[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 1.116 by root, Sat Jun 13 15:11:54 2009 UTC

…		…
2		2
3	EV - perl interface to libev, a high performance full-featured event loop	3	EV - perl interface to libev, a high performance full-featured event loop
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	use EV;	7	use EV;
		8
		9	# TIMERS
		10
		11	my $w = EV::timer 2, 0, sub {
		12	warn "is called after 2s";
		13	};
		14
		15	my $w = EV::timer 2, 2, sub {
		16	warn "is called roughly every 2s (repeat = 2)";
		17	};
		18
		19	undef $w; # destroy event watcher again
		20
		21	my $w = EV::periodic 0, 60, 0, sub {
		22	warn "is called every minute, on the minute, exactly";
		23	};
		24
		25	# IO
		26
		27	my $w = EV::io *STDIN, EV::READ, sub {
		28	my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
		29	warn "stdin is readable, you entered: ", <STDIN>;
		30	};
		31
		32	# SIGNALS
		33
		34	my $w = EV::signal 'QUIT', sub {
		35	warn "sigquit received\n";
		36	};
		37
		38	# CHILD/PID STATUS CHANGES
8		39
9	# TIMERS	40	my $w = EV::child 666, 0, sub {
		41	my ($w, $revents) = @_;
		42	my $status = $w->rstatus;
		43	};
10		44
11	my $w = EV::timer 2, 0, sub {
12	warn "is called after 2s";
13	};
14
15	my $w = EV::timer 2, 2, sub {
16	warn "is called roughly every 2s (repeat = 2)";
17	};
18
19	undef $w; # destroy event watcher again
20
21	my $w = EV::periodic 0, 60, 0, sub {
22	warn "is called every minute, on the minute, exactly";
23	};
24
25	# IO
26
27	my $w = EV::io *STDIN, EV::READ, sub {
28	my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
29	warn "stdin is readable, you entered: ", <STDIN>;
30	};
31
32	# SIGNALS
33
34	my $w = EV::signal 'QUIT', sub {
35	warn "sigquit received\n";
36	};
37
38	# CHILD/PID STATUS CHANGES
39
40	my $w = EV::child 666, sub {
41	my ($w, $revents) = @_;
42	my $status = $w->rstatus;
43	};
44
45	# STAT CHANGES	45	# STAT CHANGES
46	my $w = EV::stat "/etc/passwd", 10, sub {	46	my $w = EV::stat "/etc/passwd", 10, sub {
47	my ($w, $revents) = @_;	47	my ($w, $revents) = @_;
48	warn $w->path, " has changed somehow.\n";	48	warn $w->path, " has changed somehow.\n";
49	};	49	};
50		50
51	# MAINLOOP	51	# MAINLOOP
52	EV::loop; # loop until EV::unloop is called or all watchers stop	52	EV::loop; # loop until EV::unloop is called or all watchers stop
53	EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled	53	EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled
54	EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block	54	EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block
55		55
56	=head1 DESCRIPTION	56	=head1 DESCRIPTION
57		57
58	This module provides an interface to libev	58	This module provides an interface to libev
59	(L<http://software.schmorp.de/pkg/libev.html>). While the documentation	59	(L<http://software.schmorp.de/pkg/libev.html>). While the documentation
60	below is comprehensive, one might also consult the documentation of libev	60	below is comprehensive, one might also consult the documentation of
61	itself (L<http://cvs.schmorp.de/libev/ev.html>) for more subtle details on	61	libev itself (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod> or
62	watcher semantics or some discussion on the available backends, or how to	62	F<perldoc EV::libev>) for more subtle details on watcher semantics or some
63	force a specific backend with C<LIBEV_FLAGS>.	63	discussion on the available backends, or how to force a specific backend
		64	with C<LIBEV_FLAGS>, or just about in any case because it has much more
		65	detailed information.
		66
		67	This module is very fast and scalable. It is actually so fast that you
		68	can use it through the L<AnyEvent> module, stay portable to other event
		69	loops (if you don't rely on any watcher types not available through it)
		70	and still be faster than with any other event loop currently supported in
		71	Perl.
		72
		73	=head2 MODULE EXPORTS
		74
		75	This module does not export any symbols.
64		76
65	=cut	77	=cut
66		78
67	package EV;	79	package EV;
68		80
		81	no warnings;
69	use strict;	82	use strict;
70		83
71	BEGIN {	84	BEGIN {
72	our $VERSION = '1.4';	85	our $VERSION = '3.6';
73	use XSLoader;	86	use XSLoader;
74	XSLoader::load "EV", $VERSION;	87	XSLoader::load "EV", $VERSION;
75	}	88	}
76		89
77	@EV::IO::ISA =	90	@EV::IO::ISA =
…		…
83	@EV::Idle::ISA =	96	@EV::Idle::ISA =
84	@EV::Prepare::ISA =	97	@EV::Prepare::ISA =
85	@EV::Check::ISA =	98	@EV::Check::ISA =
86	@EV::Embed::ISA =	99	@EV::Embed::ISA =
87	@EV::Fork::ISA =	100	@EV::Fork::ISA =
		101	@EV::Async::ISA =
88	"EV::Watcher";	102	"EV::Watcher";
89		103
		104	@EV::Loop::Default::ISA = "EV::Loop";
		105
		106	=head1 EVENT LOOPS
		107
		108	EV supports multiple event loops: There is a single "default event loop"
		109	that can handle everything including signals and child watchers, and any
		110	number of "dynamic event loops" that can use different backends (with
		111	various limitations), but no child and signal watchers.
		112
		113	You do not have to do anything to create the default event loop: When
		114	the module is loaded a suitable backend is selected on the premise of
		115	selecting a working backend (which for example rules out kqueue on most
		116	BSDs). Modules should, unless they have "special needs" always use the
		117	default loop as this is fastest (perl-wise), best supported by other
		118	modules (e.g. AnyEvent or Coro) and most portable event loop.
		119
		120	For specific programs you can create additional event loops dynamically.
		121
		122	If you want to take advantage of kqueue (which often works properly for
		123	sockets only) even though the default loop doesn't enable it, you can
		124	I<embed> a kqueue loop into the default loop: running the default loop
		125	will then also service the kqueue loop to some extent. See the example in
		126	the section about embed watchers for an example on how to achieve that.
		127
		128	=over 4
		129
		130	=item $loop = new EV::Loop [$flags]
		131
		132	Create a new event loop as per the specified flags. Please refer to
		133	the C<ev_loop_new ()> function description in the libev documentation
		134	(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>,
		135	or locally-installed as F<EV::libev> manpage) for more info.
		136
		137	The loop will automatically be destroyed when it is no longer referenced
		138	by any watcher and the loop object goes out of scope.
		139
		140	If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK>
		141	is recommended, as only the default event loop is protected by this
		142	module. If you I<are> embedding this loop in the default loop, this is not
		143	necessary, as C<EV::embed> automatically does the right thing on fork.
		144
		145	=item $loop->loop_fork
		146
		147	Must be called after a fork in the child, before entering or continuing
		148	the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
		149	this function automatically, at some performance loss (refer to the libev
		150	documentation).
		151
		152	=item $loop->loop_verify
		153
		154	Calls C<ev_verify> to make internal consistency checks (for debugging
		155	libev) and abort the program if any data structures were found to be
		156	corrupted.
		157
		158	=item $loop = EV::default_loop [$flags]
		159
		160	Return the default loop (which is a singleton object). Since this module
		161	already creates the default loop with default flags, specifying flags here
		162	will not have any effect unless you destroy the default loop first, which
		163	isn't supported. So in short: don't do it, and if you break it, you get to
		164	keep the pieces.
		165
		166	=back
		167
		168
90	=head1 BASIC INTERFACE	169	=head1 BASIC INTERFACE
91		170
92	=over 4	171	=over 4
93		172
94	=item $EV::DIED	173	=item $EV::DIED
95		174
96	Must contain a reference to a function that is called when a callback	175	Must contain a reference to a function that is called when a callback
97	throws an exception (with $@ containing thr error). The default prints an	176	throws an exception (with $@ containing the error). The default prints an
98	informative message and continues.	177	informative message and continues.
99		178
100	If this callback throws an exception it will be silently ignored.	179	If this callback throws an exception it will be silently ignored.
101		180
		181	=item $flags = EV::supported_backends
		182
		183	=item $flags = EV::recommended_backends
		184
		185	=item $flags = EV::embeddable_backends
		186
		187	Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this
		188	instance of EV, the set of recommended backends (supposed to be good) for
		189	this platform and the set of embeddable backends (see EMBED WATCHERS).
		190
		191	=item EV::sleep $seconds
		192
		193	Block the process for the given number of (fractional) seconds.
		194
102	=item $time = EV::time	195	=item $time = EV::time
103		196
104	Returns the current time in (fractional) seconds since the epoch.	197	Returns the current time in (fractional) seconds since the epoch.
105		198
106	=item $time = EV::now	199	=item $time = EV::now
107		200
		201	=item $time = $loop->now
		202
108	Returns the time the last event loop iteration has been started. This	203	Returns the time the last event loop iteration has been started. This
109	is the time that (relative) timers are based on, and refering to it is	204	is the time that (relative) timers are based on, and referring to it is
110	usually faster then calling EV::time.	205	usually faster then calling EV::time.
111		206
112	=item $method = EV::method	207	=item EV::now_update
113		208
		209	=item $loop->now_update
		210
		211	Establishes the current time by querying the kernel, updating the time
		212	returned by C<EV::now> in the progress. This is a costly operation and
		213	is usually done automatically within C<EV::loop>.
		214
		215	This function is rarely useful, but when some event callback runs for a
		216	very long time without entering the event loop, updating libev's idea of
		217	the current time is a good idea.
		218
		219	=item EV::suspend
		220
		221	=item $loop->suspend
		222
		223	=item EV::resume
		224
		225	=item $loop->resume
		226
		227	These two functions suspend and resume a loop, for use when the loop is
		228	not used for a while and timeouts should not be processed.
		229
		230	A typical use case would be an interactive program such as a game: When
		231	the user presses C<^Z> to suspend the game and resumes it an hour later it
		232	would be best to handle timeouts as if no time had actually passed while
		233	the program was suspended. This can be achieved by calling C<suspend>
		234	in your C<SIGTSTP> handler, sending yourself a C<SIGSTOP> and calling
		235	C<resume> directly afterwards to resume timer processing.
		236
		237	Effectively, all C<timer> watchers will be delayed by the time spend
		238	between C<suspend> and C<resume>, and all C<periodic> watchers
		239	will be rescheduled (that is, they will lose any events that would have
		240	occured while suspended).
		241
		242	After calling C<suspend> you B<must not> call I<any> function on the given
		243	loop other than C<resume>, and you B<must not> call C<resume>
		244	without a previous call to C<suspend>.
		245
		246	Calling C<suspend>/C<resume> has the side effect of updating the event
		247	loop time (see C<now_update>).
		248
		249	=item $backend = EV::backend
		250
		251	=item $backend = $loop->backend
		252
114	Returns an integer describing the backend used by libev (EV::METHOD_SELECT	253	Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
115	or EV::METHOD_EPOLL).	254	or EV::BACKEND_EPOLL).
116		255
117	=item EV::loop [$flags]	256	=item EV::loop [$flags]
		257
		258	=item $loop->loop ([$flags])
118		259
119	Begin checking for events and calling callbacks. It returns when a	260	Begin checking for events and calling callbacks. It returns when a
120	callback calls EV::unloop.	261	callback calls EV::unloop.
121		262
122	The $flags argument can be one of the following:	263	The $flags argument can be one of the following:
…		…
125	EV::LOOP_ONESHOT block at most once (wait, but do not loop)	266	EV::LOOP_ONESHOT block at most once (wait, but do not loop)
126	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)	267	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
127		268
128	=item EV::unloop [$how]	269	=item EV::unloop [$how]
129		270
		271	=item $loop->unloop ([$how])
		272
130	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the	273	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the
131	innermost call to EV::loop return.	274	innermost call to EV::loop return.
132		275
133	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as	276	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as
134	fast as possible.	277	fast as possible.
135		278
		279	=item $count = EV::loop_count
		280
		281	=item $count = $loop->loop_count
		282
		283	Return the number of times the event loop has polled for new
		284	events. Sometimes useful as a generation counter.
		285
136	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)	286	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
		287
		288	=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
137		289
138	This function rolls together an I/O and a timer watcher for a single	290	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.	291	one-shot event without the need for managing a watcher object.
140		292
141	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>	293	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	299	If timeout is C<undef> or negative, then there will be no
148	timeout. Otherwise a EV::timer with this value will be started.	300	timeout. Otherwise a EV::timer with this value will be started.
149		301
150	When an error occurs or either the timeout or I/O watcher triggers, then	302	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	303	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>,	304	you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
153	C<EV::WRITE> and C<EV::TIMEOUT>).	305	C<EV::WRITE> and C<EV::TIMEOUT>).
154		306
155	EV::once doesn't return anything: the watchers stay active till either	307	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	308	of them triggers, then they will be stopped and freed, and the callback
157	invoked.	309	invoked.
158		310
159	=back	311	=item EV::feed_fd_event ($fd, $revents)
160		312
		313	=item $loop->feed_fd_event ($fd, $revents)
		314
		315	Feed an event on a file descriptor into EV. EV will react to this call as
		316	if the readyness notifications specified by C<$revents> (a combination of
		317	C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
		318
		319	=item EV::feed_signal_event ($signal)
		320
		321	Feed a signal event into EV. EV will react to this call as if the signal
		322	specified by C<$signal> had occured.
		323
		324	=item EV::set_io_collect_interval $time
		325
		326	=item $loop->set_io_collect_interval ($time)
		327
		328	=item EV::set_timeout_collect_interval $time
		329
		330	=item $loop->set_timeout_collect_interval ($time)
		331
		332	These advanced functions set the minimum block interval when polling for I/O events and the minimum
		333	wait interval for timer events. See the libev documentation at
		334	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP>
		335	(locally installed as F<EV::libev>) for a more detailed discussion.
		336
		337	=back
		338
		339
161	=head2 WATCHER OBJECTS	340	=head1 WATCHER OBJECTS
162		341
163	A watcher is an object that gets created to record your interest in some	342	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	343	event. For instance, if you want to wait for STDIN to become readable, you
165	would create an EV::io watcher for that:	344	would create an EV::io watcher for that:
166		345
167	my $watcher = EV::io *STDIN, EV::READ, sub {	346	my $watcher = EV::io *STDIN, EV::READ, sub {
168	my ($watcher, $revents) = @_;	347	my ($watcher, $revents) = @_;
169	warn "yeah, STDIN should not be readable without blocking!\n"	348	warn "yeah, STDIN should now be readable without blocking!\n"
170	};	349	};
171		350
172	All watchers can be active (waiting for events) or inactive (paused). Only	351	All watchers can be active (waiting for events) or inactive (paused). Only
173	active watchers will have their callbacks invoked. All callbacks will be	352	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	353	called with at least two arguments: the watcher and a bitmask of received
175	events.	354	events.
176		355
177	Each watcher type has its associated bit in revents, so you can use the	356	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	357	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,	358	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	359	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	360	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which
182	uses EV::TIMEOUT).	361	uses EV::TIMEOUT).
183		362
184	In the rare case where one wants to create a watcher but not start it at	363	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	364	the same time, each constructor has a variant with a trailing C<_ns> in
…		…
207		386
208	=item $w->stop	387	=item $w->stop
209		388
210	Stop a watcher if it is active. Also clear any pending events (events that	389	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),	390	have been received but that didn't yet result in a callback invocation),
212	regardless of wether the watcher was active or not.	391	regardless of whether the watcher was active or not.
213		392
214	=item $bool = $w->is_active	393	=item $bool = $w->is_active
215		394
216	Returns true if the watcher is active, false otherwise.	395	Returns true if the watcher is active, false otherwise.
217		396
…		…
247	The default priority of any newly-created watcher is 0.	426	The default priority of any newly-created watcher is 0.
248		427
249	Note that the priority semantics have not yet been fleshed out and are	428	Note that the priority semantics have not yet been fleshed out and are
250	subject to almost certain change.	429	subject to almost certain change.
251		430
252	=item $w->trigger ($revents)	431	=item $w->invoke ($revents)
253		432
254	Call the callback now with the given event mask.	433	Call the callback now with the given event mask.
		434
		435	=item $w->feed_event ($revents)
		436
		437	Feed some events on this watcher into EV. EV will react to this call as if
		438	the watcher had received the given C<$revents> mask.
		439
		440	=item $revents = $w->clear_pending
		441
		442	If the watcher is pending, this function clears its pending status and
		443	returns its C<$revents> bitset (as if its callback was invoked). If the
		444	watcher isn't pending it does nothing and returns C<0>.
255		445
256	=item $previous_state = $w->keepalive ($bool)	446	=item $previous_state = $w->keepalive ($bool)
257		447
258	Normally, C<EV::loop> will return when there are no active watchers	448	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	449	(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),	450	convinient 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	451	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 :).	452	finished (or they forgot to register some watchers for their task :).
263		453
264	Sometimes, however, this gets in your way, for example when you the module	454	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	455	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	456	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	457	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	458	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.	459	because you happen to have this long-running UDP port watcher.
270		460
271	In this case you can clear the keepalive status, which means that even	461	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.	462	though your watcher is active, it won't keep C<EV::loop> from returning.
273		463
274	The initial value for keepalive is true (enabled), and you cna change it	464	The initial value for keepalive is true (enabled), and you can change it
275	any time.	465	any time.
276		466
277	Example: Register an IO watcher for some UDP socket but do not keep the	467	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.	468	event loop from running just because of that watcher.
279		469
280	my $udp_socket = ...	470	my $udp_socket = ...
281	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };	471	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
282	$udp_watcher->keepalive (0);	472	$udp_watcher->keepalive (0);
283		473
284	=back	474	=item $loop = $w->loop
285		475
		476	Return the loop that this watcher is attached to.
286		477
		478	=back
		479
		480
287	=head2 WATCHER TYPES	481	=head1 WATCHER TYPES
288		482
289	Each of the following subsections describes a single watcher type.	483	Each of the following subsections describes a single watcher type.
290		484
291	=head3 IO WATCHERS - is this file descriptor readable or writable?	485	=head3 I/O WATCHERS - is this file descriptor readable or writable?
292		486
293	=over 4	487	=over 4
294		488
295	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	489	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
296		490
297	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback	491	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
		492
		493	=item $w = $loop->io ($fileno_or_fh, $eventmask, $callback)
		494
		495	=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
298		496
299	As long as the returned watcher object is alive, call the C<$callback>	497	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.	498	when at least one of events specified in C<$eventmask> occurs.
301		499
302	The $eventmask can be one or more of these constants ORed together:	500	The $eventmask can be one or more of these constants ORed together:
…		…
331	=over 4	529	=over 4
332		530
333	=item $w = EV::timer $after, $repeat, $callback	531	=item $w = EV::timer $after, $repeat, $callback
334		532
335	=item $w = EV::timer_ns $after, $repeat, $callback	533	=item $w = EV::timer_ns $after, $repeat, $callback
		534
		535	=item $w = $loop->timer ($after, $repeat, $callback)
		536
		537	=item $w = $loop->timer_ns ($after, $repeat, $callback)
336		538
337	Calls the callback after C<$after> seconds (which may be fractional). If	539	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 $repeat	540	C<$repeat> is non-zero, the timer will be restarted (with the $repeat
339	value as $after) after the callback returns.	541	value as $after) after the callback returns.
340		542
…		…
381	=over 4	583	=over 4
382		584
383	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback	585	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
384		586
385	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback	587	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
		588
		589	=item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
		590
		591	=item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback)
386		592
387	Similar to EV::timer, but is not based on relative timeouts but on	593	Similar to EV::timer, but is not based on relative timeouts but on
388	absolute times. Apart from creating "simple" timers that trigger "at" the	594	absolute times. Apart from creating "simple" timers that trigger "at" the
389	specified time, it can also be used for non-drifting absolute timers and	595	specified time, it can also be used for non-drifting absolute timers and
390	more complex, cron-like, setups that are not adversely affected by time	596	more complex, cron-like, setups that are not adversely affected by time
…		…
400	This time simply fires at the wallclock time C<$at> and doesn't repeat. It	606	This time simply fires at the wallclock time C<$at> and doesn't repeat. It
401	will not adjust when a time jump occurs, that is, if it is to be run	607	will not adjust when a time jump occurs, that is, if it is to be run
402	at January 1st 2011 then it will run when the system time reaches or	608	at January 1st 2011 then it will run when the system time reaches or
403	surpasses this time.	609	surpasses this time.
404		610
405	=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0)	611	=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
406		612
407	In this mode the watcher will always be scheduled to time out at the	613	In this mode the watcher will always be scheduled to time out at the
408	next C<$at + N * $interval> time (for some integer N) and then repeat,	614	next C<$at + N * $interval> time (for some integer N) and then repeat,
409	regardless of any time jumps.	615	regardless of any time jumps.
410		616
…		…
428	time the periodic watcher gets scheduled, the reschedule callback	634	time the periodic watcher gets scheduled, the reschedule callback
429	($reschedule_cb) will be called with the watcher as first, and the current	635	($reschedule_cb) will be called with the watcher as first, and the current
430	time as second argument.	636	time as second argument.
431		637
432	I<This callback MUST NOT stop or destroy this or any other periodic	638	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	639	watcher, ever, and MUST NOT call any event loop functions or methods>. If
434	afterwards.	640	you need to stop it, return 1e30 and stop it afterwards. You may create
		641	and start a C<EV::prepare> watcher for this task.
435		642
436	It must return the next time to trigger, based on the passed time value	643	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	644	(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	645	argument). It will usually be called just before the callback will be
439	might be called at other times, too.	646	triggered, but might be called at other times, too.
440		647
441	This can be used to create very complex timers, such as a timer that	648	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	649	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	650	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	651	in about the same space (without requiring elaborate modules), drop me a
…		…
465		672
466	=item $w->again	673	=item $w->again
467		674
468	Simply stops and starts the watcher again.	675	Simply stops and starts the watcher again.
469		676
		677	=item $time = $w->at
		678
		679	Return the time that the watcher is expected to trigger next.
		680
470	=back	681	=back
471		682
472		683
473	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!	684	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
474		685
…		…
507		718
508	=head3 CHILD WATCHERS - watch out for process status changes	719	=head3 CHILD WATCHERS - watch out for process status changes
509		720
510	=over 4	721	=over 4
511		722
512	=item $w = EV::child $pid, $callback	723	=item $w = EV::child $pid, $trace, $callback
513		724
514	=item $w = EV::child_ns $pid, $callback	725	=item $w = EV::child_ns $pid, $trace, $callback
515		726
		727	=item $w = $loop->child ($pid, $trace, $callback)
		728
		729	=item $w = $loop->child_ns ($pid, $trace, $callback)
		730
516	Call the callback when a status change for pid C<$pid> (or any pid if	731	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	732	if C<$pid> is 0) has been received (a status change happens when the
		733	process terminates or is killed, or, when trace is true, additionally when
		734	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	735	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
519	changed/zombie children and call the callback.	736	changed/zombie children and call the callback.
520		737
521	It is valid (and fully supported) to install a child watcher after a child	738	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	739	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	746	You can have as many pid watchers per pid as you want, they will all be
530	called.	747	called.
531		748
532	The C<child_ns> variant doesn't start (activate) the newly created watcher.	749	The C<child_ns> variant doesn't start (activate) the newly created watcher.
533		750
534	=item $w->set ($pid)	751	=item $w->set ($pid, $trace)
535		752
536	Reconfigures the watcher, see the constructor above for details. Can be called at	753	Reconfigures the watcher, see the constructor above for details. Can be called at
537	any time.	754	any time.
538		755
539	=item $current_pid = $w->pid	756	=item $current_pid = $w->pid
540		757
541	=item $old_pid = $w->pid ($new_pid)
542
543	Returns the previously set process id and optionally set a new one.	758	Returns the previously set process id and optionally set a new one.
544		759
545	=item $exit_status = $w->rstatus	760	=item $exit_status = $w->rstatus
546		761
547	Return the exit/wait status (as returned by waitpid, see the waitpid entry	762	Return the exit/wait status (as returned by waitpid, see the waitpid entry
…		…
560	=over 4	775	=over 4
561		776
562	=item $w = EV::stat $path, $interval, $callback	777	=item $w = EV::stat $path, $interval, $callback
563		778
564	=item $w = EV::stat_ns $path, $interval, $callback	779	=item $w = EV::stat_ns $path, $interval, $callback
		780
		781	=item $w = $loop->stat ($path, $interval, $callback)
		782
		783	=item $w = $loop->stat_ns ($path, $interval, $callback)
565		784
566	Call the callback when a file status change has been detected on	785	Call the callback when a file status change has been detected on
567	C<$path>. The C<$path> does not need to exist, changing from "path exists"	786	C<$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.	787	to "path does not exist" is a status change like any other.
569		788
…		…
576	as even with OS-supported change notifications, this can be	795	as even with OS-supported change notifications, this can be
577	resource-intensive.	796	resource-intensive.
578		797
579	The C<stat_ns> variant doesn't start (activate) the newly created watcher.	798	The C<stat_ns> variant doesn't start (activate) the newly created watcher.
580		799
		800	=item ... = $w->stat
		801
		802	This call is very similar to the perl C<stat> built-in: It stats (using
		803	C<lstat>) the path specified in the watcher and sets perls stat cache (as
		804	well as EV's idea of the current stat values) to the values found.
		805
		806	In scalar context, a boolean is return indicating success or failure of
		807	the stat. In list context, the same 13-value list as with stat is returned
		808	(except that the blksize and blocks fields are not reliable).
		809
		810	In the case of an error, errno is set to C<ENOENT> (regardless of the
		811	actual error value) and the C<nlink> value is forced to zero (if the stat
		812	was successful then nlink is guaranteed to be non-zero).
		813
		814	See also the next two entries for more info.
		815
		816	=item ... = $w->attr
		817
		818	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		819	the values most recently detected by EV. See the next entry for more info.
		820
		821	=item ... = $w->prev
		822
		823	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		824	the previous set of values, before the change.
		825
		826	That is, when the watcher callback is invoked, C<< $w->prev >> will be set
		827	to the values found I<before> a change was detected, while C<< $w->attr >>
		828	returns the values found leading to the change detection. The difference (if any)
		829	between C<prev> and C<attr> is what triggered the callback.
		830
		831	If you did something to the filesystem object and do not want to trigger
		832	yet another change, you can call C<stat> to update EV's idea of what the
		833	current attributes are.
		834
581	=item $w->set ($path, $interval)	835	=item $w->set ($path, $interval)
582		836
583	Reconfigures the watcher, see the constructor above for details. Can be	837	Reconfigures the watcher, see the constructor above for details. Can be
584	called at any time.	838	called at any time.
585		839
…		…
605		859
606	=item $w = EV::idle $callback	860	=item $w = EV::idle $callback
607		861
608	=item $w = EV::idle_ns $callback	862	=item $w = EV::idle_ns $callback
609		863
610	Call the callback when there are no pending io, timer/periodic, signal or	864	=item $w = $loop->idle ($callback)
611	child events, i.e. when the process is idle.	865
		866	=item $w = $loop->idle_ns ($callback)
		867
		868	Call the callback when there are no other pending watchers of the same or
		869	higher priority (excluding check, prepare and other idle watchers of the
		870	same or lower priority, of course). They are called idle watchers because
		871	when the watcher is the highest priority pending event in the process, the
		872	process is considered to be idle at that priority.
		873
		874	If you want a watcher that is only ever called when I<no> other events are
		875	outstanding you have to set the priority to C<EV::MINPRI>.
612		876
613	The process will not block as long as any idle watchers are active, and	877	The process will not block as long as any idle watchers are active, and
614	they will be called repeatedly until stopped.	878	they will be called repeatedly until stopped.
615		879
		880	For example, if you have idle watchers at priority C<0> and C<1>, and
		881	an I/O watcher at priority C<0>, then the idle watcher at priority C<1>
		882	and the I/O watcher will always run when ready. Only when the idle watcher
		883	at priority C<1> is stopped and the I/O watcher at priority C<0> is not
		884	pending with the C<0>-priority idle watcher be invoked.
		885
616	The C<idle_ns> variant doesn't start (activate) the newly created watcher.	886	The C<idle_ns> variant doesn't start (activate) the newly created watcher.
617		887
618	=back	888	=back
619		889
620		890
…		…
623	=over 4	893	=over 4
624		894
625	=item $w = EV::prepare $callback	895	=item $w = EV::prepare $callback
626		896
627	=item $w = EV::prepare_ns $callback	897	=item $w = EV::prepare_ns $callback
		898
		899	=item $w = $loop->prepare ($callback)
		900
		901	=item $w = $loop->prepare_ns ($callback)
628		902
629	Call the callback just before the process would block. You can still	903	Call the callback just before the process would block. You can still
630	create/modify any watchers at this point.	904	create/modify any watchers at this point.
631		905
632	See the EV::check watcher, below, for explanations and an example.	906	See the EV::check watcher, below, for explanations and an example.
…		…
641	=over 4	915	=over 4
642		916
643	=item $w = EV::check $callback	917	=item $w = EV::check $callback
644		918
645	=item $w = EV::check_ns $callback	919	=item $w = EV::check_ns $callback
		920
		921	=item $w = $loop->check ($callback)
		922
		923	=item $w = $loop->check_ns ($callback)
646		924
647	Call the callback just after the process wakes up again (after it has	925	Call the callback just after the process wakes up again (after it has
648	gathered events), but before any other callbacks have been invoked.	926	gathered events), but before any other callbacks have been invoked.
649		927
650	This is used to integrate other event-based software into the EV	928	This is used to integrate other event-based software into the EV
…		…
660	or return;	938	or return;
661		939
662	# make the dispatcher handle any outstanding stuff	940	# make the dispatcher handle any outstanding stuff
663	... not shown	941	... not shown
664		942
665	# create an IO watcher for each and every socket	943	# create an I/O watcher for each and every socket
666	@snmp_watcher = (	944	@snmp_watcher = (
667	(map { EV::io $_, EV::READ, sub { } }	945	(map { EV::io $_, EV::READ, sub { } }
668	keys %{ $dispatcher->{_descriptors} }),	946	keys %{ $dispatcher->{_descriptors} }),
669		947
670	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]	948	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
…		…
685	# make the dispatcher handle any new stuff	963	# make the dispatcher handle any new stuff
686	... not shown	964	... not shown
687	};	965	};
688		966
689	The callbacks of the created watchers will not be called as the watchers	967	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	968	are destroyed before this can happen (remember EV::check gets called
691	first).	969	first).
692		970
693	The C<check_ns> variant doesn't start (activate) the newly created watcher.	971	The C<check_ns> variant doesn't start (activate) the newly created watcher.
694		972
695	=back	973	=back
…		…
705		983
706	=item $w = EV::fork $callback	984	=item $w = EV::fork $callback
707		985
708	=item $w = EV::fork_ns $callback	986	=item $w = EV::fork_ns $callback
709		987
		988	=item $w = $loop->fork ($callback)
		989
		990	=item $w = $loop->fork_ns ($callback)
		991
710	Call the callback before the event loop is resumed in the child process	992	Call the callback before the event loop is resumed in the child process
711	after a fork.	993	after a fork.
712		994
713	The C<fork_ns> variant doesn't start (activate) the newly created watcher.	995	The C<fork_ns> variant doesn't start (activate) the newly created watcher.
714		996
715	=back	997	=back
716		998
717		999
		1000	=head3 EMBED WATCHERS - when one backend isn't enough...
		1001
		1002	This is a rather advanced watcher type that lets you embed one event loop
		1003	into another (currently only IO events are supported in the embedded
		1004	loop, other types of watchers might be handled in a delayed or incorrect
		1005	fashion and must not be used).
		1006
		1007	See the libev documentation at
		1008	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
		1009	(locally installed as F<EV::libev>) for more details.
		1010
		1011	In short, this watcher is most useful on BSD systems without working
		1012	kqueue to still be able to handle a large number of sockets:
		1013
		1014	my $socket_loop;
		1015
		1016	# check wether we use SELECT or POLL _and_ KQUEUE is supported
		1017	if (
		1018	(EV::backend & (EV::BACKEND_POLL \| EV::BACKEND_SELECT))
		1019	&& (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
		1020	) {
		1021	# use kqueue for sockets
		1022	$socket_loop = new EV::Loop EV::BACKEND_KQUEUE \| EV::FLAG_NOENV;
		1023	}
		1024
		1025	# use the default loop otherwise
		1026	$socket_loop \|\|= EV::default_loop;
		1027
		1028	=over 4
		1029
		1030	=item $w = EV::embed $otherloop[, $callback]
		1031
		1032	=item $w = EV::embed_ns $otherloop[, $callback]
		1033
		1034	=item $w = $loop->embed ($otherloop[, $callback])
		1035
		1036	=item $w = $loop->embed_ns ($otherloop[, $callback])
		1037
		1038	Call the callback when the embedded event loop (C<$otherloop>) has any
		1039	I/O activity. The C<$callback> is optional: if it is missing, then the
		1040	embedded event loop will be managed automatically (which is recommended),
		1041	otherwise you have to invoke C<sweep> yourself.
		1042
		1043	The C<embed_ns> variant doesn't start (activate) the newly created watcher.
		1044
		1045	=back
		1046
		1047	=head3 ASYNC WATCHERS - how to wake up another event loop
		1048
		1049	Async watchers are provided by EV, but have little use in perl directly,
		1050	as perl neither supports threads running in parallel nor direct access to
		1051	signal handlers or other contexts where they could be of value.
		1052
		1053	It is, however, possible to use them from the XS level.
		1054
		1055	Please see the libev documentation for further details.
		1056
		1057	=over 4
		1058
		1059	=item $w = EV::async $callback
		1060
		1061	=item $w = EV::async_ns $callback
		1062
		1063	=item $w->send
		1064
		1065	=item $bool = $w->async_pending
		1066
		1067	=back
		1068
		1069
		1070	=head1 PERL SIGNALS
		1071
		1072	While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour
		1073	with EV is as the same as any other C library: Perl-signals will only be
		1074	handled when Perl runs, which means your signal handler might be invoked
		1075	only the next time an event callback is invoked.
		1076
		1077	The solution is to use EV signal watchers (see C<EV::signal>), which will
		1078	ensure proper operations with regards to other event watchers.
		1079
		1080	If you cannot do this for whatever reason, you can also force a watcher
		1081	to be called on every event loop iteration by installing a C<EV::check>
		1082	watcher:
		1083
		1084	my $async_check = EV::check sub { };
		1085
		1086	This ensures that perl gets into control for a short time to handle any
		1087	pending signals, and also ensures (slightly) slower overall operation.
		1088
718	=head1 THREADS	1089	=head1 ITHREADS
719		1090
720	Threads are not supported by this module in any way. Perl pseudo-threads	1091	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	1092	is evil stuff and must die. Real threads as provided by Coro are fully
722	on thread support for it.	1093	supported (and enhanced support is available via L<Coro::EV>).
723		1094
724	=head1 FORK	1095	=head1 FORK
725		1096
726	Most of the "improved" event delivering mechanisms of modern operating	1097	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	1098	systems have quite a few problems with fork(2) (to put it bluntly: it is
…		…
743	our $DIED = sub {	1114	our $DIED = sub {
744	warn "EV: error in callback (ignoring): $@";	1115	warn "EV: error in callback (ignoring): $@";
745	};	1116	};
746		1117
747	default_loop	1118	default_loop
748	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	1119	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
749		1120
750	1;	1121	1;
751		1122
752	=head1 SEE ALSO	1123	=head1 SEE ALSO
753		1124
754	L<EV::DNS>.	1125	L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as
		1126	event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
		1127	coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
		1128	event-loop agnostic and portable event driven programming.
755		1129
756	=head1 AUTHOR	1130	=head1 AUTHOR
757		1131
758	Marc Lehmann <schmorp@schmorp.de>	1132	Marc Lehmann <schmorp@schmorp.de>
759	http://home.schmorp.de/	1133	http://home.schmorp.de/
760		1134
761	=cut	1135	=cut
762		1136

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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 1.116 by root, Sat Jun 13 15:11:54 2009 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 1.116 by root, Sat Jun 13 15:11:54 2009 UTC