Go Memory Model Checkpoint

1. Which operation establishes a happens-before edge by itself in Go?

Writing to a package-level variable Closing a channel Reading from an uninitialized channel Appending to a slice

2. How can you safely publish immutable snapshot state for lock-free reads?

Write to a map field without synchronization Store a pointer into atomic.Pointer after fully populating it Use `sync.Pool` as a synchronization mechanism Rely on `defer` ordering only

3. For lock-free shared state to remain safe, values published through atomic pointers should generally be:

Mutated often by readers Mutated exactly once Immutable after publication Pre-sized and packed

4. What is the memory-model term for an ordering relation that guarantees one event's writes are visible to another?