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

Comparing EV/EV.pm (file contents):
Revision 1.56 by root, Tue Nov 27 10:59:10 2007 UTC vs.
Revision 1.127 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 = '1.4';	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
		287	=item $count = EV::loop_count
		288
		289	=item $count = $loop->loop_count
		290
		291	Return the number of times the event loop has polled for new
		292	events. Sometimes useful as a generation counter.
		293
136	=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))
137		297
138	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
139	one-shot event without the need for managing a watcher object.	299	one-shot event without the need for managing a watcher object.
140		300
141	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>
…		…
147	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
148	timeout. Otherwise a EV::timer with this value will be started.	308	timeout. Otherwise a EV::timer with this value will be started.
149		309
150	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
151	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
152	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>,
153	C<EV::WRITE> and C<EV::TIMEOUT>).	313	C<EV::WRITE> and C<EV::TIMER>).
154		314
155	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
156	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
157	invoked.	317	invoked.
158		318
159	=back	319	=item EV::feed_fd_event ($fd, $revents)
160		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
161	=head2 WATCHER OBJECTS	360	=head1 WATCHER OBJECTS
162		361
163	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
164	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
165	would create an EV::io watcher for that:	364	would create an EV::io watcher for that:
166		365
167	my $watcher = EV::io *STDIN, EV::READ, sub {	366	my $watcher = EV::io *STDIN, EV::READ, sub {
168	my ($watcher, $revents) = @_;	367	my ($watcher, $revents) = @_;
169	warn "yeah, STDIN should not be readable without blocking!\n"	368	warn "yeah, STDIN should now be readable without blocking!\n"
170	};	369	};
171		370
172	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
173	active watchers will have their callbacks invoked. All callbacks will be	372	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	373	called with at least two arguments: the watcher and a bitmask of received
175	events.	374	events.
176		375
177	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
178	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
179	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,
180	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
181	(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).
182	uses EV::TIMEOUT).
183		381
184	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
185	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
186	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.
187		385
…		…
207		405
208	=item $w->stop	406	=item $w->stop
209		407
210	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
211	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),
212	regardless of wether the watcher was active or not.	410	regardless of whether the watcher was active or not.
213		411
214	=item $bool = $w->is_active	412	=item $bool = $w->is_active
215		413
216	Returns true if the watcher is active, false otherwise.	414	Returns true if the watcher is active, false otherwise.
217		415
…		…
247	The default priority of any newly-created watcher is 0.	445	The default priority of any newly-created watcher is 0.
248		446
249	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
250	subject to almost certain change.	448	subject to almost certain change.
251		449
252	=item $w->trigger ($revents)	450	=item $w->invoke ($revents)
253		451
254	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>.
255		464
256	=item $previous_state = $w->keepalive ($bool)	465	=item $previous_state = $w->keepalive ($bool)
257		466
258	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
259	(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
260	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),
261	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
262	finished (or they forgot to register some watchers for their task :).	471	finished (or they forgot to register some watchers for their task :).
263		472
264	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
265	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
266	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
267	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
268	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
269	because you happen to have this long-running UDP port watcher.	478	because you happen to have this long-running UDP port watcher.
270		479
271	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
272	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.
273		482
274	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
275	any time.	484	any time.
276		485
277	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
278	event loop from running just because of that watcher.	487	event loop from running just because of that watcher.
279		488
280	my $udp_socket = ...	489	my $udp_socket = ...
281	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };	490	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
282	$udp_watcher->keepalive (0);	491	$udp_watcher->keepalive (0);
283		492
284	=back	493	=item $loop = $w->loop
285		494
		495	Return the loop that this watcher is attached to.
286		496
		497	=back
		498
		499
287	=head2 WATCHER TYPES	500	=head1 WATCHER TYPES
288		501
289	Each of the following subsections describes a single watcher type.	502	Each of the following subsections describes a single watcher type.
290		503
291	=head3 IO WATCHERS - is this file descriptor readable or writable?	504	=head3 I/O WATCHERS - is this file descriptor readable or writable?
292		505
293	=over 4	506	=over 4
294		507
295	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	508	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
296		509
297	=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, $callback)
298		515
299	As long as the returned watcher object is alive, call the C<$callback>	516	As long as the returned watcher object is alive, call the C<$callback>
300	when at least one of events specified in C<$eventmask> occurs.	517	when at least one of events specified in C<$eventmask> occurs.
301		518
302	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:
…		…
331	=over 4	548	=over 4
332		549
333	=item $w = EV::timer $after, $repeat, $callback	550	=item $w = EV::timer $after, $repeat, $callback
334		551
335	=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, $callback)
336		557
337	Calls the callback after C<$after> seconds (which may be fractional). If	558	Calls the callback after C<$after> seconds (which may be fractional). If
338	C<$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
339	value as $after) after the callback returns.	560	value as $after) after the callback returns.
340		561
…		…
381	=over 4	602	=over 4
382		603
383	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback	604	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
384		605
385	=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, $callback)
386		611
387	Similar to EV::timer, but is not based on relative timeouts but on	612	Similar to EV::timer, but is not based on relative timeouts but on
388	absolute times. Apart from creating "simple" timers that trigger "at" the	613	absolute times. Apart from creating "simple" timers that trigger "at" the
389	specified time, it can also be used for non-drifting absolute timers and	614	specified time, it can also be used for non-drifting absolute timers and
390	more complex, cron-like, setups that are not adversely affected by time	615	more complex, cron-like, setups that are not adversely affected by time
…		…
400	This time simply fires at the wallclock time C<$at> and doesn't repeat. It	625	This time simply fires at the wallclock time C<$at> and doesn't repeat. It
401	will not adjust when a time jump occurs, that is, if it is to be run	626	will not adjust when a time jump occurs, that is, if it is to be run
402	at January 1st 2011 then it will run when the system time reaches or	627	at January 1st 2011 then it will run when the system time reaches or
403	surpasses this time.	628	surpasses this time.
404		629
405	=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0)	630	=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
406		631
407	In this mode the watcher will always be scheduled to time out at the	632	In this mode the watcher will always be scheduled to time out at the
408	next C<$at + N * $interval> time (for some integer N) and then repeat,	633	next C<$at + N * $interval> time (for some integer N) and then repeat,
409	regardless of any time jumps.	634	regardless of any time jumps.
410		635
…		…
428	time the periodic watcher gets scheduled, the reschedule callback	653	time the periodic watcher gets scheduled, the reschedule callback
429	($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
430	time as second argument.	655	time as second argument.
431		656
432	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
433	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
434	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.
435		661
436	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
437	(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
438	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
439	might be called at other times, too.	665	triggered, but might be called at other times, too.
440		666
441	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
442	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
443	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
444	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
…		…
465		691
466	=item $w->again	692	=item $w->again
467		693
468	Simply stops and starts the watcher again.	694	Simply stops and starts the watcher again.
469		695
		696	=item $time = $w->at
		697
		698	Return the time that the watcher is expected to trigger next.
		699
470	=back	700	=back
471		701
472		702
473	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!	703	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
474		704
475	=over 4	705	=over 4
476		706
477	=item $w = EV::signal $signal, $callback	707	=item $w = EV::signal $signal, $callback
478		708
479	=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)
480		714
481	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
482	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.
483		721
484	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
485	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,
486	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
487	add/remove callbacks to C<%SIG>, so watch out.	725	add/remove callbacks to C<%SIG>, so watch out.
…		…
507		745
508	=head3 CHILD WATCHERS - watch out for process status changes	746	=head3 CHILD WATCHERS - watch out for process status changes
509		747
510	=over 4	748	=over 4
511		749
512	=item $w = EV::child $pid, $callback	750	=item $w = EV::child $pid, $trace, $callback
513		751
514	=item $w = EV::child_ns $pid, $callback	752	=item $w = EV::child_ns $pid, $trace, $callback
515		753
		754	=item $w = $loop->child ($pid, $trace, $callback)
		755
		756	=item $w = $loop->child_ns ($pid, $trace, $callback)
		757
516	Call the callback when a status change for pid C<$pid> (or any pid if	758	Call the callback when a status change for pid C<$pid> (or any pid
517	C<$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
518	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
519	changed/zombie children and call the callback.	763	changed/zombie children and call the callback.
520		764
521	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
522	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
…		…
529	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
530	called.	774	called.
531		775
532	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.
533		777
534	=item $w->set ($pid)	778	=item $w->set ($pid, $trace)
535		779
536	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
537	any time.	781	any time.
538		782
539	=item $current_pid = $w->pid	783	=item $current_pid = $w->pid
540		784
541	=item $old_pid = $w->pid ($new_pid)
542
543	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.
544		786
545	=item $exit_status = $w->rstatus	787	=item $exit_status = $w->rstatus
546		788
547	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
…		…
560	=over 4	802	=over 4
561		803
562	=item $w = EV::stat $path, $interval, $callback	804	=item $w = EV::stat $path, $interval, $callback
563		805
564	=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, $callback)
565		811
566	Call the callback when a file status change has been detected on	812	Call the callback when a file status change has been detected on
567	C<$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"
568	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.
569		815
…		…
576	as even with OS-supported change notifications, this can be	822	as even with OS-supported change notifications, this can be
577	resource-intensive.	823	resource-intensive.
578		824
579	The C<stat_ns> variant doesn't start (activate) the newly created watcher.	825	The C<stat_ns> variant doesn't start (activate) the newly created watcher.
580		826
		827	=item ... = $w->stat
		828
		829	This call is very similar to the perl C<stat> built-in: It stats (using
		830	C<lstat>) the path specified in the watcher and sets perls stat cache (as
		831	well as EV's idea of the current stat values) to the values found.
		832
		833	In scalar context, a boolean is return indicating success or failure of
		834	the stat. In list context, the same 13-value list as with stat is returned
		835	(except that the blksize and blocks fields are not reliable).
		836
		837	In the case of an error, errno is set to C<ENOENT> (regardless of the
		838	actual error value) and the C<nlink> value is forced to zero (if the stat
		839	was successful then nlink is guaranteed to be non-zero).
		840
		841	See also the next two entries for more info.
		842
		843	=item ... = $w->attr
		844
		845	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		846	the values most recently detected by EV. See the next entry for more info.
		847
		848	=item ... = $w->prev
		849
		850	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		851	the previous set of values, before the change.
		852
		853	That is, when the watcher callback is invoked, C<< $w->prev >> will be set
		854	to the values found I<before> a change was detected, while C<< $w->attr >>
		855	returns the values found leading to the change detection. The difference (if any)
		856	between C<prev> and C<attr> is what triggered the callback.
		857
		858	If you did something to the filesystem object and do not want to trigger
		859	yet another change, you can call C<stat> to update EV's idea of what the
		860	current attributes are.
		861
581	=item $w->set ($path, $interval)	862	=item $w->set ($path, $interval)
582		863
583	Reconfigures the watcher, see the constructor above for details. Can be	864	Reconfigures the watcher, see the constructor above for details. Can be
584	called at any time.	865	called at any time.
585		866
…		…
605		886
606	=item $w = EV::idle $callback	887	=item $w = EV::idle $callback
607		888
608	=item $w = EV::idle_ns $callback	889	=item $w = EV::idle_ns $callback
609		890
610	Call the callback when there are no pending io, timer/periodic, signal or	891	=item $w = $loop->idle ($callback)
611	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>.
612		903
613	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
614	they will be called repeatedly until stopped.	905	they will be called repeatedly until stopped.
615		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
616	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.
617		914
618	=back	915	=back
619		916
620		917
…		…
623	=over 4	920	=over 4
624		921
625	=item $w = EV::prepare $callback	922	=item $w = EV::prepare $callback
626		923
627	=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)
628		929
629	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
630	create/modify any watchers at this point.	931	create/modify any watchers at this point.
631		932
632	See the EV::check watcher, below, for explanations and an example.	933	See the EV::check watcher, below, for explanations and an example.
…		…
641	=over 4	942	=over 4
642		943
643	=item $w = EV::check $callback	944	=item $w = EV::check $callback
644		945
645	=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)
646		951
647	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
648	gathered events), but before any other callbacks have been invoked.	953	gathered events), but before any other callbacks have been invoked.
649		954
650	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
…		…
660	or return;	965	or return;
661		966
662	# make the dispatcher handle any outstanding stuff	967	# make the dispatcher handle any outstanding stuff
663	... not shown	968	... not shown
664		969
665	# create an IO watcher for each and every socket	970	# create an I/O watcher for each and every socket
666	@snmp_watcher = (	971	@snmp_watcher = (
667	(map { EV::io $_, EV::READ, sub { } }	972	(map { EV::io $_, EV::READ, sub { } }
668	keys %{ $dispatcher->{_descriptors} }),	973	keys %{ $dispatcher->{_descriptors} }),
669		974
670	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]	975	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
…		…
685	# make the dispatcher handle any new stuff	990	# make the dispatcher handle any new stuff
686	... not shown	991	... not shown
687	};	992	};
688		993
689	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
690	are destroyed before this cna happen (remember EV::check gets called	995	are destroyed before this can happen (remember EV::check gets called
691	first).	996	first).
692		997
693	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.
694		999
695	=back	1000	=back
…		…
705		1010
706	=item $w = EV::fork $callback	1011	=item $w = EV::fork $callback
707		1012
708	=item $w = EV::fork_ns $callback	1013	=item $w = EV::fork_ns $callback
709		1014
		1015	=item $w = $loop->fork ($callback)
		1016
		1017	=item $w = $loop->fork_ns ($callback)
		1018
710	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
711	after a fork.	1020	after a fork.
712		1021
713	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.
714		1023
715	=back	1024	=back
716		1025
717		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
718	=head1 THREADS	1116	=head1 ITHREADS
719		1117
720	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
721	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
722	on thread support for it.	1120	supported (and enhanced support is available via L<Coro::EV>).
723		1121
724	=head1 FORK	1122	=head1 FORK
725		1123
726	Most of the "improved" event delivering mechanisms of modern operating	1124	Most of the "improved" event delivering mechanisms of modern operating
727	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
…		…
743	our $DIED = sub {	1141	our $DIED = sub {
744	warn "EV: error in callback (ignoring): $@";	1142	warn "EV: error in callback (ignoring): $@";
745	};	1143	};
746		1144
747	default_loop	1145	default_loop
748	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	1146	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
749		1147
750	1;	1148	1;
751		1149
752	=head1 SEE ALSO	1150	=head1 SEE ALSO
753		1151
754	L<EV::DNS>.	1152	L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as
		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.
755		1156
756	=head1 AUTHOR	1157	=head1 AUTHOR
757		1158
758	Marc Lehmann <schmorp@schmorp.de>	1159	Marc Lehmann <schmorp@schmorp.de>
759	http://home.schmorp.de/	1160	http://home.schmorp.de/
760		1161
761	=cut	1162	=cut
762		1163

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Comparing EV/EV.pm (file contents): Revision 1.56 by root, Tue Nov 27 10:59:10 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 1.56 by root, Tue Nov 27 10:59:10 2007 UTC vs.
Revision 1.127 by root, Sun Mar 28 15:48:21 2010 UTC