Advanced Operating Systems   COMP9242 2002/S2

UNSW

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Administration               
- Notices
- Course Intro
- Consultations
# On-line Survey (closed)
- Survey Results
 
Work
- Lectures
- Milestone 0
- Project Admin
- Project Spec
- Project FAQ
- Exam
 
Documentation
- ASysT Lab
- L4 source browser
- Sulima ISA Simulator
- R4x00 ISA Summary 
- MIPS R4700 Reference - MIPS R4000 User Manual 
- Network Driver
- GT64111
 
Related Info
- Aurema OS Prize
- OS Hall of Fame
 
History
- 2000
- 1999
- 1998
 
Staff
- Gernot Heiser (LiC)

 

Mungi Component Model

• Component implementation is in different PD from caller
  • Can use for invoking protected subsystems
• PDX is used for invocation
• Component data is created inside the component PD
• Client and component are mutually protected
• Mandatory security policy limits data propagation
• Single address space ==> no need to marshal arguments!

Extending extensions

• Components export interfaces.
• Component instances can invoke interfaces of other instances (and thus extend them): forwarding.
• Aggregation allows direct invocation of extended interface.

Customisation

• Delegation is a dynamic form of aggregation that allows an invocation of a base component to be transparently handled by another component.
• Avoids the semantic nightmares of virtual inheritance.

Overhead of mandatory access control

Benchmark	no MAC	with MAC	O/H
	ms	ms	%
OO1	187.8	187.8	0.0
Jigsaw	374	375	0.3
Andrew	672	674	0.3

Extension system performance: Microbenchmarks

Broken PostScript Picture -- sorry

Extension system performance: Macrobenchmarks

Environment	Time
Linux (RAM disk)	283 ms
Mungi (statically linked)	146 ms
Mungi (extension)	247 ms