Netty 3.x Source Analysis

1. Overview

Create two thread pools: one for initializing the boss array and one for initializing the worker array.

2. Boss-Array Initialization

All bosses share the same thread pool.

1. Use Selector.open to open a selector.
2. Execute a run method through the thread pool. This method is an infinite loop.
   1. Set wakeup to false.
   2. Call selector.select and block until an event needs to be processed (a client connection).
   3. Repeatedly take tasks from the task queue and execute them until the queue is empty. This method is also an infinite loop.
   4. Then process this selector.

Obtain all SelectionKey instances from the selector and iterate over them.

Take the channel corresponding to each key, randomly obtain a worker, and put a task into that worker’s task queue.

The task is to register the channel’s read event with the selector.

3. Worker-Array Initialization

All workers share the same thread pool.

1. Use Selector.open to open the selector pool.
2. Execute a run method through the thread pool. This method is an infinite loop.
   1. Set wakeup to false.
   2. Call selector.select; return directly on timeout.
   3. Repeatedly take tasks from the task queue and execute them until the queue is empty. This method is also an infinite loop.
   4. Then process this selector.

Obtain all SelectionKey instances from the selector and iterate over them.

Take the channel corresponding to each key, read the data, output it, and write it back to the client.

4. bind Operation

Use ServerSocketChannel.open to open a channel, configure it as non-blocking, and bind the address.

Randomly obtain a boss, turn the channel’s accept event into a task, and put that task into the boss’s task queue.