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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.320 by root, Mon Apr 12 02:50:31 2010 UTC vs.
Revision 1.353 by root, Thu Aug 11 20:56:07 2011 UTC

…		…
7		7
8	=head1 SYNOPSIS	8	=head1 SYNOPSIS
9		9
10	use AnyEvent;	10	use AnyEvent;
11		11
12	# if you prefer function calls, look at the L<AE> manpage for	12	# if you prefer function calls, look at the AE manpage for
13	# an alternative API.	13	# an alternative API.
14		14
15	# file handle or descriptor readable	15	# file handle or descriptor readable
16	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });	16	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
17		17
18	# one-shot or repeating timers	18	# one-shot or repeating timers
19	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });	19	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
20	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...	20	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...);
21		21
22	print AnyEvent->now; # prints current event loop time	22	print AnyEvent->now; # prints current event loop time
23	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.	23	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
24		24
25	# POSIX signal	25	# POSIX signal
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46	in a tutorial or some gentle introduction, have a look at the	46	in a tutorial or some gentle introduction, have a look at the
47	L<AnyEvent::Intro> manpage.	47	L<AnyEvent::Intro> manpage.
48		48
49	=head1 SUPPORT	49	=head1 SUPPORT
50		50
		51	An FAQ document is available as L<AnyEvent::FAQ>.
		52
51	There is a mailinglist for discussing all things AnyEvent, and an IRC	53	There also is a mailinglist for discussing all things AnyEvent, and an IRC
52	channel, too.	54	channel, too.
53		55
54	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software	56	See the AnyEvent project page at the B<Schmorpforge Ta-Sa Software
55	Repository>, at L<http://anyevent.schmorp.de>, for more info.	57	Repository>, at L<http://anyevent.schmorp.de>, for more info.
56		58
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76	module users into the same thing by forcing them to use the same event	78	module users into the same thing by forcing them to use the same event
77	model you use.	79	model you use.
78		80
79	For modules like POE or IO::Async (which is a total misnomer as it is	81	For modules like POE or IO::Async (which is a total misnomer as it is
80	actually doing all I/O I<synchronously>...), using them in your module is	82	actually doing all I/O I<synchronously>...), using them in your module is
81	like joining a cult: After you joined, you are dependent on them and you	83	like joining a cult: After you join, you are dependent on them and you
82	cannot use anything else, as they are simply incompatible to everything	84	cannot use anything else, as they are simply incompatible to everything
83	that isn't them. What's worse, all the potential users of your	85	that isn't them. What's worse, all the potential users of your
84	module are I<also> forced to use the same event loop you use.	86	module are I<also> forced to use the same event loop you use.
85		87
86	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	88	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
87	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	89	fine. AnyEvent + Tk works fine etc. etc. but none of these work together
88	with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if	90	with the rest: POE + EV? No go. Tk + Event? No go. Again: if your module
89	your module uses one of those, every user of your module has to use it,	91	uses one of those, every user of your module has to use it, too. But if
90	too. But if your module uses AnyEvent, it works transparently with all	92	your module uses AnyEvent, it works transparently with all event models it
91	event models it supports (including stuff like IO::Async, as long as those	93	supports (including stuff like IO::Async, as long as those use one of the
92	use one of the supported event loops. It is trivial to add new event loops	94	supported event loops. It is easy to add new event loops to AnyEvent, too,
93	to AnyEvent, too, so it is future-proof).	95	so it is future-proof).
94		96
95	In addition to being free of having to use I<the one and only true event	97	In addition to being free of having to use I<the one and only true event
96	model>, AnyEvent also is free of bloat and policy: with POE or similar	98	model>, AnyEvent also is free of bloat and policy: with POE or similar
97	modules, you get an enormous amount of code and strict rules you have to	99	modules, you get an enormous amount of code and strict rules you have to
98	follow. AnyEvent, on the other hand, is lean and up to the point, by only	100	follow. AnyEvent, on the other hand, is lean and to the point, by only
99	offering the functionality that is necessary, in as thin as a wrapper as	101	offering the functionality that is necessary, in as thin as a wrapper as
100	technically possible.	102	technically possible.
101		103
102	Of course, AnyEvent comes with a big (and fully optional!) toolbox	104	Of course, AnyEvent comes with a big (and fully optional!) toolbox
103	of useful functionality, such as an asynchronous DNS resolver, 100%	105	of useful functionality, such as an asynchronous DNS resolver, 100%
…		…
109	useful) and you want to force your users to use the one and only event	111	useful) and you want to force your users to use the one and only event
110	model, you should I<not> use this module.	112	model, you should I<not> use this module.
111		113
112	=head1 DESCRIPTION	114	=head1 DESCRIPTION
113		115
114	L<AnyEvent> provides an identical interface to multiple event loops. This	116	L<AnyEvent> provides a uniform interface to various event loops. This
115	allows module authors to utilise an event loop without forcing module	117	allows module authors to use event loop functionality without forcing
116	users to use the same event loop (as only a single event loop can coexist	118	module users to use a specific event loop implementation (since more
117	peacefully at any one time).	119	than one event loop cannot coexist peacefully).
118		120
119	The interface itself is vaguely similar, but not identical to the L<Event>	121	The interface itself is vaguely similar, but not identical to the L<Event>
120	module.	122	module.
121		123
122	During the first call of any watcher-creation method, the module tries	124	During the first call of any watcher-creation method, the module tries
123	to detect the currently loaded event loop by probing whether one of the	125	to detect the currently loaded event loop by probing whether one of the
124	following modules is already loaded: L<EV>,	126	following modules is already loaded: L<EV>, L<AnyEvent::Loop>,
125	L<Event>, L<Glib>, L<AnyEvent::Impl::Perl>, L<Tk>, L<Event::Lib>, L<Qt>,	127	L<Event>, L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>. The first one
126	L<POE>. The first one found is used. If none are found, the module tries	128	found is used. If none are detected, the module tries to load the first
127	to load these modules (excluding Tk, Event::Lib, Qt and POE as the pure perl	129	four modules in the order given; but note that if L<EV> is not
128	adaptor should always succeed) in the order given. The first one that can	130	available, the pure-perl L<AnyEvent::Loop> should always work, so
129	be successfully loaded will be used. If, after this, still none could be	131	the other two are not normally tried.
130	found, AnyEvent will fall back to a pure-perl event loop, which is not
131	very efficient, but should work everywhere.
132		132
133	Because AnyEvent first checks for modules that are already loaded, loading	133	Because AnyEvent first checks for modules that are already loaded, loading
134	an event model explicitly before first using AnyEvent will likely make	134	an event model explicitly before first using AnyEvent will likely make
135	that model the default. For example:	135	that model the default. For example:
136		136
…		…
138	use AnyEvent;	138	use AnyEvent;
139		139
140	# .. AnyEvent will likely default to Tk	140	# .. AnyEvent will likely default to Tk
141		141
142	The I<likely> means that, if any module loads another event model and	142	The I<likely> means that, if any module loads another event model and
143	starts using it, all bets are off. Maybe you should tell their authors to	143	starts using it, all bets are off - this case should be very rare though,
144	use AnyEvent so their modules work together with others seamlessly...	144	as very few modules hardcode event loops without announcing this very
		145	loudly.
145		146
146	The pure-perl implementation of AnyEvent is called	147	The pure-perl implementation of AnyEvent is called C<AnyEvent::Loop>. Like
147	C<AnyEvent::Impl::Perl>. Like other event modules you can load it	148	other event modules you can load it explicitly and enjoy the high
148	explicitly and enjoy the high availability of that event loop :)	149	availability of that event loop :)
149		150
150	=head1 WATCHERS	151	=head1 WATCHERS
151		152
152	AnyEvent has the central concept of a I<watcher>, which is an object that	153	AnyEvent has the central concept of a I<watcher>, which is an object that
153	stores relevant data for each kind of event you are waiting for, such as	154	stores relevant data for each kind of event you are waiting for, such as
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158	callback when the event occurs (of course, only when the event model	159	callback when the event occurs (of course, only when the event model
159	is in control).	160	is in control).
160		161
161	Note that B<callbacks must not permanently change global variables>	162	Note that B<callbacks must not permanently change global variables>
162	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<	163	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<
163	callbacks must not C<die> >>. The former is good programming practise in	164	callbacks must not C<die> >>. The former is good programming practice in
164	Perl and the latter stems from the fact that exception handling differs	165	Perl and the latter stems from the fact that exception handling differs
165	widely between event loops.	166	widely between event loops.
166		167
167	To disable the watcher you have to destroy it (e.g. by setting the	168	To disable a watcher you have to destroy it (e.g. by setting the
168	variable you store it in to C<undef> or otherwise deleting all references	169	variable you store it in to C<undef> or otherwise deleting all references
169	to it).	170	to it).
170		171
171	All watchers are created by calling a method on the C<AnyEvent> class.	172	All watchers are created by calling a method on the C<AnyEvent> class.
172		173
173	Many watchers either are used with "recursion" (repeating timers for	174	Many watchers either are used with "recursion" (repeating timers for
174	example), or need to refer to their watcher object in other ways.	175	example), or need to refer to their watcher object in other ways.
175		176
176	An any way to achieve that is this pattern:	177	One way to achieve that is this pattern:
177		178
178	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	179	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
179	# you can use $w here, for example to undef it	180	# you can use $w here, for example to undef it
180	undef $w;	181	undef $w;
181	});	182	});
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213		214
214	The I/O watcher might use the underlying file descriptor or a copy of it.	215	The I/O watcher might use the underlying file descriptor or a copy of it.
215	You must not close a file handle as long as any watcher is active on the	216	You must not close a file handle as long as any watcher is active on the
216	underlying file descriptor.	217	underlying file descriptor.
217		218
218	Some event loops issue spurious readyness notifications, so you should	219	Some event loops issue spurious readiness notifications, so you should
219	always use non-blocking calls when reading/writing from/to your file	220	always use non-blocking calls when reading/writing from/to your file
220	handles.	221	handles.
221		222
222	Example: wait for readability of STDIN, then read a line and disable the	223	Example: wait for readability of STDIN, then read a line and disable the
223	watcher.	224	watcher.
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247		248
248	Although the callback might get passed parameters, their value and	249	Although the callback might get passed parameters, their value and
249	presence is undefined and you cannot rely on them. Portable AnyEvent	250	presence is undefined and you cannot rely on them. Portable AnyEvent
250	callbacks cannot use arguments passed to time watcher callbacks.	251	callbacks cannot use arguments passed to time watcher callbacks.
251		252
252	The callback will normally be invoked once only. If you specify another	253	The callback will normally be invoked only once. If you specify another
253	parameter, C<interval>, as a strictly positive number (> 0), then the	254	parameter, C<interval>, as a strictly positive number (> 0), then the
254	callback will be invoked regularly at that interval (in fractional	255	callback will be invoked regularly at that interval (in fractional
255	seconds) after the first invocation. If C<interval> is specified with a	256	seconds) after the first invocation. If C<interval> is specified with a
256	false value, then it is treated as if it were missing.	257	false value, then it is treated as if it were not specified at all.
257		258
258	The callback will be rescheduled before invoking the callback, but no	259	The callback will be rescheduled before invoking the callback, but no
259	attempt is done to avoid timer drift in most backends, so the interval is	260	attempt is made to avoid timer drift in most backends, so the interval is
260	only approximate.	261	only approximate.
261		262
262	Example: fire an event after 7.7 seconds.	263	Example: fire an event after 7.7 seconds.
263		264
264	my $w = AnyEvent->timer (after => 7.7, cb => sub {	265	my $w = AnyEvent->timer (after => 7.7, cb => sub {
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282		283
283	While most event loops expect timers to specified in a relative way, they	284	While most event loops expect timers to specified in a relative way, they
284	use absolute time internally. This makes a difference when your clock	285	use absolute time internally. This makes a difference when your clock
285	"jumps", for example, when ntp decides to set your clock backwards from	286	"jumps", for example, when ntp decides to set your clock backwards from
286	the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to	287	the wrong date of 2014-01-01 to 2008-01-01, a watcher that is supposed to
287	fire "after" a second might actually take six years to finally fire.	288	fire "after a second" might actually take six years to finally fire.
288		289
289	AnyEvent cannot compensate for this. The only event loop that is conscious	290	AnyEvent cannot compensate for this. The only event loop that is conscious
290	about these issues is L<EV>, which offers both relative (ev_timer, based	291	of these issues is L<EV>, which offers both relative (ev_timer, based
291	on true relative time) and absolute (ev_periodic, based on wallclock time)	292	on true relative time) and absolute (ev_periodic, based on wallclock time)
292	timers.	293	timers.
293		294
294	AnyEvent always prefers relative timers, if available, matching the	295	AnyEvent always prefers relative timers, if available, matching the
295	AnyEvent API.	296	AnyEvent API.
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317	I<In almost all cases (in all cases if you don't care), this is the	318	I<In almost all cases (in all cases if you don't care), this is the
318	function to call when you want to know the current time.>	319	function to call when you want to know the current time.>
319		320
320	This function is also often faster then C<< AnyEvent->time >>, and	321	This function is also often faster then C<< AnyEvent->time >>, and
321	thus the preferred method if you want some timestamp (for example,	322	thus the preferred method if you want some timestamp (for example,
322	L<AnyEvent::Handle> uses this to update it's activity timeouts).	323	L<AnyEvent::Handle> uses this to update its activity timeouts).
323		324
324	The rest of this section is only of relevance if you try to be very exact	325	The rest of this section is only of relevance if you try to be very exact
325	with your timing, you can skip it without bad conscience.	326	with your timing; you can skip it without a bad conscience.
326		327
327	For a practical example of when these times differ, consider L<Event::Lib>	328	For a practical example of when these times differ, consider L<Event::Lib>
328	and L<EV> and the following set-up:	329	and L<EV> and the following set-up:
329		330
330	The event loop is running and has just invoked one of your callback at	331	The event loop is running and has just invoked one of your callbacks at
331	time=500 (assume no other callbacks delay processing). In your callback,	332	time=500 (assume no other callbacks delay processing). In your callback,
332	you wait a second by executing C<sleep 1> (blocking the process for a	333	you wait a second by executing C<sleep 1> (blocking the process for a
333	second) and then (at time=501) you create a relative timer that fires	334	second) and then (at time=501) you create a relative timer that fires
334	after three seconds.	335	after three seconds.
335		336
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355	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	356	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
356	account.	357	account.
357		358
358	=item AnyEvent->now_update	359	=item AnyEvent->now_update
359		360
360	Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache	361	Some event loops (such as L<EV> or L<AnyEvent::Loop>) cache the current
361	the current time for each loop iteration (see the discussion of L<<	362	time for each loop iteration (see the discussion of L<< AnyEvent->now >>,
362	AnyEvent->now >>, above).	363	above).
363		364
364	When a callback runs for a long time (or when the process sleeps), then	365	When a callback runs for a long time (or when the process sleeps), then
365	this "current" time will differ substantially from the real time, which	366	this "current" time will differ substantially from the real time, which
366	might affect timers and time-outs.	367	might affect timers and time-outs.
367		368
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428	=head3 Signal Races, Delays and Workarounds	429	=head3 Signal Races, Delays and Workarounds
429		430
430	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching	431	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
431	callbacks to signals in a generic way, which is a pity, as you cannot	432	callbacks to signals in a generic way, which is a pity, as you cannot
432	do race-free signal handling in perl, requiring C libraries for	433	do race-free signal handling in perl, requiring C libraries for
433	this. AnyEvent will try to do it's best, which means in some cases,	434	this. AnyEvent will try to do its best, which means in some cases,
434	signals will be delayed. The maximum time a signal might be delayed is	435	signals will be delayed. The maximum time a signal might be delayed is
435	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This	436	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
436	variable can be changed only before the first signal watcher is created,	437	variable can be changed only before the first signal watcher is created,
437	and should be left alone otherwise. This variable determines how often	438	and should be left alone otherwise. This variable determines how often
438	AnyEvent polls for signals (in case a wake-up was missed). Higher values	439	AnyEvent polls for signals (in case a wake-up was missed). Higher values
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440	saving.	441	saving.
441		442
442	All these problems can be avoided by installing the optional	443	All these problems can be avoided by installing the optional
443	L<Async::Interrupt> module, which works with most event loops. It will not	444	L<Async::Interrupt> module, which works with most event loops. It will not
444	work with inherently broken event loops such as L<Event> or L<Event::Lib>	445	work with inherently broken event loops such as L<Event> or L<Event::Lib>
445	(and not with L<POE> currently, as POE does it's own workaround with	446	(and not with L<POE> currently, as POE does its own workaround with
446	one-second latency). For those, you just have to suffer the delays.	447	one-second latency). For those, you just have to suffer the delays.
447		448
448	=head2 CHILD PROCESS WATCHERS	449	=head2 CHILD PROCESS WATCHERS
449		450
450	$w = AnyEvent->child (pid => <process id>, cb => <callback>);	451	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
451		452
452	You can also watch on a child process exit and catch its exit status.	453	You can also watch for a child process exit and catch its exit status.
453		454
454	The child process is specified by the C<pid> argument (one some backends,	455	The child process is specified by the C<pid> argument (on some backends,
455	using C<0> watches for any child process exit, on others this will	456	using C<0> watches for any child process exit, on others this will
456	croak). The watcher will be triggered only when the child process has	457	croak). The watcher will be triggered only when the child process has
457	finished and an exit status is available, not on any trace events	458	finished and an exit status is available, not on any trace events
458	(stopped/continued).	459	(stopped/continued).
459		460
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481	thing in an AnyEvent program, you I<have> to create at least one	482	thing in an AnyEvent program, you I<have> to create at least one
482	watcher before you C<fork> the child (alternatively, you can call	483	watcher before you C<fork> the child (alternatively, you can call
483	C<AnyEvent::detect>).	484	C<AnyEvent::detect>).
484		485
485	As most event loops do not support waiting for child events, they will be	486	As most event loops do not support waiting for child events, they will be
486	emulated by AnyEvent in most cases, in which the latency and race problems	487	emulated by AnyEvent in most cases, in which case the latency and race
487	mentioned in the description of signal watchers apply.	488	problems mentioned in the description of signal watchers apply.
488		489
489	Example: fork a process and wait for it	490	Example: fork a process and wait for it
490		491
491	my $done = AnyEvent->condvar;	492	my $done = AnyEvent->condvar;
492		493
…		…
506		507
507	=head2 IDLE WATCHERS	508	=head2 IDLE WATCHERS
508		509
509	$w = AnyEvent->idle (cb => <callback>);	510	$w = AnyEvent->idle (cb => <callback>);
510		511
511	Repeatedly invoke the callback after the process becomes idle, until	512	This will repeatedly invoke the callback after the process becomes idle,
512	either the watcher is destroyed or new events have been detected.	513	until either the watcher is destroyed or new events have been detected.
513		514
514	Idle watchers are useful when there is a need to do something, but it	515	Idle watchers are useful when there is a need to do something, but it
515	is not so important (or wise) to do it instantly. The callback will be	516	is not so important (or wise) to do it instantly. The callback will be
516	invoked only when there is "nothing better to do", which is usually	517	invoked only when there is "nothing better to do", which is usually
517	defined as "all outstanding events have been handled and no new events	518	defined as "all outstanding events have been handled and no new events
…		…
556	will actively watch for new events and call your callbacks.	557	will actively watch for new events and call your callbacks.
557		558
558	AnyEvent is slightly different: it expects somebody else to run the event	559	AnyEvent is slightly different: it expects somebody else to run the event
559	loop and will only block when necessary (usually when told by the user).	560	loop and will only block when necessary (usually when told by the user).
560		561
561	The instrument to do that is called a "condition variable", so called	562	The tool to do that is called a "condition variable", so called because
562	because they represent a condition that must become true.	563	they represent a condition that must become true.
563		564
564	Now is probably a good time to look at the examples further below.	565	Now is probably a good time to look at the examples further below.
565		566
566	Condition variables can be created by calling the C<< AnyEvent->condvar	567	Condition variables can be created by calling the C<< AnyEvent->condvar
567	>> method, usually without arguments. The only argument pair allowed is	568	>> method, usually without arguments. The only argument pair allowed is
…		…
572	After creation, the condition variable is "false" until it becomes "true"	573	After creation, the condition variable is "false" until it becomes "true"
573	by calling the C<send> method (or calling the condition variable as if it	574	by calling the C<send> method (or calling the condition variable as if it
574	were a callback, read about the caveats in the description for the C<<	575	were a callback, read about the caveats in the description for the C<<
575	->send >> method).	576	->send >> method).
576		577
577	Condition variables are similar to callbacks, except that you can	578	Since condition variables are the most complex part of the AnyEvent API, here are
578	optionally wait for them. They can also be called merge points - points	579	some different mental models of what they are - pick the ones you can connect to:
579	in time where multiple outstanding events have been processed. And yet	580
580	another way to call them is transactions - each condition variable can be	581	=over 4
581	used to represent a transaction, which finishes at some point and delivers	582
582	a result. And yet some people know them as "futures" - a promise to	583	=item * Condition variables are like callbacks - you can call them (and pass them instead
583	compute/deliver something that you can wait for.	584	of callbacks). Unlike callbacks however, you can also wait for them to be called.
		585
		586	=item * Condition variables are signals - one side can emit or send them,
		587	the other side can wait for them, or install a handler that is called when
		588	the signal fires.
		589
		590	=item * Condition variables are like "Merge Points" - points in your program
		591	where you merge multiple independent results/control flows into one.
		592
		593	=item * Condition variables represent a transaction - functions that start
		594	some kind of transaction can return them, leaving the caller the choice
		595	between waiting in a blocking fashion, or setting a callback.
		596
		597	=item * Condition variables represent future values, or promises to deliver
		598	some result, long before the result is available.
		599
		600	=back
584		601
585	Condition variables are very useful to signal that something has finished,	602	Condition variables are very useful to signal that something has finished,
586	for example, if you write a module that does asynchronous http requests,	603	for example, if you write a module that does asynchronous http requests,
587	then a condition variable would be the ideal candidate to signal the	604	then a condition variable would be the ideal candidate to signal the
588	availability of results. The user can either act when the callback is	605	availability of results. The user can either act when the callback is
…		…
601		618
602	Condition variables are represented by hash refs in perl, and the keys	619	Condition variables are represented by hash refs in perl, and the keys
603	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing	620	used by AnyEvent itself are all named C<_ae_XXX> to make subclassing
604	easy (it is often useful to build your own transaction class on top of	621	easy (it is often useful to build your own transaction class on top of
605	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call	622	AnyEvent). To subclass, use C<AnyEvent::CondVar> as base class and call
606	it's C<new> method in your own C<new> method.	623	its C<new> method in your own C<new> method.
607		624
608	There are two "sides" to a condition variable - the "producer side" which	625	There are two "sides" to a condition variable - the "producer side" which
609	eventually calls C<< -> send >>, and the "consumer side", which waits	626	eventually calls C<< -> send >>, and the "consumer side", which waits
610	for the send to occur.	627	for the send to occur.
611		628
…		…
676	they were a code reference). Calling them directly is the same as calling	693	they were a code reference). Calling them directly is the same as calling
677	C<send>.	694	C<send>.
678		695
679	=item $cv->croak ($error)	696	=item $cv->croak ($error)
680		697
681	Similar to send, but causes all call's to C<< ->recv >> to invoke	698	Similar to send, but causes all calls to C<< ->recv >> to invoke
682	C<Carp::croak> with the given error message/object/scalar.	699	C<Carp::croak> with the given error message/object/scalar.
683		700
684	This can be used to signal any errors to the condition variable	701	This can be used to signal any errors to the condition variable
685	user/consumer. Doing it this way instead of calling C<croak> directly	702	user/consumer. Doing it this way instead of calling C<croak> directly
686	delays the error detetcion, but has the overwhelmign advantage that it	703	delays the error detection, but has the overwhelming advantage that it
687	diagnoses the error at the place where the result is expected, and not	704	diagnoses the error at the place where the result is expected, and not
688	deep in some event clalback without connection to the actual code causing	705	deep in some event callback with no connection to the actual code causing
689	the problem.	706	the problem.
690		707
691	=item $cv->begin ([group callback])	708	=item $cv->begin ([group callback])
692		709
693	=item $cv->end	710	=item $cv->end
…		…
731	one call to C<begin>, so the condvar waits for all calls to C<end> before	748	one call to C<begin>, so the condvar waits for all calls to C<end> before
732	sending.	749	sending.
733		750
734	The ping example mentioned above is slightly more complicated, as the	751	The ping example mentioned above is slightly more complicated, as the
735	there are results to be passwd back, and the number of tasks that are	752	there are results to be passwd back, and the number of tasks that are
736	begung can potentially be zero:	753	begun can potentially be zero:
737		754
738	my $cv = AnyEvent->condvar;	755	my $cv = AnyEvent->condvar;
739		756
740	my %result;	757	my %result;
741	$cv->begin (sub { shift->send (\%result) });	758	$cv->begin (sub { shift->send (\%result) });
…		…
762	to be called once the counter reaches C<0>, and second, it ensures that	779	to be called once the counter reaches C<0>, and second, it ensures that
763	C<send> is called even when C<no> hosts are being pinged (the loop	780	C<send> is called even when C<no> hosts are being pinged (the loop
764	doesn't execute once).	781	doesn't execute once).
765		782
766	This is the general pattern when you "fan out" into multiple (but	783	This is the general pattern when you "fan out" into multiple (but
767	potentially none) subrequests: use an outer C<begin>/C<end> pair to set	784	potentially zero) subrequests: use an outer C<begin>/C<end> pair to set
768	the callback and ensure C<end> is called at least once, and then, for each	785	the callback and ensure C<end> is called at least once, and then, for each
769	subrequest you start, call C<begin> and for each subrequest you finish,	786	subrequest you start, call C<begin> and for each subrequest you finish,
770	call C<end>.	787	call C<end>.
771		788
772	=back	789	=back
…		…
779	=over 4	796	=over 4
780		797
781	=item $cv->recv	798	=item $cv->recv
782		799
783	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak	800	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
784	>> methods have been called on c<$cv>, while servicing other watchers	801	>> methods have been called on C<$cv>, while servicing other watchers
785	normally.	802	normally.
786		803
787	You can only wait once on a condition - additional calls are valid but	804	You can only wait once on a condition - additional calls are valid but
788	will return immediately.	805	will return immediately.
789		806
…		…
806	caller decide whether the call will block or not (for example, by coupling	823	caller decide whether the call will block or not (for example, by coupling
807	condition variables with some kind of request results and supporting	824	condition variables with some kind of request results and supporting
808	callbacks so the caller knows that getting the result will not block,	825	callbacks so the caller knows that getting the result will not block,
809	while still supporting blocking waits if the caller so desires).	826	while still supporting blocking waits if the caller so desires).
810		827
811	You can ensure that C<< -recv >> never blocks by setting a callback and	828	You can ensure that C<< ->recv >> never blocks by setting a callback and
812	only calling C<< ->recv >> from within that callback (or at a later	829	only calling C<< ->recv >> from within that callback (or at a later
813	time). This will work even when the event loop does not support blocking	830	time). This will work even when the event loop does not support blocking
814	waits otherwise.	831	waits otherwise.
815		832
816	=item $bool = $cv->ready	833	=item $bool = $cv->ready
…		…
821	=item $cb = $cv->cb ($cb->($cv))	838	=item $cb = $cv->cb ($cb->($cv))
822		839
823	This is a mutator function that returns the callback set and optionally	840	This is a mutator function that returns the callback set and optionally
824	replaces it before doing so.	841	replaces it before doing so.
825		842
826	The callback will be called when the condition becomes (or already was)	843	The callback will be called when the condition becomes "true", i.e. when
827	"true", i.e. when C<send> or C<croak> are called (or were called), with	844	C<send> or C<croak> are called, with the only argument being the
828	the only argument being the condition variable itself. Calling C<recv>	845	condition variable itself. If the condition is already true, the
		846	callback is called immediately when it is set. Calling C<recv> inside
829	inside the callback or at any later time is guaranteed not to block.	847	the callback or at any later time is guaranteed not to block.
830		848
831	=back	849	=back
832		850
833	=head1 SUPPORTED EVENT LOOPS/BACKENDS	851	=head1 SUPPORTED EVENT LOOPS/BACKENDS
834		852
…		…
842	use. If EV is not installed, then AnyEvent will fall back to its own	860	use. If EV is not installed, then AnyEvent will fall back to its own
843	pure-perl implementation, which is available everywhere as it comes with	861	pure-perl implementation, which is available everywhere as it comes with
844	AnyEvent itself.	862	AnyEvent itself.
845		863
846	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	864	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
847	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	865	AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
848		866
849	=item Backends that are transparently being picked up when they are used.	867	=item Backends that are transparently being picked up when they are used.
850		868
851	These will be used when they are currently loaded when the first watcher	869	These will be used if they are already loaded when the first watcher
852	is created, in which case it is assumed that the application is using	870	is created, in which case it is assumed that the application is using
853	them. This means that AnyEvent will automatically pick the right backend	871	them. This means that AnyEvent will automatically pick the right backend
854	when the main program loads an event module before anything starts to	872	when the main program loads an event module before anything starts to
855	create watchers. Nothing special needs to be done by the main program.	873	create watchers. Nothing special needs to be done by the main program.
856		874
…		…
858	AnyEvent::Impl::Glib based on Glib, slow but very stable.	876	AnyEvent::Impl::Glib based on Glib, slow but very stable.
859	AnyEvent::Impl::Tk based on Tk, very broken.	877	AnyEvent::Impl::Tk based on Tk, very broken.
860	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	878	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
861	AnyEvent::Impl::POE based on POE, very slow, some limitations.	879	AnyEvent::Impl::POE based on POE, very slow, some limitations.
862	AnyEvent::Impl::Irssi used when running within irssi.	880	AnyEvent::Impl::Irssi used when running within irssi.
		881	AnyEvent::Impl::IOAsync based on IO::Async.
		882	AnyEvent::Impl::Cocoa based on Cocoa::EventLoop.
		883	AnyEvent::Impl::FLTK based on FLTK.
863		884
864	=item Backends with special needs.	885	=item Backends with special needs.
865		886
866	Qt requires the Qt::Application to be instantiated first, but will	887	Qt requires the Qt::Application to be instantiated first, but will
867	otherwise be picked up automatically. As long as the main program	888	otherwise be picked up automatically. As long as the main program
868	instantiates the application before any AnyEvent watchers are created,	889	instantiates the application before any AnyEvent watchers are created,
869	everything should just work.	890	everything should just work.
870		891
871	AnyEvent::Impl::Qt based on Qt.	892	AnyEvent::Impl::Qt based on Qt.
872		893
873	Support for IO::Async can only be partial, as it is too broken and
874	architecturally limited to even support the AnyEvent API. It also
875	is the only event loop that needs the loop to be set explicitly, so
876	it can only be used by a main program knowing about AnyEvent. See
877	L<AnyEvent::Impl::Async> for the gory details.
878
879	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
880
881	=item Event loops that are indirectly supported via other backends.	894	=item Event loops that are indirectly supported via other backends.
882		895
883	Some event loops can be supported via other modules:	896	Some event loops can be supported via other modules:
884		897
885	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.	898	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
…		…
910	Contains C<undef> until the first watcher is being created, before the	923	Contains C<undef> until the first watcher is being created, before the
911	backend has been autodetected.	924	backend has been autodetected.
912		925
913	Afterwards it contains the event model that is being used, which is the	926	Afterwards it contains the event model that is being used, which is the
914	name of the Perl class implementing the model. This class is usually one	927	name of the Perl class implementing the model. This class is usually one
915	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the	928	of the C<AnyEvent::Impl::xxx> modules, but can be any other class in the
916	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it	929	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
917	will be C<urxvt::anyevent>).	930	will be C<urxvt::anyevent>).
918		931
919	=item AnyEvent::detect	932	=item AnyEvent::detect
920		933
921	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	934	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
922	if necessary. You should only call this function right before you would	935	if necessary. You should only call this function right before you would
923	have created an AnyEvent watcher anyway, that is, as late as possible at	936	have created an AnyEvent watcher anyway, that is, as late as possible at
924	runtime, and not e.g. while initialising of your module.	937	runtime, and not e.g. during initialisation of your module.
925		938
926	If you need to do some initialisation before AnyEvent watchers are	939	If you need to do some initialisation before AnyEvent watchers are
927	created, use C<post_detect>.	940	created, use C<post_detect>.
928		941
929	=item $guard = AnyEvent::post_detect { BLOCK }	942	=item $guard = AnyEvent::post_detect { BLOCK }
930		943
931	Arranges for the code block to be executed as soon as the event model is	944	Arranges for the code block to be executed as soon as the event model is
932	autodetected (or immediately if this has already happened).	945	autodetected (or immediately if that has already happened).
933		946
934	The block will be executed I<after> the actual backend has been detected	947	The block will be executed I<after> the actual backend has been detected
935	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been	948	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
936	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do	949	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
937	other initialisations - see the sources of L<AnyEvent::Strict> or	950	other initialisations - see the sources of L<AnyEvent::Strict> or
…		…
946	that automatically removes the callback again when it is destroyed (or	959	that automatically removes the callback again when it is destroyed (or
947	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for	960	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
948	a case where this is useful.	961	a case where this is useful.
949		962
950	Example: Create a watcher for the IO::AIO module and store it in	963	Example: Create a watcher for the IO::AIO module and store it in
951	C<$WATCHER>. Only do so after the event loop is initialised, though.	964	C<$WATCHER>, but do so only do so after the event loop is initialised.
952		965
953	our WATCHER;	966	our WATCHER;
954		967
955	my $guard = AnyEvent::post_detect {	968	my $guard = AnyEvent::post_detect {
956	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);	969	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
…		…
964	$WATCHER \|\|= $guard;	977	$WATCHER \|\|= $guard;
965		978
966	=item @AnyEvent::post_detect	979	=item @AnyEvent::post_detect
967		980
968	If there are any code references in this array (you can C<push> to it	981	If there are any code references in this array (you can C<push> to it
969	before or after loading AnyEvent), then they will called directly after	982	before or after loading AnyEvent), then they will be called directly
970	the event loop has been chosen.	983	after the event loop has been chosen.
971		984
972	You should check C<$AnyEvent::MODEL> before adding to this array, though:	985	You should check C<$AnyEvent::MODEL> before adding to this array, though:
973	if it is defined then the event loop has already been detected, and the	986	if it is defined then the event loop has already been detected, and the
974	array will be ignored.	987	array will be ignored.
975		988
…		…
992	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent	1005	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
993	# as soon as it is	1006	# as soon as it is
994	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };	1007	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
995	}	1008	}
996		1009
		1010	=item AnyEvent::postpone BLOCK
		1011
		1012	Arranges for the block to be executed as soon as possible, but not before
		1013	the call itself returns. In practise, the block will be executed just
		1014	before the event loop polls for new events, or shortly afterwards.
		1015
		1016	This function never returns anything (to make the C<return postpone { ...
		1017	}> idiom more useful.
		1018
		1019	To understand the usefulness of this function, consider a function that
		1020	asynchronously does something for you and returns some transaction
		1021	object or guard to let you cancel the operation. For example,
		1022	C<AnyEvent::Socket::tcp_connect>:
		1023
		1024	# start a conenction attempt unless one is active
		1025	$self->{connect_guard} \|\|= AnyEvent::Socket::tcp_connect "www.example.net", 80, sub {
		1026	delete $self->{connect_guard};
		1027	...
		1028	};
		1029
		1030	Imagine that this function could instantly call the callback, for
		1031	example, because it detects an obvious error such as a negative port
		1032	number. Invoking the callback before the function returns causes problems
		1033	however: the callback will be called and will try to delete the guard
		1034	object. But since the function hasn't returned yet, there is nothing to
		1035	delete. When the function eventually returns it will assign the guard
		1036	object to C<< $self->{connect_guard} >>, where it will likely never be
		1037	deleted, so the program thinks it is still trying to connect.
		1038
		1039	This is where C<AnyEvent::postpone> should be used. Instead of calling the
		1040	callback directly on error:
		1041
		1042	$cb->(undef), return # signal error to callback, BAD!
		1043	if $some_error_condition;
		1044
		1045	It should use C<postpone>:
		1046
		1047	AnyEvent::postpone { $cb->(undef) }, return # signal error to callback, later
		1048	if $some_error_condition;
		1049
997	=back	1050	=back
998		1051
999	=head1 WHAT TO DO IN A MODULE	1052	=head1 WHAT TO DO IN A MODULE
1000		1053
1001	As a module author, you should C<use AnyEvent> and call AnyEvent methods	1054	As a module author, you should C<use AnyEvent> and call AnyEvent methods
…		…
1011	because it will stall the whole program, and the whole point of using	1064	because it will stall the whole program, and the whole point of using
1012	events is to stay interactive.	1065	events is to stay interactive.
1013		1066
1014	It is fine, however, to call C<< ->recv >> when the user of your module	1067	It is fine, however, to call C<< ->recv >> when the user of your module
1015	requests it (i.e. if you create a http request object ad have a method	1068	requests it (i.e. if you create a http request object ad have a method
1016	called C<results> that returns the results, it should call C<< ->recv >>	1069	called C<results> that returns the results, it may call C<< ->recv >>
1017	freely, as the user of your module knows what she is doing. always).	1070	freely, as the user of your module knows what she is doing. Always).
1018		1071
1019	=head1 WHAT TO DO IN THE MAIN PROGRAM	1072	=head1 WHAT TO DO IN THE MAIN PROGRAM
1020		1073
1021	There will always be a single main program - the only place that should	1074	There will always be a single main program - the only place that should
1022	dictate which event model to use.	1075	dictate which event model to use.
1023		1076
1024	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	1077	If the program is not event-based, it need not do anything special, even
1025	do anything special (it does not need to be event-based) and let AnyEvent	1078	when it depends on a module that uses an AnyEvent. If the program itself
1026	decide which implementation to chose if some module relies on it.	1079	uses AnyEvent, but does not care which event loop is used, all it needs
		1080	to do is C<use AnyEvent>. In either case, AnyEvent will choose the best
		1081	available loop implementation.
1027		1082
1028	If the main program relies on a specific event model - for example, in	1083	If the main program relies on a specific event model - for example, in
1029	Gtk2 programs you have to rely on the Glib module - you should load the	1084	Gtk2 programs you have to rely on the Glib module - you should load the
1030	event module before loading AnyEvent or any module that uses it: generally	1085	event module before loading AnyEvent or any module that uses it: generally
1031	speaking, you should load it as early as possible. The reason is that	1086	speaking, you should load it as early as possible. The reason is that
1032	modules might create watchers when they are loaded, and AnyEvent will	1087	modules might create watchers when they are loaded, and AnyEvent will
1033	decide on the event model to use as soon as it creates watchers, and it	1088	decide on the event model to use as soon as it creates watchers, and it
1034	might chose the wrong one unless you load the correct one yourself.	1089	might choose the wrong one unless you load the correct one yourself.
1035		1090
1036	You can chose to use a pure-perl implementation by loading the	1091	You can chose to use a pure-perl implementation by loading the
1037	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1092	C<AnyEvent::Loop> module, which gives you similar behaviour
1038	everywhere, but letting AnyEvent chose the model is generally better.	1093	everywhere, but letting AnyEvent chose the model is generally better.
1039		1094
1040	=head2 MAINLOOP EMULATION	1095	=head2 MAINLOOP EMULATION
1041		1096
1042	Sometimes (often for short test scripts, or even standalone programs who	1097	Sometimes (often for short test scripts, or even standalone programs who
…		…
1057	=head1 OTHER MODULES	1112	=head1 OTHER MODULES
1058		1113
1059	The following is a non-exhaustive list of additional modules that use	1114	The following is a non-exhaustive list of additional modules that use
1060	AnyEvent as a client and can therefore be mixed easily with other AnyEvent	1115	AnyEvent as a client and can therefore be mixed easily with other AnyEvent
1061	modules and other event loops in the same program. Some of the modules	1116	modules and other event loops in the same program. Some of the modules
1062	come with AnyEvent, most are available via CPAN.	1117	come as part of AnyEvent, the others are available via CPAN.
1063		1118
1064	=over 4	1119	=over 4
1065		1120
1066	=item L<AnyEvent::Util>	1121	=item L<AnyEvent::Util>
1067		1122
1068	Contains various utility functions that replace often-used but blocking	1123	Contains various utility functions that replace often-used blocking
1069	functions such as C<inet_aton> by event-/callback-based versions.	1124	functions such as C<inet_aton> with event/callback-based versions.
1070		1125
1071	=item L<AnyEvent::Socket>	1126	=item L<AnyEvent::Socket>
1072		1127
1073	Provides various utility functions for (internet protocol) sockets,	1128	Provides various utility functions for (internet protocol) sockets,
1074	addresses and name resolution. Also functions to create non-blocking tcp	1129	addresses and name resolution. Also functions to create non-blocking tcp
…		…
1076		1131
1077	=item L<AnyEvent::Handle>	1132	=item L<AnyEvent::Handle>
1078		1133
1079	Provide read and write buffers, manages watchers for reads and writes,	1134	Provide read and write buffers, manages watchers for reads and writes,
1080	supports raw and formatted I/O, I/O queued and fully transparent and	1135	supports raw and formatted I/O, I/O queued and fully transparent and
1081	non-blocking SSL/TLS (via L<AnyEvent::TLS>.	1136	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
1082		1137
1083	=item L<AnyEvent::DNS>	1138	=item L<AnyEvent::DNS>
1084		1139
1085	Provides rich asynchronous DNS resolver capabilities.	1140	Provides rich asynchronous DNS resolver capabilities.
1086		1141
		1142	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
		1143
		1144	Implement event-based interfaces to the protocols of the same name (for
		1145	the curious, IGS is the International Go Server and FCP is the Freenet
		1146	Client Protocol).
		1147
		1148	=item L<AnyEvent::Handle::UDP>
		1149
		1150	Here be danger!
		1151
		1152	As Pauli would put it, "Not only is it not right, it's not even wrong!" -
		1153	there are so many things wrong with AnyEvent::Handle::UDP, most notably
		1154	its use of a stream-based API with a protocol that isn't streamable, that
		1155	the only way to improve it is to delete it.
		1156
		1157	It features data corruption (but typically only under load) and general
		1158	confusion. On top, the author is not only clueless about UDP but also
		1159	fact-resistant - some gems of his understanding: "connect doesn't work
		1160	with UDP", "UDP packets are not IP packets", "UDP only has datagrams, not
		1161	packets", "I don't need to implement proper error checking as UDP doesn't
		1162	support error checking" and so on - he doesn't even understand what's
		1163	wrong with his module when it is explained to him.
		1164
1087	=item L<AnyEvent::HTTP>	1165	=item L<AnyEvent::DBI>
1088		1166
1089	A simple-to-use HTTP library that is capable of making a lot of concurrent	1167	Executes L<DBI> requests asynchronously in a proxy process for you,
1090	HTTP requests.	1168	notifying you in an event-based way when the operation is finished.
		1169
		1170	=item L<AnyEvent::AIO>
		1171
		1172	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
		1173	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1174	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1175	file I/O, and much more.
1091		1176
1092	=item L<AnyEvent::HTTPD>	1177	=item L<AnyEvent::HTTPD>
1093		1178
1094	Provides a simple web application server framework.	1179	A simple embedded webserver.
1095		1180
1096	=item L<AnyEvent::FastPing>	1181	=item L<AnyEvent::FastPing>
1097		1182
1098	The fastest ping in the west.	1183	The fastest ping in the west.
1099
1100	=item L<AnyEvent::DBI>
1101
1102	Executes L<DBI> requests asynchronously in a proxy process.
1103
1104	=item L<AnyEvent::AIO>
1105
1106	Truly asynchronous I/O, should be in the toolbox of every event
1107	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1108	together.
1109
1110	=item L<AnyEvent::BDB>
1111
1112	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1113	L<BDB> and AnyEvent together.
1114
1115	=item L<AnyEvent::GPSD>
1116
1117	A non-blocking interface to gpsd, a daemon delivering GPS information.
1118
1119	=item L<AnyEvent::IRC>
1120
1121	AnyEvent based IRC client module family (replacing the older Net::IRC3).
1122
1123	=item L<AnyEvent::XMPP>
1124
1125	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1126	Net::XMPP2>.
1127
1128	=item L<AnyEvent::IGS>
1129
1130	A non-blocking interface to the Internet Go Server protocol (used by
1131	L<App::IGS>).
1132
1133	=item L<Net::FCP>
1134
1135	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1136	of AnyEvent.
1137
1138	=item L<Event::ExecFlow>
1139
1140	High level API for event-based execution flow control.
1141		1184
1142	=item L<Coro>	1185	=item L<Coro>
1143		1186
1144	Has special support for AnyEvent via L<Coro::AnyEvent>.	1187	Has special support for AnyEvent via L<Coro::AnyEvent>.
1145		1188
…		…
1149		1192
1150	package AnyEvent;	1193	package AnyEvent;
1151		1194
1152	# basically a tuned-down version of common::sense	1195	# basically a tuned-down version of common::sense
1153	sub common_sense {	1196	sub common_sense {
1154	# from common:.sense 1.0	1197	# from common:.sense 3.4
1155	${^WARNING_BITS} = "\xfc\x3f\x33\x00\x0f\xf3\xcf\xc0\xf3\xfc\x33\x00";	1198	${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
1156	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)	1199	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1157	$^H \|= 0x00000600;	1200	$^H \|= 0x00000600;
1158	}	1201	}
1159		1202
1160	BEGIN { AnyEvent::common_sense }	1203	BEGIN { AnyEvent::common_sense }
1161		1204
1162	use Carp ();	1205	use Carp ();
1163		1206
1164	our $VERSION = '5.26';	1207	our $VERSION = '5.34';
1165	our $MODEL;	1208	our $MODEL;
1166		1209
1167	our $AUTOLOAD;	1210	our $AUTOLOAD;
1168	our @ISA;	1211	our @ISA;
1169		1212
…		…
1194	$ENV{PERL_ANYEVENT_PROTOCOLS} \|\| "ipv4,ipv6";	1237	$ENV{PERL_ANYEVENT_PROTOCOLS} \|\| "ipv4,ipv6";
1195	}	1238	}
1196		1239
1197	my @models = (	1240	my @models = (
1198	[EV:: => AnyEvent::Impl::EV:: , 1],	1241	[EV:: => AnyEvent::Impl::EV:: , 1],
1199	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],	1242	[AnyEvent::Loop:: => AnyEvent::Impl::Perl:: , 1],
1200	# everything below here will not (normally) be autoprobed	1243	# everything below here will not (normally) be autoprobed
1201	# as the pureperl backend should work everywhere	1244	# as the pure perl backend should work everywhere
1202	# and is usually faster	1245	# and is usually faster
1203	[Event:: => AnyEvent::Impl::Event::, 1],	1246	[Event:: => AnyEvent::Impl::Event::, 1],
1204	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers	1247	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1205	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1248	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1206	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package	1249	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1207	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1250	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1208	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1251	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1209	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1252	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1210	[Wx:: => AnyEvent::Impl::POE::],	1253	[Wx:: => AnyEvent::Impl::POE::],
1211	[Prima:: => AnyEvent::Impl::POE::],	1254	[Prima:: => AnyEvent::Impl::POE::],
1212	# IO::Async is just too broken - we would need workarounds for its
1213	# byzantine signal and broken child handling, among others.
1214	# IO::Async is rather hard to detect, as it doesn't have any
1215	# obvious default class.
1216	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1217	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program	1255	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::],
1218	[IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program	1256	[Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1219	[AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program	1257	[FLTK:: => AnyEvent::Impl::FLTK::],
1220	);	1258	);
1221		1259
1222	our %method = map +($_ => 1),	1260	our %method = map +($_ => 1),
1223	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1261	qw(io timer time now now_update signal child idle condvar DESTROY);
1224		1262
1225	our @post_detect;	1263	our @post_detect;
1226		1264
1227	sub post_detect(&) {	1265	sub post_detect(&) {
1228	my ($cb) = @_;	1266	my ($cb) = @_;
…		…
1283	last;	1321	last;
1284	}	1322	}
1285	}	1323	}
1286		1324
1287	$MODEL	1325	$MODEL
1288	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1326	or die "AnyEvent: backend autodetection failed - did you properly install AnyEvent?\n";
1289	}	1327	}
1290	}	1328	}
1291		1329
1292	@models = (); # free probe data	1330	@models = (); # free probe data
1293		1331
1294	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	1332	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1295	unshift @ISA, $MODEL;	1333	unshift @ISA, $MODEL;
1296		1334
1297	# now nuke some methods that are overriden by the backend.	1335	# now nuke some methods that are overridden by the backend.
1298	# SUPER is not allowed.	1336	# SUPER is not allowed.
1299	for (qw(time signal child idle)) {	1337	for (qw(time signal child idle)) {
1300	undef &{"AnyEvent::Base::$_"}	1338	undef &{"AnyEvent::Base::$_"}
1301	if defined &{"$MODEL\::$_"};	1339	if defined &{"$MODEL\::$_"};
1302	}	1340	}
1303		1341
1304	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};	1342	if ($ENV{PERL_ANYEVENT_STRICT}) {
		1343	eval { require AnyEvent::Strict };
		1344	warn "AnyEvent: cannot load AnyEvent::Strict: $@"
		1345	if $@ && $VERBOSE;
		1346	}
1305		1347
1306	(shift @post_detect)->() while @post_detect;	1348	(shift @post_detect)->() while @post_detect;
1307		1349
1308	*post_detect = sub(&) {	1350	*post_detect = sub(&) {
1309	shift->();	1351	shift->();
…		…
1322		1364
1323	detect;	1365	detect;
1324		1366
1325	my $class = shift;	1367	my $class = shift;
1326	$class->$func (@_);	1368	$class->$func (@_);
		1369	}
		1370
		1371	our $POSTPONE_W;
		1372	our @POSTPONE;
		1373
		1374	sub _postpone_exec {
		1375	undef $POSTPONE_W;
		1376	(pop @POSTPONE)->()
		1377	while @POSTPONE;
		1378	}
		1379
		1380	sub postpone(&) {
		1381	push @POSTPONE, shift;
		1382
		1383	$POSTPONE_W \|\|= AE::timer (0, 0, \&_postpone_exec);
		1384
		1385	()
1327	}	1386	}
1328		1387
1329	# utility function to dup a filehandle. this is used by many backends	1388	# utility function to dup a filehandle. this is used by many backends
1330	# to support binding more than one watcher per filehandle (they usually	1389	# to support binding more than one watcher per filehandle (they usually
1331	# allow only one watcher per fd, so we dup it to get a different one).	1390	# allow only one watcher per fd, so we dup it to get a different one).
…		…
1421		1480
1422	*now = \&time;	1481	*now = \&time;
1423		1482
1424	sub now_update { }	1483	sub now_update { }
1425		1484
		1485	sub _poll {
		1486	Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
		1487	}
		1488
1426	# default implementation for ->condvar	1489	# default implementation for ->condvar
		1490	# in fact, the default should not be overwritten
1427		1491
1428	sub condvar {	1492	sub condvar {
1429	eval q{ # poor man's autoloading {}	1493	eval q{ # poor man's autoloading {}
1430	*condvar = sub {	1494	*condvar = sub {
1431	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1495	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
…		…
1616	# default implementation for ->child	1680	# default implementation for ->child
1617		1681
1618	our %PID_CB;	1682	our %PID_CB;
1619	our $CHLD_W;	1683	our $CHLD_W;
1620	our $CHLD_DELAY_W;	1684	our $CHLD_DELAY_W;
1621	our $WNOHANG;
1622		1685
1623	# used by many Impl's	1686	# used by many Impl's
1624	sub _emit_childstatus($$) {	1687	sub _emit_childstatus($$) {
1625	my (undef, $rpid, $rstatus) = @_;	1688	my (undef, $rpid, $rstatus) = @_;
1626		1689
…		…
1633	eval q{ # poor man's autoloading {}	1696	eval q{ # poor man's autoloading {}
1634	*_sigchld = sub {	1697	*_sigchld = sub {
1635	my $pid;	1698	my $pid;
1636		1699
1637	AnyEvent->_emit_childstatus ($pid, $?)	1700	AnyEvent->_emit_childstatus ($pid, $?)
1638	while ($pid = waitpid -1, $WNOHANG) > 0;	1701	while ($pid = waitpid -1, WNOHANG) > 0;
1639	};	1702	};
1640		1703
1641	*child = sub {	1704	*child = sub {
1642	my (undef, %arg) = @_;	1705	my (undef, %arg) = @_;
1643		1706
1644	defined (my $pid = $arg{pid} + 0)	1707	my $pid = $arg{pid};
1645	or Carp::croak "required option 'pid' is missing";	1708	my $cb = $arg{cb};
1646		1709
1647	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1710	$PID_CB{$pid}{$cb+0} = $cb;
1648
1649	# WNOHANG is almost cetrainly 1 everywhere
1650	$WNOHANG \|\|= $^O =~ /^(?:openbsd\|netbsd\|linux\|freebsd\|cygwin\|MSWin32)$/
1651	? 1
1652	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;
1653		1711
1654	unless ($CHLD_W) {	1712	unless ($CHLD_W) {
1655	$CHLD_W = AE::signal CHLD => \&_sigchld;	1713	$CHLD_W = AE::signal CHLD => \&_sigchld;
1656	# child could be a zombie already, so make at least one round	1714	# child could be a zombie already, so make at least one round
1657	&_sigchld;	1715	&_sigchld;
1658	}	1716	}
1659		1717
1660	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1718	bless [$pid, $cb+0], "AnyEvent::Base::child"
1661	};	1719	};
1662		1720
1663	*AnyEvent::Base::child::DESTROY = sub {	1721	*AnyEvent::Base::child::DESTROY = sub {
1664	my ($pid, $cb) = @{$_[0]};	1722	my ($pid, $icb) = @{$_[0]};
1665		1723
1666	delete $PID_CB{$pid}{$cb};	1724	delete $PID_CB{$pid}{$icb};
1667	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1725	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1668		1726
1669	undef $CHLD_W unless keys %PID_CB;	1727	undef $CHLD_W unless keys %PID_CB;
1670	};	1728	};
1671	};	1729	};
…		…
1719		1777
1720	package AnyEvent::CondVar;	1778	package AnyEvent::CondVar;
1721		1779
1722	our @ISA = AnyEvent::CondVar::Base::;	1780	our @ISA = AnyEvent::CondVar::Base::;
1723		1781
		1782	# only to be used for subclassing
		1783	sub new {
		1784	my $class = shift;
		1785	bless AnyEvent->condvar (@_), $class
		1786	}
		1787
1724	package AnyEvent::CondVar::Base;	1788	package AnyEvent::CondVar::Base;
1725		1789
1726	#use overload	1790	#use overload
1727	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1791	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
1728	# fallback => 1;	1792	# fallback => 1;
…		…
1737		1801
1738	sub _send {	1802	sub _send {
1739	# nop	1803	# nop
1740	}	1804	}
1741		1805
		1806	sub _wait {
		1807	AnyEvent->_poll until $_[0]{_ae_sent};
		1808	}
		1809
1742	sub send {	1810	sub send {
1743	my $cv = shift;	1811	my $cv = shift;
1744	$cv->{_ae_sent} = [@_];	1812	$cv->{_ae_sent} = [@_];
1745	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};	1813	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1746	$cv->_send;	1814	$cv->_send;
…		…
1753		1821
1754	sub ready {	1822	sub ready {
1755	$_[0]{_ae_sent}	1823	$_[0]{_ae_sent}
1756	}	1824	}
1757		1825
1758	sub _wait {
1759	$WAITING
1760	and !$_[0]{_ae_sent}
1761	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1762
1763	local $WAITING = 1;
1764	AnyEvent->one_event while !$_[0]{_ae_sent};
1765	}
1766
1767	sub recv {	1826	sub recv {
		1827	unless ($_[0]{_ae_sent}) {
		1828	$WAITING
		1829	and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
		1830
		1831	local $WAITING = 1;
1768	$_[0]->_wait;	1832	$_[0]->_wait;
		1833	}
1769		1834
1770	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1835	$_[0]{_ae_croak}
1771	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1836	and Carp::croak $_[0]{_ae_croak};
		1837
		1838	wantarray
		1839	? @{ $_[0]{_ae_sent} }
		1840	: $_[0]{_ae_sent}[0]
1772	}	1841	}
1773		1842
1774	sub cb {	1843	sub cb {
1775	my $cv = shift;	1844	my $cv = shift;
1776		1845
…		…
1792	&{ $_[0]{_ae_end_cb} \|\| sub { $_[0]->send } };	1861	&{ $_[0]{_ae_end_cb} \|\| sub { $_[0]->send } };
1793	}	1862	}
1794		1863
1795	# undocumented/compatibility with pre-3.4	1864	# undocumented/compatibility with pre-3.4
1796	*broadcast = \&send;	1865	*broadcast = \&send;
1797	*wait = \&_wait;	1866	*wait = \&recv;
1798		1867
1799	=head1 ERROR AND EXCEPTION HANDLING	1868	=head1 ERROR AND EXCEPTION HANDLING
1800		1869
1801	In general, AnyEvent does not do any error handling - it relies on the	1870	In general, AnyEvent does not do any error handling - it relies on the
1802	caller to do that if required. The L<AnyEvent::Strict> module (see also	1871	caller to do that if required. The L<AnyEvent::Strict> module (see also
…		…
1849	check the arguments passed to most method calls. If it finds any problems,	1918	check the arguments passed to most method calls. If it finds any problems,
1850	it will croak.	1919	it will croak.
1851		1920
1852	In other words, enables "strict" mode.	1921	In other words, enables "strict" mode.
1853		1922
1854	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>	1923	Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1855	>>, it is definitely recommended to keep it off in production. Keeping	1924	>>, it is definitely recommended to keep it off in production. Keeping
1856	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs	1925	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1857	can be very useful, however.	1926	can be very useful, however.
1858		1927
1859	=item C<PERL_ANYEVENT_MODEL>	1928	=item C<PERL_ANYEVENT_MODEL>
…		…
1865	used as event model. If it fails to load AnyEvent will proceed with	1934	used as event model. If it fails to load AnyEvent will proceed with
1866	auto detection and -probing.	1935	auto detection and -probing.
1867		1936
1868	This functionality might change in future versions.	1937	This functionality might change in future versions.
1869		1938
1870	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	1939	For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1871	could start your program like this:	1940	could start your program like this:
1872		1941
1873	PERL_ANYEVENT_MODEL=Perl perl ...	1942	PERL_ANYEVENT_MODEL=Perl perl ...
1874		1943
1875	=item C<PERL_ANYEVENT_PROTOCOLS>	1944	=item C<PERL_ANYEVENT_PROTOCOLS>
…		…
2505	unless defined $SIG{PIPE};	2574	unless defined $SIG{PIPE};
2506		2575
2507	=head1 RECOMMENDED/OPTIONAL MODULES	2576	=head1 RECOMMENDED/OPTIONAL MODULES
2508		2577
2509	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and	2578	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2510	it's built-in modules) are required to use it.	2579	its built-in modules) are required to use it.
2511		2580
2512	That does not mean that AnyEvent won't take advantage of some additional	2581	That does not mean that AnyEvent won't take advantage of some additional
2513	modules if they are installed.	2582	modules if they are installed.
2514		2583
2515	This section explains which additional modules will be used, and how they	2584	This section explains which additional modules will be used, and how they
…		…
2573	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.	2642	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2574		2643
2575	=item L<Time::HiRes>	2644	=item L<Time::HiRes>
2576		2645
2577	This module is part of perl since release 5.008. It will be used when the	2646	This module is part of perl since release 5.008. It will be used when the
2578	chosen event library does not come with a timing source on it's own. The	2647	chosen event library does not come with a timing source of its own. The
2579	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to	2648	pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2580	try to use a monotonic clock for timing stability.	2649	try to use a monotonic clock for timing stability.
2581		2650
2582	=back	2651	=back
2583		2652
2584		2653
…		…
2646	pronounced).	2715	pronounced).
2647		2716
2648		2717
2649	=head1 SEE ALSO	2718	=head1 SEE ALSO
2650		2719
		2720	Tutorial/Introduction: L<AnyEvent::Intro>.
		2721
		2722	FAQ: L<AnyEvent::FAQ>.
		2723
2651	Utility functions: L<AnyEvent::Util>.	2724	Utility functions: L<AnyEvent::Util>.
2652		2725
2653	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	2726	Event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>, L<Glib::EV>,
2654	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2727	L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2655		2728
2656	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2729	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2657	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2730	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2658	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2731	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2659	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.	2732	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
…		…
2661	Non-blocking file handles, sockets, TCP clients and	2734	Non-blocking file handles, sockets, TCP clients and
2662	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	2735	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2663		2736
2664	Asynchronous DNS: L<AnyEvent::DNS>.	2737	Asynchronous DNS: L<AnyEvent::DNS>.
2665		2738
2666	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,	2739	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2667	L<Coro::Event>,
2668		2740
2669	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,	2741	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2670	L<AnyEvent::HTTP>.	2742	L<AnyEvent::HTTP>.
2671		2743
2672		2744
2673	=head1 AUTHOR	2745	=head1 AUTHOR
2674		2746

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.320 by root, Mon Apr 12 02:50:31 2010 UTC vs. Revision 1.353 by root, Thu Aug 11 20:56:07 2011 UTC

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Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.320 by root, Mon Apr 12 02:50:31 2010 UTC vs.
Revision 1.353 by root, Thu Aug 11 20:56:07 2011 UTC