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

Comparing libev/ev.pod (file contents):
Revision 1.321 by sf-exg, Fri Oct 22 10:50:24 2010 UTC vs.
Revision 1.322 by root, Sun Oct 24 17:58:41 2010 UTC

…		…
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);
…		…
293	...	293	...
294	ev_set_syserr_cb (fatal_error);	294	ev_set_syserr_cb (fatal_error);
295		295
296	=back	296	=back
297		297
298	=head1 FUNCTIONS CONTROLLING THE EVENT LOOP	298	=head1 FUNCTIONS CONTROLLING EVENT LOOPS
299		299
300	An event loop is described by a C<struct ev_loop *> (the C<struct> is	300	An event loop is described by a C<struct ev_loop *> (the C<struct> is
301	I<not> optional in this case unless libev 3 compatibility is disabled, as	301	I<not> optional in this case unless libev 3 compatibility is disabled, as
302	libev 3 had an C<ev_loop> function colliding with the struct name).	302	libev 3 had an C<ev_loop> function colliding with the struct name).
303		303
…		…
307		307
308	=over 4	308	=over 4
309		309
310	=item struct ev_loop *ev_default_loop (unsigned int flags)	310	=item struct ev_loop *ev_default_loop (unsigned int flags)
311		311
312	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
313	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
314	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
315	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".
316		322
317	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
318	function.	324	function (or via the C<EV_DEFAULT> macro).
319		325
320	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
321	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
322	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).
323		330
324	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,
325	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
326	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
327	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
328	can simply overwrite the C<SIGCHLD> signal handler I<after> calling	335	C<SIGCHLD> signal handler I<after> calling C<ev_default_init>.
329	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.
330		362
331	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
332	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>).
333		365
334	The following flags are supported:	366	The following flags are supported:
…		…
552	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,
553	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
554	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
555	()> will be tried.	587	()> will be tried.
556		588
557	Example: This is the most typical usage.
558
559	if (!ev_default_loop (0))
560	fatal ("could not initialise libev, bad $LIBEV_FLAGS in environment?");
561
562	Example: Restrict libev to the select and poll backends, and do not allow
563	environment settings to be taken into account:
564
565	ev_default_loop (EVBACKEND_POLL \| EVBACKEND_SELECT \| EVFLAG_NOENV);
566
567	Example: Use whatever libev has to offer, but make sure that kqueue is
568	used if available (warning, breaks stuff, best use only with your own
569	private event loop and only if you know the OS supports your types of
570	fds):
571
572	ev_default_loop (ev_recommended_backends () \| EVBACKEND_KQUEUE);
573
574	=item struct ev_loop *ev_loop_new (unsigned int flags)
575
576	Similar to C<ev_default_loop>, but always creates a new event loop that is
577	always distinct from the default loop.
578
579	Note that this function I<is> thread-safe, and one common way to use
580	libev with threads is indeed to create one loop per thread, and using the
581	default loop in the "main" or "initial" thread.
582
583	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.
584		590
585	struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL \| EVFLAG_NOENV);	591	struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL \| EVFLAG_NOENV);
586	if (!epoller)	592	if (!epoller)
587	fatal ("no epoll found here, maybe it hides under your chair");	593	fatal ("no epoll found here, maybe it hides under your chair");
588		594
589	=item ev_default_destroy ()	595	=item ev_loop_destroy (loop)
590		596
591	Destroys the default loop (frees all memory and kernel state etc.). None	597	Destroys an event loop object (frees all memory and kernel state
592	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
593	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
594	either stop all watchers cleanly yourself I<before> calling this function,	600	responsibility to either stop all watchers cleanly yourself I<before>
595	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
596	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).
597		604
598	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
599	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
600	as signal and child watchers) would need to be stopped manually.	607	as signal and child watchers) would need to be stopped manually.
601		608
602	In general it is not advisable to call this function except in the	609	This function is normally used on loop objects allocated by
603	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.
604	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>
605	C<ev_loop_new> and C<ev_loop_destroy>.	616	and C<ev_loop_destroy>.
606		617
607	=item ev_loop_destroy (loop)	618	=item ev_loop_fork (loop)
608		619
609	Like C<ev_default_destroy>, but destroys an event loop created by an
610	earlier call to C<ev_loop_new>.
611
612	=item ev_default_fork ()
613
614	This function sets a flag that causes subsequent C<ev_run> iterations	620	This function sets a flag that causes subsequent C<ev_run> iterations to
615	to reinitialise the kernel state for backends that have one. Despite the	621	reinitialise the kernel state for backends that have one. Despite the
616	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
617	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
618	sense). You I<must> call it in the child before using any of the libev	624	child before resuming or calling C<ev_run>.
619	functions, and it will only take effect at the next C<ev_run> iteration.
620		625
621	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
622	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
623	because some kernel interfaces cough I<kqueue> cough do funny things	628	because some kernel interfaces cough I<kqueue> cough do funny things
624	during fork.	629	during fork.
…		…
629	call it at all (in fact, C<epoll> is so badly broken that it makes a	634	call it at all (in fact, C<epoll> is so badly broken that it makes a
630	difference, but libev will usually detect this case on its own and do a	635	difference, but libev will usually detect this case on its own and do a
631	costly reset of the backend).	636	costly reset of the backend).
632		637
633	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
634	it just in case after a fork. To make this easy, the function will fit in	639	it just in case after a fork.
635	quite nicely into a call to C<pthread_atfork>:
636		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	...
637	pthread_atfork (0, 0, ev_default_fork);	651	pthread_atfork (0, 0, post_fork_child);
638
639	=item ev_loop_fork (loop)
640
641	Like C<ev_default_fork>, but acts on an event loop created by
642	C<ev_loop_new>. Yes, you have to call this on every allocated event loop
643	after fork that you want to re-use in the child, and how you keep track of
644	them is entirely your own problem.
645		652
646	=item int ev_is_default_loop (loop)	653	=item int ev_is_default_loop (loop)
647		654
648	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
649	otherwise.	656	otherwise.
…		…
3075	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
3076	signal watchers).	3083	signal watchers).
3077		3084
3078	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
3079	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
3080	C<ev_default_destroy ()> followed by C<ev_default_loop (...)>. Destroying	3087	C<ev_loop_destroy (EV_DEFAULT)> followed by C<ev_default_loop (...)>.
3081	the default loop will "orphan" (not stop) all registered watchers, so you	3088	Destroying the default loop will "orphan" (not stop) all registered
3082	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
3083	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.
3084		3092
3085	=head3 Watcher-Specific Functions and Data Members	3093	=head3 Watcher-Specific Functions and Data Members
3086		3094
3087	=over 4	3095	=over 4
3088		3096
…		…
4830	compatibility, so most programs should still compile. Those might be	4838	compatibility, so most programs should still compile. Those might be
4831	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.
4832		4840
4833	=over 4	4841	=over 4
4834		4842
		4843	=item C<ev_default_destroy> and C<ev_default_fork> have been removed
		4844
		4845	These calls can be replaced easily by their C<ev_loop_xxx> counterparts:
		4846
		4847	ev_loop_destroy (EV_DEFAULT);
		4848	ev_loop_fork (EV_DEFAULT);
		4849
4835	=item function/symbol renames	4850	=item function/symbol renames
4836		4851
4837	A number of functions and symbols have been renamed:	4852	A number of functions and symbols have been renamed:
4838		4853
4839	ev_loop => ev_run	4854	ev_loop => ev_run

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Comparing libev/ev.pod (file contents): Revision 1.321 by sf-exg, Fri Oct 22 10:50:24 2010 UTC vs. Revision 1.322 by root, Sun Oct 24 17:58:41 2010 UTC

Diff Legend

Comparing libev/ev.pod (file contents):
Revision 1.321 by sf-exg, Fri Oct 22 10:50:24 2010 UTC vs.
Revision 1.322 by root, Sun Oct 24 17:58:41 2010 UTC