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Revision 1.276 by root, Tue Dec 29 13:11:00 2009 UTC vs.
Revision 1.332 by root, Sun Oct 24 23:30:23 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 child process events, and dynamically created event loops which
302	not.	306	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	=item struct ev_loop *ev_loop_new (unsigned int flags)
		348
		349	This will create and initialise a new event loop object. If the loop
		350	could not be initialised, returns false.
		351
		352	Note that this function I<is> thread-safe, and one common way to use
		353	libev with threads is indeed to create one loop per thread, and using the
		354	default loop in the "main" or "initial" thread.
326		355
327	The flags argument can be used to specify special behaviour or specific	356	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>).	357	backends to use, and is usually specified as C<0> (or C<EVFLAG_AUTO>).
329		358
330	The following flags are supported:	359	The following flags are supported:
…		…
345	useful to try out specific backends to test their performance, or to work	374	useful to try out specific backends to test their performance, or to work
346	around bugs.	375	around bugs.
347		376
348	=item C<EVFLAG_FORKCHECK>	377	=item C<EVFLAG_FORKCHECK>
349		378
350	Instead of calling C<ev_default_fork> or C<ev_loop_fork> manually after	379	Instead of calling C<ev_loop_fork> manually after a fork, you can also
351	a fork, you can also make libev check for a fork in each iteration by	380	make libev check for a fork in each iteration by enabling this flag.
352	enabling this flag.
353		381
354	This works by calling C<getpid ()> on every iteration of the loop,	382	This works by calling C<getpid ()> on every iteration of the loop,
355	and thus this might slow down your event loop if you do a lot of loop	383	and thus this might slow down your event loop if you do a lot of loop
356	iterations and little real work, but is usually not noticeable (on my	384	iterations and little real work, but is usually not noticeable (on my
357	GNU/Linux system for example, C<getpid> is actually a simple 5-insn sequence	385	GNU/Linux system for example, C<getpid> is actually a simple 5-insn sequence
…		…
370	When this flag is specified, then libev will not attempt to use the	398	When this flag is specified, then libev will not attempt to use the
371	I<inotify> API for it's C<ev_stat> watchers. Apart from debugging and	399	I<inotify> API for it's C<ev_stat> watchers. Apart from debugging and
372	testing, this flag can be useful to conserve inotify file descriptors, as	400	testing, this flag can be useful to conserve inotify file descriptors, as
373	otherwise each loop using C<ev_stat> watchers consumes one inotify handle.	401	otherwise each loop using C<ev_stat> watchers consumes one inotify handle.
374		402
375	=item C<EVFLAG_NOSIGFD>	403	=item C<EVFLAG_SIGNALFD>
376		404
377	When this flag is specified, then libev will not attempt to use the	405	When this flag is specified, then libev will attempt to use the
378	I<signalfd> API for it's C<ev_signal> (and C<ev_child>) watchers. This is	406	I<signalfd> API for it's C<ev_signal> (and C<ev_child>) watchers. This API
379	probably only useful to work around any bugs in libev. Consequently, this	407	delivers signals synchronously, which makes it both faster and might make
380	flag might go away once the signalfd functionality is considered stable,	408	it possible to get the queued signal data. It can also simplify signal
381	so it's useful mostly in environment variables and not in program code.	409	handling with threads, as long as you properly block signals in your
		410	threads that are not interested in handling them.
		411
		412	Signalfd will not be used by default as this changes your signal mask, and
		413	there are a lot of shoddy libraries and programs (glib's threadpool for
		414	example) that can't properly initialise their signal masks.
382		415
383	=item C<EVBACKEND_SELECT> (value 1, portable select backend)	416	=item C<EVBACKEND_SELECT> (value 1, portable select backend)
384		417
385	This is your standard select(2) backend. Not I<completely> standard, as	418	This is your standard select(2) backend. Not I<completely> standard, as
386	libev tries to roll its own fd_set with no limits on the number of fds,	419	libev tries to roll its own fd_set with no limits on the number of fds,
…		…
434	of course I<doesn't>, and epoll just loves to report events for totally	467	of course I<doesn't>, and epoll just loves to report events for totally
435	I<different> file descriptors (even already closed ones, so one cannot	468	I<different> file descriptors (even already closed ones, so one cannot
436	even remove them from the set) than registered in the set (especially	469	even remove them from the set) than registered in the set (especially
437	on SMP systems). Libev tries to counter these spurious notifications by	470	on SMP systems). Libev tries to counter these spurious notifications by
438	employing an additional generation counter and comparing that against the	471	employing an additional generation counter and comparing that against the
439	events to filter out spurious ones, recreating the set when required.	472	events to filter out spurious ones, recreating the set when required. Last
		473	not least, it also refuses to work with some file descriptors which work
		474	perfectly fine with C<select> (files, many character devices...).
440		475
441	While stopping, setting and starting an I/O watcher in the same iteration	476	While stopping, setting and starting an I/O watcher in the same iteration
442	will result in some caching, there is still a system call per such	477	will result in some caching, there is still a system call per such
443	incident (because the same I<file descriptor> could point to a different	478	incident (because the same I<file descriptor> could point to a different
444	I<file description> now), so its best to avoid that. Also, C<dup ()>'ed	479	I<file description> now), so its best to avoid that. Also, C<dup ()>'ed
…		…
542	If one or more of the backend flags are or'ed into the flags value,	577	If one or more of the backend flags are or'ed into the flags value,
543	then only these backends will be tried (in the reverse order as listed	578	then only these backends will be tried (in the reverse order as listed
544	here). If none are specified, all backends in C<ev_recommended_backends	579	here). If none are specified, all backends in C<ev_recommended_backends
545	()> will be tried.	580	()> will be tried.
546		581
547	Example: This is the most typical usage.
548
549	if (!ev_default_loop (0))
550	fatal ("could not initialise libev, bad $LIBEV_FLAGS in environment?");
551
552	Example: Restrict libev to the select and poll backends, and do not allow
553	environment settings to be taken into account:
554
555	ev_default_loop (EVBACKEND_POLL | EVBACKEND_SELECT | EVFLAG_NOENV);
556
557	Example: Use whatever libev has to offer, but make sure that kqueue is
558	used if available (warning, breaks stuff, best use only with your own
559	private event loop and only if you know the OS supports your types of
560	fds):
561
562	ev_default_loop (ev_recommended_backends () | EVBACKEND_KQUEUE);
563
564	=item struct ev_loop *ev_loop_new (unsigned int flags)
565
566	Similar to C<ev_default_loop>, but always creates a new event loop that is
567	always distinct from the default loop. Unlike the default loop, it cannot
568	handle signal and child watchers, and attempts to do so will be greeted by
569	undefined behaviour (or a failed assertion if assertions are enabled).
570
571	Note that this function I<is> thread-safe, and the recommended way to use
572	libev with threads is indeed to create one loop per thread, and using the
573	default loop in the "main" or "initial" thread.
574
575	Example: Try to create a event loop that uses epoll and nothing else.	582	Example: Try to create a event loop that uses epoll and nothing else.
576		583
577	struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV);	584	struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL | EVFLAG_NOENV);
578	if (!epoller)	585	if (!epoller)
579	fatal ("no epoll found here, maybe it hides under your chair");	586	fatal ("no epoll found here, maybe it hides under your chair");
580		587
		588	Example: Use whatever libev has to offer, but make sure that kqueue is
		589	used if available.
		590
		591	struct ev_loop *loop = ev_loop_new (ev_recommended_backends () | EVBACKEND_KQUEUE);
		592
581	=item ev_default_destroy ()	593	=item ev_loop_destroy (loop)
582		594
583	Destroys the default loop again (frees all memory and kernel state	595	Destroys an event loop object (frees all memory and kernel state
584	etc.). None of the active event watchers will be stopped in the normal	596	etc.). None of the active event watchers will be stopped in the normal
585	sense, so e.g. C<ev_is_active> might still return true. It is your	597	sense, so e.g. C<ev_is_active> might still return true. It is your
586	responsibility to either stop all watchers cleanly yourself I<before>	598	responsibility to either stop all watchers cleanly yourself I<before>
587	calling this function, or cope with the fact afterwards (which is usually	599	calling this function, or cope with the fact afterwards (which is usually
588	the easiest thing, you can just ignore the watchers and/or C<free ()> them	600	the easiest thing, you can just ignore the watchers and/or C<free ()> them
…		…
590		602
591	Note that certain global state, such as signal state (and installed signal	603	Note that certain global state, such as signal state (and installed signal
592	handlers), will not be freed by this function, and related watchers (such	604	handlers), will not be freed by this function, and related watchers (such
593	as signal and child watchers) would need to be stopped manually.	605	as signal and child watchers) would need to be stopped manually.
594		606
595	In general it is not advisable to call this function except in the	607	This function is normally used on loop objects allocated by
596	rare occasion where you really need to free e.g. the signal handling	608	C<ev_loop_new>, but it can also be used on the default loop returned by
		609	C<ev_default_loop>, in which case it is not thread-safe.
		610
		611	Note that it is not advisable to call this function on the default loop
		612	except in the rare occasion where you really need to free it's resources.
597	pipe fds. If you need dynamically allocated loops it is better to use	613	If you need dynamically allocated loops it is better to use C<ev_loop_new>
598	C<ev_loop_new> and C<ev_loop_destroy>.	614	and C<ev_loop_destroy>.
599		615
600	=item ev_loop_destroy (loop)	616	=item ev_loop_fork (loop)
601		617
602	Like C<ev_default_destroy>, but destroys an event loop created by an
603	earlier call to C<ev_loop_new>.
604
605	=item ev_default_fork ()
606
607	This function sets a flag that causes subsequent C<ev_loop> iterations	618	This function sets a flag that causes subsequent C<ev_run> iterations to
608	to reinitialise the kernel state for backends that have one. Despite the	619	reinitialise the kernel state for backends that have one. Despite the
609	name, you can call it anytime, but it makes most sense after forking, in	620	name, you can call it anytime, but it makes most sense after forking, in
610	the child process (or both child and parent, but that again makes little	621	the child process. You I<must> call it (or use C<EVFLAG_FORKCHECK>) in the
611	sense). You I<must> call it in the child before using any of the libev	622	child before resuming or calling C<ev_run>.
612	functions, and it will only take effect at the next C<ev_loop> iteration.	623
		624	Again, you I<have> to call it on I<any> loop that you want to re-use after
		625	a fork, I<even if you do not plan to use the loop in the parent>. This is
		626	because some kernel interfaces *cough* I<kqueue> *cough* do funny things
		627	during fork.
613		628
614	On the other hand, you only need to call this function in the child	629	On the other hand, you only need to call this function in the child
615	process if and only if you want to use the event library in the child. If	630	process if and only if you want to use the event loop in the child. If
616	you just fork+exec, you don't have to call it at all.	631	you just fork+exec or create a new loop in the child, you don't have to
		632	call it at all (in fact, C<epoll> is so badly broken that it makes a
		633	difference, but libev will usually detect this case on its own and do a
		634	costly reset of the backend).
617		635
618	The function itself is quite fast and it's usually not a problem to call	636	The function itself is quite fast and it's usually not a problem to call
619	it just in case after a fork. To make this easy, the function will fit in	637	it just in case after a fork.
620	quite nicely into a call to C<pthread_atfork>:
621		638
		639	Example: Automate calling C<ev_loop_fork> on the default loop when
		640	using pthreads.
		641
		642	static void
		643	post_fork_child (void)
		644	{
		645	ev_loop_fork (EV_DEFAULT);
		646	}
		647
		648	...
622	pthread_atfork (0, 0, ev_default_fork);	649	pthread_atfork (0, 0, post_fork_child);
623
624	=item ev_loop_fork (loop)
625
626	Like C<ev_default_fork>, but acts on an event loop created by
627	C<ev_loop_new>. Yes, you have to call this on every allocated event loop
628	after fork that you want to re-use in the child, and how you do this is
629	entirely your own problem.
630		650
631	=item int ev_is_default_loop (loop)	651	=item int ev_is_default_loop (loop)
632		652
633	Returns true when the given loop is, in fact, the default loop, and false	653	Returns true when the given loop is, in fact, the default loop, and false
634	otherwise.	654	otherwise.
635		655
636	=item unsigned int ev_loop_count (loop)	656	=item unsigned int ev_iteration (loop)
637		657
638	Returns the count of loop iterations for the loop, which is identical to	658	Returns the current iteration count for the event loop, which is identical
639	the number of times libev did poll for new events. It starts at C<0> and	659	to the number of times libev did poll for new events. It starts at C<0>
640	happily wraps around with enough iterations.	660	and happily wraps around with enough iterations.
641		661
642	This value can sometimes be useful as a generation counter of sorts (it	662	This value can sometimes be useful as a generation counter of sorts (it
643	"ticks" the number of loop iterations), as it roughly corresponds with	663	"ticks" the number of loop iterations), as it roughly corresponds with
644	C<ev_prepare> and C<ev_check> calls.	664	C<ev_prepare> and C<ev_check> calls - and is incremented between the
		665	prepare and check phases.
645		666
646	=item unsigned int ev_loop_depth (loop)	667	=item unsigned int ev_depth (loop)
647		668
648	Returns the number of times C<ev_loop> was entered minus the number of	669	Returns the number of times C<ev_run> was entered minus the number of
649	times C<ev_loop> was exited, in other words, the recursion depth.	670	times C<ev_run> was exited, in other words, the recursion depth.
650		671
651	Outside C<ev_loop>, this number is zero. In a callback, this number is	672	Outside C<ev_run>, this number is zero. In a callback, this number is
652	C<1>, unless C<ev_loop> was invoked recursively (or from another thread),	673	C<1>, unless C<ev_run> was invoked recursively (or from another thread),
653	in which case it is higher.	674	in which case it is higher.
654		675
655	Leaving C<ev_loop> abnormally (setjmp/longjmp, cancelling the thread	676	Leaving C<ev_run> abnormally (setjmp/longjmp, cancelling the thread
656	etc.), doesn't count as exit.	677	etc.), doesn't count as "exit" - consider this as a hint to avoid such
		678	ungentleman-like behaviour unless it's really convenient.
657		679
658	=item unsigned int ev_backend (loop)	680	=item unsigned int ev_backend (loop)
659		681
660	Returns one of the C<EVBACKEND_*> flags indicating the event backend in	682	Returns one of the C<EVBACKEND_*> flags indicating the event backend in
661	use.	683	use.
…		…
670		692
671	=item ev_now_update (loop)	693	=item ev_now_update (loop)
672		694
673	Establishes the current time by querying the kernel, updating the time	695	Establishes the current time by querying the kernel, updating the time
674	returned by C<ev_now ()> in the progress. This is a costly operation and	696	returned by C<ev_now ()> in the progress. This is a costly operation and
675	is usually done automatically within C<ev_loop ()>.	697	is usually done automatically within C<ev_run ()>.
676		698
677	This function is rarely useful, but when some event callback runs for a	699	This function is rarely useful, but when some event callback runs for a
678	very long time without entering the event loop, updating libev's idea of	700	very long time without entering the event loop, updating libev's idea of
679	the current time is a good idea.	701	the current time is a good idea.
680		702
…		…
682		704
683	=item ev_suspend (loop)	705	=item ev_suspend (loop)
684		706
685	=item ev_resume (loop)	707	=item ev_resume (loop)
686		708
687	These two functions suspend and resume a loop, for use when the loop is	709	These two functions suspend and resume an event loop, for use when the
688	not used for a while and timeouts should not be processed.	710	loop is not used for a while and timeouts should not be processed.
689		711
690	A typical use case would be an interactive program such as a game: When	712	A typical use case would be an interactive program such as a game: When
691	the user presses C<^Z> to suspend the game and resumes it an hour later it	713	the user presses C<^Z> to suspend the game and resumes it an hour later it
692	would be best to handle timeouts as if no time had actually passed while	714	would be best to handle timeouts as if no time had actually passed while
693	the program was suspended. This can be achieved by calling C<ev_suspend>	715	the program was suspended. This can be achieved by calling C<ev_suspend>
…		…
695	C<ev_resume> directly afterwards to resume timer processing.	717	C<ev_resume> directly afterwards to resume timer processing.
696		718
697	Effectively, all C<ev_timer> watchers will be delayed by the time spend	719	Effectively, all C<ev_timer> watchers will be delayed by the time spend
698	between C<ev_suspend> and C<ev_resume>, and all C<ev_periodic> watchers	720	between C<ev_suspend> and C<ev_resume>, and all C<ev_periodic> watchers
699	will be rescheduled (that is, they will lose any events that would have	721	will be rescheduled (that is, they will lose any events that would have
700	occured while suspended).	722	occurred while suspended).
701		723
702	After calling C<ev_suspend> you B<must not> call I<any> function on the	724	After calling C<ev_suspend> you B<must not> call I<any> function on the
703	given loop other than C<ev_resume>, and you B<must not> call C<ev_resume>	725	given loop other than C<ev_resume>, and you B<must not> call C<ev_resume>
704	without a previous call to C<ev_suspend>.	726	without a previous call to C<ev_suspend>.
705		727
706	Calling C<ev_suspend>/C<ev_resume> has the side effect of updating the	728	Calling C<ev_suspend>/C<ev_resume> has the side effect of updating the
707	event loop time (see C<ev_now_update>).	729	event loop time (see C<ev_now_update>).
708		730
709	=item ev_loop (loop, int flags)	731	=item ev_run (loop, int flags)
710		732
711	Finally, this is it, the event handler. This function usually is called	733	Finally, this is it, the event handler. This function usually is called
712	after you have initialised all your watchers and you want to start	734	after you have initialised all your watchers and you want to start
713	handling events.	735	handling events. It will ask the operating system for any new events, call
		736	the watcher callbacks, an then repeat the whole process indefinitely: This
		737	is why event loops are called I<loops>.
714		738
715	If the flags argument is specified as C<0>, it will not return until	739	If the flags argument is specified as C<0>, it will keep handling events
716	either no event watchers are active anymore or C<ev_unloop> was called.	740	until either no event watchers are active anymore or C<ev_break> was
		741	called.
717		742
718	Please note that an explicit C<ev_unloop> is usually better than	743	Please note that an explicit C<ev_break> is usually better than
719	relying on all watchers to be stopped when deciding when a program has	744	relying on all watchers to be stopped when deciding when a program has
720	finished (especially in interactive programs), but having a program	745	finished (especially in interactive programs), but having a program
721	that automatically loops as long as it has to and no longer by virtue	746	that automatically loops as long as it has to and no longer by virtue
722	of relying on its watchers stopping correctly, that is truly a thing of	747	of relying on its watchers stopping correctly, that is truly a thing of
723	beauty.	748	beauty.
724		749
725	A flags value of C<EVLOOP_NONBLOCK> will look for new events, will handle	750	A flags value of C<EVRUN_NOWAIT> will look for new events, will handle
726	those events and any already outstanding ones, but will not block your	751	those events and any already outstanding ones, but will not wait and
727	process in case there are no events and will return after one iteration of	752	block your process in case there are no events and will return after one
728	the loop.	753	iteration of the loop. This is sometimes useful to poll and handle new
		754	events while doing lengthy calculations, to keep the program responsive.
729		755
730	A flags value of C<EVLOOP_ONESHOT> will look for new events (waiting if	756	A flags value of C<EVRUN_ONCE> will look for new events (waiting if
731	necessary) and will handle those and any already outstanding ones. It	757	necessary) and will handle those and any already outstanding ones. It
732	will block your process until at least one new event arrives (which could	758	will block your process until at least one new event arrives (which could
733	be an event internal to libev itself, so there is no guarantee that a	759	be an event internal to libev itself, so there is no guarantee that a
734	user-registered callback will be called), and will return after one	760	user-registered callback will be called), and will return after one
735	iteration of the loop.	761	iteration of the loop.
736		762
737	This is useful if you are waiting for some external event in conjunction	763	This is useful if you are waiting for some external event in conjunction
738	with something not expressible using other libev watchers (i.e. "roll your	764	with something not expressible using other libev watchers (i.e. "roll your
739	own C<ev_loop>"). However, a pair of C<ev_prepare>/C<ev_check> watchers is	765	own C<ev_run>"). However, a pair of C<ev_prepare>/C<ev_check> watchers is
740	usually a better approach for this kind of thing.	766	usually a better approach for this kind of thing.
741		767
742	Here are the gory details of what C<ev_loop> does:	768	Here are the gory details of what C<ev_run> does:
743		769
		770	- Increment loop depth.
		771	- Reset the ev_break status.
744	- Before the first iteration, call any pending watchers.	772	- Before the first iteration, call any pending watchers.
		773	LOOP:
745	* If EVFLAG_FORKCHECK was used, check for a fork.	774	- If EVFLAG_FORKCHECK was used, check for a fork.
746	- If a fork was detected (by any means), queue and call all fork watchers.	775	- If a fork was detected (by any means), queue and call all fork watchers.
747	- Queue and call all prepare watchers.	776	- Queue and call all prepare watchers.
		777	- If ev_break was called, goto FINISH.
748	- If we have been forked, detach and recreate the kernel state	778	- If we have been forked, detach and recreate the kernel state
749	as to not disturb the other process.	779	as to not disturb the other process.
750	- Update the kernel state with all outstanding changes.	780	- Update the kernel state with all outstanding changes.
751	- Update the "event loop time" (ev_now ()).	781	- Update the "event loop time" (ev_now ()).
752	- Calculate for how long to sleep or block, if at all	782	- Calculate for how long to sleep or block, if at all
753	(active idle watchers, EVLOOP_NONBLOCK or not having	783	(active idle watchers, EVRUN_NOWAIT or not having
754	any active watchers at all will result in not sleeping).	784	any active watchers at all will result in not sleeping).
755	- Sleep if the I/O and timer collect interval say so.	785	- Sleep if the I/O and timer collect interval say so.
		786	- Increment loop iteration counter.
756	- Block the process, waiting for any events.	787	- Block the process, waiting for any events.
757	- Queue all outstanding I/O (fd) events.	788	- Queue all outstanding I/O (fd) events.
758	- Update the "event loop time" (ev_now ()), and do time jump adjustments.	789	- Update the "event loop time" (ev_now ()), and do time jump adjustments.
759	- Queue all expired timers.	790	- Queue all expired timers.
760	- Queue all expired periodics.	791	- Queue all expired periodics.
761	- Unless any events are pending now, queue all idle watchers.	792	- Queue all idle watchers with priority higher than that of pending events.
762	- Queue all check watchers.	793	- Queue all check watchers.
763	- Call all queued watchers in reverse order (i.e. check watchers first).	794	- Call all queued watchers in reverse order (i.e. check watchers first).
764	Signals and child watchers are implemented as I/O watchers, and will	795	Signals and child watchers are implemented as I/O watchers, and will
765	be handled here by queueing them when their watcher gets executed.	796	be handled here by queueing them when their watcher gets executed.
766	- If ev_unloop has been called, or EVLOOP_ONESHOT or EVLOOP_NONBLOCK	797	- If ev_break has been called, or EVRUN_ONCE or EVRUN_NOWAIT
767	were used, or there are no active watchers, return, otherwise	798	were used, or there are no active watchers, goto FINISH, otherwise
768	continue with step *.	799	continue with step LOOP.
		800	FINISH:
		801	- Reset the ev_break status iff it was EVBREAK_ONE.
		802	- Decrement the loop depth.
		803	- Return.
769		804
770	Example: Queue some jobs and then loop until no events are outstanding	805	Example: Queue some jobs and then loop until no events are outstanding
771	anymore.	806	anymore.
772		807
773	... queue jobs here, make sure they register event watchers as long	808	... queue jobs here, make sure they register event watchers as long
774	... as they still have work to do (even an idle watcher will do..)	809	... as they still have work to do (even an idle watcher will do..)
775	ev_loop (my_loop, 0);	810	ev_run (my_loop, 0);
776	... jobs done or somebody called unloop. yeah!	811	... jobs done or somebody called unloop. yeah!
777		812
778	=item ev_unloop (loop, how)	813	=item ev_break (loop, how)
779		814
780	Can be used to make a call to C<ev_loop> return early (but only after it	815	Can be used to make a call to C<ev_run> return early (but only after it
781	has processed all outstanding events). The C<how> argument must be either	816	has processed all outstanding events). The C<how> argument must be either
782	C<EVUNLOOP_ONE>, which will make the innermost C<ev_loop> call return, or	817	C<EVBREAK_ONE>, which will make the innermost C<ev_run> call return, or
783	C<EVUNLOOP_ALL>, which will make all nested C<ev_loop> calls return.	818	C<EVBREAK_ALL>, which will make all nested C<ev_run> calls return.
784		819
785	This "unloop state" will be cleared when entering C<ev_loop> again.	820	This "unloop state" will be cleared when entering C<ev_run> again.
786		821
787	It is safe to call C<ev_unloop> from otuside any C<ev_loop> calls.	822	It is safe to call C<ev_break> from outside any C<ev_run> calls. ##TODO##
788		823
789	=item ev_ref (loop)	824	=item ev_ref (loop)
790		825
791	=item ev_unref (loop)	826	=item ev_unref (loop)
792		827
793	Ref/unref can be used to add or remove a reference count on the event	828	Ref/unref can be used to add or remove a reference count on the event
794	loop: Every watcher keeps one reference, and as long as the reference	829	loop: Every watcher keeps one reference, and as long as the reference
795	count is nonzero, C<ev_loop> will not return on its own.	830	count is nonzero, C<ev_run> will not return on its own.
796		831
797	This is useful when you have a watcher that you never intend to	832	This is useful when you have a watcher that you never intend to
798	unregister, but that nevertheless should not keep C<ev_loop> from	833	unregister, but that nevertheless should not keep C<ev_run> from
799	returning. In such a case, call C<ev_unref> after starting, and C<ev_ref>	834	returning. In such a case, call C<ev_unref> after starting, and C<ev_ref>
800	before stopping it.	835	before stopping it.
801		836
802	As an example, libev itself uses this for its internal signal pipe: It	837	As an example, libev itself uses this for its internal signal pipe: It
803	is not visible to the libev user and should not keep C<ev_loop> from	838	is not visible to the libev user and should not keep C<ev_run> from
804	exiting if no event watchers registered by it are active. It is also an	839	exiting if no event watchers registered by it are active. It is also an
805	excellent way to do this for generic recurring timers or from within	840	excellent way to do this for generic recurring timers or from within
806	third-party libraries. Just remember to I<unref after start> and I<ref	841	third-party libraries. Just remember to I<unref after start> and I<ref
807	before stop> (but only if the watcher wasn't active before, or was active	842	before stop> (but only if the watcher wasn't active before, or was active
808	before, respectively. Note also that libev might stop watchers itself	843	before, respectively. Note also that libev might stop watchers itself
809	(e.g. non-repeating timers) in which case you have to C<ev_ref>	844	(e.g. non-repeating timers) in which case you have to C<ev_ref>
810	in the callback).	845	in the callback).
811		846
812	Example: Create a signal watcher, but keep it from keeping C<ev_loop>	847	Example: Create a signal watcher, but keep it from keeping C<ev_run>
813	running when nothing else is active.	848	running when nothing else is active.
814		849
815	ev_signal exitsig;	850	ev_signal exitsig;
816	ev_signal_init (&exitsig, sig_cb, SIGINT);	851	ev_signal_init (&exitsig, sig_cb, SIGINT);
817	ev_signal_start (loop, &exitsig);	852	ev_signal_start (loop, &exitsig);
…		…
862	usually doesn't make much sense to set it to a lower value than C<0.01>,	897	usually doesn't make much sense to set it to a lower value than C<0.01>,
863	as this approaches the timing granularity of most systems. Note that if	898	as this approaches the timing granularity of most systems. Note that if
864	you do transactions with the outside world and you can't increase the	899	you do transactions with the outside world and you can't increase the
865	parallelity, then this setting will limit your transaction rate (if you	900	parallelity, then this setting will limit your transaction rate (if you
866	need to poll once per transaction and the I/O collect interval is 0.01,	901	need to poll once per transaction and the I/O collect interval is 0.01,
867	then you can't do more than 100 transations per second).	902	then you can't do more than 100 transactions per second).
868		903
869	Setting the I<timeout collect interval> can improve the opportunity for	904	Setting the I<timeout collect interval> can improve the opportunity for
870	saving power, as the program will "bundle" timer callback invocations that	905	saving power, as the program will "bundle" timer callback invocations that
871	are "near" in time together, by delaying some, thus reducing the number of	906	are "near" in time together, by delaying some, thus reducing the number of
872	times the process sleeps and wakes up again. Another useful technique to	907	times the process sleeps and wakes up again. Another useful technique to
…		…
880	ev_set_io_collect_interval (EV_DEFAULT_UC_ 0.01);	915	ev_set_io_collect_interval (EV_DEFAULT_UC_ 0.01);
881		916
882	=item ev_invoke_pending (loop)	917	=item ev_invoke_pending (loop)
883		918
884	This call will simply invoke all pending watchers while resetting their	919	This call will simply invoke all pending watchers while resetting their
885	pending state. Normally, C<ev_loop> does this automatically when required,	920	pending state. Normally, C<ev_run> does this automatically when required,
886	but when overriding the invoke callback this call comes handy.	921	but when overriding the invoke callback this call comes handy. This
		922	function can be invoked from a watcher - this can be useful for example
		923	when you want to do some lengthy calculation and want to pass further
		924	event handling to another thread (you still have to make sure only one
		925	thread executes within C<ev_invoke_pending> or C<ev_run> of course).
887		926
888	=item int ev_pending_count (loop)	927	=item int ev_pending_count (loop)
889		928
890	Returns the number of pending watchers - zero indicates that no watchers	929	Returns the number of pending watchers - zero indicates that no watchers
891	are pending.	930	are pending.
892		931
893	=item ev_set_invoke_pending_cb (loop, void (*invoke_pending_cb)(EV_P))	932	=item ev_set_invoke_pending_cb (loop, void (*invoke_pending_cb)(EV_P))
894		933
895	This overrides the invoke pending functionality of the loop: Instead of	934	This overrides the invoke pending functionality of the loop: Instead of
896	invoking all pending watchers when there are any, C<ev_loop> will call	935	invoking all pending watchers when there are any, C<ev_run> will call
897	this callback instead. This is useful, for example, when you want to	936	this callback instead. This is useful, for example, when you want to
898	invoke the actual watchers inside another context (another thread etc.).	937	invoke the actual watchers inside another context (another thread etc.).
899		938
900	If you want to reset the callback, use C<ev_invoke_pending> as new	939	If you want to reset the callback, use C<ev_invoke_pending> as new
901	callback.	940	callback.
…		…
904		943
905	Sometimes you want to share the same loop between multiple threads. This	944	Sometimes you want to share the same loop between multiple threads. This
906	can be done relatively simply by putting mutex_lock/unlock calls around	945	can be done relatively simply by putting mutex_lock/unlock calls around
907	each call to a libev function.	946	each call to a libev function.
908		947
909	However, C<ev_loop> can run an indefinite time, so it is not feasible to	948	However, C<ev_run> can run an indefinite time, so it is not feasible
910	wait for it to return. One way around this is to wake up the loop via	949	to wait for it to return. One way around this is to wake up the event
911	C<ev_unloop> and C<av_async_send>, another way is to set these I<release>	950	loop via C<ev_break> and C<av_async_send>, another way is to set these
912	and I<acquire> callbacks on the loop.	951	I<release> and I<acquire> callbacks on the loop.
913		952
914	When set, then C<release> will be called just before the thread is	953	When set, then C<release> will be called just before the thread is
915	suspended waiting for new events, and C<acquire> is called just	954	suspended waiting for new events, and C<acquire> is called just
916	afterwards.	955	afterwards.
917		956
…		…
920		959
921	While event loop modifications are allowed between invocations of	960	While event loop modifications are allowed between invocations of
922	C<release> and C<acquire> (that's their only purpose after all), no	961	C<release> and C<acquire> (that's their only purpose after all), no
923	modifications done will affect the event loop, i.e. adding watchers will	962	modifications done will affect the event loop, i.e. adding watchers will
924	have no effect on the set of file descriptors being watched, or the time	963	have no effect on the set of file descriptors being watched, or the time
925	waited. Use an C<ev_async> watcher to wake up C<ev_loop> when you want it	964	waited. Use an C<ev_async> watcher to wake up C<ev_run> when you want it
926	to take note of any changes you made.	965	to take note of any changes you made.
927		966
928	In theory, threads executing C<ev_loop> will be async-cancel safe between	967	In theory, threads executing C<ev_run> will be async-cancel safe between
929	invocations of C<release> and C<acquire>.	968	invocations of C<release> and C<acquire>.
930		969
931	See also the locking example in the C<THREADS> section later in this	970	See also the locking example in the C<THREADS> section later in this
932	document.	971	document.
933		972
…		…
942	These two functions can be used to associate arbitrary data with a loop,	981	These two functions can be used to associate arbitrary data with a loop,
943	and are intended solely for the C<invoke_pending_cb>, C<release> and	982	and are intended solely for the C<invoke_pending_cb>, C<release> and
944	C<acquire> callbacks described above, but of course can be (ab-)used for	983	C<acquire> callbacks described above, but of course can be (ab-)used for
945	any other purpose as well.	984	any other purpose as well.
946		985
947	=item ev_loop_verify (loop)	986	=item ev_verify (loop)
948		987
949	This function only does something when C<EV_VERIFY> support has been	988	This function only does something when C<EV_VERIFY> support has been
950	compiled in, which is the default for non-minimal builds. It tries to go	989	compiled in, which is the default for non-minimal builds. It tries to go
951	through all internal structures and checks them for validity. If anything	990	through all internal structures and checks them for validity. If anything
952	is found to be inconsistent, it will print an error message to standard	991	is found to be inconsistent, it will print an error message to standard
…		…
963		1002
964	In the following description, uppercase C<TYPE> in names stands for the	1003	In the following description, uppercase C<TYPE> in names stands for the
965	watcher type, e.g. C<ev_TYPE_start> can mean C<ev_timer_start> for timer	1004	watcher type, e.g. C<ev_TYPE_start> can mean C<ev_timer_start> for timer
966	watchers and C<ev_io_start> for I/O watchers.	1005	watchers and C<ev_io_start> for I/O watchers.
967		1006
968	A watcher is a structure that you create and register to record your	1007	A watcher is an opaque structure that you allocate and register to record
969	interest in some event. For instance, if you want to wait for STDIN to	1008	your interest in some event. To make a concrete example, imagine you want
970	become readable, you would create an C<ev_io> watcher for that:	1009	to wait for STDIN to become readable, you would create an C<ev_io> watcher
		1010	for that:
971		1011
972	static void my_cb (struct ev_loop *loop, ev_io *w, int revents)	1012	static void my_cb (struct ev_loop *loop, ev_io *w, int revents)
973	{	1013	{
974	ev_io_stop (w);	1014	ev_io_stop (w);
975	ev_unloop (loop, EVUNLOOP_ALL);	1015	ev_break (loop, EVBREAK_ALL);
976	}	1016	}
977		1017
978	struct ev_loop *loop = ev_default_loop (0);	1018	struct ev_loop *loop = ev_default_loop (0);
979		1019
980	ev_io stdin_watcher;	1020	ev_io stdin_watcher;
981		1021
982	ev_init (&stdin_watcher, my_cb);	1022	ev_init (&stdin_watcher, my_cb);
983	ev_io_set (&stdin_watcher, STDIN_FILENO, EV_READ);	1023	ev_io_set (&stdin_watcher, STDIN_FILENO, EV_READ);
984	ev_io_start (loop, &stdin_watcher);	1024	ev_io_start (loop, &stdin_watcher);
985		1025
986	ev_loop (loop, 0);	1026	ev_run (loop, 0);
987		1027
988	As you can see, you are responsible for allocating the memory for your	1028	As you can see, you are responsible for allocating the memory for your
989	watcher structures (and it is I<usually> a bad idea to do this on the	1029	watcher structures (and it is I<usually> a bad idea to do this on the
990	stack).	1030	stack).
991		1031
992	Each watcher has an associated watcher structure (called C<struct ev_TYPE>	1032	Each watcher has an associated watcher structure (called C<struct ev_TYPE>
993	or simply C<ev_TYPE>, as typedefs are provided for all watcher structs).	1033	or simply C<ev_TYPE>, as typedefs are provided for all watcher structs).
994		1034
995	Each watcher structure must be initialised by a call to C<ev_init	1035	Each watcher structure must be initialised by a call to C<ev_init (watcher
996	(watcher *, callback)>, which expects a callback to be provided. This	1036	*, callback)>, which expects a callback to be provided. This callback is
997	callback gets invoked each time the event occurs (or, in the case of I/O	1037	invoked each time the event occurs (or, in the case of I/O watchers, each
998	watchers, each time the event loop detects that the file descriptor given	1038	time the event loop detects that the file descriptor given is readable
999	is readable and/or writable).	1039	and/or writable).
1000		1040
1001	Each watcher type further has its own C<< ev_TYPE_set (watcher *, ...) >>	1041	Each watcher type further has its own C<< ev_TYPE_set (watcher *, ...) >>
1002	macro to configure it, with arguments specific to the watcher type. There	1042	macro to configure it, with arguments specific to the watcher type. There
1003	is also a macro to combine initialisation and setting in one call: C<<	1043	is also a macro to combine initialisation and setting in one call: C<<
1004	ev_TYPE_init (watcher *, callback, ...) >>.	1044	ev_TYPE_init (watcher *, callback, ...) >>.
…		…
1027	=item C<EV_WRITE>	1067	=item C<EV_WRITE>
1028		1068
1029	The file descriptor in the C<ev_io> watcher has become readable and/or	1069	The file descriptor in the C<ev_io> watcher has become readable and/or
1030	writable.	1070	writable.
1031		1071
1032	=item C<EV_TIMEOUT>	1072	=item C<EV_TIMER>
1033		1073
1034	The C<ev_timer> watcher has timed out.	1074	The C<ev_timer> watcher has timed out.
1035		1075
1036	=item C<EV_PERIODIC>	1076	=item C<EV_PERIODIC>
1037		1077
…		…
1055		1095
1056	=item C<EV_PREPARE>	1096	=item C<EV_PREPARE>
1057		1097
1058	=item C<EV_CHECK>	1098	=item C<EV_CHECK>
1059		1099
1060	All C<ev_prepare> watchers are invoked just I<before> C<ev_loop> starts	1100	All C<ev_prepare> watchers are invoked just I<before> C<ev_run> starts
1061	to gather new events, and all C<ev_check> watchers are invoked just after	1101	to gather new events, and all C<ev_check> watchers are invoked just after
1062	C<ev_loop> has gathered them, but before it invokes any callbacks for any	1102	C<ev_run> has gathered them, but before it invokes any callbacks for any
1063	received events. Callbacks of both watcher types can start and stop as	1103	received events. Callbacks of both watcher types can start and stop as
1064	many watchers as they want, and all of them will be taken into account	1104	many watchers as they want, and all of them will be taken into account
1065	(for example, a C<ev_prepare> watcher might start an idle watcher to keep	1105	(for example, a C<ev_prepare> watcher might start an idle watcher to keep
1066	C<ev_loop> from blocking).	1106	C<ev_run> from blocking).
1067		1107
1068	=item C<EV_EMBED>	1108	=item C<EV_EMBED>
1069		1109
1070	The embedded event loop specified in the C<ev_embed> watcher needs attention.	1110	The embedded event loop specified in the C<ev_embed> watcher needs attention.
1071		1111
1072	=item C<EV_FORK>	1112	=item C<EV_FORK>
1073		1113
1074	The event loop has been resumed in the child process after fork (see	1114	The event loop has been resumed in the child process after fork (see
1075	C<ev_fork>).	1115	C<ev_fork>).
		1116
		1117	=item C<EV_CLEANUP>
		1118
		1119	The event loop is about to be destroyed (see C<ev_cleanup>).
1076		1120
1077	=item C<EV_ASYNC>	1121	=item C<EV_ASYNC>
1078		1122
1079	The given async watcher has been asynchronously notified (see C<ev_async>).	1123	The given async watcher has been asynchronously notified (see C<ev_async>).
1080		1124
…		…
1099	example it might indicate that a fd is readable or writable, and if your	1143	example it might indicate that a fd is readable or writable, and if your
1100	callbacks is well-written it can just attempt the operation and cope with	1144	callbacks is well-written it can just attempt the operation and cope with
1101	the error from read() or write(). This will not work in multi-threaded	1145	the error from read() or write(). This will not work in multi-threaded
1102	programs, though, as the fd could already be closed and reused for another	1146	programs, though, as the fd could already be closed and reused for another
1103	thing, so beware.	1147	thing, so beware.
		1148
		1149	=back
		1150
		1151	=head2 WATCHER STATES
		1152
		1153	There are various watcher states mentioned throughout this manual -
		1154	active, pending and so on. In this section these states and the rules to
		1155	transition between them will be described in more detail - and while these
		1156	rules might look complicated, they usually do "the right thing".
		1157
		1158	=over 4
		1159
		1160	=item initialiased
		1161
		1162	Before a watcher can be registered with the event looop it has to be
		1163	initialised. This can be done with a call to C<ev_TYPE_init>, or calls to
		1164	C<ev_init> followed by the watcher-specific C<ev_TYPE_set> function.
		1165
		1166	In this state it is simply some block of memory that is suitable for use
		1167	in an event loop. It can be moved around, freed, reused etc. at will.
		1168
		1169	=item started/running/active
		1170
		1171	Once a watcher has been started with a call to C<ev_TYPE_start> it becomes
		1172	property of the event loop, and is actively waiting for events. While in
		1173	this state it cannot be accessed (except in a few documented ways), moved,
		1174	freed or anything else - the only legal thing is to keep a pointer to it,
		1175	and call libev functions on it that are documented to work on active watchers.
		1176
		1177	=item pending
		1178
		1179	If a watcher is active and libev determines that an event it is interested
		1180	in has occurred (such as a timer expiring), it will become pending. It will
		1181	stay in this pending state until either it is stopped or its callback is
		1182	about to be invoked, so it is not normally pending inside the watcher
		1183	callback.
		1184
		1185	The watcher might or might not be active while it is pending (for example,
		1186	an expired non-repeating timer can be pending but no longer active). If it
		1187	is stopped, it can be freely accessed (e.g. by calling C<ev_TYPE_set>),
		1188	but it is still property of the event loop at this time, so cannot be
		1189	moved, freed or reused. And if it is active the rules described in the
		1190	previous item still apply.
		1191
		1192	It is also possible to feed an event on a watcher that is not active (e.g.
		1193	via C<ev_feed_event>), in which case it becomes pending without being
		1194	active.
		1195
		1196	=item stopped
		1197
		1198	A watcher can be stopped implicitly by libev (in which case it might still
		1199	be pending), or explicitly by calling its C<ev_TYPE_stop> function. The
		1200	latter will clear any pending state the watcher might be in, regardless
		1201	of whether it was active or not, so stopping a watcher explicitly before
		1202	freeing it is often a good idea.
		1203
		1204	While stopped (and not pending) the watcher is essentially in the
		1205	initialised state, that is it can be reused, moved, modified in any way
		1206	you wish.
1104		1207
1105	=back	1208	=back
1106		1209
1107	=head2 GENERIC WATCHER FUNCTIONS	1210	=head2 GENERIC WATCHER FUNCTIONS
1108		1211
…		…
1370		1473
1371	For example, to emulate how many other event libraries handle priorities,	1474	For example, to emulate how many other event libraries handle priorities,
1372	you can associate an C<ev_idle> watcher to each such watcher, and in	1475	you can associate an C<ev_idle> watcher to each such watcher, and in
1373	the normal watcher callback, you just start the idle watcher. The real	1476	the normal watcher callback, you just start the idle watcher. The real
1374	processing is done in the idle watcher callback. This causes libev to	1477	processing is done in the idle watcher callback. This causes libev to
1375	continously poll and process kernel event data for the watcher, but when	1478	continuously poll and process kernel event data for the watcher, but when
1376	the lock-out case is known to be rare (which in turn is rare :), this is	1479	the lock-out case is known to be rare (which in turn is rare :), this is
1377	workable.	1480	workable.
1378		1481
1379	Usually, however, the lock-out model implemented that way will perform	1482	Usually, however, the lock-out model implemented that way will perform
1380	miserably under the type of load it was designed to handle. In that case,	1483	miserably under the type of load it was designed to handle. In that case,
…		…
1394	{	1497	{
1395	// stop the I/O watcher, we received the event, but	1498	// stop the I/O watcher, we received the event, but
1396	// are not yet ready to handle it.	1499	// are not yet ready to handle it.
1397	ev_io_stop (EV_A_ w);	1500	ev_io_stop (EV_A_ w);
1398		1501
1399	// start the idle watcher to ahndle the actual event.	1502	// start the idle watcher to handle the actual event.
1400	// it will not be executed as long as other watchers	1503	// it will not be executed as long as other watchers
1401	// with the default priority are receiving events.	1504	// with the default priority are receiving events.
1402	ev_idle_start (EV_A_ &idle);	1505	ev_idle_start (EV_A_ &idle);
1403	}	1506	}
1404		1507
…		…
1458		1561
1459	If you cannot use non-blocking mode, then force the use of a	1562	If you cannot use non-blocking mode, then force the use of a
1460	known-to-be-good backend (at the time of this writing, this includes only	1563	known-to-be-good backend (at the time of this writing, this includes only
1461	C<EVBACKEND_SELECT> and C<EVBACKEND_POLL>). The same applies to file	1564	C<EVBACKEND_SELECT> and C<EVBACKEND_POLL>). The same applies to file
1462	descriptors for which non-blocking operation makes no sense (such as	1565	descriptors for which non-blocking operation makes no sense (such as
1463	files) - libev doesn't guarentee any specific behaviour in that case.	1566	files) - libev doesn't guarantee any specific behaviour in that case.
1464		1567
1465	Another thing you have to watch out for is that it is quite easy to	1568	Another thing you have to watch out for is that it is quite easy to
1466	receive "spurious" readiness notifications, that is your callback might	1569	receive "spurious" readiness notifications, that is your callback might
1467	be called with C<EV_READ> but a subsequent C<read>(2) will actually block	1570	be called with C<EV_READ> but a subsequent C<read>(2) will actually block
1468	because there is no data. Not only are some backends known to create a	1571	because there is no data. Not only are some backends known to create a
…		…
1533		1636
1534	So when you encounter spurious, unexplained daemon exits, make sure you	1637	So when you encounter spurious, unexplained daemon exits, make sure you
1535	ignore SIGPIPE (and maybe make sure you log the exit status of your daemon	1638	ignore SIGPIPE (and maybe make sure you log the exit status of your daemon
1536	somewhere, as that would have given you a big clue).	1639	somewhere, as that would have given you a big clue).
1537		1640
		1641	=head3 The special problem of accept()ing when you can't
		1642
		1643	Many implementations of the POSIX C<accept> function (for example,
		1644	found in post-2004 Linux) have the peculiar behaviour of not removing a
		1645	connection from the pending queue in all error cases.
		1646
		1647	For example, larger servers often run out of file descriptors (because
		1648	of resource limits), causing C<accept> to fail with C<ENFILE> but not
		1649	rejecting the connection, leading to libev signalling readiness on
		1650	the next iteration again (the connection still exists after all), and
		1651	typically causing the program to loop at 100% CPU usage.
		1652
		1653	Unfortunately, the set of errors that cause this issue differs between
		1654	operating systems, there is usually little the app can do to remedy the
		1655	situation, and no known thread-safe method of removing the connection to
		1656	cope with overload is known (to me).
		1657
		1658	One of the easiest ways to handle this situation is to just ignore it
		1659	- when the program encounters an overload, it will just loop until the
		1660	situation is over. While this is a form of busy waiting, no OS offers an
		1661	event-based way to handle this situation, so it's the best one can do.
		1662
		1663	A better way to handle the situation is to log any errors other than
		1664	C<EAGAIN> and C<EWOULDBLOCK>, making sure not to flood the log with such
		1665	messages, and continue as usual, which at least gives the user an idea of
		1666	what could be wrong ("raise the ulimit!"). For extra points one could stop
		1667	the C<ev_io> watcher on the listening fd "for a while", which reduces CPU
		1668	usage.
		1669
		1670	If your program is single-threaded, then you could also keep a dummy file
		1671	descriptor for overload situations (e.g. by opening F</dev/null>), and
		1672	when you run into C<ENFILE> or C<EMFILE>, close it, run C<accept>,
		1673	close that fd, and create a new dummy fd. This will gracefully refuse
		1674	clients under typical overload conditions.
		1675
		1676	The last way to handle it is to simply log the error and C<exit>, as
		1677	is often done with C<malloc> failures, but this results in an easy
		1678	opportunity for a DoS attack.
1538		1679
1539	=head3 Watcher-Specific Functions	1680	=head3 Watcher-Specific Functions
1540		1681
1541	=over 4	1682	=over 4
1542		1683
…		…
1574	...	1715	...
1575	struct ev_loop *loop = ev_default_init (0);	1716	struct ev_loop *loop = ev_default_init (0);
1576	ev_io stdin_readable;	1717	ev_io stdin_readable;
1577	ev_io_init (&stdin_readable, stdin_readable_cb, STDIN_FILENO, EV_READ);	1718	ev_io_init (&stdin_readable, stdin_readable_cb, STDIN_FILENO, EV_READ);
1578	ev_io_start (loop, &stdin_readable);	1719	ev_io_start (loop, &stdin_readable);
1579	ev_loop (loop, 0);	1720	ev_run (loop, 0);
1580		1721
1581		1722
1582	=head2 C<ev_timer> - relative and optionally repeating timeouts	1723	=head2 C<ev_timer> - relative and optionally repeating timeouts
1583		1724
1584	Timer watchers are simple relative timers that generate an event after a	1725	Timer watchers are simple relative timers that generate an event after a
…		…
1593	The callback is guaranteed to be invoked only I<after> its timeout has	1734	The callback is guaranteed to be invoked only I<after> its timeout has
1594	passed (not I<at>, so on systems with very low-resolution clocks this	1735	passed (not I<at>, so on systems with very low-resolution clocks this
1595	might introduce a small delay). If multiple timers become ready during the	1736	might introduce a small delay). If multiple timers become ready during the
1596	same loop iteration then the ones with earlier time-out values are invoked	1737	same loop iteration then the ones with earlier time-out values are invoked
1597	before ones of the same priority with later time-out values (but this is	1738	before ones of the same priority with later time-out values (but this is
1598	no longer true when a callback calls C<ev_loop> recursively).	1739	no longer true when a callback calls C<ev_run> recursively).
1599		1740
1600	=head3 Be smart about timeouts	1741	=head3 Be smart about timeouts
1601		1742
1602	Many real-world problems involve some kind of timeout, usually for error	1743	Many real-world problems involve some kind of timeout, usually for error
1603	recovery. A typical example is an HTTP request - if the other side hangs,	1744	recovery. A typical example is an HTTP request - if the other side hangs,
…		…
1689	ev_tstamp timeout = last_activity + 60.;	1830	ev_tstamp timeout = last_activity + 60.;
1690		1831
1691	// if last_activity + 60. is older than now, we did time out	1832	// if last_activity + 60. is older than now, we did time out
1692	if (timeout < now)	1833	if (timeout < now)
1693	{	1834	{
1694	// timeout occured, take action	1835	// timeout occurred, take action
1695	}	1836	}
1696	else	1837	else
1697	{	1838	{
1698	// callback was invoked, but there was some activity, re-arm	1839	// callback was invoked, but there was some activity, re-arm
1699	// the watcher to fire in last_activity + 60, which is	1840	// the watcher to fire in last_activity + 60, which is
…		…
1721	to the current time (meaning we just have some activity :), then call the	1862	to the current time (meaning we just have some activity :), then call the
1722	callback, which will "do the right thing" and start the timer:	1863	callback, which will "do the right thing" and start the timer:
1723		1864
1724	ev_init (timer, callback);	1865	ev_init (timer, callback);
1725	last_activity = ev_now (loop);	1866	last_activity = ev_now (loop);
1726	callback (loop, timer, EV_TIMEOUT);	1867	callback (loop, timer, EV_TIMER);
1727		1868
1728	And when there is some activity, simply store the current time in	1869	And when there is some activity, simply store the current time in
1729	C<last_activity>, no libev calls at all:	1870	C<last_activity>, no libev calls at all:
1730		1871
1731	last_actiivty = ev_now (loop);	1872	last_activity = ev_now (loop);
1732		1873
1733	This technique is slightly more complex, but in most cases where the	1874	This technique is slightly more complex, but in most cases where the
1734	time-out is unlikely to be triggered, much more efficient.	1875	time-out is unlikely to be triggered, much more efficient.
1735		1876
1736	Changing the timeout is trivial as well (if it isn't hard-coded in the	1877	Changing the timeout is trivial as well (if it isn't hard-coded in the
…		…
1774		1915
1775	=head3 The special problem of time updates	1916	=head3 The special problem of time updates
1776		1917
1777	Establishing the current time is a costly operation (it usually takes at	1918	Establishing the current time is a costly operation (it usually takes at
1778	least two system calls): EV therefore updates its idea of the current	1919	least two system calls): EV therefore updates its idea of the current
1779	time only before and after C<ev_loop> collects new events, which causes a	1920	time only before and after C<ev_run> collects new events, which causes a
1780	growing difference between C<ev_now ()> and C<ev_time ()> when handling	1921	growing difference between C<ev_now ()> and C<ev_time ()> when handling
1781	lots of events in one iteration.	1922	lots of events in one iteration.
1782		1923
1783	The relative timeouts are calculated relative to the C<ev_now ()>	1924	The relative timeouts are calculated relative to the C<ev_now ()>
1784	time. This is usually the right thing as this timestamp refers to the time	1925	time. This is usually the right thing as this timestamp refers to the time
…		…
1862	Returns the remaining time until a timer fires. If the timer is active,	2003	Returns the remaining time until a timer fires. If the timer is active,
1863	then this time is relative to the current event loop time, otherwise it's	2004	then this time is relative to the current event loop time, otherwise it's
1864	the timeout value currently configured.	2005	the timeout value currently configured.
1865		2006
1866	That is, after an C<ev_timer_set (w, 5, 7)>, C<ev_timer_remaining> returns	2007	That is, after an C<ev_timer_set (w, 5, 7)>, C<ev_timer_remaining> returns
1867	C<5>. When the timer is started and one second passes, C<ev_timer_remain>	2008	C<5>. When the timer is started and one second passes, C<ev_timer_remaining>
1868	will return C<4>. When the timer expires and is restarted, it will return	2009	will return C<4>. When the timer expires and is restarted, it will return
1869	roughly C<7> (likely slightly less as callback invocation takes some time,	2010	roughly C<7> (likely slightly less as callback invocation takes some time,
1870	too), and so on.	2011	too), and so on.
1871		2012
1872	=item ev_tstamp repeat [read-write]	2013	=item ev_tstamp repeat [read-write]
…		…
1901	}	2042	}
1902		2043
1903	ev_timer mytimer;	2044	ev_timer mytimer;
1904	ev_timer_init (&mytimer, timeout_cb, 0., 10.); /* note, only repeat used */	2045	ev_timer_init (&mytimer, timeout_cb, 0., 10.); /* note, only repeat used */
1905	ev_timer_again (&mytimer); /* start timer */	2046	ev_timer_again (&mytimer); /* start timer */
1906	ev_loop (loop, 0);	2047	ev_run (loop, 0);
1907		2048
1908	// and in some piece of code that gets executed on any "activity":	2049	// and in some piece of code that gets executed on any "activity":
1909	// reset the timeout to start ticking again at 10 seconds	2050	// reset the timeout to start ticking again at 10 seconds
1910	ev_timer_again (&mytimer);	2051	ev_timer_again (&mytimer);
1911		2052
…		…
1937		2078
1938	As with timers, the callback is guaranteed to be invoked only when the	2079	As with timers, the callback is guaranteed to be invoked only when the
1939	point in time where it is supposed to trigger has passed. If multiple	2080	point in time where it is supposed to trigger has passed. If multiple
1940	timers become ready during the same loop iteration then the ones with	2081	timers become ready during the same loop iteration then the ones with
1941	earlier time-out values are invoked before ones with later time-out values	2082	earlier time-out values are invoked before ones with later time-out values
1942	(but this is no longer true when a callback calls C<ev_loop> recursively).	2083	(but this is no longer true when a callback calls C<ev_run> recursively).
1943		2084
1944	=head3 Watcher-Specific Functions and Data Members	2085	=head3 Watcher-Specific Functions and Data Members
1945		2086
1946	=over 4	2087	=over 4
1947		2088
…		…
2075	Example: Call a callback every hour, or, more precisely, whenever the	2216	Example: Call a callback every hour, or, more precisely, whenever the
2076	system time is divisible by 3600. The callback invocation times have	2217	system time is divisible by 3600. The callback invocation times have
2077	potentially a lot of jitter, but good long-term stability.	2218	potentially a lot of jitter, but good long-term stability.
2078		2219
2079	static void	2220	static void
2080	clock_cb (struct ev_loop *loop, ev_io *w, int revents)	2221	clock_cb (struct ev_loop *loop, ev_periodic *w, int revents)
2081	{	2222	{
2082	... its now a full hour (UTC, or TAI or whatever your clock follows)	2223	... its now a full hour (UTC, or TAI or whatever your clock follows)
2083	}	2224	}
2084		2225
2085	ev_periodic hourly_tick;	2226	ev_periodic hourly_tick;
…		…
2132	C<SA_RESTART> (or equivalent) behaviour enabled, so system calls should	2273	C<SA_RESTART> (or equivalent) behaviour enabled, so system calls should
2133	not be unduly interrupted. If you have a problem with system calls getting	2274	not be unduly interrupted. If you have a problem with system calls getting
2134	interrupted by signals you can block all signals in an C<ev_check> watcher	2275	interrupted by signals you can block all signals in an C<ev_check> watcher
2135	and unblock them in an C<ev_prepare> watcher.	2276	and unblock them in an C<ev_prepare> watcher.
2136		2277
2137	=head3 The special problem of inheritance over execve	2278	=head3 The special problem of inheritance over fork/execve/pthread_create
2138		2279
2139	Both the signal mask (C<sigprocmask>) and the signal disposition	2280	Both the signal mask (C<sigprocmask>) and the signal disposition
2140	(C<sigaction>) are unspecified after starting a signal watcher (and after	2281	(C<sigaction>) are unspecified after starting a signal watcher (and after
2141	stopping it again), that is, libev might or might not block the signal,	2282	stopping it again), that is, libev might or might not block the signal,
2142	and might or might not set or restore the installed signal handler.	2283	and might or might not set or restore the installed signal handler.
…		…
2152		2293
2153	The simplest way to ensure that the signal mask is reset in the child is	2294	The simplest way to ensure that the signal mask is reset in the child is
2154	to install a fork handler with C<pthread_atfork> that resets it. That will	2295	to install a fork handler with C<pthread_atfork> that resets it. That will
2155	catch fork calls done by libraries (such as the libc) as well.	2296	catch fork calls done by libraries (such as the libc) as well.
2156		2297
2157	In current versions of libev, you can also ensure that the signal mask is	2298	In current versions of libev, the signal will not be blocked indefinitely
2158	not blocking any signals (except temporarily, so thread users watch out)	2299	unless you use the C<signalfd> API (C<EV_SIGNALFD>). While this reduces
2159	by specifying the C<EVFLAG_NOSIGFD> when creating the event loop. This	2300	the window of opportunity for problems, it will not go away, as libev
2160	is not guaranteed for future versions, however.	2301	I<has> to modify the signal mask, at least temporarily.
		2302
		2303	So I can't stress this enough: I<If you do not reset your signal mask when
		2304	you expect it to be empty, you have a race condition in your code>. This
		2305	is not a libev-specific thing, this is true for most event libraries.
2161		2306
2162	=head3 Watcher-Specific Functions and Data Members	2307	=head3 Watcher-Specific Functions and Data Members
2163		2308
2164	=over 4	2309	=over 4
2165		2310
…		…
2181	Example: Try to exit cleanly on SIGINT.	2326	Example: Try to exit cleanly on SIGINT.
2182		2327
2183	static void	2328	static void
2184	sigint_cb (struct ev_loop *loop, ev_signal *w, int revents)	2329	sigint_cb (struct ev_loop *loop, ev_signal *w, int revents)
2185	{	2330	{
2186	ev_unloop (loop, EVUNLOOP_ALL);	2331	ev_break (loop, EVBREAK_ALL);
2187	}	2332	}
2188		2333
2189	ev_signal signal_watcher;	2334	ev_signal signal_watcher;
2190	ev_signal_init (&signal_watcher, sigint_cb, SIGINT);	2335	ev_signal_init (&signal_watcher, sigint_cb, SIGINT);
2191	ev_signal_start (loop, &signal_watcher);	2336	ev_signal_start (loop, &signal_watcher);
…		…
2577		2722
2578	Prepare and check watchers are usually (but not always) used in pairs:	2723	Prepare and check watchers are usually (but not always) used in pairs:
2579	prepare watchers get invoked before the process blocks and check watchers	2724	prepare watchers get invoked before the process blocks and check watchers
2580	afterwards.	2725	afterwards.
2581		2726
2582	You I<must not> call C<ev_loop> or similar functions that enter	2727	You I<must not> call C<ev_run> or similar functions that enter
2583	the current event loop from either C<ev_prepare> or C<ev_check>	2728	the current event loop from either C<ev_prepare> or C<ev_check>
2584	watchers. Other loops than the current one are fine, however. The	2729	watchers. Other loops than the current one are fine, however. The
2585	rationale behind this is that you do not need to check for recursion in	2730	rationale behind this is that you do not need to check for recursion in
2586	those watchers, i.e. the sequence will always be C<ev_prepare>, blocking,	2731	those watchers, i.e. the sequence will always be C<ev_prepare>, blocking,
2587	C<ev_check> so if you have one watcher of each kind they will always be	2732	C<ev_check> so if you have one watcher of each kind they will always be
…		…
2755		2900
2756	if (timeout >= 0)	2901	if (timeout >= 0)
2757	// create/start timer	2902	// create/start timer
2758		2903
2759	// poll	2904	// poll
2760	ev_loop (EV_A_ 0);	2905	ev_run (EV_A_ 0);
2761		2906
2762	// stop timer again	2907	// stop timer again
2763	if (timeout >= 0)	2908	if (timeout >= 0)
2764	ev_timer_stop (EV_A_ &to);	2909	ev_timer_stop (EV_A_ &to);
2765		2910
…		…
2843	if you do not want that, you need to temporarily stop the embed watcher).	2988	if you do not want that, you need to temporarily stop the embed watcher).
2844		2989
2845	=item ev_embed_sweep (loop, ev_embed *)	2990	=item ev_embed_sweep (loop, ev_embed *)
2846		2991
2847	Make a single, non-blocking sweep over the embedded loop. This works	2992	Make a single, non-blocking sweep over the embedded loop. This works
2848	similarly to C<ev_loop (embedded_loop, EVLOOP_NONBLOCK)>, but in the most	2993	similarly to C<ev_run (embedded_loop, EVRUN_NOWAIT)>, but in the most
2849	appropriate way for embedded loops.	2994	appropriate way for embedded loops.
2850		2995
2851	=item struct ev_loop *other [read-only]	2996	=item struct ev_loop *other [read-only]
2852		2997
2853	The embedded event loop.	2998	The embedded event loop.
…		…
2913	C<ev_default_fork> cheats and calls it in the wrong process, the fork	3058	C<ev_default_fork> cheats and calls it in the wrong process, the fork
2914	handlers will be invoked, too, of course.	3059	handlers will be invoked, too, of course.
2915		3060
2916	=head3 The special problem of life after fork - how is it possible?	3061	=head3 The special problem of life after fork - how is it possible?
2917		3062
2918	Most uses of C<fork()> consist of forking, then some simple calls to ste	3063	Most uses of C<fork()> consist of forking, then some simple calls to set
2919	up/change the process environment, followed by a call to C<exec()>. This	3064	up/change the process environment, followed by a call to C<exec()>. This
2920	sequence should be handled by libev without any problems.	3065	sequence should be handled by libev without any problems.
2921		3066
2922	This changes when the application actually wants to do event handling	3067	This changes when the application actually wants to do event handling
2923	in the child, or both parent in child, in effect "continuing" after the	3068	in the child, or both parent in child, in effect "continuing" after the
…		…
2939	disadvantage of having to use multiple event loops (which do not support	3084	disadvantage of having to use multiple event loops (which do not support
2940	signal watchers).	3085	signal watchers).
2941		3086
2942	When this is not possible, or you want to use the default loop for	3087	When this is not possible, or you want to use the default loop for
2943	other reasons, then in the process that wants to start "fresh", call	3088	other reasons, then in the process that wants to start "fresh", call
2944	C<ev_default_destroy ()> followed by C<ev_default_loop (...)>. Destroying	3089	C<ev_loop_destroy (EV_DEFAULT)> followed by C<ev_default_loop (...)>.
2945	the default loop will "orphan" (not stop) all registered watchers, so you	3090	Destroying the default loop will "orphan" (not stop) all registered
2946	have to be careful not to execute code that modifies those watchers. Note	3091	watchers, so you have to be careful not to execute code that modifies
2947	also that in that case, you have to re-register any signal watchers.	3092	those watchers. Note also that in that case, you have to re-register any
		3093	signal watchers.
2948		3094
2949	=head3 Watcher-Specific Functions and Data Members	3095	=head3 Watcher-Specific Functions and Data Members
2950		3096
2951	=over 4	3097	=over 4
2952		3098
2953	=item ev_fork_init (ev_signal *, callback)	3099	=item ev_fork_init (ev_fork *, callback)
2954		3100
2955	Initialises and configures the fork watcher - it has no parameters of any	3101	Initialises and configures the fork watcher - it has no parameters of any
2956	kind. There is a C<ev_fork_set> macro, but using it is utterly pointless,	3102	kind. There is a C<ev_fork_set> macro, but using it is utterly pointless,
2957	believe me.	3103	really.
2958		3104
2959	=back	3105	=back
2960		3106
2961		3107
		3108	=head2 C<ev_cleanup> - even the best things end
		3109
		3110	Cleanup watchers are called just before the event loop is being destroyed
		3111	by a call to C<ev_loop_destroy>.
		3112
		3113	While there is no guarantee that the event loop gets destroyed, cleanup
		3114	watchers provide a convenient method to install cleanup hooks for your
		3115	program, worker threads and so on - you just to make sure to destroy the
		3116	loop when you want them to be invoked.
		3117
		3118	Cleanup watchers are invoked in the same way as any other watcher. Unlike
		3119	all other watchers, they do not keep a reference to the event loop (which
		3120	makes a lot of sense if you think about it). Like all other watchers, you
		3121	can call libev functions in the callback, except C<ev_cleanup_start>.
		3122
		3123	=head3 Watcher-Specific Functions and Data Members
		3124
		3125	=over 4
		3126
		3127	=item ev_cleanup_init (ev_cleanup *, callback)
		3128
		3129	Initialises and configures the cleanup watcher - it has no parameters of
		3130	any kind. There is a C<ev_cleanup_set> macro, but using it is utterly
		3131	pointless, I assure you.
		3132
		3133	=back
		3134
		3135	Example: Register an atexit handler to destroy the default loop, so any
		3136	cleanup functions are called.
		3137
		3138	static void
		3139	program_exits (void)
		3140	{
		3141	ev_loop_destroy (EV_DEFAULT_UC);
		3142	}
		3143
		3144	...
		3145	atexit (program_exits);
		3146
		3147
2962	=head2 C<ev_async> - how to wake up another event loop	3148	=head2 C<ev_async> - how to wake up an event loop
2963		3149
2964	In general, you cannot use an C<ev_loop> from multiple threads or other	3150	In general, you cannot use an C<ev_run> from multiple threads or other
2965	asynchronous sources such as signal handlers (as opposed to multiple event	3151	asynchronous sources such as signal handlers (as opposed to multiple event
2966	loops - those are of course safe to use in different threads).	3152	loops - those are of course safe to use in different threads).
2967		3153
2968	Sometimes, however, you need to wake up another event loop you do not	3154	Sometimes, however, you need to wake up an event loop you do not control,
2969	control, for example because it belongs to another thread. This is what	3155	for example because it belongs to another thread. This is what C<ev_async>
2970	C<ev_async> watchers do: as long as the C<ev_async> watcher is active, you	3156	watchers do: as long as the C<ev_async> watcher is active, you can signal
2971	can signal it by calling C<ev_async_send>, which is thread- and signal	3157	it by calling C<ev_async_send>, which is thread- and signal safe.
2972	safe.
2973		3158
2974	This functionality is very similar to C<ev_signal> watchers, as signals,	3159	This functionality is very similar to C<ev_signal> watchers, as signals,
2975	too, are asynchronous in nature, and signals, too, will be compressed	3160	too, are asynchronous in nature, and signals, too, will be compressed
2976	(i.e. the number of callback invocations may be less than the number of	3161	(i.e. the number of callback invocations may be less than the number of
2977	C<ev_async_sent> calls).	3162	C<ev_async_sent> calls).
…		…
3132		3317
3133	If C<timeout> is less than 0, then no timeout watcher will be	3318	If C<timeout> is less than 0, then no timeout watcher will be
3134	started. Otherwise an C<ev_timer> watcher with after = C<timeout> (and	3319	started. Otherwise an C<ev_timer> watcher with after = C<timeout> (and
3135	repeat = 0) will be started. C<0> is a valid timeout.	3320	repeat = 0) will be started. C<0> is a valid timeout.
3136		3321
3137	The callback has the type C<void (*cb)(int revents, void *arg)> and gets	3322	The callback has the type C<void (*cb)(int revents, void *arg)> and is
3138	passed an C<revents> set like normal event callbacks (a combination of	3323	passed an C<revents> set like normal event callbacks (a combination of
3139	C<EV_ERROR>, C<EV_READ>, C<EV_WRITE> or C<EV_TIMEOUT>) and the C<arg>	3324	C<EV_ERROR>, C<EV_READ>, C<EV_WRITE> or C<EV_TIMER>) and the C<arg>
3140	value passed to C<ev_once>. Note that it is possible to receive I<both>	3325	value passed to C<ev_once>. Note that it is possible to receive I<both>
3141	a timeout and an io event at the same time - you probably should give io	3326	a timeout and an io event at the same time - you probably should give io
3142	events precedence.	3327	events precedence.
3143		3328
3144	Example: wait up to ten seconds for data to appear on STDIN_FILENO.	3329	Example: wait up to ten seconds for data to appear on STDIN_FILENO.
3145		3330
3146	static void stdin_ready (int revents, void *arg)	3331	static void stdin_ready (int revents, void *arg)
3147	{	3332	{
3148	if (revents & EV_READ)	3333	if (revents & EV_READ)
3149	/* stdin might have data for us, joy! */;	3334	/* stdin might have data for us, joy! */;
3150	else if (revents & EV_TIMEOUT)	3335	else if (revents & EV_TIMER)
3151	/* doh, nothing entered */;	3336	/* doh, nothing entered */;
3152	}	3337	}
3153		3338
3154	ev_once (STDIN_FILENO, EV_READ, 10., stdin_ready, 0);	3339	ev_once (STDIN_FILENO, EV_READ, 10., stdin_ready, 0);
3155		3340
…		…
3289	myclass obj;	3474	myclass obj;
3290	ev::io iow;	3475	ev::io iow;
3291	iow.set <myclass, &myclass::io_cb> (&obj);	3476	iow.set <myclass, &myclass::io_cb> (&obj);
3292		3477
3293	=item w->set (object *)	3478	=item w->set (object *)
3294
3295	This is an B<experimental> feature that might go away in a future version.
3296		3479
3297	This is a variation of a method callback - leaving out the method to call	3480	This is a variation of a method callback - leaving out the method to call
3298	will default the method to C<operator ()>, which makes it possible to use	3481	will default the method to C<operator ()>, which makes it possible to use
3299	functor objects without having to manually specify the C<operator ()> all	3482	functor objects without having to manually specify the C<operator ()> all
3300	the time. Incidentally, you can then also leave out the template argument	3483	the time. Incidentally, you can then also leave out the template argument
…		…
3340	Associates a different C<struct ev_loop> with this watcher. You can only	3523	Associates a different C<struct ev_loop> with this watcher. You can only
3341	do this when the watcher is inactive (and not pending either).	3524	do this when the watcher is inactive (and not pending either).
3342		3525
3343	=item w->set ([arguments])	3526	=item w->set ([arguments])
3344		3527
3345	Basically the same as C<ev_TYPE_set>, with the same arguments. Must be	3528	Basically the same as C<ev_TYPE_set>, with the same arguments. Either this
3346	called at least once. Unlike the C counterpart, an active watcher gets	3529	method or a suitable start method must be called at least once. Unlike the
3347	automatically stopped and restarted when reconfiguring it with this	3530	C counterpart, an active watcher gets automatically stopped and restarted
3348	method.	3531	when reconfiguring it with this method.
3349		3532
3350	=item w->start ()	3533	=item w->start ()
3351		3534
3352	Starts the watcher. Note that there is no C<loop> argument, as the	3535	Starts the watcher. Note that there is no C<loop> argument, as the
3353	constructor already stores the event loop.	3536	constructor already stores the event loop.
3354		3537
		3538	=item w->start ([arguments])
		3539
		3540	Instead of calling C<set> and C<start> methods separately, it is often
		3541	convenient to wrap them in one call. Uses the same type of arguments as
		3542	the configure C<set> method of the watcher.
		3543
3355	=item w->stop ()	3544	=item w->stop ()
3356		3545
3357	Stops the watcher if it is active. Again, no C<loop> argument.	3546	Stops the watcher if it is active. Again, no C<loop> argument.
3358		3547
3359	=item w->again () (C<ev::timer>, C<ev::periodic> only)	3548	=item w->again () (C<ev::timer>, C<ev::periodic> only)
…		…
3371		3560
3372	=back	3561	=back
3373		3562
3374	=back	3563	=back
3375		3564
3376	Example: Define a class with an IO and idle watcher, start one of them in	3565	Example: Define a class with two I/O and idle watchers, start the I/O
3377	the constructor.	3566	watchers in the constructor.
3378		3567
3379	class myclass	3568	class myclass
3380	{	3569	{
3381	ev::io io ; void io_cb (ev::io &w, int revents);	3570	ev::io io ; void io_cb (ev::io &w, int revents);
		3571	ev::io2 io2 ; void io2_cb (ev::io &w, int revents);
3382	ev::idle idle; void idle_cb (ev::idle &w, int revents);	3572	ev::idle idle; void idle_cb (ev::idle &w, int revents);
3383		3573
3384	myclass (int fd)	3574	myclass (int fd)
3385	{	3575	{
3386	io .set <myclass, &myclass::io_cb > (this);	3576	io .set <myclass, &myclass::io_cb > (this);
		3577	io2 .set <myclass, &myclass::io2_cb > (this);
3387	idle.set <myclass, &myclass::idle_cb> (this);	3578	idle.set <myclass, &myclass::idle_cb> (this);
3388		3579
3389	io.start (fd, ev::READ);	3580	io.set (fd, ev::WRITE); // configure the watcher
		3581	io.start (); // start it whenever convenient
		3582
		3583	io2.start (fd, ev::READ); // set + start in one call
3390	}	3584	}
3391	};	3585	};
3392		3586
3393		3587
3394	=head1 OTHER LANGUAGE BINDINGS	3588	=head1 OTHER LANGUAGE BINDINGS
…		…
3442	Erkki Seppala has written Ocaml bindings for libev, to be found at	3636	Erkki Seppala has written Ocaml bindings for libev, to be found at
3443	L<http://modeemi.cs.tut.fi/~flux/software/ocaml-ev/>.	3637	L<http://modeemi.cs.tut.fi/~flux/software/ocaml-ev/>.
3444		3638
3445	=item Lua	3639	=item Lua
3446		3640
3447	Brian Maher has written a partial interface to libev	3641	Brian Maher has written a partial interface to libev for lua (at the
3448	for lua (only C<ev_io> and C<ev_timer>), to be found at	3642	time of this writing, only C<ev_io> and C<ev_timer>), to be found at
3449	L<http://github.com/brimworks/lua-ev>.	3643	L<http://github.com/brimworks/lua-ev>.
3450		3644
3451	=back	3645	=back
3452		3646
3453		3647
…		…
3468	loop argument"). The C<EV_A> form is used when this is the sole argument,	3662	loop argument"). The C<EV_A> form is used when this is the sole argument,
3469	C<EV_A_> is used when other arguments are following. Example:	3663	C<EV_A_> is used when other arguments are following. Example:
3470		3664
3471	ev_unref (EV_A);	3665	ev_unref (EV_A);
3472	ev_timer_add (EV_A_ watcher);	3666	ev_timer_add (EV_A_ watcher);
3473	ev_loop (EV_A_ 0);	3667	ev_run (EV_A_ 0);
3474		3668
3475	It assumes the variable C<loop> of type C<struct ev_loop *> is in scope,	3669	It assumes the variable C<loop> of type C<struct ev_loop *> is in scope,
3476	which is often provided by the following macro.	3670	which is often provided by the following macro.
3477		3671
3478	=item C<EV_P>, C<EV_P_>	3672	=item C<EV_P>, C<EV_P_>
…		…
3518	}	3712	}
3519		3713
3520	ev_check check;	3714	ev_check check;
3521	ev_check_init (&check, check_cb);	3715	ev_check_init (&check, check_cb);
3522	ev_check_start (EV_DEFAULT_ &check);	3716	ev_check_start (EV_DEFAULT_ &check);
3523	ev_loop (EV_DEFAULT_ 0);	3717	ev_run (EV_DEFAULT_ 0);
3524		3718
3525	=head1 EMBEDDING	3719	=head1 EMBEDDING
3526		3720
3527	Libev can (and often is) directly embedded into host	3721	Libev can (and often is) directly embedded into host
3528	applications. Examples of applications that embed it include the Deliantra	3722	applications. Examples of applications that embed it include the Deliantra
…		…
3608	libev.m4	3802	libev.m4
3609		3803
3610	=head2 PREPROCESSOR SYMBOLS/MACROS	3804	=head2 PREPROCESSOR SYMBOLS/MACROS
3611		3805
3612	Libev can be configured via a variety of preprocessor symbols you have to	3806	Libev can be configured via a variety of preprocessor symbols you have to
3613	define before including any of its files. The default in the absence of	3807	define before including (or compiling) any of its files. The default in
3614	autoconf is documented for every option.	3808	the absence of autoconf is documented for every option.
		3809
		3810	Symbols marked with "(h)" do not change the ABI, and can have different
		3811	values when compiling libev vs. including F<ev.h>, so it is permissible
		3812	to redefine them before including F<ev.h> without breaking compatibility
		3813	to a compiled library. All other symbols change the ABI, which means all
		3814	users of libev and the libev code itself must be compiled with compatible
		3815	settings.
3615		3816
3616	=over 4	3817	=over 4
3617		3818
		3819	=item EV_COMPAT3 (h)
		3820
		3821	Backwards compatibility is a major concern for libev. This is why this
		3822	release of libev comes with wrappers for the functions and symbols that
		3823	have been renamed between libev version 3 and 4.
		3824
		3825	You can disable these wrappers (to test compatibility with future
		3826	versions) by defining C<EV_COMPAT3> to C<0> when compiling your
		3827	sources. This has the additional advantage that you can drop the C<struct>
		3828	from C<struct ev_loop> declarations, as libev will provide an C<ev_loop>
		3829	typedef in that case.
		3830
		3831	In some future version, the default for C<EV_COMPAT3> will become C<0>,
		3832	and in some even more future version the compatibility code will be
		3833	removed completely.
		3834
3618	=item EV_STANDALONE	3835	=item EV_STANDALONE (h)
3619		3836
3620	Must always be C<1> if you do not use autoconf configuration, which	3837	Must always be C<1> if you do not use autoconf configuration, which
3621	keeps libev from including F<config.h>, and it also defines dummy	3838	keeps libev from including F<config.h>, and it also defines dummy
3622	implementations for some libevent functions (such as logging, which is not	3839	implementations for some libevent functions (such as logging, which is not
3623	supported). It will also not define any of the structs usually found in	3840	supported). It will also not define any of the structs usually found in
…		…
3773	as well as for signal and thread safety in C<ev_async> watchers.	3990	as well as for signal and thread safety in C<ev_async> watchers.
3774		3991
3775	In the absence of this define, libev will use C<sig_atomic_t volatile>	3992	In the absence of this define, libev will use C<sig_atomic_t volatile>
3776	(from F<signal.h>), which is usually good enough on most platforms.	3993	(from F<signal.h>), which is usually good enough on most platforms.
3777		3994
3778	=item EV_H	3995	=item EV_H (h)
3779		3996
3780	The name of the F<ev.h> header file used to include it. The default if	3997	The name of the F<ev.h> header file used to include it. The default if
3781	undefined is C<"ev.h"> in F<event.h>, F<ev.c> and F<ev++.h>. This can be	3998	undefined is C<"ev.h"> in F<event.h>, F<ev.c> and F<ev++.h>. This can be
3782	used to virtually rename the F<ev.h> header file in case of conflicts.	3999	used to virtually rename the F<ev.h> header file in case of conflicts.
3783		4000
3784	=item EV_CONFIG_H	4001	=item EV_CONFIG_H (h)
3785		4002
3786	If C<EV_STANDALONE> isn't C<1>, this variable can be used to override	4003	If C<EV_STANDALONE> isn't C<1>, this variable can be used to override
3787	F<ev.c>'s idea of where to find the F<config.h> file, similarly to	4004	F<ev.c>'s idea of where to find the F<config.h> file, similarly to
3788	C<EV_H>, above.	4005	C<EV_H>, above.
3789		4006
3790	=item EV_EVENT_H	4007	=item EV_EVENT_H (h)
3791		4008
3792	Similarly to C<EV_H>, this macro can be used to override F<event.c>'s idea	4009	Similarly to C<EV_H>, this macro can be used to override F<event.c>'s idea
3793	of how the F<event.h> header can be found, the default is C<"event.h">.	4010	of how the F<event.h> header can be found, the default is C<"event.h">.
3794		4011
3795	=item EV_PROTOTYPES	4012	=item EV_PROTOTYPES (h)
3796		4013
3797	If defined to be C<0>, then F<ev.h> will not define any function	4014	If defined to be C<0>, then F<ev.h> will not define any function
3798	prototypes, but still define all the structs and other symbols. This is	4015	prototypes, but still define all the structs and other symbols. This is
3799	occasionally useful if you want to provide your own wrapper functions	4016	occasionally useful if you want to provide your own wrapper functions
3800	around libev functions.	4017	around libev functions.
…		…
3822	fine.	4039	fine.
3823		4040
3824	If your embedding application does not need any priorities, defining these	4041	If your embedding application does not need any priorities, defining these
3825	both to C<0> will save some memory and CPU.	4042	both to C<0> will save some memory and CPU.
3826		4043
3827	=item EV_PERIODIC_ENABLE	4044	=item EV_PERIODIC_ENABLE, EV_IDLE_ENABLE, EV_EMBED_ENABLE, EV_STAT_ENABLE,
		4045	EV_PREPARE_ENABLE, EV_CHECK_ENABLE, EV_FORK_ENABLE, EV_SIGNAL_ENABLE,
		4046	EV_ASYNC_ENABLE, EV_CHILD_ENABLE.
3828		4047
3829	If undefined or defined to be C<1>, then periodic timers are supported. If	4048	If undefined or defined to be C<1> (and the platform supports it), then
3830	defined to be C<0>, then they are not. Disabling them saves a few kB of	4049	the respective watcher type is supported. If defined to be C<0>, then it
3831	code.	4050	is not. Disabling watcher types mainly saves code size.
3832		4051
3833	=item EV_IDLE_ENABLE	4052	=item EV_FEATURES
3834
3835	If undefined or defined to be C<1>, then idle watchers are supported. If
3836	defined to be C<0>, then they are not. Disabling them saves a few kB of
3837	code.
3838
3839	=item EV_EMBED_ENABLE
3840
3841	If undefined or defined to be C<1>, then embed watchers are supported. If
3842	defined to be C<0>, then they are not. Embed watchers rely on most other
3843	watcher types, which therefore must not be disabled.
3844
3845	=item EV_STAT_ENABLE
3846
3847	If undefined or defined to be C<1>, then stat watchers are supported. If
3848	defined to be C<0>, then they are not.
3849
3850	=item EV_FORK_ENABLE
3851
3852	If undefined or defined to be C<1>, then fork watchers are supported. If
3853	defined to be C<0>, then they are not.
3854
3855	=item EV_ASYNC_ENABLE
3856
3857	If undefined or defined to be C<1>, then async watchers are supported. If
3858	defined to be C<0>, then they are not.
3859
3860	=item EV_MINIMAL
3861		4053
3862	If you need to shave off some kilobytes of code at the expense of some	4054	If you need to shave off some kilobytes of code at the expense of some
3863	speed (but with the full API), define this symbol to C<1>. Currently this	4055	speed (but with the full API), you can define this symbol to request
3864	is used to override some inlining decisions, saves roughly 30% code size	4056	certain subsets of functionality. The default is to enable all features
3865	on amd64. It also selects a much smaller 2-heap for timer management over	4057	that can be enabled on the platform.
3866	the default 4-heap.
3867		4058
3868	You can save even more by disabling watcher types you do not need	4059	A typical way to use this symbol is to define it to C<0> (or to a bitset
3869	and setting C<EV_MAXPRI> == C<EV_MINPRI>. Also, disabling C<assert>	4060	with some broad features you want) and then selectively re-enable
3870	(C<-DNDEBUG>) will usually reduce code size a lot.	4061	additional parts you want, for example if you want everything minimal,
		4062	but multiple event loop support, async and child watchers and the poll
		4063	backend, use this:
3871		4064
3872	Defining C<EV_MINIMAL> to C<2> will additionally reduce the core API to	4065	#define EV_FEATURES 0
3873	provide a bare-bones event library. See C<ev.h> for details on what parts	4066	#define EV_MULTIPLICITY 1
3874	of the API are still available, and do not complain if this subset changes	4067	#define EV_USE_POLL 1
3875	over time.	4068	#define EV_CHILD_ENABLE 1
		4069	#define EV_ASYNC_ENABLE 1
		4070
		4071	The actual value is a bitset, it can be a combination of the following
		4072	values:
		4073
		4074	=over 4
		4075
		4076	=item C<1> - faster/larger code
		4077
		4078	Use larger code to speed up some operations.
		4079
		4080	Currently this is used to override some inlining decisions (enlarging the
		4081	code size by roughly 30% on amd64).
		4082
		4083	When optimising for size, use of compiler flags such as C<-Os> with
		4084	gcc is recommended, as well as C<-DNDEBUG>, as libev contains a number of
		4085	assertions.
		4086
		4087	=item C<2> - faster/larger data structures
		4088
		4089	Replaces the small 2-heap for timer management by a faster 4-heap, larger
		4090	hash table sizes and so on. This will usually further increase code size
		4091	and can additionally have an effect on the size of data structures at
		4092	runtime.
		4093
		4094	=item C<4> - full API configuration
		4095
		4096	This enables priorities (sets C<EV_MAXPRI>=2 and C<EV_MINPRI>=-2), and
		4097	enables multiplicity (C<EV_MULTIPLICITY>=1).
		4098
		4099	=item C<8> - full API
		4100
		4101	This enables a lot of the "lesser used" API functions. See C<ev.h> for
		4102	details on which parts of the API are still available without this
		4103	feature, and do not complain if this subset changes over time.
		4104
		4105	=item C<16> - enable all optional watcher types
		4106
		4107	Enables all optional watcher types. If you want to selectively enable
		4108	only some watcher types other than I/O and timers (e.g. prepare,
		4109	embed, async, child...) you can enable them manually by defining
		4110	C<EV_watchertype_ENABLE> to C<1> instead.
		4111
		4112	=item C<32> - enable all backends
		4113
		4114	This enables all backends - without this feature, you need to enable at
		4115	least one backend manually (C<EV_USE_SELECT> is a good choice).
		4116
		4117	=item C<64> - enable OS-specific "helper" APIs
		4118
		4119	Enable inotify, eventfd, signalfd and similar OS-specific helper APIs by
		4120	default.
		4121
		4122	=back
		4123
		4124	Compiling with C<gcc -Os -DEV_STANDALONE -DEV_USE_EPOLL=1 -DEV_FEATURES=0>
		4125	reduces the compiled size of libev from 24.7Kb code/2.8Kb data to 6.5Kb
		4126	code/0.3Kb data on my GNU/Linux amd64 system, while still giving you I/O
		4127	watchers, timers and monotonic clock support.
		4128
		4129	With an intelligent-enough linker (gcc+binutils are intelligent enough
		4130	when you use C<-Wl,--gc-sections -ffunction-sections>) functions unused by
		4131	your program might be left out as well - a binary starting a timer and an
		4132	I/O watcher then might come out at only 5Kb.
		4133
		4134	=item EV_AVOID_STDIO
		4135
		4136	If this is set to C<1> at compiletime, then libev will avoid using stdio
		4137	functions (printf, scanf, perror etc.). This will increase the code size
		4138	somewhat, but if your program doesn't otherwise depend on stdio and your
		4139	libc allows it, this avoids linking in the stdio library which is quite
		4140	big.
		4141
		4142	Note that error messages might become less precise when this option is
		4143	enabled.
3876		4144
3877	=item EV_NSIG	4145	=item EV_NSIG
3878		4146
3879	The highest supported signal number, +1 (or, the number of	4147	The highest supported signal number, +1 (or, the number of
3880	signals): Normally, libev tries to deduce the maximum number of signals	4148	signals): Normally, libev tries to deduce the maximum number of signals
3881	automatically, but sometimes this fails, in which case it can be	4149	automatically, but sometimes this fails, in which case it can be
3882	specified. Also, using a lower number than detected (C<32> should be	4150	specified. Also, using a lower number than detected (C<32> should be
3883	good for about any system in existance) can save some memory, as libev	4151	good for about any system in existence) can save some memory, as libev
3884	statically allocates some 12-24 bytes per signal number.	4152	statically allocates some 12-24 bytes per signal number.
3885		4153
3886	=item EV_PID_HASHSIZE	4154	=item EV_PID_HASHSIZE
3887		4155
3888	C<ev_child> watchers use a small hash table to distribute workload by	4156	C<ev_child> watchers use a small hash table to distribute workload by
3889	pid. The default size is C<16> (or C<1> with C<EV_MINIMAL>), usually more	4157	pid. The default size is C<16> (or C<1> with C<EV_FEATURES> disabled),
3890	than enough. If you need to manage thousands of children you might want to	4158	usually more than enough. If you need to manage thousands of children you
3891	increase this value (I<must> be a power of two).	4159	might want to increase this value (I<must> be a power of two).
3892		4160
3893	=item EV_INOTIFY_HASHSIZE	4161	=item EV_INOTIFY_HASHSIZE
3894		4162
3895	C<ev_stat> watchers use a small hash table to distribute workload by	4163	C<ev_stat> watchers use a small hash table to distribute workload by
3896	inotify watch id. The default size is C<16> (or C<1> with C<EV_MINIMAL>),	4164	inotify watch id. The default size is C<16> (or C<1> with C<EV_FEATURES>
3897	usually more than enough. If you need to manage thousands of C<ev_stat>	4165	disabled), usually more than enough. If you need to manage thousands of
3898	watchers you might want to increase this value (I<must> be a power of	4166	C<ev_stat> watchers you might want to increase this value (I<must> be a
3899	two).	4167	power of two).
3900		4168
3901	=item EV_USE_4HEAP	4169	=item EV_USE_4HEAP
3902		4170
3903	Heaps are not very cache-efficient. To improve the cache-efficiency of the	4171	Heaps are not very cache-efficient. To improve the cache-efficiency of the
3904	timer and periodics heaps, libev uses a 4-heap when this symbol is defined	4172	timer and periodics heaps, libev uses a 4-heap when this symbol is defined
3905	to C<1>. The 4-heap uses more complicated (longer) code but has noticeably	4173	to C<1>. The 4-heap uses more complicated (longer) code but has noticeably
3906	faster performance with many (thousands) of watchers.	4174	faster performance with many (thousands) of watchers.
3907		4175
3908	The default is C<1> unless C<EV_MINIMAL> is set in which case it is C<0>	4176	The default is C<1>, unless C<EV_FEATURES> overrides it, in which case it
3909	(disabled).	4177	will be C<0>.
3910		4178
3911	=item EV_HEAP_CACHE_AT	4179	=item EV_HEAP_CACHE_AT
3912		4180
3913	Heaps are not very cache-efficient. To improve the cache-efficiency of the	4181	Heaps are not very cache-efficient. To improve the cache-efficiency of the
3914	timer and periodics heaps, libev can cache the timestamp (I<at>) within	4182	timer and periodics heaps, libev can cache the timestamp (I<at>) within
3915	the heap structure (selected by defining C<EV_HEAP_CACHE_AT> to C<1>),	4183	the heap structure (selected by defining C<EV_HEAP_CACHE_AT> to C<1>),
3916	which uses 8-12 bytes more per watcher and a few hundred bytes more code,	4184	which uses 8-12 bytes more per watcher and a few hundred bytes more code,
3917	but avoids random read accesses on heap changes. This improves performance	4185	but avoids random read accesses on heap changes. This improves performance
3918	noticeably with many (hundreds) of watchers.	4186	noticeably with many (hundreds) of watchers.
3919		4187
3920	The default is C<1> unless C<EV_MINIMAL> is set in which case it is C<0>	4188	The default is C<1>, unless C<EV_FEATURES> overrides it, in which case it
3921	(disabled).	4189	will be C<0>.
3922		4190
3923	=item EV_VERIFY	4191	=item EV_VERIFY
3924		4192
3925	Controls how much internal verification (see C<ev_loop_verify ()>) will	4193	Controls how much internal verification (see C<ev_verify ()>) will
3926	be done: If set to C<0>, no internal verification code will be compiled	4194	be done: If set to C<0>, no internal verification code will be compiled
3927	in. If set to C<1>, then verification code will be compiled in, but not	4195	in. If set to C<1>, then verification code will be compiled in, but not
3928	called. If set to C<2>, then the internal verification code will be	4196	called. If set to C<2>, then the internal verification code will be
3929	called once per loop, which can slow down libev. If set to C<3>, then the	4197	called once per loop, which can slow down libev. If set to C<3>, then the
3930	verification code will be called very frequently, which will slow down	4198	verification code will be called very frequently, which will slow down
3931	libev considerably.	4199	libev considerably.
3932		4200
3933	The default is C<1>, unless C<EV_MINIMAL> is set, in which case it will be	4201	The default is C<1>, unless C<EV_FEATURES> overrides it, in which case it
3934	C<0>.	4202	will be C<0>.
3935		4203
3936	=item EV_COMMON	4204	=item EV_COMMON
3937		4205
3938	By default, all watchers have a C<void *data> member. By redefining	4206	By default, all watchers have a C<void *data> member. By redefining
3939	this macro to a something else you can include more and other types of	4207	this macro to something else you can include more and other types of
3940	members. You have to define it each time you include one of the files,	4208	members. You have to define it each time you include one of the files,
3941	though, and it must be identical each time.	4209	though, and it must be identical each time.
3942		4210
3943	For example, the perl EV module uses something like this:	4211	For example, the perl EV module uses something like this:
3944		4212
…		…
3997	file.	4265	file.
3998		4266
3999	The usage in rxvt-unicode is simpler. It has a F<ev_cpp.h> header file	4267	The usage in rxvt-unicode is simpler. It has a F<ev_cpp.h> header file
4000	that everybody includes and which overrides some configure choices:	4268	that everybody includes and which overrides some configure choices:
4001		4269
4002	#define EV_MINIMAL 1	4270	#define EV_FEATURES 8
4003	#define EV_USE_POLL 0	4271	#define EV_USE_SELECT 1
4004	#define EV_MULTIPLICITY 0
4005	#define EV_PERIODIC_ENABLE 0	4272	#define EV_PREPARE_ENABLE 1
		4273	#define EV_IDLE_ENABLE 1
4006	#define EV_STAT_ENABLE 0	4274	#define EV_SIGNAL_ENABLE 1
4007	#define EV_FORK_ENABLE 0	4275	#define EV_CHILD_ENABLE 1
		4276	#define EV_USE_STDEXCEPT 0
4008	#define EV_CONFIG_H <config.h>	4277	#define EV_CONFIG_H <config.h>
4009	#define EV_MINPRI 0
4010	#define EV_MAXPRI 0
4011		4278
4012	#include "ev++.h"	4279	#include "ev++.h"
4013		4280
4014	And a F<ev_cpp.C> implementation file that contains libev proper and is compiled:	4281	And a F<ev_cpp.C> implementation file that contains libev proper and is compiled:
4015		4282
…		…
4146	userdata *u = ev_userdata (EV_A);	4413	userdata *u = ev_userdata (EV_A);
4147	pthread_mutex_lock (&u->lock);	4414	pthread_mutex_lock (&u->lock);
4148	}	4415	}
4149		4416
4150	The event loop thread first acquires the mutex, and then jumps straight	4417	The event loop thread first acquires the mutex, and then jumps straight
4151	into C<ev_loop>:	4418	into C<ev_run>:
4152		4419
4153	void *	4420	void *
4154	l_run (void *thr_arg)	4421	l_run (void *thr_arg)
4155	{	4422	{
4156	struct ev_loop *loop = (struct ev_loop *)thr_arg;	4423	struct ev_loop *loop = (struct ev_loop *)thr_arg;
4157		4424
4158	l_acquire (EV_A);	4425	l_acquire (EV_A);
4159	pthread_setcanceltype (PTHREAD_CANCEL_ASYNCHRONOUS, 0);	4426	pthread_setcanceltype (PTHREAD_CANCEL_ASYNCHRONOUS, 0);
4160	ev_loop (EV_A_ 0);	4427	ev_run (EV_A_ 0);
4161	l_release (EV_A);	4428	l_release (EV_A);
4162		4429
4163	return 0;	4430	return 0;
4164	}	4431	}
4165		4432
…		…
4217		4484
4218	=head3 COROUTINES	4485	=head3 COROUTINES
4219		4486
4220	Libev is very accommodating to coroutines ("cooperative threads"):	4487	Libev is very accommodating to coroutines ("cooperative threads"):
4221	libev fully supports nesting calls to its functions from different	4488	libev fully supports nesting calls to its functions from different
4222	coroutines (e.g. you can call C<ev_loop> on the same loop from two	4489	coroutines (e.g. you can call C<ev_run> on the same loop from two
4223	different coroutines, and switch freely between both coroutines running	4490	different coroutines, and switch freely between both coroutines running
4224	the loop, as long as you don't confuse yourself). The only exception is	4491	the loop, as long as you don't confuse yourself). The only exception is
4225	that you must not do this from C<ev_periodic> reschedule callbacks.	4492	that you must not do this from C<ev_periodic> reschedule callbacks.
4226		4493
4227	Care has been taken to ensure that libev does not keep local state inside	4494	Care has been taken to ensure that libev does not keep local state inside
4228	C<ev_loop>, and other calls do not usually allow for coroutine switches as	4495	C<ev_run>, and other calls do not usually allow for coroutine switches as
4229	they do not call any callbacks.	4496	they do not call any callbacks.
4230		4497
4231	=head2 COMPILER WARNINGS	4498	=head2 COMPILER WARNINGS
4232		4499
4233	Depending on your compiler and compiler settings, you might get no or a	4500	Depending on your compiler and compiler settings, you might get no or a
…		…
4244	maintainable.	4511	maintainable.
4245		4512
4246	And of course, some compiler warnings are just plain stupid, or simply	4513	And of course, some compiler warnings are just plain stupid, or simply
4247	wrong (because they don't actually warn about the condition their message	4514	wrong (because they don't actually warn about the condition their message
4248	seems to warn about). For example, certain older gcc versions had some	4515	seems to warn about). For example, certain older gcc versions had some
4249	warnings that resulted an extreme number of false positives. These have	4516	warnings that resulted in an extreme number of false positives. These have
4250	been fixed, but some people still insist on making code warn-free with	4517	been fixed, but some people still insist on making code warn-free with
4251	such buggy versions.	4518	such buggy versions.
4252		4519
4253	While libev is written to generate as few warnings as possible,	4520	While libev is written to generate as few warnings as possible,
4254	"warn-free" code is not a goal, and it is recommended not to build libev	4521	"warn-free" code is not a goal, and it is recommended not to build libev
…		…
4290	I suggest using suppression lists.	4557	I suggest using suppression lists.
4291		4558
4292		4559
4293	=head1 PORTABILITY NOTES	4560	=head1 PORTABILITY NOTES
4294		4561
		4562	=head2 GNU/LINUX 32 BIT LIMITATIONS
		4563
		4564	GNU/Linux is the only common platform that supports 64 bit file/large file
		4565	interfaces but I<disables> them by default.
		4566
		4567	That means that libev compiled in the default environment doesn't support
		4568	files larger than 2GiB or so, which mainly affects C<ev_stat> watchers.
		4569
		4570	Unfortunately, many programs try to work around this GNU/Linux issue
		4571	by enabling the large file API, which makes them incompatible with the
		4572	standard libev compiled for their system.
		4573
		4574	Likewise, libev cannot enable the large file API itself as this would
		4575	suddenly make it incompatible to the default compile time environment,
		4576	i.e. all programs not using special compile switches.
		4577
		4578	=head2 OS/X AND DARWIN BUGS
		4579
		4580	The whole thing is a bug if you ask me - basically any system interface
		4581	you touch is broken, whether it is locales, poll, kqueue or even the
		4582	OpenGL drivers.
		4583
		4584	=head3 C<kqueue> is buggy
		4585
		4586	The kqueue syscall is broken in all known versions - most versions support
		4587	only sockets, many support pipes.
		4588
		4589	Libev tries to work around this by not using C<kqueue> by default on this
		4590	rotten platform, but of course you can still ask for it when creating a
		4591	loop - embedding a socket-only kqueue loop into a select-based one is
		4592	probably going to work well.
		4593
		4594	=head3 C<poll> is buggy
		4595
		4596	Instead of fixing C<kqueue>, Apple replaced their (working) C<poll>
		4597	implementation by something calling C<kqueue> internally around the 10.5.6
		4598	release, so now C<kqueue> I<and> C<poll> are broken.
		4599
		4600	Libev tries to work around this by not using C<poll> by default on
		4601	this rotten platform, but of course you can still ask for it when creating
		4602	a loop.
		4603
		4604	=head3 C<select> is buggy
		4605
		4606	All that's left is C<select>, and of course Apple found a way to fuck this
		4607	one up as well: On OS/X, C<select> actively limits the number of file
		4608	descriptors you can pass in to 1024 - your program suddenly crashes when
		4609	you use more.
		4610
		4611	There is an undocumented "workaround" for this - defining
		4612	C<_DARWIN_UNLIMITED_SELECT>, which libev tries to use, so select I<should>
		4613	work on OS/X.
		4614
		4615	=head2 SOLARIS PROBLEMS AND WORKAROUNDS
		4616
		4617	=head3 C<errno> reentrancy
		4618
		4619	The default compile environment on Solaris is unfortunately so
		4620	thread-unsafe that you can't even use components/libraries compiled
		4621	without C<-D_REENTRANT> in a threaded program, which, of course, isn't
		4622	defined by default. A valid, if stupid, implementation choice.
		4623
		4624	If you want to use libev in threaded environments you have to make sure
		4625	it's compiled with C<_REENTRANT> defined.
		4626
		4627	=head3 Event port backend
		4628
		4629	The scalable event interface for Solaris is called "event
		4630	ports". Unfortunately, this mechanism is very buggy in all major
		4631	releases. If you run into high CPU usage, your program freezes or you get
		4632	a large number of spurious wakeups, make sure you have all the relevant
		4633	and latest kernel patches applied. No, I don't know which ones, but there
		4634	are multiple ones to apply, and afterwards, event ports actually work
		4635	great.
		4636
		4637	If you can't get it to work, you can try running the program by setting
		4638	the environment variable C<LIBEV_FLAGS=3> to only allow C<poll> and
		4639	C<select> backends.
		4640
		4641	=head2 AIX POLL BUG
		4642
		4643	AIX unfortunately has a broken C<poll.h> header. Libev works around
		4644	this by trying to avoid the poll backend altogether (i.e. it's not even
		4645	compiled in), which normally isn't a big problem as C<select> works fine
		4646	with large bitsets on AIX, and AIX is dead anyway.
		4647
4295	=head2 WIN32 PLATFORM LIMITATIONS AND WORKAROUNDS	4648	=head2 WIN32 PLATFORM LIMITATIONS AND WORKAROUNDS
		4649
		4650	=head3 General issues
4296		4651
4297	Win32 doesn't support any of the standards (e.g. POSIX) that libev	4652	Win32 doesn't support any of the standards (e.g. POSIX) that libev
4298	requires, and its I/O model is fundamentally incompatible with the POSIX	4653	requires, and its I/O model is fundamentally incompatible with the POSIX
4299	model. Libev still offers limited functionality on this platform in	4654	model. Libev still offers limited functionality on this platform in
4300	the form of the C<EVBACKEND_SELECT> backend, and only supports socket	4655	the form of the C<EVBACKEND_SELECT> backend, and only supports socket
4301	descriptors. This only applies when using Win32 natively, not when using	4656	descriptors. This only applies when using Win32 natively, not when using
4302	e.g. cygwin.	4657	e.g. cygwin. Actually, it only applies to the microsofts own compilers,
		4658	as every compielr comes with a slightly differently broken/incompatible
		4659	environment.
4303		4660
4304	Lifting these limitations would basically require the full	4661	Lifting these limitations would basically require the full
4305	re-implementation of the I/O system. If you are into these kinds of	4662	re-implementation of the I/O system. If you are into this kind of thing,
4306	things, then note that glib does exactly that for you in a very portable	4663	then note that glib does exactly that for you in a very portable way (note
4307	way (note also that glib is the slowest event library known to man).	4664	also that glib is the slowest event library known to man).
4308		4665
4309	There is no supported compilation method available on windows except	4666	There is no supported compilation method available on windows except
4310	embedding it into other applications.	4667	embedding it into other applications.
4311		4668
4312	Sensible signal handling is officially unsupported by Microsoft - libev	4669	Sensible signal handling is officially unsupported by Microsoft - libev
…		…
4340	you do I<not> compile the F<ev.c> or any other embedded source files!):	4697	you do I<not> compile the F<ev.c> or any other embedded source files!):
4341		4698
4342	#include "evwrap.h"	4699	#include "evwrap.h"
4343	#include "ev.c"	4700	#include "ev.c"
4344		4701
4345	=over 4
4346
4347	=item The winsocket select function	4702	=head3 The winsocket C<select> function
4348		4703
4349	The winsocket C<select> function doesn't follow POSIX in that it	4704	The winsocket C<select> function doesn't follow POSIX in that it
4350	requires socket I<handles> and not socket I<file descriptors> (it is	4705	requires socket I<handles> and not socket I<file descriptors> (it is
4351	also extremely buggy). This makes select very inefficient, and also	4706	also extremely buggy). This makes select very inefficient, and also
4352	requires a mapping from file descriptors to socket handles (the Microsoft	4707	requires a mapping from file descriptors to socket handles (the Microsoft
…		…
4361	#define EV_SELECT_IS_WINSOCKET 1 /* forces EV_SELECT_USE_FD_SET, too */	4716	#define EV_SELECT_IS_WINSOCKET 1 /* forces EV_SELECT_USE_FD_SET, too */
4362		4717
4363	Note that winsockets handling of fd sets is O(n), so you can easily get a	4718	Note that winsockets handling of fd sets is O(n), so you can easily get a
4364	complexity in the O(n²) range when using win32.	4719	complexity in the O(n²) range when using win32.
4365		4720
4366	=item Limited number of file descriptors	4721	=head3 Limited number of file descriptors
4367		4722
4368	Windows has numerous arbitrary (and low) limits on things.	4723	Windows has numerous arbitrary (and low) limits on things.
4369		4724
4370	Early versions of winsocket's select only supported waiting for a maximum	4725	Early versions of winsocket's select only supported waiting for a maximum
4371	of C<64> handles (probably owning to the fact that all windows kernels	4726	of C<64> handles (probably owning to the fact that all windows kernels
…		…
4386	runtime libraries. This might get you to about C<512> or C<2048> sockets	4741	runtime libraries. This might get you to about C<512> or C<2048> sockets
4387	(depending on windows version and/or the phase of the moon). To get more,	4742	(depending on windows version and/or the phase of the moon). To get more,
4388	you need to wrap all I/O functions and provide your own fd management, but	4743	you need to wrap all I/O functions and provide your own fd management, but
4389	the cost of calling select (O(n²)) will likely make this unworkable.	4744	the cost of calling select (O(n²)) will likely make this unworkable.
4390		4745
4391	=back
4392
4393	=head2 PORTABILITY REQUIREMENTS	4746	=head2 PORTABILITY REQUIREMENTS
4394		4747
4395	In addition to a working ISO-C implementation and of course the	4748	In addition to a working ISO-C implementation and of course the
4396	backend-specific APIs, libev relies on a few additional extensions:	4749	backend-specific APIs, libev relies on a few additional extensions:
4397		4750
…		…
4435	watchers.	4788	watchers.
4436		4789
4437	=item C<double> must hold a time value in seconds with enough accuracy	4790	=item C<double> must hold a time value in seconds with enough accuracy
4438		4791
4439	The type C<double> is used to represent timestamps. It is required to	4792	The type C<double> is used to represent timestamps. It is required to
4440	have at least 51 bits of mantissa (and 9 bits of exponent), which is good	4793	have at least 51 bits of mantissa (and 9 bits of exponent), which is
4441	enough for at least into the year 4000. This requirement is fulfilled by	4794	good enough for at least into the year 4000 with millisecond accuracy
		4795	(the design goal for libev). This requirement is overfulfilled by
4442	implementations implementing IEEE 754, which is basically all existing	4796	implementations using IEEE 754, which is basically all existing ones. With
4443	ones. With IEEE 754 doubles, you get microsecond accuracy until at least	4797	IEEE 754 doubles, you get microsecond accuracy until at least 2200.
4444	2200.
4445		4798
4446	=back	4799	=back
4447		4800
4448	If you know of other additional requirements drop me a note.	4801	If you know of other additional requirements drop me a note.
4449		4802
…		…
4517	involves iterating over all running async watchers or all signal numbers.	4870	involves iterating over all running async watchers or all signal numbers.
4518		4871
4519	=back	4872	=back
4520		4873
4521		4874
		4875	=head1 PORTING FROM LIBEV 3.X TO 4.X
		4876
		4877	The major version 4 introduced some incompatible changes to the API.
		4878
		4879	At the moment, the C<ev.h> header file provides compatibility definitions
		4880	for all changes, so most programs should still compile. The compatibility
		4881	layer might be removed in later versions of libev, so better update to the
		4882	new API early than late.
		4883
		4884	=over 4
		4885
		4886	=item C<EV_COMPAT3> backwards compatibility mechanism
		4887
		4888	The backward compatibility mechanism can be controlled by
		4889	C<EV_COMPAT3>. See L<PREPROCESSOR SYMBOLS/MACROS> in the L<EMBEDDING>
		4890	section.
		4891
		4892	=item C<ev_default_destroy> and C<ev_default_fork> have been removed
		4893
		4894	These calls can be replaced easily by their C<ev_loop_xxx> counterparts:
		4895
		4896	ev_loop_destroy (EV_DEFAULT_UC);
		4897	ev_loop_fork (EV_DEFAULT);
		4898
		4899	=item function/symbol renames
		4900
		4901	A number of functions and symbols have been renamed:
		4902
		4903	ev_loop => ev_run
		4904	EVLOOP_NONBLOCK => EVRUN_NOWAIT
		4905	EVLOOP_ONESHOT => EVRUN_ONCE
		4906
		4907	ev_unloop => ev_break
		4908	EVUNLOOP_CANCEL => EVBREAK_CANCEL
		4909	EVUNLOOP_ONE => EVBREAK_ONE
		4910	EVUNLOOP_ALL => EVBREAK_ALL
		4911
		4912	EV_TIMEOUT => EV_TIMER
		4913
		4914	ev_loop_count => ev_iteration
		4915	ev_loop_depth => ev_depth
		4916	ev_loop_verify => ev_verify
		4917
		4918	Most functions working on C<struct ev_loop> objects don't have an
		4919	C<ev_loop_> prefix, so it was removed; C<ev_loop>, C<ev_unloop> and
		4920	associated constants have been renamed to not collide with the C<struct
		4921	ev_loop> anymore and C<EV_TIMER> now follows the same naming scheme
		4922	as all other watcher types. Note that C<ev_loop_fork> is still called
		4923	C<ev_loop_fork> because it would otherwise clash with the C<ev_fork>
		4924	typedef.
		4925
		4926	=item C<EV_MINIMAL> mechanism replaced by C<EV_FEATURES>
		4927
		4928	The preprocessor symbol C<EV_MINIMAL> has been replaced by a different
		4929	mechanism, C<EV_FEATURES>. Programs using C<EV_MINIMAL> usually compile
		4930	and work, but the library code will of course be larger.
		4931
		4932	=back
		4933
		4934
4522	=head1 GLOSSARY	4935	=head1 GLOSSARY
4523		4936
4524	=over 4	4937	=over 4
4525		4938
4526	=item active	4939	=item active
4527		4940
4528	A watcher is active as long as it has been started (has been attached to	4941	A watcher is active as long as it has been started and not yet stopped.
4529	an event loop) but not yet stopped (disassociated from the event loop).	4942	See L<WATCHER STATES> for details.
4530		4943
4531	=item application	4944	=item application
4532		4945
4533	In this document, an application is whatever is using libev.	4946	In this document, an application is whatever is using libev.
		4947
		4948	=item backend
		4949
		4950	The part of the code dealing with the operating system interfaces.
4534		4951
4535	=item callback	4952	=item callback
4536		4953
4537	The address of a function that is called when some event has been	4954	The address of a function that is called when some event has been
4538	detected. Callbacks are being passed the event loop, the watcher that	4955	detected. Callbacks are being passed the event loop, the watcher that
4539	received the event, and the actual event bitset.	4956	received the event, and the actual event bitset.
4540		4957
4541	=item callback invocation	4958	=item callback/watcher invocation
4542		4959
4543	The act of calling the callback associated with a watcher.	4960	The act of calling the callback associated with a watcher.
4544		4961
4545	=item event	4962	=item event
4546		4963
4547	A change of state of some external event, such as data now being available	4964	A change of state of some external event, such as data now being available
4548	for reading on a file descriptor, time having passed or simply not having	4965	for reading on a file descriptor, time having passed or simply not having
4549	any other events happening anymore.	4966	any other events happening anymore.
4550		4967
4551	In libev, events are represented as single bits (such as C<EV_READ> or	4968	In libev, events are represented as single bits (such as C<EV_READ> or
4552	C<EV_TIMEOUT>).	4969	C<EV_TIMER>).
4553		4970
4554	=item event library	4971	=item event library
4555		4972
4556	A software package implementing an event model and loop.	4973	A software package implementing an event model and loop.
4557		4974
…		…
4565	The model used to describe how an event loop handles and processes	4982	The model used to describe how an event loop handles and processes
4566	watchers and events.	4983	watchers and events.
4567		4984
4568	=item pending	4985	=item pending
4569		4986
4570	A watcher is pending as soon as the corresponding event has been detected,	4987	A watcher is pending as soon as the corresponding event has been
4571	and stops being pending as soon as the watcher will be invoked or its	4988	detected. See L<WATCHER STATES> for details.
4572	pending status is explicitly cleared by the application.
4573
4574	A watcher can be pending, but not active. Stopping a watcher also clears
4575	its pending status.
4576		4989
4577	=item real time	4990	=item real time
4578		4991
4579	The physical time that is observed. It is apparently strictly monotonic :)	4992	The physical time that is observed. It is apparently strictly monotonic :)
4580		4993
…		…
4587	=item watcher	5000	=item watcher
4588		5001
4589	A data structure that describes interest in certain events. Watchers need	5002	A data structure that describes interest in certain events. Watchers need
4590	to be started (attached to an event loop) before they can receive events.	5003	to be started (attached to an event loop) before they can receive events.
4591		5004
4592	=item watcher invocation
4593
4594	The act of calling the callback associated with a watcher.
4595
4596	=back	5005	=back
4597		5006
4598	=head1 AUTHOR	5007	=head1 AUTHOR
4599		5008
4600	Marc Lehmann <libev@schmorp.de>, with repeated corrections by Mikael Magnusson.	5009	Marc Lehmann <libev@schmorp.de>, with repeated corrections by Mikael Magnusson.

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