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

Comparing EV/EV.pm (file contents):
Revision 1.61 by root, Thu Dec 6 03:13:07 2007 UTC vs.
Revision 1.97 by root, Mon May 26 05:37:18 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 = '1.6';	79	our $VERSION = '3.42';
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 =
…		…
83	@EV::Idle::ISA =	90	@EV::Idle::ISA =
84	@EV::Prepare::ISA =	91	@EV::Prepare::ISA =
85	@EV::Check::ISA =	92	@EV::Check::ISA =
86	@EV::Embed::ISA =	93	@EV::Embed::ISA =
87	@EV::Fork::ISA =	94	@EV::Fork::ISA =
		95	@EV::Async::ISA =
88	"EV::Watcher";	96	"EV::Watcher";
89		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 function automatically, at some performance loss (refer to the libev
		136	documentation).
		137
		138	=item $loop->loop_verify
		139
		140	Calls C<ev_verify> to make internal consistency checks (for debugging
		141	libev) and abort the program if any data structures wree found to be
		142	corrupted.
		143
		144	=item $loop = EV::default_loop [$flags]
		145
		146	Return the default loop (which is a singleton object). Since this module
		147	already creates the default loop with default flags, specifying flags here
		148	will not have any effect unless you destroy the default loop.
		149
		150	=back
		151
		152
90	=head1 BASIC INTERFACE	153	=head1 BASIC INTERFACE
91		154
92	=over 4	155	=over 4
93		156
94	=item $EV::DIED	157	=item $EV::DIED
95		158
96	Must contain a reference to a function that is called when a callback	159	Must contain a reference to a function that is called when a callback
97	throws an exception (with $@ containing thr error). The default prints an	160	throws an exception (with $@ containing the error). The default prints an
98	informative message and continues.	161	informative message and continues.
99		162
100	If this callback throws an exception it will be silently ignored.	163	If this callback throws an exception it will be silently ignored.
101		164
		165	=item $flags = EV::supported_backends
		166
		167	=item $flags = EV::recommended_backends
		168
		169	=item $flags = EV::embeddable_backends
		170
		171	Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this
		172	instance of EV, the set of recommended backends (supposed to be good) for
		173	this platform and the set of embeddable backends (see EMBED WATCHERS).
		174
		175	=item EV::sleep $seconds
		176
		177	Block the process for the given number of (fractional) seconds.
		178
102	=item $time = EV::time	179	=item $time = EV::time
103		180
104	Returns the current time in (fractional) seconds since the epoch.	181	Returns the current time in (fractional) seconds since the epoch.
105		182
106	=item $time = EV::now	183	=item $time = EV::now
		184
		185	=item $time = $loop->now
107		186
108	Returns the time the last event loop iteration has been started. This	187	Returns the time the last event loop iteration has been started. This
109	is the time that (relative) timers are based on, and refering to it is	188	is the time that (relative) timers are based on, and refering to it is
110	usually faster then calling EV::time.	189	usually faster then calling EV::time.
111		190
112	=item $method = EV::method	191	=item $backend = EV::backend
		192
		193	=item $backend = $loop->backend
113		194
114	Returns an integer describing the backend used by libev (EV::METHOD_SELECT	195	Returns an integer describing the backend used by libev (EV::METHOD_SELECT
115	or EV::METHOD_EPOLL).	196	or EV::METHOD_EPOLL).
116		197
117	=item EV::loop [$flags]	198	=item EV::loop [$flags]
		199
		200	=item $loop->loop ([$flags])
118		201
119	Begin checking for events and calling callbacks. It returns when a	202	Begin checking for events and calling callbacks. It returns when a
120	callback calls EV::unloop.	203	callback calls EV::unloop.
121		204
122	The $flags argument can be one of the following:	205	The $flags argument can be one of the following:
…		…
125	EV::LOOP_ONESHOT block at most once (wait, but do not loop)	208	EV::LOOP_ONESHOT block at most once (wait, but do not loop)
126	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)	209	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
127		210
128	=item EV::unloop [$how]	211	=item EV::unloop [$how]
129		212
		213	=item $loop->unloop ([$how])
		214
130	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the	215	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the
131	innermost call to EV::loop return.	216	innermost call to EV::loop return.
132		217
133	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as	218	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as
134	fast as possible.	219	fast as possible.
135		220
136	=item $count = EV::loop_count	221	=item $count = EV::loop_count
137		222
		223	=item $count = $loop->loop_count
		224
138	Return the number of times the event loop has polled for new	225	Return the number of times the event loop has polled for new
139	events. Sometiems useful as a generation counter.	226	events. Sometiems useful as a generation counter.
140		227
141	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)	228	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
		229
		230	=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
142		231
143	This function rolls together an I/O and a timer watcher for a single	232	This function rolls together an I/O and a timer watcher for a single
144	one-shot event without the need for managing a watcher object.	233	one-shot event without the need for managing a watcher object.
145		234
146	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>	235	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>
…		…
152	If timeout is C<undef> or negative, then there will be no	241	If timeout is C<undef> or negative, then there will be no
153	timeout. Otherwise a EV::timer with this value will be started.	242	timeout. Otherwise a EV::timer with this value will be started.
154		243
155	When an error occurs or either the timeout or I/O watcher triggers, then	244	When an error occurs or either the timeout or I/O watcher triggers, then
156	the callback will be called with the received event set (in general	245	the callback will be called with the received event set (in general
157	you can expect it to be a combination of C<EV:ERROR>, C<EV::READ>,	246	you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
158	C<EV::WRITE> and C<EV::TIMEOUT>).	247	C<EV::WRITE> and C<EV::TIMEOUT>).
159		248
160	EV::once doesn't return anything: the watchers stay active till either	249	EV::once doesn't return anything: the watchers stay active till either
161	of them triggers, then they will be stopped and freed, and the callback	250	of them triggers, then they will be stopped and freed, and the callback
162	invoked.	251	invoked.
163		252
164	=back	253	=item EV::feed_fd_event ($fd, $revents)
165		254
		255	=item $loop->feed_fd_event ($fd, $revents)
		256
		257	Feed an event on a file descriptor into EV. EV will react to this call as
		258	if the readyness notifications specified by C<$revents> (a combination of
		259	C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
		260
		261	=item EV::feed_signal_event ($signal)
		262
		263	Feed a signal event into EV. EV will react to this call as if the signal
		264	specified by C<$signal> had occured.
		265
		266	=item EV::set_io_collect_interval $time
		267
		268	=item $loop->set_io_collect_interval ($time)
		269
		270	=item EV::set_timeout_collect_interval $time
		271
		272	=item $loop->set_timeout_collect_interval ($time)
		273
		274	These advanced functions set the minimum block interval when polling for I/O events and the minimum
		275	wait interval for timer events. See the libev documentation at
		276	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> for
		277	a more detailed discussion.
		278
		279	=back
		280
		281
166	=head2 WATCHER OBJECTS	282	=head1 WATCHER OBJECTS
167		283
168	A watcher is an object that gets created to record your interest in some	284	A watcher is an object that gets created to record your interest in some
169	event. For instance, if you want to wait for STDIN to become readable, you	285	event. For instance, if you want to wait for STDIN to become readable, you
170	would create an EV::io watcher for that:	286	would create an EV::io watcher for that:
171		287
172	my $watcher = EV::io *STDIN, EV::READ, sub {	288	my $watcher = EV::io *STDIN, EV::READ, sub {
173	my ($watcher, $revents) = @_;	289	my ($watcher, $revents) = @_;
174	warn "yeah, STDIN should not be readable without blocking!\n"	290	warn "yeah, STDIN should now be readable without blocking!\n"
175	};	291	};
176		292
177	All watchers can be active (waiting for events) or inactive (paused). Only	293	All watchers can be active (waiting for events) or inactive (paused). Only
178	active watchers will have their callbacks invoked. All callbacks will be	294	active watchers will have their callbacks invoked. All callbacks will be
179	called with at least two arguments: the watcher and a bitmask of received	295	called with at least two arguments: the watcher and a bitmask of received
180	events.	296	events.
181		297
182	Each watcher type has its associated bit in revents, so you can use the	298	Each watcher type has its associated bit in revents, so you can use the
183	same callback for multiple watchers. The event mask is named after the	299	same callback for multiple watchers. The event mask is named after the
184	type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,	300	type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
185	EV::periodic sets EV::PERIODIC and so on, with the exception of IO events	301	EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events
186	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which	302	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which
187	uses EV::TIMEOUT).	303	uses EV::TIMEOUT).
188		304
189	In the rare case where one wants to create a watcher but not start it at	305	In the rare case where one wants to create a watcher but not start it at
190	the same time, each constructor has a variant with a trailing C<_ns> in	306	the same time, each constructor has a variant with a trailing C<_ns> in
…		…
212		328
213	=item $w->stop	329	=item $w->stop
214		330
215	Stop a watcher if it is active. Also clear any pending events (events that	331	Stop a watcher if it is active. Also clear any pending events (events that
216	have been received but that didn't yet result in a callback invocation),	332	have been received but that didn't yet result in a callback invocation),
217	regardless of wether the watcher was active or not.	333	regardless of whether the watcher was active or not.
218		334
219	=item $bool = $w->is_active	335	=item $bool = $w->is_active
220		336
221	Returns true if the watcher is active, false otherwise.	337	Returns true if the watcher is active, false otherwise.
222		338
…		…
252	The default priority of any newly-created watcher is 0.	368	The default priority of any newly-created watcher is 0.
253		369
254	Note that the priority semantics have not yet been fleshed out and are	370	Note that the priority semantics have not yet been fleshed out and are
255	subject to almost certain change.	371	subject to almost certain change.
256		372
257	=item $w->trigger ($revents)	373	=item $w->invoke ($revents)
258		374
259	Call the callback now with the given event mask.	375	Call the callback now with the given event mask.
		376
		377	=item $w->feed_event ($revents)
		378
		379	Feed some events on this watcher into EV. EV will react to this call as if
		380	the watcher had received the given C<$revents> mask.
		381
		382	=item $revents = $w->clear_pending
		383
		384	If the watcher is pending, this function clears its pending status and
		385	returns its C<$revents> bitset (as if its callback was invoked). If the
		386	watcher isn't pending it does nothing and returns C<0>.
260		387
261	=item $previous_state = $w->keepalive ($bool)	388	=item $previous_state = $w->keepalive ($bool)
262		389
263	Normally, C<EV::loop> will return when there are no active watchers	390	Normally, C<EV::loop> will return when there are no active watchers
264	(which is a "deadlock" because no progress can be made anymore). This is	391	(which is a "deadlock" because no progress can be made anymore). This is
265	convinient because it allows you to start your watchers (and your jobs),	392	convinient because it allows you to start your watchers (and your jobs),
266	call C<EV::loop> once and when it returns you know that all your jobs are	393	call C<EV::loop> once and when it returns you know that all your jobs are
267	finished (or they forgot to register some watchers for their task :).	394	finished (or they forgot to register some watchers for their task :).
268		395
269	Sometimes, however, this gets in your way, for example when you the module	396	Sometimes, however, this gets in your way, for example when the module
270	that calls C<EV::loop> (usually the main program) is not the same module	397	that calls C<EV::loop> (usually the main program) is not the same module
271	as a long-living watcher (for example a DNS client module written by	398	as a long-living watcher (for example a DNS client module written by
272	somebody else even). Then you might want any outstanding requests to be	399	somebody else even). Then you might want any outstanding requests to be
273	handled, but you would not want to keep C<EV::loop> from returning just	400	handled, but you would not want to keep C<EV::loop> from returning just
274	because you happen to have this long-running UDP port watcher.	401	because you happen to have this long-running UDP port watcher.
…		…
277	though your watcher is active, it won't keep C<EV::loop> from returning.	404	though your watcher is active, it won't keep C<EV::loop> from returning.
278		405
279	The initial value for keepalive is true (enabled), and you cna change it	406	The initial value for keepalive is true (enabled), and you cna change it
280	any time.	407	any time.
281		408
282	Example: Register an IO watcher for some UDP socket but do not keep the	409	Example: Register an I/O watcher for some UDP socket but do not keep the
283	event loop from running just because of that watcher.	410	event loop from running just because of that watcher.
284		411
285	my $udp_socket = ...	412	my $udp_socket = ...
286	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };	413	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
287	$udp_watcher->keepalive (0);	414	$1000udp_watcher->keepalive (0);
288		415
289	=back	416	=item $loop = $w->loop
290		417
		418	Return the loop that this watcher is attached to.
291		419
		420	=back
		421
		422
292	=head2 WATCHER TYPES	423	=head1 WATCHER TYPES
293		424
294	Each of the following subsections describes a single watcher type.	425	Each of the following subsections describes a single watcher type.
295		426
296	=head3 IO WATCHERS - is this file descriptor readable or writable?	427	=head3 I/O WATCHERS - is this file descriptor readable or writable?
297		428
298	=over 4	429	=over 4
299		430
300	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	431	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
301		432
302	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback	433	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
		434
		435	=item $w = $loop->io ($fileno_or_fh, $eventmask, $callback)
		436
		437	=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
303		438
304	As long as the returned watcher object is alive, call the C<$callback>	439	As long as the returned watcher object is alive, call the C<$callback>
305	when at least one of events specified in C<$eventmask> occurs.	440	when at least one of events specified in C<$eventmask> occurs.
306		441
307	The $eventmask can be one or more of these constants ORed together:	442	The $eventmask can be one or more of these constants ORed together:
…		…
336	=over 4	471	=over 4
337		472
338	=item $w = EV::timer $after, $repeat, $callback	473	=item $w = EV::timer $after, $repeat, $callback
339		474
340	=item $w = EV::timer_ns $after, $repeat, $callback	475	=item $w = EV::timer_ns $after, $repeat, $callback
		476
		477	=item $w = $loop->timer ($after, $repeat, $callback)
		478
		479	=item $w = $loop->timer_ns ($after, $repeat, $callback)
341		480
342	Calls the callback after C<$after> seconds (which may be fractional). If	481	Calls the callback after C<$after> seconds (which may be fractional). If
343	C<$repeat> is non-zero, the timer will be restarted (with the $repeat	482	C<$repeat> is non-zero, the timer will be restarted (with the $repeat
344	value as $after) after the callback returns.	483	value as $after) after the callback returns.
345		484
…		…
386	=over 4	525	=over 4
387		526
388	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback	527	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
389		528
390	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback	529	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
		530
		531	=item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
		532
		533	=item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback)
391		534
392	Similar to EV::timer, but is not based on relative timeouts but on	535	Similar to EV::timer, but is not based on relative timeouts but on
393	absolute times. Apart from creating "simple" timers that trigger "at" the	536	absolute times. Apart from creating "simple" timers that trigger "at" the
394	specified time, it can also be used for non-drifting absolute timers and	537	specified time, it can also be used for non-drifting absolute timers and
395	more complex, cron-like, setups that are not adversely affected by time	538	more complex, cron-like, setups that are not adversely affected by time
…		…
405	This time simply fires at the wallclock time C<$at> and doesn't repeat. It	548	This time simply fires at the wallclock time C<$at> and doesn't repeat. It
406	will not adjust when a time jump occurs, that is, if it is to be run	549	will not adjust when a time jump occurs, that is, if it is to be run
407	at January 1st 2011 then it will run when the system time reaches or	550	at January 1st 2011 then it will run when the system time reaches or
408	surpasses this time.	551	surpasses this time.
409		552
410	=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0)	553	=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
411		554
412	In this mode the watcher will always be scheduled to time out at the	555	In this mode the watcher will always be scheduled to time out at the
413	next C<$at + N * $interval> time (for some integer N) and then repeat,	556	next C<$at + N * $interval> time (for some integer N) and then repeat,
414	regardless of any time jumps.	557	regardless of any time jumps.
415		558
…		…
433	time the periodic watcher gets scheduled, the reschedule callback	576	time the periodic watcher gets scheduled, the reschedule callback
434	($reschedule_cb) will be called with the watcher as first, and the current	577	($reschedule_cb) will be called with the watcher as first, and the current
435	time as second argument.	578	time as second argument.
436		579
437	I<This callback MUST NOT stop or destroy this or any other periodic	580	I<This callback MUST NOT stop or destroy this or any other periodic
438	watcher, ever>. If you need to stop it, return 1e30 and stop it	581	watcher, ever, and MUST NOT call any event loop functions or methods>. If
439	afterwards.	582	you need to stop it, return 1e30 and stop it afterwards. You may create
		583	and start a C<EV::prepare> watcher for this task.
440		584
441	It must return the next time to trigger, based on the passed time value	585	It must return the next time to trigger, based on the passed time value
442	(that is, the lowest time value larger than to the second argument). It	586	(that is, the lowest time value larger than or equal to to the second
443	will usually be called just before the callback will be triggered, but	587	argument). It will usually be called just before the callback will be
444	might be called at other times, too.	588	triggered, but might be called at other times, too.
445		589
446	This can be used to create very complex timers, such as a timer that	590	This can be used to create very complex timers, such as a timer that
447	triggers on each midnight, local time (actually 24 hours after the last	591	triggers on each midnight, local time (actually 24 hours after the last
448	midnight, to keep the example simple. If you know a way to do it correctly	592	midnight, to keep the example simple. If you know a way to do it correctly
449	in about the same space (without requiring elaborate modules), drop me a	593	in about the same space (without requiring elaborate modules), drop me a
…		…
470		614
471	=item $w->again	615	=item $w->again
472		616
473	Simply stops and starts the watcher again.	617	Simply stops and starts the watcher again.
474		618
		619	=item $time = $w->at
		620
		621	Return the time that the watcher is expected to trigger next.
		622
475	=back	623	=back
476		624
477		625
478	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!	626	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
479		627
…		…
512		660
513	=head3 CHILD WATCHERS - watch out for process status changes	661	=head3 CHILD WATCHERS - watch out for process status changes
514		662
515	=over 4	663	=over 4
516		664
517	=item $w = EV::child $pid, $callback	665	=item $w = EV::child $pid, $trace, $callback
518		666
519	=item $w = EV::child_ns $pid, $callback	667	=item $w = EV::child_ns $pid, $trace, $callback
520		668
		669	=item $w = $loop->child ($pid, $trace, $callback)
		670
		671	=item $w = $loop->child_ns ($pid, $trace, $callback)
		672
521	Call the callback when a status change for pid C<$pid> (or any pid if	673	Call the callback when a status change for pid C<$pid> (or any pid
522	C<$pid> is 0) has been received. More precisely: when the process receives	674	if C<$pid> is 0) has been received (a status change happens when the
		675	process terminates or is killed, or, when trace is true, additionally when
		676	it is stopped or continued). More precisely: when the process receives
523	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all	677	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
524	changed/zombie children and call the callback.	678	changed/zombie children and call the callback.
525		679
526	It is valid (and fully supported) to install a child watcher after a child	680	It is valid (and fully supported) to install a child watcher after a child
527	has exited but before the event loop has started its next iteration (for	681	has exited but before the event loop has started its next iteration (for
…		…
534	You can have as many pid watchers per pid as you want, they will all be	688	You can have as many pid watchers per pid as you want, they will all be
535	called.	689	called.
536		690
537	The C<child_ns> variant doesn't start (activate) the newly created watcher.	691	The C<child_ns> variant doesn't start (activate) the newly created watcher.
538		692
539	=item $w->set ($pid)	693	=item $w->set ($pid, $trace)
540		694
541	Reconfigures the watcher, see the constructor above for details. Can be called at	695	Reconfigures the watcher, see the constructor above for details. Can be called at
542	any time.	696	any time.
543		697
544	=item $current_pid = $w->pid	698	=item $current_pid = $w->pid
545		699
546	=item $old_pid = $w->pid ($new_pid)
547
548	Returns the previously set process id and optionally set a new one.	700	Returns the previously set process id and optionally set a new one.
549		701
550	=item $exit_status = $w->rstatus	702	=item $exit_status = $w->rstatus
551		703
552	Return the exit/wait status (as returned by waitpid, see the waitpid entry	704	Return the exit/wait status (as returned by waitpid, see the waitpid entry
…		…
565	=over 4	717	=over 4
566		718
567	=item $w = EV::stat $path, $interval, $callback	719	=item $w = EV::stat $path, $interval, $callback
568		720
569	=item $w = EV::stat_ns $path, $interval, $callback	721	=item $w = EV::stat_ns $path, $interval, $callback
		722
		723	=item $w = $loop->stat ($path, $interval, $callback)
		724
		725	=item $w = $loop->stat_ns ($path, $interval, $callback)
570		726
571	Call the callback when a file status change has been detected on	727	Call the callback when a file status change has been detected on
572	C<$path>. The C<$path> does not need to exist, changing from "path exists"	728	C<$path>. The C<$path> does not need to exist, changing from "path exists"
573	to "path does not exist" is a status change like any other.	729	to "path does not exist" is a status change like any other.
574		730
…		…
645		801
646	=item $w = EV::idle $callback	802	=item $w = EV::idle $callback
647		803
648	=item $w = EV::idle_ns $callback	804	=item $w = EV::idle_ns $callback
649		805
650	Call the callback when there are no pending io, timer/periodic, signal or	806	=item $w = $loop->idle ($callback)
651	child events, i.e. when the process is idle.	807
		808	=item $w = $loop->idle_ns ($callback)
		809
		810	Call the callback when there are no other pending watchers of the same or
		811	higher priority (excluding check, prepare and other idle watchers of the
		812	same or lower priority, of course). They are called idle watchers because
		813	when the watcher is the highest priority pending event in the process, the
		814	process is considered to be idle at that priority.
		815
		816	If you want a watcher that is only ever called when I<no> other events are
		817	outstanding you have to set the priority to C<EV::MINPRI>.
652		818
653	The process will not block as long as any idle watchers are active, and	819	The process will not block as long as any idle watchers are active, and
654	they will be called repeatedly until stopped.	820	they will be called repeatedly until stopped.
655		821
		822	For example, if you have idle watchers at priority C<0> and C<1>, and
		823	an I/O watcher at priority C<0>, then the idle watcher at priority C<1>
		824	and the I/O watcher will always run when ready. Only when the idle watcher
		825	at priority C<1> is stopped and the I/O watcher at priority C<0> is not
		826	pending with the C<0>-priority idle watcher be invoked.
		827
656	The C<idle_ns> variant doesn't start (activate) the newly created watcher.	828	The C<idle_ns> variant doesn't start (activate) the newly created watcher.
657		829
658	=back	830	=back
659		831
660		832
…		…
663	=over 4	835	=over 4
664		836
665	=item $w = EV::prepare $callback	837	=item $w = EV::prepare $callback
666		838
667	=item $w = EV::prepare_ns $callback	839	=item $w = EV::prepare_ns $callback
		840
		841	=item $w = $loop->prepare ($callback)
		842
		843	=item $w = $loop->prepare_ns ($callback)
668		844
669	Call the callback just before the process would block. You can still	845	Call the callback just before the process would block. You can still
670	create/modify any watchers at this point.	846	create/modify any watchers at this point.
671		847
672	See the EV::check watcher, below, for explanations and an example.	848	See the EV::check watcher, below, for explanations and an example.
…		…
681	=over 4	857	=over 4
682		858
683	=item $w = EV::check $callback	859	=item $w = EV::check $callback
684		860
685	=item $w = EV::check_ns $callback	861	=item $w = EV::check_ns $callback
		862
		863	=item $w = $loop->check ($callback)
		864
		865	=item $w = $loop->check_ns ($callback)
686		866
687	Call the callback just after the process wakes up again (after it has	867	Call the callback just after the process wakes up again (after it has
688	gathered events), but before any other callbacks have been invoked.	868	gathered events), but before any other callbacks have been invoked.
689		869
690	This is used to integrate other event-based software into the EV	870	This is used to integrate other event-based software into the EV
…		…
700	or return;	880	or return;
701		881
702	# make the dispatcher handle any outstanding stuff	882	# make the dispatcher handle any outstanding stuff
703	... not shown	883	... not shown
704		884
705	# create an IO watcher for each and every socket	885	# create an I/O watcher for each and every socket
706	@snmp_watcher = (	886	@snmp_watcher = (
707	(map { EV::io $_, EV::READ, sub { } }	887	(map { EV::io $_, EV::READ, sub { } }
708	keys %{ $dispatcher->{_descriptors} }),	888	keys %{ $dispatcher->{_descriptors} }),
709		889
710	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]	890	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
…		…
745		925
746	=item $w = EV::fork $callback	926	=item $w = EV::fork $callback
747		927
748	=item $w = EV::fork_ns $callback	928	=item $w = EV::fork_ns $callback
749		929
		930	=item $w = $loop->fork ($callback)
		931
		932	=item $w = $loop->fork_ns ($callback)
		933
750	Call the callback before the event loop is resumed in the child process	934	Call the callback before the event loop is resumed in the child process
751	after a fork.	935	after a fork.
752		936
753	The C<fork_ns> variant doesn't start (activate) the newly created watcher.	937	The C<fork_ns> variant doesn't start (activate) the newly created watcher.
		938
		939	=back
		940
		941
		942	=head3 EMBED WATCHERS - when one backend isn't enough...
		943
		944	This is a rather advanced watcher type that lets you embed one event loop
		945	into another (currently only IO events are supported in the embedded
		946	loop, other types of watchers might be handled in a delayed or incorrect
		947	fashion and must not be used).
		948
		949	See the libev documentation at
		950	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
		951	for more details.
		952
		953	In short, this watcher is most useful on BSD systems without working
		954	kqueue to still be able to handle a large number of sockets:
		955
		956	my $socket_loop;
		957
		958	# check wether we use SELECT or POLL _and_ KQUEUE is supported
		959	if (
		960	(EV::backend & (EV::BACKEND_POLL \| EV::BACKEND_SELECT))
		961	&& (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
		962	) {
		963	# use kqueue for sockets
		964	$socket_loop = new EV::Loop EV::BACKEND_KQUEUE \| EV::FLAG_NOENV;
		965	}
		966
		967	# use the default loop otherwise
		968	$socket_loop \|\|= EV::default_loop;
		969
		970	=over 4
		971
		972	=item $w = EV::embed $otherloop, $callback
		973
		974	=item $w = EV::embed_ns $otherloop, $callback
		975
		976	=item $w = $loop->embed ($otherloop, $callback)
		977
		978	=item $w = $loop->embed_ns ($otherloop, $callback)
		979
		980	Call the callback when the embedded event loop (C<$otherloop>) has any
		981	I/O activity. The C<$callback> should alwas be specified as C<undef> in
		982	this version of EV, which means the embedded event loop will be managed
		983	automatically.
		984
		985	The C<embed_ns> variant doesn't start (activate) the newly created watcher.
		986
		987	=back
		988
		989	=head3 ASYNC WATCHERS - how to wake up another event loop
		990
		991	Async watchers are provided by EV, but have little use in perl directly, as perl
		992	neither supports threads nor direct access to signal handlers or other
		993	contexts where they could be of value.
		994
		995	It is, however, possible to use them from the XS level.
		996
		997	Please see the libev documentation for further details.
		998
		999	=over 4
		1000
		1001	=item $w = EV::async $callback
		1002
		1003	=item $w = EV::async_ns $callback
		1004
		1005	=item $w->send
		1006
		1007	=item $bool = $w->async_pending
754		1008
755	=back	1009	=back
756		1010
757		1011
758	=head1 PERL SIGNALS	1012	=head1 PERL SIGNALS
…		…
769	to be called on every event loop iteration by installing a C<EV::check>	1023	to be called on every event loop iteration by installing a C<EV::check>
770	watcher:	1024	watcher:
771		1025
772	my $async_check = EV::check sub { };	1026	my $async_check = EV::check sub { };
773		1027
774	This ensures that perl shortly gets into control for a short time, and	1028	This ensures that perl gets into control for a short time to handle any
775	also ensures slower overall operation.	1029	pending signals, and also ensures (slightly) slower overall operation.
776		1030
777	=head1 THREADS	1031	=head1 THREADS
778		1032
779	Threads are not supported by this module in any way. Perl pseudo-threads	1033	Threads are not supported by this module in any way. Perl pseudo-threads
780	is evil stuff and must die. As soon as Perl gains real threads I will work	1034	is evil stuff and must die. As soon as Perl gains real threads I will work
…		…
802	our $DIED = sub {	1056	our $DIED = sub {
803	warn "EV: error in callback (ignoring): $@";	1057	warn "EV: error in callback (ignoring): $@";
804	};	1058	};
805		1059
806	default_loop	1060	default_loop
807	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	1061	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
808		1062
809	1;	1063	1;
810		1064
811	=head1 SEE ALSO	1065	=head1 SEE ALSO
812		1066
813	L<EV::ADNS> (asynchronous dns), L<Glib::EV> (makes Glib/Gtk2 use EV as	1067	L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as
814	event loop), L<Coro::EV> (efficient coroutines with EV).	1068	event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
		1069	coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
		1070	event-loop agnostic and portable event driven programming.
815		1071
816	=head1 AUTHOR	1072	=head1 AUTHOR
817		1073
818	Marc Lehmann <schmorp@schmorp.de>	1074	Marc Lehmann <schmorp@schmorp.de>
819	http://home.schmorp.de/	1075	http://home.schmorp.de/

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Comparing EV/EV.pm (file contents): Revision 1.61 by root, Thu Dec 6 03:13:07 2007 UTC vs. Revision 1.97 by root, Mon May 26 05:37:18 2008 UTC

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Comparing EV/EV.pm (file contents):
Revision 1.61 by root, Thu Dec 6 03:13:07 2007 UTC vs.
Revision 1.97 by root, Mon May 26 05:37:18 2008 UTC