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

Comparing EV/EV.pm (file contents):
Revision 1.49 by root, Sat Nov 24 08:28:10 2007 UTC vs.
Revision 1.73 by root, Fri Dec 21 05:10:01 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 = '1.2';	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
…		…
233	watchers with higher priority will be invoked first. The valid range of	317	watchers with higher priority will be invoked first. The valid range of
234	priorities lies between EV::MAXPRI (default 2) and EV::MINPRI (default	318	priorities lies between EV::MAXPRI (default 2) and EV::MINPRI (default
235	-2). If the priority is outside this range it will automatically be	319	-2). If the priority is outside this range it will automatically be
236	normalised to the nearest valid priority.	320	normalised to the nearest valid priority.
237		321
238	The default priority of any newly-created weatcher is 0.	322	The default priority of any newly-created watcher is 0.
239		323
		324	Note that the priority semantics have not yet been fleshed out and are
		325	subject to almost certain change.
		326
240	=item $w->trigger ($revents)	327	=item $w->invoke ($revents)
241		328
242	Call the callback now with the given event mask.	329	Call the callback now with the given event mask.
243		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>.
		341
		342	=item $previous_state = $w->keepalive ($bool)
		343
		344	Normally, C<EV::loop> will return when there are no active watchers
		345	(which is a "deadlock" because no progress can be made anymore). This is
		346	convinient because it allows you to start your watchers (and your jobs),
		347	call C<EV::loop> once and when it returns you know that all your jobs are
		348	finished (or they forgot to register some watchers for their task :).
		349
		350	Sometimes, however, this gets in your way, for example when you the module
		351	that calls C<EV::loop> (usually the main program) is not the same module
		352	as a long-living watcher (for example a DNS client module written by
		353	somebody else even). Then you might want any outstanding requests to be
		354	handled, but you would not want to keep C<EV::loop> from returning just
		355	because you happen to have this long-running UDP port watcher.
		356
		357	In this case you can clear the keepalive status, which means that even
		358	though your watcher is active, it won't keep C<EV::loop> from returning.
		359
		360	The initial value for keepalive is true (enabled), and you cna change it
		361	any time.
		362
		363	Example: Register an I/O watcher for some UDP socket but do not keep the
		364	event loop from running just because of that watcher.
		365
		366	my $udp_socket = ...
		367	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
		368	$udp_watcher->keepalive (0);
		369
		370	=back
		371
		372
		373	=head1 WATCHER TYPES
		374
		375	Each of the following subsections describes a single watcher type.
		376
		377	=head3 I/O WATCHERS - is this file descriptor readable or writable?
		378
		379	=over 4
244		380
245	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	381	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
246		382
247	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback	383	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
248		384
		385	=item $w = $loop->io 8$fileno_or_fh, $eventmask, $callback)
		386
		387	=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
		388
249	As long as the returned watcher object is alive, call the C<$callback>	389	As long as the returned watcher object is alive, call the C<$callback>
250	when the events specified in C<$eventmask>.	390	when at least one of events specified in C<$eventmask> occurs.
251		391
252	The $eventmask can be one or more of these constants ORed together:	392	The $eventmask can be one or more of these constants ORed together:
253		393
254	EV::READ wait until read() wouldn't block anymore	394	EV::READ wait until read() wouldn't block anymore
255	EV::WRITE wait until write() wouldn't block anymore	395	EV::WRITE wait until write() wouldn't block anymore
…		…
271		411
272	=item $old_eventmask = $w->events ($new_eventmask)	412	=item $old_eventmask = $w->events ($new_eventmask)
273		413
274	Returns the previously set event mask and optionally set a new one.	414	Returns the previously set event mask and optionally set a new one.
275		415
		416	=back
		417
		418
		419	=head3 TIMER WATCHERS - relative and optionally repeating timeouts
		420
		421	=over 4
276		422
277	=item $w = EV::timer $after, $repeat, $callback	423	=item $w = EV::timer $after, $repeat, $callback
278		424
279	=item $w = EV::timer_ns $after, $repeat, $callback	425	=item $w = EV::timer_ns $after, $repeat, $callback
280		426
281	Calls the callback after C<$after> seconds. If C<$repeat> is non-zero,	427	=item $w = $loop->timer ($after, $repeat, $callback)
282	the timer will be restarted (with the $repeat value as $after) after the	428
283	callback returns.	429	=item $w = $loop->timer_ns ($after, $repeat, $callback)
		430
		431	Calls the callback after C<$after> seconds (which may be fractional). If
		432	C<$repeat> is non-zero, the timer will be restarted (with the $repeat
		433	value as $after) after the callback returns.
284		434
285	This means that the callback would be called roughly after C<$after>	435	This means that the callback would be called roughly after C<$after>
286	seconds, and then every C<$repeat> seconds. The timer does his best not	436	seconds, and then every C<$repeat> seconds. The timer does his best not
287	to drift, but it will not invoke the timer more often then once per event	437	to drift, but it will not invoke the timer more often then once per event
288	loop iteration, and might drift in other cases. If that isn't acceptable,	438	loop iteration, and might drift in other cases. If that isn't acceptable,
…		…
294		444
295	The C<timer_ns> variant doesn't start (activate) the newly created watcher.	445	The C<timer_ns> variant doesn't start (activate) the newly created watcher.
296		446
297	=item $w->set ($after, $repeat)	447	=item $w->set ($after, $repeat)
298		448
299	Reconfigures the watcher, see the constructor above for details. Can be at	449	Reconfigures the watcher, see the constructor above for details. Can be called at
300	any time.	450	any time.
301		451
302	=item $w->again	452	=item $w->again
303		453
304	Similar to the C<start> method, but has special semantics for repeating timers:	454	Similar to the C<start> method, but has special semantics for repeating timers:
…		…
315	This behaviour is useful when you have a timeout for some IO	465	This behaviour is useful when you have a timeout for some IO
316	operation. You create a timer object with the same value for C<$after> and	466	operation. You create a timer object with the same value for C<$after> and
317	C<$repeat>, and then, in the read/write watcher, run the C<again> method	467	C<$repeat>, and then, in the read/write watcher, run the C<again> method
318	on the timeout.	468	on the timeout.
319		469
		470	=back
		471
		472
		473	=head3 PERIODIC WATCHERS - to cron or not to cron?
		474
		475	=over 4
320		476
321	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback	477	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
322		478
323	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback	479	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
		480
		481	=item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
		482
		483	=item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback)
324		484
325	Similar to EV::timer, but is not based on relative timeouts but on	485	Similar to EV::timer, but is not based on relative timeouts but on
326	absolute times. Apart from creating "simple" timers that trigger "at" the	486	absolute times. Apart from creating "simple" timers that trigger "at" the
327	specified time, it can also be used for non-drifting absolute timers and	487	specified time, it can also be used for non-drifting absolute timers and
328	more complex, cron-like, setups that are not adversely affected by time	488	more complex, cron-like, setups that are not adversely affected by time
…		…
396		556
397	The C<periodic_ns> variant doesn't start (activate) the newly created watcher.	557	The C<periodic_ns> variant doesn't start (activate) the newly created watcher.
398		558
399	=item $w->set ($at, $interval, $reschedule_cb)	559	=item $w->set ($at, $interval, $reschedule_cb)
400		560
401	Reconfigures the watcher, see the constructor above for details. Can be at	561	Reconfigures the watcher, see the constructor above for details. Can be called at
402	any time.	562	any time.
403		563
404	=item $w->again	564	=item $w->again
405		565
406	Simply stops and starts the watcher again.	566	Simply stops and starts the watcher again.
407		567
		568	=item $time = $w->at
		569
		570	Return the time that the watcher is expected to trigger next.
		571
		572	=back
		573
		574
		575	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
		576
		577	=over 4
408		578
409	=item $w = EV::signal $signal, $callback	579	=item $w = EV::signal $signal, $callback
410		580
411	=item $w = EV::signal_ns $signal, $callback	581	=item $w = EV::signal_ns $signal, $callback
412		582
413	Call the callback when $signal is received (the signal can be specified	583	Call the callback when $signal is received (the signal can be specified by
414	by number or by name, just as with kill or %SIG).	584	number or by name, just as with C<kill> or C<%SIG>).
415		585
416	EV will grab the signal for the process (the kernel only allows one	586	EV will grab the signal for the process (the kernel only allows one
417	component to receive a signal at a time) when you start a signal watcher,	587	component to receive a signal at a time) when you start a signal watcher,
418	and removes it again when you stop it. Perl does the same when you	588	and removes it again when you stop it. Perl does the same when you
419	add/remove callbacks to %SIG, so watch out.	589	add/remove callbacks to C<%SIG>, so watch out.
420		590
421	You can have as many signal watchers per signal as you want.	591	You can have as many signal watchers per signal as you want.
422		592
423	The C<signal_ns> variant doesn't start (activate) the newly created watcher.	593	The C<signal_ns> variant doesn't start (activate) the newly created watcher.
424		594
425	=item $w->set ($signal)	595	=item $w->set ($signal)
426		596
427	Reconfigures the watcher, see the constructor above for details. Can be at	597	Reconfigures the watcher, see the constructor above for details. Can be
428	any time.	598	called at any time.
429		599
430	=item $current_signum = $w->signal	600	=item $current_signum = $w->signal
431		601
432	=item $old_signum = $w->signal ($new_signal)	602	=item $old_signum = $w->signal ($new_signal)
433		603
434	Returns the previously set signal (always as a number not name) and	604	Returns the previously set signal (always as a number not name) and
435	optionally set a new one.	605	optionally set a new one.
436		606
		607	=back
		608
		609
		610	=head3 CHILD WATCHERS - watch out for process status changes
		611
		612	=over 4
437		613
438	=item $w = EV::child $pid, $callback	614	=item $w = EV::child $pid, $callback
439		615
440	=item $w = EV::child_ns $pid, $callback	616	=item $w = EV::child_ns $pid, $callback
441		617
		618	=item $w = $loop->child ($pid, $callback)
		619
		620	=item $w = $loop->child_ns ($pid, $callback)
		621
442	Call the callback when a status change for pid C<$pid> (or any pid	622	Call the callback when a status change for pid C<$pid> (or any pid if
443	if C<$pid> is 0) has been received. More precisely: when the process	623	C<$pid> is 0) has been received. More precisely: when the process receives
444	receives a SIGCHLD, EV will fetch the outstanding exit/wait status for all	624	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
445	changed/zombie children and call the callback.	625	changed/zombie children and call the callback.
446		626
447	You can access both status and pid by using the C<rstatus> and C<rpid>	627	It is valid (and fully supported) to install a child watcher after a child
448	methods on the watcher object.	628	has exited but before the event loop has started its next iteration (for
		629	example, first you C<fork>, then the new child process might exit, and
		630	only then do you install a child watcher in the parent for the new pid).
449		631
		632	You can access both exit (or tracing) status and pid by using the
		633	C<rstatus> and C<rpid> methods on the watcher object.
		634
450	You can have as many pid watchers per pid as you want.	635	You can have as many pid watchers per pid as you want, they will all be
		636	called.
451		637
452	The C<child_ns> variant doesn't start (activate) the newly created watcher.	638	The C<child_ns> variant doesn't start (activate) the newly created watcher.
453		639
454	=item $w->set ($pid)	640	=item $w->set ($pid)
455		641
456	Reconfigures the watcher, see the constructor above for details. Can be at	642	Reconfigures the watcher, see the constructor above for details. Can be called at
457	any time.	643	any time.
458		644
459	=item $current_pid = $w->pid	645	=item $current_pid = $w->pid
460		646
461	=item $old_pid = $w->pid ($new_pid)	647	=item $old_pid = $w->pid ($new_pid)
…		…
470	=item $pid = $w->rpid	656	=item $pid = $w->rpid
471		657
472	Return the pid of the awaited child (useful when you have installed a	658	Return the pid of the awaited child (useful when you have installed a
473	watcher for all pids).	659	watcher for all pids).
474		660
		661	=back
		662
		663
		664	=head3 STAT WATCHERS - did the file attributes just change?
		665
		666	=over 4
		667
		668	=item $w = EV::stat $path, $interval, $callback
		669
		670	=item $w = EV::stat_ns $path, $interval, $callback
		671
		672	=item $w = $loop->stat ($path, $interval, $callback)
		673
		674	=item $w = $loop->stat_ns ($path, $interval, $callback)
		675
		676	Call the callback when a file status change has been detected on
		677	C<$path>. The C<$path> does not need to exist, changing from "path exists"
		678	to "path does not exist" is a status change like any other.
		679
		680	The C<$interval> is a recommended polling interval for systems where
		681	OS-supported change notifications don't exist or are not supported. If
		682	you use C<0> then an unspecified default is used (which is highly
		683	recommended!), which is to be expected to be around five seconds usually.
		684
		685	This watcher type is not meant for massive numbers of stat watchers,
		686	as even with OS-supported change notifications, this can be
		687	resource-intensive.
		688
		689	The C<stat_ns> variant doesn't start (activate) the newly created watcher.
		690
		691	=item ... = $w->stat
		692
		693	This call is very similar to the perl C<stat> built-in: It stats (using
		694	C<lstat>) the path specified in the watcher and sets perls stat cache (as
		695	well as EV's idea of the current stat values) to the values found.
		696
		697	In scalar context, a boolean is return indicating success or failure of
		698	the stat. In list context, the same 13-value list as with stat is returned
		699	(except that the blksize and blocks fields are not reliable).
		700
		701	In the case of an error, errno is set to C<ENOENT> (regardless of the
		702	actual error value) and the C<nlink> value is forced to zero (if the stat
		703	was successful then nlink is guaranteed to be non-zero).
		704
		705	See also the next two entries for more info.
		706
		707	=item ... = $w->attr
		708
		709	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		710	the values most recently detected by EV. See the next entry for more info.
		711
		712	=item ... = $w->prev
		713
		714	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		715	the previous set of values, before the change.
		716
		717	That is, when the watcher callback is invoked, C<< $w->prev >> will be set
		718	to the values found I<before> a change was detected, while C<< $w->attr >>
		719	returns the values found leading to the change detection. The difference (if any)
		720	between C<prev> and C<attr> is what triggered the callback.
		721
		722	If you did something to the filesystem object and do not want to trigger
		723	yet another change, you can call C<stat> to update EV's idea of what the
		724	current attributes are.
		725
		726	=item $w->set ($path, $interval)
		727
		728	Reconfigures the watcher, see the constructor above for details. Can be
		729	called at any time.
		730
		731	=item $current_path = $w->path
		732
		733	=item $old_path = $w->path ($new_path)
		734
		735	Returns the previously set path and optionally set a new one.
		736
		737	=item $current_interval = $w->interval
		738
		739	=item $old_interval = $w->interval ($new_interval)
		740
		741	Returns the previously set interval and optionally set a new one. Can be
		742	used to query the actual interval used.
		743
		744	=back
		745
		746
		747	=head3 IDLE WATCHERS - when you've got nothing better to do...
		748
		749	=over 4
475		750
476	=item $w = EV::idle $callback	751	=item $w = EV::idle $callback
477		752
478	=item $w = EV::idle_ns $callback	753	=item $w = EV::idle_ns $callback
479		754
480	Call the callback when there are no pending io, timer/periodic, signal or	755	=item $w = $loop->idle ($callback)
481	child events, i.e. when the process is idle.	756
		757	=item $w = $loop->idle_ns ($callback)
		758
		759	Call the callback when there are no other pending watchers of the same or
		760	higher priority (excluding check, prepare and other idle watchers of the
		761	same or lower priority, of course). They are called idle watchers because
		762	when the watcher is the highest priority pending event in the process, the
		763	process is considered to be idle at that priority.
		764
		765	If you want a watcher that is only ever called when I<no> other events are
		766	outstanding you have to set the priority to C<EV::MINPRI>.
482		767
483	The process will not block as long as any idle watchers are active, and	768	The process will not block as long as any idle watchers are active, and
484	they will be called repeatedly until stopped.	769	they will be called repeatedly until stopped.
485		770
		771	For example, if you have idle watchers at priority C<0> and C<1>, and
		772	an I/O watcher at priority C<0>, then the idle watcher at priority C<1>
		773	and the I/O watcher will always run when ready. Only when the idle watcher
		774	at priority C<1> is stopped and the I/O watcher at priority C<0> is not
		775	pending with the C<0>-priority idle watcher be invoked.
		776
486	The C<idle_ns> variant doesn't start (activate) the newly created watcher.	777	The C<idle_ns> variant doesn't start (activate) the newly created watcher.
487		778
		779	=back
		780
		781
		782	=head3 PREPARE WATCHERS - customise your event loop!
		783
		784	=over 4
488		785
489	=item $w = EV::prepare $callback	786	=item $w = EV::prepare $callback
490		787
491	=item $w = EV::prepare_ns $callback	788	=item $w = EV::prepare_ns $callback
		789
		790	=item $w = $loop->prepare ($callback)
		791
		792	=item $w = $loop->prepare_ns 8$callback)
492		793
493	Call the callback just before the process would block. You can still	794	Call the callback just before the process would block. You can still
494	create/modify any watchers at this point.	795	create/modify any watchers at this point.
495		796
496	See the EV::check watcher, below, for explanations and an example.	797	See the EV::check watcher, below, for explanations and an example.
497		798
498	The C<prepare_ns> variant doesn't start (activate) the newly created watcher.	799	The C<prepare_ns> variant doesn't start (activate) the newly created watcher.
499		800
		801	=back
		802
		803
		804	=head3 CHECK WATCHERS - customise your event loop even more!
		805
		806	=over 4
500		807
501	=item $w = EV::check $callback	808	=item $w = EV::check $callback
502		809
503	=item $w = EV::check_ns $callback	810	=item $w = EV::check_ns $callback
		811
		812	=item $w = $loop->check ($callback)
		813
		814	=item $w = $loop->check_ns ($callback)
504		815
505	Call the callback just after the process wakes up again (after it has	816	Call the callback just after the process wakes up again (after it has
506	gathered events), but before any other callbacks have been invoked.	817	gathered events), but before any other callbacks have been invoked.
507		818
508	This is used to integrate other event-based software into the EV	819	This is used to integrate other event-based software into the EV
…		…
518	or return;	829	or return;
519		830
520	# make the dispatcher handle any outstanding stuff	831	# make the dispatcher handle any outstanding stuff
521	... not shown	832	... not shown
522		833
523	# create an IO watcher for each and every socket	834	# create an I/O watcher for each and every socket
524	@snmp_watcher = (	835	@snmp_watcher = (
525	(map { EV::io $_, EV::READ, sub { } }	836	(map { EV::io $_, EV::READ, sub { } }
526	keys %{ $dispatcher->{_descriptors} }),	837	keys %{ $dispatcher->{_descriptors} }),
527		838
528	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]	839	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
…		…
549	first).	860	first).
550		861
551	The C<check_ns> variant doesn't start (activate) the newly created watcher.	862	The C<check_ns> variant doesn't start (activate) the newly created watcher.
552		863
553	=back	864	=back
		865
		866
		867	=head3 FORK WATCHERS - the audacity to resume the event loop after a fork
		868
		869	Fork watchers are called when a C<fork ()> was detected. The invocation
		870	is done before the event loop blocks next and before C<check> watchers
		871	are being called, and only in the child after the fork.
		872
		873	=over 4
		874
		875	=item $w = EV::fork $callback
		876
		877	=item $w = EV::fork_ns $callback
		878
		879	=item $w = $loop->fork ($callback)
		880
		881	=item $w = $loop->fork_ns ($callback)
		882
		883	Call the callback before the event loop is resumed in the child process
		884	after a fork.
		885
		886	The C<fork_ns> variant doesn't start (activate) the newly created watcher.
		887
		888	=back
		889
		890
		891	=head1 PERL SIGNALS
		892
		893	While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour
		894	with EV is as the same as any other C library: Perl-signals will only be
		895	handled when Perl runs, which means your signal handler might be invoked
		896	only the next time an event callback is invoked.
		897
		898	The solution is to use EV signal watchers (see C<EV::signal>), which will
		899	ensure proper operations with regards to other event watchers.
		900
		901	If you cannot do this for whatever reason, you can also force a watcher
		902	to be called on every event loop iteration by installing a C<EV::check>
		903	watcher:
		904
		905	my $async_check = EV::check sub { };
		906
		907	This ensures that perl shortly gets into control for a short time, and
		908	also ensures slower overall operation.
554		909
555	=head1 THREADS	910	=head1 THREADS
556		911
557	Threads are not supported by this module in any way. Perl pseudo-threads	912	Threads are not supported by this module in any way. Perl pseudo-threads
558	is evil stuff and must die. As soon as Perl gains real threads I will work	913	is evil stuff and must die. As soon as Perl gains real threads I will work
…		…
580	our $DIED = sub {	935	our $DIED = sub {
581	warn "EV: error in callback (ignoring): $@";	936	warn "EV: error in callback (ignoring): $@";
582	};	937	};
583		938
584	default_loop	939	default_loop
585	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	940	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
586		941
587	1;	942	1;
588		943
589	=head1 SEE ALSO	944	=head1 SEE ALSO
590		945
591	L<EV::DNS>.	946	L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as
		947	event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
		948	coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP).
592		949
593	=head1 AUTHOR	950	=head1 AUTHOR
594		951
595	Marc Lehmann <schmorp@schmorp.de>	952	Marc Lehmann <schmorp@schmorp.de>
596	http://home.schmorp.de/	953	http://home.schmorp.de/

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Comparing EV/EV.pm (file contents): Revision 1.49 by root, Sat Nov 24 08:28:10 2007 UTC vs. Revision 1.73 by root, Fri Dec 21 05:10:01 2007 UTC

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Comparing EV/EV.pm (file contents):
Revision 1.49 by root, Sat Nov 24 08:28:10 2007 UTC vs.
Revision 1.73 by root, Fri Dec 21 05:10:01 2007 UTC