操作系統(tǒng)銀行家算法

洛陽(yáng)理工學(xué)院實(shí)驗(yàn)報(bào)告學(xué)院計(jì)信學(xué)院班級(jí)學(xué)號(hào)姓名課程名稱操作系統(tǒng)實(shí)驗(yàn)日期10.17實(shí)驗(yàn)名稱實(shí)驗(yàn)二銀行家算法成績(jī)實(shí)驗(yàn)?zāi)康模豪斫膺M(jìn)程產(chǎn)生死鎖的因素，理解為什么要進(jìn)行死鎖的避免。掌握銀行家算法的數(shù)據(jù)構(gòu)造，理解算法的執(zhí)行過(guò)程，加深對(duì)銀行家算法的理解。實(shí)驗(yàn)原理：n個(gè)并發(fā)進(jìn)程共享m個(gè)系統(tǒng)資源的系統(tǒng)，進(jìn)程可動(dòng)態(tài)申請(qǐng)資源和釋放資源。系統(tǒng)按各進(jìn)程的申請(qǐng)動(dòng)態(tài)的分派資源，先對(duì)顧客提出的請(qǐng)求進(jìn)行正當(dāng)性檢查，再進(jìn)行預(yù)分派，運(yùn)用安全性檢測(cè)算法進(jìn)行安全性檢測(cè)，如果系統(tǒng)分派資源，系統(tǒng)進(jìn)入安全狀態(tài)，則預(yù)分派就是正式分派，如果系統(tǒng)分派資源，系統(tǒng)進(jìn)入不安全狀態(tài)，則撤銷預(yù)分派。實(shí)驗(yàn)內(nèi)容：#include<stdio.h>#include<stdlib.h>#defineTRUE1#defineFALSE0inti,j,k,l;intflag;charc;typedefstructBanker{ int*Available; //可運(yùn)用資源向量 int**Max; //最大需求矩陣 int**Allocation; //分派矩陣 int**Need; //需求矩陣 int**Requst; //申請(qǐng)各類資源數(shù)量 int*Work; //工作向量 int*Finish; //結(jié)束向量}Process;intBank(Process*process,intm,intn);intSafe(Process*process,intm,intn);voidMax(Process*process,intm,intn);voidNeed(Process*process,intm,intn);voidAllocation(Process*process,intm,intn);voidAvailable(Process*process,intn);intRequst(Process*process,intm,intn);intBank(Process*process,intm,intn){ do //資源請(qǐng)求失敗或者系統(tǒng)不安全時(shí)flag=0,并重新輸入。 { if((flag=Requst(process,m,n))==1) { printf("請(qǐng)求并試分派成功。\n"); for(j=0;j<n;j++) { (process->Available)[j]-=(process->Requst)[l][j]; (process->Allocation)[l][j]+=(process->Requst)[l][j]; (process->Need)[l][j]-=(process->Requst)[l][j]; } } if(flag==1&&(flag=Safe(process,m,n))==0)//系統(tǒng)不安全，撤銷資源試分派 { printf("撤銷資源試分派。\n"); for(j=0;j<n;j++) { (process->Available)[j]+=(process->Requst)[l][j]; (process->Allocation)[l][j]-=(process->Requst)[l][j]; (process->Need)[l][j]+=(process->Requst)[l][j]; } } }while(flag==0); if(flag==1) { printf("分派成功。\n"); printf("與否繼續(xù)請(qǐng)求資源分派？輸入Y繼續(xù)，輸入y結(jié)束：\n"); getchar(); c=getchar(); if(c=='Y')return1; if(c=='y')return0; }}intSafe(Process*process,intm,intn){ (process->Work)=(int*)malloc(sizeof(int)*n); for(j=0;j<n;j++) (process->Work)[j]=(process->Available)[j];//系統(tǒng)可提供應(yīng)進(jìn)程繼續(xù)運(yùn)行所需的各類資源數(shù)目 (process->Finish)=(int*)malloc(sizeof(int)*m); for(i=0;i<m;i++) (process->Finish)[i]=FALSE; k=m; intflag1; //當(dāng)有不符合條件的資源時(shí)標(biāo)記為0 intflag2; //當(dāng)全部進(jìn)程不都分派成功時(shí)標(biāo)記為0 int*s=(int*)malloc(sizeof(int)*m);//統(tǒng)計(jì)安全序列 do { for(i=0;i<m;i++) //一輪分派 if((process->Finish)[i]==FALSE) { flag1=1; for(j=0;j<n;j++) if((process->Need)[i][j]>(process->Work)[j]) flag1=0;//有不符合條件的資源 if(flag1==1) { for(j=0;j<n;j++) *((process->Work)+j)+=*((process->Allocation)[i]+j); (process->Finish)[i]=TRUE; *s=i; s++; } } k--;//每完畢一次進(jìn)程分派時(shí)k減1,方便跳出循環(huán)和避免死循環(huán) }while(k>0); flag2=1; for(i=0;i<m;i++) //判斷與否全部進(jìn)程都完畢 { if((process->Finish)[i]==FALSE) { flag2=0; break; } } if(flag2==0) { printf("現(xiàn)在狀態(tài)不安全！\n"); return0; } else { printf("現(xiàn)在狀態(tài)安全！\n"); for(i=0;i<m;i++)s--; printf("安全序列為："); for(i=0;i<m;i++) printf("P%d",s[i]); printf("\n"); free(s); return1; }}voidMax(Process*process,intm,intn){ process->Max=(int**)malloc(sizeof(int*)*m);//分派m個(gè)指針，用來(lái)指向數(shù)組的首地址 for(i=0;i<m;i++) (process->Max)[i]=(int*)malloc(sizeof(int)*n);//為每個(gè)數(shù)組分派n個(gè)指針元素 printf("輸入各進(jìn)程對(duì)各類資源的最大需求量：\n"); for(i=0;i<m;i++) { printf("P%d:\n",i); for(j=0;j<n;j++) { scanf("%d",((process->Max)[i]+j)); } }}voidNeed(Process*process,intm,intn){ process->Need=(int**)malloc(sizeof(int*)*m); for(i=0;i<m;i++) (process->Need)[i]=(int*)malloc(sizeof(int)*n); printf("輸入各進(jìn)程對(duì)各類資源的需求量：\n"); for(i=0;i<m;i++) { printf("P%d:\n",i); for(j=0;j<n;j++) { scanf("%d",((process->Need)[i]+j)); } }}voidAllocation(Process*process,intm,intn){ process->Allocation=(int**)malloc(sizeof(int*)*m); for(i=0;i<m;i++) (process->Allocation)[i]=(int*)malloc(sizeof(int)*n); for(i=0;i<m;i++) for(j=0;j<n;j++) *((process->Allocation)[i]+j)=(*((process->Max)[i]+j))-(*((process->Need)[i]+j));}voidAvailable(Process*process,intn){ process->Available=(int*)malloc(sizeof(int)*n); printf("輸入系統(tǒng)可用資源數(shù)：\n"); for(i=0;i<n;i++) scanf("%d",&(process->Available)[i]);}intRequst(Process*process,intm,intn){ process->Requst=(int**)malloc(sizeof(int*)*m); for(i=0;i<m;i++) (process->Requst)[i]=(int*)malloc(sizeof(int)*n); printf("輸入進(jìn)程名及其資源請(qǐng)求量：\n"); scanf("%d",&i); l=i; for(j=0;j<n;j++) scanf("%d",(process->Requst)[i]+j); intflag1=1;//申請(qǐng)量不不大于需求量時(shí)標(biāo)記為0 intflag2=1;//申請(qǐng)量不不大于可運(yùn)用資源量時(shí)標(biāo)記為0 for(j=0;j<n;j++)//檢查申請(qǐng)量與否不大于等于需求量 if((process->Requst)[i][j]>(process->Need)[i][j]) flag1=0; if(flag1==0) { printf("不允許申請(qǐng)量不不大于需求量!請(qǐng)重新輸入。\n"); return0; } if(flag1==1) { for(j=0;j<n;j++)//檢查申請(qǐng)量與否不大于等于系統(tǒng)中的可運(yùn)用資源量 if((process->Requst)[i][j]>(process->Available)[j]) flag2=0; if(flag2==0) { printf("不允許申請(qǐng)量不不大于可運(yùn)用資源量!請(qǐng)重新輸入。\n"); return0; } elsereturn1; }}intmain(){ Processprocess; intm,n; printf("請(qǐng)輸入進(jìn)程數(shù)："); scanf("%d",&m); printf("請(qǐng)輸入資源種類數(shù)："); scanf("%d",&n); Max(&process,m,n); Need