[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 1.98 by root, Sat May 31 23:17:50 2008 UTC

…		…
2		2
3	EV - perl interface to libev, a high performance full-featured event loop	3	EV - perl interface to libev, a high performance full-featured event loop
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	use EV;	7	use EV;
		8
		9	# TIMERS
		10
		11	my $w = EV::timer 2, 0, sub {
		12	warn "is called after 2s";
		13	};
		14
		15	my $w = EV::timer 2, 2, sub {
		16	warn "is called roughly every 2s (repeat = 2)";
		17	};
		18
		19	undef $w; # destroy event watcher again
		20
		21	my $w = EV::periodic 0, 60, 0, sub {
		22	warn "is called every minute, on the minute, exactly";
		23	};
		24
		25	# IO
		26
		27	my $w = EV::io *STDIN, EV::READ, sub {
		28	my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
		29	warn "stdin is readable, you entered: ", <STDIN>;
		30	};
		31
		32	# SIGNALS
		33
		34	my $w = EV::signal 'QUIT', sub {
		35	warn "sigquit received\n";
		36	};
		37
		38	# CHILD/PID STATUS CHANGES
8		39
9	# TIMERS	40	my $w = EV::child 666, 0, sub {
		41	my ($w, $revents) = @_;
		42	my $status = $w->rstatus;
		43	};
10		44
11	my $w = EV::timer 2, 0, sub {
12	warn "is called after 2s";
13	};
14
15	my $w = EV::timer 2, 2, sub {
16	warn "is called roughly every 2s (repeat = 2)";
17	};
18
19	undef $w; # destroy event watcher again
20
21	my $w = EV::periodic 0, 60, 0, sub {
22	warn "is called every minute, on the minute, exactly";
23	};
24
25	# IO
26
27	my $w = EV::io *STDIN, EV::READ, sub {
28	my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
29	warn "stdin is readable, you entered: ", <STDIN>;
30	};
31
32	# SIGNALS
33
34	my $w = EV::signal 'QUIT', sub {
35	warn "sigquit received\n";
36	};
37
38	# CHILD/PID STATUS CHANGES
39
40	my $w = EV::child 666, sub {
41	my ($w, $revents) = @_;
42	my $status = $w->rstatus;
43	};
44
45	# STAT CHANGES	45	# STAT CHANGES
46	my $w = EV::stat "/etc/passwd", 10, sub {	46	my $w = EV::stat "/etc/passwd", 10, sub {
47	my ($w, $revents) = @_;	47	my ($w, $revents) = @_;
48	warn $w->path, " has changed somehow.\n";	48	warn $w->path, " has changed somehow.\n";
49	};	49	};
50		50
51	# MAINLOOP	51	# MAINLOOP
52	EV::loop; # loop until EV::unloop is called or all watchers stop	52	EV::loop; # loop until EV::unloop is called or all watchers stop
53	EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled	53	EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled
54	EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block	54	EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block
55		55
56	=head1 DESCRIPTION	56	=head1 DESCRIPTION
57		57
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://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod>) for more
62	watcher semantics or some discussion on the available backends, or how to	62	subtle details on watcher semantics or some discussion on the available
63	force a specific backend with C<LIBEV_FLAGS>.	63	backends, or how to force a specific backend with C<LIBEV_FLAGS>, or just
		64	about in any case because it has much more detailed information.
		65
		66	This module is very fast and scalable. It is actually so fast that you
		67	can use it through the L<AnyEvent> module, stay portable to other event
		68	loops (if you don't rely on any watcher types not available through it)
		69	and still be faster than with any other event loop currently supported in
		70	Perl.
64		71
65	=cut	72	=cut
66		73
67	package EV;	74	package EV;
68		75
69	use strict;	76	use strict;
70		77
71	BEGIN {	78	BEGIN {
72	our $VERSION = '1.4';	79	our $VERSION = '3.42';
73	use XSLoader;	80	use XSLoader;
74	XSLoader::load "EV", $VERSION;	81	XSLoader::load "EV", $VERSION;
75	}	82	}
76		83
77	@EV::IO::ISA =	84	@EV::IO::ISA =
78	@EV::Timer::ISA =	85	@EV::Timer::ISA =
79	@EV::Periodic::ISA =	86	@EV::Periodic::ISA =
80	@EV::Signal::ISA =	87	@EV::Signal::ISA =
		88	@EV::Child::ISA =
		89	@EV::Stat::ISA =
81	@EV::Idle::ISA =	90	@EV::Idle::ISA =
82	@EV::Prepare::ISA =	91	@EV::Prepare::ISA =
83	@EV::Check::ISA =	92	@EV::Check::ISA =
84	@EV::Child::ISA =
85	@EV::Embed::ISA =	93	@EV::Embed::ISA =
86	@EV::Stat::ISA = "EV::Watcher";	94	@EV::Fork::ISA =
		95	@EV::Async::ISA =
		96	"EV::Watcher";
		97
		98	@EV::Loop::Default::ISA = "EV::Loop";
		99
		100	=head1 EVENT LOOPS
		101
		102	EV supports multiple event loops: There is a single "default event loop"
		103	that can handle everything including signals and child watchers, and any
		104	number of "dynamic event loops" that can use different backends (with
		105	various limitations), but no child and signal watchers.
		106
		107	You do not have to do anything to create the default event loop: When
		108	the module is loaded a suitable backend is selected on the premise of
		109	selecting a working backend (which for example rules out kqueue on most
		110	BSDs). Modules should, unless they have "special needs" always use the
		111	default loop as this is fastest (perl-wise), best supported by other
		112	modules (e.g. AnyEvent or Coro) and most portable event loop.
		113
		114	For specific programs you can create additional event loops dynamically.
		115
		116	=over 4
		117
		118	=item $loop = new EV::loop [$flags]
		119
		120	Create a new event loop as per the specified flags. Please refer to the
		121	C<ev_loop_new ()> function description in the libev documentation
		122	(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>)
		123	for more info.
		124
		125	The loop will automatically be destroyed when it is no longer referenced
		126	by any watcher and the loop object goes out of scope.
		127
		128	Using C<EV::FLAG_FORKCHECK> is recommended, as only the default event loop
		129	is protected by this module.
		130
		131	=item $loop->loop_fork
		132
		133	Must be called after a fork in the child, before entering or continuing
		134	the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
		135	this function automatically, at some performance loss (refer to the libev
		136	documentation).
		137
		138	=item $loop->loop_verify
		139
		140	Calls C<ev_verify> to make internal consistency checks (for debugging
		141	libev) and abort the program if any data structures wree found to be
		142	corrupted.
		143
		144	=item $loop = EV::default_loop [$flags]
		145
		146	Return the default loop (which is a singleton object). Since this module
		147	already creates the default loop with default flags, specifying flags here
		148	will not have any effect unless you destroy the default loop.
		149
		150	=back
		151
87		152
88	=head1 BASIC INTERFACE	153	=head1 BASIC INTERFACE
89		154
90	=over 4	155	=over 4
91		156
92	=item $EV::DIED	157	=item $EV::DIED
93		158
94	Must contain a reference to a function that is called when a callback	159	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	160	throws an exception (with $@ containing the error). The default prints an
96	informative message and continues.	161	informative message and continues.
97		162
98	If this callback throws an exception it will be silently ignored.	163	If this callback throws an exception it will be silently ignored.
99		164
		165	=item $flags = EV::supported_backends
		166
		167	=item $flags = EV::recommended_backends
		168
		169	=item $flags = EV::embeddable_backends
		170
		171	Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this
		172	instance of EV, the set of recommended backends (supposed to be good) for
		173	this platform and the set of embeddable backends (see EMBED WATCHERS).
		174
		175	=item EV::sleep $seconds
		176
		177	Block the process for the given number of (fractional) seconds.
		178
100	=item $time = EV::time	179	=item $time = EV::time
101		180
102	Returns the current time in (fractional) seconds since the epoch.	181	Returns the current time in (fractional) seconds since the epoch.
103		182
104	=item $time = EV::now	183	=item $time = EV::now
		184
		185	=item $time = $loop->now
105		186
106	Returns the time the last event loop iteration has been started. This	187	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	188	is the time that (relative) timers are based on, and refering to it is
108	usually faster then calling EV::time.	189	usually faster then calling EV::time.
109		190
110	=item $method = EV::method	191	=item $backend = EV::backend
		192
		193	=item $backend = $loop->backend
111		194
112	Returns an integer describing the backend used by libev (EV::METHOD_SELECT	195	Returns an integer describing the backend used by libev (EV::METHOD_SELECT
113	or EV::METHOD_EPOLL).	196	or EV::METHOD_EPOLL).
114		197
115	=item EV::loop [$flags]	198	=item EV::loop [$flags]
		199
		200	=item $loop->loop ([$flags])
116		201
117	Begin checking for events and calling callbacks. It returns when a	202	Begin checking for events and calling callbacks. It returns when a
118	callback calls EV::unloop.	203	callback calls EV::unloop.
119		204
120	The $flags argument can be one of the following:	205	The $flags argument can be one of the following:
…		…
123	EV::LOOP_ONESHOT block at most once (wait, but do not loop)	208	EV::LOOP_ONESHOT block at most once (wait, but do not loop)
124	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)	209	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
125		210
126	=item EV::unloop [$how]	211	=item EV::unloop [$how]
127		212
		213	=item $loop->unloop ([$how])
		214
128	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the	215	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the
129	innermost call to EV::loop return.	216	innermost call to EV::loop return.
130		217
131	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as	218	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as
132	fast as possible.	219	fast as possible.
133		220
		221	=item $count = EV::loop_count
		222
		223	=item $count = $loop->loop_count
		224
		225	Return the number of times the event loop has polled for new
		226	events. Sometiems useful as a generation counter.
		227
134	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)	228	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
		229
		230	=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
135		231
136	This function rolls together an I/O and a timer watcher for a single	232	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.	233	one-shot event without the need for managing a watcher object.
138		234
139	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>	235	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	241	If timeout is C<undef> or negative, then there will be no
146	timeout. Otherwise a EV::timer with this value will be started.	242	timeout. Otherwise a EV::timer with this value will be started.
147		243
148	When an error occurs or either the timeout or I/O watcher triggers, then	244	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	245	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>,	246	you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
151	C<EV::WRITE> and C<EV::TIMEOUT>).	247	C<EV::WRITE> and C<EV::TIMEOUT>).
152		248
153	EV::once doesn't return anything: the watchers stay active till either	249	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	250	of them triggers, then they will be stopped and freed, and the callback
155	invoked.	251	invoked.
156		252
157	=back	253	=item EV::feed_fd_event ($fd, $revents)
158		254
		255	=item $loop->feed_fd_event ($fd, $revents)
		256
		257	Feed an event on a file descriptor into EV. EV will react to this call as
		258	if the readyness notifications specified by C<$revents> (a combination of
		259	C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
		260
		261	=item EV::feed_signal_event ($signal)
		262
		263	Feed a signal event into EV. EV will react to this call as if the signal
		264	specified by C<$signal> had occured.
		265
		266	=item EV::set_io_collect_interval $time
		267
		268	=item $loop->set_io_collect_interval ($time)
		269
		270	=item EV::set_timeout_collect_interval $time
		271
		272	=item $loop->set_timeout_collect_interval ($time)
		273
		274	These advanced functions set the minimum block interval when polling for I/O events and the minimum
		275	wait interval for timer events. See the libev documentation at
		276	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> for
		277	a more detailed discussion.
		278
		279	=back
		280
		281
159	=head2 WATCHER OBJECTS	282	=head1 WATCHER OBJECTS
160		283
161	A watcher is an object that gets created to record your interest in some	284	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	285	event. For instance, if you want to wait for STDIN to become readable, you
163	would create an EV::io watcher for that:	286	would create an EV::io watcher for that:
164		287
165	my $watcher = EV::io *STDIN, EV::READ, sub {	288	my $watcher = EV::io *STDIN, EV::READ, sub {
166	my ($watcher, $revents) = @_;	289	my ($watcher, $revents) = @_;
167	warn "yeah, STDIN should not be readable without blocking!\n"	290	warn "yeah, STDIN should now be readable without blocking!\n"
168	};	291	};
169		292
170	All watchers can be active (waiting for events) or inactive (paused). Only	293	All watchers can be active (waiting for events) or inactive (paused). Only
171	active watchers will have their callbacks invoked. All callbacks will be	294	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	295	called with at least two arguments: the watcher and a bitmask of received
173	events.	296	events.
174		297
175	Each watcher type has its associated bit in revents, so you can use the	298	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	299	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,	300	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	301	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	302	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which
180	uses EV::TIMEOUT).	303	uses EV::TIMEOUT).
181		304
182	In the rare case where one wants to create a watcher but not start it at	305	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	306	the same time, each constructor has a variant with a trailing C<_ns> in
…		…
205		328
206	=item $w->stop	329	=item $w->stop
207		330
208	Stop a watcher if it is active. Also clear any pending events (events that	331	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),	332	have been received but that didn't yet result in a callback invocation),
210	regardless of wether the watcher was active or not.	333	regardless of whether the watcher was active or not.
211		334
212	=item $bool = $w->is_active	335	=item $bool = $w->is_active
213		336
214	Returns true if the watcher is active, false otherwise.	337	Returns true if the watcher is active, false otherwise.
215		338
…		…
245	The default priority of any newly-created watcher is 0.	368	The default priority of any newly-created watcher is 0.
246		369
247	Note that the priority semantics have not yet been fleshed out and are	370	Note that the priority semantics have not yet been fleshed out and are
248	subject to almost certain change.	371	subject to almost certain change.
249		372
250	=item $w->trigger ($revents)	373	=item $w->invoke ($revents)
251		374
252	Call the callback now with the given event mask.	375	Call the callback now with the given event mask.
		376
		377	=item $w->feed_event ($revents)
		378
		379	Feed some events on this watcher into EV. EV will react to this call as if
		380	the watcher had received the given C<$revents> mask.
		381
		382	=item $revents = $w->clear_pending
		383
		384	If the watcher is pending, this function clears its pending status and
		385	returns its C<$revents> bitset (as if its callback was invoked). If the
		386	watcher isn't pending it does nothing and returns C<0>.
253		387
254	=item $previous_state = $w->keepalive ($bool)	388	=item $previous_state = $w->keepalive ($bool)
255		389
256	Normally, C<EV::loop> will return when there are no active watchers	390	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	391	(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),	392	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	393	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 :).	394	finished (or they forgot to register some watchers for their task :).
261		395
262	Sometimes, however, this gets in your way, for example when you the module	396	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	397	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	398	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	399	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	400	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.	401	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.	404	though your watcher is active, it won't keep C<EV::loop> from returning.
271		405
272	The initial value for keepalive is true (enabled), and you cna change it	406	The initial value for keepalive is true (enabled), and you cna change it
273	any time.	407	any time.
274		408
275	Example: Register an IO watcher for some UDP socket but do not keep the	409	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.	410	event loop from running just because of that watcher.
277		411
278	my $udp_socket = ...	412	my $udp_socket = ...
279	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };	413	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
280	$udp_watcher->keepalive (0);	414	$udp_watcher->keepalive (0);
281		415
282	=back	416	=item $loop = $w->loop
283		417
		418	Return the loop that this watcher is attached to.
284		419
		420	=back
		421
		422
285	=head2 WATCHER TYPES	423	=head1 WATCHER TYPES
286		424
287	Each of the following subsections describes a single watcher type.	425	Each of the following subsections describes a single watcher type.
288		426
289	=head3 IO WATCHERS - is this file descriptor readable or writable?	427	=head3 I/O WATCHERS - is this file descriptor readable or writable?
290		428
291	=over 4	429	=over 4
292		430
293	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	431	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
294		432
295	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback	433	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
		434
		435	=item $w = $loop->io ($fileno_or_fh, $eventmask, $callback)
		436
		437	=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
296		438
297	As long as the returned watcher object is alive, call the C<$callback>	439	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.	440	when at least one of events specified in C<$eventmask> occurs.
299		441
300	The $eventmask can be one or more of these constants ORed together:	442	The $eventmask can be one or more of these constants ORed together:
…		…
329	=over 4	471	=over 4
330		472
331	=item $w = EV::timer $after, $repeat, $callback	473	=item $w = EV::timer $after, $repeat, $callback
332		474
333	=item $w = EV::timer_ns $after, $repeat, $callback	475	=item $w = EV::timer_ns $after, $repeat, $callback
		476
		477	=item $w = $loop->timer ($after, $repeat, $callback)
		478
		479	=item $w = $loop->timer_ns ($after, $repeat, $callback)
334		480
335	Calls the callback after C<$after> seconds (which may be fractional). If	481	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 $repeat	482	C<$repeat> is non-zero, the timer will be restarted (with the $repeat
337	value as $after) after the callback returns.	483	value as $after) after the callback returns.
338		484
…		…
379	=over 4	525	=over 4
380		526
381	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback	527	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
382		528
383	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback	529	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
		530
		531	=item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
		532
		533	=item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback)
384		534
385	Similar to EV::timer, but is not based on relative timeouts but on	535	Similar to EV::timer, but is not based on relative timeouts but on
386	absolute times. Apart from creating "simple" timers that trigger "at" the	536	absolute times. Apart from creating "simple" timers that trigger "at" the
387	specified time, it can also be used for non-drifting absolute timers and	537	specified time, it can also be used for non-drifting absolute timers and
388	more complex, cron-like, setups that are not adversely affected by time	538	more complex, cron-like, setups that are not adversely affected by time
…		…
398	This time simply fires at the wallclock time C<$at> and doesn't repeat. It	548	This time simply fires at the wallclock time C<$at> and doesn't repeat. It
399	will not adjust when a time jump occurs, that is, if it is to be run	549	will not adjust when a time jump occurs, that is, if it is to be run
400	at January 1st 2011 then it will run when the system time reaches or	550	at January 1st 2011 then it will run when the system time reaches or
401	surpasses this time.	551	surpasses this time.
402		552
403	=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0)	553	=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
404		554
405	In this mode the watcher will always be scheduled to time out at the	555	In this mode the watcher will always be scheduled to time out at the
406	next C<$at + N * $interval> time (for some integer N) and then repeat,	556	next C<$at + N * $interval> time (for some integer N) and then repeat,
407	regardless of any time jumps.	557	regardless of any time jumps.
408		558
…		…
426	time the periodic watcher gets scheduled, the reschedule callback	576	time the periodic watcher gets scheduled, the reschedule callback
427	($reschedule_cb) will be called with the watcher as first, and the current	577	($reschedule_cb) will be called with the watcher as first, and the current
428	time as second argument.	578	time as second argument.
429		579
430	I<This callback MUST NOT stop or destroy this or any other periodic	580	I<This callback MUST NOT stop or destroy this or any other periodic
431	watcher, ever>. If you need to stop it, return 1e30 and stop it	581	watcher, ever, and MUST NOT call any event loop functions or methods>. If
432	afterwards.	582	you need to stop it, return 1e30 and stop it afterwards. You may create
		583	and start a C<EV::prepare> watcher for this task.
433		584
434	It must return the next time to trigger, based on the passed time value	585	It must return the next time to trigger, based on the passed time value
435	(that is, the lowest time value larger than to the second argument). It	586	(that is, the lowest time value larger than or equal to to the second
436	will usually be called just before the callback will be triggered, but	587	argument). It will usually be called just before the callback will be
437	might be called at other times, too.	588	triggered, but might be called at other times, too.
438		589
439	This can be used to create very complex timers, such as a timer that	590	This can be used to create very complex timers, such as a timer that
440	triggers on each midnight, local time (actually 24 hours after the last	591	triggers on each midnight, local time (actually 24 hours after the last
441	midnight, to keep the example simple. If you know a way to do it correctly	592	midnight, to keep the example simple. If you know a way to do it correctly
442	in about the same space (without requiring elaborate modules), drop me a	593	in about the same space (without requiring elaborate modules), drop me a
…		…
463		614
464	=item $w->again	615	=item $w->again
465		616
466	Simply stops and starts the watcher again.	617	Simply stops and starts the watcher again.
467		618
		619	=item $time = $w->at
		620
		621	Return the time that the watcher is expected to trigger next.
		622
468	=back	623	=back
469		624
470		625
471	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!	626	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
472		627
…		…
505		660
506	=head3 CHILD WATCHERS - watch out for process status changes	661	=head3 CHILD WATCHERS - watch out for process status changes
507		662
508	=over 4	663	=over 4
509		664
510	=item $w = EV::child $pid, $callback	665	=item $w = EV::child $pid, $trace, $callback
511		666
512	=item $w = EV::child_ns $pid, $callback	667	=item $w = EV::child_ns $pid, $trace, $callback
513		668
		669	=item $w = $loop->child ($pid, $trace, $callback)
		670
		671	=item $w = $loop->child_ns ($pid, $trace, $callback)
		672
514	Call the callback when a status change for pid C<$pid> (or any pid if	673	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	674	if C<$pid> is 0) has been received (a status change happens when the
		675	process terminates or is killed, or, when trace is true, additionally when
		676	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	677	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
517	changed/zombie children and call the callback.	678	changed/zombie children and call the callback.
518		679
519	It is valid (and fully supported) to install a child watcher after a child	680	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	681	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	688	You can have as many pid watchers per pid as you want, they will all be
528	called.	689	called.
529		690
530	The C<child_ns> variant doesn't start (activate) the newly created watcher.	691	The C<child_ns> variant doesn't start (activate) the newly created watcher.
531		692
532	=item $w->set ($pid)	693	=item $w->set ($pid, $trace)
533		694
534	Reconfigures the watcher, see the constructor above for details. Can be called at	695	Reconfigures the watcher, see the constructor above for details. Can be called at
535	any time.	696	any time.
536		697
537	=item $current_pid = $w->pid	698	=item $current_pid = $w->pid
538		699
539	=item $old_pid = $w->pid ($new_pid)
540
541	Returns the previously set process id and optionally set a new one.	700	Returns the previously set process id and optionally set a new one.
542		701
543	=item $exit_status = $w->rstatus	702	=item $exit_status = $w->rstatus
544		703
545	Return the exit/wait status (as returned by waitpid, see the waitpid entry	704	Return the exit/wait status (as returned by waitpid, see the waitpid entry
…		…
551	watcher for all pids).	710	watcher for all pids).
552		711
553	=back	712	=back
554		713
555		714
		715	=head3 STAT WATCHERS - did the file attributes just change?
		716
		717	=over 4
		718
		719	=item $w = EV::stat $path, $interval, $callback
		720
		721	=item $w = EV::stat_ns $path, $interval, $callback
		722
		723	=item $w = $loop->stat ($path, $interval, $callback)
		724
		725	=item $w = $loop->stat_ns ($path, $interval, $callback)
		726
		727	Call the callback when a file status change has been detected on
		728	C<$path>. The C<$path> does not need to exist, changing from "path exists"
		729	to "path does not exist" is a status change like any other.
		730
		731	The C<$interval> is a recommended polling interval for systems where
		732	OS-supported change notifications don't exist or are not supported. If
		733	you use C<0> then an unspecified default is used (which is highly
		734	recommended!), which is to be expected to be around five seconds usually.
		735
		736	This watcher type is not meant for massive numbers of stat watchers,
		737	as even with OS-supported change notifications, this can be
		738	resource-intensive.
		739
		740	The C<stat_ns> variant doesn't start (activate) the newly created watcher.
		741
		742	=item ... = $w->stat
		743
		744	This call is very similar to the perl C<stat> built-in: It stats (using
		745	C<lstat>) the path specified in the watcher and sets perls stat cache (as
		746	well as EV's idea of the current stat values) to the values found.
		747
		748	In scalar context, a boolean is return indicating success or failure of
		749	the stat. In list context, the same 13-value list as with stat is returned
		750	(except that the blksize and blocks fields are not reliable).
		751
		752	In the case of an error, errno is set to C<ENOENT> (regardless of the
		753	actual error value) and the C<nlink> value is forced to zero (if the stat
		754	was successful then nlink is guaranteed to be non-zero).
		755
		756	See also the next two entries for more info.
		757
		758	=item ... = $w->attr
		759
		760	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		761	the values most recently detected by EV. See the next entry for more info.
		762
		763	=item ... = $w->prev
		764
		765	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		766	the previous set of values, before the change.
		767
		768	That is, when the watcher callback is invoked, C<< $w->prev >> will be set
		769	to the values found I<before> a change was detected, while C<< $w->attr >>
		770	returns the values found leading to the change detection. The difference (if any)
		771	between C<prev> and C<attr> is what triggered the callback.
		772
		773	If you did something to the filesystem object and do not want to trigger
		774	yet another change, you can call C<stat> to update EV's idea of what the
		775	current attributes are.
		776
		777	=item $w->set ($path, $interval)
		778
		779	Reconfigures the watcher, see the constructor above for details. Can be
		780	called at any time.
		781
		782	=item $current_path = $w->path
		783
		784	=item $old_path = $w->path ($new_path)
		785
		786	Returns the previously set path and optionally set a new one.
		787
		788	=item $current_interval = $w->interval
		789
		790	=item $old_interval = $w->interval ($new_interval)
		791
		792	Returns the previously set interval and optionally set a new one. Can be
		793	used to query the actual interval used.
		794
		795	=back
		796
		797
556	=head3 IDLE WATCHERS - when you've got nothing better to do...	798	=head3 IDLE WATCHERS - when you've got nothing better to do...
557		799
558	=over 4	800	=over 4
559		801
560	=item $w = EV::idle $callback	802	=item $w = EV::idle $callback
561		803
562	=item $w = EV::idle_ns $callback	804	=item $w = EV::idle_ns $callback
563		805
564	Call the callback when there are no pending io, timer/periodic, signal or	806	=item $w = $loop->idle ($callback)
565	child events, i.e. when the process is idle.	807
		808	=item $w = $loop->idle_ns ($callback)
		809
		810	Call the callback when there are no other pending watchers of the same or
		811	higher priority (excluding check, prepare and other idle watchers of the
		812	same or lower priority, of course). They are called idle watchers because
		813	when the watcher is the highest priority pending event in the process, the
		814	process is considered to be idle at that priority.
		815
		816	If you want a watcher that is only ever called when I<no> other events are
		817	outstanding you have to set the priority to C<EV::MINPRI>.
566		818
567	The process will not block as long as any idle watchers are active, and	819	The process will not block as long as any idle watchers are active, and
568	they will be called repeatedly until stopped.	820	they will be called repeatedly until stopped.
569		821
		822	For example, if you have idle watchers at priority C<0> and C<1>, and
		823	an I/O watcher at priority C<0>, then the idle watcher at priority C<1>
		824	and the I/O watcher will always run when ready. Only when the idle watcher
		825	at priority C<1> is stopped and the I/O watcher at priority C<0> is not
		826	pending with the C<0>-priority idle watcher be invoked.
		827
570	The C<idle_ns> variant doesn't start (activate) the newly created watcher.	828	The C<idle_ns> variant doesn't start (activate) the newly created watcher.
571		829
572	=back	830	=back
573		831
574		832
…		…
577	=over 4	835	=over 4
578		836
579	=item $w = EV::prepare $callback	837	=item $w = EV::prepare $callback
580		838
581	=item $w = EV::prepare_ns $callback	839	=item $w = EV::prepare_ns $callback
		840
		841	=item $w = $loop->prepare ($callback)
		842
		843	=item $w = $loop->prepare_ns ($callback)
582		844
583	Call the callback just before the process would block. You can still	845	Call the callback just before the process would block. You can still
584	create/modify any watchers at this point.	846	create/modify any watchers at this point.
585		847
586	See the EV::check watcher, below, for explanations and an example.	848	See the EV::check watcher, below, for explanations and an example.
…		…
595	=over 4	857	=over 4
596		858
597	=item $w = EV::check $callback	859	=item $w = EV::check $callback
598		860
599	=item $w = EV::check_ns $callback	861	=item $w = EV::check_ns $callback
		862
		863	=item $w = $loop->check ($callback)
		864
		865	=item $w = $loop->check_ns ($callback)
600		866
601	Call the callback just after the process wakes up again (after it has	867	Call the callback just after the process wakes up again (after it has
602	gathered events), but before any other callbacks have been invoked.	868	gathered events), but before any other callbacks have been invoked.
603		869
604	This is used to integrate other event-based software into the EV	870	This is used to integrate other event-based software into the EV
…		…
614	or return;	880	or return;
615		881
616	# make the dispatcher handle any outstanding stuff	882	# make the dispatcher handle any outstanding stuff
617	... not shown	883	... not shown
618		884
619	# create an IO watcher for each and every socket	885	# create an I/O watcher for each and every socket
620	@snmp_watcher = (	886	@snmp_watcher = (
621	(map { EV::io $_, EV::READ, sub { } }	887	(map { EV::io $_, EV::READ, sub { } }
622	keys %{ $dispatcher->{_descriptors} }),	888	keys %{ $dispatcher->{_descriptors} }),
623		889
624	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]	890	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
…		…
646		912
647	The C<check_ns> variant doesn't start (activate) the newly created watcher.	913	The C<check_ns> variant doesn't start (activate) the newly created watcher.
648		914
649	=back	915	=back
650		916
651	=head3 STAT WATCHERS - did the file stats just change?
652		917
653	=over 4	918	=head3 FORK WATCHERS - the audacity to resume the event loop after a fork
654		919
655	=item $w = EV::stat $path, $interval, $callback	920	Fork watchers are called when a C<fork ()> was detected. The invocation
		921	is done before the event loop blocks next and before C<check> watchers
		922	are being called, and only in the child after the fork.
656		923
657	=item $w = EV::stat_ns $path, $interval, $callback	924	=over 4
658		925
659	Call the callback when a file status change has been detected on	926	=item $w = EV::fork $callback
660	C<$path>. The C<$path> does not need to exist, changing from "path exists"
661	to "path does not exist" is a status change like any other.
662		927
663	The C<$interval> is a recommended polling interval for systems where	928	=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		929
668	This watcher type is not meant for massive numbers of stat watchers,	930	=item $w = $loop->fork ($callback)
669	as even with OS-supported change notifications, this can be
670	resource-intensive.
671		931
		932	=item $w = $loop->fork_ns ($callback)
		933
		934	Call the callback before the event loop is resumed in the child process
		935	after a fork.
		936
672	The C<stat_ns> variant doesn't start (activate) the newly created watcher.	937	The C<fork_ns> variant doesn't start (activate) the newly created watcher.
673		938
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	939	=back
693		940
		941
		942	=head3 EMBED WATCHERS - when one backend isn't enough...
		943
		944	This is a rather advanced watcher type that lets you embed one event loop
		945	into another (currently only IO events are supported in the embedded
		946	loop, other types of watchers might be handled in a delayed or incorrect
		947	fashion and must not be used).
		948
		949	See the libev documentation at
		950	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
		951	for more details.
		952
		953	In short, this watcher is most useful on BSD systems without working
		954	kqueue to still be able to handle a large number of sockets:
		955
		956	my $socket_loop;
		957
		958	# check wether we use SELECT or POLL _and_ KQUEUE is supported
		959	if (
		960	(EV::backend & (EV::BACKEND_POLL \| EV::BACKEND_SELECT))
		961	&& (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
		962	) {
		963	# use kqueue for sockets
		964	$socket_loop = new EV::Loop EV::BACKEND_KQUEUE \| EV::FLAG_NOENV;
		965	}
		966
		967	# use the default loop otherwise
		968	$socket_loop \|\|= EV::default_loop;
		969
		970	=over 4
		971
		972	=item $w = EV::embed $otherloop, $callback
		973
		974	=item $w = EV::embed_ns $otherloop, $callback
		975
		976	=item $w = $loop->embed ($otherloop, $callback)
		977
		978	=item $w = $loop->embed_ns ($otherloop, $callback)
		979
		980	Call the callback when the embedded event loop (C<$otherloop>) has any
		981	I/O activity. The C<$callback> should alwas be specified as C<undef> in
		982	this version of EV, which means the embedded event loop will be managed
		983	automatically.
		984
		985	The C<embed_ns> variant doesn't start (activate) the newly created watcher.
		986
		987	=back
		988
		989	=head3 ASYNC WATCHERS - how to wake up another event loop
		990
		991	Async watchers are provided by EV, but have little use in perl directly, as perl
		992	neither supports threads nor direct access to signal handlers or other
		993	contexts where they could be of value.
		994
		995	It is, however, possible to use them from the XS level.
		996
		997	Please see the libev documentation for further details.
		998
		999	=over 4
		1000
		1001	=item $w = EV::async $callback
		1002
		1003	=item $w = EV::async_ns $callback
		1004
		1005	=item $w->send
		1006
		1007	=item $bool = $w->async_pending
		1008
		1009	=back
		1010
		1011
		1012	=head1 PERL SIGNALS
		1013
		1014	While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour
		1015	with EV is as the same as any other C library: Perl-signals will only be
		1016	handled when Perl runs, which means your signal handler might be invoked
		1017	only the next time an event callback is invoked.
		1018
		1019	The solution is to use EV signal watchers (see C<EV::signal>), which will
		1020	ensure proper operations with regards to other event watchers.
		1021
		1022	If you cannot do this for whatever reason, you can also force a watcher
		1023	to be called on every event loop iteration by installing a C<EV::check>
		1024	watcher:
		1025
		1026	my $async_check = EV::check sub { };
		1027
		1028	This ensures that perl gets into control for a short time to handle any
		1029	pending signals, and also ensures (slightly) slower overall operation.
694		1030
695	=head1 THREADS	1031	=head1 THREADS
696		1032
697	Threads are not supported by this module in any way. Perl pseudo-threads	1033	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	1034	is evil stuff and must die. As soon as Perl gains real threads I will work
…		…
720	our $DIED = sub {	1056	our $DIED = sub {
721	warn "EV: error in callback (ignoring): $@";	1057	warn "EV: error in callback (ignoring): $@";
722	};	1058	};
723		1059
724	default_loop	1060	default_loop
725	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	1061	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
726		1062
727	1;	1063	1;
728		1064
729	=head1 SEE ALSO	1065	=head1 SEE ALSO
730		1066
731	L<EV::DNS>.	1067	L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as
		1068	event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
		1069	coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
		1070	event-loop agnostic and portable event driven programming.
732		1071
733	=head1 AUTHOR	1072	=head1 AUTHOR
734		1073
735	Marc Lehmann <schmorp@schmorp.de>	1074	Marc Lehmann <schmorp@schmorp.de>
736	http://home.schmorp.de/	1075	http://home.schmorp.de/
737		1076
738	=cut	1077	=cut
739		1078

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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 1.98 by root, Sat May 31 23:17:50 2008 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 1.98 by root, Sat May 31 23:17:50 2008 UTC