116 lines
4.2 KiB
Python
116 lines
4.2 KiB
Python
#!/usr/bin/env python3
|
|
"""
|
|
先来先服务调度算法 (FCFS)
|
|
First Come First Served
|
|
支持 IO 模拟
|
|
"""
|
|
|
|
from typing import List, Dict, Tuple
|
|
from collections import deque
|
|
import heapq
|
|
|
|
from base import (
|
|
Process,
|
|
ProcessScheduler,
|
|
generate_random_processes,
|
|
print_processes
|
|
)
|
|
|
|
|
|
class FCFSScheduler(ProcessScheduler):
|
|
"""先来先服务调度 (First Come First Served)
|
|
|
|
支持 IO 模拟:
|
|
- 进程执行一个 CPU burst 后进入 IO 等待
|
|
- IO 等待期间 CPU 可以调度其他就绪进程
|
|
- IO 完成时进程回到就绪队列
|
|
"""
|
|
|
|
def schedule(self) -> Dict:
|
|
"""FCFS 调度算法 (支持IO模拟)"""
|
|
all_processes = list(self.processes)
|
|
for p in all_processes:
|
|
self.init_process(p, p.arrival_time)
|
|
|
|
# 事件队列: (时间, 事件类型, 唯一ID, 进程)
|
|
events = []
|
|
for p in all_processes:
|
|
heapq.heappush(events, (p.arrival_time, 'arrival', id(p), p))
|
|
|
|
ready_queue = deque() # 就绪队列 (按到达顺序)
|
|
completed = []
|
|
|
|
current_time = 0
|
|
last_processed_time = 0
|
|
|
|
while len(completed) < len(all_processes):
|
|
# 1. 处理所有当前时刻的事件
|
|
while events and events[0][0] <= current_time:
|
|
event_time, event_type, uid, p = heapq.heappop(events)
|
|
|
|
if event_type == 'arrival':
|
|
p.status = self.STATUS_READY
|
|
ready_queue.append(p)
|
|
elif event_type == 'io_complete':
|
|
if p.status == self.STATUS_IO_WAIT:
|
|
p.status = self.STATUS_READY
|
|
ready_queue.append(p)
|
|
|
|
# 2. 如果就绪队列为空，推进时间到下一个事件
|
|
if not ready_queue:
|
|
if events:
|
|
current_time = events[0][0]
|
|
continue
|
|
else:
|
|
break
|
|
|
|
# 3. FCFS: 选择队首进程
|
|
current_process = ready_queue.popleft()
|
|
|
|
if current_process.start_time == -1:
|
|
current_process.start_time = current_time
|
|
|
|
current_process.status = self.STATUS_RUNNING
|
|
|
|
# 4. 执行 CPU burst
|
|
if current_process.current_cpu_idx < len(current_process.cpu_bursts):
|
|
cpu_burst = current_process.cpu_bursts[current_process.current_cpu_idx]
|
|
|
|
self.gantt_chart.append((current_time, current_process.pid, 'CPU', cpu_burst))
|
|
|
|
current_time += cpu_burst
|
|
current_process.remaining_cpu_time -= cpu_burst
|
|
current_process.current_cpu_idx += 1
|
|
|
|
# 5. 检查是否有 IO burst
|
|
io_idx = current_process.current_cpu_idx - 1
|
|
if io_idx < len(current_process.io_bursts):
|
|
# 进入 IO 等待，添加 IO 完成事件
|
|
io_time = current_process.io_bursts[io_idx]
|
|
current_process.status = self.STATUS_IO_WAIT
|
|
io_complete_time = current_time + io_time
|
|
heapq.heappush(events, (io_complete_time, 'io_complete', id(current_process), current_process))
|
|
else:
|
|
# 进程完成
|
|
current_process.status = self.STATUS_TERMINATED
|
|
current_process.completion_time = current_time
|
|
self.calculate_metrics(current_process, current_time)
|
|
completed.append(current_process)
|
|
else:
|
|
# 进程完成
|
|
current_process.status = self.STATUS_TERMINATED
|
|
current_process.completion_time = current_time
|
|
self.calculate_metrics(current_process, current_time)
|
|
completed.append(current_process)
|
|
|
|
self.results = completed
|
|
return self.print_results("FCFS (先来先服务)")
|
|
|
|
|
|
if __name__ == "__main__":
|
|
processes = generate_random_processes(n=5, seed=42, io_probability=0.5, io_first_prob=0.3)
|
|
print_processes(processes, "测试数据")
|
|
|
|
scheduler = FCFSScheduler(processes)
|
|
scheduler.schedule()
|