Operating Systems Research Paper Example | Topics and Well Written Essays - 1500 words

Operating Systems - Research Paper Example Programs are set of instruction stored on a disc. Programs are passive entities while process is active (Dhamdhare, 2006, p. 84). A single program may have different executions. Each execution is termed as a separate process (Tanenbaum, 2009, p. 84). E.g. MS Word is a program. When we open several files in Word, each file would form a separate process. In this case, the text section would be common, but each process would have its own program counter, data, stack and heap. When a process executes, it changes its state. A state depicts the current activity of the process (Halder & Aravind, 2010, p. 96; Silberschatz et. al, 2005). There are five states a process can be in: In a multiprogramming environment, in order to maximize CPU utilization, the CPU is never allowed to stay idle (Sharma et al., 2010, p. 123). It is made to run some process or the other at all times. Time sharing means that the switching of processes from CPU at such a speed that the user can interact with any of them at any time without having to wait. Operating system has a process scheduler that selects a process to run by CPU from the available processes. In a single processor system, only process will be running at a time. In case of several processes, they will have to wait till the CPU is free from running the current and only can it be rescheduled. In the last two cases, the status of processes is eventually changed from waiting to ready and so are brought back to the ready queue. These events keeping happening till the process ends. In that case, the process is removed from all of the queues. It’s PCB and the allocated resources are also de-allocated. A process passes through various queues during the course of its lifetime (Dhotre, 2008, p. 2-8; Silberschatz et. al, 2005). The operating system provides schedulers for managing the selection of processes and appropriate queues. The two basic schedulers are: Long-term