8279339: (ch) Input/Output streams returned by Channels factory methods don't support concurrent read/write ops

Reviewed-by: lancea, bpb

src/java.base/share/classes/java/nio/channels/Channels.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2022, 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
@@ -40,8 +40,6 @@ import java.nio.charset.UnsupportedCharsetException;
 import java.nio.channels.spi.AbstractInterruptibleChannel;
 import java.util.Objects;
 import java.util.concurrent.ExecutionException;
-import sun.nio.ch.ChannelInputStream;
-import sun.nio.ch.ChannelOutputStream;
 import sun.nio.cs.StreamDecoder;
 import sun.nio.cs.StreamEncoder;
 
@@ -87,7 +85,7 @@ public final class Channels {
      */
     public static InputStream newInputStream(ReadableByteChannel ch) {
         Objects.requireNonNull(ch, "ch");
-        return new ChannelInputStream(ch);
+        return sun.nio.ch.Streams.of(ch);
     }
 
     /**
@@ -106,7 +104,7 @@ public final class Channels {
      */
     public static OutputStream newOutputStream(WritableByteChannel ch) {
         Objects.requireNonNull(ch, "ch");
-        return new ChannelOutputStream(ch);
+        return sun.nio.ch.Streams.of(ch);
     }
 
     /**

src/java.base/share/classes/sun/nio/ch/ChannelInputStream.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2001, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2001, 2022, 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
@@ -40,58 +40,52 @@ import java.util.Objects;
 import jdk.internal.util.ArraysSupport;
 
 /**
- * This class is defined here rather than in java.nio.channels.Channels
+ * An InputStream that reads bytes from a channel.
- * so that code can be shared with SocketAdaptor.
  *
  * @author Mike McCloskey
  * @author Mark Reinhold
- * @since 1.4
  */
-
+class ChannelInputStream extends InputStream {
-public class ChannelInputStream
-    extends InputStream
-{
     private static final int DEFAULT_BUFFER_SIZE = 8192;
 
-    public static int read(ReadableByteChannel ch, ByteBuffer bb,
+    private final ReadableByteChannel ch;
-                           boolean block)
+    private ByteBuffer bb;
-        throws IOException
+    private byte[] bs;       // Invoker's previous array
-    {
+    private byte[] b1;
+
+    /**
+     * Initialize a ChannelInputStream that reads from the given channel.
+     */
+    ChannelInputStream(ReadableByteChannel ch) {
+        this.ch = ch;
+    }
+
+    /**
+     * Reads a sequence of bytes from the channel into the given buffer.
+     */
+    private int read(ByteBuffer bb) throws IOException {
         if (ch instanceof SelectableChannel sc) {
             synchronized (sc.blockingLock()) {
-                boolean bm = sc.isBlocking();
+                if (!sc.isBlocking())
-                if (!bm)
                     throw new IllegalBlockingModeException();
-                if (bm != block)
+                return ch.read(bb);
-                    sc.configureBlocking(block);
-                int n = ch.read(bb);
-                if (bm != block)
-                    sc.configureBlocking(bm);
-                return n;
             }
         } else {
             return ch.read(bb);
         }
     }
 
-    protected final ReadableByteChannel ch;
+    @Override
-    private ByteBuffer bb = null;
-    private byte[] bs = null;           // Invoker's previous array
-    private byte[] b1 = null;
-
-    public ChannelInputStream(ReadableByteChannel ch) {
-        this.ch = ch;
-    }
-
     public synchronized int read() throws IOException {
         if (b1 == null)
             b1 = new byte[1];
-        int n = this.read(b1);
+        int n = read(b1);
         if (n == 1)
             return b1[0] & 0xff;
         return -1;
     }
 
+    @Override
     public synchronized int read(byte[] bs, int off, int len)
         throws IOException
     {
@@ -109,12 +103,6 @@ public class ChannelInputStream
         return read(bb);
     }
 
-    protected int read(ByteBuffer bb)
-        throws IOException
-    {
-        return ChannelInputStream.read(ch, bb, true);
-    }
-
     @Override
     public byte[] readAllBytes() throws IOException {
         if (!(ch instanceof SeekableByteChannel sbc))
@@ -201,6 +189,7 @@ public class ChannelInputStream
         return (capacity == nread) ? buf : Arrays.copyOf(buf, nread);
     }
 
+    @Override
     public int available() throws IOException {
         // special case where the channel is to a file
         if (ch instanceof SeekableByteChannel sbc) {
@@ -210,6 +199,7 @@ public class ChannelInputStream
         return 0;
     }
 
+    @Override
     public synchronized long skip(long n) throws IOException {
         // special case where the channel is to a file
         if (ch instanceof SeekableByteChannel sbc) {
@@ -230,21 +220,24 @@ public class ChannelInputStream
         return super.skip(n);
     }
 
-    public void close() throws IOException {
-        ch.close();
-    }
-
     @Override
     public long transferTo(OutputStream out) throws IOException {
         Objects.requireNonNull(out, "out");
 
-        if (out instanceof ChannelOutputStream cos
+        if (ch instanceof FileChannel fc) {
-                && ch instanceof FileChannel fc) {
+            // FileChannel -> SocketChannel
-            WritableByteChannel wbc = cos.channel();
+            if (out instanceof SocketOutputStream sos) {
-
+                SocketChannelImpl sc = sos.channel();
-            if (wbc instanceof FileChannel dst) {
+                synchronized (sc.blockingLock()) {
-                return transfer(fc, dst);
+                    if (!sc.isBlocking())
+                        throw new IllegalBlockingModeException();
+                    return transfer(fc, sc);
                 }
+            }
+
+            // FileChannel -> WritableByteChannel
+            if (out instanceof ChannelOutputStream cos) {
+                WritableByteChannel wbc = cos.channel();
 
                 if (wbc instanceof SelectableChannel sc) {
                     synchronized (sc.blockingLock()) {
@@ -256,20 +249,33 @@ public class ChannelInputStream
 
                 return transfer(fc, wbc);
             }
+        }
 
         return super.transferTo(out);
     }
 
-    private static long transfer(FileChannel src, WritableByteChannel dst) throws IOException {
+    /**
-        long initialPos = src.position();
+     * Transfers all bytes from a channel's file to a target writeable byte channel.
+     * If the writeable byte channel is a selectable channel then it must be in
+     * blocking mode.
+     */
+    private static long transfer(FileChannel fc, WritableByteChannel target)
+        throws IOException
+    {
+        long initialPos = fc.position();
         long pos = initialPos;
         try {
-            while (pos < src.size()) {
+            while (pos < fc.size()) {
-                pos += src.transferTo(pos, Long.MAX_VALUE, dst);
+                pos += fc.transferTo(pos, Long.MAX_VALUE, target);
             }
         } finally {
-            src.position(pos);
+            fc.position(pos);
         }
         return pos - initialPos;
     }
+
+    @Override
+    public void close() throws IOException {
+        ch.close();
+    }
 }

src/java.base/share/classes/sun/nio/ch/ChannelOutputStream.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2021, 2022, 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
@@ -25,68 +25,30 @@
 
 package sun.nio.ch;
 
-import java.io.*;
+import java.io.IOException;
-import java.nio.*;
+import java.io.OutputStream;
-import java.nio.channels.*;
+import java.nio.ByteBuffer;
-import java.nio.channels.spi.*;
+import java.nio.channels.IllegalBlockingModeException;
+import java.nio.channels.SelectableChannel;
+import java.nio.channels.WritableByteChannel;
 import java.util.Objects;
 
 /**
- * This class is defined here rather than in java.nio.channels.Channels
+ * An OutputStream that writes bytes to a channel.
- * so that it will be accessible from java.nio.channels.Channels and
- * sun.nio.ch.ChannelInputStream.
- *
  *
  * @author Mark Reinhold
  * @author Mike McCloskey
- * @author JSR-51 Expert Group
- * @since 18
  */
-public class ChannelOutputStream extends OutputStream {
+class ChannelOutputStream extends OutputStream {
-
     private final WritableByteChannel ch;
     private ByteBuffer bb;
     private byte[] bs;       // Invoker's previous array
     private byte[] b1;
 
     /**
-     * Write all remaining bytes in buffer to the given channel.
+     * Initialize a ChannelOutputStream that writes to the given channel.
-     * If the channel is selectable then it must be configured blocking.
      */
-    private static void writeFullyImpl(WritableByteChannel ch, ByteBuffer bb)
+    ChannelOutputStream(WritableByteChannel ch) {
-        throws IOException
-    {
-        while (bb.remaining() > 0) {
-            int n = ch.write(bb);
-            if (n <= 0)
-                throw new RuntimeException("no bytes written");
-        }
-    }
-
-    /**
-     * Write all remaining bytes in buffer to the given channel.
-     *
-     * @throws  IllegalBlockingModeException
-     *          If the channel is selectable and configured non-blocking.
-     */
-    private static void writeFully(WritableByteChannel ch, ByteBuffer bb)
-        throws IOException
-    {
-        if (ch instanceof SelectableChannel sc) {
-            synchronized (sc.blockingLock()) {
-                if (!sc.isBlocking())
-                    throw new IllegalBlockingModeException();
-                writeFullyImpl(ch, bb);
-            }
-        } else {
-            writeFullyImpl(ch, bb);
-        }
-    }
-
-    /**
-     * @param ch The channel wrapped by this stream.
-     */
-    public ChannelOutputStream(WritableByteChannel ch) {
         this.ch = ch;
     }
 
@@ -97,17 +59,30 @@ public class ChannelOutputStream extends OutputStream {
         return ch;
     }
 
+    /**
+     * Write all remaining bytes in buffer to the channel.
+     * If the channel is selectable then it must be configured blocking.
+     */
+    private void writeFully(ByteBuffer bb) throws IOException {
+        while (bb.remaining() > 0) {
+            int n = ch.write(bb);
+            if (n <= 0)
+                throw new RuntimeException("no bytes written");
+        }
+    }
+
     @Override
     public synchronized void write(int b) throws IOException {
         if (b1 == null)
             b1 = new byte[1];
         b1[0] = (byte) b;
-        this.write(b1);
+        write(b1);
     }
 
     @Override
     public synchronized void write(byte[] bs, int off, int len)
-        throws IOException {
+        throws IOException
+    {
         Objects.checkFromIndexSize(off, len, bs.length);
         if (len == 0) {
             return;
@@ -119,12 +94,20 @@ public class ChannelOutputStream extends OutputStream {
         bb.position(off);
         this.bb = bb;
         this.bs = bs;
-        writeFully(ch, bb);
+
+        if (ch instanceof SelectableChannel sc) {
+            synchronized (sc.blockingLock()) {
+                if (!sc.isBlocking())
+                    throw new IllegalBlockingModeException();
+                writeFully(bb);
+            }
+        } else {
+            writeFully(bb);
+        }
     }
 
     @Override
     public void close() throws IOException {
         ch.close();
     }
-
 }

src/java.base/share/classes/sun/nio/ch/SocketAdaptor.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2000, 2021, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2000, 2022, 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
@@ -177,32 +177,7 @@ class SocketAdaptor
             throw new SocketException("Socket is not connected");
         if (!sc.isInputOpen())
             throw new SocketException("Socket input is shutdown");
-        return new InputStream() {
+        return new SocketInputStream(sc, () -> timeout);
-            @Override
-            public int read() throws IOException {
-                byte[] a = new byte[1];
-                int n = read(a, 0, 1);
-                return (n > 0) ? (a[0] & 0xff) : -1;
-            }
-            @Override
-            public int read(byte[] b, int off, int len) throws IOException {
-                int timeout = SocketAdaptor.this.timeout;
-                if (timeout > 0) {
-                    long nanos = MILLISECONDS.toNanos(timeout);
-                    return sc.blockingRead(b, off, len, nanos);
-                } else {
-                    return sc.blockingRead(b, off, len, 0);
-                }
-            }
-            @Override
-            public int available() throws IOException {
-                return sc.available();
-            }
-            @Override
-            public void close() throws IOException {
-                sc.close();
-            }
-        };
     }
 
     @Override
@@ -213,21 +188,7 @@ class SocketAdaptor
             throw new SocketException("Socket is not connected");
         if (!sc.isOutputOpen())
             throw new SocketException("Socket output is shutdown");
-        return new OutputStream() {
+        return new SocketOutputStream(sc);
-            @Override
-            public void write(int b) throws IOException {
-                byte[] a = new byte[]{(byte) b};
-                write(a, 0, 1);
-            }
-            @Override
-            public void write(byte[] b, int off, int len) throws IOException {
-                sc.blockingWriteFully(b, off, len);
-            }
-            @Override
-            public void close() throws IOException {
-                sc.close();
-            }
-        };
     }
 
     private void setBooleanOption(SocketOption<Boolean> name, boolean value)

src/java.base/share/classes/sun/nio/ch/SocketInputStream.java

@@ -0,0 +1,83 @@
+/*
+ * Copyright (c) 2022, 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 sun.nio.ch;
+
+import java.io.IOException;
+import java.io.InputStream;
+import java.util.function.IntSupplier;
+import static java.util.concurrent.TimeUnit.MILLISECONDS;
+
+/**
+ * An InputStream that reads bytes from a socket channel.
+ */
+class SocketInputStream extends InputStream {
+    private final SocketChannelImpl sc;
+    private final IntSupplier timeoutSupplier;
+
+    /**
+     * Initialize a SocketInputStream that reads from the given socket channel.
+     * @param sc the socket channel
+     * @param timeoutSupplier supplies the read timeout, in milliseconds
+     */
+    SocketInputStream(SocketChannelImpl sc, IntSupplier timeoutSupplier) {
+        this.sc = sc;
+        this.timeoutSupplier = timeoutSupplier;
+    }
+
+    /**
+     * Initialize a SocketInputStream that reads from the given socket channel.
+     */
+    SocketInputStream(SocketChannelImpl sc) {
+        this(sc, () -> 0);
+    }
+
+    @Override
+    public int read() throws IOException {
+        byte[] a = new byte[1];
+        int n = read(a, 0, 1);
+        return (n > 0) ? (a[0] & 0xff) : -1;
+    }
+
+    @Override
+    public int read(byte[] b, int off, int len) throws IOException {
+        int timeout = timeoutSupplier.getAsInt();
+        if (timeout > 0) {
+            long nanos = MILLISECONDS.toNanos(timeout);
+            return sc.blockingRead(b, off, len, nanos);
+        } else {
+            return sc.blockingRead(b, off, len, 0);
+        }
+    }
+
+    @Override
+    public int available() throws IOException {
+        return sc.available();
+    }
+
+    @Override
+    public void close() throws IOException {
+        sc.close();
+    }
+}

src/java.base/share/classes/sun/nio/ch/SocketOutputStream.java

@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2022, 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 sun.nio.ch;
+
+import java.io.IOException;
+import java.io.OutputStream;
+
+/**
+ * An OutputStream that writes bytes to a socket channel.
+ */
+class SocketOutputStream extends OutputStream {
+    private final SocketChannelImpl sc;
+
+    /**
+     * Initialize a SocketOutputStream that writes to the given socket channel.
+     */
+    SocketOutputStream(SocketChannelImpl sc) {
+        this.sc = sc;
+    }
+
+    /**
+     * Returns the socket channel.
+     */
+    SocketChannelImpl channel() {
+        return sc;
+    }
+
+    @Override
+    public void write(int b) throws IOException {
+        byte[] a = new byte[]{(byte) b};
+        write(a, 0, 1);
+    }
+
+    @Override
+    public void write(byte[] b, int off, int len) throws IOException {
+        sc.blockingWriteFully(b, off, len);
+    }
+
+    @Override
+    public void close() throws IOException {
+        sc.close();
+    }
+}

src/java.base/share/classes/sun/nio/ch/Streams.java

@@ -0,0 +1,59 @@
+/*
+ * Copyright (c) 2021, 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 sun.nio.ch;
+
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.nio.channels.ReadableByteChannel;
+import java.nio.channels.WritableByteChannel;
+
+/**
+ * Factory methods for input/output streams based on channels.
+ */
+public class Streams {
+    private Streams() { }
+
+    /**
+     * Return an input stream that reads bytes from the given channel.
+     */
+    public static InputStream of(ReadableByteChannel ch) {
+        if (ch instanceof SocketChannelImpl sc) {
+            return new SocketInputStream(sc);
+        } else {
+            return new ChannelInputStream(ch);
+        }
+    }
+
+    /**
+     * Return an output stream that writes bytes to the given channel.
+     */
+    public static OutputStream of(WritableByteChannel ch) {
+        if (ch instanceof SocketChannelImpl sc) {
+            return new SocketOutputStream(sc);
+        } else {
+            return new ChannelOutputStream(ch);
+        }
+    }
+}

test/jdk/java/nio/channels/Channels/SocketChannelStreams.java

@@ -0,0 +1,480 @@
+/*
+ * Copyright (c) 2022, 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
+ * @bug 8279339
+ * @run testng SocketChannelStreams
+ * @summary Exercise InputStream/OutputStream returned by Channels.newXXXStream
+ *    when channel is a SocketChannel
+ */
+
+import java.io.Closeable;
+import java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+import java.net.Socket;
+import java.nio.channels.Channels;
+import java.nio.channels.IllegalBlockingModeException;
+import java.nio.channels.ServerSocketChannel;
+import java.nio.channels.SocketChannel;
+import java.util.Objects;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Executors;
+import java.util.concurrent.Future;
+import java.util.concurrent.ScheduledExecutorService;
+import java.util.concurrent.TimeUnit;
+
+import org.testng.annotations.*;
+import static org.testng.Assert.*;
+
+@Test
+public class SocketChannelStreams {
+    private ScheduledExecutorService executor;
+
+    @BeforeClass()
+    public void init() {
+        executor = Executors.newSingleThreadScheduledExecutor();
+    }
+
+    @AfterClass
+    public void finish() {
+        executor.shutdown();
+    }
+
+    /**
+     * Test read when bytes are available.
+     */
+    public void testRead1() throws Exception {
+        withConnection((sc, peer) -> {
+            write(peer, 99);
+            int n = Channels.newInputStream(sc).read();
+            assertEquals(n, 99);
+        });
+    }
+
+    /**
+     * Test read blocking before bytes are available.
+     */
+    public void testRead2() throws Exception {
+        withConnection((sc, peer) -> {
+            scheduleWrite(peer, 99, 1000);
+            int n = Channels.newInputStream(sc).read();
+            assertEquals(n, 99);
+        });
+    }
+
+    /**
+     * Test read after peer has closed connection.
+     */
+    public void testRead3() throws Exception {
+        withConnection((sc, peer) -> {
+            peer.close();
+            int n = Channels.newInputStream(sc).read();
+            assertEquals(n, -1);
+        });
+    }
+
+    /**
+     * Test read blocking before peer closes connection.
+     */
+    public void testRead4() throws Exception {
+        withConnection((sc, peer) -> {
+            scheduleClose(peer, 1000);
+            int n = Channels.newInputStream(sc).read();
+            assertEquals(n, -1);
+        });
+    }
+
+    /**
+     * Test async close of channel when thread blocked in read.
+     */
+    public void testRead5() throws Exception {
+        withConnection((sc, peer) -> {
+            scheduleClose(sc, 2000);
+            InputStream in = Channels.newInputStream(sc);
+            expectThrows(IOException.class, () -> in.read());
+        });
+    }
+
+    /**
+     * Test async close of input stream, when thread blocked in read.
+     */
+    public void testRead6() throws Exception {
+        withConnection((sc, peer) -> {
+            InputStream in = Channels.newInputStream(sc);
+            scheduleClose(in, 2000);
+            expectThrows(IOException.class, () -> in.read());
+        });
+    }
+
+    /**
+     * Test interrupt status set before read.
+     */
+    public void testRead7() throws Exception {
+        withConnection((sc, peer) -> {
+            Thread.currentThread().interrupt();
+            try {
+                InputStream in = Channels.newInputStream(sc);
+                expectThrows(IOException.class, () -> in.read());
+            } finally {
+                Thread.interrupted();  // clear interrupt
+            }
+            assertFalse(sc.isOpen());
+        });
+    }
+
+    /**
+     * Test interrupt of thread blocked in read.
+     */
+    public void testRead8() throws Exception {
+        withConnection((sc, peer) -> {
+            Future<?> interrupter = scheduleInterrupt(Thread.currentThread(), 2000);
+            try {
+                InputStream in = Channels.newInputStream(sc);
+                expectThrows(IOException.class, () -> in.read());
+            } finally {
+                interrupter.cancel(true);
+                Thread.interrupted();  // clear interrupt
+            }
+            assertFalse(sc.isOpen());
+        });
+    }
+
+    /**
+     * Test that read is untimed when SO_TIMEOUT is set on the Socket adaptor.
+     */
+    public void testRead9() throws Exception {
+        withConnection((sc, peer) -> {
+            sc.socket().setSoTimeout(100);
+            scheduleWrite(peer, 99, 2000);
+            // read should block until bytes are available
+            int b = Channels.newInputStream(sc).read();
+            assertTrue(b == 99);
+        });
+    }
+
+    /**
+     * Test write.
+     */
+    public void testWrite1() throws Exception {
+        withConnection((sc, peer) -> {
+            OutputStream out = Channels.newOutputStream(sc);
+            out.write(99);
+            int n = read(peer);
+            assertEquals(n, 99);
+        });
+    }
+
+    /**
+     * Test async close of channel when thread blocked in write.
+     */
+    public void testWrite2() throws Exception {
+        withConnection((sc, peer) -> {
+            scheduleClose(sc, 2000);
+            expectThrows(IOException.class, () -> {
+                OutputStream out = Channels.newOutputStream(sc);
+                byte[] data = new byte[64*1000];
+                while (true) {
+                    out.write(data);
+                }
+            });
+        });
+    }
+
+    /**
+     * Test async close of output stream when thread blocked in write.
+     */
+    public void testWrite3() throws Exception {
+        withConnection((sc, peer) -> {
+            OutputStream out = Channels.newOutputStream(sc);
+            scheduleClose(out, 2000);
+            expectThrows(IOException.class, () -> {
+                byte[] data = new byte[64*1000];
+                while (true) {
+                    out.write(data);
+                }
+            });
+        });
+    }
+
+    /**
+     * Test interrupt status set before write.
+     */
+    public void testWrite4() throws Exception {
+        withConnection((sc, peer) -> {
+            Thread.currentThread().interrupt();
+            try {
+                OutputStream out = Channels.newOutputStream(sc);
+                expectThrows(IOException.class, () -> out.write(99));
+            } finally {
+                Thread.interrupted();  // clear interrupt
+            }
+            assertFalse(sc.isOpen());
+        });
+    }
+
+    /**
+     * Test interrupt of thread blocked in write.
+     */
+    public void testWrite5() throws Exception {
+        withConnection((sc, peer) -> {
+            Future<?> interrupter = scheduleInterrupt(Thread.currentThread(), 2000);
+            try {
+                expectThrows(IOException.class, () -> {
+                    OutputStream out = Channels.newOutputStream(sc);
+                    byte[] data = new byte[64*1000];
+                    while (true) {
+                        out.write(data);
+                    }
+                });
+            } finally {
+                interrupter.cancel(true);
+                Thread.interrupted();  // clear interrupt
+            }
+            assertFalse(sc.isOpen());
+        });
+    }
+
+    /**
+     * Test read when another thread is blocked in write. The read should
+     * complete immediately.
+     */
+    public void testConcurrentReadWrite1() throws Exception {
+        withConnection((sc, peer) -> {
+            InputStream in = Channels.newInputStream(sc);
+            OutputStream out = Channels.newOutputStream(sc);
+
+            // block thread in write
+            fork(() -> {
+                var data = new byte[64*1024];
+                for (;;) {
+                    out.write(data);
+                }
+            });
+            Thread.sleep(1000); // give writer time to block
+
+            // test read, should not be blocked by writer thread
+            write(peer, 99);
+            int n = in.read();
+            assertEquals(n, 99);
+        });
+    }
+
+    /**
+     * Test read when another thread is blocked in write. The read should
+     * block until bytes are available.
+     */
+    public void testConcurrentReadWrite2() throws Exception {
+        withConnection((sc, peer) -> {
+            InputStream in = Channels.newInputStream(sc);
+            OutputStream out = Channels.newOutputStream(sc);
+
+            // block thread in write
+            fork(() -> {
+                var data = new byte[64*1024];
+                for (;;) {
+                    out.write(data);
+                }
+            });
+            Thread.sleep(1000); // give writer time to block
+
+            // test read, should not be blocked by writer thread
+            scheduleWrite(peer, 99, 500);
+            int n = in.read();
+            assertEquals(n, 99);
+        });
+    }
+
+    /**
+     * Test writing when another thread is blocked in read.
+     */
+    public void testConcurrentReadWrite3() throws Exception {
+        withConnection((sc, peer) -> {
+            InputStream in = Channels.newInputStream(sc);
+            OutputStream out = Channels.newOutputStream(sc);
+
+            // block thread in read
+            fork(() -> {
+                in.read();
+            });
+            Thread.sleep(100); // give reader time to block
+
+            // test write, should not be blocked by reader thread
+            out.write(99);
+            int n = read(peer);
+            assertEquals(n, 99);
+        });
+    }
+
+    /**
+     * Test read/write when channel configured non-blocking.
+     */
+    public void testIllegalBlockingMode() throws Exception {
+        withConnection((sc, peer) -> {
+            InputStream in = Channels.newInputStream(sc);
+            OutputStream out = Channels.newOutputStream(sc);
+
+            sc.configureBlocking(false);
+            expectThrows(IllegalBlockingModeException.class, () -> in.read());
+            expectThrows(IllegalBlockingModeException.class, () -> out.write(99));
+        });
+    }
+
+    /**
+     * Test NullPointerException.
+     */
+    public void testNullPointerException() throws Exception {
+        withConnection((sc, peer) -> {
+            InputStream in = Channels.newInputStream(sc);
+            OutputStream out = Channels.newOutputStream(sc);
+
+            expectThrows(NullPointerException.class, () -> in.read(null));
+            expectThrows(NullPointerException.class, () -> in.read(null, 0, 0));
+
+            expectThrows(NullPointerException.class, () -> out.write(null));
+            expectThrows(NullPointerException.class, () -> out.write(null, 0, 0));
+        });
+    }
+
+    /**
+     * Test IndexOutOfBoundsException.
+     */
+    public void testIndexOutOfBoundsException() throws Exception {
+        withConnection((sc, peer) -> {
+            InputStream in = Channels.newInputStream(sc);
+            OutputStream out = Channels.newOutputStream(sc);
+            byte[] ba = new byte[100];
+
+            expectThrows(IndexOutOfBoundsException.class, () -> in.read(ba, -1, 1));
+            expectThrows(IndexOutOfBoundsException.class, () -> in.read(ba, 0, -1));
+            expectThrows(IndexOutOfBoundsException.class, () -> in.read(ba, 0, 1000));
+            expectThrows(IndexOutOfBoundsException.class, () -> in.read(ba, 1, 100));
+
+            expectThrows(IndexOutOfBoundsException.class, () -> out.write(ba, -1, 1));
+            expectThrows(IndexOutOfBoundsException.class, () -> out.write(ba, 0, -1));
+            expectThrows(IndexOutOfBoundsException.class, () -> out.write(ba, 0, 1000));
+            expectThrows(IndexOutOfBoundsException.class, () -> out.write(ba, 1, 100));
+        });
+    }
+
+    // -- test infrastructure --
+
+    private interface ThrowingTask {
+        void run() throws Exception;
+    }
+
+    private interface ThrowingBiConsumer<T, U> {
+        void accept(T t, U u) throws Exception;
+    }
+
+    /**
+     * Invokes the consumer with a connected pair of socket channels.
+     */
+    private static void withConnection(ThrowingBiConsumer<SocketChannel, SocketChannel> consumer)
+        throws Exception
+    {
+        var loopback = InetAddress.getLoopbackAddress();
+        try (ServerSocketChannel listener = ServerSocketChannel.open()) {
+            listener.bind(new InetSocketAddress(loopback, 0));
+            try (SocketChannel sc = SocketChannel.open(listener.getLocalAddress())) {
+                try (SocketChannel peer = listener.accept()) {
+                    consumer.accept(sc, peer);
+                }
+            }
+        }
+    }
+
+    /**
+     * Forks a thread to execute the given task.
+     */
+    private Future<?> fork(ThrowingTask task) {
+        ExecutorService pool = Executors.newFixedThreadPool(1);
+        try {
+            return pool.submit(() -> {
+                task.run();
+                return null;
+            });
+        } finally {
+            pool.shutdown();
+        }
+    }
+
+    /**
+     * Read a byte from the given socket channel.
+     */
+    private int read(SocketChannel sc) throws IOException {
+        return sc.socket().getInputStream().read();
+    }
+
+    /**
+     * Write a byte to the given socket channel.
+     */
+    private void write(SocketChannel sc, int b) throws IOException {
+        sc.socket().getOutputStream().write(b);
+    }
+
+    /**
+     * Writes the given data to the socket channel after a delay.
+     */
+    private Future<?> scheduleWrite(SocketChannel sc, byte[] data, long delay) {
+        return schedule(() -> {
+            try {
+                sc.socket().getOutputStream().write(data);
+            } catch (IOException ioe) { }
+        }, delay);
+    }
+
+    /**
+     * Writes a byte to the socket channel after a delay.
+     */
+    private Future<?> scheduleWrite(SocketChannel sc, int b, long delay) {
+        return scheduleWrite(sc, new byte[] { (byte)b }, delay);
+    }
+
+    /**
+     * Closes the given object after a delay.
+     */
+    private Future<?> scheduleClose(Closeable c, long delay) {
+        return schedule(() -> {
+            try {
+                c.close();
+            } catch (IOException ioe) { }
+        }, delay);
+    }
+
+    /**
+     * Interrupts the given Thread after a delay.
+     */
+    private Future<?> scheduleInterrupt(Thread t, long delay) {
+        return schedule(() -> t.interrupt(), delay);
+    }
+
+    /**
+     * Schedules the given task to run after a delay.
+     */
+    private Future<?> schedule(Runnable task, long delay) {
+        return executor.schedule(task, delay, TimeUnit.MILLISECONDS);
+    }
+}