[ARROW-17770] [C++][Gandiva] Fix const correctness of Gandiva projector Evaluate

• Type: Bug
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 9.0.0
• Fix Version/s: 10.0.0
• Component/s: C++ - Gandiva
• Labels: pull-request-available
• External issue URL: https://github.com/apache/arrow/issues/32998

Language

C++

• Assignee: Jin Shang
• Reporter: Jin Shang
• Created: 19/Sep/22 02:53
• Updated: 11/Jan/23 11:55
• Resolved: 27/Sep/22 13:05

Description

I was trying to figure out the thread-safeness of Gandiva projector evaluation, i.e., whether I can use a single Projector to evaluate multiple inputs concurrently. I assumed it isn't safe because the Evaluate function is not marked const. However, as far as I understand, the Evaluate function merely executes a compiled function on the input, which doesn't modify a project's internal states and should be const.

Issue Links

• links to: GitHub Pull Request #14165