In this chapter, the following content will be discussed: Process concept, process scheduling, operations on processes, interprocess communication, examples of ipc systems, communication in client-server systems. | Chapter 3: Processes Chapter 3: Processes Process Concept Process Scheduling Operations on Processes Interprocess Communication Examples of IPC Systems Communication in Client-Server Systems Objectives To introduce the notion( of a process -- a program in execution, which forms the basis of all computation To describe the various features of processes, including scheduling, creation and termination, and communication To explore interprocess communication using shared memory and message passing To describe(miêu tả) communication in client-server systems Process Concept An operating system executes a variety of programs: Batch(lô) system – jobs Time-shared systems – user programs or tasks Textbook uses the terms job and process almost interchangeably Process – a program in execution; process execution must progress in sequential fashion Multiple parts The program code, also called text section Current activity including program counter, processor registers Stack . | Chapter 3: Processes Chapter 3: Processes Process Concept Process Scheduling Operations on Processes Interprocess Communication Examples of IPC Systems Communication in Client-Server Systems Objectives To introduce the notion( of a process -- a program in execution, which forms the basis of all computation To describe the various features of processes, including scheduling, creation and termination, and communication To explore interprocess communication using shared memory and message passing To describe(miêu tả) communication in client-server systems Process Concept An operating system executes a variety of programs: Batch(lô) system – jobs Time-shared systems – user programs or tasks Textbook uses the terms job and process almost interchangeably Process – a program in execution; process execution must progress in sequential fashion Multiple parts The program code, also called text section Current activity including program counter, processor registers Stack containing temporary data Function parameters, return addresses, local variables Data section containing global variables Heap containing memory dynamically allocated during run time Process Concept (Cont.) Program is passive entity stored on disk (executable file), process is active Program becomes process when executable file loaded into memory Execution of program started via GUI mouse clicks, command line entry of its name, etc One program can be several processes Consider(xét,chú ý) multiple users executing the same program Process in Memory Process State As a process executes, it changes state new: The process is being created running: Instructions are being executed waiting: The process is waiting for some event to occur ready: The process is waiting to be assigned(gán g/trị) to a processor terminated: The process has finished execution Diagram of Process State Process Control Block (PCB) Information associated with each process (also called task control block) .
