minnesotagaq.blogg.se - Multi processing operating system examples

For example in a word processor, a background thread may check spelling and grammar while a foreground thread processes user input ( keystrokes ), while yet a third thread loads images from the hard drive, and a fourth does periodic automatic backups of the file being edited.

This is particularly true when one of the tasks may block, and it is desired to allow the other tasks to proceed without blocking.Threads are very useful in modern programming whenever a process has multiple tasks to perform independently of the others.As shown in Figure 4.1, multi-threaded applications have multiple threads within a single process, each having their own program counter, stack and set of registers, but sharing common code, data, and certain structures such as open files.įigure 4.1 - Single-threaded and multithreaded processes 4.1.1 Motivation.Traditional ( heavyweight ) processes have a single thread of control - There is one program counter, and one sequence of instructions that can be carried out at any given time.

A thread is a basic unit of CPU utilization, consisting of a program counter, a stack, and a set of registers, ( and a thread ID.Abraham Silberschatz, Greg Gagne, and Peter Baer Galvin, "Operating System Concepts, Ninth Edition ", Chapter 4.