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

Comparing EV/EV.pm (file contents):
Revision 1.56 by root, Tue Nov 27 10:59:10 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 =
…		…
85	@EV::Check::ISA =	86	@EV::Check::ISA =
86	@EV::Embed::ISA =	87	@EV::Embed::ISA =
87	@EV::Fork::ISA =	88	@EV::Fork::ISA =
88	"EV::Watcher";	89	"EV::Watcher";
89		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
		137
90	=head1 BASIC INTERFACE	138	=head1 BASIC INTERFACE
91		139
92	=over 4	140	=over 4
93		141
94	=item $EV::DIED	142	=item $EV::DIED
95		143
96	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
97	throws an exception (with $@ containing thr error). The default prints an	145	throws an exception (with $@ containing the error). The default prints an
98	informative message and continues.	146	informative message and continues.
99		147
100	If this callback throws an exception it will be silently ignored.	148	If this callback throws an exception it will be silently ignored.
101		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
102	=item $time = EV::time	160	=item $time = EV::time
103		161
104	Returns the current time in (fractional) seconds since the epoch.	162	Returns the current time in (fractional) seconds since the epoch.
105		163
106	=item $time = EV::now	164	=item $time = EV::now
		165
		166	=item $time = $loop->now
107		167
108	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
109	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
110	usually faster then calling EV::time.	170	usually faster then calling EV::time.
111		171
112	=item $method = EV::method	172	=item $backend = EV::backend
		173
		174	=item $backend = $loop->backend
113		175
114	Returns an integer describing the backend used by libev (EV::METHOD_SELECT	176	Returns an integer describing the backend used by libev (EV::METHOD_SELECT
115	or EV::METHOD_EPOLL).	177	or EV::METHOD_EPOLL).
116		178
117	=item EV::loop [$flags]	179	=item EV::loop [$flags]
		180
		181	=item $loop->loop ([$flags])
118		182
119	Begin checking for events and calling callbacks. It returns when a	183	Begin checking for events and calling callbacks. It returns when a
120	callback calls EV::unloop.	184	callback calls EV::unloop.
121		185
122	The $flags argument can be one of the following:	186	The $flags argument can be one of the following:
…		…
125	EV::LOOP_ONESHOT block at most once (wait, but do not loop)	189	EV::LOOP_ONESHOT block at most once (wait, but do not loop)
126	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)	190	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
127		191
128	=item EV::unloop [$how]	192	=item EV::unloop [$how]
129		193
		194	=item $loop->unloop ([$how])
		195
130	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
131	innermost call to EV::loop return.	197	innermost call to EV::loop return.
132		198
133	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
134	fast as possible.	200	fast as possible.
135		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
136	=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))
137		212
138	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
139	one-shot event without the need for managing a watcher object.	214	one-shot event without the need for managing a watcher object.
140		215
141	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>
…		…
147	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
148	timeout. Otherwise a EV::timer with this value will be started.	223	timeout. Otherwise a EV::timer with this value will be started.
149		224
150	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
151	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
152	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>,
153	C<EV::WRITE> and C<EV::TIMEOUT>).	228	C<EV::WRITE> and C<EV::TIMEOUT>).
154		229
155	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
156	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
157	invoked.	232	invoked.
158		233
159	=back	234	=item EV::feed_fd_event ($fd, $revents)
160		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
161	=head2 WATCHER OBJECTS	263	=head1 WATCHER OBJECTS
162		264
163	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
164	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
165	would create an EV::io watcher for that:	267	would create an EV::io watcher for that:
166		268
167	my $watcher = EV::io *STDIN, EV::READ, sub {	269	my $watcher = EV::io *STDIN, EV::READ, sub {
168	my ($watcher, $revents) = @_;	270	my ($watcher, $revents) = @_;
169	warn "yeah, STDIN should not be readable without blocking!\n"	271	warn "yeah, STDIN should now be readable without blocking!\n"
170	};	272	};
171		273
172	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
173	active watchers will have their callbacks invoked. All callbacks will be	275	active watchers will have their callbacks invoked. All callbacks will be
174	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
175	events.	277	events.
176		278
177	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
178	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
179	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,
180	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
181	(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
182	uses EV::TIMEOUT).	284	uses EV::TIMEOUT).
183		285
184	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
185	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
…		…
207		309
208	=item $w->stop	310	=item $w->stop
209		311
210	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
211	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),
212	regardless of wether the watcher was active or not.	314	regardless of whether the watcher was active or not.
213		315
214	=item $bool = $w->is_active	316	=item $bool = $w->is_active
215		317
216	Returns true if the watcher is active, false otherwise.	318	Returns true if the watcher is active, false otherwise.
217		319
…		…
247	The default priority of any newly-created watcher is 0.	349	The default priority of any newly-created watcher is 0.
248		350
249	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
250	subject to almost certain change.	352	subject to almost certain change.
251		353
252	=item $w->trigger ($revents)	354	=item $w->invoke ($revents)
253		355
254	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>.
255		368
256	=item $previous_state = $w->keepalive ($bool)	369	=item $previous_state = $w->keepalive ($bool)
257		370
258	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
259	(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
260	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),
261	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
262	finished (or they forgot to register some watchers for their task :).	375	finished (or they forgot to register some watchers for their task :).
263		376
264	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
265	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
266	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
267	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
268	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
269	because you happen to have this long-running UDP port watcher.	382	because you happen to have this long-running UDP port watcher.
…		…
272	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.
273		386
274	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
275	any time.	388	any time.
276		389
277	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
278	event loop from running just because of that watcher.	391	event loop from running just because of that watcher.
279		392
280	my $udp_socket = ...	393	my $udp_socket = ...
281	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };	394	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
282	$udp_watcher->keepalive (0);	395	$1000udp_watcher->keepalive (0);
283		396
284	=back	397	=item $loop = $w->loop
285		398
		399	Return the loop that this watcher is attached to.
286		400
		401	=back
		402
		403
287	=head2 WATCHER TYPES	404	=head1 WATCHER TYPES
288		405
289	Each of the following subsections describes a single watcher type.	406	Each of the following subsections describes a single watcher type.
290		407
291	=head3 IO WATCHERS - is this file descriptor readable or writable?	408	=head3 I/O WATCHERS - is this file descriptor readable or writable?
292		409
293	=over 4	410	=over 4
294		411
295	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	412	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
296		413
297	=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, $callback)
298		419
299	As long as the returned watcher object is alive, call the C<$callback>	420	As long as the returned watcher object is alive, call the C<$callback>
300	when at least one of events specified in C<$eventmask> occurs.	421	when at least one of events specified in C<$eventmask> occurs.
301		422
302	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:
…		…
331	=over 4	452	=over 4
332		453
333	=item $w = EV::timer $after, $repeat, $callback	454	=item $w = EV::timer $after, $repeat, $callback
334		455
335	=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, $callback)
336		461
337	Calls the callback after C<$after> seconds (which may be fractional). If	462	Calls the callback after C<$after> seconds (which may be fractional). If
338	C<$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
339	value as $after) after the callback returns.	464	value as $after) after the callback returns.
340		465
…		…
381	=over 4	506	=over 4
382		507
383	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback	508	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
384		509
385	=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)
386		515
387	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
388	absolute times. Apart from creating "simple" timers that trigger "at" the	517	absolute times. Apart from creating "simple" timers that trigger "at" the
389	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
390	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
…		…
465		594
466	=item $w->again	595	=item $w->again
467		596
468	Simply stops and starts the watcher again.	597	Simply stops and starts the watcher again.
469		598
		599	=item $time = $w->at
		600
		601	Return the time that the watcher is expected to trigger next.
		602
470	=back	603	=back
471		604
472		605
473	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!	606	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
474		607
…		…
511		644
512	=item $w = EV::child $pid, $callback	645	=item $w = EV::child $pid, $callback
513		646
514	=item $w = EV::child_ns $pid, $callback	647	=item $w = EV::child_ns $pid, $callback
515		648
		649	=item $w = $loop->child ($pid, $callback)
		650
		651	=item $w = $loop->child_ns ($pid, $callback)
		652
516	Call the callback when a status change for pid C<$pid> (or any pid if	653	Call the callback when a status change for pid C<$pid> (or any pid if
517	C<$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
518	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
519	changed/zombie children and call the callback.	656	changed/zombie children and call the callback.
520		657
…		…
561		698
562	=item $w = EV::stat $path, $interval, $callback	699	=item $w = EV::stat $path, $interval, $callback
563		700
564	=item $w = EV::stat_ns $path, $interval, $callback	701	=item $w = EV::stat_ns $path, $interval, $callback
565		702
		703	=item $w = $loop->stat ($path, $interval, $callback)
		704
		705	=item $w = $loop->stat_ns ($path, $interval, $callback)
		706
566	Call the callback when a file status change has been detected on	707	Call the callback when a file status change has been detected on
567	C<$path>. The C<$path> does not need to exist, changing from "path exists"	708	C<$path>. The C<$path> does not need to exist, changing from "path exists"
568	to "path does not exist" is a status change like any other.	709	to "path does not exist" is a status change like any other.
569		710
570	The C<$interval> is a recommended polling interval for systems where	711	The C<$interval> is a recommended polling interval for systems where
…		…
576	as even with OS-supported change notifications, this can be	717	as even with OS-supported change notifications, this can be
577	resource-intensive.	718	resource-intensive.
578		719
579	The C<stat_ns> variant doesn't start (activate) the newly created watcher.	720	The C<stat_ns> variant doesn't start (activate) the newly created watcher.
580		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
581	=item $w->set ($path, $interval)	757	=item $w->set ($path, $interval)
582		758
583	Reconfigures the watcher, see the constructor above for details. Can be	759	Reconfigures the watcher, see the constructor above for details. Can be
584	called at any time.	760	called at any time.
585		761
…		…
605		781
606	=item $w = EV::idle $callback	782	=item $w = EV::idle $callback
607		783
608	=item $w = EV::idle_ns $callback	784	=item $w = EV::idle_ns $callback
609		785
610	Call the callback when there are no pending io, timer/periodic, signal or	786	=item $w = $loop->idle ($callback)
611	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>.
612		798
613	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
614	they will be called repeatedly until stopped.	800	they will be called repeatedly until stopped.
615		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
616	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.
617		809
618	=back	810	=back
619		811
620		812
…		…
623	=over 4	815	=over 4
624		816
625	=item $w = EV::prepare $callback	817	=item $w = EV::prepare $callback
626		818
627	=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)
628		824
629	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
630	create/modify any watchers at this point.	826	create/modify any watchers at this point.
631		827
632	See the EV::check watcher, below, for explanations and an example.	828	See the EV::check watcher, below, for explanations and an example.
…		…
641	=over 4	837	=over 4
642		838
643	=item $w = EV::check $callback	839	=item $w = EV::check $callback
644		840
645	=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)
646		846
647	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
648	gathered events), but before any other callbacks have been invoked.	848	gathered events), but before any other callbacks have been invoked.
649		849
650	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
…		…
660	or return;	860	or return;
661		861
662	# make the dispatcher handle any outstanding stuff	862	# make the dispatcher handle any outstanding stuff
663	... not shown	863	... not shown
664		864
665	# create an IO watcher for each and every socket	865	# create an I/O watcher for each and every socket
666	@snmp_watcher = (	866	@snmp_watcher = (
667	(map { EV::io $_, EV::READ, sub { } }	867	(map { EV::io $_, EV::READ, sub { } }
668	keys %{ $dispatcher->{_descriptors} }),	868	keys %{ $dispatcher->{_descriptors} }),
669		869
670	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]	870	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
…		…
705		905
706	=item $w = EV::fork $callback	906	=item $w = EV::fork $callback
707		907
708	=item $w = EV::fork_ns $callback	908	=item $w = EV::fork_ns $callback
709		909
		910	=item $w = $loop->fork ($callback)
		911
		912	=item $w = $loop->fork_ns ($callback)
		913
710	Call the callback before the event loop is resumed in the child process	914	Call the callback before the event loop is resumed in the child process
711	after a fork.	915	after a fork.
712		916
713	The C<fork_ns> variant doesn't start (activate) the newly created watcher.	917	The C<fork_ns> variant doesn't start (activate) the newly created watcher.
714		918
715	=back	919	=back
716		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.
717		988
718	=head1 THREADS	989	=head1 THREADS
719		990
720	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
721	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
…		…
743	our $DIED = sub {	1014	our $DIED = sub {
744	warn "EV: error in callback (ignoring): $@";	1015	warn "EV: error in callback (ignoring): $@";
745	};	1016	};
746		1017
747	default_loop	1018	default_loop
748	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	1019	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
749		1020
750	1;	1021	1;
751		1022
752	=head1 SEE ALSO	1023	=head1 SEE ALSO
753		1024
754	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).
755		1028
756	=head1 AUTHOR	1029	=head1 AUTHOR
757		1030
758	Marc Lehmann <schmorp@schmorp.de>	1031	Marc Lehmann <schmorp@schmorp.de>
759	http://home.schmorp.de/	1032	http://home.schmorp.de/

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Comparing EV/EV.pm (file contents): Revision 1.56 by root, Tue Nov 27 10:59:10 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 1.56 by root, Tue Nov 27 10:59:10 2007 UTC vs.
Revision 1.79 by root, Sat Dec 22 16:37:07 2007 UTC