[ViewVC] Diff of: cvs/libev/ev.3

Comparing libev/ev.3 (file contents):
Revision 1.38 by root, Fri Dec 7 18:09:38 2007 UTC vs.
Revision 1.44 by root, Sat Dec 8 15:30:26 2007 UTC

…		…
127	.\}	127	.\}
128	.rm #[ #] #H #V #F C	128	.rm #[ #] #H #V #F C
129	.\" ========================================================================	129	.\" ========================================================================
130	.\"	130	.\"
131	.IX Title ""<STANDARD INPUT>" 1"	131	.IX Title ""<STANDARD INPUT>" 1"
132	.TH "<STANDARD INPUT>" 1 "2007-12-07" "perl v5.8.8" "User Contributed Perl Documentation"	132	.TH "<STANDARD INPUT>" 1 "2007-12-08" "perl v5.8.8" "User Contributed Perl Documentation"
133	.SH "NAME"	133	.SH "NAME"
134	libev \- a high performance full\-featured event loop written in C	134	libev \- a high performance full\-featured event loop written in C
135	.SH "SYNOPSIS"	135	.SH "SYNOPSIS"
136	.IX Header "SYNOPSIS"	136	.IX Header "SYNOPSIS"
137	.Vb 1	137	.Vb 1
…		…
196	\& return 0;	196	\& return 0;
197	\& }	197	\& }
198	.Ve	198	.Ve
199	.SH "DESCRIPTION"	199	.SH "DESCRIPTION"
200	.IX Header "DESCRIPTION"	200	.IX Header "DESCRIPTION"
		201	The newest version of this document is also available as a html-formatted
		202	web page you might find easier to navigate when reading it for the first
		203	time: <http://cvs.schmorp.de/libev/ev.html>.
		204	.PP
201	Libev is an event loop: you register interest in certain events (such as a	205	Libev is an event loop: you register interest in certain events (such as a
202	file descriptor being readable or a timeout occuring), and it will manage	206	file descriptor being readable or a timeout occuring), and it will manage
203	these event sources and provide your program with events.	207	these event sources and provide your program with events.
204	.PP	208	.PP
205	To do this, it must take more or less complete control over your process	209	To do this, it must take more or less complete control over your process
…		…
885	.IP "bool ev_is_pending (ev_TYPE *watcher)" 4	889	.IP "bool ev_is_pending (ev_TYPE *watcher)" 4
886	.IX Item "bool ev_is_pending (ev_TYPE *watcher)"	890	.IX Item "bool ev_is_pending (ev_TYPE *watcher)"
887	Returns a true value iff the watcher is pending, (i.e. it has outstanding	891	Returns a true value iff the watcher is pending, (i.e. it has outstanding
888	events but its callback has not yet been invoked). As long as a watcher	892	events but its callback has not yet been invoked). As long as a watcher
889	is pending (but not active) you must not call an init function on it (but	893	is pending (but not active) you must not call an init function on it (but
890	\&\f(CW\(C`ev_TYPE_set\(C'\fR is safe) and you must make sure the watcher is available to	894	\&\f(CW\(C`ev_TYPE_set\(C'\fR is safe), you must not change its priority, and you must
891	libev (e.g. you cnanot \f(CW\(C`free ()\(C'\fR it).	895	make sure the watcher is available to libev (e.g. you cannot \f(CW\(C`free ()\(C'\fR
		896	it).
892	.IP "callback ev_cb (ev_TYPE *watcher)" 4	897	.IP "callback ev_cb (ev_TYPE *watcher)" 4
893	.IX Item "callback ev_cb (ev_TYPE *watcher)"	898	.IX Item "callback ev_cb (ev_TYPE *watcher)"
894	Returns the callback currently set on the watcher.	899	Returns the callback currently set on the watcher.
895	.IP "ev_cb_set (ev_TYPE *watcher, callback)" 4	900	.IP "ev_cb_set (ev_TYPE *watcher, callback)" 4
896	.IX Item "ev_cb_set (ev_TYPE *watcher, callback)"	901	.IX Item "ev_cb_set (ev_TYPE *watcher, callback)"
…		…
914	watchers on the same event and make sure one is called first.	919	watchers on the same event and make sure one is called first.
915	.Sp	920	.Sp
916	If you need to suppress invocation when higher priority events are pending	921	If you need to suppress invocation when higher priority events are pending
917	you need to look at \f(CW\(C`ev_idle\(C'\fR watchers, which provide this functionality.	922	you need to look at \f(CW\(C`ev_idle\(C'\fR watchers, which provide this functionality.
918	.Sp	923	.Sp
		924	You \fImust not\fR change the priority of a watcher as long as it is active or
		925	pending.
		926	.Sp
919	The default priority used by watchers when no priority has been set is	927	The default priority used by watchers when no priority has been set is
920	always \f(CW0\fR, which is supposed to not be too high and not be too low :).	928	always \f(CW0\fR, which is supposed to not be too high and not be too low :).
921	.Sp	929	.Sp
922	Setting a priority outside the range of \f(CW\(C`EV_MINPRI\(C'\fR to \f(CW\(C`EV_MAXPRI\(C'\fR is	930	Setting a priority outside the range of \f(CW\(C`EV_MINPRI\(C'\fR to \f(CW\(C`EV_MAXPRI\(C'\fR is
923	fine, as long as you do not mind that the priority value you query might	931	fine, as long as you do not mind that the priority value you query might
924	or might not have been adjusted to be within valid range.	932	or might not have been adjusted to be within valid range.
		933	.IP "ev_invoke (loop, ev_TYPE *watcher, int revents)" 4
		934	.IX Item "ev_invoke (loop, ev_TYPE *watcher, int revents)"
		935	Invoke the \f(CW\(C`watcher\(C'\fR with the given \f(CW\(C`loop\(C'\fR and \f(CW\(C`revents\(C'\fR. Neither
		936	\&\f(CW\(C`loop\(C'\fR nor \f(CW\(C`revents\(C'\fR need to be valid as long as the watcher callback
		937	can deal with that fact.
		938	.IP "int ev_clear_pending (loop, ev_TYPE *watcher)" 4
		939	.IX Item "int ev_clear_pending (loop, ev_TYPE *watcher)"
		940	If the watcher is pending, this function returns clears its pending status
		941	and returns its \f(CW\(C`revents\(C'\fR bitset (as if its callback was invoked). If the
		942	watcher isn't pending it does nothing and returns \f(CW0\fR.
925	.Sh "\s-1ASSOCIATING\s0 \s-1CUSTOM\s0 \s-1DATA\s0 \s-1WITH\s0 A \s-1WATCHER\s0"	943	.Sh "\s-1ASSOCIATING\s0 \s-1CUSTOM\s0 \s-1DATA\s0 \s-1WITH\s0 A \s-1WATCHER\s0"
926	.IX Subsection "ASSOCIATING CUSTOM DATA WITH A WATCHER"	944	.IX Subsection "ASSOCIATING CUSTOM DATA WITH A WATCHER"
927	Each watcher has, by default, a member \f(CW\(C`void data\*(C'\fR that you can change	945	Each watcher has, by default, a member \f(CW\(C`void data\*(C'\fR that you can change
928	and read at any time, libev will completely ignore it. This can be used	946	and read at any time, libev will completely ignore it. This can be used
929	to associate arbitrary data with your watcher. If you need more data and	947	to associate arbitrary data with your watcher. If you need more data and
…		…
1626	.PD	1644	.PD
1627	Initialises and configures the prepare or check watcher \- they have no	1645	Initialises and configures the prepare or check watcher \- they have no
1628	parameters of any kind. There are \f(CW\(C`ev_prepare_set\(C'\fR and \f(CW\(C`ev_check_set\(C'\fR	1646	parameters of any kind. There are \f(CW\(C`ev_prepare_set\(C'\fR and \f(CW\(C`ev_check_set\(C'\fR
1629	macros, but using them is utterly, utterly and completely pointless.	1647	macros, but using them is utterly, utterly and completely pointless.
1630	.PP	1648	.PP
1631	Example: To include a library such as adns, you would add \s-1IO\s0 watchers	1649	There are a number of principal ways to embed other event loops or modules
1632	and a timeout watcher in a prepare handler, as required by libadns, and	1650	into libev. Here are some ideas on how to include libadns into libev
		1651	(there is a Perl module named \f(CW\(C`EV::ADNS\(C'\fR that does this, which you could
		1652	use for an actually working example. Another Perl module named \f(CW\(C`EV::Glib\(C'\fR
		1653	embeds a Glib main context into libev, and finally, \f(CW\(C`Glib::EV\(C'\fR embeds \s-1EV\s0
		1654	into the Glib event loop).
		1655	.PP
		1656	Method 1: Add \s-1IO\s0 watchers and a timeout watcher in a prepare handler,
1633	in a check watcher, destroy them and call into libadns. What follows is	1657	and in a check watcher, destroy them and call into libadns. What follows
1634	pseudo-code only of course:	1658	is pseudo-code only of course. This requires you to either use a low
		1659	priority for the check watcher or use \f(CW\(C`ev_clear_pending\(C'\fR explicitly, as
		1660	the callbacks for the IO/timeout watchers might not have been called yet.
1635	.PP	1661	.PP
1636	.Vb 2	1662	.Vb 2
1637	\& static ev_io iow [nfd];	1663	\& static ev_io iow [nfd];
1638	\& static ev_timer tw;	1664	\& static ev_timer tw;
1639	.Ve	1665	.Ve
1640	.PP	1666	.PP
1641	.Vb 9	1667	.Vb 4
1642	\& static void	1668	\& static void
1643	\& io_cb (ev_loop loop, ev_io w, int revents)	1669	\& io_cb (ev_loop loop, ev_io w, int revents)
1644	\& {	1670	\& {
1645	\& // set the relevant poll flags
1646	\& // could also call adns_processreadable etc. here
1647	\& struct pollfd fd = (struct pollfd )w->data;
1648	\& if (revents & EV_READ ) fd->revents \|= fd->events & POLLIN;
1649	\& if (revents & EV_WRITE) fd->revents \|= fd->events & POLLOUT;
1650	\& }	1671	\& }
1651	.Ve	1672	.Ve
1652	.PP	1673	.PP
1653	.Vb 8	1674	.Vb 8
1654	\& // create io watchers for each fd and a timer before blocking	1675	\& // create io watchers for each fd and a timer before blocking
…		…
1666	\& ev_timer_init (&tw, 0, timeout * 1e-3);	1687	\& ev_timer_init (&tw, 0, timeout * 1e-3);
1667	\& ev_timer_start (loop, &tw);	1688	\& ev_timer_start (loop, &tw);
1668	.Ve	1689	.Ve
1669	.PP	1690	.PP
1670	.Vb 6	1691	.Vb 6
1671	\& // create on ev_io per pollfd	1692	\& // create one ev_io per pollfd
1672	\& for (int i = 0; i < nfd; ++i)	1693	\& for (int i = 0; i < nfd; ++i)
1673	\& {	1694	\& {
1674	\& ev_io_init (iow + i, io_cb, fds [i].fd,	1695	\& ev_io_init (iow + i, io_cb, fds [i].fd,
1675	\& ((fds [i].events & POLLIN ? EV_READ : 0)	1696	\& ((fds [i].events & POLLIN ? EV_READ : 0)
1676	\& \| (fds [i].events & POLLOUT ? EV_WRITE : 0)));	1697	\& \| (fds [i].events & POLLOUT ? EV_WRITE : 0)));
1677	.Ve	1698	.Ve
1678	.PP	1699	.PP
1679	.Vb 5	1700	.Vb 4
1680	\& fds [i].revents = 0;	1701	\& fds [i].revents = 0;
1681	\& iow [i].data = fds + i;
1682	\& ev_io_start (loop, iow + i);	1702	\& ev_io_start (loop, iow + i);
1683	\& }	1703	\& }
1684	\& }	1704	\& }
1685	.Ve	1705	.Ve
1686	.PP	1706	.PP
…		…
1690	\& adns_check_cb (ev_loop loop, ev_check w, int revents)	1710	\& adns_check_cb (ev_loop loop, ev_check w, int revents)
1691	\& {	1711	\& {
1692	\& ev_timer_stop (loop, &tw);	1712	\& ev_timer_stop (loop, &tw);
1693	.Ve	1713	.Ve
1694	.PP	1714	.PP
1695	.Vb 2	1715	.Vb 8
1696	\& for (int i = 0; i < nfd; ++i)	1716	\& for (int i = 0; i < nfd; ++i)
		1717	\& {
		1718	\& // set the relevant poll flags
		1719	\& // could also call adns_processreadable etc. here
		1720	\& struct pollfd *fd = fds + i;
		1721	\& int revents = ev_clear_pending (iow + i);
		1722	\& if (revents & EV_READ ) fd->revents \|= fd->events & POLLIN;
		1723	\& if (revents & EV_WRITE) fd->revents \|= fd->events & POLLOUT;
		1724	.Ve
		1725	.PP
		1726	.Vb 3
		1727	\& // now stop the watcher
1697	\& ev_io_stop (loop, iow + i);	1728	\& ev_io_stop (loop, iow + i);
		1729	\& }
1698	.Ve	1730	.Ve
1699	.PP	1731	.PP
1700	.Vb 2	1732	.Vb 2
1701	\& adns_afterpoll (adns, fds, nfd, timeval_from (ev_now (loop));	1733	\& adns_afterpoll (adns, fds, nfd, timeval_from (ev_now (loop));
		1734	\& }
		1735	.Ve
		1736	.PP
		1737	Method 2: This would be just like method 1, but you run \f(CW\(C`adns_afterpoll\(C'\fR
		1738	in the prepare watcher and would dispose of the check watcher.
		1739	.PP
		1740	Method 3: If the module to be embedded supports explicit event
		1741	notification (adns does), you can also make use of the actual watcher
		1742	callbacks, and only destroy/create the watchers in the prepare watcher.
		1743	.PP
		1744	.Vb 5
		1745	\& static void
		1746	\& timer_cb (EV_P_ ev_timer *w, int revents)
		1747	\& {
		1748	\& adns_state ads = (adns_state)w->data;
		1749	\& update_now (EV_A);
		1750	.Ve
		1751	.PP
		1752	.Vb 2
		1753	\& adns_processtimeouts (ads, &tv_now);
		1754	\& }
		1755	.Ve
		1756	.PP
		1757	.Vb 5
		1758	\& static void
		1759	\& io_cb (EV_P_ ev_io *w, int revents)
		1760	\& {
		1761	\& adns_state ads = (adns_state)w->data;
		1762	\& update_now (EV_A);
		1763	.Ve
		1764	.PP
		1765	.Vb 3
		1766	\& if (revents & EV_READ ) adns_processreadable (ads, w->fd, &tv_now);
		1767	\& if (revents & EV_WRITE) adns_processwriteable (ads, w->fd, &tv_now);
		1768	\& }
		1769	.Ve
		1770	.PP
		1771	.Vb 1
		1772	\& // do not ever call adns_afterpoll
		1773	.Ve
		1774	.PP
		1775	Method 4: Do not use a prepare or check watcher because the module you
		1776	want to embed is too inflexible to support it. Instead, youc na override
		1777	their poll function. The drawback with this solution is that the main
		1778	loop is now no longer controllable by \s-1EV\s0. The \f(CW\(C`Glib::EV\(C'\fR module does
		1779	this.
		1780	.PP
		1781	.Vb 4
		1782	\& static gint
		1783	\& event_poll_func (GPollFD *fds, guint nfds, gint timeout)
		1784	\& {
		1785	\& int got_events = 0;
		1786	.Ve
		1787	.PP
		1788	.Vb 2
		1789	\& for (n = 0; n < nfds; ++n)
		1790	\& // create/start io watcher that sets the relevant bits in fds[n] and increment got_events
		1791	.Ve
		1792	.PP
		1793	.Vb 2
		1794	\& if (timeout >= 0)
		1795	\& // create/start timer
		1796	.Ve
		1797	.PP
		1798	.Vb 2
		1799	\& // poll
		1800	\& ev_loop (EV_A_ 0);
		1801	.Ve
		1802	.PP
		1803	.Vb 3
		1804	\& // stop timer again
		1805	\& if (timeout >= 0)
		1806	\& ev_timer_stop (EV_A_ &to);
		1807	.Ve
		1808	.PP
		1809	.Vb 3
		1810	\& // stop io watchers again - their callbacks should have set
		1811	\& for (n = 0; n < nfds; ++n)
		1812	\& ev_io_stop (EV_A_ iow [n]);
		1813	.Ve
		1814	.PP
		1815	.Vb 2
		1816	\& return got_events;
1702	\& }	1817	\& }
1703	.Ve	1818	.Ve
1704	.ie n .Sh """ev_embed"" \- when one backend isn't enough..."	1819	.ie n .Sh """ev_embed"" \- when one backend isn't enough..."
1705	.el .Sh "\f(CWev_embed\fP \- when one backend isn't enough..."	1820	.el .Sh "\f(CWev_embed\fP \- when one backend isn't enough..."
1706	.IX Subsection "ev_embed - when one backend isn't enough..."	1821	.IX Subsection "ev_embed - when one backend isn't enough..."
…		…
1890	.PP	2005	.PP
1891	.Vb 1	2006	.Vb 1
1892	\& #include <ev++.h>	2007	\& #include <ev++.h>
1893	.Ve	2008	.Ve
1894	.PP	2009	.PP
1895	(it is not installed by default). This automatically includes \fIev.h\fR	2010	This automatically includes \fIev.h\fR and puts all of its definitions (many
1896	and puts all of its definitions (many of them macros) into the global	2011	of them macros) into the global namespace. All \*(C+ specific things are
1897	namespace. All \(C+ specific things are put into the \f(CW\(C`ev\*(C'\fR namespace.	2012	put into the \f(CW\(C`ev\(C'\fR namespace. It should support all the same embedding
		2013	options as \fIev.h\fR, most notably \f(CW\(C`EV_MULTIPLICITY\(C'\fR.
1898	.PP	2014	.PP
1899	It should support all the same embedding options as \fIev.h\fR, most notably	2015	Care has been taken to keep the overhead low. The only data member the \*(C+
1900	\&\f(CW\(C`EV_MULTIPLICITY\(C'\fR.	2016	classes add (compared to plain C\-style watchers) is the event loop pointer
		2017	that the watcher is associated with (or no additional members at all if
		2018	you disable \f(CW\(C`EV_MULTIPLICITY\(C'\fR when embedding libev).
		2019	.PP
		2020	Currently, functions, and static and non-static member functions can be
		2021	used as callbacks. Other types should be easy to add as long as they only
		2022	need one additional pointer for context. If you need support for other
		2023	types of functors please contact the author (preferably after implementing
		2024	it).
1901	.PP	2025	.PP
1902	Here is a list of things available in the \f(CW\(C`ev\(C'\fR namespace:	2026	Here is a list of things available in the \f(CW\(C`ev\(C'\fR namespace:
1903	.ie n .IP """ev::READ""\fR, \f(CW""ev::WRITE"" etc." 4	2027	.ie n .IP """ev::READ""\fR, \f(CW""ev::WRITE"" etc." 4
1904	.el .IP "\f(CWev::READ\fR, \f(CWev::WRITE\fR etc." 4	2028	.el .IP "\f(CWev::READ\fR, \f(CWev::WRITE\fR etc." 4
1905	.IX Item "ev::READ, ev::WRITE etc."	2029	.IX Item "ev::READ, ev::WRITE etc."
…		…
1917	which is called \f(CW\(C`ev::sig\(C'\fR to avoid clashes with the \f(CW\(C`signal\(C'\fR macro	2041	which is called \f(CW\(C`ev::sig\(C'\fR to avoid clashes with the \f(CW\(C`signal\(C'\fR macro
1918	defines by many implementations.	2042	defines by many implementations.
1919	.Sp	2043	.Sp
1920	All of those classes have these methods:	2044	All of those classes have these methods:
1921	.RS 4	2045	.RS 4
1922	.IP "ev::TYPE::TYPE (object , object::method )" 4	2046	.IP "ev::TYPE::TYPE ()" 4
1923	.IX Item "ev::TYPE::TYPE (object , object::method )"	2047	.IX Item "ev::TYPE::TYPE ()"
1924	.PD 0	2048	.PD 0
1925	.IP "ev::TYPE::TYPE (object , object::method , struct ev_loop *)" 4	2049	.IP "ev::TYPE::TYPE (struct ev_loop *)" 4
1926	.IX Item "ev::TYPE::TYPE (object , object::method , struct ev_loop *)"	2050	.IX Item "ev::TYPE::TYPE (struct ev_loop *)"
1927	.IP "ev::TYPE::~TYPE" 4	2051	.IP "ev::TYPE::~TYPE" 4
1928	.IX Item "ev::TYPE::~TYPE"	2052	.IX Item "ev::TYPE::~TYPE"
1929	.PD	2053	.PD
1930	The constructor takes a pointer to an object and a method pointer to	2054	The constructor (optionally) takes an event loop to associate the watcher
1931	the event handler callback to call in this class. The constructor calls	2055	with. If it is omitted, it will use \f(CW\(C`EV_DEFAULT\(C'\fR.
1932	\&\f(CW\(C`ev_init\(C'\fR for you, which means you have to call the \f(CW\(C`set\(C'\fR method	2056	.Sp
1933	before starting it. If you do not specify a loop then the constructor	2057	The constructor calls \f(CW\(C`ev_init\(C'\fR for you, which means you have to call the
1934	automatically associates the default loop with this watcher.	2058	\&\f(CW\(C`set\(C'\fR method before starting it.
		2059	.Sp
		2060	It will not set a callback, however: You have to call the templated \f(CW\(C`set\(C'\fR
		2061	method to set a callback before you can start the watcher.
		2062	.Sp
		2063	(The reason why you have to use a method is a limitation in \*(C+ which does
		2064	not allow explicit template arguments for constructors).
1935	.Sp	2065	.Sp
1936	The destructor automatically stops the watcher if it is active.	2066	The destructor automatically stops the watcher if it is active.
		2067	.IP "w\->set<class, &class::method> (object *)" 4
		2068	.IX Item "w->set<class, &class::method> (object *)"
		2069	This method sets the callback method to call. The method has to have a
		2070	signature of \f(CW\(C`void ()(ev_TYPE &, int)\*(C'\fR, it receives the watcher as
		2071	first argument and the \f(CW\(C`revents\(C'\fR as second. The object must be given as
		2072	parameter and is stored in the \f(CW\(C`data\(C'\fR member of the watcher.
		2073	.Sp
		2074	This method synthesizes efficient thunking code to call your method from
		2075	the C callback that libev requires. If your compiler can inline your
		2076	callback (i.e. it is visible to it at the place of the \f(CW\(C`set\(C'\fR call and
		2077	your compiler is good :), then the method will be fully inlined into the
		2078	thunking function, making it as fast as a direct C callback.
		2079	.Sp
		2080	Example: simple class declaration and watcher initialisation
		2081	.Sp
		2082	.Vb 4
		2083	\& struct myclass
		2084	\& {
		2085	\& void io_cb (ev::io &w, int revents) { }
		2086	\& }
		2087	.Ve
		2088	.Sp
		2089	.Vb 3
		2090	\& myclass obj;
		2091	\& ev::io iow;
		2092	\& iow.set <myclass, &myclass::io_cb> (&obj);
		2093	.Ve
		2094	.IP "w\->set<function> (void *data = 0)" 4
		2095	.IX Item "w->set<function> (void *data = 0)"
		2096	Also sets a callback, but uses a static method or plain function as
		2097	callback. The optional \f(CW\(C`data\(C'\fR argument will be stored in the watcher's
		2098	\&\f(CW\(C`data\(C'\fR member and is free for you to use.
		2099	.Sp
		2100	The prototype of the \f(CW\(C`function\(C'\fR must be \f(CW\(C`void ()(ev::TYPE &w, int)\*(C'\fR.
		2101	.Sp
		2102	See the method\-\f(CW\(C`set\(C'\fR above for more details.
		2103	.Sp
		2104	Example:
		2105	.Sp
		2106	.Vb 2
		2107	\& static void io_cb (ev::io &w, int revents) { }
		2108	\& iow.set <io_cb> ();
		2109	.Ve
1937	.IP "w\->set (struct ev_loop *)" 4	2110	.IP "w\->set (struct ev_loop *)" 4
1938	.IX Item "w->set (struct ev_loop *)"	2111	.IX Item "w->set (struct ev_loop *)"
1939	Associates a different \f(CW\(C`struct ev_loop\(C'\fR with this watcher. You can only	2112	Associates a different \f(CW\(C`struct ev_loop\(C'\fR with this watcher. You can only
1940	do this when the watcher is inactive (and not pending either).	2113	do this when the watcher is inactive (and not pending either).
1941	.IP "w\->set ([args])" 4	2114	.IP "w\->set ([args])" 4
1942	.IX Item "w->set ([args])"	2115	.IX Item "w->set ([args])"
1943	Basically the same as \f(CW\(C`ev_TYPE_set\(C'\fR, with the same args. Must be	2116	Basically the same as \f(CW\(C`ev_TYPE_set\(C'\fR, with the same args. Must be
1944	called at least once. Unlike the C counterpart, an active watcher gets	2117	called at least once. Unlike the C counterpart, an active watcher gets
1945	automatically stopped and restarted.	2118	automatically stopped and restarted when reconfiguring it with this
		2119	method.
1946	.IP "w\->start ()" 4	2120	.IP "w\->start ()" 4
1947	.IX Item "w->start ()"	2121	.IX Item "w->start ()"
1948	Starts the watcher. Note that there is no \f(CW\(C`loop\(C'\fR argument as the	2122	Starts the watcher. Note that there is no \f(CW\(C`loop\(C'\fR argument, as the
1949	constructor already takes the loop.	2123	constructor already stores the event loop.
1950	.IP "w\->stop ()" 4	2124	.IP "w\->stop ()" 4
1951	.IX Item "w->stop ()"	2125	.IX Item "w->stop ()"
1952	Stops the watcher if it is active. Again, no \f(CW\(C`loop\(C'\fR argument.	2126	Stops the watcher if it is active. Again, no \f(CW\(C`loop\(C'\fR argument.
1953	.ie n .IP "w\->again () ""ev::timer""\fR, \f(CW""ev::periodic"" only" 4	2127	.ie n .IP "w\->again () ""ev::timer""\fR, \f(CW""ev::periodic"" only" 4
1954	.el .IP "w\->again () \f(CWev::timer\fR, \f(CWev::periodic\fR only" 4	2128	.el .IP "w\->again () \f(CWev::timer\fR, \f(CWev::periodic\fR only" 4
…		…
1980	.Vb 2	2154	.Vb 2
1981	\& myclass ();	2155	\& myclass ();
1982	\& }	2156	\& }
1983	.Ve	2157	.Ve
1984	.PP	2158	.PP
1985	.Vb 6	2159	.Vb 4
1986	\& myclass::myclass (int fd)	2160	\& myclass::myclass (int fd)
1987	\& : io (this, &myclass::io_cb),
1988	\& idle (this, &myclass::idle_cb)
1989	\& {	2161	\& {
		2162	\& io .set <myclass, &myclass::io_cb > (this);
		2163	\& idle.set <myclass, &myclass::idle_cb> (this);
		2164	.Ve
		2165	.PP
		2166	.Vb 2
1990	\& io.start (fd, ev::READ);	2167	\& io.start (fd, ev::READ);
1991	\& }	2168	\& }
1992	.Ve	2169	.Ve
1993	.SH "MACRO MAGIC"	2170	.SH "MACRO MAGIC"
1994	.IX Header "MACRO MAGIC"	2171	.IX Header "MACRO MAGIC"
…		…
2274	If undefined or defined to \f(CW1\fR, then all event-loop-specific functions	2451	If undefined or defined to \f(CW1\fR, then all event-loop-specific functions
2275	will have the \f(CW\(C`struct ev_loop \*(C'\fR as first argument, and you can create	2452	will have the \f(CW\(C`struct ev_loop \*(C'\fR as first argument, and you can create
2276	additional independent event loops. Otherwise there will be no support	2453	additional independent event loops. Otherwise there will be no support
2277	for multiple event loops and there is no first event loop pointer	2454	for multiple event loops and there is no first event loop pointer
2278	argument. Instead, all functions act on the single default loop.	2455	argument. Instead, all functions act on the single default loop.
		2456	.IP "\s-1EV_MINPRI\s0" 4
		2457	.IX Item "EV_MINPRI"
		2458	.PD 0
		2459	.IP "\s-1EV_MAXPRI\s0" 4
		2460	.IX Item "EV_MAXPRI"
		2461	.PD
		2462	The range of allowed priorities. \f(CW\(C`EV_MINPRI\(C'\fR must be smaller or equal to
		2463	\&\f(CW\(C`EV_MAXPRI\(C'\fR, but otherwise there are no non-obvious limitations. You can
		2464	provide for more priorities by overriding those symbols (usually defined
		2465	to be \f(CW\(C`\-2\(C'\fR and \f(CW2\fR, respectively).
		2466	.Sp
		2467	When doing priority-based operations, libev usually has to linearly search
		2468	all the priorities, so having many of them (hundreds) uses a lot of space
		2469	and time, so using the defaults of five priorities (\-2 .. +2) is usually
		2470	fine.
		2471	.Sp
		2472	If your embedding app does not need any priorities, defining these both to
		2473	\&\f(CW0\fR will save some memory and cpu.
2279	.IP "\s-1EV_PERIODIC_ENABLE\s0" 4	2474	.IP "\s-1EV_PERIODIC_ENABLE\s0" 4
2280	.IX Item "EV_PERIODIC_ENABLE"	2475	.IX Item "EV_PERIODIC_ENABLE"
2281	If undefined or defined to be \f(CW1\fR, then periodic timers are supported. If	2476	If undefined or defined to be \f(CW1\fR, then periodic timers are supported. If
2282	defined to be \f(CW0\fR, then they are not. Disabling them saves a few kB of	2477	defined to be \f(CW0\fR, then they are not. Disabling them saves a few kB of
2283	code.	2478	code.
…		…
2382	.SH "COMPLEXITIES"	2577	.SH "COMPLEXITIES"
2383	.IX Header "COMPLEXITIES"	2578	.IX Header "COMPLEXITIES"
2384	In this section the complexities of (many of) the algorithms used inside	2579	In this section the complexities of (many of) the algorithms used inside
2385	libev will be explained. For complexity discussions about backends see the	2580	libev will be explained. For complexity discussions about backends see the
2386	documentation for \f(CW\(C`ev_default_init\(C'\fR.	2581	documentation for \f(CW\(C`ev_default_init\(C'\fR.
		2582	.Sp
		2583	All of the following are about amortised time: If an array needs to be
		2584	extended, libev needs to realloc and move the whole array, but this
		2585	happens asymptotically never with higher number of elements, so O(1) might
		2586	mean it might do a lengthy realloc operation in rare cases, but on average
		2587	it is much faster and asymptotically approaches constant time.
2387	.RS 4	2588	.RS 4
2388	.IP "Starting and stopping timer/periodic watchers: O(log skipped_other_timers)" 4	2589	.IP "Starting and stopping timer/periodic watchers: O(log skipped_other_timers)" 4
2389	.IX Item "Starting and stopping timer/periodic watchers: O(log skipped_other_timers)"	2590	.IX Item "Starting and stopping timer/periodic watchers: O(log skipped_other_timers)"
2390	.PD 0	2591	This means that, when you have a watcher that triggers in one hour and
		2592	there are 100 watchers that would trigger before that then inserting will
		2593	have to skip those 100 watchers.
2391	.IP "Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)" 4	2594	.IP "Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)" 4
2392	.IX Item "Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)"	2595	.IX Item "Changing timer/periodic watchers (by autorepeat, again): O(log skipped_other_timers)"
		2596	That means that for changing a timer costs less than removing/adding them
		2597	as only the relative motion in the event queue has to be paid for.
2393	.IP "Starting io/check/prepare/idle/signal/child watchers: O(1)" 4	2598	.IP "Starting io/check/prepare/idle/signal/child watchers: O(1)" 4
2394	.IX Item "Starting io/check/prepare/idle/signal/child watchers: O(1)"	2599	.IX Item "Starting io/check/prepare/idle/signal/child watchers: O(1)"
2395	.IP "Stopping check/prepare/idle watchers: O(1)" 4	2600	These just add the watcher into an array or at the head of a list.
2396	.IX Item "Stopping check/prepare/idle watchers: O(1)"	2601	=item Stopping check/prepare/idle watchers: O(1)
2397	.IP "Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % \s-1EV_PID_HASHSIZE\s0))" 4	2602	.IP "Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % \s-1EV_PID_HASHSIZE\s0))" 4
2398	.IX Item "Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % EV_PID_HASHSIZE))"	2603	.IX Item "Stopping an io/signal/child watcher: O(number_of_watchers_for_this_(fd/signal/pid % EV_PID_HASHSIZE))"
		2604	These watchers are stored in lists then need to be walked to find the
		2605	correct watcher to remove. The lists are usually short (you don't usually
		2606	have many watchers waiting for the same fd or signal).
2399	.IP "Finding the next timer per loop iteration: O(1)" 4	2607	.IP "Finding the next timer per loop iteration: O(1)" 4
2400	.IX Item "Finding the next timer per loop iteration: O(1)"	2608	.IX Item "Finding the next timer per loop iteration: O(1)"
		2609	.PD 0
2401	.IP "Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)" 4	2610	.IP "Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)" 4
2402	.IX Item "Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)"	2611	.IX Item "Each change on a file descriptor per loop iteration: O(number_of_watchers_for_this_fd)"
		2612	.PD
		2613	A change means an I/O watcher gets started or stopped, which requires
		2614	libev to recalculate its status (and possibly tell the kernel).
2403	.IP "Activating one watcher: O(1)" 4	2615	.IP "Activating one watcher: O(1)" 4
2404	.IX Item "Activating one watcher: O(1)"	2616	.IX Item "Activating one watcher: O(1)"
		2617	.PD 0
		2618	.IP "Priority handling: O(number_of_priorities)" 4
		2619	.IX Item "Priority handling: O(number_of_priorities)"
		2620	.PD
		2621	Priorities are implemented by allocating some space for each
		2622	priority. When doing priority-based operations, libev usually has to
		2623	linearly search all the priorities.
2405	.RE	2624	.RE
2406	.RS 4	2625	.RS 4
2407	.PD
2408	.SH "AUTHOR"	2626	.SH "AUTHOR"
2409	.IX Header "AUTHOR"	2627	.IX Header "AUTHOR"
2410	Marc Lehmann <libev@schmorp.de>.	2628	Marc Lehmann <libev@schmorp.de>.

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Comparing libev/ev.3 (file contents): Revision 1.38 by root, Fri Dec 7 18:09:38 2007 UTC vs. Revision 1.44 by root, Sat Dec 8 15:30:26 2007 UTC

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Comparing libev/ev.3 (file contents):
Revision 1.38 by root, Fri Dec 7 18:09:38 2007 UTC vs.
Revision 1.44 by root, Sat Dec 8 15:30:26 2007 UTC