[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 1.90 by root, Sat Apr 26 03:34:24 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
…		…
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://cvs.schmorp.de/libev/ev.html>) for more subtle details on
62	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
63	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.
		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 = '3.31';
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
…		…
463		605
464	=item $w->again	606	=item $w->again
465		607
466	Simply stops and starts the watcher again.	608	Simply stops and starts the watcher again.
467		609
		610	=item $time = $w->at
		611
		612	Return the time that the watcher is expected to trigger next.
		613
468	=back	614	=back
469		615
470		616
471	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!	617	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
472		618
…		…
505		651
506	=head3 CHILD WATCHERS - watch out for process status changes	652	=head3 CHILD WATCHERS - watch out for process status changes
507		653
508	=over 4	654	=over 4
509		655
510	=item $w = EV::child $pid, $callback	656	=item $w = EV::child $pid, $trace, $callback
511		657
512	=item $w = EV::child_ns $pid, $callback	658	=item $w = EV::child_ns $pid, $trace, $callback
513		659
		660	=item $w = $loop->child ($pid, $trace, $callback)
		661
		662	=item $w = $loop->child_ns ($pid, $trace, $callback)
		663
514	Call the callback when a status change for pid C<$pid> (or any pid if	664	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	665	if C<$pid> is 0) has been received (a status change happens when the
		666	process terminates or is killed, or, when trace is true, additionally when
		667	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	668	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
517	changed/zombie children and call the callback.	669	changed/zombie children and call the callback.
518		670
519	It is valid (and fully supported) to install a child watcher after a child	671	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	672	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	679	You can have as many pid watchers per pid as you want, they will all be
528	called.	680	called.
529		681
530	The C<child_ns> variant doesn't start (activate) the newly created watcher.	682	The C<child_ns> variant doesn't start (activate) the newly created watcher.
531		683
532	=item $w->set ($pid)	684	=item $w->set ($pid, $trace)
533		685
534	Reconfigures the watcher, see the constructor above for details. Can be called at	686	Reconfigures the watcher, see the constructor above for details. Can be called at
535	any time.	687	any time.
536		688
537	=item $current_pid = $w->pid	689	=item $current_pid = $w->pid
538		690
539	=item $old_pid = $w->pid ($new_pid)
540
541	Returns the previously set process id and optionally set a new one.	691	Returns the previously set process id and optionally set a new one.
542		692
543	=item $exit_status = $w->rstatus	693	=item $exit_status = $w->rstatus
544		694
545	Return the exit/wait status (as returned by waitpid, see the waitpid entry	695	Return the exit/wait status (as returned by waitpid, see the waitpid entry
…		…
551	watcher for all pids).	701	watcher for all pids).
552		702
553	=back	703	=back
554		704
555		705
		706	=head3 STAT WATCHERS - did the file attributes just change?
		707
		708	=over 4
		709
		710	=item $w = EV::stat $path, $interval, $callback
		711
		712	=item $w = EV::stat_ns $path, $interval, $callback
		713
		714	=item $w = $loop->stat ($path, $interval, $callback)
		715
		716	=item $w = $loop->stat_ns ($path, $interval, $callback)
		717
		718	Call the callback when a file status change has been detected on
		719	C<$path>. The C<$path> does not need to exist, changing from "path exists"
		720	to "path does not exist" is a status change like any other.
		721
		722	The C<$interval> is a recommended polling interval for systems where
		723	OS-supported change notifications don't exist or are not supported. If
		724	you use C<0> then an unspecified default is used (which is highly
		725	recommended!), which is to be expected to be around five seconds usually.
		726
		727	This watcher type is not meant for massive numbers of stat watchers,
		728	as even with OS-supported change notifications, this can be
		729	resource-intensive.
		730
		731	The C<stat_ns> variant doesn't start (activate) the newly created watcher.
		732
		733	=item ... = $w->stat
		734
		735	This call is very similar to the perl C<stat> built-in: It stats (using
		736	C<lstat>) the path specified in the watcher and sets perls stat cache (as
		737	well as EV's idea of the current stat values) to the values found.
		738
		739	In scalar context, a boolean is return indicating success or failure of
		740	the stat. In list context, the same 13-value list as with stat is returned
		741	(except that the blksize and blocks fields are not reliable).
		742
		743	In the case of an error, errno is set to C<ENOENT> (regardless of the
		744	actual error value) and the C<nlink> value is forced to zero (if the stat
		745	was successful then nlink is guaranteed to be non-zero).
		746
		747	See also the next two entries for more info.
		748
		749	=item ... = $w->attr
		750
		751	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		752	the values most recently detected by EV. See the next entry for more info.
		753
		754	=item ... = $w->prev
		755
		756	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		757	the previous set of values, before the change.
		758
		759	That is, when the watcher callback is invoked, C<< $w->prev >> will be set
		760	to the values found I<before> a change was detected, while C<< $w->attr >>
		761	returns the values found leading to the change detection. The difference (if any)
		762	between C<prev> and C<attr> is what triggered the callback.
		763
		764	If you did something to the filesystem object and do not want to trigger
		765	yet another change, you can call C<stat> to update EV's idea of what the
		766	current attributes are.
		767
		768	=item $w->set ($path, $interval)
		769
		770	Reconfigures the watcher, see the constructor above for details. Can be
		771	called at any time.
		772
		773	=item $current_path = $w->path
		774
		775	=item $old_path = $w->path ($new_path)
		776
		777	Returns the previously set path and optionally set a new one.
		778
		779	=item $current_interval = $w->interval
		780
		781	=item $old_interval = $w->interval ($new_interval)
		782
		783	Returns the previously set interval and optionally set a new one. Can be
		784	used to query the actual interval used.
		785
		786	=back
		787
		788
556	=head3 IDLE WATCHERS - when you've got nothing better to do...	789	=head3 IDLE WATCHERS - when you've got nothing better to do...
557		790
558	=over 4	791	=over 4
559		792
560	=item $w = EV::idle $callback	793	=item $w = EV::idle $callback
561		794
562	=item $w = EV::idle_ns $callback	795	=item $w = EV::idle_ns $callback
563		796
564	Call the callback when there are no pending io, timer/periodic, signal or	797	=item $w = $loop->idle ($callback)
565	child events, i.e. when the process is idle.	798
		799	=item $w = $loop->idle_ns ($callback)
		800
		801	Call the callback when there are no other pending watchers of the same or
		802	higher priority (excluding check, prepare and other idle watchers of the
		803	same or lower priority, of course). They are called idle watchers because
		804	when the watcher is the highest priority pending event in the process, the
		805	process is considered to be idle at that priority.
		806
		807	If you want a watcher that is only ever called when I<no> other events are
		808	outstanding you have to set the priority to C<EV::MINPRI>.
566		809
567	The process will not block as long as any idle watchers are active, and	810	The process will not block as long as any idle watchers are active, and
568	they will be called repeatedly until stopped.	811	they will be called repeatedly until stopped.
569		812
		813	For example, if you have idle watchers at priority C<0> and C<1>, and
		814	an I/O watcher at priority C<0>, then the idle watcher at priority C<1>
		815	and the I/O watcher will always run when ready. Only when the idle watcher
		816	at priority C<1> is stopped and the I/O watcher at priority C<0> is not
		817	pending with the C<0>-priority idle watcher be invoked.
		818
570	The C<idle_ns> variant doesn't start (activate) the newly created watcher.	819	The C<idle_ns> variant doesn't start (activate) the newly created watcher.
571		820
572	=back	821	=back
573		822
574		823
…		…
577	=over 4	826	=over 4
578		827
579	=item $w = EV::prepare $callback	828	=item $w = EV::prepare $callback
580		829
581	=item $w = EV::prepare_ns $callback	830	=item $w = EV::prepare_ns $callback
		831
		832	=item $w = $loop->prepare ($callback)
		833
		834	=item $w = $loop->prepare_ns ($callback)
582		835
583	Call the callback just before the process would block. You can still	836	Call the callback just before the process would block. You can still
584	create/modify any watchers at this point.	837	create/modify any watchers at this point.
585		838
586	See the EV::check watcher, below, for explanations and an example.	839	See the EV::check watcher, below, for explanations and an example.
…		…
595	=over 4	848	=over 4
596		849
597	=item $w = EV::check $callback	850	=item $w = EV::check $callback
598		851
599	=item $w = EV::check_ns $callback	852	=item $w = EV::check_ns $callback
		853
		854	=item $w = $loop->check ($callback)
		855
		856	=item $w = $loop->check_ns ($callback)
600		857
601	Call the callback just after the process wakes up again (after it has	858	Call the callback just after the process wakes up again (after it has
602	gathered events), but before any other callbacks have been invoked.	859	gathered events), but before any other callbacks have been invoked.
603		860
604	This is used to integrate other event-based software into the EV	861	This is used to integrate other event-based software into the EV
…		…
614	or return;	871	or return;
615		872
616	# make the dispatcher handle any outstanding stuff	873	# make the dispatcher handle any outstanding stuff
617	... not shown	874	... not shown
618		875
619	# create an IO watcher for each and every socket	876	# create an I/O watcher for each and every socket
620	@snmp_watcher = (	877	@snmp_watcher = (
621	(map { EV::io $_, EV::READ, sub { } }	878	(map { EV::io $_, EV::READ, sub { } }
622	keys %{ $dispatcher->{_descriptors} }),	879	keys %{ $dispatcher->{_descriptors} }),
623		880
624	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]	881	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
…		…
646		903
647	The C<check_ns> variant doesn't start (activate) the newly created watcher.	904	The C<check_ns> variant doesn't start (activate) the newly created watcher.
648		905
649	=back	906	=back
650		907
651	=head3 STAT WATCHERS - did the file stats just change?
652		908
653	=over 4	909	=head3 FORK WATCHERS - the audacity to resume the event loop after a fork
654		910
655	=item $w = EV::stat $path, $interval, $callback	911	Fork watchers are called when a C<fork ()> was detected. The invocation
		912	is done before the event loop blocks next and before C<check> watchers
		913	are being called, and only in the child after the fork.
656		914
657	=item $w = EV::stat_ns $path, $interval, $callback	915	=over 4
658		916
659	Call the callback when a file status change has been detected on	917	=item $w = EV::fork $callback
660	C<$path>. The C<$path> does not need to exist, changing from "path exists"
661	to "path does not exist" is a status change like any other.
662		918
663	The C<$interval> is a recommended polling interval for systems where	919	=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		920
668	This watcher type is not meant for massive numbers of stat watchers,	921	=item $w = $loop->fork ($callback)
669	as even with OS-supported change notifications, this can be
670	resource-intensive.
671		922
		923	=item $w = $loop->fork_ns ($callback)
		924
		925	Call the callback before the event loop is resumed in the child process
		926	after a fork.
		927
672	The C<stat_ns> variant doesn't start (activate) the newly created watcher.	928	The C<fork_ns> variant doesn't start (activate) the newly created watcher.
673		929
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	930	=back
693		931
		932
		933	=head3 EMBED WATCHERS - when one backend isn't enough...
		934
		935	This is a rather advanced watcher type that lets you embed one event loop
		936	into another (currently only IO events are supported in the embedded
		937	loop, other types of watchers might be handled in a delayed or incorrect
		938	fashion and must not be used).
		939
		940	See the libev documentation at
		941	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
		942	for more details.
		943
		944	In short, this watcher is most useful on BSD systems without working
		945	kqueue to still be able to handle a large number of sockets:
		946
		947	my $socket_loop;
		948
		949	# check wether we use SELECT or POLL _and_ KQUEUE is supported
		950	if (
		951	(EV::backend & (EV::BACKEND_POLL \| EV::BACKEND_SELECT))
		952	&& (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
		953	) {
		954	# use kqueue for sockets
		955	$socket_loop = new EV::Loop EV::BACKEND_KQUEUE \| EV::FLAG_NOENV;
		956	}
		957
		958	# use the default loop otherwise
		959	$socket_loop \|\|= EV::default_loop;
		960
		961	=over 4
		962
		963	=item $w = EV::embed $otherloop, $callback
		964
		965	=item $w = EV::embed_ns $otherloop, $callback
		966
		967	=item $w = $loop->embed ($otherloop, $callback)
		968
		969	=item $w = $loop->embed_ns ($otherloop, $callback)
		970
		971	Call the callback when the embedded event loop (C<$otherloop>) has any
		972	I/O activity. The C<$callback> should alwas be specified as C<undef> in
		973	this version of EV, which means the embedded event loop will be managed
		974	automatically.
		975
		976	The C<embed_ns> variant doesn't start (activate) the newly created watcher.
		977
		978	=back
		979
		980	=head3 ASYNC WATCHERS - how to wake up another event loop
		981
		982	Async watchers are provided by EV, but have little use in perl directly, as perl
		983	neither supports threads nor direct access to signal handlers or other
		984	contexts where they could be of value.
		985
		986	It is, however, possible to use them from the XS level.
		987
		988	Please see the libev documentation for further details.
		989
		990	=over 4
		991
		992	=item $w = EV::async $callback
		993
		994	=item $w = EV::async_ns $callback
		995
		996	=item $w->send
		997
		998	=item $bool = $w->async_pending
		999
		1000	=back
		1001
		1002
		1003	=head1 PERL SIGNALS
		1004
		1005	While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour
		1006	with EV is as the same as any other C library: Perl-signals will only be
		1007	handled when Perl runs, which means your signal handler might be invoked
		1008	only the next time an event callback is invoked.
		1009
		1010	The solution is to use EV signal watchers (see C<EV::signal>), which will
		1011	ensure proper operations with regards to other event watchers.
		1012
		1013	If you cannot do this for whatever reason, you can also force a watcher
		1014	to be called on every event loop iteration by installing a C<EV::check>
		1015	watcher:
		1016
		1017	my $async_check = EV::check sub { };
		1018
		1019	This ensures that perl gets into control for a short time to handle any
		1020	pending signals, and also ensures (slightly) slower overall operation.
694		1021
695	=head1 THREADS	1022	=head1 THREADS
696		1023
697	Threads are not supported by this module in any way. Perl pseudo-threads	1024	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	1025	is evil stuff and must die. As soon as Perl gains real threads I will work
…		…
720	our $DIED = sub {	1047	our $DIED = sub {
721	warn "EV: error in callback (ignoring): $@";	1048	warn "EV: error in callback (ignoring): $@";
722	};	1049	};
723		1050
724	default_loop	1051	default_loop
725	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	1052	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
726		1053
727	1;	1054	1;
728		1055
729	=head1 SEE ALSO	1056	=head1 SEE ALSO
730		1057
731	L<EV::DNS>.	1058	L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as
		1059	event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
		1060	coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
		1061	event-loop agnostic and portable event driven programming.
732		1062
733	=head1 AUTHOR	1063	=head1 AUTHOR
734		1064
735	Marc Lehmann <schmorp@schmorp.de>	1065	Marc Lehmann <schmorp@schmorp.de>
736	http://home.schmorp.de/	1066	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 1.90 by root, Sat Apr 26 03:34:24 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 1.90 by root, Sat Apr 26 03:34:24 2008 UTC