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

Comparing EV/EV.pm (file contents):
Revision 1.58 by root, Wed Nov 28 19:22:16 2007 UTC vs.
Revision 1.118 by root, Tue Jul 14 20:31:21 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 = '1.5';	84	our $VERSION = '3.7';
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 =
…		…
83	@EV::Idle::ISA =	95	@EV::Idle::ISA =
84	@EV::Prepare::ISA =	96	@EV::Prepare::ISA =
85	@EV::Check::ISA =	97	@EV::Check::ISA =
86	@EV::Embed::ISA =	98	@EV::Embed::ISA =
87	@EV::Fork::ISA =	99	@EV::Fork::ISA =
		100	@EV::Async::ISA =
88	"EV::Watcher";	101	"EV::Watcher";
89		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
		167
90	=head1 BASIC INTERFACE	168	=head1 BASIC INTERFACE
91		169
92	=over 4	170	=over 4
93		171
94	=item $EV::DIED	172	=item $EV::DIED
95		173
96	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
97	throws an exception (with $@ containing thr error). The default prints an	175	throws an exception (with $@ containing the error). The default prints an
98	informative message and continues.	176	informative message and continues.
99		177
100	If this callback throws an exception it will be silently ignored.	178	If this callback throws an exception it will be silently ignored.
101		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
102	=item $time = EV::time	194	=item $time = EV::time
103		195
104	Returns the current time in (fractional) seconds since the epoch.	196	Returns the current time in (fractional) seconds since the epoch.
105		197
106	=item $time = EV::now	198	=item $time = EV::now
107		199
		200	=item $time = $loop->now
		201
108	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
109	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
110	usually faster then calling EV::time.	204	usually faster then calling EV::time.
111		205
112	=item $method = EV::method	206	=item EV::now_update
113		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 = $loop->backend
		251
114	Returns an integer describing the backend used by libev (EV::METHOD_SELECT	252	Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
115	or EV::METHOD_EPOLL).	253	or EV::BACKEND_EPOLL).
116		254
117	=item EV::loop [$flags]	255	=item EV::loop [$flags]
		256
		257	=item $loop->loop ([$flags])
118		258
119	Begin checking for events and calling callbacks. It returns when a	259	Begin checking for events and calling callbacks. It returns when a
120	callback calls EV::unloop.	260	callback calls EV::unloop.
121		261
122	The $flags argument can be one of the following:	262	The $flags argument can be one of the following:
…		…
125	EV::LOOP_ONESHOT block at most once (wait, but do not loop)	265	EV::LOOP_ONESHOT block at most once (wait, but do not loop)
126	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)	266	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
127		267
128	=item EV::unloop [$how]	268	=item EV::unloop [$how]
129		269
		270	=item $loop->unloop ([$how])
		271
130	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
131	innermost call to EV::loop return.	273	innermost call to EV::loop return.
132		274
133	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
134	fast as possible.	276	fast as possible.
135		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
136	=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))
137		288
138	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
139	one-shot event without the need for managing a watcher object.	290	one-shot event without the need for managing a watcher object.
140		291
141	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>
…		…
147	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
148	timeout. Otherwise a EV::timer with this value will be started.	299	timeout. Otherwise a EV::timer with this value will be started.
149		300
150	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
151	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
152	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>,
153	C<EV::WRITE> and C<EV::TIMEOUT>).	304	C<EV::WRITE> and C<EV::TIMEOUT>).
154		305
155	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
156	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
157	invoked.	308	invoked.
158		309
159	=back	310	=item EV::feed_fd_event ($fd, $revents)
160		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
161	=head2 WATCHER OBJECTS	339	=head1 WATCHER OBJECTS
162		340
163	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
164	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
165	would create an EV::io watcher for that:	343	would create an EV::io watcher for that:
166		344
167	my $watcher = EV::io *STDIN, EV::READ, sub {	345	my $watcher = EV::io *STDIN, EV::READ, sub {
168	my ($watcher, $revents) = @_;	346	my ($watcher, $revents) = @_;
169	warn "yeah, STDIN should not be readable without blocking!\n"	347	warn "yeah, STDIN should now be readable without blocking!\n"
170	};	348	};
171		349
172	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
173	active watchers will have their callbacks invoked. All callbacks will be	351	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	352	called with at least two arguments: the watcher and a bitmask of received
175	events.	353	events.
176		354
177	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
178	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
179	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,
180	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
181	(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
182	uses EV::TIMEOUT).	360	uses EV::TIMEOUT).
183		361
184	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
185	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
…		…
207		385
208	=item $w->stop	386	=item $w->stop
209		387
210	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
211	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),
212	regardless of wether the watcher was active or not.	390	regardless of whether the watcher was active or not.
213		391
214	=item $bool = $w->is_active	392	=item $bool = $w->is_active
215		393
216	Returns true if the watcher is active, false otherwise.	394	Returns true if the watcher is active, false otherwise.
217		395
…		…
247	The default priority of any newly-created watcher is 0.	425	The default priority of any newly-created watcher is 0.
248		426
249	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
250	subject to almost certain change.	428	subject to almost certain change.
251		429
252	=item $w->trigger ($revents)	430	=item $w->invoke ($revents)
253		431
254	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>.
255		444
256	=item $previous_state = $w->keepalive ($bool)	445	=item $previous_state = $w->keepalive ($bool)
257		446
258	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
259	(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
260	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),
261	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
262	finished (or they forgot to register some watchers for their task :).	451	finished (or they forgot to register some watchers for their task :).
263		452
264	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
265	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
266	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
267	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
268	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
269	because you happen to have this long-running UDP port watcher.	458	because you happen to have this long-running UDP port watcher.
270		459
271	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
272	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.
273		462
274	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
275	any time.	464	any time.
276		465
277	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
278	event loop from running just because of that watcher.	467	event loop from running just because of that watcher.
279		468
280	my $udp_socket = ...	469	my $udp_socket = ...
281	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };	470	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
282	$udp_watcher->keepalive (0);	471	$udp_watcher->keepalive (0);
283		472
284	=back	473	=item $loop = $w->loop
285		474
		475	Return the loop that this watcher is attached to.
286		476
		477	=back
		478
		479
287	=head2 WATCHER TYPES	480	=head1 WATCHER TYPES
288		481
289	Each of the following subsections describes a single watcher type.	482	Each of the following subsections describes a single watcher type.
290		483
291	=head3 IO WATCHERS - is this file descriptor readable or writable?	484	=head3 I/O WATCHERS - is this file descriptor readable or writable?
292		485
293	=over 4	486	=over 4
294		487
295	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	488	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
296		489
297	=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, $callback)
298		495
299	As long as the returned watcher object is alive, call the C<$callback>	496	As long as the returned watcher object is alive, call the C<$callback>
300	when at least one of events specified in C<$eventmask> occurs.	497	when at least one of events specified in C<$eventmask> occurs.
301		498
302	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:
…		…
331	=over 4	528	=over 4
332		529
333	=item $w = EV::timer $after, $repeat, $callback	530	=item $w = EV::timer $after, $repeat, $callback
334		531
335	=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, $callback)
336		537
337	Calls the callback after C<$after> seconds (which may be fractional). If	538	Calls the callback after C<$after> seconds (which may be fractional). If
338	C<$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
339	value as $after) after the callback returns.	540	value as $after) after the callback returns.
340		541
…		…
381	=over 4	582	=over 4
382		583
383	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback	584	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
384		585
385	=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, $callback)
386		591
387	Similar to EV::timer, but is not based on relative timeouts but on	592	Similar to EV::timer, but is not based on relative timeouts but on
388	absolute times. Apart from creating "simple" timers that trigger "at" the	593	absolute times. Apart from creating "simple" timers that trigger "at" the
389	specified time, it can also be used for non-drifting absolute timers and	594	specified time, it can also be used for non-drifting absolute timers and
390	more complex, cron-like, setups that are not adversely affected by time	595	more complex, cron-like, setups that are not adversely affected by time
…		…
400	This time simply fires at the wallclock time C<$at> and doesn't repeat. It	605	This time simply fires at the wallclock time C<$at> and doesn't repeat. It
401	will not adjust when a time jump occurs, that is, if it is to be run	606	will not adjust when a time jump occurs, that is, if it is to be run
402	at January 1st 2011 then it will run when the system time reaches or	607	at January 1st 2011 then it will run when the system time reaches or
403	surpasses this time.	608	surpasses this time.
404		609
405	=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0)	610	=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
406		611
407	In this mode the watcher will always be scheduled to time out at the	612	In this mode the watcher will always be scheduled to time out at the
408	next C<$at + N * $interval> time (for some integer N) and then repeat,	613	next C<$at + N * $interval> time (for some integer N) and then repeat,
409	regardless of any time jumps.	614	regardless of any time jumps.
410		615
…		…
428	time the periodic watcher gets scheduled, the reschedule callback	633	time the periodic watcher gets scheduled, the reschedule callback
429	($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
430	time as second argument.	635	time as second argument.
431		636
432	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
433	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
434	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.
435		641
436	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
437	(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
438	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
439	might be called at other times, too.	645	triggered, but might be called at other times, too.
440		646
441	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
442	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
443	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
444	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
…		…
465		671
466	=item $w->again	672	=item $w->again
467		673
468	Simply stops and starts the watcher again.	674	Simply stops and starts the watcher again.
469		675
		676	=item $time = $w->at
		677
		678	Return the time that the watcher is expected to trigger next.
		679
470	=back	680	=back
471		681
472		682
473	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!	683	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
474		684
…		…
507		717
508	=head3 CHILD WATCHERS - watch out for process status changes	718	=head3 CHILD WATCHERS - watch out for process status changes
509		719
510	=over 4	720	=over 4
511		721
512	=item $w = EV::child $pid, $callback	722	=item $w = EV::child $pid, $trace, $callback
513		723
514	=item $w = EV::child_ns $pid, $callback	724	=item $w = EV::child_ns $pid, $trace, $callback
515		725
		726	=item $w = $loop->child ($pid, $trace, $callback)
		727
		728	=item $w = $loop->child_ns ($pid, $trace, $callback)
		729
516	Call the callback when a status change for pid C<$pid> (or any pid if	730	Call the callback when a status change for pid C<$pid> (or any pid
517	C<$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
518	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
519	changed/zombie children and call the callback.	735	changed/zombie children and call the callback.
520		736
521	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
522	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
…		…
529	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
530	called.	746	called.
531		747
532	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.
533		749
534	=item $w->set ($pid)	750	=item $w->set ($pid, $trace)
535		751
536	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
537	any time.	753	any time.
538		754
539	=item $current_pid = $w->pid	755	=item $current_pid = $w->pid
540		756
541	=item $old_pid = $w->pid ($new_pid)
542
543	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.
544		758
545	=item $exit_status = $w->rstatus	759	=item $exit_status = $w->rstatus
546		760
547	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
…		…
560	=over 4	774	=over 4
561		775
562	=item $w = EV::stat $path, $interval, $callback	776	=item $w = EV::stat $path, $interval, $callback
563		777
564	=item $w = EV::stat_ns $path, $interval, $callback	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, $callback)
565		783
566	Call the callback when a file status change has been detected on	784	Call the callback when a file status change has been detected on
567	C<$path>. The C<$path> does not need to exist, changing from "path exists"	785	C<$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.	786	to "path does not exist" is a status change like any other.
569		787
…		…
640		858
641	=item $w = EV::idle $callback	859	=item $w = EV::idle $callback
642		860
643	=item $w = EV::idle_ns $callback	861	=item $w = EV::idle_ns $callback
644		862
645	Call the callback when there are no pending io, timer/periodic, signal or	863	=item $w = $loop->idle ($callback)
646	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>.
647		875
648	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
649	they will be called repeatedly until stopped.	877	they will be called repeatedly until stopped.
650		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
651	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.
652		886
653	=back	887	=back
654		888
655		889
…		…
658	=over 4	892	=over 4
659		893
660	=item $w = EV::prepare $callback	894	=item $w = EV::prepare $callback
661		895
662	=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)
663		901
664	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
665	create/modify any watchers at this point.	903	create/modify any watchers at this point.
666		904
667	See the EV::check watcher, below, for explanations and an example.	905	See the EV::check watcher, below, for explanations and an example.
…		…
676	=over 4	914	=over 4
677		915
678	=item $w = EV::check $callback	916	=item $w = EV::check $callback
679		917
680	=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)
681		923
682	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
683	gathered events), but before any other callbacks have been invoked.	925	gathered events), but before any other callbacks have been invoked.
684		926
685	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
…		…
695	or return;	937	or return;
696		938
697	# make the dispatcher handle any outstanding stuff	939	# make the dispatcher handle any outstanding stuff
698	... not shown	940	... not shown
699		941
700	# create an IO watcher for each and every socket	942	# create an I/O watcher for each and every socket
701	@snmp_watcher = (	943	@snmp_watcher = (
702	(map { EV::io $_, EV::READ, sub { } }	944	(map { EV::io $_, EV::READ, sub { } }
703	keys %{ $dispatcher->{_descriptors} }),	945	keys %{ $dispatcher->{_descriptors} }),
704		946
705	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]	947	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
…		…
720	# make the dispatcher handle any new stuff	962	# make the dispatcher handle any new stuff
721	... not shown	963	... not shown
722	};	964	};
723		965
724	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
725	are destroyed before this cna happen (remember EV::check gets called	967	are destroyed before this can happen (remember EV::check gets called
726	first).	968	first).
727		969
728	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.
729		971
730	=back	972	=back
…		…
740		982
741	=item $w = EV::fork $callback	983	=item $w = EV::fork $callback
742		984
743	=item $w = EV::fork_ns $callback	985	=item $w = EV::fork_ns $callback
744		986
		987	=item $w = $loop->fork ($callback)
		988
		989	=item $w = $loop->fork_ns ($callback)
		990
745	Call the callback before the event loop is resumed in the child process	991	Call the callback before the event loop is resumed in the child process
746	after a fork.	992	after a fork.
747		993
748	The C<fork_ns> variant doesn't start (activate) the newly created watcher.	994	The C<fork_ns> variant doesn't start (activate) the newly created watcher.
749		995
750	=back	996	=back
751		997
752		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
753	=head1 THREADS	1088	=head1 ITHREADS
754		1089
755	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
756	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
757	on thread support for it.	1092	supported (and enhanced support is available via L<Coro::EV>).
758		1093
759	=head1 FORK	1094	=head1 FORK
760		1095
761	Most of the "improved" event delivering mechanisms of modern operating	1096	Most of the "improved" event delivering mechanisms of modern operating
762	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
…		…
778	our $DIED = sub {	1113	our $DIED = sub {
779	warn "EV: error in callback (ignoring): $@";	1114	warn "EV: error in callback (ignoring): $@";
780	};	1115	};
781		1116
782	default_loop	1117	default_loop
783	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	1118	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
784		1119
785	1;	1120	1;
786		1121
787	=head1 SEE ALSO	1122	=head1 SEE ALSO
788		1123
789	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.
790		1128
791	=head1 AUTHOR	1129	=head1 AUTHOR
792		1130
793	Marc Lehmann <schmorp@schmorp.de>	1131	Marc Lehmann <schmorp@schmorp.de>
794	http://home.schmorp.de/	1132	http://home.schmorp.de/
795		1133
796	=cut	1134	=cut
797		1135

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Comparing EV/EV.pm (file contents): Revision 1.58 by root, Wed Nov 28 19:22:16 2007 UTC vs. Revision 1.118 by root, Tue Jul 14 20:31:21 2009 UTC

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Comparing EV/EV.pm (file contents):
Revision 1.58 by root, Wed Nov 28 19:22:16 2007 UTC vs.
Revision 1.118 by root, Tue Jul 14 20:31:21 2009 UTC