Welcome B Visscher Aug 2001 Barts Operatin g

Welcome

B. Visscher Aug 2001 Bart’s Operatin g System Structure

Introduction Design Goals u What is BOSS u Hardware u Dependency Flow Model u Implementation resources BOSS u Perceptron application u Conclusion u Questions u

Design Goals u Easy to understand program u Transparent Hardware / Software u Fast u Reliable u Safe u Free

Traditional v. s. BOSS Applications Dependency Flow Model Operating System BOSS Hardware

Resource 2 Hardware Resource 1 Resource 3 Network Resourcen-1 Resources Linked Together in Network

Environment / Side Effects Resourcei Processors Memory Network

Dependency Flow Model u Dependency Flow Networks n u Owner structure n n u Programming Abstraction Process management Resource Structure n n n Scheduling Information Security

Dependency Flow Network Programming 1 u Sockets n Repeat Process u Ports n Storage u Channels + 2 3 5 8 13 21 etc. n Communication

Owner structure Abstraction Process management DFN Master Owner socket u Owner holds DFN status n n n Suspend Active Terminate DFN Owner socket D F N DFN D F N

Resource structure Socket : request for a process u Resource : provider of processes u Resource Socket Socket Scheduling Information Security

Socket u Part of n n n u Input Memory DFN Owner structure Resource structure Local Memory Process Represents n n Resource process (atomic) DFN (combined) Output Memory

Abstraction u Black n n Behavioral description Implicit u White n n Box = Owner Numbers Is the sum greater than 0? True / False 0 Box = DFN Dependency description Explicit Subroutine Function + Hold >

Link. Loader Resource u Converts passive dependency data into working processes (DFN) n Manages Black box processes Communicates variables u Introduces constants u Suspends / Activates / Terminates processes u n Manages Namespaces Primary namespace u Secondary namespace u Global namespace u

Complete Structure: BOSS Resource 0 Resource 1 Extension Sockets Ports Channels Network Processor N. 1 Processor N. K Extension processes Processor 1. 1 Extension processes Link. Loader processes Processor 1. P Link. Loader Resource N

Implemented processes u Naming of resource processes n u Resource: signal, boolean, byte, integer, float, double n n u Example: boolean. and(boolean, boolean)(boolean) Example: integer. +(integer, integer)(integer) Resource: flow n n u <resource>. <process>(in 0, in 1…inn)(out 0, out 1…outn) Processes: repeat, hold, sync, switch, merge, last, after All processes for data types : signal, boolean, …, @, NIL) Resource: text user interface, TUI

TUI Resource Demo Background Screen Layer Holder Layer N Layer 2 Layer 1 Layer 0 Screen divided into multiple layers u Background color u

W 0 W 1 X 1 Perceptron W 2 X 2 u Running n * Y’ = (W 0 + W 1 * X 1 + W 2 * X 2) > 0 * u Training (Determining W) n + n 0 + n Y = True, Y’ = False -> (Y-Y’)=1 Y = False, Y’ = True -> (Y-Y’)=-1 Wi new = Wi old + (Y-Y’)*Xi Hold u u > Y’ Y, Y’ : boolean {True, False} X, W : integer {-n…-2, -1, 0, 1, 2…n}

Random X 2 W 0 True / False Random Hold Training X 1 Random True W 1 W 2 W 0 Y W 1 W 2 False W 1 W 2 Random Value range: [– 127, 127] u W 0, W 1 W 2: 1 u Training: True u Y: True, False, Random u Perceptron Y’ Perceptron Demos True Random

Conclusion u Easy to understand program / Free n n n u Transparent Hardware / Software n n u Atomic processes Combined processes Fast n u DFN Owner structure / Abstraction Information in resources Parallel execution of processes Reliable / Safe n n Resource structure Autonomy of resources

Questions