Book Image

Java 9 Programming By Example

By : Peter Verhas
Book Image

Java 9 Programming By Example

By: Peter Verhas

Overview of this book

This book gets you started with essential software development easily and quickly, guiding you through Java’s different facets. By adopting this approach, you can bridge the gap between learning and doing immediately. You will learn the new features of Java 9 quickly and experience a simple and powerful approach to software development. You will be able to use the Java runtime tools, understand the Java environment, and create Java programs. We then cover more simple examples to build your foundation before diving to some complex data structure problems that will solidify your Java 9 skills. With a special focus on modularity and HTTP 2.0, this book will guide you to get employed as a top notch Java developer. By the end of the book, you will have a firm foundation to continue your journey towards becoming a professional Java developer.
Table of Contents (17 chapters)
Title Page
Credits
About the Author
About the Reviewer
www.PacktPub.com
Customer Feedback
Preface

The CPU heartbeat


These days CPUs run on 2 to 4 GHz frequency processors. It means that a processor gets 2 to 4 times 109 clock signals to do something every second. A processor cannot do any atomic operation faster than this, and also there is no reason to create a clock that is faster than what a processor can follow. It means that a CPU performs a simple operation, such as incrementing a register in half or quarter of a nanosecond. This is the heartbeat of the processor, and if we think of the bureaucrat as humans, who they are, then it is equivalent to one second, approximately, if and as their heartbeat.

Processors have registers and caches on the chip on different levels, L1, L2, and sometimes L3; there is memory, SSD, disk, network, and tapes that may be needed to retrieve data.

Accessing data that is in the L1 cache is approximately 0.5ns. You can grab a paper that is on your desk—half of a second. L2 cache is 7ns. This is a paper in the drawer. You have to push the chair a bit back...