[UIMA-5741] protect UIMA Class loader in multi-threaded get resource contexts

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 2.10.2SDK, 3.0.0SDK
• Fix Version/s: 3.0.1SDK, 2.10.3SDK
• Component/s: Core Java Framework
• Assignee: Marshall Schor
• Reporter: Marshall Schor
• Created: 06/Mar/18 16:21
• Updated: 27/Jun/18 18:05
• Resolved: 27/Jun/18 18:05

Description

I have seen one case where multiple threads were being used where a UIMA Class Loader was being used to load a resource (Type system Descriptor -> type System was resolving an "import by name"), where the getResource returned (only once) a spurious "null" result.

This is likely due to some multithreading issue in get Resource.  Add a sync using the same multi-threaded parallel approach used for class loaded, to getResource, to protect against this case.