banker.cpp

这是一个银行家算法

// banker.cpp : Defines the entry point for the console application.
//

#include "stdafx.h"

#include "windows.h"
#include<iostream.h>
#include<fstream.h>
#include<stdlib.h>

#define MAX_PROCESS 32              //The max number of processes
#define MAX_SOURCE 32              // The maximum of resource types


int MAX_REAL_PROCESS;              //The real number of processes
int MAX_REAL_SOURCE;               //The real number of resource types
int Available[MAX_SOURCE];                 //Availble resource.
int Max[MAX_PROCESS][MAX_SOURCE];          //The matrix of maximum of need 
int Allocation[MAX_PROCESS][MAX_SOURCE];   //The matrix of allocated resource
int Need[MAX_PROCESS][MAX_SOURCE];         // The need matrix

int Request_PROCESS;                       //The request process
int Request_SOURCE;                        //The request resource type
int Request_SOURCE_NEMBER;                 //The request number of resource.


typedef struct NODE
{
	int value;
	int num;
	int next;
} Node;


//input read function.
void InitRead(void)
{                            
	cout<<"Input the number of processes: ";
    cin>>MAX_REAL_PROCESS;
    cout<<"Input the number of source types: ";
	cin>>MAX_REAL_SOURCE;
	cout<<"Input the number of Available "<< MAX_REAL_SOURCE<<" kinds of resource seperately :"<<endl;
    for (int j=0; j<MAX_REAL_SOURCE; j++)
	{
		cin>>Available[j];
	}


	cout<<"\nInput the max request number of various resource of processes["<<MAX_REAL_PROCESS<<"]["<<MAX_REAL_SOURCE<<"]: "<<endl;
    cout<<"\n("<<MAX_REAL_PROCESS<<"X"<<MAX_REAL_SOURCE<<")Matrix:"<<endl;
	for (int i=0; i<MAX_REAL_PROCESS; i++)
	{
		cout <<"Process"<<i<<":"<<endl;
		for (int j=0; j<MAX_REAL_SOURCE; j++)
		{
			cout<<"the number of Allocated Resource "<< j<<" :"<<endl;
			cin>>Max[i][j];
		}
	}

}


//Initialize the allocated matrix.
void InitAllocated(void)
{                        
	cout<<"\nInput the allocated number of various resource seperately ["<<MAX_REAL_PROCESS<<"]["<<MAX_REAL_SOURCE<<"]: "<<endl;
	cout<<"\n("<<MAX_REAL_PROCESS<<"×"<<MAX_REAL_SOURCE<<") Matrix:"<<endl;
	for (int i=0; i<MAX_REAL_PROCESS; i++)
	{
		cout <<"Process"<<i<<":"<<endl;
		for (int j=0; j<MAX_REAL_SOURCE; j++)
		{
			cout<<"the number of Allocated Resource "<< j<<" :"<<endl;
			cin>>Allocation[i][j];
		}
	}
}

//Set the need matrix.
void SetNeed(void)
{       
	cout<<endl;
	cout<<"Set request matrix"<<'\n';
	for(int i=0;i<MAX_REAL_PROCESS;i++)
		for(int j=0;j<MAX_REAL_SOURCE;j++)
			Need[i][j]=Max[i][j]-Allocation[i][j];
}

//input the request.
void ReadRequest(void)
{                          
	cout<<" Input the request process:"<<endl;
	cin>>Request_PROCESS;
	cout<<" Input the request kind of resource:"<<endl;
	cin>>Request_SOURCE;
	cout<<" Input the request number of resource:"<<endl;
	cin>>Request_SOURCE_NEMBER;

}


//output the reallocated resource.
void ReAllocateResource(void)
{                     
	cout<<endl;
	cout<<"Start process "<<Request_PROCESS<<"to allocate resource "<<Request_SOURCE<<" , number is "<<Request_SOURCE_NEMBER<<" "<<endl;
	cout<<endl;
	cout<<"Congratulation!"<<endl;
}


//safety test.
void SafetyTest()
{                         
	cout<<'\n'<<"Enter safety test"<<endl;
	int Run[MAX_SOURCE];
	for(int i=0;i<MAX_REAL_SOURCE;i++)
	{
		Run[i]=Available[i];
	}

	bool Finish[MAX_PROCESS][MAX_SOURCE];
	for(i=0;i<MAX_REAL_PROCESS;i++)
	for(int j=0;j<MAX_REAL_SOURCE;j++)
		Finish[i][j]=false;
	Node Array[32];
	for(i=0;i<MAX_REAL_PROCESS;i++)
	{
		Array[i].value=Need[i][Request_SOURCE-1];
		Array[i].num=i;
	}
	for(i=0;i<MAX_REAL_PROCESS;i++)
	for(int j=i+1;j<MAX_REAL_PROCESS;j++)
	{
		if(Array[i].value>=Array[j].value)
		{
			int t;
			t=Array[j].value;
			Array[j].value=Array[i].value;
			Array[i].value=t;
			t=Array[j].num;
			Array[j].num=Array[i].num;
			Array[i].num=t;
		}
		else 
			continue;
	}

	if(Finish[Request_PROCESS][Request_SOURCE]==false
		&&Need[Request_PROCESS][Request_SOURCE]<=Run[Request_SOURCE])
	{
		Run[Request_SOURCE]=Run[Request_SOURCE]+Allocation[Request_PROCESS][Request_SOURCE];
		Finish[Request_PROCESS][Request_SOURCE]=true;
	}
	else
	{
		cout<<"Not safe, failed!"<<endl;
		return;
	}

	for(i=0;i<MAX_REAL_PROCESS;i++)
	{
		if(Array[i].num==Request_PROCESS)
			continue;
		if(Array[i].num!=Request_PROCESS
			&&Finish[Array[i].num][Request_SOURCE]==false
			&&Need[Array[i].num][Request_SOURCE]<=Run[Request_SOURCE])
		{
			Run[Request_SOURCE]=Run[Request_SOURCE]+Allocation[Array[i].num][Request_SOURCE];
			Finish[Array[i].num][Request_SOURCE]=true;
		}
	}
	for(i=0;i<MAX_REAL_PROCESS;i++)
	{
		if(Finish[i][Request_SOURCE]==true)
			continue;
		else
		{
			cout<<"Not safe, failed!"<<endl;
			return;
		}
	}
	cout<<'\n'<<"Find out safe sequence:"<<"P"<<Request_PROCESS<<"--->";
	for(i=0;i<MAX_REAL_PROCESS;i++)
	{
		if(Array[i].num==Request_PROCESS)
			continue;
		else
			cout<<"P"<<Array[i].num<<"--->";
	}
	cout<<'\n'<<"passed safe test!"<<endl;
	ReAllocateResource();
}

//Handle the condition process.
void HandleFunc(void)
{
	cout<<"Start process request..."<<endl;

	if(Request_SOURCE_NEMBER>Need[Request_PROCESS][Request_SOURCE])
	{
		cout<<'\n'<<"Process No. "<<Request_PROCESS<<" request the resource "<<Request_SOURCE<<", number is "<<Request_SOURCE_NEMBER<<" "<<endl;
		cout<<"exceed the maximum of resource."<<endl;
		Sleep(2);
		return;
	}
	if(Request_SOURCE_NEMBER>Available[Request_SOURCE])
	{
		cout<<'\n'<<"Process No."<<Request_PROCESS<<" request the resource "<<Request_SOURCE<<", number is"<<Request_SOURCE_NEMBER<<" "<<endl;
		cout<<"No enough resources. Request is dennied. So the program can be STOPPED if you are willing to do so."<<endl;
		Sleep(5);
		return;
	}
	else
	{
		Available[Request_SOURCE]=Available[Request_SOURCE]-Request_SOURCE_NEMBER;
		Allocation[Request_PROCESS][Request_SOURCE]=Allocation[Request_PROCESS][Request_SOURCE]+Request_SOURCE_NEMBER;
		Need[Request_PROCESS][Request_SOURCE]=Need[Request_PROCESS][Request_SOURCE]-Request_SOURCE_NEMBER;
		cout<<"search Ok! "<<endl;
		SafetyTest();
	}
}


 
//main function.
void main(void)
{
	InitRead();
	cout<<endl;
	cout<<MAX_REAL_SOURCE<<'\t';
	for(int i=0;i<MAX_REAL_SOURCE;i++)
		cout<<" "<<Available[i]<<'\t';
	cout<<endl<<MAX_REAL_PROCESS<<endl;
	for(i=0;i<MAX_REAL_PROCESS;i++)
	{
		for(int j=0;j<MAX_REAL_SOURCE;j++)
			cout<<" "<<Max[i][j]<<'\t';
		cout<<endl;
	}

	
	InitAllocated();
	for(i=0;i<MAX_REAL_PROCESS;i++)
	{
		for(int j=0;j<MAX_REAL_SOURCE;j++)
			cout<<" "<<Allocation[i][j]<<'\t';
		cout<<endl;
	}


	SetNeed();
	for(i=0;i<MAX_REAL_PROCESS;i++)
	{
		for(int j=0;j<MAX_REAL_SOURCE;j++)
			cout<<" "<<Need[i][j]<<'\t';
		cout<<endl;
	}

	char stop = 0;
	do{
		ReadRequest();
		cout<<'\n'<<"Process No."<<Request_PROCESS<<" request the resource "<<Request_SOURCE<<", the number is "<<Request_SOURCE_NEMBER<<" "<<endl;
		cout<<'\n'<<"read ok."<<'\n';

		HandleFunc();

		cout<< " Press q to quit or press any other key to continue"<<endl;
		cin>>stop;
	} 
	while( stop !='q' );

}