8195059: Update java.net Socket and DatagramSocket implementations to use Cleaner
Reviewed-by: chegar, plevart
--- a/make/mapfiles/libnet/mapfile-vers Fri Feb 02 10:32:59 2018 -0800
+++ b/make/mapfiles/libnet/mapfile-vers Fri Feb 02 14:17:07 2018 -0500
@@ -1,5 +1,5 @@
#
-# Copyright (c) 1997, 2017, Oracle and/or its affiliates. All rights reserved.
+# Copyright (c) 1997, 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
@@ -89,6 +89,7 @@
Java_java_net_PlainDatagramSocketImpl_setTimeToLive;
Java_java_net_AbstractPlainSocketImpl_isReusePortAvailable0;
Java_java_net_AbstractPlainDatagramSocketImpl_isReusePortAvailable0;
+ Java_java_net_SocketCleanable_cleanupClose0;
Java_jdk_net_Sockets_isReusePortAvailable0;
Java_sun_net_PortConfig_getUpper0;
Java_sun_net_PortConfig_getLower0;
--- a/src/java.base/share/classes/java/net/AbstractPlainDatagramSocketImpl.java Fri Feb 02 10:32:59 2018 -0800
+++ b/src/java.base/share/classes/java/net/AbstractPlainDatagramSocketImpl.java Fri Feb 02 14:17:07 2018 -0500
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 1996, 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1996, 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
@@ -26,11 +26,11 @@
import java.io.FileDescriptor;
import java.io.IOException;
-import java.security.AccessController;
-import sun.net.ResourceManager;
+import java.util.Collections;
+import java.util.HashSet;
import java.util.Set;
-import java.util.HashSet;
-import java.util.Collections;
+
+import sun.net.ResourceManager;
import sun.security.action.GetPropertyAction;
/**
@@ -115,6 +115,7 @@
fd = new FileDescriptor();
try {
datagramSocketCreate();
+ SocketCleanable.register(fd);
} catch (SocketException ioe) {
ResourceManager.afterUdpClose();
fd = null;
@@ -265,6 +266,7 @@
*/
protected void close() {
if (fd != null) {
+ SocketCleanable.unregister(fd);
datagramSocketClose();
ResourceManager.afterUdpClose();
fd = null;
@@ -275,11 +277,6 @@
return (fd == null) ? true : false;
}
- @SuppressWarnings("deprecation")
- protected void finalize() {
- close();
- }
-
/**
* set a value - since we only support (setting) binary options
* here, o must be a Boolean
--- a/src/java.base/share/classes/java/net/AbstractPlainSocketImpl.java Fri Feb 02 10:32:59 2018 -0800
+++ b/src/java.base/share/classes/java/net/AbstractPlainSocketImpl.java Fri Feb 02 14:17:07 2018 -0500
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 1995, 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1995, 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
@@ -25,17 +25,18 @@
package java.net;
+import java.io.FileDescriptor;
import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
-import java.io.FileDescriptor;
+
+import java.util.Collections;
+import java.util.HashSet;
+import java.util.Set;
import sun.net.ConnectionResetException;
import sun.net.NetHooks;
import sun.net.ResourceManager;
-import java.util.Set;
-import java.util.HashSet;
-import java.util.Collections;
/**
* Default Socket Implementation. This implementation does
@@ -136,6 +137,7 @@
fd = new FileDescriptor();
try {
socketCreate(false);
+ SocketCleanable.register(fd);
} catch (IOException ioe) {
ResourceManager.afterUdpClose();
fd = null;
@@ -144,6 +146,7 @@
} else {
fd = new FileDescriptor();
socketCreate(true);
+ SocketCleanable.register(fd);
}
if (socket != null)
socket.setCreated();
@@ -643,14 +646,6 @@
socketSendUrgentData (data);
}
- /**
- * Cleans up if the user forgets to close it.
- */
- @SuppressWarnings("deprecation")
- protected void finalize() throws IOException {
- close();
- }
-
/*
* "Acquires" and returns the FileDescriptor for this impl
*
@@ -748,6 +743,7 @@
* Close the socket (and release the file descriptor).
*/
protected void socketClose() throws IOException {
+ SocketCleanable.unregister(fd);
socketClose0(false);
}
--- a/src/java.base/share/classes/java/net/ServerSocket.java Fri Feb 02 10:32:59 2018 -0800
+++ b/src/java.base/share/classes/java/net/ServerSocket.java Fri Feb 02 14:17:07 2018 -0500
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 1995, 2015, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1995, 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
@@ -549,6 +549,7 @@
si.address = new InetAddress();
si.fd = new FileDescriptor();
getImpl().accept(si);
+ SocketCleanable.register(si.fd); // raw fd has been set
SecurityManager security = System.getSecurityManager();
if (security != null) {
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/java/net/SocketCleanable.java Fri Feb 02 14:17:07 2018 -0500
@@ -0,0 +1,107 @@
+/*
+ * 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. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * 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.
+ */
+package java.net;
+
+import jdk.internal.misc.JavaIOFileDescriptorAccess;
+import jdk.internal.misc.SharedSecrets;
+import jdk.internal.ref.CleanerFactory;
+import jdk.internal.ref.PhantomCleanable;
+
+import java.io.FileDescriptor;
+import java.io.IOException;
+import java.io.UncheckedIOException;
+import java.lang.ref.Cleaner;
+
+
+/**
+ * Cleanup for a socket/datagramsocket FileDescriptor when it becomes phantom reachable.
+ * Create a cleanup if the raw fd != -1. Windows closes sockets using the fd.
+ * Subclassed from {@code PhantomCleanable} so that {@code clear} can be
+ * called to disable the cleanup when the socket fd is closed by any means
+ * other than calling {@link FileDescriptor#close}.
+ * Otherwise, it would incorrectly close the handle or fd after it has been reused.
+ */
+final class SocketCleanable extends PhantomCleanable<Object> {
+
+ // Access to FileDescriptor internals
+ private static final JavaIOFileDescriptorAccess fdAccess =
+ SharedSecrets.getJavaIOFileDescriptorAccess();
+
+ // Native function to call NET_SocketClose(fd)
+ private static native void cleanupClose0(int fd) throws IOException;
+
+ // The raw fd to close
+ private final int fd;
+
+ /**
+ * Register a socket specific Cleanable with the FileDescriptor
+ * if the FileDescriptor is non-null and the raw fd is != -1.
+ *
+ * @param fdo the FileDescriptor; may be null
+ */
+ static void register(FileDescriptor fdo) {
+ if (fdo != null) {
+ int fd = fdAccess.get(fdo);
+ if (fd != -1) {
+ fdAccess.registerCleanup(fdo,
+ new SocketCleanable(fdo, CleanerFactory.cleaner(), fd));
+ }
+ }
+ }
+
+ /**
+ * Unregister a Cleanable from the FileDescriptor.
+ * @param fdo the FileDescriptor; may be null
+ */
+ static void unregister(FileDescriptor fdo) {
+ if (fdo != null) {
+ fdAccess.unregisterCleanup(fdo);
+ }
+ }
+
+ /**
+ * Constructor for a phantom cleanable reference.
+ *
+ * @param obj the object to monitor
+ * @param cleaner the cleaner
+ * @param fd file descriptor to close
+ */
+ private SocketCleanable(Object obj, Cleaner cleaner, int fd) {
+ super(obj, cleaner);
+ this.fd = fd;
+ }
+
+ /**
+ * Close the native handle or fd.
+ */
+ @Override
+ protected void performCleanup() {
+ try {
+ cleanupClose0(fd);
+ } catch (IOException ioe) {
+ throw new UncheckedIOException("close", ioe);
+ }
+ }
+}
--- a/src/java.base/share/classes/jdk/internal/misc/JavaIOFileDescriptorAccess.java Fri Feb 02 10:32:59 2018 -0800
+++ b/src/java.base/share/classes/jdk/internal/misc/JavaIOFileDescriptorAccess.java Fri Feb 02 14:17:07 2018 -0500
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2007, 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2007, 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
@@ -27,6 +27,8 @@
import java.io.FileDescriptor;
import java.io.IOException;
+import jdk.internal.ref.PhantomCleanable;
+
/*
* @author Chris Hegarty
*/
@@ -38,6 +40,8 @@
public boolean getAppend(FileDescriptor fdo);
public void close(FileDescriptor fdo) throws IOException;
public void registerCleanup(FileDescriptor fdo);
+ public void registerCleanup(FileDescriptor fdo, PhantomCleanable<Object> cleanable);
+ public void unregisterCleanup(FileDescriptor fdo);
// Only valid on Windows
public void setHandle(FileDescriptor fdo, long handle);
--- a/src/java.base/unix/classes/java/io/FileDescriptor.java Fri Feb 02 10:32:59 2018 -0800
+++ b/src/java.base/unix/classes/java/io/FileDescriptor.java Fri Feb 02 14:17:07 2018 -0500
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 1995, 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1995, 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
@@ -91,6 +91,14 @@
fdo.registerCleanup();
}
+ public void registerCleanup(FileDescriptor fdo, PhantomCleanable<Object> cleanup) {
+ fdo.registerCleanup(cleanup);
+ }
+
+ public void unregisterCleanup(FileDescriptor fdo) {
+ fdo.unregisterCleanup();
+ }
+
public void setHandle(FileDescriptor fdo, long handle) {
throw new UnsupportedOperationException();
}
@@ -105,7 +113,7 @@
/**
* Cleanup in case FileDescriptor is not explicitly closed.
*/
- private FDCleanup cleanup;
+ private PhantomCleanable<Object> cleanup;
/**
* Constructs an (invalid) FileDescriptor
@@ -206,16 +214,44 @@
}
/**
- * Register a cleanup for the current raw fd.
+ * Register a cleanup for the current handle.
* Used directly in java.io and indirectly via fdAccess.
- * The cleanup should be registered after the fd is set in the FileDescriptor.
+ * The cleanup should be registered after the handle is set in the FileDescriptor.
*/
@SuppressWarnings("unchecked")
- synchronized void registerCleanup() {
+ void registerCleanup() {
+ registerCleanup(null);
+ }
+
+ /**
+ * Register a cleanup for the current handle.
+ * Used directly in java.io and indirectly via fdAccess.
+ * The cleanup should be registered after the handle is set in the FileDescriptor.
+ * @param newCleanable a PhantomCleanable to register
+ */
+ @SuppressWarnings("unchecked")
+ synchronized void registerCleanup(PhantomCleanable<Object> newCleanable) {
if (cleanup != null) {
cleanup.clear();
}
- cleanup = FDCleanup.create(this);
+ cleanup = (newCleanable == null) ? FDCleanup.create(this) : newCleanable;
+ }
+
+ /**
+ * Unregister a cleanup for the current raw fd.
+ * Used directly in java.io and indirectly via fdAccess.
+ * Normally {@link #close()} should be used except in cases where
+ * it is certain the caller will close the raw fd and the cleanup
+ * must not close the raw fd. {@link #unregisterCleanup()} must be
+ * called before the raw fd is closed to prevent a race that makes
+ * it possible for the fd to be reallocated to another use and later
+ * the cleanup might be invoked.
+ */
+ synchronized void unregisterCleanup() {
+ if (cleanup != null) {
+ cleanup.clear();
+ }
+ cleanup = null;
}
/**
--- a/src/java.base/unix/native/libnet/SocketImpl.c Fri Feb 02 10:32:59 2018 -0800
+++ b/src/java.base/unix/native/libnet/SocketImpl.c Fri Feb 02 14:17:07 2018 -0500
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 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
@@ -27,6 +27,7 @@
#include <string.h>
#include "net_util.h"
+#include "java_net_SocketCleanable.h"
JNIEXPORT jboolean JNICALL
Java_java_net_AbstractPlainSocketImpl_isReusePortAvailable0(JNIEnv* env, jclass c1)
@@ -45,3 +46,15 @@
{
return (reuseport_available()) ? JNI_TRUE : JNI_FALSE;
}
+
+/*
+ * Class: java_net_SocketCleanable
+ * Method: cleanupClose0
+ * Signature: (I)V
+ */
+JNIEXPORT void JNICALL
+Java_java_net_SocketCleanable_cleanupClose0(JNIEnv *env, jclass c1, jint fd)
+{
+ NET_SocketClose(fd);
+}
+
--- a/src/java.base/windows/classes/java/io/FileDescriptor.java Fri Feb 02 10:32:59 2018 -0800
+++ b/src/java.base/windows/classes/java/io/FileDescriptor.java Fri Feb 02 14:17:07 2018 -0500
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2003, 2017, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2003, 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
@@ -90,7 +90,15 @@
}
public void registerCleanup(FileDescriptor fdo) {
- fdo.registerCleanup();
+ fdo.registerCleanup(null);
+ }
+
+ public void registerCleanup(FileDescriptor fdo, PhantomCleanable<Object> cleanup) {
+ fdo.registerCleanup(cleanup);
+ }
+
+ public void unregisterCleanup(FileDescriptor fdo) {
+ fdo.unregisterCleanup();
}
public void setHandle(FileDescriptor fdo, long handle) {
@@ -107,7 +115,7 @@
/**
* Cleanup in case FileDescriptor is not explicitly closed.
*/
- private FDCleanup cleanup;
+ private PhantomCleanable<Object> cleanup;
/**
* Constructs an (invalid) FileDescriptor
@@ -217,11 +225,39 @@
* The cleanup should be registered after the handle is set in the FileDescriptor.
*/
@SuppressWarnings("unchecked")
- synchronized void registerCleanup() {
+ void registerCleanup() {
+ registerCleanup(null);
+ }
+
+ /**
+ * Register a cleanup for the current handle.
+ * Used directly in java.io and indirectly via fdAccess.
+ * The cleanup should be registered after the handle is set in the FileDescriptor.
+ * @param newCleanable a PhantomCleanable to register
+ */
+ @SuppressWarnings("unchecked")
+ synchronized void registerCleanup(PhantomCleanable<Object> newCleanable) {
if (cleanup != null) {
cleanup.clear();
}
- cleanup = FDCleanup.create(this);
+ cleanup = (newCleanable == null) ? FDCleanup.create(this) : newCleanable;
+ }
+
+ /**
+ * Unregister a cleanup for the current raw fd.
+ * Used directly in java.io and indirectly via fdAccess.
+ * Normally {@link #close()} should be used except in cases where
+ * it is certain the caller will close the raw fd and the cleanup
+ * must not close the raw fd. {@link #unregisterCleanup()} must be
+ * called before the raw fd is closed to prevent a race that makes
+ * it possible for the fd to be reallocated to another use and later
+ * the cleanup might be invoked.
+ */
+ synchronized void unregisterCleanup() {
+ if (cleanup != null) {
+ cleanup.clear();
+ }
+ cleanup = null;
}
/**
@@ -319,16 +355,21 @@
/**
* Cleanup for a FileDescriptor when it becomes phantom reachable.
* Create a cleanup if handle != -1.
+ * Windows closes files using handles and sockets via the fd.
+ * Network FileDescriptors using socket fd must provide their
+ * own PhantomCleanable to {@link #registerCleanup}.
+ * This implementation only clears thehandles.
+ * <p>
* Subclassed from {@code PhantomCleanable} so that {@code clear} can be
- * called to disable the cleanup when the fd is closed by any means other
+ * called to disable the cleanup when the handle is closed by any means other
* than calling {@link FileDescriptor#close}.
- * Otherwise, it may close the handle after it has been reused.
+ * Otherwise, it may incorrectly close the handle after it has been reused.
*/
static final class FDCleanup extends PhantomCleanable<Object> {
private final long handle;
static FDCleanup create(FileDescriptor fdo) {
- return fdo.handle == -1
+ return fdo.handle == -1L
? null
: new FDCleanup(fdo, CleanerFactory.cleaner(), fdo.handle);
}
--- a/src/java.base/windows/classes/java/net/TwoStacksPlainDatagramSocketImpl.java Fri Feb 02 10:32:59 2018 -0800
+++ b/src/java.base/windows/classes/java/net/TwoStacksPlainDatagramSocketImpl.java Fri Feb 02 14:17:07 2018 -0500
@@ -86,6 +86,7 @@
fd1 = new FileDescriptor();
try {
super.create();
+ SocketCleanable.register(fd1);
} catch (SocketException e) {
fd1 = null;
throw e;
@@ -160,6 +161,8 @@
protected void close() {
if (fd != null || fd1 != null) {
+ SocketCleanable.unregister(fd);
+ SocketCleanable.unregister(fd1);
datagramSocketClose();
ResourceManager.afterUdpClose();
fd = null;
--- a/src/java.base/windows/native/libnet/SocketImpl.c Fri Feb 02 10:32:59 2018 -0800
+++ b/src/java.base/windows/native/libnet/SocketImpl.c Fri Feb 02 14:17:07 2018 -0500
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 2016, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2016, 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
@@ -24,6 +24,8 @@
*/
#include <jni.h>
+#include "net_util.h"
+#include "java_net_SocketCleanable.h"
JNIEXPORT jboolean JNICALL
Java_java_net_AbstractPlainSocketImpl_isReusePortAvailable0(JNIEnv* env, jclass c1)
@@ -45,3 +47,15 @@
// SO_REUSEPORT is not supported on Windows
return JNI_FALSE;
}
+
+/*
+ * Class: java_net_SocketCleanable
+ * Method: cleanupClose0
+ * Signature: (I)V
+ */
+JNIEXPORT void JNICALL
+Java_java_net_SocketCleanable_cleanupClose0(JNIEnv *env, jclass c1, jint fd)
+{
+ NET_SocketClose(fd);
+}
+
--- a/test/jdk/java/net/DatagramSocket/SendSize.java Fri Feb 02 10:32:59 2018 -0800
+++ b/test/jdk/java/net/DatagramSocket/SendSize.java Fri Feb 02 14:17:07 2018 -0500
@@ -1,5 +1,5 @@
/*
- * Copyright (c) 1997, 2010, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1997, 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
@@ -24,7 +24,7 @@
/* @test
*
* @bug 4095393
- *
+ * @test main SendSize
* @summary this tests a regression in 1.2, beta 2 and earlier where
* the DatagramPackets sent the entire buffer, not the buffer length
* of the packet.
@@ -43,8 +43,12 @@
public static void main(String[] args) throws Exception {
DatagramSocket serverSocket = new DatagramSocket();
- new ServerThread(serverSocket).start();
- new ClientThread(serverSocket.getLocalPort()).start();
+ Thread server = new ServerThread(serverSocket);
+ server.start();
+ Thread client = new ClientThread(serverSocket.getLocalPort());
+ client.start();
+ server.join();
+ client.join();
}
static class ServerThread extends Thread {
@@ -58,24 +62,26 @@
try {
System.err.println("started server thread: " + server);
byte[] buf = new byte[1024];
- DatagramPacket receivePacket = new DatagramPacket(buf,
- buf.length);
- server.receive(receivePacket);
- int len = receivePacket.getLength();
- switch(len) {
- case packetLength:
- System.out.println("receive length is: " + len);
- break;
- default:
- throw new RuntimeException(
- "receive length is: " + len +
- ", send length: " + packetLength +
- ", buffer length: " + buf.length);
+ for (int i = 0; i < 10; i++) {
+ DatagramPacket receivePacket = new DatagramPacket(buf,
+ buf.length);
+ server.receive(receivePacket);
+ int len = receivePacket.getLength();
+ switch (len) {
+ case packetLength:
+ System.out.println("receive length is: " + len);
+ break;
+ default:
+ throw new RuntimeException(
+ "receive length is: " + len +
+ ", send length: " + packetLength +
+ ", buffer length: " + buf.length);
+ }
}
return;
} catch (Exception e) {
e.printStackTrace();
- throw new RuntimeException("caugth: " + e);
+ throw new RuntimeException("caught: " + e);
} finally {
if (server != null) { server.close(); }
}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/test/jdk/java/net/DatagramSocket/UnreferencedDatagramSockets.java Fri Feb 02 14:17:07 2018 -0500
@@ -0,0 +1,269 @@
+/*
+ * Copyright (c) 2017, 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 UnreferencedDatagramSockets
+ * @run main/othervm -Djava.net.preferIPv4Stack=true UnreferencedDatagramSockets
+ * @summary Check that unreferenced datagram 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.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 UnreferencedDatagramSockets {
+
+ /**
+ * 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 {
+
+ DatagramSocket ss;
+
+ Server() throws IOException {
+ ss = new DatagramSocket(0);
+ System.out.printf(" DatagramServer addr: %s: %d%n",
+ this.getHost(), this.getPort());
+ pendingSockets.add(new NamedWeak(ss, pendingQueue, "serverDatagramSocket"));
+ extractRefs(ss, "serverDatagramSocket");
+ }
+
+ 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 datagram socket reference
+ ss = null;
+ } catch (Exception ioe) {
+ ioe.printStackTrace();
+ }
+ }
+ }
+
+ public static void main(String args[]) throws Exception {
+
+ // Create and close a DatagramSocket to warm up the FD count for side effects.
+ try (DatagramSocket s = new DatagramSocket(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();
+
+ DatagramSocket client = new DatagramSocket(0);
+ client.connect(svr.getHost(), svr.getPort());
+ pendingSockets.add(new NamedWeak(client, pendingQueue, "clientDatagramSocket"));
+ extractRefs(client, "clientDatagramSocket");
+
+ 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 DatagramSocket; 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 datagram implementation that will be gc'd
+ private static void extractRefs(DatagramSocket 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();
+ }
+ }
+}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/test/jdk/java/net/MulticastSocket/UnreferencedMulticastSockets.java Fri Feb 02 14:17:07 2018 -0500
@@ -0,0 +1,271 @@
+/*
+ * 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);
+ 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();
+ }
+ }
+}
--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/test/jdk/java/net/ServerSocket/UnreferencedSockets.java Fri Feb 02 14:17:07 2018 -0500
@@ -0,0 +1,294 @@
+/*
+ * Copyright (c) 2017, 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 UnreferencedSockets
+ * @run main/othervm -Djava.net.preferIPv4Stack=true UnreferencedSockets
+ * @summary Check that unreferenced sockets are closed
+ */
+
+import java.io.FileDescriptor;
+import java.io.InputStream;
+import java.io.OutputStream;
+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.ServerSocket;
+import java.net.Socket;
+import java.net.SocketImpl;
+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 UnreferencedSockets {
+
+ /**
+ * The set of sockets we have to check up on.
+ */
+ final static ArrayDeque<NamedWeak> pendingSockets = new ArrayDeque<>(100);
+
+ /**
+ * Queued sockets when they are unreferenced.
+ */
+ final static ReferenceQueue<Object> pendingQueue = new ReferenceQueue<>();
+
+ // Server to echo a stream
+ static class Server implements Runnable {
+
+ ServerSocket ss;
+
+ Server() throws IOException {
+ ss = new ServerSocket(0);
+ pendingSockets.add(new NamedWeak(ss, pendingQueue, "serverSocket"));
+ extractRefs(ss, "serverSocket");
+ }
+
+ public int localPort() {
+ return ss.getLocalPort();
+ }
+
+
+ public void run() {
+ try {
+ Socket s = ss.accept();
+ pendingSockets.add(new NamedWeak(s, pendingQueue, "acceptedSocket"));
+ extractRefs(s, "acceptedSocket");
+
+ InputStream in = s.getInputStream();
+ int b = in.read();
+ OutputStream out = s.getOutputStream();
+ out.write(b);
+ // do NOT close but 'forget' the socket reference
+ out = null;
+ in = null;
+ s = null;
+ } catch (Exception ioe) {
+ ioe.printStackTrace();
+ } finally {
+ try {
+ ss.close();
+ ss = null;
+ } catch (IOException x) {
+ x.printStackTrace();
+ }
+ }
+ }
+ }
+
+ public static void main(String args[]) throws Exception {
+
+ // Create and close a ServerSocket to warm up the FD count for side effects.
+ try (ServerSocket s = new ServerSocket(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();
+
+ Socket s = new Socket("localhost", svr.localPort());
+ pendingSockets.add(new NamedWeak(s, pendingQueue, "clientSocket"));
+ extractRefs(s, "clientSocket");
+
+ OutputStream out = s.getOutputStream();
+ out.write('x');
+ out.flush();
+ InputStream in = s.getInputStream();
+ int b = in.read(); // wait for it back
+ System.out.printf(" data sent and received%n");
+ // Do NOT close the Socket; 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 queued: %s, remaining: %d%n", ref, pendingSockets.size());
+ } else {
+ s = null;
+ out = null;
+ in = 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(Socket s, String name) {
+ try {
+
+ Field socketImplField = Socket.class.getDeclaredField("impl");
+ socketImplField.setAccessible(true);
+ Object socketImpl = socketImplField.get(s);
+
+ Field fileDescriptorField = SocketImpl.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.getClass().getName().equals("java.net.TwoStacksPlainSocketImpl")) {
+ Field fileDescriptor1Field = socketImplClass.getDeclaredField("fd1");
+ fileDescriptor1Field.setAccessible(true);
+ FileDescriptor fileDescriptor1 = (FileDescriptor) fileDescriptor1Field.get(socketImpl);
+ extractRefs(fileDescriptor1, name + "::twoStacksFd1");
+
+ }
+ } 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(" fd: %s, fd: %d, cleanup: %s%n",
+ fileDescriptor, rawfd, cleanup));
+ }
+ }
+
+ private static void extractRefs(ServerSocket s, String name) {
+ try {
+
+ Field socketImplField = ServerSocket.class.getDeclaredField("impl");
+ socketImplField.setAccessible(true);
+ Object socketImpl = socketImplField.get(s);
+
+ Field fileDescriptorField = SocketImpl.class.getDeclaredField("fd");
+ fileDescriptorField.setAccessible(true);
+ FileDescriptor fileDescriptor = (FileDescriptor) fileDescriptorField.get(socketImpl);
+
+ Field fdField = FileDescriptor.class.getDeclaredField("fd");
+ fdField.setAccessible(true);
+ int rawfd = fdField.getInt(fileDescriptor);
+
+ Field cleanupField = FileDescriptor.class.getDeclaredField("cleanup");
+ cleanupField.setAccessible(true);
+ Object cleanup = cleanupField.get(fileDescriptor);
+
+ System.out.print(String.format(" fd: %s, fd: %d, cleanup: %s, socket: %s%n",
+ fileDescriptor, rawfd, cleanup, s));
+
+ 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);
+ }
+ }
+
+ /**
+ * 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();
+ }
+ }
+}