README
1 Sections in this file describe:
2 - introduction and overview
3 - low-level vs. high-level API
4 - version numbers
5 - options to the configure script
6 - ABI stability policy
7
8 Introduction
9 ===
10
11 D-Bus is a simple system for interprocess communication and coordination.
12
13 The "and coordination" part is important; D-Bus provides a bus daemon that does things like:
14 - notify applications when other apps exit
15 - start services on demand
16 - support single-instance applications
17
18 See http://www.freedesktop.org/software/dbus/ for lots of documentation,
19 mailing lists, etc.
20
21 See also the file HACKING for notes of interest to developers working on D-Bus.
22
23 If you're considering D-Bus for use in a project, you should be aware
24 that D-Bus was designed for a couple of specific use cases, a "system
25 bus" and a "desktop session bus." These are documented in more detail
26 in the D-Bus specification and FAQ available on the web site.
27
28 If your use-case isn't one of these, D-Bus may still be useful, but
29 only by accident; so you should evaluate carefully whether D-Bus makes
30 sense for your project.
31
32 Note: low-level API vs. high-level binding APIs
33 ===
34
35 A core concept of the D-Bus implementation is that "libdbus" is
36 intended to be a low-level API. Most programmers are intended to use
37 the bindings to GLib, Qt, Python, Mono, Java, or whatever. These
38 bindings have varying levels of completeness and are maintained as
39 separate projects from the main D-Bus package. The main D-Bus package
40 contains the low-level libdbus, the bus daemon, and a few command-line
41 tools such as dbus-launch.
42
43 If you use the low-level API directly, you're signing up for some
44 pain. Think of the low-level API as analogous to Xlib or GDI, and the
45 high-level API as analogous to Qt/GTK+/HTML.
46
47 Version numbers
48 ===
49
50 D-Bus uses the common "Linux kernel" versioning system, where
51 even-numbered minor versions are stable and odd-numbered minor
52 versions are development snapshots.
53
54 So for example, development snapshots: 1.1.1, 1.1.2, 1.1.3, 1.3.4
55 Stable versions: 1.0, 1.0.1, 1.0.2, 1.2.1, 1.2.3
56
57 All pre-1.0 versions were development snapshots.
58
59 Development snapshots make no ABI stability guarantees for new ABI
60 introduced since the last stable release. Development snapshots are
61 likely to have more bugs than stable releases, obviously.
62
63 Configuration
64 ===
65
66 dbus could be build by using autotools or cmake.
67
68 When using autotools the configure step is initiated by running ./configure
69 with our without additional configuration flags.
70
71 When using cmake the configure step is initiated by running the cmake
72 program with our without additional configuration flags.
73
74 Configuration flags
75 ===
76
77 When using autools the dbus-specific configuration flags that can be given to
78 the ./configure program are these
79
80 --enable-tests enable unit test code
81 --enable-verbose-mode support verbose debug mode
82 --enable-asserts include assertion checks
83 --enable-checks include sanity checks on public API
84 --enable-xml-docs build XML documentation (requires xmlto)
85 --enable-doxygen-docs build DOXYGEN documentation (requires Doxygen)
86 --enable-gcov compile with coverage profiling instrumentation (gcc only)
87 --enable-abstract-sockets use abstract socket namespace (linux only)
88 --enable-selinux build with SELinux support
89 --enable-dnotify build with dnotify support (linux only)
90 --enable-kqueue build with kqueue support (*BSD only)
91 --with-xml=libxml/expat XML library to use
92 --with-init-scripts=redhat Style of init scripts to install
93 --with-session-socket-dir=dirname Where to put sockets for the per-login-session message bus
94 --with-test-socket-dir=dirname Where to put sockets for make check
95 --with-system-pid-file=pidfile PID file for systemwide daemon
96 --with-system-socket=filename UNIX domain socket for systemwide daemon
97 --with-console-auth-dir=dirname directory to check for console ownerhip
98 --with-dbus-user=<user> User for running the DBUS daemon (messagebus)
99 --with-gnu-ld assume the C compiler uses GNU ld [default=no]
100 --with-tags[=TAGS] include additional configurations [automatic]
101 --with-x use the X Window System
102
103 When using the cmake build system the dbus-specific configuration flags that can be given
104 to the cmake program are these (use -D<key>=<value> on command line)
105
106 CMAKE_BUILD_TYPE set dbus build mode - one of Debug|Release|RelWithDebInfo|MinSizeRel
107 DBUS_BUILD_TESTS enable unit test code default=ON
108 DBUS_BUILD_X11 Build X11-dependent code default=ON
109 HAVE_CONSOLE_OWNER_FILE enable console owner file (solaris only) ) default=ON
110 DBUS_DISABLE_ASSERTS Disable assertion checking default=OFF
111 DBUS_DISABLE_CHECKS Disable public API sanity checking default=OFF
112 DBUS_ENABLE_ABSTRACT_SOCKETS enable support for abstract sockets (linux only) default=ON
113 DBUS_ENABLE_ANSI enable -ansi -pedantic gcc flags default=OFF
114 DBUS_ENABLE_DNOTIFY build with dnotify support (linux only) default=ON
115 DBUS_ENABLE_VERBOSE_MODE support verbose debug mode default=ON
116 DBUS_ENABLE_DOXYGEN_DOCS build DOXYGEN documentation (requires Doxygen) default=ON
117 DBUS_GCOV_ENABLED compile with coverage profiling instrumentation (gcc only) default=OFF
118 DBUS_INSTALL_SYSTEM_LIBS install required system libraries default (windows only) =OFF
119 DBUS_USE_EXPAT Use expat (== ON) or libxml2 (==OFF) default=ON [1]
120 DBUS_USE_NONCE_TCP_DEFAULT_ADDRESS Use nonce tcp default address default=OFF
121 DBUS_USE_OUTPUT_DEBUG_STRING enable win32 debug port for message output default=OFF
122
123 [1] requires installed development package of the related dependency
124
125
126 API/ABI Policy
127 ===
128
129 Now that D-Bus has reached version 1.0, the objective is that all
130 applications dynamically linked to libdbus will continue working
131 indefinitely with the most recent system and session bus daemons.
132
133 - The protocol will never be broken again; any message bus should
134 work with any client forever. However, extensions are possible
135 where the protocol is extensible.
136
137 - If the library API is modified incompatibly, we will rename it
138 as in http://ometer.com/parallel.html - in other words,
139 it will always be possible to compile against and use the older
140 API, and apps will always get the API they expect.
141
142 Interfaces can and probably will be _added_. This means both new
143 functions and types in libdbus, and new methods exported to
144 applications by the bus daemon.
145
146 The above policy is intended to make D-Bus as API-stable as other
147 widely-used libraries (such as GTK+, Qt, Xlib, or your favorite
148 example). If you have questions or concerns they are very welcome on
149 the D-Bus mailing list.
150
151 NOTE ABOUT DEVELOPMENT SNAPSHOTS AND VERSIONING
152
153 Odd-numbered minor releases (1.1.x, 1.3.x, 2.1.x, etc. -
154 major.minor.micro) are devel snapshots for testing, and any new ABI
155 they introduce relative to the last stable version is subject to
156 change during the development cycle.
157
158 Any ABI found in a stable release, however, is frozen.
159
160 ABI will not be added in a stable series if we can help it. i.e. the
161 ABI of 1.2.0 and 1.2.5 you can expect to be the same, while the ABI of
162 1.4.x may add more stuff not found in 1.2.x.
163
164 NOTE ABOUT STATIC LINKING
165
166 We are not yet firmly freezing all runtime dependencies of the libdbus
167 library. For example, the library may read certain files as part of
168 its implementation, and these files may move around between versions.
169
170 As a result, we don't yet recommend statically linking to
171 libdbus. Also, reimplementations of the protocol from scratch might
172 have to work to stay in sync with how libdbus behaves.
173
174 To lock things down and declare static linking and reimplementation to
175 be safe, we'd like to see all the internal dependencies of libdbus
176 (for example, files read) well-documented in the specification, and
177 we'd like to have a high degree of confidence that these dependencies
178 are supportable over the long term and extensible where required.
179
180 NOTE ABOUT HIGH-LEVEL BINDINGS
181
182 Note that the high-level bindings are _separate projects_ from the
183 main D-Bus package, and have their own release cycles, levels of
184 maturity, and ABI stability policies. Please consult the documentation
185 for your binding.
186
README.cygwin
README.dbus4win
1 On 2009-10-21 I (Tor Lillqvist <tml (a] iki.fi>) cherry-picked a bunch of
2 commits from the dbus4win-noncetcp branch of the dbus4win repository
3 to (my clone of) dbus upstream's master branch.
4
5 The dbus4win repository is at least currently at
6 git://repo.or.cz/dbus4win.git
7
8 I went through the commits done to the dbus4win-noncetcp branch since
9 the dbus-1.2.14 tag, i.e. commit f719d454329a1a54ff2d569feaf10ceee7cead50.
10
11 The following commits were left out because they either 0) were
12 already upstream, 1) seemed broken, or 2) seemed pointless to me,
13 especially if the commit message didn't say much. For each commit left
14 out, below is three lines: its id, the first log comment line, and an
15 explanation why I left it out.
16
17 f719d454329a1a54ff2d569feaf10ceee7cead50
18 configure.in: not all gccs support -Wno-pointer-sign
19 already upstream
20
21 6eddb6e1229b617ad44c8d61107983229dc7d589
22 configure.in: fail abstract socket test gracefully when cross-compilin
23 already upstream
24
25 c54dd9eefa5ed0d54be3b09cf30c12f05130fda1
26 r783: one ifdef lesser
27 probably pointless
28
29 93c288ca3e86e7760d3ac3fa6490257c1b6dc544
30 r783: compile if ENOMEM or EINTR is undefined.
31 huh, ENOMEM and EINTR is defined in the Microsoft C library
32
33 4f4ba13357da15c35a9d4ad111bf972a5d0d5db0
34 r783: introduced _dbus_daemon_release() function called in _dbus_loop_quit()...
35 this can't be right, there can be nested dbus loops afaik
36
37 124eb334324472a10de2c7e0a1455d353431f08f
38 unix build fixes against windbus-svn
39 can't be right to make a char* const when the code below then assigns through it
40
41 594bd19a0c45822d8763871e3491d99beb4d22cb
42 introduce DBUS_DIR_SEPERATOR and make use of it. On windows, disable some system service tests
43 "forward" slashes work fine on Windows, no need to uglify code with DBUS_DIR_SEPARATOR
44
45 cd2cdb3457f72cf058d5b19796ee691ceca6b52c
46 r783: introduced DBUS_CLEANUP_OLD_SERVICES that does cleanup prev zombie-instances...
47 unsure about this. something specific to KDE-on-Windows?
48
49 eeedba5b2f5b008819619764943caddd52441adf
50 build fixes for OS X, xcode 3.1.2, gcc 4.2.1
51 doesn't apply, seems to be upstream?
52
53 7dc7f71cf3003e006f6e177b5460d14a7cdbf2de
54 configure.in: fix pthread detection
55 doesn't apply
56
57 05b37fa87b1f6aa670de9007879f53a8198a7a89
58 configure.in: suppress -fPIC, -fPIE for W32
59 doesn't apply
60
61 b0d14fed92d9f539cd3478e72dc2f3ea75f3941a
62 configure.in: only check for wspiapi.h on Windows
63 nah, no harm checking for it on UNIX too
64
65 1724fc10e516e2d570537d522d8608abba90be5e
66 prototypes cleanup
67 related to cd2cdb3457f72cf058d5b19796ee691ceca6b52c which was skipped above
68
README.wince
1 DBus Daemon for Windows CE/Windows Mobile 6.5
2 =============================================
3
4 Bugs in upstream for any window version:
5 * MoveFileExA < 0 result check bug
6 * double dbus_free somewhere I forgot where (check in -ugly)
7 * alignment issue
8 * CreateProcess process information handle leak
9 * _dbus_getsid NULL vs INVALID_HANDLE_VALUE
10 * win_account_to_sid
11
12 Customisation
13 =============
14
15 1) At installation, the following registry value should be set to the
16 installation directory of the dbus installation (the directory
17 containing the bin, etc, share folders):
18
19 HKLM\Software\freedesktop\DBus\Install Directory
20
21 2) Instead of environment variable DBUS_VERBOSE, use
22 HKLM\Software\freedesktop\DBus\Verbose
23
24 2) The keyring directory is MYDOCUMENTS\dbus-keyrings, not
25 HOMEPATH\.dbus-keyrings.
26
27
28 Compilation
29 ===========
30
31 ./configure --host=arm-mingw32ce CPPFLAGS=-I/path/to/expat/include LDFLAGS=-L/path/to/expat/lib
32
33 A recent version of libtool is required, with this change:
34
35 2010-02-28 Pierre Ossman <ossman (a] ossman.lkpg.cendio.se> (tiny change)
36 Ralf Wildenhues <Ralf.Wildenhues (a] gmx.de>
37
38 Fix deplibs check fallback for 64-bit Windows and Windows CE.
39 * libltdl/m4/libtool.m4 (_LT_CHECK_MAGIC_METHOD): Accept file formats
40 'pe-arm-wince' and 'pe-x86-64'. Add note about consistency with ...
41 * libltdl/config/ltmain.m4sh (func_win32_libid): ... the respective
42 pattern here; sync pattern from the former.
43 * tests/deplibs-mingw.at (deplibs without file command): New
44 file, new test.
45 * Makefile.am (TESTSUITE_AT): Update.
46 * NEWS: Update.
47
48
49 MB vs WCHAR
50 ===========
51
52 Windows CE only supports the Unicode interface, while DBus Daemon uses
53 the Multi-Byte interface on Windows by default. The glue code does
54 not support multibyte in all cases. In particular, the _mbsrchr
55 function is not correctly implemented. It could be correctly
56 implemented, or dbus daemon could use the wchar interface more
57 consistently on all Windows targets. For now, the Windows CE port
58 will only work for filesystems without some weird characters in file
59 names. Is this a serious limitation?
60
61
62 Known Issues
63 ============
64
65 Autolaunch is broken so far.
66
67 Environment variables are faked. Some are punted to the registry, but
68 in any case they can not be used reliably for IPC.
69
70 The test suite is not ported yet.
71
72 dbus-pipe.c:
73 * Uses libc file descriptors. Needed for --print-address and
74 --print-pid which probably don't work yet.
75
76 dbus-sysdeps-win.c:
77 * Backtraces have been disabled.
78 * _dbus_fd_set_close_on_exec Not supported, maybe we should disable
79 the warning.
80 * SearchPathA: Uses HKLM\\Software\\freedesktop\\DBus\\Install Directory
81 to locate binaries.
82
README.windbus