操作系统模拟实验(进程调度FCFS)

简陋的FCFS实现

# -*- coding: utf-8 -*-
class Pcb(object):
    def __init__(self):
        self.pid = None
        self.ppid = None # id of parent
        self.arrive_time = 0
        self.need_time = 0
        self.pprio = 0 #priority

    def set_pid(self, pid):
        self.pid = pid
    def set_parent(self, parent):
        self.ppid = parent
    def set_arrive_time(self, arrive_time):
        self.arrive_time = arrive_time
    def set_need_time(self, need_time):
        self.need_time = need_time

class Pnode(object):
    def __init__(self):
        self.node = Pcb()
        self.child = []

    def set_node_pid(self, pid):
        self.node.set_pid(pid)
    def set_node_parent(self, ppid):
        self.node.set_parent(ppid)
    def set_node_arrtime(self, arrtime):
        self.node.set_arrive_time(arrtime)
    def set_node_needtime(self, needtime):
        self.node.set_need_time(needtime)
    def get_node_pid(self):
        return self.node.pid
    def get_node_parent(self):
        return self.node.ppid
    def get_node_arrtime(self):
        return self.node.arrive_time
    def get_node_needtime(self):
        return self.node.need_time

class WaitList(object):
    def __init__(self):
        self.waitlist = {}
        self.starttime = 0
    def addtolist(self, pid, arrtime, needtime):
        l = self.waitlist
        if pid in l:
            print "process already exists"
        else:
            l[arrtime] = Pnode()
            l[arrtime].set_node_pid(pid)
            l[arrtime].set_node_arrtime(arrtime)
            l[arrtime].set_node_needtime(needtime)

    def show(self):
        l = self.waitlist
        print "pid \t\t arrive time \t\t start time"
        for p in l:
            if (p > self.starttime):
                self.starttime += p-self.starttime
            print l[p].get_node_pid(),":\t\t",l[p].get_node_arrtime(),"\t\t",self.starttime
            self.starttime += l[p].get_node_needtime()

def main():
    waitlist = WaitList()
    print "please input process number"
    n = input()
    for i in xrange(n):
        pid,arrtime,needtime = map(int,raw_input("please input process id,arrive time,need time").split())
        waitlist.addtolist(pid, arrtime, needtime)
    waitlist.show()

if __name__ == "__main__":
    main()