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

Comparing EV/EV.pm (file contents):
Revision 1.24 by root, Fri Nov 2 22:03:00 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	# 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
…		…
157		189
158	Also, all methods changing some aspect of a watcher (->set, ->priority,	190	Also, all methods changing some aspect of a watcher (->set, ->priority,
159	->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,
160	which means pending events get lost.	192	which means pending events get lost.
161		193
162	=head2 WATCHER TYPES	194	=head2 COMMON WATCHER METHODS
163		195
164	Now lets move to the existing watcher types and asociated methods.	196	This section lists methods common to all watchers.
165
166	The following methods are available for all watchers. Then followes a
167	description of each watcher constructor (EV::io, EV::timer, EV::periodic,
168	EV::signal, EV::child, EV::idle, EV::prepare and EV::check), followed by
169	any type-specific methods (if any).
170		197
171	=over 4	198	=over 4
172		199
173	=item $w->start	200	=item $w->start
174		201
…		…
183	regardless of wether the watcher was active or not.	210	regardless of wether the watcher was active or not.
184		211
185	=item $bool = $w->is_active	212	=item $bool = $w->is_active
186		213
187	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!");
188		227
189	=item $current_cb = $w->cb	228	=item $current_cb = $w->cb
190		229
191	=item $old_cb = $w->cb ($new_cb)	230	=item $old_cb = $w->cb ($new_cb)
192		231
…		…
201	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
202	priorities lies between EV::MAXPRI (default 2) and EV::MINPRI (default	241	priorities lies between EV::MAXPRI (default 2) and EV::MINPRI (default
203	-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
204	normalised to the nearest valid priority.	243	normalised to the nearest valid priority.
205		244
206	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.
207		249
208	=item $w->trigger ($revents)	250	=item $w->trigger ($revents)
209		251
210	Call the callback now with the given event mask.	252	Call the callback now with the given event mask.
211		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
212		292
213	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	293	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
214		294
215	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback	295	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
216		296
217	As long as the returned watcher object is alive, call the C<$callback>	297	As long as the returned watcher object is alive, call the C<$callback>
218	when the events specified in C<$eventmask>.	298	when at least one of events specified in C<$eventmask> occurs.
219		299
220	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:
221		301
222	EV::READ wait until read() wouldn't block anymore	302	EV::READ wait until read() wouldn't block anymore
223	EV::WRITE wait until write() wouldn't block anymore	303	EV::WRITE wait until write() wouldn't block anymore
…		…
239		319
240	=item $old_eventmask = $w->events ($new_eventmask)	320	=item $old_eventmask = $w->events ($new_eventmask)
241		321
242	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.
243		323
		324	=back
		325
		326
		327	=head3 TIMER WATCHERS - relative and optionally repeating timeouts
		328
		329	=over 4
244		330
245	=item $w = EV::timer $after, $repeat, $callback	331	=item $w = EV::timer $after, $repeat, $callback
246		332
247	=item $w = EV::timer_ns $after, $repeat, $callback	333	=item $w = EV::timer_ns $after, $repeat, $callback
248		334
249	Calls the callback after C<$after> seconds. If C<$repeat> is non-zero,	335	Calls the callback after C<$after> seconds (which may be fractional). If
250	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
251	callback returns.	337	value as $after) after the callback returns.
252		338
253	This means that the callback would be called roughly after C<$after>	339	This means that the callback would be called roughly after C<$after>
254	seconds, and then every C<$repeat> seconds. "Roughly" because the time of	340	seconds, and then every C<$repeat> seconds. The timer does his best not
255	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
256	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.
257		344
258	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
259	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
260	clock, the timer will nevertheless run (roughly) the same time.	347	clock, the timer will nevertheless run (roughly) the same time.
261		348
262	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.
263		350
264	=item $w->set ($after, $repeat)	351	=item $w->set ($after, $repeat)
265		352
266	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
267	any time.	354	any time.
268		355
269	=item $w->again	356	=item $w->again
270		357
271	Similar to the C<start> method, but has special semantics for repeating timers:	358	Similar to the C<start> method, but has special semantics for repeating timers:
		359
		360	If the timer is active and non-repeating, it will be stopped.
272		361
273	If the timer is active and repeating, reset the timeout to occur	362	If the timer is active and repeating, reset the timeout to occur
274	C<$repeat> seconds after now.	363	C<$repeat> seconds after now.
275		364
276	If the timer is active and non-repeating, it will be stopped.
277
278	If the timer is in active and repeating, start it.	365	If the timer is inactive and repeating, start it using the repeat value.
279		366
280	Otherwise do nothing.	367	Otherwise do nothing.
281		368
282	This behaviour is useful when you have a timeout for some IO	369	This behaviour is useful when you have a timeout for some IO
283	operation. You create a timer object with the same value for C<$after> and	370	operation. You create a timer object with the same value for C<$after> and
284	C<$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
285	on the timeout.	372	on the timeout.
286		373
		374	=back
287		375
		376
		377	=head3 PERIODIC WATCHERS - to cron or not to cron?
		378
		379	=over 4
		380
288	=item $w = EV::periodic $at, $interval, $callback	381	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
289		382
290	=item $w = EV::periodic_ns $at, $interval, $callback	383	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
291		384
292	Similar to EV::timer, but the time is given as an absolute point in time	385	Similar to EV::timer, but is not based on relative timeouts but on
293	(C<$at>), plus an optional C<$interval>.	386	absolute times. Apart from creating "simple" timers that trigger "at" the
		387	specified time, it can also be used for non-drifting absolute timers and
		388	more complex, cron-like, setups that are not adversely affected by time
		389	jumps (i.e. when the system clock is changed by explicit date -s or other
		390	means such as ntpd). It is also the most complex watcher type in EV.
294		391
295	If the C<$interval> is zero, then the callback will be called at the time	392	It has three distinct "modes":
296	C<$at> if that is in the future, or as soon as possible if it is in the
297	past. It will not automatically repeat.
298		393
299	If the C<$interval> is nonzero, then the watcher will always be scheduled	394	=over 4
300	to time out at the next C<$at + N * $interval> time.
301		395
302	This can be used to schedule a callback to run at very regular intervals,	396	=item * absolute timer ($interval = $reschedule_cb = 0)
303	as long as the processing time is less then the interval (otherwise	397
304	obviously events will be skipped).	398	This time simply fires at the wallclock time C<$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 $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" };
		413
		414	That doesn't mean there will always be 3600 seconds in between triggers,
		415	but only that the the clalback will be called when the system time shows a
		416	full hour (UTC).
305		417
306	Another way to think about it (for the mathematically inclined) is that	418	Another way to think about it (for the mathematically inclined) is that
307	EV::periodic will try to run the callback at the next possible time where	419	EV::periodic will try to run the callback in this mode at the next
308	C<$time = $at (mod $interval)>, regardless of any time jumps.	420	possible time where C<$time = $at (mod $interval)>, regardless of any time
		421	jumps.
309		422
310	This periodic timer is based on "wallclock time", that is, if the clock	423	=item * manual reschedule mode ($reschedule_cb = coderef)
311	changes (C<ntp>, C<date -s> etc.), then the timer will nevertheless run at	424
312	the specified time. This means it will never drift (it might jitter, but	425	In this mode $interval and $at are both being ignored. Instead, each
313	it will not drift).	426	time the periodic watcher gets scheduled, the reschedule callback
		427	($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
314		456
315	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.
316		458
317	=item $w->set ($at, $interval)	459	=item $w->set ($at, $interval, $reschedule_cb)
318		460
319	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
320	any time.	462	any time.
321		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
322		474
323	=item $w = EV::signal $signal, $callback	475	=item $w = EV::signal $signal, $callback
324		476
325	=item $w = EV::signal_ns $signal, $callback	477	=item $w = EV::signal_ns $signal, $callback
326		478
327	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
328	by number or by name, just as with kill or %SIG).	480	number or by name, just as with C<kill> or C<%SIG>).
329		481
330	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
331	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,
332	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
333	add/remove callbacks to %SIG, so watch out.	485	add/remove callbacks to C<%SIG>, so watch out.
334		486
335	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.
336		488
337	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.
338		490
339	=item $w->set ($signal)	491	=item $w->set ($signal)
340		492
341	Reconfigures the watcher, see the constructor above for details. Can be at	493	Reconfigures the watcher, see the constructor above for details. Can be
342	any time.	494	called at any time.
343		495
344	=item $current_signum = $w->signal	496	=item $current_signum = $w->signal
345		497
346	=item $old_signum = $w->signal ($new_signal)	498	=item $old_signum = $w->signal ($new_signal)
347		499
348	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
349	optionally set a new one.	501	optionally set a new one.
350		502
		503	=back
		504
		505
		506	=head3 CHILD WATCHERS - watch out for process status changes
		507
		508	=over 4
351		509
352	=item $w = EV::child $pid, $callback	510	=item $w = EV::child $pid, $callback
353		511
354	=item $w = EV::child_ns $pid, $callback	512	=item $w = EV::child_ns $pid, $callback
355		513
356	Call the callback when a status change for pid C<$pid> (or any pid	514	Call the callback when a status change for pid C<$pid> (or any pid if
357	if C<$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
358	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
359	changed/zombie children and call the callback.	517	changed/zombie children and call the callback.
360		518
361	Unlike all other callbacks, this callback will be called with an	519	It is valid (and fully supported) to install a child watcher after a child
362	additional third argument which is the exit status. See the C<waitpid>	520	has exited but before the event loop has started its next iteration (for
363	function for details.	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).
364		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
365	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.
366		529
367	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.
368		531
369	=item $w->set ($pid)	532	=item $w->set ($pid)
370		533
371	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
372	any time.	535	any time.
373		536
374	=item $current_pid = $w->pid	537	=item $current_pid = $w->pid
375		538
376	=item $old_pid = $w->pid ($new_pid)	539	=item $old_pid = $w->pid ($new_pid)
377		540
378	Returns the previously set process id and optionally set a new one.	541	Returns the previously set process id and optionally set a new one.
379		542
		543	=item $exit_status = $w->rstatus
		544
		545	Return the exit/wait status (as returned by waitpid, see the waitpid entry
		546	in perlfunc).
		547
		548	=item $pid = $w->rpid
		549
		550	Return the pid of the awaited child (useful when you have installed a
		551	watcher for all pids).
		552
		553	=back
		554
		555
		556	=head3 IDLE WATCHERS - when you've got nothing better to do...
		557
		558	=over 4
380		559
381	=item $w = EV::idle $callback	560	=item $w = EV::idle $callback
382		561
383	=item $w = EV::idle_ns $callback	562	=item $w = EV::idle_ns $callback
384		563
…		…
388	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
389	they will be called repeatedly until stopped.	568	they will be called repeatedly until stopped.
390		569
391	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.
392		571
		572	=back
		573
		574
		575	=head3 PREPARE WATCHERS - customise your event loop!
		576
		577	=over 4
393		578
394	=item $w = EV::prepare $callback	579	=item $w = EV::prepare $callback
395		580
396	=item $w = EV::prepare_ns $callback	581	=item $w = EV::prepare_ns $callback
397		582
…		…
400		585
401	See the EV::check watcher, below, for explanations and an example.	586	See the EV::check watcher, below, for explanations and an example.
402		587
403	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.
404		589
		590	=back
		591
		592
		593	=head3 CHECK WATCHERS - customise your event loop even more!
		594
		595	=over 4
405		596
406	=item $w = EV::check $callback	597	=item $w = EV::check $callback
407		598
408	=item $w = EV::check_ns $callback	599	=item $w = EV::check_ns $callback
409		600
…		…
421	# do nothing unless active	612	# do nothing unless active
422	$dispatcher->{_event_queue_h}	613	$dispatcher->{_event_queue_h}
423	or return;	614	or return;
424		615
425	# make the dispatcher handle any outstanding stuff	616	# make the dispatcher handle any outstanding stuff
		617	... not shown
426		618
427	# create an IO watcher for each and every socket	619	# create an IO watcher for each and every socket
428	@snmp_watcher = (	620	@snmp_watcher = (
429	(map { EV::io $_, EV::READ, sub { } }	621	(map { EV::io $_, EV::READ, sub { } }
430	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 { },
431	);	627	);
432
433	# if there are any timeouts, also create a timer
434	push @snmp_watcher, EV::timer $event->[Net::SNMP::Dispatcher::_TIME] - EV::now, 0, sub { }
435	if $event->[Net::SNMP::Dispatcher::_ACTIVE];
436	};	628	};
437		629
438	The callbacks are irrelevant, the only purpose of those watchers is	630	The callbacks are irrelevant (and are not even being called), the
439	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
440	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
441	clean up:	633	corresponding EV::check watcher will then clean up:
442		634
443	our $snmp_check = EV::check sub {	635	our $snmp_check = EV::check sub {
444	# destroy all watchers	636	# destroy all watchers
445	@snmp_watcher = ();	637	@snmp_watcher = ();
446		638
447	# make the dispatcher handle any new stuff	639	# make the dispatcher handle any new stuff
		640	... not shown
448	};	641	};
449		642
450	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
451	are destroyed before this cna happen (remember EV::check gets called	644	are destroyed before this cna happen (remember EV::check gets called
452	first).	645	first).
453		646
454	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.
455		648
456	=back	649	=back
457		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
458	=head1 THREADS	695	=head1 THREADS
459		696
460	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
461	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.
462		717
463	=cut	718	=cut
464		719
465	our $DIED = sub {	720	our $DIED = sub {
466	warn "EV: error in callback (ignoring): $@";	721	warn "EV: error in callback (ignoring): $@";
467	};	722	};
468		723
469	init;	724	default_loop
470		725	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';
471	push @AnyEvent::REGISTRY, [EV => "EV::AnyEvent"];
472		726
473	1;	727	1;
474		728
475	=head1 SEE ALSO	729	=head1 SEE ALSO
476		730
477	L<EV::DNS>, L<EV::AnyEvent>.	731	L<EV::DNS>.
478		732
479	=head1 AUTHOR	733	=head1 AUTHOR
480		734
481	Marc Lehmann <schmorp@schmorp.de>	735	Marc Lehmann <schmorp@schmorp.de>
482	http://home.schmorp.de/	736	http://home.schmorp.de/

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Comparing EV/EV.pm (file contents): Revision 1.24 by root, Fri Nov 2 22:03:00 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 1.24 by root, Fri Nov 2 22:03:00 2007 UTC vs.
Revision 1.54 by root, Tue Nov 27 07:27:10 2007 UTC