Fixes data race during Admin Console initialization

[avpinchuk]

Synchronize access to fields accessed from many threads.

[hs536]

What kind of problems can the current code cause?
( Is there a possibility of conflict in the loading process of the RestModule...?

[dmatej]

I believe I can see it. The init method can be called by different thread than service method, but they use the same attribute, which can sometimes lead to a situation when the service method would use an old value.

[avpinchuk]

What kind of problems can the current code cause?
( Is there a possibility of conflict in the loading process of the RestModule...?

Because Admin Console init in separate thread (the InstallerThread), service method in adapter can see inappropriate state value and therefore may try to load the console several times (in the worst case, on every request).

[avpinchuk]

The init method can be called by different thread than service method, but they use the same attribute, which can sometimes lead to a situation when the service method would use an old value.

Yes, this is also one of the possible problems

[avpinchuk]

I will make several builds of the master branch at different time. I hope this fix help stabilize application-tests.