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

Comparing EV/EV.pm (file contents):
Revision 1.53 by root, Sat Nov 24 16:57:30 2007 UTC vs.
Revision 1.103 by root, Thu Oct 2 07:49:09 2008 UTC

…		…
2		2
3	EV - perl interface to libev, a high performance full-featured event loop	3	EV - perl interface to libev, a high performance full-featured event loop
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	use EV;	7	use EV;
		8
		9	# TIMERS
		10
		11	my $w = EV::timer 2, 0, sub {
		12	warn "is called after 2s";
		13	};
		14
		15	my $w = EV::timer 2, 2, sub {
		16	warn "is called roughly every 2s (repeat = 2)";
		17	};
		18
		19	undef $w; # destroy event watcher again
		20
		21	my $w = EV::periodic 0, 60, 0, sub {
		22	warn "is called every minute, on the minute, exactly";
		23	};
		24
		25	# IO
		26
		27	my $w = EV::io *STDIN, EV::READ, sub {
		28	my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
		29	warn "stdin is readable, you entered: ", <STDIN>;
		30	};
		31
		32	# SIGNALS
		33
		34	my $w = EV::signal 'QUIT', sub {
		35	warn "sigquit received\n";
		36	};
		37
		38	# CHILD/PID STATUS CHANGES
8		39
9	# TIMERS	40	my $w = EV::child 666, 0, sub {
		41	my ($w, $revents) = @_;
		42	my $status = $w->rstatus;
		43	};
10		44
11	my $w = EV::timer 2, 0, sub {	45	# STAT CHANGES
12	warn "is called after 2s";	46	my $w = EV::stat "/etc/passwd", 10, sub {
13	};
14
15	my $w = EV::timer 2, 2, sub {
16	warn "is called roughly every 2s (repeat = 2)";
17	};
18
19	undef $w; # destroy event watcher again
20
21	my $w = EV::periodic 0, 60, 0, sub {
22	warn "is called every minute, on the minute, exactly";
23	};
24
25	# IO
26
27	my $w = EV::io *STDIN, EV::READ, sub {
28	my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
29	warn "stdin is readable, you entered: ", <STDIN>;
30	};
31
32	# SIGNALS
33
34	my $w = EV::signal 'QUIT', sub {
35	warn "sigquit received\n";
36	};
37
38	# CHILD/PID STATUS CHANGES
39
40	my $w = EV::child 666, sub {
41	my ($w, $revents) = @_;	47	my ($w, $revents) = @_;
42	my $status = $w->rstatus;	48	warn $w->path, " has changed somehow.\n";
43	};	49	};
44		50
45	# MAINLOOP	51	# MAINLOOP
46	EV::loop; # loop until EV::unloop is called or all watchers stop	52	EV::loop; # loop until EV::unloop is called or all watchers stop
47	EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled	53	EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled
48	EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block	54	EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block
49		55
50	=head1 DESCRIPTION	56	=head1 DESCRIPTION
51		57
52	This module provides an interface to libev	58	This module provides an interface to libev
53	(L<http://software.schmorp.de/pkg/libev.html>). While the documentation	59	(L<http://software.schmorp.de/pkg/libev.html>). While the documentation
54	below is comprehensive, one might also consult the documentation of libev	60	below is comprehensive, one might also consult the documentation of libev
55	itself (L<http://cvs.schmorp.de/libev/ev.html>) for more subtle details on	61	itself (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod>) for more
56	watcher semantics or some discussion on the available backends, or how to	62	subtle details on watcher semantics or some discussion on the available
57	force a specific backend with C<LIBEV_FLAGS>.	63	backends, or how to force a specific backend with C<LIBEV_FLAGS>, or just
		64	about in any case because it has much more detailed information.
		65
		66	This module is very fast and scalable. It is actually so fast that you
		67	can use it through the L<AnyEvent> module, stay portable to other event
		68	loops (if you don't rely on any watcher types not available through it)
		69	and still be faster than with any other event loop currently supported in
		70	Perl.
58		71
59	=cut	72	=cut
60		73
61	package EV;	74	package EV;
62		75
		76	no warnings;
63	use strict;	77	use strict;
64		78
65	BEGIN {	79	BEGIN {
66	our $VERSION = '1.3';	80	our $VERSION = '3.44';
67	use XSLoader;	81	use XSLoader;
68	XSLoader::load "EV", $VERSION;	82	XSLoader::load "EV", $VERSION;
69	}	83	}
70		84
71	@EV::IO::ISA =	85	@EV::IO::ISA =
72	@EV::Timer::ISA =	86	@EV::Timer::ISA =
73	@EV::Periodic::ISA =	87	@EV::Periodic::ISA =
74	@EV::Signal::ISA =	88	@EV::Signal::ISA =
		89	@EV::Child::ISA =
		90	@EV::Stat::ISA =
75	@EV::Idle::ISA =	91	@EV::Idle::ISA =
76	@EV::Prepare::ISA =	92	@EV::Prepare::ISA =
77	@EV::Check::ISA =	93	@EV::Check::ISA =
78	@EV::Child::ISA = "EV::Watcher";	94	@EV::Embed::ISA =
		95	@EV::Fork::ISA =
		96	@EV::Async::ISA =
		97	"EV::Watcher";
		98
		99	@EV::Loop::Default::ISA = "EV::Loop";
		100
		101	=head1 EVENT LOOPS
		102
		103	EV supports multiple event loops: There is a single "default event loop"
		104	that can handle everything including signals and child watchers, and any
		105	number of "dynamic event loops" that can use different backends (with
		106	various limitations), but no child and signal watchers.
		107
		108	You do not have to do anything to create the default event loop: When
		109	the module is loaded a suitable backend is selected on the premise of
		110	selecting a working backend (which for example rules out kqueue on most
		111	BSDs). Modules should, unless they have "special needs" always use the
		112	default loop as this is fastest (perl-wise), best supported by other
		113	modules (e.g. AnyEvent or Coro) and most portable event loop.
		114
		115	For specific programs you can create additional event loops dynamically.
		116
		117	If you want to take avdantage of kqueue (which often works properly for
		118	sockets only) even though the default loop doesn't enable it, you can
		119	I<embed> a kqueue loop into the default loop: running the default loop
		120	will then also service the kqueue loop to some extent. See the example in
		121	the section about embed watchers for an example on how to achieve that.
		122
		123	=over 4
		124
		125	=item $loop = new EV::loop [$flags]
		126
		127	Create a new event loop as per the specified flags. Please refer to the
		128	C<ev_loop_new ()> function description in the libev documentation
		129	(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>)
		130	for more info.
		131
		132	The loop will automatically be destroyed when it is no longer referenced
		133	by any watcher and the loop object goes out of scope.
		134
		135	If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK>
		136	is recommended, as only the default event loop is protected by this
		137	module. If you I<are> embedding this loop in the default loop, this is not
		138	necessary, as C<EV::embed> automatically does the right thing on fork.
		139
		140	=item $loop->loop_fork
		141
		142	Must be called after a fork in the child, before entering or continuing
		143	the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
		144	this function automatically, at some performance loss (refer to the libev
		145	documentation).
		146
		147	=item $loop->loop_verify
		148
		149	Calls C<ev_verify> to make internal consistency checks (for debugging
		150	libev) and abort the program if any data structures were found to be
		151	corrupted.
		152
		153	=item $loop = EV::default_loop [$flags]
		154
		155	Return the default loop (which is a singleton object). Since this module
		156	already creates the default loop with default flags, specifying flags here
		157	will not have any effect unless you destroy the default loop first, which
		158	isn't supported. So in short: don't do it, and if you break it, you get to
		159	keep the pieces.
		160
		161	=back
		162
79		163
80	=head1 BASIC INTERFACE	164	=head1 BASIC INTERFACE
81		165
82	=over 4	166	=over 4
83		167
84	=item $EV::DIED	168	=item $EV::DIED
85		169
86	Must contain a reference to a function that is called when a callback	170	Must contain a reference to a function that is called when a callback
87	throws an exception (with $@ containing thr error). The default prints an	171	throws an exception (with $@ containing the error). The default prints an
88	informative message and continues.	172	informative message and continues.
89		173
90	If this callback throws an exception it will be silently ignored.	174	If this callback throws an exception it will be silently ignored.
91		175
		176	=item $flags = EV::supported_backends
		177
		178	=item $flags = EV::recommended_backends
		179
		180	=item $flags = EV::embeddable_backends
		181
		182	Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this
		183	instance of EV, the set of recommended backends (supposed to be good) for
		184	this platform and the set of embeddable backends (see EMBED WATCHERS).
		185
		186	=item EV::sleep $seconds
		187
		188	Block the process for the given number of (fractional) seconds.
		189
92	=item $time = EV::time	190	=item $time = EV::time
93		191
94	Returns the current time in (fractional) seconds since the epoch.	192	Returns the current time in (fractional) seconds since the epoch.
95		193
96	=item $time = EV::now	194	=item $time = EV::now
		195
		196	=item $time = $loop->now
97		197
98	Returns the time the last event loop iteration has been started. This	198	Returns the time the last event loop iteration has been started. This
99	is the time that (relative) timers are based on, and refering to it is	199	is the time that (relative) timers are based on, and refering to it is
100	usually faster then calling EV::time.	200	usually faster then calling EV::time.
101		201
102	=item $method = EV::method	202	=item $backend = EV::backend
		203
		204	=item $backend = $loop->backend
103		205
104	Returns an integer describing the backend used by libev (EV::METHOD_SELECT	206	Returns an integer describing the backend used by libev (EV::METHOD_SELECT
105	or EV::METHOD_EPOLL).	207	or EV::METHOD_EPOLL).
106		208
107	=item EV::loop [$flags]	209	=item EV::loop [$flags]
		210
		211	=item $loop->loop ([$flags])
108		212
109	Begin checking for events and calling callbacks. It returns when a	213	Begin checking for events and calling callbacks. It returns when a
110	callback calls EV::unloop.	214	callback calls EV::unloop.
111		215
112	The $flags argument can be one of the following:	216	The $flags argument can be one of the following:
…		…
115	EV::LOOP_ONESHOT block at most once (wait, but do not loop)	219	EV::LOOP_ONESHOT block at most once (wait, but do not loop)
116	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)	220	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
117		221
118	=item EV::unloop [$how]	222	=item EV::unloop [$how]
119		223
		224	=item $loop->unloop ([$how])
		225
120	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the	226	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the
121	innermost call to EV::loop return.	227	innermost call to EV::loop return.
122		228
123	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as	229	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as
124	fast as possible.	230	fast as possible.
125		231
		232	=item $count = EV::loop_count
		233
		234	=item $count = $loop->loop_count
		235
		236	Return the number of times the event loop has polled for new
		237	events. Sometiems useful as a generation counter.
		238
126	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)	239	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
		240
		241	=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
127		242
128	This function rolls together an I/O and a timer watcher for a single	243	This function rolls together an I/O and a timer watcher for a single
129	one-shot event without the need for managing a watcher object.	244	one-shot event without the need for managing a watcher object.
130		245
131	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>	246	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>
…		…
137	If timeout is C<undef> or negative, then there will be no	252	If timeout is C<undef> or negative, then there will be no
138	timeout. Otherwise a EV::timer with this value will be started.	253	timeout. Otherwise a EV::timer with this value will be started.
139		254
140	When an error occurs or either the timeout or I/O watcher triggers, then	255	When an error occurs or either the timeout or I/O watcher triggers, then
141	the callback will be called with the received event set (in general	256	the callback will be called with the received event set (in general
142	you can expect it to be a combination of C<EV:ERROR>, C<EV::READ>,	257	you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
143	C<EV::WRITE> and C<EV::TIMEOUT>).	258	C<EV::WRITE> and C<EV::TIMEOUT>).
144		259
145	EV::once doesn't return anything: the watchers stay active till either	260	EV::once doesn't return anything: the watchers stay active till either
146	of them triggers, then they will be stopped and freed, and the callback	261	of them triggers, then they will be stopped and freed, and the callback
147	invoked.	262	invoked.
148		263
149	=back	264	=item EV::feed_fd_event ($fd, $revents)
150		265
151	=head2 WATCHER	266	=item $loop->feed_fd_event ($fd, $revents)
		267
		268	Feed an event on a file descriptor into EV. EV will react to this call as
		269	if the readyness notifications specified by C<$revents> (a combination of
		270	C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
		271
		272	=item EV::feed_signal_event ($signal)
		273
		274	Feed a signal event into EV. EV will react to this call as if the signal
		275	specified by C<$signal> had occured.
		276
		277	=item EV::set_io_collect_interval $time
		278
		279	=item $loop->set_io_collect_interval ($time)
		280
		281	=item EV::set_timeout_collect_interval $time
		282
		283	=item $loop->set_timeout_collect_interval ($time)
		284
		285	These advanced functions set the minimum block interval when polling for I/O events and the minimum
		286	wait interval for timer events. See the libev documentation at
		287	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> for
		288	a more detailed discussion.
		289
		290	=back
		291
		292
		293	=head1 WATCHER OBJECTS
152		294
153	A watcher is an object that gets created to record your interest in some	295	A watcher is an object that gets created to record your interest in some
154	event. For instance, if you want to wait for STDIN to become readable, you	296	event. For instance, if you want to wait for STDIN to become readable, you
155	would create an EV::io watcher for that:	297	would create an EV::io watcher for that:
156		298
157	my $watcher = EV::io *STDIN, EV::READ, sub {	299	my $watcher = EV::io *STDIN, EV::READ, sub {
158	my ($watcher, $revents) = @_;	300	my ($watcher, $revents) = @_;
159	warn "yeah, STDIN should not be readable without blocking!\n"	301	warn "yeah, STDIN should now be readable without blocking!\n"
160	};	302	};
161		303
162	All watchers can be active (waiting for events) or inactive (paused). Only	304	All watchers can be active (waiting for events) or inactive (paused). Only
163	active watchers will have their callbacks invoked. All callbacks will be	305	active watchers will have their callbacks invoked. All callbacks will be
164	called with at least two arguments: the watcher and a bitmask of received	306	called with at least two arguments: the watcher and a bitmask of received
165	events.	307	events.
166		308
167	Each watcher type has its associated bit in revents, so you can use the	309	Each watcher type has its associated bit in revents, so you can use the
168	same callback for multiple watchers. The event mask is named after the	310	same callback for multiple watchers. The event mask is named after the
169	type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,	311	type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
170	EV::periodic sets EV::PERIODIC and so on, with the exception of IO events	312	EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events
171	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which	313	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which
172	uses EV::TIMEOUT).	314	uses EV::TIMEOUT).
173		315
174	In the rare case where one wants to create a watcher but not start it at	316	In the rare case where one wants to create a watcher but not start it at
175	the same time, each constructor has a variant with a trailing C<_ns> in	317	the same time, each constructor has a variant with a trailing C<_ns> in
…		…
181		323
182	Also, all methods changing some aspect of a watcher (->set, ->priority,	324	Also, all methods changing some aspect of a watcher (->set, ->priority,
183	->fh and so on) automatically stop and start it again if it is active,	325	->fh and so on) automatically stop and start it again if it is active,
184	which means pending events get lost.	326	which means pending events get lost.
185		327
186	=head2 WATCHER TYPES	328	=head2 COMMON WATCHER METHODS
187		329
188	Now lets move to the existing watcher types and asociated methods.	330	This section lists methods common to all watchers.
189
190	The following methods are available for all watchers. Then followes a
191	description of each watcher constructor (EV::io, EV::timer, EV::periodic,
192	EV::signal, EV::child, EV::idle, EV::prepare and EV::check), followed by
193	any type-specific methods (if any).
194		331
195	=over 4	332	=over 4
196		333
197	=item $w->start	334	=item $w->start
198		335
…		…
202		339
203	=item $w->stop	340	=item $w->stop
204		341
205	Stop a watcher if it is active. Also clear any pending events (events that	342	Stop a watcher if it is active. Also clear any pending events (events that
206	have been received but that didn't yet result in a callback invocation),	343	have been received but that didn't yet result in a callback invocation),
207	regardless of wether the watcher was active or not.	344	regardless of whether the watcher was active or not.
208		345
209	=item $bool = $w->is_active	346	=item $bool = $w->is_active
210		347
211	Returns true if the watcher is active, false otherwise.	348	Returns true if the watcher is active, false otherwise.
212		349
…		…
242	The default priority of any newly-created watcher is 0.	379	The default priority of any newly-created watcher is 0.
243		380
244	Note that the priority semantics have not yet been fleshed out and are	381	Note that the priority semantics have not yet been fleshed out and are
245	subject to almost certain change.	382	subject to almost certain change.
246		383
247	=item $w->trigger ($revents)	384	=item $w->invoke ($revents)
248		385
249	Call the callback now with the given event mask.	386	Call the callback now with the given event mask.
		387
		388	=item $w->feed_event ($revents)
		389
		390	Feed some events on this watcher into EV. EV will react to this call as if
		391	the watcher had received the given C<$revents> mask.
		392
		393	=item $revents = $w->clear_pending
		394
		395	If the watcher is pending, this function clears its pending status and
		396	returns its C<$revents> bitset (as if its callback was invoked). If the
		397	watcher isn't pending it does nothing and returns C<0>.
250		398
251	=item $previous_state = $w->keepalive ($bool)	399	=item $previous_state = $w->keepalive ($bool)
252		400
253	Normally, C<EV::loop> will return when there are no active watchers	401	Normally, C<EV::loop> will return when there are no active watchers
254	(which is a "deadlock" because no progress can be made anymore). This is	402	(which is a "deadlock" because no progress can be made anymore). This is
255	convinient because it allows you to start your watchers (and your jobs),	403	convinient because it allows you to start your watchers (and your jobs),
256	call C<EV::loop> once and when it returns you know that all your jobs are	404	call C<EV::loop> once and when it returns you know that all your jobs are
257	finished (or they forgot to register some watchers for their task :).	405	finished (or they forgot to register some watchers for their task :).
258		406
259	Sometimes, however, this gets in your way, for example when you the module	407	Sometimes, however, this gets in your way, for example when the module
260	that calls C<EV::loop> (usually the main program) is not the same module	408	that calls C<EV::loop> (usually the main program) is not the same module
261	as a long-living watcher (for example a DNS client module written by	409	as a long-living watcher (for example a DNS client module written by
262	somebody else even). Then you might want any outstanding requests to be	410	somebody else even). Then you might want any outstanding requests to be
263	handled, but you would not want to keep C<EV::loop> from returning just	411	handled, but you would not want to keep C<EV::loop> from returning just
264	because you happen to have this long-running UDP port watcher.	412	because you happen to have this long-running UDP port watcher.
…		…
267	though your watcher is active, it won't keep C<EV::loop> from returning.	415	though your watcher is active, it won't keep C<EV::loop> from returning.
268		416
269	The initial value for keepalive is true (enabled), and you cna change it	417	The initial value for keepalive is true (enabled), and you cna change it
270	any time.	418	any time.
271		419
272	Example: Register an IO watcher for some UDP socket but do not keep the	420	Example: Register an I/O watcher for some UDP socket but do not keep the
273	event loop from running just because of that watcher.	421	event loop from running just because of that watcher.
274		422
275	my $udp_socket = ...	423	my $udp_socket = ...
276	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };	424	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
277	$udp_watcher->keepalive (0);	425	$udp_watcher->keepalive (0);
278		426
		427	=item $loop = $w->loop
		428
		429	Return the loop that this watcher is attached to.
		430
		431	=back
		432
		433
		434	=head1 WATCHER TYPES
		435
		436	Each of the following subsections describes a single watcher type.
		437
		438	=head3 I/O WATCHERS - is this file descriptor readable or writable?
		439
		440	=over 4
		441
279	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	442	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
280		443
281	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback	444	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
282		445
		446	=item $w = $loop->io ($fileno_or_fh, $eventmask, $callback)
		447
		448	=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
		449
283	As long as the returned watcher object is alive, call the C<$callback>	450	As long as the returned watcher object is alive, call the C<$callback>
284	when the events specified in C<$eventmask>.	451	when at least one of events specified in C<$eventmask> occurs.
285		452
286	The $eventmask can be one or more of these constants ORed together:	453	The $eventmask can be one or more of these constants ORed together:
287		454
288	EV::READ wait until read() wouldn't block anymore	455	EV::READ wait until read() wouldn't block anymore
289	EV::WRITE wait until write() wouldn't block anymore	456	EV::WRITE wait until write() wouldn't block anymore
…		…
305		472
306	=item $old_eventmask = $w->events ($new_eventmask)	473	=item $old_eventmask = $w->events ($new_eventmask)
307		474
308	Returns the previously set event mask and optionally set a new one.	475	Returns the previously set event mask and optionally set a new one.
309		476
		477	=back
		478
		479
		480	=head3 TIMER WATCHERS - relative and optionally repeating timeouts
		481
		482	=over 4
310		483
311	=item $w = EV::timer $after, $repeat, $callback	484	=item $w = EV::timer $after, $repeat, $callback
312		485
313	=item $w = EV::timer_ns $after, $repeat, $callback	486	=item $w = EV::timer_ns $after, $repeat, $callback
		487
		488	=item $w = $loop->timer ($after, $repeat, $callback)
		489
		490	=item $w = $loop->timer_ns ($after, $repeat, $callback)
314		491
315	Calls the callback after C<$after> seconds (which may be fractional). If	492	Calls the callback after C<$after> seconds (which may be fractional). If
316	C<$repeat> is non-zero, the timer will be restarted (with the $repeat	493	C<$repeat> is non-zero, the timer will be restarted (with the $repeat
317	value as $after) after the callback returns.	494	value as $after) after the callback returns.
318		495
…		…
328		505
329	The C<timer_ns> variant doesn't start (activate) the newly created watcher.	506	The C<timer_ns> variant doesn't start (activate) the newly created watcher.
330		507
331	=item $w->set ($after, $repeat)	508	=item $w->set ($after, $repeat)
332		509
333	Reconfigures the watcher, see the constructor above for details. Can be at	510	Reconfigures the watcher, see the constructor above for details. Can be called at
334	any time.	511	any time.
335		512
336	=item $w->again	513	=item $w->again
337		514
338	Similar to the C<start> method, but has special semantics for repeating timers:	515	Similar to the C<start> method, but has special semantics for repeating timers:
…		…
349	This behaviour is useful when you have a timeout for some IO	526	This behaviour is useful when you have a timeout for some IO
350	operation. You create a timer object with the same value for C<$after> and	527	operation. You create a timer object with the same value for C<$after> and
351	C<$repeat>, and then, in the read/write watcher, run the C<again> method	528	C<$repeat>, and then, in the read/write watcher, run the C<again> method
352	on the timeout.	529	on the timeout.
353		530
		531	=back
		532
		533
		534	=head3 PERIODIC WATCHERS - to cron or not to cron?
		535
		536	=over 4
354		537
355	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback	538	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
356		539
357	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback	540	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
		541
		542	=item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
		543
		544	=item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback)
358		545
359	Similar to EV::timer, but is not based on relative timeouts but on	546	Similar to EV::timer, but is not based on relative timeouts but on
360	absolute times. Apart from creating "simple" timers that trigger "at" the	547	absolute times. Apart from creating "simple" timers that trigger "at" the
361	specified time, it can also be used for non-drifting absolute timers and	548	specified time, it can also be used for non-drifting absolute timers and
362	more complex, cron-like, setups that are not adversely affected by time	549	more complex, cron-like, setups that are not adversely affected by time
…		…
372	This time simply fires at the wallclock time C<$at> and doesn't repeat. It	559	This time simply fires at the wallclock time C<$at> and doesn't repeat. It
373	will not adjust when a time jump occurs, that is, if it is to be run	560	will not adjust when a time jump occurs, that is, if it is to be run
374	at January 1st 2011 then it will run when the system time reaches or	561	at January 1st 2011 then it will run when the system time reaches or
375	surpasses this time.	562	surpasses this time.
376		563
377	=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0)	564	=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
378		565
379	In this mode the watcher will always be scheduled to time out at the	566	In this mode the watcher will always be scheduled to time out at the
380	next C<$at + N * $interval> time (for some integer N) and then repeat,	567	next C<$at + N * $interval> time (for some integer N) and then repeat,
381	regardless of any time jumps.	568	regardless of any time jumps.
382		569
…		…
400	time the periodic watcher gets scheduled, the reschedule callback	587	time the periodic watcher gets scheduled, the reschedule callback
401	($reschedule_cb) will be called with the watcher as first, and the current	588	($reschedule_cb) will be called with the watcher as first, and the current
402	time as second argument.	589	time as second argument.
403		590
404	I<This callback MUST NOT stop or destroy this or any other periodic	591	I<This callback MUST NOT stop or destroy this or any other periodic
405	watcher, ever>. If you need to stop it, return 1e30 and stop it	592	watcher, ever, and MUST NOT call any event loop functions or methods>. If
406	afterwards.	593	you need to stop it, return 1e30 and stop it afterwards. You may create
		594	and start a C<EV::prepare> watcher for this task.
407		595
408	It must return the next time to trigger, based on the passed time value	596	It must return the next time to trigger, based on the passed time value
409	(that is, the lowest time value larger than to the second argument). It	597	(that is, the lowest time value larger than or equal to to the second
410	will usually be called just before the callback will be triggered, but	598	argument). It will usually be called just before the callback will be
411	might be called at other times, too.	599	triggered, but might be called at other times, too.
412		600
413	This can be used to create very complex timers, such as a timer that	601	This can be used to create very complex timers, such as a timer that
414	triggers on each midnight, local time (actually 24 hours after the last	602	triggers on each midnight, local time (actually 24 hours after the last
415	midnight, to keep the example simple. If you know a way to do it correctly	603	midnight, to keep the example simple. If you know a way to do it correctly
416	in about the same space (without requiring elaborate modules), drop me a	604	in about the same space (without requiring elaborate modules), drop me a
…		…
430		618
431	The C<periodic_ns> variant doesn't start (activate) the newly created watcher.	619	The C<periodic_ns> variant doesn't start (activate) the newly created watcher.
432		620
433	=item $w->set ($at, $interval, $reschedule_cb)	621	=item $w->set ($at, $interval, $reschedule_cb)
434		622
435	Reconfigures the watcher, see the constructor above for details. Can be at	623	Reconfigures the watcher, see the constructor above for details. Can be called at
436	any time.	624	any time.
437		625
438	=item $w->again	626	=item $w->again
439		627
440	Simply stops and starts the watcher again.	628	Simply stops and starts the watcher again.
441		629
		630	=item $time = $w->at
		631
		632	Return the time that the watcher is expected to trigger next.
		633
		634	=back
		635
		636
		637	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
		638
		639	=over 4
442		640
443	=item $w = EV::signal $signal, $callback	641	=item $w = EV::signal $signal, $callback
444		642
445	=item $w = EV::signal_ns $signal, $callback	643	=item $w = EV::signal_ns $signal, $callback
446		644
447	Call the callback when $signal is received (the signal can be specified	645	Call the callback when $signal is received (the signal can be specified by
448	by number or by name, just as with kill or %SIG).	646	number or by name, just as with C<kill> or C<%SIG>).
449		647
450	EV will grab the signal for the process (the kernel only allows one	648	EV will grab the signal for the process (the kernel only allows one
451	component to receive a signal at a time) when you start a signal watcher,	649	component to receive a signal at a time) when you start a signal watcher,
452	and removes it again when you stop it. Perl does the same when you	650	and removes it again when you stop it. Perl does the same when you
453	add/remove callbacks to %SIG, so watch out.	651	add/remove callbacks to C<%SIG>, so watch out.
454		652
455	You can have as many signal watchers per signal as you want.	653	You can have as many signal watchers per signal as you want.
456		654
457	The C<signal_ns> variant doesn't start (activate) the newly created watcher.	655	The C<signal_ns> variant doesn't start (activate) the newly created watcher.
458		656
459	=item $w->set ($signal)	657	=item $w->set ($signal)
460		658
461	Reconfigures the watcher, see the constructor above for details. Can be at	659	Reconfigures the watcher, see the constructor above for details. Can be
462	any time.	660	called at any time.
463		661
464	=item $current_signum = $w->signal	662	=item $current_signum = $w->signal
465		663
466	=item $old_signum = $w->signal ($new_signal)	664	=item $old_signum = $w->signal ($new_signal)
467		665
468	Returns the previously set signal (always as a number not name) and	666	Returns the previously set signal (always as a number not name) and
469	optionally set a new one.	667	optionally set a new one.
470		668
		669	=back
471		670
		671
		672	=head3 CHILD WATCHERS - watch out for process status changes
		673
		674	=over 4
		675
472	=item $w = EV::child $pid, $callback	676	=item $w = EV::child $pid, $trace, $callback
473		677
474	=item $w = EV::child_ns $pid, $callback	678	=item $w = EV::child_ns $pid, $trace, $callback
		679
		680	=item $w = $loop->child ($pid, $trace, $callback)
		681
		682	=item $w = $loop->child_ns ($pid, $trace, $callback)
475		683
476	Call the callback when a status change for pid C<$pid> (or any pid	684	Call the callback when a status change for pid C<$pid> (or any pid
477	if C<$pid> is 0) has been received. More precisely: when the process	685	if C<$pid> is 0) has been received (a status change happens when the
		686	process terminates or is killed, or, when trace is true, additionally when
		687	it is stopped or continued). More precisely: when the process receives
478	receives a SIGCHLD, EV will fetch the outstanding exit/wait status for all	688	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
479	changed/zombie children and call the callback.	689	changed/zombie children and call the callback.
480		690
481	You can access both status and pid by using the C<rstatus> and C<rpid>	691	It is valid (and fully supported) to install a child watcher after a child
482	methods on the watcher object.	692	has exited but before the event loop has started its next iteration (for
		693	example, first you C<fork>, then the new child process might exit, and
		694	only then do you install a child watcher in the parent for the new pid).
483		695
		696	You can access both exit (or tracing) status and pid by using the
		697	C<rstatus> and C<rpid> methods on the watcher object.
		698
484	You can have as many pid watchers per pid as you want.	699	You can have as many pid watchers per pid as you want, they will all be
		700	called.
485		701
486	The C<child_ns> variant doesn't start (activate) the newly created watcher.	702	The C<child_ns> variant doesn't start (activate) the newly created watcher.
487		703
488	=item $w->set ($pid)	704	=item $w->set ($pid, $trace)
489		705
490	Reconfigures the watcher, see the constructor above for details. Can be at	706	Reconfigures the watcher, see the constructor above for details. Can be called at
491	any time.	707	any time.
492		708
493	=item $current_pid = $w->pid	709	=item $current_pid = $w->pid
494
495	=item $old_pid = $w->pid ($new_pid)
496		710
497	Returns the previously set process id and optionally set a new one.	711	Returns the previously set process id and optionally set a new one.
498		712
499	=item $exit_status = $w->rstatus	713	=item $exit_status = $w->rstatus
500		714
…		…
504	=item $pid = $w->rpid	718	=item $pid = $w->rpid
505		719
506	Return the pid of the awaited child (useful when you have installed a	720	Return the pid of the awaited child (useful when you have installed a
507	watcher for all pids).	721	watcher for all pids).
508		722
		723	=back
		724
		725
		726	=head3 STAT WATCHERS - did the file attributes just change?
		727
		728	=over 4
		729
		730	=item $w = EV::stat $path, $interval, $callback
		731
		732	=item $w = EV::stat_ns $path, $interval, $callback
		733
		734	=item $w = $loop->stat ($path, $interval, $callback)
		735
		736	=item $w = $loop->stat_ns ($path, $interval, $callback)
		737
		738	Call the callback when a file status change has been detected on
		739	C<$path>. The C<$path> does not need to exist, changing from "path exists"
		740	to "path does not exist" is a status change like any other.
		741
		742	The C<$interval> is a recommended polling interval for systems where
		743	OS-supported change notifications don't exist or are not supported. If
		744	you use C<0> then an unspecified default is used (which is highly
		745	recommended!), which is to be expected to be around five seconds usually.
		746
		747	This watcher type is not meant for massive numbers of stat watchers,
		748	as even with OS-supported change notifications, this can be
		749	resource-intensive.
		750
		751	The C<stat_ns> variant doesn't start (activate) the newly created watcher.
		752
		753	=item ... = $w->stat
		754
		755	This call is very similar to the perl C<stat> built-in: It stats (using
		756	C<lstat>) the path specified in the watcher and sets perls stat cache (as
		757	well as EV's idea of the current stat values) to the values found.
		758
		759	In scalar context, a boolean is return indicating success or failure of
		760	the stat. In list context, the same 13-value list as with stat is returned
		761	(except that the blksize and blocks fields are not reliable).
		762
		763	In the case of an error, errno is set to C<ENOENT> (regardless of the
		764	actual error value) and the C<nlink> value is forced to zero (if the stat
		765	was successful then nlink is guaranteed to be non-zero).
		766
		767	See also the next two entries for more info.
		768
		769	=item ... = $w->attr
		770
		771	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		772	the values most recently detected by EV. See the next entry for more info.
		773
		774	=item ... = $w->prev
		775
		776	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		777	the previous set of values, before the change.
		778
		779	That is, when the watcher callback is invoked, C<< $w->prev >> will be set
		780	to the values found I<before> a change was detected, while C<< $w->attr >>
		781	returns the values found leading to the change detection. The difference (if any)
		782	between C<prev> and C<attr> is what triggered the callback.
		783
		784	If you did something to the filesystem object and do not want to trigger
		785	yet another change, you can call C<stat> to update EV's idea of what the
		786	current attributes are.
		787
		788	=item $w->set ($path, $interval)
		789
		790	Reconfigures the watcher, see the constructor above for details. Can be
		791	called at any time.
		792
		793	=item $current_path = $w->path
		794
		795	=item $old_path = $w->path ($new_path)
		796
		797	Returns the previously set path and optionally set a new one.
		798
		799	=item $current_interval = $w->interval
		800
		801	=item $old_interval = $w->interval ($new_interval)
		802
		803	Returns the previously set interval and optionally set a new one. Can be
		804	used to query the actual interval used.
		805
		806	=back
		807
		808
		809	=head3 IDLE WATCHERS - when you've got nothing better to do...
		810
		811	=over 4
509		812
510	=item $w = EV::idle $callback	813	=item $w = EV::idle $callback
511		814
512	=item $w = EV::idle_ns $callback	815	=item $w = EV::idle_ns $callback
513		816
514	Call the callback when there are no pending io, timer/periodic, signal or	817	=item $w = $loop->idle ($callback)
515	child events, i.e. when the process is idle.	818
		819	=item $w = $loop->idle_ns ($callback)
		820
		821	Call the callback when there are no other pending watchers of the same or
		822	higher priority (excluding check, prepare and other idle watchers of the
		823	same or lower priority, of course). They are called idle watchers because
		824	when the watcher is the highest priority pending event in the process, the
		825	process is considered to be idle at that priority.
		826
		827	If you want a watcher that is only ever called when I<no> other events are
		828	outstanding you have to set the priority to C<EV::MINPRI>.
516		829
517	The process will not block as long as any idle watchers are active, and	830	The process will not block as long as any idle watchers are active, and
518	they will be called repeatedly until stopped.	831	they will be called repeatedly until stopped.
519		832
		833	For example, if you have idle watchers at priority C<0> and C<1>, and
		834	an I/O watcher at priority C<0>, then the idle watcher at priority C<1>
		835	and the I/O watcher will always run when ready. Only when the idle watcher
		836	at priority C<1> is stopped and the I/O watcher at priority C<0> is not
		837	pending with the C<0>-priority idle watcher be invoked.
		838
520	The C<idle_ns> variant doesn't start (activate) the newly created watcher.	839	The C<idle_ns> variant doesn't start (activate) the newly created watcher.
521		840
		841	=back
		842
		843
		844	=head3 PREPARE WATCHERS - customise your event loop!
		845
		846	=over 4
522		847
523	=item $w = EV::prepare $callback	848	=item $w = EV::prepare $callback
524		849
525	=item $w = EV::prepare_ns $callback	850	=item $w = EV::prepare_ns $callback
		851
		852	=item $w = $loop->prepare ($callback)
		853
		854	=item $w = $loop->prepare_ns ($callback)
526		855
527	Call the callback just before the process would block. You can still	856	Call the callback just before the process would block. You can still
528	create/modify any watchers at this point.	857	create/modify any watchers at this point.
529		858
530	See the EV::check watcher, below, for explanations and an example.	859	See the EV::check watcher, below, for explanations and an example.
531		860
532	The C<prepare_ns> variant doesn't start (activate) the newly created watcher.	861	The C<prepare_ns> variant doesn't start (activate) the newly created watcher.
533		862
		863	=back
		864
		865
		866	=head3 CHECK WATCHERS - customise your event loop even more!
		867
		868	=over 4
534		869
535	=item $w = EV::check $callback	870	=item $w = EV::check $callback
536		871
537	=item $w = EV::check_ns $callback	872	=item $w = EV::check_ns $callback
		873
		874	=item $w = $loop->check ($callback)
		875
		876	=item $w = $loop->check_ns ($callback)
538		877
539	Call the callback just after the process wakes up again (after it has	878	Call the callback just after the process wakes up again (after it has
540	gathered events), but before any other callbacks have been invoked.	879	gathered events), but before any other callbacks have been invoked.
541		880
542	This is used to integrate other event-based software into the EV	881	This is used to integrate other event-based software into the EV
…		…
552	or return;	891	or return;
553		892
554	# make the dispatcher handle any outstanding stuff	893	# make the dispatcher handle any outstanding stuff
555	... not shown	894	... not shown
556		895
557	# create an IO watcher for each and every socket	896	# create an I/O watcher for each and every socket
558	@snmp_watcher = (	897	@snmp_watcher = (
559	(map { EV::io $_, EV::READ, sub { } }	898	(map { EV::io $_, EV::READ, sub { } }
560	keys %{ $dispatcher->{_descriptors} }),	899	keys %{ $dispatcher->{_descriptors} }),
561		900
562	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]	901	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
…		…
583	first).	922	first).
584		923
585	The C<check_ns> variant doesn't start (activate) the newly created watcher.	924	The C<check_ns> variant doesn't start (activate) the newly created watcher.
586		925
587	=back	926	=back
		927
		928
		929	=head3 FORK WATCHERS - the audacity to resume the event loop after a fork
		930
		931	Fork watchers are called when a C<fork ()> was detected. The invocation
		932	is done before the event loop blocks next and before C<check> watchers
		933	are being called, and only in the child after the fork.
		934
		935	=over 4
		936
		937	=item $w = EV::fork $callback
		938
		939	=item $w = EV::fork_ns $callback
		940
		941	=item $w = $loop->fork ($callback)
		942
		943	=item $w = $loop->fork_ns ($callback)
		944
		945	Call the callback before the event loop is resumed in the child process
		946	after a fork.
		947
		948	The C<fork_ns> variant doesn't start (activate) the newly created watcher.
		949
		950	=back
		951
		952
		953	=head3 EMBED WATCHERS - when one backend isn't enough...
		954
		955	This is a rather advanced watcher type that lets you embed one event loop
		956	into another (currently only IO events are supported in the embedded
		957	loop, other types of watchers might be handled in a delayed or incorrect
		958	fashion and must not be used).
		959
		960	See the libev documentation at
		961	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
		962	for more details.
		963
		964	In short, this watcher is most useful on BSD systems without working
		965	kqueue to still be able to handle a large number of sockets:
		966
		967	my $socket_loop;
		968
		969	# check wether we use SELECT or POLL _and_ KQUEUE is supported
		970	if (
		971	(EV::backend & (EV::BACKEND_POLL \| EV::BACKEND_SELECT))
		972	&& (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
		973	) {
		974	# use kqueue for sockets
		975	$socket_loop = new EV::Loop EV::BACKEND_KQUEUE \| EV::FLAG_NOENV;
		976	}
		977
		978	# use the default loop otherwise
		979	$socket_loop \|\|= EV::default_loop;
		980
		981	=over 4
		982
		983	=item $w = EV::embed $otherloop[, $callback]
		984
		985	=item $w = EV::embed_ns $otherloop[, $callback]
		986
		987	=item $w = $loop->embed ($otherloop[, $callback])
		988
		989	=item $w = $loop->embed_ns ($otherloop[, $callback])
		990
		991	Call the callback when the embedded event loop (C<$otherloop>) has any
		992	I/O activity. The C<$callback> is optional: if it is missing, then the
		993	embedded event loop will be managed automatically (which is recommended),
		994	otherwise you have to invoke C<sweep> yourself.
		995
		996	The C<embed_ns> variant doesn't start (activate) the newly created watcher.
		997
		998	=back
		999
		1000	=head3 ASYNC WATCHERS - how to wake up another event loop
		1001
		1002	Async watchers are provided by EV, but have little use in perl directly, as perl
		1003	neither supports threads nor direct access to signal handlers or other
		1004	contexts where they could be of value.
		1005
		1006	It is, however, possible to use them from the XS level.
		1007
		1008	Please see the libev documentation for further details.
		1009
		1010	=over 4
		1011
		1012	=item $w = EV::async $callback
		1013
		1014	=item $w = EV::async_ns $callback
		1015
		1016	=item $w->send
		1017
		1018	=item $bool = $w->async_pending
		1019
		1020	=back
		1021
		1022
		1023	=head1 PERL SIGNALS
		1024
		1025	While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour
		1026	with EV is as the same as any other C library: Perl-signals will only be
		1027	handled when Perl runs, which means your signal handler might be invoked
		1028	only the next time an event callback is invoked.
		1029
		1030	The solution is to use EV signal watchers (see C<EV::signal>), which will
		1031	ensure proper operations with regards to other event watchers.
		1032
		1033	If you cannot do this for whatever reason, you can also force a watcher
		1034	to be called on every event loop iteration by installing a C<EV::check>
		1035	watcher:
		1036
		1037	my $async_check = EV::check sub { };
		1038
		1039	This ensures that perl gets into control for a short time to handle any
		1040	pending signals, and also ensures (slightly) slower overall operation.
588		1041
589	=head1 THREADS	1042	=head1 THREADS
590		1043
591	Threads are not supported by this module in any way. Perl pseudo-threads	1044	Threads are not supported by this module in any way. Perl pseudo-threads
592	is evil stuff and must die. As soon as Perl gains real threads I will work	1045	is evil stuff and must die. As soon as Perl gains real threads I will work
…		…
614	our $DIED = sub {	1067	our $DIED = sub {
615	warn "EV: error in callback (ignoring): $@";	1068	warn "EV: error in callback (ignoring): $@";
616	};	1069	};
617		1070
618	default_loop	1071	default_loop
619	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	1072	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
620		1073
621	1;	1074	1;
622		1075
623	=head1 SEE ALSO	1076	=head1 SEE ALSO
624		1077
625	L<EV::DNS>.	1078	L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as
		1079	event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
		1080	coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
		1081	event-loop agnostic and portable event driven programming.
626		1082
627	=head1 AUTHOR	1083	=head1 AUTHOR
628		1084
629	Marc Lehmann <schmorp@schmorp.de>	1085	Marc Lehmann <schmorp@schmorp.de>
630	http://home.schmorp.de/	1086	http://home.schmorp.de/
631		1087
632	=cut	1088	=cut
633		1089

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Comparing EV/EV.pm (file contents): Revision 1.53 by root, Sat Nov 24 16:57:30 2007 UTC vs. Revision 1.103 by root, Thu Oct 2 07:49:09 2008 UTC

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Comparing EV/EV.pm (file contents):
Revision 1.53 by root, Sat Nov 24 16:57:30 2007 UTC vs.
Revision 1.103 by root, Thu Oct 2 07:49:09 2008 UTC