Book Image

Software Architecture with Python

By : Anand Balachandran Pillai
Book Image

Software Architecture with Python

By: Anand Balachandran Pillai

Overview of this book

This book starts by explaining how Python fits into an application's architecture. As you move along, you will get to grips with architecturally significant demands and how to determine them. Later, you’ll gain a complete understanding of the different architectural quality requirements for building a product that satisfies business needs, such as maintainability/reusability, testability, scalability, performance, usability, and security. You will also use various techniques such as incorporating DevOps, continuous integration, and more to make your application robust. You will discover when and when not to use object orientation in your applications, and design scalable applications. The focus is on building the business logic based on the business process documentation, and understanding which frameworks to use and when to use them. The book also covers some important patterns that should be taken into account while solving design problems, as well as those in relatively new domains such as the Cloud. By the end of this book, you will have understood the ins and outs of Python so that you can make critical design decisions that not just live up to but also surpassyour clients’ expectations.
Table of Contents (18 chapters)
Software Architecture with Python
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface
Index

Pre-emptive versus cooperative multitasking


The programs we wrote earlier using multiple threads were examples of concurrency. However, we didn't have to worry about how and when the operating system chose to run the thread—we just had to prepare the threads (or processes), provide the target function, and execute them. The scheduling is taken care of by the operating system.

Every few ticks of the CPU clock, the operating system pre-empts a running thread, and replaces it with another one in a particular core. This can happen due to different reasons, but the programmer doesn't have to worry about the details. He just creates the threads, sets them up with the data they need to process, uses the correct synchronization primitives, and starts them. The operating system does the rest including switching and scheduling.

This is how almost all modern operating systems work. It guarantees each thread a fair share of the execution time, all other things being equal. This is known as pre-emptive...