[ViewVC] Diff of: cvs/EV/EV.pm

Comparing EV/EV.pm (file contents):
Revision 1.51 by root, Sat Nov 24 16:12:37 2007 UTC vs.
Revision 1.136 by root, Thu Jan 19 17:55:23 2012 UTC

…		…
2		2
3	EV - perl interface to libev, a high performance full-featured event loop	3	EV - perl interface to libev, a high performance full-featured event loop
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	use EV;	7	use EV;
		8
		9	# TIMERS
		10
		11	my $w = EV::timer 2, 0, sub {
		12	warn "is called after 2s";
		13	};
		14
		15	my $w = EV::timer 2, 2, sub {
		16	warn "is called roughly every 2s (repeat = 2)";
		17	};
		18
		19	undef $w; # destroy event watcher again
		20
		21	my $w = EV::periodic 0, 60, 0, sub {
		22	warn "is called every minute, on the minute, exactly";
		23	};
		24
		25	# IO
		26
		27	my $w = EV::io *STDIN, EV::READ, sub {
		28	my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
		29	warn "stdin is readable, you entered: ", <STDIN>;
		30	};
		31
		32	# SIGNALS
		33
		34	my $w = EV::signal 'QUIT', sub {
		35	warn "sigquit received\n";
		36	};
		37
		38	# CHILD/PID STATUS CHANGES
8		39
9	# TIMERS	40	my $w = EV::child 666, 0, sub {
		41	my ($w, $revents) = @_;
		42	my $status = $w->rstatus;
		43	};
10		44
11	my $w = EV::timer 2, 0, sub {	45	# STAT CHANGES
12	warn "is called after 2s";	46	my $w = EV::stat "/etc/passwd", 10, sub {
13	};
14
15	my $w = EV::timer 2, 2, sub {
16	warn "is called roughly every 2s (repeat = 2)";
17	};
18
19	undef $w; # destroy event watcher again
20
21	my $w = EV::periodic 0, 60, 0, sub {
22	warn "is called every minute, on the minute, exactly";
23	};
24
25	# IO
26
27	my $w = EV::io *STDIN, EV::READ, sub {
28	my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
29	warn "stdin is readable, you entered: ", <STDIN>;
30	};
31
32	# SIGNALS
33
34	my $w = EV::signal 'QUIT', sub {
35	warn "sigquit received\n";
36	};
37
38	# CHILD/PID STATUS CHANGES
39
40	my $w = EV::child 666, sub {
41	my ($w, $revents) = @_;	47	my ($w, $revents) = @_;
42	my $status = $w->rstatus;	48	warn $w->path, " has changed somehow.\n";
43	};	49	};
44		50
45	# MAINLOOP	51	# MAINLOOP
46	EV::loop; # loop until EV::unloop is called or all watchers stop	52	EV::run; # loop until EV::unloop is called or all watchers stop
47	EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled	53	EV::run EV::RUN_ONCE; # block until at least one event could be handled
48	EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block	54	EV::run EV::RUN_NOWAIT; # try to handle same events, but do not block
		55
		56	=head1 BEFORE YOU START USING THIS MODULE
		57
		58	If you only need timer, I/O, signal, child and idle watchers and not the
		59	advanced functionality of this module, consider using L<AnyEvent> instead,
		60	specifically the simplified API described in L<AE>.
		61
		62	When used with EV as backend, the L<AE> API is as fast as the native L<EV>
		63	API, but your programs/modules will still run with many other event loops.
49		64
50	=head1 DESCRIPTION	65	=head1 DESCRIPTION
51		66
52	This module provides an interface to libev	67	This module provides an interface to libev
53	(L<http://software.schmorp.de/pkg/libev.html>).	68	(L<http://software.schmorp.de/pkg/libev.html>). While the documentation
		69	below is comprehensive, one might also consult the documentation of
		70	libev itself (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod> or
		71	F<perldoc EV::libev>) for more subtle details on watcher semantics or some
		72	discussion on the available backends, or how to force a specific backend
		73	with C<LIBEV_FLAGS>, or just about in any case because it has much more
		74	detailed information.
		75
		76	This module is very fast and scalable. It is actually so fast that you
		77	can use it through the L<AnyEvent> module, stay portable to other event
		78	loops (if you don't rely on any watcher types not available through it)
		79	and still be faster than with any other event loop currently supported in
		80	Perl.
		81
		82	=head2 PORTING FROM EV 3.X to 4.X
		83
		84	EV version 4 introduces a number of incompatible changes summarised
		85	here. According to the depreciation strategy used by libev, there is a
		86	compatibility layer in place so programs should continue to run unchanged
		87	(the XS interface lacks this layer, so programs using that one need to be
		88	updated).
		89
		90	This compatibility layer will be switched off in some future release.
		91
		92	All changes relevant to Perl are renames of symbols, functions and
		93	methods:
		94
		95	EV::loop => EV::run
		96	EV::LOOP_NONBLOCK => EV::RUN_NOWAIT
		97	EV::LOOP_ONESHOT => EV::RUN_ONCE
		98
		99	EV::unloop => EV::break
		100	EV::UNLOOP_CANCEL => EV::BREAK_CANCEL
		101	EV::UNLOOP_ONE => EV::BREAK_ONE
		102	EV::UNLOOP_ALL => EV::BREAK_ALL
		103
		104	EV::TIMEOUT => EV::TIMER
		105
		106	EV::loop_count => EV::iteration
		107	EV::loop_depth => EV::depth
		108	EV::loop_verify => EV::verify
		109
		110	The loop object methods corresponding to the functions above have been
		111	similarly renamed.
		112
		113	=head2 MODULE EXPORTS
		114
		115	This module does not export any symbols.
54		116
55	=cut	117	=cut
56		118
57	package EV;	119	package EV;
58		120
59	use strict;	121	use common::sense;
60		122
61	BEGIN {	123	BEGIN {
62	our $VERSION = '1.3';	124	our $VERSION = '4.10';
63	use XSLoader;	125	use XSLoader;
64	XSLoader::load "EV", $VERSION;	126	XSLoader::load "EV", $VERSION;
65	}	127	}
66		128
67	@EV::IO::ISA =	129	@EV::IO::ISA =
68	@EV::Timer::ISA =	130	@EV::Timer::ISA =
69	@EV::Periodic::ISA =	131	@EV::Periodic::ISA =
70	@EV::Signal::ISA =	132	@EV::Signal::ISA =
		133	@EV::Child::ISA =
		134	@EV::Stat::ISA =
71	@EV::Idle::ISA =	135	@EV::Idle::ISA =
72	@EV::Prepare::ISA =	136	@EV::Prepare::ISA =
73	@EV::Check::ISA =	137	@EV::Check::ISA =
74	@EV::Child::ISA = "EV::Watcher";	138	@EV::Embed::ISA =
		139	@EV::Fork::ISA =
		140	@EV::Async::ISA =
		141	"EV::Watcher";
		142
		143	@EV::Loop::Default::ISA = "EV::Loop";
		144
		145	=head1 EVENT LOOPS
		146
		147	EV supports multiple event loops: There is a single "default event loop"
		148	that can handle everything including signals and child watchers, and any
		149	number of "dynamic event loops" that can use different backends (with
		150	various limitations), but no child and signal watchers.
		151
		152	You do not have to do anything to create the default event loop: When
		153	the module is loaded a suitable backend is selected on the premise of
		154	selecting a working backend (which for example rules out kqueue on most
		155	BSDs). Modules should, unless they have "special needs" always use the
		156	default loop as this is fastest (perl-wise), best supported by other
		157	modules (e.g. AnyEvent or Coro) and most portable event loop.
		158
		159	For specific programs you can create additional event loops dynamically.
		160
		161	If you want to take advantage of kqueue (which often works properly for
		162	sockets only) even though the default loop doesn't enable it, you can
		163	I<embed> a kqueue loop into the default loop: running the default loop
		164	will then also service the kqueue loop to some extent. See the example in
		165	the section about embed watchers for an example on how to achieve that.
		166
		167	=over 4
		168
		169	=item $loop = new EV::Loop [$flags]
		170
		171	Create a new event loop as per the specified flags. Please refer to
		172	the C<ev_loop_new ()> function description in the libev documentation
		173	(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>,
		174	or locally-installed as F<EV::libev> manpage) for more info.
		175
		176	The loop will automatically be destroyed when it is no longer referenced
		177	by any watcher and the loop object goes out of scope.
		178
		179	If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK>
		180	is recommended, as only the default event loop is protected by this
		181	module. If you I<are> embedding this loop in the default loop, this is not
		182	necessary, as C<EV::embed> automatically does the right thing on fork.
		183
		184	=item $loop->loop_fork
		185
		186	Must be called after a fork in the child, before entering or continuing
		187	the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
		188	this function automatically, at some performance loss (refer to the libev
		189	documentation).
		190
		191	=item $loop->verify
		192
		193	Calls C<ev_verify> to make internal consistency checks (for debugging
		194	libev) and abort the program if any data structures were found to be
		195	corrupted.
		196
		197	=item $loop = EV::default_loop [$flags]
		198
		199	Return the default loop (which is a singleton object). Since this module
		200	already creates the default loop with default flags, specifying flags here
		201	will not have any effect unless you destroy the default loop first, which
		202	isn't supported. So in short: don't do it, and if you break it, you get to
		203	keep the pieces.
		204
		205	=back
		206
75		207
76	=head1 BASIC INTERFACE	208	=head1 BASIC INTERFACE
77		209
78	=over 4	210	=over 4
79		211
80	=item $EV::DIED	212	=item $EV::DIED
81		213
82	Must contain a reference to a function that is called when a callback	214	Must contain a reference to a function that is called when a callback
83	throws an exception (with $@ containing thr error). The default prints an	215	throws an exception (with $@ containing the error). The default prints an
84	informative message and continues.	216	informative message and continues.
85		217
86	If this callback throws an exception it will be silently ignored.	218	If this callback throws an exception it will be silently ignored.
87		219
		220	=item $flags = EV::supported_backends
		221
		222	=item $flags = EV::recommended_backends
		223
		224	=item $flags = EV::embeddable_backends
		225
		226	Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this
		227	instance of EV, the set of recommended backends (supposed to be good) for
		228	this platform and the set of embeddable backends (see EMBED WATCHERS).
		229
		230	=item EV::sleep $seconds
		231
		232	Block the process for the given number of (fractional) seconds.
		233
88	=item $time = EV::time	234	=item $time = EV::time
89		235
90	Returns the current time in (fractional) seconds since the epoch.	236	Returns the current time in (fractional) seconds since the epoch.
91		237
92	=item $time = EV::now	238	=item $time = EV::now
93		239
		240	=item $time = $loop->now
		241
94	Returns the time the last event loop iteration has been started. This	242	Returns the time the last event loop iteration has been started. This
95	is the time that (relative) timers are based on, and refering to it is	243	is the time that (relative) timers are based on, and referring to it is
96	usually faster then calling EV::time.	244	usually faster then calling EV::time.
97		245
98	=item $method = EV::method	246	=item EV::now_update
99		247
		248	=item $loop->now_update
		249
		250	Establishes the current time by querying the kernel, updating the time
		251	returned by C<EV::now> in the progress. This is a costly operation and
		252	is usually done automatically within C<EV::loop>.
		253
		254	This function is rarely useful, but when some event callback runs for a
		255	very long time without entering the event loop, updating libev's idea of
		256	the current time is a good idea.
		257
		258	=item EV::suspend
		259
		260	=item $loop->suspend
		261
		262	=item EV::resume
		263
		264	=item $loop->resume
		265
		266	These two functions suspend and resume a loop, for use when the loop is
		267	not used for a while and timeouts should not be processed.
		268
		269	A typical use case would be an interactive program such as a game: When
		270	the user presses C<^Z> to suspend the game and resumes it an hour later it
		271	would be best to handle timeouts as if no time had actually passed while
		272	the program was suspended. This can be achieved by calling C<suspend>
		273	in your C<SIGTSTP> handler, sending yourself a C<SIGSTOP> and calling
		274	C<resume> directly afterwards to resume timer processing.
		275
		276	Effectively, all C<timer> watchers will be delayed by the time spend
		277	between C<suspend> and C<resume>, and all C<periodic> watchers
		278	will be rescheduled (that is, they will lose any events that would have
		279	occured while suspended).
		280
		281	After calling C<suspend> you B<must not> call I<any> function on the given
		282	loop other than C<resume>, and you B<must not> call C<resume>
		283	without a previous call to C<suspend>.
		284
		285	Calling C<suspend>/C<resume> has the side effect of updating the event
		286	loop time (see C<now_update>).
		287
		288	=item $backend = EV::backend
		289
		290	=item $backend = $loop->backend
		291
100	Returns an integer describing the backend used by libev (EV::METHOD_SELECT	292	Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
101	or EV::METHOD_EPOLL).	293	or EV::BACKEND_EPOLL).
102		294
103	=item EV::loop [$flags]	295	=item EV::run [$flags]
		296
		297	=item $loop->run ([$flags])
104		298
105	Begin checking for events and calling callbacks. It returns when a	299	Begin checking for events and calling callbacks. It returns when a
106	callback calls EV::unloop.	300	callback calls EV::unloop.
107		301
108	The $flags argument can be one of the following:	302	The $flags argument can be one of the following:
109		303
110	0 as above	304	0 as above
111	EV::LOOP_ONESHOT block at most once (wait, but do not loop)	305	EV::RUN_ONCE block at most once (wait, but do not loop)
112	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)	306	EV::RUN_NOWAIT do not block at all (fetch/handle events but do not wait)
113		307
114	=item EV::unloop [$how]	308	=item EV::break [$how]
115		309
		310	=item $loop->break ([$how])
		311
116	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the	312	When called with no arguments or an argument of EV::BREAK_ONE, makes the
117	innermost call to EV::loop return.	313	innermost call to EV::loop return.
118		314
119	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as	315	When called with an argument of EV::BREAK_ALL, all calls to EV::loop will
120	fast as possible.	316	return as fast as possible.
		317
		318	When called with an argument of EV::BREAK_CANCEL, any pending break will
		319	be cancelled.
		320
		321	=item $count = EV::iteration
		322
		323	=item $count = $loop->iteration
		324
		325	Return the number of times the event loop has polled for new
		326	events. Sometimes useful as a generation counter.
121		327
122	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)	328	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
		329
		330	=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
123		331
124	This function rolls together an I/O and a timer watcher for a single	332	This function rolls together an I/O and a timer watcher for a single
125	one-shot event without the need for managing a watcher object.	333	one-shot event without the need for managing a watcher object.
126		334
127	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>	335	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>
…		…
133	If timeout is C<undef> or negative, then there will be no	341	If timeout is C<undef> or negative, then there will be no
134	timeout. Otherwise a EV::timer with this value will be started.	342	timeout. Otherwise a EV::timer with this value will be started.
135		343
136	When an error occurs or either the timeout or I/O watcher triggers, then	344	When an error occurs or either the timeout or I/O watcher triggers, then
137	the callback will be called with the received event set (in general	345	the callback will be called with the received event set (in general
138	you can expect it to be a combination of C<EV:ERROR>, C<EV::READ>,	346	you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
139	C<EV::WRITE> and C<EV::TIMEOUT>).	347	C<EV::WRITE> and C<EV::TIMER>).
140		348
141	EV::once doesn't return anything: the watchers stay active till either	349	EV::once doesn't return anything: the watchers stay active till either
142	of them triggers, then they will be stopped and freed, and the callback	350	of them triggers, then they will be stopped and freed, and the callback
143	invoked.	351	invoked.
144		352
145	=back	353	=item EV::feed_fd_event $fd, $revents
146		354
147	=head2 WATCHER	355	=item $loop->feed_fd_event ($fd, $revents)
		356
		357	Feed an event on a file descriptor into EV. EV will react to this call as
		358	if the readyness notifications specified by C<$revents> (a combination of
		359	C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
		360
		361	=item EV::feed_signal_event $signal
		362
		363	Feed a signal event into the default loop. EV will react to this call as
		364	if the signal specified by C<$signal> had occured.
		365
		366	=item EV::feed_signal $signal
		367
		368	Feed a signal event into EV - unlike C<EV::feed_signal_event>, this works
		369	regardless of which loop has registered the signal, and is mainly useful
		370	fro custom signal implementations.
		371
		372	=item EV::set_io_collect_interval $time
		373
		374	=item $loop->set_io_collect_interval ($time)
		375
		376	=item EV::set_timeout_collect_interval $time
		377
		378	=item $loop->set_timeout_collect_interval ($time)
		379
		380	These advanced functions set the minimum block interval when polling for I/O events and the minimum
		381	wait interval for timer events. See the libev documentation at
		382	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP>
		383	(locally installed as F<EV::libev>) for a more detailed discussion.
		384
		385	=item $count = EV::pending_count
		386
		387	=item $count = $loop->pending_count
		388
		389	Returns the number of currently pending watchers.
		390
		391	=item EV::invoke_pending
		392
		393	=item $loop->invoke_pending
		394
		395	Invoke all currently pending watchers.
		396
		397	=back
		398
		399
		400	=head1 WATCHER OBJECTS
148		401
149	A watcher is an object that gets created to record your interest in some	402	A watcher is an object that gets created to record your interest in some
150	event. For instance, if you want to wait for STDIN to become readable, you	403	event. For instance, if you want to wait for STDIN to become readable, you
151	would create an EV::io watcher for that:	404	would create an EV::io watcher for that:
152		405
153	my $watcher = EV::io *STDIN, EV::READ, sub {	406	my $watcher = EV::io *STDIN, EV::READ, sub {
154	my ($watcher, $revents) = @_;	407	my ($watcher, $revents) = @_;
155	warn "yeah, STDIN should not be readable without blocking!\n"	408	warn "yeah, STDIN should now be readable without blocking!\n"
156	};	409	};
157		410
158	All watchers can be active (waiting for events) or inactive (paused). Only	411	All watchers can be active (waiting for events) or inactive (paused). Only
159	active watchers will have their callbacks invoked. All callbacks will be	412	active watchers will have their callbacks invoked. All callbacks will be
160	called with at least two arguments: the watcher and a bitmask of received	413	called with at least two arguments: the watcher and a bitmask of received
161	events.	414	events.
162		415
163	Each watcher type has its associated bit in revents, so you can use the	416	Each watcher type has its associated bit in revents, so you can use the
164	same callback for multiple watchers. The event mask is named after the	417	same callback for multiple watchers. The event mask is named after the
165	type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,	418	type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
166	EV::periodic sets EV::PERIODIC and so on, with the exception of IO events	419	EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events
167	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which	420	(which can set both EV::READ and EV::WRITE bits).
168	uses EV::TIMEOUT).
169		421
170	In the rare case where one wants to create a watcher but not start it at	422	In the rare case where one wants to create a watcher but not start it at
171	the same time, each constructor has a variant with a trailing C<_ns> in	423	the same time, each constructor has a variant with a trailing C<_ns> in
172	its name, e.g. EV::io has a non-starting variant EV::io_ns and so on.	424	its name, e.g. EV::io has a non-starting variant EV::io_ns and so on.
173		425
…		…
177		429
178	Also, all methods changing some aspect of a watcher (->set, ->priority,	430	Also, all methods changing some aspect of a watcher (->set, ->priority,
179	->fh and so on) automatically stop and start it again if it is active,	431	->fh and so on) automatically stop and start it again if it is active,
180	which means pending events get lost.	432	which means pending events get lost.
181		433
182	=head2 WATCHER TYPES	434	=head2 COMMON WATCHER METHODS
183		435
184	Now lets move to the existing watcher types and asociated methods.	436	This section lists methods common to all watchers.
185
186	The following methods are available for all watchers. Then followes a
187	description of each watcher constructor (EV::io, EV::timer, EV::periodic,
188	EV::signal, EV::child, EV::idle, EV::prepare and EV::check), followed by
189	any type-specific methods (if any).
190		437
191	=over 4	438	=over 4
192		439
193	=item $w->start	440	=item $w->start
194		441
…		…
198		445
199	=item $w->stop	446	=item $w->stop
200		447
201	Stop a watcher if it is active. Also clear any pending events (events that	448	Stop a watcher if it is active. Also clear any pending events (events that
202	have been received but that didn't yet result in a callback invocation),	449	have been received but that didn't yet result in a callback invocation),
203	regardless of wether the watcher was active or not.	450	regardless of whether the watcher was active or not.
204		451
205	=item $bool = $w->is_active	452	=item $bool = $w->is_active
206		453
207	Returns true if the watcher is active, false otherwise.	454	Returns true if the watcher is active, false otherwise.
208		455
…		…
238	The default priority of any newly-created watcher is 0.	485	The default priority of any newly-created watcher is 0.
239		486
240	Note that the priority semantics have not yet been fleshed out and are	487	Note that the priority semantics have not yet been fleshed out and are
241	subject to almost certain change.	488	subject to almost certain change.
242		489
243	=item $w->trigger ($revents)	490	=item $w->invoke ($revents)
244		491
245	Call the callback now with the given event mask.	492	Call the callback now with the given event mask.
		493
		494	=item $w->feed_event ($revents)
		495
		496	Feed some events on this watcher into EV. EV will react to this call as if
		497	the watcher had received the given C<$revents> mask.
		498
		499	=item $revents = $w->clear_pending
		500
		501	If the watcher is pending, this function clears its pending status and
		502	returns its C<$revents> bitset (as if its callback was invoked). If the
		503	watcher isn't pending it does nothing and returns C<0>.
246		504
247	=item $previous_state = $w->keepalive ($bool)	505	=item $previous_state = $w->keepalive ($bool)
248		506
249	Normally, C<EV::loop> will return when there are no active watchers	507	Normally, C<EV::loop> will return when there are no active watchers
250	(which is a "deadlock" because no progress can be made anymore). This is	508	(which is a "deadlock" because no progress can be made anymore). This is
251	convinient because it allows you to start your watchers (and your jobs),	509	convenient because it allows you to start your watchers (and your jobs),
252	call C<EV::loop> once and when it returns you know that all your jobs are	510	call C<EV::loop> once and when it returns you know that all your jobs are
253	finished (or they forgot to register some watchers for their task :).	511	finished (or they forgot to register some watchers for their task :).
254		512
255	Sometimes, however, this gets in your way, for example when you the module	513	Sometimes, however, this gets in your way, for example when the module
256	that calls C<EV::loop> (usually the main program) is not the same module	514	that calls C<EV::loop> (usually the main program) is not the same module
257	as a long-living watcher (for example a DNS client module written by	515	as a long-living watcher (for example a DNS client module written by
258	somebody else even). Then you might want any outstanding requests to be	516	somebody else even). Then you might want any outstanding requests to be
259	handled, but you would not want to keep C<EV::loop> from returning just	517	handled, but you would not want to keep C<EV::loop> from returning just
260	because you happen to have this long-running UDP port watcher.	518	because you happen to have this long-running UDP port watcher.
261		519
262	In this case you can clear the keepalive status, which means that even	520	In this case you can clear the keepalive status, which means that even
263	though your watcher is active, it won't keep C<EV::loop> from returning.	521	though your watcher is active, it won't keep C<EV::loop> from returning.
264		522
265	The initial value for keepalive is true (enabled), and you cna change it	523	The initial value for keepalive is true (enabled), and you can change it
266	any time.	524	any time.
267		525
268	Example: Register an IO watcher for some UDP socket but do not keep the	526	Example: Register an I/O watcher for some UDP socket but do not keep the
269	event loop from running just because of that watcher.	527	event loop from running just because of that watcher.
270		528
271	my $udp_socket = ...	529	my $udp_socket = ...
272	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };	530	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
273	$udp_watcher->keepalive (0);	531	$udp_watcher->keepalive (0);
274		532
		533	=item $loop = $w->loop
		534
		535	Return the loop that this watcher is attached to.
		536
		537	=back
		538
		539
		540	=head1 WATCHER TYPES
		541
		542	Each of the following subsections describes a single watcher type.
		543
		544	=head3 I/O WATCHERS - is this file descriptor readable or writable?
		545
		546	=over 4
		547
275	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	548	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
276		549
277	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback	550	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
278		551
		552	=item $w = $loop->io ($fileno_or_fh, $eventmask, $callback)
		553
		554	=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
		555
279	As long as the returned watcher object is alive, call the C<$callback>	556	As long as the returned watcher object is alive, call the C<$callback>
280	when the events specified in C<$eventmask>.	557	when at least one of events specified in C<$eventmask> occurs.
281		558
282	The $eventmask can be one or more of these constants ORed together:	559	The $eventmask can be one or more of these constants ORed together:
283		560
284	EV::READ wait until read() wouldn't block anymore	561	EV::READ wait until read() wouldn't block anymore
285	EV::WRITE wait until write() wouldn't block anymore	562	EV::WRITE wait until write() wouldn't block anymore
…		…
301		578
302	=item $old_eventmask = $w->events ($new_eventmask)	579	=item $old_eventmask = $w->events ($new_eventmask)
303		580
304	Returns the previously set event mask and optionally set a new one.	581	Returns the previously set event mask and optionally set a new one.
305		582
		583	=back
		584
		585
		586	=head3 TIMER WATCHERS - relative and optionally repeating timeouts
		587
		588	=over 4
306		589
307	=item $w = EV::timer $after, $repeat, $callback	590	=item $w = EV::timer $after, $repeat, $callback
308		591
309	=item $w = EV::timer_ns $after, $repeat, $callback	592	=item $w = EV::timer_ns $after, $repeat, $callback
310		593
311	Calls the callback after C<$after> seconds. If C<$repeat> is non-zero,	594	=item $w = $loop->timer ($after, $repeat, $callback)
312	the timer will be restarted (with the $repeat value as $after) after the	595
313	callback returns.	596	=item $w = $loop->timer_ns ($after, $repeat, $callback)
		597
		598	Calls the callback after C<$after> seconds (which may be fractional). If
		599	C<$repeat> is non-zero, the timer will be restarted (with the $repeat
		600	value as $after) after the callback returns.
314		601
315	This means that the callback would be called roughly after C<$after>	602	This means that the callback would be called roughly after C<$after>
316	seconds, and then every C<$repeat> seconds. The timer does his best not	603	seconds, and then every C<$repeat> seconds. The timer does his best not
317	to drift, but it will not invoke the timer more often then once per event	604	to drift, but it will not invoke the timer more often then once per event
318	loop iteration, and might drift in other cases. If that isn't acceptable,	605	loop iteration, and might drift in other cases. If that isn't acceptable,
…		…
324		611
325	The C<timer_ns> variant doesn't start (activate) the newly created watcher.	612	The C<timer_ns> variant doesn't start (activate) the newly created watcher.
326		613
327	=item $w->set ($after, $repeat)	614	=item $w->set ($after, $repeat)
328		615
329	Reconfigures the watcher, see the constructor above for details. Can be at	616	Reconfigures the watcher, see the constructor above for details. Can be called at
330	any time.	617	any time.
331		618
332	=item $w->again	619	=item $w->again
333		620
334	Similar to the C<start> method, but has special semantics for repeating timers:	621	Similar to the C<start> method, but has special semantics for repeating timers:
…		…
345	This behaviour is useful when you have a timeout for some IO	632	This behaviour is useful when you have a timeout for some IO
346	operation. You create a timer object with the same value for C<$after> and	633	operation. You create a timer object with the same value for C<$after> and
347	C<$repeat>, and then, in the read/write watcher, run the C<again> method	634	C<$repeat>, and then, in the read/write watcher, run the C<again> method
348	on the timeout.	635	on the timeout.
349		636
		637	=back
		638
		639
		640	=head3 PERIODIC WATCHERS - to cron or not to cron?
		641
		642	=over 4
350		643
351	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback	644	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
352		645
353	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback	646	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
		647
		648	=item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
		649
		650	=item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback)
354		651
355	Similar to EV::timer, but is not based on relative timeouts but on	652	Similar to EV::timer, but is not based on relative timeouts but on
356	absolute times. Apart from creating "simple" timers that trigger "at" the	653	absolute times. Apart from creating "simple" timers that trigger "at" the
357	specified time, it can also be used for non-drifting absolute timers and	654	specified time, it can also be used for non-drifting absolute timers and
358	more complex, cron-like, setups that are not adversely affected by time	655	more complex, cron-like, setups that are not adversely affected by time
…		…
368	This time simply fires at the wallclock time C<$at> and doesn't repeat. It	665	This time simply fires at the wallclock time C<$at> and doesn't repeat. It
369	will not adjust when a time jump occurs, that is, if it is to be run	666	will not adjust when a time jump occurs, that is, if it is to be run
370	at January 1st 2011 then it will run when the system time reaches or	667	at January 1st 2011 then it will run when the system time reaches or
371	surpasses this time.	668	surpasses this time.
372		669
373	=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0)	670	=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
374		671
375	In this mode the watcher will always be scheduled to time out at the	672	In this mode the watcher will always be scheduled to time out at the
376	next C<$at + N * $interval> time (for some integer N) and then repeat,	673	next C<$at + N * $interval> time (for some integer N) and then repeat,
377	regardless of any time jumps.	674	regardless of any time jumps.
378		675
…		…
396	time the periodic watcher gets scheduled, the reschedule callback	693	time the periodic watcher gets scheduled, the reschedule callback
397	($reschedule_cb) will be called with the watcher as first, and the current	694	($reschedule_cb) will be called with the watcher as first, and the current
398	time as second argument.	695	time as second argument.
399		696
400	I<This callback MUST NOT stop or destroy this or any other periodic	697	I<This callback MUST NOT stop or destroy this or any other periodic
401	watcher, ever>. If you need to stop it, return 1e30 and stop it	698	watcher, ever, and MUST NOT call any event loop functions or methods>. If
402	afterwards.	699	you need to stop it, return 1e30 and stop it afterwards. You may create
		700	and start a C<EV::prepare> watcher for this task.
403		701
404	It must return the next time to trigger, based on the passed time value	702	It must return the next time to trigger, based on the passed time value
405	(that is, the lowest time value larger than to the second argument). It	703	(that is, the lowest time value larger than or equal to to the second
406	will usually be called just before the callback will be triggered, but	704	argument). It will usually be called just before the callback will be
407	might be called at other times, too.	705	triggered, but might be called at other times, too.
408		706
409	This can be used to create very complex timers, such as a timer that	707	This can be used to create very complex timers, such as a timer that
410	triggers on each midnight, local time (actually 24 hours after the last	708	triggers on each midnight, local time (actually 24 hours after the last
411	midnight, to keep the example simple. If you know a way to do it correctly	709	midnight, to keep the example simple. If you know a way to do it correctly
412	in about the same space (without requiring elaborate modules), drop me a	710	in about the same space (without requiring elaborate modules), drop me a
…		…
426		724
427	The C<periodic_ns> variant doesn't start (activate) the newly created watcher.	725	The C<periodic_ns> variant doesn't start (activate) the newly created watcher.
428		726
429	=item $w->set ($at, $interval, $reschedule_cb)	727	=item $w->set ($at, $interval, $reschedule_cb)
430		728
431	Reconfigures the watcher, see the constructor above for details. Can be at	729	Reconfigures the watcher, see the constructor above for details. Can be called at
432	any time.	730	any time.
433		731
434	=item $w->again	732	=item $w->again
435		733
436	Simply stops and starts the watcher again.	734	Simply stops and starts the watcher again.
437		735
		736	=item $time = $w->at
		737
		738	Return the time that the watcher is expected to trigger next.
		739
		740	=back
		741
		742
		743	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
		744
		745	=over 4
438		746
439	=item $w = EV::signal $signal, $callback	747	=item $w = EV::signal $signal, $callback
440		748
441	=item $w = EV::signal_ns $signal, $callback	749	=item $w = EV::signal_ns $signal, $callback
442		750
		751	=item $w = $loop->signal ($signal, $callback)
		752
		753	=item $w = $loop->signal_ns ($signal, $callback)
		754
443	Call the callback when $signal is received (the signal can be specified	755	Call the callback when $signal is received (the signal can be specified by
444	by number or by name, just as with kill or %SIG).	756	number or by name, just as with C<kill> or C<%SIG>).
		757
		758	Only one event loop can grab a given signal - attempting to grab the same
		759	signal from two EV loops will crash the program immediately or cause data
		760	corruption.
445		761
446	EV will grab the signal for the process (the kernel only allows one	762	EV will grab the signal for the process (the kernel only allows one
447	component to receive a signal at a time) when you start a signal watcher,	763	component to receive a signal at a time) when you start a signal watcher,
448	and removes it again when you stop it. Perl does the same when you	764	and removes it again when you stop it. Perl does the same when you
449	add/remove callbacks to %SIG, so watch out.	765	add/remove callbacks to C<%SIG>, so watch out.
450		766
451	You can have as many signal watchers per signal as you want.	767	You can have as many signal watchers per signal as you want.
452		768
453	The C<signal_ns> variant doesn't start (activate) the newly created watcher.	769	The C<signal_ns> variant doesn't start (activate) the newly created watcher.
454		770
455	=item $w->set ($signal)	771	=item $w->set ($signal)
456		772
457	Reconfigures the watcher, see the constructor above for details. Can be at	773	Reconfigures the watcher, see the constructor above for details. Can be
458	any time.	774	called at any time.
459		775
460	=item $current_signum = $w->signal	776	=item $current_signum = $w->signal
461		777
462	=item $old_signum = $w->signal ($new_signal)	778	=item $old_signum = $w->signal ($new_signal)
463		779
464	Returns the previously set signal (always as a number not name) and	780	Returns the previously set signal (always as a number not name) and
465	optionally set a new one.	781	optionally set a new one.
466		782
		783	=back
467		784
		785
		786	=head3 CHILD WATCHERS - watch out for process status changes
		787
		788	=over 4
		789
468	=item $w = EV::child $pid, $callback	790	=item $w = EV::child $pid, $trace, $callback
469		791
470	=item $w = EV::child_ns $pid, $callback	792	=item $w = EV::child_ns $pid, $trace, $callback
		793
		794	=item $w = $loop->child ($pid, $trace, $callback)
		795
		796	=item $w = $loop->child_ns ($pid, $trace, $callback)
471		797
472	Call the callback when a status change for pid C<$pid> (or any pid	798	Call the callback when a status change for pid C<$pid> (or any pid
473	if C<$pid> is 0) has been received. More precisely: when the process	799	if C<$pid> is 0) has been received (a status change happens when the
		800	process terminates or is killed, or, when trace is true, additionally when
		801	it is stopped or continued). More precisely: when the process receives
474	receives a SIGCHLD, EV will fetch the outstanding exit/wait status for all	802	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
475	changed/zombie children and call the callback.	803	changed/zombie children and call the callback.
476		804
477	You can access both status and pid by using the C<rstatus> and C<rpid>	805	It is valid (and fully supported) to install a child watcher after a child
478	methods on the watcher object.	806	has exited but before the event loop has started its next iteration (for
		807	example, first you C<fork>, then the new child process might exit, and
		808	only then do you install a child watcher in the parent for the new pid).
479		809
		810	You can access both exit (or tracing) status and pid by using the
		811	C<rstatus> and C<rpid> methods on the watcher object.
		812
480	You can have as many pid watchers per pid as you want.	813	You can have as many pid watchers per pid as you want, they will all be
		814	called.
481		815
482	The C<child_ns> variant doesn't start (activate) the newly created watcher.	816	The C<child_ns> variant doesn't start (activate) the newly created watcher.
483		817
484	=item $w->set ($pid)	818	=item $w->set ($pid, $trace)
485		819
486	Reconfigures the watcher, see the constructor above for details. Can be at	820	Reconfigures the watcher, see the constructor above for details. Can be called at
487	any time.	821	any time.
488		822
489	=item $current_pid = $w->pid	823	=item $current_pid = $w->pid
490
491	=item $old_pid = $w->pid ($new_pid)
492		824
493	Returns the previously set process id and optionally set a new one.	825	Returns the previously set process id and optionally set a new one.
494		826
495	=item $exit_status = $w->rstatus	827	=item $exit_status = $w->rstatus
496		828
…		…
500	=item $pid = $w->rpid	832	=item $pid = $w->rpid
501		833
502	Return the pid of the awaited child (useful when you have installed a	834	Return the pid of the awaited child (useful when you have installed a
503	watcher for all pids).	835	watcher for all pids).
504		836
		837	=back
		838
		839
		840	=head3 STAT WATCHERS - did the file attributes just change?
		841
		842	=over 4
		843
		844	=item $w = EV::stat $path, $interval, $callback
		845
		846	=item $w = EV::stat_ns $path, $interval, $callback
		847
		848	=item $w = $loop->stat ($path, $interval, $callback)
		849
		850	=item $w = $loop->stat_ns ($path, $interval, $callback)
		851
		852	Call the callback when a file status change has been detected on
		853	C<$path>. The C<$path> does not need to exist, changing from "path exists"
		854	to "path does not exist" is a status change like any other.
		855
		856	The C<$interval> is a recommended polling interval for systems where
		857	OS-supported change notifications don't exist or are not supported. If
		858	you use C<0> then an unspecified default is used (which is highly
		859	recommended!), which is to be expected to be around five seconds usually.
		860
		861	This watcher type is not meant for massive numbers of stat watchers,
		862	as even with OS-supported change notifications, this can be
		863	resource-intensive.
		864
		865	The C<stat_ns> variant doesn't start (activate) the newly created watcher.
		866
		867	=item ... = $w->stat
		868
		869	This call is very similar to the perl C<stat> built-in: It stats (using
		870	C<lstat>) the path specified in the watcher and sets perls stat cache (as
		871	well as EV's idea of the current stat values) to the values found.
		872
		873	In scalar context, a boolean is return indicating success or failure of
		874	the stat. In list context, the same 13-value list as with stat is returned
		875	(except that the blksize and blocks fields are not reliable).
		876
		877	In the case of an error, errno is set to C<ENOENT> (regardless of the
		878	actual error value) and the C<nlink> value is forced to zero (if the stat
		879	was successful then nlink is guaranteed to be non-zero).
		880
		881	See also the next two entries for more info.
		882
		883	=item ... = $w->attr
		884
		885	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		886	the values most recently detected by EV. See the next entry for more info.
		887
		888	=item ... = $w->prev
		889
		890	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		891	the previous set of values, before the change.
		892
		893	That is, when the watcher callback is invoked, C<< $w->prev >> will be set
		894	to the values found I<before> a change was detected, while C<< $w->attr >>
		895	returns the values found leading to the change detection. The difference (if any)
		896	between C<prev> and C<attr> is what triggered the callback.
		897
		898	If you did something to the filesystem object and do not want to trigger
		899	yet another change, you can call C<stat> to update EV's idea of what the
		900	current attributes are.
		901
		902	=item $w->set ($path, $interval)
		903
		904	Reconfigures the watcher, see the constructor above for details. Can be
		905	called at any time.
		906
		907	=item $current_path = $w->path
		908
		909	=item $old_path = $w->path ($new_path)
		910
		911	Returns the previously set path and optionally set a new one.
		912
		913	=item $current_interval = $w->interval
		914
		915	=item $old_interval = $w->interval ($new_interval)
		916
		917	Returns the previously set interval and optionally set a new one. Can be
		918	used to query the actual interval used.
		919
		920	=back
		921
		922
		923	=head3 IDLE WATCHERS - when you've got nothing better to do...
		924
		925	=over 4
505		926
506	=item $w = EV::idle $callback	927	=item $w = EV::idle $callback
507		928
508	=item $w = EV::idle_ns $callback	929	=item $w = EV::idle_ns $callback
509		930
510	Call the callback when there are no pending io, timer/periodic, signal or	931	=item $w = $loop->idle ($callback)
511	child events, i.e. when the process is idle.	932
		933	=item $w = $loop->idle_ns ($callback)
		934
		935	Call the callback when there are no other pending watchers of the same or
		936	higher priority (excluding check, prepare and other idle watchers of the
		937	same or lower priority, of course). They are called idle watchers because
		938	when the watcher is the highest priority pending event in the process, the
		939	process is considered to be idle at that priority.
		940
		941	If you want a watcher that is only ever called when I<no> other events are
		942	outstanding you have to set the priority to C<EV::MINPRI>.
512		943
513	The process will not block as long as any idle watchers are active, and	944	The process will not block as long as any idle watchers are active, and
514	they will be called repeatedly until stopped.	945	they will be called repeatedly until stopped.
515		946
		947	For example, if you have idle watchers at priority C<0> and C<1>, and
		948	an I/O watcher at priority C<0>, then the idle watcher at priority C<1>
		949	and the I/O watcher will always run when ready. Only when the idle watcher
		950	at priority C<1> is stopped and the I/O watcher at priority C<0> is not
		951	pending with the C<0>-priority idle watcher be invoked.
		952
516	The C<idle_ns> variant doesn't start (activate) the newly created watcher.	953	The C<idle_ns> variant doesn't start (activate) the newly created watcher.
517		954
		955	=back
		956
		957
		958	=head3 PREPARE WATCHERS - customise your event loop!
		959
		960	=over 4
518		961
519	=item $w = EV::prepare $callback	962	=item $w = EV::prepare $callback
520		963
521	=item $w = EV::prepare_ns $callback	964	=item $w = EV::prepare_ns $callback
		965
		966	=item $w = $loop->prepare ($callback)
		967
		968	=item $w = $loop->prepare_ns ($callback)
522		969
523	Call the callback just before the process would block. You can still	970	Call the callback just before the process would block. You can still
524	create/modify any watchers at this point.	971	create/modify any watchers at this point.
525		972
526	See the EV::check watcher, below, for explanations and an example.	973	See the EV::check watcher, below, for explanations and an example.
527		974
528	The C<prepare_ns> variant doesn't start (activate) the newly created watcher.	975	The C<prepare_ns> variant doesn't start (activate) the newly created watcher.
529		976
		977	=back
		978
		979
		980	=head3 CHECK WATCHERS - customise your event loop even more!
		981
		982	=over 4
530		983
531	=item $w = EV::check $callback	984	=item $w = EV::check $callback
532		985
533	=item $w = EV::check_ns $callback	986	=item $w = EV::check_ns $callback
		987
		988	=item $w = $loop->check ($callback)
		989
		990	=item $w = $loop->check_ns ($callback)
534		991
535	Call the callback just after the process wakes up again (after it has	992	Call the callback just after the process wakes up again (after it has
536	gathered events), but before any other callbacks have been invoked.	993	gathered events), but before any other callbacks have been invoked.
537		994
538	This is used to integrate other event-based software into the EV	995	This can be used to integrate other event-based software into the EV
539	mainloop: You register a prepare callback and in there, you create io and	996	mainloop: You register a prepare callback and in there, you create io and
540	timer watchers as required by the other software. Here is a real-world	997	timer watchers as required by the other software. Here is a real-world
541	example of integrating Net::SNMP (with some details left out):	998	example of integrating Net::SNMP (with some details left out):
542		999
543	our @snmp_watcher;	1000	our @snmp_watcher;
…		…
548	or return;	1005	or return;
549		1006
550	# make the dispatcher handle any outstanding stuff	1007	# make the dispatcher handle any outstanding stuff
551	... not shown	1008	... not shown
552		1009
553	# create an IO watcher for each and every socket	1010	# create an I/O watcher for each and every socket
554	@snmp_watcher = (	1011	@snmp_watcher = (
555	(map { EV::io $_, EV::READ, sub { } }	1012	(map { EV::io $_, EV::READ, sub { } }
556	keys %{ $dispatcher->{_descriptors} }),	1013	keys %{ $dispatcher->{_descriptors} }),
557		1014
558	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]	1015	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
…		…
573	# make the dispatcher handle any new stuff	1030	# make the dispatcher handle any new stuff
574	... not shown	1031	... not shown
575	};	1032	};
576		1033
577	The callbacks of the created watchers will not be called as the watchers	1034	The callbacks of the created watchers will not be called as the watchers
578	are destroyed before this cna happen (remember EV::check gets called	1035	are destroyed before this can happen (remember EV::check gets called
579	first).	1036	first).
580		1037
581	The C<check_ns> variant doesn't start (activate) the newly created watcher.	1038	The C<check_ns> variant doesn't start (activate) the newly created watcher.
582		1039
583	=back	1040	=item EV::CHECK constant issues
584		1041
		1042	Like all other watcher types, there is a bitmask constant for use in
		1043	C<$revents> and other places. The C<EV::CHECK> is special as it has
		1044	the same name as the C<CHECK> sub called by Perl. This doesn't cause
		1045	big issues on newer perls (beginning with 5.8.9), but it means thatthe
		1046	constant must be I<inlined>, i.e. runtime calls will not work. That means
		1047	that as long as you always C<use EV> and then C<EV::CHECK> you are on the
		1048	safe side.
		1049
		1050	=back
		1051
		1052
		1053	=head3 FORK WATCHERS - the audacity to resume the event loop after a fork
		1054
		1055	Fork watchers are called when a C<fork ()> was detected. The invocation
		1056	is done before the event loop blocks next and before C<check> watchers
		1057	are being called, and only in the child after the fork.
		1058
		1059	=over 4
		1060
		1061	=item $w = EV::fork $callback
		1062
		1063	=item $w = EV::fork_ns $callback
		1064
		1065	=item $w = $loop->fork ($callback)
		1066
		1067	=item $w = $loop->fork_ns ($callback)
		1068
		1069	Call the callback before the event loop is resumed in the child process
		1070	after a fork.
		1071
		1072	The C<fork_ns> variant doesn't start (activate) the newly created watcher.
		1073
		1074	=back
		1075
		1076
		1077	=head3 EMBED WATCHERS - when one backend isn't enough...
		1078
		1079	This is a rather advanced watcher type that lets you embed one event loop
		1080	into another (currently only IO events are supported in the embedded
		1081	loop, other types of watchers might be handled in a delayed or incorrect
		1082	fashion and must not be used).
		1083
		1084	See the libev documentation at
		1085	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
		1086	(locally installed as F<EV::libev>) for more details.
		1087
		1088	In short, this watcher is most useful on BSD systems without working
		1089	kqueue to still be able to handle a large number of sockets:
		1090
		1091	my $socket_loop;
		1092
		1093	# check wether we use SELECT or POLL _and_ KQUEUE is supported
		1094	if (
		1095	(EV::backend & (EV::BACKEND_POLL \| EV::BACKEND_SELECT))
		1096	&& (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
		1097	) {
		1098	# use kqueue for sockets
		1099	$socket_loop = new EV::Loop EV::BACKEND_KQUEUE \| EV::FLAG_NOENV;
		1100	}
		1101
		1102	# use the default loop otherwise
		1103	$socket_loop \|\|= EV::default_loop;
		1104
		1105	=over 4
		1106
		1107	=item $w = EV::embed $otherloop[, $callback]
		1108
		1109	=item $w = EV::embed_ns $otherloop[, $callback]
		1110
		1111	=item $w = $loop->embed ($otherloop[, $callback])
		1112
		1113	=item $w = $loop->embed_ns ($otherloop[, $callback])
		1114
		1115	Call the callback when the embedded event loop (C<$otherloop>) has any
		1116	I/O activity. The C<$callback> is optional: if it is missing, then the
		1117	embedded event loop will be managed automatically (which is recommended),
		1118	otherwise you have to invoke C<sweep> yourself.
		1119
		1120	The C<embed_ns> variant doesn't start (activate) the newly created watcher.
		1121
		1122	=back
		1123
		1124	=head3 ASYNC WATCHERS - how to wake up another event loop
		1125
		1126	Async watchers are provided by EV, but have little use in perl directly,
		1127	as perl neither supports threads running in parallel nor direct access to
		1128	signal handlers or other contexts where they could be of value.
		1129
		1130	It is, however, possible to use them from the XS level.
		1131
		1132	Please see the libev documentation for further details.
		1133
		1134	=over 4
		1135
		1136	=item $w = EV::async $callback
		1137
		1138	=item $w = EV::async_ns $callback
		1139
		1140	=item $w->send
		1141
		1142	=item $bool = $w->async_pending
		1143
		1144	=back
		1145
		1146
		1147	=head1 PERL SIGNALS
		1148
		1149	While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour
		1150	with EV is as the same as any other C library: Perl-signals will only be
		1151	handled when Perl runs, which means your signal handler might be invoked
		1152	only the next time an event callback is invoked.
		1153
		1154	The solution is to use EV signal watchers (see C<EV::signal>), which will
		1155	ensure proper operations with regards to other event watchers.
		1156
		1157	If you cannot do this for whatever reason, you can also force a watcher
		1158	to be called on every event loop iteration by installing a C<EV::check>
		1159	watcher:
		1160
		1161	my $async_check = EV::check sub { };
		1162
		1163	This ensures that perl gets into control for a short time to handle any
		1164	pending signals, and also ensures (slightly) slower overall operation.
		1165
585	=head1 THREADS	1166	=head1 ITHREADS
586		1167
587	Threads are not supported by this module in any way. Perl pseudo-threads	1168	Ithreads are not supported by this module in any way. Perl pseudo-threads
588	is evil stuff and must die. As soon as Perl gains real threads I will work	1169	is evil stuff and must die. Real threads as provided by Coro are fully
589	on thread support for it.	1170	supported (and enhanced support is available via L<Coro::EV>).
590		1171
591	=head1 FORK	1172	=head1 FORK
592		1173
593	Most of the "improved" event delivering mechanisms of modern operating	1174	Most of the "improved" event delivering mechanisms of modern operating
594	systems have quite a few problems with fork(2) (to put it bluntly: it is	1175	systems have quite a few problems with fork(2) (to put it bluntly: it is
…		…
610	our $DIED = sub {	1191	our $DIED = sub {
611	warn "EV: error in callback (ignoring): $@";	1192	warn "EV: error in callback (ignoring): $@";
612	};	1193	};
613		1194
614	default_loop	1195	default_loop
615	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	1196	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
616		1197
617	1;	1198	1;
618		1199
619	=head1 SEE ALSO	1200	=head1 SEE ALSO
620		1201
621	L<EV::DNS>.	1202	L<EV::MakeMaker> - MakeMaker interface to XS API, L<EV::ADNS>
		1203	(asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as event
		1204	loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient thread
		1205	integration), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
		1206	event-loop agnostic and portable event driven programming.
622		1207
623	=head1 AUTHOR	1208	=head1 AUTHOR
624		1209
625	Marc Lehmann <schmorp@schmorp.de>	1210	Marc Lehmann <schmorp@schmorp.de>
626	http://home.schmorp.de/	1211	http://home.schmorp.de/
627		1212
628	=cut	1213	=cut
629		1214

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Comparing EV/EV.pm (file contents): Revision 1.51 by root, Sat Nov 24 16:12:37 2007 UTC vs. Revision 1.136 by root, Thu Jan 19 17:55:23 2012 UTC

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Comparing EV/EV.pm (file contents):
Revision 1.51 by root, Sat Nov 24 16:12:37 2007 UTC vs.
Revision 1.136 by root, Thu Jan 19 17:55:23 2012 UTC