[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 1.73 by root, Fri Dec 21 05:10:01 2007 UTC

…		…
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.
64		65
65	=cut	66	=cut
66		67
67	package EV;	68	package EV;
68		69
69	use strict;	70	use strict;
70		71
71	BEGIN {	72	BEGIN {
72	our $VERSION = '1.4';	73	our $VERSION = '2.0';
73	use XSLoader;	74	use XSLoader;
74	XSLoader::load "EV", $VERSION;	75	XSLoader::load "EV", $VERSION;
75	}	76	}
76		77
77	@EV::IO::ISA =	78	@EV::IO::ISA =
78	@EV::Timer::ISA =	79	@EV::Timer::ISA =
79	@EV::Periodic::ISA =	80	@EV::Periodic::ISA =
80	@EV::Signal::ISA =	81	@EV::Signal::ISA =
		82	@EV::Child::ISA =
		83	@EV::Stat::ISA =
81	@EV::Idle::ISA =	84	@EV::Idle::ISA =
82	@EV::Prepare::ISA =	85	@EV::Prepare::ISA =
83	@EV::Check::ISA =	86	@EV::Check::ISA =
84	@EV::Child::ISA =
85	@EV::Embed::ISA =	87	@EV::Embed::ISA =
86	@EV::Stat::ISA = "EV::Watcher";	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
87		133
88	=head1 BASIC INTERFACE	134	=head1 BASIC INTERFACE
89		135
90	=over 4	136	=over 4
91		137
92	=item $EV::DIED	138	=item $EV::DIED
93		139
94	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
95	throws an exception (with $@ containing thr error). The default prints an	141	throws an exception (with $@ containing the error). The default prints an
96	informative message and continues.	142	informative message and continues.
97		143
98	If this callback throws an exception it will be silently ignored.	144	If this callback throws an exception it will be silently ignored.
99		145
100	=item $time = EV::time	146	=item $time = EV::time
101		147
102	Returns the current time in (fractional) seconds since the epoch.	148	Returns the current time in (fractional) seconds since the epoch.
103		149
104	=item $time = EV::now	150	=item $time = EV::now
		151
		152	=item $time = $loop->now
105		153
106	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
107	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
108	usually faster then calling EV::time.	156	usually faster then calling EV::time.
109		157
110	=item $method = EV::method	158	=item $backend = EV::backend
		159
		160	=item $backend = $loop->backend
111		161
112	Returns an integer describing the backend used by libev (EV::METHOD_SELECT	162	Returns an integer describing the backend used by libev (EV::METHOD_SELECT
113	or EV::METHOD_EPOLL).	163	or EV::METHOD_EPOLL).
114		164
115	=item EV::loop [$flags]	165	=item EV::loop [$flags]
		166
		167	=item $loop->loop ([$flags])
116		168
117	Begin checking for events and calling callbacks. It returns when a	169	Begin checking for events and calling callbacks. It returns when a
118	callback calls EV::unloop.	170	callback calls EV::unloop.
119		171
120	The $flags argument can be one of the following:	172	The $flags argument can be one of the following:
…		…
123	EV::LOOP_ONESHOT block at most once (wait, but do not loop)	175	EV::LOOP_ONESHOT block at most once (wait, but do not loop)
124	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)	176	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
125		177
126	=item EV::unloop [$how]	178	=item EV::unloop [$how]
127		179
		180	=item $loop->unloop ([$how])
		181
128	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
129	innermost call to EV::loop return.	183	innermost call to EV::loop return.
130		184
131	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
132	fast as possible.	186	fast as possible.
133		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
134	=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))
135		198
136	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
137	one-shot event without the need for managing a watcher object.	200	one-shot event without the need for managing a watcher object.
138		201
139	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>
…		…
152		215
153	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
154	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
155	invoked.	218	invoked.
156		219
157	=back	220	=item EV::feed_fd_event ($fd, $revents)
158		221
		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
159	=head2 WATCHER OBJECTS	236	=head1 WATCHER OBJECTS
160		237
161	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
162	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
163	would create an EV::io watcher for that:	240	would create an EV::io watcher for that:
164		241
…		…
173	events.	250	events.
174		251
175	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
176	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
177	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,
178	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
179	(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
180	uses EV::TIMEOUT).	257	uses EV::TIMEOUT).
181		258
182	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
183	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
…		…
205		282
206	=item $w->stop	283	=item $w->stop
207		284
208	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
209	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),
210	regardless of wether the watcher was active or not.	287	regardless of whether the watcher was active or not.
211		288
212	=item $bool = $w->is_active	289	=item $bool = $w->is_active
213		290
214	Returns true if the watcher is active, false otherwise.	291	Returns true if the watcher is active, false otherwise.
215		292
…		…
245	The default priority of any newly-created watcher is 0.	322	The default priority of any newly-created watcher is 0.
246		323
247	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
248	subject to almost certain change.	325	subject to almost certain change.
249		326
250	=item $w->trigger ($revents)	327	=item $w->invoke ($revents)
251		328
252	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>.
253		341
254	=item $previous_state = $w->keepalive ($bool)	342	=item $previous_state = $w->keepalive ($bool)
255		343
256	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
257	(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
…		…
270	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.
271		359
272	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
273	any time.	361	any time.
274		362
275	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
276	event loop from running just because of that watcher.	364	event loop from running just because of that watcher.
277		365
278	my $udp_socket = ...	366	my $udp_socket = ...
279	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };	367	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
280	$udp_watcher->keepalive (0);	368	$udp_watcher->keepalive (0);
281		369
282	=back	370	=back
283		371
284		372
285	=head2 WATCHER TYPES	373	=head1 WATCHER TYPES
286		374
287	Each of the following subsections describes a single watcher type.	375	Each of the following subsections describes a single watcher type.
288		376
289	=head3 IO WATCHERS - is this file descriptor readable or writable?	377	=head3 I/O WATCHERS - is this file descriptor readable or writable?
290		378
291	=over 4	379	=over 4
292		380
293	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	381	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
294		382
295	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback	383	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
		384
		385	=item $w = $loop->io 8$fileno_or_fh, $eventmask, $callback)
		386
		387	=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
296		388
297	As long as the returned watcher object is alive, call the C<$callback>	389	As long as the returned watcher object is alive, call the C<$callback>
298	when at least one of events specified in C<$eventmask> occurs.	390	when at least one of events specified in C<$eventmask> occurs.
299		391
300	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:
…		…
329	=over 4	421	=over 4
330		422
331	=item $w = EV::timer $after, $repeat, $callback	423	=item $w = EV::timer $after, $repeat, $callback
332		424
333	=item $w = EV::timer_ns $after, $repeat, $callback	425	=item $w = EV::timer_ns $after, $repeat, $callback
		426
		427	=item $w = $loop->timer ($after, $repeat, $callback)
		428
		429	=item $w = $loop->timer_ns ($after, $repeat, $callback)
334		430
335	Calls the callback after C<$after> seconds (which may be fractional). If	431	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 $repeat	432	C<$repeat> is non-zero, the timer will be restarted (with the $repeat
337	value as $after) after the callback returns.	433	value as $after) after the callback returns.
338		434
…		…
379	=over 4	475	=over 4
380		476
381	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback	477	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
382		478
383	=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)
384		484
385	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
386	absolute times. Apart from creating "simple" timers that trigger "at" the	486	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	487	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	488	more complex, cron-like, setups that are not adversely affected by time
…		…
463		563
464	=item $w->again	564	=item $w->again
465		565
466	Simply stops and starts the watcher again.	566	Simply stops and starts the watcher again.
467		567
		568	=item $time = $w->at
		569
		570	Return the time that the watcher is expected to trigger next.
		571
468	=back	572	=back
469		573
470		574
471	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!	575	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
472		576
…		…
509		613
510	=item $w = EV::child $pid, $callback	614	=item $w = EV::child $pid, $callback
511		615
512	=item $w = EV::child_ns $pid, $callback	616	=item $w = EV::child_ns $pid, $callback
513		617
		618	=item $w = $loop->child ($pid, $callback)
		619
		620	=item $w = $loop->child_ns ($pid, $callback)
		621
514	Call the callback when a status change for pid C<$pid> (or any pid if	622	Call the callback when a status change for pid C<$pid> (or any pid if
515	C<$pid> is 0) has been received. More precisely: when the process receives	623	C<$pid> is 0) has been received. More precisely: when the process receives
516	a C<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
517	changed/zombie children and call the callback.	625	changed/zombie children and call the callback.
518		626
…		…
551	watcher for all pids).	659	watcher for all pids).
552		660
553	=back	661	=back
554		662
555		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
556	=head3 IDLE WATCHERS - when you've got nothing better to do...	747	=head3 IDLE WATCHERS - when you've got nothing better to do...
557		748
558	=over 4	749	=over 4
559		750
560	=item $w = EV::idle $callback	751	=item $w = EV::idle $callback
561		752
562	=item $w = EV::idle_ns $callback	753	=item $w = EV::idle_ns $callback
563		754
564	Call the callback when there are no pending io, timer/periodic, signal or	755	=item $w = $loop->idle ($callback)
565	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>.
566		767
567	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
568	they will be called repeatedly until stopped.	769	they will be called repeatedly until stopped.
569		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
570	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.
571		778
572	=back	779	=back
573		780
574		781
…		…
577	=over 4	784	=over 4
578		785
579	=item $w = EV::prepare $callback	786	=item $w = EV::prepare $callback
580		787
581	=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)
582		793
583	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
584	create/modify any watchers at this point.	795	create/modify any watchers at this point.
585		796
586	See the EV::check watcher, below, for explanations and an example.	797	See the EV::check watcher, below, for explanations and an example.
…		…
595	=over 4	806	=over 4
596		807
597	=item $w = EV::check $callback	808	=item $w = EV::check $callback
598		809
599	=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)
600		815
601	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
602	gathered events), but before any other callbacks have been invoked.	817	gathered events), but before any other callbacks have been invoked.
603		818
604	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
…		…
614	or return;	829	or return;
615		830
616	# make the dispatcher handle any outstanding stuff	831	# make the dispatcher handle any outstanding stuff
617	... not shown	832	... not shown
618		833
619	# create an IO watcher for each and every socket	834	# create an I/O watcher for each and every socket
620	@snmp_watcher = (	835	@snmp_watcher = (
621	(map { EV::io $_, EV::READ, sub { } }	836	(map { EV::io $_, EV::READ, sub { } }
622	keys %{ $dispatcher->{_descriptors} }),	837	keys %{ $dispatcher->{_descriptors} }),
623		838
624	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]	839	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
…		…
646		861
647	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.
648		863
649	=back	864	=back
650		865
651	=head3 STAT WATCHERS - did the file stats just change?
652		866
653	=over 4	867	=head3 FORK WATCHERS - the audacity to resume the event loop after a fork
654		868
655	=item $w = EV::stat $path, $interval, $callback	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.
656		872
657	=item $w = EV::stat_ns $path, $interval, $callback	873	=over 4
658		874
659	Call the callback when a file status change has been detected on	875	=item $w = EV::fork $callback
660	C<$path>. The C<$path> does not need to exist, changing from "path exists"
661	to "path does not exist" is a status change like any other.
662		876
663	The C<$interval> is a recommended polling interval for systems where	877	=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		878
668	This watcher type is not meant for massive numbers of stat watchers,	879	=item $w = $loop->fork ($callback)
669	as even with OS-supported change notifications, this can be
670	resource-intensive.
671		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
672	The C<stat_ns> variant doesn't start (activate) the newly created watcher.	886	The C<fork_ns> variant doesn't start (activate) the newly created watcher.
673		887
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	888	=back
693		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.
694		909
695	=head1 THREADS	910	=head1 THREADS
696		911
697	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
698	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
…		…
720	our $DIED = sub {	935	our $DIED = sub {
721	warn "EV: error in callback (ignoring): $@";	936	warn "EV: error in callback (ignoring): $@";
722	};	937	};
723		938
724	default_loop	939	default_loop
725	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	940	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
726		941
727	1;	942	1;
728		943
729	=head1 SEE ALSO	944	=head1 SEE ALSO
730		945
731	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).
732		949
733	=head1 AUTHOR	950	=head1 AUTHOR
734		951
735	Marc Lehmann <schmorp@schmorp.de>	952	Marc Lehmann <schmorp@schmorp.de>
736	http://home.schmorp.de/	953	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 1.73 by root, Fri Dec 21 05:10:01 2007 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 1.73 by root, Fri Dec 21 05:10:01 2007 UTC