Chapter 4: Security Architecture and Design - Operating System Components Part 1

A process is a program that is in memory that can be executed. When more than one process is interleavedly executed at one time, it is referred to as multiprogramming. Similarly, when more than one process is simultaneously executed, it is referred to as multitasking. There are three states a specific process can be in within a computer system: ready, running, and blocked. Ready means that the process is waiting on input, running means that it is currently being executed by the CPU, and blacked means that there is one or more impediments that are keeping the process from running. Interrupts within an operating system are important because they make running process more efficient by using a method known as time slicing. To carry out activities within the OS, threads are created by processes. One the activity is complete, the thread is destroyed. Sometimes, a software deadlock occurs. This is consequence of two process waiting on computer resources simultaneously.