diff options
Diffstat (limited to 'doc/dbus-specification.sgml')
| -rw-r--r-- | doc/dbus-specification.sgml | 48 |
1 files changed, 41 insertions, 7 deletions
diff --git a/doc/dbus-specification.sgml b/doc/dbus-specification.sgml index 5d150e86..7e2fcb35 100644 --- a/doc/dbus-specification.sgml +++ b/doc/dbus-specification.sgml @@ -1235,10 +1235,22 @@ </para> <para> The executable launched will have the environment variable - <literal>DBUS_BUS_ADDRESS</literal> set to the address of the + <literal>DBUS_ACTIVATION_ADDRESS</literal> set to the address of the message bus so it can connect and register the appropriate services. </para> <para> + The executable being launched may want to know whether the message bus + activating it is one of the well-known message buses (see <xref + linkend="message-bus-types">). To facilitate this, the bus MUST also set + the <literal>DBUS_ACTIVATION_BUS_TYPE</literal> environment variable if it is one + of the well-known buses. The currently-defined values for this variable + are <literal>system</literal> for the systemwide message bus, + and <literal>session</literal> for the per-login-session message + bus. The activated executable must still connect to the address given + in <literal>DBUS_ACTIVATION_ADDRESS</literal>, but may assume that the + resulting connection is to the well-known bus. + </para> + <para> [FIXME there should be a timeout somewhere, either specified in the .service file, by the client, or just a global value and if the client being activated fails to connect within that @@ -1247,7 +1259,7 @@ </sect2> <sect2 id="message-bus-types"> - <title>Standard Message Bus Instances</title> + <title>Well-known Message Bus Instances</title> <para> Two standard message bus instances are defined here, along with how to locate them and where their service files live. @@ -1257,9 +1269,17 @@ <para> Each time a user logs in, a <firstterm>login session message bus</firstterm> may be started. All applications in the user's login - session may interact with one another using this message bus. [specify - how to find the address of the login session message bus via - environment variable and/or X property] + session may interact with one another using this message bus. + </para> + <para> + The address of the login session message bus is given + in the <literal>DBUS_SESSION_BUS_ADDRESS</literal> environment + variable. If that variable is not set, applications may + also try to read the address from the X Window System root + window property <literal>_DBUS_SESSION_BUS_ADDRESS</literal>. + The root window property must have type <literal>STRING</literal>. + The environment variable should have precedence over the + root window property. </para> <para> [FIXME specify location of .service files, probably using @@ -1272,8 +1292,22 @@ <para> A computer may have a <firstterm>system message bus</firstterm>, accessible to all applications on the system. This message bus may be - used to broadcast system events, such as adding new hardware devices. - [specify how to find the address of the system message bus] + used to broadcast system events, such as adding new hardware devices, + changes in the printer queue, and so forth. + </para> + <para> + The address of the login session message bus is given + in the <literal>DBUS_SYSTEM_BUS_ADDRESS</literal> environment + variable. If that variable is not set, applications should try + to connect to the well-known address + <literal>unix:path=/var/run/dbus/system_bus_socket</literal>. + <footnote> + <para> + The D-BUS reference implementation actually honors the + <literal>$(localstatedir)</literal> configure option + for this address, on both client and server side. + </para> + </footnote> </para> <para> [FIXME specify location of system bus .service files] |