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

Comparing EV/EV.pm (file contents):
Revision 1.13 by root, Tue Oct 30 12:48:29 2007 UTC vs.
Revision 1.35 by root, Sat Nov 10 05:31:48 2007 UTC

1	=head1 NAME	1	=head1 NAME
2		2
3	EV - perl interface to libevent, monkey.org/~provos/libevent/	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		8
9	# TIMER	9	# TIMERS
10		10
11	my $w = EV::timer 2, 0, sub {	11	my $w = EV::timer 2, 0, sub {
12	warn "is called after 2s";	12	warn "is called after 2s";
13	};	13	};
14		14
15	my $w = EV::timer 2, 1, sub {	15	my $w = EV::timer 2, 2, sub {
16	warn "is called roughly every 2s (repeat = 1)";	16	warn "is called roughly every 2s (repeat = 2)";
17	};	17	};
18		18
19	undef $w; # destroy event watcher again	19	undef $w; # destroy event watcher again
20		20
21	my $w = EV::timer_abs 0, 60, sub {	21	my $w = EV::periodic 0, 60, 0, sub {
22	warn "is called every minute, on the minute, exactly";	22	warn "is called every minute, on the minute, exactly";
23	};	23	};
24		24
25	# IO	25	# IO
26		26
27	my $w = EV::io \*STDIN, EV::READ \| EV::PERSIST, sub {	27	my $w = EV::io *STDIN, EV::READ, sub {
28	my ($w, $events) = @_; # all callbacks get the watcher object and event mask	28	my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
29	if ($events & EV::TIMEOUT) {
30	warn "nothing received on stdin for 10 seconds, retrying";
31	} else {
32	warn "stdin is readable, you entered: ", <STDIN>;	29	warn "stdin is readable, you entered: ", <STDIN>;
33	}
34	};
35	$w->timeout (10);
36
37	my $w = EV::timed_io \*STDIN, EV::READ, 30, sub {
38	my ($w, $events) = @_;
39	if ($_[1] & EV::TIMEOUT) {
40	warn "nothing entered within 30 seconds, bye bye.\n";
41	$w->stop;
42	} else {
43	my $line = <STDIN>;
44	warn "you entered something, you again have 30 seconds.\n";
45	}
46	};	30	};
47		31
48	# SIGNALS	32	# SIGNALS
49		33
50	my $w = EV::signal 'QUIT', sub {	34	my $w = EV::signal 'QUIT', sub {
51	warn "sigquit received\n";	35	warn "sigquit received\n";
52	};	36	};
53		37
		38	# CHILD/PID STATUS CHANGES
		39
54	my $w = EV::signal 3, sub {	40	my $w = EV::child 666, sub {
55	warn "sigquit received (this is GNU/Linux, right?)\n";	41	my ($w, $revents) = @_;
		42	my $status = $w->rstatus;
56	};	43	};
57		44
58	# MAINLOOP	45	# MAINLOOP
59	EV::dispatch; # loop as long as watchers are active	46	EV::loop; # loop until EV::loop_done is called or all watchers stop
60	EV::loop; # the same thing
61	EV::loop EV::LOOP_ONCE; # block until some events could be handles	47	EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled
62	EV::loop EV::LOOP_NONBLOCK; # check and handle some events, but do not wait	48	EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block
63		49
64	=head1 DESCRIPTION	50	=head1 DESCRIPTION
65		51
66	This module provides an interface to libevent	52	This module provides an interface to libev
67	(L<http://monkey.org/~provos/libevent/>). You probably should acquaint	53	(L<http://software.schmorp.de/pkg/libev.html>).
68	yourself with its documentation and source code to be able to use this
69	module fully.
70
71	Please note thta this module disables the libevent EPOLL method by
72	default, see BUGS, below, if you need to enable it.
73		54
74	=cut	55	=cut
75		56
76	package EV;	57	package EV;
77		58
78	use strict;	59	use strict;
79		60
80	BEGIN {	61	BEGIN {
81	our $VERSION = '0.03';	62	our $VERSION = '0.7';
82	use XSLoader;	63	use XSLoader;
83	XSLoader::load "EV", $VERSION;	64	XSLoader::load "EV", $VERSION;
84	}	65	}
85		66
		67	@EV::Io::ISA =
		68	@EV::Timer::ISA =
		69	@EV::Periodic::ISA =
		70	@EV::Signal::ISA =
		71	@EV::Idle::ISA =
		72	@EV::Prepare::ISA =
		73	@EV::Check::ISA =
		74	@EV::Child::ISA = "EV::Watcher";
		75
86	=head1 BASIC INTERFACE	76	=head1 BASIC INTERFACE
87		77
88	=over 4	78	=over 4
89
90	=item $EV::NPRI
91
92	How many priority levels are available.
93		79
94	=item $EV::DIED	80	=item $EV::DIED
95		81
96	Must contain a reference to a function that is called when a callback	82	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	83	throws an exception (with $@ containing thr error). The default prints an
98	informative message and continues.	84	informative message and continues.
99		85
100	If this callback throws an exception it will be silently ignored.	86	If this callback throws an exception it will be silently ignored.
101		87
		88	=item $time = EV::time
		89
		90	Returns the current time in (fractional) seconds since the epoch.
		91
102	=item $time = EV::now	92	=item $time = EV::now
103		93
104	Returns the time in (fractional) seconds since the epoch.	94	Returns the time the last event loop iteration has been started. This
		95	is the time that (relative) timers are based on, and refering to it is
		96	usually faster then calling EV::time.
105		97
106	=item $version = EV::version
107
108	=item $method = EV::method	98	=item $method = EV::ev_method
109		99
110	Return version string and event polling method used.	100	Returns an integer describing the backend used by libev (EV::METHOD_SELECT
		101	or EV::METHOD_EPOLL).
111		102
112	=item EV::loop $flags # EV::LOOP_ONCE, EV::LOOP_ONESHOT	103	=item EV::loop [$flags]
113		104
114	=item EV::loopexit $after	105	Begin checking for events and calling callbacks. It returns when a
		106	callback calls EV::loop_done.
115		107
116	Exit any active loop or dispatch after C<$after> seconds or immediately if	108	The $flags argument can be one of the following:
117	C<$after> is missing or zero.
118		109
119	=item EV::dispatch	110	0 as above
		111	EV::LOOP_ONESHOT block at most once (wait, but do not loop)
		112	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
120		113
121	Same as C<EV::loop 0>.	114	=item EV::loop_done [$how]
122		115
123	=item EV::event $callback	116	When called with no arguments or an argument of 1, makes the innermost
		117	call to EV::loop return.
124		118
125	Creates a new event watcher waiting for nothing, calling the given callback.	119	When called with an agrument of 2, all calls to EV::loop will return as
		120	fast as possible.
126		121
		122	=back
		123
		124	=head2 WATCHER
		125
		126	A watcher is an object that gets created to record your interest in some
		127	event. For instance, if you want to wait for STDIN to become readable, you
		128	would create an EV::io watcher for that:
		129
		130	my $watcher = EV::io *STDIN, EV::READ, sub {
		131	my ($watcher, $revents) = @_;
		132	warn "yeah, STDIN should not be readable without blocking!\n"
		133	};
		134
		135	All watchers can be active (waiting for events) or inactive (paused). Only
		136	active watchers will have their callbacks invoked. All callbacks will be
		137	called with at least two arguments: the watcher and a bitmask of received
		138	events.
		139
		140	Each watcher type has its associated bit in revents, so you can use the
		141	same callback for multiple watchers. The event mask is named after the
		142	type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
		143	EV::periodic sets EV::PERIODIC and so on, with the exception of IO events
		144	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which
		145	uses EV::TIMEOUT).
		146
		147	In the rare case where one wants to create a watcher but not start it at
		148	the same time, each constructor has a variant with a trailing C<_ns> in
		149	its name, e.g. EV::io has a non-starting variant EV::io_ns and so on.
		150
		151	Please note that a watcher will automatically be stopped when the watcher
		152	object is destroyed, so you I<need> to keep the watcher objects returned by
		153	the constructors.
		154
		155	Also, all methods changing some aspect of a watcher (->set, ->priority,
		156	->fh and so on) automatically stop and start it again if it is active,
		157	which means pending events get lost.
		158
		159	=head2 WATCHER TYPES
		160
		161	Now lets move to the existing watcher types and asociated methods.
		162
		163	The following methods are available for all watchers. Then followes a
		164	description of each watcher constructor (EV::io, EV::timer, EV::periodic,
		165	EV::signal, EV::child, EV::idle, EV::prepare and EV::check), followed by
		166	any type-specific methods (if any).
		167
		168	=over 4
		169
		170	=item $w->start
		171
		172	Starts a watcher if it isn't active already. Does nothing to an already
		173	active watcher. By default, all watchers start out in the active state
		174	(see the description of the C<_ns> variants if you need stopped watchers).
		175
		176	=item $w->stop
		177
		178	Stop a watcher if it is active. Also clear any pending events (events that
		179	have been received but that didn't yet result in a callback invocation),
		180	regardless of wether the watcher was active or not.
		181
		182	=item $bool = $w->is_active
		183
		184	Returns true if the watcher is active, false otherwise.
		185
		186	=item $current_data = $w->data
		187
		188	=item $old_data = $w->data ($new_data)
		189
		190	Queries a freely usable data scalar on the watcher and optionally changes
		191	it. This is a way to associate custom data with a watcher:
		192
		193	my $w = EV::timer 60, 0, sub {
		194	warn $_[0]->data;
		195	};
		196	$w->data ("print me!");
		197
		198	=item $current_cb = $w->cb
		199
		200	=item $old_cb = $w->cb ($new_cb)
		201
		202	Queries the callback on the watcher and optionally changes it. You can do
		203	this at any time without the watcher restarting.
		204
		205	=item $current_priority = $w->priority
		206
		207	=item $old_priority = $w->priority ($new_priority)
		208
		209	Queries the priority on the watcher and optionally changes it. Pending
		210	watchers with higher priority will be invoked first. The valid range of
		211	priorities lies between EV::MAXPRI (default 2) and EV::MINPRI (default
		212	-2). If the priority is outside this range it will automatically be
		213	normalised to the nearest valid priority.
		214
		215	The default priority of any newly-created weatcher is 0.
		216
		217	=item $w->trigger ($revents)
		218
		219	Call the callback now with the given event mask.
		220
		221
127	=item my $w = EV::io $fileno_or_fh, $eventmask, $callback	222	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
128		223
129	=item my $w = EV::io_ns $fileno_or_fh, $eventmask, $callback	224	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
130		225
131	As long as the returned watcher object is alive, call the C<$callback>	226	As long as the returned watcher object is alive, call the C<$callback>
132	when the events specified in C<$eventmask> happen. Initially, the timeout	227	when the events specified in C<$eventmask>.
133	is disabled.
134		228
135	You can additionall set a timeout to occur on the watcher, but note that
136	this timeout will not be reset when you get an I/O event in the EV::PERSIST
137	case, and reaching a timeout will always stop the watcher even in the
138	EV::PERSIST case.
139
140	If you want a timeout to occur only after a specific time of inactivity, set
141	a repeating timeout and do NOT use EV::PERSIST.
142
143	Eventmask can be one or more of these constants ORed together:	229	The $eventmask can be one or more of these constants ORed together:
144		230
145	EV::READ wait until read() wouldn't block anymore	231	EV::READ wait until read() wouldn't block anymore
146	EV::WRITE wait until write() wouldn't block anymore	232	EV::WRITE wait until write() wouldn't block anymore
147	EV::PERSIST stay active after a (non-timeout) event occured
148		233
149	The C<io_ns> variant doesn't add/start the newly created watcher.	234	The C<io_ns> variant doesn't start (activate) the newly created watcher.
150		235
151	=item my $w = EV::timed_io $fileno_or_fh, $eventmask, $timeout, $callback	236	=item $w->set ($fileno_or_fh, $eventmask)
152		237
153	=item my $w = EV::timed_io_ns $fileno_or_fh, $eventmask, $timeout, $callback	238	Reconfigures the watcher, see the constructor above for details. Can be
		239	called at any time.
154		240
155	Same as C<io> and C<io_ns>, but also specifies a timeout (as if there was	241	=item $current_fh = $w->fh
156	a call to C<< $w->timeout ($timout, 1) >>. The persist flag is not allowed
157	and will automatically be cleared. The watcher will be restarted after each event.
158		242
159	If the timeout is zero or undef, no timeout will be set, and a normal	243	=item $old_fh = $w->fh ($new_fh)
160	watcher (with the persist flag set!) will be created.
161		244
162	This has the effect of timing out after the specified period of inactivity	245	Returns the previously set filehandle and optionally set a new one.
163	has happened.
164		246
165	Due to the design of libevent, this is also relatively inefficient, having	247	=item $current_eventmask = $w->events
166	one or two io watchers and a separate timeout watcher that you reset on
167	activity (by calling its C<start> method) is usually more efficient.
168		248
		249	=item $old_eventmask = $w->events ($new_eventmask)
		250
		251	Returns the previously set event mask and optionally set a new one.
		252
		253
169	=item my $w = EV::timer $after, $repeat, $callback	254	=item $w = EV::timer $after, $repeat, $callback
170		255
171	=item my $w = EV::timer_ns $after, $repeat, $callback	256	=item $w = EV::timer_ns $after, $repeat, $callback
172		257
173	Calls the callback after C<$after> seconds. If C<$repeat> is true, the	258	Calls the callback after C<$after> seconds. If C<$repeat> is non-zero,
174	timer will be restarted after the callback returns. This means that the	259	the timer will be restarted (with the $repeat value as $after) after the
175	callback would be called roughly every C<$after> seconds, prolonged by the	260	callback returns.
176	time the callback takes.
177		261
		262	This means that the callback would be called roughly after C<$after>
		263	seconds, and then every C<$repeat> seconds. "Roughly" because the time of
		264	callback processing is not taken into account, so the timer will slowly
		265	drift. If that isn't acceptable, look at EV::periodic.
		266
		267	The timer is based on a monotonic clock, that is if somebody is sitting
		268	in front of the machine while the timer is running and changes the system
		269	clock, the timer will nevertheless run (roughly) the same time.
		270
178	The C<timer_ns> variant doesn't add/start the newly created watcher.	271	The C<timer_ns> variant doesn't start (activate) the newly created watcher.
179		272
180	=item my $w = EV::timer_abs $at, $interval, $callback	273	=item $w->set ($after, $repeat)
181		274
182	=item my $w = EV::timer_abs_ns $at, $interval, $callback	275	Reconfigures the watcher, see the constructor above for details. Can be at
		276	any time.
183		277
184	Similar to EV::timer, but the time is given as an absolute point in time	278	=item $w->again
185	(C<$at>), plus an optional C<$interval>.
186		279
187	If the C<$interval> is zero, then the callback will be called at the time	280	Similar to the C<start> method, but has special semantics for repeating timers:
188	C<$at> if that is in the future, or as soon as possible if its in the
189	past. It will not automatically repeat.
190		281
191	If the C<$interval> is nonzero, then the watcher will always be scheduled	282	If the timer is active and repeating, reset the timeout to occur
192	to time out at the next C<$at + integer * $interval> time.	283	C<$repeat> seconds after now.
193		284
194	This can be used to schedule a callback to run at very regular intervals,	285	If the timer is active and non-repeating, it will be stopped.
195	as long as the processing time is less then the interval (otherwise	286
196	obviously events will be skipped).	287	If the timer is in active and repeating, start it.
		288
		289	Otherwise do nothing.
		290
		291	This behaviour is useful when you have a timeout for some IO
		292	operation. You create a timer object with the same value for C<$after> and
		293	C<$repeat>, and then, in the read/write watcher, run the C<again> method
		294	on the timeout.
		295
		296
		297	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
		298
		299	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
		300
		301	Similar to EV::timer, but is not based on relative timeouts but on
		302	absolute times. Apart from creating "simple" timers that trigger "at" the
		303	specified time, it can also be used for non-drifting absolute timers and
		304	more complex, cron-like, setups that are not adversely affected by time
		305	jumps (i.e. when the system clock is changed by explicit date -s or other
		306	means such as ntpd). It is also the most complex watcher type in EV.
		307
		308	It has three distinct "modes":
		309
		310	=over 4
		311
		312	=item * absolute timer ($interval = $reschedule_cb = 0)
		313
		314	This time simply fires at the wallclock time C<$at> and doesn't repeat. It
		315	will not adjust when a time jump occurs, that is, if it is to be run
		316	at January 1st 2011 then it will run when the system time reaches or
		317	surpasses this time.
		318
		319	=item * non-repeating interval timer ($interval > 0, $reschedule_cb = 0)
		320
		321	In this mode the watcher will always be scheduled to time out at the
		322	next C<$at + N * $interval> time (for some integer N) and then repeat,
		323	regardless of any time jumps.
		324
		325	This can be used to create timers that do not drift with respect to system
		326	time:
		327
		328	my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" };
		329
		330	That doesn't mean there will always be 3600 seconds in between triggers,
		331	but only that the the clalback will be called when the system time shows a
		332	full hour (UTC).
197		333
198	Another way to think about it (for the mathematically inclined) is that	334	Another way to think about it (for the mathematically inclined) is that
199	C<timer_abs> will try to tun the callback at the next possible time where	335	EV::periodic will try to run the callback in this mode at the next
200	C<$time = $at (mod $interval)>, regardless of any time jumps.	336	possible time where C<$time = $at (mod $interval)>, regardless of any time
		337	jumps.
201		338
		339	=item * manual reschedule mode ($reschedule_cb = coderef)
		340
		341	In this mode $interval and $at are both being ignored. Instead, each time
		342	the periodic watcher gets scheduled, the first callback ($reschedule_cb)
		343	will be called with the watcher as first, and the current time as second
		344	argument.
		345
		346	I<This callback MUST NOT stop or destroy this or any other periodic
		347	watcher, ever>. If you need to stop it, return 1e30 and stop it
		348	afterwards.
		349
		350	It must return the next time to trigger, based on the passed time value
		351	(that is, the lowest time value larger than to the second argument). It
		352	will usually be called just before the callback will be triggered, but
		353	might be called at other times, too.
		354
		355	This can be used to create very complex timers, such as a timer that
		356	triggers on each midnight, local time (actually 24 hours after the last
		357	midnight, to keep the example simple. If you know a way to do it correctly
		358	in about the same space (without requiring elaborate modules), drop me a
		359	note :):
		360
		361	my $daily = EV::periodic 0, 0, sub {
		362	my ($w, $now) = @_;
		363
		364	use Time::Local ();
		365	my (undef, undef, undef, $d, $m, $y) = localtime $now;
		366	86400 + Time::Local::timelocal 0, 0, 0, $d, $m, $y
		367	}, sub {
		368	print "it's midnight or likely shortly after, now\n";
		369	};
		370
		371	=back
		372
202	The C<timer_abs_ns> variant doesn't add/start the newly created watcher.	373	The C<periodic_ns> variant doesn't start (activate) the newly created watcher.
203		374
		375	=item $w->set ($at, $interval, $reschedule_cb)
		376
		377	Reconfigures the watcher, see the constructor above for details. Can be at
		378	any time.
		379
		380	=item $w->again
		381
		382	Simply stops and starts the watcher again.
		383
		384
204	=item my $w = EV::signal $signal, $callback	385	=item $w = EV::signal $signal, $callback
205		386
206	=item my $w = EV::signal_ns $signal, $callback	387	=item $w = EV::signal_ns $signal, $callback
207		388
208	Call the callback when $signal is received (the signal can be specified	389	Call the callback when $signal is received (the signal can be specified
209	by number or by name, just as with kill or %SIG). Signal watchers are	390	by number or by name, just as with kill or %SIG).
210	persistent no natter what.
211		391
212	EV will grab the signal for the process (the kernel only allows one	392	EV will grab the signal for the process (the kernel only allows one
213	component to receive signals) when you start a signal watcher, and	393	component to receive a signal at a time) when you start a signal watcher,
214	removes it again when you stop it. Pelr does the same when you add/remove	394	and removes it again when you stop it. Perl does the same when you
215	callbacks to %SIG, so watch out.	395	add/remove callbacks to %SIG, so watch out.
216		396
217	Unfortunately, only one handler can be registered per signal. Screw	397	You can have as many signal watchers per signal as you want.
218	libevent.
219		398
220	The C<signal_ns> variant doesn't add/start the newly created watcher.	399	The C<signal_ns> variant doesn't start (activate) the newly created watcher.
		400
		401	=item $w->set ($signal)
		402
		403	Reconfigures the watcher, see the constructor above for details. Can be at
		404	any time.
		405
		406	=item $current_signum = $w->signal
		407
		408	=item $old_signum = $w->signal ($new_signal)
		409
		410	Returns the previously set signal (always as a number not name) and
		411	optionally set a new one.
		412
		413
		414	=item $w = EV::child $pid, $callback
		415
		416	=item $w = EV::child_ns $pid, $callback
		417
		418	Call the callback when a status change for pid C<$pid> (or any pid
		419	if C<$pid> is 0) has been received. More precisely: when the process
		420	receives a SIGCHLD, EV will fetch the outstanding exit/wait status for all
		421	changed/zombie children and call the callback.
		422
		423	You can access both status and pid by using the C<rstatus> and C<rpid>
		424	methods on the watcher object.
		425
		426	You can have as many pid watchers per pid as you want.
		427
		428	The C<child_ns> variant doesn't start (activate) the newly created watcher.
		429
		430	=item $w->set ($pid)
		431
		432	Reconfigures the watcher, see the constructor above for details. Can be at
		433	any time.
		434
		435	=item $current_pid = $w->pid
		436
		437	=item $old_pid = $w->pid ($new_pid)
		438
		439	Returns the previously set process id and optionally set a new one.
		440
		441	=item $exit_status = $w->rstatus
		442
		443	Return the exit/wait status (as returned by waitpid, see the waitpid entry
		444	in perlfunc).
		445
		446	=item $pid = $w->rpid
		447
		448	Return the pid of the awaited child (useful when you have installed a
		449	watcher for all pids).
		450
		451
		452	=item $w = EV::idle $callback
		453
		454	=item $w = EV::idle_ns $callback
		455
		456	Call the callback when there are no pending io, timer/periodic, signal or
		457	child events, i.e. when the process is idle.
		458
		459	The process will not block as long as any idle watchers are active, and
		460	they will be called repeatedly until stopped.
		461
		462	The C<idle_ns> variant doesn't start (activate) the newly created watcher.
		463
		464
		465	=item $w = EV::prepare $callback
		466
		467	=item $w = EV::prepare_ns $callback
		468
		469	Call the callback just before the process would block. You can still
		470	create/modify any watchers at this point.
		471
		472	See the EV::check watcher, below, for explanations and an example.
		473
		474	The C<prepare_ns> variant doesn't start (activate) the newly created watcher.
		475
		476
		477	=item $w = EV::check $callback
		478
		479	=item $w = EV::check_ns $callback
		480
		481	Call the callback just after the process wakes up again (after it has
		482	gathered events), but before any other callbacks have been invoked.
		483
		484	This is used to integrate other event-based software into the EV
		485	mainloop: You register a prepare callback and in there, you create io and
		486	timer watchers as required by the other software. Here is a real-world
		487	example of integrating Net::SNMP (with some details left out):
		488
		489	our @snmp_watcher;
		490
		491	our $snmp_prepare = EV::prepare sub {
		492	# do nothing unless active
		493	$dispatcher->{_event_queue_h}
		494	or return;
		495
		496	# make the dispatcher handle any outstanding stuff
		497
		498	# create an IO watcher for each and every socket
		499	@snmp_watcher = (
		500	(map { EV::io $_, EV::READ, sub { } }
		501	keys %{ $dispatcher->{_descriptors} }),
		502	);
		503
		504	# if there are any timeouts, also create a timer
		505	push @snmp_watcher, EV::timer $event->[Net::SNMP::Dispatcher::_TIME] - EV::now, 0, sub { }
		506	if $event->[Net::SNMP::Dispatcher::_ACTIVE];
		507	};
		508
		509	The callbacks are irrelevant, the only purpose of those watchers is
		510	to wake up the process as soon as one of those events occurs (socket
		511	readable, or timer timed out). The corresponding EV::check watcher will then
		512	clean up:
		513
		514	our $snmp_check = EV::check sub {
		515	# destroy all watchers
		516	@snmp_watcher = ();
		517
		518	# make the dispatcher handle any new stuff
		519	};
		520
		521	The callbacks of the created watchers will not be called as the watchers
		522	are destroyed before this cna happen (remember EV::check gets called
		523	first).
		524
		525	The C<check_ns> variant doesn't start (activate) the newly created watcher.
221		526
222	=back	527	=back
223		528
224	=head1 THE EV::Event CLASS
225
226	All EV functions creating an event watcher (designated by C<my $w =>
227	above) support the following methods on the returned watcher object:
228
229	=over 4
230
231	=item $w->add ($timeout)
232
233	Stops and (re-)starts the event watcher, setting the optional timeout to
234	the given value, or clearing the timeout if none is given.
235
236	=item $w->start
237
238	Stops and (re-)starts the event watcher without touching the timeout.
239
240	=item $w->del
241
242	=item $w->stop
243
244	Stop the event watcher if it was started.
245
246	=item $current_callback = $w->cb
247
248	=item $old_callback = $w->cb ($new_callback)
249
250	Return the previously set callback and optionally set a new one.
251
252	=item $current_fh = $w->fh
253
254	=item $old_fh = $w->fh ($new_fh)
255
256	Returns the previously set filehandle and optionally set a new one (also
257	clears the EV::SIGNAL flag when setting a filehandle).
258
259	=item $current_signal = $w->signal
260
261	=item $old_signal = $w->signal ($new_signal)
262
263	Returns the previously set signal number and optionally set a new one (also sets
264	the EV::SIGNAL flag when setting a signal).
265
266	=item $current_eventmask = $w->events
267
268	=item $old_eventmask = $w->events ($new_eventmask)
269
270	Returns the previously set event mask and optionally set a new one.
271
272	=item $w->timeout ($after, $repeat)
273
274	Resets the timeout (see C<EV::timer> for details).
275
276	=item $w->timeout_abs ($at, $interval)
277
278	Resets the timeout (see C<EV::timer_abs> for details).
279
280	=item $w->priority_set ($priority)
281
282	Set the priority of the watcher to C<$priority> (0 <= $priority < $EV::NPRI).
283
284	=back
285
286	=head1 THREADS	529	=head1 THREADS
287		530
288	Threads are not supported by this in any way. Perl pseudo-threads is evil	531	Threads are not supported by this in any way. Perl pseudo-threads is evil
289	and must die.	532	stuff and must die.
290
291	=head1 BUGS
292
293	Lots. Libevent itself isn't well tested and rather buggy, and this module
294	is quite new at the moment.
295
296	Please note that the epoll method is not, in general, reliable in programs
297	that use fork (even if no libveent calls are being made in the forked
298	process). If your program behaves erratically, try setting the environment
299	variable C<EVENT_NOEPOLL> first when running the program.
300
301	In general, if you fork, then you can only use the EV module in one of the
302	children.
303		533
304	=cut	534	=cut
305		535
306	our $DIED = sub {	536	our $DIED = sub {
307	warn "EV: error in callback (ignoring): $@";	537	warn "EV: error in callback (ignoring): $@";
308	};	538	};
309		539
310	our $NPRI = 4;	540	default_loop
311	our $BASE = init;	541	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';
312	priority_init $NPRI;
313
314	push @AnyEvent::REGISTRY, [EV => "EV::AnyEvent"];
315		542
316	1;	543	1;
317		544
318	=head1 SEE ALSO	545	=head1 SEE ALSO
319		546
320	L<EV::DNS>, L<event(3)>, L<event.h>, L<evdns.h>.
321	L<EV::AnyEvent>.	547	L<EV::DNS>, L<EV::AnyEvent>.
322		548
323	=head1 AUTHOR	549	=head1 AUTHOR
324		550
325	Marc Lehmann <schmorp@schmorp.de>	551	Marc Lehmann <schmorp@schmorp.de>
326	http://home.schmorp.de/	552	http://home.schmorp.de/

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Comparing EV/EV.pm (file contents): Revision 1.13 by root, Tue Oct 30 12:48:29 2007 UTC vs. Revision 1.35 by root, Sat Nov 10 05:31:48 2007 UTC

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Revision 1.13 by root, Tue Oct 30 12:48:29 2007 UTC vs.
Revision 1.35 by root, Sat Nov 10 05:31:48 2007 UTC