The POSIX thread standard is followed by POSIX threads, sometimes referred to as pthreads. A program may be made parallel by using threads, which divide a single job into a number of separate ones that can run simultaneously. Threads in operating systems can either be user-level or kernel-level and are handled by the kernel. While the operating system manages kernel-level threads, user-level threads are totally controlled by the application. Kernel-level threads include POSIX threads. A thread creation and manipulation API is defined by the POSIX thread standard. The methods in this API allow you to start new threads, modify ... Read More

Java, with its robust object-oriented programming features, offers a multitude of mechanisms for programmers to develop flexible and efficient code. One such concept, often overlooked but critically important, is variance. Understanding variance is crucial for mastering Java, especially when working with generics and collections. This article provides an in-depth exploration of variance in Java, covering its types - covariance, contravariance, and invariance - and their practical applications. Understanding Variance Variance refers to how subtyping between more complex types relates to subtyping between their components. In simpler terms, it determines how the type hierarchy of classes is preserved when these classes ... Read More

Java is a statically-typed language known for its verbosity and strict type checking. However, with the release of Java 10, a new feature called Local-Variable Type Inference was introduced, bringing the var keyword to the language and changing the way Java developers code. This article will explore the var keyword, illustrating its use cases and discussing its implications for Java coding practices. Understanding 'var' in Java In Java, traditionally, we needed to explicitly declare the type of every variable we created. With the introduction of var in Java 10, this has changed. The var keyword allows you to declare ... Read More

Coordinating the operations of processes that are running concurrently is the core concern of process synchronization, a basic issue in computer science. A crucial component of process synchronization, the mutual exclusion issue has a well-known solution in Peterson's Algorithm. This mutual exclusion algorithm, developed by Gary Peterson in 1981, is one of the most straightforward and popular ones. Peterson's Algorithm will be thoroughly examined in this article, including its description, justification for being accurate, benefits and drawbacks, comparison to other algorithms, applications, and conclusion. Petersons Algorithm Set turn to either 0 or 1, indicating which process can enter its ... Read More

In Java, the main() method is the entry point from where the JVM begins program execution. If you've written a Java program, you're likely familiar with the traditional main() signature: public static void main(String[] args). However, did you know that there are several valid variants of the main() method in Java? This article delves into the versatility of main() in Java, showcasing its multiple valid formats and explaining their intricacies. The Canonical Main() Method Before delving into its public static void main(String[] args) In this format, public denotes that the method can be accessed from anywhere; static ... Read More

Exception handling is a fundamental aspect of Java programming that enhances the robustness of applications and promotes a seamless user experience. Key to this is understanding how to effectively use the throw, catch, and instanceof keywords to manipulate exceptions in Java. In this article, we will delve into the usage of these three mechanisms and illustrate how they collaboratively handle exceptions in Java. Understanding Exceptions in Java In Java, an exception is an event that disrupts the normal flow of a program. It's an object which is thrown by a method and caught by another method. The Java system itself ... Read More

Paging is a memory management method. The operating system may create and deallocate memory in pages, which are smaller, fixed-size pieces. The operating system can use virtual memory thanks to paging, which allows a process to access more memory than is physically accessible. Page faults and page replacement overheads are nonetheless also introduced when paging is used. Thus, while designing and refining current operating systems, paging performance is a key consideration. This article will cover a number of performance-related topics related to paging, including benchmarking, page replacement techniques, the working set model, thrashing, page size selection, TLB (Translation Lookaside Buffer) ... Read More

In Java's object-oriented paradigm, inheritance plays a significant role, allowing developers to create classes that reuse, extend, and modify the behavior defined in other classes. To facilitate seamless interaction between a superclass and its subclass, Java provides the super keyword. This article will focus on understanding and effectively using the super keyword in Java to call a base class constructor Exploring the Super Keyword The super keyword in Java is a reference variable that is used to refer to the immediate parent class object. Whenever you create an instance of a subclass, an instance of the parent class is also ... Read More

In the domain of concurrent programming in Java, controlling access to shared resources is crucial. This need is often fulfilled through synchronization mechanisms such as locks and monitors. However, these tools typically only protect a single instance of a resource. What if you have multiple copies of a resource and you need to control access to them? This is where Semaphores come into play. In this article, we will delve into the usage of Semaphores to protect more than one copy of a resource in Java. Understanding Semaphores Semaphore is a synchronization mechanism that controls access to one or more ... Read More

In the dynamic world of Java programming, achieving optimal performance is often the central goal of developers. In this realm, different wait strategies, including busy spinning, can play a pivotal role. This article aims to provide a detailed understanding of busy spinning as a wait strategy in Java, why it's important, and how it can be efficiently utilized. Understanding Wait Strategies In concurrent programming, wait strategies determine how a thread should wait when there is no work available for it. Different wait strategies can drastically impact the performance of concurrent applications. A commonly used approach is blocking, where a thread ... Read More