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

Comparing EV/EV.pm (file contents):
Revision 1.55 by root, Tue Nov 27 08:11:52 2007 UTC vs.
Revision 1.78 by root, Sat Dec 22 11:50:04 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 =
78	@EV::Timer::ISA =	79	@EV::Timer::ISA =
79	@EV::Periodic::ISA =	80	@EV::Periodic::ISA =
80	@EV::Signal::ISA =	81	@EV::Signal::ISA =
		82	@EV::Child::ISA =
		83	@EV::Stat::ISA =
81	@EV::Idle::ISA =	84	@EV::Idle::ISA =
82	@EV::Prepare::ISA =	85	@EV::Prepare::ISA =
83	@EV::Check::ISA =	86	@EV::Check::ISA =
84	@EV::Child::ISA =
85	@EV::Embed::ISA =	87	@EV::Embed::ISA =
86	@EV::Stat::ISA = "EV::Watcher";	88	@EV::Fork::ISA =
		89	"EV::Watcher";
		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 cna 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	=back
		132
87		133
88	=head1 BASIC INTERFACE	134	=head1 BASIC INTERFACE
89		135
90	=over 4	136	=over 4
91		137
92	=item $EV::DIED	138	=item $EV::DIED
93		139
94	Must contain a reference to a function that is called when a callback	140	Must contain a reference to a function that is called when a callback
95	throws an exception (with $@ containing thr error). The default prints an	141	throws an exception (with $@ containing the error). The default prints an
96	informative message and continues.	142	informative message and continues.
97		143
98	If this callback throws an exception it will be silently ignored.	144	If this callback throws an exception it will be silently ignored.
99		145
100	=item $time = EV::time	146	=item $time = EV::time
101		147
102	Returns the current time in (fractional) seconds since the epoch.	148	Returns the current time in (fractional) seconds since the epoch.
103		149
104	=item $time = EV::now	150	=item $time = EV::now
		151
		152	=item $time = $loop->now
105		153
106	Returns the time the last event loop iteration has been started. This	154	Returns the time the last event loop iteration has been started. This
107	is the time that (relative) timers are based on, and refering to it is	155	is the time that (relative) timers are based on, and refering to it is
108	usually faster then calling EV::time.	156	usually faster then calling EV::time.
109		157
110	=item $method = EV::method	158	=item $backend = EV::backend
		159
		160	=item $backend = $loop->backend
111		161
112	Returns an integer describing the backend used by libev (EV::METHOD_SELECT	162	Returns an integer describing the backend used by libev (EV::METHOD_SELECT
113	or EV::METHOD_EPOLL).	163	or EV::METHOD_EPOLL).
114		164
115	=item EV::loop [$flags]	165	=item EV::loop [$flags]
		166
		167	=item $loop->loop ([$flags])
116		168
117	Begin checking for events and calling callbacks. It returns when a	169	Begin checking for events and calling callbacks. It returns when a
118	callback calls EV::unloop.	170	callback calls EV::unloop.
119		171
120	The $flags argument can be one of the following:	172	The $flags argument can be one of the following:
…		…
123	EV::LOOP_ONESHOT block at most once (wait, but do not loop)	175	EV::LOOP_ONESHOT block at most once (wait, but do not loop)
124	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)	176	EV::LOOP_NONBLOCK do not block at all (fetch/handle events but do not wait)
125		177
126	=item EV::unloop [$how]	178	=item EV::unloop [$how]
127		179
		180	=item $loop->unloop ([$how])
		181
128	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the	182	When called with no arguments or an argument of EV::UNLOOP_ONE, makes the
129	innermost call to EV::loop return.	183	innermost call to EV::loop return.
130		184
131	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as	185	When called with an argument of EV::UNLOOP_ALL, all calls to EV::loop will return as
132	fast as possible.	186	fast as possible.
133		187
		188	=item $count = EV::loop_count
		189
		190	=item $count = $loop->loop_count
		191
		192	Return the number of times the event loop has polled for new
		193	events. Sometiems useful as a generation counter.
		194
134	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)	195	=item EV::once $fh_or_undef, $events, $timeout, $cb->($revents)
		196
		197	=item $loop->once ($fh_or_undef, $events, $timeout, $cb->($revents))
135		198
136	This function rolls together an I/O and a timer watcher for a single	199	This function rolls together an I/O and a timer watcher for a single
137	one-shot event without the need for managing a watcher object.	200	one-shot event without the need for managing a watcher object.
138		201
139	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>	202	If C<$fh_or_undef> is a filehandle or file descriptor, then C<$events>
…		…
145	If timeout is C<undef> or negative, then there will be no	208	If timeout is C<undef> or negative, then there will be no
146	timeout. Otherwise a EV::timer with this value will be started.	209	timeout. Otherwise a EV::timer with this value will be started.
147		210
148	When an error occurs or either the timeout or I/O watcher triggers, then	211	When an error occurs or either the timeout or I/O watcher triggers, then
149	the callback will be called with the received event set (in general	212	the callback will be called with the received event set (in general
150	you can expect it to be a combination of C<EV:ERROR>, C<EV::READ>,	213	you can expect it to be a combination of C<EV::ERROR>, C<EV::READ>,
151	C<EV::WRITE> and C<EV::TIMEOUT>).	214	C<EV::WRITE> and C<EV::TIMEOUT>).
152		215
153	EV::once doesn't return anything: the watchers stay active till either	216	EV::once doesn't return anything: the watchers stay active till either
154	of them triggers, then they will be stopped and freed, and the callback	217	of them triggers, then they will be stopped and freed, and the callback
155	invoked.	218	invoked.
156		219
157	=back	220	=item EV::feed_fd_event ($fd, $revents)
158		221
		222	=item $loop->feed_fd_event ($fd, $revents)
		223
		224	Feed an event on a file descriptor into EV. EV will react to this call as
		225	if the readyness notifications specified by C<$revents> (a combination of
		226	C<EV::READ> and C<EV::WRITE>) happened on the file descriptor C<$fd>.
		227
		228	=item EV::feed_signal_event ($signal)
		229
		230	Feed a signal event into EV. EV will react to this call as if the signal
		231	specified by C<$signal> had occured.
		232
		233	=back
		234
		235
159	=head2 WATCHER OBJECTS	236	=head1 WATCHER OBJECTS
160		237
161	A watcher is an object that gets created to record your interest in some	238	A watcher is an object that gets created to record your interest in some
162	event. For instance, if you want to wait for STDIN to become readable, you	239	event. For instance, if you want to wait for STDIN to become readable, you
163	would create an EV::io watcher for that:	240	would create an EV::io watcher for that:
164		241
165	my $watcher = EV::io *STDIN, EV::READ, sub {	242	my $watcher = EV::io *STDIN, EV::READ, sub {
166	my ($watcher, $revents) = @_;	243	my ($watcher, $revents) = @_;
167	warn "yeah, STDIN should not be readable without blocking!\n"	244	warn "yeah, STDIN should now be readable without blocking!\n"
168	};	245	};
169		246
170	All watchers can be active (waiting for events) or inactive (paused). Only	247	All watchers can be active (waiting for events) or inactive (paused). Only
171	active watchers will have their callbacks invoked. All callbacks will be	248	active watchers will have their callbacks invoked. All callbacks will be
172	called with at least two arguments: the watcher and a bitmask of received	249	called with at least two arguments: the watcher and a bitmask of received
173	events.	250	events.
174		251
175	Each watcher type has its associated bit in revents, so you can use the	252	Each watcher type has its associated bit in revents, so you can use the
176	same callback for multiple watchers. The event mask is named after the	253	same callback for multiple watchers. The event mask is named after the
177	type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,	254	type, i..e. EV::child sets EV::CHILD, EV::prepare sets EV::PREPARE,
178	EV::periodic sets EV::PERIODIC and so on, with the exception of IO events	255	EV::periodic sets EV::PERIODIC and so on, with the exception of I/O events
179	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which	256	(which can set both EV::READ and EV::WRITE bits), and EV::timer (which
180	uses EV::TIMEOUT).	257	uses EV::TIMEOUT).
181		258
182	In the rare case where one wants to create a watcher but not start it at	259	In the rare case where one wants to create a watcher but not start it at
183	the same time, each constructor has a variant with a trailing C<_ns> in	260	the same time, each constructor has a variant with a trailing C<_ns> in
…		…
205		282
206	=item $w->stop	283	=item $w->stop
207		284
208	Stop a watcher if it is active. Also clear any pending events (events that	285	Stop a watcher if it is active. Also clear any pending events (events that
209	have been received but that didn't yet result in a callback invocation),	286	have been received but that didn't yet result in a callback invocation),
210	regardless of wether the watcher was active or not.	287	regardless of whether the watcher was active or not.
211		288
212	=item $bool = $w->is_active	289	=item $bool = $w->is_active
213		290
214	Returns true if the watcher is active, false otherwise.	291	Returns true if the watcher is active, false otherwise.
215		292
…		…
245	The default priority of any newly-created watcher is 0.	322	The default priority of any newly-created watcher is 0.
246		323
247	Note that the priority semantics have not yet been fleshed out and are	324	Note that the priority semantics have not yet been fleshed out and are
248	subject to almost certain change.	325	subject to almost certain change.
249		326
250	=item $w->trigger ($revents)	327	=item $w->invoke ($revents)
251		328
252	Call the callback now with the given event mask.	329	Call the callback now with the given event mask.
		330
		331	=item $w->feed_event ($revents)
		332
		333	Feed some events on this watcher into EV. EV will react to this call as if
		334	the watcher had received the given C<$revents> mask.
		335
		336	=item $revents = $w->clear_pending
		337
		338	If the watcher is pending, this function clears its pending status and
		339	returns its C<$revents> bitset (as if its callback was invoked). If the
		340	watcher isn't pending it does nothing and returns C<0>.
253		341
254	=item $previous_state = $w->keepalive ($bool)	342	=item $previous_state = $w->keepalive ($bool)
255		343
256	Normally, C<EV::loop> will return when there are no active watchers	344	Normally, C<EV::loop> will return when there are no active watchers
257	(which is a "deadlock" because no progress can be made anymore). This is	345	(which is a "deadlock" because no progress can be made anymore). This is
258	convinient because it allows you to start your watchers (and your jobs),	346	convinient because it allows you to start your watchers (and your jobs),
259	call C<EV::loop> once and when it returns you know that all your jobs are	347	call C<EV::loop> once and when it returns you know that all your jobs are
260	finished (or they forgot to register some watchers for their task :).	348	finished (or they forgot to register some watchers for their task :).
261		349
262	Sometimes, however, this gets in your way, for example when you the module	350	Sometimes, however, this gets in your way, for example when the module
263	that calls C<EV::loop> (usually the main program) is not the same module	351	that calls C<EV::loop> (usually the main program) is not the same module
264	as a long-living watcher (for example a DNS client module written by	352	as a long-living watcher (for example a DNS client module written by
265	somebody else even). Then you might want any outstanding requests to be	353	somebody else even). Then you might want any outstanding requests to be
266	handled, but you would not want to keep C<EV::loop> from returning just	354	handled, but you would not want to keep C<EV::loop> from returning just
267	because you happen to have this long-running UDP port watcher.	355	because you happen to have this long-running UDP port watcher.
…		…
270	though your watcher is active, it won't keep C<EV::loop> from returning.	358	though your watcher is active, it won't keep C<EV::loop> from returning.
271		359
272	The initial value for keepalive is true (enabled), and you cna change it	360	The initial value for keepalive is true (enabled), and you cna change it
273	any time.	361	any time.
274		362
275	Example: Register an IO watcher for some UDP socket but do not keep the	363	Example: Register an I/O watcher for some UDP socket but do not keep the
276	event loop from running just because of that watcher.	364	event loop from running just because of that watcher.
277		365
278	my $udp_socket = ...	366	my $udp_socket = ...
279	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };	367	my $udp_watcher = EV::io $udp_socket, EV::READ, sub { ... };
280	$udp_watcher->keepalive (0);	368	$1000udp_watcher->keepalive (0);
281		369
282	=back	370	=item $loop = $w->loop
283		371
		372	Return the loop that this watcher is attached to.
284		373
		374	=back
		375
		376
285	=head2 WATCHER TYPES	377	=head1 WATCHER TYPES
286		378
287	Each of the following subsections describes a single watcher type.	379	Each of the following subsections describes a single watcher type.
288		380
289	=head3 IO WATCHERS - is this file descriptor readable or writable?	381	=head3 I/O WATCHERS - is this file descriptor readable or writable?
290		382
291	=over 4	383	=over 4
292		384
293	=item $w = EV::io $fileno_or_fh, $eventmask, $callback	385	=item $w = EV::io $fileno_or_fh, $eventmask, $callback
294		386
295	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback	387	=item $w = EV::io_ns $fileno_or_fh, $eventmask, $callback
		388
		389	=item $w = $loop->io ($fileno_or_fh, $eventmask, $callback)
		390
		391	=item $w = $loop->io_ns ($fileno_or_fh, $eventmask, $callback)
296		392
297	As long as the returned watcher object is alive, call the C<$callback>	393	As long as the returned watcher object is alive, call the C<$callback>
298	when at least one of events specified in C<$eventmask> occurs.	394	when at least one of events specified in C<$eventmask> occurs.
299		395
300	The $eventmask can be one or more of these constants ORed together:	396	The $eventmask can be one or more of these constants ORed together:
…		…
329	=over 4	425	=over 4
330		426
331	=item $w = EV::timer $after, $repeat, $callback	427	=item $w = EV::timer $after, $repeat, $callback
332		428
333	=item $w = EV::timer_ns $after, $repeat, $callback	429	=item $w = EV::timer_ns $after, $repeat, $callback
		430
		431	=item $w = $loop->timer ($after, $repeat, $callback)
		432
		433	=item $w = $loop->timer_ns ($after, $repeat, $callback)
334		434
335	Calls the callback after C<$after> seconds (which may be fractional). If	435	Calls the callback after C<$after> seconds (which may be fractional). If
336	C<$repeat> is non-zero, the timer will be restarted (with the $repeat	436	C<$repeat> is non-zero, the timer will be restarted (with the $repeat
337	value as $after) after the callback returns.	437	value as $after) after the callback returns.
338		438
…		…
379	=over 4	479	=over 4
380		480
381	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback	481	=item $w = EV::periodic $at, $interval, $reschedule_cb, $callback
382		482
383	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback	483	=item $w = EV::periodic_ns $at, $interval, $reschedule_cb, $callback
		484
		485	=item $w = $loop->periodic ($at, $interval, $reschedule_cb, $callback)
		486
		487	=item $w = $loop->periodic_ns ($at, $interval, $reschedule_cb, $callback)
384		488
385	Similar to EV::timer, but is not based on relative timeouts but on	489	Similar to EV::timer, but is not based on relative timeouts but on
386	absolute times. Apart from creating "simple" timers that trigger "at" the	490	absolute times. Apart from creating "simple" timers that trigger "at" the
387	specified time, it can also be used for non-drifting absolute timers and	491	specified time, it can also be used for non-drifting absolute timers and
388	more complex, cron-like, setups that are not adversely affected by time	492	more complex, cron-like, setups that are not adversely affected by time
…		…
463		567
464	=item $w->again	568	=item $w->again
465		569
466	Simply stops and starts the watcher again.	570	Simply stops and starts the watcher again.
467		571
		572	=item $time = $w->at
		573
		574	Return the time that the watcher is expected to trigger next.
		575
468	=back	576	=back
469		577
470		578
471	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!	579	=head3 SIGNAL WATCHERS - signal me when a signal gets signalled!
472		580
…		…
509		617
510	=item $w = EV::child $pid, $callback	618	=item $w = EV::child $pid, $callback
511		619
512	=item $w = EV::child_ns $pid, $callback	620	=item $w = EV::child_ns $pid, $callback
513		621
		622	=item $w = $loop->child ($pid, $callback)
		623
		624	=item $w = $loop->child_ns ($pid, $callback)
		625
514	Call the callback when a status change for pid C<$pid> (or any pid if	626	Call the callback when a status change for pid C<$pid> (or any pid if
515	C<$pid> is 0) has been received. More precisely: when the process receives	627	C<$pid> is 0) has been received. More precisely: when the process receives
516	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all	628	a C<SIGCHLD>, EV will fetch the outstanding exit/wait status for all
517	changed/zombie children and call the callback.	629	changed/zombie children and call the callback.
518		630
…		…
551	watcher for all pids).	663	watcher for all pids).
552		664
553	=back	665	=back
554		666
555		667
		668	=head3 STAT WATCHERS - did the file attributes just change?
		669
		670	=over 4
		671
		672	=item $w = EV::stat $path, $interval, $callback
		673
		674	=item $w = EV::stat_ns $path, $interval, $callback
		675
		676	=item $w = $loop->stat ($path, $interval, $callback)
		677
		678	=item $w = $loop->stat_ns ($path, $interval, $callback)
		679
		680	Call the callback when a file status change has been detected on
		681	C<$path>. The C<$path> does not need to exist, changing from "path exists"
		682	to "path does not exist" is a status change like any other.
		683
		684	The C<$interval> is a recommended polling interval for systems where
		685	OS-supported change notifications don't exist or are not supported. If
		686	you use C<0> then an unspecified default is used (which is highly
		687	recommended!), which is to be expected to be around five seconds usually.
		688
		689	This watcher type is not meant for massive numbers of stat watchers,
		690	as even with OS-supported change notifications, this can be
		691	resource-intensive.
		692
		693	The C<stat_ns> variant doesn't start (activate) the newly created watcher.
		694
		695	=item ... = $w->stat
		696
		697	This call is very similar to the perl C<stat> built-in: It stats (using
		698	C<lstat>) the path specified in the watcher and sets perls stat cache (as
		699	well as EV's idea of the current stat values) to the values found.
		700
		701	In scalar context, a boolean is return indicating success or failure of
		702	the stat. In list context, the same 13-value list as with stat is returned
		703	(except that the blksize and blocks fields are not reliable).
		704
		705	In the case of an error, errno is set to C<ENOENT> (regardless of the
		706	actual error value) and the C<nlink> value is forced to zero (if the stat
		707	was successful then nlink is guaranteed to be non-zero).
		708
		709	See also the next two entries for more info.
		710
		711	=item ... = $w->attr
		712
		713	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		714	the values most recently detected by EV. See the next entry for more info.
		715
		716	=item ... = $w->prev
		717
		718	Just like C<< $w->stat >>, but without the initial stat'ing: this returns
		719	the previous set of values, before the change.
		720
		721	That is, when the watcher callback is invoked, C<< $w->prev >> will be set
		722	to the values found I<before> a change was detected, while C<< $w->attr >>
		723	returns the values found leading to the change detection. The difference (if any)
		724	between C<prev> and C<attr> is what triggered the callback.
		725
		726	If you did something to the filesystem object and do not want to trigger
		727	yet another change, you can call C<stat> to update EV's idea of what the
		728	current attributes are.
		729
		730	=item $w->set ($path, $interval)
		731
		732	Reconfigures the watcher, see the constructor above for details. Can be
		733	called at any time.
		734
		735	=item $current_path = $w->path
		736
		737	=item $old_path = $w->path ($new_path)
		738
		739	Returns the previously set path and optionally set a new one.
		740
		741	=item $current_interval = $w->interval
		742
		743	=item $old_interval = $w->interval ($new_interval)
		744
		745	Returns the previously set interval and optionally set a new one. Can be
		746	used to query the actual interval used.
		747
		748	=back
		749
		750
556	=head3 IDLE WATCHERS - when you've got nothing better to do...	751	=head3 IDLE WATCHERS - when you've got nothing better to do...
557		752
558	=over 4	753	=over 4
559		754
560	=item $w = EV::idle $callback	755	=item $w = EV::idle $callback
561		756
562	=item $w = EV::idle_ns $callback	757	=item $w = EV::idle_ns $callback
563		758
564	Call the callback when there are no pending io, timer/periodic, signal or	759	=item $w = $loop->idle ($callback)
565	child events, i.e. when the process is idle.	760
		761	=item $w = $loop->idle_ns ($callback)
		762
		763	Call the callback when there are no other pending watchers of the same or
		764	higher priority (excluding check, prepare and other idle watchers of the
		765	same or lower priority, of course). They are called idle watchers because
		766	when the watcher is the highest priority pending event in the process, the
		767	process is considered to be idle at that priority.
		768
		769	If you want a watcher that is only ever called when I<no> other events are
		770	outstanding you have to set the priority to C<EV::MINPRI>.
566		771
567	The process will not block as long as any idle watchers are active, and	772	The process will not block as long as any idle watchers are active, and
568	they will be called repeatedly until stopped.	773	they will be called repeatedly until stopped.
569		774
		775	For example, if you have idle watchers at priority C<0> and C<1>, and
		776	an I/O watcher at priority C<0>, then the idle watcher at priority C<1>
		777	and the I/O watcher will always run when ready. Only when the idle watcher
		778	at priority C<1> is stopped and the I/O watcher at priority C<0> is not
		779	pending with the C<0>-priority idle watcher be invoked.
		780
570	The C<idle_ns> variant doesn't start (activate) the newly created watcher.	781	The C<idle_ns> variant doesn't start (activate) the newly created watcher.
571		782
572	=back	783	=back
573		784
574		785
…		…
577	=over 4	788	=over 4
578		789
579	=item $w = EV::prepare $callback	790	=item $w = EV::prepare $callback
580		791
581	=item $w = EV::prepare_ns $callback	792	=item $w = EV::prepare_ns $callback
		793
		794	=item $w = $loop->prepare ($callback)
		795
		796	=item $w = $loop->prepare_ns ($callback)
582		797
583	Call the callback just before the process would block. You can still	798	Call the callback just before the process would block. You can still
584	create/modify any watchers at this point.	799	create/modify any watchers at this point.
585		800
586	See the EV::check watcher, below, for explanations and an example.	801	See the EV::check watcher, below, for explanations and an example.
…		…
595	=over 4	810	=over 4
596		811
597	=item $w = EV::check $callback	812	=item $w = EV::check $callback
598		813
599	=item $w = EV::check_ns $callback	814	=item $w = EV::check_ns $callback
		815
		816	=item $w = $loop->check ($callback)
		817
		818	=item $w = $loop->check_ns ($callback)
600		819
601	Call the callback just after the process wakes up again (after it has	820	Call the callback just after the process wakes up again (after it has
602	gathered events), but before any other callbacks have been invoked.	821	gathered events), but before any other callbacks have been invoked.
603		822
604	This is used to integrate other event-based software into the EV	823	This is used to integrate other event-based software into the EV
…		…
614	or return;	833	or return;
615		834
616	# make the dispatcher handle any outstanding stuff	835	# make the dispatcher handle any outstanding stuff
617	... not shown	836	... not shown
618		837
619	# create an IO watcher for each and every socket	838	# create an I/O watcher for each and every socket
620	@snmp_watcher = (	839	@snmp_watcher = (
621	(map { EV::io $_, EV::READ, sub { } }	840	(map { EV::io $_, EV::READ, sub { } }
622	keys %{ $dispatcher->{_descriptors} }),	841	keys %{ $dispatcher->{_descriptors} }),
623		842
624	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]	843	EV::timer +($event->[Net::SNMP::Dispatcher::_ACTIVE]
…		…
646		865
647	The C<check_ns> variant doesn't start (activate) the newly created watcher.	866	The C<check_ns> variant doesn't start (activate) the newly created watcher.
648		867
649	=back	868	=back
650		869
651	=head3 STAT WATCHERS - did the file attributes just change?
652		870
653	=over 4	871	=head3 FORK WATCHERS - the audacity to resume the event loop after a fork
654		872
655	=item $w = EV::stat $path, $interval, $callback	873	Fork watchers are called when a C<fork ()> was detected. The invocation
		874	is done before the event loop blocks next and before C<check> watchers
		875	are being called, and only in the child after the fork.
656		876
657	=item $w = EV::stat_ns $path, $interval, $callback	877	=over 4
658		878
659	Call the callback when a file status change has been detected on	879	=item $w = EV::fork $callback
660	C<$path>. The C<$path> does not need to exist, changing from "path exists"
661	to "path does not exist" is a status change like any other.
662		880
663	The C<$interval> is a recommended polling interval for systems where	881	=item $w = EV::fork_ns $callback
664	OS-supported change notifications don't exist or are not supported. If
665	you use C<0> then an unspecified default is used (which is highly
666	recommended!), which is to be expected to be around five seconds usually.
667		882
668	This watcher type is not meant for massive numbers of stat watchers,	883	=item $w = $loop->fork ($callback)
669	as even with OS-supported change notifications, this can be
670	resource-intensive.
671		884
		885	=item $w = $loop->fork_ns ($callback)
		886
		887	Call the callback before the event loop is resumed in the child process
		888	after a fork.
		889
672	The C<stat_ns> variant doesn't start (activate) the newly created watcher.	890	The C<fork_ns> variant doesn't start (activate) the newly created watcher.
673		891
674	=item $w->set ($path, $interval)
675
676	Reconfigures the watcher, see the constructor above for details. Can be
677	called at any time.
678
679	=item $current_path = $w->path
680
681	=item $old_path = $w->path ($new_path)
682
683	Returns the previously set path and optionally set a new one.
684
685	=item $current_interval = $w->interval
686
687	=item $old_interval = $w->interval ($new_interval)
688
689	Returns the previously set interval and optionally set a new one. Can be
690	used to query the actual interval used.
691
692	=back	892	=back
693		893
		894
		895	=head1 PERL SIGNALS
		896
		897	While Perl signal handling (C<%SIG>) is not affected by EV, the behaviour
		898	with EV is as the same as any other C library: Perl-signals will only be
		899	handled when Perl runs, which means your signal handler might be invoked
		900	only the next time an event callback is invoked.
		901
		902	The solution is to use EV signal watchers (see C<EV::signal>), which will
		903	ensure proper operations with regards to other event watchers.
		904
		905	If you cannot do this for whatever reason, you can also force a watcher
		906	to be called on every event loop iteration by installing a C<EV::check>
		907	watcher:
		908
		909	my $async_check = EV::check sub { };
		910
		911	This ensures that perl gets into control for a short time to handle any
		912	pending signals, and also ensures (slightly) slower overall operation.
694		913
695	=head1 THREADS	914	=head1 THREADS
696		915
697	Threads are not supported by this module in any way. Perl pseudo-threads	916	Threads are not supported by this module in any way. Perl pseudo-threads
698	is evil stuff and must die. As soon as Perl gains real threads I will work	917	is evil stuff and must die. As soon as Perl gains real threads I will work
…		…
720	our $DIED = sub {	939	our $DIED = sub {
721	warn "EV: error in callback (ignoring): $@";	940	warn "EV: error in callback (ignoring): $@";
722	};	941	};
723		942
724	default_loop	943	default_loop
725	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_METHODS}?';	944	or die 'EV: cannot initialise libev backend. bad $ENV{LIBEV_FLAGS}?';
726		945
727	1;	946	1;
728		947
729	=head1 SEE ALSO	948	=head1 SEE ALSO
730		949
731	L<EV::DNS>.	950	L<EV::ADNS> (asynchronous DNS), L<Glib::EV> (makes Glib/Gtk2 use EV as
		951	event loop), L<EV::Glib> (embed Glib into EV), L<Coro::EV> (efficient
		952	coroutines with EV), L<Net::SNMP::EV> (asynchronous SNMP).
732		953
733	=head1 AUTHOR	954	=head1 AUTHOR
734		955
735	Marc Lehmann <schmorp@schmorp.de>	956	Marc Lehmann <schmorp@schmorp.de>
736	http://home.schmorp.de/	957	http://home.schmorp.de/

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Comparing EV/EV.pm (file contents): Revision 1.55 by root, Tue Nov 27 08:11:52 2007 UTC vs. Revision 1.78 by root, Sat Dec 22 11:50:04 2007 UTC

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Comparing EV/EV.pm (file contents):
Revision 1.55 by root, Tue Nov 27 08:11:52 2007 UTC vs.
Revision 1.78 by root, Sat Dec 22 11:50:04 2007 UTC