| name | audit-jmm |
| description | Java Memory Model audit of all VarHandle/volatile field access modes |
| context | fork |
| agent | auditor |
| disable-model-invocation | true |
Perform a Java Memory Model audit of the cache.
For every field accessed via VarHandle or Unsafe, and for every field
declared volatile or accessed under synchronization:
- State the field name, type, and declared access mode.
- List every read and write with: access mode, method/line, locks held.
- For each (write, read) pair: state whether happens-before is guaranteed.
If it depends on access mode, verify BOTH sides use compatible modes.
- Identify any field where:
- Plain/opaque write paired with plain/opaque read across threads
with no intervening synchronization
- Code relies on opaque providing ordering beyond coherence
- Volatile read on one field but non-volatile on a correlated field
Specific areas to examine:
- writeTime: encodes both timestamp and refresh-in-progress flag
- accessTime: is opaque access sufficient for expiration?
- key/value fields: do value reads provide visibility of the object's fields?
- policyWeight vs weight: correlated but updated at different times
For each issue:
- State the specific reordering or visibility failure
- Construct a concrete 2-thread execution
- Verify the execution is legal under the JMM (not just TSO)
Do not report issues that only affect performance.
Do not report deliberately racy patterns with documented stale-read tolerance.
Platform focus: Pay specific attention to aarch64 (ARM) memory ordering.
ARM's weaker-than-TSO model exposes reordering bugs invisible on x86.
Historical bug: WeakValueReference.keyReference required setRelease +
storeStoreFence (not just setRelease alone) because the field is non-final
and aarch64 reorders the field write after reference publication. Check for
similar patterns — non-final fields published via release without a fence.
