Shortest job first as a type of CPU scheduling . It's advantages and in disadvantages. Anwers should be in English please

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Shortest Job First (SJF) is a CPU scheduling algorithm that associates with each process the length of its next CPU burst. The CPU is allocated to the process with the smallest next CPU burst. If two processes have the same length, FCFS (First-Come, First-Served) scheduling is used to break the tie. SJF can be preemptive (Shortest Remaining Time First) or non-preemptive.

Here are its advantages and disadvantages:

Advantages:

  1. Optimal Average Waiting Time: SJF gives the minimum average waiting time for a given set of processes. This means processes spend less time waiting in the ready queue.
  2. Optimal Average Turnaround Time: It also results in the minimum average turnaround time, which is the total time from submission to completion.
  3. Increased Throughput: By prioritizing shorter jobs, the system can complete more jobs in a given time frame, leading to higher throughput.

Disadvantages:

  1. Starvation: Longer jobs might never get executed if there's a continuous stream of shorter jobs arriving. This is a significant problem, especially in systems with many short tasks.
  2. Difficulty in Predicting Burst Time: The main challenge is knowing the length of the next CPU burst in advance. It's impossible to predict accurately, so SJF often relies on estimations (e.g., exponential averaging of past burst times).
  3. Overhead: Estimating burst times adds overhead to the system.
  4. Not Implementable in Pure Form: Because predicting future CPU burst times is not truly possible, the pure SJF algorithm cannot be implemented in a real-time system. It's often approximated.
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