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

Comparing EV/EV.pm (file contents):
Revision 1.28 by root, Sun Nov 4 16:52:52 2007 UTC vs.
Revision 1.57 by root, Wed Nov 28 17:32:24 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	my $w = EV::signal 3, sub {
39	warn "sigquit received (this is GNU/Linux, right?)\n";
40	};
41
42	# CHILD/PID STATUS CHANGES	38	# CHILD/PID STATUS CHANGES
43		39
44	my $w = EV::child 666, sub {	40	my $w = EV::child 666, sub {
45	my ($w, $revents) = @_;	41	my ($w, $revents) = @_;
46	# my $pid = $w->rpid;
47	my $status = $w->rstatus;	42	my $status = $w->rstatus;
48	};	43	};
		44
		45	# STAT CHANGES
		46	my $w = EV::stat "/etc/passwd", 10, sub {
		47	my ($w, $revents) = @_;
		48	warn $w->path, " has changed somehow.\n";
		49	};
49		50
50	# MAINLOOP	51	# MAINLOOP
51	EV::loop; # loop until EV::loop_done is called	52	EV::loop; # loop until EV::unloop is called or all watchers stop
52	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
53	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
54		55
55	=head1 DESCRIPTION	56	=head1 DESCRIPTION
56		57
57	This module provides an interface to libev	58	This module provides an interface to libev
58	(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>.
59		64
60	=cut	65	=cut
61		66
62	package EV;	67	package EV;
63		68
64	use strict;	69	use strict;
65		70
66	BEGIN {	71	BEGIN {
67	our $VERSION = '0.5';	72	our $VERSION = '1.4';
68	use XSLoader;	73	use XSLoader;
69	XSLoader::load "EV", $VERSION;	74	XSLoader::load "EV", $VERSION;
70	}	75	}
71		76
72	@EV::Io::ISA =	77	@EV::IO::ISA =
73	@EV::Timer::ISA =	78	@EV::Timer::ISA =
74	@EV::Periodic::ISA =	79	@EV::Periodic::ISA =
75	@EV::Signal::ISA =	80	@EV::Signal::ISA =
		81	@EV::Child::ISA =
		82	@EV::Stat::ISA =
76	@EV::Idle::ISA =	83	@EV::Idle::ISA =
77	@EV::Prepare::ISA =	84	@EV::Prepare::ISA =
78	@EV::Check::ISA =	85	@EV::Check::ISA =
79	@EV::Child::ISA = "EV::Watcher";	86	@EV::Embed::ISA =
		87	@EV::Fork::ISA =
		88	"EV::Watcher";
80		89
81	=head1 BASIC INTERFACE	90	=head1 BASIC INTERFACE
82		91
83	=over 4	92	=over 4
84		93
…		…
98		107
99	Returns the time the last event loop iteration has been started. This	108	Returns the time the last event loop iteration has been started. This
100	is the time that (relative) timers are based on, and refering to it is	109	is the time that (relative) timers are based on, and refering to it is
101	usually faster then calling EV::time.	110	usually faster then calling EV::time.
102		111
103	=item $method = EV::ev_method	112	=item $method = EV::method
104		113
105	Returns an integer describing the backend used by libev (EV::METHOD_SELECT	114	Returns an integer describing the backend used by libev (EV::METHOD_SELECT
106	or EV::METHOD_EPOLL).	115	or EV::METHOD_EPOLL).
107		116
108	=item EV::loop [$flags]	117	=item EV::loop [$flags]
109		118
110	Begin checking for events and calling callbacks. It returns when a	119	Begin checking for events and calling callbacks. It returns when a
111	callback calls EV::loop_done.	120	callback calls EV::unloop.
112		121
113	The $flags argument can be one of the following:	122	The $flags argument can be one of the following:
114		123
115	0 as above	124	0 as above
116	EV::LOOP_ONESHOT block at most once (wait, but do not loop)	125	EV::LOOP_ONESHOT block at most once (wait, but do not loop)
117	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)	126	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
118		127
119	=item EV::loop_done [$how]	128	=item EV::unloop [$how]
120		129
121	When called with no arguments or an argument of 1, makes the innermost	130	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the
122	call to EV::loop return.	131	innermost call to EV::loop return.
123		132
124	When called with an agrument of 2, all calls to EV::loop will return as	133	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as
125	fast as possible.	134	fast as possible.
126		135
127	=back	136	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
128		137
		138	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.
		140
		141	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>
		142	must be a bitset containing either C<EV::READ>, C<EV::WRITE> or C<EV::READ
		143	\| EV::WRITE>, indicating the type of I/O event you want to wait for. If
		144	you do not want to wait for some I/O event, specify C<undef> for
		145	C<$fh_or_undef> and C<0> for C<$events>).
		146
		147	If timeout is C<undef> or negative, then there will be no
		148	timeout. Otherwise a EV::timer with this value will be started.
		149
		150	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
		152	you can expect it to be a combination of C<EV:ERROR>, C<EV::READ>,
		153	C<EV::WRITE> and C<EV::TIMEOUT>).
		154
		155	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
		157	invoked.
		158
		159	=back
		160
129	=head2 WATCHER	161	=head2 WATCHER OBJECTS
130		162
131	A watcher is an object that gets created to record your interest in some	163	A watcher is an object that gets created to record your interest in some
132	event. For instance, if you want to wait for STDIN to become readable, you	164	event. For instance, if you want to wait for STDIN to become readable, you
133	would create an EV::io watcher for that:	165	would create an EV::io watcher for that:
134		166
…		…
159		191
160	Also, all methods changing some aspect of a watcher (->set, ->priority,	192	Also, all methods changing some aspect of a watcher (->set, ->priority,
161	->fh and so on) automatically stop and start it again if it is active,	193	->fh and so on) automatically stop and start it again if it is active,
162	which means pending events get lost.	194	which means pending events get lost.
163		195
164	=head2 WATCHER TYPES	196	=head2 COMMON WATCHER METHODS
165		197
166	Now lets move to the existing watcher types and asociated methods.	198	This section lists methods common to all watchers.
167
168	The following methods are available for all watchers. Then followes a
169	description of each watcher constructor (EV::io, EV::timer, EV::periodic,
170	EV::signal, EV::child, EV::idle, EV::prepare and EV::check), followed by
171	any type-specific methods (if any).
172		199
173	=over 4	200	=over 4
174		201
175	=item $w->start	202	=item $w->start
176		203
…		…
185	regardless of wether the watcher was active or not.	212	regardless of wether the watcher was active or not.
186		213
187	=item $bool = $w->is_active	214	=item $bool = $w->is_active
188		215
189	Returns true if the watcher is active, false otherwise.	216	Returns true if the watcher is active, false otherwise.
		217
		218	=item $current_data = $w->data
		219
		220	=item $old_data = $w->data ($new_data)
		221
		222	Queries a freely usable data scalar on the watcher and optionally changes
		223	it. This is a way to associate custom data with a watcher:
		224
		225	my $w = EV::timer 60, 0, sub {
		226	warn $_[0]->data;
		227	};
		228	$w->data ("print me!");
190		229
191	=item $current_cb = $w->cb	230	=item $current_cb = $w->cb
192		231
193	=item $old_cb = $w->cb ($new_cb)	232	=item $old_cb = $w->cb ($new_cb)
194		233
…		…
203	watchers with higher priority will be invoked first. The valid range of	242	watchers with higher priority will be invoked first. The valid range of
204	priorities lies between EV::MAXPRI (default 2) and EV::MINPRI (default	243	priorities lies between EV::MAXPRI (default 2) and EV::MINPRI (default
205	-2). If the priority is outside this range it will automatically be	244	-2). If the priority is outside this range it will automatically be
206	normalised to the nearest valid priority.	245	normalised to the nearest valid priority.
207		246
208	The default priority of any newly-created weatcher is 0.	247	The default priority of any newly-created watcher is 0.
		248
		249	Note that the priority semantics have not yet been fleshed out and are
		250	subject to almost certain change.
209		251
210	=item $w->trigger ($revents)	252	=item $w->trigger ($revents)
211		253
212	Call the callback now with the given event mask.	254	Call the callback now with the given event mask.
213		255
		256	=item $previous_state = $w->keepalive ($bool)
		257
		258	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
		260	convinient because it allows you to start your watchers (and your jobs),
		261	call C<EV::loop> once and when it returns you know that all your jobs are
		262	finished (or they forgot to register some watchers for their task :).
		263
		264	Sometimes, however, this gets in your way, for example when you the module
		265	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
		267	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
		269	because you happen to have this long-running UDP port watcher.
		270
		271	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.
		273
		274	The initial value for keepalive is true (enabled), and you cna change it
		275	any time.
		276
		277	Example: Register an IO watcher for some UDP socket but do not keep the
		278	event loop from running just because of that watcher.
		279
		280	my $udp_socket = ...
		281	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
		282	$udp_watcher->keepalive (0);
		283
		284	=back
		285
		286
		287	=head2 WATCHER TYPES
		288
		289	Each of the following subsections describes a single watcher type.
		290
		291	=head3 IO WATCHERS - is this file descriptor readable or writable?
		292
		293	=over 4
214		294
215	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	295	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
216		296
217	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback	297	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
218		298
219	As long as the returned watcher object is alive, call the C<$callback>	299	As long as the returned watcher object is alive, call the C<$callback>
220	when the events specified in C<$eventmask>.	300	when at least one of events specified in C<$eventmask> occurs.
221		301
222	The $eventmask can be one or more of these constants ORed together:	302	The $eventmask can be one or more of these constants ORed together:
223		303
224	EV::READ wait until read() wouldn't block anymore	304	EV::READ wait until read() wouldn't block anymore
225	EV::WRITE wait until write() wouldn't block anymore	305	EV::WRITE wait until write() wouldn't block anymore
…		…
241		321
242	=item $old_eventmask = $w->events ($new_eventmask)	322	=item $old_eventmask = $w->events ($new_eventmask)
243		323
244	Returns the previously set event mask and optionally set a new one.	324	Returns the previously set event mask and optionally set a new one.
245		325
		326	=back
		327
		328
		329	=head3 TIMER WATCHERS - relative and optionally repeating timeouts
		330
		331	=over 4
246		332
247	=item $w = EV::timer $after, $repeat, $callback	333	=item $w = EV::timer $after, $repeat, $callback
248		334
249	=item $w = EV::timer_ns $after, $repeat, $callback	335	=item $w = EV::timer_ns $after, $repeat, $callback
250		336
251	Calls the callback after C<$after> seconds. If C<$repeat> is non-zero,	337	Calls the callback after C<$after> seconds (which may be fractional). If
252	the timer will be restarted (with the $repeat value as $after) after the	338	C<$repeat> is non-zero, the timer will be restarted (with the $repeat
253	callback returns.	339	value as $after) after the callback returns.
254		340
255	This means that the callback would be called roughly after C<$after>	341	This means that the callback would be called roughly after C<$after>
256	seconds, and then every C<$repeat> seconds. "Roughly" because the time of	342	seconds, and then every C<$repeat> seconds. The timer does his best not
257	callback processing is not taken into account, so the timer will slowly	343	to drift, but it will not invoke the timer more often then once per event
258	drift. If that isn't acceptable, look at EV::periodic.	344	loop iteration, and might drift in other cases. If that isn't acceptable,
		345	look at EV::periodic, which can provide long-term stable timers.
259		346
260	The timer is based on a monotonic clock, that is if somebody is sitting	347	The timer is based on a monotonic clock, that is, if somebody is sitting
261	in front of the machine while the timer is running and changes the system	348	in front of the machine while the timer is running and changes the system
262	clock, the timer will nevertheless run (roughly) the same time.	349	clock, the timer will nevertheless run (roughly) the same time.
263		350
264	The C<timer_ns> variant doesn't start (activate) the newly created watcher.	351	The C<timer_ns> variant doesn't start (activate) the newly created watcher.
265		352
266	=item $w->set ($after, $repeat)	353	=item $w->set ($after, $repeat)
267		354
268	Reconfigures the watcher, see the constructor above for details. Can be at	355	Reconfigures the watcher, see the constructor above for details. Can be called at
269	any time.	356	any time.
270		357
271	=item $w->again	358	=item $w->again
272		359
273	Similar to the C<start> method, but has special semantics for repeating timers:	360	Similar to the C<start> method, but has special semantics for repeating timers:
		361
		362	If the timer is active and non-repeating, it will be stopped.
274		363
275	If the timer is active and repeating, reset the timeout to occur	364	If the timer is active and repeating, reset the timeout to occur
276	C<$repeat> seconds after now.	365	C<$repeat> seconds after now.
277		366
278	If the timer is active and non-repeating, it will be stopped.
279
280	If the timer is in active and repeating, start it.	367	If the timer is inactive and repeating, start it using the repeat value.
281		368
282	Otherwise do nothing.	369	Otherwise do nothing.
283		370
284	This behaviour is useful when you have a timeout for some IO	371	This behaviour is useful when you have a timeout for some IO
285	operation. You create a timer object with the same value for C<$after> and	372	operation. You create a timer object with the same value for C<$after> and
286	C<$repeat>, and then, in the read/write watcher, run the C<again> method	373	C<$repeat>, and then, in the read/write watcher, run the C<again> method
287	on the timeout.	374	on the timeout.
288		375
		376	=back
289		377
		378
		379	=head3 PERIODIC WATCHERS - to cron or not to cron?
		380
		381	=over 4
		382
290	=item $w = EV::periodic $at, $interval, $callback	383	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
291		384
292	=item $w = EV::periodic_ns $at, $interval, $callback	385	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
293		386
294	Similar to EV::timer, but the time is given as an absolute point in time	387	Similar to EV::timer, but is not based on relative timeouts but on
295	(C<$at>), plus an optional C<$interval>.	388	absolute times. Apart from creating "simple" timers that trigger "at" the
		389	specified time, it can also be used for non-drifting absolute timers and
		390	more complex, cron-like, setups that are not adversely affected by time
		391	jumps (i.e. when the system clock is changed by explicit date -s or other
		392	means such as ntpd). It is also the most complex watcher type in EV.
296		393
297	If the C<$interval> is zero, then the callback will be called at the time	394	It has three distinct "modes":
298	C<$at> if that is in the future, or as soon as possible if it is in the
299	past. It will not automatically repeat.
300		395
301	If the C<$interval> is nonzero, then the watcher will always be scheduled	396	=over 4
302	to time out at the next C<$at + N * $interval> time.
303		397
304	This can be used to schedule a callback to run at very regular intervals,	398	=item * absolute timer ($interval = $reschedule_cb = 0)
305	as long as the processing time is less then the interval (otherwise	399
306	obviously events will be skipped).	400	This time simply fires at the wallclock time C<$at> and doesn't repeat. It
		401	will not adjust when a time jump occurs, that is, if it is to be run
		402	at January 1st 2011 then it will run when the system time reaches or
		403	surpasses this time.
		404
		405	=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0)
		406
		407	In this mode the watcher will always be scheduled to time out at the
		408	next C<$at + N * $interval> time (for some integer N) and then repeat,
		409	regardless of any time jumps.
		410
		411	This can be used to create timers that do not drift with respect to system
		412	time:
		413
		414	my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" };
		415
		416	That doesn't mean there will always be 3600 seconds in between triggers,
		417	but only that the the clalback will be called when the system time shows a
		418	full hour (UTC).
307		419
308	Another way to think about it (for the mathematically inclined) is that	420	Another way to think about it (for the mathematically inclined) is that
309	EV::periodic will try to run the callback at the next possible time where	421	EV::periodic will try to run the callback in this mode at the next
310	C<$time = $at (mod $interval)>, regardless of any time jumps.	422	possible time where C<$time = $at (mod $interval)>, regardless of any time
		423	jumps.
311		424
312	This periodic timer is based on "wallclock time", that is, if the clock	425	=item * manual reschedule mode ($reschedule_cb = coderef)
313	changes (C<ntp>, C<date -s> etc.), then the timer will nevertheless run at	426
314	the specified time. This means it will never drift (it might jitter, but	427	In this mode $interval and $at are both being ignored. Instead, each
315	it will not drift).	428	time the periodic watcher gets scheduled, the reschedule callback
		429	($reschedule_cb) will be called with the watcher as first, and the current
		430	time as second argument.
		431
		432	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
		434	afterwards.
		435
		436	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
		438	will usually be called just before the callback will be triggered, but
		439	might be called at other times, too.
		440
		441	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
		443	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
		445	note :):
		446
		447	my $daily = EV::periodic 0, 0, sub {
		448	my ($w, $now) = @_;
		449
		450	use Time::Local ();
		451	my (undef, undef, undef, $d, $m, $y) = localtime $now;
		452	86400 + Time::Local::timelocal 0, 0, 0, $d, $m, $y
		453	}, sub {
		454	print "it's midnight or likely shortly after, now\n";
		455	};
		456
		457	=back
316		458
317	The C<periodic_ns> variant doesn't start (activate) the newly created watcher.	459	The C<periodic_ns> variant doesn't start (activate) the newly created watcher.
318		460
319	=item $w->set ($at, $interval)	461	=item $w->set ($at, $interval, $reschedule_cb)
320		462
321	Reconfigures the watcher, see the constructor above for details. Can be at	463	Reconfigures the watcher, see the constructor above for details. Can be called at
322	any time.	464	any time.
323		465
		466	=item $w->again
		467
		468	Simply stops and starts the watcher again.
		469
		470	=back
		471
		472
		473	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
		474
		475	=over 4
324		476
325	=item $w = EV::signal $signal, $callback	477	=item $w = EV::signal $signal, $callback
326		478
327	=item $w = EV::signal_ns $signal, $callback	479	=item $w = EV::signal_ns $signal, $callback
328		480
329	Call the callback when $signal is received (the signal can be specified	481	Call the callback when $signal is received (the signal can be specified by
330	by number or by name, just as with kill or %SIG).	482	number or by name, just as with C<kill> or C<%SIG>).
331		483
332	EV will grab the signal for the process (the kernel only allows one	484	EV will grab the signal for the process (the kernel only allows one
333	component to receive a signal at a time) when you start a signal watcher,	485	component to receive a signal at a time) when you start a signal watcher,
334	and removes it again when you stop it. Perl does the same when you	486	and removes it again when you stop it. Perl does the same when you
335	add/remove callbacks to %SIG, so watch out.	487	add/remove callbacks to C<%SIG>, so watch out.
336		488
337	You can have as many signal watchers per signal as you want.	489	You can have as many signal watchers per signal as you want.
338		490
339	The C<signal_ns> variant doesn't start (activate) the newly created watcher.	491	The C<signal_ns> variant doesn't start (activate) the newly created watcher.
340		492
341	=item $w->set ($signal)	493	=item $w->set ($signal)
342		494
343	Reconfigures the watcher, see the constructor above for details. Can be at	495	Reconfigures the watcher, see the constructor above for details. Can be
344	any time.	496	called at any time.
345		497
346	=item $current_signum = $w->signal	498	=item $current_signum = $w->signal
347		499
348	=item $old_signum = $w->signal ($new_signal)	500	=item $old_signum = $w->signal ($new_signal)
349		501
350	Returns the previously set signal (always as a number not name) and	502	Returns the previously set signal (always as a number not name) and
351	optionally set a new one.	503	optionally set a new one.
352		504
		505	=back
		506
		507
		508	=head3 CHILD WATCHERS - watch out for process status changes
		509
		510	=over 4
353		511
354	=item $w = EV::child $pid, $callback	512	=item $w = EV::child $pid, $callback
355		513
356	=item $w = EV::child_ns $pid, $callback	514	=item $w = EV::child_ns $pid, $callback
357		515
358	Call the callback when a status change for pid C<$pid> (or any pid	516	Call the callback when a status change for pid C<$pid> (or any pid if
359	if C<$pid> is 0) has been received. More precisely: when the process	517	C<$pid> is 0) has been received. More precisely: when the process receives
360	receives a SIGCHLD, EV will fetch the outstanding exit/wait status for all	518	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
361	changed/zombie children and call the callback.	519	changed/zombie children and call the callback.
362		520
363	You can access both status and pid by using the C<rstatus> and C<rpid>	521	It is valid (and fully supported) to install a child watcher after a child
364	methods on the watcher object.	522	has exited but before the event loop has started its next iteration (for
		523	example, first you C<fork>, then the new child process might exit, and
		524	only then do you install a child watcher in the parent for the new pid).
365		525
		526	You can access both exit (or tracing) status and pid by using the
		527	C<rstatus> and C<rpid> methods on the watcher object.
		528
366	You can have as many pid watchers per pid as you want.	529	You can have as many pid watchers per pid as you want, they will all be
		530	called.
367		531
368	The C<child_ns> variant doesn't start (activate) the newly created watcher.	532	The C<child_ns> variant doesn't start (activate) the newly created watcher.
369		533
370	=item $w->set ($pid)	534	=item $w->set ($pid)
371		535
372	Reconfigures the watcher, see the constructor above for details. Can be at	536	Reconfigures the watcher, see the constructor above for details. Can be called at
373	any time.	537	any time.
374		538
375	=item $current_pid = $w->pid	539	=item $current_pid = $w->pid
376		540
377	=item $old_pid = $w->pid ($new_pid)	541	=item $old_pid = $w->pid ($new_pid)
…		…
386	=item $pid = $w->rpid	550	=item $pid = $w->rpid
387		551
388	Return the pid of the awaited child (useful when you have installed a	552	Return the pid of the awaited child (useful when you have installed a
389	watcher for all pids).	553	watcher for all pids).
390		554
		555	=back
		556
		557
		558	=head3 STAT WATCHERS - did the file attributes just change?
		559
		560	=over 4
		561
		562	=item $w = EV::stat $path, $interval, $callback
		563
		564	=item $w = EV::stat_ns $path, $interval, $callback
		565
		566	Call the callback when a file status change has been detected on
		567	C<$path>. The C<$path> does not need to exist, changing from "path exists"
		568	to "path does not exist" is a status change like any other.
		569
		570	The C<$interval> is a recommended polling interval for systems where
		571	OS-supported change notifications don't exist or are not supported. If
		572	you use C<0> then an unspecified default is used (which is highly
		573	recommended!), which is to be expected to be around five seconds usually.
		574
		575	This watcher type is not meant for massive numbers of stat watchers,
		576	as even with OS-supported change notifications, this can be
		577	resource-intensive.
		578
		579	The C<stat_ns> variant doesn't start (activate) the newly created watcher.
		580
		581	=item ... = $w->stat
		582
		583	This call is very similar to the perl C<stat> built-in: It stats (using
		584	C<lstat>) the path specified in the watcher and sets perls stat cache (as
		585	well as EV's idea of the current stat values) to the values found.
		586
		587	In scalar context, a boolean is return indicating success or failure of
		588	the stat. In list context, the same 13-value list as with stat is returned
		589	(except that the blksize and blocks fields are not reliable).
		590
		591	In the case of an error, errno is set to C<ENOENT> (regardless of the
		592	actual error value) and the C<nlink> value is forced to zero (if the stat
		593	was successful then nlink is guaranteed to be non-zero).
		594
		595	See also the next two entries for more info.
		596
		597	=item ... = $w->attr
		598
		599	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		600	the values most recently detected by EV. See the next entry for more info.
		601
		602	=item ... = $w->prev
		603
		604	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		605	the previous set of values, before the change.
		606
		607	That is, when the watcher callback is invoked, C<< $w->prev >> will be set
		608	to the values found I<before> a change was detected, while C<< $w->attr >>
		609	returns the values found leading to the change detection. The difference (if any)
		610	between C<prev> and C<attr> is what triggered the callback.
		611
		612	If you did something to the filesystem object and do not want to trigger
		613	yet another change, you can call C<stat> to update EV's idea of what the
		614	current attributes are.
		615
		616	=item $w->set ($path, $interval)
		617
		618	Reconfigures the watcher, see the constructor above for details. Can be
		619	called at any time.
		620
		621	=item $current_path = $w->path
		622
		623	=item $old_path = $w->path ($new_path)
		624
		625	Returns the previously set path and optionally set a new one.
		626
		627	=item $current_interval = $w->interval
		628
		629	=item $old_interval = $w->interval ($new_interval)
		630
		631	Returns the previously set interval and optionally set a new one. Can be
		632	used to query the actual interval used.
		633
		634	=back
		635
		636
		637	=head3 IDLE WATCHERS - when you've got nothing better to do...
		638
		639	=over 4
391		640
392	=item $w = EV::idle $callback	641	=item $w = EV::idle $callback
393		642
394	=item $w = EV::idle_ns $callback	643	=item $w = EV::idle_ns $callback
395		644
…		…
399	The process will not block as long as any idle watchers are active, and	648	The process will not block as long as any idle watchers are active, and
400	they will be called repeatedly until stopped.	649	they will be called repeatedly until stopped.
401		650
402	The C<idle_ns> variant doesn't start (activate) the newly created watcher.	651	The C<idle_ns> variant doesn't start (activate) the newly created watcher.
403		652
		653	=back
		654
		655
		656	=head3 PREPARE WATCHERS - customise your event loop!
		657
		658	=over 4
404		659
405	=item $w = EV::prepare $callback	660	=item $w = EV::prepare $callback
406		661
407	=item $w = EV::prepare_ns $callback	662	=item $w = EV::prepare_ns $callback
408		663
…		…
411		666
412	See the EV::check watcher, below, for explanations and an example.	667	See the EV::check watcher, below, for explanations and an example.
413		668
414	The C<prepare_ns> variant doesn't start (activate) the newly created watcher.	669	The C<prepare_ns> variant doesn't start (activate) the newly created watcher.
415		670
		671	=back
		672
		673
		674	=head3 CHECK WATCHERS - customise your event loop even more!
		675
		676	=over 4
416		677
417	=item $w = EV::check $callback	678	=item $w = EV::check $callback
418		679
419	=item $w = EV::check_ns $callback	680	=item $w = EV::check_ns $callback
420		681
…		…
432	# do nothing unless active	693	# do nothing unless active
433	$dispatcher->{_event_queue_h}	694	$dispatcher->{_event_queue_h}
434	or return;	695	or return;
435		696
436	# make the dispatcher handle any outstanding stuff	697	# make the dispatcher handle any outstanding stuff
		698	... not shown
437		699
438	# create an IO watcher for each and every socket	700	# create an IO watcher for each and every socket
439	@snmp_watcher = (	701	@snmp_watcher = (
440	(map { EV::io $_, EV::READ, sub { } }	702	(map { EV::io $_, EV::READ, sub { } }
441	keys %{ $dispatcher->{_descriptors} }),	703	keys %{ $dispatcher->{_descriptors} }),
		704
		705	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
		706	? $event->[Net::SNMP::Dispatcher::_TIME] - EV::now : 0),
		707	0, sub { },
442	);	708	);
443
444	# if there are any timeouts, also create a timer
445	push @snmp_watcher, EV::timer $event->[Net::SNMP::Dispatcher::_TIME] - EV::now, 0, sub { }
446	if $event->[Net::SNMP::Dispatcher::_ACTIVE];
447	};	709	};
448		710
449	The callbacks are irrelevant, the only purpose of those watchers is	711	The callbacks are irrelevant (and are not even being called), the
450	to wake up the process as soon as one of those events occurs (socket	712	only purpose of those watchers is to wake up the process as soon as
451	readable, or timer timed out). The corresponding EV::check watcher will then	713	one of those events occurs (socket readable, or timer timed out). The
452	clean up:	714	corresponding EV::check watcher will then clean up:
453		715
454	our $snmp_check = EV::check sub {	716	our $snmp_check = EV::check sub {
455	# destroy all watchers	717	# destroy all watchers
456	@snmp_watcher = ();	718	@snmp_watcher = ();
457		719
458	# make the dispatcher handle any new stuff	720	# make the dispatcher handle any new stuff
		721	... not shown
459	};	722	};
460		723
461	The callbacks of the created watchers will not be called as the watchers	724	The callbacks of the created watchers will not be called as the watchers
462	are destroyed before this cna happen (remember EV::check gets called	725	are destroyed before this cna happen (remember EV::check gets called
463	first).	726	first).
464		727
465	The C<check_ns> variant doesn't start (activate) the newly created watcher.	728	The C<check_ns> variant doesn't start (activate) the newly created watcher.
466		729
467	=back	730	=back
468		731
		732
		733	=head3 FORK WATCHERS - the audacity to resume the event loop after a fork
		734
		735	Fork watchers are called when a C<fork ()> was detected. The invocation
		736	is done before the event loop blocks next and before C<check> watchers
		737	are being called, and only in the child after the fork.
		738
		739	=over 4
		740
		741	=item $w = EV::fork $callback
		742
		743	=item $w = EV::fork_ns $callback
		744
		745	Call the callback before the event loop is resumed in the child process
		746	after a fork.
		747
		748	The C<fork_ns> variant doesn't start (activate) the newly created watcher.
		749
		750	=back
		751
		752
469	=head1 THREADS	753	=head1 THREADS
470		754
471	Threads are not supported by this in any way. Perl pseudo-threads is evil	755	Threads are not supported by this module in any way. Perl pseudo-threads
472	stuff and must die.	756	is evil stuff and must die. As soon as Perl gains real threads I will work
		757	on thread support for it.
		758
		759	=head1 FORK
		760
		761	Most of the "improved" event delivering mechanisms of modern operating
		762	systems have quite a few problems with fork(2) (to put it bluntly: it is
		763	not supported and usually destructive). Libev makes it possible to work
		764	around this by having a function that recreates the kernel state after
		765	fork in the child.
		766
		767	On non-win32 platforms, this module requires the pthread_atfork
		768	functionality to do this automatically for you. This function is quite
		769	buggy on most BSDs, though, so YMMV. The overhead for this is quite
		770	negligible, because everything the function currently does is set a flag
		771	that is checked only when the event loop gets used the next time, so when
		772	you do fork but not use EV, the overhead is minimal.
		773
		774	On win32, there is no notion of fork so all this doesn't apply, of course.
473		775
474	=cut	776	=cut
475		777
476	our $DIED = sub {	778	our $DIED = sub {
477	warn "EV: error in callback (ignoring): $@";	779	warn "EV: error in callback (ignoring): $@";
478	};	780	};
479		781
480	default_loop	782	default_loop
481	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	783	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';
482		784
483	push @AnyEvent::REGISTRY, [EV => "EV::AnyEvent"];
484
485	1;	785	1;
486		786
487	=head1 SEE ALSO	787	=head1 SEE ALSO
488		788
489	L<EV::DNS>, L<EV::AnyEvent>.	789	L<EV::DNS>.
490		790
491	=head1 AUTHOR	791	=head1 AUTHOR
492		792
493	Marc Lehmann <schmorp@schmorp.de>	793	Marc Lehmann <schmorp@schmorp.de>
494	http://home.schmorp.de/	794	http://home.schmorp.de/

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Comparing EV/EV.pm (file contents): Revision 1.28 by root, Sun Nov 4 16:52:52 2007 UTC vs. Revision 1.57 by root, Wed Nov 28 17:32:24 2007 UTC

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Comparing EV/EV.pm (file contents):
Revision 1.28 by root, Sun Nov 4 16:52:52 2007 UTC vs.
Revision 1.57 by root, Wed Nov 28 17:32:24 2007 UTC