#import multiprocessing import threading import time a = threading.Semaphore() b = threading.Semaphore() c = threading.Semaphore() d = threading.Semaphore() #e = threading.Semaphore()

chair_total = int(input("Enter total number of chairs: ")) chair_used = int(input("Enter number of chair used: ")) barber_chair = input("Enter status of barber's chair: ")#True = occupied bool variable

print("chair_total: ",chair_total) print("chair_used: ",chair_used) print("barber_chair: ",barber_chair)

#barber_chair #1 means occupied/false barber_sleep=0 #0 means barber is awake

def customer(): #global chair_total global chair_used #global barber_chair

while chair_used<=chair_total: if (barber_chair==True and chair_used < chair_total): chair_used+=1 #time.sleep(5) b.release() print("%s released lock"%(threading.current_thread().name)) print("semaphore b value: ",b._value) time.sleep(5) print("Chairs used",chair_used) elif (chair_used==chair_total and barber_chair==True): #time.sleep(5) c.release()#Semsignal(c) #print("semaphore c",c) print("%s released lock"%(threading.current_thread().name)) print("semaphore c value: ",c._value) balk() d.release() print("%s released lock"%(threading.current_thread().name)) print("semaphore d value: ",d._value) break else: #time.sleep(5) #print("releasing semaphore a") a.release() #Semsignal(a) +1 #print("semaphore a",a) print("%s released lock"%(threading.current_thread().name)) print("semaphore a value: ",a._value) getHaircut() break

def cutHair(): global barber_chair #print("acquiring semaphore b") #b.acquire()#semWait(b) #b.acquire() #print("semaphore b",b) #print("%s acquire lock"%(threading.current_thread().name)) #print("semaphore b value: ",b._value) if(barber_chair==True): print("Barber's chair occupied ") elif(barber_chair==False): print("Barber's chair empty") #print("%s release lock"%(threading.current_thread().name)) #print("semaphore e value: ",e._value)

def getHaircut(): #global chair_total global chair_used global barber_chair #global barber_chair #print("aquiring semaphore") a.acquire() #semWait(a) -1 print("%s acquired lock"%(threading.current_thread().name)) print("semaphore a value: ",a._value) barber_chair=True if(barber_chair==True and chair_used==0): pass else: print("Barber's chair status :",barber_chair) #b.release() #time.sleep(1) #print("%s released lock"%(threading.current_thread().name)) #print("semaphore b value: ",b._value) d.acquire() b.acquire() if(chair_used==0): pass else: #barber_chair=False #time.sleep(1) #print("%s acquired lock"%(threading.current_thread().name)) #print("semaphore e value: ",e._value) chair_used-=1 print("%s acquired lock"%(threading.current_thread().name)) print("semaphore d value: ",d._value) print("semaphore b value: ",b._value) print("Chairs used: ",chair_used) customer()

def barber(): if(chair_used!=0 and barber_chair==False): barber_sleep=0 #time.sleep(5) #b.release() #print("semaphore b",b) #print("%s released lock"%(threading.current_thread().name)) #print("semaphore b value: ",b._value) cutHair() elif(barber_chair==True): pass elif(barber_chair==False and chair_used==0): barber_sleep=1 print("barber has gone to sleep") #time.sleep(5)

def balk(): c.acquire()#////////////////////sem wait(c) #print("semaphore c:",c) print("%s acquired lock"%(threading.current_thread().name)) print("semaphore c value: ",c._value) if(chair_used==0): pass elif(chair_used==chair_total): time.sleep(1) print("Unattended customer has left shop")

def main():

# start=time.clock() #p1=multiprocessing.Process(target=customer) #p2=multiprocessing.Process(target=cutHair) #p3=multiprocessing.Process(target=getHaircut) #p4=multiprocessing.Process(target=barber) #p5=multiprocessing.Process(target=balk)

#p1.start() #p2.start() #p3.start() #p4.start() #p5.start()

#p5.join() #p2.join() #p3.join() #p4.join() #p5.join() t1 = threading.Thread(target = customer) t2 = threading.Thread(target = getHaircut) t3 = threading.Thread(target = cutHair) t4 = threading.Thread(target = barber) t5 = threading.Thread(target = balk)

t1.start() t2.start() t3.start() t4.start() t5.start()

t1.join() t2.join() t3.join() t4.join() t5.join() print("All Threads done Exiting")

# finish=time.clock() # x=finish-start # print("time = ",x) #print(f'Finished in{round(finish-start,2)}seconds') main()

Show the flowchart of this piece of code generally, emphasise and show the multithreading in your flowchart