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

Comparing EV/EV.pm (file contents):
Revision 1.52 by root, Sat Nov 24 16:20:30 2007 UTC vs.
Revision 1.75 by root, Fri Dec 21 10:36:22 2007 UTC

…		…
38	# CHILD/PID STATUS CHANGES	38	# CHILD/PID STATUS CHANGES
39		39
40	my $w = EV::child 666, sub {	40	my $w = EV::child 666, sub {
41	my ($w, $revents) = @_;	41	my ($w, $revents) = @_;
42	my $status = $w->rstatus;	42	my $status = $w->rstatus;
		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";
43	};	49	};
44		50
45	# MAINLOOP	51	# MAINLOOP
46	EV::loop; # loop until EV::unloop is called or all watchers stop	52	EV::loop; # loop until EV::unloop is called or all watchers stop
47	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
…		…
52	This module provides an interface to libev	58	This module provides an interface to libev
53	(L<http://software.schmorp.de/pkg/libev.html>). While the documentation	59	(L<http://software.schmorp.de/pkg/libev.html>). While the documentation
54	below is comprehensive, one might also consult the documentation of libev	60	below is comprehensive, one might also consult the documentation of libev
55	itself (L<http://cvs.schmorp.de/libev/ev.html>) for more subtle details on	61	itself (L<http://cvs.schmorp.de/libev/ev.html>) for more subtle details on
56	watcher semantics or some discussion on the available backends, or how to	62	watcher semantics or some discussion on the available backends, or how to
57	force a specific backend with C<LIBEV_FLAGS>.	63	force a specific backend with C<LIBEV_FLAGS>, or just about in any case
		64	because it has much more detailed information.
58		65
59	=cut	66	=cut
60		67
61	package EV;	68	package EV;
62		69
63	use strict;	70	use strict;
64		71
65	BEGIN {	72	BEGIN {
66	our $VERSION = '1.3';	73	our $VERSION = '2.0';
67	use XSLoader;	74	use XSLoader;
68	XSLoader::load "EV", $VERSION;	75	XSLoader::load "EV", $VERSION;
69	}	76	}
70		77
71	@EV::IO::ISA =	78	@EV::IO::ISA =
72	@EV::Timer::ISA =	79	@EV::Timer::ISA =
73	@EV::Periodic::ISA =	80	@EV::Periodic::ISA =
74	@EV::Signal::ISA =	81	@EV::Signal::ISA =
		82	@EV::Child::ISA =
		83	@EV::Stat::ISA =
75	@EV::Idle::ISA =	84	@EV::Idle::ISA =
76	@EV::Prepare::ISA =	85	@EV::Prepare::ISA =
77	@EV::Check::ISA =	86	@EV::Check::ISA =
78	@EV::Child::ISA = "EV::Watcher";	87	@EV::Embed::ISA =
		88	@EV::Fork::ISA =
		89	"EV::Watcher";
		90
		91	@EV::Loop::Default::ISA = "EV::Loop";
		92
		93	=head1 EVENT LOOPS
		94
		95	EV supports multiple event loops: There is a single "default event loop"
		96	that can handle everything including signals and child watchers, and any
		97	number of "dynamic event loops" that can use different backends (with
		98	various limitations), but no child and signal watchers.
		99
		100	You do not have to do anything to create the default event loop: When
		101	the module is loaded a suitable backend is selected on the premise of
		102	selecting a working backend (which for example rules out kqueue on most
		103	BSDs). Modules should, unless they have "special needs" always use the
		104	default loop as this is fastest (perl-wise), best supported by other
		105	modules (e.g. AnyEvent or Coro) and most portable event loop.
		106
		107	For specific programs you cna create additional event loops dynamically.
		108
		109	=over 4
		110
		111	=item $loop = new EV::loop [$flags]
		112
		113	Create a new event loop as per the specified flags. Please refer to the
		114	C<ev_loop_new ()> function description in the libev documentation
		115	(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>)
		116	for more info.
		117
		118	The loop will automatically be destroyed when it is no longer referenced
		119	by any watcher and the loop object goes out of scope.
		120
		121	Using C<EV::FLAG_FORKCHECK> is recommended, as only the default event loop
		122	is protected by this module.
		123
		124	=item $loop->loop_fork
		125
		126	Must be called after a fork in the child, before entering or continuing
		127	the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
		128	this fucntion automatically, at some performance loss (refer to the libev
		129	documentation).
		130
		131	=back
		132
79		133
80	=head1 BASIC INTERFACE	134	=head1 BASIC INTERFACE
81		135
82	=over 4	136	=over 4
83		137
84	=item $EV::DIED	138	=item $EV::DIED
85		139
86	Must contain a reference to a function that is called when a callback	140	Must contain a reference to a function that is called when a callback
87	throws an exception (with $@ containing thr error). The default prints an	141	throws an exception (with $@ containing the error). The default prints an
88	informative message and continues.	142	informative message and continues.
89		143
90	If this callback throws an exception it will be silently ignored.	144	If this callback throws an exception it will be silently ignored.
91		145
92	=item $time = EV::time	146	=item $time = EV::time
93		147
94	Returns the current time in (fractional) seconds since the epoch.	148	Returns the current time in (fractional) seconds since the epoch.
95		149
96	=item $time = EV::now	150	=item $time = EV::now
		151
		152	=item $time = $loop->now
97		153
98	Returns the time the last event loop iteration has been started. This	154	Returns the time the last event loop iteration has been started. This
99	is the time that (relative) timers are based on, and refering to it is	155	is the time that (relative) timers are based on, and refering to it is
100	usually faster then calling EV::time.	156	usually faster then calling EV::time.
101		157
102	=item $method = EV::method	158	=item $backend = EV::backend
		159
		160	=item $backend = $loop->backend
103		161
104	Returns an integer describing the backend used by libev (EV::METHOD_SELECT	162	Returns an integer describing the backend used by libev (EV::METHOD_SELECT
105	or EV::METHOD_EPOLL).	163	or EV::METHOD_EPOLL).
106		164
107	=item EV::loop [$flags]	165	=item EV::loop [$flags]
		166
		167	=item $loop->loop ([$flags])
108		168
109	Begin checking for events and calling callbacks. It returns when a	169	Begin checking for events and calling callbacks. It returns when a
110	callback calls EV::unloop.	170	callback calls EV::unloop.
111		171
112	The $flags argument can be one of the following:	172	The $flags argument can be one of the following:
…		…
115	EV::LOOP_ONESHOT block at most once (wait, but do not loop)	175	EV::LOOP_ONESHOT block at most once (wait, but do not loop)
116	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)	176	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
117		177
118	=item EV::unloop [$how]	178	=item EV::unloop [$how]
119		179
		180	=item $loop->unloop ([$how])
		181
120	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the	182	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the
121	innermost call to EV::loop return.	183	innermost call to EV::loop return.
122		184
123	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as	185	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as
124	fast as possible.	186	fast as possible.
125		187
		188	=item $count = EV::loop_count
		189
		190	=item $count = $loop->loop_count
		191
		192	Return the number of times the event loop has polled for new
		193	events. Sometiems useful as a generation counter.
		194
126	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)	195	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
		196
		197	=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
127		198
128	This function rolls together an I/O and a timer watcher for a single	199	This function rolls together an I/O and a timer watcher for a single
129	one-shot event without the need for managing a watcher object.	200	one-shot event without the need for managing a watcher object.
130		201
131	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>	202	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>
…		…
144		215
145	EV::once doesn't return anything: the watchers stay active till either	216	EV::once doesn't return anything: the watchers stay active till either
146	of them triggers, then they will be stopped and freed, and the callback	217	of them triggers, then they will be stopped and freed, and the callback
147	invoked.	218	invoked.
148		219
149	=back	220	=item EV::feed_fd_event ($fd, $revents)
150		221
151	=head2 WATCHER	222	=item $loop->feed_fd_event ($fd, $revents)
		223
		224	Feed an event on a file descriptor into EV. EV will react to this call as
		225	if the readyness notifications specified by C<$revents> (a combination of
		226	C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
		227
		228	=item EV::feed_signal_event ($signal)
		229
		230	Feed a signal event into EV. EV will react to this call as if the signal
		231	specified by C<$signal> had occured.
		232
		233	=back
		234
		235
		236	=head1 WATCHER OBJECTS
152		237
153	A watcher is an object that gets created to record your interest in some	238	A watcher is an object that gets created to record your interest in some
154	event. For instance, if you want to wait for STDIN to become readable, you	239	event. For instance, if you want to wait for STDIN to become readable, you
155	would create an EV::io watcher for that:	240	would create an EV::io watcher for that:
156		241
…		…
165	events.	250	events.
166		251
167	Each watcher type has its associated bit in revents, so you can use the	252	Each watcher type has its associated bit in revents, so you can use the
168	same callback for multiple watchers. The event mask is named after the	253	same callback for multiple watchers. The event mask is named after the
169	type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,	254	type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
170	EV::periodic sets EV::PERIODIC and so on, with the exception of IO events	255	EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events
171	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which	256	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which
172	uses EV::TIMEOUT).	257	uses EV::TIMEOUT).
173		258
174	In the rare case where one wants to create a watcher but not start it at	259	In the rare case where one wants to create a watcher but not start it at
175	the same time, each constructor has a variant with a trailing C<_ns> in	260	the same time, each constructor has a variant with a trailing C<_ns> in
…		…
181		266
182	Also, all methods changing some aspect of a watcher (->set, ->priority,	267	Also, all methods changing some aspect of a watcher (->set, ->priority,
183	->fh and so on) automatically stop and start it again if it is active,	268	->fh and so on) automatically stop and start it again if it is active,
184	which means pending events get lost.	269	which means pending events get lost.
185		270
186	=head2 WATCHER TYPES	271	=head2 COMMON WATCHER METHODS
187		272
188	Now lets move to the existing watcher types and asociated methods.	273	This section lists methods common to all watchers.
189
190	The following methods are available for all watchers. Then followes a
191	description of each watcher constructor (EV::io, EV::timer, EV::periodic,
192	EV::signal, EV::child, EV::idle, EV::prepare and EV::check), followed by
193	any type-specific methods (if any).
194		274
195	=over 4	275	=over 4
196		276
197	=item $w->start	277	=item $w->start
198		278
…		…
202		282
203	=item $w->stop	283	=item $w->stop
204		284
205	Stop a watcher if it is active. Also clear any pending events (events that	285	Stop a watcher if it is active. Also clear any pending events (events that
206	have been received but that didn't yet result in a callback invocation),	286	have been received but that didn't yet result in a callback invocation),
207	regardless of wether the watcher was active or not.	287	regardless of whether the watcher was active or not.
208		288
209	=item $bool = $w->is_active	289	=item $bool = $w->is_active
210		290
211	Returns true if the watcher is active, false otherwise.	291	Returns true if the watcher is active, false otherwise.
212		292
…		…
242	The default priority of any newly-created watcher is 0.	322	The default priority of any newly-created watcher is 0.
243		323
244	Note that the priority semantics have not yet been fleshed out and are	324	Note that the priority semantics have not yet been fleshed out and are
245	subject to almost certain change.	325	subject to almost certain change.
246		326
247	=item $w->trigger ($revents)	327	=item $w->invoke ($revents)
248		328
249	Call the callback now with the given event mask.	329	Call the callback now with the given event mask.
		330
		331	=item $w->feed_event ($revents)
		332
		333	Feed some events on this watcher into EV. EV will react to this call as if
		334	the watcher had received the given C<$revents> mask.
		335
		336	=item $revents = $w->clear_pending
		337
		338	If the watcher is pending, this function returns clears its pending status
		339	and returns its C<$revents> bitset (as if its callback was invoked). If the
		340	watcher isn't pending it does nothing and returns C<0>.
250		341
251	=item $previous_state = $w->keepalive ($bool)	342	=item $previous_state = $w->keepalive ($bool)
252		343
253	Normally, C<EV::loop> will return when there are no active watchers	344	Normally, C<EV::loop> will return when there are no active watchers
254	(which is a "deadlock" because no progress can be made anymore). This is	345	(which is a "deadlock" because no progress can be made anymore). This is
…		…
267	though your watcher is active, it won't keep C<EV::loop> from returning.	358	though your watcher is active, it won't keep C<EV::loop> from returning.
268		359
269	The initial value for keepalive is true (enabled), and you cna change it	360	The initial value for keepalive is true (enabled), and you cna change it
270	any time.	361	any time.
271		362
272	Example: Register an IO watcher for some UDP socket but do not keep the	363	Example: Register an I/O watcher for some UDP socket but do not keep the
273	event loop from running just because of that watcher.	364	event loop from running just because of that watcher.
274		365
275	my $udp_socket = ...	366	my $udp_socket = ...
276	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };	367	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
277	$udp_watcher->keepalive (0);	368	$1000udp_watcher->keepalive (0);
		369
		370	=item $loop = $w->loop
		371
		372	Return the loop that this watcher is attached to.
		373
		374	=back
		375
		376
		377	=head1 WATCHER TYPES
		378
		379	Each of the following subsections describes a single watcher type.
		380
		381	=head3 I/O WATCHERS - is this file descriptor readable or writable?
		382
		383	=over 4
278		384
279	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	385	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
280		386
281	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback	387	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
282		388
		389	=item $w = $loop->io 8$fileno_or_fh, $eventmask, $callback)
		390
		391	=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
		392
283	As long as the returned watcher object is alive, call the C<$callback>	393	As long as the returned watcher object is alive, call the C<$callback>
284	when the events specified in C<$eventmask>.	394	when at least one of events specified in C<$eventmask> occurs.
285		395
286	The $eventmask can be one or more of these constants ORed together:	396	The $eventmask can be one or more of these constants ORed together:
287		397
288	EV::READ wait until read() wouldn't block anymore	398	EV::READ wait until read() wouldn't block anymore
289	EV::WRITE wait until write() wouldn't block anymore	399	EV::WRITE wait until write() wouldn't block anymore
…		…
305		415
306	=item $old_eventmask = $w->events ($new_eventmask)	416	=item $old_eventmask = $w->events ($new_eventmask)
307		417
308	Returns the previously set event mask and optionally set a new one.	418	Returns the previously set event mask and optionally set a new one.
309		419
		420	=back
		421
		422
		423	=head3 TIMER WATCHERS - relative and optionally repeating timeouts
		424
		425	=over 4
310		426
311	=item $w = EV::timer $after, $repeat, $callback	427	=item $w = EV::timer $after, $repeat, $callback
312		428
313	=item $w = EV::timer_ns $after, $repeat, $callback	429	=item $w = EV::timer_ns $after, $repeat, $callback
314		430
315	Calls the callback after C<$after> seconds. If C<$repeat> is non-zero,	431	=item $w = $loop->timer ($after, $repeat, $callback)
316	the timer will be restarted (with the $repeat value as $after) after the	432
317	callback returns.	433	=item $w = $loop->timer_ns ($after, $repeat, $callback)
		434
		435	Calls the callback after C<$after> seconds (which may be fractional). If
		436	C<$repeat> is non-zero, the timer will be restarted (with the $repeat
		437	value as $after) after the callback returns.
318		438
319	This means that the callback would be called roughly after C<$after>	439	This means that the callback would be called roughly after C<$after>
320	seconds, and then every C<$repeat> seconds. The timer does his best not	440	seconds, and then every C<$repeat> seconds. The timer does his best not
321	to drift, but it will not invoke the timer more often then once per event	441	to drift, but it will not invoke the timer more often then once per event
322	loop iteration, and might drift in other cases. If that isn't acceptable,	442	loop iteration, and might drift in other cases. If that isn't acceptable,
…		…
328		448
329	The C<timer_ns> variant doesn't start (activate) the newly created watcher.	449	The C<timer_ns> variant doesn't start (activate) the newly created watcher.
330		450
331	=item $w->set ($after, $repeat)	451	=item $w->set ($after, $repeat)
332		452
333	Reconfigures the watcher, see the constructor above for details. Can be at	453	Reconfigures the watcher, see the constructor above for details. Can be called at
334	any time.	454	any time.
335		455
336	=item $w->again	456	=item $w->again
337		457
338	Similar to the C<start> method, but has special semantics for repeating timers:	458	Similar to the C<start> method, but has special semantics for repeating timers:
…		…
349	This behaviour is useful when you have a timeout for some IO	469	This behaviour is useful when you have a timeout for some IO
350	operation. You create a timer object with the same value for C<$after> and	470	operation. You create a timer object with the same value for C<$after> and
351	C<$repeat>, and then, in the read/write watcher, run the C<again> method	471	C<$repeat>, and then, in the read/write watcher, run the C<again> method
352	on the timeout.	472	on the timeout.
353		473
		474	=back
		475
		476
		477	=head3 PERIODIC WATCHERS - to cron or not to cron?
		478
		479	=over 4
354		480
355	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback	481	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
356		482
357	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback	483	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
		484
		485	=item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
		486
		487	=item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback)
358		488
359	Similar to EV::timer, but is not based on relative timeouts but on	489	Similar to EV::timer, but is not based on relative timeouts but on
360	absolute times. Apart from creating "simple" timers that trigger "at" the	490	absolute times. Apart from creating "simple" timers that trigger "at" the
361	specified time, it can also be used for non-drifting absolute timers and	491	specified time, it can also be used for non-drifting absolute timers and
362	more complex, cron-like, setups that are not adversely affected by time	492	more complex, cron-like, setups that are not adversely affected by time
…		…
430		560
431	The C<periodic_ns> variant doesn't start (activate) the newly created watcher.	561	The C<periodic_ns> variant doesn't start (activate) the newly created watcher.
432		562
433	=item $w->set ($at, $interval, $reschedule_cb)	563	=item $w->set ($at, $interval, $reschedule_cb)
434		564
435	Reconfigures the watcher, see the constructor above for details. Can be at	565	Reconfigures the watcher, see the constructor above for details. Can be called at
436	any time.	566	any time.
437		567
438	=item $w->again	568	=item $w->again
439		569
440	Simply stops and starts the watcher again.	570	Simply stops and starts the watcher again.
441		571
		572	=item $time = $w->at
		573
		574	Return the time that the watcher is expected to trigger next.
		575
		576	=back
		577
		578
		579	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
		580
		581	=over 4
442		582
443	=item $w = EV::signal $signal, $callback	583	=item $w = EV::signal $signal, $callback
444		584
445	=item $w = EV::signal_ns $signal, $callback	585	=item $w = EV::signal_ns $signal, $callback
446		586
447	Call the callback when $signal is received (the signal can be specified	587	Call the callback when $signal is received (the signal can be specified by
448	by number or by name, just as with kill or %SIG).	588	number or by name, just as with C<kill> or C<%SIG>).
449		589
450	EV will grab the signal for the process (the kernel only allows one	590	EV will grab the signal for the process (the kernel only allows one
451	component to receive a signal at a time) when you start a signal watcher,	591	component to receive a signal at a time) when you start a signal watcher,
452	and removes it again when you stop it. Perl does the same when you	592	and removes it again when you stop it. Perl does the same when you
453	add/remove callbacks to %SIG, so watch out.	593	add/remove callbacks to C<%SIG>, so watch out.
454		594
455	You can have as many signal watchers per signal as you want.	595	You can have as many signal watchers per signal as you want.
456		596
457	The C<signal_ns> variant doesn't start (activate) the newly created watcher.	597	The C<signal_ns> variant doesn't start (activate) the newly created watcher.
458		598
459	=item $w->set ($signal)	599	=item $w->set ($signal)
460		600
461	Reconfigures the watcher, see the constructor above for details. Can be at	601	Reconfigures the watcher, see the constructor above for details. Can be
462	any time.	602	called at any time.
463		603
464	=item $current_signum = $w->signal	604	=item $current_signum = $w->signal
465		605
466	=item $old_signum = $w->signal ($new_signal)	606	=item $old_signum = $w->signal ($new_signal)
467		607
468	Returns the previously set signal (always as a number not name) and	608	Returns the previously set signal (always as a number not name) and
469	optionally set a new one.	609	optionally set a new one.
470		610
		611	=back
		612
		613
		614	=head3 CHILD WATCHERS - watch out for process status changes
		615
		616	=over 4
471		617
472	=item $w = EV::child $pid, $callback	618	=item $w = EV::child $pid, $callback
473		619
474	=item $w = EV::child_ns $pid, $callback	620	=item $w = EV::child_ns $pid, $callback
475		621
		622	=item $w = $loop->child ($pid, $callback)
		623
		624	=item $w = $loop->child_ns ($pid, $callback)
		625
476	Call the callback when a status change for pid C<$pid> (or any pid	626	Call the callback when a status change for pid C<$pid> (or any pid if
477	if C<$pid> is 0) has been received. More precisely: when the process	627	C<$pid> is 0) has been received. More precisely: when the process receives
478	receives a SIGCHLD, EV will fetch the outstanding exit/wait status for all	628	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
479	changed/zombie children and call the callback.	629	changed/zombie children and call the callback.
480		630
481	You can access both status and pid by using the C<rstatus> and C<rpid>	631	It is valid (and fully supported) to install a child watcher after a child
482	methods on the watcher object.	632	has exited but before the event loop has started its next iteration (for
		633	example, first you C<fork>, then the new child process might exit, and
		634	only then do you install a child watcher in the parent for the new pid).
483		635
		636	You can access both exit (or tracing) status and pid by using the
		637	C<rstatus> and C<rpid> methods on the watcher object.
		638
484	You can have as many pid watchers per pid as you want.	639	You can have as many pid watchers per pid as you want, they will all be
		640	called.
485		641
486	The C<child_ns> variant doesn't start (activate) the newly created watcher.	642	The C<child_ns> variant doesn't start (activate) the newly created watcher.
487		643
488	=item $w->set ($pid)	644	=item $w->set ($pid)
489		645
490	Reconfigures the watcher, see the constructor above for details. Can be at	646	Reconfigures the watcher, see the constructor above for details. Can be called at
491	any time.	647	any time.
492		648
493	=item $current_pid = $w->pid	649	=item $current_pid = $w->pid
494		650
495	=item $old_pid = $w->pid ($new_pid)	651	=item $old_pid = $w->pid ($new_pid)
…		…
504	=item $pid = $w->rpid	660	=item $pid = $w->rpid
505		661
506	Return the pid of the awaited child (useful when you have installed a	662	Return the pid of the awaited child (useful when you have installed a
507	watcher for all pids).	663	watcher for all pids).
508		664
		665	=back
		666
		667
		668	=head3 STAT WATCHERS - did the file attributes just change?
		669
		670	=over 4
		671
		672	=item $w = EV::stat $path, $interval, $callback
		673
		674	=item $w = EV::stat_ns $path, $interval, $callback
		675
		676	=item $w = $loop->stat ($path, $interval, $callback)
		677
		678	=item $w = $loop->stat_ns ($path, $interval, $callback)
		679
		680	Call the callback when a file status change has been detected on
		681	C<$path>. The C<$path> does not need to exist, changing from "path exists"
		682	to "path does not exist" is a status change like any other.
		683
		684	The C<$interval> is a recommended polling interval for systems where
		685	OS-supported change notifications don't exist or are not supported. If
		686	you use C<0> then an unspecified default is used (which is highly
		687	recommended!), which is to be expected to be around five seconds usually.
		688
		689	This watcher type is not meant for massive numbers of stat watchers,
		690	as even with OS-supported change notifications, this can be
		691	resource-intensive.
		692
		693	The C<stat_ns> variant doesn't start (activate) the newly created watcher.
		694
		695	=item ... = $w->stat
		696
		697	This call is very similar to the perl C<stat> built-in: It stats (using
		698	C<lstat>) the path specified in the watcher and sets perls stat cache (as
		699	well as EV's idea of the current stat values) to the values found.
		700
		701	In scalar context, a boolean is return indicating success or failure of
		702	the stat. In list context, the same 13-value list as with stat is returned
		703	(except that the blksize and blocks fields are not reliable).
		704
		705	In the case of an error, errno is set to C<ENOENT> (regardless of the
		706	actual error value) and the C<nlink> value is forced to zero (if the stat
		707	was successful then nlink is guaranteed to be non-zero).
		708
		709	See also the next two entries for more info.
		710
		711	=item ... = $w->attr
		712
		713	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		714	the values most recently detected by EV. See the next entry for more info.
		715
		716	=item ... = $w->prev
		717
		718	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		719	the previous set of values, before the change.
		720
		721	That is, when the watcher callback is invoked, C<< $w->prev >> will be set
		722	to the values found I<before> a change was detected, while C<< $w->attr >>
		723	returns the values found leading to the change detection. The difference (if any)
		724	between C<prev> and C<attr> is what triggered the callback.
		725
		726	If you did something to the filesystem object and do not want to trigger
		727	yet another change, you can call C<stat> to update EV's idea of what the
		728	current attributes are.
		729
		730	=item $w->set ($path, $interval)
		731
		732	Reconfigures the watcher, see the constructor above for details. Can be
		733	called at any time.
		734
		735	=item $current_path = $w->path
		736
		737	=item $old_path = $w->path ($new_path)
		738
		739	Returns the previously set path and optionally set a new one.
		740
		741	=item $current_interval = $w->interval
		742
		743	=item $old_interval = $w->interval ($new_interval)
		744
		745	Returns the previously set interval and optionally set a new one. Can be
		746	used to query the actual interval used.
		747
		748	=back
		749
		750
		751	=head3 IDLE WATCHERS - when you've got nothing better to do...
		752
		753	=over 4
509		754
510	=item $w = EV::idle $callback	755	=item $w = EV::idle $callback
511		756
512	=item $w = EV::idle_ns $callback	757	=item $w = EV::idle_ns $callback
513		758
514	Call the callback when there are no pending io, timer/periodic, signal or	759	=item $w = $loop->idle ($callback)
515	child events, i.e. when the process is idle.	760
		761	=item $w = $loop->idle_ns ($callback)
		762
		763	Call the callback when there are no other pending watchers of the same or
		764	higher priority (excluding check, prepare and other idle watchers of the
		765	same or lower priority, of course). They are called idle watchers because
		766	when the watcher is the highest priority pending event in the process, the
		767	process is considered to be idle at that priority.
		768
		769	If you want a watcher that is only ever called when I<no> other events are
		770	outstanding you have to set the priority to C<EV::MINPRI>.
516		771
517	The process will not block as long as any idle watchers are active, and	772	The process will not block as long as any idle watchers are active, and
518	they will be called repeatedly until stopped.	773	they will be called repeatedly until stopped.
519		774
		775	For example, if you have idle watchers at priority C<0> and C<1>, and
		776	an I/O watcher at priority C<0>, then the idle watcher at priority C<1>
		777	and the I/O watcher will always run when ready. Only when the idle watcher
		778	at priority C<1> is stopped and the I/O watcher at priority C<0> is not
		779	pending with the C<0>-priority idle watcher be invoked.
		780
520	The C<idle_ns> variant doesn't start (activate) the newly created watcher.	781	The C<idle_ns> variant doesn't start (activate) the newly created watcher.
521		782
		783	=back
		784
		785
		786	=head3 PREPARE WATCHERS - customise your event loop!
		787
		788	=over 4
522		789
523	=item $w = EV::prepare $callback	790	=item $w = EV::prepare $callback
524		791
525	=item $w = EV::prepare_ns $callback	792	=item $w = EV::prepare_ns $callback
		793
		794	=item $w = $loop->prepare ($callback)
		795
		796	=item $w = $loop->prepare_ns 8$callback)
526		797
527	Call the callback just before the process would block. You can still	798	Call the callback just before the process would block. You can still
528	create/modify any watchers at this point.	799	create/modify any watchers at this point.
529		800
530	See the EV::check watcher, below, for explanations and an example.	801	See the EV::check watcher, below, for explanations and an example.
531		802
532	The C<prepare_ns> variant doesn't start (activate) the newly created watcher.	803	The C<prepare_ns> variant doesn't start (activate) the newly created watcher.
533		804
		805	=back
		806
		807
		808	=head3 CHECK WATCHERS - customise your event loop even more!
		809
		810	=over 4
534		811
535	=item $w = EV::check $callback	812	=item $w = EV::check $callback
536		813
537	=item $w = EV::check_ns $callback	814	=item $w = EV::check_ns $callback
		815
		816	=item $w = $loop->check ($callback)
		817
		818	=item $w = $loop->check_ns ($callback)
538		819
539	Call the callback just after the process wakes up again (after it has	820	Call the callback just after the process wakes up again (after it has
540	gathered events), but before any other callbacks have been invoked.	821	gathered events), but before any other callbacks have been invoked.
541		822
542	This is used to integrate other event-based software into the EV	823	This is used to integrate other event-based software into the EV
…		…
552	or return;	833	or return;
553		834
554	# make the dispatcher handle any outstanding stuff	835	# make the dispatcher handle any outstanding stuff
555	... not shown	836	... not shown
556		837
557	# create an IO watcher for each and every socket	838	# create an I/O watcher for each and every socket
558	@snmp_watcher = (	839	@snmp_watcher = (
559	(map { EV::io $_, EV::READ, sub { } }	840	(map { EV::io $_, EV::READ, sub { } }
560	keys %{ $dispatcher->{_descriptors} }),	841	keys %{ $dispatcher->{_descriptors} }),
561		842
562	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]	843	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
…		…
583	first).	864	first).
584		865
585	The C<check_ns> variant doesn't start (activate) the newly created watcher.	866	The C<check_ns> variant doesn't start (activate) the newly created watcher.
586		867
587	=back	868	=back
		869
		870
		871	=head3 FORK WATCHERS - the audacity to resume the event loop after a fork
		872
		873	Fork watchers are called when a C<fork ()> was detected. The invocation
		874	is done before the event loop blocks next and before C<check> watchers
		875	are being called, and only in the child after the fork.
		876
		877	=over 4
		878
		879	=item $w = EV::fork $callback
		880
		881	=item $w = EV::fork_ns $callback
		882
		883	=item $w = $loop->fork ($callback)
		884
		885	=item $w = $loop->fork_ns ($callback)
		886
		887	Call the callback before the event loop is resumed in the child process
		888	after a fork.
		889
		890	The C<fork_ns> variant doesn't start (activate) the newly created watcher.
		891
		892	=back
		893
		894
		895	=head1 PERL SIGNALS
		896
		897	While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour
		898	with EV is as the same as any other C library: Perl-signals will only be
		899	handled when Perl runs, which means your signal handler might be invoked
		900	only the next time an event callback is invoked.
		901
		902	The solution is to use EV signal watchers (see C<EV::signal>), which will
		903	ensure proper operations with regards to other event watchers.
		904
		905	If you cannot do this for whatever reason, you can also force a watcher
		906	to be called on every event loop iteration by installing a C<EV::check>
		907	watcher:
		908
		909	my $async_check = EV::check sub { };
		910
		911	This ensures that perl gets into control for a short time to handle any
		912	pending signals, and also ensures (slightly) slower overall operation.
588		913
589	=head1 THREADS	914	=head1 THREADS
590		915
591	Threads are not supported by this module in any way. Perl pseudo-threads	916	Threads are not supported by this module in any way. Perl pseudo-threads
592	is evil stuff and must die. As soon as Perl gains real threads I will work	917	is evil stuff and must die. As soon as Perl gains real threads I will work
…		…
614	our $DIED = sub {	939	our $DIED = sub {
615	warn "EV: error in callback (ignoring): $@";	940	warn "EV: error in callback (ignoring): $@";
616	};	941	};
617		942
618	default_loop	943	default_loop
619	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	944	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
620		945
621	1;	946	1;
622		947
623	=head1 SEE ALSO	948	=head1 SEE ALSO
624		949
625	L<EV::DNS>.	950	L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as
		951	event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
		952	coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP).
626		953
627	=head1 AUTHOR	954	=head1 AUTHOR
628		955
629	Marc Lehmann <schmorp@schmorp.de>	956	Marc Lehmann <schmorp@schmorp.de>
630	http://home.schmorp.de/	957	http://home.schmorp.de/

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Comparing EV/EV.pm (file contents): Revision 1.52 by root, Sat Nov 24 16:20:30 2007 UTC vs. Revision 1.75 by root, Fri Dec 21 10:36:22 2007 UTC

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Comparing EV/EV.pm (file contents):
Revision 1.52 by root, Sat Nov 24 16:20:30 2007 UTC vs.
Revision 1.75 by root, Fri Dec 21 10:36:22 2007 UTC