TaskQueue.java

package com.taskscheduler;

import java.util.concurrent.PriorityBlockingQueue;
import java.util.concurrent.TimeUnit;

/**
 * Thread-safe priority queue for tasks.
 * Higher priority tasks are dequeued before lower priority ones.
 */
public class TaskQueue {

    private final PriorityBlockingQueue<Task> queue;
    private final int capacity;

    public TaskQueue(int capacity) {
        this.capacity = capacity;
        this.queue = new PriorityBlockingQueue<>(capacity);
    }

    /**
     * Add a task to the queue. Returns false if at capacity.
     */
    public boolean submit(Task task) {
        if (queue.size() >= capacity) {
            System.err.println("[TaskQueue] Queue full! Rejecting: " + task);
            return false;
        }
        queue.offer(task);
        System.out.printf("[TaskQueue] Submitted %s (queue size: %d)%n", task, queue.size());
        return true;
    }

    /**
     * Blocks until a task is available or timeout is reached.
     */
    public Task poll(long timeout, TimeUnit unit) throws InterruptedException {
        return queue.poll(timeout, unit);
    }

    public int size()       { return queue.size(); }
    public boolean isEmpty(){ return queue.isEmpty(); }
    public int getCapacity(){ return capacity; }
}