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Revision 1.292 by sf-exg, Mon Mar 22 09:57:01 2010 UTC vs.
Revision 1.322 by root, Sun Oct 24 17:58:41 2010 UTC

…		…
26	puts ("stdin ready");	26	puts ("stdin ready");
27	// for one-shot events, one must manually stop the watcher	27	// for one-shot events, one must manually stop the watcher
28	// with its corresponding stop function.	28	// with its corresponding stop function.
29	ev_io_stop (EV_A_ w);	29	ev_io_stop (EV_A_ w);
30		30
31	// this causes all nested ev_loop's to stop iterating	31	// this causes all nested ev_run's to stop iterating
32	ev_unloop (EV_A_ EVUNLOOP_ALL);	32	ev_break (EV_A_ EVBREAK_ALL);
33	}	33	}
34		34
35	// another callback, this time for a time-out	35	// another callback, this time for a time-out
36	static void	36	static void
37	timeout_cb (EV_P_ ev_timer *w, int revents)	37	timeout_cb (EV_P_ ev_timer *w, int revents)
38	{	38	{
39	puts ("timeout");	39	puts ("timeout");
40	// this causes the innermost ev_loop to stop iterating	40	// this causes the innermost ev_run to stop iterating
41	ev_unloop (EV_A_ EVUNLOOP_ONE);	41	ev_break (EV_A_ EVBREAK_ONE);
42	}	42	}
43		43
44	int	44	int
45	main (void)	45	main (void)
46	{	46	{
47	// use the default event loop unless you have special needs	47	// use the default event loop unless you have special needs
48	struct ev_loop *loop = ev_default_loop (0);	48	struct ev_loop *loop = EV_DEFAULT;
49		49
50	// initialise an io watcher, then start it	50	// initialise an io watcher, then start it
51	// this one will watch for stdin to become readable	51	// this one will watch for stdin to become readable
52	ev_io_init (&stdin_watcher, stdin_cb, /*STDIN_FILENO*/ 0, EV_READ);	52	ev_io_init (&stdin_watcher, stdin_cb, /*STDIN_FILENO*/ 0, EV_READ);
53	ev_io_start (loop, &stdin_watcher);	53	ev_io_start (loop, &stdin_watcher);
…		…
56	// simple non-repeating 5.5 second timeout	56	// simple non-repeating 5.5 second timeout
57	ev_timer_init (&timeout_watcher, timeout_cb, 5.5, 0.);	57	ev_timer_init (&timeout_watcher, timeout_cb, 5.5, 0.);
58	ev_timer_start (loop, &timeout_watcher);	58	ev_timer_start (loop, &timeout_watcher);
59		59
60	// now wait for events to arrive	60	// now wait for events to arrive
61	ev_loop (loop, 0);	61	ev_run (loop, 0);
62		62
63	// unloop was called, so exit	63	// unloop was called, so exit
64	return 0;	64	return 0;
65	}	65	}
66		66
…		…
75	While this document tries to be as complete as possible in documenting	75	While this document tries to be as complete as possible in documenting
76	libev, its usage and the rationale behind its design, it is not a tutorial	76	libev, its usage and the rationale behind its design, it is not a tutorial
77	on event-based programming, nor will it introduce event-based programming	77	on event-based programming, nor will it introduce event-based programming
78	with libev.	78	with libev.
79		79
80	Familarity with event based programming techniques in general is assumed	80	Familiarity with event based programming techniques in general is assumed
81	throughout this document.	81	throughout this document.
82		82
83	=head1 ABOUT LIBEV	83	=head1 ABOUT LIBEV
84		84
85	Libev is an event loop: you register interest in certain events (such as a	85	Libev is an event loop: you register interest in certain events (such as a
…		…
124	this argument.	124	this argument.
125		125
126	=head2 TIME REPRESENTATION	126	=head2 TIME REPRESENTATION
127		127
128	Libev represents time as a single floating point number, representing	128	Libev represents time as a single floating point number, representing
129	the (fractional) number of seconds since the (POSIX) epoch (somewhere	129	the (fractional) number of seconds since the (POSIX) epoch (in practice
130	near the beginning of 1970, details are complicated, don't ask). This	130	somewhere near the beginning of 1970, details are complicated, don't
131	type is called C<ev_tstamp>, which is what you should use too. It usually	131	ask). This type is called C<ev_tstamp>, which is what you should use
132	aliases to the C<double> type in C. When you need to do any calculations	132	too. It usually aliases to the C<double> type in C. When you need to do
133	on it, you should treat it as some floating point value. Unlike the name	133	any calculations on it, you should treat it as some floating point value.
		134
134	component C<stamp> might indicate, it is also used for time differences	135	Unlike the name component C<stamp> might indicate, it is also used for
135	throughout libev.	136	time differences (e.g. delays) throughout libev.
136		137
137	=head1 ERROR HANDLING	138	=head1 ERROR HANDLING
138		139
139	Libev knows three classes of errors: operating system errors, usage errors	140	Libev knows three classes of errors: operating system errors, usage errors
140	and internal errors (bugs).	141	and internal errors (bugs).
…		…
164		165
165	=item ev_tstamp ev_time ()	166	=item ev_tstamp ev_time ()
166		167
167	Returns the current time as libev would use it. Please note that the	168	Returns the current time as libev would use it. Please note that the
168	C<ev_now> function is usually faster and also often returns the timestamp	169	C<ev_now> function is usually faster and also often returns the timestamp
169	you actually want to know.	170	you actually want to know. Also interesting is the combination of
		171	C<ev_update_now> and C<ev_now>.
170		172
171	=item ev_sleep (ev_tstamp interval)	173	=item ev_sleep (ev_tstamp interval)
172		174
173	Sleep for the given interval: The current thread will be blocked until	175	Sleep for the given interval: The current thread will be blocked until
174	either it is interrupted or the given time interval has passed. Basically	176	either it is interrupted or the given time interval has passed. Basically
…		…
191	as this indicates an incompatible change. Minor versions are usually	193	as this indicates an incompatible change. Minor versions are usually
192	compatible to older versions, so a larger minor version alone is usually	194	compatible to older versions, so a larger minor version alone is usually
193	not a problem.	195	not a problem.
194		196
195	Example: Make sure we haven't accidentally been linked against the wrong	197	Example: Make sure we haven't accidentally been linked against the wrong
196	version.	198	version (note, however, that this will not detect other ABI mismatches,
		199	such as LFS or reentrancy).
197		200
198	assert (("libev version mismatch",	201	assert (("libev version mismatch",
199	ev_version_major () == EV_VERSION_MAJOR	202	ev_version_major () == EV_VERSION_MAJOR
200	&& ev_version_minor () >= EV_VERSION_MINOR));	203	&& ev_version_minor () >= EV_VERSION_MINOR));
201		204
…		…
212	assert (("sorry, no epoll, no sex",	215	assert (("sorry, no epoll, no sex",
213	ev_supported_backends () & EVBACKEND_EPOLL));	216	ev_supported_backends () & EVBACKEND_EPOLL));
214		217
215	=item unsigned int ev_recommended_backends ()	218	=item unsigned int ev_recommended_backends ()
216		219
217	Return the set of all backends compiled into this binary of libev and also	220	Return the set of all backends compiled into this binary of libev and
218	recommended for this platform. This set is often smaller than the one	221	also recommended for this platform, meaning it will work for most file
		222	descriptor types. This set is often smaller than the one returned by
219	returned by C<ev_supported_backends>, as for example kqueue is broken on	223	C<ev_supported_backends>, as for example kqueue is broken on most BSDs
220	most BSDs and will not be auto-detected unless you explicitly request it	224	and will not be auto-detected unless you explicitly request it (assuming
221	(assuming you know what you are doing). This is the set of backends that	225	you know what you are doing). This is the set of backends that libev will
222	libev will probe for if you specify no backends explicitly.	226	probe for if you specify no backends explicitly.
223		227
224	=item unsigned int ev_embeddable_backends ()	228	=item unsigned int ev_embeddable_backends ()
225		229
226	Returns the set of backends that are embeddable in other event loops. This	230	Returns the set of backends that are embeddable in other event loops. This
227	is the theoretical, all-platform, value. To find which backends	231	value is platform-specific but can include backends not available on the
228	might be supported on the current system, you would need to look at	232	current system. To find which embeddable backends might be supported on
229	C<ev_embeddable_backends () & ev_supported_backends ()>, likewise for	233	the current system, you would need to look at C<ev_embeddable_backends ()
230	recommended ones.	234	& ev_supported_backends ()>, likewise for recommended ones.
231		235
232	See the description of C<ev_embed> watchers for more info.	236	See the description of C<ev_embed> watchers for more info.
233		237
234	=item ev_set_allocator (void *(*cb)(void *ptr, long size)) [NOT REENTRANT]	238	=item ev_set_allocator (void *(*cb)(void *ptr, long size)) [NOT REENTRANT]
235		239
…		…
289	...	293	...
290	ev_set_syserr_cb (fatal_error);	294	ev_set_syserr_cb (fatal_error);
291		295
292	=back	296	=back
293		297
294	=head1 FUNCTIONS CONTROLLING THE EVENT LOOP	298	=head1 FUNCTIONS CONTROLLING EVENT LOOPS
295		299
296	An event loop is described by a C<struct ev_loop *> (the C<struct>	300	An event loop is described by a C<struct ev_loop *> (the C<struct> is
297	is I<not> optional in this case, as there is also an C<ev_loop>	301	I<not> optional in this case unless libev 3 compatibility is disabled, as
298	I<function>).	302	libev 3 had an C<ev_loop> function colliding with the struct name).
299		303
300	The library knows two types of such loops, the I<default> loop, which	304	The library knows two types of such loops, the I<default> loop, which
301	supports signals and child events, and dynamically created loops which do	305	supports signals and child events, and dynamically created event loops
302	not.	306	which do not.
303		307
304	=over 4	308	=over 4
305		309
306	=item struct ev_loop *ev_default_loop (unsigned int flags)	310	=item struct ev_loop *ev_default_loop (unsigned int flags)
307		311
308	This will initialise the default event loop if it hasn't been initialised	312	This returns the "default" event loop object, which is what you should
309	yet and return it. If the default loop could not be initialised, returns	313	normally use when you just need "the event loop". Event loop objects and
310	false. If it already was initialised it simply returns it (and ignores the	314	the C<flags> parameter are described in more detail in the entry for
311	flags. If that is troubling you, check C<ev_backend ()> afterwards).	315	C<ev_loop_new>.
		316
		317	If the default loop is already initialised then this function simply
		318	returns it (and ignores the flags. If that is troubling you, check
		319	C<ev_backend ()> afterwards). Otherwise it will create it with the given
		320	flags, which should almost always be C<0>, unless the caller is also the
		321	one calling C<ev_run> or otherwise qualifies as "the main program".
312		322
313	If you don't know what event loop to use, use the one returned from this	323	If you don't know what event loop to use, use the one returned from this
314	function.	324	function (or via the C<EV_DEFAULT> macro).
315		325
316	Note that this function is I<not> thread-safe, so if you want to use it	326	Note that this function is I<not> thread-safe, so if you want to use it
317	from multiple threads, you have to lock (note also that this is unlikely,	327	from multiple threads, you have to employ some kind of mutex (note also
318	as loops cannot be shared easily between threads anyway).	328	that this case is unlikely, as loops cannot be shared easily between
		329	threads anyway).
319		330
320	The default loop is the only loop that can handle C<ev_signal> and	331	The default loop is the only loop that can handle C<ev_child> watchers,
321	C<ev_child> watchers, and to do this, it always registers a handler	332	and to do this, it always registers a handler for C<SIGCHLD>. If this is
322	for C<SIGCHLD>. If this is a problem for your application you can either	333	a problem for your application you can either create a dynamic loop with
323	create a dynamic loop with C<ev_loop_new> that doesn't do that, or you	334	C<ev_loop_new> which doesn't do that, or you can simply overwrite the
324	can simply overwrite the C<SIGCHLD> signal handler I<after> calling	335	C<SIGCHLD> signal handler I<after> calling C<ev_default_init>.
325	C<ev_default_init>.	336
		337	Example: This is the most typical usage.
		338
		339	if (!ev_default_loop (0))
		340	fatal ("could not initialise libev, bad $LIBEV_FLAGS in environment?");
		341
		342	Example: Restrict libev to the select and poll backends, and do not allow
		343	environment settings to be taken into account:
		344
		345	ev_default_loop (EVBACKEND_POLL | EVBACKEND_SELECT | EVFLAG_NOENV);
		346
		347	Example: Use whatever libev has to offer, but make sure that kqueue is
		348	used if available (warning, breaks stuff, best use only with your own
		349	private event loop and only if you know the OS supports your types of
		350	fds):
		351
		352	ev_default_loop (ev_recommended_backends () | EVBACKEND_KQUEUE);
		353
		354	=item struct ev_loop *ev_loop_new (unsigned int flags)
		355
		356	This will create and initialise a new event loop object. If the loop
		357	could not be initialised, returns false.
		358
		359	Note that this function I<is> thread-safe, and one common way to use
		360	libev with threads is indeed to create one loop per thread, and using the
		361	default loop in the "main" or "initial" thread.
326		362
327	The flags argument can be used to specify special behaviour or specific	363	The flags argument can be used to specify special behaviour or specific
328	backends to use, and is usually specified as C<0> (or C<EVFLAG_AUTO>).	364	backends to use, and is usually specified as C<0> (or C<EVFLAG_AUTO>).
329		365
330	The following flags are supported:	366	The following flags are supported:
…		…
438	of course I<doesn't>, and epoll just loves to report events for totally	474	of course I<doesn't>, and epoll just loves to report events for totally
439	I<different> file descriptors (even already closed ones, so one cannot	475	I<different> file descriptors (even already closed ones, so one cannot
440	even remove them from the set) than registered in the set (especially	476	even remove them from the set) than registered in the set (especially
441	on SMP systems). Libev tries to counter these spurious notifications by	477	on SMP systems). Libev tries to counter these spurious notifications by
442	employing an additional generation counter and comparing that against the	478	employing an additional generation counter and comparing that against the
443	events to filter out spurious ones, recreating the set when required.	479	events to filter out spurious ones, recreating the set when required. Last
		480	not least, it also refuses to work with some file descriptors which work
		481	perfectly fine with C<select> (files, many character devices...).
444		482
445	While stopping, setting and starting an I/O watcher in the same iteration	483	While stopping, setting and starting an I/O watcher in the same iteration
446	will result in some caching, there is still a system call per such	484	will result in some caching, there is still a system call per such
447	incident (because the same I<file descriptor> could point to a different	485	incident (because the same I<file descriptor> could point to a different
448	I<file description> now), so its best to avoid that. Also, C<dup ()>'ed	486	I<file description> now), so its best to avoid that. Also, C<dup ()>'ed
…		…
546	If one or more of the backend flags are or'ed into the flags value,	584	If one or more of the backend flags are or'ed into the flags value,
547	then only these backends will be tried (in the reverse order as listed	585	then only these backends will be tried (in the reverse order as listed
548	here). If none are specified, all backends in C<ev_recommended_backends	586	here). If none are specified, all backends in C<ev_recommended_backends
549	()> will be tried.	587	()> will be tried.
550		588
551	Example: This is the most typical usage.
552
553	if (!ev_default_loop (0))
554	fatal ("could not initialise libev, bad $LIBEV_FLAGS in environment?");
555
556	Example: Restrict libev to the select and poll backends, and do not allow
557	environment settings to be taken into account:
558
559	ev_default_loop (EVBACKEND_POLL | EVBACKEND_SELECT | EVFLAG_NOENV);
560
561	Example: Use whatever libev has to offer, but make sure that kqueue is
562	used if available (warning, breaks stuff, best use only with your own
563	private event loop and only if you know the OS supports your types of
564	fds):
565
566	ev_default_loop (ev_recommended_backends () | EVBACKEND_KQUEUE);
567
568	=item struct ev_loop *ev_loop_new (unsigned int flags)
569
570	Similar to C<ev_default_loop>, but always creates a new event loop that is
571	always distinct from the default loop.
572
573	Note that this function I<is> thread-safe, and one common way to use
574	libev with threads is indeed to create one loop per thread, and using the
575	default loop in the "main" or "initial" thread.
576
577	Example: Try to create a event loop that uses epoll and nothing else.	589	Example: Try to create a event loop that uses epoll and nothing else.
578		590
579	struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV);	591	struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV);
580	if (!epoller)	592	if (!epoller)
581	fatal ("no epoll found here, maybe it hides under your chair");	593	fatal ("no epoll found here, maybe it hides under your chair");
582		594
583	=item ev_default_destroy ()	595	=item ev_loop_destroy (loop)
584		596
585	Destroys the default loop (frees all memory and kernel state etc.). None	597	Destroys an event loop object (frees all memory and kernel state
586	of the active event watchers will be stopped in the normal sense, so	598	etc.). None of the active event watchers will be stopped in the normal
587	e.g. C<ev_is_active> might still return true. It is your responsibility to	599	sense, so e.g. C<ev_is_active> might still return true. It is your
588	either stop all watchers cleanly yourself I<before> calling this function,	600	responsibility to either stop all watchers cleanly yourself I<before>
589	or cope with the fact afterwards (which is usually the easiest thing, you	601	calling this function, or cope with the fact afterwards (which is usually
590	can just ignore the watchers and/or C<free ()> them for example).	602	the easiest thing, you can just ignore the watchers and/or C<free ()> them
		603	for example).
591		604
592	Note that certain global state, such as signal state (and installed signal	605	Note that certain global state, such as signal state (and installed signal
593	handlers), will not be freed by this function, and related watchers (such	606	handlers), will not be freed by this function, and related watchers (such
594	as signal and child watchers) would need to be stopped manually.	607	as signal and child watchers) would need to be stopped manually.
595		608
596	In general it is not advisable to call this function except in the	609	This function is normally used on loop objects allocated by
597	rare occasion where you really need to free e.g. the signal handling	610	C<ev_loop_new>, but it can also be used on the default loop returned by
		611	C<ev_default_loop>, in which case it is not thread-safe.
		612
		613	Note that it is not advisable to call this function on the default loop
		614	except in the rare occasion where you really need to free it's resources.
598	pipe fds. If you need dynamically allocated loops it is better to use	615	If you need dynamically allocated loops it is better to use C<ev_loop_new>
599	C<ev_loop_new> and C<ev_loop_destroy>.	616	and C<ev_loop_destroy>.
600		617
601	=item ev_loop_destroy (loop)	618	=item ev_loop_fork (loop)
602		619
603	Like C<ev_default_destroy>, but destroys an event loop created by an
604	earlier call to C<ev_loop_new>.
605
606	=item ev_default_fork ()
607
608	This function sets a flag that causes subsequent C<ev_loop> iterations	620	This function sets a flag that causes subsequent C<ev_run> iterations to
609	to reinitialise the kernel state for backends that have one. Despite the	621	reinitialise the kernel state for backends that have one. Despite the
610	name, you can call it anytime, but it makes most sense after forking, in	622	name, you can call it anytime, but it makes most sense after forking, in
611	the child process (or both child and parent, but that again makes little	623	the child process. You I<must> call it (or use C<EVFLAG_FORKCHECK>) in the
612	sense). You I<must> call it in the child before using any of the libev	624	child before resuming or calling C<ev_run>.
613	functions, and it will only take effect at the next C<ev_loop> iteration.
614		625
615	Again, you I<have> to call it on I<any> loop that you want to re-use after	626	Again, you I<have> to call it on I<any> loop that you want to re-use after
616	a fork, I<even if you do not plan to use the loop in the parent>. This is	627	a fork, I<even if you do not plan to use the loop in the parent>. This is
617	because some kernel interfaces *cough* I<kqueue> *cough* do funny things	628	because some kernel interfaces *cough* I<kqueue> *cough* do funny things
618	during fork.	629	during fork.
619		630
620	On the other hand, you only need to call this function in the child	631	On the other hand, you only need to call this function in the child
621	process if and only if you want to use the event loop in the child. If you	632	process if and only if you want to use the event loop in the child. If
622	just fork+exec or create a new loop in the child, you don't have to call	633	you just fork+exec or create a new loop in the child, you don't have to
623	it at all.	634	call it at all (in fact, C<epoll> is so badly broken that it makes a
		635	difference, but libev will usually detect this case on its own and do a
		636	costly reset of the backend).
624		637
625	The function itself is quite fast and it's usually not a problem to call	638	The function itself is quite fast and it's usually not a problem to call
626	it just in case after a fork. To make this easy, the function will fit in	639	it just in case after a fork.
627	quite nicely into a call to C<pthread_atfork>:
628		640
		641	Example: Automate calling C<ev_loop_fork> on the default loop when
		642	using pthreads.
		643
		644	static void
		645	post_fork_child (void)
		646	{
		647	ev_loop_fork (EV_DEFAULT);
		648	}
		649
		650	...
629	pthread_atfork (0, 0, ev_default_fork);	651	pthread_atfork (0, 0, post_fork_child);
630
631	=item ev_loop_fork (loop)
632
633	Like C<ev_default_fork>, but acts on an event loop created by
634	C<ev_loop_new>. Yes, you have to call this on every allocated event loop
635	after fork that you want to re-use in the child, and how you keep track of
636	them is entirely your own problem.
637		652
638	=item int ev_is_default_loop (loop)	653	=item int ev_is_default_loop (loop)
639		654
640	Returns true when the given loop is, in fact, the default loop, and false	655	Returns true when the given loop is, in fact, the default loop, and false
641	otherwise.	656	otherwise.
642		657
643	=item unsigned int ev_iteration (loop)	658	=item unsigned int ev_iteration (loop)
644		659
645	Returns the current iteration count for the loop, which is identical to	660	Returns the current iteration count for the event loop, which is identical
646	the number of times libev did poll for new events. It starts at C<0> and	661	to the number of times libev did poll for new events. It starts at C<0>
647	happily wraps around with enough iterations.	662	and happily wraps around with enough iterations.
648		663
649	This value can sometimes be useful as a generation counter of sorts (it	664	This value can sometimes be useful as a generation counter of sorts (it
650	"ticks" the number of loop iterations), as it roughly corresponds with	665	"ticks" the number of loop iterations), as it roughly corresponds with
651	C<ev_prepare> and C<ev_check> calls - and is incremented between the	666	C<ev_prepare> and C<ev_check> calls - and is incremented between the
652	prepare and check phases.	667	prepare and check phases.
653		668
654	=item unsigned int ev_depth (loop)	669	=item unsigned int ev_depth (loop)
655		670
656	Returns the number of times C<ev_loop> was entered minus the number of	671	Returns the number of times C<ev_run> was entered minus the number of
657	times C<ev_loop> was exited, in other words, the recursion depth.	672	times C<ev_run> was exited, in other words, the recursion depth.
658		673
659	Outside C<ev_loop>, this number is zero. In a callback, this number is	674	Outside C<ev_run>, this number is zero. In a callback, this number is
660	C<1>, unless C<ev_loop> was invoked recursively (or from another thread),	675	C<1>, unless C<ev_run> was invoked recursively (or from another thread),
661	in which case it is higher.	676	in which case it is higher.
662		677
663	Leaving C<ev_loop> abnormally (setjmp/longjmp, cancelling the thread	678	Leaving C<ev_run> abnormally (setjmp/longjmp, cancelling the thread
664	etc.), doesn't count as "exit" - consider this as a hint to avoid such	679	etc.), doesn't count as "exit" - consider this as a hint to avoid such
665	ungentleman behaviour unless it's really convenient.	680	ungentleman-like behaviour unless it's really convenient.
666		681
667	=item unsigned int ev_backend (loop)	682	=item unsigned int ev_backend (loop)
668		683
669	Returns one of the C<EVBACKEND_*> flags indicating the event backend in	684	Returns one of the C<EVBACKEND_*> flags indicating the event backend in
670	use.	685	use.
…		…
679		694
680	=item ev_now_update (loop)	695	=item ev_now_update (loop)
681		696
682	Establishes the current time by querying the kernel, updating the time	697	Establishes the current time by querying the kernel, updating the time
683	returned by C<ev_now ()> in the progress. This is a costly operation and	698	returned by C<ev_now ()> in the progress. This is a costly operation and
684	is usually done automatically within C<ev_loop ()>.	699	is usually done automatically within C<ev_run ()>.
685		700
686	This function is rarely useful, but when some event callback runs for a	701	This function is rarely useful, but when some event callback runs for a
687	very long time without entering the event loop, updating libev's idea of	702	very long time without entering the event loop, updating libev's idea of
688	the current time is a good idea.	703	the current time is a good idea.
689		704
…		…
691		706
692	=item ev_suspend (loop)	707	=item ev_suspend (loop)
693		708
694	=item ev_resume (loop)	709	=item ev_resume (loop)
695		710
696	These two functions suspend and resume a loop, for use when the loop is	711	These two functions suspend and resume an event loop, for use when the
697	not used for a while and timeouts should not be processed.	712	loop is not used for a while and timeouts should not be processed.
698		713
699	A typical use case would be an interactive program such as a game: When	714	A typical use case would be an interactive program such as a game: When
700	the user presses C<^Z> to suspend the game and resumes it an hour later it	715	the user presses C<^Z> to suspend the game and resumes it an hour later it
701	would be best to handle timeouts as if no time had actually passed while	716	would be best to handle timeouts as if no time had actually passed while
702	the program was suspended. This can be achieved by calling C<ev_suspend>	717	the program was suspended. This can be achieved by calling C<ev_suspend>
…		…
704	C<ev_resume> directly afterwards to resume timer processing.	719	C<ev_resume> directly afterwards to resume timer processing.
705		720
706	Effectively, all C<ev_timer> watchers will be delayed by the time spend	721	Effectively, all C<ev_timer> watchers will be delayed by the time spend
707	between C<ev_suspend> and C<ev_resume>, and all C<ev_periodic> watchers	722	between C<ev_suspend> and C<ev_resume>, and all C<ev_periodic> watchers
708	will be rescheduled (that is, they will lose any events that would have	723	will be rescheduled (that is, they will lose any events that would have
709	occured while suspended).	724	occurred while suspended).
710		725
711	After calling C<ev_suspend> you B<must not> call I<any> function on the	726	After calling C<ev_suspend> you B<must not> call I<any> function on the
712	given loop other than C<ev_resume>, and you B<must not> call C<ev_resume>	727	given loop other than C<ev_resume>, and you B<must not> call C<ev_resume>
713	without a previous call to C<ev_suspend>.	728	without a previous call to C<ev_suspend>.
714		729
715	Calling C<ev_suspend>/C<ev_resume> has the side effect of updating the	730	Calling C<ev_suspend>/C<ev_resume> has the side effect of updating the
716	event loop time (see C<ev_now_update>).	731	event loop time (see C<ev_now_update>).
717		732
718	=item ev_loop (loop, int flags)	733	=item ev_run (loop, int flags)
719		734
720	Finally, this is it, the event handler. This function usually is called	735	Finally, this is it, the event handler. This function usually is called
721	after you have initialised all your watchers and you want to start	736	after you have initialised all your watchers and you want to start
722	handling events.	737	handling events. It will ask the operating system for any new events, call
		738	the watcher callbacks, an then repeat the whole process indefinitely: This
		739	is why event loops are called I<loops>.
723		740
724	If the flags argument is specified as C<0>, it will not return until	741	If the flags argument is specified as C<0>, it will keep handling events
725	either no event watchers are active anymore or C<ev_unloop> was called.	742	until either no event watchers are active anymore or C<ev_break> was
		743	called.
726		744
727	Please note that an explicit C<ev_unloop> is usually better than	745	Please note that an explicit C<ev_break> is usually better than
728	relying on all watchers to be stopped when deciding when a program has	746	relying on all watchers to be stopped when deciding when a program has
729	finished (especially in interactive programs), but having a program	747	finished (especially in interactive programs), but having a program
730	that automatically loops as long as it has to and no longer by virtue	748	that automatically loops as long as it has to and no longer by virtue
731	of relying on its watchers stopping correctly, that is truly a thing of	749	of relying on its watchers stopping correctly, that is truly a thing of
732	beauty.	750	beauty.
733		751
734	A flags value of C<EVLOOP_NONBLOCK> will look for new events, will handle	752	A flags value of C<EVRUN_NOWAIT> will look for new events, will handle
735	those events and any already outstanding ones, but will not block your	753	those events and any already outstanding ones, but will not wait and
736	process in case there are no events and will return after one iteration of	754	block your process in case there are no events and will return after one
737	the loop.	755	iteration of the loop. This is sometimes useful to poll and handle new
		756	events while doing lengthy calculations, to keep the program responsive.
738		757
739	A flags value of C<EVLOOP_ONESHOT> will look for new events (waiting if	758	A flags value of C<EVRUN_ONCE> will look for new events (waiting if
740	necessary) and will handle those and any already outstanding ones. It	759	necessary) and will handle those and any already outstanding ones. It
741	will block your process until at least one new event arrives (which could	760	will block your process until at least one new event arrives (which could
742	be an event internal to libev itself, so there is no guarantee that a	761	be an event internal to libev itself, so there is no guarantee that a
743	user-registered callback will be called), and will return after one	762	user-registered callback will be called), and will return after one
744	iteration of the loop.	763	iteration of the loop.
745		764
746	This is useful if you are waiting for some external event in conjunction	765	This is useful if you are waiting for some external event in conjunction
747	with something not expressible using other libev watchers (i.e. "roll your	766	with something not expressible using other libev watchers (i.e. "roll your
748	own C<ev_loop>"). However, a pair of C<ev_prepare>/C<ev_check> watchers is	767	own C<ev_run>"). However, a pair of C<ev_prepare>/C<ev_check> watchers is
749	usually a better approach for this kind of thing.	768	usually a better approach for this kind of thing.
750		769
751	Here are the gory details of what C<ev_loop> does:	770	Here are the gory details of what C<ev_run> does:
752		771
		772	- Increment loop depth.
		773	- Reset the ev_break status.
753	- Before the first iteration, call any pending watchers.	774	- Before the first iteration, call any pending watchers.
		775	LOOP:
754	* If EVFLAG_FORKCHECK was used, check for a fork.	776	- If EVFLAG_FORKCHECK was used, check for a fork.
755	- If a fork was detected (by any means), queue and call all fork watchers.	777	- If a fork was detected (by any means), queue and call all fork watchers.
756	- Queue and call all prepare watchers.	778	- Queue and call all prepare watchers.
		779	- If ev_break was called, goto FINISH.
757	- If we have been forked, detach and recreate the kernel state	780	- If we have been forked, detach and recreate the kernel state
758	as to not disturb the other process.	781	as to not disturb the other process.
759	- Update the kernel state with all outstanding changes.	782	- Update the kernel state with all outstanding changes.
760	- Update the "event loop time" (ev_now ()).	783	- Update the "event loop time" (ev_now ()).
761	- Calculate for how long to sleep or block, if at all	784	- Calculate for how long to sleep or block, if at all
762	(active idle watchers, EVLOOP_NONBLOCK or not having	785	(active idle watchers, EVRUN_NOWAIT or not having
763	any active watchers at all will result in not sleeping).	786	any active watchers at all will result in not sleeping).
764	- Sleep if the I/O and timer collect interval say so.	787	- Sleep if the I/O and timer collect interval say so.
		788	- Increment loop iteration counter.
765	- Block the process, waiting for any events.	789	- Block the process, waiting for any events.
766	- Queue all outstanding I/O (fd) events.	790	- Queue all outstanding I/O (fd) events.
767	- Update the "event loop time" (ev_now ()), and do time jump adjustments.	791	- Update the "event loop time" (ev_now ()), and do time jump adjustments.
768	- Queue all expired timers.	792	- Queue all expired timers.
769	- Queue all expired periodics.	793	- Queue all expired periodics.
770	- Unless any events are pending now, queue all idle watchers.	794	- Queue all idle watchers with priority higher than that of pending events.
771	- Queue all check watchers.	795	- Queue all check watchers.
772	- Call all queued watchers in reverse order (i.e. check watchers first).	796	- Call all queued watchers in reverse order (i.e. check watchers first).
773	Signals and child watchers are implemented as I/O watchers, and will	797	Signals and child watchers are implemented as I/O watchers, and will
774	be handled here by queueing them when their watcher gets executed.	798	be handled here by queueing them when their watcher gets executed.
775	- If ev_unloop has been called, or EVLOOP_ONESHOT or EVLOOP_NONBLOCK	799	- If ev_break has been called, or EVRUN_ONCE or EVRUN_NOWAIT
776	were used, or there are no active watchers, return, otherwise	800	were used, or there are no active watchers, goto FINISH, otherwise
777	continue with step *.	801	continue with step LOOP.
		802	FINISH:
		803	- Reset the ev_break status iff it was EVBREAK_ONE.
		804	- Decrement the loop depth.
		805	- Return.
778		806
779	Example: Queue some jobs and then loop until no events are outstanding	807	Example: Queue some jobs and then loop until no events are outstanding
780	anymore.	808	anymore.
781		809
782	... queue jobs here, make sure they register event watchers as long	810	... queue jobs here, make sure they register event watchers as long
783	... as they still have work to do (even an idle watcher will do..)	811	... as they still have work to do (even an idle watcher will do..)
784	ev_loop (my_loop, 0);	812	ev_run (my_loop, 0);
785	... jobs done or somebody called unloop. yeah!	813	... jobs done or somebody called unloop. yeah!
786		814
787	=item ev_unloop (loop, how)	815	=item ev_break (loop, how)
788		816
789	Can be used to make a call to C<ev_loop> return early (but only after it	817	Can be used to make a call to C<ev_run> return early (but only after it
790	has processed all outstanding events). The C<how> argument must be either	818	has processed all outstanding events). The C<how> argument must be either
791	C<EVUNLOOP_ONE>, which will make the innermost C<ev_loop> call return, or	819	C<EVBREAK_ONE>, which will make the innermost C<ev_run> call return, or
792	C<EVUNLOOP_ALL>, which will make all nested C<ev_loop> calls return.	820	C<EVBREAK_ALL>, which will make all nested C<ev_run> calls return.
793		821
794	This "unloop state" will be cleared when entering C<ev_loop> again.	822	This "unloop state" will be cleared when entering C<ev_run> again.
795		823
796	It is safe to call C<ev_unloop> from otuside any C<ev_loop> calls.	824	It is safe to call C<ev_break> from outside any C<ev_run> calls. ##TODO##
797		825
798	=item ev_ref (loop)	826	=item ev_ref (loop)
799		827
800	=item ev_unref (loop)	828	=item ev_unref (loop)
801		829
802	Ref/unref can be used to add or remove a reference count on the event	830	Ref/unref can be used to add or remove a reference count on the event
803	loop: Every watcher keeps one reference, and as long as the reference	831	loop: Every watcher keeps one reference, and as long as the reference
804	count is nonzero, C<ev_loop> will not return on its own.	832	count is nonzero, C<ev_run> will not return on its own.
805		833
806	This is useful when you have a watcher that you never intend to	834	This is useful when you have a watcher that you never intend to
807	unregister, but that nevertheless should not keep C<ev_loop> from	835	unregister, but that nevertheless should not keep C<ev_run> from
808	returning. In such a case, call C<ev_unref> after starting, and C<ev_ref>	836	returning. In such a case, call C<ev_unref> after starting, and C<ev_ref>
809	before stopping it.	837	before stopping it.
810		838
811	As an example, libev itself uses this for its internal signal pipe: It	839	As an example, libev itself uses this for its internal signal pipe: It
812	is not visible to the libev user and should not keep C<ev_loop> from	840	is not visible to the libev user and should not keep C<ev_run> from
813	exiting if no event watchers registered by it are active. It is also an	841	exiting if no event watchers registered by it are active. It is also an
814	excellent way to do this for generic recurring timers or from within	842	excellent way to do this for generic recurring timers or from within
815	third-party libraries. Just remember to I<unref after start> and I<ref	843	third-party libraries. Just remember to I<unref after start> and I<ref
816	before stop> (but only if the watcher wasn't active before, or was active	844	before stop> (but only if the watcher wasn't active before, or was active
817	before, respectively. Note also that libev might stop watchers itself	845	before, respectively. Note also that libev might stop watchers itself
818	(e.g. non-repeating timers) in which case you have to C<ev_ref>	846	(e.g. non-repeating timers) in which case you have to C<ev_ref>
819	in the callback).	847	in the callback).
820		848
821	Example: Create a signal watcher, but keep it from keeping C<ev_loop>	849	Example: Create a signal watcher, but keep it from keeping C<ev_run>
822	running when nothing else is active.	850	running when nothing else is active.
823		851
824	ev_signal exitsig;	852	ev_signal exitsig;
825	ev_signal_init (&exitsig, sig_cb, SIGINT);	853	ev_signal_init (&exitsig, sig_cb, SIGINT);
826	ev_signal_start (loop, &exitsig);	854	ev_signal_start (loop, &exitsig);
…		…
871	usually doesn't make much sense to set it to a lower value than C<0.01>,	899	usually doesn't make much sense to set it to a lower value than C<0.01>,
872	as this approaches the timing granularity of most systems. Note that if	900	as this approaches the timing granularity of most systems. Note that if
873	you do transactions with the outside world and you can't increase the	901	you do transactions with the outside world and you can't increase the
874	parallelity, then this setting will limit your transaction rate (if you	902	parallelity, then this setting will limit your transaction rate (if you
875	need to poll once per transaction and the I/O collect interval is 0.01,	903	need to poll once per transaction and the I/O collect interval is 0.01,
876	then you can't do more than 100 transations per second).	904	then you can't do more than 100 transactions per second).
877		905
878	Setting the I<timeout collect interval> can improve the opportunity for	906	Setting the I<timeout collect interval> can improve the opportunity for
879	saving power, as the program will "bundle" timer callback invocations that	907	saving power, as the program will "bundle" timer callback invocations that
880	are "near" in time together, by delaying some, thus reducing the number of	908	are "near" in time together, by delaying some, thus reducing the number of
881	times the process sleeps and wakes up again. Another useful technique to	909	times the process sleeps and wakes up again. Another useful technique to
…		…
889	ev_set_io_collect_interval (EV_DEFAULT_UC_ 0.01);	917	ev_set_io_collect_interval (EV_DEFAULT_UC_ 0.01);
890		918
891	=item ev_invoke_pending (loop)	919	=item ev_invoke_pending (loop)
892		920
893	This call will simply invoke all pending watchers while resetting their	921	This call will simply invoke all pending watchers while resetting their
894	pending state. Normally, C<ev_loop> does this automatically when required,	922	pending state. Normally, C<ev_run> does this automatically when required,
895	but when overriding the invoke callback this call comes handy.	923	but when overriding the invoke callback this call comes handy. This
		924	function can be invoked from a watcher - this can be useful for example
		925	when you want to do some lengthy calculation and want to pass further
		926	event handling to another thread (you still have to make sure only one
		927	thread executes within C<ev_invoke_pending> or C<ev_run> of course).
896		928
897	=item int ev_pending_count (loop)	929	=item int ev_pending_count (loop)
898		930
899	Returns the number of pending watchers - zero indicates that no watchers	931	Returns the number of pending watchers - zero indicates that no watchers
900	are pending.	932	are pending.
901		933
902	=item ev_set_invoke_pending_cb (loop, void (*invoke_pending_cb)(EV_P))	934	=item ev_set_invoke_pending_cb (loop, void (*invoke_pending_cb)(EV_P))
903		935
904	This overrides the invoke pending functionality of the loop: Instead of	936	This overrides the invoke pending functionality of the loop: Instead of
905	invoking all pending watchers when there are any, C<ev_loop> will call	937	invoking all pending watchers when there are any, C<ev_run> will call
906	this callback instead. This is useful, for example, when you want to	938	this callback instead. This is useful, for example, when you want to
907	invoke the actual watchers inside another context (another thread etc.).	939	invoke the actual watchers inside another context (another thread etc.).
908		940
909	If you want to reset the callback, use C<ev_invoke_pending> as new	941	If you want to reset the callback, use C<ev_invoke_pending> as new
910	callback.	942	callback.
…		…
913		945
914	Sometimes you want to share the same loop between multiple threads. This	946	Sometimes you want to share the same loop between multiple threads. This
915	can be done relatively simply by putting mutex_lock/unlock calls around	947	can be done relatively simply by putting mutex_lock/unlock calls around
916	each call to a libev function.	948	each call to a libev function.
917		949
918	However, C<ev_loop> can run an indefinite time, so it is not feasible to	950	However, C<ev_run> can run an indefinite time, so it is not feasible
919	wait for it to return. One way around this is to wake up the loop via	951	to wait for it to return. One way around this is to wake up the event
920	C<ev_unloop> and C<av_async_send>, another way is to set these I<release>	952	loop via C<ev_break> and C<av_async_send>, another way is to set these
921	and I<acquire> callbacks on the loop.	953	I<release> and I<acquire> callbacks on the loop.
922		954
923	When set, then C<release> will be called just before the thread is	955	When set, then C<release> will be called just before the thread is
924	suspended waiting for new events, and C<acquire> is called just	956	suspended waiting for new events, and C<acquire> is called just
925	afterwards.	957	afterwards.
926		958
…		…
929		961
930	While event loop modifications are allowed between invocations of	962	While event loop modifications are allowed between invocations of
931	C<release> and C<acquire> (that's their only purpose after all), no	963	C<release> and C<acquire> (that's their only purpose after all), no
932	modifications done will affect the event loop, i.e. adding watchers will	964	modifications done will affect the event loop, i.e. adding watchers will
933	have no effect on the set of file descriptors being watched, or the time	965	have no effect on the set of file descriptors being watched, or the time
934	waited. Use an C<ev_async> watcher to wake up C<ev_loop> when you want it	966	waited. Use an C<ev_async> watcher to wake up C<ev_run> when you want it
935	to take note of any changes you made.	967	to take note of any changes you made.
936		968
937	In theory, threads executing C<ev_loop> will be async-cancel safe between	969	In theory, threads executing C<ev_run> will be async-cancel safe between
938	invocations of C<release> and C<acquire>.	970	invocations of C<release> and C<acquire>.
939		971
940	See also the locking example in the C<THREADS> section later in this	972	See also the locking example in the C<THREADS> section later in this
941	document.	973	document.
942		974
…		…
951	These two functions can be used to associate arbitrary data with a loop,	983	These two functions can be used to associate arbitrary data with a loop,
952	and are intended solely for the C<invoke_pending_cb>, C<release> and	984	and are intended solely for the C<invoke_pending_cb>, C<release> and
953	C<acquire> callbacks described above, but of course can be (ab-)used for	985	C<acquire> callbacks described above, but of course can be (ab-)used for
954	any other purpose as well.	986	any other purpose as well.
955		987
956	=item ev_loop_verify (loop)	988	=item ev_verify (loop)
957		989
958	This function only does something when C<EV_VERIFY> support has been	990	This function only does something when C<EV_VERIFY> support has been
959	compiled in, which is the default for non-minimal builds. It tries to go	991	compiled in, which is the default for non-minimal builds. It tries to go
960	through all internal structures and checks them for validity. If anything	992	through all internal structures and checks them for validity. If anything
961	is found to be inconsistent, it will print an error message to standard	993	is found to be inconsistent, it will print an error message to standard
…		…
972		1004
973	In the following description, uppercase C<TYPE> in names stands for the	1005	In the following description, uppercase C<TYPE> in names stands for the
974	watcher type, e.g. C<ev_TYPE_start> can mean C<ev_timer_start> for timer	1006	watcher type, e.g. C<ev_TYPE_start> can mean C<ev_timer_start> for timer
975	watchers and C<ev_io_start> for I/O watchers.	1007	watchers and C<ev_io_start> for I/O watchers.
976		1008
977	A watcher is a structure that you create and register to record your	1009	A watcher is an opaque structure that you allocate and register to record
978	interest in some event. For instance, if you want to wait for STDIN to	1010	your interest in some event. To make a concrete example, imagine you want
979	become readable, you would create an C<ev_io> watcher for that:	1011	to wait for STDIN to become readable, you would create an C<ev_io> watcher
		1012	for that:
980		1013
981	static void my_cb (struct ev_loop *loop, ev_io *w, int revents)	1014	static void my_cb (struct ev_loop *loop, ev_io *w, int revents)
982	{	1015	{
983	ev_io_stop (w);	1016	ev_io_stop (w);
984	ev_unloop (loop, EVUNLOOP_ALL);	1017	ev_break (loop, EVBREAK_ALL);
985	}	1018	}
986		1019
987	struct ev_loop *loop = ev_default_loop (0);	1020	struct ev_loop *loop = ev_default_loop (0);
988		1021
989	ev_io stdin_watcher;	1022	ev_io stdin_watcher;
990		1023
991	ev_init (&stdin_watcher, my_cb);	1024	ev_init (&stdin_watcher, my_cb);
992	ev_io_set (&stdin_watcher, STDIN_FILENO, EV_READ);	1025	ev_io_set (&stdin_watcher, STDIN_FILENO, EV_READ);
993	ev_io_start (loop, &stdin_watcher);	1026	ev_io_start (loop, &stdin_watcher);
994		1027
995	ev_loop (loop, 0);	1028	ev_run (loop, 0);
996		1029
997	As you can see, you are responsible for allocating the memory for your	1030	As you can see, you are responsible for allocating the memory for your
998	watcher structures (and it is I<usually> a bad idea to do this on the	1031	watcher structures (and it is I<usually> a bad idea to do this on the
999	stack).	1032	stack).
1000		1033
1001	Each watcher has an associated watcher structure (called C<struct ev_TYPE>	1034	Each watcher has an associated watcher structure (called C<struct ev_TYPE>
1002	or simply C<ev_TYPE>, as typedefs are provided for all watcher structs).	1035	or simply C<ev_TYPE>, as typedefs are provided for all watcher structs).
1003		1036
1004	Each watcher structure must be initialised by a call to C<ev_init	1037	Each watcher structure must be initialised by a call to C<ev_init (watcher
1005	(watcher *, callback)>, which expects a callback to be provided. This	1038	*, callback)>, which expects a callback to be provided. This callback is
1006	callback gets invoked each time the event occurs (or, in the case of I/O	1039	invoked each time the event occurs (or, in the case of I/O watchers, each
1007	watchers, each time the event loop detects that the file descriptor given	1040	time the event loop detects that the file descriptor given is readable
1008	is readable and/or writable).	1041	and/or writable).
1009		1042
1010	Each watcher type further has its own C<< ev_TYPE_set (watcher *, ...) >>	1043	Each watcher type further has its own C<< ev_TYPE_set (watcher *, ...) >>
1011	macro to configure it, with arguments specific to the watcher type. There	1044	macro to configure it, with arguments specific to the watcher type. There
1012	is also a macro to combine initialisation and setting in one call: C<<	1045	is also a macro to combine initialisation and setting in one call: C<<
1013	ev_TYPE_init (watcher *, callback, ...) >>.	1046	ev_TYPE_init (watcher *, callback, ...) >>.
…		…
1064		1097
1065	=item C<EV_PREPARE>	1098	=item C<EV_PREPARE>
1066		1099
1067	=item C<EV_CHECK>	1100	=item C<EV_CHECK>
1068		1101
1069	All C<ev_prepare> watchers are invoked just I<before> C<ev_loop> starts	1102	All C<ev_prepare> watchers are invoked just I<before> C<ev_run> starts
1070	to gather new events, and all C<ev_check> watchers are invoked just after	1103	to gather new events, and all C<ev_check> watchers are invoked just after
1071	C<ev_loop> has gathered them, but before it invokes any callbacks for any	1104	C<ev_run> has gathered them, but before it invokes any callbacks for any
1072	received events. Callbacks of both watcher types can start and stop as	1105	received events. Callbacks of both watcher types can start and stop as
1073	many watchers as they want, and all of them will be taken into account	1106	many watchers as they want, and all of them will be taken into account
1074	(for example, a C<ev_prepare> watcher might start an idle watcher to keep	1107	(for example, a C<ev_prepare> watcher might start an idle watcher to keep
1075	C<ev_loop> from blocking).	1108	C<ev_run> from blocking).
1076		1109
1077	=item C<EV_EMBED>	1110	=item C<EV_EMBED>
1078		1111
1079	The embedded event loop specified in the C<ev_embed> watcher needs attention.	1112	The embedded event loop specified in the C<ev_embed> watcher needs attention.
1080		1113
…		…
1108	example it might indicate that a fd is readable or writable, and if your	1141	example it might indicate that a fd is readable or writable, and if your
1109	callbacks is well-written it can just attempt the operation and cope with	1142	callbacks is well-written it can just attempt the operation and cope with
1110	the error from read() or write(). This will not work in multi-threaded	1143	the error from read() or write(). This will not work in multi-threaded
1111	programs, though, as the fd could already be closed and reused for another	1144	programs, though, as the fd could already be closed and reused for another
1112	thing, so beware.	1145	thing, so beware.
		1146
		1147	=back
		1148
		1149	=head2 WATCHER STATES
		1150
		1151	There are various watcher states mentioned throughout this manual -
		1152	active, pending and so on. In this section these states and the rules to
		1153	transition between them will be described in more detail - and while these
		1154	rules might look complicated, they usually do "the right thing".
		1155
		1156	=over 4
		1157
		1158	=item initialiased
		1159
		1160	Before a watcher can be registered with the event looop it has to be
		1161	initialised. This can be done with a call to C<ev_TYPE_init>, or calls to
		1162	C<ev_init> followed by the watcher-specific C<ev_TYPE_set> function.
		1163
		1164	In this state it is simply some block of memory that is suitable for use
		1165	in an event loop. It can be moved around, freed, reused etc. at will.
		1166
		1167	=item started/running/active
		1168
		1169	Once a watcher has been started with a call to C<ev_TYPE_start> it becomes
		1170	property of the event loop, and is actively waiting for events. While in
		1171	this state it cannot be accessed (except in a few documented ways), moved,
		1172	freed or anything else - the only legal thing is to keep a pointer to it,
		1173	and call libev functions on it that are documented to work on active watchers.
		1174
		1175	=item pending
		1176
		1177	If a watcher is active and libev determines that an event it is interested
		1178	in has occurred (such as a timer expiring), it will become pending. It will
		1179	stay in this pending state until either it is stopped or its callback is
		1180	about to be invoked, so it is not normally pending inside the watcher
		1181	callback.
		1182
		1183	The watcher might or might not be active while it is pending (for example,
		1184	an expired non-repeating timer can be pending but no longer active). If it
		1185	is stopped, it can be freely accessed (e.g. by calling C<ev_TYPE_set>),
		1186	but it is still property of the event loop at this time, so cannot be
		1187	moved, freed or reused. And if it is active the rules described in the
		1188	previous item still apply.
		1189
		1190	It is also possible to feed an event on a watcher that is not active (e.g.
		1191	via C<ev_feed_event>), in which case it becomes pending without being
		1192	active.
		1193
		1194	=item stopped
		1195
		1196	A watcher can be stopped implicitly by libev (in which case it might still
		1197	be pending), or explicitly by calling its C<ev_TYPE_stop> function. The
		1198	latter will clear any pending state the watcher might be in, regardless
		1199	of whether it was active or not, so stopping a watcher explicitly before
		1200	freeing it is often a good idea.
		1201
		1202	While stopped (and not pending) the watcher is essentially in the
		1203	initialised state, that is it can be reused, moved, modified in any way
		1204	you wish.
1113		1205
1114	=back	1206	=back
1115		1207
1116	=head2 GENERIC WATCHER FUNCTIONS	1208	=head2 GENERIC WATCHER FUNCTIONS
1117		1209
…		…
1379		1471
1380	For example, to emulate how many other event libraries handle priorities,	1472	For example, to emulate how many other event libraries handle priorities,
1381	you can associate an C<ev_idle> watcher to each such watcher, and in	1473	you can associate an C<ev_idle> watcher to each such watcher, and in
1382	the normal watcher callback, you just start the idle watcher. The real	1474	the normal watcher callback, you just start the idle watcher. The real
1383	processing is done in the idle watcher callback. This causes libev to	1475	processing is done in the idle watcher callback. This causes libev to
1384	continously poll and process kernel event data for the watcher, but when	1476	continuously poll and process kernel event data for the watcher, but when
1385	the lock-out case is known to be rare (which in turn is rare :), this is	1477	the lock-out case is known to be rare (which in turn is rare :), this is
1386	workable.	1478	workable.
1387		1479
1388	Usually, however, the lock-out model implemented that way will perform	1480	Usually, however, the lock-out model implemented that way will perform
1389	miserably under the type of load it was designed to handle. In that case,	1481	miserably under the type of load it was designed to handle. In that case,
…		…
1403	{	1495	{
1404	// stop the I/O watcher, we received the event, but	1496	// stop the I/O watcher, we received the event, but
1405	// are not yet ready to handle it.	1497	// are not yet ready to handle it.
1406	ev_io_stop (EV_A_ w);	1498	ev_io_stop (EV_A_ w);
1407		1499
1408	// start the idle watcher to ahndle the actual event.	1500	// start the idle watcher to handle the actual event.
1409	// it will not be executed as long as other watchers	1501	// it will not be executed as long as other watchers
1410	// with the default priority are receiving events.	1502	// with the default priority are receiving events.
1411	ev_idle_start (EV_A_ &idle);	1503	ev_idle_start (EV_A_ &idle);
1412	}	1504	}
1413		1505
…		…
1467		1559
1468	If you cannot use non-blocking mode, then force the use of a	1560	If you cannot use non-blocking mode, then force the use of a
1469	known-to-be-good backend (at the time of this writing, this includes only	1561	known-to-be-good backend (at the time of this writing, this includes only
1470	C<EVBACKEND_SELECT> and C<EVBACKEND_POLL>). The same applies to file	1562	C<EVBACKEND_SELECT> and C<EVBACKEND_POLL>). The same applies to file
1471	descriptors for which non-blocking operation makes no sense (such as	1563	descriptors for which non-blocking operation makes no sense (such as
1472	files) - libev doesn't guarentee any specific behaviour in that case.	1564	files) - libev doesn't guarantee any specific behaviour in that case.
1473		1565
1474	Another thing you have to watch out for is that it is quite easy to	1566	Another thing you have to watch out for is that it is quite easy to
1475	receive "spurious" readiness notifications, that is your callback might	1567	receive "spurious" readiness notifications, that is your callback might
1476	be called with C<EV_READ> but a subsequent C<read>(2) will actually block	1568	be called with C<EV_READ> but a subsequent C<read>(2) will actually block
1477	because there is no data. Not only are some backends known to create a	1569	because there is no data. Not only are some backends known to create a
…		…
1621	...	1713	...
1622	struct ev_loop *loop = ev_default_init (0);	1714	struct ev_loop *loop = ev_default_init (0);
1623	ev_io stdin_readable;	1715	ev_io stdin_readable;
1624	ev_io_init (&stdin_readable, stdin_readable_cb, STDIN_FILENO, EV_READ);	1716	ev_io_init (&stdin_readable, stdin_readable_cb, STDIN_FILENO, EV_READ);
1625	ev_io_start (loop, &stdin_readable);	1717	ev_io_start (loop, &stdin_readable);
1626	ev_loop (loop, 0);	1718	ev_run (loop, 0);
1627		1719
1628		1720
1629	=head2 C<ev_timer> - relative and optionally repeating timeouts	1721	=head2 C<ev_timer> - relative and optionally repeating timeouts
1630		1722
1631	Timer watchers are simple relative timers that generate an event after a	1723	Timer watchers are simple relative timers that generate an event after a
…		…
1640	The callback is guaranteed to be invoked only I<after> its timeout has	1732	The callback is guaranteed to be invoked only I<after> its timeout has
1641	passed (not I<at>, so on systems with very low-resolution clocks this	1733	passed (not I<at>, so on systems with very low-resolution clocks this
1642	might introduce a small delay). If multiple timers become ready during the	1734	might introduce a small delay). If multiple timers become ready during the
1643	same loop iteration then the ones with earlier time-out values are invoked	1735	same loop iteration then the ones with earlier time-out values are invoked
1644	before ones of the same priority with later time-out values (but this is	1736	before ones of the same priority with later time-out values (but this is
1645	no longer true when a callback calls C<ev_loop> recursively).	1737	no longer true when a callback calls C<ev_run> recursively).
1646		1738
1647	=head3 Be smart about timeouts	1739	=head3 Be smart about timeouts
1648		1740
1649	Many real-world problems involve some kind of timeout, usually for error	1741	Many real-world problems involve some kind of timeout, usually for error
1650	recovery. A typical example is an HTTP request - if the other side hangs,	1742	recovery. A typical example is an HTTP request - if the other side hangs,
…		…
1736	ev_tstamp timeout = last_activity + 60.;	1828	ev_tstamp timeout = last_activity + 60.;
1737		1829
1738	// if last_activity + 60. is older than now, we did time out	1830	// if last_activity + 60. is older than now, we did time out
1739	if (timeout < now)	1831	if (timeout < now)
1740	{	1832	{
1741	// timeout occured, take action	1833	// timeout occurred, take action
1742	}	1834	}
1743	else	1835	else
1744	{	1836	{
1745	// callback was invoked, but there was some activity, re-arm	1837	// callback was invoked, but there was some activity, re-arm
1746	// the watcher to fire in last_activity + 60, which is	1838	// the watcher to fire in last_activity + 60, which is
…		…
1773	callback (loop, timer, EV_TIMER);	1865	callback (loop, timer, EV_TIMER);
1774		1866
1775	And when there is some activity, simply store the current time in	1867	And when there is some activity, simply store the current time in
1776	C<last_activity>, no libev calls at all:	1868	C<last_activity>, no libev calls at all:
1777		1869
1778	last_actiivty = ev_now (loop);	1870	last_activity = ev_now (loop);
1779		1871
1780	This technique is slightly more complex, but in most cases where the	1872	This technique is slightly more complex, but in most cases where the
1781	time-out is unlikely to be triggered, much more efficient.	1873	time-out is unlikely to be triggered, much more efficient.
1782		1874
1783	Changing the timeout is trivial as well (if it isn't hard-coded in the	1875	Changing the timeout is trivial as well (if it isn't hard-coded in the
…		…
1821		1913
1822	=head3 The special problem of time updates	1914	=head3 The special problem of time updates
1823		1915
1824	Establishing the current time is a costly operation (it usually takes at	1916	Establishing the current time is a costly operation (it usually takes at
1825	least two system calls): EV therefore updates its idea of the current	1917	least two system calls): EV therefore updates its idea of the current
1826	time only before and after C<ev_loop> collects new events, which causes a	1918	time only before and after C<ev_run> collects new events, which causes a
1827	growing difference between C<ev_now ()> and C<ev_time ()> when handling	1919	growing difference between C<ev_now ()> and C<ev_time ()> when handling
1828	lots of events in one iteration.	1920	lots of events in one iteration.
1829		1921
1830	The relative timeouts are calculated relative to the C<ev_now ()>	1922	The relative timeouts are calculated relative to the C<ev_now ()>
1831	time. This is usually the right thing as this timestamp refers to the time	1923	time. This is usually the right thing as this timestamp refers to the time
…		…
1948	}	2040	}
1949		2041
1950	ev_timer mytimer;	2042	ev_timer mytimer;
1951	ev_timer_init (&mytimer, timeout_cb, 0., 10.); /* note, only repeat used */	2043	ev_timer_init (&mytimer, timeout_cb, 0., 10.); /* note, only repeat used */
1952	ev_timer_again (&mytimer); /* start timer */	2044	ev_timer_again (&mytimer); /* start timer */
1953	ev_loop (loop, 0);	2045	ev_run (loop, 0);
1954		2046
1955	// and in some piece of code that gets executed on any "activity":	2047	// and in some piece of code that gets executed on any "activity":
1956	// reset the timeout to start ticking again at 10 seconds	2048	// reset the timeout to start ticking again at 10 seconds
1957	ev_timer_again (&mytimer);	2049	ev_timer_again (&mytimer);
1958		2050
…		…
1984		2076
1985	As with timers, the callback is guaranteed to be invoked only when the	2077	As with timers, the callback is guaranteed to be invoked only when the
1986	point in time where it is supposed to trigger has passed. If multiple	2078	point in time where it is supposed to trigger has passed. If multiple
1987	timers become ready during the same loop iteration then the ones with	2079	timers become ready during the same loop iteration then the ones with
1988	earlier time-out values are invoked before ones with later time-out values	2080	earlier time-out values are invoked before ones with later time-out values
1989	(but this is no longer true when a callback calls C<ev_loop> recursively).	2081	(but this is no longer true when a callback calls C<ev_run> recursively).
1990		2082
1991	=head3 Watcher-Specific Functions and Data Members	2083	=head3 Watcher-Specific Functions and Data Members
1992		2084
1993	=over 4	2085	=over 4
1994		2086
…		…
2122	Example: Call a callback every hour, or, more precisely, whenever the	2214	Example: Call a callback every hour, or, more precisely, whenever the
2123	system time is divisible by 3600. The callback invocation times have	2215	system time is divisible by 3600. The callback invocation times have
2124	potentially a lot of jitter, but good long-term stability.	2216	potentially a lot of jitter, but good long-term stability.
2125		2217
2126	static void	2218	static void
2127	clock_cb (struct ev_loop *loop, ev_io *w, int revents)	2219	clock_cb (struct ev_loop *loop, ev_periodic *w, int revents)
2128	{	2220	{
2129	... its now a full hour (UTC, or TAI or whatever your clock follows)	2221	... its now a full hour (UTC, or TAI or whatever your clock follows)
2130	}	2222	}
2131		2223
2132	ev_periodic hourly_tick;	2224	ev_periodic hourly_tick;
…		…
2232	Example: Try to exit cleanly on SIGINT.	2324	Example: Try to exit cleanly on SIGINT.
2233		2325
2234	static void	2326	static void
2235	sigint_cb (struct ev_loop *loop, ev_signal *w, int revents)	2327	sigint_cb (struct ev_loop *loop, ev_signal *w, int revents)
2236	{	2328	{
2237	ev_unloop (loop, EVUNLOOP_ALL);	2329	ev_break (loop, EVBREAK_ALL);
2238	}	2330	}
2239		2331
2240	ev_signal signal_watcher;	2332	ev_signal signal_watcher;
2241	ev_signal_init (&signal_watcher, sigint_cb, SIGINT);	2333	ev_signal_init (&signal_watcher, sigint_cb, SIGINT);
2242	ev_signal_start (loop, &signal_watcher);	2334	ev_signal_start (loop, &signal_watcher);
…		…
2628		2720
2629	Prepare and check watchers are usually (but not always) used in pairs:	2721	Prepare and check watchers are usually (but not always) used in pairs:
2630	prepare watchers get invoked before the process blocks and check watchers	2722	prepare watchers get invoked before the process blocks and check watchers
2631	afterwards.	2723	afterwards.
2632		2724
2633	You I<must not> call C<ev_loop> or similar functions that enter	2725	You I<must not> call C<ev_run> or similar functions that enter
2634	the current event loop from either C<ev_prepare> or C<ev_check>	2726	the current event loop from either C<ev_prepare> or C<ev_check>
2635	watchers. Other loops than the current one are fine, however. The	2727	watchers. Other loops than the current one are fine, however. The
2636	rationale behind this is that you do not need to check for recursion in	2728	rationale behind this is that you do not need to check for recursion in
2637	those watchers, i.e. the sequence will always be C<ev_prepare>, blocking,	2729	those watchers, i.e. the sequence will always be C<ev_prepare>, blocking,
2638	C<ev_check> so if you have one watcher of each kind they will always be	2730	C<ev_check> so if you have one watcher of each kind they will always be
…		…
2806		2898
2807	if (timeout >= 0)	2899	if (timeout >= 0)
2808	// create/start timer	2900	// create/start timer
2809		2901
2810	// poll	2902	// poll
2811	ev_loop (EV_A_ 0);	2903	ev_run (EV_A_ 0);
2812		2904
2813	// stop timer again	2905	// stop timer again
2814	if (timeout >= 0)	2906	if (timeout >= 0)
2815	ev_timer_stop (EV_A_ &to);	2907	ev_timer_stop (EV_A_ &to);
2816		2908
…		…
2894	if you do not want that, you need to temporarily stop the embed watcher).	2986	if you do not want that, you need to temporarily stop the embed watcher).
2895		2987
2896	=item ev_embed_sweep (loop, ev_embed *)	2988	=item ev_embed_sweep (loop, ev_embed *)
2897		2989
2898	Make a single, non-blocking sweep over the embedded loop. This works	2990	Make a single, non-blocking sweep over the embedded loop. This works
2899	similarly to C<ev_loop (embedded_loop, EVLOOP_NONBLOCK)>, but in the most	2991	similarly to C<ev_run (embedded_loop, EVRUN_NOWAIT)>, but in the most
2900	appropriate way for embedded loops.	2992	appropriate way for embedded loops.
2901		2993
2902	=item struct ev_loop *other [read-only]	2994	=item struct ev_loop *other [read-only]
2903		2995
2904	The embedded event loop.	2996	The embedded event loop.
…		…
2964	C<ev_default_fork> cheats and calls it in the wrong process, the fork	3056	C<ev_default_fork> cheats and calls it in the wrong process, the fork
2965	handlers will be invoked, too, of course.	3057	handlers will be invoked, too, of course.
2966		3058
2967	=head3 The special problem of life after fork - how is it possible?	3059	=head3 The special problem of life after fork - how is it possible?
2968		3060
2969	Most uses of C<fork()> consist of forking, then some simple calls to ste	3061	Most uses of C<fork()> consist of forking, then some simple calls to set
2970	up/change the process environment, followed by a call to C<exec()>. This	3062	up/change the process environment, followed by a call to C<exec()>. This
2971	sequence should be handled by libev without any problems.	3063	sequence should be handled by libev without any problems.
2972		3064
2973	This changes when the application actually wants to do event handling	3065	This changes when the application actually wants to do event handling
2974	in the child, or both parent in child, in effect "continuing" after the	3066	in the child, or both parent in child, in effect "continuing" after the
…		…
2990	disadvantage of having to use multiple event loops (which do not support	3082	disadvantage of having to use multiple event loops (which do not support
2991	signal watchers).	3083	signal watchers).
2992		3084
2993	When this is not possible, or you want to use the default loop for	3085	When this is not possible, or you want to use the default loop for
2994	other reasons, then in the process that wants to start "fresh", call	3086	other reasons, then in the process that wants to start "fresh", call
2995	C<ev_default_destroy ()> followed by C<ev_default_loop (...)>. Destroying	3087	C<ev_loop_destroy (EV_DEFAULT)> followed by C<ev_default_loop (...)>.
2996	the default loop will "orphan" (not stop) all registered watchers, so you	3088	Destroying the default loop will "orphan" (not stop) all registered
2997	have to be careful not to execute code that modifies those watchers. Note	3089	watchers, so you have to be careful not to execute code that modifies
2998	also that in that case, you have to re-register any signal watchers.	3090	those watchers. Note also that in that case, you have to re-register any
		3091	signal watchers.
2999		3092
3000	=head3 Watcher-Specific Functions and Data Members	3093	=head3 Watcher-Specific Functions and Data Members
3001		3094
3002	=over 4	3095	=over 4
3003		3096
…		…
3008	believe me.	3101	believe me.
3009		3102
3010	=back	3103	=back
3011		3104
3012		3105
3013	=head2 C<ev_async> - how to wake up another event loop	3106	=head2 C<ev_async> - how to wake up an event loop
3014		3107
3015	In general, you cannot use an C<ev_loop> from multiple threads or other	3108	In general, you cannot use an C<ev_run> from multiple threads or other
3016	asynchronous sources such as signal handlers (as opposed to multiple event	3109	asynchronous sources such as signal handlers (as opposed to multiple event
3017	loops - those are of course safe to use in different threads).	3110	loops - those are of course safe to use in different threads).
3018		3111
3019	Sometimes, however, you need to wake up another event loop you do not	3112	Sometimes, however, you need to wake up an event loop you do not control,
3020	control, for example because it belongs to another thread. This is what	3113	for example because it belongs to another thread. This is what C<ev_async>
3021	C<ev_async> watchers do: as long as the C<ev_async> watcher is active, you	3114	watchers do: as long as the C<ev_async> watcher is active, you can signal
3022	can signal it by calling C<ev_async_send>, which is thread- and signal	3115	it by calling C<ev_async_send>, which is thread- and signal safe.
3023	safe.
3024		3116
3025	This functionality is very similar to C<ev_signal> watchers, as signals,	3117	This functionality is very similar to C<ev_signal> watchers, as signals,
3026	too, are asynchronous in nature, and signals, too, will be compressed	3118	too, are asynchronous in nature, and signals, too, will be compressed
3027	(i.e. the number of callback invocations may be less than the number of	3119	(i.e. the number of callback invocations may be less than the number of
3028	C<ev_async_sent> calls).	3120	C<ev_async_sent> calls).
…		…
3340	myclass obj;	3432	myclass obj;
3341	ev::io iow;	3433	ev::io iow;
3342	iow.set <myclass, &myclass::io_cb> (&obj);	3434	iow.set <myclass, &myclass::io_cb> (&obj);
3343		3435
3344	=item w->set (object *)	3436	=item w->set (object *)
3345
3346	This is an B<experimental> feature that might go away in a future version.
3347		3437
3348	This is a variation of a method callback - leaving out the method to call	3438	This is a variation of a method callback - leaving out the method to call
3349	will default the method to C<operator ()>, which makes it possible to use	3439	will default the method to C<operator ()>, which makes it possible to use
3350	functor objects without having to manually specify the C<operator ()> all	3440	functor objects without having to manually specify the C<operator ()> all
3351	the time. Incidentally, you can then also leave out the template argument	3441	the time. Incidentally, you can then also leave out the template argument
…		…
3391	Associates a different C<struct ev_loop> with this watcher. You can only	3481	Associates a different C<struct ev_loop> with this watcher. You can only
3392	do this when the watcher is inactive (and not pending either).	3482	do this when the watcher is inactive (and not pending either).
3393		3483
3394	=item w->set ([arguments])	3484	=item w->set ([arguments])
3395		3485
3396	Basically the same as C<ev_TYPE_set>, with the same arguments. Must be	3486	Basically the same as C<ev_TYPE_set>, with the same arguments. Either this
3397	called at least once. Unlike the C counterpart, an active watcher gets	3487	method or a suitable start method must be called at least once. Unlike the
3398	automatically stopped and restarted when reconfiguring it with this	3488	C counterpart, an active watcher gets automatically stopped and restarted
3399	method.	3489	when reconfiguring it with this method.
3400		3490
3401	=item w->start ()	3491	=item w->start ()
3402		3492
3403	Starts the watcher. Note that there is no C<loop> argument, as the	3493	Starts the watcher. Note that there is no C<loop> argument, as the
3404	constructor already stores the event loop.	3494	constructor already stores the event loop.
3405		3495
		3496	=item w->start ([arguments])
		3497
		3498	Instead of calling C<set> and C<start> methods separately, it is often
		3499	convenient to wrap them in one call. Uses the same type of arguments as
		3500	the configure C<set> method of the watcher.
		3501
3406	=item w->stop ()	3502	=item w->stop ()
3407		3503
3408	Stops the watcher if it is active. Again, no C<loop> argument.	3504	Stops the watcher if it is active. Again, no C<loop> argument.
3409		3505
3410	=item w->again () (C<ev::timer>, C<ev::periodic> only)	3506	=item w->again () (C<ev::timer>, C<ev::periodic> only)
…		…
3422		3518
3423	=back	3519	=back
3424		3520
3425	=back	3521	=back
3426		3522
3427	Example: Define a class with an IO and idle watcher, start one of them in	3523	Example: Define a class with two I/O and idle watchers, start the I/O
3428	the constructor.	3524	watchers in the constructor.
3429		3525
3430	class myclass	3526	class myclass
3431	{	3527	{
3432	ev::io io ; void io_cb (ev::io &w, int revents);	3528	ev::io io ; void io_cb (ev::io &w, int revents);
		3529	ev::io2 io2 ; void io2_cb (ev::io &w, int revents);
3433	ev::idle idle; void idle_cb (ev::idle &w, int revents);	3530	ev::idle idle; void idle_cb (ev::idle &w, int revents);
3434		3531
3435	myclass (int fd)	3532	myclass (int fd)
3436	{	3533	{
3437	io .set <myclass, &myclass::io_cb > (this);	3534	io .set <myclass, &myclass::io_cb > (this);
		3535	io2 .set <myclass, &myclass::io2_cb > (this);
3438	idle.set <myclass, &myclass::idle_cb> (this);	3536	idle.set <myclass, &myclass::idle_cb> (this);
3439		3537
3440	io.start (fd, ev::READ);	3538	io.set (fd, ev::WRITE); // configure the watcher
		3539	io.start (); // start it whenever convenient
		3540
		3541	io2.start (fd, ev::READ); // set + start in one call
3441	}	3542	}
3442	};	3543	};
3443		3544
3444		3545
3445	=head1 OTHER LANGUAGE BINDINGS	3546	=head1 OTHER LANGUAGE BINDINGS
…		…
3519	loop argument"). The C<EV_A> form is used when this is the sole argument,	3620	loop argument"). The C<EV_A> form is used when this is the sole argument,
3520	C<EV_A_> is used when other arguments are following. Example:	3621	C<EV_A_> is used when other arguments are following. Example:
3521		3622
3522	ev_unref (EV_A);	3623	ev_unref (EV_A);
3523	ev_timer_add (EV_A_ watcher);	3624	ev_timer_add (EV_A_ watcher);
3524	ev_loop (EV_A_ 0);	3625	ev_run (EV_A_ 0);
3525		3626
3526	It assumes the variable C<loop> of type C<struct ev_loop *> is in scope,	3627	It assumes the variable C<loop> of type C<struct ev_loop *> is in scope,
3527	which is often provided by the following macro.	3628	which is often provided by the following macro.
3528		3629
3529	=item C<EV_P>, C<EV_P_>	3630	=item C<EV_P>, C<EV_P_>
…		…
3569	}	3670	}
3570		3671
3571	ev_check check;	3672	ev_check check;
3572	ev_check_init (&check, check_cb);	3673	ev_check_init (&check, check_cb);
3573	ev_check_start (EV_DEFAULT_ &check);	3674	ev_check_start (EV_DEFAULT_ &check);
3574	ev_loop (EV_DEFAULT_ 0);	3675	ev_run (EV_DEFAULT_ 0);
3575		3676
3576	=head1 EMBEDDING	3677	=head1 EMBEDDING
3577		3678
3578	Libev can (and often is) directly embedded into host	3679	Libev can (and often is) directly embedded into host
3579	applications. Examples of applications that embed it include the Deliantra	3680	applications. Examples of applications that embed it include the Deliantra
…		…
3670	to a compiled library. All other symbols change the ABI, which means all	3771	to a compiled library. All other symbols change the ABI, which means all
3671	users of libev and the libev code itself must be compiled with compatible	3772	users of libev and the libev code itself must be compiled with compatible
3672	settings.	3773	settings.
3673		3774
3674	=over 4	3775	=over 4
		3776
		3777	=item EV_COMPAT3 (h)
		3778
		3779	Backwards compatibility is a major concern for libev. This is why this
		3780	release of libev comes with wrappers for the functions and symbols that
		3781	have been renamed between libev version 3 and 4.
		3782
		3783	You can disable these wrappers (to test compatibility with future
		3784	versions) by defining C<EV_COMPAT3> to C<0> when compiling your
		3785	sources. This has the additional advantage that you can drop the C<struct>
		3786	from C<struct ev_loop> declarations, as libev will provide an C<ev_loop>
		3787	typedef in that case.
		3788
		3789	In some future version, the default for C<EV_COMPAT3> will become C<0>,
		3790	and in some even more future version the compatibility code will be
		3791	removed completely.
3675		3792
3676	=item EV_STANDALONE (h)	3793	=item EV_STANDALONE (h)
3677		3794
3678	Must always be C<1> if you do not use autoconf configuration, which	3795	Must always be C<1> if you do not use autoconf configuration, which
3679	keeps libev from including F<config.h>, and it also defines dummy	3796	keeps libev from including F<config.h>, and it also defines dummy
…		…
3886	EV_PREPARE_ENABLE, EV_CHECK_ENABLE, EV_FORK_ENABLE, EV_SIGNAL_ENABLE,	4003	EV_PREPARE_ENABLE, EV_CHECK_ENABLE, EV_FORK_ENABLE, EV_SIGNAL_ENABLE,
3887	EV_ASYNC_ENABLE, EV_CHILD_ENABLE.	4004	EV_ASYNC_ENABLE, EV_CHILD_ENABLE.
3888		4005
3889	If undefined or defined to be C<1> (and the platform supports it), then	4006	If undefined or defined to be C<1> (and the platform supports it), then
3890	the respective watcher type is supported. If defined to be C<0>, then it	4007	the respective watcher type is supported. If defined to be C<0>, then it
3891	is not. Disabling watcher types mainly saves codesize.	4008	is not. Disabling watcher types mainly saves code size.
3892		4009
3893	=item EV_FEATURES	4010	=item EV_FEATURES
3894		4011
3895	If you need to shave off some kilobytes of code at the expense of some	4012	If you need to shave off some kilobytes of code at the expense of some
3896	speed (but with the full API), you can define this symbol to request	4013	speed (but with the full API), you can define this symbol to request
…		…
3916		4033
3917	=item C<1> - faster/larger code	4034	=item C<1> - faster/larger code
3918		4035
3919	Use larger code to speed up some operations.	4036	Use larger code to speed up some operations.
3920		4037
3921	Currently this is used to override some inlining decisions (enlarging the roughly	4038	Currently this is used to override some inlining decisions (enlarging the
3922	30% code size on amd64.	4039	code size by roughly 30% on amd64).
3923		4040
3924	When optimising for size, use of compiler flags such as C<-Os> with	4041	When optimising for size, use of compiler flags such as C<-Os> with
3925	gcc recommended, as well as C<-DNDEBUG>, as libev contains a number of	4042	gcc is recommended, as well as C<-DNDEBUG>, as libev contains a number of
3926	assertions.	4043	assertions.
3927		4044
3928	=item C<2> - faster/larger data structures	4045	=item C<2> - faster/larger data structures
3929		4046
3930	Replaces the small 2-heap for timer management by a faster 4-heap, larger	4047	Replaces the small 2-heap for timer management by a faster 4-heap, larger
3931	hash table sizes and so on. This will usually further increase codesize	4048	hash table sizes and so on. This will usually further increase code size
3932	and can additionally have an effect on the size of data structures at	4049	and can additionally have an effect on the size of data structures at
3933	runtime.	4050	runtime.
3934		4051
3935	=item C<4> - full API configuration	4052	=item C<4> - full API configuration
3936		4053
…		…
3973	I/O watcher then might come out at only 5Kb.	4090	I/O watcher then might come out at only 5Kb.
3974		4091
3975	=item EV_AVOID_STDIO	4092	=item EV_AVOID_STDIO
3976		4093
3977	If this is set to C<1> at compiletime, then libev will avoid using stdio	4094	If this is set to C<1> at compiletime, then libev will avoid using stdio
3978	functions (printf, scanf, perror etc.). This will increase the codesize	4095	functions (printf, scanf, perror etc.). This will increase the code size
3979	somewhat, but if your program doesn't otherwise depend on stdio and your	4096	somewhat, but if your program doesn't otherwise depend on stdio and your
3980	libc allows it, this avoids linking in the stdio library which is quite	4097	libc allows it, this avoids linking in the stdio library which is quite
3981	big.	4098	big.
3982		4099
3983	Note that error messages might become less precise when this option is	4100	Note that error messages might become less precise when this option is
…		…
3987		4104
3988	The highest supported signal number, +1 (or, the number of	4105	The highest supported signal number, +1 (or, the number of
3989	signals): Normally, libev tries to deduce the maximum number of signals	4106	signals): Normally, libev tries to deduce the maximum number of signals
3990	automatically, but sometimes this fails, in which case it can be	4107	automatically, but sometimes this fails, in which case it can be
3991	specified. Also, using a lower number than detected (C<32> should be	4108	specified. Also, using a lower number than detected (C<32> should be
3992	good for about any system in existance) can save some memory, as libev	4109	good for about any system in existence) can save some memory, as libev
3993	statically allocates some 12-24 bytes per signal number.	4110	statically allocates some 12-24 bytes per signal number.
3994		4111
3995	=item EV_PID_HASHSIZE	4112	=item EV_PID_HASHSIZE
3996		4113
3997	C<ev_child> watchers use a small hash table to distribute workload by	4114	C<ev_child> watchers use a small hash table to distribute workload by
…		…
4029	The default is C<1>, unless C<EV_FEATURES> overrides it, in which case it	4146	The default is C<1>, unless C<EV_FEATURES> overrides it, in which case it
4030	will be C<0>.	4147	will be C<0>.
4031		4148
4032	=item EV_VERIFY	4149	=item EV_VERIFY
4033		4150
4034	Controls how much internal verification (see C<ev_loop_verify ()>) will	4151	Controls how much internal verification (see C<ev_verify ()>) will
4035	be done: If set to C<0>, no internal verification code will be compiled	4152	be done: If set to C<0>, no internal verification code will be compiled
4036	in. If set to C<1>, then verification code will be compiled in, but not	4153	in. If set to C<1>, then verification code will be compiled in, but not
4037	called. If set to C<2>, then the internal verification code will be	4154	called. If set to C<2>, then the internal verification code will be
4038	called once per loop, which can slow down libev. If set to C<3>, then the	4155	called once per loop, which can slow down libev. If set to C<3>, then the
4039	verification code will be called very frequently, which will slow down	4156	verification code will be called very frequently, which will slow down
…		…
4043	will be C<0>.	4160	will be C<0>.
4044		4161
4045	=item EV_COMMON	4162	=item EV_COMMON
4046		4163
4047	By default, all watchers have a C<void *data> member. By redefining	4164	By default, all watchers have a C<void *data> member. By redefining
4048	this macro to a something else you can include more and other types of	4165	this macro to something else you can include more and other types of
4049	members. You have to define it each time you include one of the files,	4166	members. You have to define it each time you include one of the files,
4050	though, and it must be identical each time.	4167	though, and it must be identical each time.
4051		4168
4052	For example, the perl EV module uses something like this:	4169	For example, the perl EV module uses something like this:
4053		4170
…		…
4254	userdata *u = ev_userdata (EV_A);	4371	userdata *u = ev_userdata (EV_A);
4255	pthread_mutex_lock (&u->lock);	4372	pthread_mutex_lock (&u->lock);
4256	}	4373	}
4257		4374
4258	The event loop thread first acquires the mutex, and then jumps straight	4375	The event loop thread first acquires the mutex, and then jumps straight
4259	into C<ev_loop>:	4376	into C<ev_run>:
4260		4377
4261	void *	4378	void *
4262	l_run (void *thr_arg)	4379	l_run (void *thr_arg)
4263	{	4380	{
4264	struct ev_loop *loop = (struct ev_loop *)thr_arg;	4381	struct ev_loop *loop = (struct ev_loop *)thr_arg;
4265		4382
4266	l_acquire (EV_A);	4383	l_acquire (EV_A);
4267	pthread_setcanceltype (PTHREAD_CANCEL_ASYNCHRONOUS, 0);	4384	pthread_setcanceltype (PTHREAD_CANCEL_ASYNCHRONOUS, 0);
4268	ev_loop (EV_A_ 0);	4385	ev_run (EV_A_ 0);
4269	l_release (EV_A);	4386	l_release (EV_A);
4270		4387
4271	return 0;	4388	return 0;
4272	}	4389	}
4273		4390
…		…
4325		4442
4326	=head3 COROUTINES	4443	=head3 COROUTINES
4327		4444
4328	Libev is very accommodating to coroutines ("cooperative threads"):	4445	Libev is very accommodating to coroutines ("cooperative threads"):
4329	libev fully supports nesting calls to its functions from different	4446	libev fully supports nesting calls to its functions from different
4330	coroutines (e.g. you can call C<ev_loop> on the same loop from two	4447	coroutines (e.g. you can call C<ev_run> on the same loop from two
4331	different coroutines, and switch freely between both coroutines running	4448	different coroutines, and switch freely between both coroutines running
4332	the loop, as long as you don't confuse yourself). The only exception is	4449	the loop, as long as you don't confuse yourself). The only exception is
4333	that you must not do this from C<ev_periodic> reschedule callbacks.	4450	that you must not do this from C<ev_periodic> reschedule callbacks.
4334		4451
4335	Care has been taken to ensure that libev does not keep local state inside	4452	Care has been taken to ensure that libev does not keep local state inside
4336	C<ev_loop>, and other calls do not usually allow for coroutine switches as	4453	C<ev_run>, and other calls do not usually allow for coroutine switches as
4337	they do not call any callbacks.	4454	they do not call any callbacks.
4338		4455
4339	=head2 COMPILER WARNINGS	4456	=head2 COMPILER WARNINGS
4340		4457
4341	Depending on your compiler and compiler settings, you might get no or a	4458	Depending on your compiler and compiler settings, you might get no or a
…		…
4352	maintainable.	4469	maintainable.
4353		4470
4354	And of course, some compiler warnings are just plain stupid, or simply	4471	And of course, some compiler warnings are just plain stupid, or simply
4355	wrong (because they don't actually warn about the condition their message	4472	wrong (because they don't actually warn about the condition their message
4356	seems to warn about). For example, certain older gcc versions had some	4473	seems to warn about). For example, certain older gcc versions had some
4357	warnings that resulted an extreme number of false positives. These have	4474	warnings that resulted in an extreme number of false positives. These have
4358	been fixed, but some people still insist on making code warn-free with	4475	been fixed, but some people still insist on making code warn-free with
4359	such buggy versions.	4476	such buggy versions.
4360		4477
4361	While libev is written to generate as few warnings as possible,	4478	While libev is written to generate as few warnings as possible,
4362	"warn-free" code is not a goal, and it is recommended not to build libev	4479	"warn-free" code is not a goal, and it is recommended not to build libev
…		…
4398	I suggest using suppression lists.	4515	I suggest using suppression lists.
4399		4516
4400		4517
4401	=head1 PORTABILITY NOTES	4518	=head1 PORTABILITY NOTES
4402		4519
		4520	=head2 GNU/LINUX 32 BIT LIMITATIONS
		4521
		4522	GNU/Linux is the only common platform that supports 64 bit file/large file
		4523	interfaces but I<disables> them by default.
		4524
		4525	That means that libev compiled in the default environment doesn't support
		4526	files larger than 2GiB or so, which mainly affects C<ev_stat> watchers.
		4527
		4528	Unfortunately, many programs try to work around this GNU/Linux issue
		4529	by enabling the large file API, which makes them incompatible with the
		4530	standard libev compiled for their system.
		4531
		4532	Likewise, libev cannot enable the large file API itself as this would
		4533	suddenly make it incompatible to the default compile time environment,
		4534	i.e. all programs not using special compile switches.
		4535
		4536	=head2 OS/X AND DARWIN BUGS
		4537
		4538	The whole thing is a bug if you ask me - basically any system interface
		4539	you touch is broken, whether it is locales, poll, kqueue or even the
		4540	OpenGL drivers.
		4541
		4542	=head3 C<kqueue> is buggy
		4543
		4544	The kqueue syscall is broken in all known versions - most versions support
		4545	only sockets, many support pipes.
		4546
		4547	Libev tries to work around this by not using C<kqueue> by default on this
		4548	rotten platform, but of course you can still ask for it when creating a
		4549	loop - embedding a socket-only kqueue loop into a select-based one is
		4550	probably going to work well.
		4551
		4552	=head3 C<poll> is buggy
		4553
		4554	Instead of fixing C<kqueue>, Apple replaced their (working) C<poll>
		4555	implementation by something calling C<kqueue> internally around the 10.5.6
		4556	release, so now C<kqueue> I<and> C<poll> are broken.
		4557
		4558	Libev tries to work around this by not using C<poll> by default on
		4559	this rotten platform, but of course you can still ask for it when creating
		4560	a loop.
		4561
		4562	=head3 C<select> is buggy
		4563
		4564	All that's left is C<select>, and of course Apple found a way to fuck this
		4565	one up as well: On OS/X, C<select> actively limits the number of file
		4566	descriptors you can pass in to 1024 - your program suddenly crashes when
		4567	you use more.
		4568
		4569	There is an undocumented "workaround" for this - defining
		4570	C<_DARWIN_UNLIMITED_SELECT>, which libev tries to use, so select I<should>
		4571	work on OS/X.
		4572
		4573	=head2 SOLARIS PROBLEMS AND WORKAROUNDS
		4574
		4575	=head3 C<errno> reentrancy
		4576
		4577	The default compile environment on Solaris is unfortunately so
		4578	thread-unsafe that you can't even use components/libraries compiled
		4579	without C<-D_REENTRANT> in a threaded program, which, of course, isn't
		4580	defined by default. A valid, if stupid, implementation choice.
		4581
		4582	If you want to use libev in threaded environments you have to make sure
		4583	it's compiled with C<_REENTRANT> defined.
		4584
		4585	=head3 Event port backend
		4586
		4587	The scalable event interface for Solaris is called "event
		4588	ports". Unfortunately, this mechanism is very buggy in all major
		4589	releases. If you run into high CPU usage, your program freezes or you get
		4590	a large number of spurious wakeups, make sure you have all the relevant
		4591	and latest kernel patches applied. No, I don't know which ones, but there
		4592	are multiple ones to apply, and afterwards, event ports actually work
		4593	great.
		4594
		4595	If you can't get it to work, you can try running the program by setting
		4596	the environment variable C<LIBEV_FLAGS=3> to only allow C<poll> and
		4597	C<select> backends.
		4598
		4599	=head2 AIX POLL BUG
		4600
		4601	AIX unfortunately has a broken C<poll.h> header. Libev works around
		4602	this by trying to avoid the poll backend altogether (i.e. it's not even
		4603	compiled in), which normally isn't a big problem as C<select> works fine
		4604	with large bitsets on AIX, and AIX is dead anyway.
		4605
4403	=head2 WIN32 PLATFORM LIMITATIONS AND WORKAROUNDS	4606	=head2 WIN32 PLATFORM LIMITATIONS AND WORKAROUNDS
		4607
		4608	=head3 General issues
4404		4609
4405	Win32 doesn't support any of the standards (e.g. POSIX) that libev	4610	Win32 doesn't support any of the standards (e.g. POSIX) that libev
4406	requires, and its I/O model is fundamentally incompatible with the POSIX	4611	requires, and its I/O model is fundamentally incompatible with the POSIX
4407	model. Libev still offers limited functionality on this platform in	4612	model. Libev still offers limited functionality on this platform in
4408	the form of the C<EVBACKEND_SELECT> backend, and only supports socket	4613	the form of the C<EVBACKEND_SELECT> backend, and only supports socket
4409	descriptors. This only applies when using Win32 natively, not when using	4614	descriptors. This only applies when using Win32 natively, not when using
4410	e.g. cygwin.	4615	e.g. cygwin. Actually, it only applies to the microsofts own compilers,
		4616	as every compielr comes with a slightly differently broken/incompatible
		4617	environment.
4411		4618
4412	Lifting these limitations would basically require the full	4619	Lifting these limitations would basically require the full
4413	re-implementation of the I/O system. If you are into these kinds of	4620	re-implementation of the I/O system. If you are into this kind of thing,
4414	things, then note that glib does exactly that for you in a very portable	4621	then note that glib does exactly that for you in a very portable way (note
4415	way (note also that glib is the slowest event library known to man).	4622	also that glib is the slowest event library known to man).
4416		4623
4417	There is no supported compilation method available on windows except	4624	There is no supported compilation method available on windows except
4418	embedding it into other applications.	4625	embedding it into other applications.
4419		4626
4420	Sensible signal handling is officially unsupported by Microsoft - libev	4627	Sensible signal handling is officially unsupported by Microsoft - libev
…		…
4448	you do I<not> compile the F<ev.c> or any other embedded source files!):	4655	you do I<not> compile the F<ev.c> or any other embedded source files!):
4449		4656
4450	#include "evwrap.h"	4657	#include "evwrap.h"
4451	#include "ev.c"	4658	#include "ev.c"
4452		4659
4453	=over 4
4454
4455	=item The winsocket select function	4660	=head3 The winsocket C<select> function
4456		4661
4457	The winsocket C<select> function doesn't follow POSIX in that it	4662	The winsocket C<select> function doesn't follow POSIX in that it
4458	requires socket I<handles> and not socket I<file descriptors> (it is	4663	requires socket I<handles> and not socket I<file descriptors> (it is
4459	also extremely buggy). This makes select very inefficient, and also	4664	also extremely buggy). This makes select very inefficient, and also
4460	requires a mapping from file descriptors to socket handles (the Microsoft	4665	requires a mapping from file descriptors to socket handles (the Microsoft
…		…
4469	#define EV_SELECT_IS_WINSOCKET 1 /* forces EV_SELECT_USE_FD_SET, too */	4674	#define EV_SELECT_IS_WINSOCKET 1 /* forces EV_SELECT_USE_FD_SET, too */
4470		4675
4471	Note that winsockets handling of fd sets is O(n), so you can easily get a	4676	Note that winsockets handling of fd sets is O(n), so you can easily get a
4472	complexity in the O(n²) range when using win32.	4677	complexity in the O(n²) range when using win32.
4473		4678
4474	=item Limited number of file descriptors	4679	=head3 Limited number of file descriptors
4475		4680
4476	Windows has numerous arbitrary (and low) limits on things.	4681	Windows has numerous arbitrary (and low) limits on things.
4477		4682
4478	Early versions of winsocket's select only supported waiting for a maximum	4683	Early versions of winsocket's select only supported waiting for a maximum
4479	of C<64> handles (probably owning to the fact that all windows kernels	4684	of C<64> handles (probably owning to the fact that all windows kernels
…		…
4494	runtime libraries. This might get you to about C<512> or C<2048> sockets	4699	runtime libraries. This might get you to about C<512> or C<2048> sockets
4495	(depending on windows version and/or the phase of the moon). To get more,	4700	(depending on windows version and/or the phase of the moon). To get more,
4496	you need to wrap all I/O functions and provide your own fd management, but	4701	you need to wrap all I/O functions and provide your own fd management, but
4497	the cost of calling select (O(n²)) will likely make this unworkable.	4702	the cost of calling select (O(n²)) will likely make this unworkable.
4498		4703
4499	=back
4500
4501	=head2 PORTABILITY REQUIREMENTS	4704	=head2 PORTABILITY REQUIREMENTS
4502		4705
4503	In addition to a working ISO-C implementation and of course the	4706	In addition to a working ISO-C implementation and of course the
4504	backend-specific APIs, libev relies on a few additional extensions:	4707	backend-specific APIs, libev relies on a few additional extensions:
4505		4708
…		…
4543	watchers.	4746	watchers.
4544		4747
4545	=item C<double> must hold a time value in seconds with enough accuracy	4748	=item C<double> must hold a time value in seconds with enough accuracy
4546		4749
4547	The type C<double> is used to represent timestamps. It is required to	4750	The type C<double> is used to represent timestamps. It is required to
4548	have at least 51 bits of mantissa (and 9 bits of exponent), which is good	4751	have at least 51 bits of mantissa (and 9 bits of exponent), which is
4549	enough for at least into the year 4000. This requirement is fulfilled by	4752	good enough for at least into the year 4000 with millisecond accuracy
		4753	(the design goal for libev). This requirement is overfulfilled by
4550	implementations implementing IEEE 754, which is basically all existing	4754	implementations using IEEE 754, which is basically all existing ones. With
4551	ones. With IEEE 754 doubles, you get microsecond accuracy until at least	4755	IEEE 754 doubles, you get microsecond accuracy until at least 2200.
4552	2200.
4553		4756
4554	=back	4757	=back
4555		4758
4556	If you know of other additional requirements drop me a note.	4759	If you know of other additional requirements drop me a note.
4557		4760
…		…
4635	compatibility, so most programs should still compile. Those might be	4838	compatibility, so most programs should still compile. Those might be
4636	removed in later versions of libev, so better update early than late.	4839	removed in later versions of libev, so better update early than late.
4637		4840
4638	=over 4	4841	=over 4
4639		4842
4640	=item C<ev_loop_count> renamed to C<ev_iteration>	4843	=item C<ev_default_destroy> and C<ev_default_fork> have been removed
4641		4844
4642	=item C<ev_loop_depth> renamed to C<ev_depth>	4845	These calls can be replaced easily by their C<ev_loop_xxx> counterparts:
4643		4846
4644	=item C<ev_loop_verify> renamed to C<ev_verify>	4847	ev_loop_destroy (EV_DEFAULT);
		4848	ev_loop_fork (EV_DEFAULT);
		4849
		4850	=item function/symbol renames
		4851
		4852	A number of functions and symbols have been renamed:
		4853
		4854	ev_loop => ev_run
		4855	EVLOOP_NONBLOCK => EVRUN_NOWAIT
		4856	EVLOOP_ONESHOT => EVRUN_ONCE
		4857
		4858	ev_unloop => ev_break
		4859	EVUNLOOP_CANCEL => EVBREAK_CANCEL
		4860	EVUNLOOP_ONE => EVBREAK_ONE
		4861	EVUNLOOP_ALL => EVBREAK_ALL
		4862
		4863	EV_TIMEOUT => EV_TIMER
		4864
		4865	ev_loop_count => ev_iteration
		4866	ev_loop_depth => ev_depth
		4867	ev_loop_verify => ev_verify
4645		4868
4646	Most functions working on C<struct ev_loop> objects don't have an	4869	Most functions working on C<struct ev_loop> objects don't have an
4647	C<ev_loop_> prefix, so it was removed. Note that C<ev_loop_fork> is	4870	C<ev_loop_> prefix, so it was removed; C<ev_loop>, C<ev_unloop> and
		4871	associated constants have been renamed to not collide with the C<struct
		4872	ev_loop> anymore and C<EV_TIMER> now follows the same naming scheme
		4873	as all other watcher types. Note that C<ev_loop_fork> is still called
4648	still called C<ev_loop_fork> because it would otherwise clash with the	4874	C<ev_loop_fork> because it would otherwise clash with the C<ev_fork>
4649	C<ev_fork> typedef.	4875	typedef.
4650		4876
4651	=item C<EV_TIMEOUT> renamed to C<EV_TIMER> in C<revents>	4877	=item C<EV_COMPAT3> backwards compatibility mechanism
4652		4878
4653	This is a simple rename - all other watcher types use their name	4879	The backward compatibility mechanism can be controlled by
4654	as revents flag, and now C<ev_timer> does, too.	4880	C<EV_COMPAT3>. See L<PREPROCESSOR SYMBOLS/MACROS> in the L<EMBEDDING>
4655		4881	section.
4656	Both C<EV_TIMER> and C<EV_TIMEOUT> symbols were present in 3.x versions
4657	and continue to be present for the forseeable future, so this is mostly a
4658	documentation change.
4659		4882
4660	=item C<EV_MINIMAL> mechanism replaced by C<EV_FEATURES>	4883	=item C<EV_MINIMAL> mechanism replaced by C<EV_FEATURES>
4661		4884
4662	The preprocessor symbol C<EV_MINIMAL> has been replaced by a different	4885	The preprocessor symbol C<EV_MINIMAL> has been replaced by a different
4663	mechanism, C<EV_FEATURES>. Programs using C<EV_MINIMAL> usually compile	4886	mechanism, C<EV_FEATURES>. Programs using C<EV_MINIMAL> usually compile
…		…
4670		4893
4671	=over 4	4894	=over 4
4672		4895
4673	=item active	4896	=item active
4674		4897
4675	A watcher is active as long as it has been started (has been attached to	4898	A watcher is active as long as it has been started and not yet stopped.
4676	an event loop) but not yet stopped (disassociated from the event loop).	4899	See L<WATCHER STATES> for details.
4677		4900
4678	=item application	4901	=item application
4679		4902
4680	In this document, an application is whatever is using libev.	4903	In this document, an application is whatever is using libev.
		4904
		4905	=item backend
		4906
		4907	The part of the code dealing with the operating system interfaces.
4681		4908
4682	=item callback	4909	=item callback
4683		4910
4684	The address of a function that is called when some event has been	4911	The address of a function that is called when some event has been
4685	detected. Callbacks are being passed the event loop, the watcher that	4912	detected. Callbacks are being passed the event loop, the watcher that
4686	received the event, and the actual event bitset.	4913	received the event, and the actual event bitset.
4687		4914
4688	=item callback invocation	4915	=item callback/watcher invocation
4689		4916
4690	The act of calling the callback associated with a watcher.	4917	The act of calling the callback associated with a watcher.
4691		4918
4692	=item event	4919	=item event
4693		4920
…		…
4712	The model used to describe how an event loop handles and processes	4939	The model used to describe how an event loop handles and processes
4713	watchers and events.	4940	watchers and events.
4714		4941
4715	=item pending	4942	=item pending
4716		4943
4717	A watcher is pending as soon as the corresponding event has been detected,	4944	A watcher is pending as soon as the corresponding event has been
4718	and stops being pending as soon as the watcher will be invoked or its	4945	detected. See L<WATCHER STATES> for details.
4719	pending status is explicitly cleared by the application.
4720
4721	A watcher can be pending, but not active. Stopping a watcher also clears
4722	its pending status.
4723		4946
4724	=item real time	4947	=item real time
4725		4948
4726	The physical time that is observed. It is apparently strictly monotonic :)	4949	The physical time that is observed. It is apparently strictly monotonic :)
4727		4950
…		…
4734	=item watcher	4957	=item watcher
4735		4958
4736	A data structure that describes interest in certain events. Watchers need	4959	A data structure that describes interest in certain events. Watchers need
4737	to be started (attached to an event loop) before they can receive events.	4960	to be started (attached to an event loop) before they can receive events.
4738		4961
4739	=item watcher invocation
4740
4741	The act of calling the callback associated with a watcher.
4742
4743	=back	4962	=back
4744		4963
4745	=head1 AUTHOR	4964	=head1 AUTHOR
4746		4965
4747	Marc Lehmann <libev@schmorp.de>, with repeated corrections by Mikael Magnusson.	4966	Marc Lehmann <libev@schmorp.de>, with repeated corrections by Mikael Magnusson.

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