132 lines
4.7 KiB
Python
132 lines
4.7 KiB
Python
#!/usr/bin/env python3
|
|
"""
|
|
时间片轮转调度算法 (RR)
|
|
支持 IO 模拟
|
|
"""
|
|
|
|
from typing import List, Dict
|
|
from collections import deque
|
|
import heapq
|
|
|
|
from base import (
|
|
Process,
|
|
ProcessScheduler,
|
|
generate_random_processes,
|
|
print_processes
|
|
)
|
|
|
|
|
|
class RoundRobinScheduler(ProcessScheduler):
|
|
"""时间片轮转调度"""
|
|
|
|
def __init__(self, processes: List[Process], time_slice: int = 4):
|
|
super().__init__(processes)
|
|
self.time_slice = time_slice
|
|
|
|
def schedule(self) -> Dict:
|
|
"""RR 调度算法 (支持IO模拟)"""
|
|
all_processes = list(self.processes)
|
|
n = len(all_processes)
|
|
|
|
for p in all_processes:
|
|
self.init_process(p, p.arrival_time)
|
|
|
|
events = []
|
|
for p in all_processes:
|
|
heapq.heappush(events, (p.arrival_time, 'arrival', id(p), p))
|
|
|
|
ready_queue = deque()
|
|
completed = []
|
|
io_waiting = {} # {pid: IO完成时间}
|
|
process_map = {p.pid: p for p in all_processes} # pid -> Process 映射
|
|
|
|
current_time = 0
|
|
max_iterations = 10000
|
|
iterations = 0
|
|
|
|
while len(completed) < n and iterations < max_iterations:
|
|
iterations += 1
|
|
|
|
# 1. 处理到达事件
|
|
while events and events[0][0] <= current_time:
|
|
_, etype, _, p = heapq.heappop(events)
|
|
if etype == 'arrival':
|
|
p.status = self.STATUS_READY
|
|
ready_queue.append(p)
|
|
elif etype == 'io_complete':
|
|
io_waiting.pop(p.pid, None)
|
|
p.status = self.STATUS_READY
|
|
ready_queue.append(p)
|
|
|
|
# 2. 检查 IO 完成 (兜底，防止事件队列遗漏)
|
|
completed_io = []
|
|
for pid, io_end_time in list(io_waiting.items()):
|
|
if io_end_time <= current_time:
|
|
completed_io.append(pid)
|
|
for pid in completed_io:
|
|
io_waiting.pop(pid, None)
|
|
proc = process_map[pid]
|
|
proc.status = self.STATUS_READY
|
|
ready_queue.append(proc)
|
|
|
|
if not ready_queue:
|
|
# 队列为空，推进时间
|
|
next_events = [e[0] for e in events if e[0] > current_time]
|
|
next_io = [t for t in io_waiting.values() if t > current_time]
|
|
next_times = next_events + next_io
|
|
if next_times:
|
|
current_time = min(next_times)
|
|
continue
|
|
|
|
# 3. 取进程执行
|
|
p = ready_queue.popleft()
|
|
|
|
if p.start_time == -1:
|
|
p.start_time = current_time
|
|
p.status = self.STATUS_RUNNING
|
|
|
|
if p.current_cpu_idx < len(p.cpu_bursts):
|
|
cpu_burst = p.cpu_bursts[p.current_cpu_idx]
|
|
exec_t = min(self.time_slice, cpu_burst)
|
|
|
|
self.gantt_chart.append((current_time, p.pid, 'CPU', exec_t))
|
|
|
|
current_time += exec_t
|
|
p.remaining_cpu_time -= exec_t
|
|
|
|
if exec_t >= cpu_burst:
|
|
# CPU burst 完成
|
|
p.current_cpu_idx += 1
|
|
io_idx = p.current_cpu_idx - 1
|
|
if io_idx < len(p.io_bursts):
|
|
io_t = p.io_bursts[io_idx]
|
|
p.status = self.STATUS_IO_WAIT
|
|
io_waiting[p.pid] = current_time + io_t
|
|
heapq.heappush(events, (current_time + io_t, 'io_complete', id(p), p))
|
|
else:
|
|
p.status = self.STATUS_TERMINATED
|
|
p.completion_time = current_time
|
|
self.calculate_metrics(p, current_time)
|
|
completed.append(p)
|
|
else:
|
|
# 时间片用完，更新剩余 burst
|
|
p.cpu_bursts[p.current_cpu_idx] = cpu_burst - exec_t
|
|
p.status = self.STATUS_READY
|
|
ready_queue.append(p)
|
|
else:
|
|
p.status = self.STATUS_TERMINATED
|
|
p.completion_time = current_time
|
|
self.calculate_metrics(p, current_time)
|
|
completed.append(p)
|
|
|
|
self.results = completed
|
|
return self.print_results(f"RR (时间片轮转, q={self.time_slice})")
|
|
|
|
|
|
if __name__ == "__main__":
|
|
processes = generate_random_processes(n=5, seed=42, io_probability=0.5)
|
|
print_processes(processes, "测试数据")
|
|
|
|
scheduler = RoundRobinScheduler(processes, time_slice=4)
|
|
scheduler.schedule()
|