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

Comparing EV/EV.pm (file contents):
Revision 1.51 by root, Sat Nov 24 16:12:37 2007 UTC vs.
Revision 1.76 by root, Fri Dec 21 13:30:55 2007 UTC

…		…
39		39
40	my $w = EV::child 666, sub {	40	my $w = EV::child 666, sub {
41	my ($w, $revents) = @_;	41	my ($w, $revents) = @_;
42	my $status = $w->rstatus;	42	my $status = $w->rstatus;
43	};	43	};
		44
		45	# STAT CHANGES
		46	my $w = EV::stat "/etc/passwd", 10, sub {
		47	my ($w, $revents) = @_;
		48	warn $w->path, " has changed somehow.\n";
		49	};
44		50
45	# MAINLOOP	51	# MAINLOOP
46	EV::loop; # loop until EV::unloop is called or all watchers stop	52	EV::loop; # loop until EV::unloop is called or all watchers stop
47	EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled	53	EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled
48	EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block	54	EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block
49		55
50	=head1 DESCRIPTION	56	=head1 DESCRIPTION
51		57
52	This module provides an interface to libev	58	This module provides an interface to libev
53	(L<http://software.schmorp.de/pkg/libev.html>).	59	(L<http://software.schmorp.de/pkg/libev.html>). While the documentation
		60	below is comprehensive, one might also consult the documentation of libev
		61	itself (L<http://cvs.schmorp.de/libev/ev.html>) for more subtle details on
		62	watcher semantics or some discussion on the available backends, or how to
		63	force a specific backend with C<LIBEV_FLAGS>, or just about in any case
		64	because it has much more detailed information.
54		65
55	=cut	66	=cut
56		67
57	package EV;	68	package EV;
58		69
59	use strict;	70	use strict;
60		71
61	BEGIN {	72	BEGIN {
62	our $VERSION = '1.3';	73	our $VERSION = '2.0';
63	use XSLoader;	74	use XSLoader;
64	XSLoader::load "EV", $VERSION;	75	XSLoader::load "EV", $VERSION;
65	}	76	}
66		77
67	@EV::IO::ISA =	78	@EV::IO::ISA =
68	@EV::Timer::ISA =	79	@EV::Timer::ISA =
69	@EV::Periodic::ISA =	80	@EV::Periodic::ISA =
70	@EV::Signal::ISA =	81	@EV::Signal::ISA =
		82	@EV::Child::ISA =
		83	@EV::Stat::ISA =
71	@EV::Idle::ISA =	84	@EV::Idle::ISA =
72	@EV::Prepare::ISA =	85	@EV::Prepare::ISA =
73	@EV::Check::ISA =	86	@EV::Check::ISA =
74	@EV::Child::ISA = "EV::Watcher";	87	@EV::Embed::ISA =
		88	@EV::Fork::ISA =
		89	"EV::Watcher";
		90
		91	@EV::Loop::Default::ISA = "EV::Loop";
		92
		93	=head1 EVENT LOOPS
		94
		95	EV supports multiple event loops: There is a single "default event loop"
		96	that can handle everything including signals and child watchers, and any
		97	number of "dynamic event loops" that can use different backends (with
		98	various limitations), but no child and signal watchers.
		99
		100	You do not have to do anything to create the default event loop: When
		101	the module is loaded a suitable backend is selected on the premise of
		102	selecting a working backend (which for example rules out kqueue on most
		103	BSDs). Modules should, unless they have "special needs" always use the
		104	default loop as this is fastest (perl-wise), best supported by other
		105	modules (e.g. AnyEvent or Coro) and most portable event loop.
		106
		107	For specific programs you cna create additional event loops dynamically.
		108
		109	=over 4
		110
		111	=item $loop = new EV::loop [$flags]
		112
		113	Create a new event loop as per the specified flags. Please refer to the
		114	C<ev_loop_new ()> function description in the libev documentation
		115	(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>)
		116	for more info.
		117
		118	The loop will automatically be destroyed when it is no longer referenced
		119	by any watcher and the loop object goes out of scope.
		120
		121	Using C<EV::FLAG_FORKCHECK> is recommended, as only the default event loop
		122	is protected by this module.
		123
		124	=item $loop->loop_fork
		125
		126	Must be called after a fork in the child, before entering or continuing
		127	the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
		128	this fucntion automatically, at some performance loss (refer to the libev
		129	documentation).
		130
		131	=back
		132
75		133
76	=head1 BASIC INTERFACE	134	=head1 BASIC INTERFACE
77		135
78	=over 4	136	=over 4
79		137
80	=item $EV::DIED	138	=item $EV::DIED
81		139
82	Must contain a reference to a function that is called when a callback	140	Must contain a reference to a function that is called when a callback
83	throws an exception (with $@ containing thr error). The default prints an	141	throws an exception (with $@ containing the error). The default prints an
84	informative message and continues.	142	informative message and continues.
85		143
86	If this callback throws an exception it will be silently ignored.	144	If this callback throws an exception it will be silently ignored.
87		145
88	=item $time = EV::time	146	=item $time = EV::time
89		147
90	Returns the current time in (fractional) seconds since the epoch.	148	Returns the current time in (fractional) seconds since the epoch.
91		149
92	=item $time = EV::now	150	=item $time = EV::now
		151
		152	=item $time = $loop->now
93		153
94	Returns the time the last event loop iteration has been started. This	154	Returns the time the last event loop iteration has been started. This
95	is the time that (relative) timers are based on, and refering to it is	155	is the time that (relative) timers are based on, and refering to it is
96	usually faster then calling EV::time.	156	usually faster then calling EV::time.
97		157
98	=item $method = EV::method	158	=item $backend = EV::backend
		159
		160	=item $backend = $loop->backend
99		161
100	Returns an integer describing the backend used by libev (EV::METHOD_SELECT	162	Returns an integer describing the backend used by libev (EV::METHOD_SELECT
101	or EV::METHOD_EPOLL).	163	or EV::METHOD_EPOLL).
102		164
103	=item EV::loop [$flags]	165	=item EV::loop [$flags]
		166
		167	=item $loop->loop ([$flags])
104		168
105	Begin checking for events and calling callbacks. It returns when a	169	Begin checking for events and calling callbacks. It returns when a
106	callback calls EV::unloop.	170	callback calls EV::unloop.
107		171
108	The $flags argument can be one of the following:	172	The $flags argument can be one of the following:
…		…
111	EV::LOOP_ONESHOT block at most once (wait, but do not loop)	175	EV::LOOP_ONESHOT block at most once (wait, but do not loop)
112	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)	176	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
113		177
114	=item EV::unloop [$how]	178	=item EV::unloop [$how]
115		179
		180	=item $loop->unloop ([$how])
		181
116	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the	182	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the
117	innermost call to EV::loop return.	183	innermost call to EV::loop return.
118		184
119	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as	185	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as
120	fast as possible.	186	fast as possible.
121		187
		188	=item $count = EV::loop_count
		189
		190	=item $count = $loop->loop_count
		191
		192	Return the number of times the event loop has polled for new
		193	events. Sometiems useful as a generation counter.
		194
122	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)	195	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
		196
		197	=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
123		198
124	This function rolls together an I/O and a timer watcher for a single	199	This function rolls together an I/O and a timer watcher for a single
125	one-shot event without the need for managing a watcher object.	200	one-shot event without the need for managing a watcher object.
126		201
127	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>	202	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>
…		…
140		215
141	EV::once doesn't return anything: the watchers stay active till either	216	EV::once doesn't return anything: the watchers stay active till either
142	of them triggers, then they will be stopped and freed, and the callback	217	of them triggers, then they will be stopped and freed, and the callback
143	invoked.	218	invoked.
144		219
145	=back	220	=item EV::feed_fd_event ($fd, $revents)
146		221
147	=head2 WATCHER	222	=item $loop->feed_fd_event ($fd, $revents)
		223
		224	Feed an event on a file descriptor into EV. EV will react to this call as
		225	if the readyness notifications specified by C<$revents> (a combination of
		226	C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
		227
		228	=item EV::feed_signal_event ($signal)
		229
		230	Feed a signal event into EV. EV will react to this call as if the signal
		231	specified by C<$signal> had occured.
		232
		233	=back
		234
		235
		236	=head1 WATCHER OBJECTS
148		237
149	A watcher is an object that gets created to record your interest in some	238	A watcher is an object that gets created to record your interest in some
150	event. For instance, if you want to wait for STDIN to become readable, you	239	event. For instance, if you want to wait for STDIN to become readable, you
151	would create an EV::io watcher for that:	240	would create an EV::io watcher for that:
152		241
…		…
161	events.	250	events.
162		251
163	Each watcher type has its associated bit in revents, so you can use the	252	Each watcher type has its associated bit in revents, so you can use the
164	same callback for multiple watchers. The event mask is named after the	253	same callback for multiple watchers. The event mask is named after the
165	type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,	254	type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
166	EV::periodic sets EV::PERIODIC and so on, with the exception of IO events	255	EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events
167	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which	256	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which
168	uses EV::TIMEOUT).	257	uses EV::TIMEOUT).
169		258
170	In the rare case where one wants to create a watcher but not start it at	259	In the rare case where one wants to create a watcher but not start it at
171	the same time, each constructor has a variant with a trailing C<_ns> in	260	the same time, each constructor has a variant with a trailing C<_ns> in
…		…
177		266
178	Also, all methods changing some aspect of a watcher (->set, ->priority,	267	Also, all methods changing some aspect of a watcher (->set, ->priority,
179	->fh and so on) automatically stop and start it again if it is active,	268	->fh and so on) automatically stop and start it again if it is active,
180	which means pending events get lost.	269	which means pending events get lost.
181		270
182	=head2 WATCHER TYPES	271	=head2 COMMON WATCHER METHODS
183		272
184	Now lets move to the existing watcher types and asociated methods.	273	This section lists methods common to all watchers.
185
186	The following methods are available for all watchers. Then followes a
187	description of each watcher constructor (EV::io, EV::timer, EV::periodic,
188	EV::signal, EV::child, EV::idle, EV::prepare and EV::check), followed by
189	any type-specific methods (if any).
190		274
191	=over 4	275	=over 4
192		276
193	=item $w->start	277	=item $w->start
194		278
…		…
198		282
199	=item $w->stop	283	=item $w->stop
200		284
201	Stop a watcher if it is active. Also clear any pending events (events that	285	Stop a watcher if it is active. Also clear any pending events (events that
202	have been received but that didn't yet result in a callback invocation),	286	have been received but that didn't yet result in a callback invocation),
203	regardless of wether the watcher was active or not.	287	regardless of whether the watcher was active or not.
204		288
205	=item $bool = $w->is_active	289	=item $bool = $w->is_active
206		290
207	Returns true if the watcher is active, false otherwise.	291	Returns true if the watcher is active, false otherwise.
208		292
…		…
238	The default priority of any newly-created watcher is 0.	322	The default priority of any newly-created watcher is 0.
239		323
240	Note that the priority semantics have not yet been fleshed out and are	324	Note that the priority semantics have not yet been fleshed out and are
241	subject to almost certain change.	325	subject to almost certain change.
242		326
243	=item $w->trigger ($revents)	327	=item $w->invoke ($revents)
244		328
245	Call the callback now with the given event mask.	329	Call the callback now with the given event mask.
		330
		331	=item $w->feed_event ($revents)
		332
		333	Feed some events on this watcher into EV. EV will react to this call as if
		334	the watcher had received the given C<$revents> mask.
		335
		336	=item $revents = $w->clear_pending
		337
		338	If the watcher is pending, this function returns clears its pending status
		339	and returns its C<$revents> bitset (as if its callback was invoked). If the
		340	watcher isn't pending it does nothing and returns C<0>.
246		341
247	=item $previous_state = $w->keepalive ($bool)	342	=item $previous_state = $w->keepalive ($bool)
248		343
249	Normally, C<EV::loop> will return when there are no active watchers	344	Normally, C<EV::loop> will return when there are no active watchers
250	(which is a "deadlock" because no progress can be made anymore). This is	345	(which is a "deadlock" because no progress can be made anymore). This is
…		…
263	though your watcher is active, it won't keep C<EV::loop> from returning.	358	though your watcher is active, it won't keep C<EV::loop> from returning.
264		359
265	The initial value for keepalive is true (enabled), and you cna change it	360	The initial value for keepalive is true (enabled), and you cna change it
266	any time.	361	any time.
267		362
268	Example: Register an IO watcher for some UDP socket but do not keep the	363	Example: Register an I/O watcher for some UDP socket but do not keep the
269	event loop from running just because of that watcher.	364	event loop from running just because of that watcher.
270		365
271	my $udp_socket = ...	366	my $udp_socket = ...
272	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };	367	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
273	$udp_watcher->keepalive (0);	368	$1000udp_watcher->keepalive (0);
		369
		370	=item $loop = $w->loop
		371
		372	Return the loop that this watcher is attached to.
		373
		374	=back
		375
		376
		377	=head1 WATCHER TYPES
		378
		379	Each of the following subsections describes a single watcher type.
		380
		381	=head3 I/O WATCHERS - is this file descriptor readable or writable?
		382
		383	=over 4
274		384
275	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	385	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
276		386
277	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback	387	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
278		388
		389	=item $w = $loop->io ($fileno_or_fh, $eventmask, $callback)
		390
		391	=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
		392
279	As long as the returned watcher object is alive, call the C<$callback>	393	As long as the returned watcher object is alive, call the C<$callback>
280	when the events specified in C<$eventmask>.	394	when at least one of events specified in C<$eventmask> occurs.
281		395
282	The $eventmask can be one or more of these constants ORed together:	396	The $eventmask can be one or more of these constants ORed together:
283		397
284	EV::READ wait until read() wouldn't block anymore	398	EV::READ wait until read() wouldn't block anymore
285	EV::WRITE wait until write() wouldn't block anymore	399	EV::WRITE wait until write() wouldn't block anymore
…		…
301		415
302	=item $old_eventmask = $w->events ($new_eventmask)	416	=item $old_eventmask = $w->events ($new_eventmask)
303		417
304	Returns the previously set event mask and optionally set a new one.	418	Returns the previously set event mask and optionally set a new one.
305		419
		420	=back
		421
		422
		423	=head3 TIMER WATCHERS - relative and optionally repeating timeouts
		424
		425	=over 4
306		426
307	=item $w = EV::timer $after, $repeat, $callback	427	=item $w = EV::timer $after, $repeat, $callback
308		428
309	=item $w = EV::timer_ns $after, $repeat, $callback	429	=item $w = EV::timer_ns $after, $repeat, $callback
310		430
311	Calls the callback after C<$after> seconds. If C<$repeat> is non-zero,	431	=item $w = $loop->timer ($after, $repeat, $callback)
312	the timer will be restarted (with the $repeat value as $after) after the	432
313	callback returns.	433	=item $w = $loop->timer_ns ($after, $repeat, $callback)
		434
		435	Calls the callback after C<$after> seconds (which may be fractional). If
		436	C<$repeat> is non-zero, the timer will be restarted (with the $repeat
		437	value as $after) after the callback returns.
314		438
315	This means that the callback would be called roughly after C<$after>	439	This means that the callback would be called roughly after C<$after>
316	seconds, and then every C<$repeat> seconds. The timer does his best not	440	seconds, and then every C<$repeat> seconds. The timer does his best not
317	to drift, but it will not invoke the timer more often then once per event	441	to drift, but it will not invoke the timer more often then once per event
318	loop iteration, and might drift in other cases. If that isn't acceptable,	442	loop iteration, and might drift in other cases. If that isn't acceptable,
…		…
324		448
325	The C<timer_ns> variant doesn't start (activate) the newly created watcher.	449	The C<timer_ns> variant doesn't start (activate) the newly created watcher.
326		450
327	=item $w->set ($after, $repeat)	451	=item $w->set ($after, $repeat)
328		452
329	Reconfigures the watcher, see the constructor above for details. Can be at	453	Reconfigures the watcher, see the constructor above for details. Can be called at
330	any time.	454	any time.
331		455
332	=item $w->again	456	=item $w->again
333		457
334	Similar to the C<start> method, but has special semantics for repeating timers:	458	Similar to the C<start> method, but has special semantics for repeating timers:
…		…
345	This behaviour is useful when you have a timeout for some IO	469	This behaviour is useful when you have a timeout for some IO
346	operation. You create a timer object with the same value for C<$after> and	470	operation. You create a timer object with the same value for C<$after> and
347	C<$repeat>, and then, in the read/write watcher, run the C<again> method	471	C<$repeat>, and then, in the read/write watcher, run the C<again> method
348	on the timeout.	472	on the timeout.
349		473
		474	=back
		475
		476
		477	=head3 PERIODIC WATCHERS - to cron or not to cron?
		478
		479	=over 4
350		480
351	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback	481	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
352		482
353	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback	483	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
		484
		485	=item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
		486
		487	=item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback)
354		488
355	Similar to EV::timer, but is not based on relative timeouts but on	489	Similar to EV::timer, but is not based on relative timeouts but on
356	absolute times. Apart from creating "simple" timers that trigger "at" the	490	absolute times. Apart from creating "simple" timers that trigger "at" the
357	specified time, it can also be used for non-drifting absolute timers and	491	specified time, it can also be used for non-drifting absolute timers and
358	more complex, cron-like, setups that are not adversely affected by time	492	more complex, cron-like, setups that are not adversely affected by time
…		…
426		560
427	The C<periodic_ns> variant doesn't start (activate) the newly created watcher.	561	The C<periodic_ns> variant doesn't start (activate) the newly created watcher.
428		562
429	=item $w->set ($at, $interval, $reschedule_cb)	563	=item $w->set ($at, $interval, $reschedule_cb)
430		564
431	Reconfigures the watcher, see the constructor above for details. Can be at	565	Reconfigures the watcher, see the constructor above for details. Can be called at
432	any time.	566	any time.
433		567
434	=item $w->again	568	=item $w->again
435		569
436	Simply stops and starts the watcher again.	570	Simply stops and starts the watcher again.
437		571
		572	=item $time = $w->at
		573
		574	Return the time that the watcher is expected to trigger next.
		575
		576	=back
		577
		578
		579	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
		580
		581	=over 4
438		582
439	=item $w = EV::signal $signal, $callback	583	=item $w = EV::signal $signal, $callback
440		584
441	=item $w = EV::signal_ns $signal, $callback	585	=item $w = EV::signal_ns $signal, $callback
442		586
443	Call the callback when $signal is received (the signal can be specified	587	Call the callback when $signal is received (the signal can be specified by
444	by number or by name, just as with kill or %SIG).	588	number or by name, just as with C<kill> or C<%SIG>).
445		589
446	EV will grab the signal for the process (the kernel only allows one	590	EV will grab the signal for the process (the kernel only allows one
447	component to receive a signal at a time) when you start a signal watcher,	591	component to receive a signal at a time) when you start a signal watcher,
448	and removes it again when you stop it. Perl does the same when you	592	and removes it again when you stop it. Perl does the same when you
449	add/remove callbacks to %SIG, so watch out.	593	add/remove callbacks to C<%SIG>, so watch out.
450		594
451	You can have as many signal watchers per signal as you want.	595	You can have as many signal watchers per signal as you want.
452		596
453	The C<signal_ns> variant doesn't start (activate) the newly created watcher.	597	The C<signal_ns> variant doesn't start (activate) the newly created watcher.
454		598
455	=item $w->set ($signal)	599	=item $w->set ($signal)
456		600
457	Reconfigures the watcher, see the constructor above for details. Can be at	601	Reconfigures the watcher, see the constructor above for details. Can be
458	any time.	602	called at any time.
459		603
460	=item $current_signum = $w->signal	604	=item $current_signum = $w->signal
461		605
462	=item $old_signum = $w->signal ($new_signal)	606	=item $old_signum = $w->signal ($new_signal)
463		607
464	Returns the previously set signal (always as a number not name) and	608	Returns the previously set signal (always as a number not name) and
465	optionally set a new one.	609	optionally set a new one.
466		610
		611	=back
		612
		613
		614	=head3 CHILD WATCHERS - watch out for process status changes
		615
		616	=over 4
467		617
468	=item $w = EV::child $pid, $callback	618	=item $w = EV::child $pid, $callback
469		619
470	=item $w = EV::child_ns $pid, $callback	620	=item $w = EV::child_ns $pid, $callback
471		621
		622	=item $w = $loop->child ($pid, $callback)
		623
		624	=item $w = $loop->child_ns ($pid, $callback)
		625
472	Call the callback when a status change for pid C<$pid> (or any pid	626	Call the callback when a status change for pid C<$pid> (or any pid if
473	if C<$pid> is 0) has been received. More precisely: when the process	627	C<$pid> is 0) has been received. More precisely: when the process receives
474	receives a SIGCHLD, EV will fetch the outstanding exit/wait status for all	628	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
475	changed/zombie children and call the callback.	629	changed/zombie children and call the callback.
476		630
477	You can access both status and pid by using the C<rstatus> and C<rpid>	631	It is valid (and fully supported) to install a child watcher after a child
478	methods on the watcher object.	632	has exited but before the event loop has started its next iteration (for
		633	example, first you C<fork>, then the new child process might exit, and
		634	only then do you install a child watcher in the parent for the new pid).
479		635
		636	You can access both exit (or tracing) status and pid by using the
		637	C<rstatus> and C<rpid> methods on the watcher object.
		638
480	You can have as many pid watchers per pid as you want.	639	You can have as many pid watchers per pid as you want, they will all be
		640	called.
481		641
482	The C<child_ns> variant doesn't start (activate) the newly created watcher.	642	The C<child_ns> variant doesn't start (activate) the newly created watcher.
483		643
484	=item $w->set ($pid)	644	=item $w->set ($pid)
485		645
486	Reconfigures the watcher, see the constructor above for details. Can be at	646	Reconfigures the watcher, see the constructor above for details. Can be called at
487	any time.	647	any time.
488		648
489	=item $current_pid = $w->pid	649	=item $current_pid = $w->pid
490		650
491	=item $old_pid = $w->pid ($new_pid)	651	=item $old_pid = $w->pid ($new_pid)
…		…
500	=item $pid = $w->rpid	660	=item $pid = $w->rpid
501		661
502	Return the pid of the awaited child (useful when you have installed a	662	Return the pid of the awaited child (useful when you have installed a
503	watcher for all pids).	663	watcher for all pids).
504		664
		665	=back
		666
		667
		668	=head3 STAT WATCHERS - did the file attributes just change?
		669
		670	=over 4
		671
		672	=item $w = EV::stat $path, $interval, $callback
		673
		674	=item $w = EV::stat_ns $path, $interval, $callback
		675
		676	=item $w = $loop->stat ($path, $interval, $callback)
		677
		678	=item $w = $loop->stat_ns ($path, $interval, $callback)
		679
		680	Call the callback when a file status change has been detected on
		681	C<$path>. The C<$path> does not need to exist, changing from "path exists"
		682	to "path does not exist" is a status change like any other.
		683
		684	The C<$interval> is a recommended polling interval for systems where
		685	OS-supported change notifications don't exist or are not supported. If
		686	you use C<0> then an unspecified default is used (which is highly
		687	recommended!), which is to be expected to be around five seconds usually.
		688
		689	This watcher type is not meant for massive numbers of stat watchers,
		690	as even with OS-supported change notifications, this can be
		691	resource-intensive.
		692
		693	The C<stat_ns> variant doesn't start (activate) the newly created watcher.
		694
		695	=item ... = $w->stat
		696
		697	This call is very similar to the perl C<stat> built-in: It stats (using
		698	C<lstat>) the path specified in the watcher and sets perls stat cache (as
		699	well as EV's idea of the current stat values) to the values found.
		700
		701	In scalar context, a boolean is return indicating success or failure of
		702	the stat. In list context, the same 13-value list as with stat is returned
		703	(except that the blksize and blocks fields are not reliable).
		704
		705	In the case of an error, errno is set to C<ENOENT> (regardless of the
		706	actual error value) and the C<nlink> value is forced to zero (if the stat
		707	was successful then nlink is guaranteed to be non-zero).
		708
		709	See also the next two entries for more info.
		710
		711	=item ... = $w->attr
		712
		713	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		714	the values most recently detected by EV. See the next entry for more info.
		715
		716	=item ... = $w->prev
		717
		718	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		719	the previous set of values, before the change.
		720
		721	That is, when the watcher callback is invoked, C<< $w->prev >> will be set
		722	to the values found I<before> a change was detected, while C<< $w->attr >>
		723	returns the values found leading to the change detection. The difference (if any)
		724	between C<prev> and C<attr> is what triggered the callback.
		725
		726	If you did something to the filesystem object and do not want to trigger
		727	yet another change, you can call C<stat> to update EV's idea of what the
		728	current attributes are.
		729
		730	=item $w->set ($path, $interval)
		731
		732	Reconfigures the watcher, see the constructor above for details. Can be
		733	called at any time.
		734
		735	=item $current_path = $w->path
		736
		737	=item $old_path = $w->path ($new_path)
		738
		739	Returns the previously set path and optionally set a new one.
		740
		741	=item $current_interval = $w->interval
		742
		743	=item $old_interval = $w->interval ($new_interval)
		744
		745	Returns the previously set interval and optionally set a new one. Can be
		746	used to query the actual interval used.
		747
		748	=back
		749
		750
		751	=head3 IDLE WATCHERS - when you've got nothing better to do...
		752
		753	=over 4
505		754
506	=item $w = EV::idle $callback	755	=item $w = EV::idle $callback
507		756
508	=item $w = EV::idle_ns $callback	757	=item $w = EV::idle_ns $callback
509		758
510	Call the callback when there are no pending io, timer/periodic, signal or	759	=item $w = $loop->idle ($callback)
511	child events, i.e. when the process is idle.	760
		761	=item $w = $loop->idle_ns ($callback)
		762
		763	Call the callback when there are no other pending watchers of the same or
		764	higher priority (excluding check, prepare and other idle watchers of the
		765	same or lower priority, of course). They are called idle watchers because
		766	when the watcher is the highest priority pending event in the process, the
		767	process is considered to be idle at that priority.
		768
		769	If you want a watcher that is only ever called when I<no> other events are
		770	outstanding you have to set the priority to C<EV::MINPRI>.
512		771
513	The process will not block as long as any idle watchers are active, and	772	The process will not block as long as any idle watchers are active, and
514	they will be called repeatedly until stopped.	773	they will be called repeatedly until stopped.
515		774
		775	For example, if you have idle watchers at priority C<0> and C<1>, and
		776	an I/O watcher at priority C<0>, then the idle watcher at priority C<1>
		777	and the I/O watcher will always run when ready. Only when the idle watcher
		778	at priority C<1> is stopped and the I/O watcher at priority C<0> is not
		779	pending with the C<0>-priority idle watcher be invoked.
		780
516	The C<idle_ns> variant doesn't start (activate) the newly created watcher.	781	The C<idle_ns> variant doesn't start (activate) the newly created watcher.
517		782
		783	=back
		784
		785
		786	=head3 PREPARE WATCHERS - customise your event loop!
		787
		788	=over 4
518		789
519	=item $w = EV::prepare $callback	790	=item $w = EV::prepare $callback
520		791
521	=item $w = EV::prepare_ns $callback	792	=item $w = EV::prepare_ns $callback
		793
		794	=item $w = $loop->prepare ($callback)
		795
		796	=item $w = $loop->prepare_ns ($callback)
522		797
523	Call the callback just before the process would block. You can still	798	Call the callback just before the process would block. You can still
524	create/modify any watchers at this point.	799	create/modify any watchers at this point.
525		800
526	See the EV::check watcher, below, for explanations and an example.	801	See the EV::check watcher, below, for explanations and an example.
527		802
528	The C<prepare_ns> variant doesn't start (activate) the newly created watcher.	803	The C<prepare_ns> variant doesn't start (activate) the newly created watcher.
529		804
		805	=back
		806
		807
		808	=head3 CHECK WATCHERS - customise your event loop even more!
		809
		810	=over 4
530		811
531	=item $w = EV::check $callback	812	=item $w = EV::check $callback
532		813
533	=item $w = EV::check_ns $callback	814	=item $w = EV::check_ns $callback
		815
		816	=item $w = $loop->check ($callback)
		817
		818	=item $w = $loop->check_ns ($callback)
534		819
535	Call the callback just after the process wakes up again (after it has	820	Call the callback just after the process wakes up again (after it has
536	gathered events), but before any other callbacks have been invoked.	821	gathered events), but before any other callbacks have been invoked.
537		822
538	This is used to integrate other event-based software into the EV	823	This is used to integrate other event-based software into the EV
…		…
548	or return;	833	or return;
549		834
550	# make the dispatcher handle any outstanding stuff	835	# make the dispatcher handle any outstanding stuff
551	... not shown	836	... not shown
552		837
553	# create an IO watcher for each and every socket	838	# create an I/O watcher for each and every socket
554	@snmp_watcher = (	839	@snmp_watcher = (
555	(map { EV::io $_, EV::READ, sub { } }	840	(map { EV::io $_, EV::READ, sub { } }
556	keys %{ $dispatcher->{_descriptors} }),	841	keys %{ $dispatcher->{_descriptors} }),
557		842
558	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]	843	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
…		…
579	first).	864	first).
580		865
581	The C<check_ns> variant doesn't start (activate) the newly created watcher.	866	The C<check_ns> variant doesn't start (activate) the newly created watcher.
582		867
583	=back	868	=back
		869
		870
		871	=head3 FORK WATCHERS - the audacity to resume the event loop after a fork
		872
		873	Fork watchers are called when a C<fork ()> was detected. The invocation
		874	is done before the event loop blocks next and before C<check> watchers
		875	are being called, and only in the child after the fork.
		876
		877	=over 4
		878
		879	=item $w = EV::fork $callback
		880
		881	=item $w = EV::fork_ns $callback
		882
		883	=item $w = $loop->fork ($callback)
		884
		885	=item $w = $loop->fork_ns ($callback)
		886
		887	Call the callback before the event loop is resumed in the child process
		888	after a fork.
		889
		890	The C<fork_ns> variant doesn't start (activate) the newly created watcher.
		891
		892	=back
		893
		894
		895	=head1 PERL SIGNALS
		896
		897	While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour
		898	with EV is as the same as any other C library: Perl-signals will only be
		899	handled when Perl runs, which means your signal handler might be invoked
		900	only the next time an event callback is invoked.
		901
		902	The solution is to use EV signal watchers (see C<EV::signal>), which will
		903	ensure proper operations with regards to other event watchers.
		904
		905	If you cannot do this for whatever reason, you can also force a watcher
		906	to be called on every event loop iteration by installing a C<EV::check>
		907	watcher:
		908
		909	my $async_check = EV::check sub { };
		910
		911	This ensures that perl gets into control for a short time to handle any
		912	pending signals, and also ensures (slightly) slower overall operation.
584		913
585	=head1 THREADS	914	=head1 THREADS
586		915
587	Threads are not supported by this module in any way. Perl pseudo-threads	916	Threads are not supported by this module in any way. Perl pseudo-threads
588	is evil stuff and must die. As soon as Perl gains real threads I will work	917	is evil stuff and must die. As soon as Perl gains real threads I will work
…		…
610	our $DIED = sub {	939	our $DIED = sub {
611	warn "EV: error in callback (ignoring): $@";	940	warn "EV: error in callback (ignoring): $@";
612	};	941	};
613		942
614	default_loop	943	default_loop
615	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	944	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
616		945
617	1;	946	1;
618		947
619	=head1 SEE ALSO	948	=head1 SEE ALSO
620		949
621	L<EV::DNS>.	950	L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as
		951	event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
		952	coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP).
622		953
623	=head1 AUTHOR	954	=head1 AUTHOR
624		955
625	Marc Lehmann <schmorp@schmorp.de>	956	Marc Lehmann <schmorp@schmorp.de>
626	http://home.schmorp.de/	957	http://home.schmorp.de/

Diff Legend

-–
+Removed lines
-+
+Added lines
-<
+Changed lines
->
+Changed lines

Comparing EV/EV.pm (file contents): Revision 1.51 by root, Sat Nov 24 16:12:37 2007 UTC vs. Revision 1.76 by root, Fri Dec 21 13:30:55 2007 UTC

Diff Legend

Comparing EV/EV.pm (file contents):
Revision 1.51 by root, Sat Nov 24 16:12:37 2007 UTC vs.
Revision 1.76 by root, Fri Dec 21 13:30:55 2007 UTC