Capability-Based Computer Systems

1 Capability- and Object-Based System Concepts

Capability-Based Systems

Memory Addressing in Computer Systems

The Context of an Address

Protection in Computer Systems

The Object-Based Approach

Capabilities and Object-Based Systems

Summary

For Further Reading


2 Early Descriptor Architectures

Introduction

The Burroughs B5000

The Rice University Computer

The Basic Language Machine

Discussion

For Further Reading


3 Early Capability Architectures

Introduction

Dennis and Van Horn's Supervisor

The MIT PDP-1 Timesharing System

The Chicago Magic Number Machine

The CAL-TSS System

Discussion

For Further Reading


4 The Plessey System 250

Introduction

System Overview

Capability Addressing

Capability Register Usage

Inform and Outform Capabilities

Instructions and Addressing

Protected Procedure Calls

Operating System Resource Management

Input and Output

Discussion

For Further Reading


5 The Cambridge CAP Computer

Introduction

Hardware Overview

CAP Process Structure

CAP Addressing Overview

Capabilities and Virtual Addresses

Process Data Structures

Memory Address Evaluation

Subprocess Creation

The Capability Unit

Protected Procedures

Long-Term Storage and Long-Term Names

Discussion

For Further Reading


6 The Hydra System

Introduction

Hydra Overview

Hydra Objects and Types

Processes, Procedures, and Local Name Spaces

Hydra Operations

Capabilities and Rights

Supporting Protected Subsystems

Templates

Typecalls

Hydra Object Storage System

Capability Representation

Reference Counts and Garbage Collection

Discussion

For Further Reading


7 The STAROS System

Overview of STAROS

STAROS Object Support

STAROS Capabilities

Object Addressing

STAROS Abstract Type Management

Discussion

For Further Reading


8 The IBM System/38

Introduction

System Objects

Object Addressing

Virtual Memory

Pointers

Contexts

Physical Address Mapping

Profiles and Authority

Authority/Pointer Resolution

Programs/Procedures

The Instruction Stream

Program Activation and Invocation

Protected Procedures

Special Privileges

Discussion

For Further Reading


9 The Intel iAPX 432

Introduction

Segments and Objects

Object Addressing

Object Descriptors

Access Descriptors

Program Execution

Domains and Instruction Objects

Procedure Call and Context Objects

Instruction Operand Addressing

Context Allocation

Parameter Passing

Abstraction Support

Domains and Refinements

Creation of Typed Objects

Programmer-Defined Types

Storage Resources

Instructions

Discussion

For Further Reading


10 Issues in Capability-Based Architectures

Introduction

Segmentation

Storage of Capabilities

Capability Representation

Objects

Protected Procedures and Type Extension

Object Lifetimes and Garbage Collection

Object Locking

Revocation

Conclusions

Capability and Object System Bibliography

Index