银行家算法

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#include<iostream>
using namespace std;
int **allocate,*total,**need,*require;
int num_process,num_resource;
bool isDeadLock(int c=0);
bool findFinish();
void printALL(int**b_allocate,int** b_need,int* b_total);
bool isAllFinish(int**);
int main()
{
cin >> num_process >> num_resource;
need = new int* [num_process];
allocate = new int*[num_process];
total = new int [num_resource];
require = new int[num_resource];
int i,q;
for(i=0;i<num_process;i++)
{
need[i] = new int[num_resource];
allocate[i] = new int[num_resource];
}
//define the number of each resource
for(i=0;i<num_resource;i++)
cin >> total[i];
for(i=0;i<num_resource;i++)
cout << total[i];
//define the processes get how much resource
for(i=0;i<num_process;i++)
for(q=0;q<num_resource;q++)
cin >> allocate[i][q];
//cheak the resource has enough to allocate
for(i=0;i<num_resource;i++)
for(q=0;q<num_process;q++)
{ if(total[i]-allocate[q][i]>=0)
total[i]-=allocate[q][i];
else
{
cerr << "error!";
return 1;
}
}
//define how much resources will each process still need to get to finish itself now
for(i=0;i<num_process;i++)
for(q=0;q<num_resource;q++)
cin >> need[i][q];
printALL(allocate,need,total);
//cheak the allocate is deadlock or not
if(isDeadLock())
{
cerr << "dead Lock" ;
return 1;
}
else
cout << "System is safe"<<endl;
//auto test
int test;
cout << "choose 1:auto test, else:custom test. ";
cin >> test;
if(test==1)
{
isDeadLock(test);
}
//custom test
else
{
while(isAllFinish(need))
{
for(i=0;i<num_process;i++)
{
cout << i<<": require how much resource?"<<endl;
for(q=0;q<num_resource;q++)
cin >> require[q];
//determine the data of require is right
for(q=0;q<num_resource;q++)
{
if(total[q] < require[q] || need[i][q] < require[q])
{
cout << "error data information"<<endl;
i--;
break;
}
total[q]-=require[q];
need[i][q]-=require[q];
allocate[i][q]+=require[q];
}
if(isDeadLock(1))
{
i--;
cout << "System is in deadlock state"<<endl;
}
else
cout << "System is safe......"<<endl;
}
}
}
return 0;
}
//if all the processes are finished,then return true;
bool isAllFinish(int** b_need)
{
int i,q;
for(i=0;i<num_process;i++)
for(q=0;q<num_resource;q++)
{
if(b_need[i][q]!=0)
return false;
}
return true;
}
//if it is deadlock ,then return true;else return false
bool isDeadLock(int c)//c is a flag to show the information or not.
{
int **backup_allocate,**backup_need,*backup_total;
backup_need = new int* [num_process];
backup_allocate = new int*[num_process];
backup_total = new int[num_resource];
int i,q;
for(i=0;i<num_process;i++)
{
backup_need[i] = new int[num_resource];
backup_allocate[i] = new int[num_resource];
}
for(i=0;i<num_process;i++)
for(q=0;q<num_resource;q++)
{
backup_need[i][q] = need[i][q];
backup_allocate[i][q] = allocate[i][q];
}
for(i=0;i<num_resource;i++)
backup_total[i] = total[i];
// return findFinish();
if(c!=0)
printALL(backup_allocate,backup_need,backup_total);
int flag=0,count=0;
while(!isAllFinish(backup_need))
{
count=0;
for(i=0;i<num_process;i++)
{ for(q=0;q<num_resource;q++)
{
if(backup_need[i][q]>backup_total[q])
{
flag = 0;
break;
}
flag=1;
}
// find a finishing process and collect the resource
if(flag==1)
{
count++;
for(q=0;q<num_resource;q++)
{
backup_total[q]+=backup_allocate[i][q];
backup_allocate[i][q]=0;
backup_need[i][q]=0;
}
}
printALL(backup_allocate,backup_need,backup_total);
}
// if(c!=0)
// printALL(backup_allocate,backup_need,backup_total);
//if no process is finished,it means no resource is collect once.Then the deadlock appears.
if(count==0)
{
delete []backup_total;
for(i=0;i<num_process;i++)
{ delete[]backup_allocate[i];
delete[]backup_need[i];
}
delete []backup_allocate;
delete []backup_need;
return true;
}
}
return false;
}
void printALL(int**b_allocate,int** b_need,int* b_total)
{
int i,q;
cout << "Allocate need"<<endl;
for(i=0;i<num_process;i++)
{
for(q=0;q<num_resource;q++)
{
cout << b_allocate[i][q]<<" ";
}
cout << " ";
for(q=0;q<num_resource;q++)
cout << b_need[i][q]<<" ";
cout << endl;
}
cout << "total"<<endl;
for(i=0;i<num_resource;i++)
cout << b_total[i]<<" ";
cout << endl;
}
/*
bool findFinish()
{
int i,q,flag=0,count=0;
for(i=0;i<num_process;i++)
{ for(q=0;q<num_resource;q++)
{
if(need[i][q]>total[q])
{
flag = 0;
break;
}
flag=1;
}
if(flag==1)
{
count++;
for(q=0;q<num_resource;q++)
{
total[q]+=allocate[i][q];
allocate[i][q]=0;
}
}
}
if(count!=0)
return true;
return false;
}*/
  • 本文作者: 帐前卒
  • 本文链接: http://chillyc.info/2006/675602/
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