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

Comparing EV/EV.pm (file contents):
Revision 1.51 by root, Sat Nov 24 16:12:37 2007 UTC vs.
Revision 1.98 by root, Sat May 31 23:17:50 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>).	59	(L<http://software.schmorp.de/pkg/libev.html>). While the documentation
		60	below is comprehensive, one might also consult the documentation of libev
		61	itself (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod>) for more
		62	subtle details on watcher semantics or some discussion on the available
		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.
54		71
55	=cut	72	=cut
56		73
57	package EV;	74	package EV;
58		75
59	use strict;	76	use strict;
60		77
61	BEGIN {	78	BEGIN {
62	our $VERSION = '1.3';	79	our $VERSION = '3.42';
63	use XSLoader;	80	use XSLoader;
64	XSLoader::load "EV", $VERSION;	81	XSLoader::load "EV", $VERSION;
65	}	82	}
66		83
67	@EV::IO::ISA =	84	@EV::IO::ISA =
68	@EV::Timer::ISA =	85	@EV::Timer::ISA =
69	@EV::Periodic::ISA =	86	@EV::Periodic::ISA =
70	@EV::Signal::ISA =	87	@EV::Signal::ISA =
		88	@EV::Child::ISA =
		89	@EV::Stat::ISA =
71	@EV::Idle::ISA =	90	@EV::Idle::ISA =
72	@EV::Prepare::ISA =	91	@EV::Prepare::ISA =
73	@EV::Check::ISA =	92	@EV::Check::ISA =
74	@EV::Child::ISA = "EV::Watcher";	93	@EV::Embed::ISA =
		94	@EV::Fork::ISA =
		95	@EV::Async::ISA =
		96	"EV::Watcher";
		97
		98	@EV::Loop::Default::ISA = "EV::Loop";
		99
		100	=head1 EVENT LOOPS
		101
		102	EV supports multiple event loops: There is a single "default event loop"
		103	that can handle everything including signals and child watchers, and any
		104	number of "dynamic event loops" that can use different backends (with
		105	various limitations), but no child and signal watchers.
		106
		107	You do not have to do anything to create the default event loop: When
		108	the module is loaded a suitable backend is selected on the premise of
		109	selecting a working backend (which for example rules out kqueue on most
		110	BSDs). Modules should, unless they have "special needs" always use the
		111	default loop as this is fastest (perl-wise), best supported by other
		112	modules (e.g. AnyEvent or Coro) and most portable event loop.
		113
		114	For specific programs you can create additional event loops dynamically.
		115
		116	=over 4
		117
		118	=item $loop = new EV::loop [$flags]
		119
		120	Create a new event loop as per the specified flags. Please refer to the
		121	C<ev_loop_new ()> function description in the libev documentation
		122	(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>)
		123	for more info.
		124
		125	The loop will automatically be destroyed when it is no longer referenced
		126	by any watcher and the loop object goes out of scope.
		127
		128	Using C<EV::FLAG_FORKCHECK> is recommended, as only the default event loop
		129	is protected by this module.
		130
		131	=item $loop->loop_fork
		132
		133	Must be called after a fork in the child, before entering or continuing
		134	the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
		135	this function automatically, at some performance loss (refer to the libev
		136	documentation).
		137
		138	=item $loop->loop_verify
		139
		140	Calls C<ev_verify> to make internal consistency checks (for debugging
		141	libev) and abort the program if any data structures wree found to be
		142	corrupted.
		143
		144	=item $loop = EV::default_loop [$flags]
		145
		146	Return the default loop (which is a singleton object). Since this module
		147	already creates the default loop with default flags, specifying flags here
		148	will not have any effect unless you destroy the default loop.
		149
		150	=back
		151
75		152
76	=head1 BASIC INTERFACE	153	=head1 BASIC INTERFACE
77		154
78	=over 4	155	=over 4
79		156
80	=item $EV::DIED	157	=item $EV::DIED
81		158
82	Must contain a reference to a function that is called when a callback	159	Must contain a reference to a function that is called when a callback
83	throws an exception (with $@ containing thr error). The default prints an	160	throws an exception (with $@ containing the error). The default prints an
84	informative message and continues.	161	informative message and continues.
85		162
86	If this callback throws an exception it will be silently ignored.	163	If this callback throws an exception it will be silently ignored.
87		164
		165	=item $flags = EV::supported_backends
		166
		167	=item $flags = EV::recommended_backends
		168
		169	=item $flags = EV::embeddable_backends
		170
		171	Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this
		172	instance of EV, the set of recommended backends (supposed to be good) for
		173	this platform and the set of embeddable backends (see EMBED WATCHERS).
		174
		175	=item EV::sleep $seconds
		176
		177	Block the process for the given number of (fractional) seconds.
		178
88	=item $time = EV::time	179	=item $time = EV::time
89		180
90	Returns the current time in (fractional) seconds since the epoch.	181	Returns the current time in (fractional) seconds since the epoch.
91		182
92	=item $time = EV::now	183	=item $time = EV::now
		184
		185	=item $time = $loop->now
93		186
94	Returns the time the last event loop iteration has been started. This	187	Returns the time the last event loop iteration has been started. This
95	is the time that (relative) timers are based on, and refering to it is	188	is the time that (relative) timers are based on, and refering to it is
96	usually faster then calling EV::time.	189	usually faster then calling EV::time.
97		190
98	=item $method = EV::method	191	=item $backend = EV::backend
		192
		193	=item $backend = $loop->backend
99		194
100	Returns an integer describing the backend used by libev (EV::METHOD_SELECT	195	Returns an integer describing the backend used by libev (EV::METHOD_SELECT
101	or EV::METHOD_EPOLL).	196	or EV::METHOD_EPOLL).
102		197
103	=item EV::loop [$flags]	198	=item EV::loop [$flags]
		199
		200	=item $loop->loop ([$flags])
104		201
105	Begin checking for events and calling callbacks. It returns when a	202	Begin checking for events and calling callbacks. It returns when a
106	callback calls EV::unloop.	203	callback calls EV::unloop.
107		204
108	The $flags argument can be one of the following:	205	The $flags argument can be one of the following:
…		…
111	EV::LOOP_ONESHOT block at most once (wait, but do not loop)	208	EV::LOOP_ONESHOT block at most once (wait, but do not loop)
112	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)	209	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
113		210
114	=item EV::unloop [$how]	211	=item EV::unloop [$how]
115		212
		213	=item $loop->unloop ([$how])
		214
116	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the	215	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the
117	innermost call to EV::loop return.	216	innermost call to EV::loop return.
118		217
119	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as	218	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as
120	fast as possible.	219	fast as possible.
121		220
		221	=item $count = EV::loop_count
		222
		223	=item $count = $loop->loop_count
		224
		225	Return the number of times the event loop has polled for new
		226	events. Sometiems useful as a generation counter.
		227
122	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)	228	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
		229
		230	=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
123		231
124	This function rolls together an I/O and a timer watcher for a single	232	This function rolls together an I/O and a timer watcher for a single
125	one-shot event without the need for managing a watcher object.	233	one-shot event without the need for managing a watcher object.
126		234
127	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>	235	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>
…		…
133	If timeout is C<undef> or negative, then there will be no	241	If timeout is C<undef> or negative, then there will be no
134	timeout. Otherwise a EV::timer with this value will be started.	242	timeout. Otherwise a EV::timer with this value will be started.
135		243
136	When an error occurs or either the timeout or I/O watcher triggers, then	244	When an error occurs or either the timeout or I/O watcher triggers, then
137	the callback will be called with the received event set (in general	245	the callback will be called with the received event set (in general
138	you can expect it to be a combination of C<EV:ERROR>, C<EV::READ>,	246	you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
139	C<EV::WRITE> and C<EV::TIMEOUT>).	247	C<EV::WRITE> and C<EV::TIMEOUT>).
140		248
141	EV::once doesn't return anything: the watchers stay active till either	249	EV::once doesn't return anything: the watchers stay active till either
142	of them triggers, then they will be stopped and freed, and the callback	250	of them triggers, then they will be stopped and freed, and the callback
143	invoked.	251	invoked.
144		252
145	=back	253	=item EV::feed_fd_event ($fd, $revents)
146		254
147	=head2 WATCHER	255	=item $loop->feed_fd_event ($fd, $revents)
		256
		257	Feed an event on a file descriptor into EV. EV will react to this call as
		258	if the readyness notifications specified by C<$revents> (a combination of
		259	C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
		260
		261	=item EV::feed_signal_event ($signal)
		262
		263	Feed a signal event into EV. EV will react to this call as if the signal
		264	specified by C<$signal> had occured.
		265
		266	=item EV::set_io_collect_interval $time
		267
		268	=item $loop->set_io_collect_interval ($time)
		269
		270	=item EV::set_timeout_collect_interval $time
		271
		272	=item $loop->set_timeout_collect_interval ($time)
		273
		274	These advanced functions set the minimum block interval when polling for I/O events and the minimum
		275	wait interval for timer events. See the libev documentation at
		276	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> for
		277	a more detailed discussion.
		278
		279	=back
		280
		281
		282	=head1 WATCHER OBJECTS
148		283
149	A watcher is an object that gets created to record your interest in some	284	A watcher is an object that gets created to record your interest in some
150	event. For instance, if you want to wait for STDIN to become readable, you	285	event. For instance, if you want to wait for STDIN to become readable, you
151	would create an EV::io watcher for that:	286	would create an EV::io watcher for that:
152		287
153	my $watcher = EV::io *STDIN, EV::READ, sub {	288	my $watcher = EV::io *STDIN, EV::READ, sub {
154	my ($watcher, $revents) = @_;	289	my ($watcher, $revents) = @_;
155	warn "yeah, STDIN should not be readable without blocking!\n"	290	warn "yeah, STDIN should now be readable without blocking!\n"
156	};	291	};
157		292
158	All watchers can be active (waiting for events) or inactive (paused). Only	293	All watchers can be active (waiting for events) or inactive (paused). Only
159	active watchers will have their callbacks invoked. All callbacks will be	294	active watchers will have their callbacks invoked. All callbacks will be
160	called with at least two arguments: the watcher and a bitmask of received	295	called with at least two arguments: the watcher and a bitmask of received
161	events.	296	events.
162		297
163	Each watcher type has its associated bit in revents, so you can use the	298	Each watcher type has its associated bit in revents, so you can use the
164	same callback for multiple watchers. The event mask is named after the	299	same callback for multiple watchers. The event mask is named after the
165	type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,	300	type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
166	EV::periodic sets EV::PERIODIC and so on, with the exception of IO events	301	EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events
167	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which	302	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which
168	uses EV::TIMEOUT).	303	uses EV::TIMEOUT).
169		304
170	In the rare case where one wants to create a watcher but not start it at	305	In the rare case where one wants to create a watcher but not start it at
171	the same time, each constructor has a variant with a trailing C<_ns> in	306	the same time, each constructor has a variant with a trailing C<_ns> in
…		…
177		312
178	Also, all methods changing some aspect of a watcher (->set, ->priority,	313	Also, all methods changing some aspect of a watcher (->set, ->priority,
179	->fh and so on) automatically stop and start it again if it is active,	314	->fh and so on) automatically stop and start it again if it is active,
180	which means pending events get lost.	315	which means pending events get lost.
181		316
182	=head2 WATCHER TYPES	317	=head2 COMMON WATCHER METHODS
183		318
184	Now lets move to the existing watcher types and asociated methods.	319	This section lists methods common to all watchers.
185
186	The following methods are available for all watchers. Then followes a
187	description of each watcher constructor (EV::io, EV::timer, EV::periodic,
188	EV::signal, EV::child, EV::idle, EV::prepare and EV::check), followed by
189	any type-specific methods (if any).
190		320
191	=over 4	321	=over 4
192		322
193	=item $w->start	323	=item $w->start
194		324
…		…
198		328
199	=item $w->stop	329	=item $w->stop
200		330
201	Stop a watcher if it is active. Also clear any pending events (events that	331	Stop a watcher if it is active. Also clear any pending events (events that
202	have been received but that didn't yet result in a callback invocation),	332	have been received but that didn't yet result in a callback invocation),
203	regardless of wether the watcher was active or not.	333	regardless of whether the watcher was active or not.
204		334
205	=item $bool = $w->is_active	335	=item $bool = $w->is_active
206		336
207	Returns true if the watcher is active, false otherwise.	337	Returns true if the watcher is active, false otherwise.
208		338
…		…
238	The default priority of any newly-created watcher is 0.	368	The default priority of any newly-created watcher is 0.
239		369
240	Note that the priority semantics have not yet been fleshed out and are	370	Note that the priority semantics have not yet been fleshed out and are
241	subject to almost certain change.	371	subject to almost certain change.
242		372
243	=item $w->trigger ($revents)	373	=item $w->invoke ($revents)
244		374
245	Call the callback now with the given event mask.	375	Call the callback now with the given event mask.
		376
		377	=item $w->feed_event ($revents)
		378
		379	Feed some events on this watcher into EV. EV will react to this call as if
		380	the watcher had received the given C<$revents> mask.
		381
		382	=item $revents = $w->clear_pending
		383
		384	If the watcher is pending, this function clears its pending status and
		385	returns its C<$revents> bitset (as if its callback was invoked). If the
		386	watcher isn't pending it does nothing and returns C<0>.
246		387
247	=item $previous_state = $w->keepalive ($bool)	388	=item $previous_state = $w->keepalive ($bool)
248		389
249	Normally, C<EV::loop> will return when there are no active watchers	390	Normally, C<EV::loop> will return when there are no active watchers
250	(which is a "deadlock" because no progress can be made anymore). This is	391	(which is a "deadlock" because no progress can be made anymore). This is
251	convinient because it allows you to start your watchers (and your jobs),	392	convinient because it allows you to start your watchers (and your jobs),
252	call C<EV::loop> once and when it returns you know that all your jobs are	393	call C<EV::loop> once and when it returns you know that all your jobs are
253	finished (or they forgot to register some watchers for their task :).	394	finished (or they forgot to register some watchers for their task :).
254		395
255	Sometimes, however, this gets in your way, for example when you the module	396	Sometimes, however, this gets in your way, for example when the module
256	that calls C<EV::loop> (usually the main program) is not the same module	397	that calls C<EV::loop> (usually the main program) is not the same module
257	as a long-living watcher (for example a DNS client module written by	398	as a long-living watcher (for example a DNS client module written by
258	somebody else even). Then you might want any outstanding requests to be	399	somebody else even). Then you might want any outstanding requests to be
259	handled, but you would not want to keep C<EV::loop> from returning just	400	handled, but you would not want to keep C<EV::loop> from returning just
260	because you happen to have this long-running UDP port watcher.	401	because you happen to have this long-running UDP port watcher.
…		…
263	though your watcher is active, it won't keep C<EV::loop> from returning.	404	though your watcher is active, it won't keep C<EV::loop> from returning.
264		405
265	The initial value for keepalive is true (enabled), and you cna change it	406	The initial value for keepalive is true (enabled), and you cna change it
266	any time.	407	any time.
267		408
268	Example: Register an IO watcher for some UDP socket but do not keep the	409	Example: Register an I/O watcher for some UDP socket but do not keep the
269	event loop from running just because of that watcher.	410	event loop from running just because of that watcher.
270		411
271	my $udp_socket = ...	412	my $udp_socket = ...
272	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };	413	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
273	$udp_watcher->keepalive (0);	414	$udp_watcher->keepalive (0);
274		415
		416	=item $loop = $w->loop
		417
		418	Return the loop that this watcher is attached to.
		419
		420	=back
		421
		422
		423	=head1 WATCHER TYPES
		424
		425	Each of the following subsections describes a single watcher type.
		426
		427	=head3 I/O WATCHERS - is this file descriptor readable or writable?
		428
		429	=over 4
		430
275	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	431	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
276		432
277	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback	433	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
278		434
		435	=item $w = $loop->io ($fileno_or_fh, $eventmask, $callback)
		436
		437	=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
		438
279	As long as the returned watcher object is alive, call the C<$callback>	439	As long as the returned watcher object is alive, call the C<$callback>
280	when the events specified in C<$eventmask>.	440	when at least one of events specified in C<$eventmask> occurs.
281		441
282	The $eventmask can be one or more of these constants ORed together:	442	The $eventmask can be one or more of these constants ORed together:
283		443
284	EV::READ wait until read() wouldn't block anymore	444	EV::READ wait until read() wouldn't block anymore
285	EV::WRITE wait until write() wouldn't block anymore	445	EV::WRITE wait until write() wouldn't block anymore
…		…
301		461
302	=item $old_eventmask = $w->events ($new_eventmask)	462	=item $old_eventmask = $w->events ($new_eventmask)
303		463
304	Returns the previously set event mask and optionally set a new one.	464	Returns the previously set event mask and optionally set a new one.
305		465
		466	=back
		467
		468
		469	=head3 TIMER WATCHERS - relative and optionally repeating timeouts
		470
		471	=over 4
306		472
307	=item $w = EV::timer $after, $repeat, $callback	473	=item $w = EV::timer $after, $repeat, $callback
308		474
309	=item $w = EV::timer_ns $after, $repeat, $callback	475	=item $w = EV::timer_ns $after, $repeat, $callback
310		476
311	Calls the callback after C<$after> seconds. If C<$repeat> is non-zero,	477	=item $w = $loop->timer ($after, $repeat, $callback)
312	the timer will be restarted (with the $repeat value as $after) after the	478
313	callback returns.	479	=item $w = $loop->timer_ns ($after, $repeat, $callback)
		480
		481	Calls the callback after C<$after> seconds (which may be fractional). If
		482	C<$repeat> is non-zero, the timer will be restarted (with the $repeat
		483	value as $after) after the callback returns.
314		484
315	This means that the callback would be called roughly after C<$after>	485	This means that the callback would be called roughly after C<$after>
316	seconds, and then every C<$repeat> seconds. The timer does his best not	486	seconds, and then every C<$repeat> seconds. The timer does his best not
317	to drift, but it will not invoke the timer more often then once per event	487	to drift, but it will not invoke the timer more often then once per event
318	loop iteration, and might drift in other cases. If that isn't acceptable,	488	loop iteration, and might drift in other cases. If that isn't acceptable,
…		…
324		494
325	The C<timer_ns> variant doesn't start (activate) the newly created watcher.	495	The C<timer_ns> variant doesn't start (activate) the newly created watcher.
326		496
327	=item $w->set ($after, $repeat)	497	=item $w->set ($after, $repeat)
328		498
329	Reconfigures the watcher, see the constructor above for details. Can be at	499	Reconfigures the watcher, see the constructor above for details. Can be called at
330	any time.	500	any time.
331		501
332	=item $w->again	502	=item $w->again
333		503
334	Similar to the C<start> method, but has special semantics for repeating timers:	504	Similar to the C<start> method, but has special semantics for repeating timers:
…		…
345	This behaviour is useful when you have a timeout for some IO	515	This behaviour is useful when you have a timeout for some IO
346	operation. You create a timer object with the same value for C<$after> and	516	operation. You create a timer object with the same value for C<$after> and
347	C<$repeat>, and then, in the read/write watcher, run the C<again> method	517	C<$repeat>, and then, in the read/write watcher, run the C<again> method
348	on the timeout.	518	on the timeout.
349		519
		520	=back
		521
		522
		523	=head3 PERIODIC WATCHERS - to cron or not to cron?
		524
		525	=over 4
350		526
351	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback	527	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
352		528
353	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback	529	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
		530
		531	=item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
		532
		533	=item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback)
354		534
355	Similar to EV::timer, but is not based on relative timeouts but on	535	Similar to EV::timer, but is not based on relative timeouts but on
356	absolute times. Apart from creating "simple" timers that trigger "at" the	536	absolute times. Apart from creating "simple" timers that trigger "at" the
357	specified time, it can also be used for non-drifting absolute timers and	537	specified time, it can also be used for non-drifting absolute timers and
358	more complex, cron-like, setups that are not adversely affected by time	538	more complex, cron-like, setups that are not adversely affected by time
…		…
368	This time simply fires at the wallclock time C<$at> and doesn't repeat. It	548	This time simply fires at the wallclock time C<$at> and doesn't repeat. It
369	will not adjust when a time jump occurs, that is, if it is to be run	549	will not adjust when a time jump occurs, that is, if it is to be run
370	at January 1st 2011 then it will run when the system time reaches or	550	at January 1st 2011 then it will run when the system time reaches or
371	surpasses this time.	551	surpasses this time.
372		552
373	=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0)	553	=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
374		554
375	In this mode the watcher will always be scheduled to time out at the	555	In this mode the watcher will always be scheduled to time out at the
376	next C<$at + N * $interval> time (for some integer N) and then repeat,	556	next C<$at + N * $interval> time (for some integer N) and then repeat,
377	regardless of any time jumps.	557	regardless of any time jumps.
378		558
…		…
396	time the periodic watcher gets scheduled, the reschedule callback	576	time the periodic watcher gets scheduled, the reschedule callback
397	($reschedule_cb) will be called with the watcher as first, and the current	577	($reschedule_cb) will be called with the watcher as first, and the current
398	time as second argument.	578	time as second argument.
399		579
400	I<This callback MUST NOT stop or destroy this or any other periodic	580	I<This callback MUST NOT stop or destroy this or any other periodic
401	watcher, ever>. If you need to stop it, return 1e30 and stop it	581	watcher, ever, and MUST NOT call any event loop functions or methods>. If
402	afterwards.	582	you need to stop it, return 1e30 and stop it afterwards. You may create
		583	and start a C<EV::prepare> watcher for this task.
403		584
404	It must return the next time to trigger, based on the passed time value	585	It must return the next time to trigger, based on the passed time value
405	(that is, the lowest time value larger than to the second argument). It	586	(that is, the lowest time value larger than or equal to to the second
406	will usually be called just before the callback will be triggered, but	587	argument). It will usually be called just before the callback will be
407	might be called at other times, too.	588	triggered, but might be called at other times, too.
408		589
409	This can be used to create very complex timers, such as a timer that	590	This can be used to create very complex timers, such as a timer that
410	triggers on each midnight, local time (actually 24 hours after the last	591	triggers on each midnight, local time (actually 24 hours after the last
411	midnight, to keep the example simple. If you know a way to do it correctly	592	midnight, to keep the example simple. If you know a way to do it correctly
412	in about the same space (without requiring elaborate modules), drop me a	593	in about the same space (without requiring elaborate modules), drop me a
…		…
426		607
427	The C<periodic_ns> variant doesn't start (activate) the newly created watcher.	608	The C<periodic_ns> variant doesn't start (activate) the newly created watcher.
428		609
429	=item $w->set ($at, $interval, $reschedule_cb)	610	=item $w->set ($at, $interval, $reschedule_cb)
430		611
431	Reconfigures the watcher, see the constructor above for details. Can be at	612	Reconfigures the watcher, see the constructor above for details. Can be called at
432	any time.	613	any time.
433		614
434	=item $w->again	615	=item $w->again
435		616
436	Simply stops and starts the watcher again.	617	Simply stops and starts the watcher again.
437		618
		619	=item $time = $w->at
		620
		621	Return the time that the watcher is expected to trigger next.
		622
		623	=back
		624
		625
		626	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
		627
		628	=over 4
438		629
439	=item $w = EV::signal $signal, $callback	630	=item $w = EV::signal $signal, $callback
440		631
441	=item $w = EV::signal_ns $signal, $callback	632	=item $w = EV::signal_ns $signal, $callback
442		633
443	Call the callback when $signal is received (the signal can be specified	634	Call the callback when $signal is received (the signal can be specified by
444	by number or by name, just as with kill or %SIG).	635	number or by name, just as with C<kill> or C<%SIG>).
445		636
446	EV will grab the signal for the process (the kernel only allows one	637	EV will grab the signal for the process (the kernel only allows one
447	component to receive a signal at a time) when you start a signal watcher,	638	component to receive a signal at a time) when you start a signal watcher,
448	and removes it again when you stop it. Perl does the same when you	639	and removes it again when you stop it. Perl does the same when you
449	add/remove callbacks to %SIG, so watch out.	640	add/remove callbacks to C<%SIG>, so watch out.
450		641
451	You can have as many signal watchers per signal as you want.	642	You can have as many signal watchers per signal as you want.
452		643
453	The C<signal_ns> variant doesn't start (activate) the newly created watcher.	644	The C<signal_ns> variant doesn't start (activate) the newly created watcher.
454		645
455	=item $w->set ($signal)	646	=item $w->set ($signal)
456		647
457	Reconfigures the watcher, see the constructor above for details. Can be at	648	Reconfigures the watcher, see the constructor above for details. Can be
458	any time.	649	called at any time.
459		650
460	=item $current_signum = $w->signal	651	=item $current_signum = $w->signal
461		652
462	=item $old_signum = $w->signal ($new_signal)	653	=item $old_signum = $w->signal ($new_signal)
463		654
464	Returns the previously set signal (always as a number not name) and	655	Returns the previously set signal (always as a number not name) and
465	optionally set a new one.	656	optionally set a new one.
466		657
		658	=back
467		659
		660
		661	=head3 CHILD WATCHERS - watch out for process status changes
		662
		663	=over 4
		664
468	=item $w = EV::child $pid, $callback	665	=item $w = EV::child $pid, $trace, $callback
469		666
470	=item $w = EV::child_ns $pid, $callback	667	=item $w = EV::child_ns $pid, $trace, $callback
		668
		669	=item $w = $loop->child ($pid, $trace, $callback)
		670
		671	=item $w = $loop->child_ns ($pid, $trace, $callback)
471		672
472	Call the callback when a status change for pid C<$pid> (or any pid	673	Call the callback when a status change for pid C<$pid> (or any pid
473	if C<$pid> is 0) has been received. More precisely: when the process	674	if C<$pid> is 0) has been received (a status change happens when the
		675	process terminates or is killed, or, when trace is true, additionally when
		676	it is stopped or continued). More precisely: when the process receives
474	receives a SIGCHLD, EV will fetch the outstanding exit/wait status for all	677	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
475	changed/zombie children and call the callback.	678	changed/zombie children and call the callback.
476		679
477	You can access both status and pid by using the C<rstatus> and C<rpid>	680	It is valid (and fully supported) to install a child watcher after a child
478	methods on the watcher object.	681	has exited but before the event loop has started its next iteration (for
		682	example, first you C<fork>, then the new child process might exit, and
		683	only then do you install a child watcher in the parent for the new pid).
479		684
		685	You can access both exit (or tracing) status and pid by using the
		686	C<rstatus> and C<rpid> methods on the watcher object.
		687
480	You can have as many pid watchers per pid as you want.	688	You can have as many pid watchers per pid as you want, they will all be
		689	called.
481		690
482	The C<child_ns> variant doesn't start (activate) the newly created watcher.	691	The C<child_ns> variant doesn't start (activate) the newly created watcher.
483		692
484	=item $w->set ($pid)	693	=item $w->set ($pid, $trace)
485		694
486	Reconfigures the watcher, see the constructor above for details. Can be at	695	Reconfigures the watcher, see the constructor above for details. Can be called at
487	any time.	696	any time.
488		697
489	=item $current_pid = $w->pid	698	=item $current_pid = $w->pid
490
491	=item $old_pid = $w->pid ($new_pid)
492		699
493	Returns the previously set process id and optionally set a new one.	700	Returns the previously set process id and optionally set a new one.
494		701
495	=item $exit_status = $w->rstatus	702	=item $exit_status = $w->rstatus
496		703
…		…
500	=item $pid = $w->rpid	707	=item $pid = $w->rpid
501		708
502	Return the pid of the awaited child (useful when you have installed a	709	Return the pid of the awaited child (useful when you have installed a
503	watcher for all pids).	710	watcher for all pids).
504		711
		712	=back
		713
		714
		715	=head3 STAT WATCHERS - did the file attributes just change?
		716
		717	=over 4
		718
		719	=item $w = EV::stat $path, $interval, $callback
		720
		721	=item $w = EV::stat_ns $path, $interval, $callback
		722
		723	=item $w = $loop->stat ($path, $interval, $callback)
		724
		725	=item $w = $loop->stat_ns ($path, $interval, $callback)
		726
		727	Call the callback when a file status change has been detected on
		728	C<$path>. The C<$path> does not need to exist, changing from "path exists"
		729	to "path does not exist" is a status change like any other.
		730
		731	The C<$interval> is a recommended polling interval for systems where
		732	OS-supported change notifications don't exist or are not supported. If
		733	you use C<0> then an unspecified default is used (which is highly
		734	recommended!), which is to be expected to be around five seconds usually.
		735
		736	This watcher type is not meant for massive numbers of stat watchers,
		737	as even with OS-supported change notifications, this can be
		738	resource-intensive.
		739
		740	The C<stat_ns> variant doesn't start (activate) the newly created watcher.
		741
		742	=item ... = $w->stat
		743
		744	This call is very similar to the perl C<stat> built-in: It stats (using
		745	C<lstat>) the path specified in the watcher and sets perls stat cache (as
		746	well as EV's idea of the current stat values) to the values found.
		747
		748	In scalar context, a boolean is return indicating success or failure of
		749	the stat. In list context, the same 13-value list as with stat is returned
		750	(except that the blksize and blocks fields are not reliable).
		751
		752	In the case of an error, errno is set to C<ENOENT> (regardless of the
		753	actual error value) and the C<nlink> value is forced to zero (if the stat
		754	was successful then nlink is guaranteed to be non-zero).
		755
		756	See also the next two entries for more info.
		757
		758	=item ... = $w->attr
		759
		760	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		761	the values most recently detected by EV. See the next entry for more info.
		762
		763	=item ... = $w->prev
		764
		765	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		766	the previous set of values, before the change.
		767
		768	That is, when the watcher callback is invoked, C<< $w->prev >> will be set
		769	to the values found I<before> a change was detected, while C<< $w->attr >>
		770	returns the values found leading to the change detection. The difference (if any)
		771	between C<prev> and C<attr> is what triggered the callback.
		772
		773	If you did something to the filesystem object and do not want to trigger
		774	yet another change, you can call C<stat> to update EV's idea of what the
		775	current attributes are.
		776
		777	=item $w->set ($path, $interval)
		778
		779	Reconfigures the watcher, see the constructor above for details. Can be
		780	called at any time.
		781
		782	=item $current_path = $w->path
		783
		784	=item $old_path = $w->path ($new_path)
		785
		786	Returns the previously set path and optionally set a new one.
		787
		788	=item $current_interval = $w->interval
		789
		790	=item $old_interval = $w->interval ($new_interval)
		791
		792	Returns the previously set interval and optionally set a new one. Can be
		793	used to query the actual interval used.
		794
		795	=back
		796
		797
		798	=head3 IDLE WATCHERS - when you've got nothing better to do...
		799
		800	=over 4
505		801
506	=item $w = EV::idle $callback	802	=item $w = EV::idle $callback
507		803
508	=item $w = EV::idle_ns $callback	804	=item $w = EV::idle_ns $callback
509		805
510	Call the callback when there are no pending io, timer/periodic, signal or	806	=item $w = $loop->idle ($callback)
511	child events, i.e. when the process is idle.	807
		808	=item $w = $loop->idle_ns ($callback)
		809
		810	Call the callback when there are no other pending watchers of the same or
		811	higher priority (excluding check, prepare and other idle watchers of the
		812	same or lower priority, of course). They are called idle watchers because
		813	when the watcher is the highest priority pending event in the process, the
		814	process is considered to be idle at that priority.
		815
		816	If you want a watcher that is only ever called when I<no> other events are
		817	outstanding you have to set the priority to C<EV::MINPRI>.
512		818
513	The process will not block as long as any idle watchers are active, and	819	The process will not block as long as any idle watchers are active, and
514	they will be called repeatedly until stopped.	820	they will be called repeatedly until stopped.
515		821
		822	For example, if you have idle watchers at priority C<0> and C<1>, and
		823	an I/O watcher at priority C<0>, then the idle watcher at priority C<1>
		824	and the I/O watcher will always run when ready. Only when the idle watcher
		825	at priority C<1> is stopped and the I/O watcher at priority C<0> is not
		826	pending with the C<0>-priority idle watcher be invoked.
		827
516	The C<idle_ns> variant doesn't start (activate) the newly created watcher.	828	The C<idle_ns> variant doesn't start (activate) the newly created watcher.
517		829
		830	=back
		831
		832
		833	=head3 PREPARE WATCHERS - customise your event loop!
		834
		835	=over 4
518		836
519	=item $w = EV::prepare $callback	837	=item $w = EV::prepare $callback
520		838
521	=item $w = EV::prepare_ns $callback	839	=item $w = EV::prepare_ns $callback
		840
		841	=item $w = $loop->prepare ($callback)
		842
		843	=item $w = $loop->prepare_ns ($callback)
522		844
523	Call the callback just before the process would block. You can still	845	Call the callback just before the process would block. You can still
524	create/modify any watchers at this point.	846	create/modify any watchers at this point.
525		847
526	See the EV::check watcher, below, for explanations and an example.	848	See the EV::check watcher, below, for explanations and an example.
527		849
528	The C<prepare_ns> variant doesn't start (activate) the newly created watcher.	850	The C<prepare_ns> variant doesn't start (activate) the newly created watcher.
529		851
		852	=back
		853
		854
		855	=head3 CHECK WATCHERS - customise your event loop even more!
		856
		857	=over 4
530		858
531	=item $w = EV::check $callback	859	=item $w = EV::check $callback
532		860
533	=item $w = EV::check_ns $callback	861	=item $w = EV::check_ns $callback
		862
		863	=item $w = $loop->check ($callback)
		864
		865	=item $w = $loop->check_ns ($callback)
534		866
535	Call the callback just after the process wakes up again (after it has	867	Call the callback just after the process wakes up again (after it has
536	gathered events), but before any other callbacks have been invoked.	868	gathered events), but before any other callbacks have been invoked.
537		869
538	This is used to integrate other event-based software into the EV	870	This is used to integrate other event-based software into the EV
…		…
548	or return;	880	or return;
549		881
550	# make the dispatcher handle any outstanding stuff	882	# make the dispatcher handle any outstanding stuff
551	... not shown	883	... not shown
552		884
553	# create an IO watcher for each and every socket	885	# create an I/O watcher for each and every socket
554	@snmp_watcher = (	886	@snmp_watcher = (
555	(map { EV::io $_, EV::READ, sub { } }	887	(map { EV::io $_, EV::READ, sub { } }
556	keys %{ $dispatcher->{_descriptors} }),	888	keys %{ $dispatcher->{_descriptors} }),
557		889
558	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]	890	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
…		…
579	first).	911	first).
580		912
581	The C<check_ns> variant doesn't start (activate) the newly created watcher.	913	The C<check_ns> variant doesn't start (activate) the newly created watcher.
582		914
583	=back	915	=back
		916
		917
		918	=head3 FORK WATCHERS - the audacity to resume the event loop after a fork
		919
		920	Fork watchers are called when a C<fork ()> was detected. The invocation
		921	is done before the event loop blocks next and before C<check> watchers
		922	are being called, and only in the child after the fork.
		923
		924	=over 4
		925
		926	=item $w = EV::fork $callback
		927
		928	=item $w = EV::fork_ns $callback
		929
		930	=item $w = $loop->fork ($callback)
		931
		932	=item $w = $loop->fork_ns ($callback)
		933
		934	Call the callback before the event loop is resumed in the child process
		935	after a fork.
		936
		937	The C<fork_ns> variant doesn't start (activate) the newly created watcher.
		938
		939	=back
		940
		941
		942	=head3 EMBED WATCHERS - when one backend isn't enough...
		943
		944	This is a rather advanced watcher type that lets you embed one event loop
		945	into another (currently only IO events are supported in the embedded
		946	loop, other types of watchers might be handled in a delayed or incorrect
		947	fashion and must not be used).
		948
		949	See the libev documentation at
		950	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
		951	for more details.
		952
		953	In short, this watcher is most useful on BSD systems without working
		954	kqueue to still be able to handle a large number of sockets:
		955
		956	my $socket_loop;
		957
		958	# check wether we use SELECT or POLL _and_ KQUEUE is supported
		959	if (
		960	(EV::backend & (EV::BACKEND_POLL \| EV::BACKEND_SELECT))
		961	&& (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
		962	) {
		963	# use kqueue for sockets
		964	$socket_loop = new EV::Loop EV::BACKEND_KQUEUE \| EV::FLAG_NOENV;
		965	}
		966
		967	# use the default loop otherwise
		968	$socket_loop \|\|= EV::default_loop;
		969
		970	=over 4
		971
		972	=item $w = EV::embed $otherloop, $callback
		973
		974	=item $w = EV::embed_ns $otherloop, $callback
		975
		976	=item $w = $loop->embed ($otherloop, $callback)
		977
		978	=item $w = $loop->embed_ns ($otherloop, $callback)
		979
		980	Call the callback when the embedded event loop (C<$otherloop>) has any
		981	I/O activity. The C<$callback> should alwas be specified as C<undef> in
		982	this version of EV, which means the embedded event loop will be managed
		983	automatically.
		984
		985	The C<embed_ns> variant doesn't start (activate) the newly created watcher.
		986
		987	=back
		988
		989	=head3 ASYNC WATCHERS - how to wake up another event loop
		990
		991	Async watchers are provided by EV, but have little use in perl directly, as perl
		992	neither supports threads nor direct access to signal handlers or other
		993	contexts where they could be of value.
		994
		995	It is, however, possible to use them from the XS level.
		996
		997	Please see the libev documentation for further details.
		998
		999	=over 4
		1000
		1001	=item $w = EV::async $callback
		1002
		1003	=item $w = EV::async_ns $callback
		1004
		1005	=item $w->send
		1006
		1007	=item $bool = $w->async_pending
		1008
		1009	=back
		1010
		1011
		1012	=head1 PERL SIGNALS
		1013
		1014	While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour
		1015	with EV is as the same as any other C library: Perl-signals will only be
		1016	handled when Perl runs, which means your signal handler might be invoked
		1017	only the next time an event callback is invoked.
		1018
		1019	The solution is to use EV signal watchers (see C<EV::signal>), which will
		1020	ensure proper operations with regards to other event watchers.
		1021
		1022	If you cannot do this for whatever reason, you can also force a watcher
		1023	to be called on every event loop iteration by installing a C<EV::check>
		1024	watcher:
		1025
		1026	my $async_check = EV::check sub { };
		1027
		1028	This ensures that perl gets into control for a short time to handle any
		1029	pending signals, and also ensures (slightly) slower overall operation.
584		1030
585	=head1 THREADS	1031	=head1 THREADS
586		1032
587	Threads are not supported by this module in any way. Perl pseudo-threads	1033	Threads are not supported by this module in any way. Perl pseudo-threads
588	is evil stuff and must die. As soon as Perl gains real threads I will work	1034	is evil stuff and must die. As soon as Perl gains real threads I will work
…		…
610	our $DIED = sub {	1056	our $DIED = sub {
611	warn "EV: error in callback (ignoring): $@";	1057	warn "EV: error in callback (ignoring): $@";
612	};	1058	};
613		1059
614	default_loop	1060	default_loop
615	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	1061	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
616		1062
617	1;	1063	1;
618		1064
619	=head1 SEE ALSO	1065	=head1 SEE ALSO
620		1066
621	L<EV::DNS>.	1067	L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as
		1068	event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
		1069	coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
		1070	event-loop agnostic and portable event driven programming.
622		1071
623	=head1 AUTHOR	1072	=head1 AUTHOR
624		1073
625	Marc Lehmann <schmorp@schmorp.de>	1074	Marc Lehmann <schmorp@schmorp.de>
626	http://home.schmorp.de/	1075	http://home.schmorp.de/
627		1076
628	=cut	1077	=cut
629		1078

Diff Legend

-–
+Removed lines
-+
+Added lines
-<
+Changed lines
->
+Changed lines

Comparing EV/EV.pm (file contents): Revision 1.51 by root, Sat Nov 24 16:12:37 2007 UTC vs. Revision 1.98 by root, Sat May 31 23:17:50 2008 UTC

Diff Legend

Comparing EV/EV.pm (file contents):
Revision 1.51 by root, Sat Nov 24 16:12:37 2007 UTC vs.
Revision 1.98 by root, Sat May 31 23:17:50 2008 UTC