编译，链接和库

Structure:

CPU

Memory

I/O controller

 

any problem solution in computer : add another layer, define another interface and protocal

 

To use fully:

CPU: Round Robin + Priority Schedule 

( how to decide priority : 

decided by user,

IO bound thread > CPU bound thread 

long time pending thread will grow up

)

 

 

 

Build = 

prepressing-> import reference

compile-> assembly code

assemble-> machine command

link-> link with machine lib

 

complie =

Scanner -> token ( program -lex-> identifier, operator, static value, key word )

Grammar Parser -> Syntax tree ( token -yacc-> syntax tree)

Semantic Analyzer -> enhanced Syntax tree ( like add data type)

Source Code Optimizer -> Three-address Code ( like x = y op z )

Code Generator -> assembly code 

Target Code Optimizer -> more good assembly code

 

link = 

address and storage allocation,

symbol resolution,

relocation