操作系统先来先服务python讲稿.docx

操作系统大作业用python语言编写程序，计算每个进程分别在先来先服务，短进程优先，长进程优先下的平均周转时间，带权周转时间。其中增加了高响应比优先和优先级调度算法。123456789101112131415161718192021222324252627282930#coding=utf-8 import __main__import stringdeffcfs(come_time,run_b_t,run_e_t,run_t,order):#先来先服务 time_temp=come_time[0]for i in range(n): run_b_t[i]=time_temp run_e_t[i]=run_b_t[i]+run_t[i] time_temp=run_e_t[i] n_schedul=i order[n_schedul]=i+1return come_time,run_b_t,run_e_t,run_t,orderdefps(come_time,run_b_t,run_e_t,run_t,order,_prio,run_f):#优先级调度 i=0 max_priority=_prio[i] j=1while jn and come_time[i]==come_time[j]:if _prio[j]_prio[i]: max_priority=_prio[j] i=j j+=1#查找第一个被调度的进程对第一个被调度的进程求相应的参数 n_schedul=i run_b_t[n_schedul]=come_time[n_schedul] run_e_t[n_schedul]=run_b_t[n_schedul]+run_t[n_schedul] run_f[n_schedul]=1 temp_time=run_e_t[n_schedul] order[n_schedul]=1 temp_n=1while temp_nn: max_priority=0for j in range(n):if come_time[j]=temp_time and run_f[j]==0:if _prio[j]max_priority: max_priority=_prio[j] n_schedul=j #查找下一个被调度的进程#对找到的下一个被调度的进程求相应的参数 run_b_t[n_schedul]=temp_time run_e_t[n_schedul]=run_b_t[n_schedul]+run_t[n_schedul] run_f[n_schedul]=1 temp_time=run_e_t[n_schedul] temp_n+=1 order[n_schedul]=temp_n defsjf(come_time,run_b_t,run_e_t,run_t,order,_prio,run_f):#短作业优先 i=0 run_time=run_t[i] j=1while jn and come_time[i]==come_time[j]:if run_t[j]run_t[i]: run_time=run_t[j] i=j j+=1#查找第一个被调度的进程#对第一个被调度的进程求相应的参数 n_schedul=i run_b_t[n_schedul]=come_time[n_schedul] run_e_t[n_schedul]=run_b_t[n_schedul]+run_t[n_schedul] run_f[n_schedul]=1 temp_time=run_e_t[n_schedul]; order[n_schedul]=1 temp_n=1while temp_nn:for j in range(n):if come_time[j]=temp_time and run_f[j]==0: run_time=run_t[j] n_schedul=jbreakfor j in range(n):if come_time[j]=temp_time