How to solve the problem of bus charging with multiple threads in Python

Python multithreading has a wide range of applications. First, let's look at how to apply it. Let's take a look at the cases in life. I hope you will be inspired. Finally, simulate a Python multi-thread program for bus and subway IC Card Fare payment.

There are 10 card readers. Each card reader deducts a dollar each time and enters the General Ledger. Each card reader is charged 10000000 times a day. 100 original accounts. So the final general account should be 10000100. First, do not use mutex lock to lock and comment out the lock code) to see the consequences.

 
 

  
  
import time,datetime  
  
  
import threading  
  
  
def worker(a_tid,a_account):  
  
  
global g_mutex  
  
  
print "Str " , a_tid, datetime.datetime.now()  
  
  
for i in range(1000000):  
  
  
#g_mutex.acquire()  
  
  
a_account.deposite(1)  
  
  
#g_mutex.release()  
  
  
print "End " , a_tid , datetime.datetime.now()  
  
  
class Account:  
  
  
def __init__ (self, a_base ):  
  
  
self.m_amount=a_base 
  
  
def deposite(self,a_amount):  
  
  
self.m_amount+=a_amount  
  
  
def withdraw(self,a_amount):  
  
  
self.m_amount-=a_amount 
  
  
if __name__ == "__main__":  
  
  
global g_mutex  
  
  
count = 0 
  
  
dstart = datetime.datetime.now()  
  
  
print "Main Thread Start At: " , dstart  
  
  
#init thread_pool  
  
  
thread_pool = []  
  
  
#init mutex  
  
  
g_mutex = threading.Lock()  
  
  
# init thread items  
  
  
acc = Account(100)  
  
  
for i in range(10):  
  
  
th = threading.Thread(target=worker,args=(i,acc) ) ;  
  
  
thread_pool.append(th)  
  
  
# start threads one by one  
  
  
for i in range(10):  
  
  
thread_pool[i].start()  
  
  
#collect all threads  
  
  
for i in range(10):  
  
  
threading.Thread.join(thread_pool[i])  
  
  
dend = datetime.datetime.now()  
  
  
print "count=",acc.m_amount  
  
  
print "Main Thread End at: " ,dend , " time span " , 
dend-dstart; 
 
 

The above is an introduction to the related Python multithreading technology.