javaAsync race conditionMedium

Task results lost when ExecutorService tasks complete

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BugFind the bug and fix the code

What it should do

Process a list of tasks asynchronously and return their results. Example: processTasks([task1, task2]) -> [result1, result2]

What happens instead

No visible compiler or runtime errors, but task results are not collected.

import java.util.concurrent.*;

public class TaskProcessor {
    public static void processTasks(Runnable[] tasks) {
        ExecutorService executor = Executors.newFixedThreadPool(tasks.length);
        for (Runnable task : tasks) {
            executor.submit(task);
        }
        executor.shutdown();
    }
}

// Example usage
Runnable task1 = () -> System.out.println("Task 1");
Runnable task2 = () -> System.out.println("Task 2");
TaskProcessor.processTasks(new Runnable[] {task1, task2});

Test a custom input to verify an edge case (e.g. empty lists, negative numbers, duplicates).

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This bug belongs to the async and race conditions pattern

A missing await, unbuffered channel deadlocks, ConcurrentModificationException, and data races under load.

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import java.util.concurrent.*; public class TaskProcessor { public static void processTasks(Runnable[] tasks) { ExecutorService executor = Executors.newFixedThreadPool(tasks.length); for (Runnable task : tasks) { executor.submit(task); } executor.shutdown(); } } // Example usage Runnable task1 = () -> System.out.println("Task 1"); Runnable task2 = () -> System.out.println("Task 2"); TaskProcessor.processTasks(new Runnable[] {task1, task2});

Task results lost when ExecutorService tasks complete

What it should do

What happens instead

More async and race conditions to practise

Task results lost when ExecutorService tasks complete

What it should do

What happens instead

More async and race conditions to practise