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

Comparing libev/ev.pod (file contents):
Revision 1.60 by root, Wed Nov 28 18:29:30 2007 UTC vs.
Revision 1.72 by root, Fri Dec 7 20:19:16 2007 UTC

…		…
47		47
48	return 0;	48	return 0;
49	}	49	}
50		50
51	=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>.
52		56
53	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
54	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
55	these event sources and provide your program with events.	59	these event sources and provide your program with events.
56		60
…		…
266	C<LIBEV_FLAGS>. Otherwise (the default), this environment variable will	270	C<LIBEV_FLAGS>. Otherwise (the default), this environment variable will
267	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
268	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
269	around bugs.	273	around bugs.
270		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
271	=item C<EVBACKEND_SELECT> (value 1, portable select backend)	295	=item C<EVBACKEND_SELECT> (value 1, portable select backend)
272		296
273	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
274	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,
275	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
…		…
409	=item ev_loop_fork (loop)	433	=item ev_loop_fork (loop)
410		434
411	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
412	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
413	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.
414		448
415	=item unsigned int ev_backend (loop)	449	=item unsigned int ev_backend (loop)
416		450
417	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
418	use.	452	use.
…		…
714	=item ev_cb_set (ev_TYPE *watcher, callback)	748	=item ev_cb_set (ev_TYPE *watcher, callback)
715		749
716	Change the callback. You can change the callback at virtually any time	750	Change the callback. You can change the callback at virtually any time
717	(modulo threads).	751	(modulo threads).
718		752
		753	=item ev_set_priority (ev_TYPE *watcher, priority)
		754
		755	=item int ev_priority (ev_TYPE *watcher)
		756
		757	Set and query the priority of the watcher. The priority is a small
		758	integer between C<EV_MAXPRI> (default: C<2>) and C<EV_MINPRI>
		759	(default: C<-2>). Pending watchers with higher priority will be invoked
		760	before watchers with lower priority, but priority will not keep watchers
		761	from being executed (except for C<ev_idle> watchers).
		762
		763	This means that priorities are I<only> used for ordering callback
		764	invocation after new events have been received. This is useful, for
		765	example, to reduce latency after idling, or more often, to bind two
		766	watchers on the same event and make sure one is called first.
		767
		768	If you need to suppress invocation when higher priority events are pending
		769	you need to look at C<ev_idle> watchers, which provide this functionality.
		770
		771	The default priority used by watchers when no priority has been set is
		772	always C<0>, which is supposed to not be too high and not be too low :).
		773
		774	Setting a priority outside the range of C<EV_MINPRI> to C<EV_MAXPRI> is
		775	fine, as long as you do not mind that the priority value you query might
		776	or might not have been adjusted to be within valid range.
		777
719	=back	778	=back
720		779
721		780
722	=head2 ASSOCIATING CUSTOM DATA WITH A WATCHER	781	=head2 ASSOCIATING CUSTOM DATA WITH A WATCHER
723		782
…		…
828	it is best to always use non-blocking I/O: An extra C<read>(2) returning	887	it is best to always use non-blocking I/O: An extra C<read>(2) returning
829	C<EAGAIN> is far preferable to a program hanging until some data arrives.	888	C<EAGAIN> is far preferable to a program hanging until some data arrives.
830		889
831	If you cannot run the fd in non-blocking mode (for example you should not	890	If you cannot run the fd in non-blocking mode (for example you should not
832	play around with an Xlib connection), then you have to seperately re-test	891	play around with an Xlib connection), then you have to seperately re-test
833	wether a file descriptor is really ready with a known-to-be good interface	892	whether a file descriptor is really ready with a known-to-be good interface
834	such as poll (fortunately in our Xlib example, Xlib already does this on	893	such as poll (fortunately in our Xlib example, Xlib already does this on
835	its own, so its quite safe to use).	894	its own, so its quite safe to use).
836		895
837	=over 4	896	=over 4
838		897
…		…
916	=item ev_timer_again (loop)	975	=item ev_timer_again (loop)
917		976
918	This will act as if the timer timed out and restart it again if it is	977	This will act as if the timer timed out and restart it again if it is
919	repeating. The exact semantics are:	978	repeating. The exact semantics are:
920		979
		980	If the timer is pending, its pending status is cleared.
		981
921	If the timer is started but nonrepeating, stop it.	982	If the timer is started but nonrepeating, stop it (as if it timed out).
922		983
923	If the timer is repeating, either start it if necessary (with the repeat	984	If the timer is repeating, either start it if necessary (with the
924	value), or reset the running timer to the repeat value.	985	C<repeat> value), or reset the running timer to the C<repeat> value.
925		986
926	This sounds a bit complicated, but here is a useful and typical	987	This sounds a bit complicated, but here is a useful and typical
927	example: Imagine you have a tcp connection and you want a so-called	988	example: Imagine you have a tcp connection and you want a so-called idle
928	idle timeout, that is, you want to be called when there have been,	989	timeout, that is, you want to be called when there have been, say, 60
929	say, 60 seconds of inactivity on the socket. The easiest way to do	990	seconds of inactivity on the socket. The easiest way to do this is to
930	this is to configure an C<ev_timer> with C<after>=C<repeat>=C<60> and calling	991	configure an C<ev_timer> with a C<repeat> value of C<60> and then call
931	C<ev_timer_again> each time you successfully read or write some data. If	992	C<ev_timer_again> each time you successfully read or write some data. If
932	you go into an idle state where you do not expect data to travel on the	993	you go into an idle state where you do not expect data to travel on the
933	socket, you can stop the timer, and again will automatically restart it if	994	socket, you can C<ev_timer_stop> the timer, and C<ev_timer_again> will
934	need be.	995	automatically restart it if need be.
935		996
936	You can also ignore the C<after> value and C<ev_timer_start> altogether	997	That means you can ignore the C<after> value and C<ev_timer_start>
937	and only ever use the C<repeat> value:	998	altogether and only ever use the C<repeat> value and C<ev_timer_again>:
938		999
939	ev_timer_init (timer, callback, 0., 5.);	1000	ev_timer_init (timer, callback, 0., 5.);
940	ev_timer_again (loop, timer);	1001	ev_timer_again (loop, timer);
941	...	1002	...
942	timer->again = 17.;	1003	timer->again = 17.;
943	ev_timer_again (loop, timer);	1004	ev_timer_again (loop, timer);
944	...	1005	...
945	timer->again = 10.;	1006	timer->again = 10.;
946	ev_timer_again (loop, timer);	1007	ev_timer_again (loop, timer);
947		1008
948	This is more efficient then stopping/starting the timer eahc time you want	1009	This is more slightly efficient then stopping/starting the timer each time
949	to modify its timeout value.	1010	you want to modify its timeout value.
950		1011
951	=item ev_tstamp repeat [read-write]	1012	=item ev_tstamp repeat [read-write]
952		1013
953	The current C<repeat> value. Will be used each time the watcher times out	1014	The current C<repeat> value. Will be used each time the watcher times out
954	or C<ev_timer_again> is called and determines the next timeout (if any),	1015	or C<ev_timer_again> is called and determines the next timeout (if any),
…		…
1319	ev_stat_start (loop, &passwd);	1380	ev_stat_start (loop, &passwd);
1320		1381
1321		1382
1322	=head2 C<ev_idle> - when you've got nothing better to do...	1383	=head2 C<ev_idle> - when you've got nothing better to do...
1323		1384
1324	Idle watchers trigger events when there are no other events are pending	1385	Idle watchers trigger events when no other events of the same or higher
1325	(prepare, check and other idle watchers do not count). That is, as long	1386	priority are pending (prepare, check and other idle watchers do not
1326	as your process is busy handling sockets or timeouts (or even signals,	1387	count).
1327	imagine) it will not be triggered. But when your process is idle all idle	1388
1328	watchers are being called again and again, once per event loop iteration -	1389	That is, as long as your process is busy handling sockets or timeouts
		1390	(or even signals, imagine) of the same or higher priority it will not be
		1391	triggered. But when your process is idle (or only lower-priority watchers
		1392	are pending), the idle watchers are being called once per event loop
1329	until stopped, that is, or your process receives more events and becomes	1393	iteration - until stopped, that is, or your process receives more events
1330	busy.	1394	and becomes busy again with higher priority stuff.
1331		1395
1332	The most noteworthy effect is that as long as any idle watchers are	1396	The most noteworthy effect is that as long as any idle watchers are
1333	active, the process will not block when waiting for new events.	1397	active, the process will not block when waiting for new events.
1334		1398
1335	Apart from keeping your process non-blocking (which is a useful	1399	Apart from keeping your process non-blocking (which is a useful
…		…
1435		1499
1436	// create io watchers for each fd and a timer before blocking	1500	// create io watchers for each fd and a timer before blocking
1437	static void	1501	static void
1438	adns_prepare_cb (ev_loop loop, ev_prepare w, int revents)	1502	adns_prepare_cb (ev_loop loop, ev_prepare w, int revents)
1439	{	1503	{
1440	int timeout = 3600000;truct pollfd fds [nfd];	1504	int timeout = 3600000;
		1505	struct pollfd fds [nfd];
1441	// actual code will need to loop here and realloc etc.	1506	// actual code will need to loop here and realloc etc.
1442	adns_beforepoll (ads, fds, &nfd, &timeout, timeval_from (ev_time ()));	1507	adns_beforepoll (ads, fds, &nfd, &timeout, timeval_from (ev_time ()));
1443		1508
1444	/* the callback is illegal, but won't be called as we stop during check */	1509	/* the callback is illegal, but won't be called as we stop during check */
1445	ev_timer_init (&tw, 0, timeout * 1e-3);	1510	ev_timer_init (&tw, 0, timeout * 1e-3);
…		…
1679		1744
1680	To use it,	1745	To use it,
1681		1746
1682	#include <ev++.h>	1747	#include <ev++.h>
1683		1748
1684	(it is not installed by default). This automatically includes F<ev.h>	1749	This automatically includes F<ev.h> and puts all of its definitions (many
1685	and puts all of its definitions (many of them macros) into the global	1750	of them macros) into the global namespace. All C++ specific things are
1686	namespace. All C++ specific things are put into the C<ev> namespace.	1751	put into the C<ev> namespace. It should support all the same embedding
		1752	options as F<ev.h>, most notably C<EV_MULTIPLICITY>.
1687		1753
1688	It should support all the same embedding options as F<ev.h>, most notably	1754	Care has been taken to keep the overhead low. The only data member the C++
1689	C<EV_MULTIPLICITY>.	1755	classes add (compared to plain C-style watchers) is the event loop pointer
		1756	that the watcher is associated with (or no additional members at all if
		1757	you disable C<EV_MULTIPLICITY> when embedding libev).
		1758
		1759	Currently, functions, and static and non-static member functions can be
		1760	used as callbacks. Other types should be easy to add as long as they only
		1761	need one additional pointer for context. If you need support for other
		1762	types of functors please contact the author (preferably after implementing
		1763	it).
1690		1764
1691	Here is a list of things available in the C<ev> namespace:	1765	Here is a list of things available in the C<ev> namespace:
1692		1766
1693	=over 4	1767	=over 4
1694		1768
…		…
1710		1784
1711	All of those classes have these methods:	1785	All of those classes have these methods:
1712		1786
1713	=over 4	1787	=over 4
1714		1788
1715	=item ev::TYPE::TYPE (object , object::method )	1789	=item ev::TYPE::TYPE ()
1716		1790
1717	=item ev::TYPE::TYPE (object , object::method , struct ev_loop *)	1791	=item ev::TYPE::TYPE (struct ev_loop *)
1718		1792
1719	=item ev::TYPE::~TYPE	1793	=item ev::TYPE::~TYPE
1720		1794
1721	The constructor takes a pointer to an object and a method pointer to	1795	The constructor (optionally) takes an event loop to associate the watcher
1722	the event handler callback to call in this class. The constructor calls	1796	with. If it is omitted, it will use C<EV_DEFAULT>.
1723	C<ev_init> for you, which means you have to call the C<set> method	1797
1724	before starting it. If you do not specify a loop then the constructor	1798	The constructor calls C<ev_init> for you, which means you have to call the
1725	automatically associates the default loop with this watcher.	1799	C<set> method before starting it.
		1800
		1801	It will not set a callback, however: You have to call the templated C<set>
		1802	method to set a callback before you can start the watcher.
		1803
		1804	(The reason why you have to use a method is a limitation in C++ which does
		1805	not allow explicit template arguments for constructors).
1726		1806
1727	The destructor automatically stops the watcher if it is active.	1807	The destructor automatically stops the watcher if it is active.
		1808
		1809	=item w->set<class, &class::method> (object *)
		1810
		1811	This method sets the callback method to call. The method has to have a
		1812	signature of C<void (*)(ev_TYPE &, int)>, it receives the watcher as
		1813	first argument and the C<revents> as second. The object must be given as
		1814	parameter and is stored in the C<data> member of the watcher.
		1815
		1816	This method synthesizes efficient thunking code to call your method from
		1817	the C callback that libev requires. If your compiler can inline your
		1818	callback (i.e. it is visible to it at the place of the C<set> call and
		1819	your compiler is good :), then the method will be fully inlined into the
		1820	thunking function, making it as fast as a direct C callback.
		1821
		1822	Example: simple class declaration and watcher initialisation
		1823
		1824	struct myclass
		1825	{
		1826	void io_cb (ev::io &w, int revents) { }
		1827	}
		1828
		1829	myclass obj;
		1830	ev::io iow;
		1831	iow.set <myclass, &myclass::io_cb> (&obj);
		1832
		1833	=item w->set (void (function)(watcher &w, int), void data = 0)
		1834
		1835	Also sets a callback, but uses a static method or plain function as
		1836	callback. The optional C<data> argument will be stored in the watcher's
		1837	C<data> member and is free for you to use.
		1838
		1839	See the method-C<set> above for more details.
1728		1840
1729	=item w->set (struct ev_loop *)	1841	=item w->set (struct ev_loop *)
1730		1842
1731	Associates a different C<struct ev_loop> with this watcher. You can only	1843	Associates a different C<struct ev_loop> with this watcher. You can only
1732	do this when the watcher is inactive (and not pending either).	1844	do this when the watcher is inactive (and not pending either).
1733		1845
1734	=item w->set ([args])	1846	=item w->set ([args])
1735		1847
1736	Basically the same as C<ev_TYPE_set>, with the same args. Must be	1848	Basically the same as C<ev_TYPE_set>, with the same args. Must be
1737	called at least once. Unlike the C counterpart, an active watcher gets	1849	called at least once. Unlike the C counterpart, an active watcher gets
1738	automatically stopped and restarted.	1850	automatically stopped and restarted when reconfiguring it with this
		1851	method.
1739		1852
1740	=item w->start ()	1853	=item w->start ()
1741		1854
1742	Starts the watcher. Note that there is no C<loop> argument as the	1855	Starts the watcher. Note that there is no C<loop> argument, as the
1743	constructor already takes the loop.	1856	constructor already stores the event loop.
1744		1857
1745	=item w->stop ()	1858	=item w->stop ()
1746		1859
1747	Stops the watcher if it is active. Again, no C<loop> argument.	1860	Stops the watcher if it is active. Again, no C<loop> argument.
1748		1861
…		…
1773		1886
1774	myclass ();	1887	myclass ();
1775	}	1888	}
1776		1889
1777	myclass::myclass (int fd)	1890	myclass::myclass (int fd)
1778	: io (this, &myclass::io_cb),
1779	idle (this, &myclass::idle_cb)
1780	{	1891	{
		1892	io .set <myclass, &myclass::io_cb > (this);
		1893	idle.set <myclass, &myclass::idle_cb> (this);
		1894
1781	io.start (fd, ev::READ);	1895	io.start (fd, ev::READ);
1782	}	1896	}
1783		1897
1784		1898
1785	=head1 MACRO MAGIC	1899	=head1 MACRO MAGIC
1786		1900
1787	Libev can be compiled with a variety of options, the most fundemantal is	1901	Libev can be compiled with a variety of options, the most fundemantal is
1788	C<EV_MULTIPLICITY>. This option determines wether (most) functions and	1902	C<EV_MULTIPLICITY>. This option determines whether (most) functions and
1789	callbacks have an initial C<struct ev_loop *> argument.	1903	callbacks have an initial C<struct ev_loop *> argument.
1790		1904
1791	To make it easier to write programs that cope with either variant, the	1905	To make it easier to write programs that cope with either variant, the
1792	following macros are defined:	1906	following macros are defined:
1793		1907
…		…
1826	Similar to the other two macros, this gives you the value of the default	1940	Similar to the other two macros, this gives you the value of the default
1827	loop, if multiple loops are supported ("ev loop default").	1941	loop, if multiple loops are supported ("ev loop default").
1828		1942
1829	=back	1943	=back
1830		1944
1831	Example: Declare and initialise a check watcher, working regardless of	1945	Example: Declare and initialise a check watcher, utilising the above
1832	wether multiple loops are supported or not.	1946	macros so it will work regardless of whether multiple loops are supported
		1947	or not.
1833		1948
1834	static void	1949	static void
1835	check_cb (EV_P_ ev_timer *w, int revents)	1950	check_cb (EV_P_ ev_timer *w, int revents)
1836	{	1951	{
1837	ev_check_stop (EV_A_ w);	1952	ev_check_stop (EV_A_ w);
…		…
1839		1954
1840	ev_check check;	1955	ev_check check;
1841	ev_check_init (&check, check_cb);	1956	ev_check_init (&check, check_cb);
1842	ev_check_start (EV_DEFAULT_ &check);	1957	ev_check_start (EV_DEFAULT_ &check);
1843	ev_loop (EV_DEFAULT_ 0);	1958	ev_loop (EV_DEFAULT_ 0);
1844
1845		1959
1846	=head1 EMBEDDING	1960	=head1 EMBEDDING
1847		1961
1848	Libev can (and often is) directly embedded into host	1962	Libev can (and often is) directly embedded into host
1849	applications. Examples of applications that embed it include the Deliantra	1963	applications. Examples of applications that embed it include the Deliantra
…		…
1889	ev_vars.h	2003	ev_vars.h
1890	ev_wrap.h	2004	ev_wrap.h
1891		2005
1892	ev_win32.c required on win32 platforms only	2006	ev_win32.c required on win32 platforms only
1893		2007
1894	ev_select.c only when select backend is enabled (which is by default)	2008	ev_select.c only when select backend is enabled (which is enabled by default)
1895	ev_poll.c only when poll backend is enabled (disabled by default)	2009	ev_poll.c only when poll backend is enabled (disabled by default)
1896	ev_epoll.c only when the epoll backend is enabled (disabled by default)	2010	ev_epoll.c only when the epoll backend is enabled (disabled by default)
1897	ev_kqueue.c only when the kqueue backend is enabled (disabled by default)	2011	ev_kqueue.c only when the kqueue backend is enabled (disabled by default)
1898	ev_port.c only when the solaris port backend is enabled (disabled by default)	2012	ev_port.c only when the solaris port backend is enabled (disabled by default)
1899		2013
…		…
2062	will have the C<struct ev_loop *> as first argument, and you can create	2176	will have the C<struct ev_loop *> as first argument, and you can create
2063	additional independent event loops. Otherwise there will be no support	2177	additional independent event loops. Otherwise there will be no support
2064	for multiple event loops and there is no first event loop pointer	2178	for multiple event loops and there is no first event loop pointer
2065	argument. Instead, all functions act on the single default loop.	2179	argument. Instead, all functions act on the single default loop.
2066		2180
		2181	=item EV_MINPRI
		2182
		2183	=item EV_MAXPRI
		2184
		2185	The range of allowed priorities. C<EV_MINPRI> must be smaller or equal to
		2186	C<EV_MAXPRI>, but otherwise there are no non-obvious limitations. You can
		2187	provide for more priorities by overriding those symbols (usually defined
		2188	to be C<-2> and C<2>, respectively).
		2189
		2190	When doing priority-based operations, libev usually has to linearly search
		2191	all the priorities, so having many of them (hundreds) uses a lot of space
		2192	and time, so using the defaults of five priorities (-2 .. +2) is usually
		2193	fine.
		2194
		2195	If your embedding app does not need any priorities, defining these both to
		2196	C<0> will save some memory and cpu.
		2197
2067	=item EV_PERIODIC_ENABLE	2198	=item EV_PERIODIC_ENABLE
2068		2199
2069	If undefined or defined to be C<1>, then periodic timers are supported. If	2200	If undefined or defined to be C<1>, then periodic timers are supported. If
		2201	defined to be C<0>, then they are not. Disabling them saves a few kB of
		2202	code.
		2203
		2204	=item EV_IDLE_ENABLE
		2205
		2206	If undefined or defined to be C<1>, then idle watchers are supported. If
2070	defined to be C<0>, then they are not. Disabling them saves a few kB of	2207	defined to be C<0>, then they are not. Disabling them saves a few kB of
2071	code.	2208	code.
2072		2209
2073	=item EV_EMBED_ENABLE	2210	=item EV_EMBED_ENABLE
2074		2211
…		…
2141	interface) and F<EV.xs> (implementation) files. Only the F<EV.xs> file	2278	interface) and F<EV.xs> (implementation) files. Only the F<EV.xs> file
2142	will be compiled. It is pretty complex because it provides its own header	2279	will be compiled. It is pretty complex because it provides its own header
2143	file.	2280	file.
2144		2281
2145	The usage in rxvt-unicode is simpler. It has a F<ev_cpp.h> header file	2282	The usage in rxvt-unicode is simpler. It has a F<ev_cpp.h> header file
2146	that everybody includes and which overrides some autoconf choices:	2283	that everybody includes and which overrides some configure choices:
2147		2284
		2285	#define EV_MINIMAL 1
2148	#define EV_USE_POLL 0	2286	#define EV_USE_POLL 0
2149	#define EV_MULTIPLICITY 0	2287	#define EV_MULTIPLICITY 0
2150	#define EV_PERIODICS 0	2288	#define EV_PERIODIC_ENABLE 0
		2289	#define EV_STAT_ENABLE 0
		2290	#define EV_FORK_ENABLE 0
2151	#define EV_CONFIG_H <config.h>	2291	#define EV_CONFIG_H <config.h>
		2292	#define EV_MINPRI 0
		2293	#define EV_MAXPRI 0
2152		2294
2153	#include "ev++.h"	2295	#include "ev++.h"
2154		2296
2155	And a F<ev_cpp.C> implementation file that contains libev proper and is compiled:	2297	And a F<ev_cpp.C> implementation file that contains libev proper and is compiled:
2156		2298
…		…
2162		2304
2163	In this section the complexities of (many of) the algorithms used inside	2305	In this section the complexities of (many of) the algorithms used inside
2164	libev will be explained. For complexity discussions about backends see the	2306	libev will be explained. For complexity discussions about backends see the
2165	documentation for C<ev_default_init>.	2307	documentation for C<ev_default_init>.
2166		2308
		2309	All of the following are about amortised time: If an array needs to be
		2310	extended, libev needs to realloc and move the whole array, but this
		2311	happens asymptotically never with higher number of elements, so O(1) might
		2312	mean it might do a lengthy realloc operation in rare cases, but on average
		2313	it is much faster and asymptotically approaches constant time.
		2314
2167	=over 4	2315	=over 4
2168		2316
2169	=item Starting and stopping timer/periodic watchers: O(log skipped_other_timers)	2317	=item Starting and stopping timer/periodic watchers: O(log skipped_other_timers)
2170		2318
		2319	This means that, when you have a watcher that triggers in one hour and
		2320	there are 100 watchers that would trigger before that then inserting will
		2321	have to skip those 100 watchers.
		2322
2171	=item Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)	2323	=item Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)
2172		2324
		2325	That means that for changing a timer costs less than removing/adding them
		2326	as only the relative motion in the event queue has to be paid for.
		2327
2173	=item Starting io/check/prepare/idle/signal/child watchers: O(1)	2328	=item Starting io/check/prepare/idle/signal/child watchers: O(1)
2174		2329
		2330	These just add the watcher into an array or at the head of a list.
2175	=item Stopping check/prepare/idle watchers: O(1)	2331	=item Stopping check/prepare/idle watchers: O(1)
2176		2332
2177	=item Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % EV_PID_HASHSIZE))	2333	=item Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % EV_PID_HASHSIZE))
2178		2334
		2335	These watchers are stored in lists then need to be walked to find the
		2336	correct watcher to remove. The lists are usually short (you don't usually
		2337	have many watchers waiting for the same fd or signal).
		2338
2179	=item Finding the next timer per loop iteration: O(1)	2339	=item Finding the next timer per loop iteration: O(1)
2180		2340
2181	=item Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)	2341	=item Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)
2182		2342
		2343	A change means an I/O watcher gets started or stopped, which requires
		2344	libev to recalculate its status (and possibly tell the kernel).
		2345
2183	=item Activating one watcher: O(1)	2346	=item Activating one watcher: O(1)
2184		2347
		2348	=item Priority handling: O(number_of_priorities)
		2349
		2350	Priorities are implemented by allocating some space for each
		2351	priority. When doing priority-based operations, libev usually has to
		2352	linearly search all the priorities.
		2353
2185	=back	2354	=back
2186		2355
2187		2356
2188	=head1 AUTHOR	2357	=head1 AUTHOR
2189		2358

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Comparing libev/ev.pod (file contents): Revision 1.60 by root, Wed Nov 28 18:29:30 2007 UTC vs. Revision 1.72 by root, Fri Dec 7 20:19:16 2007 UTC

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Comparing libev/ev.pod (file contents):
Revision 1.60 by root, Wed Nov 28 18:29:30 2007 UTC vs.
Revision 1.72 by root, Fri Dec 7 20:19:16 2007 UTC