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"

    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:	1.10
Committed:	Thu Nov 8 18:52:45 2007 UTC (16 years, 6 months ago) by root
Branch:	MAIN
Changes since 1.9:	+1 -1 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	You need the following files in your source tree, or in a directory
28	in your include path (e.g. in libev/ when using -Ilibev):
29
30	ev.h
31	ev.c
32	ev_vars.h
33	ev_wrap.h
34	ev_win32.c
35
36	ev_select.c only when select backend is enabled (which is is by default)
37	ev_poll.c only when poll backend is enabled (disabled by default)
38	ev_epoll.c only when the epoll backend is enabled (disabled by default)
39	ev_kqueue.c only when the kqueue backend is enabled (disabled by default)
40
41	"ev.c" includes the backend files directly when enabled.
42
43	LIBEVENT COMPATIBILITY API
44
45	To include the libevent compatibility API, also include:
46
47	#include "event.c"
48
49	in the file including "ev.c", and:
50
51	#include "event.h"
52
53	in the files that want to use the libevent API. This also includes "ev.h".
54
55	You need the following additional files for this:
56
57	event.h
58	event.c
59
60	PREPROCESSOR SYMBOLS
61
62	Libev can be configured via a variety of preprocessor symbols you have to define
63	before including any of its files. The default is not to build for mulciplicity
64	and only include the select backend.
65
66	EV_STANDALONE
67
68	Must always be "1", which keeps libev from including config.h or
69	other files, and it also defines dummy implementations for some
70	libevent functions (such as logging, which is not supported). It
71	will also not define any of the structs usually found in "event.h"
72	that are not directly supported by libev code alone.
73
74	EV_USE_MONOTONIC
75
76	If undefined or defined to be "1", libev will try to detect the
77	availability of the monotonic clock option at both compiletime and
78	runtime. Otherwise no use of the monotonic clock option will be
79	attempted.
80
81	EV_USE_REALTIME
82
83	If defined to be "1", libev will try to detect the availability
84	of the realtime clock option at compiletime (and assume its
85	availability at runtime if successful). Otherwise no use of the
86	realtime clock option will be attempted. This effectively replaces
87	gettimeofday by clock_get (CLOCK_REALTIME, ...) and will not normally
88	affect correctness.
89
90	EV_USE_SELECT
91
92	If undefined or defined to be "1", libev will compile in support
93	for the select(2) backend. No attempt at autodetection will be
94	done: if no other method takes over, select will be it. Otherwise
95	the select backend will not be compiled in.
96
97	EV_SELECT_USE_WIN32_HANDLES
98
99	When defined to 1, the select backend will assume that select
100	doesn't understand file descriptors but wants osf handles on
101	win32 (this is the case when the select to be used is the winsock
102	select). This means that it will call _get_osfhandle on the fd to
103	convert it to an OS handle. Should not be defined on non-win32
104	platforms.
105
106	EV_USE_POLL
107
108	If defined to be "1", libev will compile in support for the poll(2)
109	backend. No attempt at autodetection will be done. poll usually
110	performs worse than select, so its not enabled by default (it is
111	also slightly less portable).
112
113	EV_USE_EPOLL
114
115	If defined to be "1", libev will compile in support for the Linux
116	epoll backend. Its availability will be detected at runtime,
117	otherwise another method will be used as fallback. This is the
118	preferred backend for GNU/Linux systems.
119
120	EV_USE_KQUEUE
121
122	If defined to be "1", libev will compile in support for the BSD
123	style kqueue backend. Its availability will be detected at runtime,
124	otherwise another method will be used as fallback. This is the
125	preferred backend for BSD and BSd-like systems. Darwin brokenness
126	will be detected at runtime and routed around by disabling this
127	backend.
128
129	EV_COMMON
130
131	By default, all watchers have a "void *data" member. By redefining
132	this macro to a something else you can include more and other types
133	of members. You have to define it each time you include one of the
134	files, though, and it must be identical each time.
135
136	For example, the perl EV module uses this:
137
138	#define EV_COMMON \
139	SV self; / contains this struct */ \
140	SV cb_sv, fh /* note no trailing ";" */
141
142	EV_PROTOTYPES
143
144	If defined to be "0", then "ev.h" will not define any function
145	prototypes, but still define all the structs and other
146	symbols. This is occasionally useful.
147
148	EV_MULTIPLICITY
149
150	If undefined or defined to "1", then all event-loop-specific
151	functions will have the "struct ev_loop *" as first argument, and
152	you can create additional independent event loops. Otherwise there
153	will be no support for multiple event loops and there is no first
154	event loop pointer argument. Instead, all functions act on the
155	single default loop.
156
157	EXAMPLES
158
159	For a real-world example of a program the includes libev
160	verbatim, you can have a look at the EV perl module
161	(http://software.schmorp.de/pkg/EV.html). It has the libev files in
162	the libev/ subdirectory and includes them in the EV/EVAPI.h (public
163	interface) and EV.xs (implementation) files. Only the EV.xs file will
164	be compiled.
165