[LOG4J2-2898] Avoid initializing volatile fields to their default values

• Type: Bug
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 2.13.3
• Fix Version/s: 2.14.0
• Component/s: Core
• Assignee: Carter Kozak
• Reporter: Carter Kozak
• Created: 18/Jul/20 15:57
• Updated: 18/Jul/20 16:05
• Resolved: 18/Jul/20 16:05

Description

Contribution: https://github.com/apache/logging-log4j2/pull/367

From Turbanov Andrey:

It's known that writing to a volatile field has performance impact.
It's true even if code initializes field with default value.
This PR cleans such redundant initialization and improves startup performance.
See similar improvement in JDK codebase: https://bugs.openjdk.java.net/browse/JDK-8145680.