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      required on win32 platforms only

        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

AUTOCONF SUPPORT

    Instead of using EV_STANDALONE=1 and providing your config in whatever
    way you want, you can also m4_include([libev.m4]) in your configure.ac
    and leave EV_STANDALONE off. ev.c will then include "config.h" and
    configure itself accordingly.

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 multiplicity
    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_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 in case of
        conflicts.

    EV_EVENT_H

        Similarly to EV_H, this macro cna be used to override event.c's idea
        of how the event.h header can be found.

    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.

    EV_PERIODICS

       If undefined or defined to be "1", then periodic timers are
       supported, otherwise not. This saves a few kb of code.

    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_CB_DECLARE(type)
    EV_CB_INVOKE(watcher,revents)
    ev_set_cb(ev,cb)

       Can be used to change the callback member declaration in each
       watcher, and the way callbacks are invoked and set. Must expand
       to a struct member definition and a statement, respectively. See
       the ev.v header file for their default definitions. One possible
       use for overriding these is to avoid the ev_loop pointer as first
       argument in all cases, or to use method calls instead of plain
       function calls in C++.

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:	1.22
Committed:	Sun Nov 11 17:02:08 2007 UTC (16 years, 6 months ago) by ayin
Branch:	MAIN
Changes since 1.21:	+1 -1 lines
Log Message:	Fix typos.
#	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
39	ev_win32.c required on win32 platforms only
40
41	ev_select.c only when select backend is enabled (which is is by default)
42	ev_poll.c only when poll backend is enabled (disabled by default)
43	ev_epoll.c only when the epoll backend is enabled (disabled by default)
44	ev_kqueue.c only when the kqueue backend is enabled (disabled by default)
45
46	"ev.c" includes the backend files directly when enabled.
47
48	LIBEVENT COMPATIBILITY API
49
50	To include the libevent compatibility API, also include:
51
52	#include "event.c"
53
54	in the file including "ev.c", and:
55
56	#include "event.h"
57
58	in the files that want to use the libevent API. This also includes "ev.h".
59
60	You need the following additional files for this:
61
62	event.h
63	event.c
64
65	AUTOCONF SUPPORT
66
67	Instead of using EV_STANDALONE=1 and providing your config in whatever
68	way you want, you can also m4_include([libev.m4]) in your configure.ac
69	and leave EV_STANDALONE off. ev.c will then include "config.h" and
70	configure itself accordingly.
71
72	PREPROCESSOR SYMBOLS
73
74	Libev can be configured via a variety of preprocessor symbols you have to define
75	before including any of its files. The default is not to build for multiplicity
76	and only include the select backend.
77
78	EV_STANDALONE
79
80	Must always be "1", which keeps libev from including config.h or
81	other files, and it also defines dummy implementations for some
82	libevent functions (such as logging, which is not supported). It
83	will also not define any of the structs usually found in "event.h"
84	that are not directly supported by libev code alone.
85
86	EV_USE_MONOTONIC
87
88	If undefined or defined to be "1", libev will try to detect the
89	availability of the monotonic clock option at both compiletime and
90	runtime. Otherwise no use of the monotonic clock option will be
91	attempted.
92
93	EV_USE_REALTIME
94
95	If defined to be "1", libev will try to detect the availability
96	of the realtime clock option at compiletime (and assume its
97	availability at runtime if successful). Otherwise no use of the
98	realtime clock option will be attempted. This effectively replaces
99	gettimeofday by clock_get (CLOCK_REALTIME, ...) and will not normally
100	affect correctness.
101
102	EV_USE_SELECT
103
104	If undefined or defined to be "1", libev will compile in support
105	for the select(2) backend. No attempt at autodetection will be
106	done: if no other method takes over, select will be it. Otherwise
107	the select backend will not be compiled in.
108
109	EV_SELECT_USE_WIN32_HANDLES
110
111	When defined to 1, the select backend will assume that select
112	doesn't understand file descriptors but wants osf handles on
113	win32 (this is the case when the select to be used is the winsock
114	select). This means that it will call _get_osfhandle on the fd to
115	convert it to an OS handle. Should not be defined on non-win32
116	platforms.
117
118	EV_USE_POLL
119
120	If defined to be "1", libev will compile in support for the poll(2)
121	backend. No attempt at autodetection will be done. poll usually
122	performs worse than select, so its not enabled by default (it is
123	also slightly less portable).
124
125	EV_USE_EPOLL
126
127	If defined to be "1", libev will compile in support for the Linux
128	epoll backend. Its availability will be detected at runtime,
129	otherwise another method will be used as fallback. This is the
130	preferred backend for GNU/Linux systems.
131
132	EV_USE_KQUEUE
133
134	If defined to be "1", libev will compile in support for the BSD
135	style kqueue backend. Its availability will be detected at runtime,
136	otherwise another method will be used as fallback. This is the
137	preferred backend for BSD and BSD-like systems. Darwin brokenness
138	will be detected at runtime and routed around by disabling this
139	backend.
140
141	EV_H
142
143	The name of the ev.h header file used to include it. The default
144	if undefined is <ev.h> in event.h and "ev.h" in ev.c. This can
145	be used to virtually rename the ev.h header file in case of
146	conflicts.
147
148	EV_EVENT_H
149
150	Similarly to EV_H, this macro cna be used to override event.c's idea
151	of how the event.h header can be found.
152
153	EV_PROTOTYPES
154
155	If defined to be "0", then "ev.h" will not define any function
156	prototypes, but still define all the structs and other
157	symbols. This is occasionally useful.
158
159	EV_MULTIPLICITY
160
161	If undefined or defined to "1", then all event-loop-specific
162	functions will have the "struct ev_loop *" as first argument, and
163	you can create additional independent event loops. Otherwise there
164	will be no support for multiple event loops and there is no first
165	event loop pointer argument. Instead, all functions act on the
166	single default loop.
167
168	EV_PERIODICS
169
170	If undefined or defined to be "1", then periodic timers are
171	supported, otherwise not. This saves a few kb of code.
172
173	EV_COMMON
174
175	By default, all watchers have a "void *data" member. By redefining
176	this macro to a something else you can include more and other types
177	of members. You have to define it each time you include one of the
178	files, though, and it must be identical each time.
179
180	For example, the perl EV module uses this:
181
182	#define EV_COMMON \
183	SV self; / contains this struct */ \
184	SV cb_sv, fh /* note no trailing ";" */
185
186	EV_CB_DECLARE(type)
187	EV_CB_INVOKE(watcher,revents)
188	ev_set_cb(ev,cb)
189
190	Can be used to change the callback member declaration in each
191	watcher, and the way callbacks are invoked and set. Must expand
192	to a struct member definition and a statement, respectively. See
193	the ev.v header file for their default definitions. One possible
194	use for overriding these is to avoid the ev_loop pointer as first
195	argument in all cases, or to use method calls instead of plain
196	function calls in C++.
197
198	EXAMPLES
199
200	For a real-world example of a program the includes libev
201	verbatim, you can have a look at the EV perl module
202	(http://software.schmorp.de/pkg/EV.html). It has the libev files in
203	the libev/ subdirectory and includes them in the EV/EVAPI.h (public
204	interface) and EV.xs (implementation) files. Only the EV.xs file will
205	be compiled.
206