ENVS 1800 Lecture Notes - Lecture 5: Process Control Block
14 May 2018
School
Department
Course
Professor
ENVS 1800 Lecture 5 Notes – Integrity of the Process
Introduction
• When a process is admitted to the system, the operating system is responsible for every
aspect of its operation.
• The operating system must allocate initial memory for it and must continue to assure
that memory is available to the process as it is needed.
• It must assign the necessary files and I/O devices and provide stack memory and buffers.
• It must schedule CPU execution time for the process and perform context switching
between the various executing processes.
• The operating system must maintain the integrity of the process.
• Finally, when the process is completed, it terminates the process in an orderly way and
restores the system facilities and resources to make them available to other processes.
• Processes that do not need to interact with any other processes are known as
independent processes.
• In modern systems, many processes will work together.
• They will share information and files.
• A large task will often be modularized by splitting it into subtasks, so that each process
will only handle one aspect of the task.
• Processes that work together are known as cooperating processes.
• The operating system provides mechanisms for synchronizing and communicating
between processes that are related in some way.
• If one process needs the result from another
• For example, it must know when the result is available so that it can proceed.
• This is known as synchronization.
• It must also be able to receive the result from the other process.
• This is communication.
• The operating system acts as the manager and conduit for these inter process events.
find more resources at oneclass.com
find more resources at oneclass.com
