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

Comparing EV/EV.pm (file contents):
Revision 1.20 by root, Thu Nov 1 17:17:32 2007 UTC vs.
Revision 1.55 by root, Tue Nov 27 08:11:52 2007 UTC

…		…
10		10
11	my $w = EV::timer 2, 0, sub {	11	my $w = EV::timer 2, 0, sub {
12	warn "is called after 2s";	12	warn "is called after 2s";
13	};	13	};
14		14
15	my $w = EV::timer 2, 1, sub {	15	my $w = EV::timer 2, 2, sub {
16	warn "is called roughly every 2s (repeat = 1)";	16	warn "is called roughly every 2s (repeat = 2)";
17	};	17	};
18		18
19	undef $w; # destroy event watcher again	19	undef $w; # destroy event watcher again
20		20
21	my $w = EV::periodic 0, 60, sub {	21	my $w = EV::periodic 0, 60, 0, sub {
22	warn "is called every minute, on the minute, exactly";	22	warn "is called every minute, on the minute, exactly";
23	};	23	};
24		24
25	# IO	25	# IO
26		26
27	my $w = EV::io *STDIN, EV::READ, sub {	27	my $w = EV::io *STDIN, EV::READ, sub {
28	my ($w, $revents) = @_; # all callbacks get the watcher object and event mask	28	my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
29	warn "stdin is readable, you entered: ", <STDIN>;	29	warn "stdin is readable, you entered: ", <STDIN>;
30	};	30	};
31		31
32	# SIGNALS	32	# SIGNALS
33		33
34	my $w = EV::signal 'QUIT', sub {	34	my $w = EV::signal 'QUIT', sub {
35	warn "sigquit received\n";	35	warn "sigquit received\n";
36	};	36	};
37		37
		38	# CHILD/PID STATUS CHANGES
		39
38	my $w = EV::signal 3, sub {	40	my $w = EV::child 666, sub {
39	warn "sigquit received (this is GNU/Linux, right?)\n";	41	my ($w, $revents) = @_;
		42	my $status = $w->rstatus;
40	};	43	};
41		44
42	# CHILD/PID STATUS CHANGES	45	# STAT CHANGES
43		46	my $w = EV::stat "/etc/passwd", 10, sub {
44	my $w = EV::child 666, sub {
45	my ($w, $revents, $status) = @_;	47	my ($w, $revents) = @_;
		48	warn $w->path, " has changed somehow.\n";
46	};	49	};
47		50
48	# MAINLOOP	51	# MAINLOOP
49	EV::loop; # loop until EV::loop_done is called	52	EV::loop; # loop until EV::unloop is called or all watchers stop
50	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
51	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
52		55
53	=head1 DESCRIPTION	56	=head1 DESCRIPTION
54		57
55	This module provides an interface to libev	58	This module provides an interface to libev
56	(L<http://software.schmorp.de/pkg/libev.html>).	59	(L<http://software.schmorp.de/pkg/libev.html>). While the documentation
		60	below is comprehensive, one might also consult the documentation of libev
		61	itself (L<http://cvs.schmorp.de/libev/ev.html>) for more subtle details on
		62	watcher semantics or some discussion on the available backends, or how to
		63	force a specific backend with C<LIBEV_FLAGS>.
57		64
58	=cut	65	=cut
59		66
60	package EV;	67	package EV;
61		68
62	use strict;	69	use strict;
63		70
64	BEGIN {	71	BEGIN {
65	our $VERSION = '0.1';	72	our $VERSION = '1.4';
66	use XSLoader;	73	use XSLoader;
67	XSLoader::load "EV", $VERSION;	74	XSLoader::load "EV", $VERSION;
68	}	75	}
69		76
70	@EV::Io::ISA =	77	@EV::IO::ISA =
71	@EV::Timer::ISA =	78	@EV::Timer::ISA =
72	@EV::Periodic::ISA =	79	@EV::Periodic::ISA =
73	@EV::Signal::ISA =	80	@EV::Signal::ISA =
74	@EV::Idle::ISA =	81	@EV::Idle::ISA =
75	@EV::Prepare::ISA =	82	@EV::Prepare::ISA =
76	@EV::Check::ISA =	83	@EV::Check::ISA =
		84	@EV::Child::ISA =
		85	@EV::Embed::ISA =
77	@EV::Child::ISA = "EV::Watcher";	86	@EV::Stat::ISA = "EV::Watcher";
78		87
79	=head1 BASIC INTERFACE	88	=head1 BASIC INTERFACE
80		89
81	=over 4	90	=over 4
82		91
…		…
96		105
97	Returns the time the last event loop iteration has been started. This	106	Returns the time the last event loop iteration has been started. This
98	is the time that (relative) timers are based on, and refering to it is	107	is the time that (relative) timers are based on, and refering to it is
99	usually faster then calling EV::time.	108	usually faster then calling EV::time.
100		109
101	=item $method = EV::ev_method	110	=item $method = EV::method
102		111
103	Returns an integer describing the backend used by libev (EV::METHOD_SELECT	112	Returns an integer describing the backend used by libev (EV::METHOD_SELECT
104	or EV::METHOD_EPOLL).	113	or EV::METHOD_EPOLL).
105		114
106	=item EV::loop [$flags]	115	=item EV::loop [$flags]
107		116
108	Begin checking for events and calling callbacks. It returns when a	117	Begin checking for events and calling callbacks. It returns when a
109	callback calls EV::loop_done.	118	callback calls EV::unloop.
110		119
111	The $flags argument can be one of the following:	120	The $flags argument can be one of the following:
112		121
113	0 as above	122	0 as above
114	EV::LOOP_ONESHOT block at most once (wait, but do not loop)	123	EV::LOOP_ONESHOT block at most once (wait, but do not loop)
115	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)	124	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
116		125
117	=item EV::loop_done [$how]	126	=item EV::unloop [$how]
118		127
119	When called with no arguments or an argument of 1, makes the innermost	128	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the
120	call to EV::loop return.	129	innermost call to EV::loop return.
121		130
122	When called with an agrument of 2, all calls to EV::loop will return as	131	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as
123	fast as possible.	132	fast as possible.
124		133
125	=back	134	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
126		135
		136	This function rolls together an I/O and a timer watcher for a single
		137	one-shot event without the need for managing a watcher object.
		138
		139	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>
		140	must be a bitset containing either C<EV::READ>, C<EV::WRITE> or C<EV::READ
		141	\| EV::WRITE>, indicating the type of I/O event you want to wait for. If
		142	you do not want to wait for some I/O event, specify C<undef> for
		143	C<$fh_or_undef> and C<0> for C<$events>).
		144
		145	If timeout is C<undef> or negative, then there will be no
		146	timeout. Otherwise a EV::timer with this value will be started.
		147
		148	When an error occurs or either the timeout or I/O watcher triggers, then
		149	the callback will be called with the received event set (in general
		150	you can expect it to be a combination of C<EV:ERROR>, C<EV::READ>,
		151	C<EV::WRITE> and C<EV::TIMEOUT>).
		152
		153	EV::once doesn't return anything: the watchers stay active till either
		154	of them triggers, then they will be stopped and freed, and the callback
		155	invoked.
		156
		157	=back
		158
127	=head2 WATCHER	159	=head2 WATCHER OBJECTS
128		160
129	A watcher is an object that gets created to record your interest in some	161	A watcher is an object that gets created to record your interest in some
130	event. For instance, if you want to wait for STDIN to become readable, you	162	event. For instance, if you want to wait for STDIN to become readable, you
131	would create an EV::io watcher for that:	163	would create an EV::io watcher for that:
132		164
…		…
150	In the rare case where one wants to create a watcher but not start it at	182	In the rare case where one wants to create a watcher but not start it at
151	the same time, each constructor has a variant with a trailing C<_ns> in	183	the same time, each constructor has a variant with a trailing C<_ns> in
152	its name, e.g. EV::io has a non-starting variant EV::io_ns and so on.	184	its name, e.g. EV::io has a non-starting variant EV::io_ns and so on.
153		185
154	Please note that a watcher will automatically be stopped when the watcher	186	Please note that a watcher will automatically be stopped when the watcher
155	object is returned, so you I<need> to keep the watcher objects returned by	187	object is destroyed, so you I<need> to keep the watcher objects returned by
156	the constructors.	188	the constructors.
157		189
158	=head2 WATCHER TYPES	190	Also, all methods changing some aspect of a watcher (->set, ->priority,
		191	->fh and so on) automatically stop and start it again if it is active,
		192	which means pending events get lost.
159		193
160	Now lets move to the existing watcher types and asociated methods.	194	=head2 COMMON WATCHER METHODS
161		195
162	The following methods are available for all watchers. Then followes a	196	This section lists methods common to all watchers.
163	description of each watcher constructor (EV::io, EV::timer, EV::periodic,
164	EV::signal, EV::child, EV::idle, EV::prepare and EV::check), followed by
165	any type-specific methods (if any).
166		197
167	=over 4	198	=over 4
168		199
169	=item $w->start	200	=item $w->start
170		201
…		…
180		211
181	=item $bool = $w->is_active	212	=item $bool = $w->is_active
182		213
183	Returns true if the watcher is active, false otherwise.	214	Returns true if the watcher is active, false otherwise.
184		215
		216	=item $current_data = $w->data
		217
		218	=item $old_data = $w->data ($new_data)
		219
		220	Queries a freely usable data scalar on the watcher and optionally changes
		221	it. This is a way to associate custom data with a watcher:
		222
		223	my $w = EV::timer 60, 0, sub {
		224	warn $_[0]->data;
		225	};
		226	$w->data ("print me!");
		227
185	=item $current_cb = $w->cb	228	=item $current_cb = $w->cb
186		229
187	=item $old_cb = $w->cb ($new_cb)	230	=item $old_cb = $w->cb ($new_cb)
188		231
189	Queries the callback on the watcher and optionally changes it. You cna do	232	Queries the callback on the watcher and optionally changes it. You can do
190	this at any time.	233	this at any time without the watcher restarting.
		234
		235	=item $current_priority = $w->priority
		236
		237	=item $old_priority = $w->priority ($new_priority)
		238
		239	Queries the priority on the watcher and optionally changes it. Pending
		240	watchers with higher priority will be invoked first. The valid range of
		241	priorities lies between EV::MAXPRI (default 2) and EV::MINPRI (default
		242	-2). If the priority is outside this range it will automatically be
		243	normalised to the nearest valid priority.
		244
		245	The default priority of any newly-created watcher is 0.
		246
		247	Note that the priority semantics have not yet been fleshed out and are
		248	subject to almost certain change.
191		249
192	=item $w->trigger ($revents)	250	=item $w->trigger ($revents)
193		251
194	Call the callback now with the given event mask.	252	Call the callback now with the given event mask.
195		253
		254	=item $previous_state = $w->keepalive ($bool)
		255
		256	Normally, C<EV::loop> will return when there are no active watchers
		257	(which is a "deadlock" because no progress can be made anymore). This is
		258	convinient because it allows you to start your watchers (and your jobs),
		259	call C<EV::loop> once and when it returns you know that all your jobs are
		260	finished (or they forgot to register some watchers for their task :).
		261
		262	Sometimes, however, this gets in your way, for example when you the module
		263	that calls C<EV::loop> (usually the main program) is not the same module
		264	as a long-living watcher (for example a DNS client module written by
		265	somebody else even). Then you might want any outstanding requests to be
		266	handled, but you would not want to keep C<EV::loop> from returning just
		267	because you happen to have this long-running UDP port watcher.
		268
		269	In this case you can clear the keepalive status, which means that even
		270	though your watcher is active, it won't keep C<EV::loop> from returning.
		271
		272	The initial value for keepalive is true (enabled), and you cna change it
		273	any time.
		274
		275	Example: Register an IO watcher for some UDP socket but do not keep the
		276	event loop from running just because of that watcher.
		277
		278	my $udp_socket = ...
		279	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
		280	$udp_watcher->keepalive (0);
		281
		282	=back
		283
		284
		285	=head2 WATCHER TYPES
		286
		287	Each of the following subsections describes a single watcher type.
		288
		289	=head3 IO WATCHERS - is this file descriptor readable or writable?
		290
		291	=over 4
196		292
197	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	293	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
198		294
199	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback	295	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
200		296
201	As long as the returned watcher object is alive, call the C<$callback>	297	As long as the returned watcher object is alive, call the C<$callback>
202	when the events specified in C<$eventmask>.	298	when at least one of events specified in C<$eventmask> occurs.
203		299
204	The $eventmask can be one or more of these constants ORed together:	300	The $eventmask can be one or more of these constants ORed together:
205		301
206	EV::READ wait until read() wouldn't block anymore	302	EV::READ wait until read() wouldn't block anymore
207	EV::WRITE wait until write() wouldn't block anymore	303	EV::WRITE wait until write() wouldn't block anymore
…		…
223		319
224	=item $old_eventmask = $w->events ($new_eventmask)	320	=item $old_eventmask = $w->events ($new_eventmask)
225		321
226	Returns the previously set event mask and optionally set a new one.	322	Returns the previously set event mask and optionally set a new one.
227		323
		324	=back
		325
		326
		327	=head3 TIMER WATCHERS - relative and optionally repeating timeouts
		328
		329	=over 4
228		330
229	=item $w = EV::timer $after, $repeat, $callback	331	=item $w = EV::timer $after, $repeat, $callback
230		332
231	=item $w = EV::timer_ns $after, $repeat, $callback	333	=item $w = EV::timer_ns $after, $repeat, $callback
232		334
233	Calls the callback after C<$after> seconds. If C<$repeat> is non-zero,	335	Calls the callback after C<$after> seconds (which may be fractional). If
234	the timer will be restarted (with the $repeat value as $after) after the	336	C<$repeat> is non-zero, the timer will be restarted (with the $repeat
235	callback returns.	337	value as $after) after the callback returns.
236		338
237	This means that the callback would be called roughly after C<$after>	339	This means that the callback would be called roughly after C<$after>
238	seconds, and then every C<$repeat> seconds. "Roughly" because the time of	340	seconds, and then every C<$repeat> seconds. The timer does his best not
239	callback processing is not taken into account, so the timer will slowly	341	to drift, but it will not invoke the timer more often then once per event
240	drift. If that isn't acceptable, look at EV::periodic.	342	loop iteration, and might drift in other cases. If that isn't acceptable,
		343	look at EV::periodic, which can provide long-term stable timers.
241		344
242	The timer is based on a monotonic clock, that is if somebody is sitting	345	The timer is based on a monotonic clock, that is, if somebody is sitting
243	in front of the machine while the timer is running and changes the system	346	in front of the machine while the timer is running and changes the system
244	clock, the timer will nevertheless run (roughly) the same time.	347	clock, the timer will nevertheless run (roughly) the same time.
245		348
246	The C<timer_ns> variant doesn't start (activate) the newly created watcher.	349	The C<timer_ns> variant doesn't start (activate) the newly created watcher.
247		350
248	=item $w->set ($after, $repeat)	351	=item $w->set ($after, $repeat)
249		352
250	Reconfigures the watcher, see the constructor above for details. Can be at	353	Reconfigures the watcher, see the constructor above for details. Can be called at
251	any time.	354	any time.
252		355
253	=item $w->again	356	=item $w->again
254		357
255	Similar to the C<start> method, but has special semantics for repeating timers:	358	Similar to the C<start> method, but has special semantics for repeating timers:
		359
		360	If the timer is active and non-repeating, it will be stopped.
256		361
257	If the timer is active and repeating, reset the timeout to occur	362	If the timer is active and repeating, reset the timeout to occur
258	C<$repeat> seconds after now.	363	C<$repeat> seconds after now.
259		364
260	If the timer is active and non-repeating, it will be stopped.
261
262	If the timer is in active and repeating, start it.	365	If the timer is inactive and repeating, start it using the repeat value.
263		366
264	Otherwise do nothing.	367	Otherwise do nothing.
265		368
266	This behaviour is useful when you have a timeout for some IO	369	This behaviour is useful when you have a timeout for some IO
267	operation. You create a timer object with the same value for C<$after> and	370	operation. You create a timer object with the same value for C<$after> and
268	C<$repeat>, and then, in the read/write watcher, run the C<again> method	371	C<$repeat>, and then, in the read/write watcher, run the C<again> method
269	on the timeout.	372	on the timeout.
270		373
		374	=back
271		375
		376
		377	=head3 PERIODIC WATCHERS - to cron or not to cron?
		378
		379	=over 4
		380
272	=item $w = EV::periodic $at, $interval, $callback	381	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
273		382
274	=item $w = EV::periodic_ns $at, $interval, $callback	383	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
275		384
276	Similar to EV::timer, but the time is given as an absolute point in time	385	Similar to EV::timer, but is not based on relative timeouts but on
277	(C<$at>), plus an optional C<$interval>.	386	absolute times. Apart from creating "simple" timers that trigger "at" the
		387	specified time, it can also be used for non-drifting absolute timers and
		388	more complex, cron-like, setups that are not adversely affected by time
		389	jumps (i.e. when the system clock is changed by explicit date -s or other
		390	means such as ntpd). It is also the most complex watcher type in EV.
278		391
279	If the C<$interval> is zero, then the callback will be called at the time	392	It has three distinct "modes":
280	C<$at> if that is in the future, or as soon as possible if it is in the
281	past. It will not automatically repeat.
282		393
283	If the C<$interval> is nonzero, then the watcher will always be scheduled	394	=over 4
284	to time out at the next C<$at + N * $interval> time.
285		395
286	This can be used to schedule a callback to run at very regular intervals,	396	=item * absolute timer ($interval = $reschedule_cb = 0)
287	as long as the processing time is less then the interval (otherwise	397
288	obviously events will be skipped).	398	This time simply fires at the wallclock time C<$at> and doesn't repeat. It
		399	will not adjust when a time jump occurs, that is, if it is to be run
		400	at January 1st 2011 then it will run when the system time reaches or
		401	surpasses this time.
		402
		403	=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0)
		404
		405	In this mode the watcher will always be scheduled to time out at the
		406	next C<$at + N * $interval> time (for some integer N) and then repeat,
		407	regardless of any time jumps.
		408
		409	This can be used to create timers that do not drift with respect to system
		410	time:
		411
		412	my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" };
		413
		414	That doesn't mean there will always be 3600 seconds in between triggers,
		415	but only that the the clalback will be called when the system time shows a
		416	full hour (UTC).
289		417
290	Another way to think about it (for the mathematically inclined) is that	418	Another way to think about it (for the mathematically inclined) is that
291	EV::periodic will try to run the callback at the next possible time where	419	EV::periodic will try to run the callback in this mode at the next
292	C<$time = $at (mod $interval)>, regardless of any time jumps.	420	possible time where C<$time = $at (mod $interval)>, regardless of any time
		421	jumps.
293		422
294	This periodic timer is based on "wallclock time", that is, if the clock	423	=item * manual reschedule mode ($reschedule_cb = coderef)
295	changes (C<ntp>, C<date -s> etc.), then the timer will nevertheless run at	424
296	the specified time.	425	In this mode $interval and $at are both being ignored. Instead, each
		426	time the periodic watcher gets scheduled, the reschedule callback
		427	($reschedule_cb) will be called with the watcher as first, and the current
		428	time as second argument.
		429
		430	I<This callback MUST NOT stop or destroy this or any other periodic
		431	watcher, ever>. If you need to stop it, return 1e30 and stop it
		432	afterwards.
		433
		434	It must return the next time to trigger, based on the passed time value
		435	(that is, the lowest time value larger than to the second argument). It
		436	will usually be called just before the callback will be triggered, but
		437	might be called at other times, too.
		438
		439	This can be used to create very complex timers, such as a timer that
		440	triggers on each midnight, local time (actually 24 hours after the last
		441	midnight, to keep the example simple. If you know a way to do it correctly
		442	in about the same space (without requiring elaborate modules), drop me a
		443	note :):
		444
		445	my $daily = EV::periodic 0, 0, sub {
		446	my ($w, $now) = @_;
		447
		448	use Time::Local ();
		449	my (undef, undef, undef, $d, $m, $y) = localtime $now;
		450	86400 + Time::Local::timelocal 0, 0, 0, $d, $m, $y
		451	}, sub {
		452	print "it's midnight or likely shortly after, now\n";
		453	};
		454
		455	=back
297		456
298	The C<periodic_ns> variant doesn't start (activate) the newly created watcher.	457	The C<periodic_ns> variant doesn't start (activate) the newly created watcher.
299		458
300	=item $w->set ($at, $interval)	459	=item $w->set ($at, $interval, $reschedule_cb)
301		460
302	Reconfigures the watcher, see the constructor above for details. Can be at	461	Reconfigures the watcher, see the constructor above for details. Can be called at
303	any time.	462	any time.
304		463
		464	=item $w->again
		465
		466	Simply stops and starts the watcher again.
		467
		468	=back
		469
		470
		471	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
		472
		473	=over 4
305		474
306	=item $w = EV::signal $signal, $callback	475	=item $w = EV::signal $signal, $callback
307		476
308	=item $w = EV::signal_ns $signal, $callback	477	=item $w = EV::signal_ns $signal, $callback
309		478
310	Call the callback when $signal is received (the signal can be specified	479	Call the callback when $signal is received (the signal can be specified by
311	by number or by name, just as with kill or %SIG).	480	number or by name, just as with C<kill> or C<%SIG>).
312		481
313	EV will grab the signal for the process (the kernel only allows one	482	EV will grab the signal for the process (the kernel only allows one
314	component to receive a signal at a time) when you start a signal watcher,	483	component to receive a signal at a time) when you start a signal watcher,
315	and removes it again when you stop it. Perl does the same when you	484	and removes it again when you stop it. Perl does the same when you
316	add/remove callbacks to %SIG, so watch out.	485	add/remove callbacks to C<%SIG>, so watch out.
317		486
318	You can have as many signal watchers per signal as you want.	487	You can have as many signal watchers per signal as you want.
319		488
320	The C<signal_ns> variant doesn't start (activate) the newly created watcher.	489	The C<signal_ns> variant doesn't start (activate) the newly created watcher.
321		490
322	=item $w->set ($signal)	491	=item $w->set ($signal)
323		492
324	Reconfigures the watcher, see the constructor above for details. Can be at	493	Reconfigures the watcher, see the constructor above for details. Can be
		494	called at any time.
		495
		496	=item $current_signum = $w->signal
		497
		498	=item $old_signum = $w->signal ($new_signal)
		499
		500	Returns the previously set signal (always as a number not name) and
		501	optionally set a new one.
		502
		503	=back
		504
		505
		506	=head3 CHILD WATCHERS - watch out for process status changes
		507
		508	=over 4
		509
		510	=item $w = EV::child $pid, $callback
		511
		512	=item $w = EV::child_ns $pid, $callback
		513
		514	Call the callback when a status change for pid C<$pid> (or any pid if
		515	C<$pid> is 0) has been received. More precisely: when the process receives
		516	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
		517	changed/zombie children and call the callback.
		518
		519	It is valid (and fully supported) to install a child watcher after a child
		520	has exited but before the event loop has started its next iteration (for
		521	example, first you C<fork>, then the new child process might exit, and
		522	only then do you install a child watcher in the parent for the new pid).
		523
		524	You can access both exit (or tracing) status and pid by using the
		525	C<rstatus> and C<rpid> methods on the watcher object.
		526
		527	You can have as many pid watchers per pid as you want, they will all be
		528	called.
		529
		530	The C<child_ns> variant doesn't start (activate) the newly created watcher.
		531
		532	=item $w->set ($pid)
		533
		534	Reconfigures the watcher, see the constructor above for details. Can be called at
325	any time.	535	any time.
326		536
		537	=item $current_pid = $w->pid
327		538
328	=item $w = EV::child $pid, $callback	539	=item $old_pid = $w->pid ($new_pid)
329		540
330	=item $w = EV::child_ns $pid, $callback	541	Returns the previously set process id and optionally set a new one.
331		542
332	Call the callback when a status change for pid C<$pid> (or any pid	543	=item $exit_status = $w->rstatus
333	if C<$pid> is 0) has been received. More precisely: when the process
334	receives a SIGCHLD, EV will fetch the outstanding exit/wait status for all
335	changed/zombie children and call the callback.
336		544
337	Unlike all other callbacks, this callback will be called with an	545	Return the exit/wait status (as returned by waitpid, see the waitpid entry
338	additional third argument which is the exit status. See the C<waitpid>	546	in perlfunc).
339	function for details.
340		547
341	You can have as many pid watchers per pid as you want.	548	=item $pid = $w->rpid
342		549
343	The C<child_ns> variant doesn't start (activate) the newly created watcher.	550	Return the pid of the awaited child (useful when you have installed a
		551	watcher for all pids).
344		552
345	=item $w->set ($pid)	553	=back
346		554
347	Reconfigures the watcher, see the constructor above for details. Can be at
348	any time.
349		555
		556	=head3 IDLE WATCHERS - when you've got nothing better to do...
		557
		558	=over 4
350		559
351	=item $w = EV::idle $callback	560	=item $w = EV::idle $callback
352		561
353	=item $w = EV::idle_ns $callback	562	=item $w = EV::idle_ns $callback
354		563
…		…
358	The process will not block as long as any idle watchers are active, and	567	The process will not block as long as any idle watchers are active, and
359	they will be called repeatedly until stopped.	568	they will be called repeatedly until stopped.
360		569
361	The C<idle_ns> variant doesn't start (activate) the newly created watcher.	570	The C<idle_ns> variant doesn't start (activate) the newly created watcher.
362		571
		572	=back
		573
		574
		575	=head3 PREPARE WATCHERS - customise your event loop!
		576
		577	=over 4
363		578
364	=item $w = EV::prepare $callback	579	=item $w = EV::prepare $callback
365		580
366	=item $w = EV::prepare_ns $callback	581	=item $w = EV::prepare_ns $callback
367		582
…		…
370		585
371	See the EV::check watcher, below, for explanations and an example.	586	See the EV::check watcher, below, for explanations and an example.
372		587
373	The C<prepare_ns> variant doesn't start (activate) the newly created watcher.	588	The C<prepare_ns> variant doesn't start (activate) the newly created watcher.
374		589
		590	=back
		591
		592
		593	=head3 CHECK WATCHERS - customise your event loop even more!
		594
		595	=over 4
375		596
376	=item $w = EV::check $callback	597	=item $w = EV::check $callback
377		598
378	=item $w = EV::check_ns $callback	599	=item $w = EV::check_ns $callback
379		600
…		…
391	# do nothing unless active	612	# do nothing unless active
392	$dispatcher->{_event_queue_h}	613	$dispatcher->{_event_queue_h}
393	or return;	614	or return;
394		615
395	# make the dispatcher handle any outstanding stuff	616	# make the dispatcher handle any outstanding stuff
		617	... not shown
396		618
397	# create an IO watcher for each and every socket	619	# create an IO watcher for each and every socket
398	@snmp_watcher = (	620	@snmp_watcher = (
399	(map { EV::io $_, EV::READ, sub { } }	621	(map { EV::io $_, EV::READ, sub { } }
400	keys %{ $dispatcher->{_descriptors} }),	622	keys %{ $dispatcher->{_descriptors} }),
		623
		624	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
		625	? $event->[Net::SNMP::Dispatcher::_TIME] - EV::now : 0),
		626	0, sub { },
401	);	627	);
402
403	# if there are any timeouts, also create a timer
404	push @snmp_watcher, EV::timer $event->[Net::SNMP::Dispatcher::_TIME] - EV::now, 0, sub { }
405	if $event->[Net::SNMP::Dispatcher::_ACTIVE];
406	};	628	};
407		629
408	The callbacks are irrelevant, the only purpose of those watchers is	630	The callbacks are irrelevant (and are not even being called), the
409	to wake up the process as soon as one of those events occurs (socket	631	only purpose of those watchers is to wake up the process as soon as
410	readable, or timer timed out). The corresponding EV::check watcher will then	632	one of those events occurs (socket readable, or timer timed out). The
411	clean up:	633	corresponding EV::check watcher will then clean up:
412		634
413	our $snmp_check = EV::check sub {	635	our $snmp_check = EV::check sub {
414	# destroy all watchers	636	# destroy all watchers
415	@snmp_watcher = ();	637	@snmp_watcher = ();
416		638
417	# make the dispatcher handle any new stuff	639	# make the dispatcher handle any new stuff
		640	... not shown
418	};	641	};
419		642
420	The callbacks of the created watchers will not be called as the watchers	643	The callbacks of the created watchers will not be called as the watchers
421	are destroyed before this cna happen (remember EV::check gets called	644	are destroyed before this cna happen (remember EV::check gets called
422	first).	645	first).
423		646
424	The C<check_ns> variant doesn't start (activate) the newly created watcher.	647	The C<check_ns> variant doesn't start (activate) the newly created watcher.
425		648
426	=back	649	=back
427		650
		651	=head3 STAT WATCHERS - did the file attributes just change?
		652
		653	=over 4
		654
		655	=item $w = EV::stat $path, $interval, $callback
		656
		657	=item $w = EV::stat_ns $path, $interval, $callback
		658
		659	Call the callback when a file status change has been detected on
		660	C<$path>. The C<$path> does not need to exist, changing from "path exists"
		661	to "path does not exist" is a status change like any other.
		662
		663	The C<$interval> is a recommended polling interval for systems where
		664	OS-supported change notifications don't exist or are not supported. If
		665	you use C<0> then an unspecified default is used (which is highly
		666	recommended!), which is to be expected to be around five seconds usually.
		667
		668	This watcher type is not meant for massive numbers of stat watchers,
		669	as even with OS-supported change notifications, this can be
		670	resource-intensive.
		671
		672	The C<stat_ns> variant doesn't start (activate) the newly created watcher.
		673
		674	=item $w->set ($path, $interval)
		675
		676	Reconfigures the watcher, see the constructor above for details. Can be
		677	called at any time.
		678
		679	=item $current_path = $w->path
		680
		681	=item $old_path = $w->path ($new_path)
		682
		683	Returns the previously set path and optionally set a new one.
		684
		685	=item $current_interval = $w->interval
		686
		687	=item $old_interval = $w->interval ($new_interval)
		688
		689	Returns the previously set interval and optionally set a new one. Can be
		690	used to query the actual interval used.
		691
		692	=back
		693
		694
428	=head1 THREADS	695	=head1 THREADS
429		696
430	Threads are not supported by this in any way. Perl pseudo-threads is evil	697	Threads are not supported by this module in any way. Perl pseudo-threads
431	stuff and must die.	698	is evil stuff and must die. As soon as Perl gains real threads I will work
		699	on thread support for it.
		700
		701	=head1 FORK
		702
		703	Most of the "improved" event delivering mechanisms of modern operating
		704	systems have quite a few problems with fork(2) (to put it bluntly: it is
		705	not supported and usually destructive). Libev makes it possible to work
		706	around this by having a function that recreates the kernel state after
		707	fork in the child.
		708
		709	On non-win32 platforms, this module requires the pthread_atfork
		710	functionality to do this automatically for you. This function is quite
		711	buggy on most BSDs, though, so YMMV. The overhead for this is quite
		712	negligible, because everything the function currently does is set a flag
		713	that is checked only when the event loop gets used the next time, so when
		714	you do fork but not use EV, the overhead is minimal.
		715
		716	On win32, there is no notion of fork so all this doesn't apply, of course.
432		717
433	=cut	718	=cut
434		719
435	our $DIED = sub {	720	our $DIED = sub {
436	warn "EV: error in callback (ignoring): $@";	721	warn "EV: error in callback (ignoring): $@";
437	};	722	};
438		723
439	init;	724	default_loop
440		725	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';
441	push @AnyEvent::REGISTRY, [EV => "EV::AnyEvent"];
442		726
443	1;	727	1;
444		728
445	=head1 SEE ALSO	729	=head1 SEE ALSO
446		730
447	L<EV::DNS>, L<EV::AnyEvent>.	731	L<EV::DNS>.
448		732
449	=head1 AUTHOR	733	=head1 AUTHOR
450		734
451	Marc Lehmann <schmorp@schmorp.de>	735	Marc Lehmann <schmorp@schmorp.de>
452	http://home.schmorp.de/	736	http://home.schmorp.de/

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Comparing EV/EV.pm (file contents): Revision 1.20 by root, Thu Nov 1 17:17:32 2007 UTC vs. Revision 1.55 by root, Tue Nov 27 08:11:52 2007 UTC

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Comparing EV/EV.pm (file contents):
Revision 1.20 by root, Thu Nov 1 17:17:32 2007 UTC vs.
Revision 1.55 by root, Tue Nov 27 08:11:52 2007 UTC