{"id":14873,"date":"2023-03-23T13:23:22","date_gmt":"2023-03-23T13:23:22","guid":{"rendered":"https:\/\/www.prepbytes.com\/blog\/?p=14873"},"modified":"2023-04-28T10:08:57","modified_gmt":"2023-04-28T10:08:57","slug":"volatile-keyword-in-java","status":"publish","type":"post","link":"https:\/\/prepbytes.com\/blog\/volatile-keyword-in-java\/","title":{"rendered":"Volatile Keyword in Java"},"content":{"rendered":"

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Multithreading is a powerful feature in Java that allows for the concurrent execution of multiple processes, which can optimize computation and enhance system responsiveness. However, despite its advantages, multithreading can create loopholes that developers must address to ensure stable software. One such loophole is the "Visibility Problem," which can be overcome using the volatile keyword in Java. In this article, we’ll learn about volatile keywords in Java and we will also explore various benefits of using volatile keyword in Java. But before we jump in, let’s first understand the Visibility Problem and why it’s such a critical issue to resolve.<\/p>\n

Visibility Problem in Multithreading<\/h2>\n

In a multi-threaded environment, if variables are defined as non-volatile, each thread in the CPU will copy the variables from the main memory to the CPU Caches as illustrated in the image given below.<\/p>\n

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Both threads will update the value of the variables as per their needs. Now, the value set by Thread1 is not updated back to the main memory, so Thread2 cannot see the latest value of the variable. This may lead to inconsistent data.<\/p>\n

This problem of not being able to see the latest value of the variables by the threads, since it is not updated in the main memory is known as the \u201cVisibility Problem\u201d.<\/p>\n

To solve the visibility problem, we use the volatile Keyword in Java.<\/p>\n

What is the Volatile Keyword in Java?<\/h2>\n

The volatile keyword in Java is used to indicate that a variable’s value may be modified by different threads concurrently. When a variable is declared as volatile, it ensures that any change made to it by one thread is immediately visible to all other threads, preventing the possibility of inconsistent data and unexpected behavior. The volatile keyword also guarantees that operations on the variable are executed in the correct order, and no thread can reorder the instructions for performance optimization. Therefore, using the volatile keyword in Java is an effective way to ensure thread safety and avoid concurrency issues.<\/p>\n

Here is an example of using the volatile keyword in Java:<\/p>\n

Example Code for volatile Keyword in Java:<\/strong><\/p>\n\t\t\t\t\t\t