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#include <stdio.h>
typedef struct
{
int A;
int B;
int C;
}RES;
typedef int bool;
#define false 0
#define true 1
//系统中所有进程数量
#define PNUMBER 3
//最大需求矩阵
RES Max[PNUMBER];
//已分配资源数矩阵
RES Allocation[PNUMBER];
//需求矩阵
RES Need[PNUMBER];
//可用资源向量
RES Available={0,0,0};
//安全序列
int safe[PNUMBER];
void setConfig()
{
int i=0,j=0;
printf("================开始手动配置资源==================\n");
//可分配资源
scanf("%d%d%d",&Available.A,&Available.B,&Available.C);
//最大需求矩阵MAX
for (i=0;i<PNUMBER;i++)
{
scanf("%d%d%d",&Max[i].A,&Max[i].B,&Max[i].C);
}
//已分配矩阵Alloc
for (i=0;i<PNUMBER;i++)
{
scanf("%d%d%d",&Allocation[i].A,&Allocation[i].B,&Allocation[i].C);
}
//需求矩阵
for (i=0;i<PNUMBER;i++)
{
scanf("%d%d%d",&Need[i].A,&Need[i].B,&Need[i].C);
}
printf("================结束配置资源==================\n");
}
void loadConfig()
{
FILE *fp1;
if ((fp1=fopen("config.txt","r"))==NULL)
{
printf("没有发现配置文件,请手动输入!!!\n");
setConfig();
}
else{
int i=0;
printf("发现配置文件,开始导入..");
//可分配资源
fscanf(fp1,"%d%d%d",&Available.A,&Available.B,&Available.C);
//最大需求矩阵MAX
for (i=0;i<PNUMBER;i++)
{
fscanf(fp1,"%d%d%d",&Max[i].A,&Max[i].B,&Max[i].C);
}
//已分配矩阵Alloc
for (i=0;i<PNUMBER;i++)
{
fscanf(fp1,"%d%d%d",&Allocation[i].A,&Allocation[i].B,&Allocation[i].C);
}
//需求矩阵
for (i=0;i<PNUMBER;i++)
{
fscanf(fp1,"%d%d%d",&Need[i].A,&Need[i].B,&Need[i].C);
}
printf("信息导入完成.....\n");
}
}
//试探分配
void ProbeAlloc(int process,RES *res)
{
Available.A -= res->A;
Available.B -= res->B;
Available.C -= res->C;
Allocation[process].A += res->A;
Allocation[process].B += res->B;
Allocation[process].C += res->C;
Need[process].A -= res->A;
Need[process].B -= res->B;
Need[process].C -= res->C;
}
//若试探分配后进入不安全状态，将分配回滚
void RollBack(int process,RES *res)
{
Available.A += res->A;
Available.B += res->B;
Available.C += res->C;
Allocation[process].A -= res->A;
Allocation[process].B -= res->B;
Allocation[process].C -= res->C;
Need[process].A += res->A;
Need[process].B += res->B;
Need[process].C += res->C;
}
//安全性检查
bool SafeCheck()
{
RES Work = Available;
bool Finish[PNUMBER] = {false,false,false};
int i;
int j = 0;
for (i = 0; i < PNUMBER; i++)
{
//是否已检查过
if(Finish[i] == false)
{
//是否有足够的资源分配给该进程
if(Need[i].A <= Work.A && Need[i].B <= Work.B && Need[i].C <= Work.C)
{
//有则使其执行完成，并将已分配给该进程的资源全部回收
Work.A += Allocation[i].A;
Work.B += Allocation[i].B;
Work.C += Allocation[i].C;
Finish[i] = true;
safe[j++] = i;
i = -1; //重新进行遍历
}
}
}
//如果所有进程的Finish向量都为true则处于安全状态，否则为不安全状态
for (i = 0; i < PNUMBER; i++)
{
if (Finish[i] == false)
{
return false;
}
}
return true;
}
//资源分配请求
bool request(int process,RES *res)
{
//request向量需小于Need矩阵中对应的向量
if(res->A <= Need[process].A && res->B <= Need[process].B && res->C <= Need[process].C)
{
//request向量需小于Available向量
if(res->A <= Available.A && res->B <= Available.B && res->C <= Available.C)
{
//试探分配
ProbeAlloc(process,res);
//如果安全检查成立，则请求成功，否则将分配回滚并返回失败
if(SafeCheck())
{
return true;
}
else
{
printf("安全性检查失败。原因：系统将进入不安全状态，有可能引起死锁。\n");
printf("正在回滚...\n");
RollBack(process,res);
}
}
else
{
printf("安全性检查失败。原因：请求大于可利用资源。\n");
}
}
else
{
printf("安全性检查失败。原因：请求大于需求。\n");
}
return false;
}
//输出资源分配表
void PrintTable()
{
printf("===================================资源分配表==================================\n");
printf("Process Max Allocation Need Available\n");
printf(" A B C A B C A B C A B C\n");
printf(" P0 %2d %2d %2d %2d %2d %2d %2d %2d %2d %2d %2d %2d\n",Max[0].A,Max[0].B,Max[0].C,Allocation[0].A,Allocation[0].B,Allocation[0].C,Need[0].A,Need[0].B,Need[0].C,Available.A,Available.B,Available.C);
printf(" P1 %2d %2d %2d %2d %2d %2d %2d %2d %2d\n",Max[1].A,Max[1].B,Max[1].C,Allocation[1].A,Allocation[1].B,Allocation[1].C,Need[1].A,Need[1].B,Need[1].C);
printf(" P2 %2d %2d %2d %2d %2d %2d %2d %2d %2d\n",Max[2].A,Max[2].B,Max[2].C,Allocation[2].A,Allocation[2].B,Allocation[2].C,Need[2].A,Need[2].B,Need[2].C);
printf("===============================================================================\n");
}
//银行家算法分配
void banker()
{
int ch;
//判断输入的是否是安全状态
PrintTable();
printf("先检查初始状态是否安全。\n");
if (SafeCheck())
{
printf("系统处于安全状态。\n");
printf("安全序列是{P%d,P%d,P%d}。\n",safe[0],safe[1],safe[2]);
}
else
{
printf("系统处于不安全状态。程序将退出...\n");
printf("执行完毕。\n");
getchar();
return ;
}
//开始分配
do
{
int process;
RES res;
printf("请依次输入请求分配的进程和对三类资源的请求数量：");
scanf("%d%d%d%d",&process,&res.A,&res.B,&res.C);
if(process<3 && process>=0){
if (request(process,&res))
{
printf("分配成功。\n");
PrintTable();
printf("安全序列是{P%d,P%d,P%d}。\n",safe[0],safe[1],safe[2]);
}
else
{
printf("分配失败。\n");
}
printf("是否继续分配？(Y/N):");
getchar();
ch = getchar();
}else
{
printf("输入的进程号0～2\n");
ch = 'y';
}
} while (ch == 'Y' || ch == 'y');
printf("执行完毕。\n");
}
//随机分配算法执行
bool RandRequest(int process,RES *res)
{
//request向量需小于Available向量
if(res->A <= Available.A && res->B <= Available.B && res->C <= Available.C)
{
//试探分配
ProbeAlloc(process,res);
//判断进程是否执行完，执行完释放资源
if(Max[process].A <= Allocation[process].A && Max[process].B <= Allocation[process].B && Max[process].C <= Allocation[process].C)
{
printf("\nP%d 执行完毕，释放所分配的资源...\n",process);
//有则使其执行完成，并将已分配给该进程的资源全部回收
Available.A += Allocation[process].A;
Available.B += Allocation[process].B;
Available.C += Allocation[process].C;
Allocation[process].A = 0;
Allocation[process].B = 0;
Allocation[process].C = 0;
Need[process].A = Max[process].A;
Need[process].B = Max[process].B;
Need[process].C = Max[process].C;
}
return true;
}
else
{
printf("分配失败。原因：请求大于可利用资源。\n");
}
return false;
}
//随机分配
void randPatch()
{
int ch;
//判断输入的是否是安全状态
PrintTable();
printf("先检查初始状态是否安全。\n");
if (SafeCheck())
{
printf("系统处于安全状态。\n");
printf("安全序列是{P%d,P%d,P%d}。\n",safe[0],safe[1],safe[2]);
}
else
{
printf("系统处于不安全状态。程序将退出...\n");
printf("执行完毕。\n");
getchar();
return ;
}
//开始分配
do
{
int process;
RES res;
printf("请依次输入请求分配的进程和对三类资源的请求数量：");
scanf("%d%d%d%d",&process,&res.A,&res.B,&res.C);
if (RandRequest(process,&res))
{
printf("分配成功。\n");
PrintTable();
if(!SafeCheck())
{
printf("系统发生死锁。");
getchar();
getchar();
break;
}
}
else
{
printf("分配失败。\n");
}
printf("是否继续分配？(Y/N):");
getchar();
ch = getchar();
} while (ch == 'Y' || ch == 'y');
printf("执行完毕。\n");
}
int main()
{
int x;
while(1)
{
system("clear");
printf("===============================================================================\n");
printf("\t\t\t共享资源分配与银行家算法\n");
printf("===============================================================================\n");
printf("\t\t\t 按1.导入配置信息\n");
printf("\t\t\t 按2.银行家算法\n");
printf("\t\t\t 按3.随机分配算法\n");
printf("\t\t\t 按0.退出系统\n");
printf("===============================================================================\n");
printf("您输入的是:");
scanf("%d",&x);
fflush(stdin);
system("clear");
printf("===============================================================================\n");
printf("\t\t\t共享资源分配与银行家算法");
if (x == 2)
{
printf("\t---银行家算法\n");
}else if(x==3)
{
printf("\t---随机分配算法\n");
}
printf("===============================================================================\n");
switch(x)
{
case 1:
{
//加载配置文件
loadConfig();
//打印资源分配表
PrintTable();
getchar();
getchar();
};break;
case 2: banker();break;
case 3: randPatch(); break;
case 0: return 0;break;
default:printf("请输入0~1之间的数字\n");
}
}
return 0;
}
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