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

Comparing EV/EV.pm (file contents):
Revision 1.57 by root, Wed Nov 28 17:32:24 2007 UTC vs.
Revision 1.130 by root, Sun Oct 24 17:58:41 2010 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
		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 = '1.4';	124	our $VERSION = '4.00';
73	use XSLoader;	125	use XSLoader;
74	XSLoader::load "EV", $VERSION;	126	XSLoader::load "EV", $VERSION;
75	}	127	}
76		128
77	@EV::IO::ISA =	129	@EV::IO::ISA =
…		…
83	@EV::Idle::ISA =	135	@EV::Idle::ISA =
84	@EV::Prepare::ISA =	136	@EV::Prepare::ISA =
85	@EV::Check::ISA =	137	@EV::Check::ISA =
86	@EV::Embed::ISA =	138	@EV::Embed::ISA =
87	@EV::Fork::ISA =	139	@EV::Fork::ISA =
		140	@EV::Async::ISA =
88	"EV::Watcher";	141	"EV::Watcher";
89		142
		143	@EV::Loop::Default::ISA = "EV::Loop";
		144
		145	=head1 EVENT LOOPS
		146
		147	EV supports multiple event loops: There is a single "default event loop"
		148	that can handle everything including signals and child watchers, and any
		149	number of "dynamic event loops" that can use different backends (with
		150	various limitations), but no child and signal watchers.
		151
		152	You do not have to do anything to create the default event loop: When
		153	the module is loaded a suitable backend is selected on the premise of
		154	selecting a working backend (which for example rules out kqueue on most
		155	BSDs). Modules should, unless they have "special needs" always use the
		156	default loop as this is fastest (perl-wise), best supported by other
		157	modules (e.g. AnyEvent or Coro) and most portable event loop.
		158
		159	For specific programs you can create additional event loops dynamically.
		160
		161	If you want to take advantage of kqueue (which often works properly for
		162	sockets only) even though the default loop doesn't enable it, you can
		163	I<embed> a kqueue loop into the default loop: running the default loop
		164	will then also service the kqueue loop to some extent. See the example in
		165	the section about embed watchers for an example on how to achieve that.
		166
		167	=over 4
		168
		169	=item $loop = new EV::Loop [$flags]
		170
		171	Create a new event loop as per the specified flags. Please refer to
		172	the C<ev_loop_new ()> function description in the libev documentation
		173	(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>,
		174	or locally-installed as F<EV::libev> manpage) for more info.
		175
		176	The loop will automatically be destroyed when it is no longer referenced
		177	by any watcher and the loop object goes out of scope.
		178
		179	If you are not embedding the loop, then Using C<EV::FLAG_FORKCHECK>
		180	is recommended, as only the default event loop is protected by this
		181	module. If you I<are> embedding this loop in the default loop, this is not
		182	necessary, as C<EV::embed> automatically does the right thing on fork.
		183
		184	=item $loop->loop_fork
		185
		186	Must be called after a fork in the child, before entering or continuing
		187	the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
		188	this function automatically, at some performance loss (refer to the libev
		189	documentation).
		190
		191	=item $loop->loop_verify
		192
		193	Calls C<ev_verify> to make internal consistency checks (for debugging
		194	libev) and abort the program if any data structures were found to be
		195	corrupted.
		196
		197	=item $loop = EV::default_loop [$flags]
		198
		199	Return the default loop (which is a singleton object). Since this module
		200	already creates the default loop with default flags, specifying flags here
		201	will not have any effect unless you destroy the default loop first, which
		202	isn't supported. So in short: don't do it, and if you break it, you get to
		203	keep the pieces.
		204
		205	=back
		206
		207
90	=head1 BASIC INTERFACE	208	=head1 BASIC INTERFACE
91		209
92	=over 4	210	=over 4
93		211
94	=item $EV::DIED	212	=item $EV::DIED
95		213
96	Must contain a reference to a function that is called when a callback	214	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	215	throws an exception (with $@ containing the error). The default prints an
98	informative message and continues.	216	informative message and continues.
99		217
100	If this callback throws an exception it will be silently ignored.	218	If this callback throws an exception it will be silently ignored.
101		219
		220	=item $flags = EV::supported_backends
		221
		222	=item $flags = EV::recommended_backends
		223
		224	=item $flags = EV::embeddable_backends
		225
		226	Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this
		227	instance of EV, the set of recommended backends (supposed to be good) for
		228	this platform and the set of embeddable backends (see EMBED WATCHERS).
		229
		230	=item EV::sleep $seconds
		231
		232	Block the process for the given number of (fractional) seconds.
		233
102	=item $time = EV::time	234	=item $time = EV::time
103		235
104	Returns the current time in (fractional) seconds since the epoch.	236	Returns the current time in (fractional) seconds since the epoch.
105		237
106	=item $time = EV::now	238	=item $time = EV::now
107		239
		240	=item $time = $loop->now
		241
108	Returns the time the last event loop iteration has been started. This	242	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	243	is the time that (relative) timers are based on, and referring to it is
110	usually faster then calling EV::time.	244	usually faster then calling EV::time.
111		245
112	=item $method = EV::method	246	=item EV::now_update
113		247
		248	=item $loop->now_update
		249
		250	Establishes the current time by querying the kernel, updating the time
		251	returned by C<EV::now> in the progress. This is a costly operation and
		252	is usually done automatically within C<EV::loop>.
		253
		254	This function is rarely useful, but when some event callback runs for a
		255	very long time without entering the event loop, updating libev's idea of
		256	the current time is a good idea.
		257
		258	=item EV::suspend
		259
		260	=item $loop->suspend
		261
		262	=item EV::resume
		263
		264	=item $loop->resume
		265
		266	These two functions suspend and resume a loop, for use when the loop is
		267	not used for a while and timeouts should not be processed.
		268
		269	A typical use case would be an interactive program such as a game: When
		270	the user presses C<^Z> to suspend the game and resumes it an hour later it
		271	would be best to handle timeouts as if no time had actually passed while
		272	the program was suspended. This can be achieved by calling C<suspend>
		273	in your C<SIGTSTP> handler, sending yourself a C<SIGSTOP> and calling
		274	C<resume> directly afterwards to resume timer processing.
		275
		276	Effectively, all C<timer> watchers will be delayed by the time spend
		277	between C<suspend> and C<resume>, and all C<periodic> watchers
		278	will be rescheduled (that is, they will lose any events that would have
		279	occured while suspended).
		280
		281	After calling C<suspend> you B<must not> call I<any> function on the given
		282	loop other than C<resume>, and you B<must not> call C<resume>
		283	without a previous call to C<suspend>.
		284
		285	Calling C<suspend>/C<resume> has the side effect of updating the event
		286	loop time (see C<now_update>).
		287
		288	=item $backend = EV::backend
		289
		290	=item $backend = $loop->backend
		291
114	Returns an integer describing the backend used by libev (EV::METHOD_SELECT	292	Returns an integer describing the backend used by libev (EV::BACKEND_SELECT
115	or EV::METHOD_EPOLL).	293	or EV::BACKEND_EPOLL).
116		294
117	=item EV::loop [$flags]	295	=item EV::loop [$flags]
		296
		297	=item $loop->loop ([$flags])
118		298
119	Begin checking for events and calling callbacks. It returns when a	299	Begin checking for events and calling callbacks. It returns when a
120	callback calls EV::unloop.	300	callback calls EV::unloop.
121		301
122	The $flags argument can be one of the following:	302	The $flags argument can be one of the following:
…		…
125	EV::LOOP_ONESHOT block at most once (wait, but do not loop)	305	EV::LOOP_ONESHOT block at most once (wait, but do not loop)
126	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)	306	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
127		307
128	=item EV::unloop [$how]	308	=item EV::unloop [$how]
129		309
		310	=item $loop->unloop ([$how])
		311
130	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the	312	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the
131	innermost call to EV::loop return.	313	innermost call to EV::loop return.
132		314
133	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as	315	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as
134	fast as possible.	316	fast as possible.
135		317
		318	=item $count = EV::loop_count
		319
		320	=item $count = $loop->loop_count
		321
		322	Return the number of times the event loop has polled for new
		323	events. Sometimes useful as a generation counter.
		324
136	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)	325	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
		326
		327	=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
137		328
138	This function rolls together an I/O and a timer watcher for a single	329	This function rolls together an I/O and a timer watcher for a single
139	one-shot event without the need for managing a watcher object.	330	one-shot event without the need for managing a watcher object.
140		331
141	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>	332	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>
…		…
147	If timeout is C<undef> or negative, then there will be no	338	If timeout is C<undef> or negative, then there will be no
148	timeout. Otherwise a EV::timer with this value will be started.	339	timeout. Otherwise a EV::timer with this value will be started.
149		340
150	When an error occurs or either the timeout or I/O watcher triggers, then	341	When an error occurs or either the timeout or I/O watcher triggers, then
151	the callback will be called with the received event set (in general	342	the callback will be called with the received event set (in general
152	you can expect it to be a combination of C<EV:ERROR>, C<EV::READ>,	343	you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
153	C<EV::WRITE> and C<EV::TIMEOUT>).	344	C<EV::WRITE> and C<EV::TIMER>).
154		345
155	EV::once doesn't return anything: the watchers stay active till either	346	EV::once doesn't return anything: the watchers stay active till either
156	of them triggers, then they will be stopped and freed, and the callback	347	of them triggers, then they will be stopped and freed, and the callback
157	invoked.	348	invoked.
158		349
159	=back	350	=item EV::feed_fd_event ($fd, $revents)
160		351
		352	=item $loop->feed_fd_event ($fd, $revents)
		353
		354	Feed an event on a file descriptor into EV. EV will react to this call as
		355	if the readyness notifications specified by C<$revents> (a combination of
		356	C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
		357
		358	=item EV::feed_signal_event ($signal)
		359
		360	Feed a signal event into EV. EV will react to this call as if the signal
		361	specified by C<$signal> had occured.
		362
		363	=item EV::set_io_collect_interval $time
		364
		365	=item $loop->set_io_collect_interval ($time)
		366
		367	=item EV::set_timeout_collect_interval $time
		368
		369	=item $loop->set_timeout_collect_interval ($time)
		370
		371	These advanced functions set the minimum block interval when polling for I/O events and the minimum
		372	wait interval for timer events. See the libev documentation at
		373	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP>
		374	(locally installed as F<EV::libev>) for a more detailed discussion.
		375
		376	=item $count = EV::pending_count
		377
		378	=item $count = $loop->pending_count
		379
		380	Returns the number of currently pending watchers.
		381
		382	=item EV::invoke_pending
		383
		384	=item $loop->invoke_pending
		385
		386	Invoke all currently pending watchers.
		387
		388	=back
		389
		390
161	=head2 WATCHER OBJECTS	391	=head1 WATCHER OBJECTS
162		392
163	A watcher is an object that gets created to record your interest in some	393	A watcher is an object that gets created to record your interest in some
164	event. For instance, if you want to wait for STDIN to become readable, you	394	event. For instance, if you want to wait for STDIN to become readable, you
165	would create an EV::io watcher for that:	395	would create an EV::io watcher for that:
166		396
167	my $watcher = EV::io *STDIN, EV::READ, sub {	397	my $watcher = EV::io *STDIN, EV::READ, sub {
168	my ($watcher, $revents) = @_;	398	my ($watcher, $revents) = @_;
169	warn "yeah, STDIN should not be readable without blocking!\n"	399	warn "yeah, STDIN should now be readable without blocking!\n"
170	};	400	};
171		401
172	All watchers can be active (waiting for events) or inactive (paused). Only	402	All watchers can be active (waiting for events) or inactive (paused). Only
173	active watchers will have their callbacks invoked. All callbacks will be	403	active watchers will have their callbacks invoked. All callbacks will be
174	called with at least two arguments: the watcher and a bitmask of received	404	called with at least two arguments: the watcher and a bitmask of received
175	events.	405	events.
176		406
177	Each watcher type has its associated bit in revents, so you can use the	407	Each watcher type has its associated bit in revents, so you can use the
178	same callback for multiple watchers. The event mask is named after the	408	same callback for multiple watchers. The event mask is named after the
179	type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,	409	type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
180	EV::periodic sets EV::PERIODIC and so on, with the exception of IO events	410	EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events
181	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which	411	(which can set both EV::READ and EV::WRITE bits).
182	uses EV::TIMEOUT).
183		412
184	In the rare case where one wants to create a watcher but not start it at	413	In the rare case where one wants to create a watcher but not start it at
185	the same time, each constructor has a variant with a trailing C<_ns> in	414	the same time, each constructor has a variant with a trailing C<_ns> in
186	its name, e.g. EV::io has a non-starting variant EV::io_ns and so on.	415	its name, e.g. EV::io has a non-starting variant EV::io_ns and so on.
187		416
…		…
207		436
208	=item $w->stop	437	=item $w->stop
209		438
210	Stop a watcher if it is active. Also clear any pending events (events that	439	Stop a watcher if it is active. Also clear any pending events (events that
211	have been received but that didn't yet result in a callback invocation),	440	have been received but that didn't yet result in a callback invocation),
212	regardless of wether the watcher was active or not.	441	regardless of whether the watcher was active or not.
213		442
214	=item $bool = $w->is_active	443	=item $bool = $w->is_active
215		444
216	Returns true if the watcher is active, false otherwise.	445	Returns true if the watcher is active, false otherwise.
217		446
…		…
247	The default priority of any newly-created watcher is 0.	476	The default priority of any newly-created watcher is 0.
248		477
249	Note that the priority semantics have not yet been fleshed out and are	478	Note that the priority semantics have not yet been fleshed out and are
250	subject to almost certain change.	479	subject to almost certain change.
251		480
252	=item $w->trigger ($revents)	481	=item $w->invoke ($revents)
253		482
254	Call the callback now with the given event mask.	483	Call the callback now with the given event mask.
		484
		485	=item $w->feed_event ($revents)
		486
		487	Feed some events on this watcher into EV. EV will react to this call as if
		488	the watcher had received the given C<$revents> mask.
		489
		490	=item $revents = $w->clear_pending
		491
		492	If the watcher is pending, this function clears its pending status and
		493	returns its C<$revents> bitset (as if its callback was invoked). If the
		494	watcher isn't pending it does nothing and returns C<0>.
255		495
256	=item $previous_state = $w->keepalive ($bool)	496	=item $previous_state = $w->keepalive ($bool)
257		497
258	Normally, C<EV::loop> will return when there are no active watchers	498	Normally, C<EV::loop> will return when there are no active watchers
259	(which is a "deadlock" because no progress can be made anymore). This is	499	(which is a "deadlock" because no progress can be made anymore). This is
260	convinient because it allows you to start your watchers (and your jobs),	500	convenient because it allows you to start your watchers (and your jobs),
261	call C<EV::loop> once and when it returns you know that all your jobs are	501	call C<EV::loop> once and when it returns you know that all your jobs are
262	finished (or they forgot to register some watchers for their task :).	502	finished (or they forgot to register some watchers for their task :).
263		503
264	Sometimes, however, this gets in your way, for example when you the module	504	Sometimes, however, this gets in your way, for example when the module
265	that calls C<EV::loop> (usually the main program) is not the same module	505	that calls C<EV::loop> (usually the main program) is not the same module
266	as a long-living watcher (for example a DNS client module written by	506	as a long-living watcher (for example a DNS client module written by
267	somebody else even). Then you might want any outstanding requests to be	507	somebody else even). Then you might want any outstanding requests to be
268	handled, but you would not want to keep C<EV::loop> from returning just	508	handled, but you would not want to keep C<EV::loop> from returning just
269	because you happen to have this long-running UDP port watcher.	509	because you happen to have this long-running UDP port watcher.
270		510
271	In this case you can clear the keepalive status, which means that even	511	In this case you can clear the keepalive status, which means that even
272	though your watcher is active, it won't keep C<EV::loop> from returning.	512	though your watcher is active, it won't keep C<EV::loop> from returning.
273		513
274	The initial value for keepalive is true (enabled), and you cna change it	514	The initial value for keepalive is true (enabled), and you can change it
275	any time.	515	any time.
276		516
277	Example: Register an IO watcher for some UDP socket but do not keep the	517	Example: Register an I/O watcher for some UDP socket but do not keep the
278	event loop from running just because of that watcher.	518	event loop from running just because of that watcher.
279		519
280	my $udp_socket = ...	520	my $udp_socket = ...
281	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };	521	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
282	$udp_watcher->keepalive (0);	522	$udp_watcher->keepalive (0);
283		523
284	=back	524	=item $loop = $w->loop
285		525
		526	Return the loop that this watcher is attached to.
286		527
		528	=back
		529
		530
287	=head2 WATCHER TYPES	531	=head1 WATCHER TYPES
288		532
289	Each of the following subsections describes a single watcher type.	533	Each of the following subsections describes a single watcher type.
290		534
291	=head3 IO WATCHERS - is this file descriptor readable or writable?	535	=head3 I/O WATCHERS - is this file descriptor readable or writable?
292		536
293	=over 4	537	=over 4
294		538
295	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	539	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
296		540
297	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback	541	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
		542
		543	=item $w = $loop->io ($fileno_or_fh, $eventmask, $callback)
		544
		545	=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
298		546
299	As long as the returned watcher object is alive, call the C<$callback>	547	As long as the returned watcher object is alive, call the C<$callback>
300	when at least one of events specified in C<$eventmask> occurs.	548	when at least one of events specified in C<$eventmask> occurs.
301		549
302	The $eventmask can be one or more of these constants ORed together:	550	The $eventmask can be one or more of these constants ORed together:
…		…
331	=over 4	579	=over 4
332		580
333	=item $w = EV::timer $after, $repeat, $callback	581	=item $w = EV::timer $after, $repeat, $callback
334		582
335	=item $w = EV::timer_ns $after, $repeat, $callback	583	=item $w = EV::timer_ns $after, $repeat, $callback
		584
		585	=item $w = $loop->timer ($after, $repeat, $callback)
		586
		587	=item $w = $loop->timer_ns ($after, $repeat, $callback)
336		588
337	Calls the callback after C<$after> seconds (which may be fractional). If	589	Calls the callback after C<$after> seconds (which may be fractional). If
338	C<$repeat> is non-zero, the timer will be restarted (with the $repeat	590	C<$repeat> is non-zero, the timer will be restarted (with the $repeat
339	value as $after) after the callback returns.	591	value as $after) after the callback returns.
340		592
…		…
381	=over 4	633	=over 4
382		634
383	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback	635	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
384		636
385	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback	637	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
		638
		639	=item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
		640
		641	=item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback)
386		642
387	Similar to EV::timer, but is not based on relative timeouts but on	643	Similar to EV::timer, but is not based on relative timeouts but on
388	absolute times. Apart from creating "simple" timers that trigger "at" the	644	absolute times. Apart from creating "simple" timers that trigger "at" the
389	specified time, it can also be used for non-drifting absolute timers and	645	specified time, it can also be used for non-drifting absolute timers and
390	more complex, cron-like, setups that are not adversely affected by time	646	more complex, cron-like, setups that are not adversely affected by time
…		…
400	This time simply fires at the wallclock time C<$at> and doesn't repeat. It	656	This time simply fires at the wallclock time C<$at> and doesn't repeat. It
401	will not adjust when a time jump occurs, that is, if it is to be run	657	will not adjust when a time jump occurs, that is, if it is to be run
402	at January 1st 2011 then it will run when the system time reaches or	658	at January 1st 2011 then it will run when the system time reaches or
403	surpasses this time.	659	surpasses this time.
404		660
405	=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0)	661	=item * repeating interval timer ($interval > 0, $reschedule_cb = 0)
406		662
407	In this mode the watcher will always be scheduled to time out at the	663	In this mode the watcher will always be scheduled to time out at the
408	next C<$at + N * $interval> time (for some integer N) and then repeat,	664	next C<$at + N * $interval> time (for some integer N) and then repeat,
409	regardless of any time jumps.	665	regardless of any time jumps.
410		666
…		…
428	time the periodic watcher gets scheduled, the reschedule callback	684	time the periodic watcher gets scheduled, the reschedule callback
429	($reschedule_cb) will be called with the watcher as first, and the current	685	($reschedule_cb) will be called with the watcher as first, and the current
430	time as second argument.	686	time as second argument.
431		687
432	I<This callback MUST NOT stop or destroy this or any other periodic	688	I<This callback MUST NOT stop or destroy this or any other periodic
433	watcher, ever>. If you need to stop it, return 1e30 and stop it	689	watcher, ever, and MUST NOT call any event loop functions or methods>. If
434	afterwards.	690	you need to stop it, return 1e30 and stop it afterwards. You may create
		691	and start a C<EV::prepare> watcher for this task.
435		692
436	It must return the next time to trigger, based on the passed time value	693	It must return the next time to trigger, based on the passed time value
437	(that is, the lowest time value larger than to the second argument). It	694	(that is, the lowest time value larger than or equal to to the second
438	will usually be called just before the callback will be triggered, but	695	argument). It will usually be called just before the callback will be
439	might be called at other times, too.	696	triggered, but might be called at other times, too.
440		697
441	This can be used to create very complex timers, such as a timer that	698	This can be used to create very complex timers, such as a timer that
442	triggers on each midnight, local time (actually 24 hours after the last	699	triggers on each midnight, local time (actually 24 hours after the last
443	midnight, to keep the example simple. If you know a way to do it correctly	700	midnight, to keep the example simple. If you know a way to do it correctly
444	in about the same space (without requiring elaborate modules), drop me a	701	in about the same space (without requiring elaborate modules), drop me a
…		…
465		722
466	=item $w->again	723	=item $w->again
467		724
468	Simply stops and starts the watcher again.	725	Simply stops and starts the watcher again.
469		726
		727	=item $time = $w->at
		728
		729	Return the time that the watcher is expected to trigger next.
		730
470	=back	731	=back
471		732
472		733
473	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!	734	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
474		735
475	=over 4	736	=over 4
476		737
477	=item $w = EV::signal $signal, $callback	738	=item $w = EV::signal $signal, $callback
478		739
479	=item $w = EV::signal_ns $signal, $callback	740	=item $w = EV::signal_ns $signal, $callback
		741
		742	=item $w = $loop->signal ($signal, $callback)
		743
		744	=item $w = $loop->signal_ns ($signal, $callback)
480		745
481	Call the callback when $signal is received (the signal can be specified by	746	Call the callback when $signal is received (the signal can be specified by
482	number or by name, just as with C<kill> or C<%SIG>).	747	number or by name, just as with C<kill> or C<%SIG>).
		748
		749	Only one event loop can grab a given signal - attempting to grab the same
		750	signal from two EV loops will crash the program immediately or cause data
		751	corruption.
483		752
484	EV will grab the signal for the process (the kernel only allows one	753	EV will grab the signal for the process (the kernel only allows one
485	component to receive a signal at a time) when you start a signal watcher,	754	component to receive a signal at a time) when you start a signal watcher,
486	and removes it again when you stop it. Perl does the same when you	755	and removes it again when you stop it. Perl does the same when you
487	add/remove callbacks to C<%SIG>, so watch out.	756	add/remove callbacks to C<%SIG>, so watch out.
…		…
507		776
508	=head3 CHILD WATCHERS - watch out for process status changes	777	=head3 CHILD WATCHERS - watch out for process status changes
509		778
510	=over 4	779	=over 4
511		780
512	=item $w = EV::child $pid, $callback	781	=item $w = EV::child $pid, $trace, $callback
513		782
514	=item $w = EV::child_ns $pid, $callback	783	=item $w = EV::child_ns $pid, $trace, $callback
515		784
		785	=item $w = $loop->child ($pid, $trace, $callback)
		786
		787	=item $w = $loop->child_ns ($pid, $trace, $callback)
		788
516	Call the callback when a status change for pid C<$pid> (or any pid if	789	Call the callback when a status change for pid C<$pid> (or any pid
517	C<$pid> is 0) has been received. More precisely: when the process receives	790	if C<$pid> is 0) has been received (a status change happens when the
		791	process terminates or is killed, or, when trace is true, additionally when
		792	it is stopped or continued). More precisely: when the process receives
518	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all	793	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
519	changed/zombie children and call the callback.	794	changed/zombie children and call the callback.
520		795
521	It is valid (and fully supported) to install a child watcher after a child	796	It is valid (and fully supported) to install a child watcher after a child
522	has exited but before the event loop has started its next iteration (for	797	has exited but before the event loop has started its next iteration (for
…		…
529	You can have as many pid watchers per pid as you want, they will all be	804	You can have as many pid watchers per pid as you want, they will all be
530	called.	805	called.
531		806
532	The C<child_ns> variant doesn't start (activate) the newly created watcher.	807	The C<child_ns> variant doesn't start (activate) the newly created watcher.
533		808
534	=item $w->set ($pid)	809	=item $w->set ($pid, $trace)
535		810
536	Reconfigures the watcher, see the constructor above for details. Can be called at	811	Reconfigures the watcher, see the constructor above for details. Can be called at
537	any time.	812	any time.
538		813
539	=item $current_pid = $w->pid	814	=item $current_pid = $w->pid
540		815
541	=item $old_pid = $w->pid ($new_pid)
542
543	Returns the previously set process id and optionally set a new one.	816	Returns the previously set process id and optionally set a new one.
544		817
545	=item $exit_status = $w->rstatus	818	=item $exit_status = $w->rstatus
546		819
547	Return the exit/wait status (as returned by waitpid, see the waitpid entry	820	Return the exit/wait status (as returned by waitpid, see the waitpid entry
…		…
560	=over 4	833	=over 4
561		834
562	=item $w = EV::stat $path, $interval, $callback	835	=item $w = EV::stat $path, $interval, $callback
563		836
564	=item $w = EV::stat_ns $path, $interval, $callback	837	=item $w = EV::stat_ns $path, $interval, $callback
		838
		839	=item $w = $loop->stat ($path, $interval, $callback)
		840
		841	=item $w = $loop->stat_ns ($path, $interval, $callback)
565		842
566	Call the callback when a file status change has been detected on	843	Call the callback when a file status change has been detected on
567	C<$path>. The C<$path> does not need to exist, changing from "path exists"	844	C<$path>. The C<$path> does not need to exist, changing from "path exists"
568	to "path does not exist" is a status change like any other.	845	to "path does not exist" is a status change like any other.
569		846
…		…
640		917
641	=item $w = EV::idle $callback	918	=item $w = EV::idle $callback
642		919
643	=item $w = EV::idle_ns $callback	920	=item $w = EV::idle_ns $callback
644		921
645	Call the callback when there are no pending io, timer/periodic, signal or	922	=item $w = $loop->idle ($callback)
646	child events, i.e. when the process is idle.	923
		924	=item $w = $loop->idle_ns ($callback)
		925
		926	Call the callback when there are no other pending watchers of the same or
		927	higher priority (excluding check, prepare and other idle watchers of the
		928	same or lower priority, of course). They are called idle watchers because
		929	when the watcher is the highest priority pending event in the process, the
		930	process is considered to be idle at that priority.
		931
		932	If you want a watcher that is only ever called when I<no> other events are
		933	outstanding you have to set the priority to C<EV::MINPRI>.
647		934
648	The process will not block as long as any idle watchers are active, and	935	The process will not block as long as any idle watchers are active, and
649	they will be called repeatedly until stopped.	936	they will be called repeatedly until stopped.
650		937
		938	For example, if you have idle watchers at priority C<0> and C<1>, and
		939	an I/O watcher at priority C<0>, then the idle watcher at priority C<1>
		940	and the I/O watcher will always run when ready. Only when the idle watcher
		941	at priority C<1> is stopped and the I/O watcher at priority C<0> is not
		942	pending with the C<0>-priority idle watcher be invoked.
		943
651	The C<idle_ns> variant doesn't start (activate) the newly created watcher.	944	The C<idle_ns> variant doesn't start (activate) the newly created watcher.
652		945
653	=back	946	=back
654		947
655		948
…		…
658	=over 4	951	=over 4
659		952
660	=item $w = EV::prepare $callback	953	=item $w = EV::prepare $callback
661		954
662	=item $w = EV::prepare_ns $callback	955	=item $w = EV::prepare_ns $callback
		956
		957	=item $w = $loop->prepare ($callback)
		958
		959	=item $w = $loop->prepare_ns ($callback)
663		960
664	Call the callback just before the process would block. You can still	961	Call the callback just before the process would block. You can still
665	create/modify any watchers at this point.	962	create/modify any watchers at this point.
666		963
667	See the EV::check watcher, below, for explanations and an example.	964	See the EV::check watcher, below, for explanations and an example.
…		…
677		974
678	=item $w = EV::check $callback	975	=item $w = EV::check $callback
679		976
680	=item $w = EV::check_ns $callback	977	=item $w = EV::check_ns $callback
681		978
		979	=item $w = $loop->check ($callback)
		980
		981	=item $w = $loop->check_ns ($callback)
		982
682	Call the callback just after the process wakes up again (after it has	983	Call the callback just after the process wakes up again (after it has
683	gathered events), but before any other callbacks have been invoked.	984	gathered events), but before any other callbacks have been invoked.
684		985
685	This is used to integrate other event-based software into the EV	986	This can be used to integrate other event-based software into the EV
686	mainloop: You register a prepare callback and in there, you create io and	987	mainloop: You register a prepare callback and in there, you create io and
687	timer watchers as required by the other software. Here is a real-world	988	timer watchers as required by the other software. Here is a real-world
688	example of integrating Net::SNMP (with some details left out):	989	example of integrating Net::SNMP (with some details left out):
689		990
690	our @snmp_watcher;	991	our @snmp_watcher;
…		…
695	or return;	996	or return;
696		997
697	# make the dispatcher handle any outstanding stuff	998	# make the dispatcher handle any outstanding stuff
698	... not shown	999	... not shown
699		1000
700	# create an IO watcher for each and every socket	1001	# create an I/O watcher for each and every socket
701	@snmp_watcher = (	1002	@snmp_watcher = (
702	(map { EV::io $_, EV::READ, sub { } }	1003	(map { EV::io $_, EV::READ, sub { } }
703	keys %{ $dispatcher->{_descriptors} }),	1004	keys %{ $dispatcher->{_descriptors} }),
704		1005
705	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]	1006	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
…		…
720	# make the dispatcher handle any new stuff	1021	# make the dispatcher handle any new stuff
721	... not shown	1022	... not shown
722	};	1023	};
723		1024
724	The callbacks of the created watchers will not be called as the watchers	1025	The callbacks of the created watchers will not be called as the watchers
725	are destroyed before this cna happen (remember EV::check gets called	1026	are destroyed before this can happen (remember EV::check gets called
726	first).	1027	first).
727		1028
728	The C<check_ns> variant doesn't start (activate) the newly created watcher.	1029	The C<check_ns> variant doesn't start (activate) the newly created watcher.
		1030
		1031	=item EV::CHECK constant issues
		1032
		1033	Like all other watcher types, there is a bitmask constant for use in
		1034	C<$revents> and other places. The C<EV::CHECK> is special as it has
		1035	the same name as the C<CHECK> sub called by Perl. This doesn't cause
		1036	big issues on newer perls (beginning with 5.8.9), but it means thatthe
		1037	constant must be I<inlined>, i.e. runtime calls will not work. That means
		1038	that as long as you always C<use EV> and then C<EV::CHECK> you are on the
		1039	safe side.
729		1040
730	=back	1041	=back
731		1042
732		1043
733	=head3 FORK WATCHERS - the audacity to resume the event loop after a fork	1044	=head3 FORK WATCHERS - the audacity to resume the event loop after a fork
…		…
740		1051
741	=item $w = EV::fork $callback	1052	=item $w = EV::fork $callback
742		1053
743	=item $w = EV::fork_ns $callback	1054	=item $w = EV::fork_ns $callback
744		1055
		1056	=item $w = $loop->fork ($callback)
		1057
		1058	=item $w = $loop->fork_ns ($callback)
		1059
745	Call the callback before the event loop is resumed in the child process	1060	Call the callback before the event loop is resumed in the child process
746	after a fork.	1061	after a fork.
747		1062
748	The C<fork_ns> variant doesn't start (activate) the newly created watcher.	1063	The C<fork_ns> variant doesn't start (activate) the newly created watcher.
749		1064
750	=back	1065	=back
751		1066
752		1067
		1068	=head3 EMBED WATCHERS - when one backend isn't enough...
		1069
		1070	This is a rather advanced watcher type that lets you embed one event loop
		1071	into another (currently only IO events are supported in the embedded
		1072	loop, other types of watchers might be handled in a delayed or incorrect
		1073	fashion and must not be used).
		1074
		1075	See the libev documentation at
		1076	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
		1077	(locally installed as F<EV::libev>) for more details.
		1078
		1079	In short, this watcher is most useful on BSD systems without working
		1080	kqueue to still be able to handle a large number of sockets:
		1081
		1082	my $socket_loop;
		1083
		1084	# check wether we use SELECT or POLL _and_ KQUEUE is supported
		1085	if (
		1086	(EV::backend & (EV::BACKEND_POLL \| EV::BACKEND_SELECT))
		1087	&& (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
		1088	) {
		1089	# use kqueue for sockets
		1090	$socket_loop = new EV::Loop EV::BACKEND_KQUEUE \| EV::FLAG_NOENV;
		1091	}
		1092
		1093	# use the default loop otherwise
		1094	$socket_loop \|\|= EV::default_loop;
		1095
		1096	=over 4
		1097
		1098	=item $w = EV::embed $otherloop[, $callback]
		1099
		1100	=item $w = EV::embed_ns $otherloop[, $callback]
		1101
		1102	=item $w = $loop->embed ($otherloop[, $callback])
		1103
		1104	=item $w = $loop->embed_ns ($otherloop[, $callback])
		1105
		1106	Call the callback when the embedded event loop (C<$otherloop>) has any
		1107	I/O activity. The C<$callback> is optional: if it is missing, then the
		1108	embedded event loop will be managed automatically (which is recommended),
		1109	otherwise you have to invoke C<sweep> yourself.
		1110
		1111	The C<embed_ns> variant doesn't start (activate) the newly created watcher.
		1112
		1113	=back
		1114
		1115	=head3 ASYNC WATCHERS - how to wake up another event loop
		1116
		1117	Async watchers are provided by EV, but have little use in perl directly,
		1118	as perl neither supports threads running in parallel nor direct access to
		1119	signal handlers or other contexts where they could be of value.
		1120
		1121	It is, however, possible to use them from the XS level.
		1122
		1123	Please see the libev documentation for further details.
		1124
		1125	=over 4
		1126
		1127	=item $w = EV::async $callback
		1128
		1129	=item $w = EV::async_ns $callback
		1130
		1131	=item $w->send
		1132
		1133	=item $bool = $w->async_pending
		1134
		1135	=back
		1136
		1137
		1138	=head1 PERL SIGNALS
		1139
		1140	While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour
		1141	with EV is as the same as any other C library: Perl-signals will only be
		1142	handled when Perl runs, which means your signal handler might be invoked
		1143	only the next time an event callback is invoked.
		1144
		1145	The solution is to use EV signal watchers (see C<EV::signal>), which will
		1146	ensure proper operations with regards to other event watchers.
		1147
		1148	If you cannot do this for whatever reason, you can also force a watcher
		1149	to be called on every event loop iteration by installing a C<EV::check>
		1150	watcher:
		1151
		1152	my $async_check = EV::check sub { };
		1153
		1154	This ensures that perl gets into control for a short time to handle any
		1155	pending signals, and also ensures (slightly) slower overall operation.
		1156
753	=head1 THREADS	1157	=head1 ITHREADS
754		1158
755	Threads are not supported by this module in any way. Perl pseudo-threads	1159	Ithreads are not supported by this module in any way. Perl pseudo-threads
756	is evil stuff and must die. As soon as Perl gains real threads I will work	1160	is evil stuff and must die. Real threads as provided by Coro are fully
757	on thread support for it.	1161	supported (and enhanced support is available via L<Coro::EV>).
758		1162
759	=head1 FORK	1163	=head1 FORK
760		1164
761	Most of the "improved" event delivering mechanisms of modern operating	1165	Most of the "improved" event delivering mechanisms of modern operating
762	systems have quite a few problems with fork(2) (to put it bluntly: it is	1166	systems have quite a few problems with fork(2) (to put it bluntly: it is
…		…
778	our $DIED = sub {	1182	our $DIED = sub {
779	warn "EV: error in callback (ignoring): $@";	1183	warn "EV: error in callback (ignoring): $@";
780	};	1184	};
781		1185
782	default_loop	1186	default_loop
783	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	1187	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
784		1188
785	1;	1189	1;
786		1190
787	=head1 SEE ALSO	1191	=head1 SEE ALSO
788		1192
789	L<EV::DNS>.	1193	L<EV::MakeMaker> - MakeMaker interface to XS API, L<EV::ADNS>
		1194	(asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as event
		1195	loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient thread
		1196	integration), L<Net::SNMP::EV> (asynchronous SNMP), L<AnyEvent> for
		1197	event-loop agnostic and portable event driven programming.
790		1198
791	=head1 AUTHOR	1199	=head1 AUTHOR
792		1200
793	Marc Lehmann <schmorp@schmorp.de>	1201	Marc Lehmann <schmorp@schmorp.de>
794	http://home.schmorp.de/	1202	http://home.schmorp.de/
795		1203
796	=cut	1204	=cut
797		1205

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Comparing EV/EV.pm (file contents): Revision 1.57 by root, Wed Nov 28 17:32:24 2007 UTC vs. Revision 1.130 by root, Sun Oct 24 17:58:41 2010 UTC

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Comparing EV/EV.pm (file contents):
Revision 1.57 by root, Wed Nov 28 17:32:24 2007 UTC vs.
Revision 1.130 by root, Sun Oct 24 17:58:41 2010 UTC