NOTE
Collections.synchronizedList
The synchronized List wrapper, compound operations, iteration requirements, and alternatives.
This is a historical learning note and may contain outdated or incomplete understanding.
Collections.synchronizedList(list) wraps a list so individual operations synchronize on a shared mutex.
That does not automatically make a multi-call sequence atomic. A check-then-act workflow still needs one surrounding synchronized critical section. Iteration likewise requires external synchronization on the wrapper as documented.
For high-concurrency workloads, consider a concurrent structure whose semantics match the problem instead of assuming a synchronized wrapper will scale well.