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

Comparing libev/ev.pod (file contents):
Revision 1.50 by root, Tue Nov 27 10:59:11 2007 UTC vs.
Revision 1.73 by root, Sat Dec 8 03:53:36 2007 UTC

…		…
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	#include <ev.h>	7	#include <ev.h>
8		8
		9	=head1 EXAMPLE PROGRAM
		10
		11	#include <ev.h>
		12
		13	ev_io stdin_watcher;
		14	ev_timer timeout_watcher;
		15
		16	/* called when data readable on stdin */
		17	static void
		18	stdin_cb (EV_P_ struct ev_io *w, int revents)
		19	{
		20	/* puts ("stdin ready"); */
		21	ev_io_stop (EV_A_ w); /* just a syntax example */
		22	ev_unloop (EV_A_ EVUNLOOP_ALL); /* leave all loop calls */
		23	}
		24
		25	static void
		26	timeout_cb (EV_P_ struct ev_timer *w, int revents)
		27	{
		28	/* puts ("timeout"); */
		29	ev_unloop (EV_A_ EVUNLOOP_ONE); /* leave one loop call */
		30	}
		31
		32	int
		33	main (void)
		34	{
		35	struct ev_loop *loop = ev_default_loop (0);
		36
		37	/* initialise an io watcher, then start it */
		38	ev_io_init (&stdin_watcher, stdin_cb, /STDIN_FILENO/ 0, EV_READ);
		39	ev_io_start (loop, &stdin_watcher);
		40
		41	/* simple non-repeating 5.5 second timeout */
		42	ev_timer_init (&timeout_watcher, timeout_cb, 5.5, 0.);
		43	ev_timer_start (loop, &timeout_watcher);
		44
		45	/* loop till timeout or data ready */
		46	ev_loop (loop, 0);
		47
		48	return 0;
		49	}
		50
9	=head1 DESCRIPTION	51	=head1 DESCRIPTION
		52
		53	The newest version of this document is also available as a html-formatted
		54	web page you might find easier to navigate when reading it for the first
		55	time: L<http://cvs.schmorp.de/libev/ev.html>.
10		56
11	Libev is an event loop: you register interest in certain events (such as a	57	Libev is an event loop: you register interest in certain events (such as a
12	file descriptor being readable or a timeout occuring), and it will manage	58	file descriptor being readable or a timeout occuring), and it will manage
13	these event sources and provide your program with events.	59	these event sources and provide your program with events.
14		60
…		…
21	details of the event, and then hand it over to libev by I<starting> the	67	details of the event, and then hand it over to libev by I<starting> the
22	watcher.	68	watcher.
23		69
24	=head1 FEATURES	70	=head1 FEATURES
25		71
26	Libev supports select, poll, the linux-specific epoll and the bsd-specific	72	Libev supports C<select>, C<poll>, the Linux-specific C<epoll>, the
27	kqueue mechanisms for file descriptor events, relative timers, absolute	73	BSD-specific C<kqueue> and the Solaris-specific event port mechanisms
28	timers with customised rescheduling, signal events, process status change	74	for file descriptor events (C<ev_io>), the Linux C<inotify> interface
29	events (related to SIGCHLD), and event watchers dealing with the event	75	(for C<ev_stat>), relative timers (C<ev_timer>), absolute timers
30	loop mechanism itself (idle, prepare and check watchers). It also is quite	76	with customised rescheduling (C<ev_periodic>), synchronous signals
		77	(C<ev_signal>), process status change events (C<ev_child>), and event
		78	watchers dealing with the event loop mechanism itself (C<ev_idle>,
		79	C<ev_embed>, C<ev_prepare> and C<ev_check> watchers) as well as
		80	file watchers (C<ev_stat>) and even limited support for fork events
		81	(C<ev_fork>).
		82
		83	It also is quite fast (see this
31	fast (see this L<benchmark\|http://libev.schmorp.de/bench.html> comparing	84	L<benchmark\|http://libev.schmorp.de/bench.html> comparing it to libevent
32	it to libevent for example).	85	for example).
33		86
34	=head1 CONVENTIONS	87	=head1 CONVENTIONS
35		88
36	Libev is very configurable. In this manual the default configuration	89	Libev is very configurable. In this manual the default configuration will
37	will be described, which supports multiple event loops. For more info	90	be described, which supports multiple event loops. For more info about
38	about various configuration options please have a look at the file	91	various configuration options please have a look at B<EMBED> section in
39	F<README.embed> in the libev distribution. If libev was configured without	92	this manual. If libev was configured without support for multiple event
40	support for multiple event loops, then all functions taking an initial	93	loops, then all functions taking an initial argument of name C<loop>
41	argument of name C<loop> (which is always of type C<struct ev_loop *>)	94	(which is always of type C<struct ev_loop *>) will not have this argument.
42	will not have this argument.
43		95
44	=head1 TIME REPRESENTATION	96	=head1 TIME REPRESENTATION
45		97
46	Libev represents time as a single floating point number, representing the	98	Libev represents time as a single floating point number, representing the
47	(fractional) number of seconds since the (POSIX) epoch (somewhere near	99	(fractional) number of seconds since the (POSIX) epoch (somewhere near
…		…
76	Usually, it's a good idea to terminate if the major versions mismatch,	128	Usually, it's a good idea to terminate if the major versions mismatch,
77	as this indicates an incompatible change. Minor versions are usually	129	as this indicates an incompatible change. Minor versions are usually
78	compatible to older versions, so a larger minor version alone is usually	130	compatible to older versions, so a larger minor version alone is usually
79	not a problem.	131	not a problem.
80		132
81	Example: make sure we haven't accidentally been linked against the wrong	133	Example: Make sure we haven't accidentally been linked against the wrong
82	version:	134	version.
83		135
84	assert (("libev version mismatch",	136	assert (("libev version mismatch",
85	ev_version_major () == EV_VERSION_MAJOR	137	ev_version_major () == EV_VERSION_MAJOR
86	&& ev_version_minor () >= EV_VERSION_MINOR));	138	&& ev_version_minor () >= EV_VERSION_MINOR));
87		139
…		…
117		169
118	See the description of C<ev_embed> watchers for more info.	170	See the description of C<ev_embed> watchers for more info.
119		171
120	=item ev_set_allocator (void (cb)(void *ptr, long size))	172	=item ev_set_allocator (void (cb)(void *ptr, long size))
121		173
122	Sets the allocation function to use (the prototype is similar to the	174	Sets the allocation function to use (the prototype is similar - the
123	realloc C function, the semantics are identical). It is used to allocate	175	semantics is identical - to the realloc C function). It is used to
124	and free memory (no surprises here). If it returns zero when memory	176	allocate and free memory (no surprises here). If it returns zero when
125	needs to be allocated, the library might abort or take some potentially	177	memory needs to be allocated, the library might abort or take some
126	destructive action. The default is your system realloc function.	178	potentially destructive action. The default is your system realloc
		179	function.
127		180
128	You could override this function in high-availability programs to, say,	181	You could override this function in high-availability programs to, say,
129	free some memory if it cannot allocate memory, to use a special allocator,	182	free some memory if it cannot allocate memory, to use a special allocator,
130	or even to sleep a while and retry until some memory is available.	183	or even to sleep a while and retry until some memory is available.
131		184
132	Example: replace the libev allocator with one that waits a bit and then	185	Example: Replace the libev allocator with one that waits a bit and then
133	retries: better than mine).	186	retries).
134		187
135	static void *	188	static void *
136	persistent_realloc (void *ptr, long size)	189	persistent_realloc (void *ptr, size_t size)
137	{	190	{
138	for (;;)	191	for (;;)
139	{	192	{
140	void *newptr = realloc (ptr, size);	193	void *newptr = realloc (ptr, size);
141		194
…		…
157	callback is set, then libev will expect it to remedy the sitution, no	210	callback is set, then libev will expect it to remedy the sitution, no
158	matter what, when it returns. That is, libev will generally retry the	211	matter what, when it returns. That is, libev will generally retry the
159	requested operation, or, if the condition doesn't go away, do bad stuff	212	requested operation, or, if the condition doesn't go away, do bad stuff
160	(such as abort).	213	(such as abort).
161		214
162	Example: do the same thing as libev does internally:	215	Example: This is basically the same thing that libev does internally, too.
163		216
164	static void	217	static void
165	fatal_error (const char *msg)	218	fatal_error (const char *msg)
166	{	219	{
167	perror (msg);	220	perror (msg);
…		…
217	C<LIBEV_FLAGS>. Otherwise (the default), this environment variable will	270	C<LIBEV_FLAGS>. Otherwise (the default), this environment variable will
218	override the flags completely if it is found in the environment. This is	271	override the flags completely if it is found in the environment. This is
219	useful to try out specific backends to test their performance, or to work	272	useful to try out specific backends to test their performance, or to work
220	around bugs.	273	around bugs.
221		274
		275	=item C<EVFLAG_FORKCHECK>
		276
		277	Instead of calling C<ev_default_fork> or C<ev_loop_fork> manually after
		278	a fork, you can also make libev check for a fork in each iteration by
		279	enabling this flag.
		280
		281	This works by calling C<getpid ()> on every iteration of the loop,
		282	and thus this might slow down your event loop if you do a lot of loop
		283	iterations and little real work, but is usually not noticeable (on my
		284	Linux system for example, C<getpid> is actually a simple 5-insn sequence
		285	without a syscall and thus I<very> fast, but my Linux system also has
		286	C<pthread_atfork> which is even faster).
		287
		288	The big advantage of this flag is that you can forget about fork (and
		289	forget about forgetting to tell libev about forking) when you use this
		290	flag.
		291
		292	This flag setting cannot be overriden or specified in the C<LIBEV_FLAGS>
		293	environment variable.
		294
222	=item C<EVBACKEND_SELECT> (value 1, portable select backend)	295	=item C<EVBACKEND_SELECT> (value 1, portable select backend)
223		296
224	This is your standard select(2) backend. Not I<completely> standard, as	297	This is your standard select(2) backend. Not I<completely> standard, as
225	libev tries to roll its own fd_set with no limits on the number of fds,	298	libev tries to roll its own fd_set with no limits on the number of fds,
226	but if that fails, expect a fairly low limit on the number of fds when	299	but if that fails, expect a fairly low limit on the number of fds when
…		…
313	Similar to C<ev_default_loop>, but always creates a new event loop that is	386	Similar to C<ev_default_loop>, but always creates a new event loop that is
314	always distinct from the default loop. Unlike the default loop, it cannot	387	always distinct from the default loop. Unlike the default loop, it cannot
315	handle signal and child watchers, and attempts to do so will be greeted by	388	handle signal and child watchers, and attempts to do so will be greeted by
316	undefined behaviour (or a failed assertion if assertions are enabled).	389	undefined behaviour (or a failed assertion if assertions are enabled).
317		390
318	Example: try to create a event loop that uses epoll and nothing else.	391	Example: Try to create a event loop that uses epoll and nothing else.
319		392
320	struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL \| EVFLAG_NOENV);	393	struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL \| EVFLAG_NOENV);
321	if (!epoller)	394	if (!epoller)
322	fatal ("no epoll found here, maybe it hides under your chair");	395	fatal ("no epoll found here, maybe it hides under your chair");
323		396
…		…
360	=item ev_loop_fork (loop)	433	=item ev_loop_fork (loop)
361		434
362	Like C<ev_default_fork>, but acts on an event loop created by	435	Like C<ev_default_fork>, but acts on an event loop created by
363	C<ev_loop_new>. Yes, you have to call this on every allocated event loop	436	C<ev_loop_new>. Yes, you have to call this on every allocated event loop
364	after fork, and how you do this is entirely your own problem.	437	after fork, and how you do this is entirely your own problem.
		438
		439	=item unsigned int ev_loop_count (loop)
		440
		441	Returns the count of loop iterations for the loop, which is identical to
		442	the number of times libev did poll for new events. It starts at C<0> and
		443	happily wraps around with enough iterations.
		444
		445	This value can sometimes be useful as a generation counter of sorts (it
		446	"ticks" the number of loop iterations), as it roughly corresponds with
		447	C<ev_prepare> and C<ev_check> calls.
365		448
366	=item unsigned int ev_backend (loop)	449	=item unsigned int ev_backend (loop)
367		450
368	Returns one of the C<EVBACKEND_*> flags indicating the event backend in	451	Returns one of the C<EVBACKEND_*> flags indicating the event backend in
369	use.	452	use.
…		…
422	Signals and child watchers are implemented as I/O watchers, and will	505	Signals and child watchers are implemented as I/O watchers, and will
423	be handled here by queueing them when their watcher gets executed.	506	be handled here by queueing them when their watcher gets executed.
424	- If ev_unloop has been called or EVLOOP_ONESHOT or EVLOOP_NONBLOCK	507	- If ev_unloop has been called or EVLOOP_ONESHOT or EVLOOP_NONBLOCK
425	were used, return, otherwise continue with step *.	508	were used, return, otherwise continue with step *.
426		509
427	Example: queue some jobs and then loop until no events are outsanding	510	Example: Queue some jobs and then loop until no events are outsanding
428	anymore.	511	anymore.
429		512
430	... queue jobs here, make sure they register event watchers as long	513	... queue jobs here, make sure they register event watchers as long
431	... as they still have work to do (even an idle watcher will do..)	514	... as they still have work to do (even an idle watcher will do..)
432	ev_loop (my_loop, 0);	515	ev_loop (my_loop, 0);
…		…
452	visible to the libev user and should not keep C<ev_loop> from exiting if	535	visible to the libev user and should not keep C<ev_loop> from exiting if
453	no event watchers registered by it are active. It is also an excellent	536	no event watchers registered by it are active. It is also an excellent
454	way to do this for generic recurring timers or from within third-party	537	way to do this for generic recurring timers or from within third-party
455	libraries. Just remember to I<unref after start> and I<ref before stop>.	538	libraries. Just remember to I<unref after start> and I<ref before stop>.
456		539
457	Example: create a signal watcher, but keep it from keeping C<ev_loop>	540	Example: Create a signal watcher, but keep it from keeping C<ev_loop>
458	running when nothing else is active.	541	running when nothing else is active.
459		542
460	struct dv_signal exitsig;	543	struct ev_signal exitsig;
461	ev_signal_init (&exitsig, sig_cb, SIGINT);	544	ev_signal_init (&exitsig, sig_cb, SIGINT);
462	ev_signal_start (myloop, &exitsig);	545	ev_signal_start (loop, &exitsig);
463	evf_unref (myloop);	546	evf_unref (loop);
464		547
465	Example: for some weird reason, unregister the above signal handler again.	548	Example: For some weird reason, unregister the above signal handler again.
466		549
467	ev_ref (myloop);	550	ev_ref (loop);
468	ev_signal_stop (myloop, &exitsig);	551	ev_signal_stop (loop, &exitsig);
469		552
470	=back	553	=back
471		554
472		555
473	=head1 ANATOMY OF A WATCHER	556	=head1 ANATOMY OF A WATCHER
…		…
653	=item bool ev_is_pending (ev_TYPE *watcher)	736	=item bool ev_is_pending (ev_TYPE *watcher)
654		737
655	Returns a true value iff the watcher is pending, (i.e. it has outstanding	738	Returns a true value iff the watcher is pending, (i.e. it has outstanding
656	events but its callback has not yet been invoked). As long as a watcher	739	events but its callback has not yet been invoked). As long as a watcher
657	is pending (but not active) you must not call an init function on it (but	740	is pending (but not active) you must not call an init function on it (but
658	C<ev_TYPE_set> is safe) and you must make sure the watcher is available to	741	C<ev_TYPE_set> is safe), you must not change its priority, and you must
659	libev (e.g. you cnanot C<free ()> it).	742	make sure the watcher is available to libev (e.g. you cannot C<free ()>
		743	it).
660		744
661	=item callback = ev_cb (ev_TYPE *watcher)	745	=item callback ev_cb (ev_TYPE *watcher)
662		746
663	Returns the callback currently set on the watcher.	747	Returns the callback currently set on the watcher.
664		748
665	=item ev_cb_set (ev_TYPE *watcher, callback)	749	=item ev_cb_set (ev_TYPE *watcher, callback)
666		750
667	Change the callback. You can change the callback at virtually any time	751	Change the callback. You can change the callback at virtually any time
668	(modulo threads).	752	(modulo threads).
		753
		754	=item ev_set_priority (ev_TYPE *watcher, priority)
		755
		756	=item int ev_priority (ev_TYPE *watcher)
		757
		758	Set and query the priority of the watcher. The priority is a small
		759	integer between C<EV_MAXPRI> (default: C<2>) and C<EV_MINPRI>
		760	(default: C<-2>). Pending watchers with higher priority will be invoked
		761	before watchers with lower priority, but priority will not keep watchers
		762	from being executed (except for C<ev_idle> watchers).
		763
		764	This means that priorities are I<only> used for ordering callback
		765	invocation after new events have been received. This is useful, for
		766	example, to reduce latency after idling, or more often, to bind two
		767	watchers on the same event and make sure one is called first.
		768
		769	If you need to suppress invocation when higher priority events are pending
		770	you need to look at C<ev_idle> watchers, which provide this functionality.
		771
		772	You I<must not> change the priority of a watcher as long as it is active or
		773	pending.
		774
		775	The default priority used by watchers when no priority has been set is
		776	always C<0>, which is supposed to not be too high and not be too low :).
		777
		778	Setting a priority outside the range of C<EV_MINPRI> to C<EV_MAXPRI> is
		779	fine, as long as you do not mind that the priority value you query might
		780	or might not have been adjusted to be within valid range.
669		781
670	=back	782	=back
671		783
672		784
673	=head2 ASSOCIATING CUSTOM DATA WITH A WATCHER	785	=head2 ASSOCIATING CUSTOM DATA WITH A WATCHER
…		…
694	{	806	{
695	struct my_io w = (struct my_io )w_;	807	struct my_io w = (struct my_io )w_;
696	...	808	...
697	}	809	}
698		810
699	More interesting and less C-conformant ways of catsing your callback type	811	More interesting and less C-conformant ways of casting your callback type
700	have been omitted....	812	instead have been omitted.
		813
		814	Another common scenario is having some data structure with multiple
		815	watchers:
		816
		817	struct my_biggy
		818	{
		819	int some_data;
		820	ev_timer t1;
		821	ev_timer t2;
		822	}
		823
		824	In this case getting the pointer to C<my_biggy> is a bit more complicated,
		825	you need to use C<offsetof>:
		826
		827	#include <stddef.h>
		828
		829	static void
		830	t1_cb (EV_P_ struct ev_timer *w, int revents)
		831	{
		832	struct my_biggy big = (struct my_biggy *
		833	(((char *)w) - offsetof (struct my_biggy, t1));
		834	}
		835
		836	static void
		837	t2_cb (EV_P_ struct ev_timer *w, int revents)
		838	{
		839	struct my_biggy big = (struct my_biggy *
		840	(((char *)w) - offsetof (struct my_biggy, t2));
		841	}
701		842
702		843
703	=head1 WATCHER TYPES	844	=head1 WATCHER TYPES
704		845
705	This section describes each watcher in detail, but will not repeat	846	This section describes each watcher in detail, but will not repeat
…		…
750	it is best to always use non-blocking I/O: An extra C<read>(2) returning	891	it is best to always use non-blocking I/O: An extra C<read>(2) returning
751	C<EAGAIN> is far preferable to a program hanging until some data arrives.	892	C<EAGAIN> is far preferable to a program hanging until some data arrives.
752		893
753	If you cannot run the fd in non-blocking mode (for example you should not	894	If you cannot run the fd in non-blocking mode (for example you should not
754	play around with an Xlib connection), then you have to seperately re-test	895	play around with an Xlib connection), then you have to seperately re-test
755	wether a file descriptor is really ready with a known-to-be good interface	896	whether a file descriptor is really ready with a known-to-be good interface
756	such as poll (fortunately in our Xlib example, Xlib already does this on	897	such as poll (fortunately in our Xlib example, Xlib already does this on
757	its own, so its quite safe to use).	898	its own, so its quite safe to use).
758		899
759	=over 4	900	=over 4
760		901
…		…
774		915
775	The events being watched.	916	The events being watched.
776		917
777	=back	918	=back
778		919
779	Example: call C<stdin_readable_cb> when STDIN_FILENO has become, well	920	Example: Call C<stdin_readable_cb> when STDIN_FILENO has become, well
780	readable, but only once. Since it is likely line-buffered, you could	921	readable, but only once. Since it is likely line-buffered, you could
781	attempt to read a whole line in the callback:	922	attempt to read a whole line in the callback.
782		923
783	static void	924	static void
784	stdin_readable_cb (struct ev_loop loop, struct ev_io w, int revents)	925	stdin_readable_cb (struct ev_loop loop, struct ev_io w, int revents)
785	{	926	{
786	ev_io_stop (loop, w);	927	ev_io_stop (loop, w);
…		…
838	=item ev_timer_again (loop)	979	=item ev_timer_again (loop)
839		980
840	This will act as if the timer timed out and restart it again if it is	981	This will act as if the timer timed out and restart it again if it is
841	repeating. The exact semantics are:	982	repeating. The exact semantics are:
842		983
		984	If the timer is pending, its pending status is cleared.
		985
843	If the timer is started but nonrepeating, stop it.	986	If the timer is started but nonrepeating, stop it (as if it timed out).
844		987
845	If the timer is repeating, either start it if necessary (with the repeat	988	If the timer is repeating, either start it if necessary (with the
846	value), or reset the running timer to the repeat value.	989	C<repeat> value), or reset the running timer to the C<repeat> value.
847		990
848	This sounds a bit complicated, but here is a useful and typical	991	This sounds a bit complicated, but here is a useful and typical
849	example: Imagine you have a tcp connection and you want a so-called	992	example: Imagine you have a tcp connection and you want a so-called idle
850	idle timeout, that is, you want to be called when there have been,	993	timeout, that is, you want to be called when there have been, say, 60
851	say, 60 seconds of inactivity on the socket. The easiest way to do	994	seconds of inactivity on the socket. The easiest way to do this is to
852	this is to configure an C<ev_timer> with C<after>=C<repeat>=C<60> and calling	995	configure an C<ev_timer> with a C<repeat> value of C<60> and then call
853	C<ev_timer_again> each time you successfully read or write some data. If	996	C<ev_timer_again> each time you successfully read or write some data. If
854	you go into an idle state where you do not expect data to travel on the	997	you go into an idle state where you do not expect data to travel on the
855	socket, you can stop the timer, and again will automatically restart it if	998	socket, you can C<ev_timer_stop> the timer, and C<ev_timer_again> will
856	need be.	999	automatically restart it if need be.
857		1000
858	You can also ignore the C<after> value and C<ev_timer_start> altogether	1001	That means you can ignore the C<after> value and C<ev_timer_start>
859	and only ever use the C<repeat> value:	1002	altogether and only ever use the C<repeat> value and C<ev_timer_again>:
860		1003
861	ev_timer_init (timer, callback, 0., 5.);	1004	ev_timer_init (timer, callback, 0., 5.);
862	ev_timer_again (loop, timer);	1005	ev_timer_again (loop, timer);
863	...	1006	...
864	timer->again = 17.;	1007	timer->again = 17.;
865	ev_timer_again (loop, timer);	1008	ev_timer_again (loop, timer);
866	...	1009	...
867	timer->again = 10.;	1010	timer->again = 10.;
868	ev_timer_again (loop, timer);	1011	ev_timer_again (loop, timer);
869		1012
870	This is more efficient then stopping/starting the timer eahc time you want	1013	This is more slightly efficient then stopping/starting the timer each time
871	to modify its timeout value.	1014	you want to modify its timeout value.
872		1015
873	=item ev_tstamp repeat [read-write]	1016	=item ev_tstamp repeat [read-write]
874		1017
875	The current C<repeat> value. Will be used each time the watcher times out	1018	The current C<repeat> value. Will be used each time the watcher times out
876	or C<ev_timer_again> is called and determines the next timeout (if any),	1019	or C<ev_timer_again> is called and determines the next timeout (if any),
877	which is also when any modifications are taken into account.	1020	which is also when any modifications are taken into account.
878		1021
879	=back	1022	=back
880		1023
881	Example: create a timer that fires after 60 seconds.	1024	Example: Create a timer that fires after 60 seconds.
882		1025
883	static void	1026	static void
884	one_minute_cb (struct ev_loop loop, struct ev_timer w, int revents)	1027	one_minute_cb (struct ev_loop loop, struct ev_timer w, int revents)
885	{	1028	{
886	.. one minute over, w is actually stopped right here	1029	.. one minute over, w is actually stopped right here
…		…
888		1031
889	struct ev_timer mytimer;	1032	struct ev_timer mytimer;
890	ev_timer_init (&mytimer, one_minute_cb, 60., 0.);	1033	ev_timer_init (&mytimer, one_minute_cb, 60., 0.);
891	ev_timer_start (loop, &mytimer);	1034	ev_timer_start (loop, &mytimer);
892		1035
893	Example: create a timeout timer that times out after 10 seconds of	1036	Example: Create a timeout timer that times out after 10 seconds of
894	inactivity.	1037	inactivity.
895		1038
896	static void	1039	static void
897	timeout_cb (struct ev_loop loop, struct ev_timer w, int revents)	1040	timeout_cb (struct ev_loop loop, struct ev_timer w, int revents)
898	{	1041	{
…		…
1023	switched off. Can be changed any time, but changes only take effect when	1166	switched off. Can be changed any time, but changes only take effect when
1024	the periodic timer fires or C<ev_periodic_again> is being called.	1167	the periodic timer fires or C<ev_periodic_again> is being called.
1025		1168
1026	=back	1169	=back
1027		1170
1028	Example: call a callback every hour, or, more precisely, whenever the	1171	Example: Call a callback every hour, or, more precisely, whenever the
1029	system clock is divisible by 3600. The callback invocation times have	1172	system clock is divisible by 3600. The callback invocation times have
1030	potentially a lot of jittering, but good long-term stability.	1173	potentially a lot of jittering, but good long-term stability.
1031		1174
1032	static void	1175	static void
1033	clock_cb (struct ev_loop loop, struct ev_io w, int revents)	1176	clock_cb (struct ev_loop loop, struct ev_io w, int revents)
…		…
1037		1180
1038	struct ev_periodic hourly_tick;	1181	struct ev_periodic hourly_tick;
1039	ev_periodic_init (&hourly_tick, clock_cb, 0., 3600., 0);	1182	ev_periodic_init (&hourly_tick, clock_cb, 0., 3600., 0);
1040	ev_periodic_start (loop, &hourly_tick);	1183	ev_periodic_start (loop, &hourly_tick);
1041		1184
1042	Example: the same as above, but use a reschedule callback to do it:	1185	Example: The same as above, but use a reschedule callback to do it:
1043		1186
1044	#include <math.h>	1187	#include <math.h>
1045		1188
1046	static ev_tstamp	1189	static ev_tstamp
1047	my_scheduler_cb (struct ev_periodic *w, ev_tstamp now)	1190	my_scheduler_cb (struct ev_periodic *w, ev_tstamp now)
…		…
1049	return fmod (now, 3600.) + 3600.;	1192	return fmod (now, 3600.) + 3600.;
1050	}	1193	}
1051		1194
1052	ev_periodic_init (&hourly_tick, clock_cb, 0., 0., my_scheduler_cb);	1195	ev_periodic_init (&hourly_tick, clock_cb, 0., 0., my_scheduler_cb);
1053		1196
1054	Example: call a callback every hour, starting now:	1197	Example: Call a callback every hour, starting now:
1055		1198
1056	struct ev_periodic hourly_tick;	1199	struct ev_periodic hourly_tick;
1057	ev_periodic_init (&hourly_tick, clock_cb,	1200	ev_periodic_init (&hourly_tick, clock_cb,
1058	fmod (ev_now (loop), 3600.), 3600., 0);	1201	fmod (ev_now (loop), 3600.), 3600., 0);
1059	ev_periodic_start (loop, &hourly_tick);	1202	ev_periodic_start (loop, &hourly_tick);
…		…
1120	The process exit/trace status caused by C<rpid> (see your systems	1263	The process exit/trace status caused by C<rpid> (see your systems
1121	C<waitpid> and C<sys/wait.h> documentation for details).	1264	C<waitpid> and C<sys/wait.h> documentation for details).
1122		1265
1123	=back	1266	=back
1124		1267
1125	Example: try to exit cleanly on SIGINT and SIGTERM.	1268	Example: Try to exit cleanly on SIGINT and SIGTERM.
1126		1269
1127	static void	1270	static void
1128	sigint_cb (struct ev_loop loop, struct ev_signal w, int revents)	1271	sigint_cb (struct ev_loop loop, struct ev_signal w, int revents)
1129	{	1272	{
1130	ev_unloop (loop, EVUNLOOP_ALL);	1273	ev_unloop (loop, EVUNLOOP_ALL);
…		…
1145	not exist" is a status change like any other. The condition "path does	1288	not exist" is a status change like any other. The condition "path does
1146	not exist" is signified by the C<st_nlink> field being zero (which is	1289	not exist" is signified by the C<st_nlink> field being zero (which is
1147	otherwise always forced to be at least one) and all the other fields of	1290	otherwise always forced to be at least one) and all the other fields of
1148	the stat buffer having unspecified contents.	1291	the stat buffer having unspecified contents.
1149		1292
		1293	The path I<should> be absolute and I<must not> end in a slash. If it is
		1294	relative and your working directory changes, the behaviour is undefined.
		1295
1150	Since there is no standard to do this, the portable implementation simply	1296	Since there is no standard to do this, the portable implementation simply
1151	calls C<stat (2)> regulalry on the path to see if it changed somehow. You	1297	calls C<stat (2)> regularly on the path to see if it changed somehow. You
1152	can specify a recommended polling interval for this case. If you specify	1298	can specify a recommended polling interval for this case. If you specify
1153	a polling interval of C<0> (highly recommended!) then a I<suitable,	1299	a polling interval of C<0> (highly recommended!) then a I<suitable,
1154	unspecified default> value will be used (which you can expect to be around	1300	unspecified default> value will be used (which you can expect to be around
1155	five seconds, although this might change dynamically). Libev will also	1301	five seconds, although this might change dynamically). Libev will also
1156	impose a minimum interval which is currently around C<0.1>, but thats	1302	impose a minimum interval which is currently around C<0.1>, but thats
…		…
1158		1304
1159	This watcher type is not meant for massive numbers of stat watchers,	1305	This watcher type is not meant for massive numbers of stat watchers,
1160	as even with OS-supported change notifications, this can be	1306	as even with OS-supported change notifications, this can be
1161	resource-intensive.	1307	resource-intensive.
1162		1308
1163	At the time of this writing, no specific OS backends are implemented, but	1309	At the time of this writing, only the Linux inotify interface is
1164	if demand increases, at least a kqueue and inotify backend will be added.	1310	implemented (implementing kqueue support is left as an exercise for the
		1311	reader). Inotify will be used to give hints only and should not change the
		1312	semantics of C<ev_stat> watchers, which means that libev sometimes needs
		1313	to fall back to regular polling again even with inotify, but changes are
		1314	usually detected immediately, and if the file exists there will be no
		1315	polling.
1165		1316
1166	=over 4	1317	=over 4
1167		1318
1168	=item ev_stat_init (ev_stat , callback, const char path, ev_tstamp interval)	1319	=item ev_stat_init (ev_stat , callback, const char path, ev_tstamp interval)
1169		1320
…		…
1233	ev_stat_start (loop, &passwd);	1384	ev_stat_start (loop, &passwd);
1234		1385
1235		1386
1236	=head2 C<ev_idle> - when you've got nothing better to do...	1387	=head2 C<ev_idle> - when you've got nothing better to do...
1237		1388
1238	Idle watchers trigger events when there are no other events are pending	1389	Idle watchers trigger events when no other events of the same or higher
1239	(prepare, check and other idle watchers do not count). That is, as long	1390	priority are pending (prepare, check and other idle watchers do not
1240	as your process is busy handling sockets or timeouts (or even signals,	1391	count).
1241	imagine) it will not be triggered. But when your process is idle all idle	1392
1242	watchers are being called again and again, once per event loop iteration -	1393	That is, as long as your process is busy handling sockets or timeouts
		1394	(or even signals, imagine) of the same or higher priority it will not be
		1395	triggered. But when your process is idle (or only lower-priority watchers
		1396	are pending), the idle watchers are being called once per event loop
1243	until stopped, that is, or your process receives more events and becomes	1397	iteration - until stopped, that is, or your process receives more events
1244	busy.	1398	and becomes busy again with higher priority stuff.
1245		1399
1246	The most noteworthy effect is that as long as any idle watchers are	1400	The most noteworthy effect is that as long as any idle watchers are
1247	active, the process will not block when waiting for new events.	1401	active, the process will not block when waiting for new events.
1248		1402
1249	Apart from keeping your process non-blocking (which is a useful	1403	Apart from keeping your process non-blocking (which is a useful
…		…
1259	kind. There is a C<ev_idle_set> macro, but using it is utterly pointless,	1413	kind. There is a C<ev_idle_set> macro, but using it is utterly pointless,
1260	believe me.	1414	believe me.
1261		1415
1262	=back	1416	=back
1263		1417
1264	Example: dynamically allocate an C<ev_idle>, start it, and in the	1418	Example: Dynamically allocate an C<ev_idle> watcher, start it, and in the
1265	callback, free it. Alos, use no error checking, as usual.	1419	callback, free it. Also, use no error checking, as usual.
1266		1420
1267	static void	1421	static void
1268	idle_cb (struct ev_loop loop, struct ev_idle w, int revents)	1422	idle_cb (struct ev_loop loop, struct ev_idle w, int revents)
1269	{	1423	{
1270	free (w);	1424	free (w);
…		…
1349		1503
1350	// create io watchers for each fd and a timer before blocking	1504	// create io watchers for each fd and a timer before blocking
1351	static void	1505	static void
1352	adns_prepare_cb (ev_loop loop, ev_prepare w, int revents)	1506	adns_prepare_cb (ev_loop loop, ev_prepare w, int revents)
1353	{	1507	{
1354	int timeout = 3600000;truct pollfd fds [nfd];	1508	int timeout = 3600000;
		1509	struct pollfd fds [nfd];
1355	// actual code will need to loop here and realloc etc.	1510	// actual code will need to loop here and realloc etc.
1356	adns_beforepoll (ads, fds, &nfd, &timeout, timeval_from (ev_time ()));	1511	adns_beforepoll (ads, fds, &nfd, &timeout, timeval_from (ev_time ()));
1357		1512
1358	/* the callback is illegal, but won't be called as we stop during check */	1513	/* the callback is illegal, but won't be called as we stop during check */
1359	ev_timer_init (&tw, 0, timeout * 1e-3);	1514	ev_timer_init (&tw, 0, timeout * 1e-3);
…		…
1593		1748
1594	To use it,	1749	To use it,
1595		1750
1596	#include <ev++.h>	1751	#include <ev++.h>
1597		1752
1598	(it is not installed by default). This automatically includes F<ev.h>	1753	This automatically includes F<ev.h> and puts all of its definitions (many
1599	and puts all of its definitions (many of them macros) into the global	1754	of them macros) into the global namespace. All C++ specific things are
1600	namespace. All C++ specific things are put into the C<ev> namespace.	1755	put into the C<ev> namespace. It should support all the same embedding
		1756	options as F<ev.h>, most notably C<EV_MULTIPLICITY>.
1601		1757
1602	It should support all the same embedding options as F<ev.h>, most notably	1758	Care has been taken to keep the overhead low. The only data member the C++
1603	C<EV_MULTIPLICITY>.	1759	classes add (compared to plain C-style watchers) is the event loop pointer
		1760	that the watcher is associated with (or no additional members at all if
		1761	you disable C<EV_MULTIPLICITY> when embedding libev).
		1762
		1763	Currently, functions, and static and non-static member functions can be
		1764	used as callbacks. Other types should be easy to add as long as they only
		1765	need one additional pointer for context. If you need support for other
		1766	types of functors please contact the author (preferably after implementing
		1767	it).
1604		1768
1605	Here is a list of things available in the C<ev> namespace:	1769	Here is a list of things available in the C<ev> namespace:
1606		1770
1607	=over 4	1771	=over 4
1608		1772
…		…
1624		1788
1625	All of those classes have these methods:	1789	All of those classes have these methods:
1626		1790
1627	=over 4	1791	=over 4
1628		1792
1629	=item ev::TYPE::TYPE (object , object::method )	1793	=item ev::TYPE::TYPE ()
1630		1794
1631	=item ev::TYPE::TYPE (object , object::method , struct ev_loop *)	1795	=item ev::TYPE::TYPE (struct ev_loop *)
1632		1796
1633	=item ev::TYPE::~TYPE	1797	=item ev::TYPE::~TYPE
1634		1798
1635	The constructor takes a pointer to an object and a method pointer to	1799	The constructor (optionally) takes an event loop to associate the watcher
1636	the event handler callback to call in this class. The constructor calls	1800	with. If it is omitted, it will use C<EV_DEFAULT>.
1637	C<ev_init> for you, which means you have to call the C<set> method	1801
1638	before starting it. If you do not specify a loop then the constructor	1802	The constructor calls C<ev_init> for you, which means you have to call the
1639	automatically associates the default loop with this watcher.	1803	C<set> method before starting it.
		1804
		1805	It will not set a callback, however: You have to call the templated C<set>
		1806	method to set a callback before you can start the watcher.
		1807
		1808	(The reason why you have to use a method is a limitation in C++ which does
		1809	not allow explicit template arguments for constructors).
1640		1810
1641	The destructor automatically stops the watcher if it is active.	1811	The destructor automatically stops the watcher if it is active.
		1812
		1813	=item w->set<class, &class::method> (object *)
		1814
		1815	This method sets the callback method to call. The method has to have a
		1816	signature of C<void (*)(ev_TYPE &, int)>, it receives the watcher as
		1817	first argument and the C<revents> as second. The object must be given as
		1818	parameter and is stored in the C<data> member of the watcher.
		1819
		1820	This method synthesizes efficient thunking code to call your method from
		1821	the C callback that libev requires. If your compiler can inline your
		1822	callback (i.e. it is visible to it at the place of the C<set> call and
		1823	your compiler is good :), then the method will be fully inlined into the
		1824	thunking function, making it as fast as a direct C callback.
		1825
		1826	Example: simple class declaration and watcher initialisation
		1827
		1828	struct myclass
		1829	{
		1830	void io_cb (ev::io &w, int revents) { }
		1831	}
		1832
		1833	myclass obj;
		1834	ev::io iow;
		1835	iow.set <myclass, &myclass::io_cb> (&obj);
		1836
		1837	=item w->set (void (function)(watcher &w, int), void data = 0)
		1838
		1839	Also sets a callback, but uses a static method or plain function as
		1840	callback. The optional C<data> argument will be stored in the watcher's
		1841	C<data> member and is free for you to use.
		1842
		1843	See the method-C<set> above for more details.
1642		1844
1643	=item w->set (struct ev_loop *)	1845	=item w->set (struct ev_loop *)
1644		1846
1645	Associates a different C<struct ev_loop> with this watcher. You can only	1847	Associates a different C<struct ev_loop> with this watcher. You can only
1646	do this when the watcher is inactive (and not pending either).	1848	do this when the watcher is inactive (and not pending either).
1647		1849
1648	=item w->set ([args])	1850	=item w->set ([args])
1649		1851
1650	Basically the same as C<ev_TYPE_set>, with the same args. Must be	1852	Basically the same as C<ev_TYPE_set>, with the same args. Must be
1651	called at least once. Unlike the C counterpart, an active watcher gets	1853	called at least once. Unlike the C counterpart, an active watcher gets
1652	automatically stopped and restarted.	1854	automatically stopped and restarted when reconfiguring it with this
		1855	method.
1653		1856
1654	=item w->start ()	1857	=item w->start ()
1655		1858
1656	Starts the watcher. Note that there is no C<loop> argument as the	1859	Starts the watcher. Note that there is no C<loop> argument, as the
1657	constructor already takes the loop.	1860	constructor already stores the event loop.
1658		1861
1659	=item w->stop ()	1862	=item w->stop ()
1660		1863
1661	Stops the watcher if it is active. Again, no C<loop> argument.	1864	Stops the watcher if it is active. Again, no C<loop> argument.
1662		1865
…		…
1687		1890
1688	myclass ();	1891	myclass ();
1689	}	1892	}
1690		1893
1691	myclass::myclass (int fd)	1894	myclass::myclass (int fd)
1692	: io (this, &myclass::io_cb),
1693	idle (this, &myclass::idle_cb)
1694	{	1895	{
		1896	io .set <myclass, &myclass::io_cb > (this);
		1897	idle.set <myclass, &myclass::idle_cb> (this);
		1898
1695	io.start (fd, ev::READ);	1899	io.start (fd, ev::READ);
1696	}	1900	}
1697		1901
1698		1902
1699	=head1 MACRO MAGIC	1903	=head1 MACRO MAGIC
1700		1904
1701	Libev can be compiled with a variety of options, the most fundemantal is	1905	Libev can be compiled with a variety of options, the most fundemantal is
1702	C<EV_MULTIPLICITY>. This option determines wether (most) functions and	1906	C<EV_MULTIPLICITY>. This option determines whether (most) functions and
1703	callbacks have an initial C<struct ev_loop *> argument.	1907	callbacks have an initial C<struct ev_loop *> argument.
1704		1908
1705	To make it easier to write programs that cope with either variant, the	1909	To make it easier to write programs that cope with either variant, the
1706	following macros are defined:	1910	following macros are defined:
1707		1911
…		…
1740	Similar to the other two macros, this gives you the value of the default	1944	Similar to the other two macros, this gives you the value of the default
1741	loop, if multiple loops are supported ("ev loop default").	1945	loop, if multiple loops are supported ("ev loop default").
1742		1946
1743	=back	1947	=back
1744		1948
1745	Example: Declare and initialise a check watcher, working regardless of	1949	Example: Declare and initialise a check watcher, utilising the above
1746	wether multiple loops are supported or not.	1950	macros so it will work regardless of whether multiple loops are supported
		1951	or not.
1747		1952
1748	static void	1953	static void
1749	check_cb (EV_P_ ev_timer *w, int revents)	1954	check_cb (EV_P_ ev_timer *w, int revents)
1750	{	1955	{
1751	ev_check_stop (EV_A_ w);	1956	ev_check_stop (EV_A_ w);
…		…
1753		1958
1754	ev_check check;	1959	ev_check check;
1755	ev_check_init (&check, check_cb);	1960	ev_check_init (&check, check_cb);
1756	ev_check_start (EV_DEFAULT_ &check);	1961	ev_check_start (EV_DEFAULT_ &check);
1757	ev_loop (EV_DEFAULT_ 0);	1962	ev_loop (EV_DEFAULT_ 0);
1758
1759		1963
1760	=head1 EMBEDDING	1964	=head1 EMBEDDING
1761		1965
1762	Libev can (and often is) directly embedded into host	1966	Libev can (and often is) directly embedded into host
1763	applications. Examples of applications that embed it include the Deliantra	1967	applications. Examples of applications that embed it include the Deliantra
…		…
1803	ev_vars.h	2007	ev_vars.h
1804	ev_wrap.h	2008	ev_wrap.h
1805		2009
1806	ev_win32.c required on win32 platforms only	2010	ev_win32.c required on win32 platforms only
1807		2011
1808	ev_select.c only when select backend is enabled (which is by default)	2012	ev_select.c only when select backend is enabled (which is enabled by default)
1809	ev_poll.c only when poll backend is enabled (disabled by default)	2013	ev_poll.c only when poll backend is enabled (disabled by default)
1810	ev_epoll.c only when the epoll backend is enabled (disabled by default)	2014	ev_epoll.c only when the epoll backend is enabled (disabled by default)
1811	ev_kqueue.c only when the kqueue backend is enabled (disabled by default)	2015	ev_kqueue.c only when the kqueue backend is enabled (disabled by default)
1812	ev_port.c only when the solaris port backend is enabled (disabled by default)	2016	ev_port.c only when the solaris port backend is enabled (disabled by default)
1813		2017
…		…
1938		2142
1939	=item EV_USE_DEVPOLL	2143	=item EV_USE_DEVPOLL
1940		2144
1941	reserved for future expansion, works like the USE symbols above.	2145	reserved for future expansion, works like the USE symbols above.
1942		2146
		2147	=item EV_USE_INOTIFY
		2148
		2149	If defined to be C<1>, libev will compile in support for the Linux inotify
		2150	interface to speed up C<ev_stat> watchers. Its actual availability will
		2151	be detected at runtime.
		2152
1943	=item EV_H	2153	=item EV_H
1944		2154
1945	The name of the F<ev.h> header file used to include it. The default if	2155	The name of the F<ev.h> header file used to include it. The default if
1946	undefined is C<< <ev.h> >> in F<event.h> and C<"ev.h"> in F<ev.c>. This	2156	undefined is C<< <ev.h> >> in F<event.h> and C<"ev.h"> in F<ev.c>. This
1947	can be used to virtually rename the F<ev.h> header file in case of conflicts.	2157	can be used to virtually rename the F<ev.h> header file in case of conflicts.
…		…
1970	will have the C<struct ev_loop *> as first argument, and you can create	2180	will have the C<struct ev_loop *> as first argument, and you can create
1971	additional independent event loops. Otherwise there will be no support	2181	additional independent event loops. Otherwise there will be no support
1972	for multiple event loops and there is no first event loop pointer	2182	for multiple event loops and there is no first event loop pointer
1973	argument. Instead, all functions act on the single default loop.	2183	argument. Instead, all functions act on the single default loop.
1974		2184
		2185	=item EV_MINPRI
		2186
		2187	=item EV_MAXPRI
		2188
		2189	The range of allowed priorities. C<EV_MINPRI> must be smaller or equal to
		2190	C<EV_MAXPRI>, but otherwise there are no non-obvious limitations. You can
		2191	provide for more priorities by overriding those symbols (usually defined
		2192	to be C<-2> and C<2>, respectively).
		2193
		2194	When doing priority-based operations, libev usually has to linearly search
		2195	all the priorities, so having many of them (hundreds) uses a lot of space
		2196	and time, so using the defaults of five priorities (-2 .. +2) is usually
		2197	fine.
		2198
		2199	If your embedding app does not need any priorities, defining these both to
		2200	C<0> will save some memory and cpu.
		2201
1975	=item EV_PERIODIC_ENABLE	2202	=item EV_PERIODIC_ENABLE
1976		2203
1977	If undefined or defined to be C<1>, then periodic timers are supported. If	2204	If undefined or defined to be C<1>, then periodic timers are supported. If
1978	defined to be C<0>, then they are not. Disabling them saves a few kB of	2205	defined to be C<0>, then they are not. Disabling them saves a few kB of
1979	code.	2206	code.
1980		2207
		2208	=item EV_IDLE_ENABLE
		2209
		2210	If undefined or defined to be C<1>, then idle watchers are supported. If
		2211	defined to be C<0>, then they are not. Disabling them saves a few kB of
		2212	code.
		2213
1981	=item EV_EMBED_ENABLE	2214	=item EV_EMBED_ENABLE
1982		2215
1983	If undefined or defined to be C<1>, then embed watchers are supported. If	2216	If undefined or defined to be C<1>, then embed watchers are supported. If
1984	defined to be C<0>, then they are not.	2217	defined to be C<0>, then they are not.
1985		2218
…		…
1996	=item EV_MINIMAL	2229	=item EV_MINIMAL
1997		2230
1998	If you need to shave off some kilobytes of code at the expense of some	2231	If you need to shave off some kilobytes of code at the expense of some
1999	speed, define this symbol to C<1>. Currently only used for gcc to override	2232	speed, define this symbol to C<1>. Currently only used for gcc to override
2000	some inlining decisions, saves roughly 30% codesize of amd64.	2233	some inlining decisions, saves roughly 30% codesize of amd64.
		2234
		2235	=item EV_PID_HASHSIZE
		2236
		2237	C<ev_child> watchers use a small hash table to distribute workload by
		2238	pid. The default size is C<16> (or C<1> with C<EV_MINIMAL>), usually more
		2239	than enough. If you need to manage thousands of children you might want to
		2240	increase this value (I<must> be a power of two).
		2241
		2242	=item EV_INOTIFY_HASHSIZE
		2243
		2244	C<ev_staz> watchers use a small hash table to distribute workload by
		2245	inotify watch id. The default size is C<16> (or C<1> with C<EV_MINIMAL>),
		2246	usually more than enough. If you need to manage thousands of C<ev_stat>
		2247	watchers you might want to increase this value (I<must> be a power of
		2248	two).
2001		2249
2002	=item EV_COMMON	2250	=item EV_COMMON
2003		2251
2004	By default, all watchers have a C<void *data> member. By redefining	2252	By default, all watchers have a C<void *data> member. By redefining
2005	this macro to a something else you can include more and other types of	2253	this macro to a something else you can include more and other types of
…		…
2034	interface) and F<EV.xs> (implementation) files. Only the F<EV.xs> file	2282	interface) and F<EV.xs> (implementation) files. Only the F<EV.xs> file
2035	will be compiled. It is pretty complex because it provides its own header	2283	will be compiled. It is pretty complex because it provides its own header
2036	file.	2284	file.
2037		2285
2038	The usage in rxvt-unicode is simpler. It has a F<ev_cpp.h> header file	2286	The usage in rxvt-unicode is simpler. It has a F<ev_cpp.h> header file
2039	that everybody includes and which overrides some autoconf choices:	2287	that everybody includes and which overrides some configure choices:
2040		2288
		2289	#define EV_MINIMAL 1
2041	#define EV_USE_POLL 0	2290	#define EV_USE_POLL 0
2042	#define EV_MULTIPLICITY 0	2291	#define EV_MULTIPLICITY 0
2043	#define EV_PERIODICS 0	2292	#define EV_PERIODIC_ENABLE 0
		2293	#define EV_STAT_ENABLE 0
		2294	#define EV_FORK_ENABLE 0
2044	#define EV_CONFIG_H <config.h>	2295	#define EV_CONFIG_H <config.h>
		2296	#define EV_MINPRI 0
		2297	#define EV_MAXPRI 0
2045		2298
2046	#include "ev++.h"	2299	#include "ev++.h"
2047		2300
2048	And a F<ev_cpp.C> implementation file that contains libev proper and is compiled:	2301	And a F<ev_cpp.C> implementation file that contains libev proper and is compiled:
2049		2302
…		…
2055		2308
2056	In this section the complexities of (many of) the algorithms used inside	2309	In this section the complexities of (many of) the algorithms used inside
2057	libev will be explained. For complexity discussions about backends see the	2310	libev will be explained. For complexity discussions about backends see the
2058	documentation for C<ev_default_init>.	2311	documentation for C<ev_default_init>.
2059		2312
		2313	All of the following are about amortised time: If an array needs to be
		2314	extended, libev needs to realloc and move the whole array, but this
		2315	happens asymptotically never with higher number of elements, so O(1) might
		2316	mean it might do a lengthy realloc operation in rare cases, but on average
		2317	it is much faster and asymptotically approaches constant time.
		2318
2060	=over 4	2319	=over 4
2061		2320
2062	=item Starting and stopping timer/periodic watchers: O(log skipped_other_timers)	2321	=item Starting and stopping timer/periodic watchers: O(log skipped_other_timers)
2063		2322
		2323	This means that, when you have a watcher that triggers in one hour and
		2324	there are 100 watchers that would trigger before that then inserting will
		2325	have to skip those 100 watchers.
		2326
2064	=item Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)	2327	=item Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)
2065		2328
		2329	That means that for changing a timer costs less than removing/adding them
		2330	as only the relative motion in the event queue has to be paid for.
		2331
2066	=item Starting io/check/prepare/idle/signal/child watchers: O(1)	2332	=item Starting io/check/prepare/idle/signal/child watchers: O(1)
2067		2333
		2334	These just add the watcher into an array or at the head of a list.
2068	=item Stopping check/prepare/idle watchers: O(1)	2335	=item Stopping check/prepare/idle watchers: O(1)
2069		2336
2070	=item Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % 16))	2337	=item Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % EV_PID_HASHSIZE))
		2338
		2339	These watchers are stored in lists then need to be walked to find the
		2340	correct watcher to remove. The lists are usually short (you don't usually
		2341	have many watchers waiting for the same fd or signal).
2071		2342
2072	=item Finding the next timer per loop iteration: O(1)	2343	=item Finding the next timer per loop iteration: O(1)
2073		2344
2074	=item Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)	2345	=item Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)
2075		2346
		2347	A change means an I/O watcher gets started or stopped, which requires
		2348	libev to recalculate its status (and possibly tell the kernel).
		2349
2076	=item Activating one watcher: O(1)	2350	=item Activating one watcher: O(1)
2077		2351
		2352	=item Priority handling: O(number_of_priorities)
		2353
		2354	Priorities are implemented by allocating some space for each
		2355	priority. When doing priority-based operations, libev usually has to
		2356	linearly search all the priorities.
		2357
2078	=back	2358	=back
2079		2359
2080		2360
2081	=head1 AUTHOR	2361	=head1 AUTHOR
2082		2362

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Comparing libev/ev.pod (file contents): Revision 1.50 by root, Tue Nov 27 10:59:11 2007 UTC vs. Revision 1.73 by root, Sat Dec 8 03:53:36 2007 UTC

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Comparing libev/ev.pod (file contents):
Revision 1.50 by root, Tue Nov 27 10:59:11 2007 UTC vs.
Revision 1.73 by root, Sat Dec 8 03:53:36 2007 UTC