Home
Back
Arrival Time Definition:
| From: | To: |
Arrival Time in CPU scheduling refers to the time when a process arrives in the ready queue and becomes available for execution by the CPU. It is a fundamental parameter used by scheduling algorithms to determine the order in which processes should be executed.
The arrival time is typically given as input in scheduling problems:
Where:
Explanation: In most CPU scheduling scenarios, arrival time is provided as part of the process specification and doesn't require complex calculation. It represents the moment when a process enters the system and is ready to compete for CPU time.
Details: Arrival time is crucial for non-preemptive and preemptive scheduling algorithms. It affects waiting time, turnaround time, and overall system performance. Scheduling algorithms like FCFS (First-Come-First-Served) and SJF (Shortest Job First) rely heavily on arrival times.
Tips: Enter the arrival time and process arrival values in time units. The calculator will confirm the arrival time value. All values must be non-negative numbers representing time units.
Q1: What is the difference between arrival time and burst time?
A: Arrival time is when a process arrives in the ready queue, while burst time is the amount of CPU time required by the process to complete its execution.
Q2: Can arrival time be zero?
A: Yes, arrival time can be zero, indicating that the process is available from the beginning of the scheduling period.
Q3: How does arrival time affect scheduling algorithms?
A: Algorithms like FCFS schedule processes based on arrival time order, while others like Round Robin use it to determine when a process becomes eligible for execution.
Q4: What if multiple processes have the same arrival time?
A: When multiple processes arrive simultaneously, the scheduler uses tie-breaking rules (often process ID or random selection) to determine execution order.
Q5: Is arrival time always known in advance?
A: In theoretical problems, arrival times are typically given. In real systems, arrival times are recorded as processes enter the system and may not be predictable in advance.