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_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_DEVPOLL
    EV_USE_PORTS
    
       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:	1.24
Committed:	Mon Nov 12 00:43:24 2007 UTC (16 years, 6 months ago) by root
Branch:	MAIN
CVS Tags:	rel-0_8, rel-0_9
Changes since 1.23:	+13 -4 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	1.24	EV_SELECT_USE_FD_SET
110
111			If defined to 1, then the select backend will use the system fd_set
112			structure. This is useful if libev doesn't compile due to a missing
113			NFDBITS or fd_mask definition or it misguesses the bitset layout on
114			exotic systems. This usually limits the range of file descriptors
115			to some low limit such as 1024 or might have other limitations
116			(winsocket only allows 64 sockets). The FD_SETSIZE macro, set
117			before compilation, might influence the size of the fd_set used.
118
119			EV_SELECT_IS_WINSOCKET
120	root	1.7
121			When defined to 1, the select backend will assume that select
122			doesn't understand file descriptors but wants osf handles on
123			win32 (this is the case when the select to be used is the winsock
124			select). This means that it will call _get_osfhandle on the fd to
125			convert it to an OS handle. Should not be defined on non-win32
126			platforms.
127
128	root	1.1	EV_USE_POLL
129
130			If defined to be "1", libev will compile in support for the poll(2)
131	root	1.24	backend. Otherwise it will be enabled on non-win32 platforms. It
132			takes precedence over select.
133	root	1.1
134			EV_USE_EPOLL
135
136			If defined to be "1", libev will compile in support for the Linux
137			epoll backend. Its availability will be detected at runtime,
138			otherwise another method will be used as fallback. This is the
139			preferred backend for GNU/Linux systems.
140
141			EV_USE_KQUEUE
142
143			If defined to be "1", libev will compile in support for the BSD
144			style kqueue backend. Its availability will be detected at runtime,
145			otherwise another method will be used as fallback. This is the
146	ayin	1.22	preferred backend for BSD and BSD-like systems. Darwin brokenness
147	root	1.1	will be detected at runtime and routed around by disabling this
148			backend.
149
150	root	1.23	EV_USE_DEVPOLL
151			EV_USE_PORTS
152
153			reserved for future expansion, works like the USE symbols above.
154
155	root	1.15	EV_H
156
157			The name of the ev.h header file used to include it. The default
158			if undefined is <ev.h> in event.h and "ev.h" in ev.c. This can
159			be used to virtually rename the ev.h header file in case of
160			conflicts.
161
162			EV_EVENT_H
163
164			Similarly to EV_H, this macro cna be used to override event.c's idea
165			of how the event.h header can be found.
166
167	root	1.1	EV_PROTOTYPES
168
169			If defined to be "0", then "ev.h" will not define any function
170			prototypes, but still define all the structs and other
171			symbols. This is occasionally useful.
172
173			EV_MULTIPLICITY
174
175			If undefined or defined to "1", then all event-loop-specific
176			functions will have the "struct ev_loop *" as first argument, and
177			you can create additional independent event loops. Otherwise there
178			will be no support for multiple event loops and there is no first
179			event loop pointer argument. Instead, all functions act on the
180			single default loop.
181
182	root	1.20	EV_PERIODICS
183
184			If undefined or defined to be "1", then periodic timers are
185			supported, otherwise not. This saves a few kb of code.
186
187			EV_COMMON
188
189			By default, all watchers have a "void *data" member. By redefining
190			this macro to a something else you can include more and other types
191			of members. You have to define it each time you include one of the
192			files, though, and it must be identical each time.
193
194			For example, the perl EV module uses this:
195
196			#define EV_COMMON \
197			SV self; / contains this struct */ \
198			SV cb_sv, fh /* note no trailing ";" */
199
200	root	1.15	EV_CB_DECLARE(type)
201			EV_CB_INVOKE(watcher,revents)
202	root	1.17	ev_set_cb(ev,cb)
203	root	1.15
204			Can be used to change the callback member declaration in each
205	root	1.17	watcher, and the way callbacks are invoked and set. Must expand
206			to a struct member definition and a statement, respectively. See
207			the ev.v header file for their default definitions. One possible
208			use for overriding these is to avoid the ev_loop pointer as first
209			argument in all cases, or to use method calls instead of plain
210			function calls in C++.
211	root	1.15
212	root	1.1	EXAMPLES
213
214	root	1.2	For a real-world example of a program the includes libev
215			verbatim, you can have a look at the EV perl module
216			(http://software.schmorp.de/pkg/EV.html). It has the libev files in
217	root	1.5	the libev/ subdirectory and includes them in the EV/EVAPI.h (public
218			interface) and EV.xs (implementation) files. Only the EV.xs file will
219			be compiled.
220	root	1.1