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

Comparing libev/ev.pod (file contents):
Revision 1.258 by root, Wed Jul 15 16:58:53 2009 UTC vs.
Revision 1.263 by root, Mon Jul 27 01:10:17 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?");
…		…
2076	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
2077	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
2078	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
2079	normal event processing, like any other event.	2096	normal event processing, like any other event.
2080		2097
2081	If you want signals asynchronously, just use C<sigaction> as you would	2098	If you want signals to be delivered truly asynchronously, just use
2082	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
2083	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.
2084		2102
2085	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
2086	first watcher gets started will libev actually register a signal handler	2109	When the first watcher gets started will libev actually register something
2087	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
2088	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).
2089	the last signal watcher for a signal is stopped, libev will reset the	2112
2090	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.
2091		2117
2092	If possible and supported, libev will install its handlers with	2118	If possible and supported, libev will install its handlers with
2093	C<SA_RESTART> behaviour enabled, so system calls should not be unduly	2119	C<SA_RESTART> (or equivalent) behaviour enabled, so system calls should
2094	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
2095	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
2096	them in an C<ev_prepare> watcher.	2122	and unblock them in an C<ev_prepare> watcher.
2097		2123
2098	=head3 Watcher-Specific Functions and Data Members	2124	=head3 Watcher-Specific Functions and Data Members
2099		2125
2100	=over 4	2126	=over 4
2101		2127
…		…
2146	libev)	2172	libev)
2147		2173
2148	=head3 Process Interaction	2174	=head3 Process Interaction
2149		2175
2150	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
2151	initialised. This is necessary to guarantee proper behaviour even if	2177	initialised. This is necessary to guarantee proper behaviour even if the
2152	the first child watcher is started after the child exits. The occurrence	2178	first child watcher is started after the child exits. The occurrence
2153	of C<SIGCHLD> is recorded asynchronously, but child reaping is done	2179	of C<SIGCHLD> is recorded asynchronously, but child reaping is done
2154	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
2155	children, even ones not watched.	2181	children, even ones not watched.
2156		2182
2157	=head3 Overriding the Built-In Processing	2183	=head3 Overriding the Built-In Processing
…		…
2167	=head3 Stopping the Child Watcher	2193	=head3 Stopping the Child Watcher
2168		2194
2169	Currently, the child watcher never gets stopped, even when the	2195	Currently, the child watcher never gets stopped, even when the
2170	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
2171	callback. Future versions of libev might stop the watcher automatically	2197	callback. Future versions of libev might stop the watcher automatically
2172	when a child exit is detected.	2198	when a child exit is detected (calling C<ev_child_stop> twice is not a
		2199	problem).
2173		2200
2174	=head3 Watcher-Specific Functions and Data Members	2201	=head3 Watcher-Specific Functions and Data Members
2175		2202
2176	=over 4	2203	=over 4
2177		2204
…		…
3380	=item Ocaml	3407	=item Ocaml
3381		3408
3382	Erkki Seppala has written Ocaml bindings for libev, to be found at	3409	Erkki Seppala has written Ocaml bindings for libev, to be found at
3383	L<http://modeemi.cs.tut.fi/~flux/software/ocaml-ev/>.	3410	L<http://modeemi.cs.tut.fi/~flux/software/ocaml-ev/>.
3384		3411
		3412	=item Lua
		3413
		3414	Brian Maher has written a partial interface to libev
		3415	for lua (only C<ev_io> and C<ev_timer>), to be found at
		3416	L<http://github.com/brimworks/lua-ev>.
		3417
3385	=back	3418	=back
3386		3419
3387		3420
3388	=head1 MACRO MAGIC	3421	=head1 MACRO MAGIC
3389		3422
…		…
3555	keeps libev from including F<config.h>, and it also defines dummy	3588	keeps libev from including F<config.h>, and it also defines dummy
3556	implementations for some libevent functions (such as logging, which is not	3589	implementations for some libevent functions (such as logging, which is not
3557	supported). It will also not define any of the structs usually found in	3590	supported). It will also not define any of the structs usually found in
3558	F<event.h> that are not directly supported by the libev core alone.	3591	F<event.h> that are not directly supported by the libev core alone.
3559		3592
3560	In stanbdalone mode, libev will still try to automatically deduce the	3593	In standalone mode, libev will still try to automatically deduce the
3561	configuration, but has to be more conservative.	3594	configuration, but has to be more conservative.
3562		3595
3563	=item EV_USE_MONOTONIC	3596	=item EV_USE_MONOTONIC
3564		3597
3565	If defined to be C<1>, libev will try to detect the availability of the	3598	If defined to be C<1>, libev will try to detect the availability of the
…		…
3792	Defining C<EV_MINIMAL> to C<2> will additionally reduce the core API to	3825	Defining C<EV_MINIMAL> to C<2> will additionally reduce the core API to
3793	provide a bare-bones event library. See C<ev.h> for details on what parts	3826	provide a bare-bones event library. See C<ev.h> for details on what parts
3794	of the API are still available, and do not complain if this subset changes	3827	of the API are still available, and do not complain if this subset changes
3795	over time.	3828	over time.
3796		3829
		3830	=item EV_NSIG
		3831
		3832	The highest supported signal number, +1 (or, the number of
		3833	signals): Normally, libev tries to deduce the maximum number of signals
		3834	automatically, but sometimes this fails, in which case it can be
		3835	specified. Also, using a lower number than detected (C<32> should be
		3836	good for about any system in existance) can save some memory, as libev
		3837	statically allocates some 12-24 bytes per signal number.
		3838
3797	=item EV_PID_HASHSIZE	3839	=item EV_PID_HASHSIZE
3798		3840
3799	C<ev_child> watchers use a small hash table to distribute workload by	3841	C<ev_child> watchers use a small hash table to distribute workload by
3800	pid. The default size is C<16> (or C<1> with C<EV_MINIMAL>), usually more	3842	pid. The default size is C<16> (or C<1> with C<EV_MINIMAL>), usually more
3801	than enough. If you need to manage thousands of children you might want to	3843	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 1.258 by root, Wed Jul 15 16:58:53 2009 UTC vs. Revision 1.263 by root, Mon Jul 27 01:10:17 2009 UTC

Diff Legend

Comparing libev/ev.pod (file contents):
Revision 1.258 by root, Wed Jul 15 16:58:53 2009 UTC vs.
Revision 1.263 by root, Mon Jul 27 01:10:17 2009 UTC