[CALCITE-6408] Not-null ThreadLocal

• Type: Improvement
• Status: Closed
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.38.0
• Assignee: Julian Hyde
• Reporter: Julian Hyde
• Created: 10/May/24 22:43
• Updated: 17/Oct/24 22:41
• Resolved: 17/Oct/24 22:41

Description

Many points in the code need to wrap ThreadLocal.get() in requireNonNull or castNonNull to keep checkerFramework happy. This change removes those, by providing a sub-class of ThreadLocal whose values are known to be never null.

In CALCITE-915 we added class TryThreadLocal to make it easier to remember to unset a thread-local value, and in commit f82028f4 we made its get method return a not-null value. But the only constructor was TryThreadLocal.of(T initialValue). In this change, we add TryThreadLocal.withSupplier(Supplier<T>), so that each thread can have its own value, and convert all uses of ThreadLocal where to use it.

Issue Links

• is related to: CALCITE-6552 Enable CheckerFramework in 'server' module
• relates to: CALCITE-915 Tests do not unset ThreadLocal values on exit
• links to: dev branch