Code Optimisation

A virtual machine is:

• a hardware emulation of another system

• a software emulation of another system or program

• a method of backing up data

Virtualisation software provides:

• a bridge between the host computer’s hardware and the emulated software

• a bridge between the guest computer’s hardware and software

• a bridge between the host computer’s operating system and the emulated software

A system virtual machine emulates:

• single program

• the hardware and software of a guest system

• the operating system of a guest system

A process virtual machine:

• emulates a single program

• tells the operating system which processes to handle next

• emulates the operating system of a guest system

The Java Virtual Machine translates:

• source code into object code

• source code into byte code

• byte code into machine code

The simulated computer system is referred to as the:

• Guest

• Host

• Client

• Virtualizer

One disadvantage of virtual machines is:

• They are very expensive to operate

• They require special knowledge

• They have a single point of failure (the host machine)

• They require additional hardware be installed to operate

One advantage of virtual machines is:

• You can operate multiple VMs from one host

• They are automatically configured to work on your network

• They can access files on the host

• They can run even when the host computer is turned off

The physical machine you are using is called the:

• Host

• Guest

• Environment

• Director

A __________ is an instance of a program running on a computer

• process

• process switch

• thread

• thread switch