tree 73ffa7542944cc9836149583baab14d8aae80920
parent 92decf2aa916353564a9dabe6871ab00e0f06a80
author Stefan Sperling <ssperling@sysmocom.de> 1519319789 +0100
committer Stefan Sperling <ssperling@sysmocom.de> 1519383354 +0100

ensure that osmo_fsm vty commands are only installed once

There is a desire to install osmo_fsm vty commands automatically in
a library context, rather than requiring every application which
directly or indirectly uses osmo_fsm to run osmo_fsm_vty_add_cmd().

However, the function install_element_ve() asserts that elements
about to be installed have not already been installed.

This means we cannot shift responsibility into a library context
without first making sure that osmo_fsm commands are only installed
once per combined application+library context, because applications
won't know which commands any of its libraries has already installed.

A simple solution is to use a global flag which is checked by
osmo_fsm_vty_add_cmd() before installing osmo_fsm commands, and
is set once the commands have been installed. This way, no harm
is done if osmo_fsm_vty_add_cmd() is called multiple times.

Change-Id: I10b0b1c1c1bf44c3b8eafc465c1ee06ea2590682
Related: OS#2967