[C++知识库]银行家算法C语言实现(纯记录

#include<stdio.h>
#include<time.h>
#include<unistd.h>
#include<stdlib.h>
#include<string.h>

#define True 1
#define False 0

const int left = 0;
const int right = 9; 

enum State
{
  Error,
  Block,
  Success
};

int generating_data(int left,int right)
{
  static int seed = 1;
  srand((unsigned)time(NULL) + seed * seed + seed);
  int random_data;
  random_data = rand() % (right - left + 1) + left;
  ++seed;
  return random_data;
}

void free_resouce(int** resource,int size)
{
  for(int i = 0;i < size;++i)
    free((void*)resource[i]);
  free((void*)resource);
}

void print(int* p,int size)
{
  for(int i = 0;i < size;++i)
  {
    printf("%d ",p[i]);
  }
  printf("\n");
}

void print_current_state(int processes,int resource_types,int* available,int* security_queue,
                         int** max,int** allocation,int** need,int** work_plus_allocation)
{
  printf("Available:");
  print(available,resource_types);
  enum MatrixType
  {
    Max = 0,
    Allocation,
    Need,
    Work_Plus_Allocation
  };
  printf("\t\t%-20s%-20s%-20s%s\n","Max","Allocation","Need","Work+Allocation");
  int** matrix_ptr = NULL;
  for(int i = 0;i < processes;++i)
  {
    printf("Process%d\t",security_queue[i]);
    for(enum MatrixType matrix_type = Max;matrix_type <= Work_Plus_Allocation;++matrix_type)
    {
      switch(matrix_type)
      {
        case Max:matrix_ptr = max;
          break;
        case Allocation:matrix_ptr = allocation;
          break;
        case Need:matrix_ptr = need;
          break;
        case Work_Plus_Allocation:matrix_ptr = work_plus_allocation;
          break;
        default:break;
      }
      for(int j = 0;j < resource_types;++j)
      {
        if(matrix_ptr[security_queue[i]][j] == -1)
        {
          printf("%s ","None");
          continue;
        }
        printf("%d ",matrix_ptr[security_queue[i]][j]);
      }
      int placeholder_num = 20 - (resource_types * 2);
      for(int k = 0;k < placeholder_num;++k)
        printf(" ");
    }
    printf("\n");
  }
  matrix_ptr = NULL;
}

int detect_1(int* request,int** need,int process_no,int resource_types)
{
  int is_legal = True;
  for(int i = 0;i < resource_types;++i)
  {
    if(request[i] > need[process_no][i])
    {
      is_legal = False;
      break;
    }
  }
  return is_legal;
}

int detect_2(int* request,int* available,int process_no,int resource_types)
{
  int is_legal = True;
  for(int i = 0;i < resource_types;++i)
  {
    if(request[i] > available[i])
    {
      is_legal = False;
      break;
    }
  }
  return is_legal;
}

typedef struct DataLog
{
  int* available_last;
  int* allocation_last;
  int* need_last;
}DataLog;

void record(int* p,int* p_log,int resource_types)
{
  for(int i = 0;i < resource_types;++i)
  {
    p_log[i] = p[i];
  }
}

int security_testing(int resource_types,int processes,
                     int* available,int** max,int** need,int** allocation)
{
  int* work = (int*)malloc(sizeof(int) * resource_types);
  memcpy(work,available,sizeof(int) * resource_types);
  int* security_queue = (int*)malloc(sizeof(int) * processes);
  for(int i = 0;i < processes;++i)
  {
    security_queue[i] = -1;
  }
  int* finish = (int*)malloc(sizeof(int) * processes);
  for(int i = 0;i < processes;++i)
  {
    finish[i] = False;
  }
  int** work_plus_allocation = (int**)malloc(sizeof(int*) * processes); 
  for(int i = 0;i < processes;++i)
  {
    work_plus_allocation[i] = (int*)malloc(sizeof(int) * resource_types);
  }
  int is_continue = True;
  int count = 0;
  while(is_continue)
  {
    is_continue = False;
    for(int i = 0;i < processes;++i)
    {
      if(finish[i] == True) continue;
      int legal = True;     
      for(int j = 0;j < resource_types;++j)
      {
        if(need[i][j] > work[j])
        {
          legal = False;break;
        }
      }
      if(legal)
      {
        finish[i] = True;
        security_queue[count] = i;
      #ifdef _DEBUG_
        printf("Security queue[%d]=%d\n",count,i);
      #endif
        for(int j = 0;j < resource_types;++j)
        {
          work[j] = work[j] + allocation[i][j];
          work_plus_allocation[i][j] = work[j];
        }
        is_continue = True;
        ++count;
        break;
      }
    }
  }
  int is_security = True;
  for(int i = 0;i < processes;++i)
  {
    if(finish[i] == False)
    {
      is_security = False;
      break;
    }
  }
  if(is_security)
  {
    print_current_state(processes,resource_types,available,security_queue,max,allocation,need,work_plus_allocation);
  }
  free((void*)finish);
  free((void*)security_queue);
  free((void*)work);
  free_resouce(work_plus_allocation,processes);
  return is_security;
}

DataLog* try_to_allocate(int* request,int* available,
                         int** allocation,int** need,
                         int process_no,int resource_types)
{
  DataLog* data_log = (DataLog*)malloc(sizeof(DataLog));
  data_log->available_last = (int*)malloc(sizeof(int) * resource_types);
  record(available,data_log->available_last,resource_types);
  for(int i = 0;i < resource_types;++i)
  {
    available[i] = available[i] - request[i];
  }
  data_log->allocation_last = (int*)malloc(sizeof(int) * resource_types);
  record(allocation[process_no],data_log->allocation_last,resource_types);
  for(int i = 0;i < resource_types;++i)
  {
    allocation[process_no][i] = allocation[process_no][i] + request[i];
  }
  data_log->need_last = (int*)malloc(sizeof(int) * resource_types);
  record(need[process_no],data_log->need_last,resource_types);
  for(int i = 0;i < resource_types;++i)
  {
    need[process_no][i] = need[process_no][i] - request[i];
  }
#ifdef _DEBUG_
  printf("Available last\n");
  print(data_log->available_last,resource_types);
  printf("Allocation last\n");
  print(data_log->allocation_last,resource_types);
  printf("Need last\n");
  print(data_log->need_last,resource_types);
#endif
  return data_log;
}

enum State request_resources(int processes,int resource_types,
                             int* available,int** max,int** allocation,int** need)
{
  enum State state;
  int process_no;
#ifdef _DEBUG_
  printf("Input request process number:");
  scanf("%d",&process_no);
#else
  process_no = generating_data(0,processes - 1);
#endif
  printf("Process no:%d\n",process_no);
  int* request = (int*)malloc(sizeof(int) * resource_types);
#ifdef _DEBUG_
  printf("Input request vector:");
  for(int i = 0;i < resource_types;++i)
  {
    scanf("%d",&request[i]);
  }
#else
  for(int i = 0;i < resource_types;++i)
  {
    request[i] = generating_data(left,right);
  }
#endif
  printf("Request:");
  print(request,resource_types);
  printf("\n");
  int is_legal;
  is_legal = detect_1(request,need,process_no,resource_types);
  if(is_legal == False)
  {
    state = Error;
    return state;
  }
  is_legal = detect_2(request,available,process_no,resource_types);
  if(is_legal == False)
  {
    state = Block;
    return state;
  }
  DataLog* data_log = try_to_allocate(request,available,allocation,need,process_no,resource_types);
  int is_security = security_testing(resource_types,processes,available,max,need,allocation);
  if(is_security == False)
  {
    state = Block;
    for(int i = 0;i < resource_types;++i)
    {
      available[i] = data_log->available_last[i];
      allocation[process_no][i] = data_log->allocation_last[i];
      need[process_no][i] = data_log->allocation_last[i];
    }
  }
  else
  {
    state = Success;
  }
  free((void*)data_log->available_last);
  free((void*)data_log->allocation_last);
  free((void*)data_log->need_last);
  free((void*)data_log);
  free((void*)request);
  return state;
}

int main(int argc,char** argv) {
  int processes;
  /* Generating random data */
  // The number of processe
#ifdef _DEBUG_
  printf("Input the number of processes:");
  scanf("%d",&processes);
#else
  processes = generating_data(left + 1,right - 3);
#endif
  printf("The number of processes:%d\n",processes);
  // The number of resource types
  int resource_types;
#ifdef _DEBUG_
  printf("Input the number of of resource types:");
  scanf("%d",&resource_types);
#else
  resource_types = generating_data(left + 1,right - 3);
#endif
  printf("The number of resource types:%d\n",resource_types);
  // The number of different types of resources
  int* resource_total = (int*)malloc(sizeof(int) * resource_types);
#ifdef _DEBUG_
  printf("Input the number of different types of resources:");
  for(int i = 0;i < resource_types;++i)
  {
    scanf("%d",&resource_total[i]);
  }
#else
  for(int i = 0;i < resource_types;++i)
  {
    resource_total[i] = generating_data(left + 5,right + 5);
  }
#endif
  printf("The number of different types of resources:");
  print(resource_total,resource_types);
  int* resource_total_copy = (int*)malloc(sizeof(int) * resource_types);
  memcpy(resource_total_copy,resource_total,sizeof(int) * resource_types);
  // Max
  int** max = (int**)malloc(sizeof(int*) * processes);
#ifdef _DEBUG_
  printf("Input Max:\n");
  for(int i = 0;i < processes;++i)
  {
    max[i] = (int*)malloc(sizeof(int) * resource_types);
    for(int j = 0;j < resource_types;++j)
    {
      scanf("%d",&max[i][j]);
    }
  }
#else
  for(int i = 0;i < processes;++i)
  {
    max[i] = (int*)malloc(sizeof(int) * resource_types);
    for(int j = 0;j < resource_types;++j)
    {
      // Maximum quantity required
      max[i][j] = generating_data(left,right);
    }
  }
#endif
  // Allocation
  int** allocation = (int**)malloc(sizeof(int*) * processes);
#ifdef _DEBUG_
  printf("Input Allocation:\n");
  for(int i = 0;i < processes;++i)
  {
    allocation[i] = (int*)malloc(sizeof(int) * resource_types);
    for(int j = 0;j < resource_types;++j)
    {
      scanf("%d",&allocation[i][j]);
    }
  }
#else
  for(int i = 0;i < processes;++i)
  {
    allocation[i] = (int*)malloc(sizeof(int) * resource_types);
    for(int j = 0;j < resource_types;++j)
    {
      // Number of allocated resources
      int right_range = (max[i][j] < resource_total[j] ? max[i][j] : resource_total[j]);
      allocation[i][j] = generating_data(left,right_range);
      resource_total[j] = resource_total[j] - allocation[i][j];
    }
  }
#endif
  // Need
  int** need = (int**)malloc(sizeof(int*) * processes);
  for(int i = 0;i < processes;++i)
  {
    need[i] = (int*)malloc(sizeof(int) * resource_types);
    for(int j = 0;j < resource_types;++j)
    {
      // Number of resources still needed
      need[i][j] = max[i][j] - allocation[i][j];
    }
  }
  // Available
  int* available = (int*)malloc(sizeof(int) * resource_types);
  for(int i = 0;i < resource_types;++i)
  {
    // The number of resouces
    int have_allocated = 0;
    for(int j = 0;j < processes;++j)
    {
      have_allocated += allocation[j][i];
    }
    available[i] = resource_total_copy[i] - have_allocated;
  }

  /* Manual data entry */

  /* To peek initial state */
  int** work_plus_allocation = (int**)malloc(sizeof(int*) * processes);
  for(int i = 0;i < processes;++i)
  {
    work_plus_allocation[i] = (int*)malloc(sizeof(int) * resource_types);
    for(int j = 0;j < resource_types;++j)
    {
      work_plus_allocation[i][j] = -1;
    }
  }
  int* security_queue = (int*)malloc(sizeof(int) * processes);
  for(int i = 0;i < processes;++i)
  {
    security_queue[i] = i;
  }
  print_current_state(processes,resource_types,available,security_queue,max,allocation,need,work_plus_allocation);
  free_resouce(work_plus_allocation,processes);
  free((void*)security_queue);
  /* To peek initial state */
  int is_security;
  /* Test whether time t0 is safe */
  is_security = security_testing(resource_types,processes,available,max,need,allocation);
  if(is_security == False)
  {
    printf("The initial state is unsafe\n");
  }
  else
  {
    printf("Initial state security\n");
  }
  /* Making requests */
  //enum State state = request_resources(processes,resource_types,available,max,allocation,need);
  if(is_security)
  {
    // Request 5 times
  /*
    for(int i = 0;i < 5;++i)
    {
      enum State state = request_resources(processes,resource_types,available,max,allocation,need);
      if(state == Error)
      {
        printf("Error\n");
      }
      else if(state == Block)
      {
        printf("Block\n");
      }
      else
      {
        printf("Success\n");
      }
    }
  */
    enum State state = request_resources(processes,resource_types,available,max,allocation,need);
    if(state == Error) printf("Error\n");
    else if(state == Block) printf("Block\n");
    else printf("Success\n");
  }
  /* Free resources*/
  free((void*)resource_total);
  free((void*)resource_total_copy);
  free((void*)available);
  free_resouce(max,processes);
  free_resouce(allocation,processes);
  free_resouce(need,processes);
  return 0;
}

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