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

Comparing EV/EV.pm (file contents):
Revision 1.54 by root, Tue Nov 27 07:27:10 2007 UTC vs.
Revision 1.99 by root, Tue Jul 8 09:37:37 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 {
12	warn "is called after 2s";
13	};
14
15	my $w = EV::timer 2, 2, sub {
16	warn "is called roughly every 2s (repeat = 2)";
17	};
18
19	undef $w; # destroy event watcher again
20
21	my $w = EV::periodic 0, 60, 0, sub {
22	warn "is called every minute, on the minute, exactly";
23	};
24
25	# IO
26
27	my $w = EV::io *STDIN, EV::READ, sub {
28	my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
29	warn "stdin is readable, you entered: ", <STDIN>;
30	};
31
32	# SIGNALS
33
34	my $w = EV::signal 'QUIT', sub {
35	warn "sigquit received\n";
36	};
37
38	# CHILD/PID STATUS CHANGES
39
40	my $w = EV::child 666, sub {
41	my ($w, $revents) = @_;
42	my $status = $w->rstatus;
43	};
44
45	# STAT CHANGES	45	# STAT CHANGES
46	my $w = EV::stat "/etc/passwd", 10, sub {	46	my $w = EV::stat "/etc/passwd", 10, sub {
47	my ($w, $revents) = @_;	47	my ($w, $revents) = @_;
48	warn $w->path, " has changed somehow.\n";	48	warn $w->path, " has changed somehow.\n";
49	};	49	};
50		50
51	# MAINLOOP	51	# MAINLOOP
52	EV::loop; # loop until EV::unloop is called or all watchers stop	52	EV::loop; # loop until EV::unloop is called or all watchers stop
53	EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled	53	EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled
54	EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block	54	EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block
55		55
56	=head1 DESCRIPTION	56	=head1 DESCRIPTION
57		57
58	This module provides an interface to libev	58	This module provides an interface to libev
59	(L<http://software.schmorp.de/pkg/libev.html>). While the documentation	59	(L<http://software.schmorp.de/pkg/libev.html>). While the documentation
60	below is comprehensive, one might also consult the documentation of libev	60	below is comprehensive, one might also consult the documentation of libev
61	itself (L<http://cvs.schmorp.de/libev/ev.html>) for more subtle details on	61	itself (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod>) for more
62	watcher semantics or some discussion on the available backends, or how to	62	subtle details on watcher semantics or some discussion on the available
63	force a specific backend with C<LIBEV_FLAGS>.	63	backends, or how to force a specific backend with C<LIBEV_FLAGS>, or just
		64	about in any case because it has much more detailed information.
		65
		66	This module is very fast and scalable. It is actually so fast that you
		67	can use it through the L<AnyEvent> module, stay portable to other event
		68	loops (if you don't rely on any watcher types not available through it)
		69	and still be faster than with any other event loop currently supported in
		70	Perl.
64		71
65	=cut	72	=cut
66		73
67	package EV;	74	package EV;
68		75
69	use strict;	76	use strict;
70		77
71	BEGIN {	78	BEGIN {
72	our $VERSION = '1.4';	79	our $VERSION = '3.42';
73	use XSLoader;	80	use XSLoader;
74	XSLoader::load "EV", $VERSION;	81	XSLoader::load "EV", $VERSION;
75	}	82	}
76		83
77	@EV::IO::ISA =	84	@EV::IO::ISA =
78	@EV::Timer::ISA =	85	@EV::Timer::ISA =
79	@EV::Periodic::ISA =	86	@EV::Periodic::ISA =
80	@EV::Signal::ISA =	87	@EV::Signal::ISA =
		88	@EV::Child::ISA =
		89	@EV::Stat::ISA =
81	@EV::Idle::ISA =	90	@EV::Idle::ISA =
82	@EV::Prepare::ISA =	91	@EV::Prepare::ISA =
83	@EV::Check::ISA =	92	@EV::Check::ISA =
84	@EV::Child::ISA =
85	@EV::Embed::ISA =	93	@EV::Embed::ISA =
86	@EV::Stat::ISA = "EV::Watcher";	94	@EV::Fork::ISA =
		95	@EV::Async::ISA =
		96	"EV::Watcher";
		97
		98	@EV::Loop::Default::ISA = "EV::Loop";
		99
		100	=head1 EVENT LOOPS
		101
		102	EV supports multiple event loops: There is a single "default event loop"
		103	that can handle everything including signals and child watchers, and any
		104	number of "dynamic event loops" that can use different backends (with
		105	various limitations), but no child and signal watchers.
		106
		107	You do not have to do anything to create the default event loop: When
		108	the module is loaded a suitable backend is selected on the premise of
		109	selecting a working backend (which for example rules out kqueue on most
		110	BSDs). Modules should, unless they have "special needs" always use the
		111	default loop as this is fastest (perl-wise), best supported by other
		112	modules (e.g. AnyEvent or Coro) and most portable event loop.
		113
		114	For specific programs you can create additional event loops dynamically.
		115
		116	If you want to take avdantage of kqueue (which often works properly for
		117	sockets only) even though the default loop doesn't enable it, you can
		118	I<embed> a kqueue loop into the default loop: running the default loop
		119	will then also service the kqueue loop to some extent. See the example in
		120	the section about embed watchers for an example on how to achieve that.
		121
		122	=over 4
		123
		124	=item $loop = new EV::loop [$flags]
		125
		126	Create a new event loop as per the specified flags. Please refer to the
		127	C<ev_loop_new ()> function description in the libev documentation
		128	(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>)
		129	for more info.
		130
		131	The loop will automatically be destroyed when it is no longer referenced
		132	by any watcher and the loop object goes out of scope.
		133
		134	Using C<EV::FLAG_FORKCHECK> is recommended, as only the default event loop
		135	is protected by this module.
		136
		137	=item $loop->loop_fork
		138
		139	Must be called after a fork in the child, before entering or continuing
		140	the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
		141	this function automatically, at some performance loss (refer to the libev
		142	documentation).
		143
		144	=item $loop->loop_verify
		145
		146	Calls C<ev_verify> to make internal consistency checks (for debugging
		147	libev) and abort the program if any data structures were found to be
		148	corrupted.
		149
		150	=item $loop = EV::default_loop [$flags]
		151
		152	Return the default loop (which is a singleton object). Since this module
		153	already creates the default loop with default flags, specifying flags here
		154	will not have any effect unless you destroy the default loop first, which
		155	isn't supported. So in short: don't do it, and if you break it, you get to
		156	keep the pieces.
		157
		158	=back
		159
87		160
88	=head1 BASIC INTERFACE	161	=head1 BASIC INTERFACE
89		162
90	=over 4	163	=over 4
91		164
92	=item $EV::DIED	165	=item $EV::DIED
93		166
94	Must contain a reference to a function that is called when a callback	167	Must contain a reference to a function that is called when a callback
95	throws an exception (with $@ containing thr error). The default prints an	168	throws an exception (with $@ containing the error). The default prints an
96	informative message and continues.	169	informative message and continues.
97		170
98	If this callback throws an exception it will be silently ignored.	171	If this callback throws an exception it will be silently ignored.
99		172
		173	=item $flags = EV::supported_backends
		174
		175	=item $flags = EV::recommended_backends
		176
		177	=item $flags = EV::embeddable_backends
		178
		179	Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this
		180	instance of EV, the set of recommended backends (supposed to be good) for
		181	this platform and the set of embeddable backends (see EMBED WATCHERS).
		182
		183	=item EV::sleep $seconds
		184
		185	Block the process for the given number of (fractional) seconds.
		186
100	=item $time = EV::time	187	=item $time = EV::time
101		188
102	Returns the current time in (fractional) seconds since the epoch.	189	Returns the current time in (fractional) seconds since the epoch.
103		190
104	=item $time = EV::now	191	=item $time = EV::now
		192
		193	=item $time = $loop->now
105		194
106	Returns the time the last event loop iteration has been started. This	195	Returns the time the last event loop iteration has been started. This
107	is the time that (relative) timers are based on, and refering to it is	196	is the time that (relative) timers are based on, and refering to it is
108	usually faster then calling EV::time.	197	usually faster then calling EV::time.
109		198
110	=item $method = EV::method	199	=item $backend = EV::backend
		200
		201	=item $backend = $loop->backend
111		202
112	Returns an integer describing the backend used by libev (EV::METHOD_SELECT	203	Returns an integer describing the backend used by libev (EV::METHOD_SELECT
113	or EV::METHOD_EPOLL).	204	or EV::METHOD_EPOLL).
114		205
115	=item EV::loop [$flags]	206	=item EV::loop [$flags]
		207
		208	=item $loop->loop ([$flags])
116		209
117	Begin checking for events and calling callbacks. It returns when a	210	Begin checking for events and calling callbacks. It returns when a
118	callback calls EV::unloop.	211	callback calls EV::unloop.
119		212
120	The $flags argument can be one of the following:	213	The $flags argument can be one of the following:
…		…
123	EV::LOOP_ONESHOT block at most once (wait, but do not loop)	216	EV::LOOP_ONESHOT block at most once (wait, but do not loop)
124	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)	217	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
125		218
126	=item EV::unloop [$how]	219	=item EV::unloop [$how]
127		220
		221	=item $loop->unloop ([$how])
		222
128	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the	223	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the
129	innermost call to EV::loop return.	224	innermost call to EV::loop return.
130		225
131	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as	226	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as
132	fast as possible.	227	fast as possible.
133		228
		229	=item $count = EV::loop_count
		230
		231	=item $count = $loop->loop_count
		232
		233	Return the number of times the event loop has polled for new
		234	events. Sometiems useful as a generation counter.
		235
134	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)	236	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
		237
		238	=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
135		239
136	This function rolls together an I/O and a timer watcher for a single	240	This function rolls together an I/O and a timer watcher for a single
137	one-shot event without the need for managing a watcher object.	241	one-shot event without the need for managing a watcher object.
138		242
139	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>	243	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>
…		…
145	If timeout is C<undef> or negative, then there will be no	249	If timeout is C<undef> or negative, then there will be no
146	timeout. Otherwise a EV::timer with this value will be started.	250	timeout. Otherwise a EV::timer with this value will be started.
147		251
148	When an error occurs or either the timeout or I/O watcher triggers, then	252	When an error occurs or either the timeout or I/O watcher triggers, then
149	the callback will be called with the received event set (in general	253	the callback will be called with the received event set (in general
150	you can expect it to be a combination of C<EV:ERROR>, C<EV::READ>,	254	you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
151	C<EV::WRITE> and C<EV::TIMEOUT>).	255	C<EV::WRITE> and C<EV::TIMEOUT>).
152		256
153	EV::once doesn't return anything: the watchers stay active till either	257	EV::once doesn't return anything: the watchers stay active till either
154	of them triggers, then they will be stopped and freed, and the callback	258	of them triggers, then they will be stopped and freed, and the callback
155	invoked.	259	invoked.
156		260
157	=back	261	=item EV::feed_fd_event ($fd, $revents)
158		262
		263	=item $loop->feed_fd_event ($fd, $revents)
		264
		265	Feed an event on a file descriptor into EV. EV will react to this call as
		266	if the readyness notifications specified by C<$revents> (a combination of
		267	C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
		268
		269	=item EV::feed_signal_event ($signal)
		270
		271	Feed a signal event into EV. EV will react to this call as if the signal
		272	specified by C<$signal> had occured.
		273
		274	=item EV::set_io_collect_interval $time
		275
		276	=item $loop->set_io_collect_interval ($time)
		277
		278	=item EV::set_timeout_collect_interval $time
		279
		280	=item $loop->set_timeout_collect_interval ($time)
		281
		282	These advanced functions set the minimum block interval when polling for I/O events and the minimum
		283	wait interval for timer events. See the libev documentation at
		284	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> for
		285	a more detailed discussion.
		286
		287	=back
		288
		289
159	=head2 WATCHER OBJECTS	290	=head1 WATCHER OBJECTS
160		291
161	A watcher is an object that gets created to record your interest in some	292	A watcher is an object that gets created to record your interest in some
162	event. For instance, if you want to wait for STDIN to become readable, you	293	event. For instance, if you want to wait for STDIN to become readable, you
163	would create an EV::io watcher for that:	294	would create an EV::io watcher for that:
164		295
165	my $watcher = EV::io *STDIN, EV::READ, sub {	296	my $watcher = EV::io *STDIN, EV::READ, sub {
166	my ($watcher, $revents) = @_;	297	my ($watcher, $revents) = @_;
167	warn "yeah, STDIN should not be readable without blocking!\n"	298	warn "yeah, STDIN should now be readable without blocking!\n"
168	};	299	};
169		300
170	All watchers can be active (waiting for events) or inactive (paused). Only	301	All watchers can be active (waiting for events) or inactive (paused). Only
171	active watchers will have their callbacks invoked. All callbacks will be	302	active watchers will have their callbacks invoked. All callbacks will be
172	called with at least two arguments: the watcher and a bitmask of received	303	called with at least two arguments: the watcher and a bitmask of received
173	events.	304	events.
174		305
175	Each watcher type has its associated bit in revents, so you can use the	306	Each watcher type has its associated bit in revents, so you can use the
176	same callback for multiple watchers. The event mask is named after the	307	same callback for multiple watchers. The event mask is named after the
177	type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,	308	type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
178	EV::periodic sets EV::PERIODIC and so on, with the exception of IO events	309	EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events
179	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which	310	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which
180	uses EV::TIMEOUT).	311	uses EV::TIMEOUT).
181		312
182	In the rare case where one wants to create a watcher but not start it at	313	In the rare case where one wants to create a watcher but not start it at
183	the same time, each constructor has a variant with a trailing C<_ns> in	314	the same time, each constructor has a variant with a trailing C<_ns> in
…		…
205		336
206	=item $w->stop	337	=item $w->stop
207		338
208	Stop a watcher if it is active. Also clear any pending events (events that	339	Stop a watcher if it is active. Also clear any pending events (events that
209	have been received but that didn't yet result in a callback invocation),	340	have been received but that didn't yet result in a callback invocation),
210	regardless of wether the watcher was active or not.	341	regardless of whether the watcher was active or not.
211		342
212	=item $bool = $w->is_active	343	=item $bool = $w->is_active
213		344
214	Returns true if the watcher is active, false otherwise.	345	Returns true if the watcher is active, false otherwise.
215		346
…		…
245	The default priority of any newly-created watcher is 0.	376	The default priority of any newly-created watcher is 0.
246		377
247	Note that the priority semantics have not yet been fleshed out and are	378	Note that the priority semantics have not yet been fleshed out and are
248	subject to almost certain change.	379	subject to almost certain change.
249		380
250	=item $w->trigger ($revents)	381	=item $w->invoke ($revents)
251		382
252	Call the callback now with the given event mask.	383	Call the callback now with the given event mask.
		384
		385	=item $w->feed_event ($revents)
		386
		387	Feed some events on this watcher into EV. EV will react to this call as if
		388	the watcher had received the given C<$revents> mask.
		389
		390	=item $revents = $w->clear_pending
		391
		392	If the watcher is pending, this function clears its pending status and
		393	returns its C<$revents> bitset (as if its callback was invoked). If the
		394	watcher isn't pending it does nothing and returns C<0>.
253		395
254	=item $previous_state = $w->keepalive ($bool)	396	=item $previous_state = $w->keepalive ($bool)
255		397
256	Normally, C<EV::loop> will return when there are no active watchers	398	Normally, C<EV::loop> will return when there are no active watchers
257	(which is a "deadlock" because no progress can be made anymore). This is	399	(which is a "deadlock" because no progress can be made anymore). This is
258	convinient because it allows you to start your watchers (and your jobs),	400	convinient because it allows you to start your watchers (and your jobs),
259	call C<EV::loop> once and when it returns you know that all your jobs are	401	call C<EV::loop> once and when it returns you know that all your jobs are
260	finished (or they forgot to register some watchers for their task :).	402	finished (or they forgot to register some watchers for their task :).
261		403
262	Sometimes, however, this gets in your way, for example when you the module	404	Sometimes, however, this gets in your way, for example when the module
263	that calls C<EV::loop> (usually the main program) is not the same module	405	that calls C<EV::loop> (usually the main program) is not the same module
264	as a long-living watcher (for example a DNS client module written by	406	as a long-living watcher (for example a DNS client module written by
265	somebody else even). Then you might want any outstanding requests to be	407	somebody else even). Then you might want any outstanding requests to be
266	handled, but you would not want to keep C<EV::loop> from returning just	408	handled, but you would not want to keep C<EV::loop> from returning just
267	because you happen to have this long-running UDP port watcher.	409	because you happen to have this long-running UDP port watcher.
…		…
270	though your watcher is active, it won't keep C<EV::loop> from returning.	412	though your watcher is active, it won't keep C<EV::loop> from returning.
271		413
272	The initial value for keepalive is true (enabled), and you cna change it	414	The initial value for keepalive is true (enabled), and you cna change it
273	any time.	415	any time.
274		416
275	Example: Register an IO watcher for some UDP socket but do not keep the	417	Example: Register an I/O watcher for some UDP socket but do not keep the
276	event loop from running just because of that watcher.	418	event loop from running just because of that watcher.
277		419
278	my $udp_socket = ...	420	my $udp_socket = ...
279	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };	421	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
280	$udp_watcher->keepalive (0);	422	$udp_watcher->keepalive (0);
281		423
282	=back	424	=item $loop = $w->loop
283		425
		426	Return the loop that this watcher is attached to.
284		427
		428	=back
		429
		430
285	=head2 WATCHER TYPES	431	=head1 WATCHER TYPES
286		432
287	Each of the following subsections describes a single watcher type.	433	Each of the following subsections describes a single watcher type.
288		434
289	=head3 IO WATCHERS - is this file descriptor readable or writable?	435	=head3 I/O WATCHERS - is this file descriptor readable or writable?
290		436
291	=over 4	437	=over 4
292		438
293	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	439	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
294		440
295	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback	441	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
		442
		443	=item $w = $loop->io ($fileno_or_fh, $eventmask, $callback)
		444
		445	=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
296		446
297	As long as the returned watcher object is alive, call the C<$callback>	447	As long as the returned watcher object is alive, call the C<$callback>
298	when at least one of events specified in C<$eventmask> occurs.	448	when at least one of events specified in C<$eventmask> occurs.
299		449
300	The $eventmask can be one or more of these constants ORed together:	450	The $eventmask can be one or more of these constants ORed together:
…		…
329	=over 4	479	=over 4
330		480
331	=item $w = EV::timer $after, $repeat, $callback	481	=item $w = EV::timer $after, $repeat, $callback
332		482
333	=item $w = EV::timer_ns $after, $repeat, $callback	483	=item $w = EV::timer_ns $after, $repeat, $callback
		484
		485	=item $w = $loop->timer ($after, $repeat, $callback)
		486
		487	=item $w = $loop->timer_ns ($after, $repeat, $callback)
334		488
335	Calls the callback after C<$after> seconds (which may be fractional). If	489	Calls the callback after C<$after> seconds (which may be fractional). If
336	C<$repeat> is non-zero, the timer will be restarted (with the $repeat	490	C<$repeat> is non-zero, the timer will be restarted (with the $repeat
337	value as $after) after the callback returns.	491	value as $after) after the callback returns.
338		492
…		…
379	=over 4	533	=over 4
380		534
381	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback	535	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
382		536
383	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback	537	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
		538
		539	=item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
		540
		541	=item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback)
384		542
385	Similar to EV::timer, but is not based on relative timeouts but on	543	Similar to EV::timer, but is not based on relative timeouts but on
386	absolute times. Apart from creating "simple" timers that trigger "at" the	544	absolute times. Apart from creating "simple" timers that trigger "at" the
387	specified time, it can also be used for non-drifting absolute timers and	545	specified time, it can also be used for non-drifting absolute timers and
388	more complex, cron-like, setups that are not adversely affected by time	546	more complex, cron-like, setups that are not adversely affected by time
…		…
398	This time simply fires at the wallclock time C<$at> and doesn't repeat. It	556	This time simply fires at the wallclock time C<$at> and doesn't repeat. It
399	will not adjust when a time jump occurs, that is, if it is to be run	557	will not adjust when a time jump occurs, that is, if it is to be run
400	at January 1st 2011 then it will run when the system time reaches or	558	at January 1st 2011 then it will run when the system time reaches or
401	surpasses this time.	559	surpasses this time.
402		560
403	=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0)	561	=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
404		562
405	In this mode the watcher will always be scheduled to time out at the	563	In this mode the watcher will always be scheduled to time out at the
406	next C<$at + N * $interval> time (for some integer N) and then repeat,	564	next C<$at + N * $interval> time (for some integer N) and then repeat,
407	regardless of any time jumps.	565	regardless of any time jumps.
408		566
…		…
426	time the periodic watcher gets scheduled, the reschedule callback	584	time the periodic watcher gets scheduled, the reschedule callback
427	($reschedule_cb) will be called with the watcher as first, and the current	585	($reschedule_cb) will be called with the watcher as first, and the current
428	time as second argument.	586	time as second argument.
429		587
430	I<This callback MUST NOT stop or destroy this or any other periodic	588	I<This callback MUST NOT stop or destroy this or any other periodic
431	watcher, ever>. If you need to stop it, return 1e30 and stop it	589	watcher, ever, and MUST NOT call any event loop functions or methods>. If
432	afterwards.	590	you need to stop it, return 1e30 and stop it afterwards. You may create
		591	and start a C<EV::prepare> watcher for this task.
433		592
434	It must return the next time to trigger, based on the passed time value	593	It must return the next time to trigger, based on the passed time value
435	(that is, the lowest time value larger than to the second argument). It	594	(that is, the lowest time value larger than or equal to to the second
436	will usually be called just before the callback will be triggered, but	595	argument). It will usually be called just before the callback will be
437	might be called at other times, too.	596	triggered, but might be called at other times, too.
438		597
439	This can be used to create very complex timers, such as a timer that	598	This can be used to create very complex timers, such as a timer that
440	triggers on each midnight, local time (actually 24 hours after the last	599	triggers on each midnight, local time (actually 24 hours after the last
441	midnight, to keep the example simple. If you know a way to do it correctly	600	midnight, to keep the example simple. If you know a way to do it correctly
442	in about the same space (without requiring elaborate modules), drop me a	601	in about the same space (without requiring elaborate modules), drop me a
…		…
463		622
464	=item $w->again	623	=item $w->again
465		624
466	Simply stops and starts the watcher again.	625	Simply stops and starts the watcher again.
467		626
		627	=item $time = $w->at
		628
		629	Return the time that the watcher is expected to trigger next.
		630
468	=back	631	=back
469		632
470		633
471	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!	634	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
472		635
…		…
505		668
506	=head3 CHILD WATCHERS - watch out for process status changes	669	=head3 CHILD WATCHERS - watch out for process status changes
507		670
508	=over 4	671	=over 4
509		672
510	=item $w = EV::child $pid, $callback	673	=item $w = EV::child $pid, $trace, $callback
511		674
512	=item $w = EV::child_ns $pid, $callback	675	=item $w = EV::child_ns $pid, $trace, $callback
513		676
		677	=item $w = $loop->child ($pid, $trace, $callback)
		678
		679	=item $w = $loop->child_ns ($pid, $trace, $callback)
		680
514	Call the callback when a status change for pid C<$pid> (or any pid if	681	Call the callback when a status change for pid C<$pid> (or any pid
515	C<$pid> is 0) has been received. More precisely: when the process receives	682	if C<$pid> is 0) has been received (a status change happens when the
		683	process terminates or is killed, or, when trace is true, additionally when
		684	it is stopped or continued). More precisely: when the process receives
516	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all	685	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
517	changed/zombie children and call the callback.	686	changed/zombie children and call the callback.
518		687
519	It is valid (and fully supported) to install a child watcher after a child	688	It is valid (and fully supported) to install a child watcher after a child
520	has exited but before the event loop has started its next iteration (for	689	has exited but before the event loop has started its next iteration (for
…		…
527	You can have as many pid watchers per pid as you want, they will all be	696	You can have as many pid watchers per pid as you want, they will all be
528	called.	697	called.
529		698
530	The C<child_ns> variant doesn't start (activate) the newly created watcher.	699	The C<child_ns> variant doesn't start (activate) the newly created watcher.
531		700
532	=item $w->set ($pid)	701	=item $w->set ($pid, $trace)
533		702
534	Reconfigures the watcher, see the constructor above for details. Can be called at	703	Reconfigures the watcher, see the constructor above for details. Can be called at
535	any time.	704	any time.
536		705
537	=item $current_pid = $w->pid	706	=item $current_pid = $w->pid
538		707
539	=item $old_pid = $w->pid ($new_pid)
540
541	Returns the previously set process id and optionally set a new one.	708	Returns the previously set process id and optionally set a new one.
542		709
543	=item $exit_status = $w->rstatus	710	=item $exit_status = $w->rstatus
544		711
545	Return the exit/wait status (as returned by waitpid, see the waitpid entry	712	Return the exit/wait status (as returned by waitpid, see the waitpid entry
…		…
551	watcher for all pids).	718	watcher for all pids).
552		719
553	=back	720	=back
554		721
555		722
		723	=head3 STAT WATCHERS - did the file attributes just change?
		724
		725	=over 4
		726
		727	=item $w = EV::stat $path, $interval, $callback
		728
		729	=item $w = EV::stat_ns $path, $interval, $callback
		730
		731	=item $w = $loop->stat ($path, $interval, $callback)
		732
		733	=item $w = $loop->stat_ns ($path, $interval, $callback)
		734
		735	Call the callback when a file status change has been detected on
		736	C<$path>. The C<$path> does not need to exist, changing from "path exists"
		737	to "path does not exist" is a status change like any other.
		738
		739	The C<$interval> is a recommended polling interval for systems where
		740	OS-supported change notifications don't exist or are not supported. If
		741	you use C<0> then an unspecified default is used (which is highly
		742	recommended!), which is to be expected to be around five seconds usually.
		743
		744	This watcher type is not meant for massive numbers of stat watchers,
		745	as even with OS-supported change notifications, this can be
		746	resource-intensive.
		747
		748	The C<stat_ns> variant doesn't start (activate) the newly created watcher.
		749
		750	=item ... = $w->stat
		751
		752	This call is very similar to the perl C<stat> built-in: It stats (using
		753	C<lstat>) the path specified in the watcher and sets perls stat cache (as
		754	well as EV's idea of the current stat values) to the values found.
		755
		756	In scalar context, a boolean is return indicating success or failure of
		757	the stat. In list context, the same 13-value list as with stat is returned
		758	(except that the blksize and blocks fields are not reliable).
		759
		760	In the case of an error, errno is set to C<ENOENT> (regardless of the
		761	actual error value) and the C<nlink> value is forced to zero (if the stat
		762	was successful then nlink is guaranteed to be non-zero).
		763
		764	See also the next two entries for more info.
		765
		766	=item ... = $w->attr
		767
		768	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		769	the values most recently detected by EV. See the next entry for more info.
		770
		771	=item ... = $w->prev
		772
		773	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		774	the previous set of values, before the change.
		775
		776	That is, when the watcher callback is invoked, C<< $w->prev >> will be set
		777	to the values found I<before> a change was detected, while C<< $w->attr >>
		778	returns the values found leading to the change detection. The difference (if any)
		779	between C<prev> and C<attr> is what triggered the callback.
		780
		781	If you did something to the filesystem object and do not want to trigger
		782	yet another change, you can call C<stat> to update EV's idea of what the
		783	current attributes are.
		784
		785	=item $w->set ($path, $interval)
		786
		787	Reconfigures the watcher, see the constructor above for details. Can be
		788	called at any time.
		789
		790	=item $current_path = $w->path
		791
		792	=item $old_path = $w->path ($new_path)
		793
		794	Returns the previously set path and optionally set a new one.
		795
		796	=item $current_interval = $w->interval
		797
		798	=item $old_interval = $w->interval ($new_interval)
		799
		800	Returns the previously set interval and optionally set a new one. Can be
		801	used to query the actual interval used.
		802
		803	=back
		804
		805
556	=head3 IDLE WATCHERS - when you've got nothing better to do...	806	=head3 IDLE WATCHERS - when you've got nothing better to do...
557		807
558	=over 4	808	=over 4
559		809
560	=item $w = EV::idle $callback	810	=item $w = EV::idle $callback
561		811
562	=item $w = EV::idle_ns $callback	812	=item $w = EV::idle_ns $callback
563		813
564	Call the callback when there are no pending io, timer/periodic, signal or	814	=item $w = $loop->idle ($callback)
565	child events, i.e. when the process is idle.	815
		816	=item $w = $loop->idle_ns ($callback)
		817
		818	Call the callback when there are no other pending watchers of the same or
		819	higher priority (excluding check, prepare and other idle watchers of the
		820	same or lower priority, of course). They are called idle watchers because
		821	when the watcher is the highest priority pending event in the process, the
		822	process is considered to be idle at that priority.
		823
		824	If you want a watcher that is only ever called when I<no> other events are
		825	outstanding you have to set the priority to C<EV::MINPRI>.
566		826
567	The process will not block as long as any idle watchers are active, and	827	The process will not block as long as any idle watchers are active, and
568	they will be called repeatedly until stopped.	828	they will be called repeatedly until stopped.
569		829
		830	For example, if you have idle watchers at priority C<0> and C<1>, and
		831	an I/O watcher at priority C<0>, then the idle watcher at priority C<1>
		832	and the I/O watcher will always run when ready. Only when the idle watcher
		833	at priority C<1> is stopped and the I/O watcher at priority C<0> is not
		834	pending with the C<0>-priority idle watcher be invoked.
		835
570	The C<idle_ns> variant doesn't start (activate) the newly created watcher.	836	The C<idle_ns> variant doesn't start (activate) the newly created watcher.
571		837
572	=back	838	=back
573		839
574		840
…		…
577	=over 4	843	=over 4
578		844
579	=item $w = EV::prepare $callback	845	=item $w = EV::prepare $callback
580		846
581	=item $w = EV::prepare_ns $callback	847	=item $w = EV::prepare_ns $callback
		848
		849	=item $w = $loop->prepare ($callback)
		850
		851	=item $w = $loop->prepare_ns ($callback)
582		852
583	Call the callback just before the process would block. You can still	853	Call the callback just before the process would block. You can still
584	create/modify any watchers at this point.	854	create/modify any watchers at this point.
585		855
586	See the EV::check watcher, below, for explanations and an example.	856	See the EV::check watcher, below, for explanations and an example.
…		…
595	=over 4	865	=over 4
596		866
597	=item $w = EV::check $callback	867	=item $w = EV::check $callback
598		868
599	=item $w = EV::check_ns $callback	869	=item $w = EV::check_ns $callback
		870
		871	=item $w = $loop->check ($callback)
		872
		873	=item $w = $loop->check_ns ($callback)
600		874
601	Call the callback just after the process wakes up again (after it has	875	Call the callback just after the process wakes up again (after it has
602	gathered events), but before any other callbacks have been invoked.	876	gathered events), but before any other callbacks have been invoked.
603		877
604	This is used to integrate other event-based software into the EV	878	This is used to integrate other event-based software into the EV
…		…
614	or return;	888	or return;
615		889
616	# make the dispatcher handle any outstanding stuff	890	# make the dispatcher handle any outstanding stuff
617	... not shown	891	... not shown
618		892
619	# create an IO watcher for each and every socket	893	# create an I/O watcher for each and every socket
620	@snmp_watcher = (	894	@snmp_watcher = (
621	(map { EV::io $_, EV::READ, sub { } }	895	(map { EV::io $_, EV::READ, sub { } }
622	keys %{ $dispatcher->{_descriptors} }),	896	keys %{ $dispatcher->{_descriptors} }),
623		897
624	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]	898	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
…		…
646		920
647	The C<check_ns> variant doesn't start (activate) the newly created watcher.	921	The C<check_ns> variant doesn't start (activate) the newly created watcher.
648		922
649	=back	923	=back
650		924
651	=head3 STAT WATCHERS - did the file stats just change?
652		925
653	=over 4	926	=head3 FORK WATCHERS - the audacity to resume the event loop after a fork
654		927
655	=item $w = EV::stat $path, $interval, $callback	928	Fork watchers are called when a C<fork ()> was detected. The invocation
		929	is done before the event loop blocks next and before C<check> watchers
		930	are being called, and only in the child after the fork.
656		931
657	=item $w = EV::stat_ns $path, $interval, $callback	932	=over 4
658		933
659	Call the callback when a file status change has been detected on	934	=item $w = EV::fork $callback
660	C<$path>. The C<$path> does not need to exist, changing from "path exists"
661	to "path does not exist" is a status change like any other.
662		935
663	The C<$interval> is a recommended polling interval for systems where	936	=item $w = EV::fork_ns $callback
664	OS-supported change notifications don't exist or are not supported. If
665	you use C<0> then an unspecified default is used (which is highly
666	recommended!), which is to be expected to be around five seconds usually.
667		937
668	This watcher type is not meant for massive numbers of stat watchers,	938	=item $w = $loop->fork ($callback)
669	as even with OS-supported change notifications, this can be
670	resource-intensive.
671		939
		940	=item $w = $loop->fork_ns ($callback)
		941
		942	Call the callback before the event loop is resumed in the child process
		943	after a fork.
		944
672	The C<stat_ns> variant doesn't start (activate) the newly created watcher.	945	The C<fork_ns> variant doesn't start (activate) the newly created watcher.
673		946
674	=item $w->set ($path, $interval)
675
676	Reconfigures the watcher, see the constructor above for details. Can be
677	called at any time.
678
679	=item $current_path = $w->path
680
681	=item $old_path = $w->path ($new_path)
682
683	Returns the previously set path and optionally set a new one.
684
685	=item $current_interval = $w->interval
686
687	=item $old_interval = $w->interval ($new_interval)
688
689	Returns the previously set interval and optionally set a new one. Can be
690	used to query the actual interval used.
691
692	=back	947	=back
693		948
		949
		950	=head3 EMBED WATCHERS - when one backend isn't enough...
		951
		952	This is a rather advanced watcher type that lets you embed one event loop
		953	into another (currently only IO events are supported in the embedded
		954	loop, other types of watchers might be handled in a delayed or incorrect
		955	fashion and must not be used).
		956
		957	See the libev documentation at
		958	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
		959	for more details.
		960
		961	In short, this watcher is most useful on BSD systems without working
		962	kqueue to still be able to handle a large number of sockets:
		963
		964	my $socket_loop;
		965
		966	# check wether we use SELECT or POLL _and_ KQUEUE is supported
		967	if (
		968	(EV::backend & (EV::BACKEND_POLL \| EV::BACKEND_SELECT))
		969	&& (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
		970	) {
		971	# use kqueue for sockets
		972	$socket_loop = new EV::Loop EV::BACKEND_KQUEUE \| EV::FLAG_NOENV;
		973	}
		974
		975	# use the default loop otherwise
		976	$socket_loop \|\|= EV::default_loop;
		977
		978	=over 4
		979
		980	=item $w = EV::embed $otherloop, $callback
		981
		982	=item $w = EV::embed_ns $otherloop, $callback
		983
		984	=item $w = $loop->embed ($otherloop, $callback)
		985
		986	=item $w = $loop->embed_ns ($otherloop, $callback)
		987
		988	Call the callback when the embedded event loop (C<$otherloop>) has any
		989	I/O activity. The C<$callback> should alwas be specified as C<undef> in
		990	this version of EV, which means the embedded event loop will be managed
		991	automatically.
		992
		993	The C<embed_ns> variant doesn't start (activate) the newly created watcher.
		994
		995	=back
		996
		997	=head3 ASYNC WATCHERS - how to wake up another event loop
		998
		999	Async watchers are provided by EV, but have little use in perl directly, as perl
		1000	neither supports threads nor direct access to signal handlers or other
		1001	contexts where they could be of value.
		1002
		1003	It is, however, possible to use them from the XS level.
		1004
		1005	Please see the libev documentation for further details.
		1006
		1007	=over 4
		1008
		1009	=item $w = EV::async $callback
		1010
		1011	=item $w = EV::async_ns $callback
		1012
		1013	=item $w->send
		1014
		1015	=item $bool = $w->async_pending
		1016
		1017	=back
		1018
		1019
		1020	=head1 PERL SIGNALS
		1021
		1022	While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour
		1023	with EV is as the same as any other C library: Perl-signals will only be
		1024	handled when Perl runs, which means your signal handler might be invoked
		1025	only the next time an event callback is invoked.
		1026
		1027	The solution is to use EV signal watchers (see C<EV::signal>), which will
		1028	ensure proper operations with regards to other event watchers.
		1029
		1030	If you cannot do this for whatever reason, you can also force a watcher
		1031	to be called on every event loop iteration by installing a C<EV::check>
		1032	watcher:
		1033
		1034	my $async_check = EV::check sub { };
		1035
		1036	This ensures that perl gets into control for a short time to handle any
		1037	pending signals, and also ensures (slightly) slower overall operation.
694		1038
695	=head1 THREADS	1039	=head1 THREADS
696		1040
697	Threads are not supported by this module in any way. Perl pseudo-threads	1041	Threads are not supported by this module in any way. Perl pseudo-threads
698	is evil stuff and must die. As soon as Perl gains real threads I will work	1042	is evil stuff and must die. As soon as Perl gains real threads I will work
…		…
720	our $DIED = sub {	1064	our $DIED = sub {
721	warn "EV: error in callback (ignoring): $@";	1065	warn "EV: error in callback (ignoring): $@";
722	};	1066	};
723		1067
724	default_loop	1068	default_loop
725	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	1069	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
726		1070
727	1;	1071	1;
728		1072
729	=head1 SEE ALSO	1073	=head1 SEE ALSO
730		1074
731	L<EV::DNS>.	1075	L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as
		1076	event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
		1077	coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
		1078	event-loop agnostic and portable event driven programming.
732		1079
733	=head1 AUTHOR	1080	=head1 AUTHOR
734		1081
735	Marc Lehmann <schmorp@schmorp.de>	1082	Marc Lehmann <schmorp@schmorp.de>
736	http://home.schmorp.de/	1083	http://home.schmorp.de/
737		1084
738	=cut	1085	=cut
739		1086

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Comparing EV/EV.pm (file contents): Revision 1.54 by root, Tue Nov 27 07:27:10 2007 UTC vs. Revision 1.99 by root, Tue Jul 8 09:37:37 2008 UTC

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Comparing EV/EV.pm (file contents):
Revision 1.54 by root, Tue Nov 27 07:27:10 2007 UTC vs.
Revision 1.99 by root, Tue Jul 8 09:37:37 2008 UTC