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

Comparing EV/EV.pm (file contents):
Revision 1.54 by root, Tue Nov 27 07:27:10 2007 UTC vs.
Revision 1.111 by root, Wed Jan 7 20:53:29 2009 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 {
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
39
40	my $w = EV::child 666, sub {
41	my ($w, $revents) = @_;
42	my $status = $w->rstatus;
43	};
44
45	# STAT CHANGES	45	# STAT CHANGES
46	my $w = EV::stat "/etc/passwd", 10, sub {	46	my $w = EV::stat "/etc/passwd", 10, sub {
47	my ($w, $revents) = @_;	47	my ($w, $revents) = @_;
48	warn $w->path, " has changed somehow.\n";	48	warn $w->path, " has changed somehow.\n";
49	};	49	};
50		50
51	# MAINLOOP	51	# MAINLOOP
52	EV::loop; # loop until EV::unloop is called or all watchers stop	52	EV::loop; # loop until EV::unloop is called or all watchers stop
53	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
54	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
55		55
56	=head1 DESCRIPTION	56	=head1 DESCRIPTION
57		57
58	This module provides an interface to libev	58	This module provides an interface to libev
59	(L<http://software.schmorp.de/pkg/libev.html>). While the documentation	59	(L<http://software.schmorp.de/pkg/libev.html>). While the documentation
60	below is comprehensive, one might also consult the documentation of libev	60	below is comprehensive, one might also consult the documentation of
61	itself (L<http://cvs.schmorp.de/libev/ev.html>) for more subtle details on	61	libev itself (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod> or
62	watcher semantics or some discussion on the available backends, or how to	62	F<perldoc EV::libev>) for more subtle details on watcher semantics or some
63	force a specific backend with C<LIBEV_FLAGS>.	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.
		72
		73	=head2 MODULE EXPORTS
		74
		75	This module does not export any symbols.
64		76
65	=cut	77	=cut
66		78
67	package EV;	79	package EV;
68		80
		81	no warnings;
69	use strict;	82	use strict;
70		83
71	BEGIN {	84	BEGIN {
72	our $VERSION = '1.4';	85	our $VERSION = '3.52';
73	use XSLoader;	86	use XSLoader;
74	XSLoader::load "EV", $VERSION;	87	XSLoader::load "EV", $VERSION;
75	}	88	}
76		89
77	@EV::IO::ISA =	90	@EV::IO::ISA =
78	@EV::Timer::ISA =	91	@EV::Timer::ISA =
79	@EV::Periodic::ISA =	92	@EV::Periodic::ISA =
80	@EV::Signal::ISA =	93	@EV::Signal::ISA =
		94	@EV::Child::ISA =
		95	@EV::Stat::ISA =
81	@EV::Idle::ISA =	96	@EV::Idle::ISA =
82	@EV::Prepare::ISA =	97	@EV::Prepare::ISA =
83	@EV::Check::ISA =	98	@EV::Check::ISA =
84	@EV::Child::ISA =
85	@EV::Embed::ISA =	99	@EV::Embed::ISA =
86	@EV::Stat::ISA = "EV::Watcher";	100	@EV::Fork::ISA =
		101	@EV::Async::ISA =
		102	"EV::Watcher";
		103
		104	@EV::Loop::Default::ISA = "EV::Loop";
		105
		106	=head1 EVENT LOOPS
		107
		108	EV supports multiple event loops: There is a single "default event loop"
		109	that can handle everything including signals and child watchers, and any
		110	number of "dynamic event loops" that can use different backends (with
		111	various limitations), but no child and signal watchers.
		112
		113	You do not have to do anything to create the default event loop: When
		114	the module is loaded a suitable backend is selected on the premise of
		115	selecting a working backend (which for example rules out kqueue on most
		116	BSDs). Modules should, unless they have "special needs" always use the
		117	default loop as this is fastest (perl-wise), best supported by other
		118	modules (e.g. AnyEvent or Coro) and most portable event loop.
		119
		120	For specific programs you can create additional event loops dynamically.
		121
		122	If you want to take advantage of kqueue (which often works properly for
		123	sockets only) even though the default loop doesn't enable it, you can
		124	I<embed> a kqueue loop into the default loop: running the default loop
		125	will then also service the kqueue loop to some extent. See the example in
		126	the section about embed watchers for an example on how to achieve that.
		127
		128	=over 4
		129
		130	=item $loop = new EV::loop [$flags]
		131
		132	Create a new event loop as per the specified flags. Please refer to
		133	the C<ev_loop_new ()> function description in the libev documentation
		134	(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>,
		135	or locally-installed as F<EV::libev> manpage) for more info.
		136
		137	The loop will automatically be destroyed when it is no longer referenced
		138	by any watcher and the loop object goes out of scope.
		139
		140	If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK>
		141	is recommended, as only the default event loop is protected by this
		142	module. If you I<are> embedding this loop in the default loop, this is not
		143	necessary, as C<EV::embed> automatically does the right thing on fork.
		144
		145	=item $loop->loop_fork
		146
		147	Must be called after a fork in the child, before entering or continuing
		148	the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
		149	this function automatically, at some performance loss (refer to the libev
		150	documentation).
		151
		152	=item $loop->loop_verify
		153
		154	Calls C<ev_verify> to make internal consistency checks (for debugging
		155	libev) and abort the program if any data structures were found to be
		156	corrupted.
		157
		158	=item $loop = EV::default_loop [$flags]
		159
		160	Return the default loop (which is a singleton object). Since this module
		161	already creates the default loop with default flags, specifying flags here
		162	will not have any effect unless you destroy the default loop first, which
		163	isn't supported. So in short: don't do it, and if you break it, you get to
		164	keep the pieces.
		165
		166	=back
		167
87		168
88	=head1 BASIC INTERFACE	169	=head1 BASIC INTERFACE
89		170
90	=over 4	171	=over 4
91		172
92	=item $EV::DIED	173	=item $EV::DIED
93		174
94	Must contain a reference to a function that is called when a callback	175	Must contain a reference to a function that is called when a callback
95	throws an exception (with $@ containing thr error). The default prints an	176	throws an exception (with $@ containing the error). The default prints an
96	informative message and continues.	177	informative message and continues.
97		178
98	If this callback throws an exception it will be silently ignored.	179	If this callback throws an exception it will be silently ignored.
99		180
		181	=item $flags = EV::supported_backends
		182
		183	=item $flags = EV::recommended_backends
		184
		185	=item $flags = EV::embeddable_backends
		186
		187	Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this
		188	instance of EV, the set of recommended backends (supposed to be good) for
		189	this platform and the set of embeddable backends (see EMBED WATCHERS).
		190
		191	=item EV::sleep $seconds
		192
		193	Block the process for the given number of (fractional) seconds.
		194
100	=item $time = EV::time	195	=item $time = EV::time
101		196
102	Returns the current time in (fractional) seconds since the epoch.	197	Returns the current time in (fractional) seconds since the epoch.
103		198
104	=item $time = EV::now	199	=item $time = EV::now
105		200
		201	=item $time = $loop->now
		202
106	Returns the time the last event loop iteration has been started. This	203	Returns the time the last event loop iteration has been started. This
107	is the time that (relative) timers are based on, and refering to it is	204	is the time that (relative) timers are based on, and referring to it is
108	usually faster then calling EV::time.	205	usually faster then calling EV::time.
109		206
110	=item $method = EV::method	207	=item $backend = EV::backend
111		208
		209	=item $backend = $loop->backend
		210
112	Returns an integer describing the backend used by libev (EV::METHOD_SELECT	211	Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
113	or EV::METHOD_EPOLL).	212	or EV::BACKEND_EPOLL).
114		213
115	=item EV::loop [$flags]	214	=item EV::loop [$flags]
		215
		216	=item $loop->loop ([$flags])
116		217
117	Begin checking for events and calling callbacks. It returns when a	218	Begin checking for events and calling callbacks. It returns when a
118	callback calls EV::unloop.	219	callback calls EV::unloop.
119		220
120	The $flags argument can be one of the following:	221	The $flags argument can be one of the following:
…		…
123	EV::LOOP_ONESHOT block at most once (wait, but do not loop)	224	EV::LOOP_ONESHOT block at most once (wait, but do not loop)
124	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)	225	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
125		226
126	=item EV::unloop [$how]	227	=item EV::unloop [$how]
127		228
		229	=item $loop->unloop ([$how])
		230
128	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the	231	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the
129	innermost call to EV::loop return.	232	innermost call to EV::loop return.
130		233
131	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as	234	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as
132	fast as possible.	235	fast as possible.
133		236
		237	=item $count = EV::loop_count
		238
		239	=item $count = $loop->loop_count
		240
		241	Return the number of times the event loop has polled for new
		242	events. Sometimes useful as a generation counter.
		243
134	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)	244	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
		245
		246	=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
135		247
136	This function rolls together an I/O and a timer watcher for a single	248	This function rolls together an I/O and a timer watcher for a single
137	one-shot event without the need for managing a watcher object.	249	one-shot event without the need for managing a watcher object.
138		250
139	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>	251	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>
…		…
145	If timeout is C<undef> or negative, then there will be no	257	If timeout is C<undef> or negative, then there will be no
146	timeout. Otherwise a EV::timer with this value will be started.	258	timeout. Otherwise a EV::timer with this value will be started.
147		259
148	When an error occurs or either the timeout or I/O watcher triggers, then	260	When an error occurs or either the timeout or I/O watcher triggers, then
149	the callback will be called with the received event set (in general	261	the callback will be called with the received event set (in general
150	you can expect it to be a combination of C<EV:ERROR>, C<EV::READ>,	262	you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
151	C<EV::WRITE> and C<EV::TIMEOUT>).	263	C<EV::WRITE> and C<EV::TIMEOUT>).
152		264
153	EV::once doesn't return anything: the watchers stay active till either	265	EV::once doesn't return anything: the watchers stay active till either
154	of them triggers, then they will be stopped and freed, and the callback	266	of them triggers, then they will be stopped and freed, and the callback
155	invoked.	267	invoked.
156		268
157	=back	269	=item EV::feed_fd_event ($fd, $revents)
158		270
		271	=item $loop->feed_fd_event ($fd, $revents)
		272
		273	Feed an event on a file descriptor into EV. EV will react to this call as
		274	if the readyness notifications specified by C<$revents> (a combination of
		275	C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
		276
		277	=item EV::feed_signal_event ($signal)
		278
		279	Feed a signal event into EV. EV will react to this call as if the signal
		280	specified by C<$signal> had occured.
		281
		282	=item EV::set_io_collect_interval $time
		283
		284	=item $loop->set_io_collect_interval ($time)
		285
		286	=item EV::set_timeout_collect_interval $time
		287
		288	=item $loop->set_timeout_collect_interval ($time)
		289
		290	These advanced functions set the minimum block interval when polling for I/O events and the minimum
		291	wait interval for timer events. See the libev documentation at
		292	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP>
		293	(locally installed as F<EV::libev>) for a more detailed discussion.
		294
		295	=back
		296
		297
159	=head2 WATCHER OBJECTS	298	=head1 WATCHER OBJECTS
160		299
161	A watcher is an object that gets created to record your interest in some	300	A watcher is an object that gets created to record your interest in some
162	event. For instance, if you want to wait for STDIN to become readable, you	301	event. For instance, if you want to wait for STDIN to become readable, you
163	would create an EV::io watcher for that:	302	would create an EV::io watcher for that:
164		303
165	my $watcher = EV::io *STDIN, EV::READ, sub {	304	my $watcher = EV::io *STDIN, EV::READ, sub {
166	my ($watcher, $revents) = @_;	305	my ($watcher, $revents) = @_;
167	warn "yeah, STDIN should not be readable without blocking!\n"	306	warn "yeah, STDIN should now be readable without blocking!\n"
168	};	307	};
169		308
170	All watchers can be active (waiting for events) or inactive (paused). Only	309	All watchers can be active (waiting for events) or inactive (paused). Only
171	active watchers will have their callbacks invoked. All callbacks will be	310	active watchers will have their callbacks invoked. All callbacks will be
172	called with at least two arguments: the watcher and a bitmask of received	311	called with at least two arguments: the watcher and a bitmask of received
173	events.	312	events.
174		313
175	Each watcher type has its associated bit in revents, so you can use the	314	Each watcher type has its associated bit in revents, so you can use the
176	same callback for multiple watchers. The event mask is named after the	315	same callback for multiple watchers. The event mask is named after the
177	type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,	316	type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
178	EV::periodic sets EV::PERIODIC and so on, with the exception of IO events	317	EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events
179	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which	318	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which
180	uses EV::TIMEOUT).	319	uses EV::TIMEOUT).
181		320
182	In the rare case where one wants to create a watcher but not start it at	321	In the rare case where one wants to create a watcher but not start it at
183	the same time, each constructor has a variant with a trailing C<_ns> in	322	the same time, each constructor has a variant with a trailing C<_ns> in
…		…
205		344
206	=item $w->stop	345	=item $w->stop
207		346
208	Stop a watcher if it is active. Also clear any pending events (events that	347	Stop a watcher if it is active. Also clear any pending events (events that
209	have been received but that didn't yet result in a callback invocation),	348	have been received but that didn't yet result in a callback invocation),
210	regardless of wether the watcher was active or not.	349	regardless of whether the watcher was active or not.
211		350
212	=item $bool = $w->is_active	351	=item $bool = $w->is_active
213		352
214	Returns true if the watcher is active, false otherwise.	353	Returns true if the watcher is active, false otherwise.
215		354
…		…
245	The default priority of any newly-created watcher is 0.	384	The default priority of any newly-created watcher is 0.
246		385
247	Note that the priority semantics have not yet been fleshed out and are	386	Note that the priority semantics have not yet been fleshed out and are
248	subject to almost certain change.	387	subject to almost certain change.
249		388
250	=item $w->trigger ($revents)	389	=item $w->invoke ($revents)
251		390
252	Call the callback now with the given event mask.	391	Call the callback now with the given event mask.
		392
		393	=item $w->feed_event ($revents)
		394
		395	Feed some events on this watcher into EV. EV will react to this call as if
		396	the watcher had received the given C<$revents> mask.
		397
		398	=item $revents = $w->clear_pending
		399
		400	If the watcher is pending, this function clears its pending status and
		401	returns its C<$revents> bitset (as if its callback was invoked). If the
		402	watcher isn't pending it does nothing and returns C<0>.
253		403
254	=item $previous_state = $w->keepalive ($bool)	404	=item $previous_state = $w->keepalive ($bool)
255		405
256	Normally, C<EV::loop> will return when there are no active watchers	406	Normally, C<EV::loop> will return when there are no active watchers
257	(which is a "deadlock" because no progress can be made anymore). This is	407	(which is a "deadlock" because no progress can be made anymore). This is
258	convinient because it allows you to start your watchers (and your jobs),	408	convinient because it allows you to start your watchers (and your jobs),
259	call C<EV::loop> once and when it returns you know that all your jobs are	409	call C<EV::loop> once and when it returns you know that all your jobs are
260	finished (or they forgot to register some watchers for their task :).	410	finished (or they forgot to register some watchers for their task :).
261		411
262	Sometimes, however, this gets in your way, for example when you the module	412	Sometimes, however, this gets in your way, for example when the module
263	that calls C<EV::loop> (usually the main program) is not the same module	413	that calls C<EV::loop> (usually the main program) is not the same module
264	as a long-living watcher (for example a DNS client module written by	414	as a long-living watcher (for example a DNS client module written by
265	somebody else even). Then you might want any outstanding requests to be	415	somebody else even). Then you might want any outstanding requests to be
266	handled, but you would not want to keep C<EV::loop> from returning just	416	handled, but you would not want to keep C<EV::loop> from returning just
267	because you happen to have this long-running UDP port watcher.	417	because you happen to have this long-running UDP port watcher.
268		418
269	In this case you can clear the keepalive status, which means that even	419	In this case you can clear the keepalive status, which means that even
270	though your watcher is active, it won't keep C<EV::loop> from returning.	420	though your watcher is active, it won't keep C<EV::loop> from returning.
271		421
272	The initial value for keepalive is true (enabled), and you cna change it	422	The initial value for keepalive is true (enabled), and you can change it
273	any time.	423	any time.
274		424
275	Example: Register an IO watcher for some UDP socket but do not keep the	425	Example: Register an I/O watcher for some UDP socket but do not keep the
276	event loop from running just because of that watcher.	426	event loop from running just because of that watcher.
277		427
278	my $udp_socket = ...	428	my $udp_socket = ...
279	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };	429	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
280	$udp_watcher->keepalive (0);	430	$udp_watcher->keepalive (0);
281		431
282	=back	432	=item $loop = $w->loop
283		433
		434	Return the loop that this watcher is attached to.
284		435
		436	=back
		437
		438
285	=head2 WATCHER TYPES	439	=head1 WATCHER TYPES
286		440
287	Each of the following subsections describes a single watcher type.	441	Each of the following subsections describes a single watcher type.
288		442
289	=head3 IO WATCHERS - is this file descriptor readable or writable?	443	=head3 I/O WATCHERS - is this file descriptor readable or writable?
290		444
291	=over 4	445	=over 4
292		446
293	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	447	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
294		448
295	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback	449	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
		450
		451	=item $w = $loop->io ($fileno_or_fh, $eventmask, $callback)
		452
		453	=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
296		454
297	As long as the returned watcher object is alive, call the C<$callback>	455	As long as the returned watcher object is alive, call the C<$callback>
298	when at least one of events specified in C<$eventmask> occurs.	456	when at least one of events specified in C<$eventmask> occurs.
299		457
300	The $eventmask can be one or more of these constants ORed together:	458	The $eventmask can be one or more of these constants ORed together:
…		…
329	=over 4	487	=over 4
330		488
331	=item $w = EV::timer $after, $repeat, $callback	489	=item $w = EV::timer $after, $repeat, $callback
332		490
333	=item $w = EV::timer_ns $after, $repeat, $callback	491	=item $w = EV::timer_ns $after, $repeat, $callback
		492
		493	=item $w = $loop->timer ($after, $repeat, $callback)
		494
		495	=item $w = $loop->timer_ns ($after, $repeat, $callback)
334		496
335	Calls the callback after C<$after> seconds (which may be fractional). If	497	Calls the callback after C<$after> seconds (which may be fractional). If
336	C<$repeat> is non-zero, the timer will be restarted (with the $repeat	498	C<$repeat> is non-zero, the timer will be restarted (with the $repeat
337	value as $after) after the callback returns.	499	value as $after) after the callback returns.
338		500
…		…
379	=over 4	541	=over 4
380		542
381	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback	543	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
382		544
383	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback	545	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
		546
		547	=item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
		548
		549	=item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback)
384		550
385	Similar to EV::timer, but is not based on relative timeouts but on	551	Similar to EV::timer, but is not based on relative timeouts but on
386	absolute times. Apart from creating "simple" timers that trigger "at" the	552	absolute times. Apart from creating "simple" timers that trigger "at" the
387	specified time, it can also be used for non-drifting absolute timers and	553	specified time, it can also be used for non-drifting absolute timers and
388	more complex, cron-like, setups that are not adversely affected by time	554	more complex, cron-like, setups that are not adversely affected by time
…		…
398	This time simply fires at the wallclock time C<$at> and doesn't repeat. It	564	This time simply fires at the wallclock time C<$at> and doesn't repeat. It
399	will not adjust when a time jump occurs, that is, if it is to be run	565	will not adjust when a time jump occurs, that is, if it is to be run
400	at January 1st 2011 then it will run when the system time reaches or	566	at January 1st 2011 then it will run when the system time reaches or
401	surpasses this time.	567	surpasses this time.
402		568
403	=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0)	569	=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
404		570
405	In this mode the watcher will always be scheduled to time out at the	571	In this mode the watcher will always be scheduled to time out at the
406	next C<$at + N * $interval> time (for some integer N) and then repeat,	572	next C<$at + N * $interval> time (for some integer N) and then repeat,
407	regardless of any time jumps.	573	regardless of any time jumps.
408		574
…		…
426	time the periodic watcher gets scheduled, the reschedule callback	592	time the periodic watcher gets scheduled, the reschedule callback
427	($reschedule_cb) will be called with the watcher as first, and the current	593	($reschedule_cb) will be called with the watcher as first, and the current
428	time as second argument.	594	time as second argument.
429		595
430	I<This callback MUST NOT stop or destroy this or any other periodic	596	I<This callback MUST NOT stop or destroy this or any other periodic
431	watcher, ever>. If you need to stop it, return 1e30 and stop it	597	watcher, ever, and MUST NOT call any event loop functions or methods>. If
432	afterwards.	598	you need to stop it, return 1e30 and stop it afterwards. You may create
		599	and start a C<EV::prepare> watcher for this task.
433		600
434	It must return the next time to trigger, based on the passed time value	601	It must return the next time to trigger, based on the passed time value
435	(that is, the lowest time value larger than to the second argument). It	602	(that is, the lowest time value larger than or equal to to the second
436	will usually be called just before the callback will be triggered, but	603	argument). It will usually be called just before the callback will be
437	might be called at other times, too.	604	triggered, but might be called at other times, too.
438		605
439	This can be used to create very complex timers, such as a timer that	606	This can be used to create very complex timers, such as a timer that
440	triggers on each midnight, local time (actually 24 hours after the last	607	triggers on each midnight, local time (actually 24 hours after the last
441	midnight, to keep the example simple. If you know a way to do it correctly	608	midnight, to keep the example simple. If you know a way to do it correctly
442	in about the same space (without requiring elaborate modules), drop me a	609	in about the same space (without requiring elaborate modules), drop me a
…		…
463		630
464	=item $w->again	631	=item $w->again
465		632
466	Simply stops and starts the watcher again.	633	Simply stops and starts the watcher again.
467		634
		635	=item $time = $w->at
		636
		637	Return the time that the watcher is expected to trigger next.
		638
468	=back	639	=back
469		640
470		641
471	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!	642	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
472		643
…		…
505		676
506	=head3 CHILD WATCHERS - watch out for process status changes	677	=head3 CHILD WATCHERS - watch out for process status changes
507		678
508	=over 4	679	=over 4
509		680
510	=item $w = EV::child $pid, $callback	681	=item $w = EV::child $pid, $trace, $callback
511		682
512	=item $w = EV::child_ns $pid, $callback	683	=item $w = EV::child_ns $pid, $trace, $callback
513		684
		685	=item $w = $loop->child ($pid, $trace, $callback)
		686
		687	=item $w = $loop->child_ns ($pid, $trace, $callback)
		688
514	Call the callback when a status change for pid C<$pid> (or any pid if	689	Call the callback when a status change for pid C<$pid> (or any pid
515	C<$pid> is 0) has been received. More precisely: when the process receives	690	if C<$pid> is 0) has been received (a status change happens when the
		691	process terminates or is killed, or, when trace is true, additionally when
		692	it is stopped or continued). More precisely: when the process receives
516	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all	693	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
517	changed/zombie children and call the callback.	694	changed/zombie children and call the callback.
518		695
519	It is valid (and fully supported) to install a child watcher after a child	696	It is valid (and fully supported) to install a child watcher after a child
520	has exited but before the event loop has started its next iteration (for	697	has exited but before the event loop has started its next iteration (for
…		…
527	You can have as many pid watchers per pid as you want, they will all be	704	You can have as many pid watchers per pid as you want, they will all be
528	called.	705	called.
529		706
530	The C<child_ns> variant doesn't start (activate) the newly created watcher.	707	The C<child_ns> variant doesn't start (activate) the newly created watcher.
531		708
532	=item $w->set ($pid)	709	=item $w->set ($pid, $trace)
533		710
534	Reconfigures the watcher, see the constructor above for details. Can be called at	711	Reconfigures the watcher, see the constructor above for details. Can be called at
535	any time.	712	any time.
536		713
537	=item $current_pid = $w->pid	714	=item $current_pid = $w->pid
538		715
539	=item $old_pid = $w->pid ($new_pid)
540
541	Returns the previously set process id and optionally set a new one.	716	Returns the previously set process id and optionally set a new one.
542		717
543	=item $exit_status = $w->rstatus	718	=item $exit_status = $w->rstatus
544		719
545	Return the exit/wait status (as returned by waitpid, see the waitpid entry	720	Return the exit/wait status (as returned by waitpid, see the waitpid entry
…		…
551	watcher for all pids).	726	watcher for all pids).
552		727
553	=back	728	=back
554		729
555		730
		731	=head3 STAT WATCHERS - did the file attributes just change?
		732
		733	=over 4
		734
		735	=item $w = EV::stat $path, $interval, $callback
		736
		737	=item $w = EV::stat_ns $path, $interval, $callback
		738
		739	=item $w = $loop->stat ($path, $interval, $callback)
		740
		741	=item $w = $loop->stat_ns ($path, $interval, $callback)
		742
		743	Call the callback when a file status change has been detected on
		744	C<$path>. The C<$path> does not need to exist, changing from "path exists"
		745	to "path does not exist" is a status change like any other.
		746
		747	The C<$interval> is a recommended polling interval for systems where
		748	OS-supported change notifications don't exist or are not supported. If
		749	you use C<0> then an unspecified default is used (which is highly
		750	recommended!), which is to be expected to be around five seconds usually.
		751
		752	This watcher type is not meant for massive numbers of stat watchers,
		753	as even with OS-supported change notifications, this can be
		754	resource-intensive.
		755
		756	The C<stat_ns> variant doesn't start (activate) the newly created watcher.
		757
		758	=item ... = $w->stat
		759
		760	This call is very similar to the perl C<stat> built-in: It stats (using
		761	C<lstat>) the path specified in the watcher and sets perls stat cache (as
		762	well as EV's idea of the current stat values) to the values found.
		763
		764	In scalar context, a boolean is return indicating success or failure of
		765	the stat. In list context, the same 13-value list as with stat is returned
		766	(except that the blksize and blocks fields are not reliable).
		767
		768	In the case of an error, errno is set to C<ENOENT> (regardless of the
		769	actual error value) and the C<nlink> value is forced to zero (if the stat
		770	was successful then nlink is guaranteed to be non-zero).
		771
		772	See also the next two entries for more info.
		773
		774	=item ... = $w->attr
		775
		776	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		777	the values most recently detected by EV. See the next entry for more info.
		778
		779	=item ... = $w->prev
		780
		781	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		782	the previous set of values, before the change.
		783
		784	That is, when the watcher callback is invoked, C<< $w->prev >> will be set
		785	to the values found I<before> a change was detected, while C<< $w->attr >>
		786	returns the values found leading to the change detection. The difference (if any)
		787	between C<prev> and C<attr> is what triggered the callback.
		788
		789	If you did something to the filesystem object and do not want to trigger
		790	yet another change, you can call C<stat> to update EV's idea of what the
		791	current attributes are.
		792
		793	=item $w->set ($path, $interval)
		794
		795	Reconfigures the watcher, see the constructor above for details. Can be
		796	called at any time.
		797
		798	=item $current_path = $w->path
		799
		800	=item $old_path = $w->path ($new_path)
		801
		802	Returns the previously set path and optionally set a new one.
		803
		804	=item $current_interval = $w->interval
		805
		806	=item $old_interval = $w->interval ($new_interval)
		807
		808	Returns the previously set interval and optionally set a new one. Can be
		809	used to query the actual interval used.
		810
		811	=back
		812
		813
556	=head3 IDLE WATCHERS - when you've got nothing better to do...	814	=head3 IDLE WATCHERS - when you've got nothing better to do...
557		815
558	=over 4	816	=over 4
559		817
560	=item $w = EV::idle $callback	818	=item $w = EV::idle $callback
561		819
562	=item $w = EV::idle_ns $callback	820	=item $w = EV::idle_ns $callback
563		821
564	Call the callback when there are no pending io, timer/periodic, signal or	822	=item $w = $loop->idle ($callback)
565	child events, i.e. when the process is idle.	823
		824	=item $w = $loop->idle_ns ($callback)
		825
		826	Call the callback when there are no other pending watchers of the same or
		827	higher priority (excluding check, prepare and other idle watchers of the
		828	same or lower priority, of course). They are called idle watchers because
		829	when the watcher is the highest priority pending event in the process, the
		830	process is considered to be idle at that priority.
		831
		832	If you want a watcher that is only ever called when I<no> other events are
		833	outstanding you have to set the priority to C<EV::MINPRI>.
566		834
567	The process will not block as long as any idle watchers are active, and	835	The process will not block as long as any idle watchers are active, and
568	they will be called repeatedly until stopped.	836	they will be called repeatedly until stopped.
569		837
		838	For example, if you have idle watchers at priority C<0> and C<1>, and
		839	an I/O watcher at priority C<0>, then the idle watcher at priority C<1>
		840	and the I/O watcher will always run when ready. Only when the idle watcher
		841	at priority C<1> is stopped and the I/O watcher at priority C<0> is not
		842	pending with the C<0>-priority idle watcher be invoked.
		843
570	The C<idle_ns> variant doesn't start (activate) the newly created watcher.	844	The C<idle_ns> variant doesn't start (activate) the newly created watcher.
571		845
572	=back	846	=back
573		847
574		848
…		…
577	=over 4	851	=over 4
578		852
579	=item $w = EV::prepare $callback	853	=item $w = EV::prepare $callback
580		854
581	=item $w = EV::prepare_ns $callback	855	=item $w = EV::prepare_ns $callback
		856
		857	=item $w = $loop->prepare ($callback)
		858
		859	=item $w = $loop->prepare_ns ($callback)
582		860
583	Call the callback just before the process would block. You can still	861	Call the callback just before the process would block. You can still
584	create/modify any watchers at this point.	862	create/modify any watchers at this point.
585		863
586	See the EV::check watcher, below, for explanations and an example.	864	See the EV::check watcher, below, for explanations and an example.
…		…
595	=over 4	873	=over 4
596		874
597	=item $w = EV::check $callback	875	=item $w = EV::check $callback
598		876
599	=item $w = EV::check_ns $callback	877	=item $w = EV::check_ns $callback
		878
		879	=item $w = $loop->check ($callback)
		880
		881	=item $w = $loop->check_ns ($callback)
600		882
601	Call the callback just after the process wakes up again (after it has	883	Call the callback just after the process wakes up again (after it has
602	gathered events), but before any other callbacks have been invoked.	884	gathered events), but before any other callbacks have been invoked.
603		885
604	This is used to integrate other event-based software into the EV	886	This is used to integrate other event-based software into the EV
…		…
614	or return;	896	or return;
615		897
616	# make the dispatcher handle any outstanding stuff	898	# make the dispatcher handle any outstanding stuff
617	... not shown	899	... not shown
618		900
619	# create an IO watcher for each and every socket	901	# create an I/O watcher for each and every socket
620	@snmp_watcher = (	902	@snmp_watcher = (
621	(map { EV::io $_, EV::READ, sub { } }	903	(map { EV::io $_, EV::READ, sub { } }
622	keys %{ $dispatcher->{_descriptors} }),	904	keys %{ $dispatcher->{_descriptors} }),
623		905
624	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]	906	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
…		…
639	# make the dispatcher handle any new stuff	921	# make the dispatcher handle any new stuff
640	... not shown	922	... not shown
641	};	923	};
642		924
643	The callbacks of the created watchers will not be called as the watchers	925	The callbacks of the created watchers will not be called as the watchers
644	are destroyed before this cna happen (remember EV::check gets called	926	are destroyed before this can happen (remember EV::check gets called
645	first).	927	first).
646		928
647	The C<check_ns> variant doesn't start (activate) the newly created watcher.	929	The C<check_ns> variant doesn't start (activate) the newly created watcher.
648		930
649	=back	931	=back
650		932
651	=head3 STAT WATCHERS - did the file stats just change?
652		933
653	=over 4	934	=head3 FORK WATCHERS - the audacity to resume the event loop after a fork
654		935
655	=item $w = EV::stat $path, $interval, $callback	936	Fork watchers are called when a C<fork ()> was detected. The invocation
		937	is done before the event loop blocks next and before C<check> watchers
		938	are being called, and only in the child after the fork.
656		939
657	=item $w = EV::stat_ns $path, $interval, $callback	940	=over 4
658		941
659	Call the callback when a file status change has been detected on	942	=item $w = EV::fork $callback
660	C<$path>. The C<$path> does not need to exist, changing from "path exists"
661	to "path does not exist" is a status change like any other.
662		943
663	The C<$interval> is a recommended polling interval for systems where	944	=item $w = EV::fork_ns $callback
664	OS-supported change notifications don't exist or are not supported. If
665	you use C<0> then an unspecified default is used (which is highly
666	recommended!), which is to be expected to be around five seconds usually.
667		945
668	This watcher type is not meant for massive numbers of stat watchers,	946	=item $w = $loop->fork ($callback)
669	as even with OS-supported change notifications, this can be
670	resource-intensive.
671		947
		948	=item $w = $loop->fork_ns ($callback)
		949
		950	Call the callback before the event loop is resumed in the child process
		951	after a fork.
		952
672	The C<stat_ns> variant doesn't start (activate) the newly created watcher.	953	The C<fork_ns> variant doesn't start (activate) the newly created watcher.
673		954
674	=item $w->set ($path, $interval)
675
676	Reconfigures the watcher, see the constructor above for details. Can be
677	called at any time.
678
679	=item $current_path = $w->path
680
681	=item $old_path = $w->path ($new_path)
682
683	Returns the previously set path and optionally set a new one.
684
685	=item $current_interval = $w->interval
686
687	=item $old_interval = $w->interval ($new_interval)
688
689	Returns the previously set interval and optionally set a new one. Can be
690	used to query the actual interval used.
691
692	=back	955	=back
693		956
		957
		958	=head3 EMBED WATCHERS - when one backend isn't enough...
		959
		960	This is a rather advanced watcher type that lets you embed one event loop
		961	into another (currently only IO events are supported in the embedded
		962	loop, other types of watchers might be handled in a delayed or incorrect
		963	fashion and must not be used).
		964
		965	See the libev documentation at
		966	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
		967	(locally installed as F<EV::libev>) for more details.
		968
		969	In short, this watcher is most useful on BSD systems without working
		970	kqueue to still be able to handle a large number of sockets:
		971
		972	my $socket_loop;
		973
		974	# check wether we use SELECT or POLL _and_ KQUEUE is supported
		975	if (
		976	(EV::backend & (EV::BACKEND_POLL \| EV::BACKEND_SELECT))
		977	&& (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
		978	) {
		979	# use kqueue for sockets
		980	$socket_loop = new EV::Loop EV::BACKEND_KQUEUE \| EV::FLAG_NOENV;
		981	}
		982
		983	# use the default loop otherwise
		984	$socket_loop \|\|= EV::default_loop;
		985
		986	=over 4
		987
		988	=item $w = EV::embed $otherloop[, $callback]
		989
		990	=item $w = EV::embed_ns $otherloop[, $callback]
		991
		992	=item $w = $loop->embed ($otherloop[, $callback])
		993
		994	=item $w = $loop->embed_ns ($otherloop[, $callback])
		995
		996	Call the callback when the embedded event loop (C<$otherloop>) has any
		997	I/O activity. The C<$callback> is optional: if it is missing, then the
		998	embedded event loop will be managed automatically (which is recommended),
		999	otherwise you have to invoke C<sweep> yourself.
		1000
		1001	The C<embed_ns> variant doesn't start (activate) the newly created watcher.
		1002
		1003	=back
		1004
		1005	=head3 ASYNC WATCHERS - how to wake up another event loop
		1006
		1007	Async watchers are provided by EV, but have little use in perl directly, as perl
		1008	neither supports threads nor direct access to signal handlers or other
		1009	contexts where they could be of value.
		1010
		1011	It is, however, possible to use them from the XS level.
		1012
		1013	Please see the libev documentation for further details.
		1014
		1015	=over 4
		1016
		1017	=item $w = EV::async $callback
		1018
		1019	=item $w = EV::async_ns $callback
		1020
		1021	=item $w->send
		1022
		1023	=item $bool = $w->async_pending
		1024
		1025	=back
		1026
		1027
		1028	=head1 PERL SIGNALS
		1029
		1030	While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour
		1031	with EV is as the same as any other C library: Perl-signals will only be
		1032	handled when Perl runs, which means your signal handler might be invoked
		1033	only the next time an event callback is invoked.
		1034
		1035	The solution is to use EV signal watchers (see C<EV::signal>), which will
		1036	ensure proper operations with regards to other event watchers.
		1037
		1038	If you cannot do this for whatever reason, you can also force a watcher
		1039	to be called on every event loop iteration by installing a C<EV::check>
		1040	watcher:
		1041
		1042	my $async_check = EV::check sub { };
		1043
		1044	This ensures that perl gets into control for a short time to handle any
		1045	pending signals, and also ensures (slightly) slower overall operation.
694		1046
695	=head1 THREADS	1047	=head1 THREADS
696		1048
697	Threads are not supported by this module in any way. Perl pseudo-threads	1049	Threads are not supported by this module in any way. Perl pseudo-threads
698	is evil stuff and must die. As soon as Perl gains real threads I will work	1050	is evil stuff and must die. As soon as Perl gains real threads I will work
…		…
720	our $DIED = sub {	1072	our $DIED = sub {
721	warn "EV: error in callback (ignoring): $@";	1073	warn "EV: error in callback (ignoring): $@";
722	};	1074	};
723		1075
724	default_loop	1076	default_loop
725	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	1077	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
726		1078
727	1;	1079	1;
728		1080
729	=head1 SEE ALSO	1081	=head1 SEE ALSO
730		1082
731	L<EV::DNS>.	1083	L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as
		1084	event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
		1085	coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
		1086	event-loop agnostic and portable event driven programming.
732		1087
733	=head1 AUTHOR	1088	=head1 AUTHOR
734		1089
735	Marc Lehmann <schmorp@schmorp.de>	1090	Marc Lehmann <schmorp@schmorp.de>
736	http://home.schmorp.de/	1091	http://home.schmorp.de/
737		1092
738	=cut	1093	=cut
739		1094

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Comparing EV/EV.pm (file contents): Revision 1.54 by root, Tue Nov 27 07:27:10 2007 UTC vs. Revision 1.111 by root, Wed Jan 7 20:53:29 2009 UTC

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Comparing EV/EV.pm (file contents):
Revision 1.54 by root, Tue Nov 27 07:27:10 2007 UTC vs.
Revision 1.111 by root, Wed Jan 7 20:53:29 2009 UTC