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

Comparing EV/EV.pm (file contents):
Revision 1.53 by root, Sat Nov 24 16:57:30 2007 UTC vs.
Revision 1.105 by root, Thu Oct 2 12:27:55 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, 2, sub {
16	warn "is called roughly every 2s (repeat = 2)";
17	};
18
19	undef $w; # destroy event watcher again
20
21	my $w = EV::periodic 0, 60, 0, sub {
22	warn "is called every minute, on the minute, exactly";
23	};
24
25	# IO
26
27	my $w = EV::io *STDIN, EV::READ, sub {
28	my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
29	warn "stdin is readable, you entered: ", <STDIN>;
30	};
31
32	# SIGNALS
33
34	my $w = EV::signal 'QUIT', sub {
35	warn "sigquit received\n";
36	};
37
38	# CHILD/PID STATUS CHANGES
39
40	my $w = EV::child 666, sub {
41	my ($w, $revents) = @_;	47	my ($w, $revents) = @_;
42	my $status = $w->rstatus;	48	warn $w->path, " has changed somehow.\n";
43	};	49	};
44		50
45	# MAINLOOP	51	# MAINLOOP
46	EV::loop; # loop until EV::unloop is called or all watchers stop	52	EV::loop; # loop until EV::unloop is called or all watchers stop
47	EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled	53	EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled
48	EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block	54	EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block
49		55
50	=head1 DESCRIPTION	56	=head1 DESCRIPTION
51		57
52	This module provides an interface to libev	58	This module provides an interface to libev
53	(L<http://software.schmorp.de/pkg/libev.html>). While the documentation	59	(L<http://software.schmorp.de/pkg/libev.html>). While the documentation
54	below is comprehensive, one might also consult the documentation of libev	60	below is comprehensive, one might also consult the documentation of
55	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
56	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
57	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.
58		72
59	=cut	73	=cut
60		74
61	package EV;	75	package EV;
62		76
		77	no warnings;
63	use strict;	78	use strict;
64		79
65	BEGIN {	80	BEGIN {
66	our $VERSION = '1.3';	81	our $VERSION = '3.44';
67	use XSLoader;	82	use XSLoader;
68	XSLoader::load "EV", $VERSION;	83	XSLoader::load "EV", $VERSION;
69	}	84	}
70		85
71	@EV::IO::ISA =	86	@EV::IO::ISA =
72	@EV::Timer::ISA =	87	@EV::Timer::ISA =
73	@EV::Periodic::ISA =	88	@EV::Periodic::ISA =
74	@EV::Signal::ISA =	89	@EV::Signal::ISA =
		90	@EV::Child::ISA =
		91	@EV::Stat::ISA =
75	@EV::Idle::ISA =	92	@EV::Idle::ISA =
76	@EV::Prepare::ISA =	93	@EV::Prepare::ISA =
77	@EV::Check::ISA =	94	@EV::Check::ISA =
78	@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::libev> 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
79		164
80	=head1 BASIC INTERFACE	165	=head1 BASIC INTERFACE
81		166
82	=over 4	167	=over 4
83		168
84	=item $EV::DIED	169	=item $EV::DIED
85		170
86	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
87	throws an exception (with $@ containing thr error). The default prints an	172	throws an exception (with $@ containing the error). The default prints an
88	informative message and continues.	173	informative message and continues.
89		174
90	If this callback throws an exception it will be silently ignored.	175	If this callback throws an exception it will be silently ignored.
91		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
92	=item $time = EV::time	191	=item $time = EV::time
93		192
94	Returns the current time in (fractional) seconds since the epoch.	193	Returns the current time in (fractional) seconds since the epoch.
95		194
96	=item $time = EV::now	195	=item $time = EV::now
		196
		197	=item $time = $loop->now
97		198
98	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
99	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
100	usually faster then calling EV::time.	201	usually faster then calling EV::time.
101		202
102	=item $method = EV::method	203	=item $backend = EV::backend
		204
		205	=item $backend = $loop->backend
103		206
104	Returns an integer describing the backend used by libev (EV::METHOD_SELECT	207	Returns an integer describing the backend used by libev (EV::METHOD_SELECT
105	or EV::METHOD_EPOLL).	208	or EV::METHOD_EPOLL).
106		209
107	=item EV::loop [$flags]	210	=item EV::loop [$flags]
		211
		212	=item $loop->loop ([$flags])
108		213
109	Begin checking for events and calling callbacks. It returns when a	214	Begin checking for events and calling callbacks. It returns when a
110	callback calls EV::unloop.	215	callback calls EV::unloop.
111		216
112	The $flags argument can be one of the following:	217	The $flags argument can be one of the following:
…		…
115	EV::LOOP_ONESHOT block at most once (wait, but do not loop)	220	EV::LOOP_ONESHOT block at most once (wait, but do not loop)
116	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)	221	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
117		222
118	=item EV::unloop [$how]	223	=item EV::unloop [$how]
119		224
		225	=item $loop->unloop ([$how])
		226
120	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the	227	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the
121	innermost call to EV::loop return.	228	innermost call to EV::loop return.
122		229
123	When called with an argument of EV::UNLOOP_ALL, 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
124	fast as possible.	231	fast as possible.
125		232
		233	=item $count = EV::loop_count
		234
		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
126	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)	240	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
		241
		242	=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
127		243
128	This function rolls together an I/O and a timer watcher for a single	244	This function rolls together an I/O and a timer watcher for a single
129	one-shot event without the need for managing a watcher object.	245	one-shot event without the need for managing a watcher object.
130		246
131	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>	247	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>
…		…
137	If timeout is C<undef> or negative, then there will be no	253	If timeout is C<undef> or negative, then there will be no
138	timeout. Otherwise a EV::timer with this value will be started.	254	timeout. Otherwise a EV::timer with this value will be started.
139		255
140	When an error occurs or either the timeout or I/O watcher triggers, then	256	When an error occurs or either the timeout or I/O watcher triggers, then
141	the callback will be called with the received event set (in general	257	the callback will be called with the received event set (in general
142	you can expect it to be a combination of C<EV:ERROR>, C<EV::READ>,	258	you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
143	C<EV::WRITE> and C<EV::TIMEOUT>).	259	C<EV::WRITE> and C<EV::TIMEOUT>).
144		260
145	EV::once doesn't return anything: the watchers stay active till either	261	EV::once doesn't return anything: the watchers stay active till either
146	of them triggers, then they will be stopped and freed, and the callback	262	of them triggers, then they will be stopped and freed, and the callback
147	invoked.	263	invoked.
148		264
149	=back	265	=item EV::feed_fd_event ($fd, $revents)
150		266
151	=head2 WATCHER	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::libev>) for a more detailed discussion.
		290
		291	=back
		292
		293
		294	=head1 WATCHER OBJECTS
152		295
153	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
154	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
155	would create an EV::io watcher for that:	298	would create an EV::io watcher for that:
156		299
157	my $watcher = EV::io *STDIN, EV::READ, sub {	300	my $watcher = EV::io *STDIN, EV::READ, sub {
158	my ($watcher, $revents) = @_;	301	my ($watcher, $revents) = @_;
159	warn "yeah, STDIN should not be readable without blocking!\n"	302	warn "yeah, STDIN should now be readable without blocking!\n"
160	};	303	};
161		304
162	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
163	active watchers will have their callbacks invoked. All callbacks will be	306	active watchers will have their callbacks invoked. All callbacks will be
164	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
165	events.	308	events.
166		309
167	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
168	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
169	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,
170	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
171	(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
172	uses EV::TIMEOUT).	315	uses EV::TIMEOUT).
173		316
174	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
175	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
…		…
181		324
182	Also, all methods changing some aspect of a watcher (->set, ->priority,	325	Also, all methods changing some aspect of a watcher (->set, ->priority,
183	->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,
184	which means pending events get lost.	327	which means pending events get lost.
185		328
186	=head2 WATCHER TYPES	329	=head2 COMMON WATCHER METHODS
187		330
188	Now lets move to the existing watcher types and asociated methods.	331	This section lists methods common to all watchers.
189
190	The following methods are available for all watchers. Then followes a
191	description of each watcher constructor (EV::io, EV::timer, EV::periodic,
192	EV::signal, EV::child, EV::idle, EV::prepare and EV::check), followed by
193	any type-specific methods (if any).
194		332
195	=over 4	333	=over 4
196		334
197	=item $w->start	335	=item $w->start
198		336
…		…
202		340
203	=item $w->stop	341	=item $w->stop
204		342
205	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
206	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),
207	regardless of wether the watcher was active or not.	345	regardless of whether the watcher was active or not.
208		346
209	=item $bool = $w->is_active	347	=item $bool = $w->is_active
210		348
211	Returns true if the watcher is active, false otherwise.	349	Returns true if the watcher is active, false otherwise.
212		350
…		…
242	The default priority of any newly-created watcher is 0.	380	The default priority of any newly-created watcher is 0.
243		381
244	Note that the priority semantics have not yet been fleshed out and are	382	Note that the priority semantics have not yet been fleshed out and are
245	subject to almost certain change.	383	subject to almost certain change.
246		384
247	=item $w->trigger ($revents)	385	=item $w->invoke ($revents)
248		386
249	Call the callback now with the given event mask.	387	Call the callback now with the given event mask.
		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>.
250		399
251	=item $previous_state = $w->keepalive ($bool)	400	=item $previous_state = $w->keepalive ($bool)
252		401
253	Normally, C<EV::loop> will return when there are no active watchers	402	Normally, C<EV::loop> will return when there are no active watchers
254	(which is a "deadlock" because no progress can be made anymore). This is	403	(which is a "deadlock" because no progress can be made anymore). This is
255	convinient because it allows you to start your watchers (and your jobs),	404	convinient because it allows you to start your watchers (and your jobs),
256	call C<EV::loop> once and when it returns you know that all your jobs are	405	call C<EV::loop> once and when it returns you know that all your jobs are
257	finished (or they forgot to register some watchers for their task :).	406	finished (or they forgot to register some watchers for their task :).
258		407
259	Sometimes, however, this gets in your way, for example when you the module	408	Sometimes, however, this gets in your way, for example when the module
260	that calls C<EV::loop> (usually the main program) is not the same module	409	that calls C<EV::loop> (usually the main program) is not the same module
261	as a long-living watcher (for example a DNS client module written by	410	as a long-living watcher (for example a DNS client module written by
262	somebody else even). Then you might want any outstanding requests to be	411	somebody else even). Then you might want any outstanding requests to be
263	handled, but you would not want to keep C<EV::loop> from returning just	412	handled, but you would not want to keep C<EV::loop> from returning just
264	because you happen to have this long-running UDP port watcher.	413	because you happen to have this long-running UDP port watcher.
…		…
267	though your watcher is active, it won't keep C<EV::loop> from returning.	416	though your watcher is active, it won't keep C<EV::loop> from returning.
268		417
269	The initial value for keepalive is true (enabled), and you cna change it	418	The initial value for keepalive is true (enabled), and you cna change it
270	any time.	419	any time.
271		420
272	Example: Register an IO watcher for some UDP socket but do not keep the	421	Example: Register an I/O watcher for some UDP socket but do not keep the
273	event loop from running just because of that watcher.	422	event loop from running just because of that watcher.
274		423
275	my $udp_socket = ...	424	my $udp_socket = ...
276	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };	425	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
277	$udp_watcher->keepalive (0);	426	$udp_watcher->keepalive (0);
278		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
		442
279	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	443	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
280		444
281	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback	445	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
282		446
		447	=item $w = $loop->io ($fileno_or_fh, $eventmask, $callback)
		448
		449	=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
		450
283	As long as the returned watcher object is alive, call the C<$callback>	451	As long as the returned watcher object is alive, call the C<$callback>
284	when the events specified in C<$eventmask>.	452	when at least one of events specified in C<$eventmask> occurs.
285		453
286	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:
287		455
288	EV::READ wait until read() wouldn't block anymore	456	EV::READ wait until read() wouldn't block anymore
289	EV::WRITE wait until write() wouldn't block anymore	457	EV::WRITE wait until write() wouldn't block anymore
…		…
305		473
306	=item $old_eventmask = $w->events ($new_eventmask)	474	=item $old_eventmask = $w->events ($new_eventmask)
307		475
308	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.
309		477
		478	=back
		479
		480
		481	=head3 TIMER WATCHERS - relative and optionally repeating timeouts
		482
		483	=over 4
310		484
311	=item $w = EV::timer $after, $repeat, $callback	485	=item $w = EV::timer $after, $repeat, $callback
312		486
313	=item $w = EV::timer_ns $after, $repeat, $callback	487	=item $w = EV::timer_ns $after, $repeat, $callback
		488
		489	=item $w = $loop->timer ($after, $repeat, $callback)
		490
		491	=item $w = $loop->timer_ns ($after, $repeat, $callback)
314		492
315	Calls the callback after C<$after> seconds (which may be fractional). If	493	Calls the callback after C<$after> seconds (which may be fractional). If
316	C<$repeat> is non-zero, the timer will be restarted (with the $repeat	494	C<$repeat> is non-zero, the timer will be restarted (with the $repeat
317	value as $after) after the callback returns.	495	value as $after) after the callback returns.
318		496
…		…
328		506
329	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.
330		508
331	=item $w->set ($after, $repeat)	509	=item $w->set ($after, $repeat)
332		510
333	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
334	any time.	512	any time.
335		513
336	=item $w->again	514	=item $w->again
337		515
338	Similar to the C<start> method, but has special semantics for repeating timers:	516	Similar to the C<start> method, but has special semantics for repeating timers:
…		…
349	This behaviour is useful when you have a timeout for some IO	527	This behaviour is useful when you have a timeout for some IO
350	operation. You create a timer object with the same value for C<$after> and	528	operation. You create a timer object with the same value for C<$after> and
351	C<$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
352	on the timeout.	530	on the timeout.
353		531
		532	=back
		533
		534
		535	=head3 PERIODIC WATCHERS - to cron or not to cron?
		536
		537	=over 4
354		538
355	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback	539	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
356		540
357	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback	541	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
		542
		543	=item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
		544
		545	=item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback)
358		546
359	Similar to EV::timer, but is not based on relative timeouts but on	547	Similar to EV::timer, but is not based on relative timeouts but on
360	absolute times. Apart from creating "simple" timers that trigger "at" the	548	absolute times. Apart from creating "simple" timers that trigger "at" the
361	specified time, it can also be used for non-drifting absolute timers and	549	specified time, it can also be used for non-drifting absolute timers and
362	more complex, cron-like, setups that are not adversely affected by time	550	more complex, cron-like, setups that are not adversely affected by time
…		…
372	This time simply fires at the wallclock time C<$at> and doesn't repeat. It	560	This time simply fires at the wallclock time C<$at> and doesn't repeat. It
373	will not adjust when a time jump occurs, that is, if it is to be run	561	will not adjust when a time jump occurs, that is, if it is to be run
374	at January 1st 2011 then it will run when the system time reaches or	562	at January 1st 2011 then it will run when the system time reaches or
375	surpasses this time.	563	surpasses this time.
376		564
377	=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0)	565	=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
378		566
379	In this mode the watcher will always be scheduled to time out at the	567	In this mode the watcher will always be scheduled to time out at the
380	next C<$at + N * $interval> time (for some integer N) and then repeat,	568	next C<$at + N * $interval> time (for some integer N) and then repeat,
381	regardless of any time jumps.	569	regardless of any time jumps.
382		570
…		…
400	time the periodic watcher gets scheduled, the reschedule callback	588	time the periodic watcher gets scheduled, the reschedule callback
401	($reschedule_cb) will be called with the watcher as first, and the current	589	($reschedule_cb) will be called with the watcher as first, and the current
402	time as second argument.	590	time as second argument.
403		591
404	I<This callback MUST NOT stop or destroy this or any other periodic	592	I<This callback MUST NOT stop or destroy this or any other periodic
405	watcher, ever>. If you need to stop it, return 1e30 and stop it	593	watcher, ever, and MUST NOT call any event loop functions or methods>. If
406	afterwards.	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.
407		596
408	It must return the next time to trigger, based on the passed time value	597	It must return the next time to trigger, based on the passed time value
409	(that is, the lowest time value larger than to the second argument). It	598	(that is, the lowest time value larger than or equal to to the second
410	will usually be called just before the callback will be triggered, but	599	argument). It will usually be called just before the callback will be
411	might be called at other times, too.	600	triggered, but might be called at other times, too.
412		601
413	This can be used to create very complex timers, such as a timer that	602	This can be used to create very complex timers, such as a timer that
414	triggers on each midnight, local time (actually 24 hours after the last	603	triggers on each midnight, local time (actually 24 hours after the last
415	midnight, to keep the example simple. If you know a way to do it correctly	604	midnight, to keep the example simple. If you know a way to do it correctly
416	in about the same space (without requiring elaborate modules), drop me a	605	in about the same space (without requiring elaborate modules), drop me a
…		…
430		619
431	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.
432		621
433	=item $w->set ($at, $interval, $reschedule_cb)	622	=item $w->set ($at, $interval, $reschedule_cb)
434		623
435	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
436	any time.	625	any time.
437		626
438	=item $w->again	627	=item $w->again
439		628
440	Simply stops and starts the watcher again.	629	Simply stops and starts the watcher again.
441		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
442		641
443	=item $w = EV::signal $signal, $callback	642	=item $w = EV::signal $signal, $callback
444		643
445	=item $w = EV::signal_ns $signal, $callback	644	=item $w = EV::signal_ns $signal, $callback
446		645
447	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
448	by number or by name, just as with kill or %SIG).	647	number or by name, just as with C<kill> or C<%SIG>).
449		648
450	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
451	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,
452	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
453	add/remove callbacks to %SIG, so watch out.	652	add/remove callbacks to C<%SIG>, so watch out.
454		653
455	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.
456		655
457	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.
458		657
459	=item $w->set ($signal)	658	=item $w->set ($signal)
460		659
461	Reconfigures the watcher, see the constructor above for details. Can be at	660	Reconfigures the watcher, see the constructor above for details. Can be
462	any time.	661	called at any time.
463		662
464	=item $current_signum = $w->signal	663	=item $current_signum = $w->signal
465		664
466	=item $old_signum = $w->signal ($new_signal)	665	=item $old_signum = $w->signal ($new_signal)
467		666
468	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
469	optionally set a new one.	668	optionally set a new one.
470		669
		670	=back
471		671
		672
		673	=head3 CHILD WATCHERS - watch out for process status changes
		674
		675	=over 4
		676
472	=item $w = EV::child $pid, $callback	677	=item $w = EV::child $pid, $trace, $callback
473		678
474	=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, $callback)
475		684
476	Call the callback when a status change for pid C<$pid> (or any pid	685	Call the callback when a status change for pid C<$pid> (or any pid
477	if C<$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
478	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
479	changed/zombie children and call the callback.	690	changed/zombie children and call the callback.
480		691
481	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
482	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).
483		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
484	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.
485		702
486	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.
487		704
488	=item $w->set ($pid)	705	=item $w->set ($pid, $trace)
489		706
490	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
491	any time.	708	any time.
492		709
493	=item $current_pid = $w->pid	710	=item $current_pid = $w->pid
494
495	=item $old_pid = $w->pid ($new_pid)
496		711
497	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.
498		713
499	=item $exit_status = $w->rstatus	714	=item $exit_status = $w->rstatus
500		715
…		…
504	=item $pid = $w->rpid	719	=item $pid = $w->rpid
505		720
506	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
507	watcher for all pids).	722	watcher for all pids).
508		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
509		813
510	=item $w = EV::idle $callback	814	=item $w = EV::idle $callback
511		815
512	=item $w = EV::idle_ns $callback	816	=item $w = EV::idle_ns $callback
513		817
514	Call the callback when there are no pending io, timer/periodic, signal or	818	=item $w = $loop->idle ($callback)
515	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>.
516		830
517	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
518	they will be called repeatedly until stopped.	832	they will be called repeatedly until stopped.
519		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
520	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.
521		841
		842	=back
		843
		844
		845	=head3 PREPARE WATCHERS - customise your event loop!
		846
		847	=over 4
522		848
523	=item $w = EV::prepare $callback	849	=item $w = EV::prepare $callback
524		850
525	=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)
526		856
527	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
528	create/modify any watchers at this point.	858	create/modify any watchers at this point.
529		859
530	See the EV::check watcher, below, for explanations and an example.	860	See the EV::check watcher, below, for explanations and an example.
531		861
532	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.
533		863
		864	=back
		865
		866
		867	=head3 CHECK WATCHERS - customise your event loop even more!
		868
		869	=over 4
534		870
535	=item $w = EV::check $callback	871	=item $w = EV::check $callback
536		872
537	=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)
538		878
539	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
540	gathered events), but before any other callbacks have been invoked.	880	gathered events), but before any other callbacks have been invoked.
541		881
542	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
…		…
552	or return;	892	or return;
553		893
554	# make the dispatcher handle any outstanding stuff	894	# make the dispatcher handle any outstanding stuff
555	... not shown	895	... not shown
556		896
557	# create an IO watcher for each and every socket	897	# create an I/O watcher for each and every socket
558	@snmp_watcher = (	898	@snmp_watcher = (
559	(map { EV::io $_, EV::READ, sub { } }	899	(map { EV::io $_, EV::READ, sub { } }
560	keys %{ $dispatcher->{_descriptors} }),	900	keys %{ $dispatcher->{_descriptors} }),
561		901
562	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]	902	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
…		…
583	first).	923	first).
584		924
585	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.
586		926
587	=back	927	=back
		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::libev>) 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.
588		1042
589	=head1 THREADS	1043	=head1 THREADS
590		1044
591	Threads are not supported by this module in any way. Perl pseudo-threads	1045	Threads are not supported by this module in any way. Perl pseudo-threads
592	is evil stuff and must die. As soon as Perl gains real threads I will work	1046	is evil stuff and must die. As soon as Perl gains real threads I will work
…		…
614	our $DIED = sub {	1068	our $DIED = sub {
615	warn "EV: error in callback (ignoring): $@";	1069	warn "EV: error in callback (ignoring): $@";
616	};	1070	};
617		1071
618	default_loop	1072	default_loop
619	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	1073	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
620		1074
621	1;	1075	1;
622		1076
623	=head1 SEE ALSO	1077	=head1 SEE ALSO
624		1078
625	L<EV::DNS>.	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.
626		1083
627	=head1 AUTHOR	1084	=head1 AUTHOR
628		1085
629	Marc Lehmann <schmorp@schmorp.de>	1086	Marc Lehmann <schmorp@schmorp.de>
630	http://home.schmorp.de/	1087	http://home.schmorp.de/
631		1088
632	=cut	1089	=cut
633		1090

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Comparing EV/EV.pm (file contents): Revision 1.53 by root, Sat Nov 24 16:57:30 2007 UTC vs. Revision 1.105 by root, Thu Oct 2 12:27:55 2008 UTC

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Comparing EV/EV.pm (file contents):
Revision 1.53 by root, Sat Nov 24 16:57:30 2007 UTC vs.
Revision 1.105 by root, Thu Oct 2 12:27:55 2008 UTC