Reports double-checked locking.
Double-checked locking tries to initialize a field on demand and in a thread-safe manner, while avoiding the cost of synchronization. Unfortunately it is not thread-safe when used on a field that is not declared
volatile. When using Java 1.4 or earlier, double-checked locking doesn't work even with a
volatile field. Read the article linked above for a detailed explanation of the problem.
Example of incorrect double-checked locking:
IntelliJ IDEA 2023.3, Qodana for JVM 2023.3