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

Comparing libev/ev.pod (file contents):
Revision 1.42 by root, Sat Nov 24 16:31:45 2007 UTC vs.
Revision 1.66 by root, Mon Dec 3 13:41:25 2007 UTC

…		…
3	libev - a high performance full-featured event loop written in C	3	libev - a high performance full-featured event loop written in C
4		4
5	=head1 SYNOPSIS	5	=head1 SYNOPSIS
6		6
7	#include <ev.h>	7	#include <ev.h>
		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	}
8		50
9	=head1 DESCRIPTION	51	=head1 DESCRIPTION
10		52
11	Libev is an event loop: you register interest in certain events (such as a	53	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	54	file descriptor being readable or a timeout occuring), and it will manage
…		…
21	details of the event, and then hand it over to libev by I<starting> the	63	details of the event, and then hand it over to libev by I<starting> the
22	watcher.	64	watcher.
23		65
24	=head1 FEATURES	66	=head1 FEATURES
25		67
26	Libev supports select, poll, the linux-specific epoll and the bsd-specific	68	Libev supports C<select>, C<poll>, the Linux-specific C<epoll>, the
27	kqueue mechanisms for file descriptor events, relative timers, absolute	69	BSD-specific C<kqueue> and the Solaris-specific event port mechanisms
28	timers with customised rescheduling, signal events, process status change	70	for file descriptor events (C<ev_io>), the Linux C<inotify> interface
29	events (related to SIGCHLD), and event watchers dealing with the event	71	(for C<ev_stat>), relative timers (C<ev_timer>), absolute timers
30	loop mechanism itself (idle, prepare and check watchers). It also is quite	72	with customised rescheduling (C<ev_periodic>), synchronous signals
		73	(C<ev_signal>), process status change events (C<ev_child>), and event
		74	watchers dealing with the event loop mechanism itself (C<ev_idle>,
		75	C<ev_embed>, C<ev_prepare> and C<ev_check> watchers) as well as
		76	file watchers (C<ev_stat>) and even limited support for fork events
		77	(C<ev_fork>).
		78
		79	It also is quite fast (see this
31	fast (see this L<benchmark\|http://libev.schmorp.de/bench.html> comparing	80	L<benchmark\|http://libev.schmorp.de/bench.html> comparing it to libevent
32	it to libevent for example).	81	for example).
33		82
34	=head1 CONVENTIONS	83	=head1 CONVENTIONS
35		84
36	Libev is very configurable. In this manual the default configuration	85	Libev is very configurable. In this manual the default configuration will
37	will be described, which supports multiple event loops. For more info	86	be described, which supports multiple event loops. For more info about
38	about various configuration options please have a look at the file	87	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	88	this manual. If libev was configured without support for multiple event
40	support for multiple event loops, then all functions taking an initial	89	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 *>)	90	(which is always of type C<struct ev_loop *>) will not have this argument.
42	will not have this argument.
43		91
44	=head1 TIME REPRESENTATION	92	=head1 TIME REPRESENTATION
45		93
46	Libev represents time as a single floating point number, representing the	94	Libev represents time as a single floating point number, representing the
47	(fractional) number of seconds since the (POSIX) epoch (somewhere near	95	(fractional) number of seconds since the (POSIX) epoch (somewhere near
48	the beginning of 1970, details are complicated, don't ask). This type is	96	the beginning of 1970, details are complicated, don't ask). This type is
49	called C<ev_tstamp>, which is what you should use too. It usually aliases	97	called C<ev_tstamp>, which is what you should use too. It usually aliases
50	to the C<double> type in C, and when you need to do any calculations on	98	to the C<double> type in C, and when you need to do any calculations on
51	it, you should treat it as such.	99	it, you should treat it as such.
52		100
53
54	=head1 GLOBAL FUNCTIONS	101	=head1 GLOBAL FUNCTIONS
55		102
56	These functions can be called anytime, even before initialising the	103	These functions can be called anytime, even before initialising the
57	library in any way.	104	library in any way.
58		105
…		…
77	Usually, it's a good idea to terminate if the major versions mismatch,	124	Usually, it's a good idea to terminate if the major versions mismatch,
78	as this indicates an incompatible change. Minor versions are usually	125	as this indicates an incompatible change. Minor versions are usually
79	compatible to older versions, so a larger minor version alone is usually	126	compatible to older versions, so a larger minor version alone is usually
80	not a problem.	127	not a problem.
81		128
82	Example: make sure we haven't accidentally been linked against the wrong	129	Example: Make sure we haven't accidentally been linked against the wrong
83	version:	130	version.
84		131
85	assert (("libev version mismatch",	132	assert (("libev version mismatch",
86	ev_version_major () == EV_VERSION_MAJOR	133	ev_version_major () == EV_VERSION_MAJOR
87	&& ev_version_minor () >= EV_VERSION_MINOR));	134	&& ev_version_minor () >= EV_VERSION_MINOR));
88		135
…		…
118		165
119	See the description of C<ev_embed> watchers for more info.	166	See the description of C<ev_embed> watchers for more info.
120		167
121	=item ev_set_allocator (void (cb)(void *ptr, long size))	168	=item ev_set_allocator (void (cb)(void *ptr, long size))
122		169
123	Sets the allocation function to use (the prototype is similar to the	170	Sets the allocation function to use (the prototype is similar - the
124	realloc C function, the semantics are identical). It is used to allocate	171	semantics is identical - to the realloc C function). It is used to
125	and free memory (no surprises here). If it returns zero when memory	172	allocate and free memory (no surprises here). If it returns zero when
126	needs to be allocated, the library might abort or take some potentially	173	memory needs to be allocated, the library might abort or take some
127	destructive action. The default is your system realloc function.	174	potentially destructive action. The default is your system realloc
		175	function.
128		176
129	You could override this function in high-availability programs to, say,	177	You could override this function in high-availability programs to, say,
130	free some memory if it cannot allocate memory, to use a special allocator,	178	free some memory if it cannot allocate memory, to use a special allocator,
131	or even to sleep a while and retry until some memory is available.	179	or even to sleep a while and retry until some memory is available.
132		180
133	Example: replace the libev allocator with one that waits a bit and then	181	Example: Replace the libev allocator with one that waits a bit and then
134	retries: better than mine).	182	retries).
135		183
136	static void *	184	static void *
137	persistent_realloc (void *ptr, long size)	185	persistent_realloc (void *ptr, size_t size)
138	{	186	{
139	for (;;)	187	for (;;)
140	{	188	{
141	void *newptr = realloc (ptr, size);	189	void *newptr = realloc (ptr, size);
142		190
…		…
158	callback is set, then libev will expect it to remedy the sitution, no	206	callback is set, then libev will expect it to remedy the sitution, no
159	matter what, when it returns. That is, libev will generally retry the	207	matter what, when it returns. That is, libev will generally retry the
160	requested operation, or, if the condition doesn't go away, do bad stuff	208	requested operation, or, if the condition doesn't go away, do bad stuff
161	(such as abort).	209	(such as abort).
162		210
163	Example: do the same thing as libev does internally:	211	Example: This is basically the same thing that libev does internally, too.
164		212
165	static void	213	static void
166	fatal_error (const char *msg)	214	fatal_error (const char *msg)
167	{	215	{
168	perror (msg);	216	perror (msg);
…		…
218	C<LIBEV_FLAGS>. Otherwise (the default), this environment variable will	266	C<LIBEV_FLAGS>. Otherwise (the default), this environment variable will
219	override the flags completely if it is found in the environment. This is	267	override the flags completely if it is found in the environment. This is
220	useful to try out specific backends to test their performance, or to work	268	useful to try out specific backends to test their performance, or to work
221	around bugs.	269	around bugs.
222		270
		271	=item C<EVFLAG_FORKCHECK>
		272
		273	Instead of calling C<ev_default_fork> or C<ev_loop_fork> manually after
		274	a fork, you can also make libev check for a fork in each iteration by
		275	enabling this flag.
		276
		277	This works by calling C<getpid ()> on every iteration of the loop,
		278	and thus this might slow down your event loop if you do a lot of loop
		279	iterations and little real work, but is usually not noticeable (on my
		280	Linux system for example, C<getpid> is actually a simple 5-insn sequence
		281	without a syscall and thus I<very> fast, but my Linux system also has
		282	C<pthread_atfork> which is even faster).
		283
		284	The big advantage of this flag is that you can forget about fork (and
		285	forget about forgetting to tell libev about forking) when you use this
		286	flag.
		287
		288	This flag setting cannot be overriden or specified in the C<LIBEV_FLAGS>
		289	environment variable.
		290
223	=item C<EVBACKEND_SELECT> (value 1, portable select backend)	291	=item C<EVBACKEND_SELECT> (value 1, portable select backend)
224		292
225	This is your standard select(2) backend. Not I<completely> standard, as	293	This is your standard select(2) backend. Not I<completely> standard, as
226	libev tries to roll its own fd_set with no limits on the number of fds,	294	libev tries to roll its own fd_set with no limits on the number of fds,
227	but if that fails, expect a fairly low limit on the number of fds when	295	but if that fails, expect a fairly low limit on the number of fds when
…		…
314	Similar to C<ev_default_loop>, but always creates a new event loop that is	382	Similar to C<ev_default_loop>, but always creates a new event loop that is
315	always distinct from the default loop. Unlike the default loop, it cannot	383	always distinct from the default loop. Unlike the default loop, it cannot
316	handle signal and child watchers, and attempts to do so will be greeted by	384	handle signal and child watchers, and attempts to do so will be greeted by
317	undefined behaviour (or a failed assertion if assertions are enabled).	385	undefined behaviour (or a failed assertion if assertions are enabled).
318		386
319	Example: try to create a event loop that uses epoll and nothing else.	387	Example: Try to create a event loop that uses epoll and nothing else.
320		388
321	struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL \| EVFLAG_NOENV);	389	struct ev_loop *epoller = ev_loop_new (EVBACKEND_EPOLL \| EVFLAG_NOENV);
322	if (!epoller)	390	if (!epoller)
323	fatal ("no epoll found here, maybe it hides under your chair");	391	fatal ("no epoll found here, maybe it hides under your chair");
324		392
…		…
361	=item ev_loop_fork (loop)	429	=item ev_loop_fork (loop)
362		430
363	Like C<ev_default_fork>, but acts on an event loop created by	431	Like C<ev_default_fork>, but acts on an event loop created by
364	C<ev_loop_new>. Yes, you have to call this on every allocated event loop	432	C<ev_loop_new>. Yes, you have to call this on every allocated event loop
365	after fork, and how you do this is entirely your own problem.	433	after fork, and how you do this is entirely your own problem.
		434
		435	=item unsigned int ev_loop_count (loop)
		436
		437	Returns the count of loop iterations for the loop, which is identical to
		438	the number of times libev did poll for new events. It starts at C<0> and
		439	happily wraps around with enough iterations.
		440
		441	This value can sometimes be useful as a generation counter of sorts (it
		442	"ticks" the number of loop iterations), as it roughly corresponds with
		443	C<ev_prepare> and C<ev_check> calls.
366		444
367	=item unsigned int ev_backend (loop)	445	=item unsigned int ev_backend (loop)
368		446
369	Returns one of the C<EVBACKEND_*> flags indicating the event backend in	447	Returns one of the C<EVBACKEND_*> flags indicating the event backend in
370	use.	448	use.
…		…
423	Signals and child watchers are implemented as I/O watchers, and will	501	Signals and child watchers are implemented as I/O watchers, and will
424	be handled here by queueing them when their watcher gets executed.	502	be handled here by queueing them when their watcher gets executed.
425	- If ev_unloop has been called or EVLOOP_ONESHOT or EVLOOP_NONBLOCK	503	- If ev_unloop has been called or EVLOOP_ONESHOT or EVLOOP_NONBLOCK
426	were used, return, otherwise continue with step *.	504	were used, return, otherwise continue with step *.
427		505
428	Example: queue some jobs and then loop until no events are outsanding	506	Example: Queue some jobs and then loop until no events are outsanding
429	anymore.	507	anymore.
430		508
431	... queue jobs here, make sure they register event watchers as long	509	... queue jobs here, make sure they register event watchers as long
432	... as they still have work to do (even an idle watcher will do..)	510	... as they still have work to do (even an idle watcher will do..)
433	ev_loop (my_loop, 0);	511	ev_loop (my_loop, 0);
…		…
453	visible to the libev user and should not keep C<ev_loop> from exiting if	531	visible to the libev user and should not keep C<ev_loop> from exiting if
454	no event watchers registered by it are active. It is also an excellent	532	no event watchers registered by it are active. It is also an excellent
455	way to do this for generic recurring timers or from within third-party	533	way to do this for generic recurring timers or from within third-party
456	libraries. Just remember to I<unref after start> and I<ref before stop>.	534	libraries. Just remember to I<unref after start> and I<ref before stop>.
457		535
458	Example: create a signal watcher, but keep it from keeping C<ev_loop>	536	Example: Create a signal watcher, but keep it from keeping C<ev_loop>
459	running when nothing else is active.	537	running when nothing else is active.
460		538
461	struct dv_signal exitsig;	539	struct ev_signal exitsig;
462	ev_signal_init (&exitsig, sig_cb, SIGINT);	540	ev_signal_init (&exitsig, sig_cb, SIGINT);
463	ev_signal_start (myloop, &exitsig);	541	ev_signal_start (loop, &exitsig);
464	evf_unref (myloop);	542	evf_unref (loop);
465		543
466	Example: for some weird reason, unregister the above signal handler again.	544	Example: For some weird reason, unregister the above signal handler again.
467		545
468	ev_ref (myloop);	546	ev_ref (loop);
469	ev_signal_stop (myloop, &exitsig);	547	ev_signal_stop (loop, &exitsig);
470		548
471	=back	549	=back
472		550
473		551
474	=head1 ANATOMY OF A WATCHER	552	=head1 ANATOMY OF A WATCHER
…		…
544	The signal specified in the C<ev_signal> watcher has been received by a thread.	622	The signal specified in the C<ev_signal> watcher has been received by a thread.
545		623
546	=item C<EV_CHILD>	624	=item C<EV_CHILD>
547		625
548	The pid specified in the C<ev_child> watcher has received a status change.	626	The pid specified in the C<ev_child> watcher has received a status change.
		627
		628	=item C<EV_STAT>
		629
		630	The path specified in the C<ev_stat> watcher changed its attributes somehow.
549		631
550	=item C<EV_IDLE>	632	=item C<EV_IDLE>
551		633
552	The C<ev_idle> watcher has determined that you have nothing better to do.	634	The C<ev_idle> watcher has determined that you have nothing better to do.
553		635
…		…
561	received events. Callbacks of both watcher types can start and stop as	643	received events. Callbacks of both watcher types can start and stop as
562	many watchers as they want, and all of them will be taken into account	644	many watchers as they want, and all of them will be taken into account
563	(for example, a C<ev_prepare> watcher might start an idle watcher to keep	645	(for example, a C<ev_prepare> watcher might start an idle watcher to keep
564	C<ev_loop> from blocking).	646	C<ev_loop> from blocking).
565		647
		648	=item C<EV_EMBED>
		649
		650	The embedded event loop specified in the C<ev_embed> watcher needs attention.
		651
		652	=item C<EV_FORK>
		653
		654	The event loop has been resumed in the child process after fork (see
		655	C<ev_fork>).
		656
566	=item C<EV_ERROR>	657	=item C<EV_ERROR>
567		658
568	An unspecified error has occured, the watcher has been stopped. This might	659	An unspecified error has occured, the watcher has been stopped. This might
569	happen because the watcher could not be properly started because libev	660	happen because the watcher could not be properly started because libev
570	ran out of memory, a file descriptor was found to be closed or any other	661	ran out of memory, a file descriptor was found to be closed or any other
…		…
644	events but its callback has not yet been invoked). As long as a watcher	735	events but its callback has not yet been invoked). As long as a watcher
645	is pending (but not active) you must not call an init function on it (but	736	is pending (but not active) you must not call an init function on it (but
646	C<ev_TYPE_set> is safe) and you must make sure the watcher is available to	737	C<ev_TYPE_set> is safe) and you must make sure the watcher is available to
647	libev (e.g. you cnanot C<free ()> it).	738	libev (e.g. you cnanot C<free ()> it).
648		739
649	=item callback = ev_cb (ev_TYPE *watcher)	740	=item callback ev_cb (ev_TYPE *watcher)
650		741
651	Returns the callback currently set on the watcher.	742	Returns the callback currently set on the watcher.
652		743
653	=item ev_cb_set (ev_TYPE *watcher, callback)	744	=item ev_cb_set (ev_TYPE *watcher, callback)
654		745
…		…
682	{	773	{
683	struct my_io w = (struct my_io )w_;	774	struct my_io w = (struct my_io )w_;
684	...	775	...
685	}	776	}
686		777
687	More interesting and less C-conformant ways of catsing your callback type	778	More interesting and less C-conformant ways of casting your callback type
688	have been omitted....	779	instead have been omitted.
		780
		781	Another common scenario is having some data structure with multiple
		782	watchers:
		783
		784	struct my_biggy
		785	{
		786	int some_data;
		787	ev_timer t1;
		788	ev_timer t2;
		789	}
		790
		791	In this case getting the pointer to C<my_biggy> is a bit more complicated,
		792	you need to use C<offsetof>:
		793
		794	#include <stddef.h>
		795
		796	static void
		797	t1_cb (EV_P_ struct ev_timer *w, int revents)
		798	{
		799	struct my_biggy big = (struct my_biggy *
		800	(((char *)w) - offsetof (struct my_biggy, t1));
		801	}
		802
		803	static void
		804	t2_cb (EV_P_ struct ev_timer *w, int revents)
		805	{
		806	struct my_biggy big = (struct my_biggy *
		807	(((char *)w) - offsetof (struct my_biggy, t2));
		808	}
689		809
690		810
691	=head1 WATCHER TYPES	811	=head1 WATCHER TYPES
692		812
693	This section describes each watcher in detail, but will not repeat	813	This section describes each watcher in detail, but will not repeat
694	information given in the last section.	814	information given in the last section. Any initialisation/set macros,
		815	functions and members specific to the watcher type are explained.
		816
		817	Members are additionally marked with either I<[read-only]>, meaning that,
		818	while the watcher is active, you can look at the member and expect some
		819	sensible content, but you must not modify it (you can modify it while the
		820	watcher is stopped to your hearts content), or I<[read-write]>, which
		821	means you can expect it to have some sensible content while the watcher
		822	is active, but you can also modify it. Modifying it may not do something
		823	sensible or take immediate effect (or do anything at all), but libev will
		824	not crash or malfunction in any way.
695		825
696		826
697	=head2 C<ev_io> - is this file descriptor readable or writable?	827	=head2 C<ev_io> - is this file descriptor readable or writable?
698		828
699	I/O watchers check whether a file descriptor is readable or writable	829	I/O watchers check whether a file descriptor is readable or writable
…		…
742		872
743	Configures an C<ev_io> watcher. The C<fd> is the file descriptor to	873	Configures an C<ev_io> watcher. The C<fd> is the file descriptor to
744	rceeive events for and events is either C<EV_READ>, C<EV_WRITE> or	874	rceeive events for and events is either C<EV_READ>, C<EV_WRITE> or
745	C<EV_READ \| EV_WRITE> to receive the given events.	875	C<EV_READ \| EV_WRITE> to receive the given events.
746		876
		877	=item int fd [read-only]
		878
		879	The file descriptor being watched.
		880
		881	=item int events [read-only]
		882
		883	The events being watched.
		884
747	=back	885	=back
748		886
749	Example: call C<stdin_readable_cb> when STDIN_FILENO has become, well	887	Example: Call C<stdin_readable_cb> when STDIN_FILENO has become, well
750	readable, but only once. Since it is likely line-buffered, you could	888	readable, but only once. Since it is likely line-buffered, you could
751	attempt to read a whole line in the callback:	889	attempt to read a whole line in the callback.
752		890
753	static void	891	static void
754	stdin_readable_cb (struct ev_loop loop, struct ev_io w, int revents)	892	stdin_readable_cb (struct ev_loop loop, struct ev_io w, int revents)
755	{	893	{
756	ev_io_stop (loop, w);	894	ev_io_stop (loop, w);
…		…
808	=item ev_timer_again (loop)	946	=item ev_timer_again (loop)
809		947
810	This will act as if the timer timed out and restart it again if it is	948	This will act as if the timer timed out and restart it again if it is
811	repeating. The exact semantics are:	949	repeating. The exact semantics are:
812		950
		951	If the timer is pending, its pending status is cleared.
		952
813	If the timer is started but nonrepeating, stop it.	953	If the timer is started but nonrepeating, stop it (as if it timed out).
814		954
815	If the timer is repeating, either start it if necessary (with the repeat	955	If the timer is repeating, either start it if necessary (with the
816	value), or reset the running timer to the repeat value.	956	C<repeat> value), or reset the running timer to the C<repeat> value.
817		957
818	This sounds a bit complicated, but here is a useful and typical	958	This sounds a bit complicated, but here is a useful and typical
819	example: Imagine you have a tcp connection and you want a so-called idle	959	example: Imagine you have a tcp connection and you want a so-called idle
820	timeout, that is, you want to be called when there have been, say, 60	960	timeout, that is, you want to be called when there have been, say, 60
821	seconds of inactivity on the socket. The easiest way to do this is to	961	seconds of inactivity on the socket. The easiest way to do this is to
822	configure an C<ev_timer> with after=repeat=60 and calling ev_timer_again each	962	configure an C<ev_timer> with a C<repeat> value of C<60> and then call
823	time you successfully read or write some data. If you go into an idle	963	C<ev_timer_again> each time you successfully read or write some data. If
824	state where you do not expect data to travel on the socket, you can stop	964	you go into an idle state where you do not expect data to travel on the
825	the timer, and again will automatically restart it if need be.	965	socket, you can C<ev_timer_stop> the timer, and C<ev_timer_again> will
		966	automatically restart it if need be.
		967
		968	That means you can ignore the C<after> value and C<ev_timer_start>
		969	altogether and only ever use the C<repeat> value and C<ev_timer_again>:
		970
		971	ev_timer_init (timer, callback, 0., 5.);
		972	ev_timer_again (loop, timer);
		973	...
		974	timer->again = 17.;
		975	ev_timer_again (loop, timer);
		976	...
		977	timer->again = 10.;
		978	ev_timer_again (loop, timer);
		979
		980	This is more slightly efficient then stopping/starting the timer each time
		981	you want to modify its timeout value.
		982
		983	=item ev_tstamp repeat [read-write]
		984
		985	The current C<repeat> value. Will be used each time the watcher times out
		986	or C<ev_timer_again> is called and determines the next timeout (if any),
		987	which is also when any modifications are taken into account.
826		988
827	=back	989	=back
828		990
829	Example: create a timer that fires after 60 seconds.	991	Example: Create a timer that fires after 60 seconds.
830		992
831	static void	993	static void
832	one_minute_cb (struct ev_loop loop, struct ev_timer w, int revents)	994	one_minute_cb (struct ev_loop loop, struct ev_timer w, int revents)
833	{	995	{
834	.. one minute over, w is actually stopped right here	996	.. one minute over, w is actually stopped right here
…		…
836		998
837	struct ev_timer mytimer;	999	struct ev_timer mytimer;
838	ev_timer_init (&mytimer, one_minute_cb, 60., 0.);	1000	ev_timer_init (&mytimer, one_minute_cb, 60., 0.);
839	ev_timer_start (loop, &mytimer);	1001	ev_timer_start (loop, &mytimer);
840		1002
841	Example: create a timeout timer that times out after 10 seconds of	1003	Example: Create a timeout timer that times out after 10 seconds of
842	inactivity.	1004	inactivity.
843		1005
844	static void	1006	static void
845	timeout_cb (struct ev_loop loop, struct ev_timer w, int revents)	1007	timeout_cb (struct ev_loop loop, struct ev_timer w, int revents)
846	{	1008	{
…		…
957	Simply stops and restarts the periodic watcher again. This is only useful	1119	Simply stops and restarts the periodic watcher again. This is only useful
958	when you changed some parameters or the reschedule callback would return	1120	when you changed some parameters or the reschedule callback would return
959	a different time than the last time it was called (e.g. in a crond like	1121	a different time than the last time it was called (e.g. in a crond like
960	program when the crontabs have changed).	1122	program when the crontabs have changed).
961		1123
		1124	=item ev_tstamp interval [read-write]
		1125
		1126	The current interval value. Can be modified any time, but changes only
		1127	take effect when the periodic timer fires or C<ev_periodic_again> is being
		1128	called.
		1129
		1130	=item ev_tstamp (reschedule_cb)(struct ev_periodic w, ev_tstamp now) [read-write]
		1131
		1132	The current reschedule callback, or C<0>, if this functionality is
		1133	switched off. Can be changed any time, but changes only take effect when
		1134	the periodic timer fires or C<ev_periodic_again> is being called.
		1135
962	=back	1136	=back
963		1137
964	Example: call a callback every hour, or, more precisely, whenever the	1138	Example: Call a callback every hour, or, more precisely, whenever the
965	system clock is divisible by 3600. The callback invocation times have	1139	system clock is divisible by 3600. The callback invocation times have
966	potentially a lot of jittering, but good long-term stability.	1140	potentially a lot of jittering, but good long-term stability.
967		1141
968	static void	1142	static void
969	clock_cb (struct ev_loop loop, struct ev_io w, int revents)	1143	clock_cb (struct ev_loop loop, struct ev_io w, int revents)
…		…
973		1147
974	struct ev_periodic hourly_tick;	1148	struct ev_periodic hourly_tick;
975	ev_periodic_init (&hourly_tick, clock_cb, 0., 3600., 0);	1149	ev_periodic_init (&hourly_tick, clock_cb, 0., 3600., 0);
976	ev_periodic_start (loop, &hourly_tick);	1150	ev_periodic_start (loop, &hourly_tick);
977		1151
978	Example: the same as above, but use a reschedule callback to do it:	1152	Example: The same as above, but use a reschedule callback to do it:
979		1153
980	#include <math.h>	1154	#include <math.h>
981		1155
982	static ev_tstamp	1156	static ev_tstamp
983	my_scheduler_cb (struct ev_periodic *w, ev_tstamp now)	1157	my_scheduler_cb (struct ev_periodic *w, ev_tstamp now)
…		…
985	return fmod (now, 3600.) + 3600.;	1159	return fmod (now, 3600.) + 3600.;
986	}	1160	}
987		1161
988	ev_periodic_init (&hourly_tick, clock_cb, 0., 0., my_scheduler_cb);	1162	ev_periodic_init (&hourly_tick, clock_cb, 0., 0., my_scheduler_cb);
989		1163
990	Example: call a callback every hour, starting now:	1164	Example: Call a callback every hour, starting now:
991		1165
992	struct ev_periodic hourly_tick;	1166	struct ev_periodic hourly_tick;
993	ev_periodic_init (&hourly_tick, clock_cb,	1167	ev_periodic_init (&hourly_tick, clock_cb,
994	fmod (ev_now (loop), 3600.), 3600., 0);	1168	fmod (ev_now (loop), 3600.), 3600., 0);
995	ev_periodic_start (loop, &hourly_tick);	1169	ev_periodic_start (loop, &hourly_tick);
…		…
1016	=item ev_signal_set (ev_signal *, int signum)	1190	=item ev_signal_set (ev_signal *, int signum)
1017		1191
1018	Configures the watcher to trigger on the given signal number (usually one	1192	Configures the watcher to trigger on the given signal number (usually one
1019	of the C<SIGxxx> constants).	1193	of the C<SIGxxx> constants).
1020		1194
		1195	=item int signum [read-only]
		1196
		1197	The signal the watcher watches out for.
		1198
1021	=back	1199	=back
1022		1200
1023		1201
1024	=head2 C<ev_child> - watch out for process status changes	1202	=head2 C<ev_child> - watch out for process status changes
1025		1203
…		…
1037	at the C<rstatus> member of the C<ev_child> watcher structure to see	1215	at the C<rstatus> member of the C<ev_child> watcher structure to see
1038	the status word (use the macros from C<sys/wait.h> and see your systems	1216	the status word (use the macros from C<sys/wait.h> and see your systems
1039	C<waitpid> documentation). The C<rpid> member contains the pid of the	1217	C<waitpid> documentation). The C<rpid> member contains the pid of the
1040	process causing the status change.	1218	process causing the status change.
1041		1219
		1220	=item int pid [read-only]
		1221
		1222	The process id this watcher watches out for, or C<0>, meaning any process id.
		1223
		1224	=item int rpid [read-write]
		1225
		1226	The process id that detected a status change.
		1227
		1228	=item int rstatus [read-write]
		1229
		1230	The process exit/trace status caused by C<rpid> (see your systems
		1231	C<waitpid> and C<sys/wait.h> documentation for details).
		1232
1042	=back	1233	=back
1043		1234
1044	Example: try to exit cleanly on SIGINT and SIGTERM.	1235	Example: Try to exit cleanly on SIGINT and SIGTERM.
1045		1236
1046	static void	1237	static void
1047	sigint_cb (struct ev_loop loop, struct ev_signal w, int revents)	1238	sigint_cb (struct ev_loop loop, struct ev_signal w, int revents)
1048	{	1239	{
1049	ev_unloop (loop, EVUNLOOP_ALL);	1240	ev_unloop (loop, EVUNLOOP_ALL);
1050	}	1241	}
1051		1242
1052	struct ev_signal signal_watcher;	1243	struct ev_signal signal_watcher;
1053	ev_signal_init (&signal_watcher, sigint_cb, SIGINT);	1244	ev_signal_init (&signal_watcher, sigint_cb, SIGINT);
1054	ev_signal_start (loop, &sigint_cb);	1245	ev_signal_start (loop, &sigint_cb);
		1246
		1247
		1248	=head2 C<ev_stat> - did the file attributes just change?
		1249
		1250	This watches a filesystem path for attribute changes. That is, it calls
		1251	C<stat> regularly (or when the OS says it changed) and sees if it changed
		1252	compared to the last time, invoking the callback if it did.
		1253
		1254	The path does not need to exist: changing from "path exists" to "path does
		1255	not exist" is a status change like any other. The condition "path does
		1256	not exist" is signified by the C<st_nlink> field being zero (which is
		1257	otherwise always forced to be at least one) and all the other fields of
		1258	the stat buffer having unspecified contents.
		1259
		1260	The path I<should> be absolute and I<must not> end in a slash. If it is
		1261	relative and your working directory changes, the behaviour is undefined.
		1262
		1263	Since there is no standard to do this, the portable implementation simply
		1264	calls C<stat (2)> regularly on the path to see if it changed somehow. You
		1265	can specify a recommended polling interval for this case. If you specify
		1266	a polling interval of C<0> (highly recommended!) then a I<suitable,
		1267	unspecified default> value will be used (which you can expect to be around
		1268	five seconds, although this might change dynamically). Libev will also
		1269	impose a minimum interval which is currently around C<0.1>, but thats
		1270	usually overkill.
		1271
		1272	This watcher type is not meant for massive numbers of stat watchers,
		1273	as even with OS-supported change notifications, this can be
		1274	resource-intensive.
		1275
		1276	At the time of this writing, only the Linux inotify interface is
		1277	implemented (implementing kqueue support is left as an exercise for the
		1278	reader). Inotify will be used to give hints only and should not change the
		1279	semantics of C<ev_stat> watchers, which means that libev sometimes needs
		1280	to fall back to regular polling again even with inotify, but changes are
		1281	usually detected immediately, and if the file exists there will be no
		1282	polling.
		1283
		1284	=over 4
		1285
		1286	=item ev_stat_init (ev_stat , callback, const char path, ev_tstamp interval)
		1287
		1288	=item ev_stat_set (ev_stat , const char path, ev_tstamp interval)
		1289
		1290	Configures the watcher to wait for status changes of the given
		1291	C<path>. The C<interval> is a hint on how quickly a change is expected to
		1292	be detected and should normally be specified as C<0> to let libev choose
		1293	a suitable value. The memory pointed to by C<path> must point to the same
		1294	path for as long as the watcher is active.
		1295
		1296	The callback will be receive C<EV_STAT> when a change was detected,
		1297	relative to the attributes at the time the watcher was started (or the
		1298	last change was detected).
		1299
		1300	=item ev_stat_stat (ev_stat *)
		1301
		1302	Updates the stat buffer immediately with new values. If you change the
		1303	watched path in your callback, you could call this fucntion to avoid
		1304	detecting this change (while introducing a race condition). Can also be
		1305	useful simply to find out the new values.
		1306
		1307	=item ev_statdata attr [read-only]
		1308
		1309	The most-recently detected attributes of the file. Although the type is of
		1310	C<ev_statdata>, this is usually the (or one of the) C<struct stat> types
		1311	suitable for your system. If the C<st_nlink> member is C<0>, then there
		1312	was some error while C<stat>ing the file.
		1313
		1314	=item ev_statdata prev [read-only]
		1315
		1316	The previous attributes of the file. The callback gets invoked whenever
		1317	C<prev> != C<attr>.
		1318
		1319	=item ev_tstamp interval [read-only]
		1320
		1321	The specified interval.
		1322
		1323	=item const char *path [read-only]
		1324
		1325	The filesystem path that is being watched.
		1326
		1327	=back
		1328
		1329	Example: Watch C</etc/passwd> for attribute changes.
		1330
		1331	static void
		1332	passwd_cb (struct ev_loop loop, ev_stat w, int revents)
		1333	{
		1334	/* /etc/passwd changed in some way */
		1335	if (w->attr.st_nlink)
		1336	{
		1337	printf ("passwd current size %ld\n", (long)w->attr.st_size);
		1338	printf ("passwd current atime %ld\n", (long)w->attr.st_mtime);
		1339	printf ("passwd current mtime %ld\n", (long)w->attr.st_mtime);
		1340	}
		1341	else
		1342	/* you shalt not abuse printf for puts */
		1343	puts ("wow, /etc/passwd is not there, expect problems. "
		1344	"if this is windows, they already arrived\n");
		1345	}
		1346
		1347	...
		1348	ev_stat passwd;
		1349
		1350	ev_stat_init (&passwd, passwd_cb, "/etc/passwd");
		1351	ev_stat_start (loop, &passwd);
1055		1352
1056		1353
1057	=head2 C<ev_idle> - when you've got nothing better to do...	1354	=head2 C<ev_idle> - when you've got nothing better to do...
1058		1355
1059	Idle watchers trigger events when there are no other events are pending	1356	Idle watchers trigger events when there are no other events are pending
…		…
1080	kind. There is a C<ev_idle_set> macro, but using it is utterly pointless,	1377	kind. There is a C<ev_idle_set> macro, but using it is utterly pointless,
1081	believe me.	1378	believe me.
1082		1379
1083	=back	1380	=back
1084		1381
1085	Example: dynamically allocate an C<ev_idle>, start it, and in the	1382	Example: Dynamically allocate an C<ev_idle> watcher, start it, and in the
1086	callback, free it. Alos, use no error checking, as usual.	1383	callback, free it. Also, use no error checking, as usual.
1087		1384
1088	static void	1385	static void
1089	idle_cb (struct ev_loop loop, struct ev_idle w, int revents)	1386	idle_cb (struct ev_loop loop, struct ev_idle w, int revents)
1090	{	1387	{
1091	free (w);	1388	free (w);
…		…
1102		1399
1103	Prepare and check watchers are usually (but not always) used in tandem:	1400	Prepare and check watchers are usually (but not always) used in tandem:
1104	prepare watchers get invoked before the process blocks and check watchers	1401	prepare watchers get invoked before the process blocks and check watchers
1105	afterwards.	1402	afterwards.
1106		1403
		1404	You I<must not> call C<ev_loop> or similar functions that enter
		1405	the current event loop from either C<ev_prepare> or C<ev_check>
		1406	watchers. Other loops than the current one are fine, however. The
		1407	rationale behind this is that you do not need to check for recursion in
		1408	those watchers, i.e. the sequence will always be C<ev_prepare>, blocking,
		1409	C<ev_check> so if you have one watcher of each kind they will always be
		1410	called in pairs bracketing the blocking call.
		1411
1107	Their main purpose is to integrate other event mechanisms into libev and	1412	Their main purpose is to integrate other event mechanisms into libev and
1108	their use is somewhat advanced. This could be used, for example, to track	1413	their use is somewhat advanced. This could be used, for example, to track
1109	variable changes, implement your own watchers, integrate net-snmp or a	1414	variable changes, implement your own watchers, integrate net-snmp or a
1110	coroutine library and lots more.	1415	coroutine library and lots more. They are also occasionally useful if
		1416	you cache some data and want to flush it before blocking (for example,
		1417	in X programs you might want to do an C<XFlush ()> in an C<ev_prepare>
		1418	watcher).
1111		1419
1112	This is done by examining in each prepare call which file descriptors need	1420	This is done by examining in each prepare call which file descriptors need
1113	to be watched by the other library, registering C<ev_io> watchers for	1421	to be watched by the other library, registering C<ev_io> watchers for
1114	them and starting an C<ev_timer> watcher for any timeouts (many libraries	1422	them and starting an C<ev_timer> watcher for any timeouts (many libraries
1115	provide just this functionality). Then, in the check watcher you check for	1423	provide just this functionality). Then, in the check watcher you check for
…		…
1137	parameters of any kind. There are C<ev_prepare_set> and C<ev_check_set>	1445	parameters of any kind. There are C<ev_prepare_set> and C<ev_check_set>
1138	macros, but using them is utterly, utterly and completely pointless.	1446	macros, but using them is utterly, utterly and completely pointless.
1139		1447
1140	=back	1448	=back
1141		1449
1142	Example: TODO.	1450	Example: To include a library such as adns, you would add IO watchers
		1451	and a timeout watcher in a prepare handler, as required by libadns, and
		1452	in a check watcher, destroy them and call into libadns. What follows is
		1453	pseudo-code only of course:
		1454
		1455	static ev_io iow [nfd];
		1456	static ev_timer tw;
		1457
		1458	static void
		1459	io_cb (ev_loop loop, ev_io w, int revents)
		1460	{
		1461	// set the relevant poll flags
		1462	// could also call adns_processreadable etc. here
		1463	struct pollfd fd = (struct pollfd )w->data;
		1464	if (revents & EV_READ ) fd->revents \|= fd->events & POLLIN;
		1465	if (revents & EV_WRITE) fd->revents \|= fd->events & POLLOUT;
		1466	}
		1467
		1468	// create io watchers for each fd and a timer before blocking
		1469	static void
		1470	adns_prepare_cb (ev_loop loop, ev_prepare w, int revents)
		1471	{
		1472	int timeout = 3600000;
		1473	struct pollfd fds [nfd];
		1474	// actual code will need to loop here and realloc etc.
		1475	adns_beforepoll (ads, fds, &nfd, &timeout, timeval_from (ev_time ()));
		1476
		1477	/* the callback is illegal, but won't be called as we stop during check */
		1478	ev_timer_init (&tw, 0, timeout * 1e-3);
		1479	ev_timer_start (loop, &tw);
		1480
		1481	// create on ev_io per pollfd
		1482	for (int i = 0; i < nfd; ++i)
		1483	{
		1484	ev_io_init (iow + i, io_cb, fds [i].fd,
		1485	((fds [i].events & POLLIN ? EV_READ : 0)
		1486	\| (fds [i].events & POLLOUT ? EV_WRITE : 0)));
		1487
		1488	fds [i].revents = 0;
		1489	iow [i].data = fds + i;
		1490	ev_io_start (loop, iow + i);
		1491	}
		1492	}
		1493
		1494	// stop all watchers after blocking
		1495	static void
		1496	adns_check_cb (ev_loop loop, ev_check w, int revents)
		1497	{
		1498	ev_timer_stop (loop, &tw);
		1499
		1500	for (int i = 0; i < nfd; ++i)
		1501	ev_io_stop (loop, iow + i);
		1502
		1503	adns_afterpoll (adns, fds, nfd, timeval_from (ev_now (loop));
		1504	}
1143		1505
1144		1506
1145	=head2 C<ev_embed> - when one backend isn't enough...	1507	=head2 C<ev_embed> - when one backend isn't enough...
1146		1508
1147	This is a rather advanced watcher type that lets you embed one event loop	1509	This is a rather advanced watcher type that lets you embed one event loop
…		…
1228		1590
1229	Make a single, non-blocking sweep over the embedded loop. This works	1591	Make a single, non-blocking sweep over the embedded loop. This works
1230	similarly to C<ev_loop (embedded_loop, EVLOOP_NONBLOCK)>, but in the most	1592	similarly to C<ev_loop (embedded_loop, EVLOOP_NONBLOCK)>, but in the most
1231	apropriate way for embedded loops.	1593	apropriate way for embedded loops.
1232		1594
		1595	=item struct ev_loop *loop [read-only]
		1596
		1597	The embedded event loop.
		1598
		1599	=back
		1600
		1601
		1602	=head2 C<ev_fork> - the audacity to resume the event loop after a fork
		1603
		1604	Fork watchers are called when a C<fork ()> was detected (usually because
		1605	whoever is a good citizen cared to tell libev about it by calling
		1606	C<ev_default_fork> or C<ev_loop_fork>). The invocation is done before the
		1607	event loop blocks next and before C<ev_check> watchers are being called,
		1608	and only in the child after the fork. If whoever good citizen calling
		1609	C<ev_default_fork> cheats and calls it in the wrong process, the fork
		1610	handlers will be invoked, too, of course.
		1611
		1612	=over 4
		1613
		1614	=item ev_fork_init (ev_signal *, callback)
		1615
		1616	Initialises and configures the fork watcher - it has no parameters of any
		1617	kind. There is a C<ev_fork_set> macro, but using it is utterly pointless,
		1618	believe me.
		1619
1233	=back	1620	=back
1234		1621
1235		1622
1236	=head1 OTHER FUNCTIONS	1623	=head1 OTHER FUNCTIONS
1237		1624
…		…
1399		1786
1400	=item w->sweep () C<ev::embed> only	1787	=item w->sweep () C<ev::embed> only
1401		1788
1402	Invokes C<ev_embed_sweep>.	1789	Invokes C<ev_embed_sweep>.
1403		1790
		1791	=item w->update () C<ev::stat> only
		1792
		1793	Invokes C<ev_stat_stat>.
		1794
1404	=back	1795	=back
1405		1796
1406	=back	1797	=back
1407		1798
1408	Example: Define a class with an IO and idle watcher, start one of them in	1799	Example: Define a class with an IO and idle watcher, start one of them in
…		…
1420	: io (this, &myclass::io_cb),	1811	: io (this, &myclass::io_cb),
1421	idle (this, &myclass::idle_cb)	1812	idle (this, &myclass::idle_cb)
1422	{	1813	{
1423	io.start (fd, ev::READ);	1814	io.start (fd, ev::READ);
1424	}	1815	}
		1816
		1817
		1818	=head1 MACRO MAGIC
		1819
		1820	Libev can be compiled with a variety of options, the most fundemantal is
		1821	C<EV_MULTIPLICITY>. This option determines wether (most) functions and
		1822	callbacks have an initial C<struct ev_loop *> argument.
		1823
		1824	To make it easier to write programs that cope with either variant, the
		1825	following macros are defined:
		1826
		1827	=over 4
		1828
		1829	=item C<EV_A>, C<EV_A_>
		1830
		1831	This provides the loop I<argument> for functions, if one is required ("ev
		1832	loop argument"). The C<EV_A> form is used when this is the sole argument,
		1833	C<EV_A_> is used when other arguments are following. Example:
		1834
		1835	ev_unref (EV_A);
		1836	ev_timer_add (EV_A_ watcher);
		1837	ev_loop (EV_A_ 0);
		1838
		1839	It assumes the variable C<loop> of type C<struct ev_loop *> is in scope,
		1840	which is often provided by the following macro.
		1841
		1842	=item C<EV_P>, C<EV_P_>
		1843
		1844	This provides the loop I<parameter> for functions, if one is required ("ev
		1845	loop parameter"). The C<EV_P> form is used when this is the sole parameter,
		1846	C<EV_P_> is used when other parameters are following. Example:
		1847
		1848	// this is how ev_unref is being declared
		1849	static void ev_unref (EV_P);
		1850
		1851	// this is how you can declare your typical callback
		1852	static void cb (EV_P_ ev_timer *w, int revents)
		1853
		1854	It declares a parameter C<loop> of type C<struct ev_loop *>, quite
		1855	suitable for use with C<EV_A>.
		1856
		1857	=item C<EV_DEFAULT>, C<EV_DEFAULT_>
		1858
		1859	Similar to the other two macros, this gives you the value of the default
		1860	loop, if multiple loops are supported ("ev loop default").
		1861
		1862	=back
		1863
		1864	Example: Declare and initialise a check watcher, utilising the above
		1865	macros so it will work regardless of wether multiple loops are supported
		1866	or not.
		1867
		1868	static void
		1869	check_cb (EV_P_ ev_timer *w, int revents)
		1870	{
		1871	ev_check_stop (EV_A_ w);
		1872	}
		1873
		1874	ev_check check;
		1875	ev_check_init (&check, check_cb);
		1876	ev_check_start (EV_DEFAULT_ &check);
		1877	ev_loop (EV_DEFAULT_ 0);
1425		1878
1426	=head1 EMBEDDING	1879	=head1 EMBEDDING
1427		1880
1428	Libev can (and often is) directly embedded into host	1881	Libev can (and often is) directly embedded into host
1429	applications. Examples of applications that embed it include the Deliantra	1882	applications. Examples of applications that embed it include the Deliantra
…		…
1469	ev_vars.h	1922	ev_vars.h
1470	ev_wrap.h	1923	ev_wrap.h
1471		1924
1472	ev_win32.c required on win32 platforms only	1925	ev_win32.c required on win32 platforms only
1473		1926
1474	ev_select.c only when select backend is enabled (which is is by default)	1927	ev_select.c only when select backend is enabled (which is enabled by default)
1475	ev_poll.c only when poll backend is enabled (disabled by default)	1928	ev_poll.c only when poll backend is enabled (disabled by default)
1476	ev_epoll.c only when the epoll backend is enabled (disabled by default)	1929	ev_epoll.c only when the epoll backend is enabled (disabled by default)
1477	ev_kqueue.c only when the kqueue backend is enabled (disabled by default)	1930	ev_kqueue.c only when the kqueue backend is enabled (disabled by default)
1478	ev_port.c only when the solaris port backend is enabled (disabled by default)	1931	ev_port.c only when the solaris port backend is enabled (disabled by default)
1479		1932
1480	F<ev.c> includes the backend files directly when enabled, so you only need	1933	F<ev.c> includes the backend files directly when enabled, so you only need
1481	to compile a single file.	1934	to compile this single file.
1482		1935
1483	=head3 LIBEVENT COMPATIBILITY API	1936	=head3 LIBEVENT COMPATIBILITY API
1484		1937
1485	To include the libevent compatibility API, also include:	1938	To include the libevent compatibility API, also include:
1486		1939
…		…
1499		1952
1500	=head3 AUTOCONF SUPPORT	1953	=head3 AUTOCONF SUPPORT
1501		1954
1502	Instead of using C<EV_STANDALONE=1> and providing your config in	1955	Instead of using C<EV_STANDALONE=1> and providing your config in
1503	whatever way you want, you can also C<m4_include([libev.m4])> in your	1956	whatever way you want, you can also C<m4_include([libev.m4])> in your
1504	F<configure.ac> and leave C<EV_STANDALONE> off. F<ev.c> will then include	1957	F<configure.ac> and leave C<EV_STANDALONE> undefined. F<ev.c> will then
1505	F<config.h> and configure itself accordingly.	1958	include F<config.h> and configure itself accordingly.
1506		1959
1507	For this of course you need the m4 file:	1960	For this of course you need the m4 file:
1508		1961
1509	libev.m4	1962	libev.m4
1510		1963
…		…
1604		2057
1605	=item EV_USE_DEVPOLL	2058	=item EV_USE_DEVPOLL
1606		2059
1607	reserved for future expansion, works like the USE symbols above.	2060	reserved for future expansion, works like the USE symbols above.
1608		2061
		2062	=item EV_USE_INOTIFY
		2063
		2064	If defined to be C<1>, libev will compile in support for the Linux inotify
		2065	interface to speed up C<ev_stat> watchers. Its actual availability will
		2066	be detected at runtime.
		2067
1609	=item EV_H	2068	=item EV_H
1610		2069
1611	The name of the F<ev.h> header file used to include it. The default if	2070	The name of the F<ev.h> header file used to include it. The default if
1612	undefined is C<< <ev.h> >> in F<event.h> and C<"ev.h"> in F<ev.c>. This	2071	undefined is C<< <ev.h> >> in F<event.h> and C<"ev.h"> in F<ev.c>. This
1613	can be used to virtually rename the F<ev.h> header file in case of conflicts.	2072	can be used to virtually rename the F<ev.h> header file in case of conflicts.
…		…
1636	will have the C<struct ev_loop *> as first argument, and you can create	2095	will have the C<struct ev_loop *> as first argument, and you can create
1637	additional independent event loops. Otherwise there will be no support	2096	additional independent event loops. Otherwise there will be no support
1638	for multiple event loops and there is no first event loop pointer	2097	for multiple event loops and there is no first event loop pointer
1639	argument. Instead, all functions act on the single default loop.	2098	argument. Instead, all functions act on the single default loop.
1640		2099
1641	=item EV_PERIODICS	2100	=item EV_PERIODIC_ENABLE
1642		2101
1643	If undefined or defined to be C<1>, then periodic timers are supported,	2102	If undefined or defined to be C<1>, then periodic timers are supported. If
1644	otherwise not. This saves a few kb of code.	2103	defined to be C<0>, then they are not. Disabling them saves a few kB of
		2104	code.
		2105
		2106	=item EV_EMBED_ENABLE
		2107
		2108	If undefined or defined to be C<1>, then embed watchers are supported. If
		2109	defined to be C<0>, then they are not.
		2110
		2111	=item EV_STAT_ENABLE
		2112
		2113	If undefined or defined to be C<1>, then stat watchers are supported. If
		2114	defined to be C<0>, then they are not.
		2115
		2116	=item EV_FORK_ENABLE
		2117
		2118	If undefined or defined to be C<1>, then fork watchers are supported. If
		2119	defined to be C<0>, then they are not.
		2120
		2121	=item EV_MINIMAL
		2122
		2123	If you need to shave off some kilobytes of code at the expense of some
		2124	speed, define this symbol to C<1>. Currently only used for gcc to override
		2125	some inlining decisions, saves roughly 30% codesize of amd64.
		2126
		2127	=item EV_PID_HASHSIZE
		2128
		2129	C<ev_child> watchers use a small hash table to distribute workload by
		2130	pid. The default size is C<16> (or C<1> with C<EV_MINIMAL>), usually more
		2131	than enough. If you need to manage thousands of children you might want to
		2132	increase this value (I<must> be a power of two).
		2133
		2134	=item EV_INOTIFY_HASHSIZE
		2135
		2136	C<ev_staz> watchers use a small hash table to distribute workload by
		2137	inotify watch id. The default size is C<16> (or C<1> with C<EV_MINIMAL>),
		2138	usually more than enough. If you need to manage thousands of C<ev_stat>
		2139	watchers you might want to increase this value (I<must> be a power of
		2140	two).
1645		2141
1646	=item EV_COMMON	2142	=item EV_COMMON
1647		2143
1648	By default, all watchers have a C<void *data> member. By redefining	2144	By default, all watchers have a C<void *data> member. By redefining
1649	this macro to a something else you can include more and other types of	2145	this macro to a something else you can include more and other types of
…		…
1654		2150
1655	#define EV_COMMON \	2151	#define EV_COMMON \
1656	SV self; / contains this struct */ \	2152	SV self; / contains this struct */ \
1657	SV cb_sv, fh /* note no trailing ";" */	2153	SV cb_sv, fh /* note no trailing ";" */
1658		2154
1659	=item EV_CB_DECLARE(type)	2155	=item EV_CB_DECLARE (type)
1660		2156
1661	=item EV_CB_INVOKE(watcher,revents)	2157	=item EV_CB_INVOKE (watcher, revents)
1662		2158
1663	=item ev_set_cb(ev,cb)	2159	=item ev_set_cb (ev, cb)
1664		2160
1665	Can be used to change the callback member declaration in each watcher,	2161	Can be used to change the callback member declaration in each watcher,
1666	and the way callbacks are invoked and set. Must expand to a struct member	2162	and the way callbacks are invoked and set. Must expand to a struct member
1667	definition and a statement, respectively. See the F<ev.v> header file for	2163	definition and a statement, respectively. See the F<ev.v> header file for
1668	their default definitions. One possible use for overriding these is to	2164	their default definitions. One possible use for overriding these is to
1669	avoid the ev_loop pointer as first argument in all cases, or to use method	2165	avoid the C<struct ev_loop *> as first argument in all cases, or to use
1670	calls instead of plain function calls in C++.	2166	method calls instead of plain function calls in C++.
1671		2167
1672	=head2 EXAMPLES	2168	=head2 EXAMPLES
1673		2169
1674	For a real-world example of a program the includes libev	2170	For a real-world example of a program the includes libev
1675	verbatim, you can have a look at the EV perl module	2171	verbatim, you can have a look at the EV perl module
…		…
1678	interface) and F<EV.xs> (implementation) files. Only the F<EV.xs> file	2174	interface) and F<EV.xs> (implementation) files. Only the F<EV.xs> file
1679	will be compiled. It is pretty complex because it provides its own header	2175	will be compiled. It is pretty complex because it provides its own header
1680	file.	2176	file.
1681		2177
1682	The usage in rxvt-unicode is simpler. It has a F<ev_cpp.h> header file	2178	The usage in rxvt-unicode is simpler. It has a F<ev_cpp.h> header file
1683	that everybody includes and which overrides some autoconf choices:	2179	that everybody includes and which overrides some configure choices:
1684		2180
		2181	#define EV_MINIMAL 1
1685	#define EV_USE_POLL 0	2182	#define EV_USE_POLL 0
1686	#define EV_MULTIPLICITY 0	2183	#define EV_MULTIPLICITY 0
1687	#define EV_PERIODICS 0	2184	#define EV_PERIODIC_ENABLE 0
		2185	#define EV_STAT_ENABLE 0
		2186	#define EV_FORK_ENABLE 0
1688	#define EV_CONFIG_H <config.h>	2187	#define EV_CONFIG_H <config.h>
		2188	#define EV_MINPRI 0
		2189	#define EV_MAXPRI 0
1689		2190
1690	#include "ev++.h"	2191	#include "ev++.h"
1691		2192
1692	And a F<ev_cpp.C> implementation file that contains libev proper and is compiled:	2193	And a F<ev_cpp.C> implementation file that contains libev proper and is compiled:
1693		2194
1694	#include "ev_cpp.h"	2195	#include "ev_cpp.h"
1695	#include "ev.c"	2196	#include "ev.c"
1696		2197
		2198
		2199	=head1 COMPLEXITIES
		2200
		2201	In this section the complexities of (many of) the algorithms used inside
		2202	libev will be explained. For complexity discussions about backends see the
		2203	documentation for C<ev_default_init>.
		2204
		2205	=over 4
		2206
		2207	=item Starting and stopping timer/periodic watchers: O(log skipped_other_timers)
		2208
		2209	=item Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)
		2210
		2211	=item Starting io/check/prepare/idle/signal/child watchers: O(1)
		2212
		2213	=item Stopping check/prepare/idle watchers: O(1)
		2214
		2215	=item Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % EV_PID_HASHSIZE))
		2216
		2217	=item Finding the next timer per loop iteration: O(1)
		2218
		2219	=item Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)
		2220
		2221	=item Activating one watcher: O(1)
		2222
		2223	=back
		2224
		2225
1697	=head1 AUTHOR	2226	=head1 AUTHOR
1698		2227
1699	Marc Lehmann <libev@schmorp.de>.	2228	Marc Lehmann <libev@schmorp.de>.
1700		2229

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Comparing libev/ev.pod (file contents): Revision 1.42 by root, Sat Nov 24 16:31:45 2007 UTC vs. Revision 1.66 by root, Mon Dec 3 13:41:25 2007 UTC

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Comparing libev/ev.pod (file contents):
Revision 1.42 by root, Sat Nov 24 16:31:45 2007 UTC vs.
Revision 1.66 by root, Mon Dec 3 13:41:25 2007 UTC