-XX:[+|-]PositiveIdentityHash
Eclipse OpenJ9™ allows both positive and negative identity hashcodes (System.identityHashCode / Object.hashCode). This is problematic for programs that incorrectly assume hashcodes can only be positive.
When enabled, this option limits identity hash codes to non-negative values.
Because limiting identity hash codes to non-negative values can have an impact on the performance of hash-intensive operations, this option is not enabled by default.
Syntax
-XX:[+|-]PositiveIdentityHash
| Setting | Effect | Default |
|---|---|---|
-XX:+PositiveIdentityHash |
Enable | |
-XX:-PositiveIdentityHash |
Disable | yes |