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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.130 by root, Sat May 24 17:21:50 2008 UTC vs.
Revision 1.180 by root, Sat Sep 6 07:00:45 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
7	=head1 SYNOPSIS	7	=head1 SYNOPSIS
8		8
9	use AnyEvent;	9	use AnyEvent;
10		10
11	my $w = AnyEvent->io (fh => $fh, poll => "r\|w", cb => sub {	11	my $w = AnyEvent->io (fh => $fh, poll => "r\|w", cb => sub { ... });
12	...
13	});
14		12
15	my $w = AnyEvent->timer (after => $seconds, cb => sub {	13	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
		14	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...
		15
		16	print AnyEvent->now; # prints current event loop time
		17	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
		18
		19	my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... });
		20
		21	my $w = AnyEvent->child (pid => $pid, cb => sub {
		22	my ($pid, $status) = @_;
16	...	23	...
17	});	24	});
18		25
19	my $w = AnyEvent->condvar; # stores whether a condition was flagged	26	my $w = AnyEvent->condvar; # stores whether a condition was flagged
20	$w->send; # wake up current and all future recv's	27	$w->send; # wake up current and all future recv's
21	$w->recv; # enters "main loop" till $condvar gets ->send	28	$w->recv; # enters "main loop" till $condvar gets ->send
		29	# use a condvar in callback mode:
		30	$w->cb (sub { $_[0]->recv });
		31
		32	=head1 INTRODUCTION/TUTORIAL
		33
		34	This manpage is mainly a reference manual. If you are interested
		35	in a tutorial or some gentle introduction, have a look at the
		36	L<AnyEvent::Intro> manpage.
22		37
23	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)	38	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
24		39
25	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen	40	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
26	nowadays. So what is different about AnyEvent?	41	nowadays. So what is different about AnyEvent?
27		42
28	Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of	43	Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of
29	policy> and AnyEvent is I<small and efficient>.	44	policy> and AnyEvent is I<small and efficient>.
30		45
31	First and foremost, I<AnyEvent is not an event model> itself, it only	46	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	47	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,	48	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,	49	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	50	only one event loop can be active at the same time in a process. AnyEvent
36	helps hiding the differences between those event loops.	51	cannot change this, but it can hide the differences between those event
		52	loops.
37		53
38	The goal of AnyEvent is to offer module authors the ability to do event	54	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	55	programming (waiting for I/O or timer events) without subscribing to a
40	religion, a way of living, and most importantly: without forcing your	56	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	57	module users into the same thing by forcing them to use the same event
42	model you use.	58	model you use.
43		59
44	For modules like POE or IO::Async (which is a total misnomer as it is	60	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	61	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	62	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	63	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	64	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.	65	module are I<also> forced to use the same event loop you use.
50		66
51	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	67	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
52	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	68	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	69	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,	70	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	71	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	72	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	73	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).	74	to AnyEvent, too, so it is future-proof).
59		75
60	In addition to being free of having to use I<the one and only true event	76	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	77	model>, AnyEvent also is free of bloat and policy: with POE or similar
62	modules, you get an enormous amount of code and strict rules you have to	78	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	79	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	80	offering the functionality that is necessary, in as thin as a wrapper as
65	technically possible.	81	technically possible.
66		82
		83	Of course, AnyEvent comes with a big (and fully optional!) toolbox
		84	of useful functionality, such as an asynchronous DNS resolver, 100%
		85	non-blocking connects (even with TLS/SSL, IPv6 and on broken platforms
		86	such as Windows) and lots of real-world knowledge and workarounds for
		87	platform bugs and differences.
		88
67	Of course, if you want lots of policy (this can arguably be somewhat	89	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	90	useful) and you want to force your users to use the one and only event
69	model, you should I<not> use this module.	91	model, you should I<not> use this module.
70		92
71	=head1 DESCRIPTION	93	=head1 DESCRIPTION
72		94
102	starts using it, all bets are off. Maybe you should tell their authors to	124	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...	125	use AnyEvent so their modules work together with others seamlessly...
104		126
105	The pure-perl implementation of AnyEvent is called	127	The pure-perl implementation of AnyEvent is called
106	C<AnyEvent::Impl::Perl>. Like other event modules you can load it	128	C<AnyEvent::Impl::Perl>. Like other event modules you can load it
107	explicitly.	129	explicitly and enjoy the high availability of that event loop :)
108		130
109	=head1 WATCHERS	131	=head1 WATCHERS
110		132
111	AnyEvent has the central concept of a I<watcher>, which is an object that	133	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	134	stores relevant data for each kind of event you are waiting for, such as
…		…
126	Many watchers either are used with "recursion" (repeating timers for	148	Many watchers either are used with "recursion" (repeating timers for
127	example), or need to refer to their watcher object in other ways.	149	example), or need to refer to their watcher object in other ways.
128		150
129	An any way to achieve that is this pattern:	151	An any way to achieve that is this pattern:
130		152
131	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	153	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
132	# you can use $w here, for example to undef it	154	# you can use $w here, for example to undef it
133	undef $w;	155	undef $w;
134	});	156	});
135		157
136	Note that C<my $w; $w => combination. This is necessary because in Perl,	158	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	159	my variables are only visible after the statement in which they are
138	declared.	160	declared.
139		161
140	=head2 I/O WATCHERS	162	=head2 I/O WATCHERS
141		163
142	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	164	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
143	with the following mandatory key-value pairs as arguments:	165	with the following mandatory key-value pairs as arguments:
144		166
145	C<fh> the Perl I<file handle> (I<not> file descriptor) to watch	167	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>,	168	(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,	169	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	170	waiting for "r"eadable or "w"ritable events, respectively. C<cb> is the
149	becomes ready.	171	callback to invoke each time the file handle becomes ready.
150		172
151	Although the callback might get passed parameters, their value and	173	Although the callback might get passed parameters, their value and
152	presence is undefined and you cannot rely on them. Portable AnyEvent	174	presence is undefined and you cannot rely on them. Portable AnyEvent
153	callbacks cannot use arguments passed to I/O watcher callbacks.	175	callbacks cannot use arguments passed to I/O watcher callbacks.
154		176
…		…
158		180
159	Some event loops issue spurious readyness notifications, so you should	181	Some event loops issue spurious readyness notifications, so you should
160	always use non-blocking calls when reading/writing from/to your file	182	always use non-blocking calls when reading/writing from/to your file
161	handles.	183	handles.
162		184
163	Example:
164
165	# wait for readability of STDIN, then read a line and disable the watcher	185	Example: wait for readability of STDIN, then read a line and disable the
		186	watcher.
		187
166	my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {	188	my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {
167	chomp (my $input = <STDIN>);	189	chomp (my $input = <STDIN>);
168	warn "read: $input\n";	190	warn "read: $input\n";
169	undef $w;	191	undef $w;
170	});	192	});
…		…
180		202
181	Although the callback might get passed parameters, their value and	203	Although the callback might get passed parameters, their value and
182	presence is undefined and you cannot rely on them. Portable AnyEvent	204	presence is undefined and you cannot rely on them. Portable AnyEvent
183	callbacks cannot use arguments passed to time watcher callbacks.	205	callbacks cannot use arguments passed to time watcher callbacks.
184		206
185	The timer callback will be invoked at most once: if you want a repeating	207	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	208	parameter, C<interval>, as a strictly positive number (> 0), then the
187	and Glib).	209	callback will be invoked regularly at that interval (in fractional
		210	seconds) after the first invocation. If C<interval> is specified with a
		211	false value, then it is treated as if it were missing.
188		212
189	Example:	213	The callback will be rescheduled before invoking the callback, but no
		214	attempt is done to avoid timer drift in most backends, so the interval is
		215	only approximate.
190		216
191	# fire an event after 7.7 seconds	217	Example: fire an event after 7.7 seconds.
		218
192	my $w = AnyEvent->timer (after => 7.7, cb => sub {	219	my $w = AnyEvent->timer (after => 7.7, cb => sub {
193	warn "timeout\n";	220	warn "timeout\n";
194	});	221	});
195		222
196	# to cancel the timer:	223	# to cancel the timer:
197	undef $w;	224	undef $w;
198		225
199	Example 2:
200
201	# fire an event after 0.5 seconds, then roughly every second	226	Example 2: fire an event after 0.5 seconds, then roughly every second.
202	my $w;
203		227
204	my $cb = sub {
205	# cancel the old timer while creating a new one
206	$w = AnyEvent->timer (after => 1, cb => $cb);	228	my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub {
		229	warn "timeout\n";
207	};	230	};
208
209	# start the "loop" by creating the first watcher
210	$w = AnyEvent->timer (after => 0.5, cb => $cb);
211		231
212	=head3 TIMING ISSUES	232	=head3 TIMING ISSUES
213		233
214	There are two ways to handle timers: based on real time (relative, "fire	234	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	235	in 10 seconds") and based on wallclock time (absolute, "fire at 12
…		…
227	timers.	247	timers.
228		248
229	AnyEvent always prefers relative timers, if available, matching the	249	AnyEvent always prefers relative timers, if available, matching the
230	AnyEvent API.	250	AnyEvent API.
231		251
		252	AnyEvent has two additional methods that return the "current time":
		253
		254	=over 4
		255
		256	=item AnyEvent->time
		257
		258	This returns the "current wallclock time" as a fractional number of
		259	seconds since the Epoch (the same thing as C<time> or C<Time::HiRes::time>
		260	return, and the result is guaranteed to be compatible with those).
		261
		262	It progresses independently of any event loop processing, i.e. each call
		263	will check the system clock, which usually gets updated frequently.
		264
		265	=item AnyEvent->now
		266
		267	This also returns the "current wallclock time", but unlike C<time>, above,
		268	this value might change only once per event loop iteration, depending on
		269	the event loop (most return the same time as C<time>, above). This is the
		270	time that AnyEvent's timers get scheduled against.
		271
		272	I<In almost all cases (in all cases if you don't care), this is the
		273	function to call when you want to know the current time.>
		274
		275	This function is also often faster then C<< AnyEvent->time >>, and
		276	thus the preferred method if you want some timestamp (for example,
		277	L<AnyEvent::Handle> uses this to update it's activity timeouts).
		278
		279	The rest of this section is only of relevance if you try to be very exact
		280	with your timing, you can skip it without bad conscience.
		281
		282	For a practical example of when these times differ, consider L<Event::Lib>
		283	and L<EV> and the following set-up:
		284
		285	The event loop is running and has just invoked one of your callback at
		286	time=500 (assume no other callbacks delay processing). In your callback,
		287	you wait a second by executing C<sleep 1> (blocking the process for a
		288	second) and then (at time=501) you create a relative timer that fires
		289	after three seconds.
		290
		291	With L<Event::Lib>, C<< AnyEvent->time >> and C<< AnyEvent->now >> will
		292	both return C<501>, because that is the current time, and the timer will
		293	be scheduled to fire at time=504 (C<501> + C<3>).
		294
		295	With L<EV>, C<< AnyEvent->time >> returns C<501> (as that is the current
		296	time), but C<< AnyEvent->now >> returns C<500>, as that is the time the
		297	last event processing phase started. With L<EV>, your timer gets scheduled
		298	to run at time=503 (C<500> + C<3>).
		299
		300	In one sense, L<Event::Lib> is more exact, as it uses the current time
		301	regardless of any delays introduced by event processing. However, most
		302	callbacks do not expect large delays in processing, so this causes a
		303	higher drift (and a lot more system calls to get the current time).
		304
		305	In another sense, L<EV> is more exact, as your timer will be scheduled at
		306	the same time, regardless of how long event processing actually took.
		307
		308	In either case, if you care (and in most cases, you don't), then you
		309	can get whatever behaviour you want with any event loop, by taking the
		310	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
		311	account.
		312
		313	=back
		314
232	=head2 SIGNAL WATCHERS	315	=head2 SIGNAL WATCHERS
233		316
234	You can watch for signals using a signal watcher, C<signal> is the signal	317	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	318	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
236	be invoked whenever a signal occurs.	319	callback to be invoked whenever a signal occurs.
237		320
238	Although the callback might get passed parameters, their value and	321	Although the callback might get passed parameters, their value and
239	presence is undefined and you cannot rely on them. Portable AnyEvent	322	presence is undefined and you cannot rely on them. Portable AnyEvent
240	callbacks cannot use arguments passed to signal watcher callbacks.	323	callbacks cannot use arguments passed to signal watcher callbacks.
241		324
…		…
277	AnyEvent program, you I<have> to create at least one watcher before you	360	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>).	361	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).
279		362
280	Example: fork a process and wait for it	363	Example: fork a process and wait for it
281		364
282	my $done = AnyEvent->condvar;	365	my $done = AnyEvent->condvar;
283		366
284	my $pid = fork or exit 5;	367	my $pid = fork or exit 5;
285		368
286	my $w = AnyEvent->child (	369	my $w = AnyEvent->child (
287	pid => $pid,	370	pid => $pid,
288	cb => sub {	371	cb => sub {
289	my ($pid, $status) = @_;	372	my ($pid, $status) = @_;
290	warn "pid $pid exited with status $status";	373	warn "pid $pid exited with status $status";
291	$done->send;	374	$done->send;
292	},	375	},
293	);	376	);
294		377
295	# do something else, then wait for process exit	378	# do something else, then wait for process exit
296	$done->recv;	379	$done->recv;
297		380
298	=head2 CONDITION VARIABLES	381	=head2 CONDITION VARIABLES
299		382
300	If you are familiar with some event loops you will know that all of them	383	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	384	require you to run some blocking "loop", "run" or similar function that
…		…
307	The instrument to do that is called a "condition variable", so called	390	The instrument to do that is called a "condition variable", so called
308	because they represent a condition that must become true.	391	because they represent a condition that must become true.
309		392
310	Condition variables can be created by calling the C<< AnyEvent->condvar	393	Condition variables can be created by calling the C<< AnyEvent->condvar
311	>> method, usually without arguments. The only argument pair allowed is	394	>> method, usually without arguments. The only argument pair allowed is
		395
312	C<cb>, which specifies a callback to be called when the condition variable	396	C<cb>, which specifies a callback to be called when the condition variable
313	becomes true.	397	becomes true, with the condition variable as the first argument (but not
		398	the results).
314		399
315	After creation, the condition variable is "false" until it becomes "true"	400	After creation, the condition variable is "false" until it becomes "true"
316	by calling the C<send> method.	401	by calling the C<send> method (or calling the condition variable as if it
		402	were a callback, read about the caveats in the description for the C<<
		403	->send >> method).
317		404
318	Condition variables are similar to callbacks, except that you can	405	Condition variables are similar to callbacks, except that you can
319	optionally wait for them. They can also be called merge points - points	406	optionally wait for them. They can also be called merge points - points
320	in time where multiple outstanding events have been processed. And yet	407	in time where multiple outstanding events have been processed. And yet
321	another way to call them is transactions - each condition variable can be	408	another way to call them is transactions - each condition variable can be
…		…
347		434
348	There are two "sides" to a condition variable - the "producer side" which	435	There are two "sides" to a condition variable - the "producer side" which
349	eventually calls C<< -> send >>, and the "consumer side", which waits	436	eventually calls C<< -> send >>, and the "consumer side", which waits
350	for the send to occur.	437	for the send to occur.
351		438
352	Example:	439	Example: wait for a timer.
353		440
354	# wait till the result is ready	441	# wait till the result is ready
355	my $result_ready = AnyEvent->condvar;	442	my $result_ready = AnyEvent->condvar;
356		443
357	# do something such as adding a timer	444	# do something such as adding a timer
…		…
365		452
366	# this "blocks" (while handling events) till the callback	453	# this "blocks" (while handling events) till the callback
367	# calls send	454	# calls send
368	$result_ready->recv;	455	$result_ready->recv;
369		456
		457	Example: wait for a timer, but take advantage of the fact that
		458	condition variables are also code references.
		459
		460	my $done = AnyEvent->condvar;
		461	my $delay = AnyEvent->timer (after => 5, cb => $done);
		462	$done->recv;
		463
		464	Example: Imagine an API that returns a condvar and doesn't support
		465	callbacks. This is how you make a synchronous call, for example from
		466	the main program:
		467
		468	use AnyEvent::CouchDB;
		469
		470	...
		471
		472	my @info = $couchdb->info->recv;
		473
		474	And this is how you would just ste a callback to be called whenever the
		475	results are available:
		476
		477	$couchdb->info->cb (sub {
		478	my @info = $_[0]->recv;
		479	});
		480
370	=head3 METHODS FOR PRODUCERS	481	=head3 METHODS FOR PRODUCERS
371		482
372	These methods should only be used by the producing side, i.e. the	483	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	484	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	485	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	496	If a callback has been set on the condition variable, it is called
386	immediately from within send.	497	immediately from within send.
387		498
388	Any arguments passed to the C<send> call will be returned by all	499	Any arguments passed to the C<send> call will be returned by all
389	future C<< ->recv >> calls.	500	future C<< ->recv >> calls.
		501
		502	Condition variables are overloaded so one can call them directly
		503	(as a code reference). Calling them directly is the same as calling
		504	C<send>. Note, however, that many C-based event loops do not handle
		505	overloading, so as tempting as it may be, passing a condition variable
		506	instead of a callback does not work. Both the pure perl and EV loops
		507	support overloading, however, as well as all functions that use perl to
		508	invoke a callback (as in L<AnyEvent::Socket> and L<AnyEvent::DNS> for
		509	example).
390		510
391	=item $cv->croak ($error)	511	=item $cv->croak ($error)
392		512
393	Similar to send, but causes all call's to C<< ->recv >> to invoke	513	Similar to send, but causes all call's to C<< ->recv >> to invoke
394	C<Carp::croak> with the given error message/object/scalar.	514	C<Carp::croak> with the given error message/object/scalar.
…		…
498	=item $bool = $cv->ready	618	=item $bool = $cv->ready
499		619
500	Returns true when the condition is "true", i.e. whether C<send> or	620	Returns true when the condition is "true", i.e. whether C<send> or
501	C<croak> have been called.	621	C<croak> have been called.
502		622
503	=item $cb = $cv->cb ([new callback])	623	=item $cb = $cv->cb ($cb->($cv))
504		624
505	This is a mutator function that returns the callback set and optionally	625	This is a mutator function that returns the callback set and optionally
506	replaces it before doing so.	626	replaces it before doing so.
507		627
508	The callback will be called when the condition becomes "true", i.e. when	628	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	629	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.	630	variable itself. Calling C<recv> inside the callback or at any later time
		631	is guaranteed not to block.
511		632
512	=back	633	=back
513		634
514	=head1 GLOBAL VARIABLES AND FUNCTIONS	635	=head1 GLOBAL VARIABLES AND FUNCTIONS
515		636
…		…
601		722
602	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	723	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	724	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.	725	decide which implementation to chose if some module relies on it.
605		726
606	If the main program relies on a specific event model. For example, in	727	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	728	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	729	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	730	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	731	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	732	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.	733	might chose the wrong one unless you load the correct one yourself.
613		734
614	You can chose to use a rather inefficient pure-perl implementation by	735	You can chose to use a pure-perl implementation by loading the
615	loading the C<AnyEvent::Impl::Perl> module, which gives you similar	736	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour
616	behaviour everywhere, but letting AnyEvent chose is generally better.	737	everywhere, but letting AnyEvent chose the model is generally better.
		738
		739	=head2 MAINLOOP EMULATION
		740
		741	Sometimes (often for short test scripts, or even standalone programs who
		742	only want to use AnyEvent), you do not want to run a specific event loop.
		743
		744	In that case, you can use a condition variable like this:
		745
		746	AnyEvent->condvar->recv;
		747
		748	This has the effect of entering the event loop and looping forever.
		749
		750	Note that usually your program has some exit condition, in which case
		751	it is better to use the "traditional" approach of storing a condition
		752	variable somewhere, waiting for it, and sending it when the program should
		753	exit cleanly.
		754
617		755
618	=head1 OTHER MODULES	756	=head1 OTHER MODULES
619		757
620	The following is a non-exhaustive list of additional modules that use	758	The following is a non-exhaustive list of additional modules that use
621	AnyEvent and can therefore be mixed easily with other AnyEvent modules	759	AnyEvent and can therefore be mixed easily with other AnyEvent modules
…		…
627	=item L<AnyEvent::Util>	765	=item L<AnyEvent::Util>
628		766
629	Contains various utility functions that replace often-used but blocking	767	Contains various utility functions that replace often-used but blocking
630	functions such as C<inet_aton> by event-/callback-based versions.	768	functions such as C<inet_aton> by event-/callback-based versions.
631		769
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>	770	=item L<AnyEvent::Socket>
637		771
638	Provides various utility functions for (internet protocol) sockets,	772	Provides various utility functions for (internet protocol) sockets,
639	addresses and name resolution. Also functions to create non-blocking tcp	773	addresses and name resolution. Also functions to create non-blocking tcp
640	connections or tcp servers, with IPv6 and SRV record support and more.	774	connections or tcp servers, with IPv6 and SRV record support and more.
641		775
		776	=item L<AnyEvent::Handle>
		777
		778	Provide read and write buffers, manages watchers for reads and writes,
		779	supports raw and formatted I/O, I/O queued and fully transparent and
		780	non-blocking SSL/TLS.
		781
		782	=item L<AnyEvent::DNS>
		783
		784	Provides rich asynchronous DNS resolver capabilities.
		785
		786	=item L<AnyEvent::HTTP>
		787
		788	A simple-to-use HTTP library that is capable of making a lot of concurrent
		789	HTTP requests.
		790
642	=item L<AnyEvent::HTTPD>	791	=item L<AnyEvent::HTTPD>
643		792
644	Provides a simple web application server framework.	793	Provides a simple web application server framework.
645		794
646	=item L<AnyEvent::DNS>
647
648	Provides rich asynchronous DNS resolver capabilities.
649
650	=item L<AnyEvent::FastPing>	795	=item L<AnyEvent::FastPing>
651		796
652	The fastest ping in the west.	797	The fastest ping in the west.
		798
		799	=item L<AnyEvent::DBI>
		800
		801	Executes L<DBI> requests asynchronously in a proxy process.
		802
		803	=item L<AnyEvent::AIO>
		804
		805	Truly asynchronous I/O, should be in the toolbox of every event
		806	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
		807	together.
		808
		809	=item L<AnyEvent::BDB>
		810
		811	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
		812	L<BDB> and AnyEvent together.
		813
		814	=item L<AnyEvent::GPSD>
		815
		816	A non-blocking interface to gpsd, a daemon delivering GPS information.
		817
		818	=item L<AnyEvent::IGS>
		819
		820	A non-blocking interface to the Internet Go Server protocol (used by
		821	L<App::IGS>).
653		822
654	=item L<Net::IRC3>	823	=item L<Net::IRC3>
655		824
656	AnyEvent based IRC client module family.	825	AnyEvent based IRC client module family.
657		826
…		…
670		839
671	=item L<Coro>	840	=item L<Coro>
672		841
673	Has special support for AnyEvent via L<Coro::AnyEvent>.	842	Has special support for AnyEvent via L<Coro::AnyEvent>.
674		843
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>	844	=item L<IO::Lambda>
687		845
688	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.	846	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
689		847
690	=back	848	=back
…		…
692	=cut	850	=cut
693		851
694	package AnyEvent;	852	package AnyEvent;
695		853
696	no warnings;	854	no warnings;
697	use strict;	855	use strict qw(vars subs);
698		856
699	use Carp;	857	use Carp;
700		858
701	our $VERSION = '4.0';	859	our $VERSION = 4.233;
702	our $MODEL;	860	our $MODEL;
703		861
704	our $AUTOLOAD;	862	our $AUTOLOAD;
705	our @ISA;	863	our @ISA;
706		864
		865	our @REGISTRY;
		866
		867	our $WIN32;
		868
		869	BEGIN {
		870	my $win32 = ! ! ($^O =~ /mswin32/i);
		871	eval "sub WIN32(){ $win32 }";
		872	}
		873
707	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	874	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;
708		875
709	our @REGISTRY;	876	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred
710
711	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2)
712		877
713	{	878	{
714	my $idx;	879	my $idx;
715	$PROTOCOL{$_} = ++$idx	880	$PROTOCOL{$_} = ++$idx
		881	for reverse split /\s,\s/,
716	for split /\s,\s/, $ENV{PERL_ANYEVENT_PROTOCOLS} \|\| "ipv4,ipv6";	882	$ENV{PERL_ANYEVENT_PROTOCOLS} \|\| "ipv4,ipv6";
717	}	883	}
718		884
719	my @models = (	885	my @models = (
720	[EV:: => AnyEvent::Impl::EV::],	886	[EV:: => AnyEvent::Impl::EV::],
721	[Event:: => AnyEvent::Impl::Event::],	887	[Event:: => AnyEvent::Impl::Event::],
722	[Tk:: => AnyEvent::Impl::Tk::],
723	[Wx:: => AnyEvent::Impl::POE::],
724	[Prima:: => AnyEvent::Impl::POE::],
725	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	888	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
726	# everything below here will not be autoprobed as the pureperl backend should work everywhere	889	# everything below here will not be autoprobed
727	[Glib:: => AnyEvent::Impl::Glib::],	890	# as the pureperl backend should work everywhere
		891	# and is usually faster
		892	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
		893	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
728	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	894	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
729	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	895	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
730	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	896	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
		897	[Wx:: => AnyEvent::Impl::POE::],
		898	[Prima:: => AnyEvent::Impl::POE::],
731	);	899	);
732		900
733	our %method = map +($_ => 1), qw(io timer signal child condvar one_event DESTROY);	901	our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY);
734		902
735	our @post_detect;	903	our @post_detect;
736		904
737	sub post_detect(&) {	905	sub post_detect(&) {
738	my ($cb) = @_;	906	my ($cb) = @_;
…		…
755	}	923	}
756		924
757	sub detect() {	925	sub detect() {
758	unless ($MODEL) {	926	unless ($MODEL) {
759	no strict 'refs';	927	no strict 'refs';
		928	local $SIG{__DIE__};
760		929
761	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	930	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
762	my $model = "AnyEvent::Impl::$1";	931	my $model = "AnyEvent::Impl::$1";
763	if (eval "require $model") {	932	if (eval "require $model") {
764	$MODEL = $model;	933	$MODEL = $model;
…		…
798	$MODEL	967	$MODEL
799	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";	968	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";
800	}	969	}
801	}	970	}
802		971
		972	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		973
803	unshift @ISA, $MODEL;	974	unshift @ISA, $MODEL;
804	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	975
		976	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
805		977
806	(shift @post_detect)->() while @post_detect;	978	(shift @post_detect)->() while @post_detect;
807	}	979	}
808		980
809	$MODEL	981	$MODEL
…		…
819		991
820	my $class = shift;	992	my $class = shift;
821	$class->$func (@_);	993	$class->$func (@_);
822	}	994	}
823		995
		996	# utility function to dup a filehandle. this is used by many backends
		997	# to support binding more than one watcher per filehandle (they usually
		998	# allow only one watcher per fd, so we dup it to get a different one).
		999	sub _dupfh($$$$) {
		1000	my ($poll, $fh, $r, $w) = @_;
		1001
		1002	require Fcntl;
		1003
		1004	# cygwin requires the fh mode to be matching, unix doesn't
		1005	my ($rw, $mode) = $poll eq "r" ? ($r, "<")
		1006	: $poll eq "w" ? ($w, ">")
		1007	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
		1008
		1009	open my $fh2, "$mode&" . fileno $fh
		1010	or die "cannot dup() filehandle: $!";
		1011
		1012	# we assume CLOEXEC is already set by perl in all important cases
		1013
		1014	($fh2, $rw)
		1015	}
		1016
824	package AnyEvent::Base;	1017	package AnyEvent::Base;
		1018
		1019	# default implementation for now and time
		1020
		1021	BEGIN {
		1022	if (eval "use Time::HiRes (); time (); 1") {
		1023	*_time = \&Time::HiRes::time;
		1024	# if (eval "use POSIX (); (POSIX::times())...
		1025	} else {
		1026	*_time = \&CORE::time; # epic fail
		1027	}
		1028	}
		1029
		1030	sub time { _time }
		1031	sub now { _time }
825		1032
826	# default implementation for ->condvar	1033	# default implementation for ->condvar
827		1034
828	sub condvar {	1035	sub condvar {
829	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::	1036	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::
…		…
850	sub AnyEvent::Base::Signal::DESTROY {	1057	sub AnyEvent::Base::Signal::DESTROY {
851	my ($signal, $cb) = @{$_[0]};	1058	my ($signal, $cb) = @{$_[0]};
852		1059
853	delete $SIG_CB{$signal}{$cb};	1060	delete $SIG_CB{$signal}{$cb};
854		1061
855	$SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} };	1062	delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
856	}	1063	}
857		1064
858	# default implementation for ->child	1065	# default implementation for ->child
859		1066
860	our %PID_CB;	1067	our %PID_CB;
…		…
887	or Carp::croak "required option 'pid' is missing";	1094	or Carp::croak "required option 'pid' is missing";
888		1095
889	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1096	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
890		1097
891	unless ($WNOHANG) {	1098	unless ($WNOHANG) {
892	$WNOHANG = eval { require POSIX; &POSIX::WNOHANG } \|\| 1;	1099	$WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;
893	}	1100	}
894		1101
895	unless ($CHLD_W) {	1102	unless ($CHLD_W) {
896	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1103	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
897	# child could be a zombie already, so make at least one round	1104	# child could be a zombie already, so make at least one round
…		…
914		1121
915	our @ISA = AnyEvent::CondVar::Base::;	1122	our @ISA = AnyEvent::CondVar::Base::;
916		1123
917	package AnyEvent::CondVar::Base;	1124	package AnyEvent::CondVar::Base;
918		1125
		1126	use overload
		1127	'&{}' => sub { my $self = shift; sub { $self->send (@_) } },
		1128	fallback => 1;
		1129
919	sub _send {	1130	sub _send {
920	# nop	1131	# nop
921	}	1132	}
922		1133
923	sub send {	1134	sub send {
…		…
963	}	1174	}
964		1175
965	# undocumented/compatibility with pre-3.4	1176	# undocumented/compatibility with pre-3.4
966	*broadcast = \&send;	1177	*broadcast = \&send;
967	*wait = \&_wait;	1178	*wait = \&_wait;
		1179
		1180	=head1 ERROR AND EXCEPTION HANDLING
		1181
		1182	In general, AnyEvent does not do any error handling - it relies on the
		1183	caller to do that if required. The L<AnyEvent::Strict> module (see also
		1184	the C<PERL_ANYEVENT_STRICT> environment variable, below) provides strict
		1185	checking of all AnyEvent methods, however, which is highly useful during
		1186	development.
		1187
		1188	As for exception handling (i.e. runtime errors and exceptions thrown while
		1189	executing a callback), this is not only highly event-loop specific, but
		1190	also not in any way wrapped by this module, as this is the job of the main
		1191	program.
		1192
		1193	The pure perl event loop simply re-throws the exception (usually
		1194	within C<< condvar->recv >>), the L<Event> and L<EV> modules call C<<
		1195	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
		1196	so on.
		1197
		1198	=head1 ENVIRONMENT VARIABLES
		1199
		1200	The following environment variables are used by this module or its
		1201	submodules:
		1202
		1203	=over 4
		1204
		1205	=item C<PERL_ANYEVENT_VERBOSE>
		1206
		1207	By default, AnyEvent will be completely silent except in fatal
		1208	conditions. You can set this environment variable to make AnyEvent more
		1209	talkative.
		1210
		1211	When set to C<1> or higher, causes AnyEvent to warn about unexpected
		1212	conditions, such as not being able to load the event model specified by
		1213	C<PERL_ANYEVENT_MODEL>.
		1214
		1215	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
		1216	model it chooses.
		1217
		1218	=item C<PERL_ANYEVENT_STRICT>
		1219
		1220	AnyEvent does not do much argument checking by default, as thorough
		1221	argument checking is very costly. Setting this variable to a true value
		1222	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
		1223	check the arguments passed to most method calls. If it finds any problems
		1224	it will croak.
		1225
		1226	In other words, enables "strict" mode.
		1227
		1228	Unlike C<use strict>, it is definitely recommended ot keep it off in
		1229	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while
		1230	developing programs can be very useful, however.
		1231
		1232	=item C<PERL_ANYEVENT_MODEL>
		1233
		1234	This can be used to specify the event model to be used by AnyEvent, before
		1235	auto detection and -probing kicks in. It must be a string consisting
		1236	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
		1237	and the resulting module name is loaded and if the load was successful,
		1238	used as event model. If it fails to load AnyEvent will proceed with
		1239	auto detection and -probing.
		1240
		1241	This functionality might change in future versions.
		1242
		1243	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
		1244	could start your program like this:
		1245
		1246	PERL_ANYEVENT_MODEL=Perl perl ...
		1247
		1248	=item C<PERL_ANYEVENT_PROTOCOLS>
		1249
		1250	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
		1251	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
		1252	of auto probing).
		1253
		1254	Must be set to a comma-separated list of protocols or address families,
		1255	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
		1256	used, and preference will be given to protocols mentioned earlier in the
		1257	list.
		1258
		1259	This variable can effectively be used for denial-of-service attacks
		1260	against local programs (e.g. when setuid), although the impact is likely
		1261	small, as the program has to handle connection errors already-
		1262
		1263	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
		1264	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
		1265	- only support IPv4, never try to resolve or contact IPv6
		1266	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
		1267	IPv6, but prefer IPv6 over IPv4.
		1268
		1269	=item C<PERL_ANYEVENT_EDNS0>
		1270
		1271	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
		1272	for DNS. This extension is generally useful to reduce DNS traffic, but
		1273	some (broken) firewalls drop such DNS packets, which is why it is off by
		1274	default.
		1275
		1276	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
		1277	EDNS0 in its DNS requests.
		1278
		1279	=item C<PERL_ANYEVENT_MAX_FORKS>
		1280
		1281	The maximum number of child processes that C<AnyEvent::Util::fork_call>
		1282	will create in parallel.
		1283
		1284	=back
968		1285
969	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1286	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
970		1287
971	This is an advanced topic that you do not normally need to use AnyEvent in	1288	This is an advanced topic that you do not normally need to use AnyEvent in
972	a module. This section is only of use to event loop authors who want to	1289	a module. This section is only of use to event loop authors who want to
…		…
1006		1323
1007	I<rxvt-unicode> also cheats a bit by not providing blocking access to	1324	I<rxvt-unicode> also cheats a bit by not providing blocking access to
1008	condition variables: code blocking while waiting for a condition will	1325	condition variables: code blocking while waiting for a condition will
1009	C<die>. This still works with most modules/usages, and blocking calls must	1326	C<die>. This still works with most modules/usages, and blocking calls must
1010	not be done in an interactive application, so it makes sense.	1327	not be done in an interactive application, so it makes sense.
1011
1012	=head1 ENVIRONMENT VARIABLES
1013
1014	The following environment variables are used by this module:
1015
1016	=over 4
1017
1018	=item C<PERL_ANYEVENT_VERBOSE>
1019
1020	By default, AnyEvent will be completely silent except in fatal
1021	conditions. You can set this environment variable to make AnyEvent more
1022	talkative.
1023
1024	When set to C<1> or higher, causes AnyEvent to warn about unexpected
1025	conditions, such as not being able to load the event model specified by
1026	C<PERL_ANYEVENT_MODEL>.
1027
1028	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1029	model it chooses.
1030
1031	=item C<PERL_ANYEVENT_MODEL>
1032
1033	This can be used to specify the event model to be used by AnyEvent, before
1034	auto detection and -probing kicks in. It must be a string consisting
1035	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,
1037	used as event model. If it fails to load AnyEvent will proceed with
1038	auto detection and -probing.
1039
1040	This functionality might change in future versions.
1041
1042	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
1043	could start your program like this:
1044
1045	PERL_ANYEVENT_MODEL=Perl perl ...
1046
1047	=item C<PERL_ANYEVENT_PROTOCOLS>
1048
1049	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
1051	of auto probing).
1052
1053	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
1055	used, and preference will be given to protocols mentioned earlier in the
1056	list.
1057
1058	This variable can effectively be used for denial-of-service attacks
1059	against local programs (e.g. when setuid), although the impact is likely
1060	small, as the program has to handle connection errors already-
1061
1062	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>
1064	- only support IPv4, never try to resolve or contact IPv6
1065	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1066	IPv6, but prefer IPv6 over IPv4.
1067
1068	=item C<PERL_ANYEVENT_EDNS0>
1069
1070	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
1072	some (broken) firewalls drop such DNS packets, which is why it is off by
1073	default.
1074
1075	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1076	EDNS0 in its DNS requests.
1077
1078	=back
1079		1328
1080	=head1 EXAMPLE PROGRAM	1329	=head1 EXAMPLE PROGRAM
1081		1330
1082	The following program uses an I/O watcher to read data from STDIN, a timer	1331	The following program uses an I/O watcher to read data from STDIN, a timer
1083	to display a message once per second, and a condition variable to quit the	1332	to display a message once per second, and a condition variable to quit the
…		…
1520	specified in the variable.	1769	specified in the variable.
1521		1770
1522	You can make AnyEvent completely ignore this variable by deleting it	1771	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:	1772	before the first watcher gets created, e.g. with a C<BEGIN> block:
1524		1773
1525	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }	1774	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }
1526		1775
1527	use AnyEvent;	1776	use AnyEvent;
1528		1777
1529	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can	1778	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	1779	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).	1780	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
		1781	$ENV{PERL_ANYEGENT_STRICT}.
		1782
		1783
		1784	=head1 BUGS
		1785
		1786	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
		1787	to work around. If you suffer from memleaks, first upgrade to Perl 5.10
		1788	and check wether the leaks still show up. (Perl 5.10.0 has other annoying
		1789	mamleaks, such as leaking on C<map> and C<grep> but it is usually not as
		1790	pronounced).
1532		1791
1533		1792
1534	=head1 SEE ALSO	1793	=head1 SEE ALSO
1535		1794
1536	Utility functions: L<AnyEvent::Util>.	1795	Utility functions: L<AnyEvent::Util>.
…		…
1553	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.	1812	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.
1554		1813
1555		1814
1556	=head1 AUTHOR	1815	=head1 AUTHOR
1557		1816
1558	Marc Lehmann <schmorp@schmorp.de>	1817	Marc Lehmann <schmorp@schmorp.de>
1559	http://home.schmorp.de/	1818	http://home.schmorp.de/
1560		1819
1561	=cut	1820	=cut
1562		1821
1563	1	1822	1
1564		1823

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.130 by root, Sat May 24 17:21:50 2008 UTC vs. Revision 1.180 by root, Sat Sep 6 07:00:45 2008 UTC

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Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.130 by root, Sat May 24 17:21:50 2008 UTC vs.
Revision 1.180 by root, Sat Sep 6 07:00:45 2008 UTC