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

Comparing EV/EV.pm (file contents):
Revision 1.56 by root, Tue Nov 27 10:59:10 2007 UTC vs.
Revision 1.126 by root, Tue Mar 16 17:11:48 2010 UTC

…		…
2		2
3	EV - perl interface to libev, a high performance full-featured event loop	3	EV - perl interface to libev, a high performance full-featured event loop
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	use EV;	7	use EV;
		8
		9	# TIMERS
		10
		11	my $w = EV::timer 2, 0, sub {
		12	warn "is called after 2s";
		13	};
		14
		15	my $w = EV::timer 2, 2, sub {
		16	warn "is called roughly every 2s (repeat = 2)";
		17	};
		18
		19	undef $w; # destroy event watcher again
		20
		21	my $w = EV::periodic 0, 60, 0, sub {
		22	warn "is called every minute, on the minute, exactly";
		23	};
		24
		25	# IO
		26
		27	my $w = EV::io *STDIN, EV::READ, sub {
		28	my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
		29	warn "stdin is readable, you entered: ", <STDIN>;
		30	};
		31
		32	# SIGNALS
		33
		34	my $w = EV::signal 'QUIT', sub {
		35	warn "sigquit received\n";
		36	};
		37
		38	# CHILD/PID STATUS CHANGES
8		39
9	# TIMERS	40	my $w = EV::child 666, 0, sub {
		41	my ($w, $revents) = @_;
		42	my $status = $w->rstatus;
		43	};
10		44
11	my $w = EV::timer 2, 0, sub {
12	warn "is called after 2s";
13	};
14
15	my $w = EV::timer 2, 2, sub {
16	warn "is called roughly every 2s (repeat = 2)";
17	};
18
19	undef $w; # destroy event watcher again
20
21	my $w = EV::periodic 0, 60, 0, sub {
22	warn "is called every minute, on the minute, exactly";
23	};
24
25	# IO
26
27	my $w = EV::io *STDIN, EV::READ, sub {
28	my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
29	warn "stdin is readable, you entered: ", <STDIN>;
30	};
31
32	# SIGNALS
33
34	my $w = EV::signal 'QUIT', sub {
35	warn "sigquit received\n";
36	};
37
38	# CHILD/PID STATUS CHANGES
39
40	my $w = EV::child 666, sub {
41	my ($w, $revents) = @_;
42	my $status = $w->rstatus;
43	};
44
45	# STAT CHANGES	45	# STAT CHANGES
46	my $w = EV::stat "/etc/passwd", 10, sub {	46	my $w = EV::stat "/etc/passwd", 10, sub {
47	my ($w, $revents) = @_;	47	my ($w, $revents) = @_;
48	warn $w->path, " has changed somehow.\n";	48	warn $w->path, " has changed somehow.\n";
49	};	49	};
50		50
51	# MAINLOOP	51	# MAINLOOP
52	EV::loop; # loop until EV::unloop is called or all watchers stop	52	EV::loop; # loop until EV::unloop is called or all watchers stop
53	EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled	53	EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled
54	EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block	54	EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block
55		55
56	=head1 DESCRIPTION	56	=head1 DESCRIPTION
57		57
58	This module provides an interface to libev	58	This module provides an interface to libev
59	(L<http://software.schmorp.de/pkg/libev.html>). While the documentation	59	(L<http://software.schmorp.de/pkg/libev.html>). While the documentation
60	below is comprehensive, one might also consult the documentation of libev	60	below is comprehensive, one might also consult the documentation of
61	itself (L<http://cvs.schmorp.de/libev/ev.html>) for more subtle details on	61	libev itself (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod> or
62	watcher semantics or some discussion on the available backends, or how to	62	F<perldoc EV::libev>) for more subtle details on watcher semantics or some
63	force a specific backend with C<LIBEV_FLAGS>.	63	discussion on the available backends, or how to force a specific backend
		64	with C<LIBEV_FLAGS>, or just about in any case because it has much more
		65	detailed information.
		66
		67	This module is very fast and scalable. It is actually so fast that you
		68	can use it through the L<AnyEvent> module, stay portable to other event
		69	loops (if you don't rely on any watcher types not available through it)
		70	and still be faster than with any other event loop currently supported in
		71	Perl.
		72
		73	=head2 MODULE EXPORTS
		74
		75	This module does not export any symbols.
64		76
65	=cut	77	=cut
66		78
67	package EV;	79	package EV;
68		80
69	use strict;	81	use common::sense;
70		82
71	BEGIN {	83	BEGIN {
72	our $VERSION = '1.4';	84	our $VERSION = '4.00';
73	use XSLoader;	85	use XSLoader;
74	XSLoader::load "EV", $VERSION;	86	XSLoader::load "EV", $VERSION;
75	}	87	}
76		88
77	@EV::IO::ISA =	89	@EV::IO::ISA =
…		…
83	@EV::Idle::ISA =	95	@EV::Idle::ISA =
84	@EV::Prepare::ISA =	96	@EV::Prepare::ISA =
85	@EV::Check::ISA =	97	@EV::Check::ISA =
86	@EV::Embed::ISA =	98	@EV::Embed::ISA =
87	@EV::Fork::ISA =	99	@EV::Fork::ISA =
		100	@EV::Async::ISA =
88	"EV::Watcher";	101	"EV::Watcher";
89		102
		103	@EV::Loop::Default::ISA = "EV::Loop";
		104
		105	=head1 EVENT LOOPS
		106
		107	EV supports multiple event loops: There is a single "default event loop"
		108	that can handle everything including signals and child watchers, and any
		109	number of "dynamic event loops" that can use different backends (with
		110	various limitations), but no child and signal watchers.
		111
		112	You do not have to do anything to create the default event loop: When
		113	the module is loaded a suitable backend is selected on the premise of
		114	selecting a working backend (which for example rules out kqueue on most
		115	BSDs). Modules should, unless they have "special needs" always use the
		116	default loop as this is fastest (perl-wise), best supported by other
		117	modules (e.g. AnyEvent or Coro) and most portable event loop.
		118
		119	For specific programs you can create additional event loops dynamically.
		120
		121	If you want to take advantage of kqueue (which often works properly for
		122	sockets only) even though the default loop doesn't enable it, you can
		123	I<embed> a kqueue loop into the default loop: running the default loop
		124	will then also service the kqueue loop to some extent. See the example in
		125	the section about embed watchers for an example on how to achieve that.
		126
		127	=over 4
		128
		129	=item $loop = new EV::Loop [$flags]
		130
		131	Create a new event loop as per the specified flags. Please refer to
		132	the C<ev_loop_new ()> function description in the libev documentation
		133	(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>,
		134	or locally-installed as F<EV::libev> manpage) for more info.
		135
		136	The loop will automatically be destroyed when it is no longer referenced
		137	by any watcher and the loop object goes out of scope.
		138
		139	If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK>
		140	is recommended, as only the default event loop is protected by this
		141	module. If you I<are> embedding this loop in the default loop, this is not
		142	necessary, as C<EV::embed> automatically does the right thing on fork.
		143
		144	=item $loop->loop_fork
		145
		146	Must be called after a fork in the child, before entering or continuing
		147	the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
		148	this function automatically, at some performance loss (refer to the libev
		149	documentation).
		150
		151	=item $loop->loop_verify
		152
		153	Calls C<ev_verify> to make internal consistency checks (for debugging
		154	libev) and abort the program if any data structures were found to be
		155	corrupted.
		156
		157	=item $loop = EV::default_loop [$flags]
		158
		159	Return the default loop (which is a singleton object). Since this module
		160	already creates the default loop with default flags, specifying flags here
		161	will not have any effect unless you destroy the default loop first, which
		162	isn't supported. So in short: don't do it, and if you break it, you get to
		163	keep the pieces.
		164
		165	=back
		166
		167
90	=head1 BASIC INTERFACE	168	=head1 BASIC INTERFACE
91		169
92	=over 4	170	=over 4
93		171
94	=item $EV::DIED	172	=item $EV::DIED
95		173
96	Must contain a reference to a function that is called when a callback	174	Must contain a reference to a function that is called when a callback
97	throws an exception (with $@ containing thr error). The default prints an	175	throws an exception (with $@ containing the error). The default prints an
98	informative message and continues.	176	informative message and continues.
99		177
100	If this callback throws an exception it will be silently ignored.	178	If this callback throws an exception it will be silently ignored.
101		179
		180	=item $flags = EV::supported_backends
		181
		182	=item $flags = EV::recommended_backends
		183
		184	=item $flags = EV::embeddable_backends
		185
		186	Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this
		187	instance of EV, the set of recommended backends (supposed to be good) for
		188	this platform and the set of embeddable backends (see EMBED WATCHERS).
		189
		190	=item EV::sleep $seconds
		191
		192	Block the process for the given number of (fractional) seconds.
		193
102	=item $time = EV::time	194	=item $time = EV::time
103		195
104	Returns the current time in (fractional) seconds since the epoch.	196	Returns the current time in (fractional) seconds since the epoch.
105		197
106	=item $time = EV::now	198	=item $time = EV::now
107		199
		200	=item $time = $loop->now
		201
108	Returns the time the last event loop iteration has been started. This	202	Returns the time the last event loop iteration has been started. This
109	is the time that (relative) timers are based on, and refering to it is	203	is the time that (relative) timers are based on, and referring to it is
110	usually faster then calling EV::time.	204	usually faster then calling EV::time.
111		205
112	=item $method = EV::method	206	=item EV::now_update
113		207
		208	=item $loop->now_update
		209
		210	Establishes the current time by querying the kernel, updating the time
		211	returned by C<EV::now> in the progress. This is a costly operation and
		212	is usually done automatically within C<EV::loop>.
		213
		214	This function is rarely useful, but when some event callback runs for a
		215	very long time without entering the event loop, updating libev's idea of
		216	the current time is a good idea.
		217
		218	=item EV::suspend
		219
		220	=item $loop->suspend
		221
		222	=item EV::resume
		223
		224	=item $loop->resume
		225
		226	These two functions suspend and resume a loop, for use when the loop is
		227	not used for a while and timeouts should not be processed.
		228
		229	A typical use case would be an interactive program such as a game: When
		230	the user presses C<^Z> to suspend the game and resumes it an hour later it
		231	would be best to handle timeouts as if no time had actually passed while
		232	the program was suspended. This can be achieved by calling C<suspend>
		233	in your C<SIGTSTP> handler, sending yourself a C<SIGSTOP> and calling
		234	C<resume> directly afterwards to resume timer processing.
		235
		236	Effectively, all C<timer> watchers will be delayed by the time spend
		237	between C<suspend> and C<resume>, and all C<periodic> watchers
		238	will be rescheduled (that is, they will lose any events that would have
		239	occured while suspended).
		240
		241	After calling C<suspend> you B<must not> call I<any> function on the given
		242	loop other than C<resume>, and you B<must not> call C<resume>
		243	without a previous call to C<suspend>.
		244
		245	Calling C<suspend>/C<resume> has the side effect of updating the event
		246	loop time (see C<now_update>).
		247
		248	=item $backend = EV::backend
		249
		250	=item $backend = $loop->backend
		251
114	Returns an integer describing the backend used by libev (EV::METHOD_SELECT	252	Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
115	or EV::METHOD_EPOLL).	253	or EV::BACKEND_EPOLL).
116		254
117	=item EV::loop [$flags]	255	=item EV::loop [$flags]
		256
		257	=item $loop->loop ([$flags])
118		258
119	Begin checking for events and calling callbacks. It returns when a	259	Begin checking for events and calling callbacks. It returns when a
120	callback calls EV::unloop.	260	callback calls EV::unloop.
121		261
122	The $flags argument can be one of the following:	262	The $flags argument can be one of the following:
…		…
125	EV::LOOP_ONESHOT block at most once (wait, but do not loop)	265	EV::LOOP_ONESHOT block at most once (wait, but do not loop)
126	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)	266	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
127		267
128	=item EV::unloop [$how]	268	=item EV::unloop [$how]
129		269
		270	=item $loop->unloop ([$how])
		271
130	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the	272	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the
131	innermost call to EV::loop return.	273	innermost call to EV::loop return.
132		274
133	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as	275	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as
134	fast as possible.	276	fast as possible.
135		277
		278	=item $count = EV::loop_count
		279
		280	=item $count = $loop->loop_count
		281
		282	Return the number of times the event loop has polled for new
		283	events. Sometimes useful as a generation counter.
		284
136	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)	285	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
		286
		287	=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
137		288
138	This function rolls together an I/O and a timer watcher for a single	289	This function rolls together an I/O and a timer watcher for a single
139	one-shot event without the need for managing a watcher object.	290	one-shot event without the need for managing a watcher object.
140		291
141	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>	292	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>
…		…
147	If timeout is C<undef> or negative, then there will be no	298	If timeout is C<undef> or negative, then there will be no
148	timeout. Otherwise a EV::timer with this value will be started.	299	timeout. Otherwise a EV::timer with this value will be started.
149		300
150	When an error occurs or either the timeout or I/O watcher triggers, then	301	When an error occurs or either the timeout or I/O watcher triggers, then
151	the callback will be called with the received event set (in general	302	the callback will be called with the received event set (in general
152	you can expect it to be a combination of C<EV:ERROR>, C<EV::READ>,	303	you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
153	C<EV::WRITE> and C<EV::TIMEOUT>).	304	C<EV::WRITE> and C<EV::TIMER>).
154		305
155	EV::once doesn't return anything: the watchers stay active till either	306	EV::once doesn't return anything: the watchers stay active till either
156	of them triggers, then they will be stopped and freed, and the callback	307	of them triggers, then they will be stopped and freed, and the callback
157	invoked.	308	invoked.
158		309
159	=back	310	=item EV::feed_fd_event ($fd, $revents)
160		311
		312	=item $loop->feed_fd_event ($fd, $revents)
		313
		314	Feed an event on a file descriptor into EV. EV will react to this call as
		315	if the readyness notifications specified by C<$revents> (a combination of
		316	C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
		317
		318	=item EV::feed_signal_event ($signal)
		319
		320	Feed a signal event into EV. EV will react to this call as if the signal
		321	specified by C<$signal> had occured.
		322
		323	=item EV::set_io_collect_interval $time
		324
		325	=item $loop->set_io_collect_interval ($time)
		326
		327	=item EV::set_timeout_collect_interval $time
		328
		329	=item $loop->set_timeout_collect_interval ($time)
		330
		331	These advanced functions set the minimum block interval when polling for I/O events and the minimum
		332	wait interval for timer events. See the libev documentation at
		333	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP>
		334	(locally installed as F<EV::libev>) for a more detailed discussion.
		335
		336	=item $count = EV::pending_count
		337
		338	=item $count = $loop->pending_count
		339
		340	Returns the number of currently pending watchers.
		341
		342	=item EV::invoke_pending
		343
		344	=item $loop->invoke_pending
		345
		346	Invoke all currently pending watchers.
		347
		348	=back
		349
		350
161	=head2 WATCHER OBJECTS	351	=head1 WATCHER OBJECTS
162		352
163	A watcher is an object that gets created to record your interest in some	353	A watcher is an object that gets created to record your interest in some
164	event. For instance, if you want to wait for STDIN to become readable, you	354	event. For instance, if you want to wait for STDIN to become readable, you
165	would create an EV::io watcher for that:	355	would create an EV::io watcher for that:
166		356
167	my $watcher = EV::io *STDIN, EV::READ, sub {	357	my $watcher = EV::io *STDIN, EV::READ, sub {
168	my ($watcher, $revents) = @_;	358	my ($watcher, $revents) = @_;
169	warn "yeah, STDIN should not be readable without blocking!\n"	359	warn "yeah, STDIN should now be readable without blocking!\n"
170	};	360	};
171		361
172	All watchers can be active (waiting for events) or inactive (paused). Only	362	All watchers can be active (waiting for events) or inactive (paused). Only
173	active watchers will have their callbacks invoked. All callbacks will be	363	active watchers will have their callbacks invoked. All callbacks will be
174	called with at least two arguments: the watcher and a bitmask of received	364	called with at least two arguments: the watcher and a bitmask of received
175	events.	365	events.
176		366
177	Each watcher type has its associated bit in revents, so you can use the	367	Each watcher type has its associated bit in revents, so you can use the
178	same callback for multiple watchers. The event mask is named after the	368	same callback for multiple watchers. The event mask is named after the
179	type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,	369	type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
180	EV::periodic sets EV::PERIODIC and so on, with the exception of IO events	370	EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events
181	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which	371	(which can set both EV::READ and EV::WRITE bits).
182	uses EV::TIMEOUT).
183		372
184	In the rare case where one wants to create a watcher but not start it at	373	In the rare case where one wants to create a watcher but not start it at
185	the same time, each constructor has a variant with a trailing C<_ns> in	374	the same time, each constructor has a variant with a trailing C<_ns> in
186	its name, e.g. EV::io has a non-starting variant EV::io_ns and so on.	375	its name, e.g. EV::io has a non-starting variant EV::io_ns and so on.
187		376
…		…
207		396
208	=item $w->stop	397	=item $w->stop
209		398
210	Stop a watcher if it is active. Also clear any pending events (events that	399	Stop a watcher if it is active. Also clear any pending events (events that
211	have been received but that didn't yet result in a callback invocation),	400	have been received but that didn't yet result in a callback invocation),
212	regardless of wether the watcher was active or not.	401	regardless of whether the watcher was active or not.
213		402
214	=item $bool = $w->is_active	403	=item $bool = $w->is_active
215		404
216	Returns true if the watcher is active, false otherwise.	405	Returns true if the watcher is active, false otherwise.
217		406
…		…
247	The default priority of any newly-created watcher is 0.	436	The default priority of any newly-created watcher is 0.
248		437
249	Note that the priority semantics have not yet been fleshed out and are	438	Note that the priority semantics have not yet been fleshed out and are
250	subject to almost certain change.	439	subject to almost certain change.
251		440
252	=item $w->trigger ($revents)	441	=item $w->invoke ($revents)
253		442
254	Call the callback now with the given event mask.	443	Call the callback now with the given event mask.
		444
		445	=item $w->feed_event ($revents)
		446
		447	Feed some events on this watcher into EV. EV will react to this call as if
		448	the watcher had received the given C<$revents> mask.
		449
		450	=item $revents = $w->clear_pending
		451
		452	If the watcher is pending, this function clears its pending status and
		453	returns its C<$revents> bitset (as if its callback was invoked). If the
		454	watcher isn't pending it does nothing and returns C<0>.
255		455
256	=item $previous_state = $w->keepalive ($bool)	456	=item $previous_state = $w->keepalive ($bool)
257		457
258	Normally, C<EV::loop> will return when there are no active watchers	458	Normally, C<EV::loop> will return when there are no active watchers
259	(which is a "deadlock" because no progress can be made anymore). This is	459	(which is a "deadlock" because no progress can be made anymore). This is
260	convinient because it allows you to start your watchers (and your jobs),	460	convenient because it allows you to start your watchers (and your jobs),
261	call C<EV::loop> once and when it returns you know that all your jobs are	461	call C<EV::loop> once and when it returns you know that all your jobs are
262	finished (or they forgot to register some watchers for their task :).	462	finished (or they forgot to register some watchers for their task :).
263		463
264	Sometimes, however, this gets in your way, for example when you the module	464	Sometimes, however, this gets in your way, for example when the module
265	that calls C<EV::loop> (usually the main program) is not the same module	465	that calls C<EV::loop> (usually the main program) is not the same module
266	as a long-living watcher (for example a DNS client module written by	466	as a long-living watcher (for example a DNS client module written by
267	somebody else even). Then you might want any outstanding requests to be	467	somebody else even). Then you might want any outstanding requests to be
268	handled, but you would not want to keep C<EV::loop> from returning just	468	handled, but you would not want to keep C<EV::loop> from returning just
269	because you happen to have this long-running UDP port watcher.	469	because you happen to have this long-running UDP port watcher.
270		470
271	In this case you can clear the keepalive status, which means that even	471	In this case you can clear the keepalive status, which means that even
272	though your watcher is active, it won't keep C<EV::loop> from returning.	472	though your watcher is active, it won't keep C<EV::loop> from returning.
273		473
274	The initial value for keepalive is true (enabled), and you cna change it	474	The initial value for keepalive is true (enabled), and you can change it
275	any time.	475	any time.
276		476
277	Example: Register an IO watcher for some UDP socket but do not keep the	477	Example: Register an I/O watcher for some UDP socket but do not keep the
278	event loop from running just because of that watcher.	478	event loop from running just because of that watcher.
279		479
280	my $udp_socket = ...	480	my $udp_socket = ...
281	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };	481	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
282	$udp_watcher->keepalive (0);	482	$udp_watcher->keepalive (0);
283		483
284	=back	484	=item $loop = $w->loop
285		485
		486	Return the loop that this watcher is attached to.
286		487
		488	=back
		489
		490
287	=head2 WATCHER TYPES	491	=head1 WATCHER TYPES
288		492
289	Each of the following subsections describes a single watcher type.	493	Each of the following subsections describes a single watcher type.
290		494
291	=head3 IO WATCHERS - is this file descriptor readable or writable?	495	=head3 I/O WATCHERS - is this file descriptor readable or writable?
292		496
293	=over 4	497	=over 4
294		498
295	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	499	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
296		500
297	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback	501	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
		502
		503	=item $w = $loop->io ($fileno_or_fh, $eventmask, $callback)
		504
		505	=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
298		506
299	As long as the returned watcher object is alive, call the C<$callback>	507	As long as the returned watcher object is alive, call the C<$callback>
300	when at least one of events specified in C<$eventmask> occurs.	508	when at least one of events specified in C<$eventmask> occurs.
301		509
302	The $eventmask can be one or more of these constants ORed together:	510	The $eventmask can be one or more of these constants ORed together:
…		…
331	=over 4	539	=over 4
332		540
333	=item $w = EV::timer $after, $repeat, $callback	541	=item $w = EV::timer $after, $repeat, $callback
334		542
335	=item $w = EV::timer_ns $after, $repeat, $callback	543	=item $w = EV::timer_ns $after, $repeat, $callback
		544
		545	=item $w = $loop->timer ($after, $repeat, $callback)
		546
		547	=item $w = $loop->timer_ns ($after, $repeat, $callback)
336		548
337	Calls the callback after C<$after> seconds (which may be fractional). If	549	Calls the callback after C<$after> seconds (which may be fractional). If
338	C<$repeat> is non-zero, the timer will be restarted (with the $repeat	550	C<$repeat> is non-zero, the timer will be restarted (with the $repeat
339	value as $after) after the callback returns.	551	value as $after) after the callback returns.
340		552
…		…
381	=over 4	593	=over 4
382		594
383	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback	595	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
384		596
385	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback	597	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
		598
		599	=item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
		600
		601	=item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback)
386		602
387	Similar to EV::timer, but is not based on relative timeouts but on	603	Similar to EV::timer, but is not based on relative timeouts but on
388	absolute times. Apart from creating "simple" timers that trigger "at" the	604	absolute times. Apart from creating "simple" timers that trigger "at" the
389	specified time, it can also be used for non-drifting absolute timers and	605	specified time, it can also be used for non-drifting absolute timers and
390	more complex, cron-like, setups that are not adversely affected by time	606	more complex, cron-like, setups that are not adversely affected by time
…		…
400	This time simply fires at the wallclock time C<$at> and doesn't repeat. It	616	This time simply fires at the wallclock time C<$at> and doesn't repeat. It
401	will not adjust when a time jump occurs, that is, if it is to be run	617	will not adjust when a time jump occurs, that is, if it is to be run
402	at January 1st 2011 then it will run when the system time reaches or	618	at January 1st 2011 then it will run when the system time reaches or
403	surpasses this time.	619	surpasses this time.
404		620
405	=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0)	621	=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
406		622
407	In this mode the watcher will always be scheduled to time out at the	623	In this mode the watcher will always be scheduled to time out at the
408	next C<$at + N * $interval> time (for some integer N) and then repeat,	624	next C<$at + N * $interval> time (for some integer N) and then repeat,
409	regardless of any time jumps.	625	regardless of any time jumps.
410		626
…		…
428	time the periodic watcher gets scheduled, the reschedule callback	644	time the periodic watcher gets scheduled, the reschedule callback
429	($reschedule_cb) will be called with the watcher as first, and the current	645	($reschedule_cb) will be called with the watcher as first, and the current
430	time as second argument.	646	time as second argument.
431		647
432	I<This callback MUST NOT stop or destroy this or any other periodic	648	I<This callback MUST NOT stop or destroy this or any other periodic
433	watcher, ever>. If you need to stop it, return 1e30 and stop it	649	watcher, ever, and MUST NOT call any event loop functions or methods>. If
434	afterwards.	650	you need to stop it, return 1e30 and stop it afterwards. You may create
		651	and start a C<EV::prepare> watcher for this task.
435		652
436	It must return the next time to trigger, based on the passed time value	653	It must return the next time to trigger, based on the passed time value
437	(that is, the lowest time value larger than to the second argument). It	654	(that is, the lowest time value larger than or equal to to the second
438	will usually be called just before the callback will be triggered, but	655	argument). It will usually be called just before the callback will be
439	might be called at other times, too.	656	triggered, but might be called at other times, too.
440		657
441	This can be used to create very complex timers, such as a timer that	658	This can be used to create very complex timers, such as a timer that
442	triggers on each midnight, local time (actually 24 hours after the last	659	triggers on each midnight, local time (actually 24 hours after the last
443	midnight, to keep the example simple. If you know a way to do it correctly	660	midnight, to keep the example simple. If you know a way to do it correctly
444	in about the same space (without requiring elaborate modules), drop me a	661	in about the same space (without requiring elaborate modules), drop me a
…		…
465		682
466	=item $w->again	683	=item $w->again
467		684
468	Simply stops and starts the watcher again.	685	Simply stops and starts the watcher again.
469		686
		687	=item $time = $w->at
		688
		689	Return the time that the watcher is expected to trigger next.
		690
470	=back	691	=back
471		692
472		693
473	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!	694	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
474		695
475	=over 4	696	=over 4
476		697
477	=item $w = EV::signal $signal, $callback	698	=item $w = EV::signal $signal, $callback
478		699
479	=item $w = EV::signal_ns $signal, $callback	700	=item $w = EV::signal_ns $signal, $callback
		701
		702	=item $w = $loop->signal ($signal, $callback)
		703
		704	=item $w = $loop->signal_ns ($signal, $callback)
480		705
481	Call the callback when $signal is received (the signal can be specified by	706	Call the callback when $signal is received (the signal can be specified by
482	number or by name, just as with C<kill> or C<%SIG>).	707	number or by name, just as with C<kill> or C<%SIG>).
		708
		709	Only one event loop can grab a given signal - attempting to grab the same
		710	signal from two EV loops will crash the program immediately or cause data
		711	corruption.
483		712
484	EV will grab the signal for the process (the kernel only allows one	713	EV will grab the signal for the process (the kernel only allows one
485	component to receive a signal at a time) when you start a signal watcher,	714	component to receive a signal at a time) when you start a signal watcher,
486	and removes it again when you stop it. Perl does the same when you	715	and removes it again when you stop it. Perl does the same when you
487	add/remove callbacks to C<%SIG>, so watch out.	716	add/remove callbacks to C<%SIG>, so watch out.
…		…
507		736
508	=head3 CHILD WATCHERS - watch out for process status changes	737	=head3 CHILD WATCHERS - watch out for process status changes
509		738
510	=over 4	739	=over 4
511		740
512	=item $w = EV::child $pid, $callback	741	=item $w = EV::child $pid, $trace, $callback
513		742
514	=item $w = EV::child_ns $pid, $callback	743	=item $w = EV::child_ns $pid, $trace, $callback
515		744
		745	=item $w = $loop->child ($pid, $trace, $callback)
		746
		747	=item $w = $loop->child_ns ($pid, $trace, $callback)
		748
516	Call the callback when a status change for pid C<$pid> (or any pid if	749	Call the callback when a status change for pid C<$pid> (or any pid
517	C<$pid> is 0) has been received. More precisely: when the process receives	750	if C<$pid> is 0) has been received (a status change happens when the
		751	process terminates or is killed, or, when trace is true, additionally when
		752	it is stopped or continued). More precisely: when the process receives
518	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all	753	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
519	changed/zombie children and call the callback.	754	changed/zombie children and call the callback.
520		755
521	It is valid (and fully supported) to install a child watcher after a child	756	It is valid (and fully supported) to install a child watcher after a child
522	has exited but before the event loop has started its next iteration (for	757	has exited but before the event loop has started its next iteration (for
…		…
529	You can have as many pid watchers per pid as you want, they will all be	764	You can have as many pid watchers per pid as you want, they will all be
530	called.	765	called.
531		766
532	The C<child_ns> variant doesn't start (activate) the newly created watcher.	767	The C<child_ns> variant doesn't start (activate) the newly created watcher.
533		768
534	=item $w->set ($pid)	769	=item $w->set ($pid, $trace)
535		770
536	Reconfigures the watcher, see the constructor above for details. Can be called at	771	Reconfigures the watcher, see the constructor above for details. Can be called at
537	any time.	772	any time.
538		773
539	=item $current_pid = $w->pid	774	=item $current_pid = $w->pid
540		775
541	=item $old_pid = $w->pid ($new_pid)
542
543	Returns the previously set process id and optionally set a new one.	776	Returns the previously set process id and optionally set a new one.
544		777
545	=item $exit_status = $w->rstatus	778	=item $exit_status = $w->rstatus
546		779
547	Return the exit/wait status (as returned by waitpid, see the waitpid entry	780	Return the exit/wait status (as returned by waitpid, see the waitpid entry
…		…
560	=over 4	793	=over 4
561		794
562	=item $w = EV::stat $path, $interval, $callback	795	=item $w = EV::stat $path, $interval, $callback
563		796
564	=item $w = EV::stat_ns $path, $interval, $callback	797	=item $w = EV::stat_ns $path, $interval, $callback
		798
		799	=item $w = $loop->stat ($path, $interval, $callback)
		800
		801	=item $w = $loop->stat_ns ($path, $interval, $callback)
565		802
566	Call the callback when a file status change has been detected on	803	Call the callback when a file status change has been detected on
567	C<$path>. The C<$path> does not need to exist, changing from "path exists"	804	C<$path>. The C<$path> does not need to exist, changing from "path exists"
568	to "path does not exist" is a status change like any other.	805	to "path does not exist" is a status change like any other.
569		806
…		…
576	as even with OS-supported change notifications, this can be	813	as even with OS-supported change notifications, this can be
577	resource-intensive.	814	resource-intensive.
578		815
579	The C<stat_ns> variant doesn't start (activate) the newly created watcher.	816	The C<stat_ns> variant doesn't start (activate) the newly created watcher.
580		817
		818	=item ... = $w->stat
		819
		820	This call is very similar to the perl C<stat> built-in: It stats (using
		821	C<lstat>) the path specified in the watcher and sets perls stat cache (as
		822	well as EV's idea of the current stat values) to the values found.
		823
		824	In scalar context, a boolean is return indicating success or failure of
		825	the stat. In list context, the same 13-value list as with stat is returned
		826	(except that the blksize and blocks fields are not reliable).
		827
		828	In the case of an error, errno is set to C<ENOENT> (regardless of the
		829	actual error value) and the C<nlink> value is forced to zero (if the stat
		830	was successful then nlink is guaranteed to be non-zero).
		831
		832	See also the next two entries for more info.
		833
		834	=item ... = $w->attr
		835
		836	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		837	the values most recently detected by EV. See the next entry for more info.
		838
		839	=item ... = $w->prev
		840
		841	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		842	the previous set of values, before the change.
		843
		844	That is, when the watcher callback is invoked, C<< $w->prev >> will be set
		845	to the values found I<before> a change was detected, while C<< $w->attr >>
		846	returns the values found leading to the change detection. The difference (if any)
		847	between C<prev> and C<attr> is what triggered the callback.
		848
		849	If you did something to the filesystem object and do not want to trigger
		850	yet another change, you can call C<stat> to update EV's idea of what the
		851	current attributes are.
		852
581	=item $w->set ($path, $interval)	853	=item $w->set ($path, $interval)
582		854
583	Reconfigures the watcher, see the constructor above for details. Can be	855	Reconfigures the watcher, see the constructor above for details. Can be
584	called at any time.	856	called at any time.
585		857
…		…
605		877
606	=item $w = EV::idle $callback	878	=item $w = EV::idle $callback
607		879
608	=item $w = EV::idle_ns $callback	880	=item $w = EV::idle_ns $callback
609		881
610	Call the callback when there are no pending io, timer/periodic, signal or	882	=item $w = $loop->idle ($callback)
611	child events, i.e. when the process is idle.	883
		884	=item $w = $loop->idle_ns ($callback)
		885
		886	Call the callback when there are no other pending watchers of the same or
		887	higher priority (excluding check, prepare and other idle watchers of the
		888	same or lower priority, of course). They are called idle watchers because
		889	when the watcher is the highest priority pending event in the process, the
		890	process is considered to be idle at that priority.
		891
		892	If you want a watcher that is only ever called when I<no> other events are
		893	outstanding you have to set the priority to C<EV::MINPRI>.
612		894
613	The process will not block as long as any idle watchers are active, and	895	The process will not block as long as any idle watchers are active, and
614	they will be called repeatedly until stopped.	896	they will be called repeatedly until stopped.
615		897
		898	For example, if you have idle watchers at priority C<0> and C<1>, and
		899	an I/O watcher at priority C<0>, then the idle watcher at priority C<1>
		900	and the I/O watcher will always run when ready. Only when the idle watcher
		901	at priority C<1> is stopped and the I/O watcher at priority C<0> is not
		902	pending with the C<0>-priority idle watcher be invoked.
		903
616	The C<idle_ns> variant doesn't start (activate) the newly created watcher.	904	The C<idle_ns> variant doesn't start (activate) the newly created watcher.
617		905
618	=back	906	=back
619		907
620		908
…		…
623	=over 4	911	=over 4
624		912
625	=item $w = EV::prepare $callback	913	=item $w = EV::prepare $callback
626		914
627	=item $w = EV::prepare_ns $callback	915	=item $w = EV::prepare_ns $callback
		916
		917	=item $w = $loop->prepare ($callback)
		918
		919	=item $w = $loop->prepare_ns ($callback)
628		920
629	Call the callback just before the process would block. You can still	921	Call the callback just before the process would block. You can still
630	create/modify any watchers at this point.	922	create/modify any watchers at this point.
631		923
632	See the EV::check watcher, below, for explanations and an example.	924	See the EV::check watcher, below, for explanations and an example.
…		…
641	=over 4	933	=over 4
642		934
643	=item $w = EV::check $callback	935	=item $w = EV::check $callback
644		936
645	=item $w = EV::check_ns $callback	937	=item $w = EV::check_ns $callback
		938
		939	=item $w = $loop->check ($callback)
		940
		941	=item $w = $loop->check_ns ($callback)
646		942
647	Call the callback just after the process wakes up again (after it has	943	Call the callback just after the process wakes up again (after it has
648	gathered events), but before any other callbacks have been invoked.	944	gathered events), but before any other callbacks have been invoked.
649		945
650	This is used to integrate other event-based software into the EV	946	This is used to integrate other event-based software into the EV
…		…
660	or return;	956	or return;
661		957
662	# make the dispatcher handle any outstanding stuff	958	# make the dispatcher handle any outstanding stuff
663	... not shown	959	... not shown
664		960
665	# create an IO watcher for each and every socket	961	# create an I/O watcher for each and every socket
666	@snmp_watcher = (	962	@snmp_watcher = (
667	(map { EV::io $_, EV::READ, sub { } }	963	(map { EV::io $_, EV::READ, sub { } }
668	keys %{ $dispatcher->{_descriptors} }),	964	keys %{ $dispatcher->{_descriptors} }),
669		965
670	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]	966	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
…		…
685	# make the dispatcher handle any new stuff	981	# make the dispatcher handle any new stuff
686	... not shown	982	... not shown
687	};	983	};
688		984
689	The callbacks of the created watchers will not be called as the watchers	985	The callbacks of the created watchers will not be called as the watchers
690	are destroyed before this cna happen (remember EV::check gets called	986	are destroyed before this can happen (remember EV::check gets called
691	first).	987	first).
692		988
693	The C<check_ns> variant doesn't start (activate) the newly created watcher.	989	The C<check_ns> variant doesn't start (activate) the newly created watcher.
694		990
695	=back	991	=back
…		…
705		1001
706	=item $w = EV::fork $callback	1002	=item $w = EV::fork $callback
707		1003
708	=item $w = EV::fork_ns $callback	1004	=item $w = EV::fork_ns $callback
709		1005
		1006	=item $w = $loop->fork ($callback)
		1007
		1008	=item $w = $loop->fork_ns ($callback)
		1009
710	Call the callback before the event loop is resumed in the child process	1010	Call the callback before the event loop is resumed in the child process
711	after a fork.	1011	after a fork.
712		1012
713	The C<fork_ns> variant doesn't start (activate) the newly created watcher.	1013	The C<fork_ns> variant doesn't start (activate) the newly created watcher.
714		1014
715	=back	1015	=back
716		1016
717		1017
		1018	=head3 EMBED WATCHERS - when one backend isn't enough...
		1019
		1020	This is a rather advanced watcher type that lets you embed one event loop
		1021	into another (currently only IO events are supported in the embedded
		1022	loop, other types of watchers might be handled in a delayed or incorrect
		1023	fashion and must not be used).
		1024
		1025	See the libev documentation at
		1026	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
		1027	(locally installed as F<EV::libev>) for more details.
		1028
		1029	In short, this watcher is most useful on BSD systems without working
		1030	kqueue to still be able to handle a large number of sockets:
		1031
		1032	my $socket_loop;
		1033
		1034	# check wether we use SELECT or POLL _and_ KQUEUE is supported
		1035	if (
		1036	(EV::backend & (EV::BACKEND_POLL \| EV::BACKEND_SELECT))
		1037	&& (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
		1038	) {
		1039	# use kqueue for sockets
		1040	$socket_loop = new EV::Loop EV::BACKEND_KQUEUE \| EV::FLAG_NOENV;
		1041	}
		1042
		1043	# use the default loop otherwise
		1044	$socket_loop \|\|= EV::default_loop;
		1045
		1046	=over 4
		1047
		1048	=item $w = EV::embed $otherloop[, $callback]
		1049
		1050	=item $w = EV::embed_ns $otherloop[, $callback]
		1051
		1052	=item $w = $loop->embed ($otherloop[, $callback])
		1053
		1054	=item $w = $loop->embed_ns ($otherloop[, $callback])
		1055
		1056	Call the callback when the embedded event loop (C<$otherloop>) has any
		1057	I/O activity. The C<$callback> is optional: if it is missing, then the
		1058	embedded event loop will be managed automatically (which is recommended),
		1059	otherwise you have to invoke C<sweep> yourself.
		1060
		1061	The C<embed_ns> variant doesn't start (activate) the newly created watcher.
		1062
		1063	=back
		1064
		1065	=head3 ASYNC WATCHERS - how to wake up another event loop
		1066
		1067	Async watchers are provided by EV, but have little use in perl directly,
		1068	as perl neither supports threads running in parallel nor direct access to
		1069	signal handlers or other contexts where they could be of value.
		1070
		1071	It is, however, possible to use them from the XS level.
		1072
		1073	Please see the libev documentation for further details.
		1074
		1075	=over 4
		1076
		1077	=item $w = EV::async $callback
		1078
		1079	=item $w = EV::async_ns $callback
		1080
		1081	=item $w->send
		1082
		1083	=item $bool = $w->async_pending
		1084
		1085	=back
		1086
		1087
		1088	=head1 PERL SIGNALS
		1089
		1090	While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour
		1091	with EV is as the same as any other C library: Perl-signals will only be
		1092	handled when Perl runs, which means your signal handler might be invoked
		1093	only the next time an event callback is invoked.
		1094
		1095	The solution is to use EV signal watchers (see C<EV::signal>), which will
		1096	ensure proper operations with regards to other event watchers.
		1097
		1098	If you cannot do this for whatever reason, you can also force a watcher
		1099	to be called on every event loop iteration by installing a C<EV::check>
		1100	watcher:
		1101
		1102	my $async_check = EV::check sub { };
		1103
		1104	This ensures that perl gets into control for a short time to handle any
		1105	pending signals, and also ensures (slightly) slower overall operation.
		1106
718	=head1 THREADS	1107	=head1 ITHREADS
719		1108
720	Threads are not supported by this module in any way. Perl pseudo-threads	1109	Ithreads are not supported by this module in any way. Perl pseudo-threads
721	is evil stuff and must die. As soon as Perl gains real threads I will work	1110	is evil stuff and must die. Real threads as provided by Coro are fully
722	on thread support for it.	1111	supported (and enhanced support is available via L<Coro::EV>).
723		1112
724	=head1 FORK	1113	=head1 FORK
725		1114
726	Most of the "improved" event delivering mechanisms of modern operating	1115	Most of the "improved" event delivering mechanisms of modern operating
727	systems have quite a few problems with fork(2) (to put it bluntly: it is	1116	systems have quite a few problems with fork(2) (to put it bluntly: it is
…		…
743	our $DIED = sub {	1132	our $DIED = sub {
744	warn "EV: error in callback (ignoring): $@";	1133	warn "EV: error in callback (ignoring): $@";
745	};	1134	};
746		1135
747	default_loop	1136	default_loop
748	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	1137	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
749		1138
750	1;	1139	1;
751		1140
752	=head1 SEE ALSO	1141	=head1 SEE ALSO
753		1142
754	L<EV::DNS>.	1143	L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as
		1144	event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
		1145	coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
		1146	event-loop agnostic and portable event driven programming.
755		1147
756	=head1 AUTHOR	1148	=head1 AUTHOR
757		1149
758	Marc Lehmann <schmorp@schmorp.de>	1150	Marc Lehmann <schmorp@schmorp.de>
759	http://home.schmorp.de/	1151	http://home.schmorp.de/
760		1152
761	=cut	1153	=cut
762		1154

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Comparing EV/EV.pm (file contents): Revision 1.56 by root, Tue Nov 27 10:59:10 2007 UTC vs. Revision 1.126 by root, Tue Mar 16 17:11:48 2010 UTC

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Comparing EV/EV.pm (file contents):
Revision 1.56 by root, Tue Nov 27 10:59:10 2007 UTC vs.
Revision 1.126 by root, Tue Mar 16 17:11:48 2010 UTC