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 |
You need the following files in your source tree, or in a directory |
28 |
in your include path (e.g. in libev/ when using -Ilibev): |
29 |
|
30 |
ev.h |
31 |
ev.c |
32 |
ev_vars.h |
33 |
ev_wrap.h |
34 |
ev_win32.c |
35 |
|
36 |
ev_select.c only when select backend is enabled (which is is by default) |
37 |
ev_poll.c only when poll backend is enabled (disabled by default) |
38 |
ev_epoll.c only when the epoll backend is enabled (disabled by default) |
39 |
ev_kqueue.c only when the kqueue backend is enabled (disabled by default) |
40 |
|
41 |
"ev.c" includes the backend files directly when enabled. |
42 |
|
43 |
LIBEVENT COMPATIBILITY API |
44 |
|
45 |
To include the libevent compatibility API, also include: |
46 |
|
47 |
#include "event.c" |
48 |
|
49 |
in the file including "ev.c", and: |
50 |
|
51 |
#include "event.h" |
52 |
|
53 |
in the files that want to use the libevent API. This also includes "ev.h". |
54 |
|
55 |
You need the following additional files for this: |
56 |
|
57 |
event.h |
58 |
event.c |
59 |
|
60 |
PREPROCESSOR SYMBOLS |
61 |
|
62 |
Libev can be configured via a variety of preprocessor symbols you have to define |
63 |
before including any of its files. The default is not to build for mulciplicity |
64 |
and only include the select backend. |
65 |
|
66 |
EV_STANDALONE |
67 |
|
68 |
Must always be "1", which keeps libev from including config.h or |
69 |
other files, and it also defines dummy implementations for some |
70 |
libevent functions (such as logging, which is not supported). It |
71 |
will also not define any of the structs usually found in "event.h" |
72 |
that are not directly supported by libev code alone. |
73 |
|
74 |
EV_USE_MONOTONIC |
75 |
|
76 |
If undefined or defined to be "1", libev will try to detect the |
77 |
availability of the monotonic clock option at both compiletime and |
78 |
runtime. Otherwise no use of the monotonic clock option will be |
79 |
attempted. |
80 |
|
81 |
EV_USE_REALTIME |
82 |
|
83 |
If defined to be "1", libev will try to detect the availability |
84 |
of the realtime clock option at compiletime (and assume its |
85 |
availability at runtime if successful). Otherwise no use of the |
86 |
realtime clock option will be attempted. This effectively replaces |
87 |
gettimeofday by clock_get (CLOCK_REALTIME, ...) and will not normally |
88 |
affect correctness. |
89 |
|
90 |
EV_USE_SELECT |
91 |
|
92 |
If undefined or defined to be "1", libev will compile in support |
93 |
for the select(2) backend. No attempt at autodetection will be |
94 |
done: if no other method takes over, select will be it. Otherwise |
95 |
the select backend will not be compiled in. |
96 |
|
97 |
EV_SELECT_USE_WIN32_HANDLES |
98 |
|
99 |
When defined to 1, the select backend will assume that select |
100 |
doesn't understand file descriptors but wants osf handles on |
101 |
win32 (this is the case when the select to be used is the winsock |
102 |
select). This means that it will call _get_osfhandle on the fd to |
103 |
convert it to an OS handle. Should not be defined on non-win32 |
104 |
platforms. |
105 |
|
106 |
EV_USE_POLL |
107 |
|
108 |
If defined to be "1", libev will compile in support for the poll(2) |
109 |
backend. No attempt at autodetection will be done. poll usually |
110 |
performs worse than select, so its not enabled by default (it is |
111 |
also slightly less portable). |
112 |
|
113 |
EV_USE_EPOLL |
114 |
|
115 |
If defined to be "1", libev will compile in support for the Linux |
116 |
epoll backend. Its availability will be detected at runtime, |
117 |
otherwise another method will be used as fallback. This is the |
118 |
preferred backend for GNU/Linux systems. |
119 |
|
120 |
EV_USE_KQUEUE |
121 |
|
122 |
If defined to be "1", libev will compile in support for the BSD |
123 |
style kqueue backend. Its availability will be detected at runtime, |
124 |
otherwise another method will be used as fallback. This is the |
125 |
preferred backend for BSD and BSd-like systems. Darwin brokenness |
126 |
will be detected at runtime and routed around by disabling this |
127 |
backend. |
128 |
|
129 |
EV_COMMON |
130 |
|
131 |
By default, all watchers have a "void *data" member. By redefining |
132 |
this macro to a something else you can include more and other types |
133 |
of members. You have to define it each time you include one of the |
134 |
files, though, and it must be identical each time. |
135 |
|
136 |
For example, the perl EV module uses this: |
137 |
|
138 |
#define EV_COMMON \ |
139 |
SV *self; /* contains this struct */ \ |
140 |
SV *cb_sv, *fh /* note no trailing ";" */ |
141 |
|
142 |
EV_PROTOTYPES |
143 |
|
144 |
If defined to be "0", then "ev.h" will not define any function |
145 |
prototypes, but still define all the structs and other |
146 |
symbols. This is occasionally useful. |
147 |
|
148 |
EV_MULTIPLICITY |
149 |
|
150 |
If undefined or defined to "1", then all event-loop-specific |
151 |
functions will have the "struct ev_loop *" as first argument, and |
152 |
you can create additional independent event loops. Otherwise there |
153 |
will be no support for multiple event loops and there is no first |
154 |
event loop pointer argument. Instead, all functions act on the |
155 |
single default loop. |
156 |
|
157 |
EXAMPLES |
158 |
|
159 |
For a real-world example of a program the includes libev |
160 |
verbatim, you can have a look at the EV perl module |
161 |
(http://software.schmorp.de/pkg/EV.html). It has the libev files in |
162 |
the libev/ subdirectory and includes them in the EV/EVAPI.h (public |
163 |
interface) and EV.xs (implementation) files. Only the EV.xs file will |
164 |
be compiled. |
165 |
|