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

Comparing EV/EV.pm (file contents):
Revision 1.55 by root, Tue Nov 27 08:11:52 2007 UTC vs.
Revision 1.117 by root, Tue Jul 14 00:09:59 2009 UTC

…		…
2		2
3	EV - perl interface to libev, a high performance full-featured event loop	3	EV - perl interface to libev, a high performance full-featured event loop
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	use EV;	7	use EV;
		8
		9	# TIMERS
		10
		11	my $w = EV::timer 2, 0, sub {
		12	warn "is called after 2s";
		13	};
		14
		15	my $w = EV::timer 2, 2, sub {
		16	warn "is called roughly every 2s (repeat = 2)";
		17	};
		18
		19	undef $w; # destroy event watcher again
		20
		21	my $w = EV::periodic 0, 60, 0, sub {
		22	warn "is called every minute, on the minute, exactly";
		23	};
		24
		25	# IO
		26
		27	my $w = EV::io *STDIN, EV::READ, sub {
		28	my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
		29	warn "stdin is readable, you entered: ", <STDIN>;
		30	};
		31
		32	# SIGNALS
		33
		34	my $w = EV::signal 'QUIT', sub {
		35	warn "sigquit received\n";
		36	};
		37
		38	# CHILD/PID STATUS CHANGES
8		39
9	# TIMERS	40	my $w = EV::child 666, 0, sub {
		41	my ($w, $revents) = @_;
		42	my $status = $w->rstatus;
		43	};
10		44
11	my $w = EV::timer 2, 0, sub {
12	warn "is called after 2s";
13	};
14
15	my $w = EV::timer 2, 2, sub {
16	warn "is called roughly every 2s (repeat = 2)";
17	};
18
19	undef $w; # destroy event watcher again
20
21	my $w = EV::periodic 0, 60, 0, sub {
22	warn "is called every minute, on the minute, exactly";
23	};
24
25	# IO
26
27	my $w = EV::io *STDIN, EV::READ, sub {
28	my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
29	warn "stdin is readable, you entered: ", <STDIN>;
30	};
31
32	# SIGNALS
33
34	my $w = EV::signal 'QUIT', sub {
35	warn "sigquit received\n";
36	};
37
38	# CHILD/PID STATUS CHANGES
39
40	my $w = EV::child 666, sub {
41	my ($w, $revents) = @_;
42	my $status = $w->rstatus;
43	};
44
45	# STAT CHANGES	45	# STAT CHANGES
46	my $w = EV::stat "/etc/passwd", 10, sub {	46	my $w = EV::stat "/etc/passwd", 10, sub {
47	my ($w, $revents) = @_;	47	my ($w, $revents) = @_;
48	warn $w->path, " has changed somehow.\n";	48	warn $w->path, " has changed somehow.\n";
49	};	49	};
50		50
51	# MAINLOOP	51	# MAINLOOP
52	EV::loop; # loop until EV::unloop is called or all watchers stop	52	EV::loop; # loop until EV::unloop is called or all watchers stop
53	EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled	53	EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled
54	EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block	54	EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block
55		55
56	=head1 DESCRIPTION	56	=head1 DESCRIPTION
57		57
58	This module provides an interface to libev	58	This module provides an interface to libev
59	(L<http://software.schmorp.de/pkg/libev.html>). While the documentation	59	(L<http://software.schmorp.de/pkg/libev.html>). While the documentation
60	below is comprehensive, one might also consult the documentation of libev	60	below is comprehensive, one might also consult the documentation of
61	itself (L<http://cvs.schmorp.de/libev/ev.html>) for more subtle details on	61	libev itself (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod> or
62	watcher semantics or some discussion on the available backends, or how to	62	F<perldoc EV::libev>) for more subtle details on watcher semantics or some
63	force a specific backend with C<LIBEV_FLAGS>.	63	discussion on the available backends, or how to force a specific backend
		64	with C<LIBEV_FLAGS>, or just about in any case because it has much more
		65	detailed information.
		66
		67	This module is very fast and scalable. It is actually so fast that you
		68	can use it through the L<AnyEvent> module, stay portable to other event
		69	loops (if you don't rely on any watcher types not available through it)
		70	and still be faster than with any other event loop currently supported in
		71	Perl.
		72
		73	=head2 MODULE EXPORTS
		74
		75	This module does not export any symbols.
64		76
65	=cut	77	=cut
66		78
67	package EV;	79	package EV;
68		80
69	use strict;	81	use common::sense;
70		82
71	BEGIN {	83	BEGIN {
72	our $VERSION = '1.4';	84	our $VERSION = '3.6';
73	use XSLoader;	85	use XSLoader;
74	XSLoader::load "EV", $VERSION;	86	XSLoader::load "EV", $VERSION;
75	}	87	}
76		88
77	@EV::IO::ISA =	89	@EV::IO::ISA =
78	@EV::Timer::ISA =	90	@EV::Timer::ISA =
79	@EV::Periodic::ISA =	91	@EV::Periodic::ISA =
80	@EV::Signal::ISA =	92	@EV::Signal::ISA =
		93	@EV::Child::ISA =
		94	@EV::Stat::ISA =
81	@EV::Idle::ISA =	95	@EV::Idle::ISA =
82	@EV::Prepare::ISA =	96	@EV::Prepare::ISA =
83	@EV::Check::ISA =	97	@EV::Check::ISA =
84	@EV::Child::ISA =
85	@EV::Embed::ISA =	98	@EV::Embed::ISA =
86	@EV::Stat::ISA = "EV::Watcher";	99	@EV::Fork::ISA =
		100	@EV::Async::ISA =
		101	"EV::Watcher";
		102
		103	@EV::Loop::Default::ISA = "EV::Loop";
		104
		105	=head1 EVENT LOOPS
		106
		107	EV supports multiple event loops: There is a single "default event loop"
		108	that can handle everything including signals and child watchers, and any
		109	number of "dynamic event loops" that can use different backends (with
		110	various limitations), but no child and signal watchers.
		111
		112	You do not have to do anything to create the default event loop: When
		113	the module is loaded a suitable backend is selected on the premise of
		114	selecting a working backend (which for example rules out kqueue on most
		115	BSDs). Modules should, unless they have "special needs" always use the
		116	default loop as this is fastest (perl-wise), best supported by other
		117	modules (e.g. AnyEvent or Coro) and most portable event loop.
		118
		119	For specific programs you can create additional event loops dynamically.
		120
		121	If you want to take advantage of kqueue (which often works properly for
		122	sockets only) even though the default loop doesn't enable it, you can
		123	I<embed> a kqueue loop into the default loop: running the default loop
		124	will then also service the kqueue loop to some extent. See the example in
		125	the section about embed watchers for an example on how to achieve that.
		126
		127	=over 4
		128
		129	=item $loop = new EV::Loop [$flags]
		130
		131	Create a new event loop as per the specified flags. Please refer to
		132	the C<ev_loop_new ()> function description in the libev documentation
		133	(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>,
		134	or locally-installed as F<EV::libev> manpage) for more info.
		135
		136	The loop will automatically be destroyed when it is no longer referenced
		137	by any watcher and the loop object goes out of scope.
		138
		139	If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK>
		140	is recommended, as only the default event loop is protected by this
		141	module. If you I<are> embedding this loop in the default loop, this is not
		142	necessary, as C<EV::embed> automatically does the right thing on fork.
		143
		144	=item $loop->loop_fork
		145
		146	Must be called after a fork in the child, before entering or continuing
		147	the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
		148	this function automatically, at some performance loss (refer to the libev
		149	documentation).
		150
		151	=item $loop->loop_verify
		152
		153	Calls C<ev_verify> to make internal consistency checks (for debugging
		154	libev) and abort the program if any data structures were found to be
		155	corrupted.
		156
		157	=item $loop = EV::default_loop [$flags]
		158
		159	Return the default loop (which is a singleton object). Since this module
		160	already creates the default loop with default flags, specifying flags here
		161	will not have any effect unless you destroy the default loop first, which
		162	isn't supported. So in short: don't do it, and if you break it, you get to
		163	keep the pieces.
		164
		165	=back
		166
87		167
88	=head1 BASIC INTERFACE	168	=head1 BASIC INTERFACE
89		169
90	=over 4	170	=over 4
91		171
92	=item $EV::DIED	172	=item $EV::DIED
93		173
94	Must contain a reference to a function that is called when a callback	174	Must contain a reference to a function that is called when a callback
95	throws an exception (with $@ containing thr error). The default prints an	175	throws an exception (with $@ containing the error). The default prints an
96	informative message and continues.	176	informative message and continues.
97		177
98	If this callback throws an exception it will be silently ignored.	178	If this callback throws an exception it will be silently ignored.
99		179
		180	=item $flags = EV::supported_backends
		181
		182	=item $flags = EV::recommended_backends
		183
		184	=item $flags = EV::embeddable_backends
		185
		186	Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this
		187	instance of EV, the set of recommended backends (supposed to be good) for
		188	this platform and the set of embeddable backends (see EMBED WATCHERS).
		189
		190	=item EV::sleep $seconds
		191
		192	Block the process for the given number of (fractional) seconds.
		193
100	=item $time = EV::time	194	=item $time = EV::time
101		195
102	Returns the current time in (fractional) seconds since the epoch.	196	Returns the current time in (fractional) seconds since the epoch.
103		197
104	=item $time = EV::now	198	=item $time = EV::now
105		199
		200	=item $time = $loop->now
		201
106	Returns the time the last event loop iteration has been started. This	202	Returns the time the last event loop iteration has been started. This
107	is the time that (relative) timers are based on, and refering to it is	203	is the time that (relative) timers are based on, and referring to it is
108	usually faster then calling EV::time.	204	usually faster then calling EV::time.
109		205
110	=item $method = EV::method	206	=item EV::now_update
111		207
		208	=item $loop->now_update
		209
		210	Establishes the current time by querying the kernel, updating the time
		211	returned by C<EV::now> in the progress. This is a costly operation and
		212	is usually done automatically within C<EV::loop>.
		213
		214	This function is rarely useful, but when some event callback runs for a
		215	very long time without entering the event loop, updating libev's idea of
		216	the current time is a good idea.
		217
		218	=item EV::suspend
		219
		220	=item $loop->suspend
		221
		222	=item EV::resume
		223
		224	=item $loop->resume
		225
		226	These two functions suspend and resume a loop, for use when the loop is
		227	not used for a while and timeouts should not be processed.
		228
		229	A typical use case would be an interactive program such as a game: When
		230	the user presses C<^Z> to suspend the game and resumes it an hour later it
		231	would be best to handle timeouts as if no time had actually passed while
		232	the program was suspended. This can be achieved by calling C<suspend>
		233	in your C<SIGTSTP> handler, sending yourself a C<SIGSTOP> and calling
		234	C<resume> directly afterwards to resume timer processing.
		235
		236	Effectively, all C<timer> watchers will be delayed by the time spend
		237	between C<suspend> and C<resume>, and all C<periodic> watchers
		238	will be rescheduled (that is, they will lose any events that would have
		239	occured while suspended).
		240
		241	After calling C<suspend> you B<must not> call I<any> function on the given
		242	loop other than C<resume>, and you B<must not> call C<resume>
		243	without a previous call to C<suspend>.
		244
		245	Calling C<suspend>/C<resume> has the side effect of updating the event
		246	loop time (see C<now_update>).
		247
		248	=item $backend = EV::backend
		249
		250	=item $backend = $loop->backend
		251
112	Returns an integer describing the backend used by libev (EV::METHOD_SELECT	252	Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
113	or EV::METHOD_EPOLL).	253	or EV::BACKEND_EPOLL).
114		254
115	=item EV::loop [$flags]	255	=item EV::loop [$flags]
		256
		257	=item $loop->loop ([$flags])
116		258
117	Begin checking for events and calling callbacks. It returns when a	259	Begin checking for events and calling callbacks. It returns when a
118	callback calls EV::unloop.	260	callback calls EV::unloop.
119		261
120	The $flags argument can be one of the following:	262	The $flags argument can be one of the following:
…		…
123	EV::LOOP_ONESHOT block at most once (wait, but do not loop)	265	EV::LOOP_ONESHOT block at most once (wait, but do not loop)
124	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)	266	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
125		267
126	=item EV::unloop [$how]	268	=item EV::unloop [$how]
127		269
		270	=item $loop->unloop ([$how])
		271
128	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the	272	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the
129	innermost call to EV::loop return.	273	innermost call to EV::loop return.
130		274
131	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as	275	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as
132	fast as possible.	276	fast as possible.
133		277
		278	=item $count = EV::loop_count
		279
		280	=item $count = $loop->loop_count
		281
		282	Return the number of times the event loop has polled for new
		283	events. Sometimes useful as a generation counter.
		284
134	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)	285	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
		286
		287	=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
135		288
136	This function rolls together an I/O and a timer watcher for a single	289	This function rolls together an I/O and a timer watcher for a single
137	one-shot event without the need for managing a watcher object.	290	one-shot event without the need for managing a watcher object.
138		291
139	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>	292	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>
…		…
145	If timeout is C<undef> or negative, then there will be no	298	If timeout is C<undef> or negative, then there will be no
146	timeout. Otherwise a EV::timer with this value will be started.	299	timeout. Otherwise a EV::timer with this value will be started.
147		300
148	When an error occurs or either the timeout or I/O watcher triggers, then	301	When an error occurs or either the timeout or I/O watcher triggers, then
149	the callback will be called with the received event set (in general	302	the callback will be called with the received event set (in general
150	you can expect it to be a combination of C<EV:ERROR>, C<EV::READ>,	303	you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
151	C<EV::WRITE> and C<EV::TIMEOUT>).	304	C<EV::WRITE> and C<EV::TIMEOUT>).
152		305
153	EV::once doesn't return anything: the watchers stay active till either	306	EV::once doesn't return anything: the watchers stay active till either
154	of them triggers, then they will be stopped and freed, and the callback	307	of them triggers, then they will be stopped and freed, and the callback
155	invoked.	308	invoked.
156		309
157	=back	310	=item EV::feed_fd_event ($fd, $revents)
158		311
		312	=item $loop->feed_fd_event ($fd, $revents)
		313
		314	Feed an event on a file descriptor into EV. EV will react to this call as
		315	if the readyness notifications specified by C<$revents> (a combination of
		316	C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
		317
		318	=item EV::feed_signal_event ($signal)
		319
		320	Feed a signal event into EV. EV will react to this call as if the signal
		321	specified by C<$signal> had occured.
		322
		323	=item EV::set_io_collect_interval $time
		324
		325	=item $loop->set_io_collect_interval ($time)
		326
		327	=item EV::set_timeout_collect_interval $time
		328
		329	=item $loop->set_timeout_collect_interval ($time)
		330
		331	These advanced functions set the minimum block interval when polling for I/O events and the minimum
		332	wait interval for timer events. See the libev documentation at
		333	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP>
		334	(locally installed as F<EV::libev>) for a more detailed discussion.
		335
		336	=back
		337
		338
159	=head2 WATCHER OBJECTS	339	=head1 WATCHER OBJECTS
160		340
161	A watcher is an object that gets created to record your interest in some	341	A watcher is an object that gets created to record your interest in some
162	event. For instance, if you want to wait for STDIN to become readable, you	342	event. For instance, if you want to wait for STDIN to become readable, you
163	would create an EV::io watcher for that:	343	would create an EV::io watcher for that:
164		344
165	my $watcher = EV::io *STDIN, EV::READ, sub {	345	my $watcher = EV::io *STDIN, EV::READ, sub {
166	my ($watcher, $revents) = @_;	346	my ($watcher, $revents) = @_;
167	warn "yeah, STDIN should not be readable without blocking!\n"	347	warn "yeah, STDIN should now be readable without blocking!\n"
168	};	348	};
169		349
170	All watchers can be active (waiting for events) or inactive (paused). Only	350	All watchers can be active (waiting for events) or inactive (paused). Only
171	active watchers will have their callbacks invoked. All callbacks will be	351	active watchers will have their callbacks invoked. All callbacks will be
172	called with at least two arguments: the watcher and a bitmask of received	352	called with at least two arguments: the watcher and a bitmask of received
173	events.	353	events.
174		354
175	Each watcher type has its associated bit in revents, so you can use the	355	Each watcher type has its associated bit in revents, so you can use the
176	same callback for multiple watchers. The event mask is named after the	356	same callback for multiple watchers. The event mask is named after the
177	type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,	357	type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
178	EV::periodic sets EV::PERIODIC and so on, with the exception of IO events	358	EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events
179	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which	359	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which
180	uses EV::TIMEOUT).	360	uses EV::TIMEOUT).
181		361
182	In the rare case where one wants to create a watcher but not start it at	362	In the rare case where one wants to create a watcher but not start it at
183	the same time, each constructor has a variant with a trailing C<_ns> in	363	the same time, each constructor has a variant with a trailing C<_ns> in
…		…
205		385
206	=item $w->stop	386	=item $w->stop
207		387
208	Stop a watcher if it is active. Also clear any pending events (events that	388	Stop a watcher if it is active. Also clear any pending events (events that
209	have been received but that didn't yet result in a callback invocation),	389	have been received but that didn't yet result in a callback invocation),
210	regardless of wether the watcher was active or not.	390	regardless of whether the watcher was active or not.
211		391
212	=item $bool = $w->is_active	392	=item $bool = $w->is_active
213		393
214	Returns true if the watcher is active, false otherwise.	394	Returns true if the watcher is active, false otherwise.
215		395
…		…
245	The default priority of any newly-created watcher is 0.	425	The default priority of any newly-created watcher is 0.
246		426
247	Note that the priority semantics have not yet been fleshed out and are	427	Note that the priority semantics have not yet been fleshed out and are
248	subject to almost certain change.	428	subject to almost certain change.
249		429
250	=item $w->trigger ($revents)	430	=item $w->invoke ($revents)
251		431
252	Call the callback now with the given event mask.	432	Call the callback now with the given event mask.
		433
		434	=item $w->feed_event ($revents)
		435
		436	Feed some events on this watcher into EV. EV will react to this call as if
		437	the watcher had received the given C<$revents> mask.
		438
		439	=item $revents = $w->clear_pending
		440
		441	If the watcher is pending, this function clears its pending status and
		442	returns its C<$revents> bitset (as if its callback was invoked). If the
		443	watcher isn't pending it does nothing and returns C<0>.
253		444
254	=item $previous_state = $w->keepalive ($bool)	445	=item $previous_state = $w->keepalive ($bool)
255		446
256	Normally, C<EV::loop> will return when there are no active watchers	447	Normally, C<EV::loop> will return when there are no active watchers
257	(which is a "deadlock" because no progress can be made anymore). This is	448	(which is a "deadlock" because no progress can be made anymore). This is
258	convinient because it allows you to start your watchers (and your jobs),	449	convinient because it allows you to start your watchers (and your jobs),
259	call C<EV::loop> once and when it returns you know that all your jobs are	450	call C<EV::loop> once and when it returns you know that all your jobs are
260	finished (or they forgot to register some watchers for their task :).	451	finished (or they forgot to register some watchers for their task :).
261		452
262	Sometimes, however, this gets in your way, for example when you the module	453	Sometimes, however, this gets in your way, for example when the module
263	that calls C<EV::loop> (usually the main program) is not the same module	454	that calls C<EV::loop> (usually the main program) is not the same module
264	as a long-living watcher (for example a DNS client module written by	455	as a long-living watcher (for example a DNS client module written by
265	somebody else even). Then you might want any outstanding requests to be	456	somebody else even). Then you might want any outstanding requests to be
266	handled, but you would not want to keep C<EV::loop> from returning just	457	handled, but you would not want to keep C<EV::loop> from returning just
267	because you happen to have this long-running UDP port watcher.	458	because you happen to have this long-running UDP port watcher.
268		459
269	In this case you can clear the keepalive status, which means that even	460	In this case you can clear the keepalive status, which means that even
270	though your watcher is active, it won't keep C<EV::loop> from returning.	461	though your watcher is active, it won't keep C<EV::loop> from returning.
271		462
272	The initial value for keepalive is true (enabled), and you cna change it	463	The initial value for keepalive is true (enabled), and you can change it
273	any time.	464	any time.
274		465
275	Example: Register an IO watcher for some UDP socket but do not keep the	466	Example: Register an I/O watcher for some UDP socket but do not keep the
276	event loop from running just because of that watcher.	467	event loop from running just because of that watcher.
277		468
278	my $udp_socket = ...	469	my $udp_socket = ...
279	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };	470	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
280	$udp_watcher->keepalive (0);	471	$udp_watcher->keepalive (0);
281		472
282	=back	473	=item $loop = $w->loop
283		474
		475	Return the loop that this watcher is attached to.
284		476
		477	=back
		478
		479
285	=head2 WATCHER TYPES	480	=head1 WATCHER TYPES
286		481
287	Each of the following subsections describes a single watcher type.	482	Each of the following subsections describes a single watcher type.
288		483
289	=head3 IO WATCHERS - is this file descriptor readable or writable?	484	=head3 I/O WATCHERS - is this file descriptor readable or writable?
290		485
291	=over 4	486	=over 4
292		487
293	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	488	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
294		489
295	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback	490	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
		491
		492	=item $w = $loop->io ($fileno_or_fh, $eventmask, $callback)
		493
		494	=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
296		495
297	As long as the returned watcher object is alive, call the C<$callback>	496	As long as the returned watcher object is alive, call the C<$callback>
298	when at least one of events specified in C<$eventmask> occurs.	497	when at least one of events specified in C<$eventmask> occurs.
299		498
300	The $eventmask can be one or more of these constants ORed together:	499	The $eventmask can be one or more of these constants ORed together:
…		…
329	=over 4	528	=over 4
330		529
331	=item $w = EV::timer $after, $repeat, $callback	530	=item $w = EV::timer $after, $repeat, $callback
332		531
333	=item $w = EV::timer_ns $after, $repeat, $callback	532	=item $w = EV::timer_ns $after, $repeat, $callback
		533
		534	=item $w = $loop->timer ($after, $repeat, $callback)
		535
		536	=item $w = $loop->timer_ns ($after, $repeat, $callback)
334		537
335	Calls the callback after C<$after> seconds (which may be fractional). If	538	Calls the callback after C<$after> seconds (which may be fractional). If
336	C<$repeat> is non-zero, the timer will be restarted (with the $repeat	539	C<$repeat> is non-zero, the timer will be restarted (with the $repeat
337	value as $after) after the callback returns.	540	value as $after) after the callback returns.
338		541
…		…
379	=over 4	582	=over 4
380		583
381	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback	584	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
382		585
383	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback	586	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
		587
		588	=item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
		589
		590	=item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback)
384		591
385	Similar to EV::timer, but is not based on relative timeouts but on	592	Similar to EV::timer, but is not based on relative timeouts but on
386	absolute times. Apart from creating "simple" timers that trigger "at" the	593	absolute times. Apart from creating "simple" timers that trigger "at" the
387	specified time, it can also be used for non-drifting absolute timers and	594	specified time, it can also be used for non-drifting absolute timers and
388	more complex, cron-like, setups that are not adversely affected by time	595	more complex, cron-like, setups that are not adversely affected by time
…		…
398	This time simply fires at the wallclock time C<$at> and doesn't repeat. It	605	This time simply fires at the wallclock time C<$at> and doesn't repeat. It
399	will not adjust when a time jump occurs, that is, if it is to be run	606	will not adjust when a time jump occurs, that is, if it is to be run
400	at January 1st 2011 then it will run when the system time reaches or	607	at January 1st 2011 then it will run when the system time reaches or
401	surpasses this time.	608	surpasses this time.
402		609
403	=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0)	610	=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
404		611
405	In this mode the watcher will always be scheduled to time out at the	612	In this mode the watcher will always be scheduled to time out at the
406	next C<$at + N * $interval> time (for some integer N) and then repeat,	613	next C<$at + N * $interval> time (for some integer N) and then repeat,
407	regardless of any time jumps.	614	regardless of any time jumps.
408		615
…		…
426	time the periodic watcher gets scheduled, the reschedule callback	633	time the periodic watcher gets scheduled, the reschedule callback
427	($reschedule_cb) will be called with the watcher as first, and the current	634	($reschedule_cb) will be called with the watcher as first, and the current
428	time as second argument.	635	time as second argument.
429		636
430	I<This callback MUST NOT stop or destroy this or any other periodic	637	I<This callback MUST NOT stop or destroy this or any other periodic
431	watcher, ever>. If you need to stop it, return 1e30 and stop it	638	watcher, ever, and MUST NOT call any event loop functions or methods>. If
432	afterwards.	639	you need to stop it, return 1e30 and stop it afterwards. You may create
		640	and start a C<EV::prepare> watcher for this task.
433		641
434	It must return the next time to trigger, based on the passed time value	642	It must return the next time to trigger, based on the passed time value
435	(that is, the lowest time value larger than to the second argument). It	643	(that is, the lowest time value larger than or equal to to the second
436	will usually be called just before the callback will be triggered, but	644	argument). It will usually be called just before the callback will be
437	might be called at other times, too.	645	triggered, but might be called at other times, too.
438		646
439	This can be used to create very complex timers, such as a timer that	647	This can be used to create very complex timers, such as a timer that
440	triggers on each midnight, local time (actually 24 hours after the last	648	triggers on each midnight, local time (actually 24 hours after the last
441	midnight, to keep the example simple. If you know a way to do it correctly	649	midnight, to keep the example simple. If you know a way to do it correctly
442	in about the same space (without requiring elaborate modules), drop me a	650	in about the same space (without requiring elaborate modules), drop me a
…		…
463		671
464	=item $w->again	672	=item $w->again
465		673
466	Simply stops and starts the watcher again.	674	Simply stops and starts the watcher again.
467		675
		676	=item $time = $w->at
		677
		678	Return the time that the watcher is expected to trigger next.
		679
468	=back	680	=back
469		681
470		682
471	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!	683	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
472		684
…		…
505		717
506	=head3 CHILD WATCHERS - watch out for process status changes	718	=head3 CHILD WATCHERS - watch out for process status changes
507		719
508	=over 4	720	=over 4
509		721
510	=item $w = EV::child $pid, $callback	722	=item $w = EV::child $pid, $trace, $callback
511		723
512	=item $w = EV::child_ns $pid, $callback	724	=item $w = EV::child_ns $pid, $trace, $callback
513		725
		726	=item $w = $loop->child ($pid, $trace, $callback)
		727
		728	=item $w = $loop->child_ns ($pid, $trace, $callback)
		729
514	Call the callback when a status change for pid C<$pid> (or any pid if	730	Call the callback when a status change for pid C<$pid> (or any pid
515	C<$pid> is 0) has been received. More precisely: when the process receives	731	if C<$pid> is 0) has been received (a status change happens when the
		732	process terminates or is killed, or, when trace is true, additionally when
		733	it is stopped or continued). More precisely: when the process receives
516	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all	734	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
517	changed/zombie children and call the callback.	735	changed/zombie children and call the callback.
518		736
519	It is valid (and fully supported) to install a child watcher after a child	737	It is valid (and fully supported) to install a child watcher after a child
520	has exited but before the event loop has started its next iteration (for	738	has exited but before the event loop has started its next iteration (for
…		…
527	You can have as many pid watchers per pid as you want, they will all be	745	You can have as many pid watchers per pid as you want, they will all be
528	called.	746	called.
529		747
530	The C<child_ns> variant doesn't start (activate) the newly created watcher.	748	The C<child_ns> variant doesn't start (activate) the newly created watcher.
531		749
532	=item $w->set ($pid)	750	=item $w->set ($pid, $trace)
533		751
534	Reconfigures the watcher, see the constructor above for details. Can be called at	752	Reconfigures the watcher, see the constructor above for details. Can be called at
535	any time.	753	any time.
536		754
537	=item $current_pid = $w->pid	755	=item $current_pid = $w->pid
538		756
539	=item $old_pid = $w->pid ($new_pid)
540
541	Returns the previously set process id and optionally set a new one.	757	Returns the previously set process id and optionally set a new one.
542		758
543	=item $exit_status = $w->rstatus	759	=item $exit_status = $w->rstatus
544		760
545	Return the exit/wait status (as returned by waitpid, see the waitpid entry	761	Return the exit/wait status (as returned by waitpid, see the waitpid entry
…		…
551	watcher for all pids).	767	watcher for all pids).
552		768
553	=back	769	=back
554		770
555		771
		772	=head3 STAT WATCHERS - did the file attributes just change?
		773
		774	=over 4
		775
		776	=item $w = EV::stat $path, $interval, $callback
		777
		778	=item $w = EV::stat_ns $path, $interval, $callback
		779
		780	=item $w = $loop->stat ($path, $interval, $callback)
		781
		782	=item $w = $loop->stat_ns ($path, $interval, $callback)
		783
		784	Call the callback when a file status change has been detected on
		785	C<$path>. The C<$path> does not need to exist, changing from "path exists"
		786	to "path does not exist" is a status change like any other.
		787
		788	The C<$interval> is a recommended polling interval for systems where
		789	OS-supported change notifications don't exist or are not supported. If
		790	you use C<0> then an unspecified default is used (which is highly
		791	recommended!), which is to be expected to be around five seconds usually.
		792
		793	This watcher type is not meant for massive numbers of stat watchers,
		794	as even with OS-supported change notifications, this can be
		795	resource-intensive.
		796
		797	The C<stat_ns> variant doesn't start (activate) the newly created watcher.
		798
		799	=item ... = $w->stat
		800
		801	This call is very similar to the perl C<stat> built-in: It stats (using
		802	C<lstat>) the path specified in the watcher and sets perls stat cache (as
		803	well as EV's idea of the current stat values) to the values found.
		804
		805	In scalar context, a boolean is return indicating success or failure of
		806	the stat. In list context, the same 13-value list as with stat is returned
		807	(except that the blksize and blocks fields are not reliable).
		808
		809	In the case of an error, errno is set to C<ENOENT> (regardless of the
		810	actual error value) and the C<nlink> value is forced to zero (if the stat
		811	was successful then nlink is guaranteed to be non-zero).
		812
		813	See also the next two entries for more info.
		814
		815	=item ... = $w->attr
		816
		817	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		818	the values most recently detected by EV. See the next entry for more info.
		819
		820	=item ... = $w->prev
		821
		822	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		823	the previous set of values, before the change.
		824
		825	That is, when the watcher callback is invoked, C<< $w->prev >> will be set
		826	to the values found I<before> a change was detected, while C<< $w->attr >>
		827	returns the values found leading to the change detection. The difference (if any)
		828	between C<prev> and C<attr> is what triggered the callback.
		829
		830	If you did something to the filesystem object and do not want to trigger
		831	yet another change, you can call C<stat> to update EV's idea of what the
		832	current attributes are.
		833
		834	=item $w->set ($path, $interval)
		835
		836	Reconfigures the watcher, see the constructor above for details. Can be
		837	called at any time.
		838
		839	=item $current_path = $w->path
		840
		841	=item $old_path = $w->path ($new_path)
		842
		843	Returns the previously set path and optionally set a new one.
		844
		845	=item $current_interval = $w->interval
		846
		847	=item $old_interval = $w->interval ($new_interval)
		848
		849	Returns the previously set interval and optionally set a new one. Can be
		850	used to query the actual interval used.
		851
		852	=back
		853
		854
556	=head3 IDLE WATCHERS - when you've got nothing better to do...	855	=head3 IDLE WATCHERS - when you've got nothing better to do...
557		856
558	=over 4	857	=over 4
559		858
560	=item $w = EV::idle $callback	859	=item $w = EV::idle $callback
561		860
562	=item $w = EV::idle_ns $callback	861	=item $w = EV::idle_ns $callback
563		862
564	Call the callback when there are no pending io, timer/periodic, signal or	863	=item $w = $loop->idle ($callback)
565	child events, i.e. when the process is idle.	864
		865	=item $w = $loop->idle_ns ($callback)
		866
		867	Call the callback when there are no other pending watchers of the same or
		868	higher priority (excluding check, prepare and other idle watchers of the
		869	same or lower priority, of course). They are called idle watchers because
		870	when the watcher is the highest priority pending event in the process, the
		871	process is considered to be idle at that priority.
		872
		873	If you want a watcher that is only ever called when I<no> other events are
		874	outstanding you have to set the priority to C<EV::MINPRI>.
566		875
567	The process will not block as long as any idle watchers are active, and	876	The process will not block as long as any idle watchers are active, and
568	they will be called repeatedly until stopped.	877	they will be called repeatedly until stopped.
569		878
		879	For example, if you have idle watchers at priority C<0> and C<1>, and
		880	an I/O watcher at priority C<0>, then the idle watcher at priority C<1>
		881	and the I/O watcher will always run when ready. Only when the idle watcher
		882	at priority C<1> is stopped and the I/O watcher at priority C<0> is not
		883	pending with the C<0>-priority idle watcher be invoked.
		884
570	The C<idle_ns> variant doesn't start (activate) the newly created watcher.	885	The C<idle_ns> variant doesn't start (activate) the newly created watcher.
571		886
572	=back	887	=back
573		888
574		889
…		…
577	=over 4	892	=over 4
578		893
579	=item $w = EV::prepare $callback	894	=item $w = EV::prepare $callback
580		895
581	=item $w = EV::prepare_ns $callback	896	=item $w = EV::prepare_ns $callback
		897
		898	=item $w = $loop->prepare ($callback)
		899
		900	=item $w = $loop->prepare_ns ($callback)
582		901
583	Call the callback just before the process would block. You can still	902	Call the callback just before the process would block. You can still
584	create/modify any watchers at this point.	903	create/modify any watchers at this point.
585		904
586	See the EV::check watcher, below, for explanations and an example.	905	See the EV::check watcher, below, for explanations and an example.
…		…
595	=over 4	914	=over 4
596		915
597	=item $w = EV::check $callback	916	=item $w = EV::check $callback
598		917
599	=item $w = EV::check_ns $callback	918	=item $w = EV::check_ns $callback
		919
		920	=item $w = $loop->check ($callback)
		921
		922	=item $w = $loop->check_ns ($callback)
600		923
601	Call the callback just after the process wakes up again (after it has	924	Call the callback just after the process wakes up again (after it has
602	gathered events), but before any other callbacks have been invoked.	925	gathered events), but before any other callbacks have been invoked.
603		926
604	This is used to integrate other event-based software into the EV	927	This is used to integrate other event-based software into the EV
…		…
614	or return;	937	or return;
615		938
616	# make the dispatcher handle any outstanding stuff	939	# make the dispatcher handle any outstanding stuff
617	... not shown	940	... not shown
618		941
619	# create an IO watcher for each and every socket	942	# create an I/O watcher for each and every socket
620	@snmp_watcher = (	943	@snmp_watcher = (
621	(map { EV::io $_, EV::READ, sub { } }	944	(map { EV::io $_, EV::READ, sub { } }
622	keys %{ $dispatcher->{_descriptors} }),	945	keys %{ $dispatcher->{_descriptors} }),
623		946
624	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]	947	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
…		…
639	# make the dispatcher handle any new stuff	962	# make the dispatcher handle any new stuff
640	... not shown	963	... not shown
641	};	964	};
642		965
643	The callbacks of the created watchers will not be called as the watchers	966	The callbacks of the created watchers will not be called as the watchers
644	are destroyed before this cna happen (remember EV::check gets called	967	are destroyed before this can happen (remember EV::check gets called
645	first).	968	first).
646		969
647	The C<check_ns> variant doesn't start (activate) the newly created watcher.	970	The C<check_ns> variant doesn't start (activate) the newly created watcher.
648		971
649	=back	972	=back
650		973
651	=head3 STAT WATCHERS - did the file attributes just change?
652		974
653	=over 4	975	=head3 FORK WATCHERS - the audacity to resume the event loop after a fork
654		976
655	=item $w = EV::stat $path, $interval, $callback	977	Fork watchers are called when a C<fork ()> was detected. The invocation
		978	is done before the event loop blocks next and before C<check> watchers
		979	are being called, and only in the child after the fork.
656		980
657	=item $w = EV::stat_ns $path, $interval, $callback	981	=over 4
658		982
659	Call the callback when a file status change has been detected on	983	=item $w = EV::fork $callback
660	C<$path>. The C<$path> does not need to exist, changing from "path exists"
661	to "path does not exist" is a status change like any other.
662		984
663	The C<$interval> is a recommended polling interval for systems where	985	=item $w = EV::fork_ns $callback
664	OS-supported change notifications don't exist or are not supported. If
665	you use C<0> then an unspecified default is used (which is highly
666	recommended!), which is to be expected to be around five seconds usually.
667		986
668	This watcher type is not meant for massive numbers of stat watchers,	987	=item $w = $loop->fork ($callback)
669	as even with OS-supported change notifications, this can be
670	resource-intensive.
671		988
		989	=item $w = $loop->fork_ns ($callback)
		990
		991	Call the callback before the event loop is resumed in the child process
		992	after a fork.
		993
672	The C<stat_ns> variant doesn't start (activate) the newly created watcher.	994	The C<fork_ns> variant doesn't start (activate) the newly created watcher.
673		995
674	=item $w->set ($path, $interval)
675
676	Reconfigures the watcher, see the constructor above for details. Can be
677	called at any time.
678
679	=item $current_path = $w->path
680
681	=item $old_path = $w->path ($new_path)
682
683	Returns the previously set path and optionally set a new one.
684
685	=item $current_interval = $w->interval
686
687	=item $old_interval = $w->interval ($new_interval)
688
689	Returns the previously set interval and optionally set a new one. Can be
690	used to query the actual interval used.
691
692	=back	996	=back
693		997
694		998
		999	=head3 EMBED WATCHERS - when one backend isn't enough...
		1000
		1001	This is a rather advanced watcher type that lets you embed one event loop
		1002	into another (currently only IO events are supported in the embedded
		1003	loop, other types of watchers might be handled in a delayed or incorrect
		1004	fashion and must not be used).
		1005
		1006	See the libev documentation at
		1007	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
		1008	(locally installed as F<EV::libev>) for more details.
		1009
		1010	In short, this watcher is most useful on BSD systems without working
		1011	kqueue to still be able to handle a large number of sockets:
		1012
		1013	my $socket_loop;
		1014
		1015	# check wether we use SELECT or POLL _and_ KQUEUE is supported
		1016	if (
		1017	(EV::backend & (EV::BACKEND_POLL \| EV::BACKEND_SELECT))
		1018	&& (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
		1019	) {
		1020	# use kqueue for sockets
		1021	$socket_loop = new EV::Loop EV::BACKEND_KQUEUE \| EV::FLAG_NOENV;
		1022	}
		1023
		1024	# use the default loop otherwise
		1025	$socket_loop \|\|= EV::default_loop;
		1026
		1027	=over 4
		1028
		1029	=item $w = EV::embed $otherloop[, $callback]
		1030
		1031	=item $w = EV::embed_ns $otherloop[, $callback]
		1032
		1033	=item $w = $loop->embed ($otherloop[, $callback])
		1034
		1035	=item $w = $loop->embed_ns ($otherloop[, $callback])
		1036
		1037	Call the callback when the embedded event loop (C<$otherloop>) has any
		1038	I/O activity. The C<$callback> is optional: if it is missing, then the
		1039	embedded event loop will be managed automatically (which is recommended),
		1040	otherwise you have to invoke C<sweep> yourself.
		1041
		1042	The C<embed_ns> variant doesn't start (activate) the newly created watcher.
		1043
		1044	=back
		1045
		1046	=head3 ASYNC WATCHERS - how to wake up another event loop
		1047
		1048	Async watchers are provided by EV, but have little use in perl directly,
		1049	as perl neither supports threads running in parallel nor direct access to
		1050	signal handlers or other contexts where they could be of value.
		1051
		1052	It is, however, possible to use them from the XS level.
		1053
		1054	Please see the libev documentation for further details.
		1055
		1056	=over 4
		1057
		1058	=item $w = EV::async $callback
		1059
		1060	=item $w = EV::async_ns $callback
		1061
		1062	=item $w->send
		1063
		1064	=item $bool = $w->async_pending
		1065
		1066	=back
		1067
		1068
		1069	=head1 PERL SIGNALS
		1070
		1071	While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour
		1072	with EV is as the same as any other C library: Perl-signals will only be
		1073	handled when Perl runs, which means your signal handler might be invoked
		1074	only the next time an event callback is invoked.
		1075
		1076	The solution is to use EV signal watchers (see C<EV::signal>), which will
		1077	ensure proper operations with regards to other event watchers.
		1078
		1079	If you cannot do this for whatever reason, you can also force a watcher
		1080	to be called on every event loop iteration by installing a C<EV::check>
		1081	watcher:
		1082
		1083	my $async_check = EV::check sub { };
		1084
		1085	This ensures that perl gets into control for a short time to handle any
		1086	pending signals, and also ensures (slightly) slower overall operation.
		1087
695	=head1 THREADS	1088	=head1 ITHREADS
696		1089
697	Threads are not supported by this module in any way. Perl pseudo-threads	1090	Ithreads are not supported by this module in any way. Perl pseudo-threads
698	is evil stuff and must die. As soon as Perl gains real threads I will work	1091	is evil stuff and must die. Real threads as provided by Coro are fully
699	on thread support for it.	1092	supported (and enhanced support is available via L<Coro::EV>).
700		1093
701	=head1 FORK	1094	=head1 FORK
702		1095
703	Most of the "improved" event delivering mechanisms of modern operating	1096	Most of the "improved" event delivering mechanisms of modern operating
704	systems have quite a few problems with fork(2) (to put it bluntly: it is	1097	systems have quite a few problems with fork(2) (to put it bluntly: it is
…		…
720	our $DIED = sub {	1113	our $DIED = sub {
721	warn "EV: error in callback (ignoring): $@";	1114	warn "EV: error in callback (ignoring): $@";
722	};	1115	};
723		1116
724	default_loop	1117	default_loop
725	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	1118	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
726		1119
727	1;	1120	1;
728		1121
729	=head1 SEE ALSO	1122	=head1 SEE ALSO
730		1123
731	L<EV::DNS>.	1124	L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as
		1125	event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
		1126	coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
		1127	event-loop agnostic and portable event driven programming.
732		1128
733	=head1 AUTHOR	1129	=head1 AUTHOR
734		1130
735	Marc Lehmann <schmorp@schmorp.de>	1131	Marc Lehmann <schmorp@schmorp.de>
736	http://home.schmorp.de/	1132	http://home.schmorp.de/
737		1133
738	=cut	1134	=cut
739		1135

Diff Legend

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

Comparing EV/EV.pm (file contents): Revision 1.55 by root, Tue Nov 27 08:11:52 2007 UTC vs. Revision 1.117 by root, Tue Jul 14 00:09:59 2009 UTC

Diff Legend

Comparing EV/EV.pm (file contents):
Revision 1.55 by root, Tue Nov 27 08:11:52 2007 UTC vs.
Revision 1.117 by root, Tue Jul 14 00:09:59 2009 UTC