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_port.c       only when the solaris port 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 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. If you enable this, you usually have to link against
        librt or something similar. Enabling it when the functionality
        isn't available is safe, though.

    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_FD_SET

       If defined to 1, then the select backend will use the system fd_set
       structure. This is useful if libev doesn't compile due to a missing
       NFDBITS or fd_mask definition or it misguesses the bitset layout on
       exotic systems. This usually limits the range of file descriptors
       to some low limit such as 1024 or might have other limitations
       (winsocket only allows 64 sockets). The FD_SETSIZE macro, set
       before compilation, might influence the size of the fd_set used.

    EV_SELECT_IS_WINSOCKET

       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. Otherwise it will be enabled on non-win32 platforms. It
       takes precedence over select.

    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_USE_PORT

       If defined to be "1", libev will compile in support for the Solaris
       10 port style backend. Its availability will be detected at runtime,
       otherwise another method will be used as fallback. This is the
       preferred backend for Solaris 10 systems.

    EV_USE_DEVPOLL
    
       reserved for future expansion, works like the USE symbols above.

    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:	1.26
Committed:	Fri Nov 16 10:37:28 2007 UTC (16 years, 6 months ago) by root
Branch:	MAIN
Changes since 1.25:	+6 -3 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
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	ev_port.c only when the solaris port backend is enabled (disabled by default)
46
47	"ev.c" includes the backend files directly when enabled.
48
49	LIBEVENT COMPATIBILITY API
50
51	To include the libevent compatibility API, also include:
52
53	#include "event.c"
54
55	in the file including "ev.c", and:
56
57	#include "event.h"
58
59	in the files that want to use the libevent API. This also includes "ev.h".
60
61	You need the following additional files for this:
62
63	event.h
64	event.c
65
66	AUTOCONF SUPPORT
67
68	Instead of using EV_STANDALONE=1 and providing your config in whatever
69	way you want, you can also m4_include([libev.m4]) in your configure.ac
70	and leave EV_STANDALONE off. ev.c will then include "config.h" and
71	configure itself accordingly.
72
73	PREPROCESSOR SYMBOLS
74
75	Libev can be configured via a variety of preprocessor symbols you have to define
76	before including any of its files. The default is not to build for multiplicity
77	and only include the select backend.
78
79	EV_STANDALONE
80
81	Must always be "1", which keeps libev from including config.h or
82	other files, and it also defines dummy implementations for some
83	libevent functions (such as logging, which is not supported). It
84	will also not define any of the structs usually found in "event.h"
85	that are not directly supported by libev code alone.
86
87	EV_USE_MONOTONIC
88
89	If defined to be "1", libev will try to detect the availability
90	of the monotonic clock option at both compiletime and
91	runtime. Otherwise no use of the monotonic clock option will be
92	attempted. If you enable this, you usually have to link against
93	librt or something similar. Enabling it when the functionality
94	isn't available is safe, though.
95
96	EV_USE_REALTIME
97
98	If defined to be "1", libev will try to detect the availability
99	of the realtime clock option at compiletime (and assume its
100	availability at runtime if successful). Otherwise no use of the
101	realtime clock option will be attempted. This effectively replaces
102	gettimeofday by clock_get (CLOCK_REALTIME, ...) and will not normally
103	affect correctness.
104
105	EV_USE_SELECT
106
107	If undefined or defined to be "1", libev will compile in support
108	for the select(2) backend. No attempt at autodetection will be
109	done: if no other method takes over, select will be it. Otherwise
110	the select backend will not be compiled in.
111
112	EV_SELECT_USE_FD_SET
113
114	If defined to 1, then the select backend will use the system fd_set
115	structure. This is useful if libev doesn't compile due to a missing
116	NFDBITS or fd_mask definition or it misguesses the bitset layout on
117	exotic systems. This usually limits the range of file descriptors
118	to some low limit such as 1024 or might have other limitations
119	(winsocket only allows 64 sockets). The FD_SETSIZE macro, set
120	before compilation, might influence the size of the fd_set used.
121
122	EV_SELECT_IS_WINSOCKET
123
124	When defined to 1, the select backend will assume that select
125	doesn't understand file descriptors but wants osf handles on
126	win32 (this is the case when the select to be used is the winsock
127	select). This means that it will call _get_osfhandle on the fd to
128	convert it to an OS handle. Should not be defined on non-win32
129	platforms.
130
131	EV_USE_POLL
132
133	If defined to be "1", libev will compile in support for the poll(2)
134	backend. Otherwise it will be enabled on non-win32 platforms. It
135	takes precedence over select.
136
137	EV_USE_EPOLL
138
139	If defined to be "1", libev will compile in support for the Linux
140	epoll backend. Its availability will be detected at runtime,
141	otherwise another method will be used as fallback. This is the
142	preferred backend for GNU/Linux systems.
143
144	EV_USE_KQUEUE
145
146	If defined to be "1", libev will compile in support for the BSD
147	style kqueue backend. Its availability will be detected at runtime,
148	otherwise another method will be used as fallback. This is the
149	preferred backend for BSD and BSD-like systems. Darwin brokenness
150	will be detected at runtime and routed around by disabling this
151	backend.
152
153	EV_USE_PORT
154
155	If defined to be "1", libev will compile in support for the Solaris
156	10 port style backend. Its availability will be detected at runtime,
157	otherwise another method will be used as fallback. This is the
158	preferred backend for Solaris 10 systems.
159
160	EV_USE_DEVPOLL
161
162	reserved for future expansion, works like the USE symbols above.
163
164	EV_H
165
166	The name of the ev.h header file used to include it. The default
167	if undefined is <ev.h> in event.h and "ev.h" in ev.c. This can
168	be used to virtually rename the ev.h header file in case of
169	conflicts.
170
171	EV_EVENT_H
172
173	Similarly to EV_H, this macro cna be used to override event.c's idea
174	of how the event.h header can be found.
175
176	EV_PROTOTYPES
177
178	If defined to be "0", then "ev.h" will not define any function
179	prototypes, but still define all the structs and other
180	symbols. This is occasionally useful.
181
182	EV_MULTIPLICITY
183
184	If undefined or defined to "1", then all event-loop-specific
185	functions will have the "struct ev_loop *" as first argument, and
186	you can create additional independent event loops. Otherwise there
187	will be no support for multiple event loops and there is no first
188	event loop pointer argument. Instead, all functions act on the
189	single default loop.
190
191	EV_PERIODICS
192
193	If undefined or defined to be "1", then periodic timers are
194	supported, otherwise not. This saves a few kb of code.
195
196	EV_COMMON
197
198	By default, all watchers have a "void *data" member. By redefining
199	this macro to a something else you can include more and other types
200	of members. You have to define it each time you include one of the
201	files, though, and it must be identical each time.
202
203	For example, the perl EV module uses this:
204
205	#define EV_COMMON \
206	SV self; / contains this struct */ \
207	SV cb_sv, fh /* note no trailing ";" */
208
209	EV_CB_DECLARE(type)
210	EV_CB_INVOKE(watcher,revents)
211	ev_set_cb(ev,cb)
212
213	Can be used to change the callback member declaration in each
214	watcher, and the way callbacks are invoked and set. Must expand
215	to a struct member definition and a statement, respectively. See
216	the ev.v header file for their default definitions. One possible
217	use for overriding these is to avoid the ev_loop pointer as first
218	argument in all cases, or to use method calls instead of plain
219	function calls in C++.
220
221	EXAMPLES
222
223	For a real-world example of a program the includes libev
224	verbatim, you can have a look at the EV perl module
225	(http://software.schmorp.de/pkg/EV.html). It has the libev files in
226	the libev/ subdirectory and includes them in the EV/EVAPI.h (public
227	interface) and EV.xs (implementation) files. Only the EV.xs file will
228	be compiled.
229