CPU Scheduling:- CPU scheduling is a process which allows one process to use the CPU while the execution of another process is on hold. That means in waiting for the state due to unavailability of any resource like I/O etc., thereby maximizing utilization of CPU. The job of the CPU Scheduler (the short-term scheduler) to… Continue reading CPU Scheduling
What is the difference between process and program? The difference between process and program is Programming is a process of taking an algorithm and encoding into notation but Process is the running program of the system. a program is a group of instructions to carry out a specified task whereas the process is a program in execution. Both are the same beast… Continue reading What is the difference between process and program?
Cooperating Processes The concurrent processes executing in the operating system may be either independent processes or cooperating processes. A process is independent if it cannot affect or be affected by the other processes executing in the system. Clearly, any process that does not share any data (temporary or persistent) with any other process is independent.… Continue reading Cooperating Processes
Process Creation Parent process creates child processes, which, in turn create other processes, forming a tree of processes. It is called process creation. Resource sharing: ✦ Parent and child share all resources. ✦ Children share the subset of parent’s resources. ✦ Parent and child share no resources. Execution: ✦In the Operating System, the Parent process… Continue reading What is process Creation and process Termination ?
Schedulers A schedule is a decision maker that selects the processes from one scheduling queue to another or allocates CPU for execution. The Operating System has three types of scheduler: Long-term scheduler or Job scheduler Short-term scheduler or CPU scheduler Medium-term scheduler Long-term scheduler or Job scheduler The long-term scheduler or job scheduler selects… Continue reading What is Scheduler ?
Process Scheduling Queues:- Process scheduling is an essential part of a Multiprogramming operating systems. It contains various operation such as:- Job Queue: It contains the process entered into the system for execution. This queue consists of all processes in the system; those processes are entered into the system as a new process Ready Queue: Ready… Continue reading What is Process Scheduling Queues in Operating System?
Process Control Block (PCB) In the operating system, Process Control Block contains the information about the process which manages the scheduling of a particular process. Process state Program counter CPU registers CPU scheduling information Memory-management information Accounting information I/O status information Process state: The state may be new, ready, running, waiting, halted, and SO on.… Continue reading What is Process Control Block (PCB) in Operating System ?
Hardware Protection Dual-Mode Operation I/O Protection Memory Protection CPU Protection Dual-Mode Operation Sharing system resources require the operating system to ensure that an incorrect program cannot cause other programs to execute incorrectly. Provide hardware support to differentiate between at least two modes of operations. User mode – execution is done on behalf of a user.… Continue reading Hardware Protection
Process Concept:- The process is the running program of the system. Linux and Windows both are the multi-processes operating system. The program doesn’t allocate memory but process allocate memory. Every process allocates 4GB virtual memory. The process is two types: –1)parent process 2) the Child process. The process which is created another process is called… Continue reading What is process in Operating System ?
Operating System Services Following are the five services provided by operating systems to the convenience of the users. Program Execution The purpose of computer systems is to allow the user to execute programs. So the operating system provides an environment where the user can conveniently run programs. Running a program involves the allocating and deallocating… Continue reading What are the services provided by the Operating-System…?
System Call: System calls provide an interface between the processor and the operating system. System calls allow user-level processes to request some services from the operating system which process itself is not allowed to do. For example, for I/O a process involves a system call telling the operating system to read or write a particular… Continue reading what is System call ?
Evolution of OS: 1.Mainframe Systems Reduce setup time by batching similar jobs Automatic job sequencing – automatically transfers control from one job to another. First rudimentary operating system. Resident monitor initial control in monitor control transfers to the job when the job completes control transfers to monitor Batch Processing Operating System: This type of OS… Continue reading Evaluation Of Operating System
Functions of Operating System: The functions of the operating system are given below:- Process Management A process is a program in execution. A process needs certain resources, including CPU time, memory, files, and I/O devices, to accomplish its task. The operating system is responsible for the following activities in connection with process management. ✦… Continue reading What are the functions of operating system…?
What is an Operating System? An Operating system is a program that acts as an intermediate between a user of a computer and the computer hardware. An Operating System performs all the basic tasks like managing file, process, and memory. Operating System is a collection of system programs that together control the operations of a computer system.… Continue reading What is an Operating System ?