Multiprocessing

What is Multiprocessing? 

Multiprocessing refers to the ability of a system to support more than one processor at the same time. Applications in a multiprocessing system are broken into smaller routines that run independently. The operating system allocates these threads to the processors improving system performance.

A multiprocessing system can have:

• multiprocessor, i.e. a computer with more than one central processor.
• multi-core processor, i.e. a single computing component with two or more independent actual processing units (called “cores”)

To import the multiprocessing module, we do:

import multiprocessing

Example: 1

import multiprocessing

def test():

    print("this is my multiprocessing prog")

if __name__ == '__main__':

    m = multiprocessing.Process(target=test)

    print("this is my main prog")

    m.start()

    m.join()

OUTPUT:

Example: 2

Calculate the square of the given number using multiprocessing

def square(n):

    return n**2

if __name__ == '__main__':

    with multiprocessing.Pool(processes=4) as pool :

        out = pool.map(square , [1,2,3,4,5,6,7,8,9])

        print(out)

OUTPUT:

Example: 3

import multiprocessing

def sender(conn , msg) :

    for i in msg:

        conn.send(i)

    conn.close()

def receive(conn) :

    while True :

        try :

            msg = conn.recv()

        except Exception as e :

            print(e)

            break

        print(msg)

if __name__ == '__main__' :

    msg = ["my name is sudh", "this is my msg to students", "I am taking class for multiprocessing " ]

    parent_con , child_con = multiprocessing.Pipe()

    m1  = multiprocessing.Process(target=sender , args = (child_con , msg))

    m2 = multiprocessing.Process(target=receive , args =(parent_con,))

    m1.start()

    m2.start()

    m1.join()

    child_con.close()

    m2.join()

    parent_con.close()

OUTPUT: