Schedulers

A Practical Intro to Operating Systems Internals Understanding what an operating system does inside a computer helps you write better software and design reliable systems. An OS creates a friendly space for your programs to run, protects each program from others, and manages resources like CPU time, memory, and I/O devices. It coordinates many tiny steps behind the scenes so apps feel fast and safe. A modern OS runs in two kinds of code: user mode and kernel mode. User programs run in user mode, while the kernel runs in a privileged mode. When a program needs a service, it performs a system call, the kernel checks permissions, performs the task, and returns control. This boundary keeps faults from crashing the whole system. ...

Inside Operating Systems: Processes, Schedulers, and Security An operating system (OS) coordinates the work of a computer. It acts as a bridge between programs and hardware. Three ideas show how it does this: processes, schedulers, and security. Together they keep tasks running smoothly while protecting data. Processes A process is a running program with its own memory, files, and resources. The OS creates a process, keeps track of its state (ready, running, waiting), and cleans up when it ends. Each process has a set of resources, like a memory space and a list of open files. This separation helps a browser, a text editor, and a game run without stepping on each other. ...