[DRILL-5533] Fix flag assignment in FunctionInitializer.checkInit() method

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 1.10.0
• Fix Version/s: 1.11.0
• Labels: ready-to-commit
• Assignee: Arina Ielchiieva
• Reporter: Arina Ielchiieva
• Reviewer: Sudheesh Katkam
• Created: 23/May/17 13:30
• Updated: 03/Jun/17 04:52
• Resolved: 03/Jun/17 04:47

Description

FunctionInitializer.checkInit() method uses DCL to ensure that function body is loaded only once. But flag parameter is never updated and all threads are entering synchronized block.

Also FunctionInitializer.getImports() always returns empty list.

https://github.com/apache/drill/blob/3e8b01d5b0d3013e3811913f0fd6028b22c1ac3f/exec/java-exec/src/main/java/org/apache/drill/exec/expr/fn/FunctionInitializer.java

Changes:
1. Fix DCL in FunctionInitializer.checkInit() method (update flag parameter when function body is loaded).
2. Fix ImportGrabber.getImports() method to return list with imports.
3. Add unit tests for FunctionInitializer.
4. Minor refactoring (rename methods, add javadoc).

Issue Links

• links to: GitHub Pull Request #843