Thread-safety and memory leak bug in Fluent API Region class

[azure]

Thread-safety and memory leak bug in Fluent API Region class

[milismsft]

@RikkiGibson will this be something we can address/fix in the Runtime?

[RikkiGibson]

I might be missing something but I don't see how the runtime relates to this. I can look and see if the Java runtime has a similar problem.

Up to date link to Region file: https://github.com/Azure/azure-libraries-for-net/blob/master/src/ResourceManagement/ResourceManager/Region.cs

I think what @Eldar1205 has suggested in the original issue will be a good fix.

[RikkiGibson]

In Java the Region class is also kept in the Azure libraries, not the runtime.

https://github.com/Azure/azure-libraries-for-java/blob/master/azure-mgmt-resources/src/main/java/com/microsoft/azure/management/resources/fluentcore/arm/Region.java

It seems to have a similar problem--let's just not cache instances of user-defined regions as it seems like kind of an imperceptible optimization anyway.

[weidongxu-microsoft]

Address concurrency first.

Memory leak is certainly possible, if incorrectly used. But the whole ENUM classes inherit from ExpandableStringEnum got same problem.