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/socket/connect etc. don'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. Otherwise,
       it is assumed that all these functions actually work on fds, even
       on win32. 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:	1.27
Committed:	Sat Nov 17 05:26:09 2007 UTC (16 years, 6 months ago) by root
Branch:	MAIN
CVS Tags:	rel-1_1, rel-1_2
Changes since 1.26:	+7 -6 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
125	select/socket/connect etc. don't understand file descriptors but
126	wants osf handles on win32 (this is the case when the select to
127	be used is the winsock select). This means that it will call
128	_get_osfhandle on the fd to convert it to an OS handle. Otherwise,
129	it is assumed that all these functions actually work on fds, even
130	on win32. Should not be defined on non-win32 platforms.
131
132	EV_USE_POLL
133
134	If defined to be "1", libev will compile in support for the poll(2)
135	backend. Otherwise it will be enabled on non-win32 platforms. It
136	takes precedence over select.
137
138	EV_USE_EPOLL
139
140	If defined to be "1", libev will compile in support for the Linux
141	epoll backend. Its availability will be detected at runtime,
142	otherwise another method will be used as fallback. This is the
143	preferred backend for GNU/Linux systems.
144
145	EV_USE_KQUEUE
146
147	If defined to be "1", libev will compile in support for the BSD
148	style kqueue backend. Its availability will be detected at runtime,
149	otherwise another method will be used as fallback. This is the
150	preferred backend for BSD and BSD-like systems. Darwin brokenness
151	will be detected at runtime and routed around by disabling this
152	backend.
153
154	EV_USE_PORT
155
156	If defined to be "1", libev will compile in support for the Solaris
157	10 port style backend. Its availability will be detected at runtime,
158	otherwise another method will be used as fallback. This is the
159	preferred backend for Solaris 10 systems.
160
161	EV_USE_DEVPOLL
162
163	reserved for future expansion, works like the USE symbols above.
164
165	EV_H
166
167	The name of the ev.h header file used to include it. The default
168	if undefined is <ev.h> in event.h and "ev.h" in ev.c. This can
169	be used to virtually rename the ev.h header file in case of
170	conflicts.
171
172	EV_EVENT_H
173
174	Similarly to EV_H, this macro cna be used to override event.c's idea
175	of how the event.h header can be found.
176
177	EV_PROTOTYPES
178
179	If defined to be "0", then "ev.h" will not define any function
180	prototypes, but still define all the structs and other
181	symbols. This is occasionally useful.
182
183	EV_MULTIPLICITY
184
185	If undefined or defined to "1", then all event-loop-specific
186	functions will have the "struct ev_loop *" as first argument, and
187	you can create additional independent event loops. Otherwise there
188	will be no support for multiple event loops and there is no first
189	event loop pointer argument. Instead, all functions act on the
190	single default loop.
191
192	EV_PERIODICS
193
194	If undefined or defined to be "1", then periodic timers are
195	supported, otherwise not. This saves a few kb of code.
196
197	EV_COMMON
198
199	By default, all watchers have a "void *data" member. By redefining
200	this macro to a something else you can include more and other types
201	of members. You have to define it each time you include one of the
202	files, though, and it must be identical each time.
203
204	For example, the perl EV module uses this:
205
206	#define EV_COMMON \
207	SV self; / contains this struct */ \
208	SV cb_sv, fh /* note no trailing ";" */
209
210	EV_CB_DECLARE(type)
211	EV_CB_INVOKE(watcher,revents)
212	ev_set_cb(ev,cb)
213
214	Can be used to change the callback member declaration in each
215	watcher, and the way callbacks are invoked and set. Must expand
216	to a struct member definition and a statement, respectively. See
217	the ev.v header file for their default definitions. One possible
218	use for overriding these is to avoid the ev_loop pointer as first
219	argument in all cases, or to use method calls instead of plain
220	function calls in C++.
221
222	EXAMPLES
223
224	For a real-world example of a program the includes libev
225	verbatim, you can have a look at the EV perl module
226	(http://software.schmorp.de/pkg/EV.html). It has the libev files in
227	the libev/ subdirectory and includes them in the EV/EVAPI.h (public
228	interface) and EV.xs (implementation) files. Only the EV.xs file will
229	be compiled.
230