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_H

        The name of the ev.h header file used to include it. The default
        if undefined is <ev.h> in event.h and "ev.h" in ev.c. This can be used
        to virtually rename the ev.h header file

    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:	1.12
Committed:	Fri Nov 9 17:07:59 2007 UTC (16 years, 6 months ago) by root
Branch:	MAIN
Changes since 1.11:	+6 -0 lines
Log Message:	move event_base predeclaration higher in the file
#	User	Rev	Content
1	root	1.1	EMBEDDING THE LIBEV CODE INTO YOUR OWN PROGRAMS
2
3	root	1.8	Instead of building the libev library you can also include the code
4	root	1.1	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	root	1.5	CORE EVENT LOOP
12
13	root	1.1	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	root	1.9	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	root	1.1
24			#define EV_STANDALONE 1
25			#include "ev.h"
26
27	root	1.11	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	root	1.1	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	root	1.4	ev_win32.c
39
40	root	1.10	ev_select.c only when select backend is enabled (which is is by default)
41	root	1.3	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	root	1.1
47	root	1.5	LIBEVENT COMPATIBILITY API
48
49	root	1.1	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	root	1.12	EV_H
79
80			The name of the ev.h header file used to include it. The default
81			if undefined is <ev.h> in event.h and "ev.h" in ev.c. This can be used
82			to virtually rename the ev.h header file
83
84	root	1.1	EV_USE_MONOTONIC
85
86			If undefined or defined to be "1", libev will try to detect the
87			availability of the monotonic clock option at both compiletime and
88			runtime. Otherwise no use of the monotonic clock option will be
89			attempted.
90
91			EV_USE_REALTIME
92
93			If defined to be "1", libev will try to detect the availability
94			of the realtime clock option at compiletime (and assume its
95			availability at runtime if successful). Otherwise no use of the
96			realtime clock option will be attempted. This effectively replaces
97			gettimeofday by clock_get (CLOCK_REALTIME, ...) and will not normally
98			affect correctness.
99
100			EV_USE_SELECT
101
102			If undefined or defined to be "1", libev will compile in support
103			for the select(2) backend. No attempt at autodetection will be
104			done: if no other method takes over, select will be it. Otherwise
105			the select backend will not be compiled in.
106
107	root	1.7	EV_SELECT_USE_WIN32_HANDLES
108
109			When defined to 1, the select backend will assume that select
110			doesn't understand file descriptors but wants osf handles on
111			win32 (this is the case when the select to be used is the winsock
112			select). This means that it will call _get_osfhandle on the fd to
113			convert it to an OS handle. Should not be defined on non-win32
114			platforms.
115
116	root	1.1	EV_USE_POLL
117
118			If defined to be "1", libev will compile in support for the poll(2)
119			backend. No attempt at autodetection will be done. poll usually
120			performs worse than select, so its not enabled by default (it is
121			also slightly less portable).
122
123			EV_USE_EPOLL
124
125			If defined to be "1", libev will compile in support for the Linux
126			epoll backend. Its availability will be detected at runtime,
127			otherwise another method will be used as fallback. This is the
128			preferred backend for GNU/Linux systems.
129
130			EV_USE_KQUEUE
131
132			If defined to be "1", libev will compile in support for the BSD
133			style kqueue backend. Its availability will be detected at runtime,
134			otherwise another method will be used as fallback. This is the
135			preferred backend for BSD and BSd-like systems. Darwin brokenness
136			will be detected at runtime and routed around by disabling this
137			backend.
138
139			EV_COMMON
140
141			By default, all watchers have a "void *data" member. By redefining
142			this macro to a something else you can include more and other types
143			of members. You have to define it each time you include one of the
144			files, though, and it must be identical each time.
145
146			For example, the perl EV module uses this:
147
148			#define EV_COMMON \
149			SV self; / contains this struct */ \
150	root	1.6	SV cb_sv, fh /* note no trailing ";" */
151	root	1.1
152			EV_PROTOTYPES
153
154			If defined to be "0", then "ev.h" will not define any function
155			prototypes, but still define all the structs and other
156			symbols. This is occasionally useful.
157
158			EV_MULTIPLICITY
159
160			If undefined or defined to "1", then all event-loop-specific
161			functions will have the "struct ev_loop *" as first argument, and
162			you can create additional independent event loops. Otherwise there
163			will be no support for multiple event loops and there is no first
164			event loop pointer argument. Instead, all functions act on the
165			single default loop.
166
167			EXAMPLES
168
169	root	1.2	For a real-world example of a program the includes libev
170			verbatim, you can have a look at the EV perl module
171			(http://software.schmorp.de/pkg/EV.html). It has the libev files in
172	root	1.5	the libev/ subdirectory and includes them in the EV/EVAPI.h (public
173			interface) and EV.xs (implementation) files. Only the EV.xs file will
174			be compiled.
175	root	1.1