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

Comparing EV/EV.pm (file contents):
Revision 1.61 by root, Thu Dec 6 03:13:07 2007 UTC vs.
Revision 1.162 by root, Wed Jan 22 23:17:31 2020 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::run; # loop until EV::break is called or all watchers stop
53	EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled	53	EV::run EV::RUN_ONCE; # 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::run EV::RUN_NOWAIT; # try to handle same events, but do not block
		55
		56	=head1 BEFORE YOU START USING THIS MODULE
		57
		58	If you only need timer, I/O, signal, child and idle watchers and not the
		59	advanced functionality of this module, consider using L<AnyEvent> instead,
		60	specifically the simplified API described in L<AE>.
		61
		62	When used with EV as backend, the L<AE> API is as fast as the native L<EV>
		63	API, but your programs/modules will still run with many other event loops.
55		64
56	=head1 DESCRIPTION	65	=head1 DESCRIPTION
57		66
58	This module provides an interface to libev	67	This module provides an interface to libev
59	(L<http://software.schmorp.de/pkg/libev.html>). While the documentation	68	(L<http://software.schmorp.de/pkg/libev.html>). While the documentation
60	below is comprehensive, one might also consult the documentation of libev	69	below is comprehensive, one might also consult the documentation of
61	itself (L<http://cvs.schmorp.de/libev/ev.html>) for more subtle details on	70	libev itself (L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod> or
62	watcher semantics or some discussion on the available backends, or how to	71	F<perldoc EV::libev>) for more subtle details on watcher semantics or some
63	force a specific backend with C<LIBEV_FLAGS>.	72	discussion on the available backends, or how to force a specific backend
		73	with C<LIBEV_FLAGS>, or just about in any case because it has much more
		74	detailed information.
		75
		76	This module is very fast and scalable. It is actually so fast that you
		77	can use it through the L<AnyEvent> module, stay portable to other event
		78	loops (if you don't rely on any watcher types not available through it)
		79	and still be faster than with any other event loop currently supported in
		80	Perl.
		81
		82	=head2 PORTING FROM EV 3.X to 4.X
		83
		84	EV version 4 introduces a number of incompatible changes summarised
		85	here. According to the depreciation strategy used by libev, there is a
		86	compatibility layer in place so programs should continue to run unchanged
		87	(the XS interface lacks this layer, so programs using that one need to be
		88	updated).
		89
		90	This compatibility layer will be switched off in some future release.
		91
		92	All changes relevant to Perl are renames of symbols, functions and
		93	methods:
		94
		95	EV::loop => EV::run
		96	EV::LOOP_NONBLOCK => EV::RUN_NOWAIT
		97	EV::LOOP_ONESHOT => EV::RUN_ONCE
		98
		99	EV::unloop => EV::break
		100	EV::UNLOOP_CANCEL => EV::BREAK_CANCEL
		101	EV::UNLOOP_ONE => EV::BREAK_ONE
		102	EV::UNLOOP_ALL => EV::BREAK_ALL
		103
		104	EV::TIMEOUT => EV::TIMER
		105
		106	EV::loop_count => EV::iteration
		107	EV::loop_depth => EV::depth
		108	EV::loop_verify => EV::verify
		109
		110	The loop object methods corresponding to the functions above have been
		111	similarly renamed.
		112
		113	=head2 MODULE EXPORTS
		114
		115	This module does not export any symbols.
64		116
65	=cut	117	=cut
66		118
67	package EV;	119	package EV;
68		120
69	use strict;	121	use common::sense;
70		122
71	BEGIN {	123	BEGIN {
72	our $VERSION = '1.6';	124	our $VERSION = '4.31';
73	use XSLoader;	125	use XSLoader;
		126	local $^W = 0; # avoid spurious warning
74	XSLoader::load "EV", $VERSION;	127	XSLoader::load "EV", $VERSION;
75	}	128	}
76		129
77	@EV::IO::ISA =	130	@EV::IO::ISA =
78	@EV::Timer::ISA =	131	@EV::Timer::ISA =
…		…
83	@EV::Idle::ISA =	136	@EV::Idle::ISA =
84	@EV::Prepare::ISA =	137	@EV::Prepare::ISA =
85	@EV::Check::ISA =	138	@EV::Check::ISA =
86	@EV::Embed::ISA =	139	@EV::Embed::ISA =
87	@EV::Fork::ISA =	140	@EV::Fork::ISA =
		141	@EV::Async::ISA =
88	"EV::Watcher";	142	"EV::Watcher";
89		143
		144	@EV::Loop::Default::ISA = "EV::Loop";
		145
		146	=head1 EVENT LOOPS
		147
		148	EV supports multiple event loops: There is a single "default event loop"
		149	that can handle everything including signals and child watchers, and any
		150	number of "dynamic event loops" that can use different backends (with
		151	various limitations), but no child and signal watchers.
		152
		153	You do not have to do anything to create the default event loop: When
		154	the module is loaded a suitable backend is selected on the premise of
		155	selecting a working backend (which for example rules out kqueue on most
		156	BSDs). Modules should, unless they have "special needs" always use the
		157	default loop as this is fastest (perl-wise), best supported by other
		158	modules (e.g. AnyEvent or Coro) and most portable event loop.
		159
		160	For specific programs you can create additional event loops dynamically.
		161
		162	If you want to take advantage of kqueue (which often works properly for
		163	sockets only) even though the default loop doesn't enable it, you can
		164	I<embed> a kqueue loop into the default loop: running the default loop
		165	will then also service the kqueue loop to some extent. See the example in
		166	the section about embed watchers for an example on how to achieve that.
		167
		168	=over 4
		169
		170	=item $loop = new EV::Loop [$flags]
		171
		172	Create a new event loop as per the specified flags. Please refer to
		173	the C<ev_loop_new ()> function description in the libev documentation
		174	(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>,
		175	or locally-installed as F<EV::libev> manpage) for more info.
		176
		177	The loop will automatically be destroyed when it is no longer referenced
		178	by any watcher and the loop object goes out of scope.
		179
		180	If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK>
		181	is recommended, as only the default event loop is protected by this
		182	module. If you I<are> embedding this loop in the default loop, this is not
		183	necessary, as C<EV::embed> automatically does the right thing on fork.
		184
		185	=item $loop->loop_fork
		186
		187	Must be called after a fork in the child, before entering or continuing
		188	the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
		189	this function automatically, at some performance loss (refer to the libev
		190	documentation).
		191
		192	=item $loop->verify
		193
		194	Calls C<ev_verify> to make internal consistency checks (for debugging
		195	libev) and abort the program if any data structures were found to be
		196	corrupted.
		197
		198	=item $loop = EV::default_loop [$flags]
		199
		200	Return the default loop (which is a singleton object). Since this module
		201	already creates the default loop with default flags, specifying flags here
		202	will not have any effect unless you destroy the default loop first, which
		203	isn't supported. So in short: don't do it, and if you break it, you get to
		204	keep the pieces.
		205
		206	=back
		207
		208
90	=head1 BASIC INTERFACE	209	=head1 BASIC INTERFACE
91		210
92	=over 4	211	=over 4
93		212
94	=item $EV::DIED	213	=item $EV::DIED
95		214
96	Must contain a reference to a function that is called when a callback	215	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	216	throws an exception (with $@ containing the error). The default prints an
98	informative message and continues.	217	informative message and continues.
99		218
100	If this callback throws an exception it will be silently ignored.	219	If this callback throws an exception it will be silently ignored.
101		220
		221	=item $flags = EV::supported_backends
		222
		223	=item $flags = EV::recommended_backends
		224
		225	=item $flags = EV::embeddable_backends
		226
		227	Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this
		228	instance of EV, the set of recommended backends (supposed to be good) for
		229	this platform and the set of embeddable backends (see EMBED WATCHERS).
		230
		231	=item EV::sleep $seconds
		232
		233	Block the process for the given number of (fractional) seconds.
		234
102	=item $time = EV::time	235	=item $time = EV::time
103		236
104	Returns the current time in (fractional) seconds since the epoch.	237	Returns the current time in (fractional) seconds since the epoch.
105		238
106	=item $time = EV::now	239	=item $time = EV::now
107		240
		241	=item $time = $loop->now
		242
108	Returns the time the last event loop iteration has been started. This	243	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	244	is the time that (relative) timers are based on, and referring to it is
110	usually faster then calling EV::time.	245	usually faster then calling EV::time.
111		246
112	=item $method = EV::method	247	=item EV::now_update
113		248
		249	=item $loop->now_update
		250
		251	Establishes the current time by querying the kernel, updating the time
		252	returned by C<EV::now> in the progress. This is a costly operation and
		253	is usually done automatically within C<EV::run>.
		254
		255	This function is rarely useful, but when some event callback runs for a
		256	very long time without entering the event loop, updating libev's idea of
		257	the current time is a good idea.
		258
		259	=item EV::suspend
		260
		261	=item $loop->suspend
		262
		263	=item EV::resume
		264
		265	=item $loop->resume
		266
		267	These two functions suspend and resume a loop, for use when the loop is
		268	not used for a while and timeouts should not be processed.
		269
		270	A typical use case would be an interactive program such as a game: When
		271	the user presses C<^Z> to suspend the game and resumes it an hour later it
		272	would be best to handle timeouts as if no time had actually passed while
		273	the program was suspended. This can be achieved by calling C<suspend>
		274	in your C<SIGTSTP> handler, sending yourself a C<SIGSTOP> and calling
		275	C<resume> directly afterwards to resume timer processing.
		276
		277	Effectively, all C<timer> watchers will be delayed by the time spend
		278	between C<suspend> and C<resume>, and all C<periodic> watchers
		279	will be rescheduled (that is, they will lose any events that would have
		280	occured while suspended).
		281
		282	After calling C<suspend> you B<must not> call I<any> function on the given
		283	loop other than C<resume>, and you B<must not> call C<resume>
		284	without a previous call to C<suspend>.
		285
		286	Calling C<suspend>/C<resume> has the side effect of updating the event
		287	loop time (see C<now_update>).
		288
		289	=item $backend = EV::backend
		290
		291	=item $backend = $loop->backend
		292
114	Returns an integer describing the backend used by libev (EV::METHOD_SELECT	293	Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
115	or EV::METHOD_EPOLL).	294	or EV::BACKEND_EPOLL).
116		295
117	=item EV::loop [$flags]	296	=item $active = EV::run [$flags]
		297
		298	=item $active = $loop->run ([$flags])
118		299
119	Begin checking for events and calling callbacks. It returns when a	300	Begin checking for events and calling callbacks. It returns when a
120	callback calls EV::unloop.	301	callback calls EV::break or the flags are nonzero (in which case the
		302	return value is true) or when there are no active watchers which reference
		303	the loop (keepalive is true), in which case the return value will be
		304	false. The return value can generally be interpreted as "if true, there is
		305	more work left to do".
121		306
122	The $flags argument can be one of the following:	307	The $flags argument can be one of the following:
123		308
124	0 as above	309	0 as above
125	EV::LOOP_ONESHOT block at most once (wait, but do not loop)	310	EV::RUN_ONCE block at most once (wait, but do not loop)
126	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)	311	EV::RUN_NOWAIT do not block at all (fetch/handle events but do not wait)
127		312
128	=item EV::unloop [$how]	313	=item EV::break [$how]
129		314
		315	=item $loop->break ([$how])
		316
130	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the	317	When called with no arguments or an argument of EV::BREAK_ONE, makes the
131	innermost call to EV::loop return.	318	innermost call to EV::run return.
132		319
133	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as	320	When called with an argument of EV::BREAK_ALL, all calls to EV::run will
134	fast as possible.	321	return as fast as possible.
135		322
136	=item $count = EV::loop_count	323	When called with an argument of EV::BREAK_CANCEL, any pending break will
		324	be cancelled.
		325
		326	=item $count = EV::iteration
		327
		328	=item $count = $loop->iteration
137		329
138	Return the number of times the event loop has polled for new	330	Return the number of times the event loop has polled for new
139	events. Sometiems useful as a generation counter.	331	events. Sometimes useful as a generation counter.
140		332
141	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)	333	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
		334
		335	=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
142		336
143	This function rolls together an I/O and a timer watcher for a single	337	This function rolls together an I/O and a timer watcher for a single
144	one-shot event without the need for managing a watcher object.	338	one-shot event without the need for managing a watcher object.
145		339
146	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>	340	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>
…		…
148	\| EV::WRITE>, indicating the type of I/O event you want to wait for. If	342	\| EV::WRITE>, indicating the type of I/O event you want to wait for. If
149	you do not want to wait for some I/O event, specify C<undef> for	343	you do not want to wait for some I/O event, specify C<undef> for
150	C<$fh_or_undef> and C<0> for C<$events>).	344	C<$fh_or_undef> and C<0> for C<$events>).
151		345
152	If timeout is C<undef> or negative, then there will be no	346	If timeout is C<undef> or negative, then there will be no
153	timeout. Otherwise a EV::timer with this value will be started.	347	timeout. Otherwise an C<EV::timer> with this value will be started.
154		348
155	When an error occurs or either the timeout or I/O watcher triggers, then	349	When an error occurs or either the timeout or I/O watcher triggers, then
156	the callback will be called with the received event set (in general	350	the callback will be called with the received event set (in general
157	you can expect it to be a combination of C<EV:ERROR>, C<EV::READ>,	351	you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
158	C<EV::WRITE> and C<EV::TIMEOUT>).	352	C<EV::WRITE> and C<EV::TIMER>).
159		353
160	EV::once doesn't return anything: the watchers stay active till either	354	EV::once doesn't return anything: the watchers stay active till either
161	of them triggers, then they will be stopped and freed, and the callback	355	of them triggers, then they will be stopped and freed, and the callback
162	invoked.	356	invoked.
163		357
164	=back	358	=item EV::feed_fd_event $fd, $revents
165		359
		360	=item $loop->feed_fd_event ($fd, $revents)
		361
		362	Feed an event on a file descriptor into EV. EV will react to this call as
		363	if the readyness notifications specified by C<$revents> (a combination of
		364	C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
		365
		366	=item EV::feed_signal_event $signal
		367
		368	Feed a signal event into the default loop. EV will react to this call as
		369	if the signal specified by C<$signal> had occured.
		370
		371	=item EV::feed_signal $signal
		372
		373	Feed a signal event into EV - unlike C<EV::feed_signal_event>, this works
		374	regardless of which loop has registered the signal, and is mainly useful
		375	for custom signal implementations.
		376
		377	=item EV::set_io_collect_interval $time
		378
		379	=item $loop->set_io_collect_interval ($time)
		380
		381	=item EV::set_timeout_collect_interval $time
		382
		383	=item $loop->set_timeout_collect_interval ($time)
		384
		385	These advanced functions set the minimum block interval when polling for I/O events and the minimum
		386	wait interval for timer events. See the libev documentation at
		387	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP>
		388	(locally installed as F<EV::libev>) for a more detailed discussion.
		389
		390	=item $count = EV::pending_count
		391
		392	=item $count = $loop->pending_count
		393
		394	Returns the number of currently pending watchers.
		395
		396	=item EV::invoke_pending
		397
		398	=item $loop->invoke_pending
		399
		400	Invoke all currently pending watchers.
		401
		402	=back
		403
		404
166	=head2 WATCHER OBJECTS	405	=head1 WATCHER OBJECTS
167		406
168	A watcher is an object that gets created to record your interest in some	407	A watcher is an object that gets created to record your interest in some
169	event. For instance, if you want to wait for STDIN to become readable, you	408	event. For instance, if you want to wait for STDIN to become readable, you
170	would create an EV::io watcher for that:	409	would create an EV::io watcher for that:
171		410
172	my $watcher = EV::io *STDIN, EV::READ, sub {	411	my $watcher = EV::io *STDIN, EV::READ, sub {
173	my ($watcher, $revents) = @_;	412	my ($watcher, $revents) = @_;
174	warn "yeah, STDIN should not be readable without blocking!\n"	413	warn "yeah, STDIN should now be readable without blocking!\n"
175	};	414	};
176		415
177	All watchers can be active (waiting for events) or inactive (paused). Only	416	All watchers can be active (waiting for events) or inactive (paused). Only
178	active watchers will have their callbacks invoked. All callbacks will be	417	active watchers will have their callbacks invoked. All callbacks will be
179	called with at least two arguments: the watcher and a bitmask of received	418	called with at least two arguments: the watcher and a bitmask of received
180	events.	419	events.
181		420
182	Each watcher type has its associated bit in revents, so you can use the	421	Each watcher type has its associated bit in revents, so you can use the
183	same callback for multiple watchers. The event mask is named after the	422	same callback for multiple watchers. The event mask is named after the
184	type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,	423	type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
185	EV::periodic sets EV::PERIODIC and so on, with the exception of IO events	424	EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events
186	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which	425	(which can set both EV::READ and EV::WRITE bits).
187	uses EV::TIMEOUT).
188		426
189	In the rare case where one wants to create a watcher but not start it at	427	In the rare case where one wants to create a watcher but not start it at
190	the same time, each constructor has a variant with a trailing C<_ns> in	428	the same time, each constructor has a variant with a trailing C<_ns> in
191	its name, e.g. EV::io has a non-starting variant EV::io_ns and so on.	429	its name, e.g. EV::io has a non-starting variant EV::io_ns and so on.
192		430
…		…
212		450
213	=item $w->stop	451	=item $w->stop
214		452
215	Stop a watcher if it is active. Also clear any pending events (events that	453	Stop a watcher if it is active. Also clear any pending events (events that
216	have been received but that didn't yet result in a callback invocation),	454	have been received but that didn't yet result in a callback invocation),
217	regardless of wether the watcher was active or not.	455	regardless of whether the watcher was active or not.
218		456
219	=item $bool = $w->is_active	457	=item $bool = $w->is_active
220		458
221	Returns true if the watcher is active, false otherwise.	459	Returns true if the watcher is active, false otherwise.
222		460
…		…
252	The default priority of any newly-created watcher is 0.	490	The default priority of any newly-created watcher is 0.
253		491
254	Note that the priority semantics have not yet been fleshed out and are	492	Note that the priority semantics have not yet been fleshed out and are
255	subject to almost certain change.	493	subject to almost certain change.
256		494
257	=item $w->trigger ($revents)	495	=item $w->invoke ($revents)
258		496
259	Call the callback now with the given event mask.	497	Call the callback now with the given event mask.
260		498
		499	=item $w->feed_event ($revents)
		500
		501	Feed some events on this watcher into EV. EV will react to this call as if
		502	the watcher had received the given C<$revents> mask.
		503
		504	=item $revents = $w->clear_pending
		505
		506	If the watcher is pending, this function clears its pending status and
		507	returns its C<$revents> bitset (as if its callback was invoked). If the
		508	watcher isn't pending it does nothing and returns C<0>.
		509
261	=item $previous_state = $w->keepalive ($bool)	510	=item $previous_state = $w->keepalive ($bool)
262		511
263	Normally, C<EV::loop> will return when there are no active watchers	512	Normally, C<EV::run> will return when there are no active watchers
264	(which is a "deadlock" because no progress can be made anymore). This is	513	(which is a "deadlock" because no progress can be made anymore). This is
265	convinient because it allows you to start your watchers (and your jobs),	514	convenient because it allows you to start your watchers (and your jobs),
266	call C<EV::loop> once and when it returns you know that all your jobs are	515	call C<EV::run> once and when it returns you know that all your jobs are
267	finished (or they forgot to register some watchers for their task :).	516	finished (or they forgot to register some watchers for their task :).
268		517
269	Sometimes, however, this gets in your way, for example when you the module	518	Sometimes, however, this gets in your way, for example when the module
270	that calls C<EV::loop> (usually the main program) is not the same module	519	that calls C<EV::run> (usually the main program) is not the same module
271	as a long-living watcher (for example a DNS client module written by	520	as a long-living watcher (for example a DNS client module written by
272	somebody else even). Then you might want any outstanding requests to be	521	somebody else even). Then you might want any outstanding requests to be
273	handled, but you would not want to keep C<EV::loop> from returning just	522	handled, but you would not want to keep C<EV::run> from returning just
274	because you happen to have this long-running UDP port watcher.	523	because you happen to have this long-running UDP port watcher.
275		524
276	In this case you can clear the keepalive status, which means that even	525	In this case you can clear the keepalive status, which means that even
277	though your watcher is active, it won't keep C<EV::loop> from returning.	526	though your watcher is active, it won't keep C<EV::run> from returning.
278		527
279	The initial value for keepalive is true (enabled), and you cna change it	528	The initial value for keepalive is true (enabled), and you can change it
280	any time.	529	any time.
281		530
282	Example: Register an IO watcher for some UDP socket but do not keep the	531	Example: Register an I/O watcher for some UDP socket but do not keep the
283	event loop from running just because of that watcher.	532	event loop from running just because of that watcher.
284		533
285	my $udp_socket = ...	534	my $udp_socket = ...
286	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };	535	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
287	$udp_watcher->keepalive (0);	536	$udp_watcher->keepalive (0);
288		537
289	=back	538	=item $loop = $w->loop
290		539
		540	Return the loop that this watcher is attached to.
291		541
		542	=back
		543
		544
292	=head2 WATCHER TYPES	545	=head1 WATCHER TYPES
293		546
294	Each of the following subsections describes a single watcher type.	547	Each of the following subsections describes a single watcher type.
295		548
296	=head3 IO WATCHERS - is this file descriptor readable or writable?	549	=head3 I/O WATCHERS - is this file descriptor readable or writable?
297		550
298	=over 4	551	=over 4
299		552
300	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	553	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
301		554
302	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback	555	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
		556
		557	=item $w = $loop->io ($fileno_or_fh, $eventmask, $callback)
		558
		559	=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
303		560
304	As long as the returned watcher object is alive, call the C<$callback>	561	As long as the returned watcher object is alive, call the C<$callback>
305	when at least one of events specified in C<$eventmask> occurs.	562	when at least one of events specified in C<$eventmask> occurs.
306		563
307	The $eventmask can be one or more of these constants ORed together:	564	The $eventmask can be one or more of these constants ORed together:
…		…
337		594
338	=item $w = EV::timer $after, $repeat, $callback	595	=item $w = EV::timer $after, $repeat, $callback
339		596
340	=item $w = EV::timer_ns $after, $repeat, $callback	597	=item $w = EV::timer_ns $after, $repeat, $callback
341		598
		599	=item $w = $loop->timer ($after, $repeat, $callback)
		600
		601	=item $w = $loop->timer_ns ($after, $repeat, $callback)
		602
342	Calls the callback after C<$after> seconds (which may be fractional). If	603	Calls the callback after C<$after> seconds (which may be fractional or
343	C<$repeat> is non-zero, the timer will be restarted (with the $repeat	604	negative). If C<$repeat> is non-zero, the timer will be restarted (with
344	value as $after) after the callback returns.	605	the $repeat value as $after) after the callback returns.
345		606
346	This means that the callback would be called roughly after C<$after>	607	This means that the callback would be called roughly after C<$after>
347	seconds, and then every C<$repeat> seconds. The timer does his best not	608	seconds, and then every C<$repeat> seconds. The timer does his best not
348	to drift, but it will not invoke the timer more often then once per event	609	to drift, but it will not invoke the timer more often then once per event
349	loop iteration, and might drift in other cases. If that isn't acceptable,	610	loop iteration, and might drift in other cases. If that isn't acceptable,
…		…
353	in front of the machine while the timer is running and changes the system	614	in front of the machine while the timer is running and changes the system
354	clock, the timer will nevertheless run (roughly) the same time.	615	clock, the timer will nevertheless run (roughly) the same time.
355		616
356	The C<timer_ns> variant doesn't start (activate) the newly created watcher.	617	The C<timer_ns> variant doesn't start (activate) the newly created watcher.
357		618
358	=item $w->set ($after, $repeat)	619	=item $w->set ($after, $repeat = 0)
359		620
360	Reconfigures the watcher, see the constructor above for details. Can be called at	621	Reconfigures the watcher, see the constructor above for details. Can be called at
361	any time.	622	any time.
362		623
363	=item $w->again	624	=item $w->again
		625
		626	=item $w->again ($repeat)
364		627
365	Similar to the C<start> method, but has special semantics for repeating timers:	628	Similar to the C<start> method, but has special semantics for repeating timers:
366		629
367	If the timer is active and non-repeating, it will be stopped.	630	If the timer is active and non-repeating, it will be stopped.
368		631
…		…
376	This behaviour is useful when you have a timeout for some IO	639	This behaviour is useful when you have a timeout for some IO
377	operation. You create a timer object with the same value for C<$after> and	640	operation. You create a timer object with the same value for C<$after> and
378	C<$repeat>, and then, in the read/write watcher, run the C<again> method	641	C<$repeat>, and then, in the read/write watcher, run the C<again> method
379	on the timeout.	642	on the timeout.
380		643
		644	If called with a C<$repeat> argument, then it uses this a timer repeat
		645	value.
		646
		647	=item $after = $w->remaining
		648
		649	Calculates and returns the remaining time till the timer will fire.
		650
		651	=item $old_repeat = $w->reapat ([$new_repeat])
		652
		653	Returns the current value of the repeat attribute and optionally sets a
		654	new one. Setting the new one will not restart the watcher - if the watcher
		655	is active, the new repeat value is used whenever it expires next.
		656
381	=back	657	=back
382		658
383		659
384	=head3 PERIODIC WATCHERS - to cron or not to cron?	660	=head3 PERIODIC WATCHERS - to cron or not to cron?
385		661
386	=over 4	662	=over 4
387		663
388	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback	664	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
389		665
390	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback	666	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
		667
		668	=item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
		669
		670	=item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback)
391		671
392	Similar to EV::timer, but is not based on relative timeouts but on	672	Similar to EV::timer, but is not based on relative timeouts but on
393	absolute times. Apart from creating "simple" timers that trigger "at" the	673	absolute times. Apart from creating "simple" timers that trigger "at" the
394	specified time, it can also be used for non-drifting absolute timers and	674	specified time, it can also be used for non-drifting absolute timers and
395	more complex, cron-like, setups that are not adversely affected by time	675	more complex, cron-like, setups that are not adversely affected by time
…		…
405	This time simply fires at the wallclock time C<$at> and doesn't repeat. It	685	This time simply fires at the wallclock time C<$at> and doesn't repeat. It
406	will not adjust when a time jump occurs, that is, if it is to be run	686	will not adjust when a time jump occurs, that is, if it is to be run
407	at January 1st 2011 then it will run when the system time reaches or	687	at January 1st 2011 then it will run when the system time reaches or
408	surpasses this time.	688	surpasses this time.
409		689
410	=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0)	690	=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
411		691
412	In this mode the watcher will always be scheduled to time out at the	692	In this mode the watcher will always be scheduled to time out at the
413	next C<$at + N * $interval> time (for some integer N) and then repeat,	693	next C<$at + N * $interval> time (for the lowest integer N) and then repeat,
414	regardless of any time jumps.	694	regardless of any time jumps. Note that, since C<N> can be negative, the
		695	first trigger can happen before C<$at>.
415		696
416	This can be used to create timers that do not drift with respect to system	697	This can be used to create timers that do not drift with respect to system
417	time:	698	time:
418		699
419	my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" };	700	my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" };
420		701
421	That doesn't mean there will always be 3600 seconds in between triggers,	702	That doesn't mean there will always be 3600 seconds in between triggers,
422	but only that the the clalback will be called when the system time shows a	703	but only that the the callback will be called when the system time shows a
423	full hour (UTC).	704	full hour (UTC).
424		705
425	Another way to think about it (for the mathematically inclined) is that	706	Another way to think about it (for the mathematically inclined) is that
426	EV::periodic will try to run the callback in this mode at the next	707	EV::periodic will try to run the callback in this mode at the next
427	possible time where C<$time = $at (mod $interval)>, regardless of any time	708	possible time where C<$time = $at (mod $interval)>, regardless of any time
…		…
433	time the periodic watcher gets scheduled, the reschedule callback	714	time the periodic watcher gets scheduled, the reschedule callback
434	($reschedule_cb) will be called with the watcher as first, and the current	715	($reschedule_cb) will be called with the watcher as first, and the current
435	time as second argument.	716	time as second argument.
436		717
437	I<This callback MUST NOT stop or destroy this or any other periodic	718	I<This callback MUST NOT stop or destroy this or any other periodic
438	watcher, ever>. If you need to stop it, return 1e30 and stop it	719	watcher, ever, and MUST NOT call any event loop functions or methods>. If
439	afterwards.	720	you need to stop it, return 1e30 and stop it afterwards. You may create
		721	and start an C<EV::prepare> watcher for this task.
440		722
441	It must return the next time to trigger, based on the passed time value	723	It must return the next time to trigger, based on the passed time value
442	(that is, the lowest time value larger than to the second argument). It	724	(that is, the lowest time value larger than or equal to to the second
443	will usually be called just before the callback will be triggered, but	725	argument). It will usually be called just before the callback will be
444	might be called at other times, too.	726	triggered, but might be called at other times, too.
445		727
446	This can be used to create very complex timers, such as a timer that	728	This can be used to create very complex timers, such as a timer that
447	triggers on each midnight, local time (actually 24 hours after the last	729	triggers on each midnight, local time (actually one day after the last
448	midnight, to keep the example simple. If you know a way to do it correctly	730	midnight, to keep the example simple):
449	in about the same space (without requiring elaborate modules), drop me a
450	note :):
451		731
452	my $daily = EV::periodic 0, 0, sub {	732	my $daily = EV::periodic 0, 0, sub {
453	my ($w, $now) = @_;	733	my ($w, $now) = @_;
454		734
455	use Time::Local ();	735	use Time::Local ();
456	my (undef, undef, undef, $d, $m, $y) = localtime $now;	736	my (undef, undef, undef, $d, $m, $y) = localtime $now;
457	86400 + Time::Local::timelocal 0, 0, 0, $d, $m, $y	737	Time::Local::timelocal_nocheck 0, 0, 0, $d + 1, $m, $y
458	}, sub {	738	}, sub {
459	print "it's midnight or likely shortly after, now\n";	739	print "it's midnight or likely shortly after, now\n";
460	};	740	};
461		741
462	=back	742	=back
…		…
470		750
471	=item $w->again	751	=item $w->again
472		752
473	Simply stops and starts the watcher again.	753	Simply stops and starts the watcher again.
474		754
		755	=item $time = $w->at
		756
		757	Return the time that the watcher is expected to trigger next.
		758
		759	=item $old_offset = $w->offset ([$new_offset])
		760
		761	Returns the current value of the offset attribute and optionally sets a
		762	new one. Setting the new one will not restart the watcher - if the watcher
		763	is active, the new offset value is used whenever it expires next.
		764
		765	=item $old_interval = $w->interval ([$new_interval])
		766
		767	See above, for the interval attribute.
		768
		769	=item $old_reschedule_cb = $w->reschedule_cb ([$new_reschedule_xcb])
		770
		771	See above, for the reschedule callback.
		772
475	=back	773	=back
476		774
477		775
478	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!	776	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
479		777
480	=over 4	778	=over 4
481		779
482	=item $w = EV::signal $signal, $callback	780	=item $w = EV::signal $signal, $callback
483		781
484	=item $w = EV::signal_ns $signal, $callback	782	=item $w = EV::signal_ns $signal, $callback
		783
		784	=item $w = $loop->signal ($signal, $callback)
		785
		786	=item $w = $loop->signal_ns ($signal, $callback)
485		787
486	Call the callback when $signal is received (the signal can be specified by	788	Call the callback when $signal is received (the signal can be specified by
487	number or by name, just as with C<kill> or C<%SIG>).	789	number or by name, just as with C<kill> or C<%SIG>).
		790
		791	Only one event loop can grab a given signal - attempting to grab the same
		792	signal from two EV loops will crash the program immediately or cause data
		793	corruption.
488		794
489	EV will grab the signal for the process (the kernel only allows one	795	EV will grab the signal for the process (the kernel only allows one
490	component to receive a signal at a time) when you start a signal watcher,	796	component to receive a signal at a time) when you start a signal watcher,
491	and removes it again when you stop it. Perl does the same when you	797	and removes it again when you stop it. Perl does the same when you
492	add/remove callbacks to C<%SIG>, so watch out.	798	add/remove callbacks to C<%SIG>, so watch out.
…		…
512		818
513	=head3 CHILD WATCHERS - watch out for process status changes	819	=head3 CHILD WATCHERS - watch out for process status changes
514		820
515	=over 4	821	=over 4
516		822
517	=item $w = EV::child $pid, $callback	823	=item $w = EV::child $pid, $trace, $callback
518		824
519	=item $w = EV::child_ns $pid, $callback	825	=item $w = EV::child_ns $pid, $trace, $callback
520		826
		827	=item $w = $loop->child ($pid, $trace, $callback)
		828
		829	=item $w = $loop->child_ns ($pid, $trace, $callback)
		830
521	Call the callback when a status change for pid C<$pid> (or any pid if	831	Call the callback when a status change for pid C<$pid> (or any pid
522	C<$pid> is 0) has been received. More precisely: when the process receives	832	if C<$pid> is 0) has been received (a status change happens when the
		833	process terminates or is killed, or, when trace is true, additionally when
		834	it is stopped or continued). More precisely: when the process receives
523	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all	835	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
524	changed/zombie children and call the callback.	836	changed/zombie children and call the callback.
525		837
526	It is valid (and fully supported) to install a child watcher after a child	838	It is valid (and fully supported) to install a child watcher after a child
527	has exited but before the event loop has started its next iteration (for	839	has exited but before the event loop has started its next iteration (for
…		…
534	You can have as many pid watchers per pid as you want, they will all be	846	You can have as many pid watchers per pid as you want, they will all be
535	called.	847	called.
536		848
537	The C<child_ns> variant doesn't start (activate) the newly created watcher.	849	The C<child_ns> variant doesn't start (activate) the newly created watcher.
538		850
539	=item $w->set ($pid)	851	=item $w->set ($pid, $trace)
540		852
541	Reconfigures the watcher, see the constructor above for details. Can be called at	853	Reconfigures the watcher, see the constructor above for details. Can be called at
542	any time.	854	any time.
543		855
544	=item $current_pid = $w->pid	856	=item $current_pid = $w->pid
545		857
546	=item $old_pid = $w->pid ($new_pid)
547
548	Returns the previously set process id and optionally set a new one.	858	Returns the previously set process id and optionally set a new one.
549		859
550	=item $exit_status = $w->rstatus	860	=item $exit_status = $w->rstatus
551		861
552	Return the exit/wait status (as returned by waitpid, see the waitpid entry	862	Return the exit/wait status (as returned by waitpid, see the waitpid entry
…		…
565	=over 4	875	=over 4
566		876
567	=item $w = EV::stat $path, $interval, $callback	877	=item $w = EV::stat $path, $interval, $callback
568		878
569	=item $w = EV::stat_ns $path, $interval, $callback	879	=item $w = EV::stat_ns $path, $interval, $callback
		880
		881	=item $w = $loop->stat ($path, $interval, $callback)
		882
		883	=item $w = $loop->stat_ns ($path, $interval, $callback)
570		884
571	Call the callback when a file status change has been detected on	885	Call the callback when a file status change has been detected on
572	C<$path>. The C<$path> does not need to exist, changing from "path exists"	886	C<$path>. The C<$path> does not need to exist, changing from "path exists"
573	to "path does not exist" is a status change like any other.	887	to "path does not exist" is a status change like any other.
574		888
…		…
645		959
646	=item $w = EV::idle $callback	960	=item $w = EV::idle $callback
647		961
648	=item $w = EV::idle_ns $callback	962	=item $w = EV::idle_ns $callback
649		963
650	Call the callback when there are no pending io, timer/periodic, signal or	964	=item $w = $loop->idle ($callback)
651	child events, i.e. when the process is idle.	965
		966	=item $w = $loop->idle_ns ($callback)
		967
		968	Call the callback when there are no other pending watchers of the same or
		969	higher priority (excluding check, prepare and other idle watchers of the
		970	same or lower priority, of course). They are called idle watchers because
		971	when the watcher is the highest priority pending event in the process, the
		972	process is considered to be idle at that priority.
		973
		974	If you want a watcher that is only ever called when I<no> other events are
		975	outstanding you have to set the priority to C<EV::MINPRI>.
652		976
653	The process will not block as long as any idle watchers are active, and	977	The process will not block as long as any idle watchers are active, and
654	they will be called repeatedly until stopped.	978	they will be called repeatedly until stopped.
655		979
		980	For example, if you have idle watchers at priority C<0> and C<1>, and
		981	an I/O watcher at priority C<0>, then the idle watcher at priority C<1>
		982	and the I/O watcher will always run when ready. Only when the idle watcher
		983	at priority C<1> is stopped and the I/O watcher at priority C<0> is not
		984	pending with the C<0>-priority idle watcher be invoked.
		985
656	The C<idle_ns> variant doesn't start (activate) the newly created watcher.	986	The C<idle_ns> variant doesn't start (activate) the newly created watcher.
657		987
658	=back	988	=back
659		989
660		990
…		…
663	=over 4	993	=over 4
664		994
665	=item $w = EV::prepare $callback	995	=item $w = EV::prepare $callback
666		996
667	=item $w = EV::prepare_ns $callback	997	=item $w = EV::prepare_ns $callback
		998
		999	=item $w = $loop->prepare ($callback)
		1000
		1001	=item $w = $loop->prepare_ns ($callback)
668		1002
669	Call the callback just before the process would block. You can still	1003	Call the callback just before the process would block. You can still
670	create/modify any watchers at this point.	1004	create/modify any watchers at this point.
671		1005
672	See the EV::check watcher, below, for explanations and an example.	1006	See the EV::check watcher, below, for explanations and an example.
…		…
682		1016
683	=item $w = EV::check $callback	1017	=item $w = EV::check $callback
684		1018
685	=item $w = EV::check_ns $callback	1019	=item $w = EV::check_ns $callback
686		1020
		1021	=item $w = $loop->check ($callback)
		1022
		1023	=item $w = $loop->check_ns ($callback)
		1024
687	Call the callback just after the process wakes up again (after it has	1025	Call the callback just after the process wakes up again (after it has
688	gathered events), but before any other callbacks have been invoked.	1026	gathered events), but before any other callbacks have been invoked.
689		1027
690	This is used to integrate other event-based software into the EV	1028	This can be used to integrate other event-based software into the EV
691	mainloop: You register a prepare callback and in there, you create io and	1029	mainloop: You register a prepare callback and in there, you create io and
692	timer watchers as required by the other software. Here is a real-world	1030	timer watchers as required by the other software. Here is a real-world
693	example of integrating Net::SNMP (with some details left out):	1031	example of integrating Net::SNMP (with some details left out):
694		1032
695	our @snmp_watcher;	1033	our @snmp_watcher;
…		…
700	or return;	1038	or return;
701		1039
702	# make the dispatcher handle any outstanding stuff	1040	# make the dispatcher handle any outstanding stuff
703	... not shown	1041	... not shown
704		1042
705	# create an IO watcher for each and every socket	1043	# create an I/O watcher for each and every socket
706	@snmp_watcher = (	1044	@snmp_watcher = (
707	(map { EV::io $_, EV::READ, sub { } }	1045	(map { EV::io $_, EV::READ, sub { } }
708	keys %{ $dispatcher->{_descriptors} }),	1046	keys %{ $dispatcher->{_descriptors} }),
709		1047
710	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]	1048	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
…		…
725	# make the dispatcher handle any new stuff	1063	# make the dispatcher handle any new stuff
726	... not shown	1064	... not shown
727	};	1065	};
728		1066
729	The callbacks of the created watchers will not be called as the watchers	1067	The callbacks of the created watchers will not be called as the watchers
730	are destroyed before this cna happen (remember EV::check gets called	1068	are destroyed before this can happen (remember EV::check gets called
731	first).	1069	first).
732		1070
733	The C<check_ns> variant doesn't start (activate) the newly created watcher.	1071	The C<check_ns> variant doesn't start (activate) the newly created watcher.
		1072
		1073	=item EV::CHECK constant issues
		1074
		1075	Like all other watcher types, there is a bitmask constant for use in
		1076	C<$revents> and other places. The C<EV::CHECK> is special as it has
		1077	the same name as the C<CHECK> sub called by Perl. This doesn't cause
		1078	big issues on newer perls (beginning with 5.8.9), but it means thatthe
		1079	constant must be I<inlined>, i.e. runtime calls will not work. That means
		1080	that as long as you always C<use EV> and then C<EV::CHECK> you are on the
		1081	safe side.
734		1082
735	=back	1083	=back
736		1084
737		1085
738	=head3 FORK WATCHERS - the audacity to resume the event loop after a fork	1086	=head3 FORK WATCHERS - the audacity to resume the event loop after a fork
…		…
745		1093
746	=item $w = EV::fork $callback	1094	=item $w = EV::fork $callback
747		1095
748	=item $w = EV::fork_ns $callback	1096	=item $w = EV::fork_ns $callback
749		1097
		1098	=item $w = $loop->fork ($callback)
		1099
		1100	=item $w = $loop->fork_ns ($callback)
		1101
750	Call the callback before the event loop is resumed in the child process	1102	Call the callback before the event loop is resumed in the child process
751	after a fork.	1103	after a fork.
752		1104
753	The C<fork_ns> variant doesn't start (activate) the newly created watcher.	1105	The C<fork_ns> variant doesn't start (activate) the newly created watcher.
754		1106
755	=back	1107	=back
		1108
		1109
		1110	=head3 EMBED WATCHERS - when one backend isn't enough...
		1111
		1112	This is a rather advanced watcher type that lets you embed one event loop
		1113	into another (currently only IO events are supported in the embedded
		1114	loop, other types of watchers might be handled in a delayed or incorrect
		1115	fashion and must not be used).
		1116
		1117	See the libev documentation at
		1118	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
		1119	(locally installed as F<EV::libev>) for more details.
		1120
		1121	In short, this watcher is most useful on BSD systems without working
		1122	kqueue to still be able to handle a large number of sockets:
		1123
		1124	my $socket_loop;
		1125
		1126	# check wether we use SELECT or POLL _and_ KQUEUE is supported
		1127	if (
		1128	(EV::backend & (EV::BACKEND_POLL \| EV::BACKEND_SELECT))
		1129	&& (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
		1130	) {
		1131	# use kqueue for sockets
		1132	$socket_loop = new EV::Loop EV::BACKEND_KQUEUE \| EV::FLAG_NOENV;
		1133	}
		1134
		1135	# use the default loop otherwise
		1136	$socket_loop \|\|= EV::default_loop;
		1137
		1138	=over 4
		1139
		1140	=item $w = EV::embed $otherloop[, $callback]
		1141
		1142	=item $w = EV::embed_ns $otherloop[, $callback]
		1143
		1144	=item $w = $loop->embed ($otherloop[, $callback])
		1145
		1146	=item $w = $loop->embed_ns ($otherloop[, $callback])
		1147
		1148	Call the callback when the embedded event loop (C<$otherloop>) has any
		1149	I/O activity. The C<$callback> is optional: if it is missing, then the
		1150	embedded event loop will be managed automatically (which is recommended),
		1151	otherwise you have to invoke C<sweep> yourself.
		1152
		1153	The C<embed_ns> variant doesn't start (activate) the newly created watcher.
		1154
		1155	=back
		1156
		1157	=head3 ASYNC WATCHERS - how to wake up another event loop
		1158
		1159	Async watchers are provided by EV, but have little use in perl directly,
		1160	as perl neither supports threads running in parallel nor direct access to
		1161	signal handlers or other contexts where they could be of value.
		1162
		1163	It is, however, possible to use them from the XS level.
		1164
		1165	Please see the libev documentation for further details.
		1166
		1167	=over 4
		1168
		1169	=item $w = EV::async $callback
		1170
		1171	=item $w = EV::async_ns $callback
		1172
		1173	=item $w = $loop->async ($callback)
		1174
		1175	=item $w = $loop->async_ns ($callback)
		1176
		1177	=item $w->send
		1178
		1179	=item $bool = $w->async_pending
		1180
		1181	=back
		1182
		1183	=head3 CLEANUP WATCHERS - how to clean up when the event loop goes away
		1184
		1185	Cleanup watchers are not supported on the Perl level, they can only be
		1186	used via XS currently.
756		1187
757		1188
758	=head1 PERL SIGNALS	1189	=head1 PERL SIGNALS
759		1190
760	While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour	1191	While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour
…		…
769	to be called on every event loop iteration by installing a C<EV::check>	1200	to be called on every event loop iteration by installing a C<EV::check>
770	watcher:	1201	watcher:
771		1202
772	my $async_check = EV::check sub { };	1203	my $async_check = EV::check sub { };
773		1204
774	This ensures that perl shortly gets into control for a short time, and	1205	This ensures that perl gets into control for a short time to handle any
775	also ensures slower overall operation.	1206	pending signals, and also ensures (slightly) slower overall operation.
776		1207
777	=head1 THREADS	1208	=head1 ITHREADS
778		1209
779	Threads are not supported by this module in any way. Perl pseudo-threads	1210	Ithreads are not supported by this module in any way. Perl pseudo-threads
780	is evil stuff and must die. As soon as Perl gains real threads I will work	1211	is evil stuff and must die. Real threads as provided by Coro are fully
781	on thread support for it.	1212	supported (and enhanced support is available via L<Coro::EV>).
782		1213
783	=head1 FORK	1214	=head1 FORK
784		1215
785	Most of the "improved" event delivering mechanisms of modern operating	1216	Most of the "improved" event delivering mechanisms of modern operating
786	systems have quite a few problems with fork(2) (to put it bluntly: it is	1217	systems have quite a few problems with fork(2) (to put it bluntly: it is
…		…
802	our $DIED = sub {	1233	our $DIED = sub {
803	warn "EV: error in callback (ignoring): $@";	1234	warn "EV: error in callback (ignoring): $@";
804	};	1235	};
805		1236
806	default_loop	1237	default_loop
807	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	1238	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
808		1239
809	1;	1240	1;
810		1241
811	=head1 SEE ALSO	1242	=head1 SEE ALSO
812		1243
		1244	L<EV::MakeMaker> - MakeMaker interface to XS API, L<EV::ADNS>
813	L<EV::ADNS> (asynchronous dns), L<Glib::EV> (makes Glib/Gtk2 use EV as	1245	(asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as event
814	event loop), L<Coro::EV> (efficient coroutines with EV).	1246	loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient thread
		1247	integration), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
		1248	event-loop agnostic and portable event driven programming.
815		1249
816	=head1 AUTHOR	1250	=head1 AUTHOR
817		1251
818	Marc Lehmann <schmorp@schmorp.de>	1252	Marc Lehmann <schmorp@schmorp.de>
819	http://home.schmorp.de/	1253	http://home.schmorp.de/
820		1254
821	=cut	1255	=cut
822		1256

Diff Legend

-–
+Removed lines
-+
+Added lines
-<
+Changed lines
->
+Changed lines

Comparing EV/EV.pm (file contents): Revision 1.61 by root, Thu Dec 6 03:13:07 2007 UTC vs. Revision 1.162 by root, Wed Jan 22 23:17:31 2020 UTC

Diff Legend

Comparing EV/EV.pm (file contents):
Revision 1.61 by root, Thu Dec 6 03:13:07 2007 UTC vs.
Revision 1.162 by root, Wed Jan 22 23:17:31 2020 UTC