libev/README.embed

EMBEDDING THE LIBEV CODE INTO YOUR OWN PROGRAMS

    Instead of building the libev library you can also include the code
    as-is into your programs. To update, you only have to copy a few files
    into your source tree.

    This is how it works:

FILESETS

    CORE EVENT LOOP

    To include only the libev core (all the ev_* functions):

        #define EV_STANDALONE   1
        #include "ev.c"

    This will automatically include ev.h, too, and should be done in a
    single C source file only to provide the function implementations. To
    use it, do the same for ev.h in all files wishing to use this API
    (best done by writing a wrapper around ev.h that you can include
    instead and where you can put other configuration options):

        #define EV_STANDALONE   1
        #include "ev.h"

    Both header files and implementation files can be compiled with a C++
    compiler (at least, thats a stated goal, and breakage will be treated
    as a bug).

    You need the following files in your source tree, or in a directory
    in your include path (e.g. in libev/ when using -Ilibev):

        ev.h
        ev.c
        ev_vars.h
        ev_wrap.h
        ev_win32.c

        ev_select.c     only when select backend is enabled (which is is by default)
        ev_poll.c       only when poll backend is enabled (disabled by default)
        ev_epoll.c      only when the epoll backend is enabled (disabled by default)
        ev_kqueue.c     only when the kqueue backend is enabled (disabled by default)

    "ev.c" includes the backend files directly when enabled.

    LIBEVENT COMPATIBILITY API

    To include the libevent compatibility API, also include:

        #include "event.c"

    in the file including "ev.c", and:

        #include "event.h"

    in the files that want to use the libevent API. This also includes "ev.h".

    You need the following additional files for this:

        event.h
        event.c

PREPROCESSOR SYMBOLS

    Libev can be configured via a variety of preprocessor symbols you have to define
    before including any of its files. The default is not to build for mulciplicity
    and only include the select backend.

    EV_STANDALONE

        Must always be "1", which keeps libev from including config.h or
        other files, and it also defines dummy implementations for some
        libevent functions (such as logging, which is not supported). It
        will also not define any of the structs usually found in "event.h"
        that are not directly supported by libev code alone.

    EV_USE_MONOTONIC

        If undefined or defined to be "1", libev will try to detect the
        availability of the monotonic clock option at both compiletime and
        runtime. Otherwise no use of the monotonic clock option will be
        attempted.

    EV_USE_REALTIME

        If defined to be "1", libev will try to detect the availability
        of the realtime clock option at compiletime (and assume its
        availability at runtime if successful). Otherwise no use of the
        realtime clock option will be attempted. This effectively replaces
        gettimeofday by clock_get (CLOCK_REALTIME, ...) and will not normally
        affect correctness.

    EV_USE_SELECT

       If undefined or defined to be "1", libev will compile in support
       for the select(2) backend. No attempt at autodetection will be
       done: if no other method takes over, select will be it. Otherwise
       the select backend will not be compiled in.

    EV_SELECT_USE_WIN32_HANDLES

       When defined to 1, the select backend will assume that select
       doesn't understand file descriptors but wants osf handles on
       win32 (this is the case when the select to be used is the winsock
       select). This means that it will call _get_osfhandle on the fd to
       convert it to an OS handle. Should not be defined on non-win32
       platforms.

    EV_USE_POLL

       If defined to be "1", libev will compile in support for the poll(2)
       backend. No attempt at autodetection will be done. poll usually
       performs worse than select, so its not enabled by default (it is
       also slightly less portable).

    EV_USE_EPOLL

       If defined to be "1", libev will compile in support for the Linux
       epoll backend. Its availability will be detected at runtime,
       otherwise another method will be used as fallback. This is the
       preferred backend for GNU/Linux systems.

    EV_USE_KQUEUE

       If defined to be "1", libev will compile in support for the BSD
       style kqueue backend. Its availability will be detected at runtime,
       otherwise another method will be used as fallback. This is the
       preferred backend for BSD and BSd-like systems. Darwin brokenness
       will be detected at runtime and routed around by disabling this
       backend.

    EV_COMMON
 
       By default, all watchers have a "void *data" member. By redefining
       this macro to a something else you can include more and other types
       of members. You have to define it each time you include one of the
       files, though, and it must be identical each time.

       For example, the perl EV module uses this:

           #define EV_COMMON                       \
             SV *self; /* contains this struct */  \
             SV *cb_sv, *fh /* note no trailing ";" */

    EV_PROTOTYPES

       If defined to be "0", then "ev.h" will not define any function
       prototypes, but still define all the structs and other
       symbols. This is occasionally useful.

    EV_MULTIPLICITY

       If undefined or defined to "1", then all event-loop-specific
       functions will have the "struct ev_loop *" as first argument, and
       you can create additional independent event loops. Otherwise there
       will be no support for multiple event loops and there is no first
       event loop pointer argument. Instead, all functions act on the
       single default loop.

EXAMPLES

    For a real-world example of a program the includes libev
    verbatim, you can have a look at the EV perl module
    (http://software.schmorp.de/pkg/EV.html).  It has the libev files in
    the libev/ subdirectory and includes them in the EV/EVAPI.h (public
    interface) and EV.xs (implementation) files. Only the EV.xs file will
    be compiled.

Revision:	1.11
Committed:	Thu Nov 8 22:01:02 2007 UTC (16 years, 6 months ago) by root
Branch:	MAIN
Changes since 1.10:	+4 -0 lines
Log Message:	* empty log message *
#	Content
1	EMBEDDING THE LIBEV CODE INTO YOUR OWN PROGRAMS
2
3	Instead of building the libev library you can also include the code
4	as-is into your programs. To update, you only have to copy a few files
5	into your source tree.
6
7	This is how it works:
8
9	FILESETS
10
11	CORE EVENT LOOP
12
13	To include only the libev core (all the ev_* functions):
14
15	#define EV_STANDALONE 1
16	#include "ev.c"
17
18	This will automatically include ev.h, too, and should be done in a
19	single C source file only to provide the function implementations. To
20	use it, do the same for ev.h in all files wishing to use this API
21	(best done by writing a wrapper around ev.h that you can include
22	instead and where you can put other configuration options):
23
24	#define EV_STANDALONE 1
25	#include "ev.h"
26
27	Both header files and implementation files can be compiled with a C++
28	compiler (at least, thats a stated goal, and breakage will be treated
29	as a bug).
30
31	You need the following files in your source tree, or in a directory
32	in your include path (e.g. in libev/ when using -Ilibev):
33
34	ev.h
35	ev.c
36	ev_vars.h
37	ev_wrap.h
38	ev_win32.c
39
40	ev_select.c only when select backend is enabled (which is is by default)
41	ev_poll.c only when poll backend is enabled (disabled by default)
42	ev_epoll.c only when the epoll backend is enabled (disabled by default)
43	ev_kqueue.c only when the kqueue backend is enabled (disabled by default)
44
45	"ev.c" includes the backend files directly when enabled.
46
47	LIBEVENT COMPATIBILITY API
48
49	To include the libevent compatibility API, also include:
50
51	#include "event.c"
52
53	in the file including "ev.c", and:
54
55	#include "event.h"
56
57	in the files that want to use the libevent API. This also includes "ev.h".
58
59	You need the following additional files for this:
60
61	event.h
62	event.c
63
64	PREPROCESSOR SYMBOLS
65
66	Libev can be configured via a variety of preprocessor symbols you have to define
67	before including any of its files. The default is not to build for mulciplicity
68	and only include the select backend.
69
70	EV_STANDALONE
71
72	Must always be "1", which keeps libev from including config.h or
73	other files, and it also defines dummy implementations for some
74	libevent functions (such as logging, which is not supported). It
75	will also not define any of the structs usually found in "event.h"
76	that are not directly supported by libev code alone.
77
78	EV_USE_MONOTONIC
79
80	If undefined or defined to be "1", libev will try to detect the
81	availability of the monotonic clock option at both compiletime and
82	runtime. Otherwise no use of the monotonic clock option will be
83	attempted.
84
85	EV_USE_REALTIME
86
87	If defined to be "1", libev will try to detect the availability
88	of the realtime clock option at compiletime (and assume its
89	availability at runtime if successful). Otherwise no use of the
90	realtime clock option will be attempted. This effectively replaces
91	gettimeofday by clock_get (CLOCK_REALTIME, ...) and will not normally
92	affect correctness.
93
94	EV_USE_SELECT
95
96	If undefined or defined to be "1", libev will compile in support
97	for the select(2) backend. No attempt at autodetection will be
98	done: if no other method takes over, select will be it. Otherwise
99	the select backend will not be compiled in.
100
101	EV_SELECT_USE_WIN32_HANDLES
102
103	When defined to 1, the select backend will assume that select
104	doesn't understand file descriptors but wants osf handles on
105	win32 (this is the case when the select to be used is the winsock
106	select). This means that it will call _get_osfhandle on the fd to
107	convert it to an OS handle. Should not be defined on non-win32
108	platforms.
109
110	EV_USE_POLL
111
112	If defined to be "1", libev will compile in support for the poll(2)
113	backend. No attempt at autodetection will be done. poll usually
114	performs worse than select, so its not enabled by default (it is
115	also slightly less portable).
116
117	EV_USE_EPOLL
118
119	If defined to be "1", libev will compile in support for the Linux
120	epoll backend. Its availability will be detected at runtime,
121	otherwise another method will be used as fallback. This is the
122	preferred backend for GNU/Linux systems.
123
124	EV_USE_KQUEUE
125
126	If defined to be "1", libev will compile in support for the BSD
127	style kqueue backend. Its availability will be detected at runtime,
128	otherwise another method will be used as fallback. This is the
129	preferred backend for BSD and BSd-like systems. Darwin brokenness
130	will be detected at runtime and routed around by disabling this
131	backend.
132
133	EV_COMMON
134
135	By default, all watchers have a "void *data" member. By redefining
136	this macro to a something else you can include more and other types
137	of members. You have to define it each time you include one of the
138	files, though, and it must be identical each time.
139
140	For example, the perl EV module uses this:
141
142	#define EV_COMMON \
143	SV self; / contains this struct */ \
144	SV cb_sv, fh /* note no trailing ";" */
145
146	EV_PROTOTYPES
147
148	If defined to be "0", then "ev.h" will not define any function
149	prototypes, but still define all the structs and other
150	symbols. This is occasionally useful.
151
152	EV_MULTIPLICITY
153
154	If undefined or defined to "1", then all event-loop-specific
155	functions will have the "struct ev_loop *" as first argument, and
156	you can create additional independent event loops. Otherwise there
157	will be no support for multiple event loops and there is no first
158	event loop pointer argument. Instead, all functions act on the
159	single default loop.
160
161	EXAMPLES
162
163	For a real-world example of a program the includes libev
164	verbatim, you can have a look at the EV perl module
165	(http://software.schmorp.de/pkg/EV.html). It has the libev files in
166	the libev/ subdirectory and includes them in the EV/EVAPI.h (public
167	interface) and EV.xs (implementation) files. Only the EV.xs file will
168	be compiled.
169