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Revision: 1.23
Committed: Sun Nov 11 17:59:25 2007 UTC (16 years, 6 months ago) by root
Branch: MAIN
Changes since 1.22: +5 -0 lines
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File Contents

# 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 ayin 1.22 preferred backend for BSD and BSD-like systems. Darwin brokenness
138 root 1.1 will be detected at runtime and routed around by disabling this
139     backend.
140    
141 root 1.23 EV_USE_DEVPOLL
142     EV_USE_PORTS
143    
144     reserved for future expansion, works like the USE symbols above.
145    
146 root 1.15 EV_H
147    
148     The name of the ev.h header file used to include it. The default
149     if undefined is <ev.h> in event.h and "ev.h" in ev.c. This can
150     be used to virtually rename the ev.h header file in case of
151     conflicts.
152    
153     EV_EVENT_H
154    
155     Similarly to EV_H, this macro cna be used to override event.c's idea
156     of how the event.h header can be found.
157    
158 root 1.1 EV_PROTOTYPES
159    
160     If defined to be "0", then "ev.h" will not define any function
161     prototypes, but still define all the structs and other
162     symbols. This is occasionally useful.
163    
164     EV_MULTIPLICITY
165    
166     If undefined or defined to "1", then all event-loop-specific
167     functions will have the "struct ev_loop *" as first argument, and
168     you can create additional independent event loops. Otherwise there
169     will be no support for multiple event loops and there is no first
170     event loop pointer argument. Instead, all functions act on the
171     single default loop.
172    
173 root 1.20 EV_PERIODICS
174    
175     If undefined or defined to be "1", then periodic timers are
176     supported, otherwise not. This saves a few kb of code.
177    
178     EV_COMMON
179    
180     By default, all watchers have a "void *data" member. By redefining
181     this macro to a something else you can include more and other types
182     of members. You have to define it each time you include one of the
183     files, though, and it must be identical each time.
184    
185     For example, the perl EV module uses this:
186    
187     #define EV_COMMON \
188     SV *self; /* contains this struct */ \
189     SV *cb_sv, *fh /* note no trailing ";" */
190    
191 root 1.15 EV_CB_DECLARE(type)
192     EV_CB_INVOKE(watcher,revents)
193 root 1.17 ev_set_cb(ev,cb)
194 root 1.15
195     Can be used to change the callback member declaration in each
196 root 1.17 watcher, and the way callbacks are invoked and set. Must expand
197     to a struct member definition and a statement, respectively. See
198     the ev.v header file for their default definitions. One possible
199     use for overriding these is to avoid the ev_loop pointer as first
200     argument in all cases, or to use method calls instead of plain
201     function calls in C++.
202 root 1.15
203 root 1.1 EXAMPLES
204    
205 root 1.2 For a real-world example of a program the includes libev
206     verbatim, you can have a look at the EV perl module
207     (http://software.schmorp.de/pkg/EV.html). It has the libev files in
208 root 1.5 the libev/ subdirectory and includes them in the EV/EVAPI.h (public
209     interface) and EV.xs (implementation) files. Only the EV.xs file will
210     be compiled.
211 root 1.1