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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.144 by root, Thu May 29 00:14:35 2008 UTC vs.
Revision 1.214 by root, Mon Jun 22 11:57:05 2009 UTC

…		…
1	=head1 => NAME	1	=head1 NAME
2		2
3	AnyEvent - provide framework for multiple event loops	3	AnyEvent - provide framework for multiple event loops
4		4
5	EV, Event, Glib, Tk, Perl, Event::Lib, Qt, POE - various supported event loops	5	EV, Event, Glib, Tk, Perl, Event::Lib, Qt and POE are various supported
		6	event loops.
6		7
7	=head1 SYNOPSIS	8	=head1 SYNOPSIS
8		9
9	use AnyEvent;	10	use AnyEvent;
10		11
		12	# file descriptor readable
11	my $w = AnyEvent->io (fh => $fh, poll => "r\|w", cb => sub {	13	my $w = AnyEvent->io (fh => $fh, poll => "r", cb => sub { ... });
		14
		15	# one-shot or repeating timers
		16	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
		17	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...
		18
		19	print AnyEvent->now; # prints current event loop time
		20	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
		21
		22	# POSIX signal
		23	my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... });
		24
		25	# child process exit
		26	my $w = AnyEvent->child (pid => $pid, cb => sub {
		27	my ($pid, $status) = @_;
12	...	28	...
13	});	29	});
14		30
15	my $w = AnyEvent->timer (after => $seconds, cb => sub {	31	# called when event loop idle (if applicable)
16	...	32	my $w = AnyEvent->idle (cb => sub { ... });
17	});
18		33
19	my $w = AnyEvent->condvar; # stores whether a condition was flagged	34	my $w = AnyEvent->condvar; # stores whether a condition was flagged
20	$w->send; # wake up current and all future recv's	35	$w->send; # wake up current and all future recv's
21	$w->recv; # enters "main loop" till $condvar gets ->send	36	$w->recv; # enters "main loop" till $condvar gets ->send
		37	# use a condvar in callback mode:
		38	$w->cb (sub { $_[0]->recv });
		39
		40	=head1 INTRODUCTION/TUTORIAL
		41
		42	This manpage is mainly a reference manual. If you are interested
		43	in a tutorial or some gentle introduction, have a look at the
		44	L<AnyEvent::Intro> manpage.
22		45
23	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)	46	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
24		47
25	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen	48	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
26	nowadays. So what is different about AnyEvent?	49	nowadays. So what is different about AnyEvent?
27		50
28	Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of	51	Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of
29	policy> and AnyEvent is I<small and efficient>.	52	policy> and AnyEvent is I<small and efficient>.
30		53
31	First and foremost, I<AnyEvent is not an event model> itself, it only	54	First and foremost, I<AnyEvent is not an event model> itself, it only
32	interfaces to whatever event model the main program happens to use in a	55	interfaces to whatever event model the main program happens to use, in a
33	pragmatic way. For event models and certain classes of immortals alike,	56	pragmatic way. For event models and certain classes of immortals alike,
34	the statement "there can only be one" is a bitter reality: In general,	57	the statement "there can only be one" is a bitter reality: In general,
35	only one event loop can be active at the same time in a process. AnyEvent	58	only one event loop can be active at the same time in a process. AnyEvent
36	helps hiding the differences between those event loops.	59	cannot change this, but it can hide the differences between those event
		60	loops.
37		61
38	The goal of AnyEvent is to offer module authors the ability to do event	62	The goal of AnyEvent is to offer module authors the ability to do event
39	programming (waiting for I/O or timer events) without subscribing to a	63	programming (waiting for I/O or timer events) without subscribing to a
40	religion, a way of living, and most importantly: without forcing your	64	religion, a way of living, and most importantly: without forcing your
41	module users into the same thing by forcing them to use the same event	65	module users into the same thing by forcing them to use the same event
42	model you use.	66	model you use.
43		67
44	For modules like POE or IO::Async (which is a total misnomer as it is	68	For modules like POE or IO::Async (which is a total misnomer as it is
45	actually doing all I/O I<synchronously>...), using them in your module is	69	actually doing all I/O I<synchronously>...), using them in your module is
46	like joining a cult: After you joined, you are dependent on them and you	70	like joining a cult: After you joined, you are dependent on them and you
47	cannot use anything else, as it is simply incompatible to everything that	71	cannot use anything else, as they are simply incompatible to everything
48	isn't itself. What's worse, all the potential users of your module are	72	that isn't them. What's worse, all the potential users of your
49	I<also> forced to use the same event loop you use.	73	module are I<also> forced to use the same event loop you use.
50		74
51	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	75	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
52	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	76	fine. AnyEvent + Tk works fine etc. etc. but none of these work together
53	with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if	77	with the rest: POE + IO::Async? No go. Tk + Event? No go. Again: if
54	your module uses one of those, every user of your module has to use it,	78	your module uses one of those, every user of your module has to use it,
55	too. But if your module uses AnyEvent, it works transparently with all	79	too. But if your module uses AnyEvent, it works transparently with all
56	event models it supports (including stuff like POE and IO::Async, as long	80	event models it supports (including stuff like IO::Async, as long as those
57	as those use one of the supported event loops. It is trivial to add new	81	use one of the supported event loops. It is trivial to add new event loops
58	event loops to AnyEvent, too, so it is future-proof).	82	to AnyEvent, too, so it is future-proof).
59		83
60	In addition to being free of having to use I<the one and only true event	84	In addition to being free of having to use I<the one and only true event
61	model>, AnyEvent also is free of bloat and policy: with POE or similar	85	model>, AnyEvent also is free of bloat and policy: with POE or similar
62	modules, you get an enormous amount of code and strict rules you have to	86	modules, you get an enormous amount of code and strict rules you have to
63	follow. AnyEvent, on the other hand, is lean and up to the point, by only	87	follow. AnyEvent, on the other hand, is lean and up to the point, by only
121	These watchers are normal Perl objects with normal Perl lifetime. After	145	These watchers are normal Perl objects with normal Perl lifetime. After
122	creating a watcher it will immediately "watch" for events and invoke the	146	creating a watcher it will immediately "watch" for events and invoke the
123	callback when the event occurs (of course, only when the event model	147	callback when the event occurs (of course, only when the event model
124	is in control).	148	is in control).
125		149
		150	Note that B<callbacks must not permanently change global variables>
		151	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<
		152	callbacks must not C<die> >>. The former is good programming practise in
		153	Perl and the latter stems from the fact that exception handling differs
		154	widely between event loops.
		155
126	To disable the watcher you have to destroy it (e.g. by setting the	156	To disable the watcher you have to destroy it (e.g. by setting the
127	variable you store it in to C<undef> or otherwise deleting all references	157	variable you store it in to C<undef> or otherwise deleting all references
128	to it).	158	to it).
129		159
130	All watchers are created by calling a method on the C<AnyEvent> class.	160	All watchers are created by calling a method on the C<AnyEvent> class.
…		…
132	Many watchers either are used with "recursion" (repeating timers for	162	Many watchers either are used with "recursion" (repeating timers for
133	example), or need to refer to their watcher object in other ways.	163	example), or need to refer to their watcher object in other ways.
134		164
135	An any way to achieve that is this pattern:	165	An any way to achieve that is this pattern:
136		166
137	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	167	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
138	# you can use $w here, for example to undef it	168	# you can use $w here, for example to undef it
139	undef $w;	169	undef $w;
140	});	170	});
141		171
142	Note that C<my $w; $w => combination. This is necessary because in Perl,	172	Note that C<my $w; $w => combination. This is necessary because in Perl,
143	my variables are only visible after the statement in which they are	173	my variables are only visible after the statement in which they are
144	declared.	174	declared.
145		175
146	=head2 I/O WATCHERS	176	=head2 I/O WATCHERS
147		177
148	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	178	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
149	with the following mandatory key-value pairs as arguments:	179	with the following mandatory key-value pairs as arguments:
150		180
151	C<fh> the Perl I<file handle> (I<not> file descriptor) to watch	181	C<fh> is the Perl I<file handle> (I<not> file descriptor) to watch
		182	for events (AnyEvent might or might not keep a reference to this file
		183	handle). Note that only file handles pointing to things for which
		184	non-blocking operation makes sense are allowed. This includes sockets,
		185	most character devices, pipes, fifos and so on, but not for example files
		186	or block devices.
		187
152	for events. C<poll> must be a string that is either C<r> or C<w>,	188	C<poll> must be a string that is either C<r> or C<w>, which creates a
153	which creates a watcher waiting for "r"eadable or "w"ritable events,	189	watcher waiting for "r"eadable or "w"ritable events, respectively.
		190
154	respectively. C<cb> is the callback to invoke each time the file handle	191	C<cb> is the callback to invoke each time the file handle becomes ready.
155	becomes ready.
156		192
157	Although the callback might get passed parameters, their value and	193	Although the callback might get passed parameters, their value and
158	presence is undefined and you cannot rely on them. Portable AnyEvent	194	presence is undefined and you cannot rely on them. Portable AnyEvent
159	callbacks cannot use arguments passed to I/O watcher callbacks.	195	callbacks cannot use arguments passed to I/O watcher callbacks.
160		196
…		…
164		200
165	Some event loops issue spurious readyness notifications, so you should	201	Some event loops issue spurious readyness notifications, so you should
166	always use non-blocking calls when reading/writing from/to your file	202	always use non-blocking calls when reading/writing from/to your file
167	handles.	203	handles.
168		204
169	Example:
170
171	# wait for readability of STDIN, then read a line and disable the watcher	205	Example: wait for readability of STDIN, then read a line and disable the
		206	watcher.
		207
172	my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {	208	my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {
173	chomp (my $input = <STDIN>);	209	chomp (my $input = <STDIN>);
174	warn "read: $input\n";	210	warn "read: $input\n";
175	undef $w;	211	undef $w;
176	});	212	});
…		…
186		222
187	Although the callback might get passed parameters, their value and	223	Although the callback might get passed parameters, their value and
188	presence is undefined and you cannot rely on them. Portable AnyEvent	224	presence is undefined and you cannot rely on them. Portable AnyEvent
189	callbacks cannot use arguments passed to time watcher callbacks.	225	callbacks cannot use arguments passed to time watcher callbacks.
190		226
191	The timer callback will be invoked at most once: if you want a repeating	227	The callback will normally be invoked once only. If you specify another
192	timer you have to create a new watcher (this is a limitation by both Tk	228	parameter, C<interval>, as a strictly positive number (> 0), then the
193	and Glib).	229	callback will be invoked regularly at that interval (in fractional
		230	seconds) after the first invocation. If C<interval> is specified with a
		231	false value, then it is treated as if it were missing.
194		232
195	Example:	233	The callback will be rescheduled before invoking the callback, but no
		234	attempt is done to avoid timer drift in most backends, so the interval is
		235	only approximate.
196		236
197	# fire an event after 7.7 seconds	237	Example: fire an event after 7.7 seconds.
		238
198	my $w = AnyEvent->timer (after => 7.7, cb => sub {	239	my $w = AnyEvent->timer (after => 7.7, cb => sub {
199	warn "timeout\n";	240	warn "timeout\n";
200	});	241	});
201		242
202	# to cancel the timer:	243	# to cancel the timer:
203	undef $w;	244	undef $w;
204		245
205	Example 2:
206
207	# fire an event after 0.5 seconds, then roughly every second	246	Example 2: fire an event after 0.5 seconds, then roughly every second.
208	my $w;
209		247
210	my $cb = sub {
211	# cancel the old timer while creating a new one
212	$w = AnyEvent->timer (after => 1, cb => $cb);	248	my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub {
		249	warn "timeout\n";
213	};	250	};
214
215	# start the "loop" by creating the first watcher
216	$w = AnyEvent->timer (after => 0.5, cb => $cb);
217		251
218	=head3 TIMING ISSUES	252	=head3 TIMING ISSUES
219		253
220	There are two ways to handle timers: based on real time (relative, "fire	254	There are two ways to handle timers: based on real time (relative, "fire
221	in 10 seconds") and based on wallclock time (absolute, "fire at 12	255	in 10 seconds") and based on wallclock time (absolute, "fire at 12
…		…
294	In either case, if you care (and in most cases, you don't), then you	328	In either case, if you care (and in most cases, you don't), then you
295	can get whatever behaviour you want with any event loop, by taking the	329	can get whatever behaviour you want with any event loop, by taking the
296	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	330	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
297	account.	331	account.
298		332
		333	=item AnyEvent->now_update
		334
		335	Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache
		336	the current time for each loop iteration (see the discussion of L<<
		337	AnyEvent->now >>, above).
		338
		339	When a callback runs for a long time (or when the process sleeps), then
		340	this "current" time will differ substantially from the real time, which
		341	might affect timers and time-outs.
		342
		343	When this is the case, you can call this method, which will update the
		344	event loop's idea of "current time".
		345
		346	Note that updating the time I<might> cause some events to be handled.
		347
299	=back	348	=back
300		349
301	=head2 SIGNAL WATCHERS	350	=head2 SIGNAL WATCHERS
302		351
303	You can watch for signals using a signal watcher, C<signal> is the signal	352	You can watch for signals using a signal watcher, C<signal> is the signal
304	I<name> without any C<SIG> prefix, C<cb> is the Perl callback to	353	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
305	be invoked whenever a signal occurs.	354	callback to be invoked whenever a signal occurs.
306		355
307	Although the callback might get passed parameters, their value and	356	Although the callback might get passed parameters, their value and
308	presence is undefined and you cannot rely on them. Portable AnyEvent	357	presence is undefined and you cannot rely on them. Portable AnyEvent
309	callbacks cannot use arguments passed to signal watcher callbacks.	358	callbacks cannot use arguments passed to signal watcher callbacks.
310		359
…		…
326	=head2 CHILD PROCESS WATCHERS	375	=head2 CHILD PROCESS WATCHERS
327		376
328	You can also watch on a child process exit and catch its exit status.	377	You can also watch on a child process exit and catch its exit status.
329		378
330	The child process is specified by the C<pid> argument (if set to C<0>, it	379	The child process is specified by the C<pid> argument (if set to C<0>, it
331	watches for any child process exit). The watcher will trigger as often	380	watches for any child process exit). The watcher will triggered only when
332	as status change for the child are received. This works by installing a	381	the child process has finished and an exit status is available, not on
333	signal handler for C<SIGCHLD>. The callback will be called with the pid	382	any trace events (stopped/continued).
334	and exit status (as returned by waitpid), so unlike other watcher types,	383
335	you I<can> rely on child watcher callback arguments.	384	The callback will be called with the pid and exit status (as returned by
		385	waitpid), so unlike other watcher types, you I<can> rely on child watcher
		386	callback arguments.
		387
		388	This watcher type works by installing a signal handler for C<SIGCHLD>,
		389	and since it cannot be shared, nothing else should use SIGCHLD or reap
		390	random child processes (waiting for specific child processes, e.g. inside
		391	C<system>, is just fine).
336		392
337	There is a slight catch to child watchers, however: you usually start them	393	There is a slight catch to child watchers, however: you usually start them
338	I<after> the child process was created, and this means the process could	394	I<after> the child process was created, and this means the process could
339	have exited already (and no SIGCHLD will be sent anymore).	395	have exited already (and no SIGCHLD will be sent anymore).
340		396
…		…
346	AnyEvent program, you I<have> to create at least one watcher before you	402	AnyEvent program, you I<have> to create at least one watcher before you
347	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).	403	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).
348		404
349	Example: fork a process and wait for it	405	Example: fork a process and wait for it
350		406
351	my $done = AnyEvent->condvar;	407	my $done = AnyEvent->condvar;
352		408
353	my $pid = fork or exit 5;	409	my $pid = fork or exit 5;
354		410
355	my $w = AnyEvent->child (	411	my $w = AnyEvent->child (
356	pid => $pid,	412	pid => $pid,
357	cb => sub {	413	cb => sub {
358	my ($pid, $status) = @_;	414	my ($pid, $status) = @_;
359	warn "pid $pid exited with status $status";	415	warn "pid $pid exited with status $status";
360	$done->send;	416	$done->send;
361	},	417	},
362	);	418	);
363		419
364	# do something else, then wait for process exit	420	# do something else, then wait for process exit
365	$done->recv;	421	$done->recv;
		422
		423	=head2 IDLE WATCHERS
		424
		425	Sometimes there is a need to do something, but it is not so important
		426	to do it instantly, but only when there is nothing better to do. This
		427	"nothing better to do" is usually defined to be "no other events need
		428	attention by the event loop".
		429
		430	Idle watchers ideally get invoked when the event loop has nothing
		431	better to do, just before it would block the process to wait for new
		432	events. Instead of blocking, the idle watcher is invoked.
		433
		434	Most event loops unfortunately do not really support idle watchers (only
		435	EV, Event and Glib do it in a usable fashion) - for the rest, AnyEvent
		436	will simply call the callback "from time to time".
		437
		438	Example: read lines from STDIN, but only process them when the
		439	program is otherwise idle:
		440
		441	my @lines; # read data
		442	my $idle_w;
		443	my $io_w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {
		444	push @lines, scalar <STDIN>;
		445
		446	# start an idle watcher, if not already done
		447	$idle_w \|\|= AnyEvent->idle (cb => sub {
		448	# handle only one line, when there are lines left
		449	if (my $line = shift @lines) {
		450	print "handled when idle: $line";
		451	} else {
		452	# otherwise disable the idle watcher again
		453	undef $idle_w;
		454	}
		455	});
		456	});
366		457
367	=head2 CONDITION VARIABLES	458	=head2 CONDITION VARIABLES
368		459
369	If you are familiar with some event loops you will know that all of them	460	If you are familiar with some event loops you will know that all of them
370	require you to run some blocking "loop", "run" or similar function that	461	require you to run some blocking "loop", "run" or similar function that
…		…
376	The instrument to do that is called a "condition variable", so called	467	The instrument to do that is called a "condition variable", so called
377	because they represent a condition that must become true.	468	because they represent a condition that must become true.
378		469
379	Condition variables can be created by calling the C<< AnyEvent->condvar	470	Condition variables can be created by calling the C<< AnyEvent->condvar
380	>> method, usually without arguments. The only argument pair allowed is	471	>> method, usually without arguments. The only argument pair allowed is
		472
381	C<cb>, which specifies a callback to be called when the condition variable	473	C<cb>, which specifies a callback to be called when the condition variable
382	becomes true.	474	becomes true, with the condition variable as the first argument (but not
		475	the results).
383		476
384	After creation, the condition variable is "false" until it becomes "true"	477	After creation, the condition variable is "false" until it becomes "true"
385	by calling the C<send> method (or calling the condition variable as if it	478	by calling the C<send> method (or calling the condition variable as if it
386	were a callback, read about the caveats in the description for the C<<	479	were a callback, read about the caveats in the description for the C<<
387	->send >> method).	480	->send >> method).
…		…
443		536
444	my $done = AnyEvent->condvar;	537	my $done = AnyEvent->condvar;
445	my $delay = AnyEvent->timer (after => 5, cb => $done);	538	my $delay = AnyEvent->timer (after => 5, cb => $done);
446	$done->recv;	539	$done->recv;
447		540
		541	Example: Imagine an API that returns a condvar and doesn't support
		542	callbacks. This is how you make a synchronous call, for example from
		543	the main program:
		544
		545	use AnyEvent::CouchDB;
		546
		547	...
		548
		549	my @info = $couchdb->info->recv;
		550
		551	And this is how you would just ste a callback to be called whenever the
		552	results are available:
		553
		554	$couchdb->info->cb (sub {
		555	my @info = $_[0]->recv;
		556	});
		557
448	=head3 METHODS FOR PRODUCERS	558	=head3 METHODS FOR PRODUCERS
449		559
450	These methods should only be used by the producing side, i.e. the	560	These methods should only be used by the producing side, i.e. the
451	code/module that eventually sends the signal. Note that it is also	561	code/module that eventually sends the signal. Note that it is also
452	the producer side which creates the condvar in most cases, but it isn't	562	the producer side which creates the condvar in most cases, but it isn't
…		…
585	=item $bool = $cv->ready	695	=item $bool = $cv->ready
586		696
587	Returns true when the condition is "true", i.e. whether C<send> or	697	Returns true when the condition is "true", i.e. whether C<send> or
588	C<croak> have been called.	698	C<croak> have been called.
589		699
590	=item $cb = $cv->cb ([new callback])	700	=item $cb = $cv->cb ($cb->($cv))
591		701
592	This is a mutator function that returns the callback set and optionally	702	This is a mutator function that returns the callback set and optionally
593	replaces it before doing so.	703	replaces it before doing so.
594		704
595	The callback will be called when the condition becomes "true", i.e. when	705	The callback will be called when the condition becomes "true", i.e. when
596	C<send> or C<croak> are called. Calling C<recv> inside the callback	706	C<send> or C<croak> are called, with the only argument being the condition
597	or at any later time is guaranteed not to block.	707	variable itself. Calling C<recv> inside the callback or at any later time
		708	is guaranteed not to block.
598		709
599	=back	710	=back
600		711
601	=head1 GLOBAL VARIABLES AND FUNCTIONS	712	=head1 GLOBAL VARIABLES AND FUNCTIONS
602		713
…		…
731	=item L<AnyEvent::Util>	842	=item L<AnyEvent::Util>
732		843
733	Contains various utility functions that replace often-used but blocking	844	Contains various utility functions that replace often-used but blocking
734	functions such as C<inet_aton> by event-/callback-based versions.	845	functions such as C<inet_aton> by event-/callback-based versions.
735		846
736	=item L<AnyEvent::Handle>
737
738	Provide read and write buffers and manages watchers for reads and writes.
739
740	=item L<AnyEvent::Socket>	847	=item L<AnyEvent::Socket>
741		848
742	Provides various utility functions for (internet protocol) sockets,	849	Provides various utility functions for (internet protocol) sockets,
743	addresses and name resolution. Also functions to create non-blocking tcp	850	addresses and name resolution. Also functions to create non-blocking tcp
744	connections or tcp servers, with IPv6 and SRV record support and more.	851	connections or tcp servers, with IPv6 and SRV record support and more.
745		852
		853	=item L<AnyEvent::Handle>
		854
		855	Provide read and write buffers, manages watchers for reads and writes,
		856	supports raw and formatted I/O, I/O queued and fully transparent and
		857	non-blocking SSL/TLS.
		858
746	=item L<AnyEvent::DNS>	859	=item L<AnyEvent::DNS>
747		860
748	Provides rich asynchronous DNS resolver capabilities.	861	Provides rich asynchronous DNS resolver capabilities.
749		862
		863	=item L<AnyEvent::HTTP>
		864
		865	A simple-to-use HTTP library that is capable of making a lot of concurrent
		866	HTTP requests.
		867
750	=item L<AnyEvent::HTTPD>	868	=item L<AnyEvent::HTTPD>
751		869
752	Provides a simple web application server framework.	870	Provides a simple web application server framework.
753		871
754	=item L<AnyEvent::FastPing>	872	=item L<AnyEvent::FastPing>
755		873
756	The fastest ping in the west.	874	The fastest ping in the west.
757		875
		876	=item L<AnyEvent::DBI>
		877
		878	Executes L<DBI> requests asynchronously in a proxy process.
		879
		880	=item L<AnyEvent::AIO>
		881
		882	Truly asynchronous I/O, should be in the toolbox of every event
		883	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
		884	together.
		885
		886	=item L<AnyEvent::BDB>
		887
		888	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
		889	L<BDB> and AnyEvent together.
		890
		891	=item L<AnyEvent::GPSD>
		892
		893	A non-blocking interface to gpsd, a daemon delivering GPS information.
		894
		895	=item L<AnyEvent::IGS>
		896
		897	A non-blocking interface to the Internet Go Server protocol (used by
		898	L<App::IGS>).
		899
758	=item L<Net::IRC3>	900	=item L<AnyEvent::IRC>
759		901
760	AnyEvent based IRC client module family.	902	AnyEvent based IRC client module family (replacing the older Net::IRC3).
761		903
762	=item L<Net::XMPP2>	904	=item L<Net::XMPP2>
763		905
764	AnyEvent based XMPP (Jabber protocol) module family.	906	AnyEvent based XMPP (Jabber protocol) module family.
765		907
…		…
774		916
775	=item L<Coro>	917	=item L<Coro>
776		918
777	Has special support for AnyEvent via L<Coro::AnyEvent>.	919	Has special support for AnyEvent via L<Coro::AnyEvent>.
778		920
779	=item L<AnyEvent::AIO>, L<IO::AIO>
780
781	Truly asynchronous I/O, should be in the toolbox of every event
782	programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent
783	together.
784
785	=item L<AnyEvent::BDB>, L<BDB>
786
787	Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses
788	IO::AIO and AnyEvent together.
789
790	=item L<IO::Lambda>	921	=item L<IO::Lambda>
791		922
792	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.	923	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
793		924
794	=back	925	=back
…		…
796	=cut	927	=cut
797		928
798	package AnyEvent;	929	package AnyEvent;
799		930
800	no warnings;	931	no warnings;
801	use strict;	932	use strict qw(vars subs);
802		933
803	use Carp;	934	use Carp;
804		935
805	our $VERSION = '4.05';	936	our $VERSION = 4.411;
806	our $MODEL;	937	our $MODEL;
807		938
808	our $AUTOLOAD;	939	our $AUTOLOAD;
809	our @ISA;	940	our @ISA;
810		941
811	our @REGISTRY;	942	our @REGISTRY;
812		943
813	our $WIN32;	944	our $WIN32;
814		945
815	BEGIN {	946	BEGIN {
816	my $win32 = ! ! ($^O =~ /mswin32/i);	947	eval "sub WIN32(){ " . (($^O =~ /mswin32/i)*1) ." }";
817	eval "sub WIN32(){ $win32 }";	948	eval "sub TAINT(){ " . (${^TAINT}*1) . " }";
		949
		950	delete @ENV{grep /^PERL_ANYEVENT_/, keys %ENV}
		951	if ${^TAINT};
818	}	952	}
819		953
820	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;	954	our $verbose = $ENV{PERL_ANYEVENT_VERBOSE}*1;
821		955
822	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred	956	our %PROTOCOL; # (ipv4\|ipv6) => (1\|2), higher numbers are preferred
…		…
842	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	976	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
843	[Wx:: => AnyEvent::Impl::POE::],	977	[Wx:: => AnyEvent::Impl::POE::],
844	[Prima:: => AnyEvent::Impl::POE::],	978	[Prima:: => AnyEvent::Impl::POE::],
845	);	979	);
846		980
847	our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY);	981	our %method = map +($_ => 1),
		982	qw(io timer time now now_update signal child idle condvar one_event DESTROY);
848		983
849	our @post_detect;	984	our @post_detect;
850		985
851	sub post_detect(&) {	986	sub post_detect(&) {
852	my ($cb) = @_;	987	my ($cb) = @_;
…		…
857	1	992	1
858	} else {	993	} else {
859	push @post_detect, $cb;	994	push @post_detect, $cb;
860		995
861	defined wantarray	996	defined wantarray
862	? bless \$cb, "AnyEvent::Util::PostDetect"	997	? bless \$cb, "AnyEvent::Util::postdetect"
863	: ()	998	: ()
864	}	999	}
865	}	1000	}
866		1001
867	sub AnyEvent::Util::PostDetect::DESTROY {	1002	sub AnyEvent::Util::postdetect::DESTROY {
868	@post_detect = grep $_ != ${$_[0]}, @post_detect;	1003	@post_detect = grep $_ != ${$_[0]}, @post_detect;
869	}	1004	}
870		1005
871	sub detect() {	1006	sub detect() {
872	unless ($MODEL) {	1007	unless ($MODEL) {
…		…
909	last;	1044	last;
910	}	1045	}
911	}	1046	}
912		1047
913	$MODEL	1048	$MODEL
914	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";	1049	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";
915	}	1050	}
916	}	1051	}
917		1052
		1053	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1054
918	unshift @ISA, $MODEL;	1055	unshift @ISA, $MODEL;
919	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	1056
		1057	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
920		1058
921	(shift @post_detect)->() while @post_detect;	1059	(shift @post_detect)->() while @post_detect;
922	}	1060	}
923		1061
924	$MODEL	1062	$MODEL
…		…
934		1072
935	my $class = shift;	1073	my $class = shift;
936	$class->$func (@_);	1074	$class->$func (@_);
937	}	1075	}
938		1076
		1077	# utility function to dup a filehandle. this is used by many backends
		1078	# to support binding more than one watcher per filehandle (they usually
		1079	# allow only one watcher per fd, so we dup it to get a different one).
		1080	sub _dupfh($$$$) {
		1081	my ($poll, $fh, $r, $w) = @_;
		1082
		1083	# cygwin requires the fh mode to be matching, unix doesn't
		1084	my ($rw, $mode) = $poll eq "r" ? ($r, "<")
		1085	: $poll eq "w" ? ($w, ">")
		1086	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
		1087
		1088	open my $fh2, "$mode&" . fileno $fh
		1089	or die "cannot dup() filehandle: $!,";
		1090
		1091	# we assume CLOEXEC is already set by perl in all important cases
		1092
		1093	($fh2, $rw)
		1094	}
		1095
939	package AnyEvent::Base;	1096	package AnyEvent::Base;
940		1097
941	# default implementation for now and time	1098	# default implementations for many methods
942		1099
943	use Time::HiRes ();	1100	BEGIN {
		1101	if (eval "use Time::HiRes (); Time::HiRes::time (); 1") {
		1102	*_time = \&Time::HiRes::time;
		1103	# if (eval "use POSIX (); (POSIX::times())...
		1104	} else {
		1105	*_time = sub { time }; # epic fail
		1106	}
		1107	}
944		1108
945	sub time { Time::HiRes::time }	1109	sub time { _time }
946	sub now { Time::HiRes::time }	1110	sub now { _time }
		1111	sub now_update { }
947		1112
948	# default implementation for ->condvar	1113	# default implementation for ->condvar
949		1114
950	sub condvar {	1115	sub condvar {
951	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::	1116	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, "AnyEvent::CondVar"
952	}	1117	}
953		1118
954	# default implementation for ->signal	1119	# default implementation for ->signal
955		1120
956	our %SIG_CB;	1121	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
		1122
		1123	sub _signal_exec {
		1124	sysread $SIGPIPE_R, my $dummy, 4;
		1125
		1126	while (%SIG_EV) {
		1127	for (keys %SIG_EV) {
		1128	delete $SIG_EV{$_};
		1129	$_->() for values %{ $SIG_CB{$_} \|\| {} };
		1130	}
		1131	}
		1132	}
957		1133
958	sub signal {	1134	sub signal {
959	my (undef, %arg) = @_;	1135	my (undef, %arg) = @_;
960		1136
		1137	unless ($SIGPIPE_R) {
		1138	require Fcntl;
		1139
		1140	if (AnyEvent::WIN32) {
		1141	require AnyEvent::Util;
		1142
		1143	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1144	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
		1145	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
		1146	} else {
		1147	pipe $SIGPIPE_R, $SIGPIPE_W;
		1148	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
		1149	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
		1150
		1151	# not strictly required, as $^F is normally 2, but let's make sure...
		1152	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1153	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1154	}
		1155
		1156	$SIGPIPE_R
		1157	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1158
		1159	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
		1160	}
		1161
961	my $signal = uc $arg{signal}	1162	my $signal = uc $arg{signal}
962	or Carp::croak "required option 'signal' is missing";	1163	or Carp::croak "required option 'signal' is missing";
963		1164
964	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1165	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
965	$SIG{$signal} \|\|= sub {	1166	$SIG{$signal} \|\|= sub {
966	$_->() for values %{ $SIG_CB{$signal} \|\| {} };	1167	local $!;
		1168	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1169	undef $SIG_EV{$signal};
967	};	1170	};
968		1171
969	bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"	1172	bless [$signal, $arg{cb}], "AnyEvent::Base::signal"
970	}	1173	}
971		1174
972	sub AnyEvent::Base::Signal::DESTROY {	1175	sub AnyEvent::Base::signal::DESTROY {
973	my ($signal, $cb) = @{$_[0]};	1176	my ($signal, $cb) = @{$_[0]};
974		1177
975	delete $SIG_CB{$signal}{$cb};	1178	delete $SIG_CB{$signal}{$cb};
976		1179
		1180	# delete doesn't work with older perls - they then
		1181	# print weird messages, or just unconditionally exit
		1182	# instead of getting the default action.
977	$SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} };	1183	undef $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
978	}	1184	}
979		1185
980	# default implementation for ->child	1186	# default implementation for ->child
981		1187
982	our %PID_CB;	1188	our %PID_CB;
983	our $CHLD_W;	1189	our $CHLD_W;
984	our $CHLD_DELAY_W;	1190	our $CHLD_DELAY_W;
985	our $PID_IDLE;
986	our $WNOHANG;	1191	our $WNOHANG;
987		1192
988	sub _child_wait {	1193	sub _sigchld {
989	while (0 < (my $pid = waitpid -1, $WNOHANG)) {	1194	while (0 < (my $pid = waitpid -1, $WNOHANG)) {
990	$_->($pid, $?) for (values %{ $PID_CB{$pid} \|\| {} }),	1195	$_->($pid, $?) for (values %{ $PID_CB{$pid} \|\| {} }),
991	(values %{ $PID_CB{0} \|\| {} });	1196	(values %{ $PID_CB{0} \|\| {} });
992	}	1197	}
993
994	undef $PID_IDLE;
995	}
996
997	sub _sigchld {
998	# make sure we deliver these changes "synchronous" with the event loop.
999	$CHLD_DELAY_W \|\|= AnyEvent->timer (after => 0, cb => sub {
1000	undef $CHLD_DELAY_W;
1001	&_child_wait;
1002	});
1003	}	1198	}
1004		1199
1005	sub child {	1200	sub child {
1006	my (undef, %arg) = @_;	1201	my (undef, %arg) = @_;
1007		1202
1008	defined (my $pid = $arg{pid} + 0)	1203	defined (my $pid = $arg{pid} + 0)
1009	or Carp::croak "required option 'pid' is missing";	1204	or Carp::croak "required option 'pid' is missing";
1010		1205
1011	$PID_CB{$pid}{$arg{cb}} = $arg{cb};	1206	$PID_CB{$pid}{$arg{cb}} = $arg{cb};
1012		1207
1013	unless ($WNOHANG) {
1014	$WNOHANG = eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;	1208	$WNOHANG \|\|= eval { local $SIG{__DIE__}; require POSIX; &POSIX::WNOHANG } \|\| 1;
1015	}
1016		1209
1017	unless ($CHLD_W) {	1210	unless ($CHLD_W) {
1018	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);	1211	$CHLD_W = AnyEvent->signal (signal => 'CHLD', cb => \&_sigchld);
1019	# child could be a zombie already, so make at least one round	1212	# child could be a zombie already, so make at least one round
1020	&_sigchld;	1213	&_sigchld;
1021	}	1214	}
1022		1215
1023	bless [$pid, $arg{cb}], "AnyEvent::Base::Child"	1216	bless [$pid, $arg{cb}], "AnyEvent::Base::child"
1024	}	1217	}
1025		1218
1026	sub AnyEvent::Base::Child::DESTROY {	1219	sub AnyEvent::Base::child::DESTROY {
1027	my ($pid, $cb) = @{$_[0]};	1220	my ($pid, $cb) = @{$_[0]};
1028		1221
1029	delete $PID_CB{$pid}{$cb};	1222	delete $PID_CB{$pid}{$cb};
1030	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };	1223	delete $PID_CB{$pid} unless keys %{ $PID_CB{$pid} };
1031		1224
1032	undef $CHLD_W unless keys %PID_CB;	1225	undef $CHLD_W unless keys %PID_CB;
		1226	}
		1227
		1228	# idle emulation is done by simply using a timer, regardless
		1229	# of whether the process is idle or not, and not letting
		1230	# the callback use more than 50% of the time.
		1231	sub idle {
		1232	my (undef, %arg) = @_;
		1233
		1234	my ($cb, $w, $rcb) = $arg{cb};
		1235
		1236	$rcb = sub {
		1237	if ($cb) {
		1238	$w = _time;
		1239	&$cb;
		1240	$w = _time - $w;
		1241
		1242	# never use more then 50% of the time for the idle watcher,
		1243	# within some limits
		1244	$w = 0.0001 if $w < 0.0001;
		1245	$w = 5 if $w > 5;
		1246
		1247	$w = AnyEvent->timer (after => $w, cb => $rcb);
		1248	} else {
		1249	# clean up...
		1250	undef $w;
		1251	undef $rcb;
		1252	}
		1253	};
		1254
		1255	$w = AnyEvent->timer (after => 0.05, cb => $rcb);
		1256
		1257	bless \\$cb, "AnyEvent::Base::idle"
		1258	}
		1259
		1260	sub AnyEvent::Base::idle::DESTROY {
		1261	undef $${$_[0]};
1033	}	1262	}
1034		1263
1035	package AnyEvent::CondVar;	1264	package AnyEvent::CondVar;
1036		1265
1037	our @ISA = AnyEvent::CondVar::Base::;	1266	our @ISA = AnyEvent::CondVar::Base::;
…		…
1089	}	1318	}
1090		1319
1091	# undocumented/compatibility with pre-3.4	1320	# undocumented/compatibility with pre-3.4
1092	*broadcast = \&send;	1321	*broadcast = \&send;
1093	*wait = \&_wait;	1322	*wait = \&_wait;
		1323
		1324	=head1 ERROR AND EXCEPTION HANDLING
		1325
		1326	In general, AnyEvent does not do any error handling - it relies on the
		1327	caller to do that if required. The L<AnyEvent::Strict> module (see also
		1328	the C<PERL_ANYEVENT_STRICT> environment variable, below) provides strict
		1329	checking of all AnyEvent methods, however, which is highly useful during
		1330	development.
		1331
		1332	As for exception handling (i.e. runtime errors and exceptions thrown while
		1333	executing a callback), this is not only highly event-loop specific, but
		1334	also not in any way wrapped by this module, as this is the job of the main
		1335	program.
		1336
		1337	The pure perl event loop simply re-throws the exception (usually
		1338	within C<< condvar->recv >>), the L<Event> and L<EV> modules call C<<
		1339	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
		1340	so on.
		1341
		1342	=head1 ENVIRONMENT VARIABLES
		1343
		1344	The following environment variables are used by this module or its
		1345	submodules.
		1346
		1347	Note that AnyEvent will remove I<all> environment variables starting with
		1348	C<PERL_ANYEVENT_> from C<%ENV> when it is loaded while taint mode is
		1349	enabled.
		1350
		1351	=over 4
		1352
		1353	=item C<PERL_ANYEVENT_VERBOSE>
		1354
		1355	By default, AnyEvent will be completely silent except in fatal
		1356	conditions. You can set this environment variable to make AnyEvent more
		1357	talkative.
		1358
		1359	When set to C<1> or higher, causes AnyEvent to warn about unexpected
		1360	conditions, such as not being able to load the event model specified by
		1361	C<PERL_ANYEVENT_MODEL>.
		1362
		1363	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
		1364	model it chooses.
		1365
		1366	=item C<PERL_ANYEVENT_STRICT>
		1367
		1368	AnyEvent does not do much argument checking by default, as thorough
		1369	argument checking is very costly. Setting this variable to a true value
		1370	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
		1371	check the arguments passed to most method calls. If it finds any problems
		1372	it will croak.
		1373
		1374	In other words, enables "strict" mode.
		1375
		1376	Unlike C<use strict>, it is definitely recommended ot keep it off in
		1377	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while
		1378	developing programs can be very useful, however.
		1379
		1380	=item C<PERL_ANYEVENT_MODEL>
		1381
		1382	This can be used to specify the event model to be used by AnyEvent, before
		1383	auto detection and -probing kicks in. It must be a string consisting
		1384	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
		1385	and the resulting module name is loaded and if the load was successful,
		1386	used as event model. If it fails to load AnyEvent will proceed with
		1387	auto detection and -probing.
		1388
		1389	This functionality might change in future versions.
		1390
		1391	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
		1392	could start your program like this:
		1393
		1394	PERL_ANYEVENT_MODEL=Perl perl ...
		1395
		1396	=item C<PERL_ANYEVENT_PROTOCOLS>
		1397
		1398	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
		1399	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
		1400	of auto probing).
		1401
		1402	Must be set to a comma-separated list of protocols or address families,
		1403	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
		1404	used, and preference will be given to protocols mentioned earlier in the
		1405	list.
		1406
		1407	This variable can effectively be used for denial-of-service attacks
		1408	against local programs (e.g. when setuid), although the impact is likely
		1409	small, as the program has to handle conenction and other failures anyways.
		1410
		1411	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
		1412	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
		1413	- only support IPv4, never try to resolve or contact IPv6
		1414	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
		1415	IPv6, but prefer IPv6 over IPv4.
		1416
		1417	=item C<PERL_ANYEVENT_EDNS0>
		1418
		1419	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
		1420	for DNS. This extension is generally useful to reduce DNS traffic, but
		1421	some (broken) firewalls drop such DNS packets, which is why it is off by
		1422	default.
		1423
		1424	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
		1425	EDNS0 in its DNS requests.
		1426
		1427	=item C<PERL_ANYEVENT_MAX_FORKS>
		1428
		1429	The maximum number of child processes that C<AnyEvent::Util::fork_call>
		1430	will create in parallel.
		1431
		1432	=back
1094		1433
1095	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1434	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1096		1435
1097	This is an advanced topic that you do not normally need to use AnyEvent in	1436	This is an advanced topic that you do not normally need to use AnyEvent in
1098	a module. This section is only of use to event loop authors who want to	1437	a module. This section is only of use to event loop authors who want to
…		…
1132		1471
1133	I<rxvt-unicode> also cheats a bit by not providing blocking access to	1472	I<rxvt-unicode> also cheats a bit by not providing blocking access to
1134	condition variables: code blocking while waiting for a condition will	1473	condition variables: code blocking while waiting for a condition will
1135	C<die>. This still works with most modules/usages, and blocking calls must	1474	C<die>. This still works with most modules/usages, and blocking calls must
1136	not be done in an interactive application, so it makes sense.	1475	not be done in an interactive application, so it makes sense.
1137
1138	=head1 ENVIRONMENT VARIABLES
1139
1140	The following environment variables are used by this module:
1141
1142	=over 4
1143
1144	=item C<PERL_ANYEVENT_VERBOSE>
1145
1146	By default, AnyEvent will be completely silent except in fatal
1147	conditions. You can set this environment variable to make AnyEvent more
1148	talkative.
1149
1150	When set to C<1> or higher, causes AnyEvent to warn about unexpected
1151	conditions, such as not being able to load the event model specified by
1152	C<PERL_ANYEVENT_MODEL>.
1153
1154	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1155	model it chooses.
1156
1157	=item C<PERL_ANYEVENT_MODEL>
1158
1159	This can be used to specify the event model to be used by AnyEvent, before
1160	auto detection and -probing kicks in. It must be a string consisting
1161	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
1162	and the resulting module name is loaded and if the load was successful,
1163	used as event model. If it fails to load AnyEvent will proceed with
1164	auto detection and -probing.
1165
1166	This functionality might change in future versions.
1167
1168	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
1169	could start your program like this:
1170
1171	PERL_ANYEVENT_MODEL=Perl perl ...
1172
1173	=item C<PERL_ANYEVENT_PROTOCOLS>
1174
1175	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
1176	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
1177	of auto probing).
1178
1179	Must be set to a comma-separated list of protocols or address families,
1180	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
1181	used, and preference will be given to protocols mentioned earlier in the
1182	list.
1183
1184	This variable can effectively be used for denial-of-service attacks
1185	against local programs (e.g. when setuid), although the impact is likely
1186	small, as the program has to handle connection errors already-
1187
1188	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
1189	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1190	- only support IPv4, never try to resolve or contact IPv6
1191	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1192	IPv6, but prefer IPv6 over IPv4.
1193
1194	=item C<PERL_ANYEVENT_EDNS0>
1195
1196	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
1197	for DNS. This extension is generally useful to reduce DNS traffic, but
1198	some (broken) firewalls drop such DNS packets, which is why it is off by
1199	default.
1200
1201	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1202	EDNS0 in its DNS requests.
1203
1204	=item C<PERL_ANYEVENT_MAX_FORKS>
1205
1206	The maximum number of child processes that C<AnyEvent::Util::fork_call>
1207	will create in parallel.
1208
1209	=back
1210		1476
1211	=head1 EXAMPLE PROGRAM	1477	=head1 EXAMPLE PROGRAM
1212		1478
1213	The following program uses an I/O watcher to read data from STDIN, a timer	1479	The following program uses an I/O watcher to read data from STDIN, a timer
1214	to display a message once per second, and a condition variable to quit the	1480	to display a message once per second, and a condition variable to quit the
…		…
1408	watcher.	1674	watcher.
1409		1675
1410	=head3 Results	1676	=head3 Results
1411		1677
1412	name watchers bytes create invoke destroy comment	1678	name watchers bytes create invoke destroy comment
1413	EV/EV 400000 244 0.56 0.46 0.31 EV native interface	1679	EV/EV 400000 224 0.47 0.35 0.27 EV native interface
1414	EV/Any 100000 244 2.50 0.46 0.29 EV + AnyEvent watchers	1680	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers
1415	CoroEV/Any 100000 244 2.49 0.44 0.29 coroutines + Coro::Signal	1681	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal
1416	Perl/Any 100000 513 4.92 0.87 1.12 pure perl implementation	1682	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation
1417	Event/Event 16000 516 31.88 31.30 0.85 Event native interface	1683	Event/Event 16000 517 32.20 31.80 0.81 Event native interface
1418	Event/Any 16000 590 35.75 31.42 1.08 Event + AnyEvent watchers	1684	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers
1419	Glib/Any 16000 1357 98.22 12.41 54.00 quadratic behaviour	1685	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour
1420	Tk/Any 2000 1860 26.97 67.98 14.00 SEGV with >> 2000 watchers	1686	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers
1421	POE/Event 2000 6644 108.64 736.02 14.73 via POE::Loop::Event	1687	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event
1422	POE/Select 2000 6343 94.13 809.12 565.96 via POE::Loop::Select	1688	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select
1423		1689
1424	=head3 Discussion	1690	=head3 Discussion
1425		1691
1426	The benchmark does I<not> measure scalability of the event loop very	1692	The benchmark does I<not> measure scalability of the event loop very
1427	well. For example, a select-based event loop (such as the pure perl one)	1693	well. For example, a select-based event loop (such as the pure perl one)
…		…
1629	watchers, as the management overhead dominates.	1895	watchers, as the management overhead dominates.
1630		1896
1631	=back	1897	=back
1632		1898
1633		1899
		1900	=head1 SIGNALS
		1901
		1902	AnyEvent currently installs handlers for these signals:
		1903
		1904	=over 4
		1905
		1906	=item SIGCHLD
		1907
		1908	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
		1909	emulation for event loops that do not support them natively. Also, some
		1910	event loops install a similar handler.
		1911
		1912	=item SIGPIPE
		1913
		1914	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
		1915	when AnyEvent gets loaded.
		1916
		1917	The rationale for this is that AnyEvent users usually do not really depend
		1918	on SIGPIPE delivery (which is purely an optimisation for shell use, or
		1919	badly-written programs), but C<SIGPIPE> can cause spurious and rare
		1920	program exits as a lot of people do not expect C<SIGPIPE> when writing to
		1921	some random socket.
		1922
		1923	The rationale for installing a no-op handler as opposed to ignoring it is
		1924	that this way, the handler will be restored to defaults on exec.
		1925
		1926	Feel free to install your own handler, or reset it to defaults.
		1927
		1928	=back
		1929
		1930	=cut
		1931
		1932	$SIG{PIPE} = sub { }
		1933	unless defined $SIG{PIPE};
		1934
		1935
1634	=head1 FORK	1936	=head1 FORK
1635		1937
1636	Most event libraries are not fork-safe. The ones who are usually are	1938	Most event libraries are not fork-safe. The ones who are usually are
1637	because they rely on inefficient but fork-safe C<select> or C<poll>	1939	because they rely on inefficient but fork-safe C<select> or C<poll>
1638	calls. Only L<EV> is fully fork-aware.	1940	calls. Only L<EV> is fully fork-aware.
…		…
1651	specified in the variable.	1953	specified in the variable.
1652		1954
1653	You can make AnyEvent completely ignore this variable by deleting it	1955	You can make AnyEvent completely ignore this variable by deleting it
1654	before the first watcher gets created, e.g. with a C<BEGIN> block:	1956	before the first watcher gets created, e.g. with a C<BEGIN> block:
1655		1957
1656	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }	1958	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }
1657		1959
1658	use AnyEvent;	1960	use AnyEvent;
1659		1961
1660	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can	1962	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1661	be used to probe what backend is used and gain other information (which is	1963	be used to probe what backend is used and gain other information (which is
1662	probably even less useful to an attacker than PERL_ANYEVENT_MODEL).	1964	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
		1965	$ENV{PERL_ANYEVENT_STRICT}.
		1966
		1967
		1968	=head1 BUGS
		1969
		1970	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
		1971	to work around. If you suffer from memleaks, first upgrade to Perl 5.10
		1972	and check wether the leaks still show up. (Perl 5.10.0 has other annoying
		1973	memleaks, such as leaking on C<map> and C<grep> but it is usually not as
		1974	pronounced).
1663		1975
1664		1976
1665	=head1 SEE ALSO	1977	=head1 SEE ALSO
1666		1978
1667	Utility functions: L<AnyEvent::Util>.	1979	Utility functions: L<AnyEvent::Util>.
…		…
1684	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.	1996	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.
1685		1997
1686		1998
1687	=head1 AUTHOR	1999	=head1 AUTHOR
1688		2000
1689	Marc Lehmann <schmorp@schmorp.de>	2001	Marc Lehmann <schmorp@schmorp.de>
1690	http://home.schmorp.de/	2002	http://home.schmorp.de/
1691		2003
1692	=cut	2004	=cut
1693		2005
1694	1	2006	1
1695		2007

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.144 by root, Thu May 29 00:14:35 2008 UTC vs. Revision 1.214 by root, Mon Jun 22 11:57:05 2009 UTC

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Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.144 by root, Thu May 29 00:14:35 2008 UTC vs.
Revision 1.214 by root, Mon Jun 22 11:57:05 2009 UTC