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

Comparing EV/EV.pm (file contents):
Revision 1.56 by root, Tue Nov 27 10:59:10 2007 UTC vs.
Revision 1.80 by root, Sat Dec 22 16:48:33 2007 UTC

…		…
58	This module provides an interface to libev	58	This module provides an interface to libev
59	(L<http://software.schmorp.de/pkg/libev.html>). While the documentation	59	(L<http://software.schmorp.de/pkg/libev.html>). While the documentation
60	below is comprehensive, one might also consult the documentation of libev	60	below is comprehensive, one might also consult the documentation of libev
61	itself (L<http://cvs.schmorp.de/libev/ev.html>) for more subtle details on	61	itself (L<http://cvs.schmorp.de/libev/ev.html>) for more subtle details on
62	watcher semantics or some discussion on the available backends, or how to	62	watcher semantics or some discussion on the available backends, or how to
63	force a specific backend with C<LIBEV_FLAGS>.	63	force a specific backend with C<LIBEV_FLAGS>, or just about in any case
		64	because it has much more detailed information.
64		65
65	=cut	66	=cut
66		67
67	package EV;	68	package EV;
68		69
69	use strict;	70	use strict;
70		71
71	BEGIN {	72	BEGIN {
72	our $VERSION = '1.4';	73	our $VERSION = '2.0';
73	use XSLoader;	74	use XSLoader;
74	XSLoader::load "EV", $VERSION;	75	XSLoader::load "EV", $VERSION;
75	}	76	}
76		77
77	@EV::IO::ISA =	78	@EV::IO::ISA =
…		…
85	@EV::Check::ISA =	86	@EV::Check::ISA =
86	@EV::Embed::ISA =	87	@EV::Embed::ISA =
87	@EV::Fork::ISA =	88	@EV::Fork::ISA =
88	"EV::Watcher";	89	"EV::Watcher";
89		90
		91	@EV::Loop::Default::ISA = "EV::Loop";
		92
		93	=head1 EVENT LOOPS
		94
		95	EV supports multiple event loops: There is a single "default event loop"
		96	that can handle everything including signals and child watchers, and any
		97	number of "dynamic event loops" that can use different backends (with
		98	various limitations), but no child and signal watchers.
		99
		100	You do not have to do anything to create the default event loop: When
		101	the module is loaded a suitable backend is selected on the premise of
		102	selecting a working backend (which for example rules out kqueue on most
		103	BSDs). Modules should, unless they have "special needs" always use the
		104	default loop as this is fastest (perl-wise), best supported by other
		105	modules (e.g. AnyEvent or Coro) and most portable event loop.
		106
		107	For specific programs you can create additional event loops dynamically.
		108
		109	=over 4
		110
		111	=item $loop = new EV::loop [$flags]
		112
		113	Create a new event loop as per the specified flags. Please refer to the
		114	C<ev_loop_new ()> function description in the libev documentation
		115	(L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#GLOBAL_FUNCTIONS>)
		116	for more info.
		117
		118	The loop will automatically be destroyed when it is no longer referenced
		119	by any watcher and the loop object goes out of scope.
		120
		121	Using C<EV::FLAG_FORKCHECK> is recommended, as only the default event loop
		122	is protected by this module.
		123
		124	=item $loop->loop_fork
		125
		126	Must be called after a fork in the child, before entering or continuing
		127	the event loop. An alternative is to use C<EV::FLAG_FORKCHECK> which calls
		128	this fucntion automatically, at some performance loss (refer to the libev
		129	documentation).
		130
		131	=item $loop = EV::default_loop [$flags]
		132
		133	Return the default loop (which is a singleton object).
		134
		135	=back
		136
		137
90	=head1 BASIC INTERFACE	138	=head1 BASIC INTERFACE
91		139
92	=over 4	140	=over 4
93		141
94	=item $EV::DIED	142	=item $EV::DIED
95		143
96	Must contain a reference to a function that is called when a callback	144	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	145	throws an exception (with $@ containing the error). The default prints an
98	informative message and continues.	146	informative message and continues.
99		147
100	If this callback throws an exception it will be silently ignored.	148	If this callback throws an exception it will be silently ignored.
101		149
		150	=item $flags = EV::supported_backends
		151
		152	=item $flags = EV::recommended_backends
		153
		154	=item $flags = EV::embeddable_backends
		155
		156	Returns the set (see C<EV::BACKEND_*> flags) of backends supported by this
		157	instance of EV, the set of recommended backends (supposed to be good) for
		158	this platform and the set of embeddable backends (see EMBED WATCHERS).
		159
		160	=item EV::sleep $seconds
		161
		162	Block the process for the given number of (fractional) seconds.
		163
102	=item $time = EV::time	164	=item $time = EV::time
103		165
104	Returns the current time in (fractional) seconds since the epoch.	166	Returns the current time in (fractional) seconds since the epoch.
105		167
106	=item $time = EV::now	168	=item $time = EV::now
		169
		170	=item $time = $loop->now
107		171
108	Returns the time the last event loop iteration has been started. This	172	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	173	is the time that (relative) timers are based on, and refering to it is
110	usually faster then calling EV::time.	174	usually faster then calling EV::time.
111		175
112	=item $method = EV::method	176	=item $backend = EV::backend
		177
		178	=item $backend = $loop->backend
113		179
114	Returns an integer describing the backend used by libev (EV::METHOD_SELECT	180	Returns an integer describing the backend used by libev (EV::METHOD_SELECT
115	or EV::METHOD_EPOLL).	181	or EV::METHOD_EPOLL).
116		182
117	=item EV::loop [$flags]	183	=item EV::loop [$flags]
		184
		185	=item $loop->loop ([$flags])
118		186
119	Begin checking for events and calling callbacks. It returns when a	187	Begin checking for events and calling callbacks. It returns when a
120	callback calls EV::unloop.	188	callback calls EV::unloop.
121		189
122	The $flags argument can be one of the following:	190	The $flags argument can be one of the following:
…		…
125	EV::LOOP_ONESHOT block at most once (wait, but do not loop)	193	EV::LOOP_ONESHOT block at most once (wait, but do not loop)
126	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)	194	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
127		195
128	=item EV::unloop [$how]	196	=item EV::unloop [$how]
129		197
		198	=item $loop->unloop ([$how])
		199
130	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the	200	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the
131	innermost call to EV::loop return.	201	innermost call to EV::loop return.
132		202
133	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as	203	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as
134	fast as possible.	204	fast as possible.
135		205
		206	=item $count = EV::loop_count
		207
		208	=item $count = $loop->loop_count
		209
		210	Return the number of times the event loop has polled for new
		211	events. Sometiems useful as a generation counter.
		212
136	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)	213	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
		214
		215	=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
137		216
138	This function rolls together an I/O and a timer watcher for a single	217	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.	218	one-shot event without the need for managing a watcher object.
140		219
141	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>	220	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	226	If timeout is C<undef> or negative, then there will be no
148	timeout. Otherwise a EV::timer with this value will be started.	227	timeout. Otherwise a EV::timer with this value will be started.
149		228
150	When an error occurs or either the timeout or I/O watcher triggers, then	229	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	230	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>,	231	you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
153	C<EV::WRITE> and C<EV::TIMEOUT>).	232	C<EV::WRITE> and C<EV::TIMEOUT>).
154		233
155	EV::once doesn't return anything: the watchers stay active till either	234	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	235	of them triggers, then they will be stopped and freed, and the callback
157	invoked.	236	invoked.
158		237
159	=back	238	=item EV::feed_fd_event ($fd, $revents)
160		239
		240	=item $loop->feed_fd_event ($fd, $revents)
		241
		242	Feed an event on a file descriptor into EV. EV will react to this call as
		243	if the readyness notifications specified by C<$revents> (a combination of
		244	C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
		245
		246	=item EV::feed_signal_event ($signal)
		247
		248	Feed a signal event into EV. EV will react to this call as if the signal
		249	specified by C<$signal> had occured.
		250
		251	=item EV::set_io_collect_interval $time
		252
		253	=item $loop->set_io_collect_interval ($time)
		254
		255	=item EV::set_timeout_collect_interval $time
		256
		257	=item $loop->set_timeout_collect_interval ($time)
		258
		259	These advanced functions set the minimum block interval when polling for I/O events and the minimum
		260	wait interval for timer events. See the libev documentation at
		261	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#FUNCTIONS_CONTROLLING_THE_EVENT_LOOP> for
		262	a more detailed discussion.
		263
		264	=back
		265
		266
161	=head2 WATCHER OBJECTS	267	=head1 WATCHER OBJECTS
162		268
163	A watcher is an object that gets created to record your interest in some	269	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	270	event. For instance, if you want to wait for STDIN to become readable, you
165	would create an EV::io watcher for that:	271	would create an EV::io watcher for that:
166		272
167	my $watcher = EV::io *STDIN, EV::READ, sub {	273	my $watcher = EV::io *STDIN, EV::READ, sub {
168	my ($watcher, $revents) = @_;	274	my ($watcher, $revents) = @_;
169	warn "yeah, STDIN should not be readable without blocking!\n"	275	warn "yeah, STDIN should now be readable without blocking!\n"
170	};	276	};
171		277
172	All watchers can be active (waiting for events) or inactive (paused). Only	278	All watchers can be active (waiting for events) or inactive (paused). Only
173	active watchers will have their callbacks invoked. All callbacks will be	279	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	280	called with at least two arguments: the watcher and a bitmask of received
175	events.	281	events.
176		282
177	Each watcher type has its associated bit in revents, so you can use the	283	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	284	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,	285	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	286	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	287	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which
182	uses EV::TIMEOUT).	288	uses EV::TIMEOUT).
183		289
184	In the rare case where one wants to create a watcher but not start it at	290	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	291	the same time, each constructor has a variant with a trailing C<_ns> in
…		…
207		313
208	=item $w->stop	314	=item $w->stop
209		315
210	Stop a watcher if it is active. Also clear any pending events (events that	316	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),	317	have been received but that didn't yet result in a callback invocation),
212	regardless of wether the watcher was active or not.	318	regardless of whether the watcher was active or not.
213		319
214	=item $bool = $w->is_active	320	=item $bool = $w->is_active
215		321
216	Returns true if the watcher is active, false otherwise.	322	Returns true if the watcher is active, false otherwise.
217		323
…		…
247	The default priority of any newly-created watcher is 0.	353	The default priority of any newly-created watcher is 0.
248		354
249	Note that the priority semantics have not yet been fleshed out and are	355	Note that the priority semantics have not yet been fleshed out and are
250	subject to almost certain change.	356	subject to almost certain change.
251		357
252	=item $w->trigger ($revents)	358	=item $w->invoke ($revents)
253		359
254	Call the callback now with the given event mask.	360	Call the callback now with the given event mask.
		361
		362	=item $w->feed_event ($revents)
		363
		364	Feed some events on this watcher into EV. EV will react to this call as if
		365	the watcher had received the given C<$revents> mask.
		366
		367	=item $revents = $w->clear_pending
		368
		369	If the watcher is pending, this function clears its pending status and
		370	returns its C<$revents> bitset (as if its callback was invoked). If the
		371	watcher isn't pending it does nothing and returns C<0>.
255		372
256	=item $previous_state = $w->keepalive ($bool)	373	=item $previous_state = $w->keepalive ($bool)
257		374
258	Normally, C<EV::loop> will return when there are no active watchers	375	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	376	(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),	377	convinient 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	378	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 :).	379	finished (or they forgot to register some watchers for their task :).
263		380
264	Sometimes, however, this gets in your way, for example when you the module	381	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	382	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	383	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	384	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	385	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.	386	because you happen to have this long-running UDP port watcher.
…		…
272	though your watcher is active, it won't keep C<EV::loop> from returning.	389	though your watcher is active, it won't keep C<EV::loop> from returning.
273		390
274	The initial value for keepalive is true (enabled), and you cna change it	391	The initial value for keepalive is true (enabled), and you cna change it
275	any time.	392	any time.
276		393
277	Example: Register an IO watcher for some UDP socket but do not keep the	394	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.	395	event loop from running just because of that watcher.
279		396
280	my $udp_socket = ...	397	my $udp_socket = ...
281	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };	398	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
282	$udp_watcher->keepalive (0);	399	$1000udp_watcher->keepalive (0);
283		400
284	=back	401	=item $loop = $w->loop
285		402
		403	Return the loop that this watcher is attached to.
286		404
		405	=back
		406
		407
287	=head2 WATCHER TYPES	408	=head1 WATCHER TYPES
288		409
289	Each of the following subsections describes a single watcher type.	410	Each of the following subsections describes a single watcher type.
290		411
291	=head3 IO WATCHERS - is this file descriptor readable or writable?	412	=head3 I/O WATCHERS - is this file descriptor readable or writable?
292		413
293	=over 4	414	=over 4
294		415
295	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	416	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
296		417
297	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback	418	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
		419
		420	=item $w = $loop->io ($fileno_or_fh, $eventmask, $callback)
		421
		422	=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
298		423
299	As long as the returned watcher object is alive, call the C<$callback>	424	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.	425	when at least one of events specified in C<$eventmask> occurs.
301		426
302	The $eventmask can be one or more of these constants ORed together:	427	The $eventmask can be one or more of these constants ORed together:
…		…
331	=over 4	456	=over 4
332		457
333	=item $w = EV::timer $after, $repeat, $callback	458	=item $w = EV::timer $after, $repeat, $callback
334		459
335	=item $w = EV::timer_ns $after, $repeat, $callback	460	=item $w = EV::timer_ns $after, $repeat, $callback
		461
		462	=item $w = $loop->timer ($after, $repeat, $callback)
		463
		464	=item $w = $loop->timer_ns ($after, $repeat, $callback)
336		465
337	Calls the callback after C<$after> seconds (which may be fractional). If	466	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 $repeat	467	C<$repeat> is non-zero, the timer will be restarted (with the $repeat
339	value as $after) after the callback returns.	468	value as $after) after the callback returns.
340		469
…		…
381	=over 4	510	=over 4
382		511
383	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback	512	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
384		513
385	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback	514	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
		515
		516	=item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
		517
		518	=item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback)
386		519
387	Similar to EV::timer, but is not based on relative timeouts but on	520	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	521	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	522	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	523	more complex, cron-like, setups that are not adversely affected by time
…		…
465		598
466	=item $w->again	599	=item $w->again
467		600
468	Simply stops and starts the watcher again.	601	Simply stops and starts the watcher again.
469		602
		603	=item $time = $w->at
		604
		605	Return the time that the watcher is expected to trigger next.
		606
470	=back	607	=back
471		608
472		609
473	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!	610	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
474		611
…		…
511		648
512	=item $w = EV::child $pid, $callback	649	=item $w = EV::child $pid, $callback
513		650
514	=item $w = EV::child_ns $pid, $callback	651	=item $w = EV::child_ns $pid, $callback
515		652
		653	=item $w = $loop->child ($pid, $callback)
		654
		655	=item $w = $loop->child_ns ($pid, $callback)
		656
516	Call the callback when a status change for pid C<$pid> (or any pid if	657	Call the callback when a status change for pid C<$pid> (or any pid if
517	C<$pid> is 0) has been received. More precisely: when the process receives	658	C<$pid> is 0) has been received. More precisely: when the process receives
518	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all	659	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
519	changed/zombie children and call the callback.	660	changed/zombie children and call the callback.
520		661
…		…
561		702
562	=item $w = EV::stat $path, $interval, $callback	703	=item $w = EV::stat $path, $interval, $callback
563		704
564	=item $w = EV::stat_ns $path, $interval, $callback	705	=item $w = EV::stat_ns $path, $interval, $callback
565		706
		707	=item $w = $loop->stat ($path, $interval, $callback)
		708
		709	=item $w = $loop->stat_ns ($path, $interval, $callback)
		710
566	Call the callback when a file status change has been detected on	711	Call the callback when a file status change has been detected on
567	C<$path>. The C<$path> does not need to exist, changing from "path exists"	712	C<$path>. The C<$path> does not need to exist, changing from "path exists"
568	to "path does not exist" is a status change like any other.	713	to "path does not exist" is a status change like any other.
569		714
570	The C<$interval> is a recommended polling interval for systems where	715	The C<$interval> is a recommended polling interval for systems where
…		…
576	as even with OS-supported change notifications, this can be	721	as even with OS-supported change notifications, this can be
577	resource-intensive.	722	resource-intensive.
578		723
579	The C<stat_ns> variant doesn't start (activate) the newly created watcher.	724	The C<stat_ns> variant doesn't start (activate) the newly created watcher.
580		725
		726	=item ... = $w->stat
		727
		728	This call is very similar to the perl C<stat> built-in: It stats (using
		729	C<lstat>) the path specified in the watcher and sets perls stat cache (as
		730	well as EV's idea of the current stat values) to the values found.
		731
		732	In scalar context, a boolean is return indicating success or failure of
		733	the stat. In list context, the same 13-value list as with stat is returned
		734	(except that the blksize and blocks fields are not reliable).
		735
		736	In the case of an error, errno is set to C<ENOENT> (regardless of the
		737	actual error value) and the C<nlink> value is forced to zero (if the stat
		738	was successful then nlink is guaranteed to be non-zero).
		739
		740	See also the next two entries for more info.
		741
		742	=item ... = $w->attr
		743
		744	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		745	the values most recently detected by EV. See the next entry for more info.
		746
		747	=item ... = $w->prev
		748
		749	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		750	the previous set of values, before the change.
		751
		752	That is, when the watcher callback is invoked, C<< $w->prev >> will be set
		753	to the values found I<before> a change was detected, while C<< $w->attr >>
		754	returns the values found leading to the change detection. The difference (if any)
		755	between C<prev> and C<attr> is what triggered the callback.
		756
		757	If you did something to the filesystem object and do not want to trigger
		758	yet another change, you can call C<stat> to update EV's idea of what the
		759	current attributes are.
		760
581	=item $w->set ($path, $interval)	761	=item $w->set ($path, $interval)
582		762
583	Reconfigures the watcher, see the constructor above for details. Can be	763	Reconfigures the watcher, see the constructor above for details. Can be
584	called at any time.	764	called at any time.
585		765
…		…
605		785
606	=item $w = EV::idle $callback	786	=item $w = EV::idle $callback
607		787
608	=item $w = EV::idle_ns $callback	788	=item $w = EV::idle_ns $callback
609		789
610	Call the callback when there are no pending io, timer/periodic, signal or	790	=item $w = $loop->idle ($callback)
611	child events, i.e. when the process is idle.	791
		792	=item $w = $loop->idle_ns ($callback)
		793
		794	Call the callback when there are no other pending watchers of the same or
		795	higher priority (excluding check, prepare and other idle watchers of the
		796	same or lower priority, of course). They are called idle watchers because
		797	when the watcher is the highest priority pending event in the process, the
		798	process is considered to be idle at that priority.
		799
		800	If you want a watcher that is only ever called when I<no> other events are
		801	outstanding you have to set the priority to C<EV::MINPRI>.
612		802
613	The process will not block as long as any idle watchers are active, and	803	The process will not block as long as any idle watchers are active, and
614	they will be called repeatedly until stopped.	804	they will be called repeatedly until stopped.
615		805
		806	For example, if you have idle watchers at priority C<0> and C<1>, and
		807	an I/O watcher at priority C<0>, then the idle watcher at priority C<1>
		808	and the I/O watcher will always run when ready. Only when the idle watcher
		809	at priority C<1> is stopped and the I/O watcher at priority C<0> is not
		810	pending with the C<0>-priority idle watcher be invoked.
		811
616	The C<idle_ns> variant doesn't start (activate) the newly created watcher.	812	The C<idle_ns> variant doesn't start (activate) the newly created watcher.
617		813
618	=back	814	=back
619		815
620		816
…		…
623	=over 4	819	=over 4
624		820
625	=item $w = EV::prepare $callback	821	=item $w = EV::prepare $callback
626		822
627	=item $w = EV::prepare_ns $callback	823	=item $w = EV::prepare_ns $callback
		824
		825	=item $w = $loop->prepare ($callback)
		826
		827	=item $w = $loop->prepare_ns ($callback)
628		828
629	Call the callback just before the process would block. You can still	829	Call the callback just before the process would block. You can still
630	create/modify any watchers at this point.	830	create/modify any watchers at this point.
631		831
632	See the EV::check watcher, below, for explanations and an example.	832	See the EV::check watcher, below, for explanations and an example.
…		…
641	=over 4	841	=over 4
642		842
643	=item $w = EV::check $callback	843	=item $w = EV::check $callback
644		844
645	=item $w = EV::check_ns $callback	845	=item $w = EV::check_ns $callback
		846
		847	=item $w = $loop->check ($callback)
		848
		849	=item $w = $loop->check_ns ($callback)
646		850
647	Call the callback just after the process wakes up again (after it has	851	Call the callback just after the process wakes up again (after it has
648	gathered events), but before any other callbacks have been invoked.	852	gathered events), but before any other callbacks have been invoked.
649		853
650	This is used to integrate other event-based software into the EV	854	This is used to integrate other event-based software into the EV
…		…
660	or return;	864	or return;
661		865
662	# make the dispatcher handle any outstanding stuff	866	# make the dispatcher handle any outstanding stuff
663	... not shown	867	... not shown
664		868
665	# create an IO watcher for each and every socket	869	# create an I/O watcher for each and every socket
666	@snmp_watcher = (	870	@snmp_watcher = (
667	(map { EV::io $_, EV::READ, sub { } }	871	(map { EV::io $_, EV::READ, sub { } }
668	keys %{ $dispatcher->{_descriptors} }),	872	keys %{ $dispatcher->{_descriptors} }),
669		873
670	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]	874	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
…		…
705		909
706	=item $w = EV::fork $callback	910	=item $w = EV::fork $callback
707		911
708	=item $w = EV::fork_ns $callback	912	=item $w = EV::fork_ns $callback
709		913
		914	=item $w = $loop->fork ($callback)
		915
		916	=item $w = $loop->fork_ns ($callback)
		917
710	Call the callback before the event loop is resumed in the child process	918	Call the callback before the event loop is resumed in the child process
711	after a fork.	919	after a fork.
712		920
713	The C<fork_ns> variant doesn't start (activate) the newly created watcher.	921	The C<fork_ns> variant doesn't start (activate) the newly created watcher.
714		922
715	=back	923	=back
716		924
		925
		926	=head3 EMBED WATCHERS - when one backend isn't enough...
		927
		928	This is a rather advanced watcher type that lets you embed one event loop
		929	into another (currently only IO events are supported in the embedded
		930	loop, other types of watchers might be handled in a delayed or incorrect
		931	fashion and must not be used).
		932
		933	See the libev documentation at
		934	L<http://pod.tst.eu/http://cvs.schmorp.de/libev/ev.pod#code_ev_embed_code_when_one_backend_>
		935	for more details.
		936
		937	In short, this watcher is most useful on BSD systems without working
		938	kqueue to still be able to handle a large number of sockets:
		939
		940	my $socket_loop;
		941
		942	# check wether we use SELECT or POLL _and_ KQUEUE is supported
		943	if (
		944	(EV::backend & (EV::BACKEND_POLL \| EV::BACKEND_SELECT))
		945	&& (EV::supported_backends & EV::embeddable_backends & EV::BACKEND_KQUEUE)
		946	) {
		947	# use kqueue for sockets
		948	$socket_loop = new EV::Loop EV::BACKEND_KQUEUE \| EV::FLAG_NOENV;
		949	}
		950
		951	# use the default loop otherwise
		952	$socket_loop \|\|= EV::default_loop;
		953
		954	=over 4
		955
		956	=item $w = EV::embed $otherloop, $callback
		957
		958	=item $w = EV::embed_ns $otherloop, $callback
		959
		960	=item $w = $loop->embed ($otherloop, $callback)
		961
		962	=item $w = $loop->embed_ns ($otherloop, $callback)
		963
		964	Call the callback when the embedded event loop (C<$otherloop>) has any
		965	I/O activity. The C<$callback> should alwas be specified as C<undef> in
		966	this version of EV, which means the embedded event loop will be managed
		967	automatically.
		968
		969	The C<embed_ns> variant doesn't start (activate) the newly created watcher.
		970
		971	=back
		972
		973
		974	=head1 PERL SIGNALS
		975
		976	While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour
		977	with EV is as the same as any other C library: Perl-signals will only be
		978	handled when Perl runs, which means your signal handler might be invoked
		979	only the next time an event callback is invoked.
		980
		981	The solution is to use EV signal watchers (see C<EV::signal>), which will
		982	ensure proper operations with regards to other event watchers.
		983
		984	If you cannot do this for whatever reason, you can also force a watcher
		985	to be called on every event loop iteration by installing a C<EV::check>
		986	watcher:
		987
		988	my $async_check = EV::check sub { };
		989
		990	This ensures that perl gets into control for a short time to handle any
		991	pending signals, and also ensures (slightly) slower overall operation.
717		992
718	=head1 THREADS	993	=head1 THREADS
719		994
720	Threads are not supported by this module in any way. Perl pseudo-threads	995	Threads are not supported by this module in any way. Perl pseudo-threads
721	is evil stuff and must die. As soon as Perl gains real threads I will work	996	is evil stuff and must die. As soon as Perl gains real threads I will work
…		…
743	our $DIED = sub {	1018	our $DIED = sub {
744	warn "EV: error in callback (ignoring): $@";	1019	warn "EV: error in callback (ignoring): $@";
745	};	1020	};
746		1021
747	default_loop	1022	default_loop
748	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	1023	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
749		1024
750	1;	1025	1;
751		1026
752	=head1 SEE ALSO	1027	=head1 SEE ALSO
753		1028
754	L<EV::DNS>.	1029	L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as
		1030	event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
		1031	coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP).
755		1032
756	=head1 AUTHOR	1033	=head1 AUTHOR
757		1034
758	Marc Lehmann <schmorp@schmorp.de>	1035	Marc Lehmann <schmorp@schmorp.de>
759	http://home.schmorp.de/	1036	http://home.schmorp.de/

Diff Legend

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

Comparing EV/EV.pm (file contents): Revision 1.56 by root, Tue Nov 27 10:59:10 2007 UTC vs. Revision 1.80 by root, Sat Dec 22 16:48:33 2007 UTC

Diff Legend

Comparing EV/EV.pm (file contents):
Revision 1.56 by root, Tue Nov 27 10:59:10 2007 UTC vs.
Revision 1.80 by root, Sat Dec 22 16:48:33 2007 UTC