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

Comparing EV/EV.pm (file contents):
Revision 1.60 by root, Mon Dec 3 13:41:24 2007 UTC vs.
Revision 1.127 by root, Sun Mar 28 15:48:21 2010 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
		56	=head1 BEFORE YOU START USING THIS MODULE
		57
		58	If you only need timer, I/O, signal, child and idle watchers and not the
		59	advanced functionality of this module, consider using L<AnyEvent> instead,
		60	specifically the simplified API described in L<AE>.
		61
		62	When used with EV as backend, the L<AE> API is as fast as the native L<EV>
		63	API, but your programs/modules will still run with many other event loops.
55		64
56	=head1 DESCRIPTION	65	=head1 DESCRIPTION
57		66
58	This module provides an interface to libev	67	This module provides an interface to libev
59	(L<http://software.schmorp.de/pkg/libev.html>). While the documentation	68	(L<http://software.schmorp.de/pkg/libev.html>). While the documentation
60	below is comprehensive, one might also consult the documentation of libev	69	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	70	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	71	F<perldoc EV::libev>) for more subtle details on watcher semantics or some
63	force a specific backend with C<LIBEV_FLAGS>.	72	discussion on the available backends, or how to force a specific backend
		73	with C<LIBEV_FLAGS>, or just about in any case because it has much more
		74	detailed information.
		75
		76	This module is very fast and scalable. It is actually so fast that you
		77	can use it through the L<AnyEvent> module, stay portable to other event
		78	loops (if you don't rely on any watcher types not available through it)
		79	and still be faster than with any other event loop currently supported in
		80	Perl.
		81
		82	=head2 MODULE EXPORTS
		83
		84	This module does not export any symbols.
64		85
65	=cut	86	=cut
66		87
67	package EV;	88	package EV;
68		89
69	use strict;	90	use common::sense;
70		91
71	BEGIN {	92	BEGIN {
72	our $VERSION = '1.6';	93	our $VERSION = '4.00';
73	use XSLoader;	94	use XSLoader;
74	XSLoader::load "EV", $VERSION;	95	XSLoader::load "EV", $VERSION;
75	}	96	}
76		97
77	@EV::IO::ISA =	98	@EV::IO::ISA =
…		…
83	@EV::Idle::ISA =	104	@EV::Idle::ISA =
84	@EV::Prepare::ISA =	105	@EV::Prepare::ISA =
85	@EV::Check::ISA =	106	@EV::Check::ISA =
86	@EV::Embed::ISA =	107	@EV::Embed::ISA =
87	@EV::Fork::ISA =	108	@EV::Fork::ISA =
		109	@EV::Async::ISA =
88	"EV::Watcher";	110	"EV::Watcher";
89		111
		112	@EV::Loop::Default::ISA = "EV::Loop";
		113
		114	=head1 EVENT LOOPS
		115
		116	EV supports multiple event loops: There is a single "default event loop"
		117	that can handle everything including signals and child watchers, and any
		118	number of "dynamic event loops" that can use different backends (with
		119	various limitations), but no child and signal watchers.
		120
		121	You do not have to do anything to create the default event loop: When
		122	the module is loaded a suitable backend is selected on the premise of
		123	selecting a working backend (which for example rules out kqueue on most
		124	BSDs). Modules should, unless they have "special needs" always use the
		125	default loop as this is fastest (perl-wise), best supported by other
		126	modules (e.g. AnyEvent or Coro) and most portable event loop.
		127
		128	For specific programs you can create additional event loops dynamically.
		129
		130	If you want to take advantage of kqueue (which often works properly for
		131	sockets only) even though the default loop doesn't enable it, you can
		132	I<embed> a kqueue loop into the default loop: running the default loop
		133	will then also service the kqueue loop to some extent. See the example in
		134	the section about embed watchers for an example on how to achieve that.
		135
		136	=over 4
		137
		138	=item $loop = new EV::Loop [$flags]
		139
		140	Create a new event loop as per the specified flags. Please refer to
		141	the C<ev_loop_new ()> function description in the libev documentation
		142	(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>,
		143	or locally-installed as F<EV::libev> manpage) for more info.
		144
		145	The loop will automatically be destroyed when it is no longer referenced
		146	by any watcher and the loop object goes out of scope.
		147
		148	If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK>
		149	is recommended, as only the default event loop is protected by this
		150	module. If you I<are> embedding this loop in the default loop, this is not
		151	necessary, as C<EV::embed> automatically does the right thing on fork.
		152
		153	=item $loop->loop_fork
		154
		155	Must be called after a fork in the child, before entering or continuing
		156	the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
		157	this function automatically, at some performance loss (refer to the libev
		158	documentation).
		159
		160	=item $loop->loop_verify
		161
		162	Calls C<ev_verify> to make internal consistency checks (for debugging
		163	libev) and abort the program if any data structures were found to be
		164	corrupted.
		165
		166	=item $loop = EV::default_loop [$flags]
		167
		168	Return the default loop (which is a singleton object). Since this module
		169	already creates the default loop with default flags, specifying flags here
		170	will not have any effect unless you destroy the default loop first, which
		171	isn't supported. So in short: don't do it, and if you break it, you get to
		172	keep the pieces.
		173
		174	=back
		175
		176
90	=head1 BASIC INTERFACE	177	=head1 BASIC INTERFACE
91		178
92	=over 4	179	=over 4
93		180
94	=item $EV::DIED	181	=item $EV::DIED
95		182
96	Must contain a reference to a function that is called when a callback	183	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	184	throws an exception (with $@ containing the error). The default prints an
98	informative message and continues.	185	informative message and continues.
99		186
100	If this callback throws an exception it will be silently ignored.	187	If this callback throws an exception it will be silently ignored.
101		188
		189	=item $flags = EV::supported_backends
		190
		191	=item $flags = EV::recommended_backends
		192
		193	=item $flags = EV::embeddable_backends
		194
		195	Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this
		196	instance of EV, the set of recommended backends (supposed to be good) for
		197	this platform and the set of embeddable backends (see EMBED WATCHERS).
		198
		199	=item EV::sleep $seconds
		200
		201	Block the process for the given number of (fractional) seconds.
		202
102	=item $time = EV::time	203	=item $time = EV::time
103		204
104	Returns the current time in (fractional) seconds since the epoch.	205	Returns the current time in (fractional) seconds since the epoch.
105		206
106	=item $time = EV::now	207	=item $time = EV::now
107		208
		209	=item $time = $loop->now
		210
108	Returns the time the last event loop iteration has been started. This	211	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	212	is the time that (relative) timers are based on, and referring to it is
110	usually faster then calling EV::time.	213	usually faster then calling EV::time.
111		214
112	=item $method = EV::method	215	=item EV::now_update
113		216
		217	=item $loop->now_update
		218
		219	Establishes the current time by querying the kernel, updating the time
		220	returned by C<EV::now> in the progress. This is a costly operation and
		221	is usually done automatically within C<EV::loop>.
		222
		223	This function is rarely useful, but when some event callback runs for a
		224	very long time without entering the event loop, updating libev's idea of
		225	the current time is a good idea.
		226
		227	=item EV::suspend
		228
		229	=item $loop->suspend
		230
		231	=item EV::resume
		232
		233	=item $loop->resume
		234
		235	These two functions suspend and resume a loop, for use when the loop is
		236	not used for a while and timeouts should not be processed.
		237
		238	A typical use case would be an interactive program such as a game: When
		239	the user presses C<^Z> to suspend the game and resumes it an hour later it
		240	would be best to handle timeouts as if no time had actually passed while
		241	the program was suspended. This can be achieved by calling C<suspend>
		242	in your C<SIGTSTP> handler, sending yourself a C<SIGSTOP> and calling
		243	C<resume> directly afterwards to resume timer processing.
		244
		245	Effectively, all C<timer> watchers will be delayed by the time spend
		246	between C<suspend> and C<resume>, and all C<periodic> watchers
		247	will be rescheduled (that is, they will lose any events that would have
		248	occured while suspended).
		249
		250	After calling C<suspend> you B<must not> call I<any> function on the given
		251	loop other than C<resume>, and you B<must not> call C<resume>
		252	without a previous call to C<suspend>.
		253
		254	Calling C<suspend>/C<resume> has the side effect of updating the event
		255	loop time (see C<now_update>).
		256
		257	=item $backend = EV::backend
		258
		259	=item $backend = $loop->backend
		260
114	Returns an integer describing the backend used by libev (EV::METHOD_SELECT	261	Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
115	or EV::METHOD_EPOLL).	262	or EV::BACKEND_EPOLL).
116		263
117	=item EV::loop [$flags]	264	=item EV::loop [$flags]
		265
		266	=item $loop->loop ([$flags])
118		267
119	Begin checking for events and calling callbacks. It returns when a	268	Begin checking for events and calling callbacks. It returns when a
120	callback calls EV::unloop.	269	callback calls EV::unloop.
121		270
122	The $flags argument can be one of the following:	271	The $flags argument can be one of the following:
…		…
125	EV::LOOP_ONESHOT block at most once (wait, but do not loop)	274	EV::LOOP_ONESHOT block at most once (wait, but do not loop)
126	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)	275	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
127		276
128	=item EV::unloop [$how]	277	=item EV::unloop [$how]
129		278
		279	=item $loop->unloop ([$how])
		280
130	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the	281	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the
131	innermost call to EV::loop return.	282	innermost call to EV::loop return.
132		283
133	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as	284	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as
134	fast as possible.	285	fast as possible.
135		286
136	=item $count = EV::loop_count	287	=item $count = EV::loop_count
137		288
		289	=item $count = $loop->loop_count
		290
138	Return the number of times the event loop has polled for new	291	Return the number of times the event loop has polled for new
139	events. Sometiems useful as a generation counter.	292	events. Sometimes useful as a generation counter.
140		293
141	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)	294	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
		295
		296	=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
142		297
143	This function rolls together an I/O and a timer watcher for a single	298	This function rolls together an I/O and a timer watcher for a single
144	one-shot event without the need for managing a watcher object.	299	one-shot event without the need for managing a watcher object.
145		300
146	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>	301	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>
…		…
152	If timeout is C<undef> or negative, then there will be no	307	If timeout is C<undef> or negative, then there will be no
153	timeout. Otherwise a EV::timer with this value will be started.	308	timeout. Otherwise a EV::timer with this value will be started.
154		309
155	When an error occurs or either the timeout or I/O watcher triggers, then	310	When an error occurs or either the timeout or I/O watcher triggers, then
156	the callback will be called with the received event set (in general	311	the callback will be called with the received event set (in general
157	you can expect it to be a combination of C<EV:ERROR>, C<EV::READ>,	312	you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
158	C<EV::WRITE> and C<EV::TIMEOUT>).	313	C<EV::WRITE> and C<EV::TIMER>).
159		314
160	EV::once doesn't return anything: the watchers stay active till either	315	EV::once doesn't return anything: the watchers stay active till either
161	of them triggers, then they will be stopped and freed, and the callback	316	of them triggers, then they will be stopped and freed, and the callback
162	invoked.	317	invoked.
163		318
164	=back	319	=item EV::feed_fd_event ($fd, $revents)
165		320
		321	=item $loop->feed_fd_event ($fd, $revents)
		322
		323	Feed an event on a file descriptor into EV. EV will react to this call as
		324	if the readyness notifications specified by C<$revents> (a combination of
		325	C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
		326
		327	=item EV::feed_signal_event ($signal)
		328
		329	Feed a signal event into EV. EV will react to this call as if the signal
		330	specified by C<$signal> had occured.
		331
		332	=item EV::set_io_collect_interval $time
		333
		334	=item $loop->set_io_collect_interval ($time)
		335
		336	=item EV::set_timeout_collect_interval $time
		337
		338	=item $loop->set_timeout_collect_interval ($time)
		339
		340	These advanced functions set the minimum block interval when polling for I/O events and the minimum
		341	wait interval for timer events. See the libev documentation at
		342	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP>
		343	(locally installed as F<EV::libev>) for a more detailed discussion.
		344
		345	=item $count = EV::pending_count
		346
		347	=item $count = $loop->pending_count
		348
		349	Returns the number of currently pending watchers.
		350
		351	=item EV::invoke_pending
		352
		353	=item $loop->invoke_pending
		354
		355	Invoke all currently pending watchers.
		356
		357	=back
		358
		359
166	=head2 WATCHER OBJECTS	360	=head1 WATCHER OBJECTS
167		361
168	A watcher is an object that gets created to record your interest in some	362	A watcher is an object that gets created to record your interest in some
169	event. For instance, if you want to wait for STDIN to become readable, you	363	event. For instance, if you want to wait for STDIN to become readable, you
170	would create an EV::io watcher for that:	364	would create an EV::io watcher for that:
171		365
172	my $watcher = EV::io *STDIN, EV::READ, sub {	366	my $watcher = EV::io *STDIN, EV::READ, sub {
173	my ($watcher, $revents) = @_;	367	my ($watcher, $revents) = @_;
174	warn "yeah, STDIN should not be readable without blocking!\n"	368	warn "yeah, STDIN should now be readable without blocking!\n"
175	};	369	};
176		370
177	All watchers can be active (waiting for events) or inactive (paused). Only	371	All watchers can be active (waiting for events) or inactive (paused). Only
178	active watchers will have their callbacks invoked. All callbacks will be	372	active watchers will have their callbacks invoked. All callbacks will be
179	called with at least two arguments: the watcher and a bitmask of received	373	called with at least two arguments: the watcher and a bitmask of received
180	events.	374	events.
181		375
182	Each watcher type has its associated bit in revents, so you can use the	376	Each watcher type has its associated bit in revents, so you can use the
183	same callback for multiple watchers. The event mask is named after the	377	same callback for multiple watchers. The event mask is named after the
184	type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,	378	type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
185	EV::periodic sets EV::PERIODIC and so on, with the exception of IO events	379	EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events
186	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which	380	(which can set both EV::READ and EV::WRITE bits).
187	uses EV::TIMEOUT).
188		381
189	In the rare case where one wants to create a watcher but not start it at	382	In the rare case where one wants to create a watcher but not start it at
190	the same time, each constructor has a variant with a trailing C<_ns> in	383	the same time, each constructor has a variant with a trailing C<_ns> in
191	its name, e.g. EV::io has a non-starting variant EV::io_ns and so on.	384	its name, e.g. EV::io has a non-starting variant EV::io_ns and so on.
192		385
…		…
212		405
213	=item $w->stop	406	=item $w->stop
214		407
215	Stop a watcher if it is active. Also clear any pending events (events that	408	Stop a watcher if it is active. Also clear any pending events (events that
216	have been received but that didn't yet result in a callback invocation),	409	have been received but that didn't yet result in a callback invocation),
217	regardless of wether the watcher was active or not.	410	regardless of whether the watcher was active or not.
218		411
219	=item $bool = $w->is_active	412	=item $bool = $w->is_active
220		413
221	Returns true if the watcher is active, false otherwise.	414	Returns true if the watcher is active, false otherwise.
222		415
…		…
252	The default priority of any newly-created watcher is 0.	445	The default priority of any newly-created watcher is 0.
253		446
254	Note that the priority semantics have not yet been fleshed out and are	447	Note that the priority semantics have not yet been fleshed out and are
255	subject to almost certain change.	448	subject to almost certain change.
256		449
257	=item $w->trigger ($revents)	450	=item $w->invoke ($revents)
258		451
259	Call the callback now with the given event mask.	452	Call the callback now with the given event mask.
		453
		454	=item $w->feed_event ($revents)
		455
		456	Feed some events on this watcher into EV. EV will react to this call as if
		457	the watcher had received the given C<$revents> mask.
		458
		459	=item $revents = $w->clear_pending
		460
		461	If the watcher is pending, this function clears its pending status and
		462	returns its C<$revents> bitset (as if its callback was invoked). If the
		463	watcher isn't pending it does nothing and returns C<0>.
260		464
261	=item $previous_state = $w->keepalive ($bool)	465	=item $previous_state = $w->keepalive ($bool)
262		466
263	Normally, C<EV::loop> will return when there are no active watchers	467	Normally, C<EV::loop> will return when there are no active watchers
264	(which is a "deadlock" because no progress can be made anymore). This is	468	(which is a "deadlock" because no progress can be made anymore). This is
265	convinient because it allows you to start your watchers (and your jobs),	469	convenient because it allows you to start your watchers (and your jobs),
266	call C<EV::loop> once and when it returns you know that all your jobs are	470	call C<EV::loop> once and when it returns you know that all your jobs are
267	finished (or they forgot to register some watchers for their task :).	471	finished (or they forgot to register some watchers for their task :).
268		472
269	Sometimes, however, this gets in your way, for example when you the module	473	Sometimes, however, this gets in your way, for example when the module
270	that calls C<EV::loop> (usually the main program) is not the same module	474	that calls C<EV::loop> (usually the main program) is not the same module
271	as a long-living watcher (for example a DNS client module written by	475	as a long-living watcher (for example a DNS client module written by
272	somebody else even). Then you might want any outstanding requests to be	476	somebody else even). Then you might want any outstanding requests to be
273	handled, but you would not want to keep C<EV::loop> from returning just	477	handled, but you would not want to keep C<EV::loop> from returning just
274	because you happen to have this long-running UDP port watcher.	478	because you happen to have this long-running UDP port watcher.
275		479
276	In this case you can clear the keepalive status, which means that even	480	In this case you can clear the keepalive status, which means that even
277	though your watcher is active, it won't keep C<EV::loop> from returning.	481	though your watcher is active, it won't keep C<EV::loop> from returning.
278		482
279	The initial value for keepalive is true (enabled), and you cna change it	483	The initial value for keepalive is true (enabled), and you can change it
280	any time.	484	any time.
281		485
282	Example: Register an IO watcher for some UDP socket but do not keep the	486	Example: Register an I/O watcher for some UDP socket but do not keep the
283	event loop from running just because of that watcher.	487	event loop from running just because of that watcher.
284		488
285	my $udp_socket = ...	489	my $udp_socket = ...
286	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };	490	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
287	$udp_watcher->keepalive (0);	491	$udp_watcher->keepalive (0);
288		492
289	=back	493	=item $loop = $w->loop
290		494
		495	Return the loop that this watcher is attached to.
291		496
		497	=back
		498
		499
292	=head2 WATCHER TYPES	500	=head1 WATCHER TYPES
293		501
294	Each of the following subsections describes a single watcher type.	502	Each of the following subsections describes a single watcher type.
295		503
296	=head3 IO WATCHERS - is this file descriptor readable or writable?	504	=head3 I/O WATCHERS - is this file descriptor readable or writable?
297		505
298	=over 4	506	=over 4
299		507
300	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	508	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
301		509
302	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback	510	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
		511
		512	=item $w = $loop->io ($fileno_or_fh, $eventmask, $callback)
		513
		514	=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
303		515
304	As long as the returned watcher object is alive, call the C<$callback>	516	As long as the returned watcher object is alive, call the C<$callback>
305	when at least one of events specified in C<$eventmask> occurs.	517	when at least one of events specified in C<$eventmask> occurs.
306		518
307	The $eventmask can be one or more of these constants ORed together:	519	The $eventmask can be one or more of these constants ORed together:
…		…
336	=over 4	548	=over 4
337		549
338	=item $w = EV::timer $after, $repeat, $callback	550	=item $w = EV::timer $after, $repeat, $callback
339		551
340	=item $w = EV::timer_ns $after, $repeat, $callback	552	=item $w = EV::timer_ns $after, $repeat, $callback
		553
		554	=item $w = $loop->timer ($after, $repeat, $callback)
		555
		556	=item $w = $loop->timer_ns ($after, $repeat, $callback)
341		557
342	Calls the callback after C<$after> seconds (which may be fractional). If	558	Calls the callback after C<$after> seconds (which may be fractional). If
343	C<$repeat> is non-zero, the timer will be restarted (with the $repeat	559	C<$repeat> is non-zero, the timer will be restarted (with the $repeat
344	value as $after) after the callback returns.	560	value as $after) after the callback returns.
345		561
…		…
386	=over 4	602	=over 4
387		603
388	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback	604	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
389		605
390	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback	606	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
		607
		608	=item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
		609
		610	=item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback)
391		611
392	Similar to EV::timer, but is not based on relative timeouts but on	612	Similar to EV::timer, but is not based on relative timeouts but on
393	absolute times. Apart from creating "simple" timers that trigger "at" the	613	absolute times. Apart from creating "simple" timers that trigger "at" the
394	specified time, it can also be used for non-drifting absolute timers and	614	specified time, it can also be used for non-drifting absolute timers and
395	more complex, cron-like, setups that are not adversely affected by time	615	more complex, cron-like, setups that are not adversely affected by time
…		…
405	This time simply fires at the wallclock time C<$at> and doesn't repeat. It	625	This time simply fires at the wallclock time C<$at> and doesn't repeat. It
406	will not adjust when a time jump occurs, that is, if it is to be run	626	will not adjust when a time jump occurs, that is, if it is to be run
407	at January 1st 2011 then it will run when the system time reaches or	627	at January 1st 2011 then it will run when the system time reaches or
408	surpasses this time.	628	surpasses this time.
409		629
410	=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0)	630	=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
411		631
412	In this mode the watcher will always be scheduled to time out at the	632	In this mode the watcher will always be scheduled to time out at the
413	next C<$at + N * $interval> time (for some integer N) and then repeat,	633	next C<$at + N * $interval> time (for some integer N) and then repeat,
414	regardless of any time jumps.	634	regardless of any time jumps.
415		635
…		…
433	time the periodic watcher gets scheduled, the reschedule callback	653	time the periodic watcher gets scheduled, the reschedule callback
434	($reschedule_cb) will be called with the watcher as first, and the current	654	($reschedule_cb) will be called with the watcher as first, and the current
435	time as second argument.	655	time as second argument.
436		656
437	I<This callback MUST NOT stop or destroy this or any other periodic	657	I<This callback MUST NOT stop or destroy this or any other periodic
438	watcher, ever>. If you need to stop it, return 1e30 and stop it	658	watcher, ever, and MUST NOT call any event loop functions or methods>. If
439	afterwards.	659	you need to stop it, return 1e30 and stop it afterwards. You may create
		660	and start a C<EV::prepare> watcher for this task.
440		661
441	It must return the next time to trigger, based on the passed time value	662	It must return the next time to trigger, based on the passed time value
442	(that is, the lowest time value larger than to the second argument). It	663	(that is, the lowest time value larger than or equal to to the second
443	will usually be called just before the callback will be triggered, but	664	argument). It will usually be called just before the callback will be
444	might be called at other times, too.	665	triggered, but might be called at other times, too.
445		666
446	This can be used to create very complex timers, such as a timer that	667	This can be used to create very complex timers, such as a timer that
447	triggers on each midnight, local time (actually 24 hours after the last	668	triggers on each midnight, local time (actually 24 hours after the last
448	midnight, to keep the example simple. If you know a way to do it correctly	669	midnight, to keep the example simple. If you know a way to do it correctly
449	in about the same space (without requiring elaborate modules), drop me a	670	in about the same space (without requiring elaborate modules), drop me a
…		…
470		691
471	=item $w->again	692	=item $w->again
472		693
473	Simply stops and starts the watcher again.	694	Simply stops and starts the watcher again.
474		695
		696	=item $time = $w->at
		697
		698	Return the time that the watcher is expected to trigger next.
		699
475	=back	700	=back
476		701
477		702
478	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!	703	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
479		704
480	=over 4	705	=over 4
481		706
482	=item $w = EV::signal $signal, $callback	707	=item $w = EV::signal $signal, $callback
483		708
484	=item $w = EV::signal_ns $signal, $callback	709	=item $w = EV::signal_ns $signal, $callback
		710
		711	=item $w = $loop->signal ($signal, $callback)
		712
		713	=item $w = $loop->signal_ns ($signal, $callback)
485		714
486	Call the callback when $signal is received (the signal can be specified by	715	Call the callback when $signal is received (the signal can be specified by
487	number or by name, just as with C<kill> or C<%SIG>).	716	number or by name, just as with C<kill> or C<%SIG>).
		717
		718	Only one event loop can grab a given signal - attempting to grab the same
		719	signal from two EV loops will crash the program immediately or cause data
		720	corruption.
488		721
489	EV will grab the signal for the process (the kernel only allows one	722	EV will grab the signal for the process (the kernel only allows one
490	component to receive a signal at a time) when you start a signal watcher,	723	component to receive a signal at a time) when you start a signal watcher,
491	and removes it again when you stop it. Perl does the same when you	724	and removes it again when you stop it. Perl does the same when you
492	add/remove callbacks to C<%SIG>, so watch out.	725	add/remove callbacks to C<%SIG>, so watch out.
…		…
512		745
513	=head3 CHILD WATCHERS - watch out for process status changes	746	=head3 CHILD WATCHERS - watch out for process status changes
514		747
515	=over 4	748	=over 4
516		749
517	=item $w = EV::child $pid, $callback	750	=item $w = EV::child $pid, $trace, $callback
518		751
519	=item $w = EV::child_ns $pid, $callback	752	=item $w = EV::child_ns $pid, $trace, $callback
520		753
		754	=item $w = $loop->child ($pid, $trace, $callback)
		755
		756	=item $w = $loop->child_ns ($pid, $trace, $callback)
		757
521	Call the callback when a status change for pid C<$pid> (or any pid if	758	Call the callback when a status change for pid C<$pid> (or any pid
522	C<$pid> is 0) has been received. More precisely: when the process receives	759	if C<$pid> is 0) has been received (a status change happens when the
		760	process terminates or is killed, or, when trace is true, additionally when
		761	it is stopped or continued). More precisely: when the process receives
523	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all	762	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
524	changed/zombie children and call the callback.	763	changed/zombie children and call the callback.
525		764
526	It is valid (and fully supported) to install a child watcher after a child	765	It is valid (and fully supported) to install a child watcher after a child
527	has exited but before the event loop has started its next iteration (for	766	has exited but before the event loop has started its next iteration (for
…		…
534	You can have as many pid watchers per pid as you want, they will all be	773	You can have as many pid watchers per pid as you want, they will all be
535	called.	774	called.
536		775
537	The C<child_ns> variant doesn't start (activate) the newly created watcher.	776	The C<child_ns> variant doesn't start (activate) the newly created watcher.
538		777
539	=item $w->set ($pid)	778	=item $w->set ($pid, $trace)
540		779
541	Reconfigures the watcher, see the constructor above for details. Can be called at	780	Reconfigures the watcher, see the constructor above for details. Can be called at
542	any time.	781	any time.
543		782
544	=item $current_pid = $w->pid	783	=item $current_pid = $w->pid
545		784
546	=item $old_pid = $w->pid ($new_pid)
547
548	Returns the previously set process id and optionally set a new one.	785	Returns the previously set process id and optionally set a new one.
549		786
550	=item $exit_status = $w->rstatus	787	=item $exit_status = $w->rstatus
551		788
552	Return the exit/wait status (as returned by waitpid, see the waitpid entry	789	Return the exit/wait status (as returned by waitpid, see the waitpid entry
…		…
565	=over 4	802	=over 4
566		803
567	=item $w = EV::stat $path, $interval, $callback	804	=item $w = EV::stat $path, $interval, $callback
568		805
569	=item $w = EV::stat_ns $path, $interval, $callback	806	=item $w = EV::stat_ns $path, $interval, $callback
		807
		808	=item $w = $loop->stat ($path, $interval, $callback)
		809
		810	=item $w = $loop->stat_ns ($path, $interval, $callback)
570		811
571	Call the callback when a file status change has been detected on	812	Call the callback when a file status change has been detected on
572	C<$path>. The C<$path> does not need to exist, changing from "path exists"	813	C<$path>. The C<$path> does not need to exist, changing from "path exists"
573	to "path does not exist" is a status change like any other.	814	to "path does not exist" is a status change like any other.
574		815
…		…
645		886
646	=item $w = EV::idle $callback	887	=item $w = EV::idle $callback
647		888
648	=item $w = EV::idle_ns $callback	889	=item $w = EV::idle_ns $callback
649		890
650	Call the callback when there are no pending io, timer/periodic, signal or	891	=item $w = $loop->idle ($callback)
651	child events, i.e. when the process is idle.	892
		893	=item $w = $loop->idle_ns ($callback)
		894
		895	Call the callback when there are no other pending watchers of the same or
		896	higher priority (excluding check, prepare and other idle watchers of the
		897	same or lower priority, of course). They are called idle watchers because
		898	when the watcher is the highest priority pending event in the process, the
		899	process is considered to be idle at that priority.
		900
		901	If you want a watcher that is only ever called when I<no> other events are
		902	outstanding you have to set the priority to C<EV::MINPRI>.
652		903
653	The process will not block as long as any idle watchers are active, and	904	The process will not block as long as any idle watchers are active, and
654	they will be called repeatedly until stopped.	905	they will be called repeatedly until stopped.
655		906
		907	For example, if you have idle watchers at priority C<0> and C<1>, and
		908	an I/O watcher at priority C<0>, then the idle watcher at priority C<1>
		909	and the I/O watcher will always run when ready. Only when the idle watcher
		910	at priority C<1> is stopped and the I/O watcher at priority C<0> is not
		911	pending with the C<0>-priority idle watcher be invoked.
		912
656	The C<idle_ns> variant doesn't start (activate) the newly created watcher.	913	The C<idle_ns> variant doesn't start (activate) the newly created watcher.
657		914
658	=back	915	=back
659		916
660		917
…		…
663	=over 4	920	=over 4
664		921
665	=item $w = EV::prepare $callback	922	=item $w = EV::prepare $callback
666		923
667	=item $w = EV::prepare_ns $callback	924	=item $w = EV::prepare_ns $callback
		925
		926	=item $w = $loop->prepare ($callback)
		927
		928	=item $w = $loop->prepare_ns ($callback)
668		929
669	Call the callback just before the process would block. You can still	930	Call the callback just before the process would block. You can still
670	create/modify any watchers at this point.	931	create/modify any watchers at this point.
671		932
672	See the EV::check watcher, below, for explanations and an example.	933	See the EV::check watcher, below, for explanations and an example.
…		…
681	=over 4	942	=over 4
682		943
683	=item $w = EV::check $callback	944	=item $w = EV::check $callback
684		945
685	=item $w = EV::check_ns $callback	946	=item $w = EV::check_ns $callback
		947
		948	=item $w = $loop->check ($callback)
		949
		950	=item $w = $loop->check_ns ($callback)
686		951
687	Call the callback just after the process wakes up again (after it has	952	Call the callback just after the process wakes up again (after it has
688	gathered events), but before any other callbacks have been invoked.	953	gathered events), but before any other callbacks have been invoked.
689		954
690	This is used to integrate other event-based software into the EV	955	This is used to integrate other event-based software into the EV
…		…
700	or return;	965	or return;
701		966
702	# make the dispatcher handle any outstanding stuff	967	# make the dispatcher handle any outstanding stuff
703	... not shown	968	... not shown
704		969
705	# create an IO watcher for each and every socket	970	# create an I/O watcher for each and every socket
706	@snmp_watcher = (	971	@snmp_watcher = (
707	(map { EV::io $_, EV::READ, sub { } }	972	(map { EV::io $_, EV::READ, sub { } }
708	keys %{ $dispatcher->{_descriptors} }),	973	keys %{ $dispatcher->{_descriptors} }),
709		974
710	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]	975	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
…		…
725	# make the dispatcher handle any new stuff	990	# make the dispatcher handle any new stuff
726	... not shown	991	... not shown
727	};	992	};
728		993
729	The callbacks of the created watchers will not be called as the watchers	994	The callbacks of the created watchers will not be called as the watchers
730	are destroyed before this cna happen (remember EV::check gets called	995	are destroyed before this can happen (remember EV::check gets called
731	first).	996	first).
732		997
733	The C<check_ns> variant doesn't start (activate) the newly created watcher.	998	The C<check_ns> variant doesn't start (activate) the newly created watcher.
734		999
735	=back	1000	=back
…		…
745		1010
746	=item $w = EV::fork $callback	1011	=item $w = EV::fork $callback
747		1012
748	=item $w = EV::fork_ns $callback	1013	=item $w = EV::fork_ns $callback
749		1014
		1015	=item $w = $loop->fork ($callback)
		1016
		1017	=item $w = $loop->fork_ns ($callback)
		1018
750	Call the callback before the event loop is resumed in the child process	1019	Call the callback before the event loop is resumed in the child process
751	after a fork.	1020	after a fork.
752		1021
753	The C<fork_ns> variant doesn't start (activate) the newly created watcher.	1022	The C<fork_ns> variant doesn't start (activate) the newly created watcher.
754		1023
755	=back	1024	=back
756		1025
757		1026
		1027	=head3 EMBED WATCHERS - when one backend isn't enough...
		1028
		1029	This is a rather advanced watcher type that lets you embed one event loop
		1030	into another (currently only IO events are supported in the embedded
		1031	loop, other types of watchers might be handled in a delayed or incorrect
		1032	fashion and must not be used).
		1033
		1034	See the libev documentation at
		1035	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
		1036	(locally installed as F<EV::libev>) for more details.
		1037
		1038	In short, this watcher is most useful on BSD systems without working
		1039	kqueue to still be able to handle a large number of sockets:
		1040
		1041	my $socket_loop;
		1042
		1043	# check wether we use SELECT or POLL _and_ KQUEUE is supported
		1044	if (
		1045	(EV::backend & (EV::BACKEND_POLL \| EV::BACKEND_SELECT))
		1046	&& (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
		1047	) {
		1048	# use kqueue for sockets
		1049	$socket_loop = new EV::Loop EV::BACKEND_KQUEUE \| EV::FLAG_NOENV;
		1050	}
		1051
		1052	# use the default loop otherwise
		1053	$socket_loop \|\|= EV::default_loop;
		1054
		1055	=over 4
		1056
		1057	=item $w = EV::embed $otherloop[, $callback]
		1058
		1059	=item $w = EV::embed_ns $otherloop[, $callback]
		1060
		1061	=item $w = $loop->embed ($otherloop[, $callback])
		1062
		1063	=item $w = $loop->embed_ns ($otherloop[, $callback])
		1064
		1065	Call the callback when the embedded event loop (C<$otherloop>) has any
		1066	I/O activity. The C<$callback> is optional: if it is missing, then the
		1067	embedded event loop will be managed automatically (which is recommended),
		1068	otherwise you have to invoke C<sweep> yourself.
		1069
		1070	The C<embed_ns> variant doesn't start (activate) the newly created watcher.
		1071
		1072	=back
		1073
		1074	=head3 ASYNC WATCHERS - how to wake up another event loop
		1075
		1076	Async watchers are provided by EV, but have little use in perl directly,
		1077	as perl neither supports threads running in parallel nor direct access to
		1078	signal handlers or other contexts where they could be of value.
		1079
		1080	It is, however, possible to use them from the XS level.
		1081
		1082	Please see the libev documentation for further details.
		1083
		1084	=over 4
		1085
		1086	=item $w = EV::async $callback
		1087
		1088	=item $w = EV::async_ns $callback
		1089
		1090	=item $w->send
		1091
		1092	=item $bool = $w->async_pending
		1093
		1094	=back
		1095
		1096
		1097	=head1 PERL SIGNALS
		1098
		1099	While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour
		1100	with EV is as the same as any other C library: Perl-signals will only be
		1101	handled when Perl runs, which means your signal handler might be invoked
		1102	only the next time an event callback is invoked.
		1103
		1104	The solution is to use EV signal watchers (see C<EV::signal>), which will
		1105	ensure proper operations with regards to other event watchers.
		1106
		1107	If you cannot do this for whatever reason, you can also force a watcher
		1108	to be called on every event loop iteration by installing a C<EV::check>
		1109	watcher:
		1110
		1111	my $async_check = EV::check sub { };
		1112
		1113	This ensures that perl gets into control for a short time to handle any
		1114	pending signals, and also ensures (slightly) slower overall operation.
		1115
758	=head1 THREADS	1116	=head1 ITHREADS
759		1117
760	Threads are not supported by this module in any way. Perl pseudo-threads	1118	Ithreads are not supported by this module in any way. Perl pseudo-threads
761	is evil stuff and must die. As soon as Perl gains real threads I will work	1119	is evil stuff and must die. Real threads as provided by Coro are fully
762	on thread support for it.	1120	supported (and enhanced support is available via L<Coro::EV>).
763		1121
764	=head1 FORK	1122	=head1 FORK
765		1123
766	Most of the "improved" event delivering mechanisms of modern operating	1124	Most of the "improved" event delivering mechanisms of modern operating
767	systems have quite a few problems with fork(2) (to put it bluntly: it is	1125	systems have quite a few problems with fork(2) (to put it bluntly: it is
…		…
783	our $DIED = sub {	1141	our $DIED = sub {
784	warn "EV: error in callback (ignoring): $@";	1142	warn "EV: error in callback (ignoring): $@";
785	};	1143	};
786		1144
787	default_loop	1145	default_loop
788	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	1146	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
789		1147
790	1;	1148	1;
791		1149
792	=head1 SEE ALSO	1150	=head1 SEE ALSO
793		1151
794	L<EV::ADNS> (asynchronous dns), L<Glib::EV> (makes Glib/Gtk2 use EV as	1152	L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as
795	event loop), L<Coro::EV> (efficient coroutines with EV).	1153	event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
		1154	coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
		1155	event-loop agnostic and portable event driven programming.
796		1156
797	=head1 AUTHOR	1157	=head1 AUTHOR
798		1158
799	Marc Lehmann <schmorp@schmorp.de>	1159	Marc Lehmann <schmorp@schmorp.de>
800	http://home.schmorp.de/	1160	http://home.schmorp.de/
801		1161
802	=cut	1162	=cut
803		1163

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Comparing EV/EV.pm (file contents): Revision 1.60 by root, Mon Dec 3 13:41:24 2007 UTC vs. Revision 1.127 by root, Sun Mar 28 15:48:21 2010 UTC

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Comparing EV/EV.pm (file contents):
Revision 1.60 by root, Mon Dec 3 13:41:24 2007 UTC vs.
Revision 1.127 by root, Sun Mar 28 15:48:21 2010 UTC