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