pid}{$cb};	1053	delete $PID_CB{$pid}{$cb};
845	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1054	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
846		1055
847	undef $CHLD_W unless keys %PID_CB;	1056	undef $CHLD_W unless keys %PID_CB;
848	}	1057	}
		1058
		1059	package AnyEvent::CondVar;
		1060
		1061	our @ISA = AnyEvent::CondVar::Base::;
		1062
		1063	package AnyEvent::CondVar::Base;
		1064
		1065	use overload
		1066	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },
		1067	fallback => 1;
		1068
		1069	sub _send {
		1070	# nop
		1071	}
		1072
		1073	sub send {
		1074	my $cv = shift;
		1075	$cv->{_ae_sent} = [@_];
		1076	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
		1077	$cv->_send;
		1078	}
		1079
		1080	sub croak {
		1081	$_[0]{_ae_croak} = $_[1];
		1082	$_[0]->send;
		1083	}
		1084
		1085	sub ready {
		1086	$_[0]{_ae_sent}
		1087	}
		1088
		1089	sub _wait {
		1090	AnyEvent->one_event while !$_[0]{_ae_sent};
		1091	}
		1092
		1093	sub recv {
		1094	$_[0]->_wait;
		1095
		1096	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
		1097	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
		1098	}
		1099
		1100	sub cb {
		1101	$_[0]{_ae_cb} = $_[1] if @_ > 1;
		1102	$_[0]{_ae_cb}
		1103	}
		1104
		1105	sub begin {
		1106	++$_[0]{_ae_counter};
		1107	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
		1108	}
		1109
		1110	sub end {
		1111	return if --$_[0]{_ae_counter};
		1112	&{ $_[0]{_ae_end_cb} \|\| sub { $_[0]->send } };
		1113	}
		1114
		1115	# undocumented/compatibility with pre-3.4
		1116	*broadcast = \&send;
		1117	*wait = \&_wait;
849		1118
850	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1119	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
851		1120
852	This is an advanced topic that you do not normally need to use AnyEvent in	1121	This is an advanced topic that you do not normally need to use AnyEvent in
853	a module. This section is only of use to event loop authors who want to	1122	a module. This section is only of use to event loop authors who want to
…		…
910	model it chooses.	1179	model it chooses.
911		1180
912	=item C<PERL_ANYEVENT_MODEL>	1181	=item C<PERL_ANYEVENT_MODEL>
913		1182
914	This can be used to specify the event model to be used by AnyEvent, before	1183	This can be used to specify the event model to be used by AnyEvent, before
915	autodetection and -probing kicks in. It must be a string consisting	1184	auto detection and -probing kicks in. It must be a string consisting
916	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	1185	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
917	and the resulting module name is loaded and if the load was successful,	1186	and the resulting module name is loaded and if the load was successful,
918	used as event model. If it fails to load AnyEvent will proceed with	1187	used as event model. If it fails to load AnyEvent will proceed with
919	autodetection and -probing.	1188	auto detection and -probing.
920		1189
921	This functionality might change in future versions.	1190	This functionality might change in future versions.
922		1191
923	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	1192	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
924	could start your program like this:	1193	could start your program like this:
925		1194
926	PERL_ANYEVENT_MODEL=Perl perl ...	1195	PERL_ANYEVENT_MODEL=Perl perl ...
		1196
		1197	=item C<PERL_ANYEVENT_PROTOCOLS>
		1198
		1199	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
		1200	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
		1201	of auto probing).
		1202
		1203	Must be set to a comma-separated list of protocols or address families,
		1204	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
		1205	used, and preference will be given to protocols mentioned earlier in the
		1206	list.
		1207
		1208	This variable can effectively be used for denial-of-service attacks
		1209	against local programs (e.g. when setuid), although the impact is likely
		1210	small, as the program has to handle connection errors already-
		1211
		1212	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
		1213	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
		1214	- only support IPv4, never try to resolve or contact IPv6
		1215	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
		1216	IPv6, but prefer IPv6 over IPv4.
		1217
		1218	=item C<PERL_ANYEVENT_EDNS0>
		1219
		1220	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
		1221	for DNS. This extension is generally useful to reduce DNS traffic, but
		1222	some (broken) firewalls drop such DNS packets, which is why it is off by
		1223	default.
		1224
		1225	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
		1226	EDNS0 in its DNS requests.
		1227
		1228	=item C<PERL_ANYEVENT_MAX_FORKS>
		1229
		1230	The maximum number of child processes that C<AnyEvent::Util::fork_call>
		1231	will create in parallel.
927		1232
928	=back	1233	=back
929		1234
930	=head1 EXAMPLE PROGRAM	1235	=head1 EXAMPLE PROGRAM
931		1236
…		…
942	poll => 'r',	1247	poll => 'r',
943	cb => sub {	1248	cb => sub {
944	warn "io event <$_[0]>\n"; # will always output <r>	1249	warn "io event <$_[0]>\n"; # will always output <r>
945	chomp (my $input = <STDIN>); # read a line	1250	chomp (my $input = <STDIN>); # read a line
946	warn "read: $input\n"; # output what has been read	1251	warn "read: $input\n"; # output what has been read
947	$cv->broadcast if $input =~ /^q/i; # quit program if /^q/i	1252	$cv->send if $input =~ /^q/i; # quit program if /^q/i
948	},	1253	},
949	);	1254	);
950		1255
951	my $time_watcher; # can only be used once	1256	my $time_watcher; # can only be used once
952		1257
…		…
957	});	1262	});
958	}	1263	}
959		1264
960	new_timer; # create first timer	1265	new_timer; # create first timer
961		1266
962	$cv->wait; # wait until user enters /^q/i	1267	$cv->recv; # wait until user enters /^q/i
963		1268
964	=head1 REAL-WORLD EXAMPLE	1269	=head1 REAL-WORLD EXAMPLE
965		1270
966	Consider the L<Net::FCP> module. It features (among others) the following	1271	Consider the L<Net::FCP> module. It features (among others) the following
967	API calls, which are to freenet what HTTP GET requests are to http:	1272	API calls, which are to freenet what HTTP GET requests are to http:
…		…
1017	syswrite $txn->{fh}, $txn->{request}	1322	syswrite $txn->{fh}, $txn->{request}
1018	or die "connection or write error";	1323	or die "connection or write error";
1019	$txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r });	1324	$txn->{w} = AnyEvent->io (fh => $txn->{fh}, poll => 'r', cb => sub { $txn->fh_ready_r });
1020		1325
1021	Again, C<fh_ready_r> waits till all data has arrived, and then stores the	1326	Again, C<fh_ready_r> waits till all data has arrived, and then stores the
1022	result and signals any possible waiters that the request ahs finished:	1327	result and signals any possible waiters that the request has finished:
1023		1328
1024	sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf};	1329	sysread $txn->{fh}, $txn->{buf}, length $txn->{$buf};
1025		1330
1026	if (end-of-file or data complete) {	1331	if (end-of-file or data complete) {
1027	$txn->{result} = $txn->{buf};	1332	$txn->{result} = $txn->{buf};
1028	$txn->{finished}->broadcast;	1333	$txn->{finished}->send;
1029	$txb->{cb}->($txn) of $txn->{cb}; # also call callback	1334	$txb->{cb}->($txn) of $txn->{cb}; # also call callback
1030	}	1335	}
1031		1336
1032	The C<result> method, finally, just waits for the finished signal (if the	1337	The C<result> method, finally, just waits for the finished signal (if the
1033	request was already finished, it doesn't wait, of course, and returns the	1338	request was already finished, it doesn't wait, of course, and returns the
1034	data:	1339	data:
1035		1340
1036	$txn->{finished}->wait;	1341	$txn->{finished}->recv;
1037	return $txn->{result};	1342	return $txn->{result};
1038		1343
1039	The actual code goes further and collects all errors (C<die>s, exceptions)	1344	The actual code goes further and collects all errors (C<die>s, exceptions)
1040	that occured during request processing. The C<result> method detects	1345	that occurred during request processing. The C<result> method detects
1041	whether an exception as thrown (it is stored inside the $txn object)	1346	whether an exception as thrown (it is stored inside the $txn object)
1042	and just throws the exception, which means connection errors and other	1347	and just throws the exception, which means connection errors and other
1043	problems get reported tot he code that tries to use the result, not in a	1348	problems get reported tot he code that tries to use the result, not in a
1044	random callback.	1349	random callback.
1045		1350
…		…
1076		1381
1077	my $quit = AnyEvent->condvar;	1382	my $quit = AnyEvent->condvar;
1078		1383
1079	$fcp->txn_client_get ($url)->cb (sub {	1384	$fcp->txn_client_get ($url)->cb (sub {
1080	...	1385	...
1081	$quit->broadcast;	1386	$quit->send;
1082	});	1387	});
1083		1388
1084	$quit->wait;	1389	$quit->recv;
1085		1390
1086		1391
1087	=head1 BENCHMARKS	1392	=head1 BENCHMARKS
1088		1393
1089	To give you an idea of the performance and overheads that AnyEvent adds	1394	To give you an idea of the performance and overheads that AnyEvent adds
…		…
1091	of various event loops I prepared some benchmarks.	1396	of various event loops I prepared some benchmarks.
1092		1397
1093	=head2 BENCHMARKING ANYEVENT OVERHEAD	1398	=head2 BENCHMARKING ANYEVENT OVERHEAD
1094		1399
1095	Here is a benchmark of various supported event models used natively and	1400	Here is a benchmark of various supported event models used natively and
1096	through anyevent. The benchmark creates a lot of timers (with a zero	1401	through AnyEvent. The benchmark creates a lot of timers (with a zero
1097	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	1402	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1098	which it is), lets them fire exactly once and destroys them again.	1403	which it is), lets them fire exactly once and destroys them again.
1099		1404
1100	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	1405	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1101	distribution.	1406	distribution.
…		…
1118	all watchers, to avoid adding memory overhead. That means closure creation	1423	all watchers, to avoid adding memory overhead. That means closure creation
1119	and memory usage is not included in the figures.	1424	and memory usage is not included in the figures.
1120		1425
1121	I<invoke> is the time, in microseconds, used to invoke a simple	1426	I<invoke> is the time, in microseconds, used to invoke a simple
1122	callback. The callback simply counts down a Perl variable and after it was	1427	callback. The callback simply counts down a Perl variable and after it was
1123	invoked "watcher" times, it would C<< ->broadcast >> a condvar once to	1428	invoked "watcher" times, it would C<< ->send >> a condvar once to
1124	signal the end of this phase.	1429	signal the end of this phase.
1125		1430
1126	I<destroy> is the time, in microseconds, that it takes to destroy a single	1431	I<destroy> is the time, in microseconds, that it takes to destroy a single
1127	watcher.	1432	watcher.
1128		1433
…		…
1224		1529
1225	=back	1530	=back
1226		1531
1227	=head2 BENCHMARKING THE LARGE SERVER CASE	1532	=head2 BENCHMARKING THE LARGE SERVER CASE
1228		1533
1229	This benchmark atcually benchmarks the event loop itself. It works by	1534	This benchmark actually benchmarks the event loop itself. It works by
1230	creating a number of "servers": each server consists of a socketpair, a	1535	creating a number of "servers": each server consists of a socket pair, a
1231	timeout watcher that gets reset on activity (but never fires), and an I/O	1536	timeout watcher that gets reset on activity (but never fires), and an I/O
1232	watcher waiting for input on one side of the socket. Each time the socket	1537	watcher waiting for input on one side of the socket. Each time the socket
1233	watcher reads a byte it will write that byte to a random other "server".	1538	watcher reads a byte it will write that byte to a random other "server".
1234		1539
1235	The effect is that there will be a lot of I/O watchers, only part of which	1540	The effect is that there will be a lot of I/O watchers, only part of which
1236	are active at any one point (so there is a constant number of active	1541	are active at any one point (so there is a constant number of active
1237	fds for each loop iterstaion, but which fds these are is random). The	1542	fds for each loop iteration, but which fds these are is random). The
1238	timeout is reset each time something is read because that reflects how	1543	timeout is reset each time something is read because that reflects how
1239	most timeouts work (and puts extra pressure on the event loops).	1544	most timeouts work (and puts extra pressure on the event loops).
1240		1545
1241	In this benchmark, we use 10000 socketpairs (20000 sockets), of which 100	1546	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
1242	(1%) are active. This mirrors the activity of large servers with many	1547	(1%) are active. This mirrors the activity of large servers with many
1243	connections, most of which are idle at any one point in time.	1548	connections, most of which are idle at any one point in time.
1244		1549
1245	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	1550	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
1246	distribution.	1551	distribution.
…		…
1248	=head3 Explanation of the columns	1553	=head3 Explanation of the columns
1249		1554
1250	I<sockets> is the number of sockets, and twice the number of "servers" (as	1555	I<sockets> is the number of sockets, and twice the number of "servers" (as
1251	each server has a read and write socket end).	1556	each server has a read and write socket end).
1252		1557
1253	I<create> is the time it takes to create a socketpair (which is	1558	I<create> is the time it takes to create a socket pair (which is
1254	nontrivial) and two watchers: an I/O watcher and a timeout watcher.	1559	nontrivial) and two watchers: an I/O watcher and a timeout watcher.
1255		1560
1256	I<request>, the most important value, is the time it takes to handle a	1561	I<request>, the most important value, is the time it takes to handle a
1257	single "request", that is, reading the token from the pipe and forwarding	1562	single "request", that is, reading the token from the pipe and forwarding
1258	it to another server. This includes deleting the old timeout and creating	1563	it to another server. This includes deleting the old timeout and creating
…		…
1331	speed most when you have lots of watchers, not when you only have a few of	1636	speed most when you have lots of watchers, not when you only have a few of
1332	them).	1637	them).
1333		1638
1334	EV is again fastest.	1639	EV is again fastest.
1335		1640
1336	Perl again comes second. It is noticably faster than the C-based event	1641	Perl again comes second. It is noticeably faster than the C-based event
1337	loops Event and Glib, although the difference is too small to really	1642	loops Event and Glib, although the difference is too small to really
1338	matter.	1643	matter.
1339		1644
1340	POE also performs much better in this case, but is is still far behind the	1645	POE also performs much better in this case, but is is still far behind the
1341	others.	1646	others.
…		…
1370	specified in the variable.	1675	specified in the variable.
1371		1676
1372	You can make AnyEvent completely ignore this variable by deleting it	1677	You can make AnyEvent completely ignore this variable by deleting it
1373	before the first watcher gets created, e.g. with a C<BEGIN> block:	1678	before the first watcher gets created, e.g. with a C<BEGIN> block:
1374		1679
1375	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }	1680	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }
1376		1681
1377	use AnyEvent;	1682	use AnyEvent;
		1683
		1684	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
		1685	be used to probe what backend is used and gain other information (which is
		1686	probably even less useful to an attacker than PERL_ANYEVENT_MODEL).
		1687
		1688
		1689	=head1 BUGS
		1690
		1691	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
		1692	to work around. If you suffer from memleaks, first upgrade to Perl 5.10
		1693	and check wether the leaks still show up. (Perl 5.10.0 has other annoying
		1694	mamleaks, such as leaking on C<map> and C<grep> but it is usually not as
		1695	pronounced).
1378		1696
1379		1697
1380	=head1 SEE ALSO	1698	=head1 SEE ALSO
1381		1699
1382	Event modules: L<Coro::EV>, L<EV>, L<EV::Glib>, L<Glib::EV>,	1700	Utility functions: L<AnyEvent::Util>.
1383	L<Coro::Event>, L<Event>, L<Glib::Event>, L<Glib>, L<Coro>, L<Tk>,	1701
		1702	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,
1384	L<Event::Lib>, L<Qt>, L<POE>.	1703	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
1385		1704
1386	Implementations: L<AnyEvent::Impl::CoroEV>, L<AnyEvent::Impl::EV>,	1705	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
1387	L<AnyEvent::Impl::CoroEvent>, L<AnyEvent::Impl::Event>, L<AnyEvent::Impl::Glib>,	1706	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
1388	L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>, L<AnyEvent::Impl::EventLib>,	1707	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
1389	L<AnyEvent::Impl::Qt>, L<AnyEvent::Impl::POE>.	1708	L<AnyEvent::Impl::POE>.
1390		1709
		1710	Non-blocking file handles, sockets, TCP clients and
		1711	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>.
		1712
		1713	Asynchronous DNS: L<AnyEvent::DNS>.
		1714
		1715	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>,
		1716
1391	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>.	1717	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.
1392		1718
1393		1719
1394	=head1 AUTHOR	1720	=head1 AUTHOR
1395		1721
1396	Marc Lehmann <schmorp@schmorp.de>	1722	Marc Lehmann <schmorp@schmorp.de>
1397	http://home.schmorp.de/	1723	http://home.schmorp.de/
1398		1724
1399	=cut	1725	=cut
1400		1726
1401	1	1727	1
1402		1728

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.105 by root, Thu May 1 12:35:54 2008 UTC vs. Revision 1.164 by root, Tue Jul 8 19:50:25 2008 UTC

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Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.105 by root, Thu May 1 12:35:54 2008 UTC vs.
Revision 1.164 by root, Tue Jul 8 19:50:25 2008 UTC