操作系统 & 图论传参一个AOE图，得到按其拓扑排序及权值执行临界区代码的线程数组

Posted 2022-02-18 嘉然今天吃甚么

import java.util.concurrent.Semaphore;

public class Solution 

	final static float INF = Float.POSITIVE_INFINITY;
	static Semaphore[][] semaphores;

	public static Thread[] AOEThreads(float[][] matrix) 

		semaphores = new Semaphore[matrix.length][matrix.length];
		int v = 0;

		for (int i = 0; i < matrix.length; i++) 
			for (int j = 0; j < matrix[0].length; j++) 
				if (matrix[i][j] != 0 && matrix[i][j] != INF) 
					v++;
					semaphores[i][j] = new Semaphore(0);
				
			
		

		Thread[] threads = new Thread[v];
		int index = 0;

		for (int i = 0; i < matrix.length; i++) 
			for (int j = 0; j < matrix[0].length; j++) 

				if (semaphores[i][j] != null) 

					int x = i;
					int y = j;
					float f = matrix[x][y];

					threads[index++] = new Thread(() -> 
						try 

							for (int k = 0; k < semaphores.length; k++) 
								if (semaphores[k][x] != null) 
//									System.out.println(Thread.currentThread().getName() + "发现自己受制于vertex[" + k + "][" + x + "]");
									semaphores[k][x].acquire();
//									System.out.println(Thread.currentThread().getName() + "发现vertex[" + k + "][" + x + "]已开锁");
								
							

							System.out.println(Thread.currentThread().getName() + "开始执行");
							Thread.sleep((int) f * 1000);
							System.out.println(Thread.currentThread().getName() + "执行了" + f + "妙后执行完毕");


							for (int k = 0; k < semaphores.length; k++) 
								if (semaphores[y][k] != null) 
									semaphores[x][y].release();
//									System.out.println(Thread.currentThread().getName() + "已解锁");
								
							

						 catch (Exception e) 
							e.printStackTrace();
						
					, "vertex[" + x + "][" + y + "]");

				

			
		

		return threads;

	

	public static void main(String[] args) 

		float[][] matrix = new float[][]
				0, 3, 2, INF, INF, INF,
				INF, 0, INF, 2, 3, INF,
				INF, INF, 0, 4, INF, 3,
				INF, INF, INF, 0, INF, 2,
				INF, INF, INF, INF, 0, 1,
				INF, INF, INF, INF, INF, 0
		;

		Thread[] threads = AOEThreads(matrix);

		for (Thread thread : threads) 
			thread.start();