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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.132 by root, Sun May 25 01:05:27 2008 UTC vs.
Revision 1.179 by root, Thu Sep 4 10:58:58 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 (or calling the condition variable as if it	401	by calling the C<send> method (or calling the condition variable as if it
317	were a callback).	402	were a callback, read about the caveats in the description for the C<<
		403	->send >> method).
318		404
319	Condition variables are similar to callbacks, except that you can	405	Condition variables are similar to callbacks, except that you can
320	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
321	in time where multiple outstanding events have been processed. And yet	407	in time where multiple outstanding events have been processed. And yet
322	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
…		…
373		459
374	my $done = AnyEvent->condvar;	460	my $done = AnyEvent->condvar;
375	my $delay = AnyEvent->timer (after => 5, cb => $done);	461	my $delay = AnyEvent->timer (after => 5, cb => $done);
376	$done->recv;	462	$done->recv;
377		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
378	=head3 METHODS FOR PRODUCERS	481	=head3 METHODS FOR PRODUCERS
379		482
380	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
381	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
382	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
…		…
394	immediately from within send.	497	immediately from within send.
395		498
396	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
397	future C<< ->recv >> calls.	500	future C<< ->recv >> calls.
398		501
399	Condition variables are overloaded so one can call them directly (as a	502	Condition variables are overloaded so one can call them directly
400	code reference). Calling them directly is the same as calling C<send>.	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).
401		510
402	=item $cv->croak ($error)	511	=item $cv->croak ($error)
403		512
404	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
405	C<Carp::croak> with the given error message/object/scalar.	514	C<Carp::croak> with the given error message/object/scalar.
…		…
509	=item $bool = $cv->ready	618	=item $bool = $cv->ready
510		619
511	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
512	C<croak> have been called.	621	C<croak> have been called.
513		622
514	=item $cb = $cv->cb ([new callback])	623	=item $cb = $cv->cb ($cb->($cv))
515		624
516	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
517	replaces it before doing so.	626	replaces it before doing so.
518		627
519	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
520	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
521	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.
522		632
523	=back	633	=back
524		634
525	=head1 GLOBAL VARIABLES AND FUNCTIONS	635	=head1 GLOBAL VARIABLES AND FUNCTIONS
526		636
…		…
612		722
613	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
614	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
615	decide which implementation to chose if some module relies on it.	725	decide which implementation to chose if some module relies on it.
616		726
617	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
618	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
619	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
620	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
621	modules might create watchers when they are loaded, and AnyEvent will	731	modules might create watchers when they are loaded, and AnyEvent will
622	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
623	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.
624		734
625	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
626	loading the C<AnyEvent::Impl::Perl> module, which gives you similar	736	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour
627	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
628		755
629	=head1 OTHER MODULES	756	=head1 OTHER MODULES
630		757
631	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
632	AnyEvent and can therefore be mixed easily with other AnyEvent modules	759	AnyEvent and can therefore be mixed easily with other AnyEvent modules
…		…
638	=item L<AnyEvent::Util>	765	=item L<AnyEvent::Util>
639		766
640	Contains various utility functions that replace often-used but blocking	767	Contains various utility functions that replace often-used but blocking
641	functions such as C<inet_aton> by event-/callback-based versions.	768	functions such as C<inet_aton> by event-/callback-based versions.
642		769
643	=item L<AnyEvent::Handle>
644
645	Provide read and write buffers and manages watchers for reads and writes.
646
647	=item L<AnyEvent::Socket>	770	=item L<AnyEvent::Socket>
648		771
649	Provides various utility functions for (internet protocol) sockets,	772	Provides various utility functions for (internet protocol) sockets,
650	addresses and name resolution. Also functions to create non-blocking tcp	773	addresses and name resolution. Also functions to create non-blocking tcp
651	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.
652		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
653	=item L<AnyEvent::HTTPD>	791	=item L<AnyEvent::HTTPD>
654		792
655	Provides a simple web application server framework.	793	Provides a simple web application server framework.
656		794
657	=item L<AnyEvent::DNS>
658
659	Provides rich asynchronous DNS resolver capabilities.
660
661	=item L<AnyEvent::FastPing>	795	=item L<AnyEvent::FastPing>
662		796
663	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>).
664		822
665	=item L<Net::IRC3>	823	=item L<Net::IRC3>
666		824
667	AnyEvent based IRC client module family.	825	AnyEvent based IRC client module family.
668		826
…		…
681		839
682	=item L<Coro>	840	=item L<Coro>
683		841
684	Has special support for AnyEvent via L<Coro::AnyEvent>.	842	Has special support for AnyEvent via L<Coro::AnyEvent>.
685		843
686	=item L<AnyEvent::AIO>, L<IO::AIO>
687
688	Truly asynchronous I/O, should be in the toolbox of every event
689	programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent
690	together.
691
692	=item L<AnyEvent::BDB>, L<BDB>
693
694	Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses
695	IO::AIO and AnyEvent together.
696
697	=item L<IO::Lambda>	844	=item L<IO::Lambda>
698		845
699	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.
700		847
701	=back	848	=back
…		…
707	no warnings;	854	no warnings;
708	use strict;	855	use strict;
709		856
710	use Carp;	857	use Carp;
711		858
712	our $VERSION = '4.03';	859	our $VERSION = 4.233;
713	our $MODEL;	860	our $MODEL;
714		861
715	our $AUTOLOAD;	862	our $AUTOLOAD;
716	our @ISA;	863	our @ISA;
717		864
		865	our @REGISTRY;
		866
		867	our $WIN32;
		868
		869	BEGIN {
		870	my $win32 = ! ! ($^O =~ /mswin32/i);
		871	eval "sub WIN32(){ $win32 }";
		872	}
		873
718	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	874	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;
719		875
720	our @REGISTRY;	876	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred
721
722	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2)
723		877
724	{	878	{
725	my $idx;	879	my $idx;
726	$PROTOCOL{$_} = ++$idx	880	$PROTOCOL{$_} = ++$idx
		881	for reverse split /\s,\s/,
727	for split /\s,\s/, $ENV{PERL_ANYEVENT_PROTOCOLS} \|\| "ipv4,ipv6";	882	$ENV{PERL_ANYEVENT_PROTOCOLS} \|\| "ipv4,ipv6";
728	}	883	}
729		884
730	my @models = (	885	my @models = (
731	[EV:: => AnyEvent::Impl::EV::],	886	[EV:: => AnyEvent::Impl::EV::],
732	[Event:: => AnyEvent::Impl::Event::],	887	[Event:: => AnyEvent::Impl::Event::],
733	[Tk:: => AnyEvent::Impl::Tk::],
734	[Wx:: => AnyEvent::Impl::POE::],
735	[Prima:: => AnyEvent::Impl::POE::],
736	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],	888	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl::],
737	# everything below here will not be autoprobed as the pureperl backend should work everywhere	889	# everything below here will not be autoprobed
738	[Glib:: => AnyEvent::Impl::Glib::],	890	# as the pureperl backend should work everywhere
		891	# and is usually faster
		892	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
		893	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
739	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	894	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
740	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	895	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
741	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	896	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
		897	[Wx:: => AnyEvent::Impl::POE::],
		898	[Prima:: => AnyEvent::Impl::POE::],
742	);	899	);
743		900
744	our %method = map +($_ => 1), qw(io timer signal child condvar one_event DESTROY);	901	our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY);
745		902
746	our @post_detect;	903	our @post_detect;
747		904
748	sub post_detect(&) {	905	sub post_detect(&) {
749	my ($cb) = @_;	906	my ($cb) = @_;
…		…
766	}	923	}
767		924
768	sub detect() {	925	sub detect() {
769	unless ($MODEL) {	926	unless ($MODEL) {
770	no strict 'refs';	927	no strict 'refs';
		928	local $SIG{__DIE__};
771		929
772	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	930	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
773	my $model = "AnyEvent::Impl::$1";	931	my $model = "AnyEvent::Impl::$1";
774	if (eval "require $model") {	932	if (eval "require $model") {
775	$MODEL = $model;	933	$MODEL = $model;
…		…
809	$MODEL	967	$MODEL
810	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";	968	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";
811	}	969	}
812	}	970	}
813		971
		972	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		973
814	unshift @ISA, $MODEL;	974	unshift @ISA, $MODEL;
815	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	975
		976	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
816		977
817	(shift @post_detect)->() while @post_detect;	978	(shift @post_detect)->() while @post_detect;
818	}	979	}
819		980
820	$MODEL	981	$MODEL
…		…
830		991
831	my $class = shift;	992	my $class = shift;
832	$class->$func (@_);	993	$class->$func (@_);
833	}	994	}
834		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
835	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 }
836		1032
837	# default implementation for ->condvar	1033	# default implementation for ->condvar
838		1034
839	sub condvar {	1035	sub condvar {
840	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::	1036	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::
…		…
861	sub AnyEvent::Base::Signal::DESTROY {	1057	sub AnyEvent::Base::Signal::DESTROY {
862	my ($signal, $cb) = @{$_[0]};	1058	my ($signal, $cb) = @{$_[0]};
863		1059
864	delete $SIG_CB{$signal}{$cb};	1060	delete $SIG_CB{$signal}{$cb};
865		1061
866	$SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} };	1062	delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
867	}	1063	}
868		1064
869	# default implementation for ->child	1065	# default implementation for ->child
870		1066
871	our %PID_CB;	1067	our %PID_CB;
…		…
898	or Carp::croak "required option 'pid' is missing";	1094	or Carp::croak "required option 'pid' is missing";
899		1095
900	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1096	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
901		1097
902	unless ($WNOHANG) {	1098	unless ($WNOHANG) {
903	$WNOHANG = eval { require POSIX; &POSIX::WNOHANG } \|\| 1;	1099	$WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;
904	}	1100	}
905		1101
906	unless ($CHLD_W) {	1102	unless ($CHLD_W) {
907	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1103	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
908	# 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
…		…
1041	C<PERL_ANYEVENT_MODEL>.	1237	C<PERL_ANYEVENT_MODEL>.
1042		1238
1043	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	1239	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1044	model it chooses.	1240	model it chooses.
1045		1241
		1242	=item C<PERL_ANYEVENT_STRICT>
		1243
		1244	AnyEvent does not do much argument checking by default, as thorough
		1245	argument checking is very costly. Setting this variable to a true value
		1246	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
		1247	check the arguments passed to most method calls. If it finds any problems
		1248	it will croak.
		1249
		1250	In other words, enables "strict" mode.
		1251
		1252	Unlike C<use strict> it is definitely recommended ot keep it off in
		1253	production.
		1254
1046	=item C<PERL_ANYEVENT_MODEL>	1255	=item C<PERL_ANYEVENT_MODEL>
1047		1256
1048	This can be used to specify the event model to be used by AnyEvent, before	1257	This can be used to specify the event model to be used by AnyEvent, before
1049	auto detection and -probing kicks in. It must be a string consisting	1258	auto detection and -probing kicks in. It must be a string consisting
1050	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	1259	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
…		…
1055	This functionality might change in future versions.	1264	This functionality might change in future versions.
1056		1265
1057	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	1266	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
1058	could start your program like this:	1267	could start your program like this:
1059		1268
1060	PERL_ANYEVENT_MODEL=Perl perl ...	1269	PERL_ANYEVENT_MODEL=Perl perl ...
1061		1270
1062	=item C<PERL_ANYEVENT_PROTOCOLS>	1271	=item C<PERL_ANYEVENT_PROTOCOLS>
1063		1272
1064	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences	1273	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
1065	for IPv4 or IPv6. The default is unspecified (and might change, or be the result	1274	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
…		…
1087	some (broken) firewalls drop such DNS packets, which is why it is off by	1296	some (broken) firewalls drop such DNS packets, which is why it is off by
1088	default.	1297	default.
1089		1298
1090	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce	1299	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1091	EDNS0 in its DNS requests.	1300	EDNS0 in its DNS requests.
		1301
		1302	=item C<PERL_ANYEVENT_MAX_FORKS>
		1303
		1304	The maximum number of child processes that C<AnyEvent::Util::fork_call>
		1305	will create in parallel.
1092		1306
1093	=back	1307	=back
1094		1308
1095	=head1 EXAMPLE PROGRAM	1309	=head1 EXAMPLE PROGRAM
1096		1310
…		…
1535	specified in the variable.	1749	specified in the variable.
1536		1750
1537	You can make AnyEvent completely ignore this variable by deleting it	1751	You can make AnyEvent completely ignore this variable by deleting it
1538	before the first watcher gets created, e.g. with a C<BEGIN> block:	1752	before the first watcher gets created, e.g. with a C<BEGIN> block:
1539		1753
1540	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }	1754	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }
1541		1755
1542	use AnyEvent;	1756	use AnyEvent;
1543		1757
1544	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can	1758	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1545	be used to probe what backend is used and gain other information (which is	1759	be used to probe what backend is used and gain other information (which is
1546	probably even less useful to an attacker than PERL_ANYEVENT_MODEL).	1760	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
		1761	$ENV{PERL_ANYEGENT_STRICT}.
		1762
		1763
		1764	=head1 BUGS
		1765
		1766	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
		1767	to work around. If you suffer from memleaks, first upgrade to Perl 5.10
		1768	and check wether the leaks still show up. (Perl 5.10.0 has other annoying
		1769	mamleaks, such as leaking on C<map> and C<grep> but it is usually not as
		1770	pronounced).
1547		1771
1548		1772
1549	=head1 SEE ALSO	1773	=head1 SEE ALSO
1550		1774
1551	Utility functions: L<AnyEvent::Util>.	1775	Utility functions: L<AnyEvent::Util>.
…		…
1568	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.	1792	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.
1569		1793
1570		1794
1571	=head1 AUTHOR	1795	=head1 AUTHOR
1572		1796
1573	Marc Lehmann <schmorp@schmorp.de>	1797	Marc Lehmann <schmorp@schmorp.de>
1574	http://home.schmorp.de/	1798	http://home.schmorp.de/
1575		1799
1576	=cut	1800	=cut
1577		1801
1578	1	1802	1
1579		1803

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.132 by root, Sun May 25 01:05:27 2008 UTC vs. Revision 1.179 by root, Thu Sep 4 10:58:58 2008 UTC

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Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.132 by root, Sun May 25 01:05:27 2008 UTC vs.
Revision 1.179 by root, Thu Sep 4 10:58:58 2008 UTC