NOTE
Netty Source: Assigning an Accepted Channel to an EventLoop
Selecting a worker event loop and registering the accepted child channel for thread-confined I/O processing.
This is a historical learning note and may contain outdated or incomplete understanding.
The server’s child group chooses an event loop for the accepted channel and registers the channel with that event loop’s selector/transport machinery.
After assignment, channel events are normally serialized on that event-loop thread. This is the basis for Netty’s common rule that a handler can keep channel-local state without additional locks when it is only accessed from the event loop.
Explicit offloading/external callbacks can break that simple assumption and require their own concurrency design.