[ViewVC] Diff of: cvs/libev/ev.pod

Comparing libev/ev.pod (file contents):
Revision 1.309 by root, Thu Oct 21 09:23:21 2010 UTC vs.
Revision 1.322 by root, Sun Oct 24 17:58:41 2010 UTC

…		…
26	puts ("stdin ready");	26	puts ("stdin ready");
27	// for one-shot events, one must manually stop the watcher	27	// for one-shot events, one must manually stop the watcher
28	// with its corresponding stop function.	28	// with its corresponding stop function.
29	ev_io_stop (EV_A_ w);	29	ev_io_stop (EV_A_ w);
30		30
31	// this causes all nested ev_loop's to stop iterating	31	// this causes all nested ev_run's to stop iterating
32	ev_unloop (EV_A_ EVUNLOOP_ALL);	32	ev_break (EV_A_ EVBREAK_ALL);
33	}	33	}
34		34
35	// another callback, this time for a time-out	35	// another callback, this time for a time-out
36	static void	36	static void
37	timeout_cb (EV_P_ ev_timer *w, int revents)	37	timeout_cb (EV_P_ ev_timer *w, int revents)
38	{	38	{
39	puts ("timeout");	39	puts ("timeout");
40	// this causes the innermost ev_loop to stop iterating	40	// this causes the innermost ev_run to stop iterating
41	ev_unloop (EV_A_ EVUNLOOP_ONE);	41	ev_break (EV_A_ EVBREAK_ONE);
42	}	42	}
43		43
44	int	44	int
45	main (void)	45	main (void)
46	{	46	{
47	// use the default event loop unless you have special needs	47	// use the default event loop unless you have special needs
48	struct ev_loop *loop = ev_default_loop (0);	48	struct ev_loop *loop = EV_DEFAULT;
49		49
50	// initialise an io watcher, then start it	50	// initialise an io watcher, then start it
51	// this one will watch for stdin to become readable	51	// this one will watch for stdin to become readable
52	ev_io_init (&stdin_watcher, stdin_cb, /STDIN_FILENO/ 0, EV_READ);	52	ev_io_init (&stdin_watcher, stdin_cb, /STDIN_FILENO/ 0, EV_READ);
53	ev_io_start (loop, &stdin_watcher);	53	ev_io_start (loop, &stdin_watcher);
…		…
56	// simple non-repeating 5.5 second timeout	56	// simple non-repeating 5.5 second timeout
57	ev_timer_init (&timeout_watcher, timeout_cb, 5.5, 0.);	57	ev_timer_init (&timeout_watcher, timeout_cb, 5.5, 0.);
58	ev_timer_start (loop, &timeout_watcher);	58	ev_timer_start (loop, &timeout_watcher);
59		59
60	// now wait for events to arrive	60	// now wait for events to arrive
61	ev_loop (loop, 0);	61	ev_run (loop, 0);
62		62
63	// unloop was called, so exit	63	// unloop was called, so exit
64	return 0;	64	return 0;
65	}	65	}
66		66
…		…
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 (in practise	129	the (fractional) number of seconds since the (POSIX) epoch (in practice
130	somewhere near the beginning of 1970, details are complicated, don't	130	somewhere near the beginning of 1970, details are complicated, don't
131	ask). This type is called C<ev_tstamp>, which is what you should use	131	ask). This type is called C<ev_tstamp>, which is what you should use
132	too. It usually aliases to the C<double> type in C. When you need to do	132	too. It usually aliases to the C<double> type in C. When you need to do
133	any calculations on it, you should treat it as some floating point value.	133	any calculations on it, you should treat it as some floating point value.
134		134
…		…
165		165
166	=item ev_tstamp ev_time ()	166	=item ev_tstamp ev_time ()
167		167
168	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
169	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
170	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>.
171		172
172	=item ev_sleep (ev_tstamp interval)	173	=item ev_sleep (ev_tstamp interval)
173		174
174	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
175	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
…		…
192	as this indicates an incompatible change. Minor versions are usually	193	as this indicates an incompatible change. Minor versions are usually
193	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
194	not a problem.	195	not a problem.
195		196
196	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
197	version (note, however, that this will not detect ABI mismatches :).	198	version (note, however, that this will not detect other ABI mismatches,
		199	such as LFS or reentrancy).
198		200
199	assert (("libev version mismatch",	201	assert (("libev version mismatch",
200	ev_version_major () == EV_VERSION_MAJOR	202	ev_version_major () == EV_VERSION_MAJOR
201	&& ev_version_minor () >= EV_VERSION_MINOR));	203	&& ev_version_minor () >= EV_VERSION_MINOR));
202		204
…		…
213	assert (("sorry, no epoll, no sex",	215	assert (("sorry, no epoll, no sex",
214	ev_supported_backends () & EVBACKEND_EPOLL));	216	ev_supported_backends () & EVBACKEND_EPOLL));
215		217
216	=item unsigned int ev_recommended_backends ()	218	=item unsigned int ev_recommended_backends ()
217		219
218	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
219	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
220	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
221	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
222	(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
223	libev will probe for if you specify no backends explicitly.	226	probe for if you specify no backends explicitly.
224		227
225	=item unsigned int ev_embeddable_backends ()	228	=item unsigned int ev_embeddable_backends ()
226		229
227	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
228	is the theoretical, all-platform, value. To find which backends	231	value is platform-specific but can include backends not available on the
229	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
230	C<ev_embeddable_backends () & ev_supported_backends ()>, likewise for	233	the current system, you would need to look at C<ev_embeddable_backends ()
231	recommended ones.	234	& ev_supported_backends ()>, likewise for recommended ones.
232		235
233	See the description of C<ev_embed> watchers for more info.	236	See the description of C<ev_embed> watchers for more info.
234		237
235	=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]
236		239
…		…
290	...	293	...
291	ev_set_syserr_cb (fatal_error);	294	ev_set_syserr_cb (fatal_error);
292		295
293	=back	296	=back
294		297
295	=head1 FUNCTIONS CONTROLLING THE EVENT LOOP	298	=head1 FUNCTIONS CONTROLLING EVENT LOOPS
296		299
297	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
298	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
299	I<function>).	302	libev 3 had an C<ev_loop> function colliding with the struct name).
300		303
301	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
302	supports signals and child events, and dynamically created loops which do	305	supports signals and child events, and dynamically created event loops
303	not.	306	which do not.
304		307
305	=over 4	308	=over 4
306		309
307	=item struct ev_loop *ev_default_loop (unsigned int flags)	310	=item struct ev_loop *ev_default_loop (unsigned int flags)
308		311
309	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
310	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
311	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
312	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".
313		322
314	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
315	function.	324	function (or via the C<EV_DEFAULT> macro).
316		325
317	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
318	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
319	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).
320		330
321	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,
322	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
323	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
324	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
325	can simply overwrite the C<SIGCHLD> signal handler I<after> calling	335	C<SIGCHLD> signal handler I<after> calling C<ev_default_init>.
326	C<ev_default_init>.	336
		337	Example: This is the most typical usage.
		338
		339	if (!ev_default_loop (0))
		340	fatal ("could not initialise libev, bad $LIBEV_FLAGS in environment?");
		341
		342	Example: Restrict libev to the select and poll backends, and do not allow
		343	environment settings to be taken into account:
		344
		345	ev_default_loop (EVBACKEND_POLL \| EVBACKEND_SELECT \| EVFLAG_NOENV);
		346
		347	Example: Use whatever libev has to offer, but make sure that kqueue is
		348	used if available (warning, breaks stuff, best use only with your own
		349	private event loop and only if you know the OS supports your types of
		350	fds):
		351
		352	ev_default_loop (ev_recommended_backends () \| EVBACKEND_KQUEUE);
		353
		354	=item struct ev_loop *ev_loop_new (unsigned int flags)
		355
		356	This will create and initialise a new event loop object. If the loop
		357	could not be initialised, returns false.
		358
		359	Note that this function I<is> thread-safe, and one common way to use
		360	libev with threads is indeed to create one loop per thread, and using the
		361	default loop in the "main" or "initial" thread.
327		362
328	The flags argument can be used to specify special behaviour or specific	363	The flags argument can be used to specify special behaviour or specific
329	backends to use, and is usually specified as C<0> (or C<EVFLAG_AUTO>).	364	backends to use, and is usually specified as C<0> (or C<EVFLAG_AUTO>).
330		365
331	The following flags are supported:	366	The following flags are supported:
…		…
549	If one or more of the backend flags are or'ed into the flags value,	584	If one or more of the backend flags are or'ed into the flags value,
550	then only these backends will be tried (in the reverse order as listed	585	then only these backends will be tried (in the reverse order as listed
551	here). If none are specified, all backends in C<ev_recommended_backends	586	here). If none are specified, all backends in C<ev_recommended_backends
552	()> will be tried.	587	()> will be tried.
553		588
554	Example: This is the most typical usage.
555
556	if (!ev_default_loop (0))
557	fatal ("could not initialise libev, bad $LIBEV_FLAGS in environment?");
558
559	Example: Restrict libev to the select and poll backends, and do not allow
560	environment settings to be taken into account:
561
562	ev_default_loop (EVBACKEND_POLL \| EVBACKEND_SELECT \| EVFLAG_NOENV);
563
564	Example: Use whatever libev has to offer, but make sure that kqueue is
565	used if available (warning, breaks stuff, best use only with your own
566	private event loop and only if you know the OS supports your types of
567	fds):
568
569	ev_default_loop (ev_recommended_backends () \| EVBACKEND_KQUEUE);
570
571	=item struct ev_loop *ev_loop_new (unsigned int flags)
572
573	Similar to C<ev_default_loop>, but always creates a new event loop that is
574	always distinct from the default loop.
575
576	Note that this function I<is> thread-safe, and one common way to use
577	libev with threads is indeed to create one loop per thread, and using the
578	default loop in the "main" or "initial" thread.
579
580	Example: Try to create a event loop that uses epoll and nothing else.	589	Example: Try to create a event loop that uses epoll and nothing else.
581		590
582	struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL \| EVFLAG_NOENV);	591	struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL \| EVFLAG_NOENV);
583	if (!epoller)	592	if (!epoller)
584	fatal ("no epoll found here, maybe it hides under your chair");	593	fatal ("no epoll found here, maybe it hides under your chair");
585		594
586	=item ev_default_destroy ()	595	=item ev_loop_destroy (loop)
587		596
588	Destroys the default loop (frees all memory and kernel state etc.). None	597	Destroys an event loop object (frees all memory and kernel state
589	of the active event watchers will be stopped in the normal sense, so	598	etc.). None of the active event watchers will be stopped in the normal
590	e.g. C<ev_is_active> might still return true. It is your responsibility to	599	sense, so e.g. C<ev_is_active> might still return true. It is your
591	either stop all watchers cleanly yourself I<before> calling this function,	600	responsibility to either stop all watchers cleanly yourself I<before>
592	or cope with the fact afterwards (which is usually the easiest thing, you	601	calling this function, or cope with the fact afterwards (which is usually
593	can just ignore the watchers and/or C<free ()> them for example).	602	the easiest thing, you can just ignore the watchers and/or C<free ()> them
		603	for example).
594		604
595	Note that certain global state, such as signal state (and installed signal	605	Note that certain global state, such as signal state (and installed signal
596	handlers), will not be freed by this function, and related watchers (such	606	handlers), will not be freed by this function, and related watchers (such
597	as signal and child watchers) would need to be stopped manually.	607	as signal and child watchers) would need to be stopped manually.
598		608
599	In general it is not advisable to call this function except in the	609	This function is normally used on loop objects allocated by
600	rare occasion where you really need to free e.g. the signal handling	610	C<ev_loop_new>, but it can also be used on the default loop returned by
		611	C<ev_default_loop>, in which case it is not thread-safe.
		612
		613	Note that it is not advisable to call this function on the default loop
		614	except in the rare occasion where you really need to free it's resources.
601	pipe fds. If you need dynamically allocated loops it is better to use	615	If you need dynamically allocated loops it is better to use C<ev_loop_new>
602	C<ev_loop_new> and C<ev_loop_destroy>.	616	and C<ev_loop_destroy>.
603		617
604	=item ev_loop_destroy (loop)	618	=item ev_loop_fork (loop)
605		619
606	Like C<ev_default_destroy>, but destroys an event loop created by an
607	earlier call to C<ev_loop_new>.
608
609	=item ev_default_fork ()
610
611	This function sets a flag that causes subsequent C<ev_loop> iterations	620	This function sets a flag that causes subsequent C<ev_run> iterations to
612	to reinitialise the kernel state for backends that have one. Despite the	621	reinitialise the kernel state for backends that have one. Despite the
613	name, you can call it anytime, but it makes most sense after forking, in	622	name, you can call it anytime, but it makes most sense after forking, in
614	the child process (or both child and parent, but that again makes little	623	the child process. You I<must> call it (or use C<EVFLAG_FORKCHECK>) in the
615	sense). You I<must> call it in the child before using any of the libev	624	child before resuming or calling C<ev_run>.
616	functions, and it will only take effect at the next C<ev_loop> iteration.
617		625
618	Again, you I<have> to call it on I<any> loop that you want to re-use after	626	Again, you I<have> to call it on I<any> loop that you want to re-use after
619	a fork, I<even if you do not plan to use the loop in the parent>. This is	627	a fork, I<even if you do not plan to use the loop in the parent>. This is
620	because some kernel interfaces cough I<kqueue> cough do funny things	628	because some kernel interfaces cough I<kqueue> cough do funny things
621	during fork.	629	during fork.
622		630
623	On the other hand, you only need to call this function in the child	631	On the other hand, you only need to call this function in the child
624	process if and only if you want to use the event loop in the child. If you	632	process if and only if you want to use the event loop in the child. If
625	just fork+exec or create a new loop in the child, you don't have to call	633	you just fork+exec or create a new loop in the child, you don't have to
626	it at all.	634	call it at all (in fact, C<epoll> is so badly broken that it makes a
		635	difference, but libev will usually detect this case on its own and do a
		636	costly reset of the backend).
627		637
628	The function itself is quite fast and it's usually not a problem to call	638	The function itself is quite fast and it's usually not a problem to call
629	it just in case after a fork. To make this easy, the function will fit in	639	it just in case after a fork.
630	quite nicely into a call to C<pthread_atfork>:
631		640
		641	Example: Automate calling C<ev_loop_fork> on the default loop when
		642	using pthreads.
		643
		644	static void
		645	post_fork_child (void)
		646	{
		647	ev_loop_fork (EV_DEFAULT);
		648	}
		649
		650	...
632	pthread_atfork (0, 0, ev_default_fork);	651	pthread_atfork (0, 0, post_fork_child);
633
634	=item ev_loop_fork (loop)
635
636	Like C<ev_default_fork>, but acts on an event loop created by
637	C<ev_loop_new>. Yes, you have to call this on every allocated event loop
638	after fork that you want to re-use in the child, and how you keep track of
639	them is entirely your own problem.
640		652
641	=item int ev_is_default_loop (loop)	653	=item int ev_is_default_loop (loop)
642		654
643	Returns true when the given loop is, in fact, the default loop, and false	655	Returns true when the given loop is, in fact, the default loop, and false
644	otherwise.	656	otherwise.
645		657
646	=item unsigned int ev_iteration (loop)	658	=item unsigned int ev_iteration (loop)
647		659
648	Returns the current iteration count for the loop, which is identical to	660	Returns the current iteration count for the event loop, which is identical
649	the number of times libev did poll for new events. It starts at C<0> and	661	to the number of times libev did poll for new events. It starts at C<0>
650	happily wraps around with enough iterations.	662	and happily wraps around with enough iterations.
651		663
652	This value can sometimes be useful as a generation counter of sorts (it	664	This value can sometimes be useful as a generation counter of sorts (it
653	"ticks" the number of loop iterations), as it roughly corresponds with	665	"ticks" the number of loop iterations), as it roughly corresponds with
654	C<ev_prepare> and C<ev_check> calls - and is incremented between the	666	C<ev_prepare> and C<ev_check> calls - and is incremented between the
655	prepare and check phases.	667	prepare and check phases.
656		668
657	=item unsigned int ev_depth (loop)	669	=item unsigned int ev_depth (loop)
658		670
659	Returns the number of times C<ev_loop> was entered minus the number of	671	Returns the number of times C<ev_run> was entered minus the number of
660	times C<ev_loop> was exited, in other words, the recursion depth.	672	times C<ev_run> was exited, in other words, the recursion depth.
661		673
662	Outside C<ev_loop>, this number is zero. In a callback, this number is	674	Outside C<ev_run>, this number is zero. In a callback, this number is
663	C<1>, unless C<ev_loop> was invoked recursively (or from another thread),	675	C<1>, unless C<ev_run> was invoked recursively (or from another thread),
664	in which case it is higher.	676	in which case it is higher.
665		677
666	Leaving C<ev_loop> abnormally (setjmp/longjmp, cancelling the thread	678	Leaving C<ev_run> abnormally (setjmp/longjmp, cancelling the thread
667	etc.), doesn't count as "exit" - consider this as a hint to avoid such	679	etc.), doesn't count as "exit" - consider this as a hint to avoid such
668	ungentleman behaviour unless it's really convenient.	680	ungentleman-like behaviour unless it's really convenient.
669		681
670	=item unsigned int ev_backend (loop)	682	=item unsigned int ev_backend (loop)
671		683
672	Returns one of the C<EVBACKEND_*> flags indicating the event backend in	684	Returns one of the C<EVBACKEND_*> flags indicating the event backend in
673	use.	685	use.
…		…
682		694
683	=item ev_now_update (loop)	695	=item ev_now_update (loop)
684		696
685	Establishes the current time by querying the kernel, updating the time	697	Establishes the current time by querying the kernel, updating the time
686	returned by C<ev_now ()> in the progress. This is a costly operation and	698	returned by C<ev_now ()> in the progress. This is a costly operation and
687	is usually done automatically within C<ev_loop ()>.	699	is usually done automatically within C<ev_run ()>.
688		700
689	This function is rarely useful, but when some event callback runs for a	701	This function is rarely useful, but when some event callback runs for a
690	very long time without entering the event loop, updating libev's idea of	702	very long time without entering the event loop, updating libev's idea of
691	the current time is a good idea.	703	the current time is a good idea.
692		704
…		…
694		706
695	=item ev_suspend (loop)	707	=item ev_suspend (loop)
696		708
697	=item ev_resume (loop)	709	=item ev_resume (loop)
698		710
699	These two functions suspend and resume a loop, for use when the loop is	711	These two functions suspend and resume an event loop, for use when the
700	not used for a while and timeouts should not be processed.	712	loop is not used for a while and timeouts should not be processed.
701		713
702	A typical use case would be an interactive program such as a game: When	714	A typical use case would be an interactive program such as a game: When
703	the user presses C<^Z> to suspend the game and resumes it an hour later it	715	the user presses C<^Z> to suspend the game and resumes it an hour later it
704	would be best to handle timeouts as if no time had actually passed while	716	would be best to handle timeouts as if no time had actually passed while
705	the program was suspended. This can be achieved by calling C<ev_suspend>	717	the program was suspended. This can be achieved by calling C<ev_suspend>
…		…
716	without a previous call to C<ev_suspend>.	728	without a previous call to C<ev_suspend>.
717		729
718	Calling C<ev_suspend>/C<ev_resume> has the side effect of updating the	730	Calling C<ev_suspend>/C<ev_resume> has the side effect of updating the
719	event loop time (see C<ev_now_update>).	731	event loop time (see C<ev_now_update>).
720		732
721	=item ev_loop (loop, int flags)	733	=item ev_run (loop, int flags)
722		734
723	Finally, this is it, the event handler. This function usually is called	735	Finally, this is it, the event handler. This function usually is called
724	after you have initialised all your watchers and you want to start	736	after you have initialised all your watchers and you want to start
725	handling events.	737	handling events. It will ask the operating system for any new events, call
		738	the watcher callbacks, an then repeat the whole process indefinitely: This
		739	is why event loops are called I<loops>.
726		740
727	If the flags argument is specified as C<0>, it will not return until	741	If the flags argument is specified as C<0>, it will keep handling events
728	either no event watchers are active anymore or C<ev_unloop> was called.	742	until either no event watchers are active anymore or C<ev_break> was
		743	called.
729		744
730	Please note that an explicit C<ev_unloop> is usually better than	745	Please note that an explicit C<ev_break> is usually better than
731	relying on all watchers to be stopped when deciding when a program has	746	relying on all watchers to be stopped when deciding when a program has
732	finished (especially in interactive programs), but having a program	747	finished (especially in interactive programs), but having a program
733	that automatically loops as long as it has to and no longer by virtue	748	that automatically loops as long as it has to and no longer by virtue
734	of relying on its watchers stopping correctly, that is truly a thing of	749	of relying on its watchers stopping correctly, that is truly a thing of
735	beauty.	750	beauty.
736		751
737	A flags value of C<EVLOOP_NONBLOCK> will look for new events, will handle	752	A flags value of C<EVRUN_NOWAIT> will look for new events, will handle
738	those events and any already outstanding ones, but will not block your	753	those events and any already outstanding ones, but will not wait and
739	process in case there are no events and will return after one iteration of	754	block your process in case there are no events and will return after one
740	the loop.	755	iteration of the loop. This is sometimes useful to poll and handle new
		756	events while doing lengthy calculations, to keep the program responsive.
741		757
742	A flags value of C<EVLOOP_ONESHOT> will look for new events (waiting if	758	A flags value of C<EVRUN_ONCE> will look for new events (waiting if
743	necessary) and will handle those and any already outstanding ones. It	759	necessary) and will handle those and any already outstanding ones. It
744	will block your process until at least one new event arrives (which could	760	will block your process until at least one new event arrives (which could
745	be an event internal to libev itself, so there is no guarantee that a	761	be an event internal to libev itself, so there is no guarantee that a
746	user-registered callback will be called), and will return after one	762	user-registered callback will be called), and will return after one
747	iteration of the loop.	763	iteration of the loop.
748		764
749	This is useful if you are waiting for some external event in conjunction	765	This is useful if you are waiting for some external event in conjunction
750	with something not expressible using other libev watchers (i.e. "roll your	766	with something not expressible using other libev watchers (i.e. "roll your
751	own C<ev_loop>"). However, a pair of C<ev_prepare>/C<ev_check> watchers is	767	own C<ev_run>"). However, a pair of C<ev_prepare>/C<ev_check> watchers is
752	usually a better approach for this kind of thing.	768	usually a better approach for this kind of thing.
753		769
754	Here are the gory details of what C<ev_loop> does:	770	Here are the gory details of what C<ev_run> does:
755		771
		772	- Increment loop depth.
		773	- Reset the ev_break status.
756	- Before the first iteration, call any pending watchers.	774	- Before the first iteration, call any pending watchers.
		775	LOOP:
757	* If EVFLAG_FORKCHECK was used, check for a fork.	776	- If EVFLAG_FORKCHECK was used, check for a fork.
758	- If a fork was detected (by any means), queue and call all fork watchers.	777	- If a fork was detected (by any means), queue and call all fork watchers.
759	- Queue and call all prepare watchers.	778	- Queue and call all prepare watchers.
		779	- If ev_break was called, goto FINISH.
760	- If we have been forked, detach and recreate the kernel state	780	- If we have been forked, detach and recreate the kernel state
761	as to not disturb the other process.	781	as to not disturb the other process.
762	- Update the kernel state with all outstanding changes.	782	- Update the kernel state with all outstanding changes.
763	- Update the "event loop time" (ev_now ()).	783	- Update the "event loop time" (ev_now ()).
764	- Calculate for how long to sleep or block, if at all	784	- Calculate for how long to sleep or block, if at all
765	(active idle watchers, EVLOOP_NONBLOCK or not having	785	(active idle watchers, EVRUN_NOWAIT or not having
766	any active watchers at all will result in not sleeping).	786	any active watchers at all will result in not sleeping).
767	- Sleep if the I/O and timer collect interval say so.	787	- Sleep if the I/O and timer collect interval say so.
		788	- Increment loop iteration counter.
768	- Block the process, waiting for any events.	789	- Block the process, waiting for any events.
769	- Queue all outstanding I/O (fd) events.	790	- Queue all outstanding I/O (fd) events.
770	- Update the "event loop time" (ev_now ()), and do time jump adjustments.	791	- Update the "event loop time" (ev_now ()), and do time jump adjustments.
771	- Queue all expired timers.	792	- Queue all expired timers.
772	- Queue all expired periodics.	793	- Queue all expired periodics.
773	- Unless any events are pending now, queue all idle watchers.	794	- Queue all idle watchers with priority higher than that of pending events.
774	- Queue all check watchers.	795	- Queue all check watchers.
775	- Call all queued watchers in reverse order (i.e. check watchers first).	796	- Call all queued watchers in reverse order (i.e. check watchers first).
776	Signals and child watchers are implemented as I/O watchers, and will	797	Signals and child watchers are implemented as I/O watchers, and will
777	be handled here by queueing them when their watcher gets executed.	798	be handled here by queueing them when their watcher gets executed.
778	- If ev_unloop has been called, or EVLOOP_ONESHOT or EVLOOP_NONBLOCK	799	- If ev_break has been called, or EVRUN_ONCE or EVRUN_NOWAIT
779	were used, or there are no active watchers, return, otherwise	800	were used, or there are no active watchers, goto FINISH, otherwise
780	continue with step *.	801	continue with step LOOP.
		802	FINISH:
		803	- Reset the ev_break status iff it was EVBREAK_ONE.
		804	- Decrement the loop depth.
		805	- Return.
781		806
782	Example: Queue some jobs and then loop until no events are outstanding	807	Example: Queue some jobs and then loop until no events are outstanding
783	anymore.	808	anymore.
784		809
785	... queue jobs here, make sure they register event watchers as long	810	... queue jobs here, make sure they register event watchers as long
786	... as they still have work to do (even an idle watcher will do..)	811	... as they still have work to do (even an idle watcher will do..)
787	ev_loop (my_loop, 0);	812	ev_run (my_loop, 0);
788	... jobs done or somebody called unloop. yeah!	813	... jobs done or somebody called unloop. yeah!
789		814
790	=item ev_unloop (loop, how)	815	=item ev_break (loop, how)
791		816
792	Can be used to make a call to C<ev_loop> return early (but only after it	817	Can be used to make a call to C<ev_run> return early (but only after it
793	has processed all outstanding events). The C<how> argument must be either	818	has processed all outstanding events). The C<how> argument must be either
794	C<EVUNLOOP_ONE>, which will make the innermost C<ev_loop> call return, or	819	C<EVBREAK_ONE>, which will make the innermost C<ev_run> call return, or
795	C<EVUNLOOP_ALL>, which will make all nested C<ev_loop> calls return.	820	C<EVBREAK_ALL>, which will make all nested C<ev_run> calls return.
796		821
797	This "unloop state" will be cleared when entering C<ev_loop> again.	822	This "unloop state" will be cleared when entering C<ev_run> again.
798		823
799	It is safe to call C<ev_unloop> from outside any C<ev_loop> calls.	824	It is safe to call C<ev_break> from outside any C<ev_run> calls. ##TODO##
800		825
801	=item ev_ref (loop)	826	=item ev_ref (loop)
802		827
803	=item ev_unref (loop)	828	=item ev_unref (loop)
804		829
805	Ref/unref can be used to add or remove a reference count on the event	830	Ref/unref can be used to add or remove a reference count on the event
806	loop: Every watcher keeps one reference, and as long as the reference	831	loop: Every watcher keeps one reference, and as long as the reference
807	count is nonzero, C<ev_loop> will not return on its own.	832	count is nonzero, C<ev_run> will not return on its own.
808		833
809	This is useful when you have a watcher that you never intend to	834	This is useful when you have a watcher that you never intend to
810	unregister, but that nevertheless should not keep C<ev_loop> from	835	unregister, but that nevertheless should not keep C<ev_run> from
811	returning. In such a case, call C<ev_unref> after starting, and C<ev_ref>	836	returning. In such a case, call C<ev_unref> after starting, and C<ev_ref>
812	before stopping it.	837	before stopping it.
813		838
814	As an example, libev itself uses this for its internal signal pipe: It	839	As an example, libev itself uses this for its internal signal pipe: It
815	is not visible to the libev user and should not keep C<ev_loop> from	840	is not visible to the libev user and should not keep C<ev_run> from
816	exiting if no event watchers registered by it are active. It is also an	841	exiting if no event watchers registered by it are active. It is also an
817	excellent way to do this for generic recurring timers or from within	842	excellent way to do this for generic recurring timers or from within
818	third-party libraries. Just remember to I<unref after start> and I<ref	843	third-party libraries. Just remember to I<unref after start> and I<ref
819	before stop> (but only if the watcher wasn't active before, or was active	844	before stop> (but only if the watcher wasn't active before, or was active
820	before, respectively. Note also that libev might stop watchers itself	845	before, respectively. Note also that libev might stop watchers itself
821	(e.g. non-repeating timers) in which case you have to C<ev_ref>	846	(e.g. non-repeating timers) in which case you have to C<ev_ref>
822	in the callback).	847	in the callback).
823		848
824	Example: Create a signal watcher, but keep it from keeping C<ev_loop>	849	Example: Create a signal watcher, but keep it from keeping C<ev_run>
825	running when nothing else is active.	850	running when nothing else is active.
826		851
827	ev_signal exitsig;	852	ev_signal exitsig;
828	ev_signal_init (&exitsig, sig_cb, SIGINT);	853	ev_signal_init (&exitsig, sig_cb, SIGINT);
829	ev_signal_start (loop, &exitsig);	854	ev_signal_start (loop, &exitsig);
…		…
892	ev_set_io_collect_interval (EV_DEFAULT_UC_ 0.01);	917	ev_set_io_collect_interval (EV_DEFAULT_UC_ 0.01);
893		918
894	=item ev_invoke_pending (loop)	919	=item ev_invoke_pending (loop)
895		920
896	This call will simply invoke all pending watchers while resetting their	921	This call will simply invoke all pending watchers while resetting their
897	pending state. Normally, C<ev_loop> does this automatically when required,	922	pending state. Normally, C<ev_run> does this automatically when required,
898	but when overriding the invoke callback this call comes handy.	923	but when overriding the invoke callback this call comes handy. This
		924	function can be invoked from a watcher - this can be useful for example
		925	when you want to do some lengthy calculation and want to pass further
		926	event handling to another thread (you still have to make sure only one
		927	thread executes within C<ev_invoke_pending> or C<ev_run> of course).
899		928
900	=item int ev_pending_count (loop)	929	=item int ev_pending_count (loop)
901		930
902	Returns the number of pending watchers - zero indicates that no watchers	931	Returns the number of pending watchers - zero indicates that no watchers
903	are pending.	932	are pending.
904		933
905	=item ev_set_invoke_pending_cb (loop, void (*invoke_pending_cb)(EV_P))	934	=item ev_set_invoke_pending_cb (loop, void (*invoke_pending_cb)(EV_P))
906		935
907	This overrides the invoke pending functionality of the loop: Instead of	936	This overrides the invoke pending functionality of the loop: Instead of
908	invoking all pending watchers when there are any, C<ev_loop> will call	937	invoking all pending watchers when there are any, C<ev_run> will call
909	this callback instead. This is useful, for example, when you want to	938	this callback instead. This is useful, for example, when you want to
910	invoke the actual watchers inside another context (another thread etc.).	939	invoke the actual watchers inside another context (another thread etc.).
911		940
912	If you want to reset the callback, use C<ev_invoke_pending> as new	941	If you want to reset the callback, use C<ev_invoke_pending> as new
913	callback.	942	callback.
…		…
916		945
917	Sometimes you want to share the same loop between multiple threads. This	946	Sometimes you want to share the same loop between multiple threads. This
918	can be done relatively simply by putting mutex_lock/unlock calls around	947	can be done relatively simply by putting mutex_lock/unlock calls around
919	each call to a libev function.	948	each call to a libev function.
920		949
921	However, C<ev_loop> can run an indefinite time, so it is not feasible to	950	However, C<ev_run> can run an indefinite time, so it is not feasible
922	wait for it to return. One way around this is to wake up the loop via	951	to wait for it to return. One way around this is to wake up the event
923	C<ev_unloop> and C<av_async_send>, another way is to set these I<release>	952	loop via C<ev_break> and C<av_async_send>, another way is to set these
924	and I<acquire> callbacks on the loop.	953	I<release> and I<acquire> callbacks on the loop.
925		954
926	When set, then C<release> will be called just before the thread is	955	When set, then C<release> will be called just before the thread is
927	suspended waiting for new events, and C<acquire> is called just	956	suspended waiting for new events, and C<acquire> is called just
928	afterwards.	957	afterwards.
929		958
…		…
932		961
933	While event loop modifications are allowed between invocations of	962	While event loop modifications are allowed between invocations of
934	C<release> and C<acquire> (that's their only purpose after all), no	963	C<release> and C<acquire> (that's their only purpose after all), no
935	modifications done will affect the event loop, i.e. adding watchers will	964	modifications done will affect the event loop, i.e. adding watchers will
936	have no effect on the set of file descriptors being watched, or the time	965	have no effect on the set of file descriptors being watched, or the time
937	waited. Use an C<ev_async> watcher to wake up C<ev_loop> when you want it	966	waited. Use an C<ev_async> watcher to wake up C<ev_run> when you want it
938	to take note of any changes you made.	967	to take note of any changes you made.
939		968
940	In theory, threads executing C<ev_loop> will be async-cancel safe between	969	In theory, threads executing C<ev_run> will be async-cancel safe between
941	invocations of C<release> and C<acquire>.	970	invocations of C<release> and C<acquire>.
942		971
943	See also the locking example in the C<THREADS> section later in this	972	See also the locking example in the C<THREADS> section later in this
944	document.	973	document.
945		974
…		…
975		1004
976	In the following description, uppercase C<TYPE> in names stands for the	1005	In the following description, uppercase C<TYPE> in names stands for the
977	watcher type, e.g. C<ev_TYPE_start> can mean C<ev_timer_start> for timer	1006	watcher type, e.g. C<ev_TYPE_start> can mean C<ev_timer_start> for timer
978	watchers and C<ev_io_start> for I/O watchers.	1007	watchers and C<ev_io_start> for I/O watchers.
979		1008
980	A watcher is a structure that you create and register to record your	1009	A watcher is an opaque structure that you allocate and register to record
981	interest in some event. For instance, if you want to wait for STDIN to	1010	your interest in some event. To make a concrete example, imagine you want
982	become readable, you would create an C<ev_io> watcher for that:	1011	to wait for STDIN to become readable, you would create an C<ev_io> watcher
		1012	for that:
983		1013
984	static void my_cb (struct ev_loop loop, ev_io w, int revents)	1014	static void my_cb (struct ev_loop loop, ev_io w, int revents)
985	{	1015	{
986	ev_io_stop (w);	1016	ev_io_stop (w);
987	ev_unloop (loop, EVUNLOOP_ALL);	1017	ev_break (loop, EVBREAK_ALL);
988	}	1018	}
989		1019
990	struct ev_loop *loop = ev_default_loop (0);	1020	struct ev_loop *loop = ev_default_loop (0);
991		1021
992	ev_io stdin_watcher;	1022	ev_io stdin_watcher;
993		1023
994	ev_init (&stdin_watcher, my_cb);	1024	ev_init (&stdin_watcher, my_cb);
995	ev_io_set (&stdin_watcher, STDIN_FILENO, EV_READ);	1025	ev_io_set (&stdin_watcher, STDIN_FILENO, EV_READ);
996	ev_io_start (loop, &stdin_watcher);	1026	ev_io_start (loop, &stdin_watcher);
997		1027
998	ev_loop (loop, 0);	1028	ev_run (loop, 0);
999		1029
1000	As you can see, you are responsible for allocating the memory for your	1030	As you can see, you are responsible for allocating the memory for your
1001	watcher structures (and it is I<usually> a bad idea to do this on the	1031	watcher structures (and it is I<usually> a bad idea to do this on the
1002	stack).	1032	stack).
1003		1033
1004	Each watcher has an associated watcher structure (called C<struct ev_TYPE>	1034	Each watcher has an associated watcher structure (called C<struct ev_TYPE>
1005	or simply C<ev_TYPE>, as typedefs are provided for all watcher structs).	1035	or simply C<ev_TYPE>, as typedefs are provided for all watcher structs).
1006		1036
1007	Each watcher structure must be initialised by a call to C<ev_init	1037	Each watcher structure must be initialised by a call to C<ev_init (watcher
1008	(watcher *, callback)>, which expects a callback to be provided. This	1038	*, callback)>, which expects a callback to be provided. This callback is
1009	callback gets invoked each time the event occurs (or, in the case of I/O	1039	invoked each time the event occurs (or, in the case of I/O watchers, each
1010	watchers, each time the event loop detects that the file descriptor given	1040	time the event loop detects that the file descriptor given is readable
1011	is readable and/or writable).	1041	and/or writable).
1012		1042
1013	Each watcher type further has its own C<< ev_TYPE_set (watcher *, ...) >>	1043	Each watcher type further has its own C<< ev_TYPE_set (watcher *, ...) >>
1014	macro to configure it, with arguments specific to the watcher type. There	1044	macro to configure it, with arguments specific to the watcher type. There
1015	is also a macro to combine initialisation and setting in one call: C<<	1045	is also a macro to combine initialisation and setting in one call: C<<
1016	ev_TYPE_init (watcher *, callback, ...) >>.	1046	ev_TYPE_init (watcher *, callback, ...) >>.
…		…
1067		1097
1068	=item C<EV_PREPARE>	1098	=item C<EV_PREPARE>
1069		1099
1070	=item C<EV_CHECK>	1100	=item C<EV_CHECK>
1071		1101
1072	All C<ev_prepare> watchers are invoked just I<before> C<ev_loop> starts	1102	All C<ev_prepare> watchers are invoked just I<before> C<ev_run> starts
1073	to gather new events, and all C<ev_check> watchers are invoked just after	1103	to gather new events, and all C<ev_check> watchers are invoked just after
1074	C<ev_loop> has gathered them, but before it invokes any callbacks for any	1104	C<ev_run> has gathered them, but before it invokes any callbacks for any
1075	received events. Callbacks of both watcher types can start and stop as	1105	received events. Callbacks of both watcher types can start and stop as
1076	many watchers as they want, and all of them will be taken into account	1106	many watchers as they want, and all of them will be taken into account
1077	(for example, a C<ev_prepare> watcher might start an idle watcher to keep	1107	(for example, a C<ev_prepare> watcher might start an idle watcher to keep
1078	C<ev_loop> from blocking).	1108	C<ev_run> from blocking).
1079		1109
1080	=item C<EV_EMBED>	1110	=item C<EV_EMBED>
1081		1111
1082	The embedded event loop specified in the C<ev_embed> watcher needs attention.	1112	The embedded event loop specified in the C<ev_embed> watcher needs attention.
1083		1113
…		…
1111	example it might indicate that a fd is readable or writable, and if your	1141	example it might indicate that a fd is readable or writable, and if your
1112	callbacks is well-written it can just attempt the operation and cope with	1142	callbacks is well-written it can just attempt the operation and cope with
1113	the error from read() or write(). This will not work in multi-threaded	1143	the error from read() or write(). This will not work in multi-threaded
1114	programs, though, as the fd could already be closed and reused for another	1144	programs, though, as the fd could already be closed and reused for another
1115	thing, so beware.	1145	thing, so beware.
		1146
		1147	=back
		1148
		1149	=head2 WATCHER STATES
		1150
		1151	There are various watcher states mentioned throughout this manual -
		1152	active, pending and so on. In this section these states and the rules to
		1153	transition between them will be described in more detail - and while these
		1154	rules might look complicated, they usually do "the right thing".
		1155
		1156	=over 4
		1157
		1158	=item initialiased
		1159
		1160	Before a watcher can be registered with the event looop it has to be
		1161	initialised. This can be done with a call to C<ev_TYPE_init>, or calls to
		1162	C<ev_init> followed by the watcher-specific C<ev_TYPE_set> function.
		1163
		1164	In this state it is simply some block of memory that is suitable for use
		1165	in an event loop. It can be moved around, freed, reused etc. at will.
		1166
		1167	=item started/running/active
		1168
		1169	Once a watcher has been started with a call to C<ev_TYPE_start> it becomes
		1170	property of the event loop, and is actively waiting for events. While in
		1171	this state it cannot be accessed (except in a few documented ways), moved,
		1172	freed or anything else - the only legal thing is to keep a pointer to it,
		1173	and call libev functions on it that are documented to work on active watchers.
		1174
		1175	=item pending
		1176
		1177	If a watcher is active and libev determines that an event it is interested
		1178	in has occurred (such as a timer expiring), it will become pending. It will
		1179	stay in this pending state until either it is stopped or its callback is
		1180	about to be invoked, so it is not normally pending inside the watcher
		1181	callback.
		1182
		1183	The watcher might or might not be active while it is pending (for example,
		1184	an expired non-repeating timer can be pending but no longer active). If it
		1185	is stopped, it can be freely accessed (e.g. by calling C<ev_TYPE_set>),
		1186	but it is still property of the event loop at this time, so cannot be
		1187	moved, freed or reused. And if it is active the rules described in the
		1188	previous item still apply.
		1189
		1190	It is also possible to feed an event on a watcher that is not active (e.g.
		1191	via C<ev_feed_event>), in which case it becomes pending without being
		1192	active.
		1193
		1194	=item stopped
		1195
		1196	A watcher can be stopped implicitly by libev (in which case it might still
		1197	be pending), or explicitly by calling its C<ev_TYPE_stop> function. The
		1198	latter will clear any pending state the watcher might be in, regardless
		1199	of whether it was active or not, so stopping a watcher explicitly before
		1200	freeing it is often a good idea.
		1201
		1202	While stopped (and not pending) the watcher is essentially in the
		1203	initialised state, that is it can be reused, moved, modified in any way
		1204	you wish.
1116		1205
1117	=back	1206	=back
1118		1207
1119	=head2 GENERIC WATCHER FUNCTIONS	1208	=head2 GENERIC WATCHER FUNCTIONS
1120		1209
…		…
1624	...	1713	...
1625	struct ev_loop *loop = ev_default_init (0);	1714	struct ev_loop *loop = ev_default_init (0);
1626	ev_io stdin_readable;	1715	ev_io stdin_readable;
1627	ev_io_init (&stdin_readable, stdin_readable_cb, STDIN_FILENO, EV_READ);	1716	ev_io_init (&stdin_readable, stdin_readable_cb, STDIN_FILENO, EV_READ);
1628	ev_io_start (loop, &stdin_readable);	1717	ev_io_start (loop, &stdin_readable);
1629	ev_loop (loop, 0);	1718	ev_run (loop, 0);
1630		1719
1631		1720
1632	=head2 C<ev_timer> - relative and optionally repeating timeouts	1721	=head2 C<ev_timer> - relative and optionally repeating timeouts
1633		1722
1634	Timer watchers are simple relative timers that generate an event after a	1723	Timer watchers are simple relative timers that generate an event after a
…		…
1643	The callback is guaranteed to be invoked only I<after> its timeout has	1732	The callback is guaranteed to be invoked only I<after> its timeout has
1644	passed (not I<at>, so on systems with very low-resolution clocks this	1733	passed (not I<at>, so on systems with very low-resolution clocks this
1645	might introduce a small delay). If multiple timers become ready during the	1734	might introduce a small delay). If multiple timers become ready during the
1646	same loop iteration then the ones with earlier time-out values are invoked	1735	same loop iteration then the ones with earlier time-out values are invoked
1647	before ones of the same priority with later time-out values (but this is	1736	before ones of the same priority with later time-out values (but this is
1648	no longer true when a callback calls C<ev_loop> recursively).	1737	no longer true when a callback calls C<ev_run> recursively).
1649		1738
1650	=head3 Be smart about timeouts	1739	=head3 Be smart about timeouts
1651		1740
1652	Many real-world problems involve some kind of timeout, usually for error	1741	Many real-world problems involve some kind of timeout, usually for error
1653	recovery. A typical example is an HTTP request - if the other side hangs,	1742	recovery. A typical example is an HTTP request - if the other side hangs,
…		…
1824		1913
1825	=head3 The special problem of time updates	1914	=head3 The special problem of time updates
1826		1915
1827	Establishing the current time is a costly operation (it usually takes at	1916	Establishing the current time is a costly operation (it usually takes at
1828	least two system calls): EV therefore updates its idea of the current	1917	least two system calls): EV therefore updates its idea of the current
1829	time only before and after C<ev_loop> collects new events, which causes a	1918	time only before and after C<ev_run> collects new events, which causes a
1830	growing difference between C<ev_now ()> and C<ev_time ()> when handling	1919	growing difference between C<ev_now ()> and C<ev_time ()> when handling
1831	lots of events in one iteration.	1920	lots of events in one iteration.
1832		1921
1833	The relative timeouts are calculated relative to the C<ev_now ()>	1922	The relative timeouts are calculated relative to the C<ev_now ()>
1834	time. This is usually the right thing as this timestamp refers to the time	1923	time. This is usually the right thing as this timestamp refers to the time
…		…
1951	}	2040	}
1952		2041
1953	ev_timer mytimer;	2042	ev_timer mytimer;
1954	ev_timer_init (&mytimer, timeout_cb, 0., 10.); /* note, only repeat used */	2043	ev_timer_init (&mytimer, timeout_cb, 0., 10.); /* note, only repeat used */
1955	ev_timer_again (&mytimer); /* start timer */	2044	ev_timer_again (&mytimer); /* start timer */
1956	ev_loop (loop, 0);	2045	ev_run (loop, 0);
1957		2046
1958	// and in some piece of code that gets executed on any "activity":	2047	// and in some piece of code that gets executed on any "activity":
1959	// reset the timeout to start ticking again at 10 seconds	2048	// reset the timeout to start ticking again at 10 seconds
1960	ev_timer_again (&mytimer);	2049	ev_timer_again (&mytimer);
1961		2050
…		…
1987		2076
1988	As with timers, the callback is guaranteed to be invoked only when the	2077	As with timers, the callback is guaranteed to be invoked only when the
1989	point in time where it is supposed to trigger has passed. If multiple	2078	point in time where it is supposed to trigger has passed. If multiple
1990	timers become ready during the same loop iteration then the ones with	2079	timers become ready during the same loop iteration then the ones with
1991	earlier time-out values are invoked before ones with later time-out values	2080	earlier time-out values are invoked before ones with later time-out values
1992	(but this is no longer true when a callback calls C<ev_loop> recursively).	2081	(but this is no longer true when a callback calls C<ev_run> recursively).
1993		2082
1994	=head3 Watcher-Specific Functions and Data Members	2083	=head3 Watcher-Specific Functions and Data Members
1995		2084
1996	=over 4	2085	=over 4
1997		2086
…		…
2235	Example: Try to exit cleanly on SIGINT.	2324	Example: Try to exit cleanly on SIGINT.
2236		2325
2237	static void	2326	static void
2238	sigint_cb (struct ev_loop loop, ev_signal w, int revents)	2327	sigint_cb (struct ev_loop loop, ev_signal w, int revents)
2239	{	2328	{
2240	ev_unloop (loop, EVUNLOOP_ALL);	2329	ev_break (loop, EVBREAK_ALL);
2241	}	2330	}
2242		2331
2243	ev_signal signal_watcher;	2332	ev_signal signal_watcher;
2244	ev_signal_init (&signal_watcher, sigint_cb, SIGINT);	2333	ev_signal_init (&signal_watcher, sigint_cb, SIGINT);
2245	ev_signal_start (loop, &signal_watcher);	2334	ev_signal_start (loop, &signal_watcher);
…		…
2631		2720
2632	Prepare and check watchers are usually (but not always) used in pairs:	2721	Prepare and check watchers are usually (but not always) used in pairs:
2633	prepare watchers get invoked before the process blocks and check watchers	2722	prepare watchers get invoked before the process blocks and check watchers
2634	afterwards.	2723	afterwards.
2635		2724
2636	You I<must not> call C<ev_loop> or similar functions that enter	2725	You I<must not> call C<ev_run> or similar functions that enter
2637	the current event loop from either C<ev_prepare> or C<ev_check>	2726	the current event loop from either C<ev_prepare> or C<ev_check>
2638	watchers. Other loops than the current one are fine, however. The	2727	watchers. Other loops than the current one are fine, however. The
2639	rationale behind this is that you do not need to check for recursion in	2728	rationale behind this is that you do not need to check for recursion in
2640	those watchers, i.e. the sequence will always be C<ev_prepare>, blocking,	2729	those watchers, i.e. the sequence will always be C<ev_prepare>, blocking,
2641	C<ev_check> so if you have one watcher of each kind they will always be	2730	C<ev_check> so if you have one watcher of each kind they will always be
…		…
2809		2898
2810	if (timeout >= 0)	2899	if (timeout >= 0)
2811	// create/start timer	2900	// create/start timer
2812		2901
2813	// poll	2902	// poll
2814	ev_loop (EV_A_ 0);	2903	ev_run (EV_A_ 0);
2815		2904
2816	// stop timer again	2905	// stop timer again
2817	if (timeout >= 0)	2906	if (timeout >= 0)
2818	ev_timer_stop (EV_A_ &to);	2907	ev_timer_stop (EV_A_ &to);
2819		2908
…		…
2897	if you do not want that, you need to temporarily stop the embed watcher).	2986	if you do not want that, you need to temporarily stop the embed watcher).
2898		2987
2899	=item ev_embed_sweep (loop, ev_embed *)	2988	=item ev_embed_sweep (loop, ev_embed *)
2900		2989
2901	Make a single, non-blocking sweep over the embedded loop. This works	2990	Make a single, non-blocking sweep over the embedded loop. This works
2902	similarly to C<ev_loop (embedded_loop, EVLOOP_NONBLOCK)>, but in the most	2991	similarly to C<ev_run (embedded_loop, EVRUN_NOWAIT)>, but in the most
2903	appropriate way for embedded loops.	2992	appropriate way for embedded loops.
2904		2993
2905	=item struct ev_loop *other [read-only]	2994	=item struct ev_loop *other [read-only]
2906		2995
2907	The embedded event loop.	2996	The embedded event loop.
…		…
2993	disadvantage of having to use multiple event loops (which do not support	3082	disadvantage of having to use multiple event loops (which do not support
2994	signal watchers).	3083	signal watchers).
2995		3084
2996	When this is not possible, or you want to use the default loop for	3085	When this is not possible, or you want to use the default loop for
2997	other reasons, then in the process that wants to start "fresh", call	3086	other reasons, then in the process that wants to start "fresh", call
2998	C<ev_default_destroy ()> followed by C<ev_default_loop (...)>. Destroying	3087	C<ev_loop_destroy (EV_DEFAULT)> followed by C<ev_default_loop (...)>.
2999	the default loop will "orphan" (not stop) all registered watchers, so you	3088	Destroying the default loop will "orphan" (not stop) all registered
3000	have to be careful not to execute code that modifies those watchers. Note	3089	watchers, so you have to be careful not to execute code that modifies
3001	also that in that case, you have to re-register any signal watchers.	3090	those watchers. Note also that in that case, you have to re-register any
		3091	signal watchers.
3002		3092
3003	=head3 Watcher-Specific Functions and Data Members	3093	=head3 Watcher-Specific Functions and Data Members
3004		3094
3005	=over 4	3095	=over 4
3006		3096
…		…
3013	=back	3103	=back
3014		3104
3015		3105
3016	=head2 C<ev_async> - how to wake up an event loop	3106	=head2 C<ev_async> - how to wake up an event loop
3017		3107
3018	In general, you cannot use an C<ev_loop> from multiple threads or other	3108	In general, you cannot use an C<ev_run> from multiple threads or other
3019	asynchronous sources such as signal handlers (as opposed to multiple event	3109	asynchronous sources such as signal handlers (as opposed to multiple event
3020	loops - those are of course safe to use in different threads).	3110	loops - those are of course safe to use in different threads).
3021		3111
3022	Sometimes, however, you need to wake up an event loop you do not control,	3112	Sometimes, however, you need to wake up an event loop you do not control,
3023	for example because it belongs to another thread. This is what C<ev_async>	3113	for example because it belongs to another thread. This is what C<ev_async>
…		…
3530	loop argument"). The C<EV_A> form is used when this is the sole argument,	3620	loop argument"). The C<EV_A> form is used when this is the sole argument,
3531	C<EV_A_> is used when other arguments are following. Example:	3621	C<EV_A_> is used when other arguments are following. Example:
3532		3622
3533	ev_unref (EV_A);	3623	ev_unref (EV_A);
3534	ev_timer_add (EV_A_ watcher);	3624	ev_timer_add (EV_A_ watcher);
3535	ev_loop (EV_A_ 0);	3625	ev_run (EV_A_ 0);
3536		3626
3537	It assumes the variable C<loop> of type C<struct ev_loop *> is in scope,	3627	It assumes the variable C<loop> of type C<struct ev_loop *> is in scope,
3538	which is often provided by the following macro.	3628	which is often provided by the following macro.
3539		3629
3540	=item C<EV_P>, C<EV_P_>	3630	=item C<EV_P>, C<EV_P_>
…		…
3580	}	3670	}
3581		3671
3582	ev_check check;	3672	ev_check check;
3583	ev_check_init (&check, check_cb);	3673	ev_check_init (&check, check_cb);
3584	ev_check_start (EV_DEFAULT_ &check);	3674	ev_check_start (EV_DEFAULT_ &check);
3585	ev_loop (EV_DEFAULT_ 0);	3675	ev_run (EV_DEFAULT_ 0);
3586		3676
3587	=head1 EMBEDDING	3677	=head1 EMBEDDING
3588		3678
3589	Libev can (and often is) directly embedded into host	3679	Libev can (and often is) directly embedded into host
3590	applications. Examples of applications that embed it include the Deliantra	3680	applications. Examples of applications that embed it include the Deliantra
…		…
3681	to a compiled library. All other symbols change the ABI, which means all	3771	to a compiled library. All other symbols change the ABI, which means all
3682	users of libev and the libev code itself must be compiled with compatible	3772	users of libev and the libev code itself must be compiled with compatible
3683	settings.	3773	settings.
3684		3774
3685	=over 4	3775	=over 4
		3776
		3777	=item EV_COMPAT3 (h)
		3778
		3779	Backwards compatibility is a major concern for libev. This is why this
		3780	release of libev comes with wrappers for the functions and symbols that
		3781	have been renamed between libev version 3 and 4.
		3782
		3783	You can disable these wrappers (to test compatibility with future
		3784	versions) by defining C<EV_COMPAT3> to C<0> when compiling your
		3785	sources. This has the additional advantage that you can drop the C<struct>
		3786	from C<struct ev_loop> declarations, as libev will provide an C<ev_loop>
		3787	typedef in that case.
		3788
		3789	In some future version, the default for C<EV_COMPAT3> will become C<0>,
		3790	and in some even more future version the compatibility code will be
		3791	removed completely.
3686		3792
3687	=item EV_STANDALONE (h)	3793	=item EV_STANDALONE (h)
3688		3794
3689	Must always be C<1> if you do not use autoconf configuration, which	3795	Must always be C<1> if you do not use autoconf configuration, which
3690	keeps libev from including F<config.h>, and it also defines dummy	3796	keeps libev from including F<config.h>, and it also defines dummy
…		…
4265	userdata *u = ev_userdata (EV_A);	4371	userdata *u = ev_userdata (EV_A);
4266	pthread_mutex_lock (&u->lock);	4372	pthread_mutex_lock (&u->lock);
4267	}	4373	}
4268		4374
4269	The event loop thread first acquires the mutex, and then jumps straight	4375	The event loop thread first acquires the mutex, and then jumps straight
4270	into C<ev_loop>:	4376	into C<ev_run>:
4271		4377
4272	void *	4378	void *
4273	l_run (void *thr_arg)	4379	l_run (void *thr_arg)
4274	{	4380	{
4275	struct ev_loop loop = (struct ev_loop )thr_arg;	4381	struct ev_loop loop = (struct ev_loop )thr_arg;
4276		4382
4277	l_acquire (EV_A);	4383	l_acquire (EV_A);
4278	pthread_setcanceltype (PTHREAD_CANCEL_ASYNCHRONOUS, 0);	4384	pthread_setcanceltype (PTHREAD_CANCEL_ASYNCHRONOUS, 0);
4279	ev_loop (EV_A_ 0);	4385	ev_run (EV_A_ 0);
4280	l_release (EV_A);	4386	l_release (EV_A);
4281		4387
4282	return 0;	4388	return 0;
4283	}	4389	}
4284		4390
…		…
4336		4442
4337	=head3 COROUTINES	4443	=head3 COROUTINES
4338		4444
4339	Libev is very accommodating to coroutines ("cooperative threads"):	4445	Libev is very accommodating to coroutines ("cooperative threads"):
4340	libev fully supports nesting calls to its functions from different	4446	libev fully supports nesting calls to its functions from different
4341	coroutines (e.g. you can call C<ev_loop> on the same loop from two	4447	coroutines (e.g. you can call C<ev_run> on the same loop from two
4342	different coroutines, and switch freely between both coroutines running	4448	different coroutines, and switch freely between both coroutines running
4343	the loop, as long as you don't confuse yourself). The only exception is	4449	the loop, as long as you don't confuse yourself). The only exception is
4344	that you must not do this from C<ev_periodic> reschedule callbacks.	4450	that you must not do this from C<ev_periodic> reschedule callbacks.
4345		4451
4346	Care has been taken to ensure that libev does not keep local state inside	4452	Care has been taken to ensure that libev does not keep local state inside
4347	C<ev_loop>, and other calls do not usually allow for coroutine switches as	4453	C<ev_run>, and other calls do not usually allow for coroutine switches as
4348	they do not call any callbacks.	4454	they do not call any callbacks.
4349		4455
4350	=head2 COMPILER WARNINGS	4456	=head2 COMPILER WARNINGS
4351		4457
4352	Depending on your compiler and compiler settings, you might get no or a	4458	Depending on your compiler and compiler settings, you might get no or a
…		…
4436	=head3 C<kqueue> is buggy	4542	=head3 C<kqueue> is buggy
4437		4543
4438	The kqueue syscall is broken in all known versions - most versions support	4544	The kqueue syscall is broken in all known versions - most versions support
4439	only sockets, many support pipes.	4545	only sockets, many support pipes.
4440		4546
4441	Libev tries to work around this by not using C<kqueue> by default on	4547	Libev tries to work around this by not using C<kqueue> by default on this
4442	this rotten platform, but of course you can still ask for it when creating	4548	rotten platform, but of course you can still ask for it when creating a
4443	a loop.	4549	loop - embedding a socket-only kqueue loop into a select-based one is
		4550	probably going to work well.
4444		4551
4445	=head3 C<poll> is buggy	4552	=head3 C<poll> is buggy
4446		4553
4447	Instead of fixing C<kqueue>, Apple replaced their (working) C<poll>	4554	Instead of fixing C<kqueue>, Apple replaced their (working) C<poll>
4448	implementation by something calling C<kqueue> internally around the 10.5.6	4555	implementation by something calling C<kqueue> internally around the 10.5.6
…		…
4467		4574
4468	=head3 C<errno> reentrancy	4575	=head3 C<errno> reentrancy
4469		4576
4470	The default compile environment on Solaris is unfortunately so	4577	The default compile environment on Solaris is unfortunately so
4471	thread-unsafe that you can't even use components/libraries compiled	4578	thread-unsafe that you can't even use components/libraries compiled
4472	without C<-D_REENTRANT> (as long as they use C<errno>), which, of course,	4579	without C<-D_REENTRANT> in a threaded program, which, of course, isn't
4473	isn't defined by default.	4580	defined by default. A valid, if stupid, implementation choice.
4474		4581
4475	If you want to use libev in threaded environments you have to make sure	4582	If you want to use libev in threaded environments you have to make sure
4476	it's compiled with C<_REENTRANT> defined.	4583	it's compiled with C<_REENTRANT> defined.
4477		4584
4478	=head3 Event port backend	4585	=head3 Event port backend
4479		4586
4480	The scalable event interface for Solaris is called "event ports". Unfortunately,	4587	The scalable event interface for Solaris is called "event
4481	this mechanism is very buggy. If you run into high CPU usage, your program	4588	ports". Unfortunately, this mechanism is very buggy in all major
		4589	releases. If you run into high CPU usage, your program freezes or you get
4482	freezes or you get a large number of spurious wakeups, make sure you have	4590	a large number of spurious wakeups, make sure you have all the relevant
4483	all the relevant and latest kernel patches applied. No, I don't know which	4591	and latest kernel patches applied. No, I don't know which ones, but there
4484	ones, but there are multiple ones.	4592	are multiple ones to apply, and afterwards, event ports actually work
		4593	great.
4485		4594
4486	If you can't get it to work, you can try running the program by setting	4595	If you can't get it to work, you can try running the program by setting
4487	the environment variable C<LIBEV_FLAGS=3> to only allow C<poll> and	4596	the environment variable C<LIBEV_FLAGS=3> to only allow C<poll> and
4488	C<select> backends.	4597	C<select> backends.
4489		4598
4490	=head2 AIX POLL BUG	4599	=head2 AIX POLL BUG
4491		4600
4492	AIX unfortunately has a broken C<poll.h> header. Libev works around	4601	AIX unfortunately has a broken C<poll.h> header. Libev works around
4493	this by trying to avoid the poll backend altogether (i.e. it's not even	4602	this by trying to avoid the poll backend altogether (i.e. it's not even
4494	compiled in), which normally isn't a big problem as C<select> works fine	4603	compiled in), which normally isn't a big problem as C<select> works fine
4495	with large bitsets, and AIX is dead anyway.	4604	with large bitsets on AIX, and AIX is dead anyway.
4496		4605
4497	=head2 WIN32 PLATFORM LIMITATIONS AND WORKAROUNDS	4606	=head2 WIN32 PLATFORM LIMITATIONS AND WORKAROUNDS
4498		4607
4499	=head3 General issues	4608	=head3 General issues
4500		4609
…		…
4729	compatibility, so most programs should still compile. Those might be	4838	compatibility, so most programs should still compile. Those might be
4730	removed in later versions of libev, so better update early than late.	4839	removed in later versions of libev, so better update early than late.
4731		4840
4732	=over 4	4841	=over 4
4733		4842
4734	=item C<ev_loop_count> renamed to C<ev_iteration>	4843	=item C<ev_default_destroy> and C<ev_default_fork> have been removed
4735		4844
4736	=item C<ev_loop_depth> renamed to C<ev_depth>	4845	These calls can be replaced easily by their C<ev_loop_xxx> counterparts:
4737		4846
4738	=item C<ev_loop_verify> renamed to C<ev_verify>	4847	ev_loop_destroy (EV_DEFAULT);
		4848	ev_loop_fork (EV_DEFAULT);
		4849
		4850	=item function/symbol renames
		4851
		4852	A number of functions and symbols have been renamed:
		4853
		4854	ev_loop => ev_run
		4855	EVLOOP_NONBLOCK => EVRUN_NOWAIT
		4856	EVLOOP_ONESHOT => EVRUN_ONCE
		4857
		4858	ev_unloop => ev_break
		4859	EVUNLOOP_CANCEL => EVBREAK_CANCEL
		4860	EVUNLOOP_ONE => EVBREAK_ONE
		4861	EVUNLOOP_ALL => EVBREAK_ALL
		4862
		4863	EV_TIMEOUT => EV_TIMER
		4864
		4865	ev_loop_count => ev_iteration
		4866	ev_loop_depth => ev_depth
		4867	ev_loop_verify => ev_verify
4739		4868
4740	Most functions working on C<struct ev_loop> objects don't have an	4869	Most functions working on C<struct ev_loop> objects don't have an
4741	C<ev_loop_> prefix, so it was removed. Note that C<ev_loop_fork> is	4870	C<ev_loop_> prefix, so it was removed; C<ev_loop>, C<ev_unloop> and
		4871	associated constants have been renamed to not collide with the C<struct
		4872	ev_loop> anymore and C<EV_TIMER> now follows the same naming scheme
		4873	as all other watcher types. Note that C<ev_loop_fork> is still called
4742	still called C<ev_loop_fork> because it would otherwise clash with the	4874	C<ev_loop_fork> because it would otherwise clash with the C<ev_fork>
4743	C<ev_fork> typedef.	4875	typedef.
4744		4876
4745	=item C<EV_TIMEOUT> renamed to C<EV_TIMER> in C<revents>	4877	=item C<EV_COMPAT3> backwards compatibility mechanism
4746		4878
4747	This is a simple rename - all other watcher types use their name	4879	The backward compatibility mechanism can be controlled by
4748	as revents flag, and now C<ev_timer> does, too.	4880	C<EV_COMPAT3>. See L<PREPROCESSOR SYMBOLS/MACROS> in the L<EMBEDDING>
4749		4881	section.
4750	Both C<EV_TIMER> and C<EV_TIMEOUT> symbols were present in 3.x versions
4751	and continue to be present for the foreseeable future, so this is mostly a
4752	documentation change.
4753		4882
4754	=item C<EV_MINIMAL> mechanism replaced by C<EV_FEATURES>	4883	=item C<EV_MINIMAL> mechanism replaced by C<EV_FEATURES>
4755		4884
4756	The preprocessor symbol C<EV_MINIMAL> has been replaced by a different	4885	The preprocessor symbol C<EV_MINIMAL> has been replaced by a different
4757	mechanism, C<EV_FEATURES>. Programs using C<EV_MINIMAL> usually compile	4886	mechanism, C<EV_FEATURES>. Programs using C<EV_MINIMAL> usually compile
…		…
4764		4893
4765	=over 4	4894	=over 4
4766		4895
4767	=item active	4896	=item active
4768		4897
4769	A watcher is active as long as it has been started (has been attached to	4898	A watcher is active as long as it has been started and not yet stopped.
4770	an event loop) but not yet stopped (disassociated from the event loop).	4899	See L<WATCHER STATES> for details.
4771		4900
4772	=item application	4901	=item application
4773		4902
4774	In this document, an application is whatever is using libev.	4903	In this document, an application is whatever is using libev.
		4904
		4905	=item backend
		4906
		4907	The part of the code dealing with the operating system interfaces.
4775		4908
4776	=item callback	4909	=item callback
4777		4910
4778	The address of a function that is called when some event has been	4911	The address of a function that is called when some event has been
4779	detected. Callbacks are being passed the event loop, the watcher that	4912	detected. Callbacks are being passed the event loop, the watcher that
4780	received the event, and the actual event bitset.	4913	received the event, and the actual event bitset.
4781		4914
4782	=item callback invocation	4915	=item callback/watcher invocation
4783		4916
4784	The act of calling the callback associated with a watcher.	4917	The act of calling the callback associated with a watcher.
4785		4918
4786	=item event	4919	=item event
4787		4920
…		…
4806	The model used to describe how an event loop handles and processes	4939	The model used to describe how an event loop handles and processes
4807	watchers and events.	4940	watchers and events.
4808		4941
4809	=item pending	4942	=item pending
4810		4943
4811	A watcher is pending as soon as the corresponding event has been detected,	4944	A watcher is pending as soon as the corresponding event has been
4812	and stops being pending as soon as the watcher will be invoked or its	4945	detected. See L<WATCHER STATES> for details.
4813	pending status is explicitly cleared by the application.
4814
4815	A watcher can be pending, but not active. Stopping a watcher also clears
4816	its pending status.
4817		4946
4818	=item real time	4947	=item real time
4819		4948
4820	The physical time that is observed. It is apparently strictly monotonic :)	4949	The physical time that is observed. It is apparently strictly monotonic :)
4821		4950
…		…
4828	=item watcher	4957	=item watcher
4829		4958
4830	A data structure that describes interest in certain events. Watchers need	4959	A data structure that describes interest in certain events. Watchers need
4831	to be started (attached to an event loop) before they can receive events.	4960	to be started (attached to an event loop) before they can receive events.
4832		4961
4833	=item watcher invocation
4834
4835	The act of calling the callback associated with a watcher.
4836
4837	=back	4962	=back
4838		4963
4839	=head1 AUTHOR	4964	=head1 AUTHOR
4840		4965
4841	Marc Lehmann <libev@schmorp.de>, with repeated corrections by Mikael Magnusson.	4966	Marc Lehmann <libev@schmorp.de>, with repeated corrections by Mikael Magnusson.

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Comparing libev/ev.pod (file contents): Revision 1.309 by root, Thu Oct 21 09:23:21 2010 UTC vs. Revision 1.322 by root, Sun Oct 24 17:58:41 2010 UTC

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Comparing libev/ev.pod (file contents):
Revision 1.309 by root, Thu Oct 21 09:23:21 2010 UTC vs.
Revision 1.322 by root, Sun Oct 24 17:58:41 2010 UTC