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Comparing AnyEvent/README (file contents):
Revision 1.59 by root, Tue Jan 5 10:45:25 2010 UTC vs.
Revision 1.66 by root, Sun Aug 21 03:02:32 2011 UTC

…		…
1	NAME	1	NAME
2	AnyEvent - the DBI of event loop programming	2	AnyEvent - the DBI of event loop programming
3		3
4	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async,	4	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async,
5	Qt and POE are various supported event loops/environments.	5	Qt, FLTK and POE are various supported event loops/environments.
6		6
7	SYNOPSIS	7	SYNOPSIS
8	use AnyEvent;	8	use AnyEvent;
9		9
		10	# if you prefer function calls, look at the AE manpage for
		11	# an alternative API.
		12
10	# file descriptor readable	13	# file handle or descriptor readable
11	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });	14	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
12		15
13	# one-shot or repeating timers	16	# one-shot or repeating timers
14	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });	17	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
15	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...	18	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...);
16		19
17	print AnyEvent->now; # prints current event loop time	20	print AnyEvent->now; # prints current event loop time
18	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.	21	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
19		22
20	# POSIX signal	23	# POSIX signal
39	This manpage is mainly a reference manual. If you are interested in a	42	This manpage is mainly a reference manual. If you are interested in a
40	tutorial or some gentle introduction, have a look at the AnyEvent::Intro	43	tutorial or some gentle introduction, have a look at the AnyEvent::Intro
41	manpage.	44	manpage.
42		45
43	SUPPORT	46	SUPPORT
		47	An FAQ document is available as AnyEvent::FAQ.
		48
44	There is a mailinglist for discussing all things AnyEvent, and an IRC	49	There also is a mailinglist for discussing all things AnyEvent, and an
45	channel, too.	50	IRC channel, too.
46		51
47	See the AnyEvent project page at the Schmorpforge Ta-Sa Software	52	See the AnyEvent project page at the Schmorpforge Ta-Sa Software
48	Repository, at <http://anyevent.schmorp.de>, for more info.	53	Repository, at <http://anyevent.schmorp.de>, for more info.
49		54
50	WHY YOU SHOULD USE THIS MODULE (OR NOT)	55	WHY YOU SHOULD USE THIS MODULE (OR NOT)
…		…
68	module users into the same thing by forcing them to use the same event	73	module users into the same thing by forcing them to use the same event
69	model you use.	74	model you use.
70		75
71	For modules like POE or IO::Async (which is a total misnomer as it is	76	For modules like POE or IO::Async (which is a total misnomer as it is
72	actually doing all I/O synchronously...), using them in your module is	77	actually doing all I/O synchronously...), using them in your module is
73	like joining a cult: After you joined, you are dependent on them and you	78	like joining a cult: After you join, you are dependent on them and you
74	cannot use anything else, as they are simply incompatible to everything	79	cannot use anything else, as they are simply incompatible to everything
75	that isn't them. What's worse, all the potential users of your module	80	that isn't them. What's worse, all the potential users of your module
76	are also forced to use the same event loop you use.	81	are also forced to use the same event loop you use.
77		82
78	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	83	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
79	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	84	fine. AnyEvent + Tk works fine etc. etc. but none of these work together
80	with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if your	85	with the rest: POE + EV? No go. Tk + Event? No go. Again: if your module
81	module uses one of those, every user of your module has to use it, too.	86	uses one of those, every user of your module has to use it, too. But if
82	But if your module uses AnyEvent, it works transparently with all event	87	your module uses AnyEvent, it works transparently with all event models
83	models it supports (including stuff like IO::Async, as long as those use	88	it supports (including stuff like IO::Async, as long as those use one of
84	one of the supported event loops. It is trivial to add new event loops	89	the supported event loops. It is easy to add new event loops to
85	to AnyEvent, too, so it is future-proof).	90	AnyEvent, too, so it is future-proof).
86		91
87	In addition to being free of having to use *the one and only true event	92	In addition to being free of having to use *the one and only true event
88	model*, AnyEvent also is free of bloat and policy: with POE or similar	93	model*, AnyEvent also is free of bloat and policy: with POE or similar
89	modules, you get an enormous amount of code and strict rules you have to	94	modules, you get an enormous amount of code and strict rules you have to
90	follow. AnyEvent, on the other hand, is lean and up to the point, by	95	follow. AnyEvent, on the other hand, is lean and to the point, by only
91	only offering the functionality that is necessary, in as thin as a	96	offering the functionality that is necessary, in as thin as a wrapper as
92	wrapper as technically possible.	97	technically possible.
93		98
94	Of course, AnyEvent comes with a big (and fully optional!) toolbox of	99	Of course, AnyEvent comes with a big (and fully optional!) toolbox of
95	useful functionality, such as an asynchronous DNS resolver, 100%	100	useful functionality, such as an asynchronous DNS resolver, 100%
96	non-blocking connects (even with TLS/SSL, IPv6 and on broken platforms	101	non-blocking connects (even with TLS/SSL, IPv6 and on broken platforms
97	such as Windows) and lots of real-world knowledge and workarounds for	102	such as Windows) and lots of real-world knowledge and workarounds for
…		…
100	Now, if you do want lots of policy (this can arguably be somewhat	105	Now, if you do want lots of policy (this can arguably be somewhat
101	useful) and you want to force your users to use the one and only event	106	useful) and you want to force your users to use the one and only event
102	model, you should not use this module.	107	model, you should not use this module.
103		108
104	DESCRIPTION	109	DESCRIPTION
105	AnyEvent provides an identical interface to multiple event loops. This	110	AnyEvent provides a uniform interface to various event loops. This
106	allows module authors to utilise an event loop without forcing module	111	allows module authors to use event loop functionality without forcing
107	users to use the same event loop (as only a single event loop can	112	module users to use a specific event loop implementation (since more
108	coexist peacefully at any one time).	113	than one event loop cannot coexist peacefully).
109		114
110	The interface itself is vaguely similar, but not identical to the Event	115	The interface itself is vaguely similar, but not identical to the Event
111	module.	116	module.
112		117
113	During the first call of any watcher-creation method, the module tries	118	During the first call of any watcher-creation method, the module tries
114	to detect the currently loaded event loop by probing whether one of the	119	to detect the currently loaded event loop by probing whether one of the
115	following modules is already loaded: EV, Event, Glib,	120	following modules is already loaded: EV, AnyEvent::Loop, Event, Glib,
116	AnyEvent::Impl::Perl, Tk, Event::Lib, Qt, POE. The first one found is	121	Tk, Event::Lib, Qt, POE. The first one found is used. If none are
117	used. If none are found, the module tries to load these modules	122	detected, the module tries to load the first four modules in the order
118	(excluding Tk, Event::Lib, Qt and POE as the pure perl adaptor should	123	given; but note that if EV is not available, the pure-perl
119	always succeed) in the order given. The first one that can be	124	AnyEvent::Loop should always work, so the other two are not normally
120	successfully loaded will be used. If, after this, still none could be	125	tried.
121	found, AnyEvent will fall back to a pure-perl event loop, which is not
122	very efficient, but should work everywhere.
123		126
124	Because AnyEvent first checks for modules that are already loaded,	127	Because AnyEvent first checks for modules that are already loaded,
125	loading an event model explicitly before first using AnyEvent will	128	loading an event model explicitly before first using AnyEvent will
126	likely make that model the default. For example:	129	likely make that model the default. For example:
127		130
…		…
129	use AnyEvent;	132	use AnyEvent;
130		133
131	# .. AnyEvent will likely default to Tk	134	# .. AnyEvent will likely default to Tk
132		135
133	The likely means that, if any module loads another event model and	136	The likely means that, if any module loads another event model and
134	starts using it, all bets are off. Maybe you should tell their authors	137	starts using it, all bets are off - this case should be very rare
135	to use AnyEvent so their modules work together with others seamlessly...	138	though, as very few modules hardcode event loops without announcing this
		139	very loudly.
136		140
137	The pure-perl implementation of AnyEvent is called	141	The pure-perl implementation of AnyEvent is called "AnyEvent::Loop".
138	"AnyEvent::Impl::Perl". Like other event modules you can load it	142	Like other event modules you can load it explicitly and enjoy the high
139	explicitly and enjoy the high availability of that event loop :)	143	availability of that event loop :)
140		144
141	WATCHERS	145	WATCHERS
142	AnyEvent has the central concept of a watcher, which is an object that	146	AnyEvent has the central concept of a watcher, which is an object that
143	stores relevant data for each kind of event you are waiting for, such as	147	stores relevant data for each kind of event you are waiting for, such as
144	the callback to call, the file handle to watch, etc.	148	the callback to call, the file handle to watch, etc.
…		…
148	callback when the event occurs (of course, only when the event model is	152	callback when the event occurs (of course, only when the event model is
149	in control).	153	in control).
150		154
151	Note that callbacks must not permanently change global variables	155	Note that callbacks must not permanently change global variables
152	potentially in use by the event loop (such as $_ or $[) and that	156	potentially in use by the event loop (such as $_ or $[) and that
153	callbacks must not "die". The former is good programming practise in	157	callbacks must not "die". The former is good programming practice in
154	Perl and the latter stems from the fact that exception handling differs	158	Perl and the latter stems from the fact that exception handling differs
155	widely between event loops.	159	widely between event loops.
156		160
157	To disable the watcher you have to destroy it (e.g. by setting the	161	To disable a watcher you have to destroy it (e.g. by setting the
158	variable you store it in to "undef" or otherwise deleting all references	162	variable you store it in to "undef" or otherwise deleting all references
159	to it).	163	to it).
160		164
161	All watchers are created by calling a method on the "AnyEvent" class.	165	All watchers are created by calling a method on the "AnyEvent" class.
162		166
163	Many watchers either are used with "recursion" (repeating timers for	167	Many watchers either are used with "recursion" (repeating timers for
164	example), or need to refer to their watcher object in other ways.	168	example), or need to refer to their watcher object in other ways.
165		169
166	An any way to achieve that is this pattern:	170	One way to achieve that is this pattern:
167		171
168	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	172	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
169	# you can use $w here, for example to undef it	173	# you can use $w here, for example to undef it
170	undef $w;	174	undef $w;
171	});	175	});
…		…
202		206
203	The I/O watcher might use the underlying file descriptor or a copy of	207	The I/O watcher might use the underlying file descriptor or a copy of
204	it. You must not close a file handle as long as any watcher is active on	208	it. You must not close a file handle as long as any watcher is active on
205	the underlying file descriptor.	209	the underlying file descriptor.
206		210
207	Some event loops issue spurious readyness notifications, so you should	211	Some event loops issue spurious readiness notifications, so you should
208	always use non-blocking calls when reading/writing from/to your file	212	always use non-blocking calls when reading/writing from/to your file
209	handles.	213	handles.
210		214
211	Example: wait for readability of STDIN, then read a line and disable the	215	Example: wait for readability of STDIN, then read a line and disable the
212	watcher.	216	watcher.
…		…
235		239
236	Although the callback might get passed parameters, their value and	240	Although the callback might get passed parameters, their value and
237	presence is undefined and you cannot rely on them. Portable AnyEvent	241	presence is undefined and you cannot rely on them. Portable AnyEvent
238	callbacks cannot use arguments passed to time watcher callbacks.	242	callbacks cannot use arguments passed to time watcher callbacks.
239		243
240	The callback will normally be invoked once only. If you specify another	244	The callback will normally be invoked only once. If you specify another
241	parameter, "interval", as a strictly positive number (> 0), then the	245	parameter, "interval", as a strictly positive number (> 0), then the
242	callback will be invoked regularly at that interval (in fractional	246	callback will be invoked regularly at that interval (in fractional
243	seconds) after the first invocation. If "interval" is specified with a	247	seconds) after the first invocation. If "interval" is specified with a
244	false value, then it is treated as if it were missing.	248	false value, then it is treated as if it were not specified at all.
245		249
246	The callback will be rescheduled before invoking the callback, but no	250	The callback will be rescheduled before invoking the callback, but no
247	attempt is done to avoid timer drift in most backends, so the interval	251	attempt is made to avoid timer drift in most backends, so the interval
248	is only approximate.	252	is only approximate.
249		253
250	Example: fire an event after 7.7 seconds.	254	Example: fire an event after 7.7 seconds.
251		255
252	my $w = AnyEvent->timer (after => 7.7, cb => sub {	256	my $w = AnyEvent->timer (after => 7.7, cb => sub {
…		…
269		273
270	While most event loops expect timers to specified in a relative way,	274	While most event loops expect timers to specified in a relative way,
271	they use absolute time internally. This makes a difference when your	275	they use absolute time internally. This makes a difference when your
272	clock "jumps", for example, when ntp decides to set your clock backwards	276	clock "jumps", for example, when ntp decides to set your clock backwards
273	from the wrong date of 2014-01-01 to 2008-01-01, a watcher that is	277	from the wrong date of 2014-01-01 to 2008-01-01, a watcher that is
274	supposed to fire "after" a second might actually take six years to	278	supposed to fire "after a second" might actually take six years to
275	finally fire.	279	finally fire.
276		280
277	AnyEvent cannot compensate for this. The only event loop that is	281	AnyEvent cannot compensate for this. The only event loop that is
278	conscious about these issues is EV, which offers both relative	282	conscious of these issues is EV, which offers both relative (ev_timer,
279	(ev_timer, based on true relative time) and absolute (ev_periodic, based	283	based on true relative time) and absolute (ev_periodic, based on
280	on wallclock time) timers.	284	wallclock time) timers.
281		285
282	AnyEvent always prefers relative timers, if available, matching the	286	AnyEvent always prefers relative timers, if available, matching the
283	AnyEvent API.	287	AnyEvent API.
284		288
285	AnyEvent has two additional methods that return the "current time":	289	AnyEvent has two additional methods that return the "current time":
…		…
304	*In almost all cases (in all cases if you don't care), this is the	308	*In almost all cases (in all cases if you don't care), this is the
305	function to call when you want to know the current time.*	309	function to call when you want to know the current time.*
306		310
307	This function is also often faster then "AnyEvent->time", and thus	311	This function is also often faster then "AnyEvent->time", and thus
308	the preferred method if you want some timestamp (for example,	312	the preferred method if you want some timestamp (for example,
309	AnyEvent::Handle uses this to update it's activity timeouts).	313	AnyEvent::Handle uses this to update its activity timeouts).
310		314
311	The rest of this section is only of relevance if you try to be very	315	The rest of this section is only of relevance if you try to be very
312	exact with your timing, you can skip it without bad conscience.	316	exact with your timing; you can skip it without a bad conscience.
313		317
314	For a practical example of when these times differ, consider	318	For a practical example of when these times differ, consider
315	Event::Lib and EV and the following set-up:	319	Event::Lib and EV and the following set-up:
316		320
317	The event loop is running and has just invoked one of your callback	321	The event loop is running and has just invoked one of your callbacks
318	at time=500 (assume no other callbacks delay processing). In your	322	at time=500 (assume no other callbacks delay processing). In your
319	callback, you wait a second by executing "sleep 1" (blocking the	323	callback, you wait a second by executing "sleep 1" (blocking the
320	process for a second) and then (at time=501) you create a relative	324	process for a second) and then (at time=501) you create a relative
321	timer that fires after three seconds.	325	timer that fires after three seconds.
322		326
…		…
343	can get whatever behaviour you want with any event loop, by taking	347	can get whatever behaviour you want with any event loop, by taking
344	the difference between "AnyEvent->time" and "AnyEvent->now" into	348	the difference between "AnyEvent->time" and "AnyEvent->now" into
345	account.	349	account.
346		350
347	AnyEvent->now_update	351	AnyEvent->now_update
348	Some event loops (such as EV or AnyEvent::Impl::Perl) cache the	352	Some event loops (such as EV or AnyEvent::Loop) cache the current
349	current time for each loop iteration (see the discussion of	353	time for each loop iteration (see the discussion of AnyEvent->now,
350	AnyEvent->now, above).	354	above).
351		355
352	When a callback runs for a long time (or when the process sleeps),	356	When a callback runs for a long time (or when the process sleeps),
353	then this "current" time will differ substantially from the real	357	then this "current" time will differ substantially from the real
354	time, which might affect timers and time-outs.	358	time, which might affect timers and time-outs.
355		359
…		…
411		415
412	Signal Races, Delays and Workarounds	416	Signal Races, Delays and Workarounds
413	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching	417	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
414	callbacks to signals in a generic way, which is a pity, as you cannot do	418	callbacks to signals in a generic way, which is a pity, as you cannot do
415	race-free signal handling in perl, requiring C libraries for this.	419	race-free signal handling in perl, requiring C libraries for this.
416	AnyEvent will try to do it's best, which means in some cases, signals	420	AnyEvent will try to do its best, which means in some cases, signals
417	will be delayed. The maximum time a signal might be delayed is specified	421	will be delayed. The maximum time a signal might be delayed is specified
418	in $AnyEvent::MAX_SIGNAL_LATENCY (default: 10 seconds). This variable	422	in $AnyEvent::MAX_SIGNAL_LATENCY (default: 10 seconds). This variable
419	can be changed only before the first signal watcher is created, and	423	can be changed only before the first signal watcher is created, and
420	should be left alone otherwise. This variable determines how often	424	should be left alone otherwise. This variable determines how often
421	AnyEvent polls for signals (in case a wake-up was missed). Higher values	425	AnyEvent polls for signals (in case a wake-up was missed). Higher values
…		…
423	saving.	427	saving.
424		428
425	All these problems can be avoided by installing the optional	429	All these problems can be avoided by installing the optional
426	Async::Interrupt module, which works with most event loops. It will not	430	Async::Interrupt module, which works with most event loops. It will not
427	work with inherently broken event loops such as Event or Event::Lib (and	431	work with inherently broken event loops such as Event or Event::Lib (and
428	not with POE currently, as POE does it's own workaround with one-second	432	not with POE currently, as POE does its own workaround with one-second
429	latency). For those, you just have to suffer the delays.	433	latency). For those, you just have to suffer the delays.
430		434
431	CHILD PROCESS WATCHERS	435	CHILD PROCESS WATCHERS
432	$w = AnyEvent->child (pid => <process id>, cb => <callback>);	436	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
433		437
434	You can also watch on a child process exit and catch its exit status.	438	You can also watch for a child process exit and catch its exit status.
435		439
436	The child process is specified by the "pid" argument (one some backends,	440	The child process is specified by the "pid" argument (on some backends,
437	using 0 watches for any child process exit, on others this will croak).	441	using 0 watches for any child process exit, on others this will croak).
438	The watcher will be triggered only when the child process has finished	442	The watcher will be triggered only when the child process has finished
439	and an exit status is available, not on any trace events	443	and an exit status is available, not on any trace events
440	(stopped/continued).	444	(stopped/continued).
441		445
…		…
462	This means you cannot create a child watcher as the very first thing in	466	This means you cannot create a child watcher as the very first thing in
463	an AnyEvent program, you have to create at least one watcher before	467	an AnyEvent program, you have to create at least one watcher before
464	you "fork" the child (alternatively, you can call "AnyEvent::detect").	468	you "fork" the child (alternatively, you can call "AnyEvent::detect").
465		469
466	As most event loops do not support waiting for child events, they will	470	As most event loops do not support waiting for child events, they will
467	be emulated by AnyEvent in most cases, in which the latency and race	471	be emulated by AnyEvent in most cases, in which case the latency and
468	problems mentioned in the description of signal watchers apply.	472	race problems mentioned in the description of signal watchers apply.
469		473
470	Example: fork a process and wait for it	474	Example: fork a process and wait for it
471		475
472	my $done = AnyEvent->condvar;	476	my $done = AnyEvent->condvar;
473		477
…		…
486	$done->recv;	490	$done->recv;
487		491
488	IDLE WATCHERS	492	IDLE WATCHERS
489	$w = AnyEvent->idle (cb => <callback>);	493	$w = AnyEvent->idle (cb => <callback>);
490		494
491	Repeatedly invoke the callback after the process becomes idle, until	495	This will repeatedly invoke the callback after the process becomes idle,
492	either the watcher is destroyed or new events have been detected.	496	until either the watcher is destroyed or new events have been detected.
493		497
494	Idle watchers are useful when there is a need to do something, but it is	498	Idle watchers are useful when there is a need to do something, but it is
495	not so important (or wise) to do it instantly. The callback will be	499	not so important (or wise) to do it instantly. The callback will be
496	invoked only when there is "nothing better to do", which is usually	500	invoked only when there is "nothing better to do", which is usually
497	defined as "all outstanding events have been handled and no new events	501	defined as "all outstanding events have been handled and no new events
…		…
536		540
537	AnyEvent is slightly different: it expects somebody else to run the	541	AnyEvent is slightly different: it expects somebody else to run the
538	event loop and will only block when necessary (usually when told by the	542	event loop and will only block when necessary (usually when told by the
539	user).	543	user).
540		544
541	The instrument to do that is called a "condition variable", so called	545	The tool to do that is called a "condition variable", so called because
542	because they represent a condition that must become true.	546	they represent a condition that must become true.
543		547
544	Now is probably a good time to look at the examples further below.	548	Now is probably a good time to look at the examples further below.
545		549
546	Condition variables can be created by calling the "AnyEvent->condvar"	550	Condition variables can be created by calling the "AnyEvent->condvar"
547	method, usually without arguments. The only argument pair allowed is	551	method, usually without arguments. The only argument pair allowed is
…		…
552	After creation, the condition variable is "false" until it becomes	556	After creation, the condition variable is "false" until it becomes
553	"true" by calling the "send" method (or calling the condition variable	557	"true" by calling the "send" method (or calling the condition variable
554	as if it were a callback, read about the caveats in the description for	558	as if it were a callback, read about the caveats in the description for
555	the "->send" method).	559	the "->send" method).
556		560
557	Condition variables are similar to callbacks, except that you can	561	Since condition variables are the most complex part of the AnyEvent API,
558	optionally wait for them. They can also be called merge points - points	562	here are some different mental models of what they are - pick the ones
559	in time where multiple outstanding events have been processed. And yet	563	you can connect to:
560	another way to call them is transactions - each condition variable can	564
561	be used to represent a transaction, which finishes at some point and	565	* Condition variables are like callbacks - you can call them (and pass
562	delivers a result. And yet some people know them as "futures" - a	566	them instead of callbacks). Unlike callbacks however, you can also
563	promise to compute/deliver something that you can wait for.	567	wait for them to be called.
		568
		569	* Condition variables are signals - one side can emit or send them,
		570	the other side can wait for them, or install a handler that is
		571	called when the signal fires.
		572
		573	* Condition variables are like "Merge Points" - points in your program
		574	where you merge multiple independent results/control flows into one.
		575
		576	* Condition variables represent a transaction - functions that start
		577	some kind of transaction can return them, leaving the caller the
		578	choice between waiting in a blocking fashion, or setting a callback.
		579
		580	* Condition variables represent future values, or promises to deliver
		581	some result, long before the result is available.
564		582
565	Condition variables are very useful to signal that something has	583	Condition variables are very useful to signal that something has
566	finished, for example, if you write a module that does asynchronous http	584	finished, for example, if you write a module that does asynchronous http
567	requests, then a condition variable would be the ideal candidate to	585	requests, then a condition variable would be the ideal candidate to
568	signal the availability of results. The user can either act when the	586	signal the availability of results. The user can either act when the
…		…
581		599
582	Condition variables are represented by hash refs in perl, and the keys	600	Condition variables are represented by hash refs in perl, and the keys
583	used by AnyEvent itself are all named "_ae_XXX" to make subclassing easy	601	used by AnyEvent itself are all named "_ae_XXX" to make subclassing easy
584	(it is often useful to build your own transaction class on top of	602	(it is often useful to build your own transaction class on top of
585	AnyEvent). To subclass, use "AnyEvent::CondVar" as base class and call	603	AnyEvent). To subclass, use "AnyEvent::CondVar" as base class and call
586	it's "new" method in your own "new" method.	604	its "new" method in your own "new" method.
587		605
588	There are two "sides" to a condition variable - the "producer side"	606	There are two "sides" to a condition variable - the "producer side"
589	which eventually calls "-> send", and the "consumer side", which waits	607	which eventually calls "-> send", and the "consumer side", which waits
590	for the send to occur.	608	for the send to occur.
591		609
592	Example: wait for a timer.	610	Example: wait for a timer.
593		611
594	# wait till the result is ready	612	# condition: "wait till the timer is fired"
595	my $result_ready = AnyEvent->condvar;	613	my $timer_fired = AnyEvent->condvar;
596		614
597	# do something such as adding a timer	615	# create the timer - we could wait for, say
598	# or socket watcher the calls $result_ready->send	616	# a handle becomign ready, or even an
599	# when the "result" is ready.	617	# AnyEvent::HTTP request to finish, but
600	# in this case, we simply use a timer:	618	# in this case, we simply use a timer:
601	my $w = AnyEvent->timer (	619	my $w = AnyEvent->timer (
602	after => 1,	620	after => 1,
603	cb => sub { $result_ready->send },	621	cb => sub { $timer_fired->send },
604	);	622	);
605		623
606	# this "blocks" (while handling events) till the callback	624	# this "blocks" (while handling events) till the callback
607	# calls ->send	625	# calls ->send
608	$result_ready->recv;	626	$timer_fired->recv;
609		627
610	Example: wait for a timer, but take advantage of the fact that condition	628	Example: wait for a timer, but take advantage of the fact that condition
611	variables are also callable directly.	629	variables are also callable directly.
612		630
613	my $done = AnyEvent->condvar;	631	my $done = AnyEvent->condvar;
…		…
651	Condition variables are overloaded so one can call them directly (as	669	Condition variables are overloaded so one can call them directly (as
652	if they were a code reference). Calling them directly is the same as	670	if they were a code reference). Calling them directly is the same as
653	calling "send".	671	calling "send".
654		672
655	$cv->croak ($error)	673	$cv->croak ($error)
656	Similar to send, but causes all call's to "->recv" to invoke	674	Similar to send, but causes all calls to "->recv" to invoke
657	"Carp::croak" with the given error message/object/scalar.	675	"Carp::croak" with the given error message/object/scalar.
658		676
659	This can be used to signal any errors to the condition variable	677	This can be used to signal any errors to the condition variable
660	user/consumer. Doing it this way instead of calling "croak" directly	678	user/consumer. Doing it this way instead of calling "croak" directly
661	delays the error detetcion, but has the overwhelmign advantage that	679	delays the error detection, but has the overwhelming advantage that
662	it diagnoses the error at the place where the result is expected,	680	it diagnoses the error at the place where the result is expected,
663	and not deep in some event clalback without connection to the actual	681	and not deep in some event callback with no connection to the actual
664	code causing the problem.	682	code causing the problem.
665		683
666	$cv->begin ([group callback])	684	$cv->begin ([group callback])
667	$cv->end	685	$cv->end
668	These two methods can be used to combine many transactions/events	686	These two methods can be used to combine many transactions/events
…		…
705	there is one call to "begin", so the condvar waits for all calls to	723	there is one call to "begin", so the condvar waits for all calls to
706	"end" before sending.	724	"end" before sending.
707		725
708	The ping example mentioned above is slightly more complicated, as	726	The ping example mentioned above is slightly more complicated, as
709	the there are results to be passwd back, and the number of tasks	727	the there are results to be passwd back, and the number of tasks
710	that are begung can potentially be zero:	728	that are begun can potentially be zero:
711		729
712	my $cv = AnyEvent->condvar;	730	my $cv = AnyEvent->condvar;
713		731
714	my %result;	732	my %result;
715	$cv->begin (sub { shift->send (\%result) });	733	$cv->begin (sub { shift->send (\%result) });
…		…
736	callback to be called once the counter reaches 0, and second, it	754	callback to be called once the counter reaches 0, and second, it
737	ensures that "send" is called even when "no" hosts are being pinged	755	ensures that "send" is called even when "no" hosts are being pinged
738	(the loop doesn't execute once).	756	(the loop doesn't execute once).
739		757
740	This is the general pattern when you "fan out" into multiple (but	758	This is the general pattern when you "fan out" into multiple (but
741	potentially none) subrequests: use an outer "begin"/"end" pair to	759	potentially zero) subrequests: use an outer "begin"/"end" pair to
742	set the callback and ensure "end" is called at least once, and then,	760	set the callback and ensure "end" is called at least once, and then,
743	for each subrequest you start, call "begin" and for each subrequest	761	for each subrequest you start, call "begin" and for each subrequest
744	you finish, call "end".	762	you finish, call "end".
745		763
746	METHODS FOR CONSUMERS	764	METHODS FOR CONSUMERS
747	These methods should only be used by the consuming side, i.e. the code	765	These methods should only be used by the consuming side, i.e. the code
748	awaits the condition.	766	awaits the condition.
749		767
750	$cv->recv	768	$cv->recv
751	Wait (blocking if necessary) until the "->send" or "->croak" methods	769	Wait (blocking if necessary) until the "->send" or "->croak" methods
752	have been called on c<$cv>, while servicing other watchers normally.	770	have been called on $cv, while servicing other watchers normally.
753		771
754	You can only wait once on a condition - additional calls are valid	772	You can only wait once on a condition - additional calls are valid
755	but will return immediately.	773	but will return immediately.
756		774
757	If an error condition has been set by calling "->croak", then this	775	If an error condition has been set by calling "->croak", then this
…		…
774	example, by coupling condition variables with some kind of request	792	example, by coupling condition variables with some kind of request
775	results and supporting callbacks so the caller knows that getting	793	results and supporting callbacks so the caller knows that getting
776	the result will not block, while still supporting blocking waits if	794	the result will not block, while still supporting blocking waits if
777	the caller so desires).	795	the caller so desires).
778		796
779	You can ensure that "-recv" never blocks by setting a callback and	797	You can ensure that "->recv" never blocks by setting a callback and
780	only calling "->recv" from within that callback (or at a later	798	only calling "->recv" from within that callback (or at a later
781	time). This will work even when the event loop does not support	799	time). This will work even when the event loop does not support
782	blocking waits otherwise.	800	blocking waits otherwise.
783		801
784	$bool = $cv->ready	802	$bool = $cv->ready
…		…
787		805
788	$cb = $cv->cb ($cb->($cv))	806	$cb = $cv->cb ($cb->($cv))
789	This is a mutator function that returns the callback set and	807	This is a mutator function that returns the callback set and
790	optionally replaces it before doing so.	808	optionally replaces it before doing so.
791		809
792	The callback will be called when the condition becomes (or already	810	The callback will be called when the condition becomes "true", i.e.
793	was) "true", i.e. when "send" or "croak" are called (or were	811	when "send" or "croak" are called, with the only argument being the
794	called), with the only argument being the condition variable itself.	812	condition variable itself. If the condition is already true, the
795	Calling "recv" inside the callback or at any later time is	813	callback is called immediately when it is set. Calling "recv" inside
796	guaranteed not to block.	814	the callback or at any later time is guaranteed not to block.
797		815
798	SUPPORTED EVENT LOOPS/BACKENDS	816	SUPPORTED EVENT LOOPS/BACKENDS
799	The available backend classes are (every class has its own manpage):	817	The available backend classes are (every class has its own manpage):
800		818
801	Backends that are autoprobed when no other event loop can be found.	819	Backends that are autoprobed when no other event loop can be found.
…		…
803	use. If EV is not installed, then AnyEvent will fall back to its own	821	use. If EV is not installed, then AnyEvent will fall back to its own
804	pure-perl implementation, which is available everywhere as it comes	822	pure-perl implementation, which is available everywhere as it comes
805	with AnyEvent itself.	823	with AnyEvent itself.
806		824
807	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	825	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
808	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	826	AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
809		827
810	Backends that are transparently being picked up when they are used.	828	Backends that are transparently being picked up when they are used.
811	These will be used when they are currently loaded when the first	829	These will be used if they are already loaded when the first watcher
812	watcher is created, in which case it is assumed that the application	830	is created, in which case it is assumed that the application is
813	is using them. This means that AnyEvent will automatically pick the	831	using them. This means that AnyEvent will automatically pick the
814	right backend when the main program loads an event module before	832	right backend when the main program loads an event module before
815	anything starts to create watchers. Nothing special needs to be done	833	anything starts to create watchers. Nothing special needs to be done
816	by the main program.	834	by the main program.
817		835
818	AnyEvent::Impl::Event based on Event, very stable, few glitches.	836	AnyEvent::Impl::Event based on Event, very stable, few glitches.
819	AnyEvent::Impl::Glib based on Glib, slow but very stable.	837	AnyEvent::Impl::Glib based on Glib, slow but very stable.
820	AnyEvent::Impl::Tk based on Tk, very broken.	838	AnyEvent::Impl::Tk based on Tk, very broken.
821	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	839	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
822	AnyEvent::Impl::POE based on POE, very slow, some limitations.	840	AnyEvent::Impl::POE based on POE, very slow, some limitations.
823	AnyEvent::Impl::Irssi used when running within irssi.	841	AnyEvent::Impl::Irssi used when running within irssi.
		842	AnyEvent::Impl::IOAsync based on IO::Async.
		843	AnyEvent::Impl::Cocoa based on Cocoa::EventLoop.
		844	AnyEvent::Impl::FLTK2 based on FLTK (fltk 2 binding).
824		845
825	Backends with special needs.	846	Backends with special needs.
826	Qt requires the Qt::Application to be instantiated first, but will	847	Qt requires the Qt::Application to be instantiated first, but will
827	otherwise be picked up automatically. As long as the main program	848	otherwise be picked up automatically. As long as the main program
828	instantiates the application before any AnyEvent watchers are	849	instantiates the application before any AnyEvent watchers are
829	created, everything should just work.	850	created, everything should just work.
830		851
831	AnyEvent::Impl::Qt based on Qt.	852	AnyEvent::Impl::Qt based on Qt.
832		853
833	Support for IO::Async can only be partial, as it is too broken and
834	architecturally limited to even support the AnyEvent API. It also is
835	the only event loop that needs the loop to be set explicitly, so it
836	can only be used by a main program knowing about AnyEvent. See
837	AnyEvent::Impl::Async for the gory details.
838
839	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
840
841	Event loops that are indirectly supported via other backends.	854	Event loops that are indirectly supported via other backends.
842	Some event loops can be supported via other modules:	855	Some event loops can be supported via other modules:
843		856
844	There is no direct support for WxWidgets (Wx) or Prima.	857	There is no direct support for WxWidgets (Wx) or Prima.
845		858
…		…
863	Contains "undef" until the first watcher is being created, before	876	Contains "undef" until the first watcher is being created, before
864	the backend has been autodetected.	877	the backend has been autodetected.
865		878
866	Afterwards it contains the event model that is being used, which is	879	Afterwards it contains the event model that is being used, which is
867	the name of the Perl class implementing the model. This class is	880	the name of the Perl class implementing the model. This class is
868	usually one of the "AnyEvent::Impl:xxx" modules, but can be any	881	usually one of the "AnyEvent::Impl::xxx" modules, but can be any
869	other class in the case AnyEvent has been extended at runtime (e.g.	882	other class in the case AnyEvent has been extended at runtime (e.g.
870	in rxvt-unicode it will be "urxvt::anyevent").	883	in rxvt-unicode it will be "urxvt::anyevent").
871		884
872	AnyEvent::detect	885	AnyEvent::detect
873	Returns $AnyEvent::MODEL, forcing autodetection of the event model	886	Returns $AnyEvent::MODEL, forcing autodetection of the event model
874	if necessary. You should only call this function right before you	887	if necessary. You should only call this function right before you
875	would have created an AnyEvent watcher anyway, that is, as late as	888	would have created an AnyEvent watcher anyway, that is, as late as
876	possible at runtime, and not e.g. while initialising of your module.	889	possible at runtime, and not e.g. during initialisation of your
		890	module.
		891
		892	The effect of calling this function is as if a watcher had been
		893	created (specifically, actions that happen "when the first watcher
		894	is created" happen when calling detetc as well).
877		895
878	If you need to do some initialisation before AnyEvent watchers are	896	If you need to do some initialisation before AnyEvent watchers are
879	created, use "post_detect".	897	created, use "post_detect".
880		898
881	$guard = AnyEvent::post_detect { BLOCK }	899	$guard = AnyEvent::post_detect { BLOCK }
882	Arranges for the code block to be executed as soon as the event	900	Arranges for the code block to be executed as soon as the event
883	model is autodetected (or immediately if this has already happened).	901	model is autodetected (or immediately if that has already happened).
884		902
885	The block will be executed after the actual backend has been	903	The block will be executed after the actual backend has been
886	detected ($AnyEvent::MODEL is set), but before any watchers have	904	detected ($AnyEvent::MODEL is set), but before any watchers have
887	been created, so it is possible to e.g. patch @AnyEvent::ISA or do	905	been created, so it is possible to e.g. patch @AnyEvent::ISA or do
888	other initialisations - see the sources of AnyEvent::Strict or	906	other initialisations - see the sources of AnyEvent::Strict or
…		…
897	object that automatically removes the callback again when it is	915	object that automatically removes the callback again when it is
898	destroyed (or "undef" when the hook was immediately executed). See	916	destroyed (or "undef" when the hook was immediately executed). See
899	AnyEvent::AIO for a case where this is useful.	917	AnyEvent::AIO for a case where this is useful.
900		918
901	Example: Create a watcher for the IO::AIO module and store it in	919	Example: Create a watcher for the IO::AIO module and store it in
902	$WATCHER. Only do so after the event loop is initialised, though.	920	$WATCHER, but do so only do so after the event loop is initialised.
903		921
904	our WATCHER;	922	our WATCHER;
905		923
906	my $guard = AnyEvent::post_detect {	924	my $guard = AnyEvent::post_detect {
907	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);	925	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
…		…
914		932
915	$WATCHER \|\|= $guard;	933	$WATCHER \|\|= $guard;
916		934
917	@AnyEvent::post_detect	935	@AnyEvent::post_detect
918	If there are any code references in this array (you can "push" to it	936	If there are any code references in this array (you can "push" to it
919	before or after loading AnyEvent), then they will called directly	937	before or after loading AnyEvent), then they will be called directly
920	after the event loop has been chosen.	938	after the event loop has been chosen.
921		939
922	You should check $AnyEvent::MODEL before adding to this array,	940	You should check $AnyEvent::MODEL before adding to this array,
923	though: if it is defined then the event loop has already been	941	though: if it is defined then the event loop has already been
924	detected, and the array will be ignored.	942	detected, and the array will be ignored.
…		…
943	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent	961	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
944	# as soon as it is	962	# as soon as it is
945	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };	963	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
946	}	964	}
947		965
		966	AnyEvent::postpone { BLOCK }
		967	Arranges for the block to be executed as soon as possible, but not
		968	before the call itself returns. In practise, the block will be
		969	executed just before the event loop polls for new events, or shortly
		970	afterwards.
		971
		972	This function never returns anything (to make the "return postpone {
		973	... }" idiom more useful.
		974
		975	To understand the usefulness of this function, consider a function
		976	that asynchronously does something for you and returns some
		977	transaction object or guard to let you cancel the operation. For
		978	example, "AnyEvent::Socket::tcp_connect":
		979
		980	# start a conenction attempt unless one is active
		981	$self->{connect_guard} \|\|= AnyEvent::Socket::tcp_connect "www.example.net", 80, sub {
		982	delete $self->{connect_guard};
		983	...
		984	};
		985
		986	Imagine that this function could instantly call the callback, for
		987	example, because it detects an obvious error such as a negative port
		988	number. Invoking the callback before the function returns causes
		989	problems however: the callback will be called and will try to delete
		990	the guard object. But since the function hasn't returned yet, there
		991	is nothing to delete. When the function eventually returns it will
		992	assign the guard object to "$self->{connect_guard}", where it will
		993	likely never be deleted, so the program thinks it is still trying to
		994	connect.
		995
		996	This is where "AnyEvent::postpone" should be used. Instead of
		997	calling the callback directly on error:
		998
		999	$cb->(undef), return # signal error to callback, BAD!
		1000	if $some_error_condition;
		1001
		1002	It should use "postpone":
		1003
		1004	AnyEvent::postpone { $cb->(undef) }, return # signal error to callback, later
		1005	if $some_error_condition;
		1006
		1007	AnyEvent::log $level, $msg[, @args]
		1008	Log the given $msg at the given $level.
		1009
		1010	Loads AnyEvent::Log on first use and calls "AnyEvent::Log::log" -
		1011	consequently, look at the AnyEvent::Log documentation for details.
		1012
		1013	If you want to sprinkle loads of logging calls around your code,
		1014	consider creating a logger callback with the "AnyEvent::Log::logger"
		1015	function.
		1016
948	WHAT TO DO IN A MODULE	1017	WHAT TO DO IN A MODULE
949	As a module author, you should "use AnyEvent" and call AnyEvent methods	1018	As a module author, you should "use AnyEvent" and call AnyEvent methods
950	freely, but you should not load a specific event module or rely on it.	1019	freely, but you should not load a specific event module or rely on it.
951		1020
952	Be careful when you create watchers in the module body - AnyEvent will	1021	Be careful when you create watchers in the module body - AnyEvent will
…		…
959	stall the whole program, and the whole point of using events is to stay	1028	stall the whole program, and the whole point of using events is to stay
960	interactive.	1029	interactive.
961		1030
962	It is fine, however, to call "->recv" when the user of your module	1031	It is fine, however, to call "->recv" when the user of your module
963	requests it (i.e. if you create a http request object ad have a method	1032	requests it (i.e. if you create a http request object ad have a method
964	called "results" that returns the results, it should call "->recv"	1033	called "results" that returns the results, it may call "->recv" freely,
965	freely, as the user of your module knows what she is doing. always).	1034	as the user of your module knows what she is doing. Always).
966		1035
967	WHAT TO DO IN THE MAIN PROGRAM	1036	WHAT TO DO IN THE MAIN PROGRAM
968	There will always be a single main program - the only place that should	1037	There will always be a single main program - the only place that should
969	dictate which event model to use.	1038	dictate which event model to use.
970		1039
971	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	1040	If the program is not event-based, it need not do anything special, even
972	do anything special (it does not need to be event-based) and let	1041	when it depends on a module that uses an AnyEvent. If the program itself
973	AnyEvent decide which implementation to chose if some module relies on	1042	uses AnyEvent, but does not care which event loop is used, all it needs
974	it.	1043	to do is "use AnyEvent". In either case, AnyEvent will choose the best
		1044	available loop implementation.
975		1045
976	If the main program relies on a specific event model - for example, in	1046	If the main program relies on a specific event model - for example, in
977	Gtk2 programs you have to rely on the Glib module - you should load the	1047	Gtk2 programs you have to rely on the Glib module - you should load the
978	event module before loading AnyEvent or any module that uses it:	1048	event module before loading AnyEvent or any module that uses it:
979	generally speaking, you should load it as early as possible. The reason	1049	generally speaking, you should load it as early as possible. The reason
980	is that modules might create watchers when they are loaded, and AnyEvent	1050	is that modules might create watchers when they are loaded, and AnyEvent
981	will decide on the event model to use as soon as it creates watchers,	1051	will decide on the event model to use as soon as it creates watchers,
982	and it might chose the wrong one unless you load the correct one	1052	and it might choose the wrong one unless you load the correct one
983	yourself.	1053	yourself.
984		1054
985	You can chose to use a pure-perl implementation by loading the	1055	You can chose to use a pure-perl implementation by loading the
986	"AnyEvent::Impl::Perl" module, which gives you similar behaviour	1056	"AnyEvent::Loop" module, which gives you similar behaviour everywhere,
987	everywhere, but letting AnyEvent chose the model is generally better.	1057	but letting AnyEvent chose the model is generally better.
988		1058
989	MAINLOOP EMULATION	1059	MAINLOOP EMULATION
990	Sometimes (often for short test scripts, or even standalone programs who	1060	Sometimes (often for short test scripts, or even standalone programs who
991	only want to use AnyEvent), you do not want to run a specific event	1061	only want to use AnyEvent), you do not want to run a specific event
992	loop.	1062	loop.
…		…
1004		1074
1005	OTHER MODULES	1075	OTHER MODULES
1006	The following is a non-exhaustive list of additional modules that use	1076	The following is a non-exhaustive list of additional modules that use
1007	AnyEvent as a client and can therefore be mixed easily with other	1077	AnyEvent as a client and can therefore be mixed easily with other
1008	AnyEvent modules and other event loops in the same program. Some of the	1078	AnyEvent modules and other event loops in the same program. Some of the
1009	modules come with AnyEvent, most are available via CPAN.	1079	modules come as part of AnyEvent, the others are available via CPAN (see
		1080	<http://search.cpan.org/search?m=module&q=anyevent%3A%3A*> for a longer
		1081	non-exhaustive list), and the list is heavily biased towards modules of
		1082	the AnyEvent author himself :)
1010		1083
1011	AnyEvent::Util	1084	AnyEvent::Util
1012	Contains various utility functions that replace often-used but	1085	Contains various utility functions that replace often-used blocking
1013	blocking functions such as "inet_aton" by event-/callback-based	1086	functions such as "inet_aton" with event/callback-based versions.
1014	versions.
1015		1087
1016	AnyEvent::Socket	1088	AnyEvent::Socket
1017	Provides various utility functions for (internet protocol) sockets,	1089	Provides various utility functions for (internet protocol) sockets,
1018	addresses and name resolution. Also functions to create non-blocking	1090	addresses and name resolution. Also functions to create non-blocking
1019	tcp connections or tcp servers, with IPv6 and SRV record support and	1091	tcp connections or tcp servers, with IPv6 and SRV record support and
1020	more.	1092	more.
1021		1093
1022	AnyEvent::Handle	1094	AnyEvent::Handle
1023	Provide read and write buffers, manages watchers for reads and	1095	Provide read and write buffers, manages watchers for reads and
1024	writes, supports raw and formatted I/O, I/O queued and fully	1096	writes, supports raw and formatted I/O, I/O queued and fully
1025	transparent and non-blocking SSL/TLS (via AnyEvent::TLS.	1097	transparent and non-blocking SSL/TLS (via AnyEvent::TLS).
1026		1098
1027	AnyEvent::DNS	1099	AnyEvent::DNS
1028	Provides rich asynchronous DNS resolver capabilities.	1100	Provides rich asynchronous DNS resolver capabilities.
1029		1101
		1102	AnyEvent::HTTP, AnyEvent::IRC, AnyEvent::XMPP, AnyEvent::GPSD,
		1103	AnyEvent::IGS, AnyEvent::FCP
		1104	Implement event-based interfaces to the protocols of the same name
		1105	(for the curious, IGS is the International Go Server and FCP is the
		1106	Freenet Client Protocol).
		1107
		1108	AnyEvent::Handle::UDP
		1109	Here be danger!
		1110
		1111	As Pauli would put it, "Not only is it not right, it's not even
		1112	wrong!" - there are so many things wrong with AnyEvent::Handle::UDP,
		1113	most notably its use of a stream-based API with a protocol that
		1114	isn't streamable, that the only way to improve it is to delete it.
		1115
		1116	It features data corruption (but typically only under load) and
		1117	general confusion. On top, the author is not only clueless about UDP
		1118	but also fact-resistant - some gems of his understanding: "connect
		1119	doesn't work with UDP", "UDP packets are not IP packets", "UDP only
		1120	has datagrams, not packets", "I don't need to implement proper error
		1121	checking as UDP doesn't support error checking" and so on - he
		1122	doesn't even understand what's wrong with his module when it is
		1123	explained to him.
		1124
1030	AnyEvent::HTTP	1125	AnyEvent::DBI
1031	A simple-to-use HTTP library that is capable of making a lot of	1126	Executes DBI requests asynchronously in a proxy process for you,
1032	concurrent HTTP requests.	1127	notifying you in an event-based way when the operation is finished.
		1128
		1129	AnyEvent::AIO
		1130	Truly asynchronous (as opposed to non-blocking) I/O, should be in
		1131	the toolbox of every event programmer. AnyEvent::AIO transparently
		1132	fuses IO::AIO and AnyEvent together, giving AnyEvent access to
		1133	event-based file I/O, and much more.
1033		1134
1034	AnyEvent::HTTPD	1135	AnyEvent::HTTPD
1035	Provides a simple web application server framework.	1136	A simple embedded webserver.
1036		1137
1037	AnyEvent::FastPing	1138	AnyEvent::FastPing
1038	The fastest ping in the west.	1139	The fastest ping in the west.
1039
1040	AnyEvent::DBI
1041	Executes DBI requests asynchronously in a proxy process.
1042
1043	AnyEvent::AIO
1044	Truly asynchronous I/O, should be in the toolbox of every event
1045	programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent
1046	together.
1047
1048	AnyEvent::BDB
1049	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently
1050	fuses BDB and AnyEvent together.
1051
1052	AnyEvent::GPSD
1053	A non-blocking interface to gpsd, a daemon delivering GPS
1054	information.
1055
1056	AnyEvent::IRC
1057	AnyEvent based IRC client module family (replacing the older
1058	Net::IRC3).
1059
1060	AnyEvent::XMPP
1061	AnyEvent based XMPP (Jabber protocol) module family (replacing the
1062	older Net::XMPP2>.
1063
1064	AnyEvent::IGS
1065	A non-blocking interface to the Internet Go Server protocol (used by
1066	App::IGS).
1067
1068	Net::FCP
1069	AnyEvent-based implementation of the Freenet Client Protocol,
1070	birthplace of AnyEvent.
1071
1072	Event::ExecFlow
1073	High level API for event-based execution flow control.
1074		1140
1075	Coro	1141	Coro
1076	Has special support for AnyEvent via Coro::AnyEvent.	1142	Has special support for AnyEvent via Coro::AnyEvent.
1077		1143
1078	SIMPLIFIED AE API	1144	SIMPLIFIED AE API
1079	Starting with version 5.0, AnyEvent officially supports a second, much	1145	Starting with version 5.0, AnyEvent officially supports a second, much
1080	simpler, API that is designed to reduce the calling, typing and memory	1146	simpler, API that is designed to reduce the calling, typing and memory
1081	overhead.	1147	overhead by using function call syntax and a fixed number of parameters.
1082		1148
1083	See the AE manpage for details.	1149	See the AE manpage for details.
1084		1150
1085	ERROR AND EXCEPTION HANDLING	1151	ERROR AND EXCEPTION HANDLING
1086	In general, AnyEvent does not do any error handling - it relies on the	1152	In general, AnyEvent does not do any error handling - it relies on the
…		…
1109	"PERL_ANYEVENT_VERBOSE"	1175	"PERL_ANYEVENT_VERBOSE"
1110	By default, AnyEvent will be completely silent except in fatal	1176	By default, AnyEvent will be completely silent except in fatal
1111	conditions. You can set this environment variable to make AnyEvent	1177	conditions. You can set this environment variable to make AnyEvent
1112	more talkative.	1178	more talkative.
1113		1179
1114	When set to 1 or higher, causes AnyEvent to warn about unexpected	1180	When set to 5 or higher, causes AnyEvent to warn about unexpected
1115	conditions, such as not being able to load the event model specified	1181	conditions, such as not being able to load the event model specified
1116	by "PERL_ANYEVENT_MODEL".	1182	by "PERL_ANYEVENT_MODEL".
1117		1183
1118	When set to 2 or higher, cause AnyEvent to report to STDERR which	1184	When set to 7 or higher, cause AnyEvent to report to STDERR which
1119	event model it chooses.	1185	event model it chooses.
1120		1186
1121	When set to 8 or higher, then AnyEvent will report extra information	1187	When set to 8 or higher, then AnyEvent will report extra information
1122	on which optional modules it loads and how it implements certain	1188	on which optional modules it loads and how it implements certain
1123	features.	1189	features.
…		…
1129	thoroughly check the arguments passed to most method calls. If it	1195	thoroughly check the arguments passed to most method calls. If it
1130	finds any problems, it will croak.	1196	finds any problems, it will croak.
1131		1197
1132	In other words, enables "strict" mode.	1198	In other words, enables "strict" mode.
1133		1199
1134	Unlike "use strict" (or it's modern cousin, "use common::sense", it	1200	Unlike "use strict" (or its modern cousin, "use common::sense", it
1135	is definitely recommended to keep it off in production. Keeping	1201	is definitely recommended to keep it off in production. Keeping
1136	"PERL_ANYEVENT_STRICT=1" in your environment while developing	1202	"PERL_ANYEVENT_STRICT=1" in your environment while developing
1137	programs can be very useful, however.	1203	programs can be very useful, however.
1138		1204
		1205	"PERL_ANYEVENT_DEBUG_SHELL"
		1206	If this env variable is set, then its contents will be interpreted
		1207	by "AnyEvent::Socket::parse_hostport" (after replacing every
		1208	occurance of $$ by the process pid) and an "AnyEvent::Debug::shell"
		1209	is bound on that port. The shell object is saved in
		1210	$AnyEvent::Debug::SHELL.
		1211
		1212	This takes place when the first watcher is created.
		1213
		1214	For example, to bind a debug shell on a unix domain socket in
		1215	/tmp/debug<pid>.sock, you could use this:
		1216
		1217	PERL_ANYEVENT_DEBUG_SHELL=/tmp/debug\$\$.sock perlprog
		1218
		1219	Note that creating sockets in /tmp is very unsafe on multiuser
		1220	systems.
		1221
		1222	"PERL_ANYEVENT_DEBUG_WRAP"
		1223	Can be set to 0, 1 or 2 and enables wrapping of all watchers for
		1224	debugging purposes. See "AnyEvent::Debug::wrap" for details.
		1225
1139	"PERL_ANYEVENT_MODEL"	1226	"PERL_ANYEVENT_MODEL"
1140	This can be used to specify the event model to be used by AnyEvent,	1227	This can be used to specify the event model to be used by AnyEvent,
1141	before auto detection and -probing kicks in. It must be a string	1228	before auto detection and -probing kicks in.
1142	consisting entirely of ASCII letters. The string "AnyEvent::Impl::"	1229
1143	gets prepended and the resulting module name is loaded and if the	1230	It normally is a string consisting entirely of ASCII letters (e.g.
1144	load was successful, used as event model. If it fails to load	1231	"EV" or "IOAsync"). The string "AnyEvent::Impl::" gets prepended and
		1232	the resulting module name is loaded and - if the load was successful
		1233	- used as event model backend. If it fails to load then AnyEvent
1145	AnyEvent will proceed with auto detection and -probing.	1234	will proceed with auto detection and -probing.
1146		1235
1147	This functionality might change in future versions.	1236	If the string ends with "::" instead (e.g. "AnyEvent::Impl::EV::")
		1237	then nothing gets prepended and the module name is used as-is (hint:
		1238	"::" at the end of a string designates a module name and quotes it
		1239	appropriately).
1148		1240
1149	For example, to force the pure perl model (AnyEvent::Impl::Perl) you	1241	For example, to force the pure perl model (AnyEvent::Loop::Perl) you
1150	could start your program like this:	1242	could start your program like this:
1151		1243
1152	PERL_ANYEVENT_MODEL=Perl perl ...	1244	PERL_ANYEVENT_MODEL=Perl perl ...
1153		1245
1154	"PERL_ANYEVENT_PROTOCOLS"	1246	"PERL_ANYEVENT_PROTOCOLS"
…		…
1351		1443
1352	The actual code goes further and collects all errors ("die"s,	1444	The actual code goes further and collects all errors ("die"s,
1353	exceptions) that occurred during request processing. The "result" method	1445	exceptions) that occurred during request processing. The "result" method
1354	detects whether an exception as thrown (it is stored inside the $txn	1446	detects whether an exception as thrown (it is stored inside the $txn
1355	object) and just throws the exception, which means connection errors and	1447	object) and just throws the exception, which means connection errors and
1356	other problems get reported tot he code that tries to use the result,	1448	other problems get reported to the code that tries to use the result,
1357	not in a random callback.	1449	not in a random callback.
1358		1450
1359	All of this enables the following usage styles:	1451	All of this enables the following usage styles:
1360		1452
1361	1. Blocking:	1453	1. Blocking:
…		…
1527	when used without AnyEvent), but most event loops have acceptable	1619	when used without AnyEvent), but most event loops have acceptable
1528	performance with or without AnyEvent.	1620	performance with or without AnyEvent.
1529		1621
1530	* The overhead AnyEvent adds is usually much smaller than the overhead	1622	* The overhead AnyEvent adds is usually much smaller than the overhead
1531	of the actual event loop, only with extremely fast event loops such	1623	of the actual event loop, only with extremely fast event loops such
1532	as EV adds AnyEvent significant overhead.	1624	as EV does AnyEvent add significant overhead.
1533		1625
1534	* You should avoid POE like the plague if you want performance or	1626	* You should avoid POE like the plague if you want performance or
1535	reasonable memory usage.	1627	reasonable memory usage.
1536		1628
1537	BENCHMARKING THE LARGE SERVER CASE	1629	BENCHMARKING THE LARGE SERVER CASE
…		…
1735		1827
1736	Feel free to install your own handler, or reset it to defaults.	1828	Feel free to install your own handler, or reset it to defaults.
1737		1829
1738	RECOMMENDED/OPTIONAL MODULES	1830	RECOMMENDED/OPTIONAL MODULES
1739	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and	1831	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
1740	it's built-in modules) are required to use it.	1832	its built-in modules) are required to use it.
1741		1833
1742	That does not mean that AnyEvent won't take advantage of some additional	1834	That does not mean that AnyEvent won't take advantage of some additional
1743	modules if they are installed.	1835	modules if they are installed.
1744		1836
1745	This section explains which additional modules will be used, and how	1837	This section explains which additional modules will be used, and how
…		…
1774	clock is available, can take avdantage of advanced kernel interfaces	1866	clock is available, can take avdantage of advanced kernel interfaces
1775	such as "epoll" and "kqueue", and is the fastest backend by far.	1867	such as "epoll" and "kqueue", and is the fastest backend by far.
1776	You can even embed Glib/Gtk2 in it (or vice versa, see EV::Glib and	1868	You can even embed Glib/Gtk2 in it (or vice versa, see EV::Glib and
1777	Glib::EV).	1869	Glib::EV).
1778		1870
		1871	If you only use backends that rely on another event loop (e.g.
		1872	"Tk"), then this module will do nothing for you.
		1873
1779	Guard	1874	Guard
1780	The guard module, when used, will be used to implement	1875	The guard module, when used, will be used to implement
1781	"AnyEvent::Util::guard". This speeds up guards considerably (and	1876	"AnyEvent::Util::guard". This speeds up guards considerably (and
1782	uses a lot less memory), but otherwise doesn't affect guard	1877	uses a lot less memory), but otherwise doesn't affect guard
1783	operation much. It is purely used for performance.	1878	operation much. It is purely used for performance.
1784		1879
1785	JSON and JSON::XS	1880	JSON and JSON::XS
1786	One of these modules is required when you want to read or write JSON	1881	One of these modules is required when you want to read or write JSON
1787	data via AnyEvent::Handle. It is also written in pure-perl, but can	1882	data via AnyEvent::Handle. JSON is also written in pure-perl, but
1788	take advantage of the ultra-high-speed JSON::XS module when it is	1883	can take advantage of the ultra-high-speed JSON::XS module when it
1789	installed.	1884	is installed.
1790
1791	In fact, AnyEvent::Handle will use JSON::XS by default if it is
1792	installed.
1793		1885
1794	Net::SSLeay	1886	Net::SSLeay
1795	Implementing TLS/SSL in Perl is certainly interesting, but not very	1887	Implementing TLS/SSL in Perl is certainly interesting, but not very
1796	worthwhile: If this module is installed, then AnyEvent::Handle (with	1888	worthwhile: If this module is installed, then AnyEvent::Handle (with
1797	the help of AnyEvent::TLS), gains the ability to do TLS/SSL.	1889	the help of AnyEvent::TLS), gains the ability to do TLS/SSL.
1798		1890
1799	Time::HiRes	1891	Time::HiRes
1800	This module is part of perl since release 5.008. It will be used	1892	This module is part of perl since release 5.008. It will be used
1801	when the chosen event library does not come with a timing source on	1893	when the chosen event library does not come with a timing source of
1802	it's own. The pure-perl event loop (AnyEvent::Impl::Perl) will	1894	its own. The pure-perl event loop (AnyEvent::Loop) will additionally
1803	additionally use it to try to use a monotonic clock for timing	1895	load it to try to use a monotonic clock for timing stability.
1804	stability.
1805		1896
1806	FORK	1897	FORK
1807	Most event libraries are not fork-safe. The ones who are usually are	1898	Most event libraries are not fork-safe. The ones who are usually are
1808	because they rely on inefficient but fork-safe "select" or "poll" calls	1899	because they rely on inefficient but fork-safe "select" or "poll" calls
1809	- higher performance APIs such as BSD's kqueue or the dreaded Linux	1900	- higher performance APIs such as BSD's kqueue or the dreaded Linux
…		…
1860	5.10 and check wether the leaks still show up. (Perl 5.10.0 has other	1951	5.10 and check wether the leaks still show up. (Perl 5.10.0 has other
1861	annoying memleaks, such as leaking on "map" and "grep" but it is usually	1952	annoying memleaks, such as leaking on "map" and "grep" but it is usually
1862	not as pronounced).	1953	not as pronounced).
1863		1954
1864	SEE ALSO	1955	SEE ALSO
1865	Utility functions: AnyEvent::Util.	1956	Tutorial/Introduction: AnyEvent::Intro.
1866		1957
1867	Event modules: EV, EV::Glib, Glib::EV, Event, Glib::Event, Glib, Tk,	1958	FAQ: AnyEvent::FAQ.
1868	Event::Lib, Qt, POE.	1959
		1960	Utility functions: AnyEvent::Util (misc. grab-bag), AnyEvent::Log
		1961	(simply logging).
		1962
		1963	Development/Debugging: AnyEvent::Strict (stricter checking),
		1964	AnyEvent::Debug (interactive shell, watcher tracing).
		1965
		1966	Supported event modules: AnyEvent::Loop, EV, EV::Glib, Glib::EV, Event,
		1967	Glib::Event, Glib, Tk, Event::Lib, Qt, POE, FLTK.
1869		1968
1870	Implementations: AnyEvent::Impl::EV, AnyEvent::Impl::Event,	1969	Implementations: AnyEvent::Impl::EV, AnyEvent::Impl::Event,
1871	AnyEvent::Impl::Glib, AnyEvent::Impl::Tk, AnyEvent::Impl::Perl,	1970	AnyEvent::Impl::Glib, AnyEvent::Impl::Tk, AnyEvent::Impl::Perl,
1872	AnyEvent::Impl::EventLib, AnyEvent::Impl::Qt, AnyEvent::Impl::POE,	1971	AnyEvent::Impl::EventLib, AnyEvent::Impl::Qt, AnyEvent::Impl::POE,
1873	AnyEvent::Impl::IOAsync, Anyevent::Impl::Irssi.	1972	AnyEvent::Impl::IOAsync, Anyevent::Impl::Irssi, AnyEvent::Impl::FLTK.
1874		1973
1875	Non-blocking file handles, sockets, TCP clients and servers:	1974	Non-blocking handles, pipes, stream sockets, TCP clients and servers:
1876	AnyEvent::Handle, AnyEvent::Socket, AnyEvent::TLS.	1975	AnyEvent::Handle, AnyEvent::Socket, AnyEvent::TLS.
1877		1976
1878	Asynchronous DNS: AnyEvent::DNS.	1977	Asynchronous DNS: AnyEvent::DNS.
1879		1978
1880	Coroutine support: Coro, Coro::AnyEvent, Coro::EV, Coro::Event,	1979	Thread support: Coro, Coro::AnyEvent, Coro::EV, Coro::Event.
1881		1980
1882	Nontrivial usage examples: AnyEvent::GPSD, AnyEvent::XMPP,	1981	Nontrivial usage examples: AnyEvent::GPSD, AnyEvent::IRC,
1883	AnyEvent::HTTP.	1982	AnyEvent::HTTP.
1884		1983
1885	AUTHOR	1984	AUTHOR
1886	Marc Lehmann <schmorp@schmorp.de>	1985	Marc Lehmann <schmorp@schmorp.de>
1887	http://home.schmorp.de/	1986	http://home.schmorp.de/

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Comparing AnyEvent/README (file contents): Revision 1.59 by root, Tue Jan 5 10:45:25 2010 UTC vs. Revision 1.66 by root, Sun Aug 21 03:02:32 2011 UTC

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Comparing AnyEvent/README (file contents):
Revision 1.59 by root, Tue Jan 5 10:45:25 2010 UTC vs.
Revision 1.66 by root, Sun Aug 21 03:02:32 2011 UTC