Notes on Thread and threading module in python

This post encompasses some notes about thread and
Threading module in python, that I used as a quick recap.

What is Thread.

Thread Is a basic unit of CPU Utlization, the smallest unit of processing that can be performed in an OS and an entity within a process. One process can have Multiple threads.

What thread contains?

It contains specific information in a Thread Control Block (TCB) such as :

• Thread ID which is assign to every new thread.

• Stack pointer that contains the local variables under thread’s scope.

• Program counter Or Register that contains the address of the current instruction being excuted by the Tthread.

• Parent Process Pointer to point to Process control block
  (PCB) of the parent process that this thread lives on.

Threading module provides a very simple and intuitive API for implementing multiple threads. Thread in this module encapsulates threads and provide an interface to workwith them.

Python has a complicated relationship with threading thanks to its GIL,

To create a new thread is by calling threading.Thread

from threading import Thread

def foo():
    print("Hola Hola")

f1 = Thread(target = foo)
# the thread will never be excuted unless `start` is called
f1.start()

Note Start will run and terminated. Calling thread_name.start again will cuase a RuntimeError

You can find the code on the following repository, this repo is a chapter in a Python for profesional Book repo.

To Read:

• How to Kill a Thread

• StoppableThread & ch116.5