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

Comparing EV/EV.pm (file contents):
Revision 1.56 by root, Tue Nov 27 10:59:10 2007 UTC vs.
Revision 1.100 by root, Tue Jul 8 18:53:11 2008 UTC

…		…
2		2
3	EV - perl interface to libev, a high performance full-featured event loop	3	EV - perl interface to libev, a high performance full-featured event loop
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	use EV;	7	use EV;
		8
		9	# TIMERS
		10
		11	my $w = EV::timer 2, 0, sub {
		12	warn "is called after 2s";
		13	};
		14
		15	my $w = EV::timer 2, 2, sub {
		16	warn "is called roughly every 2s (repeat = 2)";
		17	};
		18
		19	undef $w; # destroy event watcher again
		20
		21	my $w = EV::periodic 0, 60, 0, sub {
		22	warn "is called every minute, on the minute, exactly";
		23	};
		24
		25	# IO
		26
		27	my $w = EV::io *STDIN, EV::READ, sub {
		28	my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
		29	warn "stdin is readable, you entered: ", <STDIN>;
		30	};
		31
		32	# SIGNALS
		33
		34	my $w = EV::signal 'QUIT', sub {
		35	warn "sigquit received\n";
		36	};
		37
		38	# CHILD/PID STATUS CHANGES
8		39
9	# TIMERS	40	my $w = EV::child 666, 0, sub {
		41	my ($w, $revents) = @_;
		42	my $status = $w->rstatus;
		43	};
10		44
11	my $w = EV::timer 2, 0, sub {
12	warn "is called after 2s";
13	};
14
15	my $w = EV::timer 2, 2, sub {
16	warn "is called roughly every 2s (repeat = 2)";
17	};
18
19	undef $w; # destroy event watcher again
20
21	my $w = EV::periodic 0, 60, 0, sub {
22	warn "is called every minute, on the minute, exactly";
23	};
24
25	# IO
26
27	my $w = EV::io *STDIN, EV::READ, sub {
28	my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
29	warn "stdin is readable, you entered: ", <STDIN>;
30	};
31
32	# SIGNALS
33
34	my $w = EV::signal 'QUIT', sub {
35	warn "sigquit received\n";
36	};
37
38	# CHILD/PID STATUS CHANGES
39
40	my $w = EV::child 666, sub {
41	my ($w, $revents) = @_;
42	my $status = $w->rstatus;
43	};
44
45	# STAT CHANGES	45	# STAT CHANGES
46	my $w = EV::stat "/etc/passwd", 10, sub {	46	my $w = EV::stat "/etc/passwd", 10, sub {
47	my ($w, $revents) = @_;	47	my ($w, $revents) = @_;
48	warn $w->path, " has changed somehow.\n";	48	warn $w->path, " has changed somehow.\n";
49	};	49	};
50		50
51	# MAINLOOP	51	# MAINLOOP
52	EV::loop; # loop until EV::unloop is called or all watchers stop	52	EV::loop; # loop until EV::unloop is called or all watchers stop
53	EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled	53	EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled
54	EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block	54	EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block
55		55
56	=head1 DESCRIPTION	56	=head1 DESCRIPTION
57		57
58	This module provides an interface to libev	58	This module provides an interface to libev
59	(L<http://software.schmorp.de/pkg/libev.html>). While the documentation	59	(L<http://software.schmorp.de/pkg/libev.html>). While the documentation
60	below is comprehensive, one might also consult the documentation of libev	60	below is comprehensive, one might also consult the documentation of libev
61	itself (L<http://cvs.schmorp.de/libev/ev.html>) for more subtle details on	61	itself (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod>) for more
62	watcher semantics or some discussion on the available backends, or how to	62	subtle details on watcher semantics or some discussion on the available
63	force a specific backend with C<LIBEV_FLAGS>.	63	backends, or how to force a specific backend with C<LIBEV_FLAGS>, or just
		64	about in any case because it has much more detailed information.
		65
		66	This module is very fast and scalable. It is actually so fast that you
		67	can use it through the L<AnyEvent> module, stay portable to other event
		68	loops (if you don't rely on any watcher types not available through it)
		69	and still be faster than with any other event loop currently supported in
		70	Perl.
64		71
65	=cut	72	=cut
66		73
67	package EV;	74	package EV;
68		75
		76	no warnings;
69	use strict;	77	use strict;
70		78
71	BEGIN {	79	BEGIN {
72	our $VERSION = '1.4';	80	our $VERSION = '3.43';
73	use XSLoader;	81	use XSLoader;
74	XSLoader::load "EV", $VERSION;	82	XSLoader::load "EV", $VERSION;
75	}	83	}
76		84
77	@EV::IO::ISA =	85	@EV::IO::ISA =
…		…
83	@EV::Idle::ISA =	91	@EV::Idle::ISA =
84	@EV::Prepare::ISA =	92	@EV::Prepare::ISA =
85	@EV::Check::ISA =	93	@EV::Check::ISA =
86	@EV::Embed::ISA =	94	@EV::Embed::ISA =
87	@EV::Fork::ISA =	95	@EV::Fork::ISA =
		96	@EV::Async::ISA =
88	"EV::Watcher";	97	"EV::Watcher";
89		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	Using C<EV::FLAG_FORKCHECK> is recommended, as only the default event loop
		136	is protected by this module.
		137
		138	=item $loop->loop_fork
		139
		140	Must be called after a fork in the child, before entering or continuing
		141	the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
		142	this function automatically, at some performance loss (refer to the libev
		143	documentation).
		144
		145	=item $loop->loop_verify
		146
		147	Calls C<ev_verify> to make internal consistency checks (for debugging
		148	libev) and abort the program if any data structures were found to be
		149	corrupted.
		150
		151	=item $loop = EV::default_loop [$flags]
		152
		153	Return the default loop (which is a singleton object). Since this module
		154	already creates the default loop with default flags, specifying flags here
		155	will not have any effect unless you destroy the default loop first, which
		156	isn't supported. So in short: don't do it, and if you break it, you get to
		157	keep the pieces.
		158
		159	=back
		160
		161
90	=head1 BASIC INTERFACE	162	=head1 BASIC INTERFACE
91		163
92	=over 4	164	=over 4
93		165
94	=item $EV::DIED	166	=item $EV::DIED
95		167
96	Must contain a reference to a function that is called when a callback	168	Must contain a reference to a function that is called when a callback
97	throws an exception (with $@ containing thr error). The default prints an	169	throws an exception (with $@ containing the error). The default prints an
98	informative message and continues.	170	informative message and continues.
99		171
100	If this callback throws an exception it will be silently ignored.	172	If this callback throws an exception it will be silently ignored.
101		173
		174	=item $flags = EV::supported_backends
		175
		176	=item $flags = EV::recommended_backends
		177
		178	=item $flags = EV::embeddable_backends
		179
		180	Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this
		181	instance of EV, the set of recommended backends (supposed to be good) for
		182	this platform and the set of embeddable backends (see EMBED WATCHERS).
		183
		184	=item EV::sleep $seconds
		185
		186	Block the process for the given number of (fractional) seconds.
		187
102	=item $time = EV::time	188	=item $time = EV::time
103		189
104	Returns the current time in (fractional) seconds since the epoch.	190	Returns the current time in (fractional) seconds since the epoch.
105		191
106	=item $time = EV::now	192	=item $time = EV::now
		193
		194	=item $time = $loop->now
107		195
108	Returns the time the last event loop iteration has been started. This	196	Returns the time the last event loop iteration has been started. This
109	is the time that (relative) timers are based on, and refering to it is	197	is the time that (relative) timers are based on, and refering to it is
110	usually faster then calling EV::time.	198	usually faster then calling EV::time.
111		199
112	=item $method = EV::method	200	=item $backend = EV::backend
		201
		202	=item $backend = $loop->backend
113		203
114	Returns an integer describing the backend used by libev (EV::METHOD_SELECT	204	Returns an integer describing the backend used by libev (EV::METHOD_SELECT
115	or EV::METHOD_EPOLL).	205	or EV::METHOD_EPOLL).
116		206
117	=item EV::loop [$flags]	207	=item EV::loop [$flags]
		208
		209	=item $loop->loop ([$flags])
118		210
119	Begin checking for events and calling callbacks. It returns when a	211	Begin checking for events and calling callbacks. It returns when a
120	callback calls EV::unloop.	212	callback calls EV::unloop.
121		213
122	The $flags argument can be one of the following:	214	The $flags argument can be one of the following:
…		…
125	EV::LOOP_ONESHOT block at most once (wait, but do not loop)	217	EV::LOOP_ONESHOT block at most once (wait, but do not loop)
126	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)	218	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
127		219
128	=item EV::unloop [$how]	220	=item EV::unloop [$how]
129		221
		222	=item $loop->unloop ([$how])
		223
130	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the	224	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the
131	innermost call to EV::loop return.	225	innermost call to EV::loop return.
132		226
133	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as	227	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as
134	fast as possible.	228	fast as possible.
135		229
		230	=item $count = EV::loop_count
		231
		232	=item $count = $loop->loop_count
		233
		234	Return the number of times the event loop has polled for new
		235	events. Sometiems useful as a generation counter.
		236
136	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)	237	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
		238
		239	=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
137		240
138	This function rolls together an I/O and a timer watcher for a single	241	This function rolls together an I/O and a timer watcher for a single
139	one-shot event without the need for managing a watcher object.	242	one-shot event without the need for managing a watcher object.
140		243
141	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>	244	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>
…		…
147	If timeout is C<undef> or negative, then there will be no	250	If timeout is C<undef> or negative, then there will be no
148	timeout. Otherwise a EV::timer with this value will be started.	251	timeout. Otherwise a EV::timer with this value will be started.
149		252
150	When an error occurs or either the timeout or I/O watcher triggers, then	253	When an error occurs or either the timeout or I/O watcher triggers, then
151	the callback will be called with the received event set (in general	254	the callback will be called with the received event set (in general
152	you can expect it to be a combination of C<EV:ERROR>, C<EV::READ>,	255	you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
153	C<EV::WRITE> and C<EV::TIMEOUT>).	256	C<EV::WRITE> and C<EV::TIMEOUT>).
154		257
155	EV::once doesn't return anything: the watchers stay active till either	258	EV::once doesn't return anything: the watchers stay active till either
156	of them triggers, then they will be stopped and freed, and the callback	259	of them triggers, then they will be stopped and freed, and the callback
157	invoked.	260	invoked.
158		261
159	=back	262	=item EV::feed_fd_event ($fd, $revents)
160		263
		264	=item $loop->feed_fd_event ($fd, $revents)
		265
		266	Feed an event on a file descriptor into EV. EV will react to this call as
		267	if the readyness notifications specified by C<$revents> (a combination of
		268	C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
		269
		270	=item EV::feed_signal_event ($signal)
		271
		272	Feed a signal event into EV. EV will react to this call as if the signal
		273	specified by C<$signal> had occured.
		274
		275	=item EV::set_io_collect_interval $time
		276
		277	=item $loop->set_io_collect_interval ($time)
		278
		279	=item EV::set_timeout_collect_interval $time
		280
		281	=item $loop->set_timeout_collect_interval ($time)
		282
		283	These advanced functions set the minimum block interval when polling for I/O events and the minimum
		284	wait interval for timer events. See the libev documentation at
		285	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> for
		286	a more detailed discussion.
		287
		288	=back
		289
		290
161	=head2 WATCHER OBJECTS	291	=head1 WATCHER OBJECTS
162		292
163	A watcher is an object that gets created to record your interest in some	293	A watcher is an object that gets created to record your interest in some
164	event. For instance, if you want to wait for STDIN to become readable, you	294	event. For instance, if you want to wait for STDIN to become readable, you
165	would create an EV::io watcher for that:	295	would create an EV::io watcher for that:
166		296
167	my $watcher = EV::io *STDIN, EV::READ, sub {	297	my $watcher = EV::io *STDIN, EV::READ, sub {
168	my ($watcher, $revents) = @_;	298	my ($watcher, $revents) = @_;
169	warn "yeah, STDIN should not be readable without blocking!\n"	299	warn "yeah, STDIN should now be readable without blocking!\n"
170	};	300	};
171		301
172	All watchers can be active (waiting for events) or inactive (paused). Only	302	All watchers can be active (waiting for events) or inactive (paused). Only
173	active watchers will have their callbacks invoked. All callbacks will be	303	active watchers will have their callbacks invoked. All callbacks will be
174	called with at least two arguments: the watcher and a bitmask of received	304	called with at least two arguments: the watcher and a bitmask of received
175	events.	305	events.
176		306
177	Each watcher type has its associated bit in revents, so you can use the	307	Each watcher type has its associated bit in revents, so you can use the
178	same callback for multiple watchers. The event mask is named after the	308	same callback for multiple watchers. The event mask is named after the
179	type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,	309	type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
180	EV::periodic sets EV::PERIODIC and so on, with the exception of IO events	310	EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events
181	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which	311	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which
182	uses EV::TIMEOUT).	312	uses EV::TIMEOUT).
183		313
184	In the rare case where one wants to create a watcher but not start it at	314	In the rare case where one wants to create a watcher but not start it at
185	the same time, each constructor has a variant with a trailing C<_ns> in	315	the same time, each constructor has a variant with a trailing C<_ns> in
…		…
207		337
208	=item $w->stop	338	=item $w->stop
209		339
210	Stop a watcher if it is active. Also clear any pending events (events that	340	Stop a watcher if it is active. Also clear any pending events (events that
211	have been received but that didn't yet result in a callback invocation),	341	have been received but that didn't yet result in a callback invocation),
212	regardless of wether the watcher was active or not.	342	regardless of whether the watcher was active or not.
213		343
214	=item $bool = $w->is_active	344	=item $bool = $w->is_active
215		345
216	Returns true if the watcher is active, false otherwise.	346	Returns true if the watcher is active, false otherwise.
217		347
…		…
247	The default priority of any newly-created watcher is 0.	377	The default priority of any newly-created watcher is 0.
248		378
249	Note that the priority semantics have not yet been fleshed out and are	379	Note that the priority semantics have not yet been fleshed out and are
250	subject to almost certain change.	380	subject to almost certain change.
251		381
252	=item $w->trigger ($revents)	382	=item $w->invoke ($revents)
253		383
254	Call the callback now with the given event mask.	384	Call the callback now with the given event mask.
		385
		386	=item $w->feed_event ($revents)
		387
		388	Feed some events on this watcher into EV. EV will react to this call as if
		389	the watcher had received the given C<$revents> mask.
		390
		391	=item $revents = $w->clear_pending
		392
		393	If the watcher is pending, this function clears its pending status and
		394	returns its C<$revents> bitset (as if its callback was invoked). If the
		395	watcher isn't pending it does nothing and returns C<0>.
255		396
256	=item $previous_state = $w->keepalive ($bool)	397	=item $previous_state = $w->keepalive ($bool)
257		398
258	Normally, C<EV::loop> will return when there are no active watchers	399	Normally, C<EV::loop> will return when there are no active watchers
259	(which is a "deadlock" because no progress can be made anymore). This is	400	(which is a "deadlock" because no progress can be made anymore). This is
260	convinient because it allows you to start your watchers (and your jobs),	401	convinient because it allows you to start your watchers (and your jobs),
261	call C<EV::loop> once and when it returns you know that all your jobs are	402	call C<EV::loop> once and when it returns you know that all your jobs are
262	finished (or they forgot to register some watchers for their task :).	403	finished (or they forgot to register some watchers for their task :).
263		404
264	Sometimes, however, this gets in your way, for example when you the module	405	Sometimes, however, this gets in your way, for example when the module
265	that calls C<EV::loop> (usually the main program) is not the same module	406	that calls C<EV::loop> (usually the main program) is not the same module
266	as a long-living watcher (for example a DNS client module written by	407	as a long-living watcher (for example a DNS client module written by
267	somebody else even). Then you might want any outstanding requests to be	408	somebody else even). Then you might want any outstanding requests to be
268	handled, but you would not want to keep C<EV::loop> from returning just	409	handled, but you would not want to keep C<EV::loop> from returning just
269	because you happen to have this long-running UDP port watcher.	410	because you happen to have this long-running UDP port watcher.
…		…
272	though your watcher is active, it won't keep C<EV::loop> from returning.	413	though your watcher is active, it won't keep C<EV::loop> from returning.
273		414
274	The initial value for keepalive is true (enabled), and you cna change it	415	The initial value for keepalive is true (enabled), and you cna change it
275	any time.	416	any time.
276		417
277	Example: Register an IO watcher for some UDP socket but do not keep the	418	Example: Register an I/O watcher for some UDP socket but do not keep the
278	event loop from running just because of that watcher.	419	event loop from running just because of that watcher.
279		420
280	my $udp_socket = ...	421	my $udp_socket = ...
281	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };	422	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
282	$udp_watcher->keepalive (0);	423	$udp_watcher->keepalive (0);
283		424
284	=back	425	=item $loop = $w->loop
285		426
		427	Return the loop that this watcher is attached to.
286		428
		429	=back
		430
		431
287	=head2 WATCHER TYPES	432	=head1 WATCHER TYPES
288		433
289	Each of the following subsections describes a single watcher type.	434	Each of the following subsections describes a single watcher type.
290		435
291	=head3 IO WATCHERS - is this file descriptor readable or writable?	436	=head3 I/O WATCHERS - is this file descriptor readable or writable?
292		437
293	=over 4	438	=over 4
294		439
295	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	440	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
296		441
297	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback	442	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
		443
		444	=item $w = $loop->io ($fileno_or_fh, $eventmask, $callback)
		445
		446	=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
298		447
299	As long as the returned watcher object is alive, call the C<$callback>	448	As long as the returned watcher object is alive, call the C<$callback>
300	when at least one of events specified in C<$eventmask> occurs.	449	when at least one of events specified in C<$eventmask> occurs.
301		450
302	The $eventmask can be one or more of these constants ORed together:	451	The $eventmask can be one or more of these constants ORed together:
…		…
331	=over 4	480	=over 4
332		481
333	=item $w = EV::timer $after, $repeat, $callback	482	=item $w = EV::timer $after, $repeat, $callback
334		483
335	=item $w = EV::timer_ns $after, $repeat, $callback	484	=item $w = EV::timer_ns $after, $repeat, $callback
		485
		486	=item $w = $loop->timer ($after, $repeat, $callback)
		487
		488	=item $w = $loop->timer_ns ($after, $repeat, $callback)
336		489
337	Calls the callback after C<$after> seconds (which may be fractional). If	490	Calls the callback after C<$after> seconds (which may be fractional). If
338	C<$repeat> is non-zero, the timer will be restarted (with the $repeat	491	C<$repeat> is non-zero, the timer will be restarted (with the $repeat
339	value as $after) after the callback returns.	492	value as $after) after the callback returns.
340		493
…		…
381	=over 4	534	=over 4
382		535
383	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback	536	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
384		537
385	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback	538	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
		539
		540	=item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
		541
		542	=item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback)
386		543
387	Similar to EV::timer, but is not based on relative timeouts but on	544	Similar to EV::timer, but is not based on relative timeouts but on
388	absolute times. Apart from creating "simple" timers that trigger "at" the	545	absolute times. Apart from creating "simple" timers that trigger "at" the
389	specified time, it can also be used for non-drifting absolute timers and	546	specified time, it can also be used for non-drifting absolute timers and
390	more complex, cron-like, setups that are not adversely affected by time	547	more complex, cron-like, setups that are not adversely affected by time
…		…
400	This time simply fires at the wallclock time C<$at> and doesn't repeat. It	557	This time simply fires at the wallclock time C<$at> and doesn't repeat. It
401	will not adjust when a time jump occurs, that is, if it is to be run	558	will not adjust when a time jump occurs, that is, if it is to be run
402	at January 1st 2011 then it will run when the system time reaches or	559	at January 1st 2011 then it will run when the system time reaches or
403	surpasses this time.	560	surpasses this time.
404		561
405	=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0)	562	=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
406		563
407	In this mode the watcher will always be scheduled to time out at the	564	In this mode the watcher will always be scheduled to time out at the
408	next C<$at + N * $interval> time (for some integer N) and then repeat,	565	next C<$at + N * $interval> time (for some integer N) and then repeat,
409	regardless of any time jumps.	566	regardless of any time jumps.
410		567
…		…
428	time the periodic watcher gets scheduled, the reschedule callback	585	time the periodic watcher gets scheduled, the reschedule callback
429	($reschedule_cb) will be called with the watcher as first, and the current	586	($reschedule_cb) will be called with the watcher as first, and the current
430	time as second argument.	587	time as second argument.
431		588
432	I<This callback MUST NOT stop or destroy this or any other periodic	589	I<This callback MUST NOT stop or destroy this or any other periodic
433	watcher, ever>. If you need to stop it, return 1e30 and stop it	590	watcher, ever, and MUST NOT call any event loop functions or methods>. If
434	afterwards.	591	you need to stop it, return 1e30 and stop it afterwards. You may create
		592	and start a C<EV::prepare> watcher for this task.
435		593
436	It must return the next time to trigger, based on the passed time value	594	It must return the next time to trigger, based on the passed time value
437	(that is, the lowest time value larger than to the second argument). It	595	(that is, the lowest time value larger than or equal to to the second
438	will usually be called just before the callback will be triggered, but	596	argument). It will usually be called just before the callback will be
439	might be called at other times, too.	597	triggered, but might be called at other times, too.
440		598
441	This can be used to create very complex timers, such as a timer that	599	This can be used to create very complex timers, such as a timer that
442	triggers on each midnight, local time (actually 24 hours after the last	600	triggers on each midnight, local time (actually 24 hours after the last
443	midnight, to keep the example simple. If you know a way to do it correctly	601	midnight, to keep the example simple. If you know a way to do it correctly
444	in about the same space (without requiring elaborate modules), drop me a	602	in about the same space (without requiring elaborate modules), drop me a
…		…
465		623
466	=item $w->again	624	=item $w->again
467		625
468	Simply stops and starts the watcher again.	626	Simply stops and starts the watcher again.
469		627
		628	=item $time = $w->at
		629
		630	Return the time that the watcher is expected to trigger next.
		631
470	=back	632	=back
471		633
472		634
473	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!	635	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
474		636
…		…
507		669
508	=head3 CHILD WATCHERS - watch out for process status changes	670	=head3 CHILD WATCHERS - watch out for process status changes
509		671
510	=over 4	672	=over 4
511		673
512	=item $w = EV::child $pid, $callback	674	=item $w = EV::child $pid, $trace, $callback
513		675
514	=item $w = EV::child_ns $pid, $callback	676	=item $w = EV::child_ns $pid, $trace, $callback
515		677
		678	=item $w = $loop->child ($pid, $trace, $callback)
		679
		680	=item $w = $loop->child_ns ($pid, $trace, $callback)
		681
516	Call the callback when a status change for pid C<$pid> (or any pid if	682	Call the callback when a status change for pid C<$pid> (or any pid
517	C<$pid> is 0) has been received. More precisely: when the process receives	683	if C<$pid> is 0) has been received (a status change happens when the
		684	process terminates or is killed, or, when trace is true, additionally when
		685	it is stopped or continued). More precisely: when the process receives
518	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all	686	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
519	changed/zombie children and call the callback.	687	changed/zombie children and call the callback.
520		688
521	It is valid (and fully supported) to install a child watcher after a child	689	It is valid (and fully supported) to install a child watcher after a child
522	has exited but before the event loop has started its next iteration (for	690	has exited but before the event loop has started its next iteration (for
…		…
529	You can have as many pid watchers per pid as you want, they will all be	697	You can have as many pid watchers per pid as you want, they will all be
530	called.	698	called.
531		699
532	The C<child_ns> variant doesn't start (activate) the newly created watcher.	700	The C<child_ns> variant doesn't start (activate) the newly created watcher.
533		701
534	=item $w->set ($pid)	702	=item $w->set ($pid, $trace)
535		703
536	Reconfigures the watcher, see the constructor above for details. Can be called at	704	Reconfigures the watcher, see the constructor above for details. Can be called at
537	any time.	705	any time.
538		706
539	=item $current_pid = $w->pid	707	=item $current_pid = $w->pid
540		708
541	=item $old_pid = $w->pid ($new_pid)
542
543	Returns the previously set process id and optionally set a new one.	709	Returns the previously set process id and optionally set a new one.
544		710
545	=item $exit_status = $w->rstatus	711	=item $exit_status = $w->rstatus
546		712
547	Return the exit/wait status (as returned by waitpid, see the waitpid entry	713	Return the exit/wait status (as returned by waitpid, see the waitpid entry
…		…
560	=over 4	726	=over 4
561		727
562	=item $w = EV::stat $path, $interval, $callback	728	=item $w = EV::stat $path, $interval, $callback
563		729
564	=item $w = EV::stat_ns $path, $interval, $callback	730	=item $w = EV::stat_ns $path, $interval, $callback
		731
		732	=item $w = $loop->stat ($path, $interval, $callback)
		733
		734	=item $w = $loop->stat_ns ($path, $interval, $callback)
565		735
566	Call the callback when a file status change has been detected on	736	Call the callback when a file status change has been detected on
567	C<$path>. The C<$path> does not need to exist, changing from "path exists"	737	C<$path>. The C<$path> does not need to exist, changing from "path exists"
568	to "path does not exist" is a status change like any other.	738	to "path does not exist" is a status change like any other.
569		739
…		…
576	as even with OS-supported change notifications, this can be	746	as even with OS-supported change notifications, this can be
577	resource-intensive.	747	resource-intensive.
578		748
579	The C<stat_ns> variant doesn't start (activate) the newly created watcher.	749	The C<stat_ns> variant doesn't start (activate) the newly created watcher.
580		750
		751	=item ... = $w->stat
		752
		753	This call is very similar to the perl C<stat> built-in: It stats (using
		754	C<lstat>) the path specified in the watcher and sets perls stat cache (as
		755	well as EV's idea of the current stat values) to the values found.
		756
		757	In scalar context, a boolean is return indicating success or failure of
		758	the stat. In list context, the same 13-value list as with stat is returned
		759	(except that the blksize and blocks fields are not reliable).
		760
		761	In the case of an error, errno is set to C<ENOENT> (regardless of the
		762	actual error value) and the C<nlink> value is forced to zero (if the stat
		763	was successful then nlink is guaranteed to be non-zero).
		764
		765	See also the next two entries for more info.
		766
		767	=item ... = $w->attr
		768
		769	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		770	the values most recently detected by EV. See the next entry for more info.
		771
		772	=item ... = $w->prev
		773
		774	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		775	the previous set of values, before the change.
		776
		777	That is, when the watcher callback is invoked, C<< $w->prev >> will be set
		778	to the values found I<before> a change was detected, while C<< $w->attr >>
		779	returns the values found leading to the change detection. The difference (if any)
		780	between C<prev> and C<attr> is what triggered the callback.
		781
		782	If you did something to the filesystem object and do not want to trigger
		783	yet another change, you can call C<stat> to update EV's idea of what the
		784	current attributes are.
		785
581	=item $w->set ($path, $interval)	786	=item $w->set ($path, $interval)
582		787
583	Reconfigures the watcher, see the constructor above for details. Can be	788	Reconfigures the watcher, see the constructor above for details. Can be
584	called at any time.	789	called at any time.
585		790
…		…
605		810
606	=item $w = EV::idle $callback	811	=item $w = EV::idle $callback
607		812
608	=item $w = EV::idle_ns $callback	813	=item $w = EV::idle_ns $callback
609		814
610	Call the callback when there are no pending io, timer/periodic, signal or	815	=item $w = $loop->idle ($callback)
611	child events, i.e. when the process is idle.	816
		817	=item $w = $loop->idle_ns ($callback)
		818
		819	Call the callback when there are no other pending watchers of the same or
		820	higher priority (excluding check, prepare and other idle watchers of the
		821	same or lower priority, of course). They are called idle watchers because
		822	when the watcher is the highest priority pending event in the process, the
		823	process is considered to be idle at that priority.
		824
		825	If you want a watcher that is only ever called when I<no> other events are
		826	outstanding you have to set the priority to C<EV::MINPRI>.
612		827
613	The process will not block as long as any idle watchers are active, and	828	The process will not block as long as any idle watchers are active, and
614	they will be called repeatedly until stopped.	829	they will be called repeatedly until stopped.
615		830
		831	For example, if you have idle watchers at priority C<0> and C<1>, and
		832	an I/O watcher at priority C<0>, then the idle watcher at priority C<1>
		833	and the I/O watcher will always run when ready. Only when the idle watcher
		834	at priority C<1> is stopped and the I/O watcher at priority C<0> is not
		835	pending with the C<0>-priority idle watcher be invoked.
		836
616	The C<idle_ns> variant doesn't start (activate) the newly created watcher.	837	The C<idle_ns> variant doesn't start (activate) the newly created watcher.
617		838
618	=back	839	=back
619		840
620		841
…		…
623	=over 4	844	=over 4
624		845
625	=item $w = EV::prepare $callback	846	=item $w = EV::prepare $callback
626		847
627	=item $w = EV::prepare_ns $callback	848	=item $w = EV::prepare_ns $callback
		849
		850	=item $w = $loop->prepare ($callback)
		851
		852	=item $w = $loop->prepare_ns ($callback)
628		853
629	Call the callback just before the process would block. You can still	854	Call the callback just before the process would block. You can still
630	create/modify any watchers at this point.	855	create/modify any watchers at this point.
631		856
632	See the EV::check watcher, below, for explanations and an example.	857	See the EV::check watcher, below, for explanations and an example.
…		…
641	=over 4	866	=over 4
642		867
643	=item $w = EV::check $callback	868	=item $w = EV::check $callback
644		869
645	=item $w = EV::check_ns $callback	870	=item $w = EV::check_ns $callback
		871
		872	=item $w = $loop->check ($callback)
		873
		874	=item $w = $loop->check_ns ($callback)
646		875
647	Call the callback just after the process wakes up again (after it has	876	Call the callback just after the process wakes up again (after it has
648	gathered events), but before any other callbacks have been invoked.	877	gathered events), but before any other callbacks have been invoked.
649		878
650	This is used to integrate other event-based software into the EV	879	This is used to integrate other event-based software into the EV
…		…
660	or return;	889	or return;
661		890
662	# make the dispatcher handle any outstanding stuff	891	# make the dispatcher handle any outstanding stuff
663	... not shown	892	... not shown
664		893
665	# create an IO watcher for each and every socket	894	# create an I/O watcher for each and every socket
666	@snmp_watcher = (	895	@snmp_watcher = (
667	(map { EV::io $_, EV::READ, sub { } }	896	(map { EV::io $_, EV::READ, sub { } }
668	keys %{ $dispatcher->{_descriptors} }),	897	keys %{ $dispatcher->{_descriptors} }),
669		898
670	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]	899	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
…		…
705		934
706	=item $w = EV::fork $callback	935	=item $w = EV::fork $callback
707		936
708	=item $w = EV::fork_ns $callback	937	=item $w = EV::fork_ns $callback
709		938
		939	=item $w = $loop->fork ($callback)
		940
		941	=item $w = $loop->fork_ns ($callback)
		942
710	Call the callback before the event loop is resumed in the child process	943	Call the callback before the event loop is resumed in the child process
711	after a fork.	944	after a fork.
712		945
713	The C<fork_ns> variant doesn't start (activate) the newly created watcher.	946	The C<fork_ns> variant doesn't start (activate) the newly created watcher.
714		947
715	=back	948	=back
716		949
		950
		951	=head3 EMBED WATCHERS - when one backend isn't enough...
		952
		953	This is a rather advanced watcher type that lets you embed one event loop
		954	into another (currently only IO events are supported in the embedded
		955	loop, other types of watchers might be handled in a delayed or incorrect
		956	fashion and must not be used).
		957
		958	See the libev documentation at
		959	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
		960	for more details.
		961
		962	In short, this watcher is most useful on BSD systems without working
		963	kqueue to still be able to handle a large number of sockets:
		964
		965	my $socket_loop;
		966
		967	# check wether we use SELECT or POLL _and_ KQUEUE is supported
		968	if (
		969	(EV::backend & (EV::BACKEND_POLL \| EV::BACKEND_SELECT))
		970	&& (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
		971	) {
		972	# use kqueue for sockets
		973	$socket_loop = new EV::Loop EV::BACKEND_KQUEUE \| EV::FLAG_NOENV;
		974	}
		975
		976	# use the default loop otherwise
		977	$socket_loop \|\|= EV::default_loop;
		978
		979	=over 4
		980
		981	=item $w = EV::embed $otherloop, $callback
		982
		983	=item $w = EV::embed_ns $otherloop, $callback
		984
		985	=item $w = $loop->embed ($otherloop, $callback)
		986
		987	=item $w = $loop->embed_ns ($otherloop, $callback)
		988
		989	Call the callback when the embedded event loop (C<$otherloop>) has any
		990	I/O activity. The C<$callback> should alwas be specified as C<undef> in
		991	this version of EV, which means the embedded event loop will be managed
		992	automatically.
		993
		994	The C<embed_ns> variant doesn't start (activate) the newly created watcher.
		995
		996	=back
		997
		998	=head3 ASYNC WATCHERS - how to wake up another event loop
		999
		1000	Async watchers are provided by EV, but have little use in perl directly, as perl
		1001	neither supports threads nor direct access to signal handlers or other
		1002	contexts where they could be of value.
		1003
		1004	It is, however, possible to use them from the XS level.
		1005
		1006	Please see the libev documentation for further details.
		1007
		1008	=over 4
		1009
		1010	=item $w = EV::async $callback
		1011
		1012	=item $w = EV::async_ns $callback
		1013
		1014	=item $w->send
		1015
		1016	=item $bool = $w->async_pending
		1017
		1018	=back
		1019
		1020
		1021	=head1 PERL SIGNALS
		1022
		1023	While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour
		1024	with EV is as the same as any other C library: Perl-signals will only be
		1025	handled when Perl runs, which means your signal handler might be invoked
		1026	only the next time an event callback is invoked.
		1027
		1028	The solution is to use EV signal watchers (see C<EV::signal>), which will
		1029	ensure proper operations with regards to other event watchers.
		1030
		1031	If you cannot do this for whatever reason, you can also force a watcher
		1032	to be called on every event loop iteration by installing a C<EV::check>
		1033	watcher:
		1034
		1035	my $async_check = EV::check sub { };
		1036
		1037	This ensures that perl gets into control for a short time to handle any
		1038	pending signals, and also ensures (slightly) slower overall operation.
717		1039
718	=head1 THREADS	1040	=head1 THREADS
719		1041
720	Threads are not supported by this module in any way. Perl pseudo-threads	1042	Threads are not supported by this module in any way. Perl pseudo-threads
721	is evil stuff and must die. As soon as Perl gains real threads I will work	1043	is evil stuff and must die. As soon as Perl gains real threads I will work
…		…
743	our $DIED = sub {	1065	our $DIED = sub {
744	warn "EV: error in callback (ignoring): $@";	1066	warn "EV: error in callback (ignoring): $@";
745	};	1067	};
746		1068
747	default_loop	1069	default_loop
748	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	1070	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
749		1071
750	1;	1072	1;
751		1073
752	=head1 SEE ALSO	1074	=head1 SEE ALSO
753		1075
754	L<EV::DNS>.	1076	L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as
		1077	event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
		1078	coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
		1079	event-loop agnostic and portable event driven programming.
755		1080
756	=head1 AUTHOR	1081	=head1 AUTHOR
757		1082
758	Marc Lehmann <schmorp@schmorp.de>	1083	Marc Lehmann <schmorp@schmorp.de>
759	http://home.schmorp.de/	1084	http://home.schmorp.de/
760		1085
761	=cut	1086	=cut
762		1087

Diff Legend

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

Comparing EV/EV.pm (file contents): Revision 1.56 by root, Tue Nov 27 10:59:10 2007 UTC vs. Revision 1.100 by root, Tue Jul 8 18:53:11 2008 UTC

Diff Legend

Comparing EV/EV.pm (file contents):
Revision 1.56 by root, Tue Nov 27 10:59:10 2007 UTC vs.
Revision 1.100 by root, Tue Jul 8 18:53:11 2008 UTC