Advanced Programming | 23. Java Memory Model and Thread Safety by Abraham | Learn Smarter
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23. Java Memory Model and Thread Safety

23. Java Memory Model and Thread Safety

The Java Memory Model (JMM) is essential for understanding thread interactions and ensuring thread safety in concurrent programming. This chapter outlines key concepts such as visibility, atomicity, and ordering, while discussing thread safety challenges like race conditions and memory consistency errors. Various mechanisms in Java, including synchronized methods, the volatile keyword, and atomic variables, provide solutions for writing thread-safe applications.

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  1. 23
    Java Memory Model And Thread Safety

    This section explores the Java Memory Model (JMM) and thread safety,...

  2. 23.1
    The Java Memory Model (Jmm)

    The Java Memory Model outlines the interactions between threads and memory,...

  3. 23.1.1
    What Is The Java Memory Model?

    The Java Memory Model (JMM) specifies how threads interact through shared...

  4. 23.1.2
    Key Concepts In Jmm

    The key concepts in the Java Memory Model (JMM) define how threads interact...

  5. 23.2
    Thread Safety

    Thread safety refers to the property of a class ensuring safe access to...

  6. 23.2.1
    What Is Thread Safety?

    Thread safety ensures that multiple threads can access shared data without...

  7. 23.2.2
    Why Thread Safety Is Hard?

    Thread safety can be challenging due to race conditions, atomicity...

  8. 23.3
    Visibility Problems In Multithreading

    This section discusses visibility problems in multithreading, particularly...

  9. 23.3.1
    Without Synchronization

    This section discusses the potential visibility issues that occur when...

  10. 23.4
    Synchronization In Java

    Synchronization in Java provides a mechanism to ensure thread safety by...

  11. 23.4.1
    The Synchronized Keyword

    The synchronized keyword in Java ensures mutual exclusion and visibility...

  12. 23.4.2
    Intrinsic Locks And Monitors

    Intrinsic locks, also known as monitors, are built-in synchronization...

  13. 23.4.3
    Memory Effects Of Synchronization

    This section explores how synchronization in Java affects memory visibility...

  14. 23.5
    Volatile Keyword

    The 'volatile' keyword in Java ensures that a variable's value is visible to...

  15. 23.5.1
    What Is Volatile?

    The volatile keyword in Java ensures visibility of variable changes across...

  16. 23.5.2
    When To Use Volatile?

    The volatile keyword in Java ensures visibility of variables across threads...

  17. 23.6
    Atomic Variables

    The section covers the use of atomic variables in Java, found in the...

  18. 23.6.1
    Java.util.concurrent.atomic Package

    The `java.util.concurrent.atomic` package provides a set of classes that...

  19. 23.7
    Immutable Objects

    Immutable objects are inherently thread-safe and simplify reasoning about...

  20. 23.7.1
    Benefits Of Immutability

    Immutability provides built-in thread safety and simplifies reasoning about...

  21. 23.8
    Thread-Safe Collections

    Thread-safe collections in Java ensure safe access to shared data in...

  22. 23.8.1
    Legacy Synchronization

    Legacy synchronization through classes like Vector and Hashtable is...

  23. 23.8.2
    Modern Alternatives

    This section discusses modern alternatives for thread-safe collections in...

  24. 23.9
    Thread Confinement And Local Variables

    This section covers the concept of thread confinement in Java, emphasizing...

  25. 23.9.1
    Thread Confinement

    Thread confinement refers to the restriction of data to a single thread,...

  26. 23.9.2

    The ThreadLocal class provides thread-local variables, allowing each thread...

  27. 23.10
    Best Practices For Thread Safety

    This section outlines essential best practices for achieving thread safety...

What we have learnt

  • The Java Memory Model defines how threads interact with shared memory and ensures safe communication.
  • Thread safety is crucial for preventing data corruption in multi-threaded applications, requiring proper synchronization practices.
  • Understanding and implementing thread-safe designs, such as immutability and concurrent collections, can significantly reduce concurrency-related bugs.

Key Concepts

-- Java Memory Model (JMM)
A part of the Java Language Specification that describes how threads communicate through shared memory and how changes become visible across threads.
-- Thread Safety
The property of a class that guarantees safe access to shared data by multiple threads without causing inconsistencies.
-- Synchronization
A mechanism that controls access to shared resources by multiple threads to prevent race conditions.
-- Volatile Keyword
A keyword in Java that ensures visibility of changes to variables across threads but does not guarantee atomicity.
-- Atomic Variables
Classes in the java.util.concurrent.atomic package that provide thread-safe operations on single variables without needing synchronization.
-- Immutability
The characteristic of an object whose state cannot be modified after it is created, leading to inherent thread safety.
-- ThreadLocal
A class that allows the creation of variables that are tied to a specific thread, providing each thread with its own isolated copy.

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