Just released: Delphi Event-based and Asynchronous Programming - Complete version - 291 Pages
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 single-threaded 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.
Table of Contents
1. The LoopHidden complexity
Peeking at the console
Main event loop
2. Messaging SystemsWindows messaging system
Windows messaging system in VCL
Custom messaging systems and patterns
3. Life, the Universe, and EverythingLife, the Universe, and Everything
Automatic memory management
Anonymous methods and lambdas
4. Asynchronous Programming and MultithreadingAsynchronous programming and multithreading
Making the first dive...
Application.ProcessMessages reentrancy problem
Moving long operations to a background thread
Asynchronous message dialog
5. Thread SafetyWhat is thread safety anyway?
The importance of thread safety
Achieving thread safety
Avoiding shared data
Protecting shared data
6. GUI and MultithreadingMain (GUI) thread
Communicating with the main thread