Question

Programming Assignment

You will learn how to deal with multiple processes and use a process pool.

You will write a program creating multiple processes (p=5).

Each process will receive integer value (y) and compute y multiplying by 3 (y*3). A collection of y values is a list of integers [0 to 9].

You must use a process pool, so you need to map these 5 processes to take one value from the list and compute y*3 for all y.

Reuse these process whenever available and do the following: Your program should print out the following three.

(1) Show the output of y*3 in list (in increasing order).

(2) Show the output of y*3 in random order of process mapping.

(3) Show each process ID (PID) of the process being mapped in list. When doing the above, let them sleep for 5 seconds each.

Execution example: >> python3 ./assignment2.2.py

Output of (1): Output in order: [0, 3, 6, 9, 12, 15, 18, 21, 24, 27]

Output of (2): Output in random order:

0

9

3

6

12

15

18

21

27

24

Output of (3)

PID: [19473, 19475, 19474, 19472]

Answer 1

(1)

import multiprocessing

import os

def multiplyThree(x): #function to print 3 times x

print(x*3)

if __name__=="__main__":

for i in range(10): #running a loop for i=0 to 9

p1=multiprocessing.Process(target=multiplyThree,args=(i,)) #creating a thread for every value of i

p1.start() #starting the thread

p1.join() #making sure that this thread is executed before the ones created later

Output:

(2)

import multiprocessing

import os

def multiplyThree(x): #function to print 3 times x

print(x*3)

if __name__=="__main__":

for i in range(10): #running a loop for i=0 to 9

p1=multiprocessing.Process(target=multiplyThree,args=(i,)) #creating a thread for every value of i

p1.start() #starting the thread

Output:

(3)

import multiprocessing

import os

def multiplyThree(x): #function to print 3 times x

print(x*3)

if __name__=="__main__":

for i in range(10): #running a loop for i=0 to 9

p1=multiprocessing.Process(target=multiplyThree,args=(i,)) #creating a thread for every value of i

p1.start() #starting the thread

print(p1.pid) #printing pid of thread

Output: