[STANBOL-1428] Import resolution is not thread-safe

• Type: Bug
• Status: Resolved
• Priority: Critical
• Resolution: Fixed
• Affects Version/s: 1.0.0
• Component/s: Ontology Manager
• Labels: concurrency thread-safety
• Environment: cross-platform
• Assignee: Alessandro Adamou
• Reporter: Alessandro Adamou
• Created: 18/Jun/15 16:41
• Updated: 18/Jun/15 17:14
• Resolved: 18/Jun/15 17:14

Description

When loading an ontology with imports, the ClerezzaOntologyProvider keeps triple iterators running on the target graph for longer than required. Since Clerezza introduced Lockable the MGraph, this thread-unsafety has resulted in concurrent exceptions being thrown.

The solution is now to

• minimize the lifetime of iterators (do not keep them open during import resolution)
• use mutex locks as documented in https://clerezza.apache.org/faq/