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libwebsockets/minimal-examples/dbus-client/minimal-dbus-client/README.md
Andy Green 31dfc4aa12 role: dbus
This adds support for the integrating libdbus into the lws event loop.

Unlike the other roles, lws doesn't completely adopt the fd and libdbus insists
to retain control over the fd lifecycle.  However libdbus provides apis for
foreign code (lws) to provide event loop services to libdbus for the fd.

Accordingly, unlike the other roles rx and writeable are not subsumed into
lws callback messages and the events remain the property of libdbus.

A context struct wrapper is provided that is available in the libdbus
callbacks to bridge between the lws and dbus worlds, along with
a minimal example dbus client and server.
2018-10-13 08:16:27 +08:00

1.3 KiB

lws minimal dbus client

This demonstrates nonblocking, asynchronous dbus method calls as the client.

build

Using libdbus requires additional non-default include paths setting, same as is necessary for lws build described in ./lib/roles/dbus/README.md

CMake can guess one path and the library name usually, see the README above for details of how to override for custom libdbus and cross build.

Fedora example:

$ cmake .. -DLWS_DBUS_INCLUDE2="/usr/lib64/dbus-1.0/include"
$ make

Ubuntu example:

$ cmake .. -DLWS_DBUS_INCLUDE2="/usr/lib/x86_64-linux-gnu/dbus-1.0/include"
$ make

usage

Commandline option Meaning
-d Debug verbosity in decimal, eg, -d15

The minimal client connects to the minimal dbus server example, which is expected to be listening on its default abstract unix domain socket path.

It call the server Echo method with "Hello!" and returns to the event loop. When the reply comes, it prints the returned message.

Afterwards it just sits there receiving unsolicited messages from the server example, until closed by the user.

 $ ./lws-minimal-dbus-client
ctx
[2018/10/05 06:08:31:4901] NOTICE: pending_call_notify
[2018/10/05 06:08:31:4929] USER: pending_call_notify: received 'Hello!'
^C[2018/10/05 06:09:22:4409] NOTICE: destroy_dbus_client_conn
[2018/10/05 06:09:22:4691] NOTICE: Exiting cleanly
...