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:	1.21
Committed:	Sun Nov 11 03:13:07 2007 UTC (16 years, 6 months ago) by root
Branch:	MAIN
Changes since 1.20:	+2 -1 lines
Log Message:	* empty log message *
#	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	1.21
39			ev_win32.c required on win32 platforms only
40	root	1.4
41	root	1.10	ev_select.c only when select backend is enabled (which is is by default)
42	root	1.3	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	root	1.1
48	root	1.5	LIBEVENT COMPATIBILITY API
49
50	root	1.1	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	root	1.18	AUTOCONF SUPPORT
66
67			Instead of using EV_STANDALONE=1 and providing your config in whatever
68	root	1.19	way you want, you can also m4_include([libev.m4]) in your configure.ac
69	root	1.18	and leave EV_STANDALONE off. ev.c will then include "config.h" and
70			configure itself accordingly.
71
72	root	1.1	PREPROCESSOR SYMBOLS
73
74			Libev can be configured via a variety of preprocessor symbols you have to define
75	root	1.18	before including any of its files. The default is not to build for multiplicity
76	root	1.1	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	root	1.7	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	root	1.1	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	root	1.15	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	root	1.1	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	root	1.20	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	root	1.15	EV_CB_DECLARE(type)
187			EV_CB_INVOKE(watcher,revents)
188	root	1.17	ev_set_cb(ev,cb)
189	root	1.15
190			Can be used to change the callback member declaration in each
191	root	1.17	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	root	1.15
198	root	1.1	EXAMPLES
199
200	root	1.2	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	root	1.5	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	root	1.1