.
Program Execution
Web Services
Access to I/O devices
Controlled Access to files
It is also called the Nucleus
It is part of the operating system in main memory
It includes system utilities
It contains the most frequently-used functions
Allowing more than one program to be executed at the same time
Designing and developing more than one program at the same time
Debugging more than one program at the same time
Managing more than one PC at the same time
Memory protection
Larger Disks
Better compilers
More precise timers
A program in execution
An instance of a program running on a computer
The execution of the scheduler or other parts of the operating system
A unit of activity characterized by a single sequential thread of execution, a current state, and an associated set of system resources
Synchronization between processes
Automatic allocation and management of memory
Protection and access control
Process isolation
To extend the amount of physical memory that is being used
To improve the performance of the disk
To run programs which are much larger than the size of the physical memory on the machine
To allow machines to communicate over the network
Allow only the parts of the program that are needed at that time to be in main memory
Increase the efficiency of main memory
Increase multiprogramming
Increase the speed of program execution
Manage the physical memory of the machine
Manage the translation between vertical and physical addresses
Manage the interface between main memory and the disk
Manage the interface between the processor and main memory
Address space management
Interprocess Communication
File System Services
Basic scheduling
A dispatch-able unit of work
A process that has finished execution
A process with interrupts disabled
A fast I/O device
Accesses I/O devices directly
Controls the L2 cache
Allows many threads to be executed in its address space
Can modify the system scheduler
A separate copy of the OS must be run on a machine with only a one processor
A separate copy of the OS must be run on a machine with symmetric processors
Different parts of the OS are distributed to several applications running on the same machine
Different parts of the OS are distributed to several machines and are run at the same time
Windows NT/2000/XP
VxWorks
Unix
Solaris
Window NT/2000/XP
VxWorks
Unix
Nucleus