Advanced Programming Terminology

Master essential advanced programming concepts that every developer should know.

1. Dependency Injection (DI)

Definition: A design pattern where objects receive their dependencies from external sources rather than creating them internally.

Without DI

public class UserService
{
    private Database _db = new Database(); // Tight coupling
    
    public User GetUser(int id)
    {
        return _db.Query(id);
    }
}

With DI

public class UserService
{
    private readonly IDatabase _db;
    
    // Dependency injected via constructor
    public UserService(IDatabase database)
    {
        _db = database;
    }
    
    public User GetUser(int id)
    {
        return _db.Query(id);
    }
}

Benefits: Testability, loose coupling, easier maintenance

2. Mutex (Mutual Exclusion)

Definition: A synchronization primitive that prevents multiple threads from accessing a shared resource simultaneously.

private static Mutex mutex = new Mutex();

public void AccessSharedResource()
{
    mutex.WaitOne(); // Acquire lock
    try
    {
        // Critical section - only one thread at a time
        Console.WriteLine("Accessing shared resource");
        Thread.Sleep(1000);
    }
    finally
    {
        mutex.ReleaseMutex(); // Release lock
    }
}

3. Lock

Definition: A lightweight synchronization mechanism in C# for thread-safe access to shared resources.

private static object lockObject = new object();
private static int counter = 0;

public void IncrementCounter()
{
    lock (lockObject)
    {
        counter++; // Thread-safe increment
        Console.WriteLine($"Counter: {counter}");
    }
}

Difference: Mutex can work across processes, Lock only within the same process

4. Watchdog

Definition: A monitoring mechanism that detects and recovers from system failures or hangs.

public class Watchdog
{
    private Timer _timer;
    private DateTime _lastHeartbeat;
    
    public void Start()
    {
        _lastHeartbeat = DateTime.Now;
        _timer = new Timer(CheckHeartbeat, null, 0, 5000); // Check every 5s
    }
    
    private void CheckHeartbeat(object state)
    {
        if ((DateTime.Now - _lastHeartbeat).TotalSeconds > 10)
        {
            Console.WriteLine("System hang detected! Restarting...");
            RestartSystem();
        }
    }
    
    public void Heartbeat()
    {
        _lastHeartbeat = DateTime.Now; // Reset watchdog
    }
}

5. CancellationToken

Definition: A mechanism to signal cancellation of asynchronous operations.

public async Task LongRunningOperation(CancellationToken token)
{
    for (int i = 0; i < 100; i++)
    {
        token.ThrowIfCancellationRequested(); // Check for cancellation
        
        await Task.Delay(100);
        Console.WriteLine($"Progress: {i}%");
    }
}

// Usage
var cts = new CancellationTokenSource();
var task = LongRunningOperation(cts.Token);

// Cancel after 2 seconds
await Task.Delay(2000);
cts.Cancel(); // Triggers cancellation

6. Scaffolding

Definition: Automatic code generation based on templates to create boilerplate code quickly.

# ASP.NET Core scaffolding example
dotnet aspnet-codegenerator controller -name ProductController -m Product -dc AppDbContext --relativeFolderPath Controllers --useDefaultLayout

# Generates:
# - ProductController.cs with CRUD actions
# - Views (Index, Create, Edit, Delete, Details)
# - Routes and model binding

Benefits: Faster development, consistency, reduced errors

Comparison Table

Concept	Purpose	Use Case
Dependency Injection	Loose coupling	Testable, maintainable code
Mutex	Cross-process synchronization	Shared resources across processes
Lock	Thread synchronization	Thread-safe operations
Watchdog	System monitoring	Detect and recover from hangs
CancellationToken	Async cancellation	Stop long-running operations
Scaffolding	Code generation	Rapid development