Operating System

Scheduling in operating system is the process of selecting a process from a ready queue. And allotting CPU to this process for execution. The operating system schedules the processes in such a way that the CPU doesn't sit idle. And keeps processing some or the other process. Scheduling is an important part of an operating system. As perfect scheduling increases the … [Read more...] about Scheduling in Operating System

A process in operating system is a program that is currently in the execution phase. The operating system maintains a table that has an entry of each process in the system. This entry has information about the particular process. In this context, we will discuss the operating system's process. Along with process types, its life cycle, its states and the associated … [Read more...] about Process in Operating System

A system call is a function used by the user program to request the operating system's services. System call creates an interface that helps user programmers to communicate with the operating system to request its services. System calls are always executed in the kernel mode of the operating system. In this context, we will be discussing the system call, and how to invoke … [Read more...] about System Call in Operating System

The operating system structure illustrates the organization of modules inside it. The structure of the operating system varies from system to system. Engineers design it more carefully. So that the operating system functions properly and adopts the modification easily. We will be discussing different structures of the operating systems. We will learn how are modules … [Read more...] about Operating System Structure

Synchronization hardware is a hardware-based solution to resolve the critical section problem. In our earlier content of the critical section, we have discussed how the multiple processes sharing common resources must be synchronized to avoid inconsistent results. Well, we can synchronize the processes sharing a common variable in two ways. First is the software-based … [Read more...] about Synchronization Hardware

The fork() and exec() are the system calls that are used for controlling processes. Both are used to create a new process where the process is the program in execution. The fork() system call when invoked by any process creates a new duplicate child process of the invoking process. However, the exec() system call when invoked by any process replaces the invoking process … [Read more...] about Difference Between fork() and exec() System Call

Multiple processor scheduling or multiprocessor scheduling focuses on designing the scheduling function for the system which is consist of 'more than one processor'. With multiple processors in the system, the load sharing becomes feasible but it makes scheduling more complex. As there is no policy or rule which can be declared as the best scheduling solution to a system … [Read more...] about Multiple Processor Scheduling

There are several threading issues when we are in a multithreading environment. In this section, we will discuss the threading issues with system calls, cancellation of thread, signal handling, thread pool and thread-specific data. Along with the threading issues, we will also discuss how these issues can be deal or resolve to retain the benefit of the multithreaded … [Read more...] about Threading Issues in OS

Structure of page table simply defines, in how many ways a page table can be structured. Well, the paging is a memory management technique where a large process is divided into pages and is placed in physical memory which is also divided into frames. Frame and page size is equivalent. The operating system uses a page table to map the logical address of the page generated by CPU … [Read more...] about Structure of Page Table

Deadlock characterization describes the distinctive features that are the cause of deadlock occurrence. Deadlock is a condition in the multiprogramming environment where the executing processes get stuck in the middle of execution waiting for the resources that have been held by the other waiting processes thereby preventing the execution of the processes. In this content, … [Read more...] about Deadlock Characterization