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

Comparing EV/EV.pm (file contents):
Revision 1.28 by root, Sun Nov 4 16:52:52 2007 UTC vs.
Revision 1.104 by root, Thu Oct 2 12:26:25 2008 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, 1, sub {
16	warn "is called roughly every 2s (repeat = 1)";
17	};
18
19	undef $w; # destroy event watcher again
20
21	my $w = EV::periodic 0, 60, 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 get the watcher object 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	my $w = EV::signal 3, sub {
39	warn "sigquit received (this is GNU/Linux, right?)\n";
40	};
41
42	# CHILD/PID STATUS CHANGES
43
44	my $w = EV::child 666, sub {
45	my ($w, $revents) = @_;	47	my ($w, $revents) = @_;
46	# my $pid = $w->rpid;	48	warn $w->path, " has changed somehow.\n";
47	my $status = $w->rstatus;
48	};	49	};
49		50
50	# MAINLOOP	51	# MAINLOOP
51	EV::loop; # loop until EV::loop_done is called	52	EV::loop; # loop until EV::unloop is called or all watchers stop
52	EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled	53	EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled
53	EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block	54	EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block
54		55
55	=head1 DESCRIPTION	56	=head1 DESCRIPTION
56		57
57	This module provides an interface to libev	58	This module provides an interface to libev
58	(L<http://software.schmorp.de/pkg/libev.html>).	59	(L<http://software.schmorp.de/pkg/libev.html>). While the documentation
		60	below is comprehensive, one might also consult the documentation of
		61	libev itself (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod> or
		62	F<perldoc EV::c_doc>) for more subtle details on watcher semantics or some
		63	discussion on the available backends, or how to force a specific backend
		64	with C<LIBEV_FLAGS>, or just about in any case because it has much more
		65	detailed information.
		66
		67	This module is very fast and scalable. It is actually so fast that you
		68	can use it through the L<AnyEvent> module, stay portable to other event
		69	loops (if you don't rely on any watcher types not available through it)
		70	and still be faster than with any other event loop currently supported in
		71	Perl.
59		72
60	=cut	73	=cut
61		74
62	package EV;	75	package EV;
63		76
		77	no warnings;
64	use strict;	78	use strict;
65		79
66	BEGIN {	80	BEGIN {
67	our $VERSION = '0.5';	81	our $VERSION = '3.44';
68	use XSLoader;	82	use XSLoader;
69	XSLoader::load "EV", $VERSION;	83	XSLoader::load "EV", $VERSION;
70	}	84	}
71		85
72	@EV::Io::ISA =	86	@EV::IO::ISA =
73	@EV::Timer::ISA =	87	@EV::Timer::ISA =
74	@EV::Periodic::ISA =	88	@EV::Periodic::ISA =
75	@EV::Signal::ISA =	89	@EV::Signal::ISA =
		90	@EV::Child::ISA =
		91	@EV::Stat::ISA =
76	@EV::Idle::ISA =	92	@EV::Idle::ISA =
77	@EV::Prepare::ISA =	93	@EV::Prepare::ISA =
78	@EV::Check::ISA =	94	@EV::Check::ISA =
79	@EV::Child::ISA = "EV::Watcher";	95	@EV::Embed::ISA =
		96	@EV::Fork::ISA =
		97	@EV::Async::ISA =
		98	"EV::Watcher";
		99
		100	@EV::Loop::Default::ISA = "EV::Loop";
		101
		102	=head1 EVENT LOOPS
		103
		104	EV supports multiple event loops: There is a single "default event loop"
		105	that can handle everything including signals and child watchers, and any
		106	number of "dynamic event loops" that can use different backends (with
		107	various limitations), but no child and signal watchers.
		108
		109	You do not have to do anything to create the default event loop: When
		110	the module is loaded a suitable backend is selected on the premise of
		111	selecting a working backend (which for example rules out kqueue on most
		112	BSDs). Modules should, unless they have "special needs" always use the
		113	default loop as this is fastest (perl-wise), best supported by other
		114	modules (e.g. AnyEvent or Coro) and most portable event loop.
		115
		116	For specific programs you can create additional event loops dynamically.
		117
		118	If you want to take avdantage of kqueue (which often works properly for
		119	sockets only) even though the default loop doesn't enable it, you can
		120	I<embed> a kqueue loop into the default loop: running the default loop
		121	will then also service the kqueue loop to some extent. See the example in
		122	the section about embed watchers for an example on how to achieve that.
		123
		124	=over 4
		125
		126	=item $loop = new EV::loop [$flags]
		127
		128	Create a new event loop as per the specified flags. Please refer to
		129	the C<ev_loop_new ()> function description in the libev documentation
		130	(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>,
		131	or locally-installed as F<EV::c_doc> manpage) for more info.
		132
		133	The loop will automatically be destroyed when it is no longer referenced
		134	by any watcher and the loop object goes out of scope.
		135
		136	If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK>
		137	is recommended, as only the default event loop is protected by this
		138	module. If you I<are> embedding this loop in the default loop, this is not
		139	necessary, as C<EV::embed> automatically does the right thing on fork.
		140
		141	=item $loop->loop_fork
		142
		143	Must be called after a fork in the child, before entering or continuing
		144	the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
		145	this function automatically, at some performance loss (refer to the libev
		146	documentation).
		147
		148	=item $loop->loop_verify
		149
		150	Calls C<ev_verify> to make internal consistency checks (for debugging
		151	libev) and abort the program if any data structures were found to be
		152	corrupted.
		153
		154	=item $loop = EV::default_loop [$flags]
		155
		156	Return the default loop (which is a singleton object). Since this module
		157	already creates the default loop with default flags, specifying flags here
		158	will not have any effect unless you destroy the default loop first, which
		159	isn't supported. So in short: don't do it, and if you break it, you get to
		160	keep the pieces.
		161
		162	=back
		163
80		164
81	=head1 BASIC INTERFACE	165	=head1 BASIC INTERFACE
82		166
83	=over 4	167	=over 4
84		168
85	=item $EV::DIED	169	=item $EV::DIED
86		170
87	Must contain a reference to a function that is called when a callback	171	Must contain a reference to a function that is called when a callback
88	throws an exception (with $@ containing thr error). The default prints an	172	throws an exception (with $@ containing the error). The default prints an
89	informative message and continues.	173	informative message and continues.
90		174
91	If this callback throws an exception it will be silently ignored.	175	If this callback throws an exception it will be silently ignored.
92		176
		177	=item $flags = EV::supported_backends
		178
		179	=item $flags = EV::recommended_backends
		180
		181	=item $flags = EV::embeddable_backends
		182
		183	Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this
		184	instance of EV, the set of recommended backends (supposed to be good) for
		185	this platform and the set of embeddable backends (see EMBED WATCHERS).
		186
		187	=item EV::sleep $seconds
		188
		189	Block the process for the given number of (fractional) seconds.
		190
93	=item $time = EV::time	191	=item $time = EV::time
94		192
95	Returns the current time in (fractional) seconds since the epoch.	193	Returns the current time in (fractional) seconds since the epoch.
96		194
97	=item $time = EV::now	195	=item $time = EV::now
		196
		197	=item $time = $loop->now
98		198
99	Returns the time the last event loop iteration has been started. This	199	Returns the time the last event loop iteration has been started. This
100	is the time that (relative) timers are based on, and refering to it is	200	is the time that (relative) timers are based on, and refering to it is
101	usually faster then calling EV::time.	201	usually faster then calling EV::time.
102		202
103	=item $method = EV::ev_method	203	=item $backend = EV::backend
		204
		205	=item $backend = $loop->backend
104		206
105	Returns an integer describing the backend used by libev (EV::METHOD_SELECT	207	Returns an integer describing the backend used by libev (EV::METHOD_SELECT
106	or EV::METHOD_EPOLL).	208	or EV::METHOD_EPOLL).
107		209
108	=item EV::loop [$flags]	210	=item EV::loop [$flags]
109		211
		212	=item $loop->loop ([$flags])
		213
110	Begin checking for events and calling callbacks. It returns when a	214	Begin checking for events and calling callbacks. It returns when a
111	callback calls EV::loop_done.	215	callback calls EV::unloop.
112		216
113	The $flags argument can be one of the following:	217	The $flags argument can be one of the following:
114		218
115	0 as above	219	0 as above
116	EV::LOOP_ONESHOT block at most once (wait, but do not loop)	220	EV::LOOP_ONESHOT block at most once (wait, but do not loop)
117	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)	221	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
118		222
119	=item EV::loop_done [$how]	223	=item EV::unloop [$how]
120		224
		225	=item $loop->unloop ([$how])
		226
121	When called with no arguments or an argument of 1, makes the innermost	227	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the
122	call to EV::loop return.	228	innermost call to EV::loop return.
123		229
124	When called with an agrument of 2, all calls to EV::loop will return as	230	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as
125	fast as possible.	231	fast as possible.
126		232
127	=back	233	=item $count = EV::loop_count
128		234
129	=head2 WATCHER	235	=item $count = $loop->loop_count
		236
		237	Return the number of times the event loop has polled for new
		238	events. Sometiems useful as a generation counter.
		239
		240	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
		241
		242	=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
		243
		244	This function rolls together an I/O and a timer watcher for a single
		245	one-shot event without the need for managing a watcher object.
		246
		247	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>
		248	must be a bitset containing either C<EV::READ>, C<EV::WRITE> or C<EV::READ
		249	\| EV::WRITE>, indicating the type of I/O event you want to wait for. If
		250	you do not want to wait for some I/O event, specify C<undef> for
		251	C<$fh_or_undef> and C<0> for C<$events>).
		252
		253	If timeout is C<undef> or negative, then there will be no
		254	timeout. Otherwise a EV::timer with this value will be started.
		255
		256	When an error occurs or either the timeout or I/O watcher triggers, then
		257	the callback will be called with the received event set (in general
		258	you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
		259	C<EV::WRITE> and C<EV::TIMEOUT>).
		260
		261	EV::once doesn't return anything: the watchers stay active till either
		262	of them triggers, then they will be stopped and freed, and the callback
		263	invoked.
		264
		265	=item EV::feed_fd_event ($fd, $revents)
		266
		267	=item $loop->feed_fd_event ($fd, $revents)
		268
		269	Feed an event on a file descriptor into EV. EV will react to this call as
		270	if the readyness notifications specified by C<$revents> (a combination of
		271	C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
		272
		273	=item EV::feed_signal_event ($signal)
		274
		275	Feed a signal event into EV. EV will react to this call as if the signal
		276	specified by C<$signal> had occured.
		277
		278	=item EV::set_io_collect_interval $time
		279
		280	=item $loop->set_io_collect_interval ($time)
		281
		282	=item EV::set_timeout_collect_interval $time
		283
		284	=item $loop->set_timeout_collect_interval ($time)
		285
		286	These advanced functions set the minimum block interval when polling for I/O events and the minimum
		287	wait interval for timer events. See the libev documentation at
		288	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP>
		289	(locally installed as F<EV::c_doc>) for a more detailed discussion.
		290
		291	=back
		292
		293
		294	=head1 WATCHER OBJECTS
130		295
131	A watcher is an object that gets created to record your interest in some	296	A watcher is an object that gets created to record your interest in some
132	event. For instance, if you want to wait for STDIN to become readable, you	297	event. For instance, if you want to wait for STDIN to become readable, you
133	would create an EV::io watcher for that:	298	would create an EV::io watcher for that:
134		299
135	my $watcher = EV::io *STDIN, EV::READ, sub {	300	my $watcher = EV::io *STDIN, EV::READ, sub {
136	my ($watcher, $revents) = @_;	301	my ($watcher, $revents) = @_;
137	warn "yeah, STDIN should not be readable without blocking!\n"	302	warn "yeah, STDIN should now be readable without blocking!\n"
138	};	303	};
139		304
140	All watchers can be active (waiting for events) or inactive (paused). Only	305	All watchers can be active (waiting for events) or inactive (paused). Only
141	active watchers will have their callbacks invoked. All callbacks will be	306	active watchers will have their callbacks invoked. All callbacks will be
142	called with at least two arguments: the watcher and a bitmask of received	307	called with at least two arguments: the watcher and a bitmask of received
143	events.	308	events.
144		309
145	Each watcher type has its associated bit in revents, so you can use the	310	Each watcher type has its associated bit in revents, so you can use the
146	same callback for multiple watchers. The event mask is named after the	311	same callback for multiple watchers. The event mask is named after the
147	type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,	312	type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
148	EV::periodic sets EV::PERIODIC and so on, with the exception of IO events	313	EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events
149	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which	314	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which
150	uses EV::TIMEOUT).	315	uses EV::TIMEOUT).
151		316
152	In the rare case where one wants to create a watcher but not start it at	317	In the rare case where one wants to create a watcher but not start it at
153	the same time, each constructor has a variant with a trailing C<_ns> in	318	the same time, each constructor has a variant with a trailing C<_ns> in
…		…
159		324
160	Also, all methods changing some aspect of a watcher (->set, ->priority,	325	Also, all methods changing some aspect of a watcher (->set, ->priority,
161	->fh and so on) automatically stop and start it again if it is active,	326	->fh and so on) automatically stop and start it again if it is active,
162	which means pending events get lost.	327	which means pending events get lost.
163		328
164	=head2 WATCHER TYPES	329	=head2 COMMON WATCHER METHODS
165		330
166	Now lets move to the existing watcher types and asociated methods.	331	This section lists methods common to all watchers.
167
168	The following methods are available for all watchers. Then followes a
169	description of each watcher constructor (EV::io, EV::timer, EV::periodic,
170	EV::signal, EV::child, EV::idle, EV::prepare and EV::check), followed by
171	any type-specific methods (if any).
172		332
173	=over 4	333	=over 4
174		334
175	=item $w->start	335	=item $w->start
176		336
…		…
180		340
181	=item $w->stop	341	=item $w->stop
182		342
183	Stop a watcher if it is active. Also clear any pending events (events that	343	Stop a watcher if it is active. Also clear any pending events (events that
184	have been received but that didn't yet result in a callback invocation),	344	have been received but that didn't yet result in a callback invocation),
185	regardless of wether the watcher was active or not.	345	regardless of whether the watcher was active or not.
186		346
187	=item $bool = $w->is_active	347	=item $bool = $w->is_active
188		348
189	Returns true if the watcher is active, false otherwise.	349	Returns true if the watcher is active, false otherwise.
		350
		351	=item $current_data = $w->data
		352
		353	=item $old_data = $w->data ($new_data)
		354
		355	Queries a freely usable data scalar on the watcher and optionally changes
		356	it. This is a way to associate custom data with a watcher:
		357
		358	my $w = EV::timer 60, 0, sub {
		359	warn $_[0]->data;
		360	};
		361	$w->data ("print me!");
190		362
191	=item $current_cb = $w->cb	363	=item $current_cb = $w->cb
192		364
193	=item $old_cb = $w->cb ($new_cb)	365	=item $old_cb = $w->cb ($new_cb)
194		366
…		…
203	watchers with higher priority will be invoked first. The valid range of	375	watchers with higher priority will be invoked first. The valid range of
204	priorities lies between EV::MAXPRI (default 2) and EV::MINPRI (default	376	priorities lies between EV::MAXPRI (default 2) and EV::MINPRI (default
205	-2). If the priority is outside this range it will automatically be	377	-2). If the priority is outside this range it will automatically be
206	normalised to the nearest valid priority.	378	normalised to the nearest valid priority.
207		379
208	The default priority of any newly-created weatcher is 0.	380	The default priority of any newly-created watcher is 0.
209		381
		382	Note that the priority semantics have not yet been fleshed out and are
		383	subject to almost certain change.
		384
210	=item $w->trigger ($revents)	385	=item $w->invoke ($revents)
211		386
212	Call the callback now with the given event mask.	387	Call the callback now with the given event mask.
213		388
		389	=item $w->feed_event ($revents)
		390
		391	Feed some events on this watcher into EV. EV will react to this call as if
		392	the watcher had received the given C<$revents> mask.
		393
		394	=item $revents = $w->clear_pending
		395
		396	If the watcher is pending, this function clears its pending status and
		397	returns its C<$revents> bitset (as if its callback was invoked). If the
		398	watcher isn't pending it does nothing and returns C<0>.
		399
		400	=item $previous_state = $w->keepalive ($bool)
		401
		402	Normally, C<EV::loop> will return when there are no active watchers
		403	(which is a "deadlock" because no progress can be made anymore). This is
		404	convinient because it allows you to start your watchers (and your jobs),
		405	call C<EV::loop> once and when it returns you know that all your jobs are
		406	finished (or they forgot to register some watchers for their task :).
		407
		408	Sometimes, however, this gets in your way, for example when the module
		409	that calls C<EV::loop> (usually the main program) is not the same module
		410	as a long-living watcher (for example a DNS client module written by
		411	somebody else even). Then you might want any outstanding requests to be
		412	handled, but you would not want to keep C<EV::loop> from returning just
		413	because you happen to have this long-running UDP port watcher.
		414
		415	In this case you can clear the keepalive status, which means that even
		416	though your watcher is active, it won't keep C<EV::loop> from returning.
		417
		418	The initial value for keepalive is true (enabled), and you cna change it
		419	any time.
		420
		421	Example: Register an I/O watcher for some UDP socket but do not keep the
		422	event loop from running just because of that watcher.
		423
		424	my $udp_socket = ...
		425	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
		426	$udp_watcher->keepalive (0);
		427
		428	=item $loop = $w->loop
		429
		430	Return the loop that this watcher is attached to.
		431
		432	=back
		433
		434
		435	=head1 WATCHER TYPES
		436
		437	Each of the following subsections describes a single watcher type.
		438
		439	=head3 I/O WATCHERS - is this file descriptor readable or writable?
		440
		441	=over 4
214		442
215	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	443	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
216		444
217	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback	445	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
218		446
		447	=item $w = $loop->io ($fileno_or_fh, $eventmask, $callback)
		448
		449	=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
		450
219	As long as the returned watcher object is alive, call the C<$callback>	451	As long as the returned watcher object is alive, call the C<$callback>
220	when the events specified in C<$eventmask>.	452	when at least one of events specified in C<$eventmask> occurs.
221		453
222	The $eventmask can be one or more of these constants ORed together:	454	The $eventmask can be one or more of these constants ORed together:
223		455
224	EV::READ wait until read() wouldn't block anymore	456	EV::READ wait until read() wouldn't block anymore
225	EV::WRITE wait until write() wouldn't block anymore	457	EV::WRITE wait until write() wouldn't block anymore
…		…
241		473
242	=item $old_eventmask = $w->events ($new_eventmask)	474	=item $old_eventmask = $w->events ($new_eventmask)
243		475
244	Returns the previously set event mask and optionally set a new one.	476	Returns the previously set event mask and optionally set a new one.
245		477
		478	=back
		479
		480
		481	=head3 TIMER WATCHERS - relative and optionally repeating timeouts
		482
		483	=over 4
246		484
247	=item $w = EV::timer $after, $repeat, $callback	485	=item $w = EV::timer $after, $repeat, $callback
248		486
249	=item $w = EV::timer_ns $after, $repeat, $callback	487	=item $w = EV::timer_ns $after, $repeat, $callback
250		488
251	Calls the callback after C<$after> seconds. If C<$repeat> is non-zero,	489	=item $w = $loop->timer ($after, $repeat, $callback)
252	the timer will be restarted (with the $repeat value as $after) after the	490
253	callback returns.	491	=item $w = $loop->timer_ns ($after, $repeat, $callback)
		492
		493	Calls the callback after C<$after> seconds (which may be fractional). If
		494	C<$repeat> is non-zero, the timer will be restarted (with the $repeat
		495	value as $after) after the callback returns.
254		496
255	This means that the callback would be called roughly after C<$after>	497	This means that the callback would be called roughly after C<$after>
256	seconds, and then every C<$repeat> seconds. "Roughly" because the time of	498	seconds, and then every C<$repeat> seconds. The timer does his best not
257	callback processing is not taken into account, so the timer will slowly	499	to drift, but it will not invoke the timer more often then once per event
258	drift. If that isn't acceptable, look at EV::periodic.	500	loop iteration, and might drift in other cases. If that isn't acceptable,
		501	look at EV::periodic, which can provide long-term stable timers.
259		502
260	The timer is based on a monotonic clock, that is if somebody is sitting	503	The timer is based on a monotonic clock, that is, if somebody is sitting
261	in front of the machine while the timer is running and changes the system	504	in front of the machine while the timer is running and changes the system
262	clock, the timer will nevertheless run (roughly) the same time.	505	clock, the timer will nevertheless run (roughly) the same time.
263		506
264	The C<timer_ns> variant doesn't start (activate) the newly created watcher.	507	The C<timer_ns> variant doesn't start (activate) the newly created watcher.
265		508
266	=item $w->set ($after, $repeat)	509	=item $w->set ($after, $repeat)
267		510
268	Reconfigures the watcher, see the constructor above for details. Can be at	511	Reconfigures the watcher, see the constructor above for details. Can be called at
269	any time.	512	any time.
270		513
271	=item $w->again	514	=item $w->again
272		515
273	Similar to the C<start> method, but has special semantics for repeating timers:	516	Similar to the C<start> method, but has special semantics for repeating timers:
		517
		518	If the timer is active and non-repeating, it will be stopped.
274		519
275	If the timer is active and repeating, reset the timeout to occur	520	If the timer is active and repeating, reset the timeout to occur
276	C<$repeat> seconds after now.	521	C<$repeat> seconds after now.
277		522
278	If the timer is active and non-repeating, it will be stopped.
279
280	If the timer is in active and repeating, start it.	523	If the timer is inactive and repeating, start it using the repeat value.
281		524
282	Otherwise do nothing.	525	Otherwise do nothing.
283		526
284	This behaviour is useful when you have a timeout for some IO	527	This behaviour is useful when you have a timeout for some IO
285	operation. You create a timer object with the same value for C<$after> and	528	operation. You create a timer object with the same value for C<$after> and
286	C<$repeat>, and then, in the read/write watcher, run the C<again> method	529	C<$repeat>, and then, in the read/write watcher, run the C<again> method
287	on the timeout.	530	on the timeout.
288		531
		532	=back
289		533
		534
		535	=head3 PERIODIC WATCHERS - to cron or not to cron?
		536
		537	=over 4
		538
290	=item $w = EV::periodic $at, $interval, $callback	539	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
291		540
292	=item $w = EV::periodic_ns $at, $interval, $callback	541	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
293		542
294	Similar to EV::timer, but the time is given as an absolute point in time	543	=item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
295	(C<$at>), plus an optional C<$interval>.
296		544
297	If the C<$interval> is zero, then the callback will be called at the time	545	=item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback)
298	C<$at> if that is in the future, or as soon as possible if it is in the
299	past. It will not automatically repeat.
300		546
301	If the C<$interval> is nonzero, then the watcher will always be scheduled	547	Similar to EV::timer, but is not based on relative timeouts but on
302	to time out at the next C<$at + N * $interval> time.	548	absolute times. Apart from creating "simple" timers that trigger "at" the
		549	specified time, it can also be used for non-drifting absolute timers and
		550	more complex, cron-like, setups that are not adversely affected by time
		551	jumps (i.e. when the system clock is changed by explicit date -s or other
		552	means such as ntpd). It is also the most complex watcher type in EV.
303		553
304	This can be used to schedule a callback to run at very regular intervals,	554	It has three distinct "modes":
305	as long as the processing time is less then the interval (otherwise	555
306	obviously events will be skipped).	556	=over 4
		557
		558	=item * absolute timer ($interval = $reschedule_cb = 0)
		559
		560	This time simply fires at the wallclock time C<$at> and doesn't repeat. It
		561	will not adjust when a time jump occurs, that is, if it is to be run
		562	at January 1st 2011 then it will run when the system time reaches or
		563	surpasses this time.
		564
		565	=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
		566
		567	In this mode the watcher will always be scheduled to time out at the
		568	next C<$at + N * $interval> time (for some integer N) and then repeat,
		569	regardless of any time jumps.
		570
		571	This can be used to create timers that do not drift with respect to system
		572	time:
		573
		574	my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" };
		575
		576	That doesn't mean there will always be 3600 seconds in between triggers,
		577	but only that the the clalback will be called when the system time shows a
		578	full hour (UTC).
307		579
308	Another way to think about it (for the mathematically inclined) is that	580	Another way to think about it (for the mathematically inclined) is that
309	EV::periodic will try to run the callback at the next possible time where	581	EV::periodic will try to run the callback in this mode at the next
310	C<$time = $at (mod $interval)>, regardless of any time jumps.	582	possible time where C<$time = $at (mod $interval)>, regardless of any time
		583	jumps.
311		584
312	This periodic timer is based on "wallclock time", that is, if the clock	585	=item * manual reschedule mode ($reschedule_cb = coderef)
313	changes (C<ntp>, C<date -s> etc.), then the timer will nevertheless run at	586
314	the specified time. This means it will never drift (it might jitter, but	587	In this mode $interval and $at are both being ignored. Instead, each
315	it will not drift).	588	time the periodic watcher gets scheduled, the reschedule callback
		589	($reschedule_cb) will be called with the watcher as first, and the current
		590	time as second argument.
		591
		592	I<This callback MUST NOT stop or destroy this or any other periodic
		593	watcher, ever, and MUST NOT call any event loop functions or methods>. If
		594	you need to stop it, return 1e30 and stop it afterwards. You may create
		595	and start a C<EV::prepare> watcher for this task.
		596
		597	It must return the next time to trigger, based on the passed time value
		598	(that is, the lowest time value larger than or equal to to the second
		599	argument). It will usually be called just before the callback will be
		600	triggered, but might be called at other times, too.
		601
		602	This can be used to create very complex timers, such as a timer that
		603	triggers on each midnight, local time (actually 24 hours after the last
		604	midnight, to keep the example simple. If you know a way to do it correctly
		605	in about the same space (without requiring elaborate modules), drop me a
		606	note :):
		607
		608	my $daily = EV::periodic 0, 0, sub {
		609	my ($w, $now) = @_;
		610
		611	use Time::Local ();
		612	my (undef, undef, undef, $d, $m, $y) = localtime $now;
		613	86400 + Time::Local::timelocal 0, 0, 0, $d, $m, $y
		614	}, sub {
		615	print "it's midnight or likely shortly after, now\n";
		616	};
		617
		618	=back
316		619
317	The C<periodic_ns> variant doesn't start (activate) the newly created watcher.	620	The C<periodic_ns> variant doesn't start (activate) the newly created watcher.
318		621
319	=item $w->set ($at, $interval)	622	=item $w->set ($at, $interval, $reschedule_cb)
320		623
321	Reconfigures the watcher, see the constructor above for details. Can be at	624	Reconfigures the watcher, see the constructor above for details. Can be called at
322	any time.	625	any time.
323		626
		627	=item $w->again
		628
		629	Simply stops and starts the watcher again.
		630
		631	=item $time = $w->at
		632
		633	Return the time that the watcher is expected to trigger next.
		634
		635	=back
		636
		637
		638	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
		639
		640	=over 4
324		641
325	=item $w = EV::signal $signal, $callback	642	=item $w = EV::signal $signal, $callback
326		643
327	=item $w = EV::signal_ns $signal, $callback	644	=item $w = EV::signal_ns $signal, $callback
328		645
329	Call the callback when $signal is received (the signal can be specified	646	Call the callback when $signal is received (the signal can be specified by
330	by number or by name, just as with kill or %SIG).	647	number or by name, just as with C<kill> or C<%SIG>).
331		648
332	EV will grab the signal for the process (the kernel only allows one	649	EV will grab the signal for the process (the kernel only allows one
333	component to receive a signal at a time) when you start a signal watcher,	650	component to receive a signal at a time) when you start a signal watcher,
334	and removes it again when you stop it. Perl does the same when you	651	and removes it again when you stop it. Perl does the same when you
335	add/remove callbacks to %SIG, so watch out.	652	add/remove callbacks to C<%SIG>, so watch out.
336		653
337	You can have as many signal watchers per signal as you want.	654	You can have as many signal watchers per signal as you want.
338		655
339	The C<signal_ns> variant doesn't start (activate) the newly created watcher.	656	The C<signal_ns> variant doesn't start (activate) the newly created watcher.
340		657
341	=item $w->set ($signal)	658	=item $w->set ($signal)
342		659
343	Reconfigures the watcher, see the constructor above for details. Can be at	660	Reconfigures the watcher, see the constructor above for details. Can be
344	any time.	661	called at any time.
345		662
346	=item $current_signum = $w->signal	663	=item $current_signum = $w->signal
347		664
348	=item $old_signum = $w->signal ($new_signal)	665	=item $old_signum = $w->signal ($new_signal)
349		666
350	Returns the previously set signal (always as a number not name) and	667	Returns the previously set signal (always as a number not name) and
351	optionally set a new one.	668	optionally set a new one.
352		669
		670	=back
353		671
		672
		673	=head3 CHILD WATCHERS - watch out for process status changes
		674
		675	=over 4
		676
354	=item $w = EV::child $pid, $callback	677	=item $w = EV::child $pid, $trace, $callback
355		678
356	=item $w = EV::child_ns $pid, $callback	679	=item $w = EV::child_ns $pid, $trace, $callback
		680
		681	=item $w = $loop->child ($pid, $trace, $callback)
		682
		683	=item $w = $loop->child_ns ($pid, $trace, $callback)
357		684
358	Call the callback when a status change for pid C<$pid> (or any pid	685	Call the callback when a status change for pid C<$pid> (or any pid
359	if C<$pid> is 0) has been received. More precisely: when the process	686	if C<$pid> is 0) has been received (a status change happens when the
		687	process terminates or is killed, or, when trace is true, additionally when
		688	it is stopped or continued). More precisely: when the process receives
360	receives a SIGCHLD, EV will fetch the outstanding exit/wait status for all	689	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
361	changed/zombie children and call the callback.	690	changed/zombie children and call the callback.
362		691
363	You can access both status and pid by using the C<rstatus> and C<rpid>	692	It is valid (and fully supported) to install a child watcher after a child
364	methods on the watcher object.	693	has exited but before the event loop has started its next iteration (for
		694	example, first you C<fork>, then the new child process might exit, and
		695	only then do you install a child watcher in the parent for the new pid).
365		696
		697	You can access both exit (or tracing) status and pid by using the
		698	C<rstatus> and C<rpid> methods on the watcher object.
		699
366	You can have as many pid watchers per pid as you want.	700	You can have as many pid watchers per pid as you want, they will all be
		701	called.
367		702
368	The C<child_ns> variant doesn't start (activate) the newly created watcher.	703	The C<child_ns> variant doesn't start (activate) the newly created watcher.
369		704
370	=item $w->set ($pid)	705	=item $w->set ($pid, $trace)
371		706
372	Reconfigures the watcher, see the constructor above for details. Can be at	707	Reconfigures the watcher, see the constructor above for details. Can be called at
373	any time.	708	any time.
374		709
375	=item $current_pid = $w->pid	710	=item $current_pid = $w->pid
376
377	=item $old_pid = $w->pid ($new_pid)
378		711
379	Returns the previously set process id and optionally set a new one.	712	Returns the previously set process id and optionally set a new one.
380		713
381	=item $exit_status = $w->rstatus	714	=item $exit_status = $w->rstatus
382		715
…		…
386	=item $pid = $w->rpid	719	=item $pid = $w->rpid
387		720
388	Return the pid of the awaited child (useful when you have installed a	721	Return the pid of the awaited child (useful when you have installed a
389	watcher for all pids).	722	watcher for all pids).
390		723
		724	=back
		725
		726
		727	=head3 STAT WATCHERS - did the file attributes just change?
		728
		729	=over 4
		730
		731	=item $w = EV::stat $path, $interval, $callback
		732
		733	=item $w = EV::stat_ns $path, $interval, $callback
		734
		735	=item $w = $loop->stat ($path, $interval, $callback)
		736
		737	=item $w = $loop->stat_ns ($path, $interval, $callback)
		738
		739	Call the callback when a file status change has been detected on
		740	C<$path>. The C<$path> does not need to exist, changing from "path exists"
		741	to "path does not exist" is a status change like any other.
		742
		743	The C<$interval> is a recommended polling interval for systems where
		744	OS-supported change notifications don't exist or are not supported. If
		745	you use C<0> then an unspecified default is used (which is highly
		746	recommended!), which is to be expected to be around five seconds usually.
		747
		748	This watcher type is not meant for massive numbers of stat watchers,
		749	as even with OS-supported change notifications, this can be
		750	resource-intensive.
		751
		752	The C<stat_ns> variant doesn't start (activate) the newly created watcher.
		753
		754	=item ... = $w->stat
		755
		756	This call is very similar to the perl C<stat> built-in: It stats (using
		757	C<lstat>) the path specified in the watcher and sets perls stat cache (as
		758	well as EV's idea of the current stat values) to the values found.
		759
		760	In scalar context, a boolean is return indicating success or failure of
		761	the stat. In list context, the same 13-value list as with stat is returned
		762	(except that the blksize and blocks fields are not reliable).
		763
		764	In the case of an error, errno is set to C<ENOENT> (regardless of the
		765	actual error value) and the C<nlink> value is forced to zero (if the stat
		766	was successful then nlink is guaranteed to be non-zero).
		767
		768	See also the next two entries for more info.
		769
		770	=item ... = $w->attr
		771
		772	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		773	the values most recently detected by EV. See the next entry for more info.
		774
		775	=item ... = $w->prev
		776
		777	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		778	the previous set of values, before the change.
		779
		780	That is, when the watcher callback is invoked, C<< $w->prev >> will be set
		781	to the values found I<before> a change was detected, while C<< $w->attr >>
		782	returns the values found leading to the change detection. The difference (if any)
		783	between C<prev> and C<attr> is what triggered the callback.
		784
		785	If you did something to the filesystem object and do not want to trigger
		786	yet another change, you can call C<stat> to update EV's idea of what the
		787	current attributes are.
		788
		789	=item $w->set ($path, $interval)
		790
		791	Reconfigures the watcher, see the constructor above for details. Can be
		792	called at any time.
		793
		794	=item $current_path = $w->path
		795
		796	=item $old_path = $w->path ($new_path)
		797
		798	Returns the previously set path and optionally set a new one.
		799
		800	=item $current_interval = $w->interval
		801
		802	=item $old_interval = $w->interval ($new_interval)
		803
		804	Returns the previously set interval and optionally set a new one. Can be
		805	used to query the actual interval used.
		806
		807	=back
		808
		809
		810	=head3 IDLE WATCHERS - when you've got nothing better to do...
		811
		812	=over 4
391		813
392	=item $w = EV::idle $callback	814	=item $w = EV::idle $callback
393		815
394	=item $w = EV::idle_ns $callback	816	=item $w = EV::idle_ns $callback
395		817
396	Call the callback when there are no pending io, timer/periodic, signal or	818	=item $w = $loop->idle ($callback)
397	child events, i.e. when the process is idle.	819
		820	=item $w = $loop->idle_ns ($callback)
		821
		822	Call the callback when there are no other pending watchers of the same or
		823	higher priority (excluding check, prepare and other idle watchers of the
		824	same or lower priority, of course). They are called idle watchers because
		825	when the watcher is the highest priority pending event in the process, the
		826	process is considered to be idle at that priority.
		827
		828	If you want a watcher that is only ever called when I<no> other events are
		829	outstanding you have to set the priority to C<EV::MINPRI>.
398		830
399	The process will not block as long as any idle watchers are active, and	831	The process will not block as long as any idle watchers are active, and
400	they will be called repeatedly until stopped.	832	they will be called repeatedly until stopped.
401		833
		834	For example, if you have idle watchers at priority C<0> and C<1>, and
		835	an I/O watcher at priority C<0>, then the idle watcher at priority C<1>
		836	and the I/O watcher will always run when ready. Only when the idle watcher
		837	at priority C<1> is stopped and the I/O watcher at priority C<0> is not
		838	pending with the C<0>-priority idle watcher be invoked.
		839
402	The C<idle_ns> variant doesn't start (activate) the newly created watcher.	840	The C<idle_ns> variant doesn't start (activate) the newly created watcher.
403		841
		842	=back
		843
		844
		845	=head3 PREPARE WATCHERS - customise your event loop!
		846
		847	=over 4
404		848
405	=item $w = EV::prepare $callback	849	=item $w = EV::prepare $callback
406		850
407	=item $w = EV::prepare_ns $callback	851	=item $w = EV::prepare_ns $callback
		852
		853	=item $w = $loop->prepare ($callback)
		854
		855	=item $w = $loop->prepare_ns ($callback)
408		856
409	Call the callback just before the process would block. You can still	857	Call the callback just before the process would block. You can still
410	create/modify any watchers at this point.	858	create/modify any watchers at this point.
411		859
412	See the EV::check watcher, below, for explanations and an example.	860	See the EV::check watcher, below, for explanations and an example.
413		861
414	The C<prepare_ns> variant doesn't start (activate) the newly created watcher.	862	The C<prepare_ns> variant doesn't start (activate) the newly created watcher.
415		863
		864	=back
		865
		866
		867	=head3 CHECK WATCHERS - customise your event loop even more!
		868
		869	=over 4
416		870
417	=item $w = EV::check $callback	871	=item $w = EV::check $callback
418		872
419	=item $w = EV::check_ns $callback	873	=item $w = EV::check_ns $callback
		874
		875	=item $w = $loop->check ($callback)
		876
		877	=item $w = $loop->check_ns ($callback)
420		878
421	Call the callback just after the process wakes up again (after it has	879	Call the callback just after the process wakes up again (after it has
422	gathered events), but before any other callbacks have been invoked.	880	gathered events), but before any other callbacks have been invoked.
423		881
424	This is used to integrate other event-based software into the EV	882	This is used to integrate other event-based software into the EV
…		…
432	# do nothing unless active	890	# do nothing unless active
433	$dispatcher->{_event_queue_h}	891	$dispatcher->{_event_queue_h}
434	or return;	892	or return;
435		893
436	# make the dispatcher handle any outstanding stuff	894	# make the dispatcher handle any outstanding stuff
		895	... not shown
437		896
438	# create an IO watcher for each and every socket	897	# create an I/O watcher for each and every socket
439	@snmp_watcher = (	898	@snmp_watcher = (
440	(map { EV::io $_, EV::READ, sub { } }	899	(map { EV::io $_, EV::READ, sub { } }
441	keys %{ $dispatcher->{_descriptors} }),	900	keys %{ $dispatcher->{_descriptors} }),
		901
		902	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
		903	? $event->[Net::SNMP::Dispatcher::_TIME] - EV::now : 0),
		904	0, sub { },
442	);	905	);
443
444	# if there are any timeouts, also create a timer
445	push @snmp_watcher, EV::timer $event->[Net::SNMP::Dispatcher::_TIME] - EV::now, 0, sub { }
446	if $event->[Net::SNMP::Dispatcher::_ACTIVE];
447	};	906	};
448		907
449	The callbacks are irrelevant, the only purpose of those watchers is	908	The callbacks are irrelevant (and are not even being called), the
450	to wake up the process as soon as one of those events occurs (socket	909	only purpose of those watchers is to wake up the process as soon as
451	readable, or timer timed out). The corresponding EV::check watcher will then	910	one of those events occurs (socket readable, or timer timed out). The
452	clean up:	911	corresponding EV::check watcher will then clean up:
453		912
454	our $snmp_check = EV::check sub {	913	our $snmp_check = EV::check sub {
455	# destroy all watchers	914	# destroy all watchers
456	@snmp_watcher = ();	915	@snmp_watcher = ();
457		916
458	# make the dispatcher handle any new stuff	917	# make the dispatcher handle any new stuff
		918	... not shown
459	};	919	};
460		920
461	The callbacks of the created watchers will not be called as the watchers	921	The callbacks of the created watchers will not be called as the watchers
462	are destroyed before this cna happen (remember EV::check gets called	922	are destroyed before this cna happen (remember EV::check gets called
463	first).	923	first).
464		924
465	The C<check_ns> variant doesn't start (activate) the newly created watcher.	925	The C<check_ns> variant doesn't start (activate) the newly created watcher.
466		926
467	=back	927	=back
468		928
		929
		930	=head3 FORK WATCHERS - the audacity to resume the event loop after a fork
		931
		932	Fork watchers are called when a C<fork ()> was detected. The invocation
		933	is done before the event loop blocks next and before C<check> watchers
		934	are being called, and only in the child after the fork.
		935
		936	=over 4
		937
		938	=item $w = EV::fork $callback
		939
		940	=item $w = EV::fork_ns $callback
		941
		942	=item $w = $loop->fork ($callback)
		943
		944	=item $w = $loop->fork_ns ($callback)
		945
		946	Call the callback before the event loop is resumed in the child process
		947	after a fork.
		948
		949	The C<fork_ns> variant doesn't start (activate) the newly created watcher.
		950
		951	=back
		952
		953
		954	=head3 EMBED WATCHERS - when one backend isn't enough...
		955
		956	This is a rather advanced watcher type that lets you embed one event loop
		957	into another (currently only IO events are supported in the embedded
		958	loop, other types of watchers might be handled in a delayed or incorrect
		959	fashion and must not be used).
		960
		961	See the libev documentation at
		962	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
		963	(locally installed as F<EV::c_doc>) for more details.
		964
		965	In short, this watcher is most useful on BSD systems without working
		966	kqueue to still be able to handle a large number of sockets:
		967
		968	my $socket_loop;
		969
		970	# check wether we use SELECT or POLL _and_ KQUEUE is supported
		971	if (
		972	(EV::backend & (EV::BACKEND_POLL \| EV::BACKEND_SELECT))
		973	&& (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
		974	) {
		975	# use kqueue for sockets
		976	$socket_loop = new EV::Loop EV::BACKEND_KQUEUE \| EV::FLAG_NOENV;
		977	}
		978
		979	# use the default loop otherwise
		980	$socket_loop \|\|= EV::default_loop;
		981
		982	=over 4
		983
		984	=item $w = EV::embed $otherloop[, $callback]
		985
		986	=item $w = EV::embed_ns $otherloop[, $callback]
		987
		988	=item $w = $loop->embed ($otherloop[, $callback])
		989
		990	=item $w = $loop->embed_ns ($otherloop[, $callback])
		991
		992	Call the callback when the embedded event loop (C<$otherloop>) has any
		993	I/O activity. The C<$callback> is optional: if it is missing, then the
		994	embedded event loop will be managed automatically (which is recommended),
		995	otherwise you have to invoke C<sweep> yourself.
		996
		997	The C<embed_ns> variant doesn't start (activate) the newly created watcher.
		998
		999	=back
		1000
		1001	=head3 ASYNC WATCHERS - how to wake up another event loop
		1002
		1003	Async watchers are provided by EV, but have little use in perl directly, as perl
		1004	neither supports threads nor direct access to signal handlers or other
		1005	contexts where they could be of value.
		1006
		1007	It is, however, possible to use them from the XS level.
		1008
		1009	Please see the libev documentation for further details.
		1010
		1011	=over 4
		1012
		1013	=item $w = EV::async $callback
		1014
		1015	=item $w = EV::async_ns $callback
		1016
		1017	=item $w->send
		1018
		1019	=item $bool = $w->async_pending
		1020
		1021	=back
		1022
		1023
		1024	=head1 PERL SIGNALS
		1025
		1026	While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour
		1027	with EV is as the same as any other C library: Perl-signals will only be
		1028	handled when Perl runs, which means your signal handler might be invoked
		1029	only the next time an event callback is invoked.
		1030
		1031	The solution is to use EV signal watchers (see C<EV::signal>), which will
		1032	ensure proper operations with regards to other event watchers.
		1033
		1034	If you cannot do this for whatever reason, you can also force a watcher
		1035	to be called on every event loop iteration by installing a C<EV::check>
		1036	watcher:
		1037
		1038	my $async_check = EV::check sub { };
		1039
		1040	This ensures that perl gets into control for a short time to handle any
		1041	pending signals, and also ensures (slightly) slower overall operation.
		1042
469	=head1 THREADS	1043	=head1 THREADS
470		1044
471	Threads are not supported by this in any way. Perl pseudo-threads is evil	1045	Threads are not supported by this module in any way. Perl pseudo-threads
472	stuff and must die.	1046	is evil stuff and must die. As soon as Perl gains real threads I will work
		1047	on thread support for it.
		1048
		1049	=head1 FORK
		1050
		1051	Most of the "improved" event delivering mechanisms of modern operating
		1052	systems have quite a few problems with fork(2) (to put it bluntly: it is
		1053	not supported and usually destructive). Libev makes it possible to work
		1054	around this by having a function that recreates the kernel state after
		1055	fork in the child.
		1056
		1057	On non-win32 platforms, this module requires the pthread_atfork
		1058	functionality to do this automatically for you. This function is quite
		1059	buggy on most BSDs, though, so YMMV. The overhead for this is quite
		1060	negligible, because everything the function currently does is set a flag
		1061	that is checked only when the event loop gets used the next time, so when
		1062	you do fork but not use EV, the overhead is minimal.
		1063
		1064	On win32, there is no notion of fork so all this doesn't apply, of course.
473		1065
474	=cut	1066	=cut
475		1067
476	our $DIED = sub {	1068	our $DIED = sub {
477	warn "EV: error in callback (ignoring): $@";	1069	warn "EV: error in callback (ignoring): $@";
478	};	1070	};
479		1071
480	default_loop	1072	default_loop
481	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	1073	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
482
483	push @AnyEvent::REGISTRY, [EV => "EV::AnyEvent"];
484		1074
485	1;	1075	1;
486		1076
487	=head1 SEE ALSO	1077	=head1 SEE ALSO
488		1078
489	L<EV::DNS>, L<EV::AnyEvent>.	1079	L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as
		1080	event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
		1081	coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
		1082	event-loop agnostic and portable event driven programming.
490		1083
491	=head1 AUTHOR	1084	=head1 AUTHOR
492		1085
493	Marc Lehmann <schmorp@schmorp.de>	1086	Marc Lehmann <schmorp@schmorp.de>
494	http://home.schmorp.de/	1087	http://home.schmorp.de/
495		1088
496	=cut	1089	=cut
497		1090

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Comparing EV/EV.pm (file contents): Revision 1.28 by root, Sun Nov 4 16:52:52 2007 UTC vs. Revision 1.104 by root, Thu Oct 2 12:26:25 2008 UTC

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Comparing EV/EV.pm (file contents):
Revision 1.28 by root, Sun Nov 4 16:52:52 2007 UTC vs.
Revision 1.104 by root, Thu Oct 2 12:26:25 2008 UTC