ViewVC Help

View File | Revision Log | Show Annotations | Download File

/cvs/AnyEvent/lib/AnyEvent.pm

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.263 by root, Wed Jul 29 12:39:21 2009 UTC vs.
Revision 1.341 by root, Sun Dec 5 11:41:45 2010 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 AE manpage for
		13	# an alternative API.
		14
12	# file descriptor readable	15	# file handle or descriptor readable
13	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });	16	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
14		17
15	# one-shot or repeating timers	18	# one-shot or repeating timers
16	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });	19	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
17	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...	20	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...);
18		21
19	print AnyEvent->now; # prints current event loop time	22	print AnyEvent->now; # prints current event loop time
20	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.	23	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
21		24
22	# POSIX signal	25	# POSIX signal
…		…
43	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
44	L<AnyEvent::Intro> manpage.	47	L<AnyEvent::Intro> manpage.
45		48
46	=head1 SUPPORT	49	=head1 SUPPORT
47		50
		51	An FAQ document is available as L<AnyEvent::FAQ>.
		52
48	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
49	channel, too.	54	channel, too.
50		55
51	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
52	Repository>, at L<http://anyevent.schmorp.de>, for more info.	57	Repository>, at L<http://anyevent.schmorp.de>, for more info.
53		58
…		…
73	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
74	model you use.	79	model you use.
75		80
76	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
77	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
78	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
79	cannot use anything else, as they are simply incompatible to everything	84	cannot use anything else, as they are simply incompatible to everything
80	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
81	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.
82		87
83	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	88	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
84	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
85	with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if	90	with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if
86	your module uses one of those, every user of your module has to use it,	91	your module uses one of those, every user of your module has to use it,
87	too. But if your module uses AnyEvent, it works transparently with all	92	too. But if your module uses AnyEvent, it works transparently with all
88	event models it supports (including stuff like IO::Async, as long as those	93	event models it supports (including stuff like IO::Async, as long as those
89	use one of the supported event loops. It is trivial to add new event loops	94	use one of the supported event loops. It is easy to add new event loops
90	to AnyEvent, too, so it is future-proof).	95	to AnyEvent, too, so it is future-proof).
91		96
92	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
93	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
94	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
95	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
96	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
97	technically possible.	102	technically possible.
98		103
99	Of course, AnyEvent comes with a big (and fully optional!) toolbox	104	Of course, AnyEvent comes with a big (and fully optional!) toolbox
100	of useful functionality, such as an asynchronous DNS resolver, 100%	105	of useful functionality, such as an asynchronous DNS resolver, 100%
…		…
106	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
107	model, you should I<not> use this module.	112	model, you should I<not> use this module.
108		113
109	=head1 DESCRIPTION	114	=head1 DESCRIPTION
110		115
111	L<AnyEvent> provides an identical interface to multiple event loops. This	116	L<AnyEvent> provides a uniform interface to various event loops. This
112	allows module authors to utilise an event loop without forcing module	117	allows module authors to use event loop functionality without forcing
113	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
114	peacefully at any one time).	119	than one event loop cannot coexist peacefully).
115		120
116	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>
117	module.	122	module.
118		123
119	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
120	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
121	following modules is already loaded: L<EV>,	126	following modules is already loaded: L<EV>, L<AnyEvent::Impl::Perl>,
122	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
123	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
124	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
125	adaptor should always succeed) in the order given. The first one that can	130	available, the pure-perl L<AnyEvent::Impl::Perl> should always work, so
126	be successfully loaded will be used. If, after this, still none could be	131	the other two are not normally tried.
127	found, AnyEvent will fall back to a pure-perl event loop, which is not
128	very efficient, but should work everywhere.
129		132
130	Because AnyEvent first checks for modules that are already loaded, loading	133	Because AnyEvent first checks for modules that are already loaded, loading
131	an event model explicitly before first using AnyEvent will likely make	134	an event model explicitly before first using AnyEvent will likely make
132	that model the default. For example:	135	that model the default. For example:
133		136
…		…
135	use AnyEvent;	138	use AnyEvent;
136		139
137	# .. AnyEvent will likely default to Tk	140	# .. AnyEvent will likely default to Tk
138		141
139	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
140	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,
141	use AnyEvent so their modules work together with others seamlessly...	144	as very few modules hardcode event loops without announcing this very
		145	loudly.
142		146
143	The pure-perl implementation of AnyEvent is called	147	The pure-perl implementation of AnyEvent is called
144	C<AnyEvent::Impl::Perl>. Like other event modules you can load it	148	C<AnyEvent::Impl::Perl>. Like other event modules you can load it
145	explicitly and enjoy the high availability of that event loop :)	149	explicitly and enjoy the high availability of that event loop :)
146		150
…		…
155	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
156	is in control).	160	is in control).
157		161
158	Note that B<callbacks must not permanently change global variables>	162	Note that B<callbacks must not permanently change global variables>
159	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<<
160	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
161	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
162	widely between event loops.	166	widely between event loops.
163		167
164	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
165	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
166	to it).	170	to it).
167		171
168	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.
169		173
170	Many watchers either are used with "recursion" (repeating timers for	174	Many watchers either are used with "recursion" (repeating timers for
171	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.
172		176
173	An any way to achieve that is this pattern:	177	One way to achieve that is this pattern:
174		178
175	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	179	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
176	# you can use $w here, for example to undef it	180	# you can use $w here, for example to undef it
177	undef $w;	181	undef $w;
178	});	182	});
…		…
180	Note that C<my $w; $w => combination. This is necessary because in Perl,	184	Note that C<my $w; $w => combination. This is necessary because in Perl,
181	my variables are only visible after the statement in which they are	185	my variables are only visible after the statement in which they are
182	declared.	186	declared.
183		187
184	=head2 I/O WATCHERS	188	=head2 I/O WATCHERS
		189
		190	$w = AnyEvent->io (
		191	fh => <filehandle_or_fileno>,
		192	poll => <"r" or "w">,
		193	cb => <callback>,
		194	);
185		195
186	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	196	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
187	with the following mandatory key-value pairs as arguments:	197	with the following mandatory key-value pairs as arguments:
188		198
189	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch	199	C<fh> is the Perl I<file handle> (or a naked file descriptor) to watch
…		…
204		214
205	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.
206	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
207	underlying file descriptor.	217	underlying file descriptor.
208		218
209	Some event loops issue spurious readyness notifications, so you should	219	Some event loops issue spurious readiness notifications, so you should
210	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
211	handles.	221	handles.
212		222
213	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
214	watcher.	224	watcher.
…		…
219	undef $w;	229	undef $w;
220	});	230	});
221		231
222	=head2 TIME WATCHERS	232	=head2 TIME WATCHERS
223		233
		234	$w = AnyEvent->timer (after => <seconds>, cb => <callback>);
		235
		236	$w = AnyEvent->timer (
		237	after => <fractional_seconds>,
		238	interval => <fractional_seconds>,
		239	cb => <callback>,
		240	);
		241
224	You can create a time watcher by calling the C<< AnyEvent->timer >>	242	You can create a time watcher by calling the C<< AnyEvent->timer >>
225	method with the following mandatory arguments:	243	method with the following mandatory arguments:
226		244
227	C<after> specifies after how many seconds (fractional values are	245	C<after> specifies after how many seconds (fractional values are
228	supported) the callback should be invoked. C<cb> is the callback to invoke	246	supported) the callback should be invoked. C<cb> is the callback to invoke
…		…
230		248
231	Although the callback might get passed parameters, their value and	249	Although the callback might get passed parameters, their value and
232	presence is undefined and you cannot rely on them. Portable AnyEvent	250	presence is undefined and you cannot rely on them. Portable AnyEvent
233	callbacks cannot use arguments passed to time watcher callbacks.	251	callbacks cannot use arguments passed to time watcher callbacks.
234		252
235	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
236	parameter, C<interval>, as a strictly positive number (> 0), then the	254	parameter, C<interval>, as a strictly positive number (> 0), then the
237	callback will be invoked regularly at that interval (in fractional	255	callback will be invoked regularly at that interval (in fractional
238	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
239	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.
240		258
241	The callback will be rescheduled before invoking the callback, but no	259	The callback will be rescheduled before invoking the callback, but no
242	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
243	only approximate.	261	only approximate.
244		262
245	Example: fire an event after 7.7 seconds.	263	Example: fire an event after 7.7 seconds.
246		264
247	my $w = AnyEvent->timer (after => 7.7, cb => sub {	265	my $w = AnyEvent->timer (after => 7.7, cb => sub {
…		…
265		283
266	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
267	use absolute time internally. This makes a difference when your clock	285	use absolute time internally. This makes a difference when your clock
268	"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
269	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
270	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.
271		289
272	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
273	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
274	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)
275	timers.	293	timers.
276		294
277	AnyEvent always prefers relative timers, if available, matching the	295	AnyEvent always prefers relative timers, if available, matching the
278	AnyEvent API.	296	AnyEvent API.
…		…
300	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
301	function to call when you want to know the current time.>	319	function to call when you want to know the current time.>
302		320
303	This function is also often faster then C<< AnyEvent->time >>, and	321	This function is also often faster then C<< AnyEvent->time >>, and
304	thus the preferred method if you want some timestamp (for example,	322	thus the preferred method if you want some timestamp (for example,
305	L<AnyEvent::Handle> uses this to update it's activity timeouts).	323	L<AnyEvent::Handle> uses this to update its activity timeouts).
306		324
307	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
308	with your timing, you can skip it without bad conscience.	326	with your timing; you can skip it without a bad conscience.
309		327
310	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>
311	and L<EV> and the following set-up:	329	and L<EV> and the following set-up:
312		330
313	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
314	time=500 (assume no other callbacks delay processing). In your callback,	332	time=500 (assume no other callbacks delay processing). In your callback,
315	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
316	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
317	after three seconds.	335	after three seconds.
318		336
…		…
349	might affect timers and time-outs.	367	might affect timers and time-outs.
350		368
351	When this is the case, you can call this method, which will update the	369	When this is the case, you can call this method, which will update the
352	event loop's idea of "current time".	370	event loop's idea of "current time".
353		371
		372	A typical example would be a script in a web server (e.g. C<mod_perl>) -
		373	when mod_perl executes the script, then the event loop will have the wrong
		374	idea about the "current time" (being potentially far in the past, when the
		375	script ran the last time). In that case you should arrange a call to C<<
		376	AnyEvent->now_update >> each time the web server process wakes up again
		377	(e.g. at the start of your script, or in a handler).
		378
354	Note that updating the time I<might> cause some events to be handled.	379	Note that updating the time I<might> cause some events to be handled.
355		380
356	=back	381	=back
357		382
358	=head2 SIGNAL WATCHERS	383	=head2 SIGNAL WATCHERS
		384
		385	$w = AnyEvent->signal (signal => <uppercase_signal_name>, cb => <callback>);
359		386
360	You can watch for signals using a signal watcher, C<signal> is the signal	387	You can watch for signals using a signal watcher, C<signal> is the signal
361	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl	388	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
362	callback to be invoked whenever a signal occurs.	389	callback to be invoked whenever a signal occurs.
363		390
…		…
380		407
381	Example: exit on SIGINT	408	Example: exit on SIGINT
382		409
383	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	410	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
384		411
		412	=head3 Restart Behaviour
		413
		414	While restart behaviour is up to the event loop implementation, most will
		415	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		416	pure perl implementation).
		417
		418	=head3 Safe/Unsafe Signals
		419
		420	Perl signals can be either "safe" (synchronous to opcode handling) or
		421	"unsafe" (asynchronous) - the former might get delayed indefinitely, the
		422	latter might corrupt your memory.
		423
		424	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		425	i.e. they will not interrupt your running perl program but will only be
		426	called as part of the normal event handling (just like timer, I/O etc.
		427	callbacks, too).
		428
385	=head3 Signal Races, Delays and Workarounds	429	=head3 Signal Races, Delays and Workarounds
386		430
387	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching	431	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
388	callbacks to signals in a generic way, which is a pity, as you cannot do	432	callbacks to signals in a generic way, which is a pity, as you cannot
389	race-free signal handling in perl. AnyEvent will try to do it's best, but	433	do race-free signal handling in perl, requiring C libraries for
		434	this. AnyEvent will try to do its best, which means in some cases,
390	in some cases, signals will be delayed. The maximum time a signal might	435	signals will be delayed. The maximum time a signal might be delayed is
391	be delayed is specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10	436	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
392	seconds). This variable can be changed only before the first signal	437	variable can be changed only before the first signal watcher is created,
393	watcher is created, and should be left alone otherwise. Higher values	438	and should be left alone otherwise. This variable determines how often
		439	AnyEvent polls for signals (in case a wake-up was missed). Higher values
394	will cause fewer spurious wake-ups, which is better for power and CPU	440	will cause fewer spurious wake-ups, which is better for power and CPU
		441	saving.
		442
395	saving. All these problems can be avoided by installing the optional	443	All these problems can be avoided by installing the optional
396	L<Async::Interrupt> module. This will not work with inherently broken	444	L<Async::Interrupt> module, which works with most event loops. It will not
397	event loops such as L<Event> or L<Event::Lib> (and not with L<POE>	445	work with inherently broken event loops such as L<Event> or L<Event::Lib>
398	currently, as POE does it's own workaround with one-second latency). With	446	(and not with L<POE> currently, as POE does its own workaround with
399	those, you just have to suffer the delays.	447	one-second latency). For those, you just have to suffer the delays.
400		448
401	=head2 CHILD PROCESS WATCHERS	449	=head2 CHILD PROCESS WATCHERS
402		450
		451	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
		452
403	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.
404		454
405	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,
406	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
407	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
408	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
409	(stopped/continued).	459	(stopped/continued).
410		460
…		…
455	# do something else, then wait for process exit	505	# do something else, then wait for process exit
456	$done->recv;	506	$done->recv;
457		507
458	=head2 IDLE WATCHERS	508	=head2 IDLE WATCHERS
459		509
460	Sometimes there is a need to do something, but it is not so important	510	$w = AnyEvent->idle (cb => <callback>);
461	to do it instantly, but only when there is nothing better to do. This
462	"nothing better to do" is usually defined to be "no other events need
463	attention by the event loop".
464		511
465	Idle watchers ideally get invoked when the event loop has nothing	512	This will repeatedly invoke the callback after the process becomes idle,
466	better to do, just before it would block the process to wait for new	513	until either the watcher is destroyed or new events have been detected.
467	events. Instead of blocking, the idle watcher is invoked.
468		514
469	Most event loops unfortunately do not really support idle watchers (only	515	Idle watchers are useful when there is a need to do something, but it
		516	is not so important (or wise) to do it instantly. The callback will be
		517	invoked only when there is "nothing better to do", which is usually
		518	defined as "all outstanding events have been handled and no new events
		519	have been detected". That means that idle watchers ideally get invoked
		520	when the event loop has just polled for new events but none have been
		521	detected. Instead of blocking to wait for more events, the idle watchers
		522	will be invoked.
		523
		524	Unfortunately, most event loops do not really support idle watchers (only
470	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent	525	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
471	will simply call the callback "from time to time".	526	will simply call the callback "from time to time".
472		527
473	Example: read lines from STDIN, but only process them when the	528	Example: read lines from STDIN, but only process them when the
474	program is otherwise idle:	529	program is otherwise idle:
…		…
490	});	545	});
491	});	546	});
492		547
493	=head2 CONDITION VARIABLES	548	=head2 CONDITION VARIABLES
494		549
		550	$cv = AnyEvent->condvar;
		551
		552	$cv->send (<list>);
		553	my @res = $cv->recv;
		554
495	If you are familiar with some event loops you will know that all of them	555	If you are familiar with some event loops you will know that all of them
496	require you to run some blocking "loop", "run" or similar function that	556	require you to run some blocking "loop", "run" or similar function that
497	will actively watch for new events and call your callbacks.	557	will actively watch for new events and call your callbacks.
498		558
499	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
500	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).
501		561
502	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
503	because they represent a condition that must become true.	563	they represent a condition that must become true.
504		564
505	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.
506		566
507	Condition variables can be created by calling the C<< AnyEvent->condvar	567	Condition variables can be created by calling the C<< AnyEvent->condvar
508	>> method, usually without arguments. The only argument pair allowed is	568	>> method, usually without arguments. The only argument pair allowed is
…		…
513	After creation, the condition variable is "false" until it becomes "true"	573	After creation, the condition variable is "false" until it becomes "true"
514	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
515	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<<
516	->send >> method).	576	->send >> method).
517		577
518	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
519	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:
520	in time where multiple outstanding events have been processed. And yet	580
521	another way to call them is transactions - each condition variable can be	581	=over 4
522	used to represent a transaction, which finishes at some point and delivers	582
523	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
524	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
525		601
526	Condition variables are very useful to signal that something has finished,	602	Condition variables are very useful to signal that something has finished,
527	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,
528	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
529	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
…		…
542		618
543	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
544	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
545	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
546	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
547	it's C<new> method in your own C<new> method.	623	its C<new> method in your own C<new> method.
548		624
549	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
550	eventually calls C<< -> send >>, and the "consumer side", which waits	626	eventually calls C<< -> send >>, and the "consumer side", which waits
551	for the send to occur.	627	for the send to occur.
552		628
553	Example: wait for a timer.	629	Example: wait for a timer.
554		630
555	# wait till the result is ready	631	# condition: "wait till the timer is fired"
556	my $result_ready = AnyEvent->condvar;	632	my $timer_fired = AnyEvent->condvar;
557		633
558	# do something such as adding a timer	634	# create the timer - we could wait for, say
559	# or socket watcher the calls $result_ready->send	635	# a handle becomign ready, or even an
560	# when the "result" is ready.	636	# AnyEvent::HTTP request to finish, but
561	# in this case, we simply use a timer:	637	# in this case, we simply use a timer:
562	my $w = AnyEvent->timer (	638	my $w = AnyEvent->timer (
563	after => 1,	639	after => 1,
564	cb => sub { $result_ready->send },	640	cb => sub { $timer_fired->send },
565	);	641	);
566		642
567	# this "blocks" (while handling events) till the callback	643	# this "blocks" (while handling events) till the callback
568	# calls -<send	644	# calls ->send
569	$result_ready->recv;	645	$timer_fired->recv;
570		646
571	Example: wait for a timer, but take advantage of the fact that condition	647	Example: wait for a timer, but take advantage of the fact that condition
572	variables are also callable directly.	648	variables are also callable directly.
573		649
574	my $done = AnyEvent->condvar;	650	my $done = AnyEvent->condvar;
…		…
617	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
618	C<send>.	694	C<send>.
619		695
620	=item $cv->croak ($error)	696	=item $cv->croak ($error)
621		697
622	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
623	C<Carp::croak> with the given error message/object/scalar.	699	C<Carp::croak> with the given error message/object/scalar.
624		700
625	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
626	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
627	delays the error detetcion, but has the overwhelmign advantage that it	703	delays the error detection, but has the overwhelming advantage that it
628	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
629	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
630	the problem.	706	the problem.
631		707
632	=item $cv->begin ([group callback])	708	=item $cv->begin ([group callback])
633		709
634	=item $cv->end	710	=item $cv->end
…		…
637	one. For example, a function that pings many hosts in parallel might want	713	one. For example, a function that pings many hosts in parallel might want
638	to use a condition variable for the whole process.	714	to use a condition variable for the whole process.
639		715
640	Every call to C<< ->begin >> will increment a counter, and every call to	716	Every call to C<< ->begin >> will increment a counter, and every call to
641	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end	717	C<< ->end >> will decrement it. If the counter reaches C<0> in C<< ->end
642	>>, the (last) callback passed to C<begin> will be executed. That callback	718	>>, the (last) callback passed to C<begin> will be executed, passing the
643	is I<supposed> to call C<< ->send >>, but that is not required. If no	719	condvar as first argument. That callback is I<supposed> to call C<< ->send
644	callback was set, C<send> will be called without any arguments.	720	>>, but that is not required. If no group callback was set, C<send> will
		721	be called without any arguments.
645		722
646	You can think of C<< $cv->send >> giving you an OR condition (one call	723	You can think of C<< $cv->send >> giving you an OR condition (one call
647	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND	724	sends), while C<< $cv->begin >> and C<< $cv->end >> giving you an AND
648	condition (all C<begin> calls must be C<end>'ed before the condvar sends).	725	condition (all C<begin> calls must be C<end>'ed before the condvar sends).
649		726
…		…
671	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
672	sending.	749	sending.
673		750
674	The ping example mentioned above is slightly more complicated, as the	751	The ping example mentioned above is slightly more complicated, as the
675	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
676	begung can potentially be zero:	753	begun can potentially be zero:
677		754
678	my $cv = AnyEvent->condvar;	755	my $cv = AnyEvent->condvar;
679		756
680	my %result;	757	my %result;
681	$cv->begin (sub { $cv->send (\%result) });	758	$cv->begin (sub { shift->send (\%result) });
682		759
683	for my $host (@list_of_hosts) {	760	for my $host (@list_of_hosts) {
684	$cv->begin;	761	$cv->begin;
685	ping_host_then_call_callback $host, sub {	762	ping_host_then_call_callback $host, sub {
686	$result{$host} = ...;	763	$result{$host} = ...;
…		…
702	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
703	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
704	doesn't execute once).	781	doesn't execute once).
705		782
706	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
707	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
708	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
709	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,
710	call C<end>.	787	call C<end>.
711		788
712	=back	789	=back
…		…
719	=over 4	796	=over 4
720		797
721	=item $cv->recv	798	=item $cv->recv
722		799
723	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak	800	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
724	>> methods have been called on c<$cv>, while servicing other watchers	801	>> methods have been called on C<$cv>, while servicing other watchers
725	normally.	802	normally.
726		803
727	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
728	will return immediately.	805	will return immediately.
729		806
…		…
746	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
747	condition variables with some kind of request results and supporting	824	condition variables with some kind of request results and supporting
748	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,
749	while still supporting blocking waits if the caller so desires).	826	while still supporting blocking waits if the caller so desires).
750		827
751	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
752	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
753	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
754	waits otherwise.	831	waits otherwise.
755		832
756	=item $bool = $cv->ready	833	=item $bool = $cv->ready
…		…
762		839
763	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
764	replaces it before doing so.	841	replaces it before doing so.
765		842
766	The callback will be called when the condition becomes "true", i.e. when	843	The callback will be called when the condition becomes "true", i.e. when
767	C<send> or C<croak> are called, with the only argument being the condition	844	C<send> or C<croak> are called, with the only argument being the
768	variable itself. Calling C<recv> inside the callback or at any later time	845	condition variable itself. If the condition is already true, the
769	is guaranteed not to block.	846	callback is called immediately when it is set. Calling C<recv> inside
		847	the callback or at any later time is guaranteed not to block.
770		848
771	=back	849	=back
772		850
773	=head1 SUPPORTED EVENT LOOPS/BACKENDS	851	=head1 SUPPORTED EVENT LOOPS/BACKENDS
774		852
…		…
777	=over 4	855	=over 4
778		856
779	=item Backends that are autoprobed when no other event loop can be found.	857	=item Backends that are autoprobed when no other event loop can be found.
780		858
781	EV is the preferred backend when no other event loop seems to be in	859	EV is the preferred backend when no other event loop seems to be in
782	use. If EV is not installed, then AnyEvent will try Event, and, failing	860	use. If EV is not installed, then AnyEvent will fall back to its own
783	that, will fall back to its own pure-perl implementation, which is	861	pure-perl implementation, which is available everywhere as it comes with
784	available everywhere as it comes with AnyEvent itself.	862	AnyEvent itself.
785		863
786	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	864	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
787	AnyEvent::Impl::Event based on Event, very stable, few glitches.
788	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	865	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.
789		866
790	=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.
791		868
792	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
793	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
794	them. This means that AnyEvent will automatically pick the right backend	871	them. This means that AnyEvent will automatically pick the right backend
795	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
796	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.
797		874
		875	AnyEvent::Impl::Event based on Event, very stable, few glitches.
798	AnyEvent::Impl::Glib based on Glib, slow but very stable.	876	AnyEvent::Impl::Glib based on Glib, slow but very stable.
799	AnyEvent::Impl::Tk based on Tk, very broken.	877	AnyEvent::Impl::Tk based on Tk, very broken.
800	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	878	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
801	AnyEvent::Impl::POE based on POE, very slow, some limitations.	879	AnyEvent::Impl::POE based on POE, very slow, some limitations.
802	AnyEvent::Impl::Irssi used when running within irssi.	880	AnyEvent::Impl::Irssi used when running within irssi.
…		…
812		890
813	Support for IO::Async can only be partial, as it is too broken and	891	Support for IO::Async can only be partial, as it is too broken and
814	architecturally limited to even support the AnyEvent API. It also	892	architecturally limited to even support the AnyEvent API. It also
815	is the only event loop that needs the loop to be set explicitly, so	893	is the only event loop that needs the loop to be set explicitly, so
816	it can only be used by a main program knowing about AnyEvent. See	894	it can only be used by a main program knowing about AnyEvent. See
817	L<AnyEvent::Impl::Async> for the gory details.	895	L<AnyEvent::Impl::IOAsync> for the gory details.
818		896
819	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.	897	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
820		898
821	=item Event loops that are indirectly supported via other backends.	899	=item Event loops that are indirectly supported via other backends.
822		900
…		…
850	Contains C<undef> until the first watcher is being created, before the	928	Contains C<undef> until the first watcher is being created, before the
851	backend has been autodetected.	929	backend has been autodetected.
852		930
853	Afterwards it contains the event model that is being used, which is the	931	Afterwards it contains the event model that is being used, which is the
854	name of the Perl class implementing the model. This class is usually one	932	name of the Perl class implementing the model. This class is usually one
855	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the	933	of the C<AnyEvent::Impl::xxx> modules, but can be any other class in the
856	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it	934	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
857	will be C<urxvt::anyevent>).	935	will be C<urxvt::anyevent>).
858		936
859	=item AnyEvent::detect	937	=item AnyEvent::detect
860		938
861	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	939	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
862	if necessary. You should only call this function right before you would	940	if necessary. You should only call this function right before you would
863	have created an AnyEvent watcher anyway, that is, as late as possible at	941	have created an AnyEvent watcher anyway, that is, as late as possible at
864	runtime, and not e.g. while initialising of your module.	942	runtime, and not e.g. during initialisation of your module.
865		943
866	If you need to do some initialisation before AnyEvent watchers are	944	If you need to do some initialisation before AnyEvent watchers are
867	created, use C<post_detect>.	945	created, use C<post_detect>.
868		946
869	=item $guard = AnyEvent::post_detect { BLOCK }	947	=item $guard = AnyEvent::post_detect { BLOCK }
870		948
871	Arranges for the code block to be executed as soon as the event model is	949	Arranges for the code block to be executed as soon as the event model is
872	autodetected (or immediately if this has already happened).	950	autodetected (or immediately if that has already happened).
873		951
874	The block will be executed I<after> the actual backend has been detected	952	The block will be executed I<after> the actual backend has been detected
875	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been	953	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
876	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do	954	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
877	other initialisations - see the sources of L<AnyEvent::Strict> or	955	other initialisations - see the sources of L<AnyEvent::Strict> or
…		…
886	that automatically removes the callback again when it is destroyed (or	964	that automatically removes the callback again when it is destroyed (or
887	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for	965	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
888	a case where this is useful.	966	a case where this is useful.
889		967
890	Example: Create a watcher for the IO::AIO module and store it in	968	Example: Create a watcher for the IO::AIO module and store it in
891	C<$WATCHER>. Only do so after the event loop is initialised, though.	969	C<$WATCHER>, but do so only do so after the event loop is initialised.
892		970
893	our WATCHER;	971	our WATCHER;
894		972
895	my $guard = AnyEvent::post_detect {	973	my $guard = AnyEvent::post_detect {
896	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);	974	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
…		…
904	$WATCHER ||= $guard;	982	$WATCHER ||= $guard;
905		983
906	=item @AnyEvent::post_detect	984	=item @AnyEvent::post_detect
907		985
908	If there are any code references in this array (you can C<push> to it	986	If there are any code references in this array (you can C<push> to it
909	before or after loading AnyEvent), then they will called directly after	987	before or after loading AnyEvent), then they will be called directly
910	the event loop has been chosen.	988	after the event loop has been chosen.
911		989
912	You should check C<$AnyEvent::MODEL> before adding to this array, though:	990	You should check C<$AnyEvent::MODEL> before adding to this array, though:
913	if it is defined then the event loop has already been detected, and the	991	if it is defined then the event loop has already been detected, and the
914	array will be ignored.	992	array will be ignored.
915		993
916	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows	994	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
917	it,as it takes care of these details.	995	it, as it takes care of these details.
918		996
919	This variable is mainly useful for modules that can do something useful	997	This variable is mainly useful for modules that can do something useful
920	when AnyEvent is used and thus want to know when it is initialised, but do	998	when AnyEvent is used and thus want to know when it is initialised, but do
921	not need to even load it by default. This array provides the means to hook	999	not need to even load it by default. This array provides the means to hook
922	into AnyEvent passively, without loading it.	1000	into AnyEvent passively, without loading it.
923		1001
		1002	Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
		1003	together, you could put this into Coro (this is the actual code used by
		1004	Coro to accomplish this):
		1005
		1006	if (defined $AnyEvent::MODEL) {
		1007	# AnyEvent already initialised, so load Coro::AnyEvent
		1008	require Coro::AnyEvent;
		1009	} else {
		1010	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
		1011	# as soon as it is
		1012	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
		1013	}
		1014
924	=back	1015	=back
925		1016
926	=head1 WHAT TO DO IN A MODULE	1017	=head1 WHAT TO DO IN A MODULE
927		1018
928	As a module author, you should C<use AnyEvent> and call AnyEvent methods	1019	As a module author, you should C<use AnyEvent> and call AnyEvent methods
…		…
938	because it will stall the whole program, and the whole point of using	1029	because it will stall the whole program, and the whole point of using
939	events is to stay interactive.	1030	events is to stay interactive.
940		1031
941	It is fine, however, to call C<< ->recv >> when the user of your module	1032	It is fine, however, to call C<< ->recv >> when the user of your module
942	requests it (i.e. if you create a http request object ad have a method	1033	requests it (i.e. if you create a http request object ad have a method
943	called C<results> that returns the results, it should call C<< ->recv >>	1034	called C<results> that returns the results, it may call C<< ->recv >>
944	freely, as the user of your module knows what she is doing. always).	1035	freely, as the user of your module knows what she is doing. Always).
945		1036
946	=head1 WHAT TO DO IN THE MAIN PROGRAM	1037	=head1 WHAT TO DO IN THE MAIN PROGRAM
947		1038
948	There will always be a single main program - the only place that should	1039	There will always be a single main program - the only place that should
949	dictate which event model to use.	1040	dictate which event model to use.
950		1041
951	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	1042	If the program is not event-based, it need not do anything special, even
952	do anything special (it does not need to be event-based) and let AnyEvent	1043	when it depends on a module that uses an AnyEvent. If the program itself
953	decide which implementation to chose if some module relies on it.	1044	uses AnyEvent, but does not care which event loop is used, all it needs
		1045	to do is C<use AnyEvent>. In either case, AnyEvent will choose the best
		1046	available loop implementation.
954		1047
955	If the main program relies on a specific event model - for example, in	1048	If the main program relies on a specific event model - for example, in
956	Gtk2 programs you have to rely on the Glib module - you should load the	1049	Gtk2 programs you have to rely on the Glib module - you should load the
957	event module before loading AnyEvent or any module that uses it: generally	1050	event module before loading AnyEvent or any module that uses it: generally
958	speaking, you should load it as early as possible. The reason is that	1051	speaking, you should load it as early as possible. The reason is that
959	modules might create watchers when they are loaded, and AnyEvent will	1052	modules might create watchers when they are loaded, and AnyEvent will
960	decide on the event model to use as soon as it creates watchers, and it	1053	decide on the event model to use as soon as it creates watchers, and it
961	might chose the wrong one unless you load the correct one yourself.	1054	might choose the wrong one unless you load the correct one yourself.
962		1055
963	You can chose to use a pure-perl implementation by loading the	1056	You can chose to use a pure-perl implementation by loading the
964	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1057	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour
965	everywhere, but letting AnyEvent chose the model is generally better.	1058	everywhere, but letting AnyEvent chose the model is generally better.
966		1059
…		…
984	=head1 OTHER MODULES	1077	=head1 OTHER MODULES
985		1078
986	The following is a non-exhaustive list of additional modules that use	1079	The following is a non-exhaustive list of additional modules that use
987	AnyEvent as a client and can therefore be mixed easily with other AnyEvent	1080	AnyEvent as a client and can therefore be mixed easily with other AnyEvent
988	modules and other event loops in the same program. Some of the modules	1081	modules and other event loops in the same program. Some of the modules
989	come with AnyEvent, most are available via CPAN.	1082	come as part of AnyEvent, the others are available via CPAN.
990		1083
991	=over 4	1084	=over 4
992		1085
993	=item L<AnyEvent::Util>	1086	=item L<AnyEvent::Util>
994		1087
995	Contains various utility functions that replace often-used but blocking	1088	Contains various utility functions that replace often-used blocking
996	functions such as C<inet_aton> by event-/callback-based versions.	1089	functions such as C<inet_aton> with event/callback-based versions.
997		1090
998	=item L<AnyEvent::Socket>	1091	=item L<AnyEvent::Socket>
999		1092
1000	Provides various utility functions for (internet protocol) sockets,	1093	Provides various utility functions for (internet protocol) sockets,
1001	addresses and name resolution. Also functions to create non-blocking tcp	1094	addresses and name resolution. Also functions to create non-blocking tcp
…		…
1003		1096
1004	=item L<AnyEvent::Handle>	1097	=item L<AnyEvent::Handle>
1005		1098
1006	Provide read and write buffers, manages watchers for reads and writes,	1099	Provide read and write buffers, manages watchers for reads and writes,
1007	supports raw and formatted I/O, I/O queued and fully transparent and	1100	supports raw and formatted I/O, I/O queued and fully transparent and
1008	non-blocking SSL/TLS (via L<AnyEvent::TLS>.	1101	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
1009		1102
1010	=item L<AnyEvent::DNS>	1103	=item L<AnyEvent::DNS>
1011		1104
1012	Provides rich asynchronous DNS resolver capabilities.	1105	Provides rich asynchronous DNS resolver capabilities.
1013		1106
		1107	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
		1108
		1109	Implement event-based interfaces to the protocols of the same name (for
		1110	the curious, IGS is the International Go Server and FCP is the Freenet
		1111	Client Protocol).
		1112
		1113	=item L<AnyEvent::Handle::UDP>
		1114
		1115	Here be danger!
		1116
		1117	As Pauli would put it, "Not only is it not right, it's not even wrong!" -
		1118	there are so many things wrong with AnyEvent::Handle::UDP, most notably
		1119	its use of a stream-based API with a protocol that isn't streamable, that
		1120	the only way to improve it is to delete it.
		1121
		1122	It features data corruption (but typically only under load) and general
		1123	confusion. On top, the author is not only clueless about UDP but also
		1124	fact-resistant - some gems of his understanding: "connect doesn't work
		1125	with UDP", "UDP packets are not IP packets", "UDP only has datagrams, not
		1126	packets", "I don't need to implement proper error checking as UDP doesn't
		1127	support error checking" and so on - he doesn't even understand what's
		1128	wrong with his module when it is explained to him.
		1129
1014	=item L<AnyEvent::HTTP>	1130	=item L<AnyEvent::DBI>
1015		1131
1016	A simple-to-use HTTP library that is capable of making a lot of concurrent	1132	Executes L<DBI> requests asynchronously in a proxy process for you,
1017	HTTP requests.	1133	notifying you in an event-based way when the operation is finished.
		1134
		1135	=item L<AnyEvent::AIO>
		1136
		1137	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
		1138	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1139	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1140	file I/O, and much more.
1018		1141
1019	=item L<AnyEvent::HTTPD>	1142	=item L<AnyEvent::HTTPD>
1020		1143
1021	Provides a simple web application server framework.	1144	A simple embedded webserver.
1022		1145
1023	=item L<AnyEvent::FastPing>	1146	=item L<AnyEvent::FastPing>
1024		1147
1025	The fastest ping in the west.	1148	The fastest ping in the west.
1026
1027	=item L<AnyEvent::DBI>
1028
1029	Executes L<DBI> requests asynchronously in a proxy process.
1030
1031	=item L<AnyEvent::AIO>
1032
1033	Truly asynchronous I/O, should be in the toolbox of every event
1034	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1035	together.
1036
1037	=item L<AnyEvent::BDB>
1038
1039	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1040	L<BDB> and AnyEvent together.
1041
1042	=item L<AnyEvent::GPSD>
1043
1044	A non-blocking interface to gpsd, a daemon delivering GPS information.
1045
1046	=item L<AnyEvent::IRC>
1047
1048	AnyEvent based IRC client module family (replacing the older Net::IRC3).
1049
1050	=item L<AnyEvent::XMPP>
1051
1052	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1053	Net::XMPP2>.
1054
1055	=item L<AnyEvent::IGS>
1056
1057	A non-blocking interface to the Internet Go Server protocol (used by
1058	L<App::IGS>).
1059
1060	=item L<Net::FCP>
1061
1062	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1063	of AnyEvent.
1064
1065	=item L<Event::ExecFlow>
1066
1067	High level API for event-based execution flow control.
1068		1149
1069	=item L<Coro>	1150	=item L<Coro>
1070		1151
1071	Has special support for AnyEvent via L<Coro::AnyEvent>.	1152	Has special support for AnyEvent via L<Coro::AnyEvent>.
1072		1153
…		…
1076		1157
1077	package AnyEvent;	1158	package AnyEvent;
1078		1159
1079	# basically a tuned-down version of common::sense	1160	# basically a tuned-down version of common::sense
1080	sub common_sense {	1161	sub common_sense {
1081	# no warnings	1162	# from common:.sense 3.3
1082	${^WARNING_BITS} ^= ${^WARNING_BITS};	1163	${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf3\x0f\xc0\xf0\xfc\x33\x00";
1083	# use strict vars subs	1164	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1084	$^H |= 0x00000600;	1165	$^H |= 0x00000600;
1085	}	1166	}
1086		1167
1087	BEGIN { AnyEvent::common_sense }	1168	BEGIN { AnyEvent::common_sense }
1088		1169
1089	use Carp ();	1170	use Carp ();
1090		1171
1091	our $VERSION = 4.881;	1172	our $VERSION = '5.29';
1092	our $MODEL;	1173	our $MODEL;
1093		1174
1094	our $AUTOLOAD;	1175	our $AUTOLOAD;
1095	our @ISA;	1176	our @ISA;
1096		1177
1097	our @REGISTRY;	1178	our @REGISTRY;
1098		1179
1099	our $WIN32;
1100
1101	our $VERBOSE;	1180	our $VERBOSE;
1102		1181
1103	BEGIN {	1182	BEGIN {
1104	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1183	require "AnyEvent/constants.pl";
		1184
1105	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1185	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1106		1186
1107	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1187	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1108	if ${^TAINT};	1188	if ${^TAINT};
1109		1189
1110	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1190	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
…		…
1122	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1202	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1123	}	1203	}
1124		1204
1125	my @models = (	1205	my @models = (
1126	[EV:: => AnyEvent::Impl::EV:: , 1],	1206	[EV:: => AnyEvent::Impl::EV:: , 1],
1127	[Event:: => AnyEvent::Impl::Event::, 1],
1128	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],	1207	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1129	# everything below here will not (normally) be autoprobed	1208	# everything below here will not (normally) be autoprobed
1130	# as the pureperl backend should work everywhere	1209	# as the pureperl backend should work everywhere
1131	# and is usually faster	1210	# and is usually faster
		1211	[Event:: => AnyEvent::Impl::Event::, 1],
1132	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers	1212	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1133	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1213	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1134	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package	1214	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1135	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1215	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1136	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1216	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
…		…
1139	[Prima:: => AnyEvent::Impl::POE::],	1219	[Prima:: => AnyEvent::Impl::POE::],
1140	# IO::Async is just too broken - we would need workarounds for its	1220	# IO::Async is just too broken - we would need workarounds for its
1141	# byzantine signal and broken child handling, among others.	1221	# byzantine signal and broken child handling, among others.
1142	# IO::Async is rather hard to detect, as it doesn't have any	1222	# IO::Async is rather hard to detect, as it doesn't have any
1143	# obvious default class.	1223	# obvious default class.
1144	# [0, IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program	1224	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1145	# [0, IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program	1225	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1146	# [0, IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program	1226	[IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
		1227	[AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1147	);	1228	);
1148		1229
1149	our %method = map +($_ => 1),	1230	our %method = map +($_ => 1),
1150	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1231	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
1151		1232
1152	our @post_detect;	1233	our @post_detect;
1153		1234
1154	sub post_detect(&) {	1235	sub post_detect(&) {
1155	my ($cb) = @_;	1236	my ($cb) = @_;
1156		1237
1157	if ($MODEL) {
1158	$cb->();
1159
1160	undef
1161	} else {
1162	push @post_detect, $cb;	1238	push @post_detect, $cb;
1163		1239
1164	defined wantarray	1240	defined wantarray
1165	? bless \$cb, "AnyEvent::Util::postdetect"	1241	? bless \$cb, "AnyEvent::Util::postdetect"
1166	: ()	1242	: ()
1167	}
1168	}	1243	}
1169		1244
1170	sub AnyEvent::Util::postdetect::DESTROY {	1245	sub AnyEvent::Util::postdetect::DESTROY {
1171	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1246	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1172	}	1247	}
1173		1248
1174	sub detect() {	1249	sub detect() {
		1250	# free some memory
		1251	*detect = sub () { $MODEL };
		1252
		1253	local $!; # for good measure
		1254	local $SIG{__DIE__};
		1255
		1256	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {
		1257	my $model = "AnyEvent::Impl::$1";
		1258	if (eval "require $model") {
		1259	$MODEL = $model;
		1260	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
		1261	} else {
		1262	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
		1263	}
		1264	}
		1265
		1266	# check for already loaded models
1175	unless ($MODEL) {	1267	unless ($MODEL) {
1176	local $SIG{__DIE__};	1268	for (@REGISTRY, @models) {
1177		1269	my ($package, $model) = @$_;
1178	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1270	if (${"$package\::VERSION"} > 0) {
1179	my $model = "AnyEvent::Impl::$1";
1180	if (eval "require $model") {	1271	if (eval "require $model") {
1181	$MODEL = $model;	1272	$MODEL = $model;
1182	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;	1273	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1183	} else {	1274	last;
1184	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;	1275	}
1185	}	1276	}
1186	}	1277	}
1187		1278
1188	# check for already loaded models
1189	unless ($MODEL) {	1279	unless ($MODEL) {
		1280	# try to autoload a model
1190	for (@REGISTRY, @models) {	1281	for (@REGISTRY, @models) {
1191	my ($package, $model) = @$_;	1282	my ($package, $model, $autoload) = @$_;
		1283	if (
		1284	$autoload
		1285	and eval "require $package"
1192	if (${"$package\::VERSION"} > 0) {	1286	and ${"$package\::VERSION"} > 0
1193	if (eval "require $model") {	1287	and eval "require $model"
		1288	) {
1194	$MODEL = $model;	1289	$MODEL = $model;
1195	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;	1290	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1196	last;	1291	last;
1197	}
1198	}	1292	}
1199	}	1293	}
1200		1294
1201	unless ($MODEL) {
1202	# try to autoload a model
1203	for (@REGISTRY, @models) {
1204	my ($package, $model, $autoload) = @$_;
1205	if (
1206	$autoload
1207	and eval "require $package"
1208	and ${"$package\::VERSION"} > 0
1209	and eval "require $model"
1210	) {
1211	$MODEL = $model;
1212	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1213	last;
1214	}
1215	}
1216
1217	$MODEL	1295	$MODEL
1218	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1296	or die "AnyEvent: backend autodetection failed - did you properly install AnyEvent?\n";
1219	}
1220	}	1297	}
1221
1222	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1223
1224	unshift @ISA, $MODEL;
1225
1226	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1227
1228	(shift @post_detect)->() while @post_detect;
1229	}	1298	}
		1299
		1300	@models = (); # free probe data
		1301
		1302	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1303	unshift @ISA, $MODEL;
		1304
		1305	# now nuke some methods that are overridden by the backend.
		1306	# SUPER is not allowed.
		1307	for (qw(time signal child idle)) {
		1308	undef &{"AnyEvent::Base::$_"}
		1309	if defined &{"$MODEL\::$_"};
		1310	}
		1311
		1312	if ($ENV{PERL_ANYEVENT_STRICT}) {
		1313	eval { require AnyEvent::Strict };
		1314	warn "AnyEvent: cannot load AnyEvent::Strict: $@"
		1315	if $@ && $VERBOSE;
		1316	}
		1317
		1318	(shift @post_detect)->() while @post_detect;
		1319
		1320	*post_detect = sub(&) {
		1321	shift->();
		1322
		1323	undef
		1324	};
1230		1325
1231	$MODEL	1326	$MODEL
1232	}	1327	}
1233		1328
1234	sub AUTOLOAD {	1329	sub AUTOLOAD {
1235	(my $func = $AUTOLOAD) =~ s/.*://;	1330	(my $func = $AUTOLOAD) =~ s/.*://;
1236		1331
1237	$method{$func}	1332	$method{$func}
1238	or Carp::croak "$func: not a valid method for AnyEvent objects";	1333	or Carp::croak "$func: not a valid AnyEvent class method";
1239		1334
1240	detect unless $MODEL;	1335	detect;
1241		1336
1242	my $class = shift;	1337	my $class = shift;
1243	$class->$func (@_);	1338	$class->$func (@_);
1244	}	1339	}
1245		1340
…		…
1258	# we assume CLOEXEC is already set by perl in all important cases	1353	# we assume CLOEXEC is already set by perl in all important cases
1259		1354
1260	($fh2, $rw)	1355	($fh2, $rw)
1261	}	1356	}
1262		1357
		1358	=head1 SIMPLIFIED AE API
		1359
		1360	Starting with version 5.0, AnyEvent officially supports a second, much
		1361	simpler, API that is designed to reduce the calling, typing and memory
		1362	overhead by using function call syntax and a fixed number of parameters.
		1363
		1364	See the L<AE> manpage for details.
		1365
		1366	=cut
		1367
		1368	package AE;
		1369
		1370	our $VERSION = $AnyEvent::VERSION;
		1371
		1372	# fall back to the main API by default - backends and AnyEvent::Base
		1373	# implementations can overwrite these.
		1374
		1375	sub io($$$) {
		1376	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1377	}
		1378
		1379	sub timer($$$) {
		1380	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1381	}
		1382
		1383	sub signal($$) {
		1384	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1385	}
		1386
		1387	sub child($$) {
		1388	AnyEvent->child (pid => $_[0], cb => $_[1])
		1389	}
		1390
		1391	sub idle($) {
		1392	AnyEvent->idle (cb => $_[0])
		1393	}
		1394
		1395	sub cv(;&) {
		1396	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1397	}
		1398
		1399	sub now() {
		1400	AnyEvent->now
		1401	}
		1402
		1403	sub now_update() {
		1404	AnyEvent->now_update
		1405	}
		1406
		1407	sub time() {
		1408	AnyEvent->time
		1409	}
		1410
1263	package AnyEvent::Base;	1411	package AnyEvent::Base;
1264		1412
1265	# default implementations for many methods	1413	# default implementations for many methods
1266		1414
1267	sub _time {	1415	sub time {
		1416	eval q{ # poor man's autoloading {}
1268	# probe for availability of Time::HiRes	1417	# probe for availability of Time::HiRes
1269	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1418	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1270	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1419	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
1271	*_time = \&Time::HiRes::time;	1420	*AE::time = \&Time::HiRes::time;
1272	# if (eval "use POSIX (); (POSIX::times())...	1421	# if (eval "use POSIX (); (POSIX::times())...
1273	} else {	1422	} else {
1274	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1423	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1275	*_time = sub { time }; # epic fail	1424	*AE::time = sub (){ time }; # epic fail
		1425	}
		1426
		1427	*time = sub { AE::time }; # different prototypes
1276	}	1428	};
		1429	die if $@;
1277		1430
1278	&_time	1431	&time
1279	}	1432	}
1280		1433
1281	sub time { _time }	1434	*now = \&time;
1282	sub now { _time }	1435
1283	sub now_update { }	1436	sub now_update { }
1284		1437
1285	# default implementation for ->condvar	1438	# default implementation for ->condvar
1286		1439
1287	sub condvar {	1440	sub condvar {
		1441	eval q{ # poor man's autoloading {}
		1442	*condvar = sub {
1288	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1443	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1444	};
		1445
		1446	*AE::cv = sub (;&) {
		1447	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1448	};
		1449	};
		1450	die if $@;
		1451
		1452	&condvar
1289	}	1453	}
1290		1454
1291	# default implementation for ->signal	1455	# default implementation for ->signal
1292		1456
1293	our $HAVE_ASYNC_INTERRUPT;	1457	our $HAVE_ASYNC_INTERRUPT;
1294		1458
1295	sub _have_async_interrupt() {	1459	sub _have_async_interrupt() {
1296	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}	1460	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
1297	&& eval "use Async::Interrupt 1.0 (); 1")	1461	&& eval "use Async::Interrupt 1.02 (); 1")
1298	unless defined $HAVE_ASYNC_INTERRUPT;	1462	unless defined $HAVE_ASYNC_INTERRUPT;
1299		1463
1300	$HAVE_ASYNC_INTERRUPT	1464	$HAVE_ASYNC_INTERRUPT
1301	}	1465	}
1302		1466
1303	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1467	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1304	our (%SIG_ASY, %SIG_ASY_W);	1468	our (%SIG_ASY, %SIG_ASY_W);
1305	our ($SIG_COUNT, $SIG_TW);	1469	our ($SIG_COUNT, $SIG_TW);
1306		1470
1307	sub _signal_exec {
1308	$HAVE_ASYNC_INTERRUPT
1309	? $SIGPIPE_R->drain
1310	: sysread $SIGPIPE_R, my $dummy, 9;
1311
1312	while (%SIG_EV) {
1313	for (keys %SIG_EV) {
1314	delete $SIG_EV{$_};
1315	$_->() for values %{ $SIG_CB{$_} || {} };
1316	}
1317	}
1318	}
1319
1320	# install a dummy wakeup watcher to reduce signal catching latency	1471	# install a dummy wakeup watcher to reduce signal catching latency
		1472	# used by Impls
1321	sub _sig_add() {	1473	sub _sig_add() {
1322	unless ($SIG_COUNT++) {	1474	unless ($SIG_COUNT++) {
1323	# try to align timer on a full-second boundary, if possible	1475	# try to align timer on a full-second boundary, if possible
1324	my $NOW = AnyEvent->now;	1476	my $NOW = AE::now;
1325		1477
1326	$SIG_TW = AnyEvent->timer (	1478	$SIG_TW = AE::timer
1327	after => $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),	1479	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1328	interval => $MAX_SIGNAL_LATENCY,	1480	$MAX_SIGNAL_LATENCY,
1329	cb => sub { }, # just for the PERL_ASYNC_CHECK	1481	sub { } # just for the PERL_ASYNC_CHECK
1330	);	1482	;
1331	}	1483	}
1332	}	1484	}
1333		1485
1334	sub _sig_del {	1486	sub _sig_del {
1335	undef $SIG_TW	1487	undef $SIG_TW
1336	unless --$SIG_COUNT;	1488	unless --$SIG_COUNT;
1337	}	1489	}
1338		1490
1339	our %SIGNAME2NUM;
1340	our @SIGNUM2NAME;
1341	our $_sig_name_init; $_sig_name_init = sub {	1491	our $_sig_name_init; $_sig_name_init = sub {
		1492	eval q{ # poor man's autoloading {}
1342	undef $_sig_name_init;	1493	undef $_sig_name_init;
1343		1494
1344	if (_have_async_interrupt) {	1495	if (_have_async_interrupt) {
1345	*sig2num = \&Async::Interrupt::sig2num;	1496	*sig2num = \&Async::Interrupt::sig2num;
1346	*sig2name = \&Async::Interrupt::sig2name;	1497	*sig2name = \&Async::Interrupt::sig2name;
1347	} else {	1498	} else {
1348	require Config;	1499	require Config;
1349		1500
		1501	my %signame2num;
1350	@SIGNAME2NUM{ split ' ', $Config::Config{sig_name} }	1502	@signame2num{ split ' ', $Config::Config{sig_name} }
1351	= split ' ', $Config::Config{sig_num};	1503	= split ' ', $Config::Config{sig_num};
1352	@SIGNUM2NAME[values %SIGNAME2NUM] = keys %SIGNAME2NUM;
1353		1504
		1505	my @signum2name;
		1506	@signum2name[values %signame2num] = keys %signame2num;
		1507
1354	*sig2num = sub($) {	1508	*sig2num = sub($) {
1355	$_[0] > 0 ? shift : $SIGNAME2NUM{+shift}	1509	$_[0] > 0 ? shift : $signame2num{+shift}
1356	};	1510	};
1357	*sig2name = sub ($) {	1511	*sig2name = sub ($) {
1358	$_[0] > 0 ? $SIGNUM2NAME[+shift] : shift	1512	$_[0] > 0 ? $signum2name[+shift] : shift
		1513	};
1359	};	1514	}
1360	}	1515	};
		1516	die if $@;
1361	};	1517	};
1362		1518
1363	sub sig2num ($) { &$_sig_name_init; &sig2num }	1519	sub sig2num ($) { &$_sig_name_init; &sig2num }
1364	sub sig2name($) { &$_sig_name_init; &sig2name }	1520	sub sig2name($) { &$_sig_name_init; &sig2name }
1365		1521
1366	sub _signal {	1522	sub signal {
		1523	eval q{ # poor man's autoloading {}
		1524	# probe for availability of Async::Interrupt
		1525	if (_have_async_interrupt) {
		1526	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
		1527
		1528	$SIGPIPE_R = new Async::Interrupt::EventPipe;
		1529	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
		1530
		1531	} else {
		1532	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
		1533
		1534	if (AnyEvent::WIN32) {
		1535	require AnyEvent::Util;
		1536
		1537	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1538	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
		1539	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
		1540	} else {
		1541	pipe $SIGPIPE_R, $SIGPIPE_W;
		1542	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
		1543	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
		1544
		1545	# not strictly required, as $^F is normally 2, but let's make sure...
		1546	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
		1547	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
		1548	}
		1549
		1550	$SIGPIPE_R
		1551	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1552
		1553	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
		1554	}
		1555
		1556	*signal = $HAVE_ASYNC_INTERRUPT
		1557	? sub {
1367	my (undef, %arg) = @_;	1558	my (undef, %arg) = @_;
1368		1559
1369	my $signal = uc $arg{signal}
1370	or Carp::croak "required option 'signal' is missing";
1371
1372	if ($HAVE_ASYNC_INTERRUPT) {
1373	# async::interrupt	1560	# async::interrupt
1374
1375	$signal = sig2num $signal;	1561	my $signal = sig2num $arg{signal};
1376	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1562	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1377		1563
1378	$SIG_ASY{$signal} ||= new Async::Interrupt	1564	$SIG_ASY{$signal} ||= new Async::Interrupt
1379	cb => sub { undef $SIG_EV{$signal} },	1565	cb => sub { undef $SIG_EV{$signal} },
1380	signal => $signal,	1566	signal => $signal,
1381	pipe => [$SIGPIPE_R->filenos],	1567	pipe => [$SIGPIPE_R->filenos],
1382	pipe_autodrain => 0,	1568	pipe_autodrain => 0,
		1569	;
		1570
		1571	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1572	}
		1573	: sub {
		1574	my (undef, %arg) = @_;
		1575
		1576	# pure perl
		1577	my $signal = sig2name $arg{signal};
		1578	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1579
		1580	$SIG{$signal} ||= sub {
		1581	local $!;
		1582	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1583	undef $SIG_EV{$signal};
		1584	};
		1585
		1586	# can't do signal processing without introducing races in pure perl,
		1587	# so limit the signal latency.
		1588	_sig_add;
		1589
		1590	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1591	}
1383	;	1592	;
1384		1593
1385	} else {	1594	*AnyEvent::Base::signal::DESTROY = sub {
1386	# pure perl	1595	my ($signal, $cb) = @{$_[0]};
1387		1596
1388	# AE::Util has been loaded in signal	1597	_sig_del;
1389	$signal = sig2name $signal;
1390	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1391		1598
1392	$SIG{$signal} ||= sub {	1599	delete $SIG_CB{$signal}{$cb};
1393	local $!;	1600
1394	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1601	$HAVE_ASYNC_INTERRUPT
		1602	? delete $SIG_ASY{$signal}
		1603	: # delete doesn't work with older perls - they then
		1604	# print weird messages, or just unconditionally exit
		1605	# instead of getting the default action.
1395	undef $SIG_EV{$signal};	1606	undef $SIG{$signal}
		1607	unless keys %{ $SIG_CB{$signal} };
1396	};	1608	};
1397		1609
1398	# can't do signal processing without introducing races in pure perl,	1610	*_signal_exec = sub {
1399	# so limit the signal latency.	1611	$HAVE_ASYNC_INTERRUPT
1400	_sig_add;	1612	? $SIGPIPE_R->drain
1401	}	1613	: sysread $SIGPIPE_R, (my $dummy), 9;
1402		1614
1403	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1615	while (%SIG_EV) {
1404	}	1616	for (keys %SIG_EV) {
1405		1617	delete $SIG_EV{$_};
1406	sub signal {	1618	$_->() for values %{ $SIG_CB{$_} || {} };
1407	# probe for availability of Async::Interrupt	1619	}
1408	if (_have_async_interrupt) {	1620	}
1409	warn "AnyEvent: using Async::Interrupt for race-free signal handling.\n" if $VERBOSE >= 8;
1410
1411	$SIGPIPE_R = new Async::Interrupt::EventPipe;
1412	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R->fileno, poll => "r", cb => \&_signal_exec);
1413
1414	} else {
1415	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1416
1417	require Fcntl;
1418
1419	if (AnyEvent::WIN32) {
1420	require AnyEvent::Util;
1421
1422	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1423	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
1424	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
1425	} else {
1426	pipe $SIGPIPE_R, $SIGPIPE_W;
1427	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
1428	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
1429
1430	# not strictly required, as $^F is normally 2, but let's make sure...
1431	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1432	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
1433	}	1621	};
1434
1435	$SIGPIPE_R
1436	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1437
1438	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
1439	}	1622	};
		1623	die if $@;
1440		1624
1441	*signal = \&_signal;
1442	&signal	1625	&signal
1443	}
1444
1445	sub AnyEvent::Base::signal::DESTROY {
1446	my ($signal, $cb) = @{$_[0]};
1447
1448	_sig_del;
1449
1450	delete $SIG_CB{$signal}{$cb};
1451
1452	$HAVE_ASYNC_INTERRUPT
1453	? delete $SIG_ASY{$signal}
1454	: # delete doesn't work with older perls - they then
1455	# print weird messages, or just unconditionally exit
1456	# instead of getting the default action.
1457	undef $SIG{$signal}
1458	unless keys %{ $SIG_CB{$signal} };
1459	}	1626	}
1460		1627
1461	# default implementation for ->child	1628	# default implementation for ->child
1462		1629
1463	our %PID_CB;	1630	our %PID_CB;
1464	our $CHLD_W;	1631	our $CHLD_W;
1465	our $CHLD_DELAY_W;	1632	our $CHLD_DELAY_W;
1466	our $WNOHANG;
1467		1633
		1634	# used by many Impl's
1468	sub _emit_childstatus($$) {	1635	sub _emit_childstatus($$) {
1469	my (undef, $rpid, $rstatus) = @_;	1636	my (undef, $rpid, $rstatus) = @_;
1470		1637
1471	$_->($rpid, $rstatus)	1638	$_->($rpid, $rstatus)
1472	for values %{ $PID_CB{$rpid} || {} },	1639	for values %{ $PID_CB{$rpid} || {} },
1473	values %{ $PID_CB{0} || {} };	1640	values %{ $PID_CB{0} || {} };
1474	}	1641	}
1475		1642
1476	sub _sigchld {
1477	my $pid;
1478
1479	AnyEvent->_emit_childstatus ($pid, $?)
1480	while ($pid = waitpid -1, $WNOHANG) > 0;
1481	}
1482
1483	sub child {	1643	sub child {
		1644	eval q{ # poor man's autoloading {}
		1645	*_sigchld = sub {
		1646	my $pid;
		1647
		1648	AnyEvent->_emit_childstatus ($pid, $?)
		1649	while ($pid = waitpid -1, WNOHANG) > 0;
		1650	};
		1651
		1652	*child = sub {
1484	my (undef, %arg) = @_;	1653	my (undef, %arg) = @_;
1485		1654
1486	defined (my $pid = $arg{pid} + 0)	1655	defined (my $pid = $arg{pid} + 0)
1487	or Carp::croak "required option 'pid' is missing";	1656	or Carp::croak "required option 'pid' is missing";
1488		1657
1489	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1658	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1490		1659
1491	# WNOHANG is almost cetrainly 1 everywhere
1492	$WNOHANG ||= $^O =~ /^(?:openbsd|netbsd|linux|freebsd|cygwin|MSWin32)$/
1493	? 1
1494	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } || 1;
1495
1496	unless ($CHLD_W) {	1660	unless ($CHLD_W) {
1497	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1661	$CHLD_W = AE::signal CHLD => \&_sigchld;
1498	# child could be a zombie already, so make at least one round	1662	# child could be a zombie already, so make at least one round
1499	&_sigchld;	1663	&_sigchld;
1500	}	1664	}
1501		1665
1502	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1666	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1503	}	1667	};
1504		1668
1505	sub AnyEvent::Base::child::DESTROY {	1669	*AnyEvent::Base::child::DESTROY = sub {
1506	my ($pid, $cb) = @{$_[0]};	1670	my ($pid, $cb) = @{$_[0]};
1507		1671
1508	delete $PID_CB{$pid}{$cb};	1672	delete $PID_CB{$pid}{$cb};
1509	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1673	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1510		1674
1511	undef $CHLD_W unless keys %PID_CB;	1675	undef $CHLD_W unless keys %PID_CB;
		1676	};
		1677	};
		1678	die if $@;
		1679
		1680	&child
1512	}	1681	}
1513		1682
1514	# idle emulation is done by simply using a timer, regardless	1683	# idle emulation is done by simply using a timer, regardless
1515	# of whether the process is idle or not, and not letting	1684	# of whether the process is idle or not, and not letting
1516	# the callback use more than 50% of the time.	1685	# the callback use more than 50% of the time.
1517	sub idle {	1686	sub idle {
		1687	eval q{ # poor man's autoloading {}
		1688	*idle = sub {
1518	my (undef, %arg) = @_;	1689	my (undef, %arg) = @_;
1519		1690
1520	my ($cb, $w, $rcb) = $arg{cb};	1691	my ($cb, $w, $rcb) = $arg{cb};
1521		1692
1522	$rcb = sub {	1693	$rcb = sub {
1523	if ($cb) {	1694	if ($cb) {
1524	$w = _time;	1695	$w = _time;
1525	&$cb;	1696	&$cb;
1526	$w = _time - $w;	1697	$w = _time - $w;
1527		1698
1528	# never use more then 50% of the time for the idle watcher,	1699	# never use more then 50% of the time for the idle watcher,
1529	# within some limits	1700	# within some limits
1530	$w = 0.0001 if $w < 0.0001;	1701	$w = 0.0001 if $w < 0.0001;
1531	$w = 5 if $w > 5;	1702	$w = 5 if $w > 5;
1532		1703
1533	$w = AnyEvent->timer (after => $w, cb => $rcb);	1704	$w = AE::timer $w, 0, $rcb;
1534	} else {	1705	} else {
1535	# clean up...	1706	# clean up...
1536	undef $w;	1707	undef $w;
1537	undef $rcb;	1708	undef $rcb;
		1709	}
		1710	};
		1711
		1712	$w = AE::timer 0.05, 0, $rcb;
		1713
		1714	bless \\$cb, "AnyEvent::Base::idle"
1538	}	1715	};
		1716
		1717	*AnyEvent::Base::idle::DESTROY = sub {
		1718	undef $${$_[0]};
		1719	};
1539	};	1720	};
		1721	die if $@;
1540		1722
1541	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1723	&idle
1542
1543	bless \\$cb, "AnyEvent::Base::idle"
1544	}
1545
1546	sub AnyEvent::Base::idle::DESTROY {
1547	undef $${$_[0]};
1548	}	1724	}
1549		1725
1550	package AnyEvent::CondVar;	1726	package AnyEvent::CondVar;
1551		1727
1552	our @ISA = AnyEvent::CondVar::Base::;	1728	our @ISA = AnyEvent::CondVar::Base::;
		1729
		1730	# only to be used for subclassing
		1731	sub new {
		1732	my $class = shift;
		1733	bless AnyEvent->condvar (@_), $class
		1734	}
1553		1735
1554	package AnyEvent::CondVar::Base;	1736	package AnyEvent::CondVar::Base;
1555		1737
1556	#use overload	1738	#use overload
1557	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1739	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
…		…
1600	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1782	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};
1601	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1783	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]
1602	}	1784	}
1603		1785
1604	sub cb {	1786	sub cb {
1605	$_[0]{_ae_cb} = $_[1] if @_ > 1;	1787	my $cv = shift;
		1788
		1789	@_
		1790	and $cv->{_ae_cb} = shift
		1791	and $cv->{_ae_sent}
		1792	and (delete $cv->{_ae_cb})->($cv);
		1793
1606	$_[0]{_ae_cb}	1794	$cv->{_ae_cb}
1607	}	1795	}
1608		1796
1609	sub begin {	1797	sub begin {
1610	++$_[0]{_ae_counter};	1798	++$_[0]{_ae_counter};
1611	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	1799	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1673	check the arguments passed to most method calls. If it finds any problems,	1861	check the arguments passed to most method calls. If it finds any problems,
1674	it will croak.	1862	it will croak.
1675		1863
1676	In other words, enables "strict" mode.	1864	In other words, enables "strict" mode.
1677		1865
1678	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>	1866	Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1679	>>, it is definitely recommended to keep it off in production. Keeping	1867	>>, it is definitely recommended to keep it off in production. Keeping
1680	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs	1868	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1681	can be very useful, however.	1869	can be very useful, however.
1682		1870
1683	=item C<PERL_ANYEVENT_MODEL>	1871	=item C<PERL_ANYEVENT_MODEL>
…		…
1820	warn "read: $input\n"; # output what has been read	2008	warn "read: $input\n"; # output what has been read
1821	$cv->send if $input =~ /^q/i; # quit program if /^q/i	2009	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1822	},	2010	},
1823	);	2011	);
1824		2012
1825	my $time_watcher; # can only be used once
1826
1827	sub new_timer {
1828	$timer = AnyEvent->timer (after => 1, cb => sub {	2013	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1829	warn "timeout\n"; # print 'timeout' about every second	2014	warn "timeout\n"; # print 'timeout' at most every second
1830	&new_timer; # and restart the time
1831	});	2015	});
1832	}
1833
1834	new_timer; # create first timer
1835		2016
1836	$cv->recv; # wait until user enters /^q/i	2017	$cv->recv; # wait until user enters /^q/i
1837		2018
1838	=head1 REAL-WORLD EXAMPLE	2019	=head1 REAL-WORLD EXAMPLE
1839		2020
…		…
1912		2093
1913	The actual code goes further and collects all errors (C<die>s, exceptions)	2094	The actual code goes further and collects all errors (C<die>s, exceptions)
1914	that occurred during request processing. The C<result> method detects	2095	that occurred during request processing. The C<result> method detects
1915	whether an exception as thrown (it is stored inside the $txn object)	2096	whether an exception as thrown (it is stored inside the $txn object)
1916	and just throws the exception, which means connection errors and other	2097	and just throws the exception, which means connection errors and other
1917	problems get reported tot he code that tries to use the result, not in a	2098	problems get reported to the code that tries to use the result, not in a
1918	random callback.	2099	random callback.
1919		2100
1920	All of this enables the following usage styles:	2101	All of this enables the following usage styles:
1921		2102
1922	1. Blocking:	2103	1. Blocking:
…		…
1970	through AnyEvent. The benchmark creates a lot of timers (with a zero	2151	through AnyEvent. The benchmark creates a lot of timers (with a zero
1971	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,	2152	timeout) and I/O watchers (watching STDOUT, a pty, to become writable,
1972	which it is), lets them fire exactly once and destroys them again.	2153	which it is), lets them fire exactly once and destroys them again.
1973		2154
1974	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2155	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1975	distribution.	2156	distribution. It uses the L<AE> interface, which makes a real difference
		2157	for the EV and Perl backends only.
1976		2158
1977	=head3 Explanation of the columns	2159	=head3 Explanation of the columns
1978		2160
1979	I<watcher> is the number of event watchers created/destroyed. Since	2161	I<watcher> is the number of event watchers created/destroyed. Since
1980	different event models feature vastly different performances, each event	2162	different event models feature vastly different performances, each event
…		…
2001	watcher.	2183	watcher.
2002		2184
2003	=head3 Results	2185	=head3 Results
2004		2186
2005	name watchers bytes create invoke destroy comment	2187	name watchers bytes create invoke destroy comment
2006	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2188	EV/EV 100000 223 0.47 0.43 0.27 EV native interface
2007	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers	2189	EV/Any 100000 223 0.48 0.42 0.26 EV + AnyEvent watchers
2008	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal	2190	Coro::EV/Any 100000 223 0.47 0.42 0.26 coroutines + Coro::Signal
2009	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation	2191	Perl/Any 100000 431 2.70 0.74 0.92 pure perl implementation
2010	Event/Event 16000 517 32.20 31.80 0.81 Event native interface	2192	Event/Event 16000 516 31.16 31.84 0.82 Event native interface
2011	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers	2193	Event/Any 16000 1203 42.61 34.79 1.80 Event + AnyEvent watchers
2012	IOAsync/Any 16000 989 38.10 32.77 11.13 via IO::Async::Loop::IO_Poll	2194	IOAsync/Any 16000 1911 41.92 27.45 16.81 via IO::Async::Loop::IO_Poll
2013	IOAsync/Any 16000 990 37.59 29.50 10.61 via IO::Async::Loop::Epoll	2195	IOAsync/Any 16000 1726 40.69 26.37 15.25 via IO::Async::Loop::Epoll
2014	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour	2196	Glib/Any 16000 1118 89.00 12.57 51.17 quadratic behaviour
2015	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers	2197	Tk/Any 2000 1346 20.96 10.75 8.00 SEGV with >> 2000 watchers
2016	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event	2198	POE/Any 2000 6951 108.97 795.32 14.24 via POE::Loop::Event
2017	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select	2199	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
2018		2200
2019	=head3 Discussion	2201	=head3 Discussion
2020		2202
2021	The benchmark does I<not> measure scalability of the event loop very	2203	The benchmark does I<not> measure scalability of the event loop very
2022	well. For example, a select-based event loop (such as the pure perl one)	2204	well. For example, a select-based event loop (such as the pure perl one)
…		…
2034	benchmark machine, handling an event takes roughly 1600 CPU cycles with	2216	benchmark machine, handling an event takes roughly 1600 CPU cycles with
2035	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU	2217	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
2036	cycles with POE.	2218	cycles with POE.
2037		2219
2038	C<EV> is the sole leader regarding speed and memory use, which are both	2220	C<EV> is the sole leader regarding speed and memory use, which are both
2039	maximal/minimal, respectively. Even when going through AnyEvent, it uses	2221	maximal/minimal, respectively. When using the L<AE> API there is zero
		2222	overhead (when going through the AnyEvent API create is about 5-6 times
		2223	slower, with other times being equal, so still uses far less memory than
2040	far less memory than any other event loop and is still faster than Event	2224	any other event loop and is still faster than Event natively).
2041	natively.
2042		2225
2043	The pure perl implementation is hit in a few sweet spots (both the	2226	The pure perl implementation is hit in a few sweet spots (both the
2044	constant timeout and the use of a single fd hit optimisations in the perl	2227	constant timeout and the use of a single fd hit optimisations in the perl
2045	interpreter and the backend itself). Nevertheless this shows that it	2228	interpreter and the backend itself). Nevertheless this shows that it
2046	adds very little overhead in itself. Like any select-based backend its	2229	adds very little overhead in itself. Like any select-based backend its
…		…
2120	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2303	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100
2121	(1%) are active. This mirrors the activity of large servers with many	2304	(1%) are active. This mirrors the activity of large servers with many
2122	connections, most of which are idle at any one point in time.	2305	connections, most of which are idle at any one point in time.
2123		2306
2124	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2307	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
2125	distribution.	2308	distribution. It uses the L<AE> interface, which makes a real difference
		2309	for the EV and Perl backends only.
2126		2310
2127	=head3 Explanation of the columns	2311	=head3 Explanation of the columns
2128		2312
2129	I<sockets> is the number of sockets, and twice the number of "servers" (as	2313	I<sockets> is the number of sockets, and twice the number of "servers" (as
2130	each server has a read and write socket end).	2314	each server has a read and write socket end).
…		…
2138	a new one that moves the timeout into the future.	2322	a new one that moves the timeout into the future.
2139		2323
2140	=head3 Results	2324	=head3 Results
2141		2325
2142	name sockets create request	2326	name sockets create request
2143	EV 20000 69.01 11.16	2327	EV 20000 62.66 7.99
2144	Perl 20000 73.32 35.87	2328	Perl 20000 68.32 32.64
2145	IOAsync 20000 157.00 98.14 epoll	2329	IOAsync 20000 174.06 101.15 epoll
2146	IOAsync 20000 159.31 616.06 poll	2330	IOAsync 20000 174.67 610.84 poll
2147	Event 20000 212.62 257.32	2331	Event 20000 202.69 242.91
2148	Glib 20000 651.16 1896.30	2332	Glib 20000 557.01 1689.52
2149	POE 20000 349.67 12317.24 uses POE::Loop::Event	2333	POE 20000 341.54 12086.32 uses POE::Loop::Event
2150		2334
2151	=head3 Discussion	2335	=head3 Discussion
2152		2336
2153	This benchmark I<does> measure scalability and overall performance of the	2337	This benchmark I<does> measure scalability and overall performance of the
2154	particular event loop.	2338	particular event loop.
…		…
2280	As you can see, the AnyEvent + EV combination even beats the	2464	As you can see, the AnyEvent + EV combination even beats the
2281	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2465	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2282	backend easily beats IO::Lambda and POE.	2466	backend easily beats IO::Lambda and POE.
2283		2467
2284	And even the 100% non-blocking version written using the high-level (and	2468	And even the 100% non-blocking version written using the high-level (and
2285	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a	2469	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2286	large margin, even though it does all of DNS, tcp-connect and socket I/O	2470	higher level ("unoptimised") abstractions by a large margin, even though
2287	in a non-blocking way.	2471	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2288		2472
2289	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2473	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2290	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are	2474	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2291	part of the IO::lambda distribution and were used without any changes.	2475	part of the IO::Lambda distribution and were used without any changes.
2292		2476
2293		2477
2294	=head1 SIGNALS	2478	=head1 SIGNALS
2295		2479
2296	AnyEvent currently installs handlers for these signals:	2480	AnyEvent currently installs handlers for these signals:
…		…
2333	unless defined $SIG{PIPE};	2517	unless defined $SIG{PIPE};
2334		2518
2335	=head1 RECOMMENDED/OPTIONAL MODULES	2519	=head1 RECOMMENDED/OPTIONAL MODULES
2336		2520
2337	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and	2521	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2338	it's built-in modules) are required to use it.	2522	its built-in modules) are required to use it.
2339		2523
2340	That does not mean that AnyEvent won't take advantage of some additional	2524	That does not mean that AnyEvent won't take advantage of some additional
2341	modules if they are installed.	2525	modules if they are installed.
2342		2526
2343	This section epxlains which additional modules will be used, and how they	2527	This section explains which additional modules will be used, and how they
2344	affect AnyEvent's operetion.	2528	affect AnyEvent's operation.
2345		2529
2346	=over 4	2530	=over 4
2347		2531
2348	=item L<Async::Interrupt>	2532	=item L<Async::Interrupt>
2349		2533
…		…
2354	catch the signals) with some delay (default is 10 seconds, look for	2538	catch the signals) with some delay (default is 10 seconds, look for
2355	C<$AnyEvent::MAX_SIGNAL_LATENCY>).	2539	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2356		2540
2357	If this module is available, then it will be used to implement signal	2541	If this module is available, then it will be used to implement signal
2358	catching, which means that signals will not be delayed, and the event loop	2542	catching, which means that signals will not be delayed, and the event loop
2359	will not be interrupted regularly, which is more efficient (And good for	2543	will not be interrupted regularly, which is more efficient (and good for
2360	battery life on laptops).	2544	battery life on laptops).
2361		2545
2362	This affects not just the pure-perl event loop, but also other event loops	2546	This affects not just the pure-perl event loop, but also other event loops
2363	that have no signal handling on their own (e.g. Glib, Tk, Qt).	2547	that have no signal handling on their own (e.g. Glib, Tk, Qt).
2364		2548
…		…
2376	automatic timer adjustments even when no monotonic clock is available,	2560	automatic timer adjustments even when no monotonic clock is available,
2377	can take avdantage of advanced kernel interfaces such as C<epoll> and	2561	can take avdantage of advanced kernel interfaces such as C<epoll> and
2378	C<kqueue>, and is the fastest backend I<by far>. You can even embed	2562	C<kqueue>, and is the fastest backend I<by far>. You can even embed
2379	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).	2563	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2380		2564
		2565	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2566	then this module will do nothing for you.
		2567
2381	=item L<Guard>	2568	=item L<Guard>
2382		2569
2383	The guard module, when used, will be used to implement	2570	The guard module, when used, will be used to implement
2384	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a	2571	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2385	lot less memory), but otherwise doesn't affect guard operation much. It is	2572	lot less memory), but otherwise doesn't affect guard operation much. It is
2386	purely used for performance.	2573	purely used for performance.
2387		2574
2388	=item L<JSON> and L<JSON::XS>	2575	=item L<JSON> and L<JSON::XS>
2389		2576
2390	This module is required when you want to read or write JSON data via	2577	One of these modules is required when you want to read or write JSON data
2391	L<AnyEvent::Handle>. It is also written in pure-perl, but can take	2578	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2392	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.	2579	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2393
2394	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2395	installed.
2396		2580
2397	=item L<Net::SSLeay>	2581	=item L<Net::SSLeay>
2398		2582
2399	Implementing TLS/SSL in Perl is certainly interesting, but not very	2583	Implementing TLS/SSL in Perl is certainly interesting, but not very
2400	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2584	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2401	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.	2585	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2402		2586
2403	=item L<Time::HiRes>	2587	=item L<Time::HiRes>
2404		2588
2405	This module is part of perl since release 5.008. It will be used when the	2589	This module is part of perl since release 5.008. It will be used when the
2406	chosen event library does not come with a timing source on it's own. The	2590	chosen event library does not come with a timing source of its own. The
2407	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to	2591	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to
2408	try to use a monotonic clock for timing stability.	2592	try to use a monotonic clock for timing stability.
2409		2593
2410	=back	2594	=back
2411		2595
2412		2596
2413	=head1 FORK	2597	=head1 FORK
2414		2598
2415	Most event libraries are not fork-safe. The ones who are usually are	2599	Most event libraries are not fork-safe. The ones who are usually are
2416	because they rely on inefficient but fork-safe C<select> or C<poll>	2600	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2417	calls. Only L<EV> is fully fork-aware.	2601	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2602	are usually badly thought-out hacks that are incompatible with fork in
		2603	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2604	continue event-processing in both parent and child (or both, if you know
		2605	what you are doing).
		2606
		2607	This means that, in general, you cannot fork and do event processing in
		2608	the child if the event library was initialised before the fork (which
		2609	usually happens when the first AnyEvent watcher is created, or the library
		2610	is loaded).
2418		2611
2419	If you have to fork, you must either do so I<before> creating your first	2612	If you have to fork, you must either do so I<before> creating your first
2420	watcher OR you must not use AnyEvent at all in the child OR you must do	2613	watcher OR you must not use AnyEvent at all in the child OR you must do
2421	something completely out of the scope of AnyEvent.	2614	something completely out of the scope of AnyEvent.
		2615
		2616	The problem of doing event processing in the parent I<and> the child
		2617	is much more complicated: even for backends that I<are> fork-aware or
		2618	fork-safe, their behaviour is not usually what you want: fork clones all
		2619	watchers, that means all timers, I/O watchers etc. are active in both
		2620	parent and child, which is almost never what you want. USing C<exec>
		2621	to start worker children from some kind of manage rprocess is usually
		2622	preferred, because it is much easier and cleaner, at the expense of having
		2623	to have another binary.
2422		2624
2423		2625
2424	=head1 SECURITY CONSIDERATIONS	2626	=head1 SECURITY CONSIDERATIONS
2425		2627
2426	AnyEvent can be forced to load any event model via	2628	AnyEvent can be forced to load any event model via
…		…
2456	pronounced).	2658	pronounced).
2457		2659
2458		2660
2459	=head1 SEE ALSO	2661	=head1 SEE ALSO
2460		2662
		2663	Tutorial/Introduction: L<AnyEvent::Intro>.
		2664
		2665	FAQ: L<AnyEvent::FAQ>.
		2666
2461	Utility functions: L<AnyEvent::Util>.	2667	Utility functions: L<AnyEvent::Util>.
2462		2668
2463	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	2669	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,
2464	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2670	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2465		2671
…		…
2471	Non-blocking file handles, sockets, TCP clients and	2677	Non-blocking file handles, sockets, TCP clients and
2472	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	2678	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2473		2679
2474	Asynchronous DNS: L<AnyEvent::DNS>.	2680	Asynchronous DNS: L<AnyEvent::DNS>.
2475		2681
2476	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,	2682	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2477	L<Coro::Event>,
2478		2683
2479	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,	2684	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2480	L<AnyEvent::HTTP>.	2685	L<AnyEvent::HTTP>.
2481		2686
2482		2687
2483	=head1 AUTHOR	2688	=head1 AUTHOR
2484		2689

Diff Legend

–	Removed lines
+	Added lines
<	Changed lines
>	Changed lines