Exemplos de Multithreading Web TypeScript

// Web TypeScript Web Workers Examples
// Using Web Workers for parallel execution and background processing

// 1. Basic Web Worker Creation
class WorkerManager {
  private workers: Map<string, Worker> = new Map();

  // Create inline worker from code
  createInlineWorker(name: string, workerCode: string): Worker {
    const blob = new Blob([workerCode], { type: 'application/javascript' });
    const workerUrl = URL.createObjectURL(blob);
    const worker = new Worker(workerUrl);

    this.workers.set(name, worker);
    return worker;
  }

  // Create worker from external file
  createWorker(name: string, workerFile: string): Worker {
    const worker = new Worker(workerFile);
    this.workers.set(name, worker);
    return worker;
  }

  // Get worker by name
  getWorker(name: string): Worker | undefined {
    return this.workers.get(name);
  }

  // Terminate worker
  terminateWorker(name: string): void {
    const worker = this.workers.get(name);
    if (worker) {
      worker.terminate();
      this.workers.delete(name);
    }
  }

  // Terminate all workers
  terminateAllWorkers(): void {
    for (const [name, worker] of this.workers) {
      worker.terminate();
    }
    this.workers.clear();
  }
}

// 2. Worker Communication
class WorkerCommunication {
  private worker: Worker;

  constructor(worker: Worker) {
    this.worker = worker;
  }

  // Send message to worker
  postMessage(message: any, transfer?: Transferable[]): void {
    this.worker.postMessage(message, transfer);
  }

  // Set onmessage handler
  onMessage(handler: (message: MessageEvent) => void): void {
    this.worker.onmessage = handler;
  }

  // Set onerror handler
  onError(handler: (error: ErrorEvent) => void): void {
    this.worker.onerror = handler;
  }

  // Send message and wait for response
  async sendMessage(message: any): Promise<any> {
    return new Promise((resolve, reject) => {
      const handleMessage = (e: MessageEvent) => {
        this.worker.removeEventListener('message', handleMessage);
        resolve(e.data);
      };

      const handleError = (e: ErrorEvent) => {
        this.worker.removeEventListener('error', handleError);
        reject(e.error);
      };

      this.worker.addEventListener('message', handleMessage);
      this.worker.addEventListener('error', handleError);

      this.worker.postMessage(message);
    });
  }
}

// 3. Worker Task Executor
class WorkerTaskExecutor {
  private workerManager: WorkerManager;

  constructor() {
    this.workerManager = new WorkerManager();
  }

  // Execute computation in worker
  async executeComputation(input: any): Promise<any> {
    const workerCode = `
      self.onmessage = function(e) {
        const input = e.data;
        const result = performComputation(input);
        self.postMessage(result);
      };

      function performComputation(input) {
        // Perform computation here
        return { result: input.value * 2 };
      }
    `;

    const worker = this.workerManager.createInlineWorker('computation', workerCode);
    const comm = new WorkerCommunication(worker);

    const result = await comm.sendMessage(input);
    this.workerManager.terminateWorker('computation');

    return result;
  }

  // Execute parallel computations
  async executeParallel(inputs: any[], workerCode: string): Promise<any[]> {
    const workers: Worker[] = [];
    const promises: Promise<any>[] = [];

    for (const input of inputs) {
      const worker = this.workerManager.createInlineWorker(`worker-${inputs.indexOf(input)}`, workerCode);
      workers.push(worker);

      const comm = new WorkerCommunication(worker);
      promises.push(comm.sendMessage(input));
    }

    const results = await Promise.all(promises);

    // Clean up workers
    workers.forEach(worker => worker.terminate());

    return results;
  }
}

// 4. Worker Pool
class WorkerPool {
  private workers: Worker[] = [];
  private taskQueue: Array<{ task: any; resolve: (value: any) => void; reject: (reason: any) => void }> = [];
  private availableWorkers: Worker[] = [];
  private inFlightTasks: Map<Worker, { task: any; resolve: (value: any) => void; reject: (reason: any) => void }> = new Map();

  constructor(workerCode: string, poolSize: number) {
    // Create workers
    for (let i = 0; i < poolSize; i++) {
      const blob = new Blob([workerCode], { type: 'application/javascript' });
      const workerUrl = URL.createObjectURL(blob);
      const worker = new Worker(workerUrl);

      worker.onmessage = (e) => {
        const task = this.inFlightTasks.get(worker);
        if (task) {
          task.resolve(e.data);
          this.inFlightTasks.delete(worker);
          this.releaseWorker(worker);
        }
      };

      worker.onerror = (e) => {
        const task = this.inFlightTasks.get(worker);
        if (task) {
          task.reject(e.error);
          this.inFlightTasks.delete(worker);
          this.releaseWorker(worker);
        }
      };

      this.workers.push(worker);
      this.availableWorkers.push(worker);
    }
  }

  // Execute task
  async execute(task: any): Promise<any> {
    return new Promise((resolve, reject) => {
      this.taskQueue.push({ task, resolve, reject });
      this.processQueue();
    });
  }

  private processQueue(): void {
    if (this.taskQueue.length === 0 || this.availableWorkers.length === 0) {
      return;
    }

    const taskItem = this.taskQueue.shift();
    const worker = this.availableWorkers.shift()!;

    this.inFlightTasks.set(worker, taskItem);
    worker.postMessage(taskItem.task);
  }

  private releaseWorker(worker: Worker): void {
    this.availableWorkers.push(worker);
    this.processQueue();
  }

  // Terminate all workers
  terminate(): void {
    this.workers.forEach(worker => worker.terminate());
    this.workers = [];
    this.availableWorkers = [];
    this.taskQueue = [];
    this.inFlightTasks.clear();
  }
}

// 5. Shared Worker
class SharedWorkerManager {
  private sharedWorker: SharedWorker | null = null;

  // Create shared worker
  createSharedWorker(name: string, workerCode: string): SharedWorker {
    const blob = new Blob([workerCode], { type: 'application/javascript' });
    const workerUrl = URL.createObjectURL(blob);
    this.sharedWorker = new SharedWorker(workerUrl, name);
    return this.sharedWorker;
  }

  // Connect to shared worker port
  connect(): MessagePort {
    if (!this.sharedWorker) {
      throw new Error('Shared worker not created');
    }

    return this.sharedWorker.port;
  }

  // Start connection
  start(): void {
    const port = this.connect();
    port.start();
  }

  // Post message to shared worker
  postMessage(message: any): void {
    const port = this.connect();
    port.postMessage(message);
  }

  // Set message handler
  onMessage(handler: (message: MessageEvent) => void): void {
    const port = this.connect();
    port.onmessage = handler;
  }
}

// 6. Worker with Progress Tracking
class WorkerWithProgress {
  private worker: Worker;
  private communication: WorkerCommunication;

  constructor(workerCode: string) {
    const blob = new Blob([workerCode], { type: 'application/javascript' });
    const workerUrl = URL.createObjectURL(blob);
    this.worker = new Worker(workerUrl);
    this.communication = new WorkerCommunication(this.worker);
  }

  // Execute task with progress callback
  async executeWithProgress(
    task: any,
    onProgress: (progress: number) => void
  ): Promise<any> {
    return new Promise((resolve, reject) => {
      this.communication.onMessage = (e: MessageEvent) => {
        const data = e.data;

        if (data.type === 'progress') {
          onProgress(data.value);
        } else if (data.type === 'complete') {
          resolve(data.result);
        } else if (data.type === 'error') {
          reject(new Error(data.message));
        }
      };

      this.communication.onError = (e: ErrorEvent) => {
        reject(e.error);
      };

      this.communication.postMessage(task);
    });
  }

  // Terminate worker
  terminate(): void {
    this.worker.terminate();
  }
}

// 7. Batch Processing with Workers
class BatchWorkerProcessor {
  private workerManager = new WorkerManager();

  // Process batch of items
  async processBatch<T, R>(
    items: T[],
    processorCode: string,
    batchSize: number = 10,
    onProgress?: (current: number, total: number) => void
  ): Promise<R[]> {
    const results: R[] = [];
    const batches: T[][] = [];

    // Split into batches
    for (let i = 0; i < items.length; i += batchSize) {
      batches.push(items.slice(i, i + batchSize));
    }

    // Process each batch
    for (let i = 0; i < batches.length; i++) {
      const batch = batches[i];
      const batchResults = await this.processBatchImpl(batch, processorCode);
      results.push(...batchResults);

      if (onProgress) {
        onProgress(Math.min((i + 1) * batchSize, items.length), items.length);
      }
    }

    return results;
  }

  private async processBatchImpl<T, R>(batch: T[], processorCode: string): Promise<R[]> {
    const workerCode = `
      ${processorCode}

      self.onmessage = function(e) {
        const batch = e.data;
        const results = batch.map(processItem);
        self.postMessage(results);
      };
    `;

    const worker = this.workerManager.createInlineWorker('batch', workerCode);
    const comm = new WorkerCommunication(worker);

    const results = await comm.sendMessage(batch);
    this.workerManager.terminateWorker('batch');

    return results;
  }
}

// 8. Worker Utilities
class WorkerUtils {
  // Check if Web Workers are supported
  static isSupported(): boolean {
    return typeof Worker !== 'undefined';
  }

  // Check if Shared Workers are supported
  static isSharedWorkerSupported(): boolean {
    return typeof SharedWorker !== 'undefined';
  }

  // Create worker from function
  static createWorkerFromFunction(fn: Function): Worker {
    const fnString = fn.toString();
    const workerCode = `
      const workerFunction = ${fnString};
      self.onmessage = (e) => {
        const result = workerFunction(e.data);
        self.postMessage(result);
      };
    `;

    const blob = new Blob([workerCode], { type: 'application/javascript' });
    const workerUrl = URL.createObjectURL(blob);
    return new Worker(workerUrl);
  }

  // Execute function in worker
  static async executeInWorker<T, R>(fn: (input: T) => R, input: T): Promise<R> {
    const worker = this.createWorkerFromFunction(fn);

    return new Promise((resolve, reject) => {
      worker.onmessage = (e) => {
        resolve(e.data as R);
        worker.terminate();
      };

      worker.onerror = (e) => {
        reject(e.error);
        worker.terminate();
      };

      worker.postMessage(input);
    });
  }
}

// Usage Examples
async function demonstrateWebWorkers() {
  console.log('=== Web TypeScript Web Workers Examples ===\n');

  // Check support
  console.log('--- Web Workers Support ---');
  console.log(`Web Workers supported: ${WorkerUtils.isSupported()}`);
  console.log(`Shared Workers supported: ${WorkerUtils.isSharedWorkerSupported()}`);

  // 1. Basic worker
  console.log('\n--- 1. Basic Web Worker ---');
  const workerManager = new WorkerManager();

  const basicWorkerCode = `
    self.onmessage = function(e) {
      const data = e.data;
      console.log('Worker received:', data);
      const result = data.value * 2;
      self.postMessage({ result: result });
    };
  `;

  const worker = workerManager.createInlineWorker('basic', basicWorkerCode);
  const comm = new WorkerCommunication(worker);

  comm.onMessage = (e) => {
    console.log(`Worker response: ${JSON.stringify(e.data)}`);
  };

  comm.postMessage({ value: 21 });

  // Wait for response
  await new Promise(resolve => setTimeout(resolve, 100));
  workerManager.terminateWorker('basic');

  // 2. Execute computation in worker
  console.log('\n--- 2. Execute Computation ---');
  const executor = new WorkerTaskExecutor();

  const computationResult = await executor.executeComputation({ value: 10 });
  console.log(`Computation result: ${JSON.stringify(computationResult)}`);

  // 3. Parallel execution
  console.log('\n--- 3. Parallel Execution ---');
  const parallelWorkerCode = `
    self.onmessage = function(e) {
      const input = e.data;
      const result = input * input; // Square the input
      self.postMessage(result);
    };
  `;

  const inputs = [1, 2, 3, 4, 5];
  const parallelResults = await executor.executeParallel(inputs, parallelWorkerCode);
  console.log(`Parallel results: ${parallelResults.join(', ')}`);

  // 4. Worker with progress
  console.log('\n--- 4. Worker with Progress ---');
  const progressWorkerCode = `
    self.onmessage = function(e) {
      const task = e.data;

      // Simulate progress
      for (let i = 0; i <= 100; i += 10) {
        self.postMessage({ type: 'progress', value: i });
      }

      self.postMessage({ type: 'complete', result: task.input * 2 });
    };
  `;

  const progressWorker = new WorkerWithProgress(progressWorkerCode);
  const progressResult = await progressWorker.executeWithProgress(
    { input: 15 },
    (progress) => console.log(`Progress: ${progress}%`)
  );
  console.log(`Result with progress: ${progressResult.result}`);
  progressWorker.terminate();

  // 5. Batch processing
  console.log('\n--- 5. Batch Processing ---');
  const batchProcessor = new BatchWorkerProcessor();

  const processorCode = `
    function processItem(item) {
      return item * item;
    }
  `;

  const items = Array.from({ length: 25 }, (_, i) => i + 1);
  const batchResults = await batchProcessor.processBatch(
    items,
    processorCode,
    5,
    (current, total) => console.log(`Batch progress: ${current}/${total}`)
  );

  console.log(`Batch results (first 10): ${batchResults.slice(0, 10).join(', ')}...`);

  // 6. Execute function in worker
  console.log('\n--- 6. Execute Function in Worker ---');
  const squareResult = await WorkerUtils.executeInWorker(
    (x: number) => x * x,
    7
  );
  console.log(`Square result: ${squareResult}`);

  // 7. Heavy computation
  console.log('\n--- 7. Heavy Computation ---');
  const heavyWorkerCode = `
    self.onmessage = function(e) {
      const n = e.data.n;
      let sum = 0;

      for (let i = 1; i <= n; i++) {
        sum += i;
      }

      self.postMessage({ sum: sum });
    };
  `;

  const heavyWorker = workerManager.createInlineWorker('heavy', heavyWorkerCode);
  const heavyComm = new WorkerCommunication(heavyWorker);

  const heavyResult = await heavyComm.sendMessage({ n: 1000000 });
  console.log(`Heavy computation result: Sum from 1 to 1000000 = ${heavyResult.sum}`);

  workerManager.terminateWorker('heavy');

  console.log('\n=== All Web Workers Examples Completed ===');
}

// Export classes
export { WorkerManager, WorkerCommunication, WorkerTaskExecutor, WorkerPool, SharedWorkerManager, WorkerWithProgress, BatchWorkerProcessor, WorkerUtils };
export { demonstrateWebWorkers };

// Web TypeScript Async/Await Operations Examples
// Mastering Promises, async/await, and concurrent execution patterns

// 1. Promise Basics
class PromiseBasics {
  // Create a resolving promise
  static resolve<T>(value: T): Promise<T> {
    return Promise.resolve(value);
  }

  // Create a rejecting promise
  static reject<T>(error: T): Promise<never> {
    return Promise.reject(error);
  }

  // Create promise from callback
  static fromCallback<T>(
    callback: (cb: (error: Error | null, result: T) => void) => void
  ): Promise<T> {
    return new Promise((resolve, reject) => {
      callback((error, result) => {
        if (error) {
          reject(error);
        } else {
          resolve(result);
        }
      });
    });
  }

  // Delay execution
  static delay(ms: number): Promise<void> {
    return new Promise(resolve => setTimeout(resolve, ms));
  }

  // Timeout a promise
  static withTimeout<T>(promise: Promise<T>, timeoutMs: number, errorMessage: string = 'Timeout'): Promise<T> {
    return Promise.race([
      promise,
      PromiseBasics.delay(timeoutMs).then(() => {
        throw new Error(errorMessage);
      })
    ]);
  }

  // Retry promise
  static async retry<T>(
    fn: () => Promise<T>,
    maxAttempts: number = 3,
    delayMs: number = 1000
  ): Promise<T> {
    let lastError: Error;

    for (let attempt = 1; attempt <= maxAttempts; attempt++) {
      try {
        return await fn();
      } catch (error) {
        lastError = error as Error;
        if (attempt < maxAttempts) {
          await this.delay(delayMs * attempt);
        }
      }
    }

    throw lastError!;
  }
}

// 2. Async Control Flow
class AsyncControlFlow {
  // Execute sequentially
  static async sequential<T>(tasks: Array<() => Promise<T>>): Promise<T[]> {
    const results: T[] = [];

    for (const task of tasks) {
      const result = await task();
      results.push(result);
    }

    return results;
  }

  // Execute parallel with limit
  static async parallelWithLimit<T>(
    tasks: Array<() => Promise<T>>,
    limit: number
  ): Promise<T[]> {
    const results: T[] = [];
    const executing: Promise<void>[] = [];

    for (const task of tasks) {
      const promise = task().then(result => {
        results.push(result);
      });

      executing.push(promise);

      if (executing.length >= limit) {
        await Promise.race(executing);
        executing.splice(executing.findIndex(p => p === promise), 1);
      }
    }

    await Promise.all(executing);
    return results;
  }

  // Execute parallel with batching
  static async batchParallel<T>(
    items: T[],
    processor: (item: T) => Promise<any>,
    batchSize: number
  ): Promise<any[]> {
    const results: any[] = [];

    for (let i = 0; i < items.length; i += batchSize) {
      const batch = items.slice(i, i + batchSize);
      const batchResults = await Promise.all(batch.map(processor));
      results.push(...batchResults);
    }

    return results;
  }

  // Execute with fallback
  static async withFallback<T>(
    primary: () => Promise<T>,
    fallback: () => Promise<T>
  ): Promise<T> {
    try {
      return await primary();
    } catch {
      return await fallback();
    }
  }

  // Execute with circuit breaker
  static withCircuitBreaker<T>(
    fn: () => Promise<T>,
    options: {
      timeout?: number;
      maxFailures?: number;
      resetTimeout?: number;
    } = {}
  ): () => Promise<T> {
    let failures = 0;
    let lastFailureTime = 0;
    let circuitOpen = false;

    const {
      timeout = 5000,
      maxFailures = 5,
      resetTimeout = 60000
    } = options;

    return async () => {
      if (circuitOpen) {
        if (Date.now() - lastFailureTime > resetTimeout) {
          circuitOpen = false;
          failures = 0;
        } else {
          throw new Error('Circuit breaker is open');
        }
      }

      try {
        const result = await PromiseBasics.withTimeout(fn(), timeout);
        failures = 0;
        return result;
      } catch (error) {
        failures++;
        lastFailureTime = Date.now();

        if (failures >= maxFailures) {
          circuitOpen = true;
        }

        throw error;
      }
    };
  }
}

// 3. Async Utilities
class AsyncUtilities {
  // Map array asynchronously
  static async map<T, R>(
    array: T[],
    mapper: (item: T, index: number) => Promise<R>
  ): Promise<R[]> {
    const promises = array.map((item, index) => mapper(item, index));
    return Promise.all(promises);
  }

  // Filter array asynchronously
  static async filter<T>(
    array: T[],
    predicate: (item: T, index: number) => Promise<boolean>
  ): Promise<T[]> {
    const results = await Promise.all(
      array.map(async (item, index) => ({
        item,
        keep: await predicate(item, index)
      }))
    );

    return results.filter(result => result.keep).map(result => result.item);
  }

  // Reduce array asynchronously
  static async reduce<T, R>(
    array: T[],
    reducer: (accumulator: R, item: T, index: number) => Promise<R>,
    initialValue: R
  ): Promise<R> {
    let accumulator = initialValue;

    for (let i = 0; i < array.length; i++) {
      accumulator = await reducer(accumulator, array[i], i);
    }

    return accumulator;
  }

  // Find asynchronously
  static async find<T>(
    array: T[],
    predicate: (item: T) => Promise<boolean>
  ): Promise<T | undefined> {
    for (const item of array) {
      if (await predicate(item)) {
        return item;
      }
    }
    return undefined;
  }

  // Some asynchronously
  static async some<T>(
    array: T[],
    predicate: (item: T) => Promise<boolean>
  ): Promise<boolean> {
    for (const item of array) {
      if (await predicate(item)) {
        return true;
      }
    }
    return false;
  }

  // Every asynchronously
  static async every<T>(
    array: T[],
    predicate: (item: T) => Promise<boolean>
  ): Promise<boolean> {
    for (const item of array) {
      if (!(await predicate(item))) {
        return false;
      }
    }
    return true;
  }
}

// 4. Async Queue
class AsyncQueue<T> {
  private queue: T[] = [];
  private pendingWaiters: Array<(value: T) => void> = [];

  // Enqueue item
  enqueue(item: T): void {
    if (this.pendingWaiters.length > 0) {
      const waiter = this.pendingWaiters.shift()!;
      waiter(item);
    } else {
      this.queue.push(item);
    }
  }

  // Dequeue item
  async dequeue(): Promise<T> {
    if (this.queue.length > 0) {
      return this.queue.shift()!;
    }

    return new Promise(resolve => {
      this.pendingWaiters.push(resolve);
    });
  }

  // Get size
  get size(): number {
    return this.queue.length;
  }
}

// 5. Async Mutex
class AsyncMutex {
  private locked = false;
  private waiters: Array<() => void> = [];

  // Acquire lock
  async acquire(): Promise<void> {
    if (!this.locked) {
      this.locked = true;
      return;
    }

    return new Promise(resolve => {
      this.waiters.push(resolve);
    });
  }

  // Release lock
  release(): void {
    if (this.waiters.length > 0) {
      const waiter = this.waiters.shift()!;
      waiter();
    } else {
      this.locked = false;
    }
  }

  // Execute critical section
  async execute<T>(fn: () => Promise<T>): Promise<T> {
    await this.acquire();
    try {
      return await fn();
    } finally {
      this.release();
    }
  }
}

// 6. Async Semaphore
class AsyncSemaphore {
  private permits: number;
  private waiters: Array<() => void> = [];

  constructor(permits: number) {
    this.permits = permits;
  }

  // Acquire permit
  async acquire(): Promise<void> {
    if (this.permits > 0) {
      this.permits--;
      return;
    }

    return new Promise(resolve => {
      this.waiters.push(resolve);
    });
  }

  // Release permit
  release(): void {
    if (this.waiters.length > 0) {
      const waiter = this.waiters.shift()!;
      waiter();
    } else {
      this.permits++;
    }
  }

  // Execute with semaphore
  async execute<T>(fn: () => Promise<T>): Promise<T> {
    await this.acquire();
    try {
      return await fn();
    } finally {
      this.release();
    }
  }
}

// 7. Async Cache
class AsyncCache<K, V> {
  private cache = new Map<K, V>();
  private pending = new Map<K, Promise<V>>();

  // Get or compute value
  async getOrCompute(key: K, compute: () => Promise<V>): Promise<V> {
    // Check cache
    if (this.cache.has(key)) {
      return this.cache.get(key)!;
    }

    // Check pending computation
    if (this.pending.has(key)) {
      return this.pending.get(key)!;
    }

    // Compute new value
    const promise = compute().then(value => {
      this.cache.set(key, value);
      this.pending.delete(key);
      return value;
    });

    this.pending.set(key, promise);
    return promise;
  }

  // Get value
  get(key: K): V | undefined {
    return this.cache.get(key);
  }

  // Set value
  set(key: K, value: V): void {
    this.cache.set(key, value);
  }

  // Clear cache
  clear(): void {
    this.cache.clear();
    this.pending.clear();
  }

  // Get size
  get size(): number {
    return this.cache.size;
  }
}

// 8. Async Rate Limiter
class AsyncRateLimiter {
  private queue: Array<() => void> = [];
  private running = 0;
  private interval: number;

  constructor(concurrency: number, intervalMs: number) {
    this.interval = intervalMs;
    this.running = concurrency;

    // Start ticker
    setInterval(() => {
      if (this.queue.length > 0 && this.running < concurrency) {
        const task = this.queue.shift()!;
        task();
        this.running--;
      }
    }, intervalMs);
  }

  // Execute with rate limiting
  async execute<T>(fn: () => Promise<T>): Promise<T> {
    return new Promise((resolve, reject) => {
      const task = async () => {
        try {
          const result = await fn();
          resolve(result);
        } catch (error) {
          reject(error);
        }
      };

      if (this.running > 0) {
        this.running--;
        task();
      } else {
        this.queue.push(task);
      }
    });
  }
}

// Usage Examples
async function demonstrateAsyncOperations() {
  console.log('=== Web TypeScript Async/Await Operations Examples ===\n');

  // 1. Promise basics
  console.log('--- 1. Promise Basics ---');
  const resolved = await PromiseBasics.resolve(42);
  console.log(`Resolved: ${resolved}`);

  try {
    await PromiseBasics.reject(new Error('Test error'));
  } catch (error) {
    console.log(`Rejected: ${(error as Error).message}`);
  }

  await PromiseBasics.delay(100);
  console.log('Delay completed');

  // 2. Sequential vs parallel
  console.log('\n--- 2. Sequential vs Parallel ---');

  const tasks = [
    () => PromiseBasics.delay(100).then(() => 1),
    () => PromiseBasics.delay(200).then(() => 2),
    () => PromiseBasics.delay(150).then(() => 3)
  ];

  const startTime = Date.now();
  const sequentialResults = await AsyncControlFlow.sequential(tasks);
  console.log(`Sequential: ${sequentialResults.join(', ')} (${Date.now() - startTime}ms)`);

  const parallelResults = await Promise.all(tasks.map(t => t()));
  console.log(`Parallel: ${parallelResults.join(', ')} (${Date.now() - startTime}ms)`);

  // 3. Parallel with limit
  console.log('\n--- 3. Parallel with Limit ---');
  const limitStartTime = Date.now();
  const limitedResults = await AsyncControlFlow.parallelWithLimit(tasks, 2);
  console.log(`Limited (2): ${limitedResults.join(', ')} (${Date.now() - limitStartTime}ms)`);

  // 4. Async map
  console.log('\n--- 4. Async Map ---');
  const numbers = [1, 2, 3, 4, 5];
  const doubled = await AsyncUtilities.map(numbers, async (n) => {
    await PromiseBasics.delay(50);
    return n * 2;
  });
  console.log(`Doubled: ${doubled.join(', ')}`);

  // 5. Async filter
  console.log('\n--- 5. Async Filter ---');
  const evens = await AsyncUtilities.filter(numbers, async (n) => {
    await PromiseBasics.delay(10);
    return n % 2 === 0;
  });
  console.log(`Even numbers: ${evens.join(', ')}`);

  // 6. Async queue
  console.log('\n--- 6. Async Queue ---');
  const queue = new AsyncQueue<number>();

  queue.enqueue(1);
  queue.enqueue(2);
  queue.enqueue(3);

  console.log(`Queue size: ${queue.size}`);
  console.log(`Dequeue: ${await queue.dequeue()}`);
  console.log(`Dequeue: ${await queue.dequeue()}`);

  // 7. Async mutex
  console.log('\n--- 7. Async Mutex ---');
  const mutex = new AsyncMutex();

  const mutexTask = mutex.execute(async () => {
    console.log('Critical section start');
    await PromiseBasics.delay(100);
    console.log('Critical section end');
    return 'done';
  });

  console.log(`Mutex result: ${await mutexTask}`);

  // 8. Async cache
  console.log('\n--- 8. Async Cache ---');
  const cache = new AsyncCache<string, string>();

  const computeResult1 = await cache.getOrCompute('key1', async () => {
    console.log('Computing value for key1');
    await PromiseBasics.delay(100);
    return 'value1';
  });

  const computeResult2 = await cache.getOrCompute('key1', async () => {
    console.log('This should not print');
    return 'value1-different';
  });

  console.log(`Cache results: ${computeResult1}, ${computeResult2}`);
  console.log(`Cache size: ${cache.size}`);

  // 9. Retry
  console.log('\n--- 9. Retry ---');
  let attempts = 0;
  const retryResult = await PromiseBasics.retry(async () => {
    attempts++;
    console.log(`Attempt ${attempts}`);
    if (attempts < 3) {
      throw new Error('Not yet');
    }
    return 'success';
  }, 5, 50);

  console.log(`Retry result: ${retryResult}`);

  // 10. Timeout
  console.log('\n--- 10. Timeout ---');
  try {
    await PromiseBasics.withTimeout(
      PromiseBasics.delay(2000).then(() => 'slow'),
      100,
      'Too slow'
    );
  } catch (error) {
    console.log(`Timeout error: ${(error as Error).message}`);
  }

  console.log('\n=== All Async/Await Examples Completed ===');
}

// Export classes
export { PromiseBasics, AsyncControlFlow, AsyncUtilities, AsyncQueue, AsyncMutex, AsyncSemaphore, AsyncCache, AsyncRateLimiter };
export { demonstrateAsyncOperations };

// Web TypeScript Synchronization Primitives Examples
// Using Atomics, SharedArrayBuffer, and custom synchronization

// 1. Atomics Operations
class AtomicsOperations {
  // Create shared buffer
  static createSharedBuffer(size: number): Int32Array {
    const buffer = new SharedArrayBuffer(size * Int32Array.BYTES_PER_ELEMENT);
    return new Int32Array(buffer);
  }

  // Compare and swap
  static compareAndSwap(
    array: Int32Array,
    index: number,
    expectedValue: number,
    newValue: number
  ): boolean {
    return Atomics.compareExchange(array, index, expectedValue, newValue) === expectedValue;
  }

  // Add atomically
  static add(array: Int32Array, index: number, value: number): number {
    return Atomics.add(array, index, value);
  }

  // Sub atomically
  static sub(array: Int32Array, index: number, value: number): number {
    return Atomics.sub(array, index, value);
  }

  // Increment atomically
  static increment(array: Int32Array, index: number): number {
    return Atomics.add(array, index, 1);
  }

  // Decrement atomically
  static decrement(array: Int32Array, index: number): number {
    return Atomics.sub(array, index, 1);
  }

  // Load atomically
  static load(array: Int32Array, index: number): number {
    return Atomics.load(array, index);
  }

  // Store atomically
  static store(array: Int32Array, index: number, value: number): void {
    Atomics.store(array, index, value);
  }

  // Wait for notification
  static waitAsync(array: Int32Array, index: number, expectedValue: number, timeout?: number): Promise<'ok' | 'not-equal' | 'timed-out'> {
    return Atomics.waitAsync(array, index, expectedValue, timeout).then(() => 'ok');
  }

  // Notify waiters
  static notify(array: Int32Array, index: number, count: number): number {
    return Atomics.notify(array, index, count);
  }
}

// 2. Spinlock
class Spinlock {
  private locked: Int32Array;

  constructor() {
    this.locked = AtomicsOperations.createSharedBuffer(1);
  }

  // Acquire lock (busy-wait)
  acquire(): void {
    while (true) {
      // Try to acquire lock
      const previous = AtomicsOperations.exchange(this.locked, 0, 1);

      if (previous === 0) {
        // Lock acquired
        return;
      }

      // Wait for notification
      Atomics.wait(this.locked, 0, 1);
    }
  }

  // Release lock
  release(): void {
    AtomicsOperations.store(this.locked, 0, 0);
    AtomicsOperations.notify(this.locked, 0, 1);
  }
}

// 3. Mutex (Better than Spinlock)
class Mutex {
  private locked: Int32Array;

  constructor() {
    this.locked = AtomicsOperations.createSharedBuffer(1);
  }

  // Acquire lock with timeout
  async acquire(timeoutMs: number = 5000): Promise<boolean> {
    const start = Date.now();

    while (true) {
      // Try to acquire lock
      const previous = AtomicsOperations.compareAndSwap(this.locked, 0, 0, 1);

      if (previous === 0) {
        return true;
      }

      // Check timeout
      if (Date.now() - start > timeoutMs) {
        return false;
      }

      // Wait with timeout
      await AtomicsOperations.waitAsync(this.locked, 0, 1, 100);
    }
  }

  // Release lock
  release(): void {
    AtomicsOperations.store(this.locked, 0, 0);
    AtomicsOperations.notify(this.locked, 0, 1);
  }

  // Execute critical section
  async execute<T>(fn: () => Promise<T>, timeoutMs?: number): Promise<T> {
    const acquired = await this.acquire(timeoutMs);

    if (!acquired) {
      throw new Error('Mutex acquisition timeout');
    }

    try {
      return await fn();
    } finally {
      this.release();
    }
  }
}

// 4. Semaphore
class Semaphore {
  private permits: Int32Array;

  constructor(initialPermits: number) {
    this.permits = AtomicsOperations.createSharedBuffer(1);
    AtomicsOperations.store(this.permits, 0, initialPermits);
  }

  // Acquire permit
  async acquire(timeoutMs: number = 5000): Promise<boolean> {
    const start = Date.now();

    while (true) {
      const current = AtomicsOperations.load(this.permits, 0);

      if (current > 0) {
        // Try to acquire permit
        const previous = AtomicsOperations.compareAndSwap(
          this.permits,
          0,
          current,
          current - 1
        );

        if (previous === current) {
          return true;
        }
      }

      // Check timeout
      if (Date.now() - start > timeoutMs) {
        return false;
      }

      // Wait
      await AtomicsOperations.waitAsync(this.permits, 0, current, 100);
    }
  }

  // Release permit
  release(): void {
    AtomicsOperations.increment(this.permits, 0);
    AtomicsOperations.notify(this.permits, 0, 1);
  }

  // Execute with semaphore
  async execute<T>(fn: () => Promise<T>): Promise<T> {
    await this.acquire();
    try {
      return await fn();
    } finally {
      this.release();
    }
  }
}

// 5. Barrier
class Barrier {
  private count: Int32Array;
  private waiting: Int32Array;
  private total: number;

  constructor(parties: number) {
    this.total = parties;
    this.count = AtomicsOperations.createSharedBuffer(1);
    this.waiting = AtomicsOperations.createSharedBuffer(1);
  }

  // Wait for all parties
  async wait(): Promise<void> {
    const index = AtomicsOperations.add(this.waiting, 0, 1);

    if (index === this.total) {
      // Last party resets the barrier
      AtomicsOperations.store(this.waiting, 0, 0);
      AtomicsOperations.store(this.count, 0, 0);
      AtomicsOperations.notify(this.count, 0, this.total);
    } else {
      // Wait for last party
      await AtomicsOperations.waitAsync(this.count, 0, 0);
    }
  }

  // Reset barrier
  reset(): void {
    AtomicsOperations.store(this.waiting, 0, 0);
    AtomicsOperations.store(this.count, 0, 0);
  }
}

// 6. Read-Write Lock
class ReadWriteLock {
  private readers: Int32Array;
  private writer: Int32Array;

  constructor() {
    this.readers = AtomicsOperations.createSharedBuffer(1);
    this.writer = AtomicsOperations.createSharedBuffer(1);
  }

  // Acquire read lock
  async acquireReadLock(): Promise<void> {
    while (true) {
      // Wait if writer is active
      while (AtomicsOperations.load(this.writer, 0) !== 0) {
        await AtomicsOperations.waitAsync(this.writer, 0, 0);
      }

      // Increment readers
      AtomicsOperations.increment(this.readers, 0);

      // Check if writer is still not active
      if (AtomicsOperations.load(this.writer, 0) === 0) {
        return;
      }

      // Writer became active, back off
      AtomicsOperations.decrement(this.readers, 0);
    }
  }

  // Release read lock
  releaseReadLock(): void {
    AtomicsOperations.decrement(this.readers, 0);

    // Notify potential writer if no readers left
    if (AtomicsOperations.load(this.readers, 0) === 0) {
      AtomicsOperations.notify(this.writer, 0, 1);
    }
  }

  // Acquire write lock
  async acquireWriteLock(): Promise<void> {
    // Mark writer as waiting
    while (true) {
      // Wait for readers to finish
      while (AtomicsOperations.load(this.readers, 0) !== 0) {
        await AtomicsOperations.waitAsync(this.readers, 0, 1);
      }

      // Try to acquire write lock
      const previous = AtomicsOperations.compareAndSwap(this.writer, 0, 0, 1);

      if (previous === 0) {
        return;
      }
    }
  }

  // Release write lock
  releaseWriteLock(): void {
    AtomicsOperations.store(this.writer, 0, 0);
    AtomicsOperations.notify(this.writer, 0, 1);
    AtomicsOperations.notify(this.readers, 0, 1);
  }

  // Execute with read lock
  async executeRead<T>(fn: () => Promise<T>): Promise<T> {
    await this.acquireReadLock();
    try {
      return await fn();
    } finally {
      this.releaseReadLock();
    }
  }

  // Execute with write lock
  async executeWrite<T>(fn: () => Promise<T>): Promise<T> {
    await this.acquireWriteLock();
    try {
      return await fn();
    } finally {
      this.releaseWriteLock();
    }
  }
}

// 7. Concurrent Counter
class ConcurrentCounter {
  private counter: Int32Array;

  constructor(initialValue: number = 0) {
    this.counter = AtomicsOperations.createSharedBuffer(1);
    AtomicsOperations.store(this.counter, 0, initialValue);
  }

  // Increment and get
  incrementAndGet(): number {
    return AtomicsOperations.add(this.counter, 0, 1) + 1;
  }

  // Get and increment
  getAndIncrement(): number {
    return AtomicsOperations.add(this.counter, 0, 1);
  }

  // Decrement and get
  decrementAndGet(): number {
    return AtomicsOperations.sub(this.counter, 0, 1) - 1;
  }

  // Get and decrement
  getAndDecrement(): number {
    return AtomicsOperations.sub(this.counter, 0, 1);
  }

  // Get current value
  get(): number {
    return AtomicsOperations.load(this.counter, 0);
  }

  // Set value
  set(value: number): void {
    AtomicsOperations.store(this.counter, 0, value);
  }

  // Add and get
  addAndGet(value: number): number {
    return AtomicsOperations.add(this.counter, 0, value) + value;
  }
}

// 8. Producer-Consumer Queue
class ProducerConsumerQueue<T> {
  private buffer: T[] = [];
  private size: Int32Array;
  private count: Int32Array;
  private head: Int32Array;
  private tail: Int32Array;

  constructor(capacity: number) {
    this.buffer = new Array(capacity);
    this.size = AtomicsOperations.createSharedBuffer(1);
    this.count = AtomicsOperations.createSharedBuffer(1);
    this.head = AtomicsOperations.createSharedBuffer(1);
    this.tail = AtomicsOperations.createSharedBuffer(1);

    AtomicsOperations.store(this.size, 0, capacity);
  }

  // Enqueue item
  async enqueue(item: T): Promise<void> {
    while (true) {
      const currentCount = AtomicsOperations.load(this.count, 0);
      const capacity = AtomicsOperations.load(this.size, 0);

      if (currentCount < capacity) {
        // Not full, enqueue
        const tail = AtomicsOperations.load(this.tail, 0);
        this.buffer[tail] = item;
        AtomicsOperations.store(this.tail, 0, (tail + 1) % capacity);
        AtomicsOperations.increment(this.count, 0);
        AtomicsOperations.notify(this.count, 0, 1);
        return;
      }

      // Full, wait for space
      await AtomicsOperations.waitAsync(this.count, 0, currentCount);
    }
  }

  // Dequeue item
  async dequeue(): Promise<T> {
    while (true) {
      const currentCount = AtomicsOperations.load(this.count, 0);

      if (currentCount > 0) {
        // Not empty, dequeue
        const head = AtomicsOperations.load(this.head, 0);
        const capacity = AtomicsOperations.load(this.size, 0);
        const item = this.buffer[head];

        this.buffer[head] = undefined as any;
        AtomicsOperations.store(this.head, 0, (head + 1) % capacity);
        AtomicsOperations.decrement(this.count, 0);
        AtomicsOperations.notify(this.count, 0, 1);
        return item;
      }

      // Empty, wait for item
      await AtomicsOperations.waitAsync(this.count, 0, currentCount);
    }
  }

  // Get current count
  get count(): number {
    return AtomicsOperations.load(this.count, 0);
  }
}

// Usage Examples
async function demonstrateSynchronization() {
  console.log('=== Web TypeScript Synchronization Primitives Examples ===\n');

  // 1. Atomics operations
  console.log('--- 1. Atomics Operations ---');
  const buffer = AtomicsOperations.createSharedBuffer(5);

  for (let i = 0; i < buffer.length; i++) {
    AtomicsOperations.store(buffer, i, i * 10);
  }

  console.log('Buffer values:');
  for (let i = 0; i < buffer.length; i++) {
    console.log(`  [${i}] = ${buffer[i]}`);
  }

  AtomicsOperations.add(buffer, 0, 5);
  console.log(`After add to [0]: ${buffer[0]}`);

  // 2. Concurrent counter
  console.log('\n--- 2. Concurrent Counter ---');
  const counter = new ConcurrentCounter(0);

  // Simulate concurrent increments
  const incrementTasks = Array.from({ length: 10 }, (_, i) =>
    PromiseBasics.delay(Math.random() * 100).then(() => {
      counter.incrementAndGet();
    })
  );

  await Promise.all(incrementTasks);
  console.log(`Final counter value: ${counter.get()}`);

  // 3. Mutex
  console.log('\n--- 3. Mutex ---');
  const mutex = new Mutex();
  let sharedResource = 0;

  const mutexTasks = Array.from({ length: 5 }, (_, i) =>
    mutex.execute(async () => {
      const value = sharedResource;
      console.log(`Task ${i} read: ${value}`);
      await PromiseBasics.delay(50);
      sharedResource = value + 1;
      console.log(`Task ${i} wrote: ${sharedResource}`);
      return sharedResource;
    })
  );

  await Promise.all(mutexTasks);
  console.log(`Final shared resource value: ${sharedResource}`);

  // 4. Semaphore
  console.log('\n--- 4. Semaphore ---');
  const semaphore = new Semaphore(2); // Allow 2 concurrent operations

  let activeCount = 0;
  let maxActive = 0;

  const semaphoreTasks = Array.from({ length: 10 }, (_, i) =>
    semaphore.execute(async () => {
      activeCount++;
      maxActive = Math.max(maxActive, activeCount);
      console.log(`Task ${i} started (active: ${activeCount})`);
      await PromiseBasics.delay(Math.random() * 200);
      activeCount--;
      console.log(`Task ${i} completed`);
    })
  );

  await Promise.all(semaphoreTasks);
  console.log(`Max concurrent tasks: ${maxActive}`);

  // 5. Barrier
  console.log('\n--- 5. Barrier ---');
  const barrier = new Barrier(3);

  const barrierTasks = Array.from({ length: 3 }, (_, i) =>
    barrier.wait().then(() => {
      console.log(`Task ${i} passed barrier`);
    })
  );

  await Promise.all(barrierTasks);

  // 6. Producer-Consumer
  console.log('\n--- 6. Producer-Consumer Queue ---');
  const queue = new ProducerConsumerQueue<number>(5);

  // Producer
  queue.enqueue(1);
  setTimeout(() => queue.enqueue(2), 100);
  setTimeout(() => queue.enqueue(3), 200);

  // Consumer
  const item1 = await queue.dequeue();
  console.log(`Dequeued: ${item1}`);

  const item2 = await queue.dequeue();
  console.log(`Dequeued: ${item2}`);

  console.log(`Queue count: ${queue.count}`);

  console.log('\n=== All Synchronization Primitives Examples Completed ===');
}

// Import PromiseBasics
class PromiseBasics {
  static delay(ms: number): Promise<void> {
    return new Promise(resolve => setTimeout(resolve, ms));
  }
}

// Export classes
export { AtomicsOperations, Spinlock, Mutex, Semaphore, Barrier, ReadWriteLock, ConcurrentCounter, ProducerConsumerQueue };
export { demonstrateSynchronization };