Video summary

L-1.5: Process States in Operating System| Schedulers(Long term,Short term,Medium term)

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Educational

Summary of Video: L-1.5: Process States in Operating System | Schedulers (Long term, Short term, Medium term)

Main Ideas and Concepts:

  • Process States and Life Cycle:

    The video discusses the various states that a process goes through from creation to termination, referred to as the process life cycle. The states include New, Ready, Running, Terminated, and Waiting/Blocked.

  • Primary States:
    • New State: The process is created and stored in secondary memory, not yet executed.
    • Ready State: The process is loaded into RAM and is ready to be executed.
    • Running State: The process is currently being executed by the CPU.
    • Terminated State: The process has completed execution and resources are deallocated.
    • Waiting/Blocked State: The process cannot continue until a specific event occurs (e.g., completion of an I/O operation).
  • Schedulers:
    • Long Term Scheduler: Responsible for bringing processes into the ready state, promoting multi-programming.
    • Short Term Scheduler: Responsible for selecting processes from the ready queue to execute on the CPU. It can operate in pre-emptive (interrupts current process) or non-pre-emptive (lets current process finish) modes.
    • Medium Term Scheduler: Manages processes that need to be temporarily suspended and moved to secondary memory to free up RAM.
  • I/O Requests:

    When a process requires I/O, it goes into the waiting state. Once the I/O operation completes, it returns to the ready state.

  • Additional States:
    • Suspend Wait/Block State: When the waiting queue is full, processes may be suspended and moved to secondary memory.
    • Suspend Ready State: Similar to the suspend wait state but applies to processes in the ready queue when it is full.
  • Examples of Scheduling:

    The video uses analogies and examples, such as supermarket billing, to explain how processes are managed based on priority and time quantum.

  • Practical Application:

    The video highlights how to view processes in operating systems like Windows (using Task Manager) and UNIX/Linux (using the ps command).

Key Instructions/Methodology:

  • Understand the definitions and functions of each process state.
  • Familiarize yourself with the roles of long-term, short-term, and medium-term Schedulers.
  • Recognize the difference between pre-emptive and non-pre-emptive scheduling.
  • Learn how I/O requests affect Process States and the overall scheduling mechanism.

Speakers/Sources Featured:

The video is presented by Gate Smashers.

Original video