Home Java javaTutorial What are the Key Differences Between Atomic, Volatile, and Synchronized Operations in Multithreaded Programming?

What are the Key Differences Between Atomic, Volatile, and Synchronized Operations in Multithreaded Programming?

Dec 01, 2024 am 08:37 AM

What are the Key Differences Between Atomic, Volatile, and Synchronized Operations in Multithreaded Programming?

Examining the Differences in Atomic, Volatile, and Synchronized

In multithreaded programming, maintaining data integrity and ensuring thread safety is crucial. Understanding the differences between atomic, volatile, and synchronized is essential for effective concurrency management.

Atomic Operations

The AtomicInteger class utilizes compare-and-swap (CAS) operations, a low-level CPU instruction that executes in a loop. CAS reads the current value of a variable and attempts to update it with a new value only if the current value matches an expected value. This ensures atomicity, meaning the operation takes place as a single, indivisible action, preventing race conditions.

Volatile Variables

Volatile variables are shared across threads but do not enforce atomic operations. They guarantee visibility, ensuring that all threads see the latest changes made to the variable. However, operations on volatile variables are not atomic and can result in race conditions when multiple threads attempt to modify the same variable concurrently.

Synchronized Blocks

Synchronized blocks provide a more explicit means of thread-safe access to shared data. When a thread enters a synchronized block, it acquires a lock on an associated object. No other thread can enter the same block while the first thread is holding the lock. This ensures exclusive access to the data within the block, eliminating race conditions.

Example Code Comparisons

Code 1, without any synchronization, is prone to race conditions and is not thread-safe. Code 2, using AtomicInteger, guarantees atomicity and thread safety. Code 3, with volatile but without synchronization, is not thread-safe due to the race condition in the pre/post-increment operation.

Volatile with Multiple Independent Synchronized Blocks

Code 4, attempting to use synchronized blocks on a primitive variable (i), is incorrect. Synchronized blocks require the use of a common lock object, which in this case changes dynamically, rendering the synchronization ineffective.

Local Copies and Visibility

It's a misconception that threads have local copies of variables. In reality, volatile variables ensure visibility, meaning any changes made to the variable by one thread are immediately visible to all other threads. Atomic variables provide both atomicity and visibility.

The above is the detailed content of What are the Key Differences Between Atomic, Volatile, and Synchronized Operations in Multithreaded Programming?. For more information, please follow other related articles on the PHP Chinese website!

Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn

Hot AI Tools

Undresser.AI Undress

Undresser.AI Undress

AI-powered app for creating realistic nude photos

AI Clothes Remover

AI Clothes Remover

Online AI tool for removing clothes from photos.

Undress AI Tool

Undress AI Tool

Undress images for free

Clothoff.io

Clothoff.io

AI clothes remover

Video Face Swap

Video Face Swap

Swap faces in any video effortlessly with our completely free AI face swap tool!

Hot Tools

Notepad++7.3.1

Notepad++7.3.1

Easy-to-use and free code editor

SublimeText3 Chinese version

SublimeText3 Chinese version

Chinese version, very easy to use

Zend Studio 13.0.1

Zend Studio 13.0.1

Powerful PHP integrated development environment

Dreamweaver CS6

Dreamweaver CS6

Visual web development tools

SublimeText3 Mac version

SublimeText3 Mac version

God-level code editing software (SublimeText3)

Is the company's security software causing the application to fail to run? How to troubleshoot and solve it? Is the company's security software causing the application to fail to run? How to troubleshoot and solve it? Apr 19, 2025 pm 04:51 PM

Troubleshooting and solutions to the company's security software that causes some applications to not function properly. Many companies will deploy security software in order to ensure internal network security. ...

How to simplify field mapping issues in system docking using MapStruct? How to simplify field mapping issues in system docking using MapStruct? Apr 19, 2025 pm 06:21 PM

Field mapping processing in system docking often encounters a difficult problem when performing system docking: how to effectively map the interface fields of system A...

How to elegantly obtain entity class variable names to build database query conditions? How to elegantly obtain entity class variable names to build database query conditions? Apr 19, 2025 pm 11:42 PM

When using MyBatis-Plus or other ORM frameworks for database operations, it is often necessary to construct query conditions based on the attribute name of the entity class. If you manually every time...

How do I convert names to numbers to implement sorting and maintain consistency in groups? How do I convert names to numbers to implement sorting and maintain consistency in groups? Apr 19, 2025 pm 11:30 PM

Solutions to convert names to numbers to implement sorting In many application scenarios, users may need to sort in groups, especially in one...

How does IntelliJ IDEA identify the port number of a Spring Boot project without outputting a log? How does IntelliJ IDEA identify the port number of a Spring Boot project without outputting a log? Apr 19, 2025 pm 11:45 PM

Start Spring using IntelliJIDEAUltimate version...

How to safely convert Java objects to arrays? How to safely convert Java objects to arrays? Apr 19, 2025 pm 11:33 PM

Conversion of Java Objects and Arrays: In-depth discussion of the risks and correct methods of cast type conversion Many Java beginners will encounter the conversion of an object into an array...

E-commerce platform SKU and SPU database design: How to take into account both user-defined attributes and attributeless products? E-commerce platform SKU and SPU database design: How to take into account both user-defined attributes and attributeless products? Apr 19, 2025 pm 11:27 PM

Detailed explanation of the design of SKU and SPU tables on e-commerce platforms This article will discuss the database design issues of SKU and SPU in e-commerce platforms, especially how to deal with user-defined sales...

How to elegantly get entity class variable name building query conditions when using TKMyBatis for database query? How to elegantly get entity class variable name building query conditions when using TKMyBatis for database query? Apr 19, 2025 pm 09:51 PM

When using TKMyBatis for database queries, how to gracefully get entity class variable names to build query conditions is a common problem. This article will pin...

See all articles