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

Comparing EV/EV.pm (file contents):
Revision 1.54 by root, Tue Nov 27 07:27:10 2007 UTC vs.
Revision 1.95 by root, Wed May 21 23:35:00 2008 UTC

…		…
35	warn "sigquit received\n";	35	warn "sigquit received\n";
36	};	36	};
37		37
38	# CHILD/PID STATUS CHANGES	38	# CHILD/PID STATUS CHANGES
39		39
40	my $w = EV::child 666, sub {	40	my $w = EV::child 666, 0, sub {
41	my ($w, $revents) = @_;	41	my ($w, $revents) = @_;
42	my $status = $w->rstatus;	42	my $status = $w->rstatus;
43	};	43	};
44		44
45	# STAT CHANGES	45	# STAT CHANGES
…		…
56	=head1 DESCRIPTION	56	=head1 DESCRIPTION
57		57
58	This module provides an interface to libev	58	This module provides an interface to libev
59	(L<http://software.schmorp.de/pkg/libev.html>). While the documentation	59	(L<http://software.schmorp.de/pkg/libev.html>). While the documentation
60	below is comprehensive, one might also consult the documentation of libev	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	61	itself (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod>) for more
62	watcher semantics or some discussion on the available backends, or how to	62	subtle details on watcher semantics or some discussion on the available
63	force a specific backend with C<LIBEV_FLAGS>.	63	backends, or how to force a specific backend with C<LIBEV_FLAGS>, or just
		64	about in any case because it has much more detailed information.
		65
		66	This module is very fast and scalable. It is actually so fast that you
		67	can use it through the L<AnyEvent> module, stay portable to other event
		68	loops (if you don't rely on any watcher types not available through it)
		69	and still be faster than with any other event loop currently supported in
		70	Perl.
64		71
65	=cut	72	=cut
66		73
67	package EV;	74	package EV;
68		75
69	use strict;	76	use strict;
70		77
71	BEGIN {	78	BEGIN {
72	our $VERSION = '1.4';	79	our $VERSION = '3.41';
73	use XSLoader;	80	use XSLoader;
74	XSLoader::load "EV", $VERSION;	81	XSLoader::load "EV", $VERSION;
75	}	82	}
76		83
77	@EV::IO::ISA =	84	@EV::IO::ISA =
78	@EV::Timer::ISA =	85	@EV::Timer::ISA =
79	@EV::Periodic::ISA =	86	@EV::Periodic::ISA =
80	@EV::Signal::ISA =	87	@EV::Signal::ISA =
		88	@EV::Child::ISA =
		89	@EV::Stat::ISA =
81	@EV::Idle::ISA =	90	@EV::Idle::ISA =
82	@EV::Prepare::ISA =	91	@EV::Prepare::ISA =
83	@EV::Check::ISA =	92	@EV::Check::ISA =
84	@EV::Child::ISA =
85	@EV::Embed::ISA =	93	@EV::Embed::ISA =
86	@EV::Stat::ISA = "EV::Watcher";	94	@EV::Fork::ISA =
		95	@EV::Async::ISA =
		96	"EV::Watcher";
		97
		98	@EV::Loop::Default::ISA = "EV::Loop";
		99
		100	=head1 EVENT LOOPS
		101
		102	EV supports multiple event loops: There is a single "default event loop"
		103	that can handle everything including signals and child watchers, and any
		104	number of "dynamic event loops" that can use different backends (with
		105	various limitations), but no child and signal watchers.
		106
		107	You do not have to do anything to create the default event loop: When
		108	the module is loaded a suitable backend is selected on the premise of
		109	selecting a working backend (which for example rules out kqueue on most
		110	BSDs). Modules should, unless they have "special needs" always use the
		111	default loop as this is fastest (perl-wise), best supported by other
		112	modules (e.g. AnyEvent or Coro) and most portable event loop.
		113
		114	For specific programs you can create additional event loops dynamically.
		115
		116	=over 4
		117
		118	=item $loop = new EV::loop [$flags]
		119
		120	Create a new event loop as per the specified flags. Please refer to the
		121	C<ev_loop_new ()> function description in the libev documentation
		122	(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>)
		123	for more info.
		124
		125	The loop will automatically be destroyed when it is no longer referenced
		126	by any watcher and the loop object goes out of scope.
		127
		128	Using C<EV::FLAG_FORKCHECK> is recommended, as only the default event loop
		129	is protected by this module.
		130
		131	=item $loop->loop_fork
		132
		133	Must be called after a fork in the child, before entering or continuing
		134	the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
		135	this fucntion automatically, at some performance loss (refer to the libev
		136	documentation).
		137
		138	=item $loop = EV::default_loop [$flags]
		139
		140	Return the default loop (which is a singleton object).
		141
		142	=back
		143
87		144
88	=head1 BASIC INTERFACE	145	=head1 BASIC INTERFACE
89		146
90	=over 4	147	=over 4
91		148
92	=item $EV::DIED	149	=item $EV::DIED
93		150
94	Must contain a reference to a function that is called when a callback	151	Must contain a reference to a function that is called when a callback
95	throws an exception (with $@ containing thr error). The default prints an	152	throws an exception (with $@ containing the error). The default prints an
96	informative message and continues.	153	informative message and continues.
97		154
98	If this callback throws an exception it will be silently ignored.	155	If this callback throws an exception it will be silently ignored.
99		156
		157	=item $flags = EV::supported_backends
		158
		159	=item $flags = EV::recommended_backends
		160
		161	=item $flags = EV::embeddable_backends
		162
		163	Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this
		164	instance of EV, the set of recommended backends (supposed to be good) for
		165	this platform and the set of embeddable backends (see EMBED WATCHERS).
		166
		167	=item EV::sleep $seconds
		168
		169	Block the process for the given number of (fractional) seconds.
		170
100	=item $time = EV::time	171	=item $time = EV::time
101		172
102	Returns the current time in (fractional) seconds since the epoch.	173	Returns the current time in (fractional) seconds since the epoch.
103		174
104	=item $time = EV::now	175	=item $time = EV::now
		176
		177	=item $time = $loop->now
105		178
106	Returns the time the last event loop iteration has been started. This	179	Returns the time the last event loop iteration has been started. This
107	is the time that (relative) timers are based on, and refering to it is	180	is the time that (relative) timers are based on, and refering to it is
108	usually faster then calling EV::time.	181	usually faster then calling EV::time.
109		182
110	=item $method = EV::method	183	=item $backend = EV::backend
		184
		185	=item $backend = $loop->backend
111		186
112	Returns an integer describing the backend used by libev (EV::METHOD_SELECT	187	Returns an integer describing the backend used by libev (EV::METHOD_SELECT
113	or EV::METHOD_EPOLL).	188	or EV::METHOD_EPOLL).
114		189
115	=item EV::loop [$flags]	190	=item EV::loop [$flags]
		191
		192	=item $loop->loop ([$flags])
116		193
117	Begin checking for events and calling callbacks. It returns when a	194	Begin checking for events and calling callbacks. It returns when a
118	callback calls EV::unloop.	195	callback calls EV::unloop.
119		196
120	The $flags argument can be one of the following:	197	The $flags argument can be one of the following:
…		…
123	EV::LOOP_ONESHOT block at most once (wait, but do not loop)	200	EV::LOOP_ONESHOT block at most once (wait, but do not loop)
124	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)	201	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
125		202
126	=item EV::unloop [$how]	203	=item EV::unloop [$how]
127		204
		205	=item $loop->unloop ([$how])
		206
128	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the	207	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the
129	innermost call to EV::loop return.	208	innermost call to EV::loop return.
130		209
131	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as	210	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as
132	fast as possible.	211	fast as possible.
133		212
		213	=item $count = EV::loop_count
		214
		215	=item $count = $loop->loop_count
		216
		217	Return the number of times the event loop has polled for new
		218	events. Sometiems useful as a generation counter.
		219
134	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)	220	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
		221
		222	=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
135		223
136	This function rolls together an I/O and a timer watcher for a single	224	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.	225	one-shot event without the need for managing a watcher object.
138		226
139	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>	227	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>
…		…
145	If timeout is C<undef> or negative, then there will be no	233	If timeout is C<undef> or negative, then there will be no
146	timeout. Otherwise a EV::timer with this value will be started.	234	timeout. Otherwise a EV::timer with this value will be started.
147		235
148	When an error occurs or either the timeout or I/O watcher triggers, then	236	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	237	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>,	238	you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
151	C<EV::WRITE> and C<EV::TIMEOUT>).	239	C<EV::WRITE> and C<EV::TIMEOUT>).
152		240
153	EV::once doesn't return anything: the watchers stay active till either	241	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	242	of them triggers, then they will be stopped and freed, and the callback
155	invoked.	243	invoked.
156		244
157	=back	245	=item EV::feed_fd_event ($fd, $revents)
158		246
		247	=item $loop->feed_fd_event ($fd, $revents)
		248
		249	Feed an event on a file descriptor into EV. EV will react to this call as
		250	if the readyness notifications specified by C<$revents> (a combination of
		251	C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
		252
		253	=item EV::feed_signal_event ($signal)
		254
		255	Feed a signal event into EV. EV will react to this call as if the signal
		256	specified by C<$signal> had occured.
		257
		258	=item EV::set_io_collect_interval $time
		259
		260	=item $loop->set_io_collect_interval ($time)
		261
		262	=item EV::set_timeout_collect_interval $time
		263
		264	=item $loop->set_timeout_collect_interval ($time)
		265
		266	These advanced functions set the minimum block interval when polling for I/O events and the minimum
		267	wait interval for timer events. See the libev documentation at
		268	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> for
		269	a more detailed discussion.
		270
		271	=back
		272
		273
159	=head2 WATCHER OBJECTS	274	=head1 WATCHER OBJECTS
160		275
161	A watcher is an object that gets created to record your interest in some	276	A watcher is an object that gets created to record your interest in some
162	event. For instance, if you want to wait for STDIN to become readable, you	277	event. For instance, if you want to wait for STDIN to become readable, you
163	would create an EV::io watcher for that:	278	would create an EV::io watcher for that:
164		279
165	my $watcher = EV::io *STDIN, EV::READ, sub {	280	my $watcher = EV::io *STDIN, EV::READ, sub {
166	my ($watcher, $revents) = @_;	281	my ($watcher, $revents) = @_;
167	warn "yeah, STDIN should not be readable without blocking!\n"	282	warn "yeah, STDIN should now be readable without blocking!\n"
168	};	283	};
169		284
170	All watchers can be active (waiting for events) or inactive (paused). Only	285	All watchers can be active (waiting for events) or inactive (paused). Only
171	active watchers will have their callbacks invoked. All callbacks will be	286	active watchers will have their callbacks invoked. All callbacks will be
172	called with at least two arguments: the watcher and a bitmask of received	287	called with at least two arguments: the watcher and a bitmask of received
173	events.	288	events.
174		289
175	Each watcher type has its associated bit in revents, so you can use the	290	Each watcher type has its associated bit in revents, so you can use the
176	same callback for multiple watchers. The event mask is named after the	291	same callback for multiple watchers. The event mask is named after the
177	type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,	292	type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
178	EV::periodic sets EV::PERIODIC and so on, with the exception of IO events	293	EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events
179	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which	294	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which
180	uses EV::TIMEOUT).	295	uses EV::TIMEOUT).
181		296
182	In the rare case where one wants to create a watcher but not start it at	297	In the rare case where one wants to create a watcher but not start it at
183	the same time, each constructor has a variant with a trailing C<_ns> in	298	the same time, each constructor has a variant with a trailing C<_ns> in
…		…
205		320
206	=item $w->stop	321	=item $w->stop
207		322
208	Stop a watcher if it is active. Also clear any pending events (events that	323	Stop a watcher if it is active. Also clear any pending events (events that
209	have been received but that didn't yet result in a callback invocation),	324	have been received but that didn't yet result in a callback invocation),
210	regardless of wether the watcher was active or not.	325	regardless of whether the watcher was active or not.
211		326
212	=item $bool = $w->is_active	327	=item $bool = $w->is_active
213		328
214	Returns true if the watcher is active, false otherwise.	329	Returns true if the watcher is active, false otherwise.
215		330
…		…
245	The default priority of any newly-created watcher is 0.	360	The default priority of any newly-created watcher is 0.
246		361
247	Note that the priority semantics have not yet been fleshed out and are	362	Note that the priority semantics have not yet been fleshed out and are
248	subject to almost certain change.	363	subject to almost certain change.
249		364
250	=item $w->trigger ($revents)	365	=item $w->invoke ($revents)
251		366
252	Call the callback now with the given event mask.	367	Call the callback now with the given event mask.
		368
		369	=item $w->feed_event ($revents)
		370
		371	Feed some events on this watcher into EV. EV will react to this call as if
		372	the watcher had received the given C<$revents> mask.
		373
		374	=item $revents = $w->clear_pending
		375
		376	If the watcher is pending, this function clears its pending status and
		377	returns its C<$revents> bitset (as if its callback was invoked). If the
		378	watcher isn't pending it does nothing and returns C<0>.
253		379
254	=item $previous_state = $w->keepalive ($bool)	380	=item $previous_state = $w->keepalive ($bool)
255		381
256	Normally, C<EV::loop> will return when there are no active watchers	382	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	383	(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),	384	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	385	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 :).	386	finished (or they forgot to register some watchers for their task :).
261		387
262	Sometimes, however, this gets in your way, for example when you the module	388	Sometimes, however, this gets in your way, for example when the module
263	that calls C<EV::loop> (usually the main program) is not the same module	389	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	390	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	391	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	392	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.	393	because you happen to have this long-running UDP port watcher.
…		…
270	though your watcher is active, it won't keep C<EV::loop> from returning.	396	though your watcher is active, it won't keep C<EV::loop> from returning.
271		397
272	The initial value for keepalive is true (enabled), and you cna change it	398	The initial value for keepalive is true (enabled), and you cna change it
273	any time.	399	any time.
274		400
275	Example: Register an IO watcher for some UDP socket but do not keep the	401	Example: Register an I/O watcher for some UDP socket but do not keep the
276	event loop from running just because of that watcher.	402	event loop from running just because of that watcher.
277		403
278	my $udp_socket = ...	404	my $udp_socket = ...
279	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };	405	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
280	$udp_watcher->keepalive (0);	406	$1000udp_watcher->keepalive (0);
281		407
282	=back	408	=item $loop = $w->loop
283		409
		410	Return the loop that this watcher is attached to.
284		411
		412	=back
		413
		414
285	=head2 WATCHER TYPES	415	=head1 WATCHER TYPES
286		416
287	Each of the following subsections describes a single watcher type.	417	Each of the following subsections describes a single watcher type.
288		418
289	=head3 IO WATCHERS - is this file descriptor readable or writable?	419	=head3 I/O WATCHERS - is this file descriptor readable or writable?
290		420
291	=over 4	421	=over 4
292		422
293	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	423	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
294		424
295	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback	425	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
		426
		427	=item $w = $loop->io ($fileno_or_fh, $eventmask, $callback)
		428
		429	=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
296		430
297	As long as the returned watcher object is alive, call the C<$callback>	431	As long as the returned watcher object is alive, call the C<$callback>
298	when at least one of events specified in C<$eventmask> occurs.	432	when at least one of events specified in C<$eventmask> occurs.
299		433
300	The $eventmask can be one or more of these constants ORed together:	434	The $eventmask can be one or more of these constants ORed together:
…		…
329	=over 4	463	=over 4
330		464
331	=item $w = EV::timer $after, $repeat, $callback	465	=item $w = EV::timer $after, $repeat, $callback
332		466
333	=item $w = EV::timer_ns $after, $repeat, $callback	467	=item $w = EV::timer_ns $after, $repeat, $callback
		468
		469	=item $w = $loop->timer ($after, $repeat, $callback)
		470
		471	=item $w = $loop->timer_ns ($after, $repeat, $callback)
334		472
335	Calls the callback after C<$after> seconds (which may be fractional). If	473	Calls the callback after C<$after> seconds (which may be fractional). If
336	C<$repeat> is non-zero, the timer will be restarted (with the $repeat	474	C<$repeat> is non-zero, the timer will be restarted (with the $repeat
337	value as $after) after the callback returns.	475	value as $after) after the callback returns.
338		476
…		…
379	=over 4	517	=over 4
380		518
381	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback	519	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
382		520
383	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback	521	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
		522
		523	=item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
		524
		525	=item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback)
384		526
385	Similar to EV::timer, but is not based on relative timeouts but on	527	Similar to EV::timer, but is not based on relative timeouts but on
386	absolute times. Apart from creating "simple" timers that trigger "at" the	528	absolute times. Apart from creating "simple" timers that trigger "at" the
387	specified time, it can also be used for non-drifting absolute timers and	529	specified time, it can also be used for non-drifting absolute timers and
388	more complex, cron-like, setups that are not adversely affected by time	530	more complex, cron-like, setups that are not adversely affected by time
…		…
398	This time simply fires at the wallclock time C<$at> and doesn't repeat. It	540	This time simply fires at the wallclock time C<$at> and doesn't repeat. It
399	will not adjust when a time jump occurs, that is, if it is to be run	541	will not adjust when a time jump occurs, that is, if it is to be run
400	at January 1st 2011 then it will run when the system time reaches or	542	at January 1st 2011 then it will run when the system time reaches or
401	surpasses this time.	543	surpasses this time.
402		544
403	=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0)	545	=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
404		546
405	In this mode the watcher will always be scheduled to time out at the	547	In this mode the watcher will always be scheduled to time out at the
406	next C<$at + N * $interval> time (for some integer N) and then repeat,	548	next C<$at + N * $interval> time (for some integer N) and then repeat,
407	regardless of any time jumps.	549	regardless of any time jumps.
408		550
…		…
426	time the periodic watcher gets scheduled, the reschedule callback	568	time the periodic watcher gets scheduled, the reschedule callback
427	($reschedule_cb) will be called with the watcher as first, and the current	569	($reschedule_cb) will be called with the watcher as first, and the current
428	time as second argument.	570	time as second argument.
429		571
430	I<This callback MUST NOT stop or destroy this or any other periodic	572	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	573	watcher, ever, and MUST NOT call any event loop functions or methods>. If
432	afterwards.	574	you need to stop it, return 1e30 and stop it afterwards. You may create
		575	and start a C<EV::prepare> watcher for this task.
433		576
434	It must return the next time to trigger, based on the passed time value	577	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	578	(that is, the lowest time value larger than or equal to to the second
436	will usually be called just before the callback will be triggered, but	579	argument). It will usually be called just before the callback will be
437	might be called at other times, too.	580	triggered, but might be called at other times, too.
438		581
439	This can be used to create very complex timers, such as a timer that	582	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	583	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	584	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	585	in about the same space (without requiring elaborate modules), drop me a
…		…
463		606
464	=item $w->again	607	=item $w->again
465		608
466	Simply stops and starts the watcher again.	609	Simply stops and starts the watcher again.
467		610
		611	=item $time = $w->at
		612
		613	Return the time that the watcher is expected to trigger next.
		614
468	=back	615	=back
469		616
470		617
471	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!	618	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
472		619
…		…
505		652
506	=head3 CHILD WATCHERS - watch out for process status changes	653	=head3 CHILD WATCHERS - watch out for process status changes
507		654
508	=over 4	655	=over 4
509		656
510	=item $w = EV::child $pid, $callback	657	=item $w = EV::child $pid, $trace, $callback
511		658
512	=item $w = EV::child_ns $pid, $callback	659	=item $w = EV::child_ns $pid, $trace, $callback
513		660
		661	=item $w = $loop->child ($pid, $trace, $callback)
		662
		663	=item $w = $loop->child_ns ($pid, $trace, $callback)
		664
514	Call the callback when a status change for pid C<$pid> (or any pid if	665	Call the callback when a status change for pid C<$pid> (or any pid
515	C<$pid> is 0) has been received. More precisely: when the process receives	666	if C<$pid> is 0) has been received (a status change happens when the
		667	process terminates or is killed, or, when trace is true, additionally when
		668	it is stopped or continued). More precisely: when the process receives
516	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all	669	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
517	changed/zombie children and call the callback.	670	changed/zombie children and call the callback.
518		671
519	It is valid (and fully supported) to install a child watcher after a child	672	It is valid (and fully supported) to install a child watcher after a child
520	has exited but before the event loop has started its next iteration (for	673	has exited but before the event loop has started its next iteration (for
…		…
527	You can have as many pid watchers per pid as you want, they will all be	680	You can have as many pid watchers per pid as you want, they will all be
528	called.	681	called.
529		682
530	The C<child_ns> variant doesn't start (activate) the newly created watcher.	683	The C<child_ns> variant doesn't start (activate) the newly created watcher.
531		684
532	=item $w->set ($pid)	685	=item $w->set ($pid, $trace)
533		686
534	Reconfigures the watcher, see the constructor above for details. Can be called at	687	Reconfigures the watcher, see the constructor above for details. Can be called at
535	any time.	688	any time.
536		689
537	=item $current_pid = $w->pid	690	=item $current_pid = $w->pid
538		691
539	=item $old_pid = $w->pid ($new_pid)
540
541	Returns the previously set process id and optionally set a new one.	692	Returns the previously set process id and optionally set a new one.
542		693
543	=item $exit_status = $w->rstatus	694	=item $exit_status = $w->rstatus
544		695
545	Return the exit/wait status (as returned by waitpid, see the waitpid entry	696	Return the exit/wait status (as returned by waitpid, see the waitpid entry
…		…
551	watcher for all pids).	702	watcher for all pids).
552		703
553	=back	704	=back
554		705
555		706
		707	=head3 STAT WATCHERS - did the file attributes just change?
		708
		709	=over 4
		710
		711	=item $w = EV::stat $path, $interval, $callback
		712
		713	=item $w = EV::stat_ns $path, $interval, $callback
		714
		715	=item $w = $loop->stat ($path, $interval, $callback)
		716
		717	=item $w = $loop->stat_ns ($path, $interval, $callback)
		718
		719	Call the callback when a file status change has been detected on
		720	C<$path>. The C<$path> does not need to exist, changing from "path exists"
		721	to "path does not exist" is a status change like any other.
		722
		723	The C<$interval> is a recommended polling interval for systems where
		724	OS-supported change notifications don't exist or are not supported. If
		725	you use C<0> then an unspecified default is used (which is highly
		726	recommended!), which is to be expected to be around five seconds usually.
		727
		728	This watcher type is not meant for massive numbers of stat watchers,
		729	as even with OS-supported change notifications, this can be
		730	resource-intensive.
		731
		732	The C<stat_ns> variant doesn't start (activate) the newly created watcher.
		733
		734	=item ... = $w->stat
		735
		736	This call is very similar to the perl C<stat> built-in: It stats (using
		737	C<lstat>) the path specified in the watcher and sets perls stat cache (as
		738	well as EV's idea of the current stat values) to the values found.
		739
		740	In scalar context, a boolean is return indicating success or failure of
		741	the stat. In list context, the same 13-value list as with stat is returned
		742	(except that the blksize and blocks fields are not reliable).
		743
		744	In the case of an error, errno is set to C<ENOENT> (regardless of the
		745	actual error value) and the C<nlink> value is forced to zero (if the stat
		746	was successful then nlink is guaranteed to be non-zero).
		747
		748	See also the next two entries for more info.
		749
		750	=item ... = $w->attr
		751
		752	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		753	the values most recently detected by EV. See the next entry for more info.
		754
		755	=item ... = $w->prev
		756
		757	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		758	the previous set of values, before the change.
		759
		760	That is, when the watcher callback is invoked, C<< $w->prev >> will be set
		761	to the values found I<before> a change was detected, while C<< $w->attr >>
		762	returns the values found leading to the change detection. The difference (if any)
		763	between C<prev> and C<attr> is what triggered the callback.
		764
		765	If you did something to the filesystem object and do not want to trigger
		766	yet another change, you can call C<stat> to update EV's idea of what the
		767	current attributes are.
		768
		769	=item $w->set ($path, $interval)
		770
		771	Reconfigures the watcher, see the constructor above for details. Can be
		772	called at any time.
		773
		774	=item $current_path = $w->path
		775
		776	=item $old_path = $w->path ($new_path)
		777
		778	Returns the previously set path and optionally set a new one.
		779
		780	=item $current_interval = $w->interval
		781
		782	=item $old_interval = $w->interval ($new_interval)
		783
		784	Returns the previously set interval and optionally set a new one. Can be
		785	used to query the actual interval used.
		786
		787	=back
		788
		789
556	=head3 IDLE WATCHERS - when you've got nothing better to do...	790	=head3 IDLE WATCHERS - when you've got nothing better to do...
557		791
558	=over 4	792	=over 4
559		793
560	=item $w = EV::idle $callback	794	=item $w = EV::idle $callback
561		795
562	=item $w = EV::idle_ns $callback	796	=item $w = EV::idle_ns $callback
563		797
564	Call the callback when there are no pending io, timer/periodic, signal or	798	=item $w = $loop->idle ($callback)
565	child events, i.e. when the process is idle.	799
		800	=item $w = $loop->idle_ns ($callback)
		801
		802	Call the callback when there are no other pending watchers of the same or
		803	higher priority (excluding check, prepare and other idle watchers of the
		804	same or lower priority, of course). They are called idle watchers because
		805	when the watcher is the highest priority pending event in the process, the
		806	process is considered to be idle at that priority.
		807
		808	If you want a watcher that is only ever called when I<no> other events are
		809	outstanding you have to set the priority to C<EV::MINPRI>.
566		810
567	The process will not block as long as any idle watchers are active, and	811	The process will not block as long as any idle watchers are active, and
568	they will be called repeatedly until stopped.	812	they will be called repeatedly until stopped.
569		813
		814	For example, if you have idle watchers at priority C<0> and C<1>, and
		815	an I/O watcher at priority C<0>, then the idle watcher at priority C<1>
		816	and the I/O watcher will always run when ready. Only when the idle watcher
		817	at priority C<1> is stopped and the I/O watcher at priority C<0> is not
		818	pending with the C<0>-priority idle watcher be invoked.
		819
570	The C<idle_ns> variant doesn't start (activate) the newly created watcher.	820	The C<idle_ns> variant doesn't start (activate) the newly created watcher.
571		821
572	=back	822	=back
573		823
574		824
…		…
577	=over 4	827	=over 4
578		828
579	=item $w = EV::prepare $callback	829	=item $w = EV::prepare $callback
580		830
581	=item $w = EV::prepare_ns $callback	831	=item $w = EV::prepare_ns $callback
		832
		833	=item $w = $loop->prepare ($callback)
		834
		835	=item $w = $loop->prepare_ns ($callback)
582		836
583	Call the callback just before the process would block. You can still	837	Call the callback just before the process would block. You can still
584	create/modify any watchers at this point.	838	create/modify any watchers at this point.
585		839
586	See the EV::check watcher, below, for explanations and an example.	840	See the EV::check watcher, below, for explanations and an example.
…		…
595	=over 4	849	=over 4
596		850
597	=item $w = EV::check $callback	851	=item $w = EV::check $callback
598		852
599	=item $w = EV::check_ns $callback	853	=item $w = EV::check_ns $callback
		854
		855	=item $w = $loop->check ($callback)
		856
		857	=item $w = $loop->check_ns ($callback)
600		858
601	Call the callback just after the process wakes up again (after it has	859	Call the callback just after the process wakes up again (after it has
602	gathered events), but before any other callbacks have been invoked.	860	gathered events), but before any other callbacks have been invoked.
603		861
604	This is used to integrate other event-based software into the EV	862	This is used to integrate other event-based software into the EV
…		…
614	or return;	872	or return;
615		873
616	# make the dispatcher handle any outstanding stuff	874	# make the dispatcher handle any outstanding stuff
617	... not shown	875	... not shown
618		876
619	# create an IO watcher for each and every socket	877	# create an I/O watcher for each and every socket
620	@snmp_watcher = (	878	@snmp_watcher = (
621	(map { EV::io $_, EV::READ, sub { } }	879	(map { EV::io $_, EV::READ, sub { } }
622	keys %{ $dispatcher->{_descriptors} }),	880	keys %{ $dispatcher->{_descriptors} }),
623		881
624	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]	882	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
…		…
646		904
647	The C<check_ns> variant doesn't start (activate) the newly created watcher.	905	The C<check_ns> variant doesn't start (activate) the newly created watcher.
648		906
649	=back	907	=back
650		908
651	=head3 STAT WATCHERS - did the file stats just change?
652		909
653	=over 4	910	=head3 FORK WATCHERS - the audacity to resume the event loop after a fork
654		911
655	=item $w = EV::stat $path, $interval, $callback	912	Fork watchers are called when a C<fork ()> was detected. The invocation
		913	is done before the event loop blocks next and before C<check> watchers
		914	are being called, and only in the child after the fork.
656		915
657	=item $w = EV::stat_ns $path, $interval, $callback	916	=over 4
658		917
659	Call the callback when a file status change has been detected on	918	=item $w = EV::fork $callback
660	C<$path>. The C<$path> does not need to exist, changing from "path exists"
661	to "path does not exist" is a status change like any other.
662		919
663	The C<$interval> is a recommended polling interval for systems where	920	=item $w = EV::fork_ns $callback
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		921
668	This watcher type is not meant for massive numbers of stat watchers,	922	=item $w = $loop->fork ($callback)
669	as even with OS-supported change notifications, this can be
670	resource-intensive.
671		923
		924	=item $w = $loop->fork_ns ($callback)
		925
		926	Call the callback before the event loop is resumed in the child process
		927	after a fork.
		928
672	The C<stat_ns> variant doesn't start (activate) the newly created watcher.	929	The C<fork_ns> variant doesn't start (activate) the newly created watcher.
673		930
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	931	=back
693		932
		933
		934	=head3 EMBED WATCHERS - when one backend isn't enough...
		935
		936	This is a rather advanced watcher type that lets you embed one event loop
		937	into another (currently only IO events are supported in the embedded
		938	loop, other types of watchers might be handled in a delayed or incorrect
		939	fashion and must not be used).
		940
		941	See the libev documentation at
		942	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
		943	for more details.
		944
		945	In short, this watcher is most useful on BSD systems without working
		946	kqueue to still be able to handle a large number of sockets:
		947
		948	my $socket_loop;
		949
		950	# check wether we use SELECT or POLL _and_ KQUEUE is supported
		951	if (
		952	(EV::backend & (EV::BACKEND_POLL \| EV::BACKEND_SELECT))
		953	&& (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
		954	) {
		955	# use kqueue for sockets
		956	$socket_loop = new EV::Loop EV::BACKEND_KQUEUE \| EV::FLAG_NOENV;
		957	}
		958
		959	# use the default loop otherwise
		960	$socket_loop \|\|= EV::default_loop;
		961
		962	=over 4
		963
		964	=item $w = EV::embed $otherloop, $callback
		965
		966	=item $w = EV::embed_ns $otherloop, $callback
		967
		968	=item $w = $loop->embed ($otherloop, $callback)
		969
		970	=item $w = $loop->embed_ns ($otherloop, $callback)
		971
		972	Call the callback when the embedded event loop (C<$otherloop>) has any
		973	I/O activity. The C<$callback> should alwas be specified as C<undef> in
		974	this version of EV, which means the embedded event loop will be managed
		975	automatically.
		976
		977	The C<embed_ns> variant doesn't start (activate) the newly created watcher.
		978
		979	=back
		980
		981	=head3 ASYNC WATCHERS - how to wake up another event loop
		982
		983	Async watchers are provided by EV, but have little use in perl directly, as perl
		984	neither supports threads nor direct access to signal handlers or other
		985	contexts where they could be of value.
		986
		987	It is, however, possible to use them from the XS level.
		988
		989	Please see the libev documentation for further details.
		990
		991	=over 4
		992
		993	=item $w = EV::async $callback
		994
		995	=item $w = EV::async_ns $callback
		996
		997	=item $w->send
		998
		999	=item $bool = $w->async_pending
		1000
		1001	=back
		1002
		1003
		1004	=head1 PERL SIGNALS
		1005
		1006	While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour
		1007	with EV is as the same as any other C library: Perl-signals will only be
		1008	handled when Perl runs, which means your signal handler might be invoked
		1009	only the next time an event callback is invoked.
		1010
		1011	The solution is to use EV signal watchers (see C<EV::signal>), which will
		1012	ensure proper operations with regards to other event watchers.
		1013
		1014	If you cannot do this for whatever reason, you can also force a watcher
		1015	to be called on every event loop iteration by installing a C<EV::check>
		1016	watcher:
		1017
		1018	my $async_check = EV::check sub { };
		1019
		1020	This ensures that perl gets into control for a short time to handle any
		1021	pending signals, and also ensures (slightly) slower overall operation.
694		1022
695	=head1 THREADS	1023	=head1 THREADS
696		1024
697	Threads are not supported by this module in any way. Perl pseudo-threads	1025	Threads are not supported by this module in any way. Perl pseudo-threads
698	is evil stuff and must die. As soon as Perl gains real threads I will work	1026	is evil stuff and must die. As soon as Perl gains real threads I will work
…		…
720	our $DIED = sub {	1048	our $DIED = sub {
721	warn "EV: error in callback (ignoring): $@";	1049	warn "EV: error in callback (ignoring): $@";
722	};	1050	};
723		1051
724	default_loop	1052	default_loop
725	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	1053	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
726		1054
727	1;	1055	1;
728		1056
729	=head1 SEE ALSO	1057	=head1 SEE ALSO
730		1058
731	L<EV::DNS>.	1059	L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as
		1060	event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
		1061	coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
		1062	event-loop agnostic and portable event driven programming.
732		1063
733	=head1 AUTHOR	1064	=head1 AUTHOR
734		1065
735	Marc Lehmann <schmorp@schmorp.de>	1066	Marc Lehmann <schmorp@schmorp.de>
736	http://home.schmorp.de/	1067	http://home.schmorp.de/

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Comparing EV/EV.pm (file contents): Revision 1.54 by root, Tue Nov 27 07:27:10 2007 UTC vs. Revision 1.95 by root, Wed May 21 23:35:00 2008 UTC

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Comparing EV/EV.pm (file contents):
Revision 1.54 by root, Tue Nov 27 07:27:10 2007 UTC vs.
Revision 1.95 by root, Wed May 21 23:35:00 2008 UTC