Book Image

Mastering the Java Virtual Machine

By : Otavio Santana
Book Image

Mastering the Java Virtual Machine

By: Otavio Santana

Overview of this book

Mastering the Java Virtual Machine is a comprehensive guide that will take you into the heart of Java programming, guiding you through the intricate workings of the Java Virtual Machine (JVM) and equipping you with essential skills to become a proficient Java developer. You’ll start by understanding the JVM, exploring its architecture and how it executes Java code. Through detailed explanations and real-world examples, you’ll gain a deep understanding of JVM internals, enabling you to write efficient and optimized Java applications. As you progress, you’ll delve into memory management and execution, unraveling the complexities of heap and stack management, garbage collection, and memory profiling. You'll learn how memory is allocated and reclaimed in the JVM, as well as how to optimize memory usage and identify performance bottlenecks in your applications. With this knowledge, you’ll be able to create Java programs that are not only robust but also highly performant. By the end of this book, you’ll have the skills needed to excel in Java programming, writing efficient, maintainable code.
Table of Contents (19 chapters)
Free Chapter
1
Part 1: Understanding the JVM
5
Part 2: Memory Management and Execution
9
Part 3: Alternative JVMs
12
Part 4: Advanced Java Topics

Heap

At the heart of the JVM lies the heap, a shared space among all JVM threads, and the dynamic runtime data area responsible for allocating memory to all class instances and arrays. As a foundational component created during virtual machine startup, the heap plays a pivotal role in executing Java applications.

An automatic storage management system, commonly known as a garbage collector, orchestrates memory management within the heap. Notably, objects in the heap are never explicitly deallocated, relying on the automatic system to reclaim storage. The JVM remains agnostic to a specific storage management technique, allowing flexibility in its implementation to cater to varied system requirements. The heap’s size can be fixed or dynamically adjusted based on computational needs, expanding or contracting as necessary. This adaptability, combined with non-contiguous memory allocation, ensures efficient utilization.

By empowering JVM implementations with flexibility, programmers...