Book Image

Python Parallel Programming Cookbook

By : Giancarlo Zaccone
Book Image

Python Parallel Programming Cookbook

By: Giancarlo Zaccone

Overview of this book

This book will teach you parallel programming techniques using examples in Python and will help you explore the many ways in which you can write code that allows more than one process to happen at once. Starting with introducing you to the world of parallel computing, it moves on to cover the fundamentals in Python. This is followed by exploring the thread-based parallelism model using the Python threading module by synchronizing threads and using locks, mutex, semaphores queues, GIL, and the thread pool. Next you will be taught about process-based parallelism where you will synchronize processes using message passing along with learning about the performance of MPI Python Modules. You will then go on to learn the asynchronous parallel programming model using the Python asyncio module along with handling exceptions. Moving on, you will discover distributed computing with Python, and learn how to install a broker, use Celery Python Module, and create a worker. You will understand anche Pycsp, the Scoop framework, and disk modules in Python. Further on, you will learnGPU programming withPython using the PyCUDA module along with evaluating performance limitations.
Table of Contents (13 chapters)
Python Parallel Programming Cookbook
Credits
About the Author
About the Reviewers
www.PacktPub.com
Preface
Index

How to kill a process


It's possible to kill a process immediately using the terminate() method. Also, we use the is_alive() method to keep track of whether the process is alive or not.

How to do it...

In this example, a process is created with the target function foo(). After the start, we kill it with the terminate() function:

#kill a Process: Chapter 3: Process Based Parallelism
import multiprocessing
import time

def foo():
    print ('Starting function')
    time.sleep(0.1)
    print ('Finished function')

if __name__ == '__main__':
    p = multiprocessing.Process(target=foo)
    print ('Process before execution:', p, p.is_alive())
    p.start()
    print ('Process running:', p, p.is_alive())
    p.terminate()
    print ('Process terminated:', p, p.is_alive())
    p.join()
    print ('Process joined:', p, p.is_alive())
    print ('Process exit code:', p.exitcode)

The following is the output we get when we use the preceding command:

How it works...

We create the process and then monitor its...