[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 1.79 by root, Sat Dec 22 16:37:07 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 can 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	=item $loop = EV::default_loop [$flags]
		132
		133	Return the default loop (which is a singleton object).
		134
		135	=back
		136
87		137
88	=head1 BASIC INTERFACE	138	=head1 BASIC INTERFACE
89		139
90	=over 4	140	=over 4
91		141
92	=item $EV::DIED	142	=item $EV::DIED
93		143
94	Must contain a reference to a function that is called when a callback	144	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	145	throws an exception (with $@ containing the error). The default prints an
96	informative message and continues.	146	informative message and continues.
97		147
98	If this callback throws an exception it will be silently ignored.	148	If this callback throws an exception it will be silently ignored.
99		149
		150	=item $flags = EV::supported_backends
		151
		152	=item $flags = EV::recommended_backends
		153
		154	=item $flags = EV::embeddable_backends
		155
		156	Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this
		157	instance of EV, the set of recommended backends (supposed to be good) for
		158	this platform and the set of embeddable backends (see EMBED WATCHERS).
		159
100	=item $time = EV::time	160	=item $time = EV::time
101		161
102	Returns the current time in (fractional) seconds since the epoch.	162	Returns the current time in (fractional) seconds since the epoch.
103		163
104	=item $time = EV::now	164	=item $time = EV::now
		165
		166	=item $time = $loop->now
105		167
106	Returns the time the last event loop iteration has been started. This	168	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	169	is the time that (relative) timers are based on, and refering to it is
108	usually faster then calling EV::time.	170	usually faster then calling EV::time.
109		171
110	=item $method = EV::method	172	=item $backend = EV::backend
		173
		174	=item $backend = $loop->backend
111		175
112	Returns an integer describing the backend used by libev (EV::METHOD_SELECT	176	Returns an integer describing the backend used by libev (EV::METHOD_SELECT
113	or EV::METHOD_EPOLL).	177	or EV::METHOD_EPOLL).
114		178
115	=item EV::loop [$flags]	179	=item EV::loop [$flags]
		180
		181	=item $loop->loop ([$flags])
116		182
117	Begin checking for events and calling callbacks. It returns when a	183	Begin checking for events and calling callbacks. It returns when a
118	callback calls EV::unloop.	184	callback calls EV::unloop.
119		185
120	The $flags argument can be one of the following:	186	The $flags argument can be one of the following:
…		…
123	EV::LOOP_ONESHOT block at most once (wait, but do not loop)	189	EV::LOOP_ONESHOT block at most once (wait, but do not loop)
124	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)	190	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
125		191
126	=item EV::unloop [$how]	192	=item EV::unloop [$how]
127		193
		194	=item $loop->unloop ([$how])
		195
128	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the	196	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the
129	innermost call to EV::loop return.	197	innermost call to EV::loop return.
130		198
131	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as	199	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as
132	fast as possible.	200	fast as possible.
133		201
		202	=item $count = EV::loop_count
		203
		204	=item $count = $loop->loop_count
		205
		206	Return the number of times the event loop has polled for new
		207	events. Sometiems useful as a generation counter.
		208
134	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)	209	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
		210
		211	=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
135		212
136	This function rolls together an I/O and a timer watcher for a single	213	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.	214	one-shot event without the need for managing a watcher object.
138		215
139	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>	216	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>
…		…
145	If timeout is C<undef> or negative, then there will be no	222	If timeout is C<undef> or negative, then there will be no
146	timeout. Otherwise a EV::timer with this value will be started.	223	timeout. Otherwise a EV::timer with this value will be started.
147		224
148	When an error occurs or either the timeout or I/O watcher triggers, then	225	When an error occurs or either the timeout or I/O watcher triggers, then
149	the callback will be called with the received event set (in general	226	the callback will be called with the received event set (in general
150	you can expect it to be a combination of C<EV:ERROR>, C<EV::READ>,	227	you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
151	C<EV::WRITE> and C<EV::TIMEOUT>).	228	C<EV::WRITE> and C<EV::TIMEOUT>).
152		229
153	EV::once doesn't return anything: the watchers stay active till either	230	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	231	of them triggers, then they will be stopped and freed, and the callback
155	invoked.	232	invoked.
156		233
157	=back	234	=item EV::feed_fd_event ($fd, $revents)
158		235
		236	=item $loop->feed_fd_event ($fd, $revents)
		237
		238	Feed an event on a file descriptor into EV. EV will react to this call as
		239	if the readyness notifications specified by C<$revents> (a combination of
		240	C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
		241
		242	=item EV::feed_signal_event ($signal)
		243
		244	Feed a signal event into EV. EV will react to this call as if the signal
		245	specified by C<$signal> had occured.
		246
		247	=item EV::set_io_collect_interval $time
		248
		249	=item $loop->set_io_collect_interval ($time)
		250
		251	=item EV::set_timeout_collect_interval $time
		252
		253	=item $loop->set_timeout_collect_interval ($time)
		254
		255	These advanced functions set the minimum block interval when polling for I/O events and the minimum
		256	wait interval for timer events. See the libev documentation at
		257	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> for
		258	a more detailed discussion.
		259
		260	=back
		261
		262
159	=head2 WATCHER OBJECTS	263	=head1 WATCHER OBJECTS
160		264
161	A watcher is an object that gets created to record your interest in some	265	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	266	event. For instance, if you want to wait for STDIN to become readable, you
163	would create an EV::io watcher for that:	267	would create an EV::io watcher for that:
164		268
165	my $watcher = EV::io *STDIN, EV::READ, sub {	269	my $watcher = EV::io *STDIN, EV::READ, sub {
166	my ($watcher, $revents) = @_;	270	my ($watcher, $revents) = @_;
167	warn "yeah, STDIN should not be readable without blocking!\n"	271	warn "yeah, STDIN should now be readable without blocking!\n"
168	};	272	};
169		273
170	All watchers can be active (waiting for events) or inactive (paused). Only	274	All watchers can be active (waiting for events) or inactive (paused). Only
171	active watchers will have their callbacks invoked. All callbacks will be	275	active watchers will have their callbacks invoked. All callbacks will be
172	called with at least two arguments: the watcher and a bitmask of received	276	called with at least two arguments: the watcher and a bitmask of received
173	events.	277	events.
174		278
175	Each watcher type has its associated bit in revents, so you can use the	279	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	280	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,	281	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	282	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	283	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which
180	uses EV::TIMEOUT).	284	uses EV::TIMEOUT).
181		285
182	In the rare case where one wants to create a watcher but not start it at	286	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	287	the same time, each constructor has a variant with a trailing C<_ns> in
…		…
205		309
206	=item $w->stop	310	=item $w->stop
207		311
208	Stop a watcher if it is active. Also clear any pending events (events that	312	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),	313	have been received but that didn't yet result in a callback invocation),
210	regardless of wether the watcher was active or not.	314	regardless of whether the watcher was active or not.
211		315
212	=item $bool = $w->is_active	316	=item $bool = $w->is_active
213		317
214	Returns true if the watcher is active, false otherwise.	318	Returns true if the watcher is active, false otherwise.
215		319
…		…
245	The default priority of any newly-created watcher is 0.	349	The default priority of any newly-created watcher is 0.
246		350
247	Note that the priority semantics have not yet been fleshed out and are	351	Note that the priority semantics have not yet been fleshed out and are
248	subject to almost certain change.	352	subject to almost certain change.
249		353
250	=item $w->trigger ($revents)	354	=item $w->invoke ($revents)
251		355
252	Call the callback now with the given event mask.	356	Call the callback now with the given event mask.
		357
		358	=item $w->feed_event ($revents)
		359
		360	Feed some events on this watcher into EV. EV will react to this call as if
		361	the watcher had received the given C<$revents> mask.
		362
		363	=item $revents = $w->clear_pending
		364
		365	If the watcher is pending, this function clears its pending status and
		366	returns its C<$revents> bitset (as if its callback was invoked). If the
		367	watcher isn't pending it does nothing and returns C<0>.
253		368
254	=item $previous_state = $w->keepalive ($bool)	369	=item $previous_state = $w->keepalive ($bool)
255		370
256	Normally, C<EV::loop> will return when there are no active watchers	371	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	372	(which is a "deadlock" because no progress can be made anymore). This is
258	convinient because it allows you to start your watchers (and your jobs),	373	convinient because it allows you to start your watchers (and your jobs),
259	call C<EV::loop> once and when it returns you know that all your jobs are	374	call C<EV::loop> once and when it returns you know that all your jobs are
260	finished (or they forgot to register some watchers for their task :).	375	finished (or they forgot to register some watchers for their task :).
261		376
262	Sometimes, however, this gets in your way, for example when you the module	377	Sometimes, however, this gets in your way, for example when the module
263	that calls C<EV::loop> (usually the main program) is not the same module	378	that calls C<EV::loop> (usually the main program) is not the same module
264	as a long-living watcher (for example a DNS client module written by	379	as a long-living watcher (for example a DNS client module written by
265	somebody else even). Then you might want any outstanding requests to be	380	somebody else even). Then you might want any outstanding requests to be
266	handled, but you would not want to keep C<EV::loop> from returning just	381	handled, but you would not want to keep C<EV::loop> from returning just
267	because you happen to have this long-running UDP port watcher.	382	because you happen to have this long-running UDP port watcher.
…		…
270	though your watcher is active, it won't keep C<EV::loop> from returning.	385	though your watcher is active, it won't keep C<EV::loop> from returning.
271		386
272	The initial value for keepalive is true (enabled), and you cna change it	387	The initial value for keepalive is true (enabled), and you cna change it
273	any time.	388	any time.
274		389
275	Example: Register an IO watcher for some UDP socket but do not keep the	390	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.	391	event loop from running just because of that watcher.
277		392
278	my $udp_socket = ...	393	my $udp_socket = ...
279	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };	394	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
280	$udp_watcher->keepalive (0);	395	$1000udp_watcher->keepalive (0);
281		396
282	=back	397	=item $loop = $w->loop
283		398
		399	Return the loop that this watcher is attached to.
284		400
		401	=back
		402
		403
285	=head2 WATCHER TYPES	404	=head1 WATCHER TYPES
286		405
287	Each of the following subsections describes a single watcher type.	406	Each of the following subsections describes a single watcher type.
288		407
289	=head3 IO WATCHERS - is this file descriptor readable or writable?	408	=head3 I/O WATCHERS - is this file descriptor readable or writable?
290		409
291	=over 4	410	=over 4
292		411
293	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	412	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
294		413
295	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback	414	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
		415
		416	=item $w = $loop->io ($fileno_or_fh, $eventmask, $callback)
		417
		418	=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
296		419
297	As long as the returned watcher object is alive, call the C<$callback>	420	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.	421	when at least one of events specified in C<$eventmask> occurs.
299		422
300	The $eventmask can be one or more of these constants ORed together:	423	The $eventmask can be one or more of these constants ORed together:
…		…
329	=over 4	452	=over 4
330		453
331	=item $w = EV::timer $after, $repeat, $callback	454	=item $w = EV::timer $after, $repeat, $callback
332		455
333	=item $w = EV::timer_ns $after, $repeat, $callback	456	=item $w = EV::timer_ns $after, $repeat, $callback
		457
		458	=item $w = $loop->timer ($after, $repeat, $callback)
		459
		460	=item $w = $loop->timer_ns ($after, $repeat, $callback)
334		461
335	Calls the callback after C<$after> seconds (which may be fractional). If	462	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 $repeat	463	C<$repeat> is non-zero, the timer will be restarted (with the $repeat
337	value as $after) after the callback returns.	464	value as $after) after the callback returns.
338		465
…		…
379	=over 4	506	=over 4
380		507
381	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback	508	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
382		509
383	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback	510	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
		511
		512	=item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
		513
		514	=item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback)
384		515
385	Similar to EV::timer, but is not based on relative timeouts but on	516	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	517	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	518	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	519	more complex, cron-like, setups that are not adversely affected by time
…		…
463		594
464	=item $w->again	595	=item $w->again
465		596
466	Simply stops and starts the watcher again.	597	Simply stops and starts the watcher again.
467		598
		599	=item $time = $w->at
		600
		601	Return the time that the watcher is expected to trigger next.
		602
468	=back	603	=back
469		604
470		605
471	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!	606	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
472		607
…		…
509		644
510	=item $w = EV::child $pid, $callback	645	=item $w = EV::child $pid, $callback
511		646
512	=item $w = EV::child_ns $pid, $callback	647	=item $w = EV::child_ns $pid, $callback
513		648
		649	=item $w = $loop->child ($pid, $callback)
		650
		651	=item $w = $loop->child_ns ($pid, $callback)
		652
514	Call the callback when a status change for pid C<$pid> (or any pid if	653	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	654	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	655	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
517	changed/zombie children and call the callback.	656	changed/zombie children and call the callback.
518		657
…		…
551	watcher for all pids).	690	watcher for all pids).
552		691
553	=back	692	=back
554		693
555		694
		695	=head3 STAT WATCHERS - did the file attributes just change?
		696
		697	=over 4
		698
		699	=item $w = EV::stat $path, $interval, $callback
		700
		701	=item $w = EV::stat_ns $path, $interval, $callback
		702
		703	=item $w = $loop->stat ($path, $interval, $callback)
		704
		705	=item $w = $loop->stat_ns ($path, $interval, $callback)
		706
		707	Call the callback when a file status change has been detected on
		708	C<$path>. The C<$path> does not need to exist, changing from "path exists"
		709	to "path does not exist" is a status change like any other.
		710
		711	The C<$interval> is a recommended polling interval for systems where
		712	OS-supported change notifications don't exist or are not supported. If
		713	you use C<0> then an unspecified default is used (which is highly
		714	recommended!), which is to be expected to be around five seconds usually.
		715
		716	This watcher type is not meant for massive numbers of stat watchers,
		717	as even with OS-supported change notifications, this can be
		718	resource-intensive.
		719
		720	The C<stat_ns> variant doesn't start (activate) the newly created watcher.
		721
		722	=item ... = $w->stat
		723
		724	This call is very similar to the perl C<stat> built-in: It stats (using
		725	C<lstat>) the path specified in the watcher and sets perls stat cache (as
		726	well as EV's idea of the current stat values) to the values found.
		727
		728	In scalar context, a boolean is return indicating success or failure of
		729	the stat. In list context, the same 13-value list as with stat is returned
		730	(except that the blksize and blocks fields are not reliable).
		731
		732	In the case of an error, errno is set to C<ENOENT> (regardless of the
		733	actual error value) and the C<nlink> value is forced to zero (if the stat
		734	was successful then nlink is guaranteed to be non-zero).
		735
		736	See also the next two entries for more info.
		737
		738	=item ... = $w->attr
		739
		740	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		741	the values most recently detected by EV. See the next entry for more info.
		742
		743	=item ... = $w->prev
		744
		745	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		746	the previous set of values, before the change.
		747
		748	That is, when the watcher callback is invoked, C<< $w->prev >> will be set
		749	to the values found I<before> a change was detected, while C<< $w->attr >>
		750	returns the values found leading to the change detection. The difference (if any)
		751	between C<prev> and C<attr> is what triggered the callback.
		752
		753	If you did something to the filesystem object and do not want to trigger
		754	yet another change, you can call C<stat> to update EV's idea of what the
		755	current attributes are.
		756
		757	=item $w->set ($path, $interval)
		758
		759	Reconfigures the watcher, see the constructor above for details. Can be
		760	called at any time.
		761
		762	=item $current_path = $w->path
		763
		764	=item $old_path = $w->path ($new_path)
		765
		766	Returns the previously set path and optionally set a new one.
		767
		768	=item $current_interval = $w->interval
		769
		770	=item $old_interval = $w->interval ($new_interval)
		771
		772	Returns the previously set interval and optionally set a new one. Can be
		773	used to query the actual interval used.
		774
		775	=back
		776
		777
556	=head3 IDLE WATCHERS - when you've got nothing better to do...	778	=head3 IDLE WATCHERS - when you've got nothing better to do...
557		779
558	=over 4	780	=over 4
559		781
560	=item $w = EV::idle $callback	782	=item $w = EV::idle $callback
561		783
562	=item $w = EV::idle_ns $callback	784	=item $w = EV::idle_ns $callback
563		785
564	Call the callback when there are no pending io, timer/periodic, signal or	786	=item $w = $loop->idle ($callback)
565	child events, i.e. when the process is idle.	787
		788	=item $w = $loop->idle_ns ($callback)
		789
		790	Call the callback when there are no other pending watchers of the same or
		791	higher priority (excluding check, prepare and other idle watchers of the
		792	same or lower priority, of course). They are called idle watchers because
		793	when the watcher is the highest priority pending event in the process, the
		794	process is considered to be idle at that priority.
		795
		796	If you want a watcher that is only ever called when I<no> other events are
		797	outstanding you have to set the priority to C<EV::MINPRI>.
566		798
567	The process will not block as long as any idle watchers are active, and	799	The process will not block as long as any idle watchers are active, and
568	they will be called repeatedly until stopped.	800	they will be called repeatedly until stopped.
569		801
		802	For example, if you have idle watchers at priority C<0> and C<1>, and
		803	an I/O watcher at priority C<0>, then the idle watcher at priority C<1>
		804	and the I/O watcher will always run when ready. Only when the idle watcher
		805	at priority C<1> is stopped and the I/O watcher at priority C<0> is not
		806	pending with the C<0>-priority idle watcher be invoked.
		807
570	The C<idle_ns> variant doesn't start (activate) the newly created watcher.	808	The C<idle_ns> variant doesn't start (activate) the newly created watcher.
571		809
572	=back	810	=back
573		811
574		812
…		…
577	=over 4	815	=over 4
578		816
579	=item $w = EV::prepare $callback	817	=item $w = EV::prepare $callback
580		818
581	=item $w = EV::prepare_ns $callback	819	=item $w = EV::prepare_ns $callback
		820
		821	=item $w = $loop->prepare ($callback)
		822
		823	=item $w = $loop->prepare_ns ($callback)
582		824
583	Call the callback just before the process would block. You can still	825	Call the callback just before the process would block. You can still
584	create/modify any watchers at this point.	826	create/modify any watchers at this point.
585		827
586	See the EV::check watcher, below, for explanations and an example.	828	See the EV::check watcher, below, for explanations and an example.
…		…
595	=over 4	837	=over 4
596		838
597	=item $w = EV::check $callback	839	=item $w = EV::check $callback
598		840
599	=item $w = EV::check_ns $callback	841	=item $w = EV::check_ns $callback
		842
		843	=item $w = $loop->check ($callback)
		844
		845	=item $w = $loop->check_ns ($callback)
600		846
601	Call the callback just after the process wakes up again (after it has	847	Call the callback just after the process wakes up again (after it has
602	gathered events), but before any other callbacks have been invoked.	848	gathered events), but before any other callbacks have been invoked.
603		849
604	This is used to integrate other event-based software into the EV	850	This is used to integrate other event-based software into the EV
…		…
614	or return;	860	or return;
615		861
616	# make the dispatcher handle any outstanding stuff	862	# make the dispatcher handle any outstanding stuff
617	... not shown	863	... not shown
618		864
619	# create an IO watcher for each and every socket	865	# create an I/O watcher for each and every socket
620	@snmp_watcher = (	866	@snmp_watcher = (
621	(map { EV::io $_, EV::READ, sub { } }	867	(map { EV::io $_, EV::READ, sub { } }
622	keys %{ $dispatcher->{_descriptors} }),	868	keys %{ $dispatcher->{_descriptors} }),
623		869
624	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]	870	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
…		…
646		892
647	The C<check_ns> variant doesn't start (activate) the newly created watcher.	893	The C<check_ns> variant doesn't start (activate) the newly created watcher.
648		894
649	=back	895	=back
650		896
651	=head3 STAT WATCHERS - did the file stats just change?
652		897
653	=over 4	898	=head3 FORK WATCHERS - the audacity to resume the event loop after a fork
654		899
655	=item $w = EV::stat $path, $interval, $callback	900	Fork watchers are called when a C<fork ()> was detected. The invocation
		901	is done before the event loop blocks next and before C<check> watchers
		902	are being called, and only in the child after the fork.
656		903
657	=item $w = EV::stat_ns $path, $interval, $callback	904	=over 4
658		905
659	Call the callback when a file status change has been detected on	906	=item $w = EV::fork $callback
660	C<$path>. The C<$path> does not need to exist, changing from "path exists"
661	to "path does not exist" is a status change like any other.
662		907
663	The C<$interval> is a recommended polling interval for systems where	908	=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		909
668	This watcher type is not meant for massive numbers of stat watchers,	910	=item $w = $loop->fork ($callback)
669	as even with OS-supported change notifications, this can be
670	resource-intensive.
671		911
		912	=item $w = $loop->fork_ns ($callback)
		913
		914	Call the callback before the event loop is resumed in the child process
		915	after a fork.
		916
672	The C<stat_ns> variant doesn't start (activate) the newly created watcher.	917	The C<fork_ns> variant doesn't start (activate) the newly created watcher.
673		918
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	919	=back
693		920
		921
		922	=head3 EMBED WATCHERS - when one backend isn't enough...
		923
		924	This is a rather advanced watcher type that lets you embed one event loop
		925	into another (currently only IO events are supported in the embedded
		926	loop, other types of watchers might be handled in a delayed or incorrect
		927	fashion and must not be used).
		928
		929	See the libev documentation at
		930	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
		931	for more details.
		932
		933	In short, this watcher is most useful on BSD systems without working
		934	kqueue to still be able to handle a large number of sockets:
		935
		936	my $socket_loop;
		937
		938	# check wether we use SELECT or POLL _and_ KQUEUE is supported
		939	if (
		940	(EV::backend & (EV::BACKEND_POLL \| EV::BACKEND_SELECT))
		941	&& (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
		942	) {
		943	# use kqueue for sockets
		944	$socket_loop = new EV::Loop EV::BACKEND_KQUEUE \| EV::FLAG_NOENV;
		945	}
		946
		947	# use the default loop otherwise
		948	$socket_loop \|\|= EV::default_loop;
		949
		950	=over 4
		951
		952	=item $w = EV::embed $otherloop, $callback
		953
		954	=item $w = EV::embed_ns $otherloop, $callback
		955
		956	=item $w = $loop->embed ($otherloop, $callback)
		957
		958	=item $w = $loop->embed_ns ($otherloop, $callback)
		959
		960	Call the callback when the embedded event loop (C<$otherloop>) has any
		961	I/O activity. The C<$callback> should alwas be specified as C<undef> in
		962	this version of EV, which means the embedded event loop will be managed
		963	automatically.
		964
		965	The C<embed_ns> variant doesn't start (activate) the newly created watcher.
		966
		967	=back
		968
		969
		970	=head1 PERL SIGNALS
		971
		972	While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour
		973	with EV is as the same as any other C library: Perl-signals will only be
		974	handled when Perl runs, which means your signal handler might be invoked
		975	only the next time an event callback is invoked.
		976
		977	The solution is to use EV signal watchers (see C<EV::signal>), which will
		978	ensure proper operations with regards to other event watchers.
		979
		980	If you cannot do this for whatever reason, you can also force a watcher
		981	to be called on every event loop iteration by installing a C<EV::check>
		982	watcher:
		983
		984	my $async_check = EV::check sub { };
		985
		986	This ensures that perl gets into control for a short time to handle any
		987	pending signals, and also ensures (slightly) slower overall operation.
694		988
695	=head1 THREADS	989	=head1 THREADS
696		990
697	Threads are not supported by this module in any way. Perl pseudo-threads	991	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	992	is evil stuff and must die. As soon as Perl gains real threads I will work
…		…
720	our $DIED = sub {	1014	our $DIED = sub {
721	warn "EV: error in callback (ignoring): $@";	1015	warn "EV: error in callback (ignoring): $@";
722	};	1016	};
723		1017
724	default_loop	1018	default_loop
725	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	1019	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
726		1020
727	1;	1021	1;
728		1022
729	=head1 SEE ALSO	1023	=head1 SEE ALSO
730		1024
731	L<EV::DNS>.	1025	L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as
		1026	event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
		1027	coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP).
732		1028
733	=head1 AUTHOR	1029	=head1 AUTHOR
734		1030
735	Marc Lehmann <schmorp@schmorp.de>	1031	Marc Lehmann <schmorp@schmorp.de>
736	http://home.schmorp.de/	1032	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 1.79 by root, Sat Dec 22 16:37:07 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 1.79 by root, Sat Dec 22 16:37:07 2007 UTC