[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 1.54 by root, Tue Nov 27 07:27:10 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 =
76	@EV::Idle::ISA =	81	@EV::Idle::ISA =
77	@EV::Prepare::ISA =	82	@EV::Prepare::ISA =
78	@EV::Check::ISA =	83	@EV::Check::ISA =
		84	@EV::Child::ISA =
		85	@EV::Embed::ISA =
79	@EV::Child::ISA = "EV::Watcher";	86	@EV::Stat::ISA = "EV::Watcher";
80		87
81	=head1 BASIC INTERFACE	88	=head1 BASIC INTERFACE
82		89
83	=over 4	90	=over 4
84		91
…		…
98		105
99	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
100	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
101	usually faster then calling EV::time.	108	usually faster then calling EV::time.
102		109
103	=item $method = EV::ev_method	110	=item $method = EV::method
104		111
105	Returns an integer describing the backend used by libev (EV::METHOD_SELECT	112	Returns an integer describing the backend used by libev (EV::METHOD_SELECT
106	or EV::METHOD_EPOLL).	113	or EV::METHOD_EPOLL).
107		114
108	=item EV::loop [$flags]	115	=item EV::loop [$flags]
109		116
110	Begin checking for events and calling callbacks. It returns when a	117	Begin checking for events and calling callbacks. It returns when a
111	callback calls EV::loop_done.	118	callback calls EV::unloop.
112		119
113	The $flags argument can be one of the following:	120	The $flags argument can be one of the following:
114		121
115	0 as above	122	0 as above
116	EV::LOOP_ONESHOT block at most once (wait, but do not loop)	123	EV::LOOP_ONESHOT block at most once (wait, but do not loop)
117	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)	124	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
118		125
119	=item EV::loop_done [$how]	126	=item EV::unloop [$how]
120		127
121	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
122	call to EV::loop return.	129	innermost call to EV::loop return.
123		130
124	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
125	fast as possible.	132	fast as possible.
126		133
127	=back	134	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
128		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
129	=head2 WATCHER	159	=head2 WATCHER OBJECTS
130		160
131	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
132	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
133	would create an EV::io watcher for that:	163	would create an EV::io watcher for that:
134		164
…		…
159		189
160	Also, all methods changing some aspect of a watcher (->set, ->priority,	190	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,	191	->fh and so on) automatically stop and start it again if it is active,
162	which means pending events get lost.	192	which means pending events get lost.
163		193
164	=head2 WATCHER TYPES	194	=head2 COMMON WATCHER METHODS
165		195
166	Now lets move to the existing watcher types and asociated methods.	196	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		197
173	=over 4	198	=over 4
174		199
175	=item $w->start	200	=item $w->start
176		201
…		…
185	regardless of wether the watcher was active or not.	210	regardless of wether the watcher was active or not.
186		211
187	=item $bool = $w->is_active	212	=item $bool = $w->is_active
188		213
189	Returns true if the watcher is active, false otherwise.	214	Returns true if the watcher is active, false otherwise.
		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!");
190		227
191	=item $current_cb = $w->cb	228	=item $current_cb = $w->cb
192		229
193	=item $old_cb = $w->cb ($new_cb)	230	=item $old_cb = $w->cb ($new_cb)
194		231
…		…
203	watchers with higher priority will be invoked first. The valid range of	240	watchers with higher priority will be invoked first. The valid range of
204	priorities lies between EV::MAXPRI (default 2) and EV::MINPRI (default	241	priorities lies between EV::MAXPRI (default 2) and EV::MINPRI (default
205	-2). If the priority is outside this range it will automatically be	242	-2). If the priority is outside this range it will automatically be
206	normalised to the nearest valid priority.	243	normalised to the nearest valid priority.
207		244
208	The default priority of any newly-created weatcher is 0.	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.
209		249
210	=item $w->trigger ($revents)	250	=item $w->trigger ($revents)
211		251
212	Call the callback now with the given event mask.	252	Call the callback now with the given event mask.
213		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
214		292
215	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	293	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
216		294
217	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback	295	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
218		296
219	As long as the returned watcher object is alive, call the C<$callback>	297	As long as the returned watcher object is alive, call the C<$callback>
220	when the events specified in C<$eventmask>.	298	when at least one of events specified in C<$eventmask> occurs.
221		299
222	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:
223		301
224	EV::READ wait until read() wouldn't block anymore	302	EV::READ wait until read() wouldn't block anymore
225	EV::WRITE wait until write() wouldn't block anymore	303	EV::WRITE wait until write() wouldn't block anymore
…		…
241		319
242	=item $old_eventmask = $w->events ($new_eventmask)	320	=item $old_eventmask = $w->events ($new_eventmask)
243		321
244	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.
245		323
		324	=back
		325
		326
		327	=head3 TIMER WATCHERS - relative and optionally repeating timeouts
		328
		329	=over 4
246		330
247	=item $w = EV::timer $after, $repeat, $callback	331	=item $w = EV::timer $after, $repeat, $callback
248		332
249	=item $w = EV::timer_ns $after, $repeat, $callback	333	=item $w = EV::timer_ns $after, $repeat, $callback
250		334
251	Calls the callback after C<$after> seconds. If C<$repeat> is non-zero,	335	Calls the callback after C<$after> seconds (which may be fractional). If
252	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
253	callback returns.	337	value as $after) after the callback returns.
254		338
255	This means that the callback would be called roughly after C<$after>	339	This means that the callback would be called roughly after C<$after>
256	seconds, and then every C<$repeat> seconds. "Roughly" because the time of	340	seconds, and then every C<$repeat> seconds. The timer does his best not
257	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
258	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.
259		344
260	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
261	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
262	clock, the timer will nevertheless run (roughly) the same time.	347	clock, the timer will nevertheless run (roughly) the same time.
263		348
264	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.
265		350
266	=item $w->set ($after, $repeat)	351	=item $w->set ($after, $repeat)
267		352
268	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
269	any time.	354	any time.
270		355
271	=item $w->again	356	=item $w->again
272		357
273	Similar to the C<start> method, but has special semantics for repeating timers:	358	Similar to the C<start> method, but has special semantics for repeating timers:
		359
		360	If the timer is active and non-repeating, it will be stopped.
274		361
275	If the timer is active and repeating, reset the timeout to occur	362	If the timer is active and repeating, reset the timeout to occur
276	C<$repeat> seconds after now.	363	C<$repeat> seconds after now.
277		364
278	If the timer is active and non-repeating, it will be stopped.
279
280	If the timer is in active and repeating, start it.	365	If the timer is inactive and repeating, start it using the repeat value.
281		366
282	Otherwise do nothing.	367	Otherwise do nothing.
283		368
284	This behaviour is useful when you have a timeout for some IO	369	This behaviour is useful when you have a timeout for some IO
285	operation. You create a timer object with the same value for C<$after> and	370	operation. You create a timer object with the same value for C<$after> and
286	C<$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
287	on the timeout.	372	on the timeout.
288		373
		374	=back
289		375
		376
		377	=head3 PERIODIC WATCHERS - to cron or not to cron?
		378
		379	=over 4
		380
290	=item $w = EV::periodic $at, $interval, $callback	381	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
291		382
292	=item $w = EV::periodic_ns $at, $interval, $callback	383	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
293		384
294	Similar to EV::timer, but the time is given as an absolute point in time	385	Similar to EV::timer, but is not based on relative timeouts but on
295	(C<$at>), plus an optional C<$interval>.	386	absolute times. Apart from creating "simple" timers that trigger "at" the
		387	specified time, it can also be used for non-drifting absolute timers and
		388	more complex, cron-like, setups that are not adversely affected by time
		389	jumps (i.e. when the system clock is changed by explicit date -s or other
		390	means such as ntpd). It is also the most complex watcher type in EV.
296		391
297	If the C<$interval> is zero, then the callback will be called at the time	392	It has three distinct "modes":
298	C<$at> if that is in the future, or as soon as possible if it is in the
299	past. It will not automatically repeat.
300		393
301	If the C<$interval> is nonzero, then the watcher will always be scheduled	394	=over 4
302	to time out at the next C<$at + N * $interval> time.
303		395
304	This can be used to schedule a callback to run at very regular intervals,	396	=item * absolute timer ($interval = $reschedule_cb = 0)
305	as long as the processing time is less then the interval (otherwise	397
306	obviously events will be skipped).	398	This time simply fires at the wallclock time C<$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 $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" };
		413
		414	That doesn't mean there will always be 3600 seconds in between triggers,
		415	but only that the the clalback will be called when the system time shows a
		416	full hour (UTC).
307		417
308	Another way to think about it (for the mathematically inclined) is that	418	Another way to think about it (for the mathematically inclined) is that
309	EV::periodic will try to run the callback at the next possible time where	419	EV::periodic will try to run the callback in this mode at the next
310	C<$time = $at (mod $interval)>, regardless of any time jumps.	420	possible time where C<$time = $at (mod $interval)>, regardless of any time
		421	jumps.
311		422
312	This periodic timer is based on "wallclock time", that is, if the clock	423	=item * manual reschedule mode ($reschedule_cb = coderef)
313	changes (C<ntp>, C<date -s> etc.), then the timer will nevertheless run at	424
314	the specified time. This means it will never drift (it might jitter, but	425	In this mode $interval and $at are both being ignored. Instead, each
315	it will not drift).	426	time the periodic watcher gets scheduled, the reschedule callback
		427	($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
316		456
317	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.
318		458
319	=item $w->set ($at, $interval)	459	=item $w->set ($at, $interval, $reschedule_cb)
320		460
321	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
322	any time.	462	any time.
323		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
324		474
325	=item $w = EV::signal $signal, $callback	475	=item $w = EV::signal $signal, $callback
326		476
327	=item $w = EV::signal_ns $signal, $callback	477	=item $w = EV::signal_ns $signal, $callback
328		478
329	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
330	by number or by name, just as with kill or %SIG).	480	number or by name, just as with C<kill> or C<%SIG>).
331		481
332	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
333	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,
334	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
335	add/remove callbacks to %SIG, so watch out.	485	add/remove callbacks to C<%SIG>, so watch out.
336		486
337	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.
338		488
339	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.
340		490
341	=item $w->set ($signal)	491	=item $w->set ($signal)
342		492
343	Reconfigures the watcher, see the constructor above for details. Can be at	493	Reconfigures the watcher, see the constructor above for details. Can be
344	any time.	494	called at any time.
345		495
346	=item $current_signum = $w->signal	496	=item $current_signum = $w->signal
347		497
348	=item $old_signum = $w->signal ($new_signal)	498	=item $old_signum = $w->signal ($new_signal)
349		499
350	Returns the previously set signal (always as a number not name) and	500	Returns the previously set signal (always as a number not name) and
351	optionally set a new one.	501	optionally set a new one.
352		502
		503	=back
		504
		505
		506	=head3 CHILD WATCHERS - watch out for process status changes
		507
		508	=over 4
353		509
354	=item $w = EV::child $pid, $callback	510	=item $w = EV::child $pid, $callback
355		511
356	=item $w = EV::child_ns $pid, $callback	512	=item $w = EV::child_ns $pid, $callback
357		513
358	Call the callback when a status change for pid C<$pid> (or any pid	514	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	515	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	516	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
361	changed/zombie children and call the callback.	517	changed/zombie children and call the callback.
362		518
363	You can access both status and pid by using the C<rstatus> and C<rpid>	519	It is valid (and fully supported) to install a child watcher after a child
364	methods on the watcher object.	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).
365		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
366	You can have as many pid watchers per pid as you want.	527	You can have as many pid watchers per pid as you want, they will all be
		528	called.
367		529
368	The C<child_ns> variant doesn't start (activate) the newly created watcher.	530	The C<child_ns> variant doesn't start (activate) the newly created watcher.
369		531
370	=item $w->set ($pid)	532	=item $w->set ($pid)
371		533
372	Reconfigures the watcher, see the constructor above for details. Can be at	534	Reconfigures the watcher, see the constructor above for details. Can be called at
373	any time.	535	any time.
374		536
375	=item $current_pid = $w->pid	537	=item $current_pid = $w->pid
376		538
377	=item $old_pid = $w->pid ($new_pid)	539	=item $old_pid = $w->pid ($new_pid)
…		…
386	=item $pid = $w->rpid	548	=item $pid = $w->rpid
387		549
388	Return the pid of the awaited child (useful when you have installed a	550	Return the pid of the awaited child (useful when you have installed a
389	watcher for all pids).	551	watcher for all pids).
390		552
		553	=back
		554
		555
		556	=head3 IDLE WATCHERS - when you've got nothing better to do...
		557
		558	=over 4
391		559
392	=item $w = EV::idle $callback	560	=item $w = EV::idle $callback
393		561
394	=item $w = EV::idle_ns $callback	562	=item $w = EV::idle_ns $callback
395		563
…		…
399	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
400	they will be called repeatedly until stopped.	568	they will be called repeatedly until stopped.
401		569
402	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.
403		571
		572	=back
		573
		574
		575	=head3 PREPARE WATCHERS - customise your event loop!
		576
		577	=over 4
404		578
405	=item $w = EV::prepare $callback	579	=item $w = EV::prepare $callback
406		580
407	=item $w = EV::prepare_ns $callback	581	=item $w = EV::prepare_ns $callback
408		582
…		…
411		585
412	See the EV::check watcher, below, for explanations and an example.	586	See the EV::check watcher, below, for explanations and an example.
413		587
414	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.
415		589
		590	=back
		591
		592
		593	=head3 CHECK WATCHERS - customise your event loop even more!
		594
		595	=over 4
416		596
417	=item $w = EV::check $callback	597	=item $w = EV::check $callback
418		598
419	=item $w = EV::check_ns $callback	599	=item $w = EV::check_ns $callback
420		600
…		…
432	# do nothing unless active	612	# do nothing unless active
433	$dispatcher->{_event_queue_h}	613	$dispatcher->{_event_queue_h}
434	or return;	614	or return;
435		615
436	# make the dispatcher handle any outstanding stuff	616	# make the dispatcher handle any outstanding stuff
		617	... not shown
437		618
438	# create an IO watcher for each and every socket	619	# create an IO watcher for each and every socket
439	@snmp_watcher = (	620	@snmp_watcher = (
440	(map { EV::io $_, EV::READ, sub { } }	621	(map { EV::io $_, EV::READ, sub { } }
441	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 { },
442	);	627	);
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	};	628	};
448		629
449	The callbacks are irrelevant, the only purpose of those watchers is	630	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	631	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	632	one of those events occurs (socket readable, or timer timed out). The
452	clean up:	633	corresponding EV::check watcher will then clean up:
453		634
454	our $snmp_check = EV::check sub {	635	our $snmp_check = EV::check sub {
455	# destroy all watchers	636	# destroy all watchers
456	@snmp_watcher = ();	637	@snmp_watcher = ();
457		638
458	# make the dispatcher handle any new stuff	639	# make the dispatcher handle any new stuff
		640	... not shown
459	};	641	};
460		642
461	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
462	are destroyed before this cna happen (remember EV::check gets called	644	are destroyed before this cna happen (remember EV::check gets called
463	first).	645	first).
464		646
465	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.
466		648
467	=back	649	=back
468		650
		651	=head3 STAT WATCHERS - did the file stats 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
469	=head1 THREADS	695	=head1 THREADS
470		696
471	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
472	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.
473		717
474	=cut	718	=cut
475		719
476	our $DIED = sub {	720	our $DIED = sub {
477	warn "EV: error in callback (ignoring): $@";	721	warn "EV: error in callback (ignoring): $@";
478	};	722	};
479		723
480	default_loop	724	default_loop
481	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	725	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';
482		726
483	push @AnyEvent::REGISTRY, [EV => "EV::AnyEvent"];
484
485	1;	727	1;
486		728
487	=head1 SEE ALSO	729	=head1 SEE ALSO
488		730
489	L<EV::DNS>, L<EV::AnyEvent>.	731	L<EV::DNS>.
490		732
491	=head1 AUTHOR	733	=head1 AUTHOR
492		734
493	Marc Lehmann <schmorp@schmorp.de>	735	Marc Lehmann <schmorp@schmorp.de>
494	http://home.schmorp.de/	736	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 1.54 by root, Tue Nov 27 07:27:10 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 1.54 by root, Tue Nov 27 07:27:10 2007 UTC