用python编程实现进程调度算法中的:短进程优先调度算法
时间: 2023-10-22 08:11:32 浏览: 127
下面是一个简单的Python实现短进程优先调度算法的示例代码:
```python
# 定义进程类
class Process:
def __init__(self, pid, arrival_time, burst_time):
self.pid = pid # 进程ID
self.arrival_time = arrival_time # 到达时间
self.burst_time = burst_time # 执行时间
def __str__(self):
return f'进程{self.pid}:到达时间={self.arrival_time},执行时间={self.burst_time}'
# 短进程优先调度算法
def sjf(processes):
current_time = 0 # 当前时间
waiting_time = 0 # 总等待时间
n = len(processes)
queue = [] # 任务队列
while True:
for i in range(n):
# 将到达时间小于等于当前时间的进程加入队列
if processes[i].arrival_time <= current_time and processes[i] not in queue:
queue.append(processes[i])
if len(queue) == 0:
break
# 按照执行时间排序,选择执行时间最短的进程
queue.sort(key=lambda x: x.burst_time)
process = queue.pop(0)
waiting_time += current_time - process.arrival_time
current_time += process.burst_time
return waiting_time / n
# 测试
if __name__ == '__main__':
processes = [
Process(1, 0, 5),
Process(2, 2, 3),
Process(3, 4, 1),
Process(4, 5, 4),
Process(5, 6, 2),
]
avg_waiting_time = sjf(processes)
print(f'平均等待时间:{avg_waiting_time:.2f}')
```
以上代码实现了一个简单的短进程优先调度算法,并通过一组测试数据进行了测试。
阅读全文