[ViewVC] Diff of: cvs/EV/README

Comparing EV/README (file contents):
Revision 1.28 by root, Tue Jul 8 18:56:48 2008 UTC vs.
Revision 1.44 by root, Mon Jul 13 19:47:53 2015 UTC

…		…
2	EV - perl interface to libev, a high performance full-featured event	2	EV - perl interface to libev, a high performance full-featured event
3	loop	3	loop
4		4
5	SYNOPSIS	5	SYNOPSIS
6	use EV;	6	use EV;
7		7
8	# TIMERS	8	# TIMERS
9		9
10	my $w = EV::timer 2, 0, sub {	10	my $w = EV::timer 2, 0, sub {
11	warn "is called after 2s";	11	warn "is called after 2s";
12	};	12	};
13		13
14	my $w = EV::timer 2, 2, sub {	14	my $w = EV::timer 2, 2, sub {
15	warn "is called roughly every 2s (repeat = 2)";	15	warn "is called roughly every 2s (repeat = 2)";
16	};	16	};
17		17
18	undef $w; # destroy event watcher again	18	undef $w; # destroy event watcher again
19		19
20	my $w = EV::periodic 0, 60, 0, sub {	20	my $w = EV::periodic 0, 60, 0, sub {
21	warn "is called every minute, on the minute, exactly";	21	warn "is called every minute, on the minute, exactly";
22	};	22	};
		23
23		24	# IO
24	# IO	25
25
26	my $w = EV::io *STDIN, EV::READ, sub {	26	my $w = EV::io *STDIN, EV::READ, sub {
27	my ($w, $revents) = @_; # all callbacks receive the watcher and event mask	27	my ($w, $revents) = @_; # all callbacks receive the watcher and event mask
28	warn "stdin is readable, you entered: ", <STDIN>;	28	warn "stdin is readable, you entered: ", <STDIN>;
29	};	29	};
30		30
31	# SIGNALS	31	# SIGNALS
32		32
33	my $w = EV::signal 'QUIT', sub {	33	my $w = EV::signal 'QUIT', sub {
34	warn "sigquit received\n";	34	warn "sigquit received\n";
35	};	35	};
36		36
37	# CHILD/PID STATUS CHANGES	37	# CHILD/PID STATUS CHANGES
38		38
39	my $w = EV::child 666, 0, sub {	39	my $w = EV::child 666, 0, sub {
40	my ($w, $revents) = @_;	40	my ($w, $revents) = @_;
41	my $status = $w->rstatus;	41	my $status = $w->rstatus;
42	};	42	};
43		43
44	# STAT CHANGES	44	# STAT CHANGES
45	my $w = EV::stat "/etc/passwd", 10, sub {	45	my $w = EV::stat "/etc/passwd", 10, sub {
46	my ($w, $revents) = @_;	46	my ($w, $revents) = @_;
47	warn $w->path, " has changed somehow.\n";	47	warn $w->path, " has changed somehow.\n";
48	};	48	};
49		49
50	# MAINLOOP	50	# MAINLOOP
51	EV::loop; # loop until EV::unloop is called or all watchers stop	51	EV::run; # loop until EV::break is called or all watchers stop
52	EV::loop EV::LOOP_ONESHOT; # block until at least one event could be handled	52	EV::run EV::RUN_ONCE; # block until at least one event could be handled
53	EV::loop EV::LOOP_NONBLOCK; # try to handle same events, but do not block	53	EV::run EV::RUN_NOWAIT; # try to handle same events, but do not block
		54
		55	BEFORE YOU START USING THIS MODULE
		56	If you only need timer, I/O, signal, child and idle watchers and not the
		57	advanced functionality of this module, consider using AnyEvent instead,
		58	specifically the simplified API described in AE.
		59
		60	When used with EV as backend, the AE API is as fast as the native EV
		61	API, but your programs/modules will still run with many other event
		62	loops.
54		63
55	DESCRIPTION	64	DESCRIPTION
56	This module provides an interface to libev	65	This module provides an interface to libev
57	(<http://software.schmorp.de/pkg/libev.html>). While the documentation	66	(<http://software.schmorp.de/pkg/libev.html>). While the documentation
58	below is comprehensive, one might also consult the documentation of	67	below is comprehensive, one might also consult the documentation of
59	libev itself (<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod>)	68	libev itself (<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod> or
60	for more subtle details on watcher semantics or some discussion on the	69	perldoc EV::libev) for more subtle details on watcher semantics or some
61	available backends, or how to force a specific backend with	70	discussion on the available backends, or how to force a specific backend
62	"LIBEV_FLAGS", or just about in any case because it has much more	71	with "LIBEV_FLAGS", or just about in any case because it has much more
63	detailed information.	72	detailed information.
64		73
65	This module is very fast and scalable. It is actually so fast that you	74	This module is very fast and scalable. It is actually so fast that you
66	can use it through the AnyEvent module, stay portable to other event	75	can use it through the AnyEvent module, stay portable to other event
67	loops (if you don't rely on any watcher types not available through it)	76	loops (if you don't rely on any watcher types not available through it)
68	and still be faster than with any other event loop currently supported	77	and still be faster than with any other event loop currently supported
69	in Perl.	78	in Perl.
		79
		80	PORTING FROM EV 3.X to 4.X
		81	EV version 4 introduces a number of incompatible changes summarised
		82	here. According to the depreciation strategy used by libev, there is a
		83	compatibility layer in place so programs should continue to run
		84	unchanged (the XS interface lacks this layer, so programs using that one
		85	need to be updated).
		86
		87	This compatibility layer will be switched off in some future release.
		88
		89	All changes relevant to Perl are renames of symbols, functions and
		90	methods:
		91
		92	EV::loop => EV::run
		93	EV::LOOP_NONBLOCK => EV::RUN_NOWAIT
		94	EV::LOOP_ONESHOT => EV::RUN_ONCE
		95
		96	EV::unloop => EV::break
		97	EV::UNLOOP_CANCEL => EV::BREAK_CANCEL
		98	EV::UNLOOP_ONE => EV::BREAK_ONE
		99	EV::UNLOOP_ALL => EV::BREAK_ALL
		100
		101	EV::TIMEOUT => EV::TIMER
		102
		103	EV::loop_count => EV::iteration
		104	EV::loop_depth => EV::depth
		105	EV::loop_verify => EV::verify
		106
		107	The loop object methods corresponding to the functions above have been
		108	similarly renamed.
		109
		110	MODULE EXPORTS
		111	This module does not export any symbols.
70		112
71	EVENT LOOPS	113	EVENT LOOPS
72	EV supports multiple event loops: There is a single "default event loop"	114	EV supports multiple event loops: There is a single "default event loop"
73	that can handle everything including signals and child watchers, and any	115	that can handle everything including signals and child watchers, and any
74	number of "dynamic event loops" that can use different backends (with	116	number of "dynamic event loops" that can use different backends (with
…		…
81	default loop as this is fastest (perl-wise), best supported by other	123	default loop as this is fastest (perl-wise), best supported by other
82	modules (e.g. AnyEvent or Coro) and most portable event loop.	124	modules (e.g. AnyEvent or Coro) and most portable event loop.
83		125
84	For specific programs you can create additional event loops dynamically.	126	For specific programs you can create additional event loops dynamically.
85		127
86	If you want to take avdantage of kqueue (which often works properly for	128	If you want to take advantage of kqueue (which often works properly for
87	sockets only) even though the default loop doesn't enable it, you can	129	sockets only) even though the default loop doesn't enable it, you can
88	embed a kqueue loop into the default loop: running the default loop	130	embed a kqueue loop into the default loop: running the default loop
89	will then also service the kqueue loop to some extent. See the example	131	will then also service the kqueue loop to some extent. See the example
90	in the section about embed watchers for an example on how to achieve	132	in the section about embed watchers for an example on how to achieve
91	that.	133	that.
92		134
93	$loop = new EV::loop [$flags]	135	$loop = new EV::Loop [$flags]
94	Create a new event loop as per the specified flags. Please refer to	136	Create a new event loop as per the specified flags. Please refer to
95	the "ev_loop_new ()" function description in the libev documentation	137	the "ev_loop_new ()" function description in the libev documentation
96	(<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTI	138	(<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTI
97	ONS>) for more info.	139	ONS>, or locally-installed as EV::libev manpage) for more info.
98		140
99	The loop will automatically be destroyed when it is no longer	141	The loop will automatically be destroyed when it is no longer
100	referenced by any watcher and the loop object goes out of scope.	142	referenced by any watcher and the loop object goes out of scope.
101		143
102	Using "EV::FLAG_FORKCHECK" is recommended, as only the default event	144	If you are not embedding the loop, then Using "EV::FLAG_FORKCHECK"
103	loop is protected by this module.	145	is recommended, as only the default event loop is protected by this
		146	module. If you are embedding this loop in the default loop, this
		147	is not necessary, as "EV::embed" automatically does the right thing
		148	on fork.
104		149
105	$loop->loop_fork	150	$loop->loop_fork
106	Must be called after a fork in the child, before entering or	151	Must be called after a fork in the child, before entering or
107	continuing the event loop. An alternative is to use	152	continuing the event loop. An alternative is to use
108	"EV::FLAG_FORKCHECK" which calls this function automatically, at	153	"EV::FLAG_FORKCHECK" which calls this function automatically, at
109	some performance loss (refer to the libev documentation).	154	some performance loss (refer to the libev documentation).
110		155
111	$loop->loop_verify	156	$loop->verify
112	Calls "ev_verify" to make internal consistency checks (for debugging	157	Calls "ev_verify" to make internal consistency checks (for debugging
113	libev) and abort the program if any data structures were found to be	158	libev) and abort the program if any data structures were found to be
114	corrupted.	159	corrupted.
115		160
116	$loop = EV::default_loop [$flags]	161	$loop = EV::default_loop [$flags]
…		…
143	Returns the current time in (fractional) seconds since the epoch.	188	Returns the current time in (fractional) seconds since the epoch.
144		189
145	$time = EV::now	190	$time = EV::now
146	$time = $loop->now	191	$time = $loop->now
147	Returns the time the last event loop iteration has been started.	192	Returns the time the last event loop iteration has been started.
148	This is the time that (relative) timers are based on, and refering	193	This is the time that (relative) timers are based on, and referring
149	to it is usually faster then calling EV::time.	194	to it is usually faster then calling EV::time.
		195
		196	EV::now_update
		197	$loop->now_update
		198	Establishes the current time by querying the kernel, updating the
		199	time returned by "EV::now" in the progress. This is a costly
		200	operation and is usually done automatically within "EV::loop".
		201
		202	This function is rarely useful, but when some event callback runs
		203	for a very long time without entering the event loop, updating
		204	libev's idea of the current time is a good idea.
		205
		206	EV::suspend
		207	$loop->suspend
		208	EV::resume
		209	$loop->resume
		210	These two functions suspend and resume a loop, for use when the loop
		211	is not used for a while and timeouts should not be processed.
		212
		213	A typical use case would be an interactive program such as a game:
		214	When the user presses "^Z" to suspend the game and resumes it an
		215	hour later it would be best to handle timeouts as if no time had
		216	actually passed while the program was suspended. This can be
		217	achieved by calling "suspend" in your "SIGTSTP" handler, sending
		218	yourself a "SIGSTOP" and calling "resume" directly afterwards to
		219	resume timer processing.
		220
		221	Effectively, all "timer" watchers will be delayed by the time spend
		222	between "suspend" and "resume", and all "periodic" watchers will be
		223	rescheduled (that is, they will lose any events that would have
		224	occured while suspended).
		225
		226	After calling "suspend" you must not call any function on the
		227	given loop other than "resume", and you must not call "resume"
		228	without a previous call to "suspend".
		229
		230	Calling "suspend"/"resume" has the side effect of updating the event
		231	loop time (see "now_update").
150		232
151	$backend = EV::backend	233	$backend = EV::backend
152	$backend = $loop->backend	234	$backend = $loop->backend
153	Returns an integer describing the backend used by libev	235	Returns an integer describing the backend used by libev
154	(EV::METHOD_SELECT or EV::METHOD_EPOLL).	236	(EV::BACKEND_SELECT or EV::BACKEND_EPOLL).
155		237
156	EV::loop [$flags]	238	$active = EV::run [$flags]
157	$loop->loop ([$flags])	239	$active = $loop->run ([$flags])
158	Begin checking for events and calling callbacks. It returns when a	240	Begin checking for events and calling callbacks. It returns when a
159	callback calls EV::unloop.	241	callback calls EV::break or the flasg are nonzero (in which case the
		242	return value is true) or when there are no active watchers which
		243	reference the loop (keepalive is true), in which case the return
		244	value will be false. The returnv alue can generally be interpreted
		245	as "if true, there is more work left to do".
160		246
161	The $flags argument can be one of the following:	247	The $flags argument can be one of the following:
162		248
163	0 as above	249	0 as above
164	EV::LOOP_ONESHOT block at most once (wait, but do not loop)	250	EV::RUN_ONCE block at most once (wait, but do not loop)
165	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)	251	EV::RUN_NOWAIT do not block at all (fetch/handle events but do not wait)
166		252
167	EV::unloop [$how]	253	EV::break [$how]
168	$loop->unloop ([$how])	254	$loop->break ([$how])
169	When called with no arguments or an argument of EV::UNLOOP_ONE,	255	When called with no arguments or an argument of EV::BREAK_ONE, makes
170	makes the innermost call to EV::loop return.	256	the innermost call to EV::loop return.
171		257
172	When called with an argument of EV::UNLOOP_ALL, all calls to	258	When called with an argument of EV::BREAK_ALL, all calls to EV::loop
173	EV::loop will return as fast as possible.	259	will return as fast as possible.
174		260
175	$count = EV::loop_count	261	When called with an argument of EV::BREAK_CANCEL, any pending break
176	$count = $loop->loop_count	262	will be cancelled.
		263
		264	$count = EV::iteration
		265	$count = $loop->iteration
177	Return the number of times the event loop has polled for new events.	266	Return the number of times the event loop has polled for new events.
178	Sometiems useful as a generation counter.	267	Sometimes useful as a generation counter.
179		268
180	EV::once $fh_or_undef, $events, $timeout, $cb->($revents)	269	EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
181	$loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))	270	$loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
182	This function rolls together an I/O and a timer watcher for a single	271	This function rolls together an I/O and a timer watcher for a single
183	one-shot event without the need for managing a watcher object.	272	one-shot event without the need for managing a watcher object.
…		…
192	Otherwise a EV::timer with this value will be started.	281	Otherwise a EV::timer with this value will be started.
193		282
194	When an error occurs or either the timeout or I/O watcher triggers,	283	When an error occurs or either the timeout or I/O watcher triggers,
195	then the callback will be called with the received event set (in	284	then the callback will be called with the received event set (in
196	general you can expect it to be a combination of "EV::ERROR",	285	general you can expect it to be a combination of "EV::ERROR",
197	"EV::READ", "EV::WRITE" and "EV::TIMEOUT").	286	"EV::READ", "EV::WRITE" and "EV::TIMER").
198		287
199	EV::once doesn't return anything: the watchers stay active till	288	EV::once doesn't return anything: the watchers stay active till
200	either of them triggers, then they will be stopped and freed, and	289	either of them triggers, then they will be stopped and freed, and
201	the callback invoked.	290	the callback invoked.
202		291
203	EV::feed_fd_event ($fd, $revents)	292	EV::feed_fd_event $fd, $revents
204	$loop->feed_fd_event ($fd, $revents)	293	$loop->feed_fd_event ($fd, $revents)
205	Feed an event on a file descriptor into EV. EV will react to this	294	Feed an event on a file descriptor into EV. EV will react to this
206	call as if the readyness notifications specified by $revents (a	295	call as if the readyness notifications specified by $revents (a
207	combination of "EV::READ" and "EV::WRITE") happened on the file	296	combination of "EV::READ" and "EV::WRITE") happened on the file
208	descriptor $fd.	297	descriptor $fd.
209		298
210	EV::feed_signal_event ($signal)	299	EV::feed_signal_event $signal
211	Feed a signal event into EV. EV will react to this call as if the	300	Feed a signal event into the default loop. EV will react to this
212	signal specified by $signal had occured.	301	call as if the signal specified by $signal had occured.
		302
		303	EV::feed_signal $signal
		304	Feed a signal event into EV - unlike "EV::feed_signal_event", this
		305	works regardless of which loop has registered the signal, and is
		306	mainly useful fro custom signal implementations.
213		307
214	EV::set_io_collect_interval $time	308	EV::set_io_collect_interval $time
215	$loop->set_io_collect_interval ($time)	309	$loop->set_io_collect_interval ($time)
216	EV::set_timeout_collect_interval $time	310	EV::set_timeout_collect_interval $time
217	$loop->set_timeout_collect_interval ($time)	311	$loop->set_timeout_collect_interval ($time)
218	These advanced functions set the minimum block interval when polling	312	These advanced functions set the minimum block interval when polling
219	for I/O events and the minimum wait interval for timer events. See	313	for I/O events and the minimum wait interval for timer events. See
220	the libev documentation at	314	the libev documentation at
221	<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONT	315	<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONT
222	ROLLING_THE_EVENT_LOOP> for a more detailed discussion.	316	ROLLING_THE_EVENT_LOOP> (locally installed as EV::libev) for a more
		317	detailed discussion.
		318
		319	$count = EV::pending_count
		320	$count = $loop->pending_count
		321	Returns the number of currently pending watchers.
		322
		323	EV::invoke_pending
		324	$loop->invoke_pending
		325	Invoke all currently pending watchers.
223		326
224	WATCHER OBJECTS	327	WATCHER OBJECTS
225	A watcher is an object that gets created to record your interest in some	328	A watcher is an object that gets created to record your interest in some
226	event. For instance, if you want to wait for STDIN to become readable,	329	event. For instance, if you want to wait for STDIN to become readable,
227	you would create an EV::io watcher for that:	330	you would create an EV::io watcher for that:
…		…
236	will be called with at least two arguments: the watcher and a bitmask of	339	will be called with at least two arguments: the watcher and a bitmask of
237	received events.	340	received events.
238		341
239	Each watcher type has its associated bit in revents, so you can use the	342	Each watcher type has its associated bit in revents, so you can use the
240	same callback for multiple watchers. The event mask is named after the	343	same callback for multiple watchers. The event mask is named after the
241	type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,	344	type, i.e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
242	EV::periodic sets EV::PERIODIC and so on, with the exception of I/O	345	EV::periodic sets EV::PERIODIC and so on, with the exception of I/O
243	events (which can set both EV::READ and EV::WRITE bits), and EV::timer	346	events (which can set both EV::READ and EV::WRITE bits).
244	(which uses EV::TIMEOUT).
245		347
246	In the rare case where one wants to create a watcher but not start it at	348	In the rare case where one wants to create a watcher but not start it at
247	the same time, each constructor has a variant with a trailing "_ns" in	349	the same time, each constructor has a variant with a trailing "_ns" in
248	its name, e.g. EV::io has a non-starting variant EV::io_ns and so on.	350	its name, e.g. EV::io has a non-starting variant EV::io_ns and so on.
249		351
…		…
314	the watcher isn't pending it does nothing and returns 0.	416	the watcher isn't pending it does nothing and returns 0.
315		417
316	$previous_state = $w->keepalive ($bool)	418	$previous_state = $w->keepalive ($bool)
317	Normally, "EV::loop" will return when there are no active watchers	419	Normally, "EV::loop" will return when there are no active watchers
318	(which is a "deadlock" because no progress can be made anymore).	420	(which is a "deadlock" because no progress can be made anymore).
319	This is convinient because it allows you to start your watchers (and	421	This is convenient because it allows you to start your watchers (and
320	your jobs), call "EV::loop" once and when it returns you know that	422	your jobs), call "EV::loop" once and when it returns you know that
321	all your jobs are finished (or they forgot to register some watchers	423	all your jobs are finished (or they forgot to register some watchers
322	for their task :).	424	for their task :).
323		425
324	Sometimes, however, this gets in your way, for example when the	426	Sometimes, however, this gets in your way, for example when the
…		…
331		433
332	In this case you can clear the keepalive status, which means that	434	In this case you can clear the keepalive status, which means that
333	even though your watcher is active, it won't keep "EV::loop" from	435	even though your watcher is active, it won't keep "EV::loop" from
334	returning.	436	returning.
335		437
336	The initial value for keepalive is true (enabled), and you cna	438	The initial value for keepalive is true (enabled), and you can
337	change it any time.	439	change it any time.
338		440
339	Example: Register an I/O watcher for some UDP socket but do not keep	441	Example: Register an I/O watcher for some UDP socket but do not keep
340	the event loop from running just because of that watcher.	442	the event loop from running just because of that watcher.
341		443
…		…
399	the same time.	501	the same time.
400		502
401	The "timer_ns" variant doesn't start (activate) the newly created	503	The "timer_ns" variant doesn't start (activate) the newly created
402	watcher.	504	watcher.
403		505
404	$w->set ($after, $repeat)	506	$w->set ($after, $repeat = 0)
405	Reconfigures the watcher, see the constructor above for details. Can	507	Reconfigures the watcher, see the constructor above for details. Can
406	be called at any time.	508	be called at any time.
407		509
408	$w->again	510	$w->again
		511	$w->again ($repeat)
409	Similar to the "start" method, but has special semantics for	512	Similar to the "start" method, but has special semantics for
410	repeating timers:	513	repeating timers:
411		514
412	If the timer is active and non-repeating, it will be stopped.	515	If the timer is active and non-repeating, it will be stopped.
413		516
…		…
421		524
422	This behaviour is useful when you have a timeout for some IO	525	This behaviour is useful when you have a timeout for some IO
423	operation. You create a timer object with the same value for $after	526	operation. You create a timer object with the same value for $after
424	and $repeat, and then, in the read/write watcher, run the "again"	527	and $repeat, and then, in the read/write watcher, run the "again"
425	method on the timeout.	528	method on the timeout.
		529
		530	If called with a $repeat argument, then it uses this a timer repeat
		531	value.
		532
		533	$after = $w->remaining
		534	Calculates and returns the remaining time till the timer will fire.
426		535
427	PERIODIC WATCHERS - to cron or not to cron?	536	PERIODIC WATCHERS - to cron or not to cron?
428	$w = EV::periodic $at, $interval, $reschedule_cb, $callback	537	$w = EV::periodic $at, $interval, $reschedule_cb, $callback
429	$w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback	538	$w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
430	$w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)	539	$w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
…		…
456	to system time:	565	to system time:
457		566
458	my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" };	567	my $hourly = EV::periodic 0, 3600, 0, sub { print "once/hour\n" };
459		568
460	That doesn't mean there will always be 3600 seconds in between	569	That doesn't mean there will always be 3600 seconds in between
461	triggers, but only that the the clalback will be called when the	570	triggers, but only that the the callback will be called when the
462	system time shows a full hour (UTC).	571	system time shows a full hour (UTC).
463		572
464	Another way to think about it (for the mathematically inclined)	573	Another way to think about it (for the mathematically inclined)
465	is that EV::periodic will try to run the callback in this mode	574	is that EV::periodic will try to run the callback in this mode
466	at the next possible time where "$time = $at (mod $interval)",	575	at the next possible time where "$time = $at (mod $interval)",
…		…
515	Return the time that the watcher is expected to trigger next.	624	Return the time that the watcher is expected to trigger next.
516		625
517	SIGNAL WATCHERS - signal me when a signal gets signalled!	626	SIGNAL WATCHERS - signal me when a signal gets signalled!
518	$w = EV::signal $signal, $callback	627	$w = EV::signal $signal, $callback
519	$w = EV::signal_ns $signal, $callback	628	$w = EV::signal_ns $signal, $callback
		629	$w = $loop->signal ($signal, $callback)
		630	$w = $loop->signal_ns ($signal, $callback)
520	Call the callback when $signal is received (the signal can be	631	Call the callback when $signal is received (the signal can be
521	specified by number or by name, just as with "kill" or %SIG).	632	specified by number or by name, just as with "kill" or %SIG).
		633
		634	Only one event loop can grab a given signal - attempting to grab the
		635	same signal from two EV loops will crash the program immediately or
		636	cause data corruption.
522		637
523	EV will grab the signal for the process (the kernel only allows one	638	EV will grab the signal for the process (the kernel only allows one
524	component to receive a signal at a time) when you start a signal	639	component to receive a signal at a time) when you start a signal
525	watcher, and removes it again when you stop it. Perl does the same	640	watcher, and removes it again when you stop it. Perl does the same
526	when you add/remove callbacks to %SIG, so watch out.	641	when you add/remove callbacks to %SIG, so watch out.
…		…
700	$w = $loop->check_ns ($callback)	815	$w = $loop->check_ns ($callback)
701	Call the callback just after the process wakes up again (after it	816	Call the callback just after the process wakes up again (after it
702	has gathered events), but before any other callbacks have been	817	has gathered events), but before any other callbacks have been
703	invoked.	818	invoked.
704		819
705	This is used to integrate other event-based software into the EV	820	This can be used to integrate other event-based software into the EV
706	mainloop: You register a prepare callback and in there, you create	821	mainloop: You register a prepare callback and in there, you create
707	io and timer watchers as required by the other software. Here is a	822	io and timer watchers as required by the other software. Here is a
708	real-world example of integrating Net::SNMP (with some details left	823	real-world example of integrating Net::SNMP (with some details left
709	out):	824	out):
710		825
…		…
741	# make the dispatcher handle any new stuff	856	# make the dispatcher handle any new stuff
742	... not shown	857	... not shown
743	};	858	};
744		859
745	The callbacks of the created watchers will not be called as the	860	The callbacks of the created watchers will not be called as the
746	watchers are destroyed before this cna happen (remember EV::check	861	watchers are destroyed before this can happen (remember EV::check
747	gets called first).	862	gets called first).
748		863
749	The "check_ns" variant doesn't start (activate) the newly created	864	The "check_ns" variant doesn't start (activate) the newly created
750	watcher.	865	watcher.
		866
		867	EV::CHECK constant issues
		868	Like all other watcher types, there is a bitmask constant for use in
		869	$revents and other places. The "EV::CHECK" is special as it has the
		870	same name as the "CHECK" sub called by Perl. This doesn't cause big
		871	issues on newer perls (beginning with 5.8.9), but it means thatthe
		872	constant must be inlined, i.e. runtime calls will not work. That
		873	means that as long as you always "use EV" and then "EV::CHECK" you
		874	are on the safe side.
751		875
752	FORK WATCHERS - the audacity to resume the event loop after a fork	876	FORK WATCHERS - the audacity to resume the event loop after a fork
753	Fork watchers are called when a "fork ()" was detected. The invocation	877	Fork watchers are called when a "fork ()" was detected. The invocation
754	is done before the event loop blocks next and before "check" watchers	878	is done before the event loop blocks next and before "check" watchers
755	are being called, and only in the child after the fork.	879	are being called, and only in the child after the fork.
…		…
770	embedded loop, other types of watchers might be handled in a delayed or	894	embedded loop, other types of watchers might be handled in a delayed or
771	incorrect fashion and must not be used).	895	incorrect fashion and must not be used).
772		896
773	See the libev documentation at	897	See the libev documentation at
774	<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code	898	<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code
775	_when_one_backend_> for more details.	899	_when_one_backend_> (locally installed as EV::libev) for more details.
776		900
777	In short, this watcher is most useful on BSD systems without working	901	In short, this watcher is most useful on BSD systems without working
778	kqueue to still be able to handle a large number of sockets:	902	kqueue to still be able to handle a large number of sockets:
779		903
780	my $socket_loop;	904	my $socket_loop;
781		905
782	# check wether we use SELECT or POLL _and_ KQUEUE is supported	906	# check wether we use SELECT or POLL _and_ KQUEUE is supported
783	if (	907	if (
784	(EV::backend & (EV::BACKEND_POLL \| EV::BACKEND_SELECT))	908	(EV::backend & (EV::BACKEND_POLL \| EV::BACKEND_SELECT))
785	&& (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)	909	&& (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
786	) {	910	) {
787	# use kqueue for sockets	911	# use kqueue for sockets
788	$socket_loop = new EV::Loop EV::BACKEND_KQUEUE \| EV::FLAG_NOENV;	912	$socket_loop = new EV::Loop EV::BACKEND_KQUEUE \| EV::FLAG_NOENV;
789	}	913	}
790		914
791	# use the default loop otherwise	915	# use the default loop otherwise
792	$socket_loop \|\|= EV::default_loop;	916	$socket_loop \|\|= EV::default_loop;
793		917
794	$w = EV::embed $otherloop, $callback	918	$w = EV::embed $otherloop[, $callback]
795	$w = EV::embed_ns $otherloop, $callback	919	$w = EV::embed_ns $otherloop[, $callback]
796	$w = $loop->embed ($otherloop, $callback)	920	$w = $loop->embed ($otherloop[, $callback])
797	$w = $loop->embed_ns ($otherloop, $callback)	921	$w = $loop->embed_ns ($otherloop[, $callback])
798	Call the callback when the embedded event loop ($otherloop) has any	922	Call the callback when the embedded event loop ($otherloop) has any
799	I/O activity. The $callback should alwas be specified as "undef" in	923	I/O activity. The $callback is optional: if it is missing, then the
800	this version of EV, which means the embedded event loop will be	924	embedded event loop will be managed automatically (which is
801	managed automatically.	925	recommended), otherwise you have to invoke "sweep" yourself.
802		926
803	The "embed_ns" variant doesn't start (activate) the newly created	927	The "embed_ns" variant doesn't start (activate) the newly created
804	watcher.	928	watcher.
805		929
806	ASYNC WATCHERS - how to wake up another event loop	930	ASYNC WATCHERS - how to wake up another event loop
807	Async watchers are provided by EV, but have little use in perl directly,	931	Async watchers are provided by EV, but have little use in perl directly,
808	as perl neither supports threads nor direct access to signal handlers or	932	as perl neither supports threads running in parallel nor direct access
809	other contexts where they could be of value.	933	to signal handlers or other contexts where they could be of value.
810		934
811	It is, however, possible to use them from the XS level.	935	It is, however, possible to use them from the XS level.
812		936
813	Please see the libev documentation for further details.	937	Please see the libev documentation for further details.
814		938
815	$w = EV::async $callback	939	$w = EV::async $callback
816	$w = EV::async_ns $callback	940	$w = EV::async_ns $callback
		941	$w = $loop->async ($callback)
		942	$w = $loop->async_ns ($callback)
817	$w->send	943	$w->send
818	$bool = $w->async_pending	944	$bool = $w->async_pending
		945
		946	CLEANUP WATCHERS - how to clean up when the event loop goes away
		947	Cleanup watchers are not supported on the Perl level, they can only be
		948	used via XS currently.
819		949
820	PERL SIGNALS	950	PERL SIGNALS
821	While Perl signal handling (%SIG) is not affected by EV, the behaviour	951	While Perl signal handling (%SIG) is not affected by EV, the behaviour
822	with EV is as the same as any other C library: Perl-signals will only be	952	with EV is as the same as any other C library: Perl-signals will only be
823	handled when Perl runs, which means your signal handler might be invoked	953	handled when Perl runs, which means your signal handler might be invoked
…		…
833	my $async_check = EV::check sub { };	963	my $async_check = EV::check sub { };
834		964
835	This ensures that perl gets into control for a short time to handle any	965	This ensures that perl gets into control for a short time to handle any
836	pending signals, and also ensures (slightly) slower overall operation.	966	pending signals, and also ensures (slightly) slower overall operation.
837		967
838	THREADS	968	ITHREADS
839	Threads are not supported by this module in any way. Perl pseudo-threads	969	Ithreads are not supported by this module in any way. Perl
840	is evil stuff and must die. As soon as Perl gains real threads I will	970	pseudo-threads is evil stuff and must die. Real threads as provided by
841	work on thread support for it.	971	Coro are fully supported (and enhanced support is available via
		972	Coro::EV).
842		973
843	FORK	974	FORK
844	Most of the "improved" event delivering mechanisms of modern operating	975	Most of the "improved" event delivering mechanisms of modern operating
845	systems have quite a few problems with fork(2) (to put it bluntly: it is	976	systems have quite a few problems with fork(2) (to put it bluntly: it is
846	not supported and usually destructive). Libev makes it possible to work	977	not supported and usually destructive). Libev makes it possible to work
…		…
856		987
857	On win32, there is no notion of fork so all this doesn't apply, of	988	On win32, there is no notion of fork so all this doesn't apply, of
858	course.	989	course.
859		990
860	SEE ALSO	991	SEE ALSO
861	EV::ADNS (asynchronous DNS), Glib::EV (makes Glib/Gtk2 use EV as event	992	EV::MakeMaker - MakeMaker interface to XS API, EV::ADNS (asynchronous
862	loop), EV::Glib (embed Glib into EV), Coro::EV (efficient coroutines	993	DNS), Glib::EV (makes Glib/Gtk2 use EV as event loop), EV::Glib (embed
863	with EV), Net::SNMP::EV (asynchronous SNMP), AnyEvent for event-loop	994	Glib into EV), Coro::EV (efficient thread integration), Net::SNMP::EV
864	agnostic and portable event driven programming.	995	(asynchronous SNMP), AnyEvent for event-loop agnostic and portable event
		996	driven programming.
865		997
866	AUTHOR	998	AUTHOR
867	Marc Lehmann <schmorp@schmorp.de>	999	Marc Lehmann <schmorp@schmorp.de>
868	http://home.schmorp.de/	1000	http://home.schmorp.de/
869		1001

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Comparing EV/README (file contents): Revision 1.28 by root, Tue Jul 8 18:56:48 2008 UTC vs. Revision 1.44 by root, Mon Jul 13 19:47:53 2015 UTC

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Comparing EV/README (file contents):
Revision 1.28 by root, Tue Jul 8 18:56:48 2008 UTC vs.
Revision 1.44 by root, Mon Jul 13 19:47:53 2015 UTC