What does NTSTATUS 0xC0000510 (STATUS_ALREADY_INITIALIZED) mean?

STATUS_ALREADY_INITIALIZED

The object has already completed one-time initialization

Windows returns STATUS_ALREADY_INITIALIZED while handling job, task, callback, or isolation state. A second initialization attempt reached an object whose lifecycle allows initialization only once. Retrying without teardown can leak resources or overwrite established state.

Identify duplicate callers and race conditions, make initialization ownership explicit, and use a query operation to detect existing state.

When this is unexpected, identify which caller won the first initialization and which caller attempted the second. Initialization guards should cover the complete object lifetime, not only the allocation path.

If callers can arrive concurrently, record the winning initialization path and make later callers consume the initialized object instead of attempting a second setup.

References

• Microsoft: Job Objects
• Microsoft: nested jobs
• Microsoft: PsGetJobSilo