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 *
#	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	root	1.26	ev_port.c only when the solaris port backend is enabled (disabled by default)
46	root	1.3
47			"ev.c" includes the backend files directly when enabled.
48	root	1.1
49	root	1.5	LIBEVENT COMPATIBILITY API
50
51	root	1.1	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	root	1.18	AUTOCONF SUPPORT
67
68			Instead of using EV_STANDALONE=1 and providing your config in whatever
69	root	1.19	way you want, you can also m4_include([libev.m4]) in your configure.ac
70	root	1.18	and leave EV_STANDALONE off. ev.c will then include "config.h" and
71			configure itself accordingly.
72
73	root	1.1	PREPROCESSOR SYMBOLS
74
75			Libev can be configured via a variety of preprocessor symbols you have to define
76	root	1.18	before including any of its files. The default is not to build for multiplicity
77	root	1.1	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	root	1.26	If defined to be "1", libev will try to detect the availability
90			of the monotonic clock option at both compiletime and
91	root	1.1	runtime. Otherwise no use of the monotonic clock option will be
92	root	1.26	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	root	1.1
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	root	1.24	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	root	1.7
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	root	1.1	EV_USE_POLL
132
133			If defined to be "1", libev will compile in support for the poll(2)
134	root	1.24	backend. Otherwise it will be enabled on non-win32 platforms. It
135			takes precedence over select.
136	root	1.1
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	ayin	1.22	preferred backend for BSD and BSD-like systems. Darwin brokenness
150	root	1.1	will be detected at runtime and routed around by disabling this
151			backend.
152
153	root	1.25	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	root	1.23	EV_USE_DEVPOLL
161
162			reserved for future expansion, works like the USE symbols above.
163
164	root	1.15	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	root	1.1	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	root	1.20	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	root	1.15	EV_CB_DECLARE(type)
210			EV_CB_INVOKE(watcher,revents)
211	root	1.17	ev_set_cb(ev,cb)
212	root	1.15
213			Can be used to change the callback member declaration in each
214	root	1.17	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	root	1.15
221	root	1.1	EXAMPLES
222
223	root	1.2	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	root	1.5	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	root	1.1