import java.io.IOException;
import java.net.ServerSocket;
import java.net.Socket;
import java.net.SocketTimeoutException;

/*
   Trying to reproduce the scenario when Glide got blocked trying to close a socket
   because it called read() with timeout but got stuck trying to acquire the read lock
   in JDK library.

   Run with:
        javac SocketTimeoutNotRespected.java && java SocketTimeoutNotRespected

   The output:
		server started on port 3434
		blocker thread started on port 3434
		thread2 is reading from port 3434 with timeout 500
        ... waiting forever ...

   "blocker" thread stack:
		read0:-1, SocketDispatcher (sun.nio.ch)
		read:47, SocketDispatcher (sun.nio.ch)
		tryRead:266, NioSocketImpl (sun.nio.ch)
		implRead:317, NioSocketImpl (sun.nio.ch)
		read:355, NioSocketImpl (sun.nio.ch)
		read:808, NioSocketImpl$1 (sun.nio.ch)
		read:966, Socket$SocketInputStream (java.net)
		read:961, Socket$SocketInputStream (java.net)
		lambda$main$1:71, SocketTimeoutNotRespected
		run:-1, SocketTimeoutNotRespected$$Lambda$18/0x000000014d000c28
		run:840, Thread (java.lang)

  "main" thread stack:
		park:-1, Unsafe (jdk.internal.misc)
		park:211, LockSupport (java.util.concurrent.locks)
		acquire:715, AbstractQueuedSynchronizer (java.util.concurrent.locks)
		acquire:938, AbstractQueuedSynchronizer (java.util.concurrent.locks)
		lock:153, ReentrantLock$Sync (java.util.concurrent.locks)
		lock:322, ReentrantLock (java.util.concurrent.locks)
		read:348, NioSocketImpl (sun.nio.ch)
		read:808, NioSocketImpl$1 (sun.nio.ch)
		read:966, Socket$SocketInputStream (java.net)
		read:961, Socket$SocketInputStream (java.net)
		main:91, SocketTimeoutNotRespected
*/
public class SocketTimeoutNotRespected {
	private static final int PORT = 3434;       // Anu open port of your choice

	public static void main(String[] args) throws Exception {
		Thread server = new Thread(() -> {
			try (ServerSocket serverSocket = new ServerSocket(PORT)) {
				final Socket connectedSocket = serverSocket.accept();
				int c = connectedSocket.getInputStream().read();
				System.err.printf("Not expected: the server has received data: %d ('%c')\n", c, c);
			} catch (IOException e) {
				System.err.println("unexpected server exception: " + e.getMessage());
				e.printStackTrace();
			}
		});
		server.setName("server");
		server.setDaemon(true);
		server.start();
		System.out.println("server started on port " + PORT);

		// client threads share the socket
		Socket clientSocket = new Socket("localhost", PORT);

		// The blocker thread blocks is reading data forever. It is holding readLock while waiting
		Thread blocker = new Thread(() -> {
			try {
				int c = clientSocket.getInputStream().read();
				System.err.printf("Not expected: the blocker thread has received data: %d ('%c')\n", c, c);
			} catch (IOException e) {
				System.err.println("unexpected blocker thread exception: " + e.getMessage());
				e.printStackTrace();
			}
		});
		blocker.setName("blocker");
		blocker.setDaemon(true);
		blocker.start();
		System.out.println("blocker thread started on port " + PORT);

		// Sleep a bit to let "blocker" start the read
		Thread.sleep(100);

		// We should exit with timeout, but since the "blocker" thread is holding the reentrantLock
		// and the JDK tries to acquire it unconditionally, the socket timeout is not respected
		try {
			clientSocket.setSoTimeout(500);
			System.out.println("thread2 is reading from port " + PORT + " with timeout " + clientSocket.getSoTimeout());
			int c = clientSocket.getInputStream().read();       // <<<<<<<<<<  gets stuck trying to obtain a reentrant lock w/o timeout
			System.err.printf("thread2 has unexpectedly received data: %d ('%c')\n", c, c);
		} catch (SocketTimeoutException e) {
			System.out.println("thread2 has failed with timeout, good");
		}
	}
}