Delphi Event Based And Asynchronous Programming

Event-based programming is everywhere. Nowadays, you can hardly write any kind of application without leaning on events and messages.This simple, yet extremely powerful mechanism is also the cornerstone of asynchronous and multithreaded programming. Without events, we would not know when some task was completed.But, asynchronous and multithreaded programming consists of more than just handling multiple threads, protecting shared resources, and synchronization. It also includes designing and understanding program flow. That design aspect is often forgotten, taken for granted, and solving all the fine-grained nuances of multithreaded programming hogs the spotlight.Without understanding asynchronous flow and the bigger picture it can be hard to properly solve all the other issues, including multithreading. What used to be plain spaghetti code, now becomes temporal spaghetti.You can lose control over your objects, have bits of code creating and releasing them all over the place, even without adding multithreading into the mix. Memory leaks, crashes, and holding references to dead data long after its destruction are perfectly possible even in a singlethreaded environment.While the starting point of this book is giving a proper introduction to event-based and asynchronous programming flow and design, it also provides the necessary implementation details, explanations and code examples needed to put those designs into practice.

Explore Twisted, the Python-based event-driven networking engine, and review several of its most popular application projects. It is written by community leaders who have contributed to many of the projects covered, and share their hard-won insights and experience. Expert Twisted starts with an introduction to event-driven programming, explaining it in the context of what makes Twisted unique. It shows how Twisted's design emphasizes testability as a solution to common challenges of reliability, debugging, and start-to-finish causality that are inherent in event-driven programming. It also explains asynchronous programming, and the importance of functions, deferreds, and coroutines. It then uses two popular applications, treq and klein, to demonstrate calling and writing Web APIs with Twisted. The second part of the book dives into Twisted projects, in each case explaining how the project fits into the Twisted ecosystem and what it does, and offers several examples to bring readers up to speed, with pointers to additional resources for more depth. Examples include using Twisted with Docker, as a WSGI container, for file sharing, and more. What You'll LearnIntegrate Twisted and asyncio using adapters Automate software build, test, and release processes with Buildbot Create clients and servers with Autobahn Transfer files with Magic Wormhole Distribute cloud-based file storage with Tahoe LAFSUnderstand HTTP/2 with Python and Twisted Support for asynchronous tasks using Django Channels Who This Book Is For Readers should have some Python experience and understand the essentials of containers and protocols, but need not be familiar with Twisted or the associated projects covered in the book.

Explore Twisted, the Python-based event-driven networking engine, and review several of its most popular application projects. It is written by community leaders who have contributed to many of the projects covered, and share their hard-won insights and experience. Expert Twisted starts with an introduction to event-driven programming, explaining it in the context of what makes Twisted unique. It shows how Twisted's design emphasizes testability as a solution to common challenges of reliability, debugging, and start-to-finish causality that are inherent in event-driven programming. It also explains asynchronous programming, and the importance of functions, deferreds, and coroutines. It then uses two popular applications, treq and klein, to demonstrate calling and writing Web APIs with Twisted. The second part of the book dives into Twisted projects, in each case explaining how the project fits into the Twisted ecosystem and what it does, and offers several examples to bring readers up to speed, with pointers to additional resources for more depth. Examples include using Twisted with Docker, as a WSGI container, for file sharing, and more.

Use structural, behavioral, and concurrent patterns in Delphi to skillfully develop applications Key FeaturesDelve into the core patterns and components of Delphi to enhance your application's designLearn how to select the right patterns to improve your program's efficiency and productivityDiscover how parallel programming and memory management can optimize your codeBook Description Delphi is a cross-platform Integrated Development Environment (IDE) that supports rapid application development for most operating systems, including Microsoft Windows, iOS, and now Linux with RAD Studio 10.2. If you know how to use the features of Delphi, you can easily create scalable applications in no time. This Learning Path begins by explaining how to find performance bottlenecks and apply the correct algorithm to fix them. You'll brush up on tricks, techniques, and best practices to solve common design and architectural challenges. Then, you'll see how to leverage external libraries to write better-performing programs. You'll also learn about the eight most important patterns that'll enable you to develop and improve the interface between items and harmonize shared memories within threads. As you progress, you'll also delve into improving the performance of your code and mastering cross-platform RTL improvements. By the end of this Learning Path, you'll be able to address common design problems and feel confident while building scalable projects. This Learning Path includes content from the following Packt products: Delphi High Performance by Primož GabrijelčičHands-On Design Patterns with Delphi by Primož GabrijelčičWhat you will learnUnderstand parallel programming and work with the various tools included with DelphiExplore memory managers and their implementationLeverage external libraries to write better-performing programsKeep up to date with the latest additions and design techniques in DelphiGet to grips with various modern multithreading approachesBreak a design problem down into its component partsWho this book is for This Learning Path is for intermediate-level Delphi programmers who want to build robust applications using Delphi features. Prior knowledge of Delphi is assumed.

In today’s app-driven era, when programs are asynchronous and responsiveness is so vital, reactive programming can help you write code that’s more reliable, easier to scale, and better-performing. With this practical book, Java developers will first learn how to view problems in the reactive way, and then build programs that leverage the best features of this exciting new programming paradigm. Authors Tomasz Nurkiewicz and Ben Christensen include concrete examples that use the RxJava library to solve real-world performance issues on Android devices as well as the server. You’ll learn how RxJava leverages parallelism and concurrency to help you solve today’s problems. This book also provides a preview of the upcoming 2.0 release. Write programs that react to multiple asynchronous sources of input without descending into "callback hell" Get to that aha! moment when you understand how to solve problems in the reactive way Cope with Observables that produce data too quickly to be consumed Explore strategies to debug and to test programs written in the reactive style Efficiently exploit parallelism and concurrency in your programs Learn about the transition to RxJava version 2

Get up to speed with creational, structural, behavioral and concurrent patterns in Delphi to write clear, concise and effective code Key FeaturesDelve into the core patterns and components of Delphi in order to master your application's designBrush up on tricks, techniques, and best practices to solve common design and architectural challengesChoose the right patterns to improve your program’s efficiency and productivityBook Description Design patterns have proven to be the go-to solution for many common programming scenarios. This book focuses on design patterns applied to the Delphi language. The book will provide you with insights into the language and its capabilities of a runtime library. You'll start by exploring a variety of design patterns and understanding them through real-world examples. This will entail a short explanation of the concept of design patterns and the original set of the 'Gang of Four' patterns, which will help you in structuring your designs efficiently. Next, you'll cover the most important 'anti-patterns' (essentially bad software development practices) to aid you in steering clear of problems during programming. You'll then learn about the eight most important patterns for each creational, structural, and behavioral type. After this, you'll be introduced to the concept of 'concurrency' patterns, which are design patterns specifically related to multithreading and parallel computation. These will enable you to develop and improve an interface between items and harmonize shared memories within threads. Toward the concluding chapters, you'll explore design patterns specific to program design and other categories of patterns that do not fall under the 'design' umbrella. By the end of this book, you'll be able to address common design problems encountered while developing applications and feel confident while building scalable projects. What you will learnGain insights into the concept of design patternsStudy modern programming techniques with DelphiKeep up to date with the latest additions and program design techniques in DelphiGet to grips with various modern multithreading approachesDiscover creational, structural, behavioral, and concurrent patternsDetermine how to break a design problem down into its component partsWho this book is for Hands-On Design Patterns with Delphi is aimed at beginner-level Delphi developers who want to build scalable and robust applications. Basic knowledge of Delphi is a must.

This book shows how to develop software based on parts that interact primarily through an event mechanism. The book demonstrates the use of events in all sorts of situations to solve recurring development problems without incurring coupling. A novel form of software diagram is introduced, called Signal Wiring Diagram. These diagrams are similar to the circuit diagrams used by hardware designers. A series of case studies concludes the book, bringing all the next concepts introduced together. Source code is provided in both C# and VB.NET

Create modern yet effective multi-platform applications by building interactive UIs following a single codebase approach to boost productivity Key FeaturesDelve into the FireMonkey framework and explore its powerful capabilitiesEnhance the user experience by using various technologies included in Delphi and FMXBoost developer productivity through the cross-platform capabilities enabled by the frameworkBook Description FireMonkey (FMX) is a cross-platform application framework that allows developers to create exciting user interfaces and deliver applications on multiple operating systems (OS). This book will help you learn visual programming with Delphi and FMX. Starting with an overview of the FMX framework, including a general discussion of the underlying philosophy and approach, you’ll then move on to the fundamentals and architectural details of FMX. You’ll also cover a significant comparison between Delphi and the Visual Component Library (VCL). Next, you’ll focus on the main FMX components, data access/data binding, and style concepts, in addition to understanding how to deliver visually responsive UIs. To address modern application development, the book takes you through topics such as animations and effects, and provides you with a general introduction to parallel programming, specifically targeting UI-related aspects, including application responsiveness. Later, you’ll explore the most important cross-platform services in the FMX framework, which are essential for delivering your application on multiple platforms while retaining the single codebase approach. Finally, you’ll learn about FMX’s built-in 3D functionalities. By the end of this book, you’ll be familiar with the FMX framework and be able to build effective cross-platform apps. What you will learnExplore FMX’s fundamental components with a brief comparison to VCLAchieve visual responsiveness through alignment capabilities and layout componentsEnrich the user experience with the help of transitions and visual animationsGet to grips with data access and visual data bindingBuild exciting and responsive UIs for desktop and mobile platformsUnderstand the importance of responsive applications using parallel programmingCreate visual continuity through your applications with TFrameStand and TFormStandExplore the 3D functionalities offered by FMXWho this book is for This book is for Delphi developers who are looking to discover the full potential of the FireMonkey framework in order to build interactive cross-platform GUI applications and achieve an optimal UI/UX. Basic familiarity with Delphi programming and the VCL will be beneficial but not mandatory.