Netty

Netty
Every IO operation on a Channel in Netty is non-blocking and asynchronous.

Keywords

• channel:kinda a connection and is registered for its with a single eventloop.
• bootstrap: bootstrap a channel
• eventloopgroup: one or more eventloops
• eventloop: handles all the I/O operations for a Channel once registered, and
  all I/O events in an eventloop are handled on its decidated Thread

Inbound
works for read-in IO event by adding order of handler
Head–>A–>B–C–>Tail

ChannelHandlerContext.fireChannelRegistered()
ChannelHandlerContext.fireChannelActive()
ChannelHandlerContext.fireChannelRead(Object)
ChannelHandlerContext.fireChannelReadComplete()
ChannelHandlerContext.fireExceptionCaught(Throwable)
ChannelHandlerContext.fireUserEventTriggered(Object)
ChannelHandlerContext.fireChannelWritabilityChanged()
ChannelHandlerContext.fireChannelInactive()
ChannelHandlerContext.fireChannelUnregistered()

Outbound

works for write-out IO eent by revert adding order of handler
tail–>C(event start)–>B–>A–head
ChannelHandlerContext.bind(SocketAddress, ChannelPromise)
ChannelHandlerContext.connect(SocketAddress, SocketAddress, ChannelPromise)
ChannelHandlerContext.write(Object, ChannelPromise)
ChannelHandlerContext.flush()
ChannelHandlerContext.read()
ChannelHandlerContext.disconnect(ChannelPromise)
ChannelHandlerContext.close(ChannelPromise)

Pipeline
pipeline is a bi-direction queue, and is filled with inbound and outbound
handlers.

links
http://tutorials.jenkov.com/netty/netty-tcp-client.html
http://tutorials.jenkov.com/netty/netty-tcp-server.html

caution
context.write is not handler.write(call tail)