批处理系统的作业调度 高响应比优先算法

#include "jobRun.h" //作业处理 void JobRun::run(jcbStruct (&jobTable)[10],int & jobCount) { double priority[MaxJobNumber]; //存储作业优先权 for (int i = 0; i < MaxJobNumber;i++) { priority[i] = 0.0; } while(jobCount > 0) { int pJCB = 0; //第一个JCB所在数组位置标示 for (int n = 0; n < MaxJobNumber ;n++) { if(jobTable[n].runTime > 0) //求出第一个PCB的位置 { pJCB = n; break; } } //求所有JCB的优先权 for (int temp = 0; temp < jobCount; temp++) { if(pJCB <= -1) break; //超出末尾 //求优先权,注意waitTime已经预先全部加1，后继程序注意处理 if(jobTable[pJCB].runTime > 0) //防止0错 priority[pJCB] = 1.0 + (jobTable[pJCB].waitTime++)/jobTable[pJCB].runTime; pJCB = jobTable[pJCB].next; //下一个JCB位置 } //比较，得出最大的优先权 double tempPriority = 0.0; //存储找到最大优先权 int priJCB = 0; //存储优先权最大的位置 for (int m = 0; m < MaxJobNumber; m ++) { if (priority[m] > tempPriority) { tempPriority = priority[m]; //找到最大优先权 priJCB = m; } } //处理最大优先权的job jobTable[priJCB].waitTime --; //返回预处理减去的时间 jobTable[priJCB].runTime --; //要求服务时间减少1 //特殊情况，job处理完成 if (jobTable[priJCB].runTime == 0) { //前一位置的JCB的next指针重新定位 for (int l = 0; l < priJCB; l++) { if (jobTable[l].next == priJCB) { jobTable[l].next = jobTable[priJCB].next; break; } } jobTable[priJCB].next = -32767; //清空该JCB jobTable[priJCB].waitTime = 0; priority[priJCB] = 0.0; cout<<"线程 "<<jobTable[priJCB].name<<" 处理完毕 !"<<endl; jobCount --; } } };