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

Comparing libev/ev.pod (file contents):
Revision 1.257 by root, Wed Jul 15 16:08:24 2009 UTC vs.
Revision 1.262 by root, Sat Jul 25 10:14:34 2009 UTC

…		…
98	=head2 FEATURES	98	=head2 FEATURES
99		99
100	Libev supports C<select>, C<poll>, the Linux-specific C<epoll>, the	100	Libev supports C<select>, C<poll>, the Linux-specific C<epoll>, the
101	BSD-specific C<kqueue> and the Solaris-specific event port mechanisms	101	BSD-specific C<kqueue> and the Solaris-specific event port mechanisms
102	for file descriptor events (C<ev_io>), the Linux C<inotify> interface	102	for file descriptor events (C<ev_io>), the Linux C<inotify> interface
103	(for C<ev_stat>), relative timers (C<ev_timer>), absolute timers	103	(for C<ev_stat>), Linux eventfd/signalfd (for faster and cleaner
104	with customised rescheduling (C<ev_periodic>), synchronous signals	104	inter-thread wakeup (C<ev_async>)/signal handling (C<ev_signal>)) relative
105	(C<ev_signal>), process status change events (C<ev_child>), and event	105	timers (C<ev_timer>), absolute timers with customised rescheduling
106	watchers dealing with the event loop mechanism itself (C<ev_idle>,	106	(C<ev_periodic>), synchronous signals (C<ev_signal>), process status
107	C<ev_embed>, C<ev_prepare> and C<ev_check> watchers) as well as	107	change events (C<ev_child>), and event watchers dealing with the event
108	file watchers (C<ev_stat>) and even limited support for fork events	108	loop mechanism itself (C<ev_idle>, C<ev_embed>, C<ev_prepare> and
109	(C<ev_fork>).	109	C<ev_check> watchers) as well as file watchers (C<ev_stat>) and even
		110	limited support for fork events (C<ev_fork>).
110		111
111	It also is quite fast (see this	112	It also is quite fast (see this
112	L<benchmark\|http://libev.schmorp.de/bench.html> comparing it to libevent	113	L<benchmark\|http://libev.schmorp.de/bench.html> comparing it to libevent
113	for example).	114	for example).
114		115
…		…
361	forget about forgetting to tell libev about forking) when you use this	362	forget about forgetting to tell libev about forking) when you use this
362	flag.	363	flag.
363		364
364	This flag setting cannot be overridden or specified in the C<LIBEV_FLAGS>	365	This flag setting cannot be overridden or specified in the C<LIBEV_FLAGS>
365	environment variable.	366	environment variable.
		367
		368	=item C<EVFLAG_NOINOTIFY>
		369
		370	When this flag is specified, then libev will not attempt to use the
		371	I<inotify> API for it's C<ev_stat> watchers. Apart from debugging and
		372	testing, this flag can be useful to conserve inotify file descriptors, as
		373	otherwise each loop using C<ev_stat> watchers consumes one inotify handle.
		374
		375	=item C<EVFLAG_NOSIGNALFD>
		376
		377	When this flag is specified, then libev will not attempt to use the
		378	I<signalfd> API for it's C<ev_signal> (and C<ev_child>) watchers. This is
		379	probably only useful to work around any bugs in libev. Consequently, this
		380	flag might go away once the signalfd functionality is considered stable,
		381	so it's useful mostly in environment variables and not in program code.
366		382
367	=item C<EVBACKEND_SELECT> (value 1, portable select backend)	383	=item C<EVBACKEND_SELECT> (value 1, portable select backend)
368		384
369	This is your standard select(2) backend. Not I<completely> standard, as	385	This is your standard select(2) backend. Not I<completely> standard, as
370	libev tries to roll its own fd_set with no limits on the number of fds,	386	libev tries to roll its own fd_set with no limits on the number of fds,
…		…
518		534
519	It is definitely not recommended to use this flag.	535	It is definitely not recommended to use this flag.
520		536
521	=back	537	=back
522		538
523	If one or more of these are or'ed into the flags value, then only these	539	If one or more of the backend flags are or'ed into the flags value,
524	backends will be tried (in the reverse order as listed here). If none are	540	then only these backends will be tried (in the reverse order as listed
525	specified, all backends in C<ev_recommended_backends ()> will be tried.	541	here). If none are specified, all backends in C<ev_recommended_backends
		542	()> will be tried.
526		543
527	Example: This is the most typical usage.	544	Example: This is the most typical usage.
528		545
529	if (!ev_default_loop (0))	546	if (!ev_default_loop (0))
530	fatal ("could not initialise libev, bad $LIBEV_FLAGS in environment?");	547	fatal ("could not initialise libev, bad $LIBEV_FLAGS in environment?");
…		…
1820	C<repeat> value), or reset the running timer to the C<repeat> value.	1837	C<repeat> value), or reset the running timer to the C<repeat> value.
1821		1838
1822	This sounds a bit complicated, see L<Be smart about timeouts>, above, for a	1839	This sounds a bit complicated, see L<Be smart about timeouts>, above, for a
1823	usage example.	1840	usage example.
1824		1841
		1842	=item ev_timer_remaining (loop, ev_timer *)
		1843
		1844	Returns the remaining time until a timer fires. If the timer is active,
		1845	then this time is relative to the current event loop time, otherwise it's
		1846	the timeout value currently configured.
		1847
		1848	That is, after an C<ev_timer_set (w, 5, 7)>, C<ev_timer_remaining> returns
		1849	C<5>. When the timer is started and one second passes, C<ev_timer_remain>
		1850	will return C<4>. When the timer expires and is restarted, it will return
		1851	roughly C<7> (likely slightly less as callback invocation takes some time,
		1852	too), and so on.
		1853
1825	=item ev_tstamp repeat [read-write]	1854	=item ev_tstamp repeat [read-write]
1826		1855
1827	The current C<repeat> value. Will be used each time the watcher times out	1856	The current C<repeat> value. Will be used each time the watcher times out
1828	or C<ev_timer_again> is called, and determines the next timeout (if any),	1857	or C<ev_timer_again> is called, and determines the next timeout (if any),
1829	which is also when any modifications are taken into account.	1858	which is also when any modifications are taken into account.
…		…
2064	Signal watchers will trigger an event when the process receives a specific	2093	Signal watchers will trigger an event when the process receives a specific
2065	signal one or more times. Even though signals are very asynchronous, libev	2094	signal one or more times. Even though signals are very asynchronous, libev
2066	will try it's best to deliver signals synchronously, i.e. as part of the	2095	will try it's best to deliver signals synchronously, i.e. as part of the
2067	normal event processing, like any other event.	2096	normal event processing, like any other event.
2068		2097
2069	If you want signals asynchronously, just use C<sigaction> as you would	2098	If you want signals to be delivered truly asynchronously, just use
2070	do without libev and forget about sharing the signal. You can even use	2099	C<sigaction> as you would do without libev and forget about sharing
2071	C<ev_async> from a signal handler to synchronously wake up an event loop.	2100	the signal. You can even use C<ev_async> from a signal handler to
		2101	synchronously wake up an event loop.
2072		2102
2073	You can configure as many watchers as you like per signal. Only when the	2103	You can configure as many watchers as you like for the same signal, but
		2104	only within the same loop, i.e. you can watch for C<SIGINT> in your
		2105	default loop and for C<SIGIO> in another loop, but you cannot watch for
		2106	C<SIGINT> in both the default loop and another loop at the same time. At
		2107	the moment, C<SIGCHLD> is permanently tied to the default loop.
		2108
2074	first watcher gets started will libev actually register a signal handler	2109	When the first watcher gets started will libev actually register something
2075	with the kernel (thus it coexists with your own signal handlers as long as	2110	with the kernel (thus it coexists with your own signal handlers as long as
2076	you don't register any with libev for the same signal). Similarly, when	2111	you don't register any with libev for the same signal).
2077	the last signal watcher for a signal is stopped, libev will reset the	2112
2078	signal handler to SIG_DFL (regardless of what it was set to before).	2113	Both the signal mask state (C<sigprocmask>) and the signal handler state
		2114	(C<sigaction>) are unspecified after starting a signal watcher (and after
		2115	sotpping it again), that is, libev might or might not block the signal,
		2116	and might or might not set or restore the installed signal handler.
2079		2117
2080	If possible and supported, libev will install its handlers with	2118	If possible and supported, libev will install its handlers with
2081	C<SA_RESTART> behaviour enabled, so system calls should not be unduly	2119	C<SA_RESTART> (or equivalent) behaviour enabled, so system calls should
2082	interrupted. If you have a problem with system calls getting interrupted by	2120	not be unduly interrupted. If you have a problem with system calls getting
2083	signals you can block all signals in an C<ev_check> watcher and unblock	2121	interrupted by signals you can block all signals in an C<ev_check> watcher
2084	them in an C<ev_prepare> watcher.	2122	and unblock them in an C<ev_prepare> watcher.
2085		2123
2086	=head3 Watcher-Specific Functions and Data Members	2124	=head3 Watcher-Specific Functions and Data Members
2087		2125
2088	=over 4	2126	=over 4
2089		2127
…		…
2134	libev)	2172	libev)
2135		2173
2136	=head3 Process Interaction	2174	=head3 Process Interaction
2137		2175
2138	Libev grabs C<SIGCHLD> as soon as the default event loop is	2176	Libev grabs C<SIGCHLD> as soon as the default event loop is
2139	initialised. This is necessary to guarantee proper behaviour even if	2177	initialised. This is necessary to guarantee proper behaviour even if the
2140	the first child watcher is started after the child exits. The occurrence	2178	first child watcher is started after the child exits. The occurrence
2141	of C<SIGCHLD> is recorded asynchronously, but child reaping is done	2179	of C<SIGCHLD> is recorded asynchronously, but child reaping is done
2142	synchronously as part of the event loop processing. Libev always reaps all	2180	synchronously as part of the event loop processing. Libev always reaps all
2143	children, even ones not watched.	2181	children, even ones not watched.
2144		2182
2145	=head3 Overriding the Built-In Processing	2183	=head3 Overriding the Built-In Processing
…		…
2155	=head3 Stopping the Child Watcher	2193	=head3 Stopping the Child Watcher
2156		2194
2157	Currently, the child watcher never gets stopped, even when the	2195	Currently, the child watcher never gets stopped, even when the
2158	child terminates, so normally one needs to stop the watcher in the	2196	child terminates, so normally one needs to stop the watcher in the
2159	callback. Future versions of libev might stop the watcher automatically	2197	callback. Future versions of libev might stop the watcher automatically
2160	when a child exit is detected.	2198	when a child exit is detected (calling C<ev_child_stop> twice is not a
		2199	problem).
2161		2200
2162	=head3 Watcher-Specific Functions and Data Members	2201	=head3 Watcher-Specific Functions and Data Members
2163		2202
2164	=over 4	2203	=over 4
2165		2204
…		…
3543	keeps libev from including F<config.h>, and it also defines dummy	3582	keeps libev from including F<config.h>, and it also defines dummy
3544	implementations for some libevent functions (such as logging, which is not	3583	implementations for some libevent functions (such as logging, which is not
3545	supported). It will also not define any of the structs usually found in	3584	supported). It will also not define any of the structs usually found in
3546	F<event.h> that are not directly supported by the libev core alone.	3585	F<event.h> that are not directly supported by the libev core alone.
3547		3586
3548	In stanbdalone mode, libev will still try to automatically deduce the	3587	In standalone mode, libev will still try to automatically deduce the
3549	configuration, but has to be more conservative.	3588	configuration, but has to be more conservative.
3550		3589
3551	=item EV_USE_MONOTONIC	3590	=item EV_USE_MONOTONIC
3552		3591
3553	If defined to be C<1>, libev will try to detect the availability of the	3592	If defined to be C<1>, libev will try to detect the availability of the
…		…
3780	Defining C<EV_MINIMAL> to C<2> will additionally reduce the core API to	3819	Defining C<EV_MINIMAL> to C<2> will additionally reduce the core API to
3781	provide a bare-bones event library. See C<ev.h> for details on what parts	3820	provide a bare-bones event library. See C<ev.h> for details on what parts
3782	of the API are still available, and do not complain if this subset changes	3821	of the API are still available, and do not complain if this subset changes
3783	over time.	3822	over time.
3784		3823
		3824	=item EV_NSIG
		3825
		3826	The highest supported signal number, +1 (or, the number of
		3827	signals): Normally, libev tries to deduce the maximum number of signals
		3828	automatically, but sometimes this fails, in which case it can be
		3829	specified. Also, using a lower number than detected (C<32> should be
		3830	good for about any system in existance) can save some memory, as libev
		3831	statically allocates some 12-24 bytes per signal number.
		3832
3785	=item EV_PID_HASHSIZE	3833	=item EV_PID_HASHSIZE
3786		3834
3787	C<ev_child> watchers use a small hash table to distribute workload by	3835	C<ev_child> watchers use a small hash table to distribute workload by
3788	pid. The default size is C<16> (or C<1> with C<EV_MINIMAL>), usually more	3836	pid. The default size is C<16> (or C<1> with C<EV_MINIMAL>), usually more
3789	than enough. If you need to manage thousands of children you might want to	3837	than enough. If you need to manage thousands of children you might want to

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Comparing libev/ev.pod (file contents): Revision 1.257 by root, Wed Jul 15 16:08:24 2009 UTC vs. Revision 1.262 by root, Sat Jul 25 10:14:34 2009 UTC

Diff Legend

Comparing libev/ev.pod (file contents):
Revision 1.257 by root, Wed Jul 15 16:08:24 2009 UTC vs.
Revision 1.262 by root, Sat Jul 25 10:14:34 2009 UTC