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

Comparing EV/EV.pm (file contents):
Revision 1.52 by root, Sat Nov 24 16:20:30 2007 UTC vs.
Revision 1.106 by root, Thu Oct 23 04:56:49 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.
		72
		73	=head2 MODULE EXPORTS
		74
		75	This module does not export any symbols.
58		76
59	=cut	77	=cut
60		78
61	package EV;	79	package EV;
62		80
		81	no warnings;
63	use strict;	82	use strict;
64		83
65	BEGIN {	84	BEGIN {
66	our $VERSION = '1.3';	85	our $VERSION = '3.45';
67	use XSLoader;	86	use XSLoader;
68	XSLoader::load "EV", $VERSION;	87	XSLoader::load "EV", $VERSION;
69	}	88	}
70		89
71	@EV::IO::ISA =	90	@EV::IO::ISA =
72	@EV::Timer::ISA =	91	@EV::Timer::ISA =
73	@EV::Periodic::ISA =	92	@EV::Periodic::ISA =
74	@EV::Signal::ISA =	93	@EV::Signal::ISA =
		94	@EV::Child::ISA =
		95	@EV::Stat::ISA =
75	@EV::Idle::ISA =	96	@EV::Idle::ISA =
76	@EV::Prepare::ISA =	97	@EV::Prepare::ISA =
77	@EV::Check::ISA =	98	@EV::Check::ISA =
78	@EV::Child::ISA = "EV::Watcher";	99	@EV::Embed::ISA =
		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 avdantage 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
79		168
80	=head1 BASIC INTERFACE	169	=head1 BASIC INTERFACE
81		170
82	=over 4	171	=over 4
83		172
84	=item $EV::DIED	173	=item $EV::DIED
85		174
86	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
87	throws an exception (with $@ containing thr error). The default prints an	176	throws an exception (with $@ containing the error). The default prints an
88	informative message and continues.	177	informative message and continues.
89		178
90	If this callback throws an exception it will be silently ignored.	179	If this callback throws an exception it will be silently ignored.
91		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
92	=item $time = EV::time	195	=item $time = EV::time
93		196
94	Returns the current time in (fractional) seconds since the epoch.	197	Returns the current time in (fractional) seconds since the epoch.
95		198
96	=item $time = EV::now	199	=item $time = EV::now
		200
		201	=item $time = $loop->now
97		202
98	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
99	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 refering to it is
100	usually faster then calling EV::time.	205	usually faster then calling EV::time.
101		206
102	=item $method = EV::method	207	=item $backend = EV::backend
		208
		209	=item $backend = $loop->backend
103		210
104	Returns an integer describing the backend used by libev (EV::METHOD_SELECT	211	Returns an integer describing the backend used by libev (EV::METHOD_SELECT
105	or EV::METHOD_EPOLL).	212	or EV::METHOD_EPOLL).
106		213
107	=item EV::loop [$flags]	214	=item EV::loop [$flags]
		215
		216	=item $loop->loop ([$flags])
108		217
109	Begin checking for events and calling callbacks. It returns when a	218	Begin checking for events and calling callbacks. It returns when a
110	callback calls EV::unloop.	219	callback calls EV::unloop.
111		220
112	The $flags argument can be one of the following:	221	The $flags argument can be one of the following:
…		…
115	EV::LOOP_ONESHOT block at most once (wait, but do not loop)	224	EV::LOOP_ONESHOT block at most once (wait, but do not loop)
116	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)	225	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
117		226
118	=item EV::unloop [$how]	227	=item EV::unloop [$how]
119		228
		229	=item $loop->unloop ([$how])
		230
120	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
121	innermost call to EV::loop return.	232	innermost call to EV::loop return.
122		233
123	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
124	fast as possible.	235	fast as possible.
125		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. Sometiems useful as a generation counter.
		243
126	=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))
127		247
128	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
129	one-shot event without the need for managing a watcher object.	249	one-shot event without the need for managing a watcher object.
130		250
131	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>
…		…
137	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
138	timeout. Otherwise a EV::timer with this value will be started.	258	timeout. Otherwise a EV::timer with this value will be started.
139		259
140	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
141	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
142	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>,
143	C<EV::WRITE> and C<EV::TIMEOUT>).	263	C<EV::WRITE> and C<EV::TIMEOUT>).
144		264
145	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
146	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
147	invoked.	267	invoked.
148		268
149	=back	269	=item EV::feed_fd_event ($fd, $revents)
150		270
151	=head2 WATCHER	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
		298	=head1 WATCHER OBJECTS
152		299
153	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
154	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
155	would create an EV::io watcher for that:	302	would create an EV::io watcher for that:
156		303
157	my $watcher = EV::io *STDIN, EV::READ, sub {	304	my $watcher = EV::io *STDIN, EV::READ, sub {
158	my ($watcher, $revents) = @_;	305	my ($watcher, $revents) = @_;
159	warn "yeah, STDIN should not be readable without blocking!\n"	306	warn "yeah, STDIN should now be readable without blocking!\n"
160	};	307	};
161		308
162	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
163	active watchers will have their callbacks invoked. All callbacks will be	310	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	311	called with at least two arguments: the watcher and a bitmask of received
165	events.	312	events.
166		313
167	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
168	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
169	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,
170	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
171	(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
172	uses EV::TIMEOUT).	319	uses EV::TIMEOUT).
173		320
174	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
175	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
…		…
181		328
182	Also, all methods changing some aspect of a watcher (->set, ->priority,	329	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,	330	->fh and so on) automatically stop and start it again if it is active,
184	which means pending events get lost.	331	which means pending events get lost.
185		332
186	=head2 WATCHER TYPES	333	=head2 COMMON WATCHER METHODS
187		334
188	Now lets move to the existing watcher types and asociated methods.	335	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		336
195	=over 4	337	=over 4
196		338
197	=item $w->start	339	=item $w->start
198		340
…		…
202		344
203	=item $w->stop	345	=item $w->stop
204		346
205	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
206	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),
207	regardless of wether the watcher was active or not.	349	regardless of whether the watcher was active or not.
208		350
209	=item $bool = $w->is_active	351	=item $bool = $w->is_active
210		352
211	Returns true if the watcher is active, false otherwise.	353	Returns true if the watcher is active, false otherwise.
212		354
…		…
242	The default priority of any newly-created watcher is 0.	384	The default priority of any newly-created watcher is 0.
243		385
244	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
245	subject to almost certain change.	387	subject to almost certain change.
246		388
247	=item $w->trigger ($revents)	389	=item $w->invoke ($revents)
248		390
249	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>.
250		403
251	=item $previous_state = $w->keepalive ($bool)	404	=item $previous_state = $w->keepalive ($bool)
252		405
253	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
254	(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
255	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),
256	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
257	finished (or they forgot to register some watchers for their task :).	410	finished (or they forgot to register some watchers for their task :).
258		411
259	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
260	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
261	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
262	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
263	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
264	because you happen to have this long-running UDP port watcher.	417	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.	420	though your watcher is active, it won't keep C<EV::loop> from returning.
268		421
269	The initial value for keepalive is true (enabled), and you cna change it	422	The initial value for keepalive is true (enabled), and you cna change it
270	any time.	423	any time.
271		424
272	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
273	event loop from running just because of that watcher.	426	event loop from running just because of that watcher.
274		427
275	my $udp_socket = ...	428	my $udp_socket = ...
276	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };	429	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
277	$udp_watcher->keepalive (0);	430	$udp_watcher->keepalive (0);
278		431
		432	=item $loop = $w->loop
		433
		434	Return the loop that this watcher is attached to.
		435
		436	=back
		437
		438
		439	=head1 WATCHER TYPES
		440
		441	Each of the following subsections describes a single watcher type.
		442
		443	=head3 I/O WATCHERS - is this file descriptor readable or writable?
		444
		445	=over 4
		446
279	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	447	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
280		448
281	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback	449	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
282		450
		451	=item $w = $loop->io ($fileno_or_fh, $eventmask, $callback)
		452
		453	=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
		454
283	As long as the returned watcher object is alive, call the C<$callback>	455	As long as the returned watcher object is alive, call the C<$callback>
284	when the events specified in C<$eventmask>.	456	when at least one of events specified in C<$eventmask> occurs.
285		457
286	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:
287		459
288	EV::READ wait until read() wouldn't block anymore	460	EV::READ wait until read() wouldn't block anymore
289	EV::WRITE wait until write() wouldn't block anymore	461	EV::WRITE wait until write() wouldn't block anymore
…		…
305		477
306	=item $old_eventmask = $w->events ($new_eventmask)	478	=item $old_eventmask = $w->events ($new_eventmask)
307		479
308	Returns the previously set event mask and optionally set a new one.	480	Returns the previously set event mask and optionally set a new one.
309		481
		482	=back
		483
		484
		485	=head3 TIMER WATCHERS - relative and optionally repeating timeouts
		486
		487	=over 4
310		488
311	=item $w = EV::timer $after, $repeat, $callback	489	=item $w = EV::timer $after, $repeat, $callback
312		490
313	=item $w = EV::timer_ns $after, $repeat, $callback	491	=item $w = EV::timer_ns $after, $repeat, $callback
314		492
315	Calls the callback after C<$after> seconds. If C<$repeat> is non-zero,	493	=item $w = $loop->timer ($after, $repeat, $callback)
316	the timer will be restarted (with the $repeat value as $after) after the	494
317	callback returns.	495	=item $w = $loop->timer_ns ($after, $repeat, $callback)
		496
		497	Calls the callback after C<$after> seconds (which may be fractional). If
		498	C<$repeat> is non-zero, the timer will be restarted (with the $repeat
		499	value as $after) after the callback returns.
318		500
319	This means that the callback would be called roughly after C<$after>	501	This means that the callback would be called roughly after C<$after>
320	seconds, and then every C<$repeat> seconds. The timer does his best not	502	seconds, and then every C<$repeat> seconds. The timer does his best not
321	to drift, but it will not invoke the timer more often then once per event	503	to drift, but it will not invoke the timer more often then once per event
322	loop iteration, and might drift in other cases. If that isn't acceptable,	504	loop iteration, and might drift in other cases. If that isn't acceptable,
…		…
328		510
329	The C<timer_ns> variant doesn't start (activate) the newly created watcher.	511	The C<timer_ns> variant doesn't start (activate) the newly created watcher.
330		512
331	=item $w->set ($after, $repeat)	513	=item $w->set ($after, $repeat)
332		514
333	Reconfigures the watcher, see the constructor above for details. Can be at	515	Reconfigures the watcher, see the constructor above for details. Can be called at
334	any time.	516	any time.
335		517
336	=item $w->again	518	=item $w->again
337		519
338	Similar to the C<start> method, but has special semantics for repeating timers:	520	Similar to the C<start> method, but has special semantics for repeating timers:
…		…
349	This behaviour is useful when you have a timeout for some IO	531	This behaviour is useful when you have a timeout for some IO
350	operation. You create a timer object with the same value for C<$after> and	532	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	533	C<$repeat>, and then, in the read/write watcher, run the C<again> method
352	on the timeout.	534	on the timeout.
353		535
		536	=back
		537
		538
		539	=head3 PERIODIC WATCHERS - to cron or not to cron?
		540
		541	=over 4
354		542
355	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback	543	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
356		544
357	=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, $callback)
358		550
359	Similar to EV::timer, but is not based on relative timeouts but on	551	Similar to EV::timer, but is not based on relative timeouts but on
360	absolute times. Apart from creating "simple" timers that trigger "at" the	552	absolute times. Apart from creating "simple" timers that trigger "at" the
361	specified time, it can also be used for non-drifting absolute timers and	553	specified time, it can also be used for non-drifting absolute timers and
362	more complex, cron-like, setups that are not adversely affected by time	554	more complex, cron-like, setups that are not adversely affected by time
…		…
372	This time simply fires at the wallclock time C<$at> and doesn't repeat. It	564	This time simply fires at the wallclock time C<$at> and doesn't repeat. It
373	will not adjust when a time jump occurs, that is, if it is to be run	565	will not adjust when a time jump occurs, that is, if it is to be run
374	at January 1st 2011 then it will run when the system time reaches or	566	at January 1st 2011 then it will run when the system time reaches or
375	surpasses this time.	567	surpasses this time.
376		568
377	=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0)	569	=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
378		570
379	In this mode the watcher will always be scheduled to time out at the	571	In this mode the watcher will always be scheduled to time out at the
380	next C<$at + N * $interval> time (for some integer N) and then repeat,	572	next C<$at + N * $interval> time (for some integer N) and then repeat,
381	regardless of any time jumps.	573	regardless of any time jumps.
382		574
…		…
400	time the periodic watcher gets scheduled, the reschedule callback	592	time the periodic watcher gets scheduled, the reschedule callback
401	($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
402	time as second argument.	594	time as second argument.
403		595
404	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
405	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
406	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.
407		600
408	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
409	(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
410	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
411	might be called at other times, too.	604	triggered, but might be called at other times, too.
412		605
413	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
414	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
415	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
416	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
…		…
430		623
431	The C<periodic_ns> variant doesn't start (activate) the newly created watcher.	624	The C<periodic_ns> variant doesn't start (activate) the newly created watcher.
432		625
433	=item $w->set ($at, $interval, $reschedule_cb)	626	=item $w->set ($at, $interval, $reschedule_cb)
434		627
435	Reconfigures the watcher, see the constructor above for details. Can be at	628	Reconfigures the watcher, see the constructor above for details. Can be called at
436	any time.	629	any time.
437		630
438	=item $w->again	631	=item $w->again
439		632
440	Simply stops and starts the watcher again.	633	Simply stops and starts the watcher again.
441		634
		635	=item $time = $w->at
		636
		637	Return the time that the watcher is expected to trigger next.
		638
		639	=back
		640
		641
		642	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
		643
		644	=over 4
442		645
443	=item $w = EV::signal $signal, $callback	646	=item $w = EV::signal $signal, $callback
444		647
445	=item $w = EV::signal_ns $signal, $callback	648	=item $w = EV::signal_ns $signal, $callback
446		649
447	Call the callback when $signal is received (the signal can be specified	650	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).	651	number or by name, just as with C<kill> or C<%SIG>).
449		652
450	EV will grab the signal for the process (the kernel only allows one	653	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,	654	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	655	and removes it again when you stop it. Perl does the same when you
453	add/remove callbacks to %SIG, so watch out.	656	add/remove callbacks to C<%SIG>, so watch out.
454		657
455	You can have as many signal watchers per signal as you want.	658	You can have as many signal watchers per signal as you want.
456		659
457	The C<signal_ns> variant doesn't start (activate) the newly created watcher.	660	The C<signal_ns> variant doesn't start (activate) the newly created watcher.
458		661
459	=item $w->set ($signal)	662	=item $w->set ($signal)
460		663
461	Reconfigures the watcher, see the constructor above for details. Can be at	664	Reconfigures the watcher, see the constructor above for details. Can be
462	any time.	665	called at any time.
463		666
464	=item $current_signum = $w->signal	667	=item $current_signum = $w->signal
465		668
466	=item $old_signum = $w->signal ($new_signal)	669	=item $old_signum = $w->signal ($new_signal)
467		670
468	Returns the previously set signal (always as a number not name) and	671	Returns the previously set signal (always as a number not name) and
469	optionally set a new one.	672	optionally set a new one.
470		673
		674	=back
471		675
		676
		677	=head3 CHILD WATCHERS - watch out for process status changes
		678
		679	=over 4
		680
472	=item $w = EV::child $pid, $callback	681	=item $w = EV::child $pid, $trace, $callback
473		682
474	=item $w = EV::child_ns $pid, $callback	683	=item $w = EV::child_ns $pid, $trace, $callback
		684
		685	=item $w = $loop->child ($pid, $trace, $callback)
		686
		687	=item $w = $loop->child_ns ($pid, $trace, $callback)
475		688
476	Call the callback when a status change for pid C<$pid> (or any pid	689	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	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
478	receives a 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
479	changed/zombie children and call the callback.	694	changed/zombie children and call the callback.
480		695
481	You can access both status and pid by using the C<rstatus> and C<rpid>	696	It is valid (and fully supported) to install a child watcher after a child
482	methods on the watcher object.	697	has exited but before the event loop has started its next iteration (for
		698	example, first you C<fork>, then the new child process might exit, and
		699	only then do you install a child watcher in the parent for the new pid).
483		700
		701	You can access both exit (or tracing) status and pid by using the
		702	C<rstatus> and C<rpid> methods on the watcher object.
		703
484	You can have as many pid watchers per pid as you want.	704	You can have as many pid watchers per pid as you want, they will all be
		705	called.
485		706
486	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.
487		708
488	=item $w->set ($pid)	709	=item $w->set ($pid, $trace)
489		710
490	Reconfigures the watcher, see the constructor above for details. Can be at	711	Reconfigures the watcher, see the constructor above for details. Can be called at
491	any time.	712	any time.
492		713
493	=item $current_pid = $w->pid	714	=item $current_pid = $w->pid
494
495	=item $old_pid = $w->pid ($new_pid)
496		715
497	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.
498		717
499	=item $exit_status = $w->rstatus	718	=item $exit_status = $w->rstatus
500		719
…		…
504	=item $pid = $w->rpid	723	=item $pid = $w->rpid
505		724
506	Return the pid of the awaited child (useful when you have installed a	725	Return the pid of the awaited child (useful when you have installed a
507	watcher for all pids).	726	watcher for all pids).
508		727
		728	=back
		729
		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
		814	=head3 IDLE WATCHERS - when you've got nothing better to do...
		815
		816	=over 4
509		817
510	=item $w = EV::idle $callback	818	=item $w = EV::idle $callback
511		819
512	=item $w = EV::idle_ns $callback	820	=item $w = EV::idle_ns $callback
513		821
514	Call the callback when there are no pending io, timer/periodic, signal or	822	=item $w = $loop->idle ($callback)
515	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>.
516		834
517	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
518	they will be called repeatedly until stopped.	836	they will be called repeatedly until stopped.
519		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
520	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.
521		845
		846	=back
		847
		848
		849	=head3 PREPARE WATCHERS - customise your event loop!
		850
		851	=over 4
522		852
523	=item $w = EV::prepare $callback	853	=item $w = EV::prepare $callback
524		854
525	=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)
526		860
527	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
528	create/modify any watchers at this point.	862	create/modify any watchers at this point.
529		863
530	See the EV::check watcher, below, for explanations and an example.	864	See the EV::check watcher, below, for explanations and an example.
531		865
532	The C<prepare_ns> variant doesn't start (activate) the newly created watcher.	866	The C<prepare_ns> variant doesn't start (activate) the newly created watcher.
533		867
		868	=back
		869
		870
		871	=head3 CHECK WATCHERS - customise your event loop even more!
		872
		873	=over 4
534		874
535	=item $w = EV::check $callback	875	=item $w = EV::check $callback
536		876
537	=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)
538		882
539	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
540	gathered events), but before any other callbacks have been invoked.	884	gathered events), but before any other callbacks have been invoked.
541		885
542	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
…		…
552	or return;	896	or return;
553		897
554	# make the dispatcher handle any outstanding stuff	898	# make the dispatcher handle any outstanding stuff
555	... not shown	899	... not shown
556		900
557	# create an IO watcher for each and every socket	901	# create an I/O watcher for each and every socket
558	@snmp_watcher = (	902	@snmp_watcher = (
559	(map { EV::io $_, EV::READ, sub { } }	903	(map { EV::io $_, EV::READ, sub { } }
560	keys %{ $dispatcher->{_descriptors} }),	904	keys %{ $dispatcher->{_descriptors} }),
561		905
562	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]	906	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
…		…
583	first).	927	first).
584		928
585	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.
586		930
587	=back	931	=back
		932
		933
		934	=head3 FORK WATCHERS - the audacity to resume the event loop after a fork
		935
		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.
		939
		940	=over 4
		941
		942	=item $w = EV::fork $callback
		943
		944	=item $w = EV::fork_ns $callback
		945
		946	=item $w = $loop->fork ($callback)
		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
		953	The C<fork_ns> variant doesn't start (activate) the newly created watcher.
		954
		955	=back
		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.
588		1046
589	=head1 THREADS	1047	=head1 THREADS
590		1048
591	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
592	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
…		…
614	our $DIED = sub {	1072	our $DIED = sub {
615	warn "EV: error in callback (ignoring): $@";	1073	warn "EV: error in callback (ignoring): $@";
616	};	1074	};
617		1075
618	default_loop	1076	default_loop
619	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	1077	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
620		1078
621	1;	1079	1;
622		1080
623	=head1 SEE ALSO	1081	=head1 SEE ALSO
624		1082
625	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.
626		1087
627	=head1 AUTHOR	1088	=head1 AUTHOR
628		1089
629	Marc Lehmann <schmorp@schmorp.de>	1090	Marc Lehmann <schmorp@schmorp.de>
630	http://home.schmorp.de/	1091	http://home.schmorp.de/
631		1092
632	=cut	1093	=cut
633		1094

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Comparing EV/EV.pm (file contents): Revision 1.52 by root, Sat Nov 24 16:20:30 2007 UTC vs. Revision 1.106 by root, Thu Oct 23 04:56:49 2008 UTC

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Comparing EV/EV.pm (file contents):
Revision 1.52 by root, Sat Nov 24 16:20:30 2007 UTC vs.
Revision 1.106 by root, Thu Oct 23 04:56:49 2008 UTC