[YARN-4630] Remove useless boxing/unboxing code

• Type: Improvement
• Status: Resolved
• Priority: Minor
• Resolution: Fixed
• Affects Version/s: 3.0.0-alpha1
• Fix Version/s: 2.8.0, 3.0.0-alpha1
• Component/s: yarn
• Hadoop Flags: Reviewed
• Assignee: Kousuke Saruta
• Reporter: Kousuke Saruta
• Created: 22/Jan/16 19:36
• Updated: 30/Aug/16 01:06
• Resolved: 11/Apr/16 05:57

Description

There are lots of places where useless boxing/unboxing occur.
To avoid performance issue, let's remove them.