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

Comparing EV/EV.pm (file contents):
Revision 1.55 by root, Tue Nov 27 08:11:52 2007 UTC vs.
Revision 1.83 by root, Mon Jan 28 12:24:05 2008 UTC

…		…
35	warn "sigquit received\n";	35	warn "sigquit received\n";
36	};	36	};
37		37
38	# CHILD/PID STATUS CHANGES	38	# CHILD/PID STATUS CHANGES
39		39
40	my $w = EV::child 666, sub {	40	my $w = EV::child 666, 0, sub {
41	my ($w, $revents) = @_;	41	my ($w, $revents) = @_;
42	my $status = $w->rstatus;	42	my $status = $w->rstatus;
43	};	43	};
44		44
45	# STAT CHANGES	45	# STAT CHANGES
…		…
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 = '3.0';
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
		160	=item EV::sleep $seconds
		161
		162	Block the process for the given number of (fractional) seconds.
		163
100	=item $time = EV::time	164	=item $time = EV::time
101		165
102	Returns the current time in (fractional) seconds since the epoch.	166	Returns the current time in (fractional) seconds since the epoch.
103		167
104	=item $time = EV::now	168	=item $time = EV::now
		169
		170	=item $time = $loop->now
105		171
106	Returns the time the last event loop iteration has been started. This	172	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	173	is the time that (relative) timers are based on, and refering to it is
108	usually faster then calling EV::time.	174	usually faster then calling EV::time.
109		175
110	=item $method = EV::method	176	=item $backend = EV::backend
		177
		178	=item $backend = $loop->backend
111		179
112	Returns an integer describing the backend used by libev (EV::METHOD_SELECT	180	Returns an integer describing the backend used by libev (EV::METHOD_SELECT
113	or EV::METHOD_EPOLL).	181	or EV::METHOD_EPOLL).
114		182
115	=item EV::loop [$flags]	183	=item EV::loop [$flags]
		184
		185	=item $loop->loop ([$flags])
116		186
117	Begin checking for events and calling callbacks. It returns when a	187	Begin checking for events and calling callbacks. It returns when a
118	callback calls EV::unloop.	188	callback calls EV::unloop.
119		189
120	The $flags argument can be one of the following:	190	The $flags argument can be one of the following:
…		…
123	EV::LOOP_ONESHOT block at most once (wait, but do not loop)	193	EV::LOOP_ONESHOT block at most once (wait, but do not loop)
124	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)	194	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
125		195
126	=item EV::unloop [$how]	196	=item EV::unloop [$how]
127		197
		198	=item $loop->unloop ([$how])
		199
128	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the	200	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the
129	innermost call to EV::loop return.	201	innermost call to EV::loop return.
130		202
131	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as	203	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as
132	fast as possible.	204	fast as possible.
133		205
		206	=item $count = EV::loop_count
		207
		208	=item $count = $loop->loop_count
		209
		210	Return the number of times the event loop has polled for new
		211	events. Sometiems useful as a generation counter.
		212
134	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)	213	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
		214
		215	=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
135		216
136	This function rolls together an I/O and a timer watcher for a single	217	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.	218	one-shot event without the need for managing a watcher object.
138		219
139	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>	220	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	226	If timeout is C<undef> or negative, then there will be no
146	timeout. Otherwise a EV::timer with this value will be started.	227	timeout. Otherwise a EV::timer with this value will be started.
147		228
148	When an error occurs or either the timeout or I/O watcher triggers, then	229	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	230	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>,	231	you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
151	C<EV::WRITE> and C<EV::TIMEOUT>).	232	C<EV::WRITE> and C<EV::TIMEOUT>).
152		233
153	EV::once doesn't return anything: the watchers stay active till either	234	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	235	of them triggers, then they will be stopped and freed, and the callback
155	invoked.	236	invoked.
156		237
157	=back	238	=item EV::feed_fd_event ($fd, $revents)
158		239
		240	=item $loop->feed_fd_event ($fd, $revents)
		241
		242	Feed an event on a file descriptor into EV. EV will react to this call as
		243	if the readyness notifications specified by C<$revents> (a combination of
		244	C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
		245
		246	=item EV::feed_signal_event ($signal)
		247
		248	Feed a signal event into EV. EV will react to this call as if the signal
		249	specified by C<$signal> had occured.
		250
		251	=item EV::set_io_collect_interval $time
		252
		253	=item $loop->set_io_collect_interval ($time)
		254
		255	=item EV::set_timeout_collect_interval $time
		256
		257	=item $loop->set_timeout_collect_interval ($time)
		258
		259	These advanced functions set the minimum block interval when polling for I/O events and the minimum
		260	wait interval for timer events. See the libev documentation at
		261	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> for
		262	a more detailed discussion.
		263
		264	=back
		265
		266
159	=head2 WATCHER OBJECTS	267	=head1 WATCHER OBJECTS
160		268
161	A watcher is an object that gets created to record your interest in some	269	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	270	event. For instance, if you want to wait for STDIN to become readable, you
163	would create an EV::io watcher for that:	271	would create an EV::io watcher for that:
164		272
165	my $watcher = EV::io *STDIN, EV::READ, sub {	273	my $watcher = EV::io *STDIN, EV::READ, sub {
166	my ($watcher, $revents) = @_;	274	my ($watcher, $revents) = @_;
167	warn "yeah, STDIN should not be readable without blocking!\n"	275	warn "yeah, STDIN should now be readable without blocking!\n"
168	};	276	};
169		277
170	All watchers can be active (waiting for events) or inactive (paused). Only	278	All watchers can be active (waiting for events) or inactive (paused). Only
171	active watchers will have their callbacks invoked. All callbacks will be	279	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	280	called with at least two arguments: the watcher and a bitmask of received
173	events.	281	events.
174		282
175	Each watcher type has its associated bit in revents, so you can use the	283	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	284	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,	285	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	286	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	287	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which
180	uses EV::TIMEOUT).	288	uses EV::TIMEOUT).
181		289
182	In the rare case where one wants to create a watcher but not start it at	290	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	291	the same time, each constructor has a variant with a trailing C<_ns> in
…		…
205		313
206	=item $w->stop	314	=item $w->stop
207		315
208	Stop a watcher if it is active. Also clear any pending events (events that	316	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),	317	have been received but that didn't yet result in a callback invocation),
210	regardless of wether the watcher was active or not.	318	regardless of whether the watcher was active or not.
211		319
212	=item $bool = $w->is_active	320	=item $bool = $w->is_active
213		321
214	Returns true if the watcher is active, false otherwise.	322	Returns true if the watcher is active, false otherwise.
215		323
…		…
245	The default priority of any newly-created watcher is 0.	353	The default priority of any newly-created watcher is 0.
246		354
247	Note that the priority semantics have not yet been fleshed out and are	355	Note that the priority semantics have not yet been fleshed out and are
248	subject to almost certain change.	356	subject to almost certain change.
249		357
250	=item $w->trigger ($revents)	358	=item $w->invoke ($revents)
251		359
252	Call the callback now with the given event mask.	360	Call the callback now with the given event mask.
		361
		362	=item $w->feed_event ($revents)
		363
		364	Feed some events on this watcher into EV. EV will react to this call as if
		365	the watcher had received the given C<$revents> mask.
		366
		367	=item $revents = $w->clear_pending
		368
		369	If the watcher is pending, this function clears its pending status and
		370	returns its C<$revents> bitset (as if its callback was invoked). If the
		371	watcher isn't pending it does nothing and returns C<0>.
253		372
254	=item $previous_state = $w->keepalive ($bool)	373	=item $previous_state = $w->keepalive ($bool)
255		374
256	Normally, C<EV::loop> will return when there are no active watchers	375	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	376	(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),	377	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	378	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 :).	379	finished (or they forgot to register some watchers for their task :).
261		380
262	Sometimes, however, this gets in your way, for example when you the module	381	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	382	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	383	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	384	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	385	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.	386	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.	389	though your watcher is active, it won't keep C<EV::loop> from returning.
271		390
272	The initial value for keepalive is true (enabled), and you cna change it	391	The initial value for keepalive is true (enabled), and you cna change it
273	any time.	392	any time.
274		393
275	Example: Register an IO watcher for some UDP socket but do not keep the	394	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.	395	event loop from running just because of that watcher.
277		396
278	my $udp_socket = ...	397	my $udp_socket = ...
279	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };	398	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
280	$udp_watcher->keepalive (0);	399	$1000udp_watcher->keepalive (0);
281		400
282	=back	401	=item $loop = $w->loop
283		402
		403	Return the loop that this watcher is attached to.
284		404
		405	=back
		406
		407
285	=head2 WATCHER TYPES	408	=head1 WATCHER TYPES
286		409
287	Each of the following subsections describes a single watcher type.	410	Each of the following subsections describes a single watcher type.
288		411
289	=head3 IO WATCHERS - is this file descriptor readable or writable?	412	=head3 I/O WATCHERS - is this file descriptor readable or writable?
290		413
291	=over 4	414	=over 4
292		415
293	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	416	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
294		417
295	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback	418	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
		419
		420	=item $w = $loop->io ($fileno_or_fh, $eventmask, $callback)
		421
		422	=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
296		423
297	As long as the returned watcher object is alive, call the C<$callback>	424	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.	425	when at least one of events specified in C<$eventmask> occurs.
299		426
300	The $eventmask can be one or more of these constants ORed together:	427	The $eventmask can be one or more of these constants ORed together:
…		…
329	=over 4	456	=over 4
330		457
331	=item $w = EV::timer $after, $repeat, $callback	458	=item $w = EV::timer $after, $repeat, $callback
332		459
333	=item $w = EV::timer_ns $after, $repeat, $callback	460	=item $w = EV::timer_ns $after, $repeat, $callback
		461
		462	=item $w = $loop->timer ($after, $repeat, $callback)
		463
		464	=item $w = $loop->timer_ns ($after, $repeat, $callback)
334		465
335	Calls the callback after C<$after> seconds (which may be fractional). If	466	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 $repeat	467	C<$repeat> is non-zero, the timer will be restarted (with the $repeat
337	value as $after) after the callback returns.	468	value as $after) after the callback returns.
338		469
…		…
379	=over 4	510	=over 4
380		511
381	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback	512	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
382		513
383	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback	514	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
		515
		516	=item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
		517
		518	=item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback)
384		519
385	Similar to EV::timer, but is not based on relative timeouts but on	520	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	521	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	522	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	523	more complex, cron-like, setups that are not adversely affected by time
…		…
463		598
464	=item $w->again	599	=item $w->again
465		600
466	Simply stops and starts the watcher again.	601	Simply stops and starts the watcher again.
467		602
		603	=item $time = $w->at
		604
		605	Return the time that the watcher is expected to trigger next.
		606
468	=back	607	=back
469		608
470		609
471	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!	610	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
472		611
…		…
505		644
506	=head3 CHILD WATCHERS - watch out for process status changes	645	=head3 CHILD WATCHERS - watch out for process status changes
507		646
508	=over 4	647	=over 4
509		648
510	=item $w = EV::child $pid, $callback	649	=item $w = EV::child $pid, $trace, $callback
511		650
512	=item $w = EV::child_ns $pid, $callback	651	=item $w = EV::child_ns $pid, $trace, $callback
513		652
		653	=item $w = $loop->child ($pid, $trace, $callback)
		654
		655	=item $w = $loop->child_ns ($pid, $trace, $callback)
		656
514	Call the callback when a status change for pid C<$pid> (or any pid if	657	Call the callback when a status change for pid C<$pid> (or any pid
515	C<$pid> is 0) has been received. More precisely: when the process receives	658	if C<$pid> is 0) has been received (a status change happens when the
		659	process terminates or is killed, or, when trace is true, additionally when
		660	it is stopped or continued). More precisely: when the process receives
516	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all	661	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
517	changed/zombie children and call the callback.	662	changed/zombie children and call the callback.
518		663
519	It is valid (and fully supported) to install a child watcher after a child	664	It is valid (and fully supported) to install a child watcher after a child
520	has exited but before the event loop has started its next iteration (for	665	has exited but before the event loop has started its next iteration (for
…		…
527	You can have as many pid watchers per pid as you want, they will all be	672	You can have as many pid watchers per pid as you want, they will all be
528	called.	673	called.
529		674
530	The C<child_ns> variant doesn't start (activate) the newly created watcher.	675	The C<child_ns> variant doesn't start (activate) the newly created watcher.
531		676
532	=item $w->set ($pid)	677	=item $w->set ($pid, $trace)
533		678
534	Reconfigures the watcher, see the constructor above for details. Can be called at	679	Reconfigures the watcher, see the constructor above for details. Can be called at
535	any time.	680	any time.
536		681
537	=item $current_pid = $w->pid	682	=item $current_pid = $w->pid
538		683
539	=item $old_pid = $w->pid ($new_pid)
540
541	Returns the previously set process id and optionally set a new one.	684	Returns the previously set process id and optionally set a new one.
542		685
543	=item $exit_status = $w->rstatus	686	=item $exit_status = $w->rstatus
544		687
545	Return the exit/wait status (as returned by waitpid, see the waitpid entry	688	Return the exit/wait status (as returned by waitpid, see the waitpid entry
…		…
551	watcher for all pids).	694	watcher for all pids).
552		695
553	=back	696	=back
554		697
555		698
		699	=head3 STAT WATCHERS - did the file attributes just change?
		700
		701	=over 4
		702
		703	=item $w = EV::stat $path, $interval, $callback
		704
		705	=item $w = EV::stat_ns $path, $interval, $callback
		706
		707	=item $w = $loop->stat ($path, $interval, $callback)
		708
		709	=item $w = $loop->stat_ns ($path, $interval, $callback)
		710
		711	Call the callback when a file status change has been detected on
		712	C<$path>. The C<$path> does not need to exist, changing from "path exists"
		713	to "path does not exist" is a status change like any other.
		714
		715	The C<$interval> is a recommended polling interval for systems where
		716	OS-supported change notifications don't exist or are not supported. If
		717	you use C<0> then an unspecified default is used (which is highly
		718	recommended!), which is to be expected to be around five seconds usually.
		719
		720	This watcher type is not meant for massive numbers of stat watchers,
		721	as even with OS-supported change notifications, this can be
		722	resource-intensive.
		723
		724	The C<stat_ns> variant doesn't start (activate) the newly created watcher.
		725
		726	=item ... = $w->stat
		727
		728	This call is very similar to the perl C<stat> built-in: It stats (using
		729	C<lstat>) the path specified in the watcher and sets perls stat cache (as
		730	well as EV's idea of the current stat values) to the values found.
		731
		732	In scalar context, a boolean is return indicating success or failure of
		733	the stat. In list context, the same 13-value list as with stat is returned
		734	(except that the blksize and blocks fields are not reliable).
		735
		736	In the case of an error, errno is set to C<ENOENT> (regardless of the
		737	actual error value) and the C<nlink> value is forced to zero (if the stat
		738	was successful then nlink is guaranteed to be non-zero).
		739
		740	See also the next two entries for more info.
		741
		742	=item ... = $w->attr
		743
		744	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		745	the values most recently detected by EV. See the next entry for more info.
		746
		747	=item ... = $w->prev
		748
		749	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		750	the previous set of values, before the change.
		751
		752	That is, when the watcher callback is invoked, C<< $w->prev >> will be set
		753	to the values found I<before> a change was detected, while C<< $w->attr >>
		754	returns the values found leading to the change detection. The difference (if any)
		755	between C<prev> and C<attr> is what triggered the callback.
		756
		757	If you did something to the filesystem object and do not want to trigger
		758	yet another change, you can call C<stat> to update EV's idea of what the
		759	current attributes are.
		760
		761	=item $w->set ($path, $interval)
		762
		763	Reconfigures the watcher, see the constructor above for details. Can be
		764	called at any time.
		765
		766	=item $current_path = $w->path
		767
		768	=item $old_path = $w->path ($new_path)
		769
		770	Returns the previously set path and optionally set a new one.
		771
		772	=item $current_interval = $w->interval
		773
		774	=item $old_interval = $w->interval ($new_interval)
		775
		776	Returns the previously set interval and optionally set a new one. Can be
		777	used to query the actual interval used.
		778
		779	=back
		780
		781
556	=head3 IDLE WATCHERS - when you've got nothing better to do...	782	=head3 IDLE WATCHERS - when you've got nothing better to do...
557		783
558	=over 4	784	=over 4
559		785
560	=item $w = EV::idle $callback	786	=item $w = EV::idle $callback
561		787
562	=item $w = EV::idle_ns $callback	788	=item $w = EV::idle_ns $callback
563		789
564	Call the callback when there are no pending io, timer/periodic, signal or	790	=item $w = $loop->idle ($callback)
565	child events, i.e. when the process is idle.	791
		792	=item $w = $loop->idle_ns ($callback)
		793
		794	Call the callback when there are no other pending watchers of the same or
		795	higher priority (excluding check, prepare and other idle watchers of the
		796	same or lower priority, of course). They are called idle watchers because
		797	when the watcher is the highest priority pending event in the process, the
		798	process is considered to be idle at that priority.
		799
		800	If you want a watcher that is only ever called when I<no> other events are
		801	outstanding you have to set the priority to C<EV::MINPRI>.
566		802
567	The process will not block as long as any idle watchers are active, and	803	The process will not block as long as any idle watchers are active, and
568	they will be called repeatedly until stopped.	804	they will be called repeatedly until stopped.
569		805
		806	For example, if you have idle watchers at priority C<0> and C<1>, and
		807	an I/O watcher at priority C<0>, then the idle watcher at priority C<1>
		808	and the I/O watcher will always run when ready. Only when the idle watcher
		809	at priority C<1> is stopped and the I/O watcher at priority C<0> is not
		810	pending with the C<0>-priority idle watcher be invoked.
		811
570	The C<idle_ns> variant doesn't start (activate) the newly created watcher.	812	The C<idle_ns> variant doesn't start (activate) the newly created watcher.
571		813
572	=back	814	=back
573		815
574		816
…		…
577	=over 4	819	=over 4
578		820
579	=item $w = EV::prepare $callback	821	=item $w = EV::prepare $callback
580		822
581	=item $w = EV::prepare_ns $callback	823	=item $w = EV::prepare_ns $callback
		824
		825	=item $w = $loop->prepare ($callback)
		826
		827	=item $w = $loop->prepare_ns ($callback)
582		828
583	Call the callback just before the process would block. You can still	829	Call the callback just before the process would block. You can still
584	create/modify any watchers at this point.	830	create/modify any watchers at this point.
585		831
586	See the EV::check watcher, below, for explanations and an example.	832	See the EV::check watcher, below, for explanations and an example.
…		…
595	=over 4	841	=over 4
596		842
597	=item $w = EV::check $callback	843	=item $w = EV::check $callback
598		844
599	=item $w = EV::check_ns $callback	845	=item $w = EV::check_ns $callback
		846
		847	=item $w = $loop->check ($callback)
		848
		849	=item $w = $loop->check_ns ($callback)
600		850
601	Call the callback just after the process wakes up again (after it has	851	Call the callback just after the process wakes up again (after it has
602	gathered events), but before any other callbacks have been invoked.	852	gathered events), but before any other callbacks have been invoked.
603		853
604	This is used to integrate other event-based software into the EV	854	This is used to integrate other event-based software into the EV
…		…
614	or return;	864	or return;
615		865
616	# make the dispatcher handle any outstanding stuff	866	# make the dispatcher handle any outstanding stuff
617	... not shown	867	... not shown
618		868
619	# create an IO watcher for each and every socket	869	# create an I/O watcher for each and every socket
620	@snmp_watcher = (	870	@snmp_watcher = (
621	(map { EV::io $_, EV::READ, sub { } }	871	(map { EV::io $_, EV::READ, sub { } }
622	keys %{ $dispatcher->{_descriptors} }),	872	keys %{ $dispatcher->{_descriptors} }),
623		873
624	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]	874	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
…		…
646		896
647	The C<check_ns> variant doesn't start (activate) the newly created watcher.	897	The C<check_ns> variant doesn't start (activate) the newly created watcher.
648		898
649	=back	899	=back
650		900
651	=head3 STAT WATCHERS - did the file attributes just change?
652		901
653	=over 4	902	=head3 FORK WATCHERS - the audacity to resume the event loop after a fork
654		903
655	=item $w = EV::stat $path, $interval, $callback	904	Fork watchers are called when a C<fork ()> was detected. The invocation
		905	is done before the event loop blocks next and before C<check> watchers
		906	are being called, and only in the child after the fork.
656		907
657	=item $w = EV::stat_ns $path, $interval, $callback	908	=over 4
658		909
659	Call the callback when a file status change has been detected on	910	=item $w = EV::fork $callback
660	C<$path>. The C<$path> does not need to exist, changing from "path exists"
661	to "path does not exist" is a status change like any other.
662		911
663	The C<$interval> is a recommended polling interval for systems where	912	=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		913
668	This watcher type is not meant for massive numbers of stat watchers,	914	=item $w = $loop->fork ($callback)
669	as even with OS-supported change notifications, this can be
670	resource-intensive.
671		915
		916	=item $w = $loop->fork_ns ($callback)
		917
		918	Call the callback before the event loop is resumed in the child process
		919	after a fork.
		920
672	The C<stat_ns> variant doesn't start (activate) the newly created watcher.	921	The C<fork_ns> variant doesn't start (activate) the newly created watcher.
673		922
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	923	=back
693		924
		925
		926	=head3 EMBED WATCHERS - when one backend isn't enough...
		927
		928	This is a rather advanced watcher type that lets you embed one event loop
		929	into another (currently only IO events are supported in the embedded
		930	loop, other types of watchers might be handled in a delayed or incorrect
		931	fashion and must not be used).
		932
		933	See the libev documentation at
		934	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
		935	for more details.
		936
		937	In short, this watcher is most useful on BSD systems without working
		938	kqueue to still be able to handle a large number of sockets:
		939
		940	my $socket_loop;
		941
		942	# check wether we use SELECT or POLL _and_ KQUEUE is supported
		943	if (
		944	(EV::backend & (EV::BACKEND_POLL \| EV::BACKEND_SELECT))
		945	&& (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
		946	) {
		947	# use kqueue for sockets
		948	$socket_loop = new EV::Loop EV::BACKEND_KQUEUE \| EV::FLAG_NOENV;
		949	}
		950
		951	# use the default loop otherwise
		952	$socket_loop \|\|= EV::default_loop;
		953
		954	=over 4
		955
		956	=item $w = EV::embed $otherloop, $callback
		957
		958	=item $w = EV::embed_ns $otherloop, $callback
		959
		960	=item $w = $loop->embed ($otherloop, $callback)
		961
		962	=item $w = $loop->embed_ns ($otherloop, $callback)
		963
		964	Call the callback when the embedded event loop (C<$otherloop>) has any
		965	I/O activity. The C<$callback> should alwas be specified as C<undef> in
		966	this version of EV, which means the embedded event loop will be managed
		967	automatically.
		968
		969	The C<embed_ns> variant doesn't start (activate) the newly created watcher.
		970
		971	=back
		972
		973
		974	=head1 PERL SIGNALS
		975
		976	While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour
		977	with EV is as the same as any other C library: Perl-signals will only be
		978	handled when Perl runs, which means your signal handler might be invoked
		979	only the next time an event callback is invoked.
		980
		981	The solution is to use EV signal watchers (see C<EV::signal>), which will
		982	ensure proper operations with regards to other event watchers.
		983
		984	If you cannot do this for whatever reason, you can also force a watcher
		985	to be called on every event loop iteration by installing a C<EV::check>
		986	watcher:
		987
		988	my $async_check = EV::check sub { };
		989
		990	This ensures that perl gets into control for a short time to handle any
		991	pending signals, and also ensures (slightly) slower overall operation.
694		992
695	=head1 THREADS	993	=head1 THREADS
696		994
697	Threads are not supported by this module in any way. Perl pseudo-threads	995	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	996	is evil stuff and must die. As soon as Perl gains real threads I will work
…		…
720	our $DIED = sub {	1018	our $DIED = sub {
721	warn "EV: error in callback (ignoring): $@";	1019	warn "EV: error in callback (ignoring): $@";
722	};	1020	};
723		1021
724	default_loop	1022	default_loop
725	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	1023	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
726		1024
727	1;	1025	1;
728		1026
729	=head1 SEE ALSO	1027	=head1 SEE ALSO
730		1028
731	L<EV::DNS>.	1029	L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as
		1030	event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
		1031	coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP).
732		1032
733	=head1 AUTHOR	1033	=head1 AUTHOR
734		1034
735	Marc Lehmann <schmorp@schmorp.de>	1035	Marc Lehmann <schmorp@schmorp.de>
736	http://home.schmorp.de/	1036	http://home.schmorp.de/

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Comparing EV/EV.pm (file contents): Revision 1.55 by root, Tue Nov 27 08:11:52 2007 UTC vs. Revision 1.83 by root, Mon Jan 28 12:24:05 2008 UTC

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Comparing EV/EV.pm (file contents):
Revision 1.55 by root, Tue Nov 27 08:11:52 2007 UTC vs.
Revision 1.83 by root, Mon Jan 28 12:24:05 2008 UTC