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 1.386 by root, Mon Sep 26 11:32:19 2011 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	AnyEvent - the DBI of event loop programming	3	AnyEvent - the DBI of event loop programming
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt	5	EV, Event, Glib, Tk, Perl, Event::Lib, Irssi, rxvt-unicode, IO::Async, Qt,
6	and POE are various supported event loops/environments.	6	FLTK and POE are various supported event loops/environments.
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 + EV? No go. Tk + Event? No go. Again: if your module
86	your module uses one of those, every user of your module has to use it,	91	uses one of those, every user of your module has to use it, too. But if
87	too. But if your module uses AnyEvent, it works transparently with all	92	your module uses AnyEvent, it works transparently with all event models it
88	event models it supports (including stuff like IO::Async, as long as those	93	supports (including stuff like IO::Async, as long as those use one of the
89	use one of the supported event loops. It is trivial to add new event loops	94	supported event loops. It is easy to add new event loops to AnyEvent, too,
90	to AnyEvent, too, so it is future-proof).	95	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::Loop>,
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::Loop> 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 C<AnyEvent::Loop>. Like
144	C<AnyEvent::Impl::Perl>. Like other event modules you can load it	148	other event modules you can load it explicitly and enjoy the high
145	explicitly and enjoy the high availability of that event loop :)	149	availability of that event loop :)
146		150
147	=head1 WATCHERS	151	=head1 WATCHERS
148		152
149	AnyEvent has the central concept of a I<watcher>, which is an object that	153	AnyEvent has the central concept of a I<watcher>, which is an object that
150	stores relevant data for each kind of event you are waiting for, such as	154	stores relevant data for each kind of event you are waiting for, such as
…		…
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
…		…
338	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	356	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
339	account.	357	account.
340		358
341	=item AnyEvent->now_update	359	=item AnyEvent->now_update
342		360
343	Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache	361	Some event loops (such as L<EV> or L<AnyEvent::Loop>) cache the current
344	the current time for each loop iteration (see the discussion of L<<	362	time for each loop iteration (see the discussion of L<< AnyEvent->now >>,
345	AnyEvent->now >>, above).	363	above).
346		364
347	When a callback runs for a long time (or when the process sleeps), then	365	When a callback runs for a long time (or when the process sleeps), then
348	this "current" time will differ substantially from the real time, which	366	this "current" time will differ substantially from the real time, which
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
…		…
432	thing in an AnyEvent program, you I<have> to create at least one	482	thing in an AnyEvent program, you I<have> to create at least one
433	watcher before you C<fork> the child (alternatively, you can call	483	watcher before you C<fork> the child (alternatively, you can call
434	C<AnyEvent::detect>).	484	C<AnyEvent::detect>).
435		485
436	As most event loops do not support waiting for child events, they will be	486	As most event loops do not support waiting for child events, they will be
437	emulated by AnyEvent in most cases, in which the latency and race problems	487	emulated by AnyEvent in most cases, in which case the latency and race
438	mentioned in the description of signal watchers apply.	488	problems mentioned in the description of signal watchers apply.
439		489
440	Example: fork a process and wait for it	490	Example: fork a process and wait for it
441		491
442	my $done = AnyEvent->condvar;	492	my $done = AnyEvent->condvar;
443		493
…		…
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 AnyEvent::Loop, 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.
		881	AnyEvent::Impl::IOAsync based on IO::Async.
		882	AnyEvent::Impl::Cocoa based on Cocoa::EventLoop.
		883	AnyEvent::Impl::FLTK based on FLTK (fltk 2 binding).
803		884
804	=item Backends with special needs.	885	=item Backends with special needs.
805		886
806	Qt requires the Qt::Application to be instantiated first, but will	887	Qt requires the Qt::Application to be instantiated first, but will
807	otherwise be picked up automatically. As long as the main program	888	otherwise be picked up automatically. As long as the main program
808	instantiates the application before any AnyEvent watchers are created,	889	instantiates the application before any AnyEvent watchers are created,
809	everything should just work.	890	everything should just work.
810		891
811	AnyEvent::Impl::Qt based on Qt.	892	AnyEvent::Impl::Qt based on Qt.
812		893
813	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
815	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
817	L<AnyEvent::Impl::Async> for the gory details.
818
819	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
820
821	=item Event loops that are indirectly supported via other backends.	894	=item Event loops that are indirectly supported via other backends.
822		895
823	Some event loops can be supported via other modules:	896	Some event loops can be supported via other modules:
824		897
825	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.	898	There is no direct support for WxWidgets (L<Wx>) or L<Prima>.
…		…
850	Contains C<undef> until the first watcher is being created, before the	923	Contains C<undef> until the first watcher is being created, before the
851	backend has been autodetected.	924	backend has been autodetected.
852		925
853	Afterwards it contains the event model that is being used, which is the	926	Afterwards it contains the event model that is being used, which is the
854	name of the Perl class implementing the model. This class is usually one	927	name of the Perl class implementing the model. This class is usually one
855	of the C<AnyEvent::Impl:xxx> modules, but can be any other class in the	928	of the C<AnyEvent::Impl::xxx> modules, but can be any other class in the
856	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it	929	case AnyEvent has been extended at runtime (e.g. in I<rxvt-unicode> it
857	will be C<urxvt::anyevent>).	930	will be C<urxvt::anyevent>).
858		931
859	=item AnyEvent::detect	932	=item AnyEvent::detect
860		933
861	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	934	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
862	if necessary. You should only call this function right before you would	935	if necessary. You should only call this function right before you would
863	have created an AnyEvent watcher anyway, that is, as late as possible at	936	have created an AnyEvent watcher anyway, that is, as late as possible at
864	runtime, and not e.g. while initialising of your module.	937	runtime, and not e.g. during initialisation of your module.
		938
		939	The effect of calling this function is as if a watcher had been created
		940	(specifically, actions that happen "when the first watcher is created"
		941	happen when calling detetc as well).
865		942
866	If you need to do some initialisation before AnyEvent watchers are	943	If you need to do some initialisation before AnyEvent watchers are
867	created, use C<post_detect>.	944	created, use C<post_detect>.
868		945
869	=item $guard = AnyEvent::post_detect { BLOCK }	946	=item $guard = AnyEvent::post_detect { BLOCK }
870		947
871	Arranges for the code block to be executed as soon as the event model is	948	Arranges for the code block to be executed as soon as the event model is
872	autodetected (or immediately if this has already happened).	949	autodetected (or immediately if that has already happened).
873		950
874	The block will be executed I<after> the actual backend has been detected	951	The block will be executed I<after> the actual backend has been detected
875	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been	952	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
876	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do	953	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
877	other initialisations - see the sources of L<AnyEvent::Strict> or	954	other initialisations - see the sources of L<AnyEvent::Strict> or
…		…
886	that automatically removes the callback again when it is destroyed (or	963	that automatically removes the callback again when it is destroyed (or
887	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for	964	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
888	a case where this is useful.	965	a case where this is useful.
889		966
890	Example: Create a watcher for the IO::AIO module and store it in	967	Example: Create a watcher for the IO::AIO module and store it in
891	C<$WATCHER>. Only do so after the event loop is initialised, though.	968	C<$WATCHER>, but do so only do so after the event loop is initialised.
892		969
893	our WATCHER;	970	our WATCHER;
894		971
895	my $guard = AnyEvent::post_detect {	972	my $guard = AnyEvent::post_detect {
896	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);	973	$WATCHER = AnyEvent->io (fh => IO::AIO::poll_fileno, poll => 'r', cb => \&IO::AIO::poll_cb);
…		…
904	$WATCHER ||= $guard;	981	$WATCHER ||= $guard;
905		982
906	=item @AnyEvent::post_detect	983	=item @AnyEvent::post_detect
907		984
908	If there are any code references in this array (you can C<push> to it	985	If there are any code references in this array (you can C<push> to it
909	before or after loading AnyEvent), then they will called directly after	986	before or after loading AnyEvent), then they will be called directly
910	the event loop has been chosen.	987	after the event loop has been chosen.
911		988
912	You should check C<$AnyEvent::MODEL> before adding to this array, though:	989	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	990	if it is defined then the event loop has already been detected, and the
914	array will be ignored.	991	array will be ignored.
915		992
916	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows	993	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
917	it,as it takes care of these details.	994	it, as it takes care of these details.
918		995
919	This variable is mainly useful for modules that can do something useful	996	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	997	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	998	not need to even load it by default. This array provides the means to hook
922	into AnyEvent passively, without loading it.	999	into AnyEvent passively, without loading it.
923		1000
		1001	Example: To load Coro::AnyEvent whenever Coro and AnyEvent are used
		1002	together, you could put this into Coro (this is the actual code used by
		1003	Coro to accomplish this):
		1004
		1005	if (defined $AnyEvent::MODEL) {
		1006	# AnyEvent already initialised, so load Coro::AnyEvent
		1007	require Coro::AnyEvent;
		1008	} else {
		1009	# AnyEvent not yet initialised, so make sure to load Coro::AnyEvent
		1010	# as soon as it is
		1011	push @AnyEvent::post_detect, sub { require Coro::AnyEvent };
		1012	}
		1013
		1014	=item AnyEvent::postpone { BLOCK }
		1015
		1016	Arranges for the block to be executed as soon as possible, but not before
		1017	the call itself returns. In practise, the block will be executed just
		1018	before the event loop polls for new events, or shortly afterwards.
		1019
		1020	This function never returns anything (to make the C<return postpone { ...
		1021	}> idiom more useful.
		1022
		1023	To understand the usefulness of this function, consider a function that
		1024	asynchronously does something for you and returns some transaction
		1025	object or guard to let you cancel the operation. For example,
		1026	C<AnyEvent::Socket::tcp_connect>:
		1027
		1028	# start a conenction attempt unless one is active
		1029	$self->{connect_guard} ||= AnyEvent::Socket::tcp_connect "www.example.net", 80, sub {
		1030	delete $self->{connect_guard};
		1031	...
		1032	};
		1033
		1034	Imagine that this function could instantly call the callback, for
		1035	example, because it detects an obvious error such as a negative port
		1036	number. Invoking the callback before the function returns causes problems
		1037	however: the callback will be called and will try to delete the guard
		1038	object. But since the function hasn't returned yet, there is nothing to
		1039	delete. When the function eventually returns it will assign the guard
		1040	object to C<< $self->{connect_guard} >>, where it will likely never be
		1041	deleted, so the program thinks it is still trying to connect.
		1042
		1043	This is where C<AnyEvent::postpone> should be used. Instead of calling the
		1044	callback directly on error:
		1045
		1046	$cb->(undef), return # signal error to callback, BAD!
		1047	if $some_error_condition;
		1048
		1049	It should use C<postpone>:
		1050
		1051	AnyEvent::postpone { $cb->(undef) }, return # signal error to callback, later
		1052	if $some_error_condition;
		1053
		1054	=item AnyEvent::log $level, $msg[, @args]
		1055
		1056	Log the given C<$msg> at the given C<$level>.
		1057
		1058	If L<AnyEvent::Log> is not loaded then this function makes a simple test
		1059	to see whether the message will be logged. If the test succeeds it will
		1060	load AnyEvent::Log and call C<AnyEvent::Log::log> - consequently, look at
		1061	the L<AnyEvent::Log> documentation for details.
		1062
		1063	If the test fails it will simply return. Right now this happens when a
		1064	numerical loglevel is used and it is larger than the level specified via
		1065	C<$ENV{PERL_ANYEVENT_VERBOSE}>.
		1066
		1067	If you want to sprinkle loads of logging calls around your code, consider
		1068	creating a logger callback with the C<AnyEvent::Log::logger> function,
		1069	which can reduce typing, codesize and can reduce the logging overhead
		1070	enourmously.
		1071
924	=back	1072	=back
925		1073
926	=head1 WHAT TO DO IN A MODULE	1074	=head1 WHAT TO DO IN A MODULE
927		1075
928	As a module author, you should C<use AnyEvent> and call AnyEvent methods	1076	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	1086	because it will stall the whole program, and the whole point of using
939	events is to stay interactive.	1087	events is to stay interactive.
940		1088
941	It is fine, however, to call C<< ->recv >> when the user of your module	1089	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	1090	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 >>	1091	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).	1092	freely, as the user of your module knows what she is doing. Always).
945		1093
946	=head1 WHAT TO DO IN THE MAIN PROGRAM	1094	=head1 WHAT TO DO IN THE MAIN PROGRAM
947		1095
948	There will always be a single main program - the only place that should	1096	There will always be a single main program - the only place that should
949	dictate which event model to use.	1097	dictate which event model to use.
950		1098
951	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	1099	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	1100	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.	1101	uses AnyEvent, but does not care which event loop is used, all it needs
		1102	to do is C<use AnyEvent>. In either case, AnyEvent will choose the best
		1103	available loop implementation.
954		1104
955	If the main program relies on a specific event model - for example, in	1105	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	1106	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	1107	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	1108	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	1109	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	1110	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.	1111	might choose the wrong one unless you load the correct one yourself.
962		1112
963	You can chose to use a pure-perl implementation by loading the	1113	You can chose to use a pure-perl implementation by loading the
964	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1114	C<AnyEvent::Loop> module, which gives you similar behaviour
965	everywhere, but letting AnyEvent chose the model is generally better.	1115	everywhere, but letting AnyEvent chose the model is generally better.
966		1116
967	=head2 MAINLOOP EMULATION	1117	=head2 MAINLOOP EMULATION
968		1118
969	Sometimes (often for short test scripts, or even standalone programs who	1119	Sometimes (often for short test scripts, or even standalone programs who
…		…
982		1132
983		1133
984	=head1 OTHER MODULES	1134	=head1 OTHER MODULES
985		1135
986	The following is a non-exhaustive list of additional modules that use	1136	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	1137	AnyEvent as a client and can therefore be mixed easily with other
988	modules and other event loops in the same program. Some of the modules	1138	AnyEvent modules and other event loops in the same program. Some of the
989	come with AnyEvent, most are available via CPAN.	1139	modules come as part of AnyEvent, the others are available via CPAN (see
		1140	L<http://search.cpan.org/search?m=module&q=anyevent%3A%3A*> for
		1141	a longer non-exhaustive list), and the list is heavily biased towards
		1142	modules of the AnyEvent author himself :)
990		1143
991	=over 4	1144	=over 4
992		1145
993	=item L<AnyEvent::Util>	1146	=item L<AnyEvent::Util>
994		1147
995	Contains various utility functions that replace often-used but blocking	1148	Contains various utility functions that replace often-used blocking
996	functions such as C<inet_aton> by event-/callback-based versions.	1149	functions such as C<inet_aton> with event/callback-based versions.
997		1150
998	=item L<AnyEvent::Socket>	1151	=item L<AnyEvent::Socket>
999		1152
1000	Provides various utility functions for (internet protocol) sockets,	1153	Provides various utility functions for (internet protocol) sockets,
1001	addresses and name resolution. Also functions to create non-blocking tcp	1154	addresses and name resolution. Also functions to create non-blocking tcp
…		…
1003		1156
1004	=item L<AnyEvent::Handle>	1157	=item L<AnyEvent::Handle>
1005		1158
1006	Provide read and write buffers, manages watchers for reads and writes,	1159	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	1160	supports raw and formatted I/O, I/O queued and fully transparent and
1008	non-blocking SSL/TLS (via L<AnyEvent::TLS>.	1161	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
1009		1162
1010	=item L<AnyEvent::DNS>	1163	=item L<AnyEvent::DNS>
1011		1164
1012	Provides rich asynchronous DNS resolver capabilities.	1165	Provides rich asynchronous DNS resolver capabilities.
1013		1166
		1167	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
		1168
		1169	Implement event-based interfaces to the protocols of the same name (for
		1170	the curious, IGS is the International Go Server and FCP is the Freenet
		1171	Client Protocol).
		1172
1014	=item L<AnyEvent::HTTP>	1173	=item L<AnyEvent::AIO>
1015		1174
1016	A simple-to-use HTTP library that is capable of making a lot of concurrent	1175	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
1017	HTTP requests.	1176	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1177	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1178	file I/O, and much more.
		1179
		1180	=item L<AnyEvent::Filesys::Notify>
		1181
		1182	AnyEvent is good for non-blocking stuff, but it can't detect file or
		1183	path changes (e.g. "watch this directory for new files", "watch this
		1184	file for changes"). The L<AnyEvent::Filesys::Notify> module promises to
		1185	do just that in a portbale fashion, supporting inotify on GNU/Linux and
		1186	some weird, without doubt broken, stuff on OS X to monitor files. It can
		1187	fall back to blocking scans at regular intervals transparently on other
		1188	platforms, so it's about as portable as it gets.
		1189
		1190	(I haven't used it myself, but I haven't heard anybody complaining about
		1191	it yet).
		1192
		1193	=item L<AnyEvent::DBI>
		1194
		1195	Executes L<DBI> requests asynchronously in a proxy process for you,
		1196	notifying you in an event-based way when the operation is finished.
1018		1197
1019	=item L<AnyEvent::HTTPD>	1198	=item L<AnyEvent::HTTPD>
1020		1199
1021	Provides a simple web application server framework.	1200	A simple embedded webserver.
1022		1201
1023	=item L<AnyEvent::FastPing>	1202	=item L<AnyEvent::FastPing>
1024		1203
1025	The fastest ping in the west.	1204	The fastest ping in the west.
1026		1205
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
1069	=item L<Coro>	1206	=item L<Coro>
1070		1207
1071	Has special support for AnyEvent via L<Coro::AnyEvent>.	1208	Has special support for AnyEvent via L<Coro::AnyEvent>, which allows you
		1209	to simply invert the flow control - don't call us, we will call you:
		1210
		1211	async {
		1212	Coro::AnyEvent::sleep 5; # creates a 5s timer and waits for it
		1213	print "5 seconds later!\n";
		1214
		1215	Coro::AnyEvent::readable *STDIN; # uses an I/O watcher
		1216	my $line = <STDIN>; # works for ttys
		1217
		1218	AnyEvent::HTTP::http_get "url", Coro::rouse_cb;
		1219	my ($body, $hdr) = Coro::rouse_wait;
		1220	};
1072		1221
1073	=back	1222	=back
1074		1223
1075	=cut	1224	=cut
1076		1225
1077	package AnyEvent;	1226	package AnyEvent;
1078		1227
1079	# basically a tuned-down version of common::sense	1228	# basically a tuned-down version of common::sense
1080	sub common_sense {	1229	sub common_sense {
1081	# no warnings	1230	# from common:.sense 3.4
1082	${^WARNING_BITS} ^= ${^WARNING_BITS};	1231	${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
1083	# use strict vars subs	1232	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1084	$^H |= 0x00000600;	1233	$^H |= 0x00000600;
1085	}	1234	}
1086		1235
1087	BEGIN { AnyEvent::common_sense }	1236	BEGIN { AnyEvent::common_sense }
1088		1237
1089	use Carp ();	1238	use Carp ();
1090		1239
1091	our $VERSION = 4.881;	1240	our $VERSION = '6.02';
1092	our $MODEL;	1241	our $MODEL;
1093
1094	our $AUTOLOAD;
1095	our @ISA;	1242	our @ISA;
1096
1097	our @REGISTRY;	1243	our @REGISTRY;
1098
1099	our $WIN32;
1100
1101	our $VERBOSE;	1244	our $VERBOSE;
		1245	our $MAX_SIGNAL_LATENCY = 10;
		1246	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred
1102		1247
1103	BEGIN {	1248	BEGIN {
1104	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1249	require "AnyEvent/constants.pl";
		1250
1105	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1251	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1106		1252
1107	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1253	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1108	if ${^TAINT};	1254	if ${^TAINT};
1109		1255
1110	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1256	$ENV{"PERL_ANYEVENT_$_"} = $ENV{"AE_$_"}
		1257	for grep s/^AE_// && !exists $ENV{"PERL_ANYEVENT_$_"}, keys %ENV;
1111		1258
1112	}	1259	@ENV{grep /^PERL_ANYEVENT_/, keys %ENV} = ()
		1260	if ${^TAINT};
1113		1261
1114	our $MAX_SIGNAL_LATENCY = 10;	1262	# $ENV{PERL_ANYEVENT_xxx} now valid
1115		1263
1116	our %PROTOCOL; # (ipv4|ipv6) => (1|2), higher numbers are preferred	1264	$VERBOSE = length $ENV{PERL_ANYEVENT_VERBOSE} ? $ENV{PERL_ANYEVENT_VERBOSE}*1 : 4;
1117		1265
1118	{
1119	my $idx;	1266	my $idx;
1120	$PROTOCOL{$_} = ++$idx	1267	$PROTOCOL{$_} = ++$idx
1121	for reverse split /\s*,\s*/,	1268	for reverse split /\s*,\s*/,
1122	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";	1269	$ENV{PERL_ANYEVENT_PROTOCOLS} || "ipv4,ipv6";
1123	}	1270	}
1124		1271
		1272	our @post_detect;
		1273
		1274	sub post_detect(&) {
		1275	my ($cb) = @_;
		1276
		1277	push @post_detect, $cb;
		1278
		1279	defined wantarray
		1280	? bless \$cb, "AnyEvent::Util::postdetect"
		1281	: ()
		1282	}
		1283
		1284	sub AnyEvent::Util::postdetect::DESTROY {
		1285	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		1286	}
		1287
		1288	our $POSTPONE_W;
		1289	our @POSTPONE;
		1290
		1291	sub _postpone_exec {
		1292	undef $POSTPONE_W;
		1293
		1294	&{ shift @POSTPONE }
		1295	while @POSTPONE;
		1296	}
		1297
		1298	sub postpone(&) {
		1299	push @POSTPONE, shift;
		1300
		1301	$POSTPONE_W ||= AE::timer (0, 0, \&_postpone_exec);
		1302
		1303	()
		1304	}
		1305
		1306	sub log($$;@) {
		1307	# only load the big bloated module when we actually are about to log something
		1308	if ($_[0] <= ($VERBOSE || 1)) { # also catches non-numeric levels(!) and fatal
		1309	require AnyEvent::Log; # among other things, sets $VERBOSE to 9
		1310	# AnyEvent::Log overwrites this function
		1311	goto &log;
		1312	}
		1313
		1314	0 # not logged
		1315	}
		1316
		1317	sub logger($;$) {
		1318	package AnyEvent::Log;
		1319
		1320	my ($level, $renabled) = @_;
		1321
		1322	$$renabled = $level <= $VERBOSE;
		1323
		1324	my $pkg = (caller)[0];
		1325
		1326	my $logger = [$pkg, $level, $renabled];
		1327
		1328	our %LOGGER;
		1329	$LOGGER{$logger+0} = $logger;
		1330
		1331	require AnyEvent::Util;
		1332	my $guard = AnyEvent::Util::guard (sub {
		1333	# "clean up"
		1334	delete $LOGGER{$logger+0};
		1335	});
		1336
		1337	sub {
		1338	return 0 unless $$renabled;
		1339
		1340	$guard if 0; # keep guard alive, but don't cause runtime overhead
		1341	require AnyEvent::Log unless $AnyEvent::Log::VERSION;
		1342	package AnyEvent::Log;
		1343	_log ($logger->[0], $level, @_) # logger->[0] has been converted at load time
		1344	}
		1345	}
		1346
		1347	if (length $ENV{PERL_ANYEVENT_LOG}) {
		1348	require AnyEvent::Log; # AnyEvent::Log does the thing for us
		1349	}
		1350
1125	my @models = (	1351	our @models = (
1126	[EV:: => AnyEvent::Impl::EV:: , 1],	1352	[EV:: => AnyEvent::Impl::EV::],
1127	[Event:: => AnyEvent::Impl::Event::, 1],	1353	[AnyEvent::Loop:: => AnyEvent::Impl::Perl::],
1128	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],
1129	# everything below here will not (normally) be autoprobed	1354	# everything below here will not (normally) be autoprobed
1130	# as the pureperl backend should work everywhere	1355	# as the pure perl backend should work everywhere
1131	# and is usually faster	1356	# and is usually faster
		1357	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package, so msut be near the top
		1358	[Event:: => AnyEvent::Impl::Event::], # slow, stable
1132	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers	1359	[Glib:: => AnyEvent::Impl::Glib::], # becomes extremely slow with many watchers
		1360	# everything below here should not be autoloaded
1133	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1361	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1134	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1135	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1362	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1136	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1363	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1137	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1364	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1138	[Wx:: => AnyEvent::Impl::POE::],	1365	[Wx:: => AnyEvent::Impl::POE::],
1139	[Prima:: => AnyEvent::Impl::POE::],	1366	[Prima:: => AnyEvent::Impl::POE::],
1140	# IO::Async is just too broken - we would need workarounds for its	1367	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1141	# byzantine signal and broken child handling, among others.	1368	[Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1142	# IO::Async is rather hard to detect, as it doesn't have any	1369	[FLTK:: => AnyEvent::Impl::FLTK::],
1143	# obvious default class.
1144	# [0, IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1145	# [0, IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1146	# [0, IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1147	);	1370	);
1148		1371
1149	our %method = map +($_ => 1),	1372	our @isa_hook;
		1373
		1374	sub _isa_set {
		1375	my @pkg = ("AnyEvent", (map $_->[0], grep defined, @isa_hook), $MODEL);
		1376
		1377	@{"$pkg[$_-1]::ISA"} = $pkg[$_]
		1378	for 1 .. $#pkg;
		1379
		1380	grep $_ && $_->[1], @isa_hook
		1381	and AE::_reset ();
		1382	}
		1383
		1384	# used for hooking AnyEvent::Strict and AnyEvent::Debug::Wrap into the class hierarchy
		1385	sub _isa_hook($$;$) {
		1386	my ($i, $pkg, $reset_ae) = @_;
		1387
		1388	$isa_hook[$i] = $pkg ? [$pkg, $reset_ae] : undef;
		1389
		1390	_isa_set;
		1391	}
		1392
		1393	# all autoloaded methods reserve the complete glob, not just the method slot.
		1394	# due to bugs in perls method cache implementation.
1150	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1395	our @methods = qw(io timer time now now_update signal child idle condvar);
1151		1396
1152	our @post_detect;
1153
1154	sub post_detect(&) {	1397	sub detect() {
1155	my ($cb) = @_;	1398	return $MODEL if $MODEL; # some programs keep references to detect
1156		1399
1157	if ($MODEL) {	1400	# IO::Async::Loop::AnyEvent is extremely evil, refuse to work with it
1158	$cb->();	1401	# the author knows about the problems and what it does to AnyEvent as a whole
		1402	# (and the ability of others to use AnyEvent), but simply wants to abuse AnyEvent
		1403	# anyway.
		1404	AnyEvent::log fatal => "AnyEvent: IO::Async::Loop::AnyEvent detected - this module is broken by design,\n"
		1405	. "abuses internals and breaks AnyEvent, will not continue."
		1406	if exists $INC{"IO/Async/Loop/AnyEvent.pm"};
1159		1407
1160	undef	1408	local $!; # for good measure
		1409	local $SIG{__DIE__}; # we use eval
		1410
		1411	# free some memory
		1412	*detect = sub () { $MODEL };
		1413	# undef &func doesn't correctly update the method cache. grmbl.
		1414	# so we delete the whole glob. grmbl.
		1415	# otoh, perl doesn't let me undef an active usb, but it lets me free
		1416	# a glob with an active sub. hrm. i hope it works, but perl is
		1417	# usually buggy in this department. sigh.
		1418	delete @{"AnyEvent::"}{@methods};
		1419	undef @methods;
		1420
		1421	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) {
		1422	my $model = $1;
		1423	$model = "AnyEvent::Impl::$model" unless $model =~ s/::$//;
		1424	if (eval "require $model") {
		1425	AnyEvent::log 7 => "loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.";
		1426	$MODEL = $model;
1161	} else {	1427	} else {
1162	push @post_detect, $cb;	1428	AnyEvent::log 4 => "unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@";
1163		1429	}
1164	defined wantarray
1165	? bless \$cb, "AnyEvent::Util::postdetect"
1166	: ()
1167	}	1430	}
1168	}
1169		1431
1170	sub AnyEvent::Util::postdetect::DESTROY {	1432	# check for already loaded models
1171	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1172	}
1173
1174	sub detect() {
1175	unless ($MODEL) {	1433	unless ($MODEL) {
1176	local $SIG{__DIE__};	1434	for (@REGISTRY, @models) {
1177		1435	my ($package, $model) = @$_;
1178	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1436	if (${"$package\::VERSION"} > 0) {
1179	my $model = "AnyEvent::Impl::$1";
1180	if (eval "require $model") {	1437	if (eval "require $model") {
		1438	AnyEvent::log 7 => "autodetected model '$model', using it.";
1181	$MODEL = $model;	1439	$MODEL = $model;
1182	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;	1440	last;
1183	} else {	1441	}
1184	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1185	}	1442	}
1186	}	1443	}
1187		1444
1188	# check for already loaded models
1189	unless ($MODEL) {	1445	unless ($MODEL) {
		1446	# try to autoload a model
1190	for (@REGISTRY, @models) {	1447	for (@REGISTRY, @models) {
1191	my ($package, $model) = @$_;	1448	my ($package, $model) = @$_;
		1449	if (
		1450	eval "require $package"
1192	if (${"$package\::VERSION"} > 0) {	1451	and ${"$package\::VERSION"} > 0
1193	if (eval "require $model") {	1452	and eval "require $model"
		1453	) {
		1454	AnyEvent::log 7 => "autoloaded model '$model', using it.";
1194	$MODEL = $model;	1455	$MODEL = $model;
1195	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1196	last;	1456	last;
1197	}
1198	}	1457	}
1199	}	1458	}
1200		1459
1201	unless ($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	1460	$MODEL
1218	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1461	or AnyEvent::log fatal => "AnyEvent: backend autodetection failed - did you properly install AnyEvent?";
1219	}
1220	}	1462	}
1221
1222	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1223
1224	unshift @ISA, $MODEL;
1225
1226	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1227
1228	(shift @post_detect)->() while @post_detect;
1229	}	1463	}
1230		1464
		1465	# free memory only needed for probing
		1466	undef @models;
		1467	undef @REGISTRY;
		1468
		1469	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1470
		1471	# now nuke some methods that are overridden by the backend.
		1472	# SUPER usage is not allowed in these.
		1473	for (qw(time signal child idle)) {
		1474	undef &{"AnyEvent::Base::$_"}
		1475	if defined &{"$MODEL\::$_"};
		1476	}
		1477
		1478	_isa_set;
		1479
		1480	# we're officially open!
		1481
		1482	if ($ENV{PERL_ANYEVENT_STRICT}) {
		1483	require AnyEvent::Strict;
		1484	}
		1485
		1486	if ($ENV{PERL_ANYEVENT_DEBUG_WRAP}) {
		1487	require AnyEvent::Debug;
		1488	AnyEvent::Debug::wrap ($ENV{PERL_ANYEVENT_DEBUG_WRAP});
		1489	}
		1490
		1491	if (length $ENV{PERL_ANYEVENT_DEBUG_SHELL}) {
		1492	require AnyEvent::Socket;
		1493	require AnyEvent::Debug;
		1494
		1495	my $shell = $ENV{PERL_ANYEVENT_DEBUG_SHELL};
		1496	$shell =~ s/\$\$/$$/g;
		1497
		1498	my ($host, $service) = AnyEvent::Socket::parse_hostport ($shell);
		1499	$AnyEvent::Debug::SHELL = AnyEvent::Debug::shell ($host, $service);
		1500	}
		1501
		1502	# now the anyevent environment is set up as the user told us to, so
		1503	# call the actual user code - post detects
		1504
		1505	(shift @post_detect)->() while @post_detect;
		1506	undef @post_detect;
		1507
		1508	*post_detect = sub(&) {
		1509	shift->();
		1510
		1511	undef
		1512	};
		1513
1231	$MODEL	1514	$MODEL
1232	}	1515	}
1233		1516
1234	sub AUTOLOAD {	1517	for my $name (@methods) {
1235	(my $func = $AUTOLOAD) =~ s/.*://;	1518	*$name = sub {
1236		1519	detect;
1237	$method{$func}	1520	# we use goto because
1238	or Carp::croak "$func: not a valid method for AnyEvent objects";	1521	# a) it makes the thunk more transparent
1239		1522	# b) it allows us to delete the thunk later
1240	detect unless $MODEL;	1523	goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
1241		1524	};
1242	my $class = shift;
1243	$class->$func (@_);
1244	}	1525	}
1245		1526
1246	# utility function to dup a filehandle. this is used by many backends	1527	# utility function to dup a filehandle. this is used by many backends
1247	# to support binding more than one watcher per filehandle (they usually	1528	# to support binding more than one watcher per filehandle (they usually
1248	# allow only one watcher per fd, so we dup it to get a different one).	1529	# allow only one watcher per fd, so we dup it to get a different one).
…		…
1258	# we assume CLOEXEC is already set by perl in all important cases	1539	# we assume CLOEXEC is already set by perl in all important cases
1259		1540
1260	($fh2, $rw)	1541	($fh2, $rw)
1261	}	1542	}
1262		1543
		1544	=head1 SIMPLIFIED AE API
		1545
		1546	Starting with version 5.0, AnyEvent officially supports a second, much
		1547	simpler, API that is designed to reduce the calling, typing and memory
		1548	overhead by using function call syntax and a fixed number of parameters.
		1549
		1550	See the L<AE> manpage for details.
		1551
		1552	=cut
		1553
		1554	package AE;
		1555
		1556	our $VERSION = $AnyEvent::VERSION;
		1557
		1558	sub _reset() {
		1559	eval q{
		1560	# fall back to the main API by default - backends and AnyEvent::Base
		1561	# implementations can overwrite these.
		1562
		1563	sub io($$$) {
		1564	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
		1565	}
		1566
		1567	sub timer($$$) {
		1568	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
		1569	}
		1570
		1571	sub signal($$) {
		1572	AnyEvent->signal (signal => $_[0], cb => $_[1])
		1573	}
		1574
		1575	sub child($$) {
		1576	AnyEvent->child (pid => $_[0], cb => $_[1])
		1577	}
		1578
		1579	sub idle($) {
		1580	AnyEvent->idle (cb => $_[0]);
		1581	}
		1582
		1583	sub cv(;&) {
		1584	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
		1585	}
		1586
		1587	sub now() {
		1588	AnyEvent->now
		1589	}
		1590
		1591	sub now_update() {
		1592	AnyEvent->now_update
		1593	}
		1594
		1595	sub time() {
		1596	AnyEvent->time
		1597	}
		1598
		1599	*postpone = \&AnyEvent::postpone;
		1600	*log = \&AnyEvent::log;
		1601	};
		1602	die if $@;
		1603	}
		1604
		1605	BEGIN { _reset }
		1606
1263	package AnyEvent::Base;	1607	package AnyEvent::Base;
1264		1608
1265	# default implementations for many methods	1609	# default implementations for many methods
1266		1610
1267	sub _time {	1611	sub time {
		1612	eval q{ # poor man's autoloading {}
1268	# probe for availability of Time::HiRes	1613	# probe for availability of Time::HiRes
1269	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1614	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1270	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1615	*time = sub { Time::HiRes::time () };
1271	*_time = \&Time::HiRes::time;	1616	*AE::time = \& Time::HiRes::time ;
		1617	*now = \&time;
		1618	AnyEvent::log 8 => "AnyEvent: using Time::HiRes for sub-second timing accuracy.";
1272	# if (eval "use POSIX (); (POSIX::times())...	1619	# if (eval "use POSIX (); (POSIX::times())...
1273	} else {	1620	} else {
		1621	*time = sub { CORE::time };
		1622	*AE::time = sub (){ CORE::time };
		1623	*now = \&time;
1274	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1624	AnyEvent::log 3 => "using built-in time(), WARNING, no sub-second resolution!";
1275	*_time = sub { time }; # epic fail	1625	}
1276	}	1626	};
		1627	die if $@;
1277		1628
1278	&_time	1629	&time
1279	}	1630	}
1280		1631
1281	sub time { _time }	1632	*now = \&time;
1282	sub now { _time }
1283	sub now_update { }	1633	sub now_update { }
1284		1634
		1635	sub _poll {
		1636	Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
		1637	}
		1638
1285	# default implementation for ->condvar	1639	# default implementation for ->condvar
		1640	# in fact, the default should not be overwritten
1286		1641
1287	sub condvar {	1642	sub condvar {
		1643	eval q{ # poor man's autoloading {}
		1644	*condvar = sub {
1288	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1645	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1646	};
		1647
		1648	*AE::cv = sub (;&) {
		1649	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1650	};
		1651	};
		1652	die if $@;
		1653
		1654	&condvar
1289	}	1655	}
1290		1656
1291	# default implementation for ->signal	1657	# default implementation for ->signal
1292		1658
1293	our $HAVE_ASYNC_INTERRUPT;	1659	our $HAVE_ASYNC_INTERRUPT;
1294		1660
1295	sub _have_async_interrupt() {	1661	sub _have_async_interrupt() {
1296	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}	1662	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
1297	&& eval "use Async::Interrupt 1.0 (); 1")	1663	&& eval "use Async::Interrupt 1.02 (); 1")
1298	unless defined $HAVE_ASYNC_INTERRUPT;	1664	unless defined $HAVE_ASYNC_INTERRUPT;
1299		1665
1300	$HAVE_ASYNC_INTERRUPT	1666	$HAVE_ASYNC_INTERRUPT
1301	}	1667	}
1302		1668
1303	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1669	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1304	our (%SIG_ASY, %SIG_ASY_W);	1670	our (%SIG_ASY, %SIG_ASY_W);
1305	our ($SIG_COUNT, $SIG_TW);	1671	our ($SIG_COUNT, $SIG_TW);
1306		1672
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	1673	# install a dummy wakeup watcher to reduce signal catching latency
		1674	# used by Impls
1321	sub _sig_add() {	1675	sub _sig_add() {
1322	unless ($SIG_COUNT++) {	1676	unless ($SIG_COUNT++) {
1323	# try to align timer on a full-second boundary, if possible	1677	# try to align timer on a full-second boundary, if possible
1324	my $NOW = AnyEvent->now;	1678	my $NOW = AE::now;
1325		1679
1326	$SIG_TW = AnyEvent->timer (	1680	$SIG_TW = AE::timer
1327	after => $MAX_SIGNAL_LATENCY - ($NOW - int $NOW),	1681	$MAX_SIGNAL_LATENCY - ($NOW - int $NOW),
1328	interval => $MAX_SIGNAL_LATENCY,	1682	$MAX_SIGNAL_LATENCY,
1329	cb => sub { }, # just for the PERL_ASYNC_CHECK	1683	sub { } # just for the PERL_ASYNC_CHECK
1330	);	1684	;
1331	}	1685	}
1332	}	1686	}
1333		1687
1334	sub _sig_del {	1688	sub _sig_del {
1335	undef $SIG_TW	1689	undef $SIG_TW
1336	unless --$SIG_COUNT;	1690	unless --$SIG_COUNT;
1337	}	1691	}
1338		1692
1339	our %SIGNAME2NUM;
1340	our @SIGNUM2NAME;
1341	our $_sig_name_init; $_sig_name_init = sub {	1693	our $_sig_name_init; $_sig_name_init = sub {
		1694	eval q{ # poor man's autoloading {}
1342	undef $_sig_name_init;	1695	undef $_sig_name_init;
1343		1696
1344	if (_have_async_interrupt) {	1697	if (_have_async_interrupt) {
1345	*sig2num = \&Async::Interrupt::sig2num;	1698	*sig2num = \&Async::Interrupt::sig2num;
1346	*sig2name = \&Async::Interrupt::sig2name;	1699	*sig2name = \&Async::Interrupt::sig2name;
1347	} else {	1700	} else {
1348	require Config;	1701	require Config;
1349		1702
		1703	my %signame2num;
1350	@SIGNAME2NUM{ split ' ', $Config::Config{sig_name} }	1704	@signame2num{ split ' ', $Config::Config{sig_name} }
1351	= split ' ', $Config::Config{sig_num};	1705	= split ' ', $Config::Config{sig_num};
1352	@SIGNUM2NAME[values %SIGNAME2NUM] = keys %SIGNAME2NUM;
1353		1706
		1707	my @signum2name;
		1708	@signum2name[values %signame2num] = keys %signame2num;
		1709
1354	*sig2num = sub($) {	1710	*sig2num = sub($) {
1355	$_[0] > 0 ? shift : $SIGNAME2NUM{+shift}	1711	$_[0] > 0 ? shift : $signame2num{+shift}
1356	};	1712	};
1357	*sig2name = sub ($) {	1713	*sig2name = sub ($) {
1358	$_[0] > 0 ? $SIGNUM2NAME[+shift] : shift	1714	$_[0] > 0 ? $signum2name[+shift] : shift
		1715	};
1359	};	1716	}
1360	}	1717	};
		1718	die if $@;
1361	};	1719	};
1362		1720
1363	sub sig2num ($) { &$_sig_name_init; &sig2num }	1721	sub sig2num ($) { &$_sig_name_init; &sig2num }
1364	sub sig2name($) { &$_sig_name_init; &sig2name }	1722	sub sig2name($) { &$_sig_name_init; &sig2name }
1365		1723
1366	sub _signal {	1724	sub signal {
		1725	eval q{ # poor man's autoloading {}
		1726	# probe for availability of Async::Interrupt
		1727	if (_have_async_interrupt) {
		1728	AnyEvent::log 8 => "using Async::Interrupt for race-free signal handling.";
		1729
		1730	$SIGPIPE_R = new Async::Interrupt::EventPipe;
		1731	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
		1732
		1733	} else {
		1734	AnyEvent::log 8 => "using emulated perl signal handling with latency timer.";
		1735
		1736	if (AnyEvent::WIN32) {
		1737	require AnyEvent::Util;
		1738
		1739	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1740	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
		1741	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
		1742	} else {
		1743	pipe $SIGPIPE_R, $SIGPIPE_W;
		1744	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
		1745	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
		1746
		1747	# not strictly required, as $^F is normally 2, but let's make sure...
		1748	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
		1749	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
		1750	}
		1751
		1752	$SIGPIPE_R
		1753	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1754
		1755	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
		1756	}
		1757
		1758	*signal = $HAVE_ASYNC_INTERRUPT
		1759	? sub {
1367	my (undef, %arg) = @_;	1760	my (undef, %arg) = @_;
1368		1761
1369	my $signal = uc $arg{signal}
1370	or Carp::croak "required option 'signal' is missing";
1371
1372	if ($HAVE_ASYNC_INTERRUPT) {
1373	# async::interrupt	1762	# async::interrupt
1374
1375	$signal = sig2num $signal;	1763	my $signal = sig2num $arg{signal};
1376	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1764	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1377		1765
1378	$SIG_ASY{$signal} ||= new Async::Interrupt	1766	$SIG_ASY{$signal} ||= new Async::Interrupt
1379	cb => sub { undef $SIG_EV{$signal} },	1767	cb => sub { undef $SIG_EV{$signal} },
1380	signal => $signal,	1768	signal => $signal,
1381	pipe => [$SIGPIPE_R->filenos],	1769	pipe => [$SIGPIPE_R->filenos],
1382	pipe_autodrain => 0,	1770	pipe_autodrain => 0,
		1771	;
		1772
		1773	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1774	}
		1775	: sub {
		1776	my (undef, %arg) = @_;
		1777
		1778	# pure perl
		1779	my $signal = sig2name $arg{signal};
		1780	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
		1781
		1782	$SIG{$signal} ||= sub {
		1783	local $!;
		1784	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1785	undef $SIG_EV{$signal};
		1786	};
		1787
		1788	# can't do signal processing without introducing races in pure perl,
		1789	# so limit the signal latency.
		1790	_sig_add;
		1791
		1792	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1793	}
1383	;	1794	;
1384		1795
1385	} else {	1796	*AnyEvent::Base::signal::DESTROY = sub {
1386	# pure perl	1797	my ($signal, $cb) = @{$_[0]};
1387		1798
1388	# AE::Util has been loaded in signal	1799	_sig_del;
1389	$signal = sig2name $signal;
1390	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1391		1800
1392	$SIG{$signal} ||= sub {	1801	delete $SIG_CB{$signal}{$cb};
1393	local $!;	1802
1394	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1803	$HAVE_ASYNC_INTERRUPT
		1804	? delete $SIG_ASY{$signal}
		1805	: # delete doesn't work with older perls - they then
		1806	# print weird messages, or just unconditionally exit
		1807	# instead of getting the default action.
1395	undef $SIG_EV{$signal};	1808	undef $SIG{$signal}
		1809	unless keys %{ $SIG_CB{$signal} };
1396	};	1810	};
1397		1811
1398	# can't do signal processing without introducing races in pure perl,	1812	*_signal_exec = sub {
1399	# so limit the signal latency.	1813	$HAVE_ASYNC_INTERRUPT
1400	_sig_add;	1814	? $SIGPIPE_R->drain
1401	}	1815	: sysread $SIGPIPE_R, (my $dummy), 9;
1402		1816
1403	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1817	while (%SIG_EV) {
1404	}	1818	for (keys %SIG_EV) {
1405		1819	delete $SIG_EV{$_};
1406	sub signal {	1820	&$_ for values %{ $SIG_CB{$_} || {} };
1407	# probe for availability of Async::Interrupt	1821	}
1408	if (_have_async_interrupt) {	1822	}
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	}	1823	};
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	}	1824	};
		1825	die if $@;
1440		1826
1441	*signal = \&_signal;
1442	&signal	1827	&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	}	1828	}
1460		1829
1461	# default implementation for ->child	1830	# default implementation for ->child
1462		1831
1463	our %PID_CB;	1832	our %PID_CB;
1464	our $CHLD_W;	1833	our $CHLD_W;
1465	our $CHLD_DELAY_W;	1834	our $CHLD_DELAY_W;
1466	our $WNOHANG;
1467		1835
		1836	# used by many Impl's
1468	sub _emit_childstatus($$) {	1837	sub _emit_childstatus($$) {
1469	my (undef, $rpid, $rstatus) = @_;	1838	my (undef, $rpid, $rstatus) = @_;
1470		1839
1471	$_->($rpid, $rstatus)	1840	$_->($rpid, $rstatus)
1472	for values %{ $PID_CB{$rpid} || {} },	1841	for values %{ $PID_CB{$rpid} || {} },
1473	values %{ $PID_CB{0} || {} };	1842	values %{ $PID_CB{0} || {} };
1474	}	1843	}
1475		1844
1476	sub _sigchld {
1477	my $pid;
1478
1479	AnyEvent->_emit_childstatus ($pid, $?)
1480	while ($pid = waitpid -1, $WNOHANG) > 0;
1481	}
1482
1483	sub child {	1845	sub child {
		1846	eval q{ # poor man's autoloading {}
		1847	*_sigchld = sub {
		1848	my $pid;
		1849
		1850	AnyEvent->_emit_childstatus ($pid, $?)
		1851	while ($pid = waitpid -1, WNOHANG) > 0;
		1852	};
		1853
		1854	*child = sub {
1484	my (undef, %arg) = @_;	1855	my (undef, %arg) = @_;
1485		1856
1486	defined (my $pid = $arg{pid} + 0)	1857	my $pid = $arg{pid};
1487	or Carp::croak "required option 'pid' is missing";	1858	my $cb = $arg{cb};
1488		1859
1489	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1860	$PID_CB{$pid}{$cb+0} = $cb;
1490		1861
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) {	1862	unless ($CHLD_W) {
1497	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1863	$CHLD_W = AE::signal CHLD => \&_sigchld;
1498	# child could be a zombie already, so make at least one round	1864	# child could be a zombie already, so make at least one round
1499	&_sigchld;	1865	&_sigchld;
1500	}	1866	}
1501		1867
1502	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1868	bless [$pid, $cb+0], "AnyEvent::Base::child"
1503	}	1869	};
1504		1870
1505	sub AnyEvent::Base::child::DESTROY {	1871	*AnyEvent::Base::child::DESTROY = sub {
1506	my ($pid, $cb) = @{$_[0]};	1872	my ($pid, $icb) = @{$_[0]};
1507		1873
1508	delete $PID_CB{$pid}{$cb};	1874	delete $PID_CB{$pid}{$icb};
1509	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1875	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1510		1876
1511	undef $CHLD_W unless keys %PID_CB;	1877	undef $CHLD_W unless keys %PID_CB;
		1878	};
		1879	};
		1880	die if $@;
		1881
		1882	&child
1512	}	1883	}
1513		1884
1514	# idle emulation is done by simply using a timer, regardless	1885	# idle emulation is done by simply using a timer, regardless
1515	# of whether the process is idle or not, and not letting	1886	# of whether the process is idle or not, and not letting
1516	# the callback use more than 50% of the time.	1887	# the callback use more than 50% of the time.
1517	sub idle {	1888	sub idle {
		1889	eval q{ # poor man's autoloading {}
		1890	*idle = sub {
1518	my (undef, %arg) = @_;	1891	my (undef, %arg) = @_;
1519		1892
1520	my ($cb, $w, $rcb) = $arg{cb};	1893	my ($cb, $w, $rcb) = $arg{cb};
1521		1894
1522	$rcb = sub {	1895	$rcb = sub {
1523	if ($cb) {	1896	if ($cb) {
1524	$w = _time;	1897	$w = AE::time;
1525	&$cb;	1898	&$cb;
1526	$w = _time - $w;	1899	$w = AE::time - $w;
1527		1900
1528	# never use more then 50% of the time for the idle watcher,	1901	# never use more then 50% of the time for the idle watcher,
1529	# within some limits	1902	# within some limits
1530	$w = 0.0001 if $w < 0.0001;	1903	$w = 0.0001 if $w < 0.0001;
1531	$w = 5 if $w > 5;	1904	$w = 5 if $w > 5;
1532		1905
1533	$w = AnyEvent->timer (after => $w, cb => $rcb);	1906	$w = AE::timer $w, 0, $rcb;
1534	} else {	1907	} else {
1535	# clean up...	1908	# clean up...
1536	undef $w;	1909	undef $w;
1537	undef $rcb;	1910	undef $rcb;
		1911	}
		1912	};
		1913
		1914	$w = AE::timer 0.05, 0, $rcb;
		1915
		1916	bless \\$cb, "AnyEvent::Base::idle"
1538	}	1917	};
		1918
		1919	*AnyEvent::Base::idle::DESTROY = sub {
		1920	undef $${$_[0]};
		1921	};
1539	};	1922	};
		1923	die if $@;
1540		1924
1541	$w = AnyEvent->timer (after => 0.05, cb => $rcb);	1925	&idle
1542
1543	bless \\$cb, "AnyEvent::Base::idle"
1544	}
1545
1546	sub AnyEvent::Base::idle::DESTROY {
1547	undef $${$_[0]};
1548	}	1926	}
1549		1927
1550	package AnyEvent::CondVar;	1928	package AnyEvent::CondVar;
1551		1929
1552	our @ISA = AnyEvent::CondVar::Base::;	1930	our @ISA = AnyEvent::CondVar::Base::;
		1931
		1932	# only to be used for subclassing
		1933	sub new {
		1934	my $class = shift;
		1935	bless AnyEvent->condvar (@_), $class
		1936	}
1553		1937
1554	package AnyEvent::CondVar::Base;	1938	package AnyEvent::CondVar::Base;
1555		1939
1556	#use overload	1940	#use overload
1557	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1941	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
…		…
1567		1951
1568	sub _send {	1952	sub _send {
1569	# nop	1953	# nop
1570	}	1954	}
1571		1955
		1956	sub _wait {
		1957	AnyEvent->_poll until $_[0]{_ae_sent};
		1958	}
		1959
1572	sub send {	1960	sub send {
1573	my $cv = shift;	1961	my $cv = shift;
1574	$cv->{_ae_sent} = [@_];	1962	$cv->{_ae_sent} = [@_];
1575	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};	1963	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1576	$cv->_send;	1964	$cv->_send;
…		…
1583		1971
1584	sub ready {	1972	sub ready {
1585	$_[0]{_ae_sent}	1973	$_[0]{_ae_sent}
1586	}	1974	}
1587		1975
1588	sub _wait {
1589	$WAITING
1590	and !$_[0]{_ae_sent}
1591	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1592
1593	local $WAITING = 1;
1594	AnyEvent->one_event while !$_[0]{_ae_sent};
1595	}
1596
1597	sub recv {	1976	sub recv {
		1977	unless ($_[0]{_ae_sent}) {
		1978	$WAITING
		1979	and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
		1980
		1981	local $WAITING = 1;
1598	$_[0]->_wait;	1982	$_[0]->_wait;
		1983	}
1599		1984
1600	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1985	$_[0]{_ae_croak}
1601	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1986	and Carp::croak $_[0]{_ae_croak};
		1987
		1988	wantarray
		1989	? @{ $_[0]{_ae_sent} }
		1990	: $_[0]{_ae_sent}[0]
1602	}	1991	}
1603		1992
1604	sub cb {	1993	sub cb {
1605	$_[0]{_ae_cb} = $_[1] if @_ > 1;	1994	my $cv = shift;
		1995
		1996	@_
		1997	and $cv->{_ae_cb} = shift
		1998	and $cv->{_ae_sent}
		1999	and (delete $cv->{_ae_cb})->($cv);
		2000
1606	$_[0]{_ae_cb}	2001	$cv->{_ae_cb}
1607	}	2002	}
1608		2003
1609	sub begin {	2004	sub begin {
1610	++$_[0]{_ae_counter};	2005	++$_[0]{_ae_counter};
1611	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;	2006	$_[0]{_ae_end_cb} = $_[1] if @_ > 1;
…		…
1616	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };	2011	&{ $_[0]{_ae_end_cb} || sub { $_[0]->send } };
1617	}	2012	}
1618		2013
1619	# undocumented/compatibility with pre-3.4	2014	# undocumented/compatibility with pre-3.4
1620	*broadcast = \&send;	2015	*broadcast = \&send;
1621	*wait = \&_wait;	2016	*wait = \&recv;
1622		2017
1623	=head1 ERROR AND EXCEPTION HANDLING	2018	=head1 ERROR AND EXCEPTION HANDLING
1624		2019
1625	In general, AnyEvent does not do any error handling - it relies on the	2020	In general, AnyEvent does not do any error handling - it relies on the
1626	caller to do that if required. The L<AnyEvent::Strict> module (see also	2021	caller to do that if required. The L<AnyEvent::Strict> module (see also
…		…
1638	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and	2033	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
1639	so on.	2034	so on.
1640		2035
1641	=head1 ENVIRONMENT VARIABLES	2036	=head1 ENVIRONMENT VARIABLES
1642		2037
1643	The following environment variables are used by this module or its	2038	AnyEvent supports a number of environment variables that tune the
1644	submodules.	2039	runtime behaviour. They are usually evaluated when AnyEvent is
		2040	loaded, initialised, or a submodule that uses them is loaded. Many of
		2041	them also cause AnyEvent to load additional modules - for example,
		2042	C<PERL_ANYEVENT_DEBUG_WRAP> causes the L<AnyEvent::Debug> module to be
		2043	loaded.
1645		2044
1646	Note that AnyEvent will remove I<all> environment variables starting with	2045	All the environment variables documented here start with
1647	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is	2046	C<PERL_ANYEVENT_>, which is what AnyEvent considers its own
1648	enabled.	2047	namespace. Other modules are encouraged (but by no means required) to use
		2048	C<PERL_ANYEVENT_SUBMODULE> if they have registered the AnyEvent::Submodule
		2049	namespace on CPAN, for any submodule. For example, L<AnyEvent::HTTP> could
		2050	be expected to use C<PERL_ANYEVENT_HTTP_PROXY> (it should not access env
		2051	variables starting with C<AE_>, see below).
		2052
		2053	All variables can also be set via the C<AE_> prefix, that is, instead
		2054	of setting C<PERL_ANYEVENT_VERBOSE> you can also set C<AE_VERBOSE>. In
		2055	case there is a clash btween anyevent and another program that uses
		2056	C<AE_something> you can set the corresponding C<PERL_ANYEVENT_something>
		2057	variable to the empty string, as those variables take precedence.
		2058
		2059	When AnyEvent is first loaded, it copies all C<AE_xxx> env variables
		2060	to their C<PERL_ANYEVENT_xxx> counterpart unless that variable already
		2061	exists. If taint mode is on, then AnyEvent will remove I<all> environment
		2062	variables starting with C<PERL_ANYEVENT_> from C<%ENV> (or replace them
		2063	with C<undef> or the empty string, if the corresaponding C<AE_> variable
		2064	is set).
		2065
		2066	The exact algorithm is currently:
		2067
		2068	1. if taint mode enabled, delete all PERL_ANYEVENT_xyz variables from %ENV
		2069	2. copy over AE_xyz to PERL_ANYEVENT_xyz unless the latter alraedy exists
		2070	3. if taint mode enabled, set all PERL_ANYEVENT_xyz variables to undef.
		2071
		2072	This ensures that child processes will not see the C<AE_> variables.
		2073
		2074	The following environment variables are currently known to AnyEvent:
1649		2075
1650	=over 4	2076	=over 4
1651		2077
1652	=item C<PERL_ANYEVENT_VERBOSE>	2078	=item C<PERL_ANYEVENT_VERBOSE>
1653		2079
1654	By default, AnyEvent will be completely silent except in fatal	2080	By default, AnyEvent will only log messages with loglevel C<3>
1655	conditions. You can set this environment variable to make AnyEvent more	2081	(C<critical>) or higher (see L<AnyEvent::Log>). You can set this
		2082	environment variable to a numerical loglevel to make AnyEvent more (or
1656	talkative.	2083	less) talkative.
1657		2084
		2085	If you want to do more than just set the global logging level
		2086	you should have a look at C<PERL_ANYEVENT_LOG>, which allows much more
		2087	complex specifications.
		2088
		2089	When set to C<0> (C<off>), then no messages whatsoever will be logged with
		2090	the default logging settings.
		2091
1658	When set to C<1> or higher, causes AnyEvent to warn about unexpected	2092	When set to C<5> or higher (C<warn>), causes AnyEvent to warn about
1659	conditions, such as not being able to load the event model specified by	2093	unexpected conditions, such as not being able to load the event model
1660	C<PERL_ANYEVENT_MODEL>.	2094	specified by C<PERL_ANYEVENT_MODEL>, or a guard callback throwing an
		2095	exception - this is the minimum recommended level.
1661		2096
1662	When set to C<2> or higher, cause AnyEvent to report to STDERR which event	2097	When set to C<7> or higher (info), cause AnyEvent to report which event model it
1663	model it chooses.	2098	chooses.
1664		2099
1665	When set to C<8> or higher, then AnyEvent will report extra information on	2100	When set to C<8> or higher (debug), then AnyEvent will report extra information on
1666	which optional modules it loads and how it implements certain features.	2101	which optional modules it loads and how it implements certain features.
		2102
		2103	=item C<PERL_ANYEVENT_LOG>
		2104
		2105	Accepts rather complex logging specifications. For example, you could log
		2106	all C<debug> messages of some module to stderr, warnings and above to
		2107	stderr, and errors and above to syslog, with:
		2108
		2109	PERL_ANYEVENT_LOG=Some::Module=debug,+log:filter=warn,+%syslog:%syslog=error,syslog
		2110
		2111	For the rather extensive details, see L<AnyEvent::Log>.
		2112
		2113	This variable is evaluated when AnyEvent (or L<AnyEvent::Log>) is loaded,
		2114	so will take effect even before AnyEvent has initialised itself.
		2115
		2116	Note that specifying this environment variable causes the L<AnyEvent::Log>
		2117	module to be loaded, while C<PERL_ANYEVENT_VERBOSE> does not, so only
		2118	using the latter saves a few hundred kB of memory until the first message
		2119	is being logged.
1667		2120
1668	=item C<PERL_ANYEVENT_STRICT>	2121	=item C<PERL_ANYEVENT_STRICT>
1669		2122
1670	AnyEvent does not do much argument checking by default, as thorough	2123	AnyEvent does not do much argument checking by default, as thorough
1671	argument checking is very costly. Setting this variable to a true value	2124	argument checking is very costly. Setting this variable to a true value
…		…
1673	check the arguments passed to most method calls. If it finds any problems,	2126	check the arguments passed to most method calls. If it finds any problems,
1674	it will croak.	2127	it will croak.
1675		2128
1676	In other words, enables "strict" mode.	2129	In other words, enables "strict" mode.
1677		2130
1678	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>	2131	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	2132	>>, it is definitely recommended to keep it off in production. Keeping
1680	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs	2133	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1681	can be very useful, however.	2134	can be very useful, however.
1682		2135
		2136	=item C<PERL_ANYEVENT_DEBUG_SHELL>
		2137
		2138	If this env variable is nonempty, then its contents will be interpreted by
		2139	C<AnyEvent::Socket::parse_hostport> and C<AnyEvent::Debug::shell> (after
		2140	replacing every occurance of C<$$> by the process pid). The shell object
		2141	is saved in C<$AnyEvent::Debug::SHELL>.
		2142
		2143	This happens when the first watcher is created.
		2144
		2145	For example, to bind a debug shell on a unix domain socket in
		2146	F<< /tmp/debug<pid>.sock >>, you could use this:
		2147
		2148	PERL_ANYEVENT_DEBUG_SHELL=/tmp/debug\$\$.sock perlprog
		2149	# connect with e.g.: socat readline /tmp/debug123.sock
		2150
		2151	Or to bind to tcp port 4545 on localhost:
		2152
		2153	PERL_ANYEVENT_DEBUG_SHELL=127.0.0.1:4545 perlprog
		2154	# connect with e.g.: telnet localhost 4545
		2155
		2156	Note that creating sockets in F</tmp> or on localhost is very unsafe on
		2157	multiuser systems.
		2158
		2159	=item C<PERL_ANYEVENT_DEBUG_WRAP>
		2160
		2161	Can be set to C<0>, C<1> or C<2> and enables wrapping of all watchers for
		2162	debugging purposes. See C<AnyEvent::Debug::wrap> for details.
		2163
1683	=item C<PERL_ANYEVENT_MODEL>	2164	=item C<PERL_ANYEVENT_MODEL>
1684		2165
1685	This can be used to specify the event model to be used by AnyEvent, before	2166	This can be used to specify the event model to be used by AnyEvent, before
1686	auto detection and -probing kicks in. It must be a string consisting	2167	auto detection and -probing kicks in.
1687	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	2168
		2169	It normally is a string consisting entirely of ASCII letters (e.g. C<EV>
		2170	or C<IOAsync>). The string C<AnyEvent::Impl::> gets prepended and the
1688	and the resulting module name is loaded and if the load was successful,	2171	resulting module name is loaded and - if the load was successful - used as
1689	used as event model. If it fails to load AnyEvent will proceed with	2172	event model backend. If it fails to load then AnyEvent will proceed with
1690	auto detection and -probing.	2173	auto detection and -probing.
1691		2174
1692	This functionality might change in future versions.	2175	If the string ends with C<::> instead (e.g. C<AnyEvent::Impl::EV::>) then
		2176	nothing gets prepended and the module name is used as-is (hint: C<::> at
		2177	the end of a string designates a module name and quotes it appropriately).
1693		2178
1694	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	2179	For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1695	could start your program like this:	2180	could start your program like this:
1696		2181
1697	PERL_ANYEVENT_MODEL=Perl perl ...	2182	PERL_ANYEVENT_MODEL=Perl perl ...
1698		2183
1699	=item C<PERL_ANYEVENT_PROTOCOLS>	2184	=item C<PERL_ANYEVENT_PROTOCOLS>
…		…
1715	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>	2200	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1716	- only support IPv4, never try to resolve or contact IPv6	2201	- only support IPv4, never try to resolve or contact IPv6
1717	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or	2202	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1718	IPv6, but prefer IPv6 over IPv4.	2203	IPv6, but prefer IPv6 over IPv4.
1719		2204
		2205	=item C<PERL_ANYEVENT_HOSTS>
		2206
		2207	This variable, if specified, overrides the F</etc/hosts> file used by
		2208	L<AnyEvent::Socket>C<::resolve_sockaddr>, i.e. hosts aliases will be read
		2209	from that file instead.
		2210
1720	=item C<PERL_ANYEVENT_EDNS0>	2211	=item C<PERL_ANYEVENT_EDNS0>
1721		2212
1722	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension	2213	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension for
1723	for DNS. This extension is generally useful to reduce DNS traffic, but	2214	DNS. This extension is generally useful to reduce DNS traffic, especially
1724	some (broken) firewalls drop such DNS packets, which is why it is off by	2215	when DNSSEC is involved, but some (broken) firewalls drop such DNS
1725	default.	2216	packets, which is why it is off by default.
1726		2217
1727	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce	2218	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1728	EDNS0 in its DNS requests.	2219	EDNS0 in its DNS requests.
1729		2220
1730	=item C<PERL_ANYEVENT_MAX_FORKS>	2221	=item C<PERL_ANYEVENT_MAX_FORKS>
…		…
1738	resolver - this is the maximum number of parallel DNS requests that are	2229	resolver - this is the maximum number of parallel DNS requests that are
1739	sent to the DNS server.	2230	sent to the DNS server.
1740		2231
1741	=item C<PERL_ANYEVENT_RESOLV_CONF>	2232	=item C<PERL_ANYEVENT_RESOLV_CONF>
1742		2233
1743	The file to use instead of F</etc/resolv.conf> (or OS-specific	2234	The absolute path to a F<resolv.conf>-style file to use instead of
1744	configuration) in the default resolver. When set to the empty string, no	2235	F</etc/resolv.conf> (or the OS-specific configuration) in the default
1745	default config will be used.	2236	resolver, or the empty string to select the default configuration.
1746		2237
1747	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.	2238	=item C<PERL_ANYEVENT_CA_FILE>, C<PERL_ANYEVENT_CA_PATH>.
1748		2239
1749	When neither C<ca_file> nor C<ca_path> was specified during	2240	When neither C<ca_file> nor C<ca_path> was specified during
1750	L<AnyEvent::TLS> context creation, and either of these environment	2241	L<AnyEvent::TLS> context creation, and either of these environment
1751	variables exist, they will be used to specify CA certificate locations	2242	variables are nonempty, they will be used to specify CA certificate
1752	instead of a system-dependent default.	2243	locations instead of a system-dependent default.
1753		2244
1754	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>	2245	=item C<PERL_ANYEVENT_AVOID_GUARD> and C<PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT>
1755		2246
1756	When these are set to C<1>, then the respective modules are not	2247	When these are set to C<1>, then the respective modules are not
1757	loaded. Mostly good for testing AnyEvent itself.	2248	loaded. Mostly good for testing AnyEvent itself.
…		…
1820	warn "read: $input\n"; # output what has been read	2311	warn "read: $input\n"; # output what has been read
1821	$cv->send if $input =~ /^q/i; # quit program if /^q/i	2312	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1822	},	2313	},
1823	);	2314	);
1824		2315
1825	my $time_watcher; # can only be used once
1826
1827	sub new_timer {
1828	$timer = AnyEvent->timer (after => 1, cb => sub {	2316	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1829	warn "timeout\n"; # print 'timeout' about every second	2317	warn "timeout\n"; # print 'timeout' at most every second
1830	&new_timer; # and restart the time
1831	});	2318	});
1832	}
1833
1834	new_timer; # create first timer
1835		2319
1836	$cv->recv; # wait until user enters /^q/i	2320	$cv->recv; # wait until user enters /^q/i
1837		2321
1838	=head1 REAL-WORLD EXAMPLE	2322	=head1 REAL-WORLD EXAMPLE
1839		2323
…		…
1912		2396
1913	The actual code goes further and collects all errors (C<die>s, exceptions)	2397	The actual code goes further and collects all errors (C<die>s, exceptions)
1914	that occurred during request processing. The C<result> method detects	2398	that occurred during request processing. The C<result> method detects
1915	whether an exception as thrown (it is stored inside the $txn object)	2399	whether an exception as thrown (it is stored inside the $txn object)
1916	and just throws the exception, which means connection errors and other	2400	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	2401	problems get reported to the code that tries to use the result, not in a
1918	random callback.	2402	random callback.
1919		2403
1920	All of this enables the following usage styles:	2404	All of this enables the following usage styles:
1921		2405
1922	1. Blocking:	2406	1. Blocking:
…		…
1970	through AnyEvent. The benchmark creates a lot of timers (with a zero	2454	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,	2455	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.	2456	which it is), lets them fire exactly once and destroys them again.
1973		2457
1974	Source code for this benchmark is found as F<eg/bench> in the AnyEvent	2458	Source code for this benchmark is found as F<eg/bench> in the AnyEvent
1975	distribution.	2459	distribution. It uses the L<AE> interface, which makes a real difference
		2460	for the EV and Perl backends only.
1976		2461
1977	=head3 Explanation of the columns	2462	=head3 Explanation of the columns
1978		2463
1979	I<watcher> is the number of event watchers created/destroyed. Since	2464	I<watcher> is the number of event watchers created/destroyed. Since
1980	different event models feature vastly different performances, each event	2465	different event models feature vastly different performances, each event
…		…
2001	watcher.	2486	watcher.
2002		2487
2003	=head3 Results	2488	=head3 Results
2004		2489
2005	name watchers bytes create invoke destroy comment	2490	name watchers bytes create invoke destroy comment
2006	EV/EV 400000 224 0.47 0.35 0.27 EV native interface	2491	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	2492	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	2493	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	2494	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	2495	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	2496	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	2497	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	2498	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	2499	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	2500	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	2501	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	2502	POE/Any 2000 6648 94.79 774.40 575.51 via POE::Loop::Select
2018		2503
2019	=head3 Discussion	2504	=head3 Discussion
2020		2505
2021	The benchmark does I<not> measure scalability of the event loop very	2506	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)	2507	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	2519	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	2520	EV, 3100 CPU cycles with AnyEvent's pure perl loop and almost 3000000 CPU
2036	cycles with POE.	2521	cycles with POE.
2037		2522
2038	C<EV> is the sole leader regarding speed and memory use, which are both	2523	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	2524	maximal/minimal, respectively. When using the L<AE> API there is zero
		2525	overhead (when going through the AnyEvent API create is about 5-6 times
		2526	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	2527	any other event loop and is still faster than Event natively).
2041	natively.
2042		2528
2043	The pure perl implementation is hit in a few sweet spots (both the	2529	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	2530	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	2531	interpreter and the backend itself). Nevertheless this shows that it
2046	adds very little overhead in itself. Like any select-based backend its	2532	adds very little overhead in itself. Like any select-based backend its
…		…
2094	(even when used without AnyEvent), but most event loops have acceptable	2580	(even when used without AnyEvent), but most event loops have acceptable
2095	performance with or without AnyEvent.	2581	performance with or without AnyEvent.
2096		2582
2097	=item * The overhead AnyEvent adds is usually much smaller than the overhead of	2583	=item * The overhead AnyEvent adds is usually much smaller than the overhead of
2098	the actual event loop, only with extremely fast event loops such as EV	2584	the actual event loop, only with extremely fast event loops such as EV
2099	adds AnyEvent significant overhead.	2585	does AnyEvent add significant overhead.
2100		2586
2101	=item * You should avoid POE like the plague if you want performance or	2587	=item * You should avoid POE like the plague if you want performance or
2102	reasonable memory usage.	2588	reasonable memory usage.
2103		2589
2104	=back	2590	=back
…		…
2120	In this benchmark, we use 10000 socket pairs (20000 sockets), of which 100	2606	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	2607	(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.	2608	connections, most of which are idle at any one point in time.
2123		2609
2124	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent	2610	Source code for this benchmark is found as F<eg/bench2> in the AnyEvent
2125	distribution.	2611	distribution. It uses the L<AE> interface, which makes a real difference
		2612	for the EV and Perl backends only.
2126		2613
2127	=head3 Explanation of the columns	2614	=head3 Explanation of the columns
2128		2615
2129	I<sockets> is the number of sockets, and twice the number of "servers" (as	2616	I<sockets> is the number of sockets, and twice the number of "servers" (as
2130	each server has a read and write socket end).	2617	each server has a read and write socket end).
…		…
2138	a new one that moves the timeout into the future.	2625	a new one that moves the timeout into the future.
2139		2626
2140	=head3 Results	2627	=head3 Results
2141		2628
2142	name sockets create request	2629	name sockets create request
2143	EV 20000 69.01 11.16	2630	EV 20000 62.66 7.99
2144	Perl 20000 73.32 35.87	2631	Perl 20000 68.32 32.64
2145	IOAsync 20000 157.00 98.14 epoll	2632	IOAsync 20000 174.06 101.15 epoll
2146	IOAsync 20000 159.31 616.06 poll	2633	IOAsync 20000 174.67 610.84 poll
2147	Event 20000 212.62 257.32	2634	Event 20000 202.69 242.91
2148	Glib 20000 651.16 1896.30	2635	Glib 20000 557.01 1689.52
2149	POE 20000 349.67 12317.24 uses POE::Loop::Event	2636	POE 20000 341.54 12086.32 uses POE::Loop::Event
2150		2637
2151	=head3 Discussion	2638	=head3 Discussion
2152		2639
2153	This benchmark I<does> measure scalability and overall performance of the	2640	This benchmark I<does> measure scalability and overall performance of the
2154	particular event loop.	2641	particular event loop.
…		…
2280	As you can see, the AnyEvent + EV combination even beats the	2767	As you can see, the AnyEvent + EV combination even beats the
2281	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2768	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2282	backend easily beats IO::Lambda and POE.	2769	backend easily beats IO::Lambda and POE.
2283		2770
2284	And even the 100% non-blocking version written using the high-level (and	2771	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	2772	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	2773	higher level ("unoptimised") abstractions by a large margin, even though
2287	in a non-blocking way.	2774	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2288		2775
2289	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2776	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	2777	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.	2778	part of the IO::Lambda distribution and were used without any changes.
2292		2779
2293		2780
2294	=head1 SIGNALS	2781	=head1 SIGNALS
2295		2782
2296	AnyEvent currently installs handlers for these signals:	2783	AnyEvent currently installs handlers for these signals:
…		…
2333	unless defined $SIG{PIPE};	2820	unless defined $SIG{PIPE};
2334		2821
2335	=head1 RECOMMENDED/OPTIONAL MODULES	2822	=head1 RECOMMENDED/OPTIONAL MODULES
2336		2823
2337	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and	2824	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2338	it's built-in modules) are required to use it.	2825	its built-in modules) are required to use it.
2339		2826
2340	That does not mean that AnyEvent won't take advantage of some additional	2827	That does not mean that AnyEvent won't take advantage of some additional
2341	modules if they are installed.	2828	modules if they are installed.
2342		2829
2343	This section epxlains which additional modules will be used, and how they	2830	This section explains which additional modules will be used, and how they
2344	affect AnyEvent's operetion.	2831	affect AnyEvent's operation.
2345		2832
2346	=over 4	2833	=over 4
2347		2834
2348	=item L<Async::Interrupt>	2835	=item L<Async::Interrupt>
2349		2836
…		…
2354	catch the signals) with some delay (default is 10 seconds, look for	2841	catch the signals) with some delay (default is 10 seconds, look for
2355	C<$AnyEvent::MAX_SIGNAL_LATENCY>).	2842	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2356		2843
2357	If this module is available, then it will be used to implement signal	2844	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	2845	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	2846	will not be interrupted regularly, which is more efficient (and good for
2360	battery life on laptops).	2847	battery life on laptops).
2361		2848
2362	This affects not just the pure-perl event loop, but also other event loops	2849	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).	2850	that have no signal handling on their own (e.g. Glib, Tk, Qt).
2364		2851
…		…
2376	automatic timer adjustments even when no monotonic clock is available,	2863	automatic timer adjustments even when no monotonic clock is available,
2377	can take avdantage of advanced kernel interfaces such as C<epoll> and	2864	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	2865	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>).	2866	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2380		2867
		2868	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2869	then this module will do nothing for you.
		2870
2381	=item L<Guard>	2871	=item L<Guard>
2382		2872
2383	The guard module, when used, will be used to implement	2873	The guard module, when used, will be used to implement
2384	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a	2874	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	2875	lot less memory), but otherwise doesn't affect guard operation much. It is
2386	purely used for performance.	2876	purely used for performance.
2387		2877
2388	=item L<JSON> and L<JSON::XS>	2878	=item L<JSON> and L<JSON::XS>
2389		2879
2390	This module is required when you want to read or write JSON data via	2880	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	2881	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.	2882	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		2883
2397	=item L<Net::SSLeay>	2884	=item L<Net::SSLeay>
2398		2885
2399	Implementing TLS/SSL in Perl is certainly interesting, but not very	2886	Implementing TLS/SSL in Perl is certainly interesting, but not very
2400	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2887	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.	2888	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2402		2889
2403	=item L<Time::HiRes>	2890	=item L<Time::HiRes>
2404		2891
2405	This module is part of perl since release 5.008. It will be used when the	2892	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	2893	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	2894	pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2408	try to use a monotonic clock for timing stability.	2895	try to use a monotonic clock for timing stability.
2409		2896
2410	=back	2897	=back
2411		2898
2412		2899
2413	=head1 FORK	2900	=head1 FORK
2414		2901
2415	Most event libraries are not fork-safe. The ones who are usually are	2902	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>	2903	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2417	calls. Only L<EV> is fully fork-aware.	2904	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2905	are usually badly thought-out hacks that are incompatible with fork in
		2906	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2907	continue event-processing in both parent and child (or both, if you know
		2908	what you are doing).
		2909
		2910	This means that, in general, you cannot fork and do event processing in
		2911	the child if the event library was initialised before the fork (which
		2912	usually happens when the first AnyEvent watcher is created, or the library
		2913	is loaded).
2418		2914
2419	If you have to fork, you must either do so I<before> creating your first	2915	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	2916	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.	2917	something completely out of the scope of AnyEvent.
		2918
		2919	The problem of doing event processing in the parent I<and> the child
		2920	is much more complicated: even for backends that I<are> fork-aware or
		2921	fork-safe, their behaviour is not usually what you want: fork clones all
		2922	watchers, that means all timers, I/O watchers etc. are active in both
		2923	parent and child, which is almost never what you want. USing C<exec>
		2924	to start worker children from some kind of manage rprocess is usually
		2925	preferred, because it is much easier and cleaner, at the expense of having
		2926	to have another binary.
2422		2927
2423		2928
2424	=head1 SECURITY CONSIDERATIONS	2929	=head1 SECURITY CONSIDERATIONS
2425		2930
2426	AnyEvent can be forced to load any event model via	2931	AnyEvent can be forced to load any event model via
…		…
2456	pronounced).	2961	pronounced).
2457		2962
2458		2963
2459	=head1 SEE ALSO	2964	=head1 SEE ALSO
2460		2965
2461	Utility functions: L<AnyEvent::Util>.	2966	Tutorial/Introduction: L<AnyEvent::Intro>.
2462		2967
2463	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	2968	FAQ: L<AnyEvent::FAQ>.
2464	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2969
		2970	Utility functions: L<AnyEvent::Util> (misc. grab-bag), L<AnyEvent::Log>
		2971	(simply logging).
		2972
		2973	Development/Debugging: L<AnyEvent::Strict> (stricter checking),
		2974	L<AnyEvent::Debug> (interactive shell, watcher tracing).
		2975
		2976	Supported event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>,
		2977	L<Glib::EV>, L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>,
		2978	L<Qt>, L<POE>, L<FLTK>.
2465		2979
2466	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2980	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2467	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2981	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2468	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2982	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2469	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.	2983	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>,
		2984	L<AnyEvent::Impl::FLTK>.
2470		2985
2471	Non-blocking file handles, sockets, TCP clients and	2986	Non-blocking handles, pipes, stream sockets, TCP clients and
2472	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	2987	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2473		2988
2474	Asynchronous DNS: L<AnyEvent::DNS>.	2989	Asynchronous DNS: L<AnyEvent::DNS>.
2475		2990
2476	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,	2991	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2477	L<Coro::Event>,
2478		2992
2479	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,	2993	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2480	L<AnyEvent::HTTP>.	2994	L<AnyEvent::HTTP>.
2481		2995
2482		2996
2483	=head1 AUTHOR	2997	=head1 AUTHOR
2484		2998

Diff Legend

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