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

Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.143 by root, Wed May 28 23:57:38 2008 UTC vs.
Revision 1.205 by root, Sun Apr 19 12:09:46 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, POE - various supported event loops
6		6
7	=head1 SYNOPSIS	7	=head1 SYNOPSIS
8		8
9	use AnyEvent;	9	use AnyEvent;
10		10
11	my $w = AnyEvent->io (fh => $fh, poll => "r\|w", cb => sub {	11	my $w = AnyEvent->io (fh => $fh, poll => "r\|w", cb => sub { ... });
12	...
13	});
14		12
15	my $w = AnyEvent->timer (after => $seconds, cb => sub {	13	my $w = AnyEvent->timer (after => $seconds, cb => sub { ... });
		14	my $w = AnyEvent->timer (after => $seconds, interval => $seconds, cb => ...
		15
		16	print AnyEvent->now; # prints current event loop time
		17	print AnyEvent->time; # think Time::HiRes::time or simply CORE::time.
		18
		19	my $w = AnyEvent->signal (signal => "TERM", cb => sub { ... });
		20
		21	my $w = AnyEvent->child (pid => $pid, cb => sub {
		22	my ($pid, $status) = @_;
16	...	23	...
17	});	24	});
18		25
19	my $w = AnyEvent->condvar; # stores whether a condition was flagged	26	my $w = AnyEvent->condvar; # stores whether a condition was flagged
20	$w->send; # wake up current and all future recv's	27	$w->send; # wake up current and all future recv's
21	$w->recv; # enters "main loop" till $condvar gets ->send	28	$w->recv; # enters "main loop" till $condvar gets ->send
		29	# use a condvar in callback mode:
		30	$w->cb (sub { $_[0]->recv });
		31
		32	=head1 INTRODUCTION/TUTORIAL
		33
		34	This manpage is mainly a reference manual. If you are interested
		35	in a tutorial or some gentle introduction, have a look at the
		36	L<AnyEvent::Intro> manpage.
22		37
23	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)	38	=head1 WHY YOU SHOULD USE THIS MODULE (OR NOT)
24		39
25	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen	40	Glib, POE, IO::Async, Event... CPAN offers event models by the dozen
26	nowadays. So what is different about AnyEvent?	41	nowadays. So what is different about AnyEvent?
27		42
28	Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of	43	Executive Summary: AnyEvent is I<compatible>, AnyEvent is I<free of
29	policy> and AnyEvent is I<small and efficient>.	44	policy> and AnyEvent is I<small and efficient>.
30		45
31	First and foremost, I<AnyEvent is not an event model> itself, it only	46	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	47	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,	48	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,	49	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	50	only one event loop can be active at the same time in a process. AnyEvent
36	helps hiding the differences between those event loops.	51	cannot change this, but it can hide the differences between those event
		52	loops.
37		53
38	The goal of AnyEvent is to offer module authors the ability to do event	54	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	55	programming (waiting for I/O or timer events) without subscribing to a
40	religion, a way of living, and most importantly: without forcing your	56	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	57	module users into the same thing by forcing them to use the same event
42	model you use.	58	model you use.
43		59
44	For modules like POE or IO::Async (which is a total misnomer as it is	60	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	61	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	62	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	63	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	64	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.	65	module are I<also> forced to use the same event loop you use.
50		66
51	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works	67	AnyEvent is different: AnyEvent + POE works fine. AnyEvent + Glib works
52	fine. AnyEvent + Tk works fine etc. etc. but none of these work together	68	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	69	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,	70	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	71	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	72	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	73	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).	74	to AnyEvent, too, so it is future-proof).
59		75
60	In addition to being free of having to use I<the one and only true event	76	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	77	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	78	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	79	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	137	These watchers are normal Perl objects with normal Perl lifetime. After
122	creating a watcher it will immediately "watch" for events and invoke the	138	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	139	callback when the event occurs (of course, only when the event model
124	is in control).	140	is in control).
125		141
		142	Note that B<callbacks must not permanently change global variables>
		143	potentially in use by the event loop (such as C<$_> or C<$[>) and that B<<
		144	callbacks must not C<die> >>. The former is good programming practise in
		145	Perl and the latter stems from the fact that exception handling differs
		146	widely between event loops.
		147
126	To disable the watcher you have to destroy it (e.g. by setting the	148	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	149	variable you store it in to C<undef> or otherwise deleting all references
128	to it).	150	to it).
129		151
130	All watchers are created by calling a method on the C<AnyEvent> class.	152	All watchers are created by calling a method on the C<AnyEvent> class.
…		…
132	Many watchers either are used with "recursion" (repeating timers for	154	Many watchers either are used with "recursion" (repeating timers for
133	example), or need to refer to their watcher object in other ways.	155	example), or need to refer to their watcher object in other ways.
134		156
135	An any way to achieve that is this pattern:	157	An any way to achieve that is this pattern:
136		158
137	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {	159	my $w; $w = AnyEvent->type (arg => value ..., cb => sub {
138	# you can use $w here, for example to undef it	160	# you can use $w here, for example to undef it
139	undef $w;	161	undef $w;
140	});	162	});
141		163
142	Note that C<my $w; $w => combination. This is necessary because in Perl,	164	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	165	my variables are only visible after the statement in which they are
144	declared.	166	declared.
145		167
146	=head2 I/O WATCHERS	168	=head2 I/O WATCHERS
147		169
148	You can create an I/O watcher by calling the C<< AnyEvent->io >> method	170	You can create an I/O watcher by calling the C<< AnyEvent->io >> method
149	with the following mandatory key-value pairs as arguments:	171	with the following mandatory key-value pairs as arguments:
150		172
151	C<fh> the Perl I<file handle> (I<not> file descriptor) to watch	173	C<fh> is the Perl I<file handle> (I<not> file descriptor) to watch
		174	for events (AnyEvent might or might not keep a reference to this file
		175	handle). Note that only file handles pointing to things for which
		176	non-blocking operation makes sense are allowed. This includes sockets,
		177	most character devices, pipes, fifos and so on, but not for example files
		178	or block devices.
		179
152	for events. C<poll> must be a string that is either C<r> or C<w>,	180	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,	181	watcher waiting for "r"eadable or "w"ritable events, respectively.
		182
154	respectively. C<cb> is the callback to invoke each time the file handle	183	C<cb> is the callback to invoke each time the file handle becomes ready.
155	becomes ready.
156		184
157	Although the callback might get passed parameters, their value and	185	Although the callback might get passed parameters, their value and
158	presence is undefined and you cannot rely on them. Portable AnyEvent	186	presence is undefined and you cannot rely on them. Portable AnyEvent
159	callbacks cannot use arguments passed to I/O watcher callbacks.	187	callbacks cannot use arguments passed to I/O watcher callbacks.
160		188
…		…
164		192
165	Some event loops issue spurious readyness notifications, so you should	193	Some event loops issue spurious readyness notifications, so you should
166	always use non-blocking calls when reading/writing from/to your file	194	always use non-blocking calls when reading/writing from/to your file
167	handles.	195	handles.
168		196
169	Example:
170
171	# wait for readability of STDIN, then read a line and disable the watcher	197	Example: wait for readability of STDIN, then read a line and disable the
		198	watcher.
		199
172	my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {	200	my $w; $w = AnyEvent->io (fh => \*STDIN, poll => 'r', cb => sub {
173	chomp (my $input = <STDIN>);	201	chomp (my $input = <STDIN>);
174	warn "read: $input\n";	202	warn "read: $input\n";
175	undef $w;	203	undef $w;
176	});	204	});
…		…
186		214
187	Although the callback might get passed parameters, their value and	215	Although the callback might get passed parameters, their value and
188	presence is undefined and you cannot rely on them. Portable AnyEvent	216	presence is undefined and you cannot rely on them. Portable AnyEvent
189	callbacks cannot use arguments passed to time watcher callbacks.	217	callbacks cannot use arguments passed to time watcher callbacks.
190		218
191	The timer callback will be invoked at most once: if you want a repeating	219	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	220	parameter, C<interval>, as a strictly positive number (> 0), then the
193	and Glib).	221	callback will be invoked regularly at that interval (in fractional
		222	seconds) after the first invocation. If C<interval> is specified with a
		223	false value, then it is treated as if it were missing.
194		224
195	Example:	225	The callback will be rescheduled before invoking the callback, but no
		226	attempt is done to avoid timer drift in most backends, so the interval is
		227	only approximate.
196		228
197	# fire an event after 7.7 seconds	229	Example: fire an event after 7.7 seconds.
		230
198	my $w = AnyEvent->timer (after => 7.7, cb => sub {	231	my $w = AnyEvent->timer (after => 7.7, cb => sub {
199	warn "timeout\n";	232	warn "timeout\n";
200	});	233	});
201		234
202	# to cancel the timer:	235	# to cancel the timer:
203	undef $w;	236	undef $w;
204		237
205	Example 2:
206
207	# fire an event after 0.5 seconds, then roughly every second	238	Example 2: fire an event after 0.5 seconds, then roughly every second.
208	my $w;
209		239
210	my $cb = sub {
211	# cancel the old timer while creating a new one
212	$w = AnyEvent->timer (after => 1, cb => $cb);	240	my $w = AnyEvent->timer (after => 0.5, interval => 1, cb => sub {
		241	warn "timeout\n";
213	};	242	};
214
215	# start the "loop" by creating the first watcher
216	$w = AnyEvent->timer (after => 0.5, cb => $cb);
217		243
218	=head3 TIMING ISSUES	244	=head3 TIMING ISSUES
219		245
220	There are two ways to handle timers: based on real time (relative, "fire	246	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	247	in 10 seconds") and based on wallclock time (absolute, "fire at 12
…		…
243		269
244	This returns the "current wallclock time" as a fractional number of	270	This returns the "current wallclock time" as a fractional number of
245	seconds since the Epoch (the same thing as C<time> or C<Time::HiRes::time>	271	seconds since the Epoch (the same thing as C<time> or C<Time::HiRes::time>
246	return, and the result is guaranteed to be compatible with those).	272	return, and the result is guaranteed to be compatible with those).
247		273
248	It progresses independently of any event loop processing.	274	It progresses independently of any event loop processing, i.e. each call
249		275	will check the system clock, which usually gets updated frequently.
250	In almost all cases (in all cases if you don't care), this is the function
251	to call when you want to know the current time.
252		276
253	=item AnyEvent->now	277	=item AnyEvent->now
254		278
255	This also returns the "current wallclock time", but unlike C<time>, above,	279	This also returns the "current wallclock time", but unlike C<time>, above,
256	this value might change only once per event loop iteration, depending on	280	this value might change only once per event loop iteration, depending on
257	the event loop (most return the same time as C<time>, above). This is the	281	the event loop (most return the same time as C<time>, above). This is the
258	time that AnyEvent timers get scheduled against.	282	time that AnyEvent's timers get scheduled against.
		283
		284	I<In almost all cases (in all cases if you don't care), this is the
		285	function to call when you want to know the current time.>
		286
		287	This function is also often faster then C<< AnyEvent->time >>, and
		288	thus the preferred method if you want some timestamp (for example,
		289	L<AnyEvent::Handle> uses this to update it's activity timeouts).
		290
		291	The rest of this section is only of relevance if you try to be very exact
		292	with your timing, you can skip it without bad conscience.
259		293
260	For a practical example of when these times differ, consider L<Event::Lib>	294	For a practical example of when these times differ, consider L<Event::Lib>
261	and L<EV> and the following set-up:	295	and L<EV> and the following set-up:
262		296
263	The event loop is running and has just invoked one of your callback at	297	The event loop is running and has just invoked one of your callback at
…		…
268		302
269	With L<Event::Lib>, C<< AnyEvent->time >> and C<< AnyEvent->now >> will	303	With L<Event::Lib>, C<< AnyEvent->time >> and C<< AnyEvent->now >> will
270	both return C<501>, because that is the current time, and the timer will	304	both return C<501>, because that is the current time, and the timer will
271	be scheduled to fire at time=504 (C<501> + C<3>).	305	be scheduled to fire at time=504 (C<501> + C<3>).
272		306
273	With L<EV>m C<< AnyEvent->time >> returns C<501> (as that is the current	307	With L<EV>, C<< AnyEvent->time >> returns C<501> (as that is the current
274	time), but C<< AnyEvent->now >> returns C<500>, as that is the time the	308	time), but C<< AnyEvent->now >> returns C<500>, as that is the time the
275	last event processing phase started. With L<EV>, your timer gets scheduled	309	last event processing phase started. With L<EV>, your timer gets scheduled
276	to run at time=503 (C<500> + C<3>).	310	to run at time=503 (C<500> + C<3>).
277		311
278	In one sense, L<Event::Lib> is more exact, as it uses the current time	312	In one sense, L<Event::Lib> is more exact, as it uses the current time
279	regardless of any delays introduced by event processing. However, most	313	regardless of any delays introduced by event processing. However, most
280	callbacks do not expect large delays in processing, so this causes a	314	callbacks do not expect large delays in processing, so this causes a
281	higher drift (and a lot more syscalls to get the current time).	315	higher drift (and a lot more system calls to get the current time).
282		316
283	In another sense, L<EV> is more exact, as your timer will be scheduled at	317	In another sense, L<EV> is more exact, as your timer will be scheduled at
284	the same time, regardless of how long event processing actually took.	318	the same time, regardless of how long event processing actually took.
285		319
286	In either case, if you care (and in most cases, you don't), then you	320	In either case, if you care (and in most cases, you don't), then you
287	can get whatever behaviour you want with any event loop, by taking the	321	can get whatever behaviour you want with any event loop, by taking the
288	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into	322	difference between C<< AnyEvent->time >> and C<< AnyEvent->now >> into
289	account.	323	account.
290		324
		325	=item AnyEvent->now_update
		326
		327	Some event loops (such as L<EV> or L<AnyEvent::Impl::Perl>) cache
		328	the current time for each loop iteration (see the discussion of L<<
		329	AnyEvent->now >>, above).
		330
		331	When a callback runs for a long time (or when the process sleeps), then
		332	this "current" time will differ substantially from the real time, which
		333	might affect timers and time-outs.
		334
		335	When this is the case, you can call this method, which will update the
		336	event loop's idea of "current time".
		337
		338	Note that updating the time I<might> cause some events to be handled.
		339
291	=back	340	=back
292		341
293	=head2 SIGNAL WATCHERS	342	=head2 SIGNAL WATCHERS
294		343
295	You can watch for signals using a signal watcher, C<signal> is the signal	344	You can watch for signals using a signal watcher, C<signal> is the signal
296	I<name> without any C<SIG> prefix, C<cb> is the Perl callback to	345	I<name> in uppercase and without any C<SIG> prefix, C<cb> is the Perl
297	be invoked whenever a signal occurs.	346	callback to be invoked whenever a signal occurs.
298		347
299	Although the callback might get passed parameters, their value and	348	Although the callback might get passed parameters, their value and
300	presence is undefined and you cannot rely on them. Portable AnyEvent	349	presence is undefined and you cannot rely on them. Portable AnyEvent
301	callbacks cannot use arguments passed to signal watcher callbacks.	350	callbacks cannot use arguments passed to signal watcher callbacks.
302		351
…		…
318	=head2 CHILD PROCESS WATCHERS	367	=head2 CHILD PROCESS WATCHERS
319		368
320	You can also watch on a child process exit and catch its exit status.	369	You can also watch on a child process exit and catch its exit status.
321		370
322	The child process is specified by the C<pid> argument (if set to C<0>, it	371	The child process is specified by the C<pid> argument (if set to C<0>, it
323	watches for any child process exit). The watcher will trigger as often	372	watches for any child process exit). The watcher will triggered only when
324	as status change for the child are received. This works by installing a	373	the child process has finished and an exit status is available, not on
325	signal handler for C<SIGCHLD>. The callback will be called with the pid	374	any trace events (stopped/continued).
326	and exit status (as returned by waitpid), so unlike other watcher types,	375
327	you I<can> rely on child watcher callback arguments.	376	The callback will be called with the pid and exit status (as returned by
		377	waitpid), so unlike other watcher types, you I<can> rely on child watcher
		378	callback arguments.
		379
		380	This watcher type works by installing a signal handler for C<SIGCHLD>,
		381	and since it cannot be shared, nothing else should use SIGCHLD or reap
		382	random child processes (waiting for specific child processes, e.g. inside
		383	C<system>, is just fine).
328		384
329	There is a slight catch to child watchers, however: you usually start them	385	There is a slight catch to child watchers, however: you usually start them
330	I<after> the child process was created, and this means the process could	386	I<after> the child process was created, and this means the process could
331	have exited already (and no SIGCHLD will be sent anymore).	387	have exited already (and no SIGCHLD will be sent anymore).
332		388
…		…
338	AnyEvent program, you I<have> to create at least one watcher before you	394	AnyEvent program, you I<have> to create at least one watcher before you
339	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).	395	C<fork> the child (alternatively, you can call C<AnyEvent::detect>).
340		396
341	Example: fork a process and wait for it	397	Example: fork a process and wait for it
342		398
343	my $done = AnyEvent->condvar;	399	my $done = AnyEvent->condvar;
344		400
345	my $pid = fork or exit 5;	401	my $pid = fork or exit 5;
346		402
347	my $w = AnyEvent->child (	403	my $w = AnyEvent->child (
348	pid => $pid,	404	pid => $pid,
349	cb => sub {	405	cb => sub {
350	my ($pid, $status) = @_;	406	my ($pid, $status) = @_;
351	warn "pid $pid exited with status $status";	407	warn "pid $pid exited with status $status";
352	$done->send;	408	$done->send;
353	},	409	},
354	);	410	);
355		411
356	# do something else, then wait for process exit	412	# do something else, then wait for process exit
357	$done->recv;	413	$done->recv;
358		414
359	=head2 CONDITION VARIABLES	415	=head2 CONDITION VARIABLES
360		416
361	If you are familiar with some event loops you will know that all of them	417	If you are familiar with some event loops you will know that all of them
362	require you to run some blocking "loop", "run" or similar function that	418	require you to run some blocking "loop", "run" or similar function that
…		…
368	The instrument to do that is called a "condition variable", so called	424	The instrument to do that is called a "condition variable", so called
369	because they represent a condition that must become true.	425	because they represent a condition that must become true.
370		426
371	Condition variables can be created by calling the C<< AnyEvent->condvar	427	Condition variables can be created by calling the C<< AnyEvent->condvar
372	>> method, usually without arguments. The only argument pair allowed is	428	>> method, usually without arguments. The only argument pair allowed is
		429
373	C<cb>, which specifies a callback to be called when the condition variable	430	C<cb>, which specifies a callback to be called when the condition variable
374	becomes true.	431	becomes true, with the condition variable as the first argument (but not
		432	the results).
375		433
376	After creation, the condition variable is "false" until it becomes "true"	434	After creation, the condition variable is "false" until it becomes "true"
377	by calling the C<send> method (or calling the condition variable as if it	435	by calling the C<send> method (or calling the condition variable as if it
378	were a callback, read about the caveats in the description for the C<<	436	were a callback, read about the caveats in the description for the C<<
379	->send >> method).	437	->send >> method).
…		…
435		493
436	my $done = AnyEvent->condvar;	494	my $done = AnyEvent->condvar;
437	my $delay = AnyEvent->timer (after => 5, cb => $done);	495	my $delay = AnyEvent->timer (after => 5, cb => $done);
438	$done->recv;	496	$done->recv;
439		497
		498	Example: Imagine an API that returns a condvar and doesn't support
		499	callbacks. This is how you make a synchronous call, for example from
		500	the main program:
		501
		502	use AnyEvent::CouchDB;
		503
		504	...
		505
		506	my @info = $couchdb->info->recv;
		507
		508	And this is how you would just ste a callback to be called whenever the
		509	results are available:
		510
		511	$couchdb->info->cb (sub {
		512	my @info = $_[0]->recv;
		513	});
		514
440	=head3 METHODS FOR PRODUCERS	515	=head3 METHODS FOR PRODUCERS
441		516
442	These methods should only be used by the producing side, i.e. the	517	These methods should only be used by the producing side, i.e. the
443	code/module that eventually sends the signal. Note that it is also	518	code/module that eventually sends the signal. Note that it is also
444	the producer side which creates the condvar in most cases, but it isn't	519	the producer side which creates the condvar in most cases, but it isn't
…		…
577	=item $bool = $cv->ready	652	=item $bool = $cv->ready
578		653
579	Returns true when the condition is "true", i.e. whether C<send> or	654	Returns true when the condition is "true", i.e. whether C<send> or
580	C<croak> have been called.	655	C<croak> have been called.
581		656
582	=item $cb = $cv->cb ([new callback])	657	=item $cb = $cv->cb ($cb->($cv))
583		658
584	This is a mutator function that returns the callback set and optionally	659	This is a mutator function that returns the callback set and optionally
585	replaces it before doing so.	660	replaces it before doing so.
586		661
587	The callback will be called when the condition becomes "true", i.e. when	662	The callback will be called when the condition becomes "true", i.e. when
588	C<send> or C<croak> are called. Calling C<recv> inside the callback	663	C<send> or C<croak> are called, with the only argument being the condition
589	or at any later time is guaranteed not to block.	664	variable itself. Calling C<recv> inside the callback or at any later time
		665	is guaranteed not to block.
590		666
591	=back	667	=back
592		668
593	=head1 GLOBAL VARIABLES AND FUNCTIONS	669	=head1 GLOBAL VARIABLES AND FUNCTIONS
594		670
…		…
723	=item L<AnyEvent::Util>	799	=item L<AnyEvent::Util>
724		800
725	Contains various utility functions that replace often-used but blocking	801	Contains various utility functions that replace often-used but blocking
726	functions such as C<inet_aton> by event-/callback-based versions.	802	functions such as C<inet_aton> by event-/callback-based versions.
727		803
728	=item L<AnyEvent::Handle>
729
730	Provide read and write buffers and manages watchers for reads and writes.
731
732	=item L<AnyEvent::Socket>	804	=item L<AnyEvent::Socket>
733		805
734	Provides various utility functions for (internet protocol) sockets,	806	Provides various utility functions for (internet protocol) sockets,
735	addresses and name resolution. Also functions to create non-blocking tcp	807	addresses and name resolution. Also functions to create non-blocking tcp
736	connections or tcp servers, with IPv6 and SRV record support and more.	808	connections or tcp servers, with IPv6 and SRV record support and more.
737		809
		810	=item L<AnyEvent::Handle>
		811
		812	Provide read and write buffers, manages watchers for reads and writes,
		813	supports raw and formatted I/O, I/O queued and fully transparent and
		814	non-blocking SSL/TLS.
		815
738	=item L<AnyEvent::DNS>	816	=item L<AnyEvent::DNS>
739		817
740	Provides rich asynchronous DNS resolver capabilities.	818	Provides rich asynchronous DNS resolver capabilities.
741		819
		820	=item L<AnyEvent::HTTP>
		821
		822	A simple-to-use HTTP library that is capable of making a lot of concurrent
		823	HTTP requests.
		824
742	=item L<AnyEvent::HTTPD>	825	=item L<AnyEvent::HTTPD>
743		826
744	Provides a simple web application server framework.	827	Provides a simple web application server framework.
745		828
746	=item L<AnyEvent::FastPing>	829	=item L<AnyEvent::FastPing>
747		830
748	The fastest ping in the west.	831	The fastest ping in the west.
749		832
		833	=item L<AnyEvent::DBI>
		834
		835	Executes L<DBI> requests asynchronously in a proxy process.
		836
		837	=item L<AnyEvent::AIO>
		838
		839	Truly asynchronous I/O, should be in the toolbox of every event
		840	programmer. AnyEvent::AIO transparently fuses L<IO::AIO> and AnyEvent
		841	together.
		842
		843	=item L<AnyEvent::BDB>
		844
		845	Truly asynchronous Berkeley DB access. AnyEvent::BDB transparently fuses
		846	L<BDB> and AnyEvent together.
		847
		848	=item L<AnyEvent::GPSD>
		849
		850	A non-blocking interface to gpsd, a daemon delivering GPS information.
		851
		852	=item L<AnyEvent::IGS>
		853
		854	A non-blocking interface to the Internet Go Server protocol (used by
		855	L<App::IGS>).
		856
750	=item L<Net::IRC3>	857	=item L<AnyEvent::IRC>
751		858
752	AnyEvent based IRC client module family.	859	AnyEvent based IRC client module family (replacing the older Net::IRC3).
753		860
754	=item L<Net::XMPP2>	861	=item L<Net::XMPP2>
755		862
756	AnyEvent based XMPP (Jabber protocol) module family.	863	AnyEvent based XMPP (Jabber protocol) module family.
757		864
…		…
766		873
767	=item L<Coro>	874	=item L<Coro>
768		875
769	Has special support for AnyEvent via L<Coro::AnyEvent>.	876	Has special support for AnyEvent via L<Coro::AnyEvent>.
770		877
771	=item L<AnyEvent::AIO>, L<IO::AIO>
772
773	Truly asynchronous I/O, should be in the toolbox of every event
774	programmer. AnyEvent::AIO transparently fuses IO::AIO and AnyEvent
775	together.
776
777	=item L<AnyEvent::BDB>, L<BDB>
778
779	Truly asynchronous Berkeley DB access. AnyEvent::AIO transparently fuses
780	IO::AIO and AnyEvent together.
781
782	=item L<IO::Lambda>	878	=item L<IO::Lambda>
783		879
784	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.	880	The lambda approach to I/O - don't ask, look there. Can use AnyEvent.
785		881
786	=back	882	=back
…		…
788	=cut	884	=cut
789		885
790	package AnyEvent;	886	package AnyEvent;
791		887
792	no warnings;	888	no warnings;
793	use strict;	889	use strict qw(vars subs);
794		890
795	use Carp;	891	use Carp;
796		892
797	our $VERSION = '4.05';	893	our $VERSION = 4.351;
798	our $MODEL;	894	our $MODEL;
799		895
800	our $AUTOLOAD;	896	our $AUTOLOAD;
801	our @ISA;	897	our @ISA;
802		898
…		…
834	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza	930	[POE::Kernel:: => AnyEvent::Impl::POE::], # lasciate ogni speranza
835	[Wx:: => AnyEvent::Impl::POE::],	931	[Wx:: => AnyEvent::Impl::POE::],
836	[Prima:: => AnyEvent::Impl::POE::],	932	[Prima:: => AnyEvent::Impl::POE::],
837	);	933	);
838		934
839	our %method = map +($_ => 1), qw(io timer time now signal child condvar one_event DESTROY);	935	our %method = map +($_ => 1),
		936	qw(io timer time now now_update signal child condvar one_event DESTROY);
840		937
841	our @post_detect;	938	our @post_detect;
842		939
843	sub post_detect(&) {	940	sub post_detect(&) {
844	my ($cb) = @_;	941	my ($cb) = @_;
…		…
901	last;	998	last;
902	}	999	}
903	}	1000	}
904		1001
905	$MODEL	1002	$MODEL
906	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.";	1003	or die "No event module selected for AnyEvent and autodetect failed. Install any one of these modules: EV, Event or Glib.\n";
907	}	1004	}
908	}	1005	}
909		1006
		1007	push @{"$MODEL\::ISA"}, "AnyEvent::Base";
		1008
910	unshift @ISA, $MODEL;	1009	unshift @ISA, $MODEL;
911	push @{"$MODEL\::ISA"}, "AnyEvent::Base";	1010
		1011	require AnyEvent::Strict if $ENV{PERL_ANYEVENT_STRICT};
912		1012
913	(shift @post_detect)->() while @post_detect;	1013	(shift @post_detect)->() while @post_detect;
914	}	1014	}
915		1015
916	$MODEL	1016	$MODEL
…		…
926		1026
927	my $class = shift;	1027	my $class = shift;
928	$class->$func (@_);	1028	$class->$func (@_);
929	}	1029	}
930		1030
		1031	# utility function to dup a filehandle. this is used by many backends
		1032	# to support binding more than one watcher per filehandle (they usually
		1033	# allow only one watcher per fd, so we dup it to get a different one).
		1034	sub _dupfh($$$$) {
		1035	my ($poll, $fh, $r, $w) = @_;
		1036
		1037	# cygwin requires the fh mode to be matching, unix doesn't
		1038	my ($rw, $mode) = $poll eq "r" ? ($r, "<")
		1039	: $poll eq "w" ? ($w, ">")
		1040	: Carp::croak "AnyEvent->io requires poll set to either 'r' or 'w'";
		1041
		1042	open my $fh2, "$mode&" . fileno $fh
		1043	or die "cannot dup() filehandle: $!,";
		1044
		1045	# we assume CLOEXEC is already set by perl in all important cases
		1046
		1047	($fh2, $rw)
		1048	}
		1049
931	package AnyEvent::Base;	1050	package AnyEvent::Base;
932		1051
933	# default implementation for now and time	1052	# default implementations for many methods
934		1053
935	use Time::HiRes ();	1054	BEGIN {
		1055	if (eval "use Time::HiRes (); time (); 1") {
		1056	*_time = \&Time::HiRes::time;
		1057	# if (eval "use POSIX (); (POSIX::times())...
		1058	} else {
		1059	*_time = sub { time }; # epic fail
		1060	}
		1061	}
936		1062
937	sub time { Time::HiRes::time }	1063	sub time { _time }
938	sub now { Time::HiRes::time }	1064	sub now { _time }
		1065	sub now_update { }
939		1066
940	# default implementation for ->condvar	1067	# default implementation for ->condvar
941		1068
942	sub condvar {	1069	sub condvar {
943	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::	1070	bless { @_ == 3 ? (_ae_cb => $_[2]) : () }, AnyEvent::CondVar::
944	}	1071	}
945		1072
946	# default implementation for ->signal	1073	# default implementation for ->signal
947		1074
948	our %SIG_CB;	1075	our ($SIGPIPE_R, $SIGPIPE_W, %SIG_CB, %SIG_EV, $SIG_IO);
		1076
		1077	sub _signal_exec {
		1078	sysread $SIGPIPE_R, my $dummy, 4;
		1079
		1080	while (%SIG_EV) {
		1081	for (keys %SIG_EV) {
		1082	delete $SIG_EV{$_};
		1083	$_->() for values %{ $SIG_CB{$_} \|\| {} };
		1084	}
		1085	}
		1086	}
949		1087
950	sub signal {	1088	sub signal {
951	my (undef, %arg) = @_;	1089	my (undef, %arg) = @_;
952		1090
		1091	unless ($SIGPIPE_R) {
		1092	require Fcntl;
		1093
		1094	if (AnyEvent::WIN32) {
		1095	require AnyEvent::Util;
		1096
		1097	($SIGPIPE_R, $SIGPIPE_W) = AnyEvent::Util::portable_pipe ();
		1098	AnyEvent::Util::fh_nonblocking ($SIGPIPE_R) if $SIGPIPE_R;
		1099	AnyEvent::Util::fh_nonblocking ($SIGPIPE_W) if $SIGPIPE_W; # just in case
		1100	} else {
		1101	pipe $SIGPIPE_R, $SIGPIPE_W;
		1102	fcntl $SIGPIPE_R, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_R;
		1103	fcntl $SIGPIPE_W, &Fcntl::F_SETFL, &Fcntl::O_NONBLOCK if $SIGPIPE_W; # just in case
		1104	}
		1105
		1106	$SIGPIPE_R
		1107	or Carp::croak "AnyEvent: unable to create a signal reporting pipe: $!\n";
		1108
		1109	# not strictly required, as $^F is normally 2, but let's make sure...
		1110	fcntl $SIGPIPE_R, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1111	fcntl $SIGPIPE_W, &Fcntl::F_SETFD, &Fcntl::FD_CLOEXEC;
		1112
		1113	$SIG_IO = AnyEvent->io (fh => $SIGPIPE_R, poll => "r", cb => \&_signal_exec);
		1114	}
		1115
953	my $signal = uc $arg{signal}	1116	my $signal = uc $arg{signal}
954	or Carp::croak "required option 'signal' is missing";	1117	or Carp::croak "required option 'signal' is missing";
955		1118
956	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};	1119	$SIG_CB{$signal}{$arg{cb}} = $arg{cb};
957	$SIG{$signal} \|\|= sub {	1120	$SIG{$signal} \|\|= sub {
958	$_->() for values %{ $SIG_CB{$signal} \|\| {} };	1121	local $!;
		1122	syswrite $SIGPIPE_W, "\x00", 1 unless %SIG_EV;
		1123	undef $SIG_EV{$signal};
959	};	1124	};
960		1125
961	bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"	1126	bless [$signal, $arg{cb}], "AnyEvent::Base::Signal"
962	}	1127	}
963		1128
964	sub AnyEvent::Base::Signal::DESTROY {	1129	sub AnyEvent::Base::Signal::DESTROY {
965	my ($signal, $cb) = @{$_[0]};	1130	my ($signal, $cb) = @{$_[0]};
966		1131
967	delete $SIG_CB{$signal}{$cb};	1132	delete $SIG_CB{$signal}{$cb};
968		1133
969	$SIG{$signal} = 'DEFAULT' unless keys %{ $SIG_CB{$signal} };	1134	delete $SIG{$signal} unless keys %{ $SIG_CB{$signal} };
970	}	1135	}
971		1136
972	# default implementation for ->child	1137	# default implementation for ->child
973		1138
974	our %PID_CB;	1139	our %PID_CB;
…		…
1082		1247
1083	# undocumented/compatibility with pre-3.4	1248	# undocumented/compatibility with pre-3.4
1084	*broadcast = \&send;	1249	*broadcast = \&send;
1085	*wait = \&_wait;	1250	*wait = \&_wait;
1086		1251
		1252	=head1 ERROR AND EXCEPTION HANDLING
		1253
		1254	In general, AnyEvent does not do any error handling - it relies on the
		1255	caller to do that if required. The L<AnyEvent::Strict> module (see also
		1256	the C<PERL_ANYEVENT_STRICT> environment variable, below) provides strict
		1257	checking of all AnyEvent methods, however, which is highly useful during
		1258	development.
		1259
		1260	As for exception handling (i.e. runtime errors and exceptions thrown while
		1261	executing a callback), this is not only highly event-loop specific, but
		1262	also not in any way wrapped by this module, as this is the job of the main
		1263	program.
		1264
		1265	The pure perl event loop simply re-throws the exception (usually
		1266	within C<< condvar->recv >>), the L<Event> and L<EV> modules call C<<
		1267	$Event/EV::DIED->() >>, L<Glib> uses C<< install_exception_handler >> and
		1268	so on.
		1269
		1270	=head1 ENVIRONMENT VARIABLES
		1271
		1272	The following environment variables are used by this module or its
		1273	submodules:
		1274
		1275	=over 4
		1276
		1277	=item C<PERL_ANYEVENT_VERBOSE>
		1278
		1279	By default, AnyEvent will be completely silent except in fatal
		1280	conditions. You can set this environment variable to make AnyEvent more
		1281	talkative.
		1282
		1283	When set to C<1> or higher, causes AnyEvent to warn about unexpected
		1284	conditions, such as not being able to load the event model specified by
		1285	C<PERL_ANYEVENT_MODEL>.
		1286
		1287	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
		1288	model it chooses.
		1289
		1290	=item C<PERL_ANYEVENT_STRICT>
		1291
		1292	AnyEvent does not do much argument checking by default, as thorough
		1293	argument checking is very costly. Setting this variable to a true value
		1294	will cause AnyEvent to load C<AnyEvent::Strict> and then to thoroughly
		1295	check the arguments passed to most method calls. If it finds any problems
		1296	it will croak.
		1297
		1298	In other words, enables "strict" mode.
		1299
		1300	Unlike C<use strict>, it is definitely recommended ot keep it off in
		1301	production. Keeping C<PERL_ANYEVENT_STRICT=1> in your environment while
		1302	developing programs can be very useful, however.
		1303
		1304	=item C<PERL_ANYEVENT_MODEL>
		1305
		1306	This can be used to specify the event model to be used by AnyEvent, before
		1307	auto detection and -probing kicks in. It must be a string consisting
		1308	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
		1309	and the resulting module name is loaded and if the load was successful,
		1310	used as event model. If it fails to load AnyEvent will proceed with
		1311	auto detection and -probing.
		1312
		1313	This functionality might change in future versions.
		1314
		1315	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
		1316	could start your program like this:
		1317
		1318	PERL_ANYEVENT_MODEL=Perl perl ...
		1319
		1320	=item C<PERL_ANYEVENT_PROTOCOLS>
		1321
		1322	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
		1323	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
		1324	of auto probing).
		1325
		1326	Must be set to a comma-separated list of protocols or address families,
		1327	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
		1328	used, and preference will be given to protocols mentioned earlier in the
		1329	list.
		1330
		1331	This variable can effectively be used for denial-of-service attacks
		1332	against local programs (e.g. when setuid), although the impact is likely
		1333	small, as the program has to handle conenction and other failures anyways.
		1334
		1335	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
		1336	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
		1337	- only support IPv4, never try to resolve or contact IPv6
		1338	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
		1339	IPv6, but prefer IPv6 over IPv4.
		1340
		1341	=item C<PERL_ANYEVENT_EDNS0>
		1342
		1343	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
		1344	for DNS. This extension is generally useful to reduce DNS traffic, but
		1345	some (broken) firewalls drop such DNS packets, which is why it is off by
		1346	default.
		1347
		1348	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
		1349	EDNS0 in its DNS requests.
		1350
		1351	=item C<PERL_ANYEVENT_MAX_FORKS>
		1352
		1353	The maximum number of child processes that C<AnyEvent::Util::fork_call>
		1354	will create in parallel.
		1355
		1356	=back
		1357
1087	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE	1358	=head1 SUPPLYING YOUR OWN EVENT MODEL INTERFACE
1088		1359
1089	This is an advanced topic that you do not normally need to use AnyEvent in	1360	This is an advanced topic that you do not normally need to use AnyEvent in
1090	a module. This section is only of use to event loop authors who want to	1361	a module. This section is only of use to event loop authors who want to
1091	provide AnyEvent compatibility.	1362	provide AnyEvent compatibility.
…		…
1124		1395
1125	I<rxvt-unicode> also cheats a bit by not providing blocking access to	1396	I<rxvt-unicode> also cheats a bit by not providing blocking access to
1126	condition variables: code blocking while waiting for a condition will	1397	condition variables: code blocking while waiting for a condition will
1127	C<die>. This still works with most modules/usages, and blocking calls must	1398	C<die>. This still works with most modules/usages, and blocking calls must
1128	not be done in an interactive application, so it makes sense.	1399	not be done in an interactive application, so it makes sense.
1129
1130	=head1 ENVIRONMENT VARIABLES
1131
1132	The following environment variables are used by this module:
1133
1134	=over 4
1135
1136	=item C<PERL_ANYEVENT_VERBOSE>
1137
1138	By default, AnyEvent will be completely silent except in fatal
1139	conditions. You can set this environment variable to make AnyEvent more
1140	talkative.
1141
1142	When set to C<1> or higher, causes AnyEvent to warn about unexpected
1143	conditions, such as not being able to load the event model specified by
1144	C<PERL_ANYEVENT_MODEL>.
1145
1146	When set to C<2> or higher, cause AnyEvent to report to STDERR which event
1147	model it chooses.
1148
1149	=item C<PERL_ANYEVENT_MODEL>
1150
1151	This can be used to specify the event model to be used by AnyEvent, before
1152	auto detection and -probing kicks in. It must be a string consisting
1153	entirely of ASCII letters. The string C<AnyEvent::Impl::> gets prepended
1154	and the resulting module name is loaded and if the load was successful,
1155	used as event model. If it fails to load AnyEvent will proceed with
1156	auto detection and -probing.
1157
1158	This functionality might change in future versions.
1159
1160	For example, to force the pure perl model (L<AnyEvent::Impl::Perl>) you
1161	could start your program like this:
1162
1163	PERL_ANYEVENT_MODEL=Perl perl ...
1164
1165	=item C<PERL_ANYEVENT_PROTOCOLS>
1166
1167	Used by both L<AnyEvent::DNS> and L<AnyEvent::Socket> to determine preferences
1168	for IPv4 or IPv6. The default is unspecified (and might change, or be the result
1169	of auto probing).
1170
1171	Must be set to a comma-separated list of protocols or address families,
1172	current supported: C<ipv4> and C<ipv6>. Only protocols mentioned will be
1173	used, and preference will be given to protocols mentioned earlier in the
1174	list.
1175
1176	This variable can effectively be used for denial-of-service attacks
1177	against local programs (e.g. when setuid), although the impact is likely
1178	small, as the program has to handle connection errors already-
1179
1180	Examples: C<PERL_ANYEVENT_PROTOCOLS=ipv4,ipv6> - prefer IPv4 over IPv6,
1181	but support both and try to use both. C<PERL_ANYEVENT_PROTOCOLS=ipv4>
1182	- only support IPv4, never try to resolve or contact IPv6
1183	addresses. C<PERL_ANYEVENT_PROTOCOLS=ipv6,ipv4> support either IPv4 or
1184	IPv6, but prefer IPv6 over IPv4.
1185
1186	=item C<PERL_ANYEVENT_EDNS0>
1187
1188	Used by L<AnyEvent::DNS> to decide whether to use the EDNS0 extension
1189	for DNS. This extension is generally useful to reduce DNS traffic, but
1190	some (broken) firewalls drop such DNS packets, which is why it is off by
1191	default.
1192
1193	Setting this variable to C<1> will cause L<AnyEvent::DNS> to announce
1194	EDNS0 in its DNS requests.
1195
1196	=item C<PERL_ANYEVENT_MAX_FORKS>
1197
1198	The maximum number of child processes that C<AnyEvent::Util::fork_call>
1199	will create in parallel.
1200
1201	=back
1202		1400
1203	=head1 EXAMPLE PROGRAM	1401	=head1 EXAMPLE PROGRAM
1204		1402
1205	The following program uses an I/O watcher to read data from STDIN, a timer	1403	The following program uses an I/O watcher to read data from STDIN, a timer
1206	to display a message once per second, and a condition variable to quit the	1404	to display a message once per second, and a condition variable to quit the
…		…
1400	watcher.	1598	watcher.
1401		1599
1402	=head3 Results	1600	=head3 Results
1403		1601
1404	name watchers bytes create invoke destroy comment	1602	name watchers bytes create invoke destroy comment
1405	EV/EV 400000 244 0.56 0.46 0.31 EV native interface	1603	EV/EV 400000 224 0.47 0.35 0.27 EV native interface
1406	EV/Any 100000 244 2.50 0.46 0.29 EV + AnyEvent watchers	1604	EV/Any 100000 224 2.88 0.34 0.27 EV + AnyEvent watchers
1407	CoroEV/Any 100000 244 2.49 0.44 0.29 coroutines + Coro::Signal	1605	CoroEV/Any 100000 224 2.85 0.35 0.28 coroutines + Coro::Signal
1408	Perl/Any 100000 513 4.92 0.87 1.12 pure perl implementation	1606	Perl/Any 100000 452 4.13 0.73 0.95 pure perl implementation
1409	Event/Event 16000 516 31.88 31.30 0.85 Event native interface	1607	Event/Event 16000 517 32.20 31.80 0.81 Event native interface
1410	Event/Any 16000 590 35.75 31.42 1.08 Event + AnyEvent watchers	1608	Event/Any 16000 590 35.85 31.55 1.06 Event + AnyEvent watchers
1411	Glib/Any 16000 1357 98.22 12.41 54.00 quadratic behaviour	1609	Glib/Any 16000 1357 102.33 12.31 51.00 quadratic behaviour
1412	Tk/Any 2000 1860 26.97 67.98 14.00 SEGV with >> 2000 watchers	1610	Tk/Any 2000 1860 27.20 66.31 14.00 SEGV with >> 2000 watchers
1413	POE/Event 2000 6644 108.64 736.02 14.73 via POE::Loop::Event	1611	POE/Event 2000 6328 109.99 751.67 14.02 via POE::Loop::Event
1414	POE/Select 2000 6343 94.13 809.12 565.96 via POE::Loop::Select	1612	POE/Select 2000 6027 94.54 809.13 579.80 via POE::Loop::Select
1415		1613
1416	=head3 Discussion	1614	=head3 Discussion
1417		1615
1418	The benchmark does I<not> measure scalability of the event loop very	1616	The benchmark does I<not> measure scalability of the event loop very
1419	well. For example, a select-based event loop (such as the pure perl one)	1617	well. For example, a select-based event loop (such as the pure perl one)
…		…
1621	watchers, as the management overhead dominates.	1819	watchers, as the management overhead dominates.
1622		1820
1623	=back	1821	=back
1624		1822
1625		1823
		1824	=head1 SIGNALS
		1825
		1826	AnyEvent currently installs handlers for these signals:
		1827
		1828	=over 4
		1829
		1830	=item SIGCHLD
		1831
		1832	A handler for C<SIGCHLD> is installed by AnyEvent's child watcher
		1833	emulation for event loops that do not support them natively. Also, some
		1834	event loops install a similar handler.
		1835
		1836	=item SIGPIPE
		1837
		1838	A no-op handler is installed for C<SIGPIPE> when C<$SIG{PIPE}> is C<undef>
		1839	when AnyEvent gets loaded.
		1840
		1841	The rationale for this is that AnyEvent users usually do not really depend
		1842	on SIGPIPE delivery (which is purely an optimisation for shell use, or
		1843	badly-written programs), but C<SIGPIPE> can cause spurious and rare
		1844	program exits as a lot of people do not expect C<SIGPIPE> when writing to
		1845	some random socket.
		1846
		1847	The rationale for installing a no-op handler as opposed to ignoring it is
		1848	that this way, the handler will be restored to defaults on exec.
		1849
		1850	Feel free to install your own handler, or reset it to defaults.
		1851
		1852	=back
		1853
		1854	=cut
		1855
		1856	$SIG{PIPE} = sub { }
		1857	unless defined $SIG{PIPE};
		1858
		1859
1626	=head1 FORK	1860	=head1 FORK
1627		1861
1628	Most event libraries are not fork-safe. The ones who are usually are	1862	Most event libraries are not fork-safe. The ones who are usually are
1629	because they rely on inefficient but fork-safe C<select> or C<poll>	1863	because they rely on inefficient but fork-safe C<select> or C<poll>
1630	calls. Only L<EV> is fully fork-aware.	1864	calls. Only L<EV> is fully fork-aware.
…		…
1643	specified in the variable.	1877	specified in the variable.
1644		1878
1645	You can make AnyEvent completely ignore this variable by deleting it	1879	You can make AnyEvent completely ignore this variable by deleting it
1646	before the first watcher gets created, e.g. with a C<BEGIN> block:	1880	before the first watcher gets created, e.g. with a C<BEGIN> block:
1647		1881
1648	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }	1882	BEGIN { delete $ENV{PERL_ANYEVENT_MODEL} }
1649		1883
1650	use AnyEvent;	1884	use AnyEvent;
1651		1885
1652	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can	1886	Similar considerations apply to $ENV{PERL_ANYEVENT_VERBOSE}, as that can
1653	be used to probe what backend is used and gain other information (which is	1887	be used to probe what backend is used and gain other information (which is
1654	probably even less useful to an attacker than PERL_ANYEVENT_MODEL).	1888	probably even less useful to an attacker than PERL_ANYEVENT_MODEL), and
		1889	$ENV{PERL_ANYEGENT_STRICT}.
		1890
		1891
		1892	=head1 BUGS
		1893
		1894	Perl 5.8 has numerous memleaks that sometimes hit this module and are hard
		1895	to work around. If you suffer from memleaks, first upgrade to Perl 5.10
		1896	and check wether the leaks still show up. (Perl 5.10.0 has other annoying
		1897	memleaks, such as leaking on C<map> and C<grep> but it is usually not as
		1898	pronounced).
1655		1899
1656		1900
1657	=head1 SEE ALSO	1901	=head1 SEE ALSO
1658		1902
1659	Utility functions: L<AnyEvent::Util>.	1903	Utility functions: L<AnyEvent::Util>.
…		…
1676	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.	1920	Nontrivial usage examples: L<Net::FCP>, L<Net::XMPP2>, L<AnyEvent::DNS>.
1677		1921
1678		1922
1679	=head1 AUTHOR	1923	=head1 AUTHOR
1680		1924
1681	Marc Lehmann <schmorp@schmorp.de>	1925	Marc Lehmann <schmorp@schmorp.de>
1682	http://home.schmorp.de/	1926	http://home.schmorp.de/
1683		1927
1684	=cut	1928	=cut
1685		1929
1686	1	1930	1
1687		1931

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Comparing AnyEvent/lib/AnyEvent.pm (file contents): Revision 1.143 by root, Wed May 28 23:57:38 2008 UTC vs. Revision 1.205 by root, Sun Apr 19 12:09:46 2009 UTC

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Comparing AnyEvent/lib/AnyEvent.pm (file contents):
Revision 1.143 by root, Wed May 28 23:57:38 2008 UTC vs.
Revision 1.205 by root, Sun Apr 19 12:09:46 2009 UTC