test/jdk/java/net/MulticastSocket/UnreferencedMulticastSockets.java - platform/libcore - Git at Google

 /*
  * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */

 /**
  * @test
  * @modules java.management java.base/java.io:+open java.base/java.net:+open
  * @run main/othervm -Djava.net.preferIPv4Stack=true UnreferencedMulticastSockets
  * @run main/othervm UnreferencedMulticastSockets
  * @summary Check that unreferenced multicast sockets are closed
  */

 import java.io.FileDescriptor;
 import java.lang.management.ManagementFactory;
 import java.lang.management.OperatingSystemMXBean;
 import java.lang.ref.ReferenceQueue;
 import java.lang.ref.WeakReference;
 import java.lang.reflect.Field;
 import java.io.IOException;
 import java.net.DatagramPacket;
 import java.net.DatagramSocket;
 import java.net.DatagramSocketImpl;
 import java.net.InetAddress;
 import java.net.MulticastSocket;
 import java.net.UnknownHostException;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.nio.file.Paths;
 import java.util.ArrayDeque;
 import java.util.List;
 import java.util.Optional;
 import java.util.concurrent.TimeUnit;

 import com.sun.management.UnixOperatingSystemMXBean;

 public class UnreferencedMulticastSockets {

     /**
      * The set of sockets we have to check up on.
      */
     final static ArrayDeque<NamedWeak> pendingSockets = new ArrayDeque<>(5);

     /**
      * Queued objects when they are unreferenced.
      */
     final static ReferenceQueue<Object> pendingQueue = new ReferenceQueue<>();

     // Server to echo a datagram packet
     static class Server implements Runnable {

         MulticastSocket ss;

         Server() throws IOException {
             ss = new MulticastSocket(0);
             System.out.printf("  DatagramServer addr: %s: %d%n",
                     this.getHost(), this.getPort());
             pendingSockets.add(new NamedWeak(ss, pendingQueue, "serverMulticastSocket"));
             extractRefs(ss, "serverMulticastSocket");
         }

         InetAddress getHost() throws UnknownHostException {
             InetAddress localhost = InetAddress.getByName("localhost"); //.getLocalHost();
             return localhost;
         }

         int getPort() {
             return ss.getLocalPort();
         }

         // Receive a byte and send back a byte
         public void run() {
             try {
                 byte[] buffer = new byte[50];
                 DatagramPacket p = new DatagramPacket(buffer, buffer.length);
                 ss.receive(p);
                 buffer[0] += 1;
                 ss.send(p);         // send back +1

                 // do NOT close but 'forget' the socket reference
                 ss = null;
             } catch (Exception ioe) {
                 ioe.printStackTrace();
             }
         }
     }

     public static void main(String args[]) throws Exception {

         // Create and close a MulticastSocket to warm up the FD count for side effects.
         try (MulticastSocket s = new MulticastSocket(0)) {
             // no-op; close immediately
             s.getLocalPort();   // no-op
         }

         long fdCount0 = getFdCount();
         listProcFD();

         // start a server
         Server svr = new Server();
         Thread thr = new Thread(svr);
         thr.start();

         MulticastSocket client = new MulticastSocket(0);
         System.out.printf("  client bound port: %d%n", client.getLocalPort());
         client.connect(svr.getHost(), svr.getPort());
         pendingSockets.add(new NamedWeak(client, pendingQueue, "clientMulticastSocket"));
         extractRefs(client, "clientMulticastSocket");

         byte[] msg = new byte[1];
         msg[0] = 1;
         DatagramPacket p = new DatagramPacket(msg, msg.length, svr.getHost(), svr.getPort());
         client.send(p);

         p = new DatagramPacket(msg, msg.length);
         client.receive(p);

         System.out.printf("echo received from: %s%n", p.getSocketAddress());
         if (msg[0] != 2) {
             throw new AssertionError("incorrect data received: expected: 2, actual: " + msg[0]);
         }

         // Do NOT close the MulticastSocket; forget it

         Object ref;
         int loops = 20;
         while (!pendingSockets.isEmpty() && loops-- > 0) {
             ref = pendingQueue.remove(1000L);
             if (ref != null) {
                 pendingSockets.remove(ref);
                 System.out.printf("  ref freed: %s, remaining: %d%n", ref, pendingSockets.size());
             } else {
                 client = null;
                 p = null;
                 msg = null;
                 System.gc();
             }
         }

         thr.join();

         // List the open file descriptors
         long fdCount = getFdCount();
         System.out.printf("Initial fdCount: %d, final fdCount: %d%n", fdCount0, fdCount);
         listProcFD();

         if (loops == 0) {
             throw new AssertionError("Not all references reclaimed");
         }
     }

     // Get the count of open file descriptors, or -1 if not available
     private static long getFdCount() {
         OperatingSystemMXBean mxBean = ManagementFactory.getOperatingSystemMXBean();
         return (mxBean instanceof UnixOperatingSystemMXBean)
                 ? ((UnixOperatingSystemMXBean) mxBean).getOpenFileDescriptorCount()
                 : -1L;
     }

     // Reflect to find references in the socket implementation that will be gc'd
     private static void extractRefs(MulticastSocket s, String name) {
         try {

             Field socketImplField = DatagramSocket.class.getDeclaredField("impl");
             socketImplField.setAccessible(true);
             Object socketImpl = socketImplField.get(s);

             Field fileDescriptorField = DatagramSocketImpl.class.getDeclaredField("fd");
             fileDescriptorField.setAccessible(true);
             FileDescriptor fileDescriptor = (FileDescriptor) fileDescriptorField.get(socketImpl);
             extractRefs(fileDescriptor, name);

             Class<?> socketImplClass = socketImpl.getClass();
             System.out.printf("socketImplClass: %s%n", socketImplClass);
             if (socketImplClass.getName().equals("java.net.TwoStacksPlainDatagramSocketImpl")) {
                 Field fileDescriptor1Field = socketImplClass.getDeclaredField("fd1");
                 fileDescriptor1Field.setAccessible(true);
                 FileDescriptor fileDescriptor1 = (FileDescriptor) fileDescriptor1Field.get(socketImpl);
                 extractRefs(fileDescriptor1, name + "::twoStacksFd1");

             } else {
                 System.out.printf("socketImpl class name not matched: %s != %s%n",
                         socketImplClass.getName(), "java.net.TwoStacksPlainDatagramSocketImpl");
             }
         } catch (NoSuchFieldException | IllegalAccessException ex) {
             ex.printStackTrace();
             throw new AssertionError("missing field", ex);
         }
     }

     private static void extractRefs(FileDescriptor fileDescriptor, String name) {
         Object cleanup = null;
         int rawfd = -1;
         try {
             if (fileDescriptor != null) {
                 Field fd1Field = FileDescriptor.class.getDeclaredField("fd");
                 fd1Field.setAccessible(true);
                 rawfd = fd1Field.getInt(fileDescriptor);

                 Field cleanupfdField = FileDescriptor.class.getDeclaredField("cleanup");
                 cleanupfdField.setAccessible(true);
                 cleanup = cleanupfdField.get(fileDescriptor);
                 pendingSockets.add(new NamedWeak(fileDescriptor, pendingQueue,
                         name + "::fileDescriptor: " + rawfd));
                 pendingSockets.add(new NamedWeak(cleanup, pendingQueue, name + "::fdCleanup: " + rawfd));

             }
         } catch (NoSuchFieldException | IllegalAccessException ex) {
             ex.printStackTrace();
             throw new AssertionError("missing field", ex);
         } finally {
             System.out.print(String.format("  %s:: fd: %s, fd: %d, cleanup: %s%n",
                     name, fileDescriptor, rawfd, cleanup));
         }
     }

     /**
      * Method to list the open file descriptors (if supported by the 'lsof' command).
      */
     static void listProcFD() {
         List<String> lsofDirs = List.of("/usr/bin", "/usr/sbin");
         Optional<Path> lsof = lsofDirs.stream()
                 .map(s -> Paths.get(s, "lsof"))
                 .filter(f -> Files.isExecutable(f))
                 .findFirst();
         lsof.ifPresent(exe -> {
             try {
                 System.out.printf("Open File Descriptors:%n");
                 long pid = ProcessHandle.current().pid();
                 ProcessBuilder pb = new ProcessBuilder(exe.toString(), "-p", Integer.toString((int) pid));
                 pb.inheritIO();
                 Process p = pb.start();
                 p.waitFor(10, TimeUnit.SECONDS);
             } catch (IOException | InterruptedException ie) {
                 ie.printStackTrace();
             }
         });
     }


     // Simple class to identify which refs have been queued
     static class NamedWeak extends WeakReference<Object> {
         private final String name;

         NamedWeak(Object o, ReferenceQueue<Object> queue, String name) {
             super(o, queue);
             this.name = name;
         }

         public String toString() {
             return name + "; " + super.toString();
         }
     }
 }
	/*
	* Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	/**
	* @test
	* @modules java.management java.base/java.io:+open java.base/java.net:+open
	* @run main/othervm -Djava.net.preferIPv4Stack=true UnreferencedMulticastSockets
	* @run main/othervm UnreferencedMulticastSockets
	* @summary Check that unreferenced multicast sockets are closed
	*/

	import java.io.FileDescriptor;
	import java.lang.management.ManagementFactory;
	import java.lang.management.OperatingSystemMXBean;
	import java.lang.ref.ReferenceQueue;
	import java.lang.ref.WeakReference;
	import java.lang.reflect.Field;
	import java.io.IOException;
	import java.net.DatagramPacket;
	import java.net.DatagramSocket;
	import java.net.DatagramSocketImpl;
	import java.net.InetAddress;
	import java.net.MulticastSocket;
	import java.net.UnknownHostException;
	import java.nio.file.Files;
	import java.nio.file.Path;
	import java.nio.file.Paths;
	import java.util.ArrayDeque;
	import java.util.List;
	import java.util.Optional;
	import java.util.concurrent.TimeUnit;

	import com.sun.management.UnixOperatingSystemMXBean;

	public class UnreferencedMulticastSockets {

	/**
	* The set of sockets we have to check up on.
	*/
	final static ArrayDeque<NamedWeak> pendingSockets = new ArrayDeque<>(5);

	/**
	* Queued objects when they are unreferenced.
	*/
	final static ReferenceQueue<Object> pendingQueue = new ReferenceQueue<>();

	// Server to echo a datagram packet
	static class Server implements Runnable {

	MulticastSocket ss;

	Server() throws IOException {
	ss = new MulticastSocket(0);
	System.out.printf(" DatagramServer addr: %s: %d%n",
	this.getHost(), this.getPort());
	pendingSockets.add(new NamedWeak(ss, pendingQueue, "serverMulticastSocket"));
	extractRefs(ss, "serverMulticastSocket");
	}

	InetAddress getHost() throws UnknownHostException {
	InetAddress localhost = InetAddress.getByName("localhost"); //.getLocalHost();
	return localhost;
	}

	int getPort() {
	return ss.getLocalPort();
	}

	// Receive a byte and send back a byte
	public void run() {
	try {
	byte[] buffer = new byte[50];
	DatagramPacket p = new DatagramPacket(buffer, buffer.length);
	ss.receive(p);
	buffer[0] += 1;
	ss.send(p); // send back +1

	// do NOT close but 'forget' the socket reference
	ss = null;
	} catch (Exception ioe) {
	ioe.printStackTrace();
	}
	}
	}

	public static void main(String args[]) throws Exception {

	// Create and close a MulticastSocket to warm up the FD count for side effects.
	try (MulticastSocket s = new MulticastSocket(0)) {
	// no-op; close immediately
	s.getLocalPort(); // no-op
	}

	long fdCount0 = getFdCount();
	listProcFD();

	// start a server
	Server svr = new Server();
	Thread thr = new Thread(svr);
	thr.start();

	MulticastSocket client = new MulticastSocket(0);
	System.out.printf(" client bound port: %d%n", client.getLocalPort());
	client.connect(svr.getHost(), svr.getPort());
	pendingSockets.add(new NamedWeak(client, pendingQueue, "clientMulticastSocket"));
	extractRefs(client, "clientMulticastSocket");

	byte[] msg = new byte[1];
	msg[0] = 1;
	DatagramPacket p = new DatagramPacket(msg, msg.length, svr.getHost(), svr.getPort());
	client.send(p);

	p = new DatagramPacket(msg, msg.length);
	client.receive(p);

	System.out.printf("echo received from: %s%n", p.getSocketAddress());
	if (msg[0] != 2) {
	throw new AssertionError("incorrect data received: expected: 2, actual: " + msg[0]);
	}

	// Do NOT close the MulticastSocket; forget it

	Object ref;
	int loops = 20;
	while (!pendingSockets.isEmpty() && loops-- > 0) {
	ref = pendingQueue.remove(1000L);
	if (ref != null) {
	pendingSockets.remove(ref);
	System.out.printf(" ref freed: %s, remaining: %d%n", ref, pendingSockets.size());
	} else {
	client = null;
	p = null;
	msg = null;
	System.gc();
	}
	}

	thr.join();

	// List the open file descriptors
	long fdCount = getFdCount();
	System.out.printf("Initial fdCount: %d, final fdCount: %d%n", fdCount0, fdCount);
	listProcFD();

	if (loops == 0) {
	throw new AssertionError("Not all references reclaimed");
	}
	}

	// Get the count of open file descriptors, or -1 if not available
	private static long getFdCount() {
	OperatingSystemMXBean mxBean = ManagementFactory.getOperatingSystemMXBean();
	return (mxBean instanceof UnixOperatingSystemMXBean)
	? ((UnixOperatingSystemMXBean) mxBean).getOpenFileDescriptorCount()
	: -1L;
	}

	// Reflect to find references in the socket implementation that will be gc'd
	private static void extractRefs(MulticastSocket s, String name) {
	try {

	Field socketImplField = DatagramSocket.class.getDeclaredField("impl");
	socketImplField.setAccessible(true);
	Object socketImpl = socketImplField.get(s);

	Field fileDescriptorField = DatagramSocketImpl.class.getDeclaredField("fd");
	fileDescriptorField.setAccessible(true);
	FileDescriptor fileDescriptor = (FileDescriptor) fileDescriptorField.get(socketImpl);
	extractRefs(fileDescriptor, name);

	Class<?> socketImplClass = socketImpl.getClass();
	System.out.printf("socketImplClass: %s%n", socketImplClass);
	if (socketImplClass.getName().equals("java.net.TwoStacksPlainDatagramSocketImpl")) {
	Field fileDescriptor1Field = socketImplClass.getDeclaredField("fd1");
	fileDescriptor1Field.setAccessible(true);
	FileDescriptor fileDescriptor1 = (FileDescriptor) fileDescriptor1Field.get(socketImpl);
	extractRefs(fileDescriptor1, name + "::twoStacksFd1");

	} else {
	System.out.printf("socketImpl class name not matched: %s != %s%n",
	socketImplClass.getName(), "java.net.TwoStacksPlainDatagramSocketImpl");
	}
	} catch (NoSuchFieldException \| IllegalAccessException ex) {
	ex.printStackTrace();
	throw new AssertionError("missing field", ex);
	}
	}

	private static void extractRefs(FileDescriptor fileDescriptor, String name) {
	Object cleanup = null;
	int rawfd = -1;
	try {
	if (fileDescriptor != null) {
	Field fd1Field = FileDescriptor.class.getDeclaredField("fd");
	fd1Field.setAccessible(true);
	rawfd = fd1Field.getInt(fileDescriptor);

	Field cleanupfdField = FileDescriptor.class.getDeclaredField("cleanup");
	cleanupfdField.setAccessible(true);
	cleanup = cleanupfdField.get(fileDescriptor);
	pendingSockets.add(new NamedWeak(fileDescriptor, pendingQueue,
	name + "::fileDescriptor: " + rawfd));
	pendingSockets.add(new NamedWeak(cleanup, pendingQueue, name + "::fdCleanup: " + rawfd));

	}
	} catch (NoSuchFieldException \| IllegalAccessException ex) {
	ex.printStackTrace();
	throw new AssertionError("missing field", ex);
	} finally {
	System.out.print(String.format(" %s:: fd: %s, fd: %d, cleanup: %s%n",
	name, fileDescriptor, rawfd, cleanup));
	}
	}

	/**
	* Method to list the open file descriptors (if supported by the 'lsof' command).
	*/
	static void listProcFD() {
	List<String> lsofDirs = List.of("/usr/bin", "/usr/sbin");
	Optional<Path> lsof = lsofDirs.stream()
	.map(s -> Paths.get(s, "lsof"))
	.filter(f -> Files.isExecutable(f))
	.findFirst();
	lsof.ifPresent(exe -> {
	try {
	System.out.printf("Open File Descriptors:%n");
	long pid = ProcessHandle.current().pid();
	ProcessBuilder pb = new ProcessBuilder(exe.toString(), "-p", Integer.toString((int) pid));
	pb.inheritIO();
	Process p = pb.start();
	p.waitFor(10, TimeUnit.SECONDS);
	} catch (IOException \| InterruptedException ie) {
	ie.printStackTrace();
	}
	});
	}


	// Simple class to identify which refs have been queued
	static class NamedWeak extends WeakReference<Object> {
	private final String name;

	NamedWeak(Object o, ReferenceQueue<Object> queue, String name) {
	super(o, queue);
	this.name = name;
	}

	public String toString() {
	return name + "; " + super.toString();
	}
	}
	}