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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.279 by root, Sun Aug 9 16:05:11 2009 UTC vs.
Revision 1.363 by root, Sun Aug 14 13:56:52 2011 UTC

…		…
7		7
8	=head1 SYNOPSIS	8	=head1 SYNOPSIS
9		9
10	use AnyEvent;	10	use AnyEvent;
11		11
		12	# if you prefer function calls, look at the 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
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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
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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	});
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210		214
211	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.
212	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
213	underlying file descriptor.	217	underlying file descriptor.
214		218
215	Some event loops issue spurious readyness notifications, so you should	219	Some event loops issue spurious readiness notifications, so you should
216	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
217	handles.	221	handles.
218		222
219	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
220	watcher.	224	watcher.
…		…
244		248
245	Although the callback might get passed parameters, their value and	249	Although the callback might get passed parameters, their value and
246	presence is undefined and you cannot rely on them. Portable AnyEvent	250	presence is undefined and you cannot rely on them. Portable AnyEvent
247	callbacks cannot use arguments passed to time watcher callbacks.	251	callbacks cannot use arguments passed to time watcher callbacks.
248		252
249	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
250	parameter, C<interval>, as a strictly positive number (> 0), then the	254	parameter, C<interval>, as a strictly positive number (> 0), then the
251	callback will be invoked regularly at that interval (in fractional	255	callback will be invoked regularly at that interval (in fractional
252	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
253	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.
254		258
255	The callback will be rescheduled before invoking the callback, but no	259	The callback will be rescheduled before invoking the callback, but no
256	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
257	only approximate.	261	only approximate.
258		262
259	Example: fire an event after 7.7 seconds.	263	Example: fire an event after 7.7 seconds.
260		264
261	my $w = AnyEvent->timer (after => 7.7, cb => sub {	265	my $w = AnyEvent->timer (after => 7.7, cb => sub {
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279		283
280	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
281	use absolute time internally. This makes a difference when your clock	285	use absolute time internally. This makes a difference when your clock
282	"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
283	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
284	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.
285		289
286	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
287	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
288	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)
289	timers.	293	timers.
290		294
291	AnyEvent always prefers relative timers, if available, matching the	295	AnyEvent always prefers relative timers, if available, matching the
292	AnyEvent API.	296	AnyEvent API.
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314	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
315	function to call when you want to know the current time.>	319	function to call when you want to know the current time.>
316		320
317	This function is also often faster then C<< AnyEvent->time >>, and	321	This function is also often faster then C<< AnyEvent->time >>, and
318	thus the preferred method if you want some timestamp (for example,	322	thus the preferred method if you want some timestamp (for example,
319	L<AnyEvent::Handle> uses this to update it's activity timeouts).	323	L<AnyEvent::Handle> uses this to update its activity timeouts).
320		324
321	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
322	with your timing, you can skip it without bad conscience.	326	with your timing; you can skip it without a bad conscience.
323		327
324	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>
325	and L<EV> and the following set-up:	329	and L<EV> and the following set-up:
326		330
327	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
328	time=500 (assume no other callbacks delay processing). In your callback,	332	time=500 (assume no other callbacks delay processing). In your callback,
329	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
330	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
331	after three seconds.	335	after three seconds.
332		336
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352	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	356	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
353	account.	357	account.
354		358
355	=item AnyEvent->now_update	359	=item AnyEvent->now_update
356		360
357	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
358	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 >>,
359	AnyEvent->now >>, above).	363	above).
360		364
361	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
362	this "current" time will differ substantially from the real time, which	366	this "current" time will differ substantially from the real time, which
363	might affect timers and time-outs.	367	might affect timers and time-outs.
364		368
365	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
366	event loop's idea of "current time".	370	event loop's idea of "current time".
		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).
367		378
368	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.
369		380
370	=back	381	=back
371		382
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396		407
397	Example: exit on SIGINT	408	Example: exit on SIGINT
398		409
399	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });	410	my $w = AnyEvent->signal (signal => "INT", cb => sub { exit 1 });
400		411
		412	=head3 Restart Behaviour
		413
		414	While restart behaviour is up to the event loop implementation, most will
		415	not restart syscalls (that includes L<Async::Interrupt> and AnyEvent's
		416	pure perl implementation).
		417
		418	=head3 Safe/Unsafe Signals
		419
		420	Perl signals can be either "safe" (synchronous to opcode handling) or
		421	"unsafe" (asynchronous) - the former might get delayed indefinitely, the
		422	latter might corrupt your memory.
		423
		424	AnyEvent signal handlers are, in addition, synchronous to the event loop,
		425	i.e. they will not interrupt your running perl program but will only be
		426	called as part of the normal event handling (just like timer, I/O etc.
		427	callbacks, too).
		428
401	=head3 Signal Races, Delays and Workarounds	429	=head3 Signal Races, Delays and Workarounds
402		430
403	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching	431	Many event loops (e.g. Glib, Tk, Qt, IO::Async) do not support attaching
404	callbacks to signals in a generic way, which is a pity, as you cannot	432	callbacks to signals in a generic way, which is a pity, as you cannot
405	do race-free signal handling in perl, requiring C libraries for	433	do race-free signal handling in perl, requiring C libraries for
406	this. AnyEvent will try to do it's best, which means in some cases,	434	this. AnyEvent will try to do its best, which means in some cases,
407	signals will be delayed. The maximum time a signal might be delayed is	435	signals will be delayed. The maximum time a signal might be delayed is
408	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This	436	specified in C<$AnyEvent::MAX_SIGNAL_LATENCY> (default: 10 seconds). This
409	variable can be changed only before the first signal watcher is created,	437	variable can be changed only before the first signal watcher is created,
410	and should be left alone otherwise. This variable determines how often	438	and should be left alone otherwise. This variable determines how often
411	AnyEvent polls for signals (in case a wake-up was missed). Higher values	439	AnyEvent polls for signals (in case a wake-up was missed). Higher values
…		…
413	saving.	441	saving.
414		442
415	All these problems can be avoided by installing the optional	443	All these problems can be avoided by installing the optional
416	L<Async::Interrupt> module, which works with most event loops. It will not	444	L<Async::Interrupt> module, which works with most event loops. It will not
417	work with inherently broken event loops such as L<Event> or L<Event::Lib>	445	work with inherently broken event loops such as L<Event> or L<Event::Lib>
418	(and not with L<POE> currently, as POE does it's own workaround with	446	(and not with L<POE> currently, as POE does its own workaround with
419	one-second latency). For those, you just have to suffer the delays.	447	one-second latency). For those, you just have to suffer the delays.
420		448
421	=head2 CHILD PROCESS WATCHERS	449	=head2 CHILD PROCESS WATCHERS
422		450
423	$w = AnyEvent->child (pid => <process id>, cb => <callback>);	451	$w = AnyEvent->child (pid => <process id>, cb => <callback>);
424		452
425	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.
426		454
427	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,
428	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
429	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
430	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
431	(stopped/continued).	459	(stopped/continued).
432		460
…		…
454	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
455	watcher before you C<fork> the child (alternatively, you can call	483	watcher before you C<fork> the child (alternatively, you can call
456	C<AnyEvent::detect>).	484	C<AnyEvent::detect>).
457		485
458	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
459	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
460	mentioned in the description of signal watchers apply.	488	problems mentioned in the description of signal watchers apply.
461		489
462	Example: fork a process and wait for it	490	Example: fork a process and wait for it
463		491
464	my $done = AnyEvent->condvar;	492	my $done = AnyEvent->condvar;
465		493
…		…
479		507
480	=head2 IDLE WATCHERS	508	=head2 IDLE WATCHERS
481		509
482	$w = AnyEvent->idle (cb => <callback>);	510	$w = AnyEvent->idle (cb => <callback>);
483		511
484	Sometimes there is a need to do something, but it is not so important	512	This will repeatedly invoke the callback after the process becomes idle,
485	to do it instantly, but only when there is nothing better to do. This	513	until either the watcher is destroyed or new events have been detected.
486	"nothing better to do" is usually defined to be "no other events need
487	attention by the event loop".
488		514
489	Idle watchers ideally get invoked when the event loop has nothing	515	Idle watchers are useful when there is a need to do something, but it
490	better to do, just before it would block the process to wait for new	516	is not so important (or wise) to do it instantly. The callback will be
491	events. Instead of blocking, the idle watcher is invoked.	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.
492		523
493	Most event loops unfortunately do not really support idle watchers (only	524	Unfortunately, most event loops do not really support idle watchers (only
494	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
495	will simply call the callback "from time to time".	526	will simply call the callback "from time to time".
496		527
497	Example: read lines from STDIN, but only process them when the	528	Example: read lines from STDIN, but only process them when the
498	program is otherwise idle:	529	program is otherwise idle:
…		…
526	will actively watch for new events and call your callbacks.	557	will actively watch for new events and call your callbacks.
527		558
528	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
529	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).
530		561
531	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
532	because they represent a condition that must become true.	563	they represent a condition that must become true.
533		564
534	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.
535		566
536	Condition variables can be created by calling the C<< AnyEvent->condvar	567	Condition variables can be created by calling the C<< AnyEvent->condvar
537	>> method, usually without arguments. The only argument pair allowed is	568	>> method, usually without arguments. The only argument pair allowed is
…		…
542	After creation, the condition variable is "false" until it becomes "true"	573	After creation, the condition variable is "false" until it becomes "true"
543	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
544	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<<
545	->send >> method).	576	->send >> method).
546		577
547	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
548	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:
549	in time where multiple outstanding events have been processed. And yet	580
550	another way to call them is transactions - each condition variable can be	581	=over 4
551	used to represent a transaction, which finishes at some point and delivers	582
552	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
553	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
554		601
555	Condition variables are very useful to signal that something has finished,	602	Condition variables are very useful to signal that something has finished,
556	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,
557	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
558	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
…		…
571		618
572	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
573	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
574	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
575	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
576	it's C<new> method in your own C<new> method.	623	its C<new> method in your own C<new> method.
577		624
578	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
579	eventually calls C<< -> send >>, and the "consumer side", which waits	626	eventually calls C<< -> send >>, and the "consumer side", which waits
580	for the send to occur.	627	for the send to occur.
581		628
582	Example: wait for a timer.	629	Example: wait for a timer.
583		630
584	# wait till the result is ready	631	# condition: "wait till the timer is fired"
585	my $result_ready = AnyEvent->condvar;	632	my $timer_fired = AnyEvent->condvar;
586		633
587	# do something such as adding a timer	634	# create the timer - we could wait for, say
588	# or socket watcher the calls $result_ready->send	635	# a handle becomign ready, or even an
589	# when the "result" is ready.	636	# AnyEvent::HTTP request to finish, but
590	# in this case, we simply use a timer:	637	# in this case, we simply use a timer:
591	my $w = AnyEvent->timer (	638	my $w = AnyEvent->timer (
592	after => 1,	639	after => 1,
593	cb => sub { $result_ready->send },	640	cb => sub { $timer_fired->send },
594	);	641	);
595		642
596	# this "blocks" (while handling events) till the callback	643	# this "blocks" (while handling events) till the callback
597	# calls -<send	644	# calls ->send
598	$result_ready->recv;	645	$timer_fired->recv;
599		646
600	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
601	variables are also callable directly.	648	variables are also callable directly.
602		649
603	my $done = AnyEvent->condvar;	650	my $done = AnyEvent->condvar;
…		…
646	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
647	C<send>.	694	C<send>.
648		695
649	=item $cv->croak ($error)	696	=item $cv->croak ($error)
650		697
651	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
652	C<Carp::croak> with the given error message/object/scalar.	699	C<Carp::croak> with the given error message/object/scalar.
653		700
654	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
655	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
656	delays the error detetcion, but has the overwhelmign advantage that it	703	delays the error detection, but has the overwhelming advantage that it
657	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
658	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
659	the problem.	706	the problem.
660		707
661	=item $cv->begin ([group callback])	708	=item $cv->begin ([group callback])
662		709
663	=item $cv->end	710	=item $cv->end
…		…
666	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
667	to use a condition variable for the whole process.	714	to use a condition variable for the whole process.
668		715
669	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
670	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
671	>>, 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
672	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
673	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.
674		722
675	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
676	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
677	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).
678		726
…		…
700	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
701	sending.	749	sending.
702		750
703	The ping example mentioned above is slightly more complicated, as the	751	The ping example mentioned above is slightly more complicated, as the
704	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
705	begung can potentially be zero:	753	begun can potentially be zero:
706		754
707	my $cv = AnyEvent->condvar;	755	my $cv = AnyEvent->condvar;
708		756
709	my %result;	757	my %result;
710	$cv->begin (sub { $cv->send (\%result) });	758	$cv->begin (sub { shift->send (\%result) });
711		759
712	for my $host (@list_of_hosts) {	760	for my $host (@list_of_hosts) {
713	$cv->begin;	761	$cv->begin;
714	ping_host_then_call_callback $host, sub {	762	ping_host_then_call_callback $host, sub {
715	$result{$host} = ...;	763	$result{$host} = ...;
…		…
731	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
732	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
733	doesn't execute once).	781	doesn't execute once).
734		782
735	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
736	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
737	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
738	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,
739	call C<end>.	787	call C<end>.
740		788
741	=back	789	=back
…		…
748	=over 4	796	=over 4
749		797
750	=item $cv->recv	798	=item $cv->recv
751		799
752	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak	800	Wait (blocking if necessary) until the C<< ->send >> or C<< ->croak
753	>> methods have been called on c<$cv>, while servicing other watchers	801	>> methods have been called on C<$cv>, while servicing other watchers
754	normally.	802	normally.
755		803
756	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
757	will return immediately.	805	will return immediately.
758		806
…		…
775	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
776	condition variables with some kind of request results and supporting	824	condition variables with some kind of request results and supporting
777	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,
778	while still supporting blocking waits if the caller so desires).	826	while still supporting blocking waits if the caller so desires).
779		827
780	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
781	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
782	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
783	waits otherwise.	831	waits otherwise.
784		832
785	=item $bool = $cv->ready	833	=item $bool = $cv->ready
…		…
790	=item $cb = $cv->cb ($cb->($cv))	838	=item $cb = $cv->cb ($cb->($cv))
791		839
792	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
793	replaces it before doing so.	841	replaces it before doing so.
794		842
795	The callback will be called when the condition becomes (or already was)	843	The callback will be called when the condition becomes "true", i.e. when
796	"true", i.e. when C<send> or C<croak> are called (or were called), with	844	C<send> or C<croak> are called, with the only argument being the
797	the only argument being the condition variable itself. Calling C<recv>	845	condition variable itself. If the condition is already true, the
		846	callback is called immediately when it is set. Calling C<recv> inside
798	inside the callback or at any later time is guaranteed not to block.	847	the callback or at any later time is guaranteed not to block.
799		848
800	=back	849	=back
801		850
802	=head1 SUPPORTED EVENT LOOPS/BACKENDS	851	=head1 SUPPORTED EVENT LOOPS/BACKENDS
803		852
…		…
811	use. If EV is not installed, then AnyEvent will fall back to its own	860	use. If EV is not installed, then AnyEvent will fall back to its own
812	pure-perl implementation, which is available everywhere as it comes with	861	pure-perl implementation, which is available everywhere as it comes with
813	AnyEvent itself.	862	AnyEvent itself.
814		863
815	AnyEvent::Impl::EV based on EV (interface to libev, best choice).	864	AnyEvent::Impl::EV based on EV (interface to libev, best choice).
816	AnyEvent::Impl::Perl pure-perl implementation, fast and portable.	865	AnyEvent::Impl::Perl pure-perl AnyEvent::Loop, fast and portable.
817		866
818	=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.
819		868
820	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
821	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
822	them. This means that AnyEvent will automatically pick the right backend	871	them. This means that AnyEvent will automatically pick the right backend
823	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
824	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.
825		874
…		…
827	AnyEvent::Impl::Glib based on Glib, slow but very stable.	876	AnyEvent::Impl::Glib based on Glib, slow but very stable.
828	AnyEvent::Impl::Tk based on Tk, very broken.	877	AnyEvent::Impl::Tk based on Tk, very broken.
829	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.	878	AnyEvent::Impl::EventLib based on Event::Lib, leaks memory and worse.
830	AnyEvent::Impl::POE based on POE, very slow, some limitations.	879	AnyEvent::Impl::POE based on POE, very slow, some limitations.
831	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::FLTK2 based on FLTK (fltk 2 binding).
832		884
833	=item Backends with special needs.	885	=item Backends with special needs.
834		886
835	Qt requires the Qt::Application to be instantiated first, but will	887	Qt requires the Qt::Application to be instantiated first, but will
836	otherwise be picked up automatically. As long as the main program	888	otherwise be picked up automatically. As long as the main program
837	instantiates the application before any AnyEvent watchers are created,	889	instantiates the application before any AnyEvent watchers are created,
838	everything should just work.	890	everything should just work.
839		891
840	AnyEvent::Impl::Qt based on Qt.	892	AnyEvent::Impl::Qt based on Qt.
841		893
842	Support for IO::Async can only be partial, as it is too broken and
843	architecturally limited to even support the AnyEvent API. It also
844	is the only event loop that needs the loop to be set explicitly, so
845	it can only be used by a main program knowing about AnyEvent. See
846	L<AnyEvent::Impl::Async> for the gory details.
847
848	AnyEvent::Impl::IOAsync based on IO::Async, cannot be autoprobed.
849
850	=item Event loops that are indirectly supported via other backends.	894	=item Event loops that are indirectly supported via other backends.
851		895
852	Some event loops can be supported via other modules:	896	Some event loops can be supported via other modules:
853		897
854	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>.
…		…
879	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
880	backend has been autodetected.	924	backend has been autodetected.
881		925
882	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
883	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
884	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
885	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
886	will be C<urxvt::anyevent>).	930	will be C<urxvt::anyevent>).
887		931
888	=item AnyEvent::detect	932	=item AnyEvent::detect
889		933
890	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model	934	Returns C<$AnyEvent::MODEL>, forcing autodetection of the event model
891	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
892	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
893	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).
894		942
895	If you need to do some initialisation before AnyEvent watchers are	943	If you need to do some initialisation before AnyEvent watchers are
896	created, use C<post_detect>.	944	created, use C<post_detect>.
897		945
898	=item $guard = AnyEvent::post_detect { BLOCK }	946	=item $guard = AnyEvent::post_detect { BLOCK }
899		947
900	Arranges for the code block to be executed as soon as the event model is	948	Arranges for the code block to be executed as soon as the event model is
901	autodetected (or immediately if this has already happened).	949	autodetected (or immediately if that has already happened).
902		950
903	The block will be executed I<after> the actual backend has been detected	951	The block will be executed I<after> the actual backend has been detected
904	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been	952	(C<$AnyEvent::MODEL> is set), but I<before> any watchers have been
905	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do	953	created, so it is possible to e.g. patch C<@AnyEvent::ISA> or do
906	other initialisations - see the sources of L<AnyEvent::Strict> or	954	other initialisations - see the sources of L<AnyEvent::Strict> or
…		…
915	that automatically removes the callback again when it is destroyed (or	963	that automatically removes the callback again when it is destroyed (or
916	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for	964	C<undef> when the hook was immediately executed). See L<AnyEvent::AIO> for
917	a case where this is useful.	965	a case where this is useful.
918		966
919	Example: Create a watcher for the IO::AIO module and store it in	967	Example: Create a watcher for the IO::AIO module and store it in
920	C<$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.
921		969
922	our WATCHER;	970	our WATCHER;
923		971
924	my $guard = AnyEvent::post_detect {	972	my $guard = AnyEvent::post_detect {
925	$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);
…		…
933	$WATCHER \|\|= $guard;	981	$WATCHER \|\|= $guard;
934		982
935	=item @AnyEvent::post_detect	983	=item @AnyEvent::post_detect
936		984
937	If there are any code references in this array (you can C<push> to it	985	If there are any code references in this array (you can C<push> to it
938	before or after loading AnyEvent), then they will called directly after	986	before or after loading AnyEvent), then they will be called directly
939	the event loop has been chosen.	987	after the event loop has been chosen.
940		988
941	You should check C<$AnyEvent::MODEL> before adding to this array, though:	989	You should check C<$AnyEvent::MODEL> before adding to this array, though:
942	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
943	array will be ignored.	991	array will be ignored.
944		992
945	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows	993	Best use C<AnyEvent::post_detect { BLOCK }> when your application allows
946	it,as it takes care of these details.	994	it, as it takes care of these details.
947		995
948	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
949	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
950	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
951	into AnyEvent passively, without loading it.	999	into AnyEvent passively, without loading it.
952		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
953	=back	1054	=back
954		1055
955	=head1 WHAT TO DO IN A MODULE	1056	=head1 WHAT TO DO IN A MODULE
956		1057
957	As a module author, you should C<use AnyEvent> and call AnyEvent methods	1058	As a module author, you should C<use AnyEvent> and call AnyEvent methods
…		…
967	because it will stall the whole program, and the whole point of using	1068	because it will stall the whole program, and the whole point of using
968	events is to stay interactive.	1069	events is to stay interactive.
969		1070
970	It is fine, however, to call C<< ->recv >> when the user of your module	1071	It is fine, however, to call C<< ->recv >> when the user of your module
971	requests it (i.e. if you create a http request object ad have a method	1072	requests it (i.e. if you create a http request object ad have a method
972	called C<results> that returns the results, it should call C<< ->recv >>	1073	called C<results> that returns the results, it may call C<< ->recv >>
973	freely, as the user of your module knows what she is doing. always).	1074	freely, as the user of your module knows what she is doing. Always).
974		1075
975	=head1 WHAT TO DO IN THE MAIN PROGRAM	1076	=head1 WHAT TO DO IN THE MAIN PROGRAM
976		1077
977	There will always be a single main program - the only place that should	1078	There will always be a single main program - the only place that should
978	dictate which event model to use.	1079	dictate which event model to use.
979		1080
980	If it doesn't care, it can just "use AnyEvent" and use it itself, or not	1081	If the program is not event-based, it need not do anything special, even
981	do anything special (it does not need to be event-based) and let AnyEvent	1082	when it depends on a module that uses an AnyEvent. If the program itself
982	decide which implementation to chose if some module relies on it.	1083	uses AnyEvent, but does not care which event loop is used, all it needs
		1084	to do is C<use AnyEvent>. In either case, AnyEvent will choose the best
		1085	available loop implementation.
983		1086
984	If the main program relies on a specific event model - for example, in	1087	If the main program relies on a specific event model - for example, in
985	Gtk2 programs you have to rely on the Glib module - you should load the	1088	Gtk2 programs you have to rely on the Glib module - you should load the
986	event module before loading AnyEvent or any module that uses it: generally	1089	event module before loading AnyEvent or any module that uses it: generally
987	speaking, you should load it as early as possible. The reason is that	1090	speaking, you should load it as early as possible. The reason is that
988	modules might create watchers when they are loaded, and AnyEvent will	1091	modules might create watchers when they are loaded, and AnyEvent will
989	decide on the event model to use as soon as it creates watchers, and it	1092	decide on the event model to use as soon as it creates watchers, and it
990	might chose the wrong one unless you load the correct one yourself.	1093	might choose the wrong one unless you load the correct one yourself.
991		1094
992	You can chose to use a pure-perl implementation by loading the	1095	You can chose to use a pure-perl implementation by loading the
993	C<AnyEvent::Impl::Perl> module, which gives you similar behaviour	1096	C<AnyEvent::Loop> module, which gives you similar behaviour
994	everywhere, but letting AnyEvent chose the model is generally better.	1097	everywhere, but letting AnyEvent chose the model is generally better.
995		1098
996	=head2 MAINLOOP EMULATION	1099	=head2 MAINLOOP EMULATION
997		1100
998	Sometimes (often for short test scripts, or even standalone programs who	1101	Sometimes (often for short test scripts, or even standalone programs who
…		…
1013	=head1 OTHER MODULES	1116	=head1 OTHER MODULES
1014		1117
1015	The following is a non-exhaustive list of additional modules that use	1118	The following is a non-exhaustive list of additional modules that use
1016	AnyEvent as a client and can therefore be mixed easily with other AnyEvent	1119	AnyEvent as a client and can therefore be mixed easily with other AnyEvent
1017	modules and other event loops in the same program. Some of the modules	1120	modules and other event loops in the same program. Some of the modules
1018	come with AnyEvent, most are available via CPAN.	1121	come as part of AnyEvent, the others are available via CPAN.
1019		1122
1020	=over 4	1123	=over 4
1021		1124
1022	=item L<AnyEvent::Util>	1125	=item L<AnyEvent::Util>
1023		1126
1024	Contains various utility functions that replace often-used but blocking	1127	Contains various utility functions that replace often-used blocking
1025	functions such as C<inet_aton> by event-/callback-based versions.	1128	functions such as C<inet_aton> with event/callback-based versions.
1026		1129
1027	=item L<AnyEvent::Socket>	1130	=item L<AnyEvent::Socket>
1028		1131
1029	Provides various utility functions for (internet protocol) sockets,	1132	Provides various utility functions for (internet protocol) sockets,
1030	addresses and name resolution. Also functions to create non-blocking tcp	1133	addresses and name resolution. Also functions to create non-blocking tcp
…		…
1032		1135
1033	=item L<AnyEvent::Handle>	1136	=item L<AnyEvent::Handle>
1034		1137
1035	Provide read and write buffers, manages watchers for reads and writes,	1138	Provide read and write buffers, manages watchers for reads and writes,
1036	supports raw and formatted I/O, I/O queued and fully transparent and	1139	supports raw and formatted I/O, I/O queued and fully transparent and
1037	non-blocking SSL/TLS (via L<AnyEvent::TLS>.	1140	non-blocking SSL/TLS (via L<AnyEvent::TLS>).
1038		1141
1039	=item L<AnyEvent::DNS>	1142	=item L<AnyEvent::DNS>
1040		1143
1041	Provides rich asynchronous DNS resolver capabilities.	1144	Provides rich asynchronous DNS resolver capabilities.
1042		1145
		1146	=item L<AnyEvent::HTTP>, L<AnyEvent::IRC>, L<AnyEvent::XMPP>, L<AnyEvent::GPSD>, L<AnyEvent::IGS>, L<AnyEvent::FCP>
		1147
		1148	Implement event-based interfaces to the protocols of the same name (for
		1149	the curious, IGS is the International Go Server and FCP is the Freenet
		1150	Client Protocol).
		1151
		1152	=item L<AnyEvent::Handle::UDP>
		1153
		1154	Here be danger!
		1155
		1156	As Pauli would put it, "Not only is it not right, it's not even wrong!" -
		1157	there are so many things wrong with AnyEvent::Handle::UDP, most notably
		1158	its use of a stream-based API with a protocol that isn't streamable, that
		1159	the only way to improve it is to delete it.
		1160
		1161	It features data corruption (but typically only under load) and general
		1162	confusion. On top, the author is not only clueless about UDP but also
		1163	fact-resistant - some gems of his understanding: "connect doesn't work
		1164	with UDP", "UDP packets are not IP packets", "UDP only has datagrams, not
		1165	packets", "I don't need to implement proper error checking as UDP doesn't
		1166	support error checking" and so on - he doesn't even understand what's
		1167	wrong with his module when it is explained to him.
		1168
1043	=item L<AnyEvent::HTTP>	1169	=item L<AnyEvent::DBI>
1044		1170
1045	A simple-to-use HTTP library that is capable of making a lot of concurrent	1171	Executes L<DBI> requests asynchronously in a proxy process for you,
1046	HTTP requests.	1172	notifying you in an event-based way when the operation is finished.
		1173
		1174	=item L<AnyEvent::AIO>
		1175
		1176	Truly asynchronous (as opposed to non-blocking) I/O, should be in the
		1177	toolbox of every event programmer. AnyEvent::AIO transparently fuses
		1178	L<IO::AIO> and AnyEvent together, giving AnyEvent access to event-based
		1179	file I/O, and much more.
1047		1180
1048	=item L<AnyEvent::HTTPD>	1181	=item L<AnyEvent::HTTPD>
1049		1182
1050	Provides a simple web application server framework.	1183	A simple embedded webserver.
1051		1184
1052	=item L<AnyEvent::FastPing>	1185	=item L<AnyEvent::FastPing>
1053		1186
1054	The fastest ping in the west.	1187	The fastest ping in the west.
1055
1056	=item L<AnyEvent::DBI>
1057
1058	Executes L<DBI> requests asynchronously in a proxy process.
1059
1060	=item L<AnyEvent::AIO>
1061
1062	Truly asynchronous I/O, should be in the toolbox of every event
1063	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
1064	together.
1065
1066	=item L<AnyEvent::BDB>
1067
1068	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
1069	L<BDB> and AnyEvent together.
1070
1071	=item L<AnyEvent::GPSD>
1072
1073	A non-blocking interface to gpsd, a daemon delivering GPS information.
1074
1075	=item L<AnyEvent::IRC>
1076
1077	AnyEvent based IRC client module family (replacing the older Net::IRC3).
1078
1079	=item L<AnyEvent::XMPP>
1080
1081	AnyEvent based XMPP (Jabber protocol) module family (replacing the older
1082	Net::XMPP2>.
1083
1084	=item L<AnyEvent::IGS>
1085
1086	A non-blocking interface to the Internet Go Server protocol (used by
1087	L<App::IGS>).
1088
1089	=item L<Net::FCP>
1090
1091	AnyEvent-based implementation of the Freenet Client Protocol, birthplace
1092	of AnyEvent.
1093
1094	=item L<Event::ExecFlow>
1095
1096	High level API for event-based execution flow control.
1097		1188
1098	=item L<Coro>	1189	=item L<Coro>
1099		1190
1100	Has special support for AnyEvent via L<Coro::AnyEvent>.	1191	Has special support for AnyEvent via L<Coro::AnyEvent>.
1101		1192
…		…
1105		1196
1106	package AnyEvent;	1197	package AnyEvent;
1107		1198
1108	# basically a tuned-down version of common::sense	1199	# basically a tuned-down version of common::sense
1109	sub common_sense {	1200	sub common_sense {
1110	# no warnings	1201	# from common:.sense 3.4
1111	${^WARNING_BITS} ^= ${^WARNING_BITS};	1202	${^WARNING_BITS} ^= ${^WARNING_BITS} ^ "\x3c\x3f\x33\x00\x0f\xf0\x0f\xc0\xf0\xfc\x33\x00";
1112	# use strict vars subs	1203	# use strict vars subs - NO UTF-8, as Util.pm doesn't like this atm. (uts46data.pl)
1113	$^H \|= 0x00000600;	1204	$^H \|= 0x00000600;
1114	}	1205	}
1115		1206
1116	BEGIN { AnyEvent::common_sense }	1207	BEGIN { AnyEvent::common_sense }
1117		1208
1118	use Carp ();	1209	use Carp ();
1119		1210
1120	our $VERSION = '5.0';	1211	our $VERSION = '6.01';
1121	our $MODEL;	1212	our $MODEL;
1122		1213
1123	our $AUTOLOAD;
1124	our @ISA;	1214	our @ISA;
1125		1215
1126	our @REGISTRY;	1216	our @REGISTRY;
1127		1217
1128	our $WIN32;
1129
1130	our $VERBOSE;	1218	our $VERBOSE;
1131		1219
1132	BEGIN {	1220	BEGIN {
1133	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";	1221	require "AnyEvent/constants.pl";
		1222
1134	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";	1223	eval "sub TAINT (){" . (${^TAINT}*1) . "}";
1135		1224
1136	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}	1225	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
1137	if ${^TAINT};	1226	if ${^TAINT};
1138		1227
1139	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;	1228	$VERBOSE = $ENV{PERL_ANYEVENT_VERBOSE}*1;
…		…
1149	$PROTOCOL{$_} = ++$idx	1238	$PROTOCOL{$_} = ++$idx
1150	for reverse split /\s,\s/,	1239	for reverse split /\s,\s/,
1151	$ENV{PERL_ANYEVENT_PROTOCOLS} \|\| "ipv4,ipv6";	1240	$ENV{PERL_ANYEVENT_PROTOCOLS} \|\| "ipv4,ipv6";
1152	}	1241	}
1153		1242
		1243	our @post_detect;
		1244
		1245	sub post_detect(&) {
		1246	my ($cb) = @_;
		1247
		1248	push @post_detect, $cb;
		1249
		1250	defined wantarray
		1251	? bless \$cb, "AnyEvent::Util::postdetect"
		1252	: ()
		1253	}
		1254
		1255	sub AnyEvent::Util::postdetect::DESTROY {
		1256	@post_detect = grep $_ != ${$_[0]}, @post_detect;
		1257	}
		1258
		1259	our $POSTPONE_W;
		1260	our @POSTPONE;
		1261
		1262	sub _postpone_exec {
		1263	undef $POSTPONE_W;
		1264
		1265	&{ shift @POSTPONE }
		1266	while @POSTPONE;
		1267	}
		1268
		1269	sub postpone(&) {
		1270	push @POSTPONE, shift;
		1271
		1272	$POSTPONE_W \|\|= AE::timer (0, 0, \&_postpone_exec);
		1273
		1274	()
		1275	}
		1276
1154	my @models = (	1277	our @models = (
1155	[EV:: => AnyEvent::Impl::EV:: , 1],	1278	[EV:: => AnyEvent::Impl::EV:: , 1],
1156	[AnyEvent::Impl::Perl:: => AnyEvent::Impl::Perl:: , 1],	1279	[AnyEvent::Loop:: => AnyEvent::Impl::Perl:: , 1],
1157	# everything below here will not (normally) be autoprobed	1280	# everything below here will not (normally) be autoprobed
1158	# as the pureperl backend should work everywhere	1281	# as the pure perl backend should work everywhere
1159	# and is usually faster	1282	# and is usually faster
1160	[Event:: => AnyEvent::Impl::Event::, 1],	1283	[Event:: => AnyEvent::Impl::Event::, 1],
1161	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers	1284	[Glib:: => AnyEvent::Impl::Glib:: , 1], # becomes extremely slow with many watchers
1162	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy	1285	[Event::Lib:: => AnyEvent::Impl::EventLib::], # too buggy
1163	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package	1286	[Irssi:: => AnyEvent::Impl::Irssi::], # Irssi has a bogus "Event" package
1164	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles	1287	[Tk:: => AnyEvent::Impl::Tk::], # crashes with many handles
1165	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program	1288	[Qt:: => AnyEvent::Impl::Qt::], # requires special main program
1166	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	1289	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
1167	[Wx:: => AnyEvent::Impl::POE::],	1290	[Wx:: => AnyEvent::Impl::POE::],
1168	[Prima:: => AnyEvent::Impl::POE::],	1291	[Prima:: => AnyEvent::Impl::POE::],
1169	# IO::Async is just too broken - we would need workarounds for its	1292	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # a bitch to autodetect
1170	# byzantine signal and broken child handling, among others.	1293	[Cocoa::EventLoop:: => AnyEvent::Impl::Cocoa::],
1171	# IO::Async is rather hard to detect, as it doesn't have any	1294	[FLTK:: => AnyEvent::Impl::FLTK2::],
1172	# obvious default class.
1173	[IO::Async:: => AnyEvent::Impl::IOAsync::], # requires special main program
1174	[IO::Async::Loop:: => AnyEvent::Impl::IOAsync::], # requires special main program
1175	[IO::Async::Notifier:: => AnyEvent::Impl::IOAsync::], # requires special main program
1176	[AnyEvent::Impl::IOAsync:: => AnyEvent::Impl::IOAsync::], # requires special main program
1177	);	1295	);
1178		1296
1179	our %method = map +($_ => 1),	1297	our @isa_hook;
		1298
		1299	sub _isa_set {
		1300	my @pkg = ("AnyEvent", (map $_->[0], grep defined, @isa_hook), $MODEL);
		1301
		1302	@{"$pkg[$_-1]::ISA"} = $pkg[$_]
		1303	for 1 .. $#pkg;
		1304
		1305	grep $_ && $_->[1], @isa_hook
		1306	and AE::_reset ();
		1307	}
		1308
		1309	# used for hooking AnyEvent::Strict and AnyEvent::Debug::Wrap into the class hierarchy
		1310	sub _isa_hook($$;$) {
		1311	my ($i, $pkg, $reset_ae) = @_;
		1312
		1313	$isa_hook[$i] = $pkg ? [$pkg, $reset_ae] : undef;
		1314
		1315	_isa_set;
		1316	}
		1317
		1318	# all autoloaded methods reserve the complete glob, not just the method slot.
		1319	# due to bugs in perls method cache implementation.
1180	qw(io timer time now now_update signal child idle condvar one_event DESTROY);	1320	our @methods = qw(io timer time now now_update signal child idle condvar);
1181		1321
1182	our @post_detect;
1183
1184	sub post_detect(&) {	1322	sub detect() {
1185	my ($cb) = @_;	1323	return $MODEL if $MODEL; # some programs keep references to detect
1186		1324
1187	if ($MODEL) {	1325	local $!; # for good measure
1188	$cb->();	1326	local $SIG{__DIE__}; # we use eval
1189		1327
1190	undef	1328	# free some memory
		1329	*detect = sub () { $MODEL };
		1330	# undef &func doesn't correctly update the method cache. grmbl.
		1331	# so we delete the whole glob. grmbl.
		1332	# otoh, perl doesn't let me undef an active usb, but it lets me free
		1333	# a glob with an active sub. hrm. i hope it works, but perl is
		1334	# usually buggy in this department. sigh.
		1335	delete @{"AnyEvent::"}{@methods};
		1336	undef @methods;
		1337
		1338	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z0-9:]+)$/) {
		1339	my $model = $1;
		1340	$model = "AnyEvent::Impl::$model" unless $model =~ s/::$//;
		1341	if (eval "require $model") {
		1342	$MODEL = $model;
		1343	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;
1191	} else {	1344	} else {
1192	push @post_detect, $cb;	1345	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;
1193		1346	}
1194	defined wantarray
1195	? bless \$cb, "AnyEvent::Util::postdetect"
1196	: ()
1197	}	1347	}
1198	}
1199		1348
1200	sub AnyEvent::Util::postdetect::DESTROY {	1349	# check for already loaded models
1201	@post_detect = grep $_ != ${$_[0]}, @post_detect;
1202	}
1203
1204	sub detect() {
1205	unless ($MODEL) {	1350	unless ($MODEL) {
1206	local $SIG{__DIE__};	1351	for (@REGISTRY, @models) {
1207		1352	my ($package, $model) = @$_;
1208	if ($ENV{PERL_ANYEVENT_MODEL} =~ /^([a-zA-Z]+)$/) {	1353	if (${"$package\::VERSION"} > 0) {
1209	my $model = "AnyEvent::Impl::$1";
1210	if (eval "require $model") {	1354	if (eval "require $model") {
1211	$MODEL = $model;	1355	$MODEL = $model;
1212	warn "AnyEvent: loaded model '$model' (forced by \$ENV{PERL_ANYEVENT_MODEL}), using it.\n" if $VERBOSE >= 2;	1356	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;
1213	} else {	1357	last;
1214	warn "AnyEvent: unable to load model '$model' (from \$ENV{PERL_ANYEVENT_MODEL}):\n$@" if $VERBOSE;	1358	}
1215	}	1359	}
1216	}	1360	}
1217		1361
1218	# check for already loaded models
1219	unless ($MODEL) {	1362	unless ($MODEL) {
		1363	# try to autoload a model
1220	for (@REGISTRY, @models) {	1364	for (@REGISTRY, @models) {
1221	my ($package, $model) = @$_;	1365	my ($package, $model, $autoload) = @$_;
		1366	if (
		1367	$autoload
		1368	and eval "require $package"
1222	if (${"$package\::VERSION"} > 0) {	1369	and ${"$package\::VERSION"} > 0
1223	if (eval "require $model") {	1370	and eval "require $model"
		1371	) {
1224	$MODEL = $model;	1372	$MODEL = $model;
1225	warn "AnyEvent: autodetected model '$model', using it.\n" if $VERBOSE >= 2;	1373	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1226	last;	1374	last;
1227	}
1228	}	1375	}
1229	}	1376	}
1230		1377
1231	unless ($MODEL) {
1232	# try to autoload a model
1233	for (@REGISTRY, @models) {
1234	my ($package, $model, $autoload) = @$_;
1235	if (
1236	$autoload
1237	and eval "require $package"
1238	and ${"$package\::VERSION"} > 0
1239	and eval "require $model"
1240	) {
1241	$MODEL = $model;
1242	warn "AnyEvent: autoloaded model '$model', using it.\n" if $VERBOSE >= 2;
1243	last;
1244	}
1245	}
1246
1247	$MODEL	1378	$MODEL
1248	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";	1379	or die "AnyEvent: backend autodetection failed - did you properly install AnyEvent?\n";
1249	}
1250	}	1380	}
1251
1252	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
1253
1254	unshift @ISA, $MODEL;
1255
1256	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
1257
1258	(shift @post_detect)->() while @post_detect;
1259	}	1381	}
1260		1382
		1383	# free memory only needed for probing
		1384	undef @models;
		1385	undef @REGISTRY;
		1386
		1387	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1388
		1389	# now nuke some methods that are overridden by the backend.
		1390	# SUPER usage is not allowed in these.
		1391	for (qw(time signal child idle)) {
		1392	undef &{"AnyEvent::Base::$_"}
		1393	if defined &{"$MODEL\::$_"};
		1394	}
		1395
		1396	_isa_set;
		1397
		1398	if ($ENV{PERL_ANYEVENT_STRICT}) {
		1399	require AnyEvent::Strict;
		1400	}
		1401
		1402	if ($ENV{PERL_ANYEVENT_DEBUG_WRAP}) {
		1403	require AnyEvent::Debug;
		1404	AnyEvent::Debug::wrap ($ENV{PERL_ANYEVENT_DEBUG_WRAP});
		1405	}
		1406
		1407	if (exists $ENV{PERL_ANYEVENT_DEBUG_SHELL}) {
		1408	require AnyEvent::Socket;
		1409	require AnyEvent::Debug;
		1410
		1411	my $shell = $ENV{PERL_ANYEVENT_DEBUG_SHELL};
		1412	$shell =~ s/\$\$/$$/g;
		1413
		1414	my ($host, $service) = AnyEvent::Socket::parse_hostport ($shell);
		1415	$AnyEvent::Debug::SHELL = AnyEvent::Debug::shell ($host, $service);
		1416	}
		1417
		1418	(shift @post_detect)->() while @post_detect;
		1419	undef @post_detect;
		1420
		1421	*post_detect = sub(&) {
		1422	shift->();
		1423
		1424	undef
		1425	};
		1426
1261	$MODEL	1427	$MODEL
1262	}	1428	}
1263		1429
1264	sub AUTOLOAD {	1430	for my $name (@methods) {
1265	(my $func = $AUTOLOAD) =~ s/.*://;	1431	*$name = sub {
1266		1432	detect;
1267	$method{$func}	1433	# we use goto because
1268	or Carp::croak "$func: not a valid method for AnyEvent objects";	1434	# a) it makes the thunk more transparent
1269		1435	# b) it allows us to delete the thunk later
1270	detect unless $MODEL;	1436	goto &{ UNIVERSAL::can AnyEvent => "SUPER::$name" }
1271		1437	};
1272	my $class = shift;
1273	$class->$func (@_);
1274	}	1438	}
1275		1439
1276	# utility function to dup a filehandle. this is used by many backends	1440	# utility function to dup a filehandle. this is used by many backends
1277	# to support binding more than one watcher per filehandle (they usually	1441	# to support binding more than one watcher per filehandle (they usually
1278	# allow only one watcher per fd, so we dup it to get a different one).	1442	# allow only one watcher per fd, so we dup it to get a different one).
…		…
1292		1456
1293	=head1 SIMPLIFIED AE API	1457	=head1 SIMPLIFIED AE API
1294		1458
1295	Starting with version 5.0, AnyEvent officially supports a second, much	1459	Starting with version 5.0, AnyEvent officially supports a second, much
1296	simpler, API that is designed to reduce the calling, typing and memory	1460	simpler, API that is designed to reduce the calling, typing and memory
1297	overhead.	1461	overhead by using function call syntax and a fixed number of parameters.
1298		1462
1299	See the L<AE> manpage for details.	1463	See the L<AE> manpage for details.
1300		1464
1301	=cut	1465	=cut
1302		1466
1303	package AE;	1467	package AE;
1304		1468
1305	our $VERSION = $AnyEvent::VERSION;	1469	our $VERSION = $AnyEvent::VERSION;
1306		1470
		1471	sub _reset() {
		1472	eval q{
		1473	# fall back to the main API by default - backends and AnyEvent::Base
		1474	# implementations can overwrite these.
		1475
1307	sub io($$$) {	1476	sub io($$$) {
1308	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])	1477	AnyEvent->io (fh => $_[0], poll => $_[1] ? "w" : "r", cb => $_[2])
1309	}	1478	}
1310		1479
1311	sub timer($$$) {	1480	sub timer($$$) {
1312	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])	1481	AnyEvent->timer (after => $_[0], interval => $_[1], cb => $_[2])
1313	}	1482	}
1314		1483
1315	sub signal($$) {	1484	sub signal($$) {
1316	AnyEvent->signal (signal => $_[0], cb => $_[1])	1485	AnyEvent->signal (signal => $_[0], cb => $_[1])
1317	}	1486	}
1318		1487
1319	sub child($$) {	1488	sub child($$) {
1320	AnyEvent->child (pid => $_[0], cb => $_[1])	1489	AnyEvent->child (pid => $_[0], cb => $_[1])
1321	}	1490	}
1322		1491
1323	sub idle($) {	1492	sub idle($) {
1324	AnyEvent->idle (cb => $_[0])	1493	AnyEvent->idle (cb => $_[0]);
1325	}	1494	}
1326		1495
1327	sub cv(;&) {	1496	sub cv(;&) {
1328	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())	1497	AnyEvent->condvar (@_ ? (cb => $_[0]) : ())
1329	}	1498	}
1330		1499
1331	sub now() {	1500	sub now() {
1332	AnyEvent->now	1501	AnyEvent->now
1333	}	1502	}
1334		1503
1335	sub now_update() {	1504	sub now_update() {
1336	AnyEvent->now_update	1505	AnyEvent->now_update
1337	}	1506	}
1338		1507
1339	sub time() {	1508	sub time() {
1340	AnyEvent->time	1509	AnyEvent->time
		1510	}
		1511
		1512	*postpone = \&AnyEvent::postpone;
		1513	};
		1514	die if $@;
1341	}	1515	}
		1516
		1517	BEGIN { _reset }
1342		1518
1343	package AnyEvent::Base;	1519	package AnyEvent::Base;
1344		1520
1345	# default implementations for many methods	1521	# default implementations for many methods
1346		1522
1347	sub _time {	1523	sub time {
		1524	eval q{ # poor man's autoloading {}
1348	# probe for availability of Time::HiRes	1525	# probe for availability of Time::HiRes
1349	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {	1526	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
1350	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;	1527	warn "AnyEvent: using Time::HiRes for sub-second timing accuracy.\n" if $VERBOSE >= 8;
		1528	*time = sub { Time::HiRes::time () };
1351	*_time = \&Time::HiRes::time;	1529	*AE::time = \& Time::HiRes::time ;
1352	# if (eval "use POSIX (); (POSIX::times())...	1530	# if (eval "use POSIX (); (POSIX::times())...
1353	} else {	1531	} else {
1354	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;	1532	warn "AnyEvent: using built-in time(), WARNING, no sub-second resolution!\n" if $VERBOSE;
1355	*_time = sub { time }; # epic fail	1533	*time = sub { CORE::time };
		1534	*AE::time = sub (){ CORE::time };
		1535	}
		1536
		1537	*now = \&time;
1356	}	1538	};
		1539	die if $@;
1357		1540
1358	&_time	1541	&time
1359	}	1542	}
1360		1543
1361	sub time { _time }	1544	*now = \&time;
1362	sub now { _time }
1363	sub now_update { }	1545	sub now_update { }
1364		1546
		1547	sub _poll {
		1548	Carp::croak "$AnyEvent::MODEL does not support blocking waits. Caught";
		1549	}
		1550
1365	# default implementation for ->condvar	1551	# default implementation for ->condvar
		1552	# in fact, the default should not be overwritten
1366		1553
1367	sub condvar {	1554	sub condvar {
		1555	eval q{ # poor man's autoloading {}
		1556	*condvar = sub {
1368	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"	1557	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
		1558	};
		1559
		1560	*AE::cv = sub (;&) {
		1561	bless { @_ ? (_ae_cb => shift) : () }, "AnyEvent::CondVar"
		1562	};
		1563	};
		1564	die if $@;
		1565
		1566	&condvar
1369	}	1567	}
1370		1568
1371	# default implementation for ->signal	1569	# default implementation for ->signal
1372		1570
1373	our $HAVE_ASYNC_INTERRUPT;	1571	our $HAVE_ASYNC_INTERRUPT;
1374		1572
1375	sub _have_async_interrupt() {	1573	sub _have_async_interrupt() {
1376	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}	1574	$HAVE_ASYNC_INTERRUPT = 1*(!$ENV{PERL_ANYEVENT_AVOID_ASYNC_INTERRUPT}
1377	&& eval "use Async::Interrupt 1.0 (); 1")	1575	&& eval "use Async::Interrupt 1.02 (); 1")
1378	unless defined $HAVE_ASYNC_INTERRUPT;	1576	unless defined $HAVE_ASYNC_INTERRUPT;
1379		1577
1380	$HAVE_ASYNC_INTERRUPT	1578	$HAVE_ASYNC_INTERRUPT
1381	}	1579	}
1382		1580
1383	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);	1581	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
1384	our (%SIG_ASY, %SIG_ASY_W);	1582	our (%SIG_ASY, %SIG_ASY_W);
1385	our ($SIG_COUNT, $SIG_TW);	1583	our ($SIG_COUNT, $SIG_TW);
1386		1584
1387	sub _signal_exec {
1388	$HAVE_ASYNC_INTERRUPT
1389	? $SIGPIPE_R->drain
1390	: sysread $SIGPIPE_R, my $dummy, 9;
1391
1392	while (%SIG_EV) {
1393	for (keys %SIG_EV) {
1394	delete $SIG_EV{$_};
1395	$_->() for values %{ $SIG_CB{$_} \|\| {} };
1396	}
1397	}
1398	}
1399
1400	# install a dummy wakeup watcher to reduce signal catching latency	1585	# install a dummy wakeup watcher to reduce signal catching latency
		1586	# used by Impls
1401	sub _sig_add() {	1587	sub _sig_add() {
1402	unless ($SIG_COUNT++) {	1588	unless ($SIG_COUNT++) {
1403	# try to align timer on a full-second boundary, if possible	1589	# try to align timer on a full-second boundary, if possible
1404	my $NOW = AE::now;	1590	my $NOW = AE::now;
1405		1591
…		…
1415	undef $SIG_TW	1601	undef $SIG_TW
1416	unless --$SIG_COUNT;	1602	unless --$SIG_COUNT;
1417	}	1603	}
1418		1604
1419	our $_sig_name_init; $_sig_name_init = sub {	1605	our $_sig_name_init; $_sig_name_init = sub {
1420	eval q{ # poor man's autoloading	1606	eval q{ # poor man's autoloading {}
1421	undef $_sig_name_init;	1607	undef $_sig_name_init;
1422		1608
1423	if (_have_async_interrupt) {	1609	if (_have_async_interrupt) {
1424	*sig2num = \&Async::Interrupt::sig2num;	1610	*sig2num = \&Async::Interrupt::sig2num;
1425	*sig2name = \&Async::Interrupt::sig2name;	1611	*sig2name = \&Async::Interrupt::sig2name;
…		…
1457	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;	1643	$SIG_IO = AE::io $SIGPIPE_R->fileno, 0, \&_signal_exec;
1458		1644
1459	} else {	1645	} else {
1460	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;	1646	warn "AnyEvent: using emulated perl signal handling with latency timer.\n" if $VERBOSE >= 8;
1461		1647
1462	require Fcntl;
1463
1464	if (AnyEvent::WIN32) {	1648	if (AnyEvent::WIN32) {
1465	require AnyEvent::Util;	1649	require AnyEvent::Util;
1466		1650
1467	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();	1651	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
1468	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;	1652	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R, 1) if $SIGPIPE_R;
1469	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case	1653	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W, 1) if $SIGPIPE_W; # just in case
1470	} else {	1654	} else {
1471	pipe $SIGPIPE_R, $SIGPIPE_W;	1655	pipe $SIGPIPE_R, $SIGPIPE_W;
1472	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;	1656	fcntl $SIGPIPE_R, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_R;
1473	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case	1657	fcntl $SIGPIPE_W, AnyEvent::F_SETFL, AnyEvent::O_NONBLOCK if $SIGPIPE_W; # just in case
1474		1658
1475	# not strictly required, as $^F is normally 2, but let's make sure...	1659	# not strictly required, as $^F is normally 2, but let's make sure...
1476	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1660	fcntl $SIGPIPE_R, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1477	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;	1661	fcntl $SIGPIPE_W, AnyEvent::F_SETFD, AnyEvent::FD_CLOEXEC;
1478	}	1662	}
1479		1663
1480	$SIGPIPE_R	1664	$SIGPIPE_R
1481	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";	1665	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
1482		1666
1483	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;	1667	$SIG_IO = AE::io $SIGPIPE_R, 0, \&_signal_exec;
1484	}	1668	}
1485		1669
1486	*signal = sub {	1670	*signal = $HAVE_ASYNC_INTERRUPT
		1671	? sub {
1487	my (undef, %arg) = @_;	1672	my (undef, %arg) = @_;
1488		1673
1489	my $signal = uc $arg{signal}
1490	or Carp::croak "required option 'signal' is missing";
1491
1492	if ($HAVE_ASYNC_INTERRUPT) {
1493	# async::interrupt	1674	# async::interrupt
1494
1495	$signal = sig2num $signal;	1675	my $signal = sig2num $arg{signal};
1496	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1676	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1497		1677
1498	$SIG_ASY{$signal} \|\|= new Async::Interrupt	1678	$SIG_ASY{$signal} \|\|= new Async::Interrupt
1499	cb => sub { undef $SIG_EV{$signal} },	1679	cb => sub { undef $SIG_EV{$signal} },
1500	signal => $signal,	1680	signal => $signal,
1501	pipe => [$SIGPIPE_R->filenos],	1681	pipe => [$SIGPIPE_R->filenos],
1502	pipe_autodrain => 0,	1682	pipe_autodrain => 0,
1503	;	1683	;
1504		1684
1505	} else {	1685	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1686	}
		1687	: sub {
		1688	my (undef, %arg) = @_;
		1689
1506	# pure perl	1690	# pure perl
1507
1508	# AE::Util has been loaded in signal
1509	$signal = sig2name $signal;	1691	my $signal = sig2name $arg{signal};
1510	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1692	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
1511		1693
1512	$SIG{$signal} \|\|= sub {	1694	$SIG{$signal} \|\|= sub {
1513	local $!;	1695	local $!;
1514	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;	1696	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
1515	undef $SIG_EV{$signal};	1697	undef $SIG_EV{$signal};
1516	};	1698	};
1517		1699
1518	# can't do signal processing without introducing races in pure perl,	1700	# can't do signal processing without introducing races in pure perl,
1519	# so limit the signal latency.	1701	# so limit the signal latency.
1520	_sig_add;	1702	_sig_add;
1521	}
1522		1703
1523	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"	1704	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
		1705	}
1524	};	1706	;
1525		1707
1526	*AnyEvent::Base::signal::DESTROY = sub {	1708	*AnyEvent::Base::signal::DESTROY = sub {
1527	my ($signal, $cb) = @{$_[0]};	1709	my ($signal, $cb) = @{$_[0]};
1528		1710
1529	_sig_del;	1711	_sig_del;
…		…
1536	# print weird messages, or just unconditionally exit	1718	# print weird messages, or just unconditionally exit
1537	# instead of getting the default action.	1719	# instead of getting the default action.
1538	undef $SIG{$signal}	1720	undef $SIG{$signal}
1539	unless keys %{ $SIG_CB{$signal} };	1721	unless keys %{ $SIG_CB{$signal} };
1540	};	1722	};
		1723
		1724	*_signal_exec = sub {
		1725	$HAVE_ASYNC_INTERRUPT
		1726	? $SIGPIPE_R->drain
		1727	: sysread $SIGPIPE_R, (my $dummy), 9;
		1728
		1729	while (%SIG_EV) {
		1730	for (keys %SIG_EV) {
		1731	delete $SIG_EV{$_};
		1732	&$_ for values %{ $SIG_CB{$_} \|\| {} };
		1733	}
		1734	}
		1735	};
1541	};	1736	};
1542	die if $@;	1737	die if $@;
		1738
1543	&signal	1739	&signal
1544	}	1740	}
1545		1741
1546	# default implementation for ->child	1742	# default implementation for ->child
1547		1743
1548	our %PID_CB;	1744	our %PID_CB;
1549	our $CHLD_W;	1745	our $CHLD_W;
1550	our $CHLD_DELAY_W;	1746	our $CHLD_DELAY_W;
1551	our $WNOHANG;
1552		1747
		1748	# used by many Impl's
1553	sub _emit_childstatus($$) {	1749	sub _emit_childstatus($$) {
1554	my (undef, $rpid, $rstatus) = @_;	1750	my (undef, $rpid, $rstatus) = @_;
1555		1751
1556	$_->($rpid, $rstatus)	1752	$_->($rpid, $rstatus)
1557	for values %{ $PID_CB{$rpid} \|\| {} },	1753	for values %{ $PID_CB{$rpid} \|\| {} },
1558	values %{ $PID_CB{0} \|\| {} };	1754	values %{ $PID_CB{0} \|\| {} };
1559	}	1755	}
1560		1756
1561	sub _sigchld {
1562	my $pid;
1563
1564	AnyEvent->_emit_childstatus ($pid, $?)
1565	while ($pid = waitpid -1, $WNOHANG) > 0;
1566	}
1567
1568	sub child {	1757	sub child {
		1758	eval q{ # poor man's autoloading {}
		1759	*_sigchld = sub {
		1760	my $pid;
		1761
		1762	AnyEvent->_emit_childstatus ($pid, $?)
		1763	while ($pid = waitpid -1, WNOHANG) > 0;
		1764	};
		1765
		1766	*child = sub {
1569	my (undef, %arg) = @_;	1767	my (undef, %arg) = @_;
1570		1768
1571	defined (my $pid = $arg{pid} + 0)	1769	my $pid = $arg{pid};
1572	or Carp::croak "required option 'pid' is missing";	1770	my $cb = $arg{cb};
1573		1771
1574	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1772	$PID_CB{$pid}{$cb+0} = $cb;
1575		1773
1576	# WNOHANG is almost cetrainly 1 everywhere
1577	$WNOHANG \|\|= $^O =~ /^(?:openbsd\|netbsd\|linux\|freebsd\|cygwin\|MSWin32)$/
1578	? 1
1579	: eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;
1580
1581	unless ($CHLD_W) {	1774	unless ($CHLD_W) {
1582	$CHLD_W = AE::signal CHLD => \&_sigchld;	1775	$CHLD_W = AE::signal CHLD => \&_sigchld;
1583	# child could be a zombie already, so make at least one round	1776	# child could be a zombie already, so make at least one round
1584	&_sigchld;	1777	&_sigchld;
1585	}	1778	}
1586		1779
1587	bless [$pid, $arg{cb}], "AnyEvent::Base::child"	1780	bless [$pid, $cb+0], "AnyEvent::Base::child"
1588	}	1781	};
1589		1782
1590	sub AnyEvent::Base::child::DESTROY {	1783	*AnyEvent::Base::child::DESTROY = sub {
1591	my ($pid, $cb) = @{$_[0]};	1784	my ($pid, $icb) = @{$_[0]};
1592		1785
1593	delete $PID_CB{$pid}{$cb};	1786	delete $PID_CB{$pid}{$icb};
1594	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1787	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1595		1788
1596	undef $CHLD_W unless keys %PID_CB;	1789	undef $CHLD_W unless keys %PID_CB;
		1790	};
		1791	};
		1792	die if $@;
		1793
		1794	&child
1597	}	1795	}
1598		1796
1599	# idle emulation is done by simply using a timer, regardless	1797	# idle emulation is done by simply using a timer, regardless
1600	# of whether the process is idle or not, and not letting	1798	# of whether the process is idle or not, and not letting
1601	# the callback use more than 50% of the time.	1799	# the callback use more than 50% of the time.
1602	sub idle {	1800	sub idle {
		1801	eval q{ # poor man's autoloading {}
		1802	*idle = sub {
1603	my (undef, %arg) = @_;	1803	my (undef, %arg) = @_;
1604		1804
1605	my ($cb, $w, $rcb) = $arg{cb};	1805	my ($cb, $w, $rcb) = $arg{cb};
1606		1806
1607	$rcb = sub {	1807	$rcb = sub {
1608	if ($cb) {	1808	if ($cb) {
1609	$w = _time;	1809	$w = AE::time;
1610	&$cb;	1810	&$cb;
1611	$w = _time - $w;	1811	$w = AE::time - $w;
1612		1812
1613	# never use more then 50% of the time for the idle watcher,	1813	# never use more then 50% of the time for the idle watcher,
1614	# within some limits	1814	# within some limits
1615	$w = 0.0001 if $w < 0.0001;	1815	$w = 0.0001 if $w < 0.0001;
1616	$w = 5 if $w > 5;	1816	$w = 5 if $w > 5;
1617		1817
1618	$w = AE::timer $w, 0, $rcb;	1818	$w = AE::timer $w, 0, $rcb;
1619	} else {	1819	} else {
1620	# clean up...	1820	# clean up...
1621	undef $w;	1821	undef $w;
1622	undef $rcb;	1822	undef $rcb;
		1823	}
		1824	};
		1825
		1826	$w = AE::timer 0.05, 0, $rcb;
		1827
		1828	bless \\$cb, "AnyEvent::Base::idle"
1623	}	1829	};
		1830
		1831	*AnyEvent::Base::idle::DESTROY = sub {
		1832	undef $${$_[0]};
		1833	};
1624	};	1834	};
		1835	die if $@;
1625		1836
1626	$w = AE::timer 0.05, 0, $rcb;	1837	&idle
1627
1628	bless \\$cb, "AnyEvent::Base::idle"
1629	}
1630
1631	sub AnyEvent::Base::idle::DESTROY {
1632	undef $${$_[0]};
1633	}	1838	}
1634		1839
1635	package AnyEvent::CondVar;	1840	package AnyEvent::CondVar;
1636		1841
1637	our @ISA = AnyEvent::CondVar::Base::;	1842	our @ISA = AnyEvent::CondVar::Base::;
		1843
		1844	# only to be used for subclassing
		1845	sub new {
		1846	my $class = shift;
		1847	bless AnyEvent->condvar (@_), $class
		1848	}
1638		1849
1639	package AnyEvent::CondVar::Base;	1850	package AnyEvent::CondVar::Base;
1640		1851
1641	#use overload	1852	#use overload
1642	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },	1853	# '&{}' => sub { my $self = shift; sub { $self->send (@_) } },
…		…
1652		1863
1653	sub _send {	1864	sub _send {
1654	# nop	1865	# nop
1655	}	1866	}
1656		1867
		1868	sub _wait {
		1869	AnyEvent->_poll until $_[0]{_ae_sent};
		1870	}
		1871
1657	sub send {	1872	sub send {
1658	my $cv = shift;	1873	my $cv = shift;
1659	$cv->{_ae_sent} = [@_];	1874	$cv->{_ae_sent} = [@_];
1660	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};	1875	(delete $cv->{_ae_cb})->($cv) if $cv->{_ae_cb};
1661	$cv->_send;	1876	$cv->_send;
…		…
1668		1883
1669	sub ready {	1884	sub ready {
1670	$_[0]{_ae_sent}	1885	$_[0]{_ae_sent}
1671	}	1886	}
1672		1887
1673	sub _wait {
1674	$WAITING
1675	and !$_[0]{_ae_sent}
1676	and Carp::croak "AnyEvent::CondVar: recursive blocking wait detected";
1677
1678	local $WAITING = 1;
1679	AnyEvent->one_event while !$_[0]{_ae_sent};
1680	}
1681
1682	sub recv {	1888	sub recv {
		1889	unless ($_[0]{_ae_sent}) {
		1890	$WAITING
		1891	and Carp::croak "AnyEvent::CondVar: recursive blocking wait attempted";
		1892
		1893	local $WAITING = 1;
1683	$_[0]->_wait;	1894	$_[0]->_wait;
		1895	}
1684		1896
1685	Carp::croak $_[0]{_ae_croak} if $_[0]{_ae_croak};	1897	$_[0]{_ae_croak}
1686	wantarray ? @{ $_[0]{_ae_sent} } : $_[0]{_ae_sent}[0]	1898	and Carp::croak $_[0]{_ae_croak};
		1899
		1900	wantarray
		1901	? @{ $_[0]{_ae_sent} }
		1902	: $_[0]{_ae_sent}[0]
1687	}	1903	}
1688		1904
1689	sub cb {	1905	sub cb {
1690	my $cv = shift;	1906	my $cv = shift;
1691		1907
…		…
1707	&{ $_[0]{_ae_end_cb} \|\| sub { $_[0]->send } };	1923	&{ $_[0]{_ae_end_cb} \|\| sub { $_[0]->send } };
1708	}	1924	}
1709		1925
1710	# undocumented/compatibility with pre-3.4	1926	# undocumented/compatibility with pre-3.4
1711	*broadcast = \&send;	1927	*broadcast = \&send;
1712	*wait = \&_wait;	1928	*wait = \&recv;
1713		1929
1714	=head1 ERROR AND EXCEPTION HANDLING	1930	=head1 ERROR AND EXCEPTION HANDLING
1715		1931
1716	In general, AnyEvent does not do any error handling - it relies on the	1932	In general, AnyEvent does not do any error handling - it relies on the
1717	caller to do that if required. The L<AnyEvent::Strict> module (see also	1933	caller to do that if required. The L<AnyEvent::Strict> module (see also
…		…
1764	check the arguments passed to most method calls. If it finds any problems,	1980	check the arguments passed to most method calls. If it finds any problems,
1765	it will croak.	1981	it will croak.
1766		1982
1767	In other words, enables "strict" mode.	1983	In other words, enables "strict" mode.
1768		1984
1769	Unlike C<use strict> (or it's modern cousin, C<< use L<common::sense>	1985	Unlike C<use strict> (or its modern cousin, C<< use L<common::sense>
1770	>>, it is definitely recommended to keep it off in production. Keeping	1986	>>, it is definitely recommended to keep it off in production. Keeping
1771	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs	1987	C<PERL_ANYEVENT_STRICT=1> in your environment while developing programs
1772	can be very useful, however.	1988	can be very useful, however.
1773		1989
		1990	=item C<PERL_ANYEVENT_DEBUG_SHELL>
		1991
		1992	If this env variable is set, then its contents will be interpreted by
		1993	C<AnyEvent::Socket::parse_hostport> (after replacing every occurance of
		1994	C<$$> by the process pid) and an C<AnyEvent::Debug::shell> is bound on
		1995	that port. The shell object is saved in C<$AnyEvent::Debug::SHELL>.
		1996
		1997	This takes place when the first watcher is created.
		1998
		1999	For example, to bind a debug shell on a unix domain socket in
		2000	F<< /tmp/debug<pid>.sock >>, you could use this:
		2001
		2002	PERL_ANYEVENT_DEBUG_SHELL=unix/:/tmp/debug\$\$.sock perlprog
		2003
		2004	Note that creating sockets in F</tmp> is very unsafe on multiuser
		2005	systems.
		2006
		2007	=item C<PERL_ANYEVENT_DEBUG_WRAP>
		2008
		2009	Can be set to C<0>, C<1> or C<2> and enables wrapping of all watchers for
		2010	debugging purposes. See C<AnyEvent::Debug::wrap> for details.
		2011
1774	=item C<PERL_ANYEVENT_MODEL>	2012	=item C<PERL_ANYEVENT_MODEL>
1775		2013
1776	This can be used to specify the event model to be used by AnyEvent, before	2014	This can be used to specify the event model to be used by AnyEvent, before
1777	auto detection and -probing kicks in. It must be a string consisting	2015	auto detection and -probing kicks in.
1778	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended	2016
		2017	It normally is a string consisting entirely of ASCII letters (e.g. C<EV>
		2018	or C<IOAsync>). The string C<AnyEvent::Impl::> gets prepended and the
1779	and the resulting module name is loaded and if the load was successful,	2019	resulting module name is loaded and - if the load was successful - used as
1780	used as event model. If it fails to load AnyEvent will proceed with	2020	event model backend. If it fails to load then AnyEvent will proceed with
1781	auto detection and -probing.	2021	auto detection and -probing.
1782		2022
1783	This functionality might change in future versions.	2023	If the string ends with C<::> instead (e.g. C<AnyEvent::Impl::EV::>) then
		2024	nothing gets prepended and the module name is used as-is (hint: C<::> at
		2025	the end of a string designates a module name and quotes it appropriately).
1784		2026
1785	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you	2027	For example, to force the pure perl model (L<AnyEvent::Loop::Perl>) you
1786	could start your program like this:	2028	could start your program like this:
1787		2029
1788	PERL_ANYEVENT_MODEL=Perl perl ...	2030	PERL_ANYEVENT_MODEL=Perl perl ...
1789		2031
1790	=item C<PERL_ANYEVENT_PROTOCOLS>	2032	=item C<PERL_ANYEVENT_PROTOCOLS>
…		…
1911	warn "read: $input\n"; # output what has been read	2153	warn "read: $input\n"; # output what has been read
1912	$cv->send if $input =~ /^q/i; # quit program if /^q/i	2154	$cv->send if $input =~ /^q/i; # quit program if /^q/i
1913	},	2155	},
1914	);	2156	);
1915		2157
1916	my $time_watcher; # can only be used once
1917
1918	sub new_timer {
1919	$timer = AnyEvent->timer (after => 1, cb => sub {	2158	my $time_watcher = AnyEvent->timer (after => 1, interval => 1, cb => sub {
1920	warn "timeout\n"; # print 'timeout' about every second	2159	warn "timeout\n"; # print 'timeout' at most every second
1921	&new_timer; # and restart the time
1922	});	2160	});
1923	}
1924
1925	new_timer; # create first timer
1926		2161
1927	$cv->recv; # wait until user enters /^q/i	2162	$cv->recv; # wait until user enters /^q/i
1928		2163
1929	=head1 REAL-WORLD EXAMPLE	2164	=head1 REAL-WORLD EXAMPLE
1930		2165
…		…
2003		2238
2004	The actual code goes further and collects all errors (C<die>s, exceptions)	2239	The actual code goes further and collects all errors (C<die>s, exceptions)
2005	that occurred during request processing. The C<result> method detects	2240	that occurred during request processing. The C<result> method detects
2006	whether an exception as thrown (it is stored inside the $txn object)	2241	whether an exception as thrown (it is stored inside the $txn object)
2007	and just throws the exception, which means connection errors and other	2242	and just throws the exception, which means connection errors and other
2008	problems get reported tot he code that tries to use the result, not in a	2243	problems get reported to the code that tries to use the result, not in a
2009	random callback.	2244	random callback.
2010		2245
2011	All of this enables the following usage styles:	2246	All of this enables the following usage styles:
2012		2247
2013	1. Blocking:	2248	1. Blocking:
…		…
2187	(even when used without AnyEvent), but most event loops have acceptable	2422	(even when used without AnyEvent), but most event loops have acceptable
2188	performance with or without AnyEvent.	2423	performance with or without AnyEvent.
2189		2424
2190	=item * The overhead AnyEvent adds is usually much smaller than the overhead of	2425	=item * The overhead AnyEvent adds is usually much smaller than the overhead of
2191	the actual event loop, only with extremely fast event loops such as EV	2426	the actual event loop, only with extremely fast event loops such as EV
2192	adds AnyEvent significant overhead.	2427	does AnyEvent add significant overhead.
2193		2428
2194	=item * You should avoid POE like the plague if you want performance or	2429	=item * You should avoid POE like the plague if you want performance or
2195	reasonable memory usage.	2430	reasonable memory usage.
2196		2431
2197	=back	2432	=back
…		…
2374	As you can see, the AnyEvent + EV combination even beats the	2609	As you can see, the AnyEvent + EV combination even beats the
2375	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl	2610	hand-optimised "raw sockets benchmark", while AnyEvent + its pure perl
2376	backend easily beats IO::Lambda and POE.	2611	backend easily beats IO::Lambda and POE.
2377		2612
2378	And even the 100% non-blocking version written using the high-level (and	2613	And even the 100% non-blocking version written using the high-level (and
2379	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda by a	2614	slow :) L<AnyEvent::Handle> abstraction beats both POE and IO::Lambda
2380	large margin, even though it does all of DNS, tcp-connect and socket I/O	2615	higher level ("unoptimised") abstractions by a large margin, even though
2381	in a non-blocking way.	2616	it does all of DNS, tcp-connect and socket I/O in a non-blocking way.
2382		2617
2383	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and	2618	The two AnyEvent benchmarks programs can be found as F<eg/ae0.pl> and
2384	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are	2619	F<eg/ae2.pl> in the AnyEvent distribution, the remaining benchmarks are
2385	part of the IO::lambda distribution and were used without any changes.	2620	part of the IO::Lambda distribution and were used without any changes.
2386		2621
2387		2622
2388	=head1 SIGNALS	2623	=head1 SIGNALS
2389		2624
2390	AnyEvent currently installs handlers for these signals:	2625	AnyEvent currently installs handlers for these signals:
…		…
2427	unless defined $SIG{PIPE};	2662	unless defined $SIG{PIPE};
2428		2663
2429	=head1 RECOMMENDED/OPTIONAL MODULES	2664	=head1 RECOMMENDED/OPTIONAL MODULES
2430		2665
2431	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and	2666	One of AnyEvent's main goals is to be 100% Pure-Perl(tm): only perl (and
2432	it's built-in modules) are required to use it.	2667	its built-in modules) are required to use it.
2433		2668
2434	That does not mean that AnyEvent won't take advantage of some additional	2669	That does not mean that AnyEvent won't take advantage of some additional
2435	modules if they are installed.	2670	modules if they are installed.
2436		2671
2437	This section epxlains which additional modules will be used, and how they	2672	This section explains which additional modules will be used, and how they
2438	affect AnyEvent's operetion.	2673	affect AnyEvent's operation.
2439		2674
2440	=over 4	2675	=over 4
2441		2676
2442	=item L<Async::Interrupt>	2677	=item L<Async::Interrupt>
2443		2678
…		…
2448	catch the signals) with some delay (default is 10 seconds, look for	2683	catch the signals) with some delay (default is 10 seconds, look for
2449	C<$AnyEvent::MAX_SIGNAL_LATENCY>).	2684	C<$AnyEvent::MAX_SIGNAL_LATENCY>).
2450		2685
2451	If this module is available, then it will be used to implement signal	2686	If this module is available, then it will be used to implement signal
2452	catching, which means that signals will not be delayed, and the event loop	2687	catching, which means that signals will not be delayed, and the event loop
2453	will not be interrupted regularly, which is more efficient (And good for	2688	will not be interrupted regularly, which is more efficient (and good for
2454	battery life on laptops).	2689	battery life on laptops).
2455		2690
2456	This affects not just the pure-perl event loop, but also other event loops	2691	This affects not just the pure-perl event loop, but also other event loops
2457	that have no signal handling on their own (e.g. Glib, Tk, Qt).	2692	that have no signal handling on their own (e.g. Glib, Tk, Qt).
2458		2693
…		…
2470	automatic timer adjustments even when no monotonic clock is available,	2705	automatic timer adjustments even when no monotonic clock is available,
2471	can take avdantage of advanced kernel interfaces such as C<epoll> and	2706	can take avdantage of advanced kernel interfaces such as C<epoll> and
2472	C<kqueue>, and is the fastest backend I<by far>. You can even embed	2707	C<kqueue>, and is the fastest backend I<by far>. You can even embed
2473	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).	2708	L<Glib>/L<Gtk2> in it (or vice versa, see L<EV::Glib> and L<Glib::EV>).
2474		2709
		2710	If you only use backends that rely on another event loop (e.g. C<Tk>),
		2711	then this module will do nothing for you.
		2712
2475	=item L<Guard>	2713	=item L<Guard>
2476		2714
2477	The guard module, when used, will be used to implement	2715	The guard module, when used, will be used to implement
2478	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a	2716	C<AnyEvent::Util::guard>. This speeds up guards considerably (and uses a
2479	lot less memory), but otherwise doesn't affect guard operation much. It is	2717	lot less memory), but otherwise doesn't affect guard operation much. It is
2480	purely used for performance.	2718	purely used for performance.
2481		2719
2482	=item L<JSON> and L<JSON::XS>	2720	=item L<JSON> and L<JSON::XS>
2483		2721
2484	This module is required when you want to read or write JSON data via	2722	One of these modules is required when you want to read or write JSON data
2485	L<AnyEvent::Handle>. It is also written in pure-perl, but can take	2723	via L<AnyEvent::Handle>. L<JSON> is also written in pure-perl, but can take
2486	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.	2724	advantage of the ultra-high-speed L<JSON::XS> module when it is installed.
2487
2488	In fact, L<AnyEvent::Handle> will use L<JSON::XS> by default if it is
2489	installed.
2490		2725
2491	=item L<Net::SSLeay>	2726	=item L<Net::SSLeay>
2492		2727
2493	Implementing TLS/SSL in Perl is certainly interesting, but not very	2728	Implementing TLS/SSL in Perl is certainly interesting, but not very
2494	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with	2729	worthwhile: If this module is installed, then L<AnyEvent::Handle> (with
2495	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.	2730	the help of L<AnyEvent::TLS>), gains the ability to do TLS/SSL.
2496		2731
2497	=item L<Time::HiRes>	2732	=item L<Time::HiRes>
2498		2733
2499	This module is part of perl since release 5.008. It will be used when the	2734	This module is part of perl since release 5.008. It will be used when the
2500	chosen event library does not come with a timing source on it's own. The	2735	chosen event library does not come with a timing source of its own. The
2501	pure-perl event loop (L<AnyEvent::Impl::Perl>) will additionally use it to	2736	pure-perl event loop (L<AnyEvent::Loop>) will additionally load it to
2502	try to use a monotonic clock for timing stability.	2737	try to use a monotonic clock for timing stability.
2503		2738
2504	=back	2739	=back
2505		2740
2506		2741
2507	=head1 FORK	2742	=head1 FORK
2508		2743
2509	Most event libraries are not fork-safe. The ones who are usually are	2744	Most event libraries are not fork-safe. The ones who are usually are
2510	because they rely on inefficient but fork-safe C<select> or C<poll>	2745	because they rely on inefficient but fork-safe C<select> or C<poll> calls
2511	calls. Only L<EV> is fully fork-aware.	2746	- higher performance APIs such as BSD's kqueue or the dreaded Linux epoll
		2747	are usually badly thought-out hacks that are incompatible with fork in
		2748	one way or another. Only L<EV> is fully fork-aware and ensures that you
		2749	continue event-processing in both parent and child (or both, if you know
		2750	what you are doing).
		2751
		2752	This means that, in general, you cannot fork and do event processing in
		2753	the child if the event library was initialised before the fork (which
		2754	usually happens when the first AnyEvent watcher is created, or the library
		2755	is loaded).
2512		2756
2513	If you have to fork, you must either do so I<before> creating your first	2757	If you have to fork, you must either do so I<before> creating your first
2514	watcher OR you must not use AnyEvent at all in the child OR you must do	2758	watcher OR you must not use AnyEvent at all in the child OR you must do
2515	something completely out of the scope of AnyEvent.	2759	something completely out of the scope of AnyEvent.
		2760
		2761	The problem of doing event processing in the parent I<and> the child
		2762	is much more complicated: even for backends that I<are> fork-aware or
		2763	fork-safe, their behaviour is not usually what you want: fork clones all
		2764	watchers, that means all timers, I/O watchers etc. are active in both
		2765	parent and child, which is almost never what you want. USing C<exec>
		2766	to start worker children from some kind of manage rprocess is usually
		2767	preferred, because it is much easier and cleaner, at the expense of having
		2768	to have another binary.
2516		2769
2517		2770
2518	=head1 SECURITY CONSIDERATIONS	2771	=head1 SECURITY CONSIDERATIONS
2519		2772
2520	AnyEvent can be forced to load any event model via	2773	AnyEvent can be forced to load any event model via
…		…
2550	pronounced).	2803	pronounced).
2551		2804
2552		2805
2553	=head1 SEE ALSO	2806	=head1 SEE ALSO
2554		2807
		2808	Tutorial/Introduction: L<AnyEvent::Intro>.
		2809
		2810	FAQ: L<AnyEvent::FAQ>.
		2811
2555	Utility functions: L<AnyEvent::Util>.	2812	Utility functions: L<AnyEvent::Util>.
2556		2813
2557	Event modules: L<EV>, L<EV::Glib>, L<Glib::EV>, L<Event>, L<Glib::Event>,	2814	Event modules: L<AnyEvent::Loop>, L<EV>, L<EV::Glib>, L<Glib::EV>,
2558	L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.	2815	L<Event>, L<Glib::Event>, L<Glib>, L<Tk>, L<Event::Lib>, L<Qt>, L<POE>.
2559		2816
2560	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,	2817	Implementations: L<AnyEvent::Impl::EV>, L<AnyEvent::Impl::Event>,
2561	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,	2818	L<AnyEvent::Impl::Glib>, L<AnyEvent::Impl::Tk>, L<AnyEvent::Impl::Perl>,
2562	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,	2819	L<AnyEvent::Impl::EventLib>, L<AnyEvent::Impl::Qt>,
2563	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.	2820	L<AnyEvent::Impl::POE>, L<AnyEvent::Impl::IOAsync>, L<Anyevent::Impl::Irssi>.
…		…
2565	Non-blocking file handles, sockets, TCP clients and	2822	Non-blocking file handles, sockets, TCP clients and
2566	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.	2823	servers: L<AnyEvent::Handle>, L<AnyEvent::Socket>, L<AnyEvent::TLS>.
2567		2824
2568	Asynchronous DNS: L<AnyEvent::DNS>.	2825	Asynchronous DNS: L<AnyEvent::DNS>.
2569		2826
2570	Coroutine support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>,	2827	Thread support: L<Coro>, L<Coro::AnyEvent>, L<Coro::EV>, L<Coro::Event>.
2571	L<Coro::Event>,
2572		2828
2573	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::XMPP>,	2829	Nontrivial usage examples: L<AnyEvent::GPSD>, L<AnyEvent::IRC>,
2574	L<AnyEvent::HTTP>.	2830	L<AnyEvent::HTTP>.
2575		2831
2576		2832
2577	=head1 AUTHOR	2833	=head1 AUTHOR
2578		2834

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.279 by root, Sun Aug 9 16:05:11 2009 UTC vs. Revision 1.363 by root, Sun Aug 14 13:56:52 2011 UTC

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Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.279 by root, Sun Aug 9 16:05:11 2009 UTC vs.
Revision 1.363 by root, Sun Aug 14 13:56:52 2011 UTC