evals for 6/6

Aaras P VASA (avasa@cs.ucsd.edu)
Tue, 6 Jun 2000 10:04:44 -0700 (PDT)

hello sir
final evals

Extensibilty, safety and performance in SPiN

Spin allows apllication to change interface and implementation dynamically
to meet its performance and functional requirements

SPIN and its extensions are written in Modula-3. it uses
language and link-time mechanisms to export interfaces
protection is achieved with capabilities which are implemented
using pointers
extensions are definede in terms of events and handlers

i rhink this was a great idea of customising the operating system
according to application needs . the size of the kernel seems an
obvious concern since the extensions are added to the kernel
but results show this is not a big problem

Exokernel: An operating system architecture for application-level
resource mangement

It provides application-level management of physical resources

the minimal kernel(exokernel) exports hardware resources securely
using secure binding , abort protocol and visiblr resorce revocation
secure binding helps in decoupling management and protection
the Library operating system above the exokernel implements higher
level abstraction.

the results helped in proving that exokernels can be made eficient ,
application-level implentation does work
this really helps in reducing the size of the kernel and reducing
the context-switches required
i think the protection provided thru secure binding is better than
the one provided by SPIN which is at the language level