Banker's Algorithm Program.

     Assignment 3:

Banker's Algorithm Program.

    bankers.h

                    #include <stdio.h>

#include <stdlib.h>

int max[5][3]={7,5,3,3,2,2,9,0,2,2,2,2,4,3,3},avail[3]={3,3,2},allocation[5][3]={0,1,0,2,0,0,3,0,2,2,1,1,0,0,2},need[5][3],finish[5],work[3],safe[5],request[3];

int n,m,proc;

/*void accept_requestR(int m)

{

int i,proc;

printf("\nenter the process number\n");

scanf("%d",&proc);

if(proc>=n)

printf("\nInvalid process");

else

{

for(i=0;i<m;i++)

{

printf("\nenter the request matrix for R[%d]",i);

scanf("%d",&request[i]);

}

}

}

*/

void accept_maxM(int n,int m)

{

int i,j;

for(i=0;i<n;i++)

{

for(j=0;j<m;j++)

{

printf("\nenter the max matrix for M[%d][%d]",i,j);

scanf("%d",&max[i][j]);

}

}

}

void display_maxM(int n,int m)

{

int i,j;

for(i=0;i<n;i++)

{

printf("\n P%d \t",i);

for(j=0;j<m;j++)

{

printf("%d \t",max[i][j]);

}

}

}

void accept_allocationA(int n,int m)

{

int i,j;

for(i=0;i<n;i++)

{

for(j=0;j<m;j++)

{

printf("\nenter the allocation matrix for A[%d][%d]",i,j);

scanf("%d",&allocation[i][j]);

}

}

}

void display_allocationA(int n,int m)

{

int i,j;

for(i=0;i<n;i++)

{

printf("\n P%d \t",i);

for(j=0;j<m;j++)

{

printf("%d \t",allocation[i][j]);

}

}

}

void accept_availAv(int m)

{

int i;

for(i=0;i<m;i++)

{

printf("\nenter the available matrix Av[%d][%d]",i);

scanf("%d",&avail[i]);

}

}

void display_availAv(int m)

{

int i;

for(i=0;i<m;i++)

{

printf("%d \t",avail[i]);

}

}

void display()

{

int i,j;

for(i=0;i<n;i++)

{

printf("\n P%d \t",i);

for(j=0;j<m;j++)

{

printf("%d \t",need[i][j]);

}

}

}

void find_need(int n,int m)

{

int i,j;

for(i=0;i<n;i++)

{

for(j=0;j<m;j++)

{

need[i][j]=max[i][j]-allocation[i][j];

}

}

}

int compare_need(int p,int m)

{

int i,flag=0;

for(i=0;i<m;i++)

{

if(need[p][i]>work[i])

{

flag=1;

break;

}

}

if(flag==0)

return p;

else

return -1;

}

int  safety(int n,int m)

{

int i,k,flag,over=0,pno,l=0,cnt=0;

for(i=0;i<n;i++)

{

safe[i]=0;

finish[i]=0;

}

for(i=0;i<m;i++)

{

work[i]=avail[i];

}

while(!over)

{

for(i=0;i<n;i=(i+1)%n)

{

if(cnt==n)

{

return -1;

}

if(finish[i]==0)

{

flag=0;

pno=compare_need(i,m);

                                        if(pno==-1)

{

if(i==m-1)

cnt++;

continue;

}

else

{

if(i<n && pno>=0)

{

for(k=0;k<m;k++)

{

work[k]+=allocation[pno][k];

printf("\nW %d\n",work[k]);

}

finish[pno]=1;

safe[l++]=pno;

                                       // printf("\n p %d",pno);

if(l==n)

{

printf("\nSafe sequence is:\n");

for(i=0;i<n;i++)

printf("\n P%d\t",safe[i]);

over=1;return 1;

}

}

}

}

}

}

}

void resource_request(int proc)

{

//accept_requestR(m);

int i;

for(i=0;i<m;i++)

{

if(request[i]>need[proc][i])

{

printf("error..process exceed its max demand");

return;

}

}

for(i=0;i<m;i++)

{

if(request[i]>avail[i])

{

printf("Process must wait,resources not available");

return;

}

}

for(i=0;i<m;i++)

{

avail[i]=avail[i]-request[i];

allocation[proc][i]=allocation[proc][i]+request[i];

need[proc][i]=need[proc][i]-request[i];

}

printf("\nAllocation Matrix is :\n");

display_allocationA(n,m);

printf("\nAvailable Matrix is :\n");

display_availAv(m);

printf("\nNeed Matrix is :\n");

display();

if(safety(n,m)==-1)

printf("\nSafe sequence does not exists ... ");

}

        bankers.c

        

                #include <stdio.h>

#include "bankers.h" 

int main(void)

{

int ch,i;

printf("\nenter the number of process\n");

scanf("%d",&n);

printf("\nEnter the number of resources\n");

scanf("%d",&m);

do

{

printf("\n1.accept\n2.display\n3.Need\n4.Safety\n5.Resource\n6.Exit\n");

scanf("%d",&ch);

switch(ch)

{

case 1:

//accept_maxM(n,m);

//accept_allocationA(n,m);

//accept_availAv(m);

break;

case 2:

printf("\n Max matrix is: \n");

display_maxM(n,m);

printf("\n Allocation matrix is: \n");

display_allocationA(n,m);

printf("\n Available matrix is: \n");

display_availAv(m);

break;

case 3:

printf("\n Need matrix is: \n");

find_need(n,m);

display();

break;

case 4:

if(safety(n,m)==-1)

printf("\nSafe sequence does not exists ... ");

break;

case 5:

printf("\nenter the process number\n");

scanf("%d",&proc);

if(proc>=n)

printf("\nInvalid process");

else

{

for(i=0;i<m;i++)

{

printf("\nenter the request matrix for R[%d]",i);

scanf("%d",&request[i]);

}

}

resource_request(proc);

break;

case 6:

exit(0);

break;

}

}

while(ch<7);

}