bakery.c

#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>  //Header file for sleep(). man 3 sleep for details.
#include <pthread.h>

#define FOUR_SEAT 1
#define TWO_SEAT 2
#define ONE_SEAT 4
#define ONE_MINUTE 60

int getQueue();
void addQueue(int seatNumber);
void addNewQueueAfterSeatComplete();
void sleepThreadBySeat(int seatNumber);
void* addToSeat(void* number);
void listQueue();



int currentFourSeat = 0;
int currentTwoSeat = 0;
int currentOneSeat = 0;

int queue[100];
int currentQueueIndex = 0;

int seatTypes[] = {1,2,4};

pthread_mutex_t lock;

int getQueue(){
  int seatNumber = queue[currentQueueIndex];
  currentQueueIndex--;
  return seatNumber;
}
void addQueue(int seatNumber){
  queue[currentQueueIndex] = seatNumber;
  currentQueueIndex++;
}
void addNewQueueAfterSeatComplete(){
  int seatNumber = getQueue();
  addToSeat(seatNumber);
}

void sleepThreadBySeat(int seatNumber){
  int minute;
  if(seatNumber == 4){
    minute = 3; // 15;
  }else if(seatNumber == 2){
    minute = 2; //10;
  }else if(seatNumber == 1){
    minute = 1; // 5
  }
  sleep(minute);
  printf("Finish from %d minute\n", minute);
  addNewQueueAfterSeatComplete();
}

void* addToSeat(void* number){
  int seatNumber = (int *) number;
  printf("%d\n",seatNumber);
  printf("Add To Queue\n");
  if(seatNumber == 4){
    if(currentFourSeat < FOUR_SEAT){
      currentFourSeat++;
      sleepThreadBySeat(seatNumber);
    }else{
      addQueue(seatNumber);
    }
  }else if(seatNumber == 2){
    if(currentTwoSeat < TWO_SEAT){
      currentTwoSeat++;
      sleepThreadBySeat(seatNumber);
    }else{
      addQueue(seatNumber);
    }
  }else if(seatNumber == 1){
    if(currentOneSeat < ONE_SEAT){
      currentOneSeat++;
      sleepThreadBySeat(seatNumber);
    }else{
      addQueue(seatNumber);
    }
  }
  return NULL;
}

void listQueue(){
  printf("List Queue\n");
  int i;
  for(i = 0;i < currentQueueIndex; i++){
    printf("%d, ",queue[i]);
  }
  printf("\n\n");
}




int randInRange(int min, int max)
{
  return ( rand() % ( max - min ) ) + min;
}
int main()
{
    pthread_t thread_id;
    printf("Before Thread\n");
    pthread_mutex_lock(&lock);
    int i = 0;
    srand(time(NULL));
    while( i < 120){
      int randomGenerateQueue = randInRange(1,9);
      if(randomGenerateQueue < 4){
        int seatIndex = randInRange(0,3);
        int seatNumber = seatTypes[seatIndex];
        pthread_create(&thread_id, NULL, addToSeat, (void *) seatNumber);
      }
      i++;
    }
    pthread_mutex_unlock(&lock);


    // int j = 0;
    // while(j < 5){
    //
    // }
    pthread_join(thread_id, NULL);

    printf("After Thread\n");
    exit(0);
}