Sleeping Barber's Problem.py

import threading
import time
import random

# Define the maximum number of customers and the number of chairs in the waiting room
max_customers = int(input("Enter max no. of customers: "))
num_chairs = int(input("Enter max no. of chairs: "))

# Define the semaphores for the barber, the customers and the mutex
barber_semaphore = threading.Semaphore(0)
customer_semaphore = threading.Semaphore(0)
mutex = threading.Semaphore(1)

# Define a list to keep track of the waiting customers
waiting_customers = []

# Define the barber thread function
def barber():
    while(True):
        print("The barber is sleeping......")
        barber_semaphore.acquire()
        mutex.acquire()
        if len(waiting_customers) > 0:
            customer = waiting_customers.pop(0)
            print(f"The barber is cutting hair for customer {customer}.")
            mutex.release()
            time.sleep(random.randint(1, 5))
            print(f"The barber has finished cutting hair for customer {customer}.")
            customer_semaphore.release()
        else:
            mutex.release()

# Define the customer thread function
def customer(index):
    while(True):
        global waiting_customers
        time.sleep(random.randint(1, 5))
        mutex.acquire()
        if len(waiting_customers) < num_chairs:
            waiting_customers.append(index)
            print(f"Customer {index} is waiting in the waiting room.")
            mutex.release()
            barber_semaphore.release()
            customer_semaphore.acquire()
            print(f"Customer {index} has finished getting the haircut.")
        else:
            print(f"Customer {index} is leaving, because the waiting room is full.")
            mutex.release()

# Create a thread for the barber
barber_thread = threading.Thread(target=barber)

# Create a thread for each customer
customer_threads = []
for i in range(max_customers):
    customer_threads.append(threading.Thread(target=customer, args=(i, )))

# Start the barber and customer threads
barber_thread.start()
for thread in customer_threads:
    thread.start()

# Wait for the customer