jdk/src/share/classes/sun/nio/ch/DatagramChannelImpl.java
changeset 2 90ce3da70b43
child 1152 29d6145d1097
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/jdk/src/share/classes/sun/nio/ch/DatagramChannelImpl.java	Sat Dec 01 00:00:00 2007 +0000
@@ -0,0 +1,707 @@
+/*
+ * Copyright 2001-2006 Sun Microsystems, Inc.  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.  Sun designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ */
+
+package sun.nio.ch;
+
+import java.io.FileDescriptor;
+import java.io.IOException;
+import java.net.*;
+import java.nio.ByteBuffer;
+import java.nio.channels.*;
+import java.nio.channels.spi.*;
+import java.lang.ref.SoftReference;
+
+
+/**
+ * An implementation of DatagramChannels.
+ */
+
+class DatagramChannelImpl
+    extends DatagramChannel
+    implements SelChImpl
+{
+
+    // Used to make native read and write calls
+    private static NativeDispatcher nd = new DatagramDispatcher();
+
+    // Our file descriptor
+    FileDescriptor fd = null;
+
+    // fd value needed for dev/poll. This value will remain valid
+    // even after the value in the file descriptor object has been set to -1
+    int fdVal;
+
+    // IDs of native threads doing reads and writes, for signalling
+    private volatile long readerThread = 0;
+    private volatile long writerThread = 0;
+
+    // Cached InetAddress and port for unconnected DatagramChannels
+    // used by receive0
+    private InetAddress cachedSenderInetAddress = null;
+    private int cachedSenderPort = 0;
+
+    // Lock held by current reading or connecting thread
+    private final Object readLock = new Object();
+
+    // Lock held by current writing or connecting thread
+    private final Object writeLock = new Object();
+
+    // Lock held by any thread that modifies the state fields declared below
+    // DO NOT invoke a blocking I/O operation while holding this lock!
+    private final Object stateLock = new Object();
+
+    // -- The following fields are protected by stateLock
+
+    // State (does not necessarily increase monotonically)
+    private static final int ST_UNINITIALIZED = -1;
+    private static int ST_UNCONNECTED = 0;
+    private static int ST_CONNECTED = 1;
+    private static final int ST_KILLED = 2;
+    private int state = ST_UNINITIALIZED;
+
+    // Binding
+    private SocketAddress localAddress = null;
+    SocketAddress remoteAddress = null;
+
+    // Options
+    private SocketOpts.IP options = null;
+
+    // Our socket adaptor, if any
+    private DatagramSocket socket = null;
+
+    // -- End of fields protected by stateLock
+
+
+    public DatagramChannelImpl(SelectorProvider sp)
+        throws IOException
+    {
+        super(sp);
+        this.fd = Net.socket(false);
+        this.fdVal = IOUtil.fdVal(fd);
+        this.state = ST_UNCONNECTED;
+    }
+
+    public DatagramChannelImpl(SelectorProvider sp, FileDescriptor fd)
+        throws IOException
+    {
+        super(sp);
+        this.fd = fd;
+        this.fdVal = IOUtil.fdVal(fd);
+        this.state = ST_UNCONNECTED;
+    }
+
+    public DatagramSocket socket() {
+        synchronized (stateLock) {
+            if (socket == null)
+                socket = DatagramSocketAdaptor.create(this);
+            return socket;
+        }
+    }
+
+    private void ensureOpen() throws ClosedChannelException {
+        if (!isOpen())
+            throw new ClosedChannelException();
+    }
+
+    private SocketAddress sender;       // Set by receive0 (## ugh)
+
+    public SocketAddress receive(ByteBuffer dst) throws IOException {
+        if (dst.isReadOnly())
+            throw new IllegalArgumentException("Read-only buffer");
+        if (dst == null)
+            throw new NullPointerException();
+        synchronized (readLock) {
+            ensureOpen();
+            // If socket is not bound then behave as if nothing received
+            if (!isBound())             // ## NotYetBoundException ??
+                return null;
+            int n = 0;
+            ByteBuffer bb = null;
+            try {
+                begin();
+                if (!isOpen())
+                    return null;
+                SecurityManager security = System.getSecurityManager();
+                readerThread = NativeThread.current();
+                if (isConnected() || (security == null)) {
+                    do {
+                        n = receive(fd, dst);
+                    } while ((n == IOStatus.INTERRUPTED) && isOpen());
+                    if (n == IOStatus.UNAVAILABLE)
+                        return null;
+                } else {
+                    bb = Util.getTemporaryDirectBuffer(dst.remaining());
+                    for (;;) {
+                        do {
+                            n = receive(fd, bb);
+                        } while ((n == IOStatus.INTERRUPTED) && isOpen());
+                        if (n == IOStatus.UNAVAILABLE)
+                            return null;
+                        InetSocketAddress isa = (InetSocketAddress)sender;
+                        try {
+                            security.checkAccept(
+                                isa.getAddress().getHostAddress(),
+                                isa.getPort());
+                        } catch (SecurityException se) {
+                            // Ignore packet
+                            bb.clear();
+                            n = 0;
+                            continue;
+                        }
+                        bb.flip();
+                        dst.put(bb);
+                        break;
+                    }
+                }
+                return sender;
+            } finally {
+                if (bb != null)
+                    Util.releaseTemporaryDirectBuffer(bb);
+                readerThread = 0;
+                end((n > 0) || (n == IOStatus.UNAVAILABLE));
+                assert IOStatus.check(n);
+            }
+        }
+    }
+
+    private int receive(FileDescriptor fd, ByteBuffer dst)
+        throws IOException
+    {
+        int pos = dst.position();
+        int lim = dst.limit();
+        assert (pos <= lim);
+        int rem = (pos <= lim ? lim - pos : 0);
+        if (dst instanceof DirectBuffer && rem > 0)
+            return receiveIntoNativeBuffer(fd, dst, rem, pos);
+
+        // Substitute a native buffer. If the supplied buffer is empty
+        // we must instead use a nonempty buffer, otherwise the call
+        // will not block waiting for a datagram on some platforms.
+        int newSize = Math.max(rem, 1);
+        ByteBuffer bb = null;
+        try {
+            bb = Util.getTemporaryDirectBuffer(newSize);
+            int n = receiveIntoNativeBuffer(fd, bb, newSize, 0);
+            bb.flip();
+            if (n > 0 && rem > 0)
+                dst.put(bb);
+            return n;
+        } finally {
+            Util.releaseTemporaryDirectBuffer(bb);
+        }
+    }
+
+    private int receiveIntoNativeBuffer(FileDescriptor fd, ByteBuffer bb,
+                                        int rem, int pos)
+        throws IOException
+    {
+        int n = receive0(fd, ((DirectBuffer)bb).address() + pos, rem,
+                         isConnected());
+        if (n > 0)
+            bb.position(pos + n);
+        return n;
+    }
+
+    public int send(ByteBuffer src, SocketAddress target)
+        throws IOException
+    {
+        if (src == null)
+            throw new NullPointerException();
+
+        synchronized (writeLock) {
+            ensureOpen();
+            InetSocketAddress isa = (InetSocketAddress)target;
+            InetAddress ia = isa.getAddress();
+            if (ia == null)
+                throw new IOException("Target address not resolved");
+            synchronized (stateLock) {
+                if (!isConnected()) {
+                    if (target == null)
+                        throw new NullPointerException();
+                    SecurityManager sm = System.getSecurityManager();
+                    if (sm != null) {
+                        if (ia.isMulticastAddress()) {
+                            sm.checkMulticast(isa.getAddress());
+                        } else {
+                            sm.checkConnect(isa.getAddress().getHostAddress(),
+                                            isa.getPort());
+                        }
+                    }
+                } else { // Connected case; Check address then write
+                    if (!target.equals(remoteAddress)) {
+                        throw new IllegalArgumentException(
+                            "Connected address not equal to target address");
+                    }
+                    return write(src);
+                }
+            }
+
+            int n = 0;
+            try {
+                begin();
+                if (!isOpen())
+                    return 0;
+                writerThread = NativeThread.current();
+                do {
+                    n = send(fd, src, target);
+                } while ((n == IOStatus.INTERRUPTED) && isOpen());
+                return IOStatus.normalize(n);
+            } finally {
+                writerThread = 0;
+                end((n > 0) || (n == IOStatus.UNAVAILABLE));
+                assert IOStatus.check(n);
+            }
+        }
+    }
+
+    private int send(FileDescriptor fd, ByteBuffer src, SocketAddress target)
+        throws IOException
+    {
+        if (src instanceof DirectBuffer)
+            return sendFromNativeBuffer(fd, src, target);
+
+        // Substitute a native buffer
+        int pos = src.position();
+        int lim = src.limit();
+        assert (pos <= lim);
+        int rem = (pos <= lim ? lim - pos : 0);
+
+        ByteBuffer bb = null;
+        try {
+            bb = Util.getTemporaryDirectBuffer(rem);
+            bb.put(src);
+            bb.flip();
+            // Do not update src until we see how many bytes were written
+            src.position(pos);
+
+            int n = sendFromNativeBuffer(fd, bb, target);
+            if (n > 0) {
+                // now update src
+                src.position(pos + n);
+            }
+            return n;
+        } finally {
+            Util.releaseTemporaryDirectBuffer(bb);
+        }
+    }
+
+    private int sendFromNativeBuffer(FileDescriptor fd, ByteBuffer bb,
+                                            SocketAddress target)
+        throws IOException
+    {
+        int pos = bb.position();
+        int lim = bb.limit();
+        assert (pos <= lim);
+        int rem = (pos <= lim ? lim - pos : 0);
+
+        int written = send0(fd, ((DirectBuffer)bb).address() + pos,
+                            rem, target);
+        if (written > 0)
+            bb.position(pos + written);
+        return written;
+    }
+
+    public int read(ByteBuffer buf) throws IOException {
+        if (buf == null)
+            throw new NullPointerException();
+        synchronized (readLock) {
+            synchronized (stateLock) {
+                ensureOpen();
+                if (!isConnected())
+                    throw new NotYetConnectedException();
+            }
+            int n = 0;
+            try {
+                begin();
+                if (!isOpen())
+                    return 0;
+                readerThread = NativeThread.current();
+                do {
+                    n = IOUtil.read(fd, buf, -1, nd, readLock);
+                } while ((n == IOStatus.INTERRUPTED) && isOpen());
+                return IOStatus.normalize(n);
+            } finally {
+                readerThread = 0;
+                end((n > 0) || (n == IOStatus.UNAVAILABLE));
+                assert IOStatus.check(n);
+            }
+        }
+    }
+
+    private long read0(ByteBuffer[] bufs) throws IOException {
+        if (bufs == null)
+            throw new NullPointerException();
+        synchronized (readLock) {
+            synchronized (stateLock) {
+                ensureOpen();
+                if (!isConnected())
+                    throw new NotYetConnectedException();
+            }
+            long n = 0;
+            try {
+                begin();
+                if (!isOpen())
+                    return 0;
+                readerThread = NativeThread.current();
+                do {
+                    n = IOUtil.read(fd, bufs, nd);
+                } while ((n == IOStatus.INTERRUPTED) && isOpen());
+                return IOStatus.normalize(n);
+            } finally {
+                readerThread = 0;
+                end((n > 0) || (n == IOStatus.UNAVAILABLE));
+                assert IOStatus.check(n);
+            }
+        }
+    }
+
+    public long read(ByteBuffer[] dsts, int offset, int length)
+        throws IOException
+    {
+        if ((offset < 0) || (length < 0) || (offset > dsts.length - length))
+           throw new IndexOutOfBoundsException();
+        // ## Fix IOUtil.write so that we can avoid this array copy
+        return read0(Util.subsequence(dsts, offset, length));
+    }
+
+    public int write(ByteBuffer buf) throws IOException {
+        if (buf == null)
+            throw new NullPointerException();
+        synchronized (writeLock) {
+            synchronized (stateLock) {
+                ensureOpen();
+                if (!isConnected())
+                    throw new NotYetConnectedException();
+            }
+            int n = 0;
+            try {
+                begin();
+                if (!isOpen())
+                    return 0;
+                writerThread = NativeThread.current();
+                do {
+                    n = IOUtil.write(fd, buf, -1, nd, writeLock);
+                } while ((n == IOStatus.INTERRUPTED) && isOpen());
+                return IOStatus.normalize(n);
+            } finally {
+                writerThread = 0;
+                end((n > 0) || (n == IOStatus.UNAVAILABLE));
+                assert IOStatus.check(n);
+            }
+        }
+    }
+
+    private long write0(ByteBuffer[] bufs) throws IOException {
+        if (bufs == null)
+            throw new NullPointerException();
+        synchronized (writeLock) {
+            synchronized (stateLock) {
+                ensureOpen();
+                if (!isConnected())
+                    throw new NotYetConnectedException();
+            }
+            long n = 0;
+            try {
+                begin();
+                if (!isOpen())
+                    return 0;
+                writerThread = NativeThread.current();
+                do {
+                    n = IOUtil.write(fd, bufs, nd);
+                } while ((n == IOStatus.INTERRUPTED) && isOpen());
+                return IOStatus.normalize(n);
+            } finally {
+                writerThread = 0;
+                end((n > 0) || (n == IOStatus.UNAVAILABLE));
+                assert IOStatus.check(n);
+            }
+        }
+    }
+
+    public long write(ByteBuffer[] srcs, int offset, int length)
+        throws IOException
+    {
+        if ((offset < 0) || (length < 0) || (offset > srcs.length - length))
+            throw new IndexOutOfBoundsException();
+        // ## Fix IOUtil.write so that we can avoid this array copy
+        return write0(Util.subsequence(srcs, offset, length));
+    }
+
+    protected void implConfigureBlocking(boolean block) throws IOException {
+        IOUtil.configureBlocking(fd, block);
+    }
+
+    public SocketOpts options() {
+        synchronized (stateLock) {
+            if (options == null) {
+                SocketOptsImpl.Dispatcher d
+                    = new SocketOptsImpl.Dispatcher() {
+                            int getInt(int opt) throws IOException {
+                                return Net.getIntOption(fd, opt);
+                            }
+                            void setInt(int opt, int arg)
+                                throws IOException
+                            {
+                                Net.setIntOption(fd, opt, arg);
+                            }
+                        };
+                options = new SocketOptsImpl.IP(d);
+            }
+            return options;
+        }
+    }
+
+    public boolean isBound() {
+        return Net.localPortNumber(fd) != 0;
+    }
+
+    public SocketAddress localAddress() {
+        synchronized (stateLock) {
+            if (isConnected() && (localAddress == null)) {
+                // Socket was not bound before connecting,
+                // so ask what the address turned out to be
+                localAddress = Net.localAddress(fd);
+            }
+            SecurityManager sm = System.getSecurityManager();
+            if (sm != null) {
+                InetSocketAddress isa = (InetSocketAddress)localAddress;
+                sm.checkConnect(isa.getAddress().getHostAddress(), -1);
+            }
+            return localAddress;
+        }
+    }
+
+    public SocketAddress remoteAddress() {
+        synchronized (stateLock) {
+            return remoteAddress;
+        }
+    }
+
+    public void bind(SocketAddress local) throws IOException {
+        synchronized (readLock) {
+            synchronized (writeLock) {
+                synchronized (stateLock) {
+                    ensureOpen();
+                    if (isBound())
+                        throw new AlreadyBoundException();
+                    InetSocketAddress isa = Net.checkAddress(local);
+                    SecurityManager sm = System.getSecurityManager();
+                    if (sm != null)
+                        sm.checkListen(isa.getPort());
+                    Net.bind(fd, isa.getAddress(), isa.getPort());
+                    localAddress = Net.localAddress(fd);
+                }
+            }
+        }
+    }
+
+    public boolean isConnected() {
+        synchronized (stateLock) {
+            return (state == ST_CONNECTED);
+        }
+    }
+
+    void ensureOpenAndUnconnected() throws IOException { // package-private
+        synchronized (stateLock) {
+            if (!isOpen())
+                throw new ClosedChannelException();
+            if (state != ST_UNCONNECTED)
+                throw new IllegalStateException("Connect already invoked");
+        }
+    }
+
+    public DatagramChannel connect(SocketAddress sa) throws IOException {
+        int trafficClass = 0;
+        int localPort = 0;
+
+        synchronized(readLock) {
+            synchronized(writeLock) {
+                synchronized (stateLock) {
+                    ensureOpenAndUnconnected();
+                    InetSocketAddress isa = Net.checkAddress(sa);
+                    SecurityManager sm = System.getSecurityManager();
+                    if (sm != null)
+                        sm.checkConnect(isa.getAddress().getHostAddress(),
+                                        isa.getPort());
+                    int n = Net.connect(fd,
+                                        isa.getAddress(),
+                                        isa.getPort(),
+                                        trafficClass);
+                    if (n <= 0)
+                        throw new Error();      // Can't happen
+
+                    // Connection succeeded; disallow further invocation
+                    state = ST_CONNECTED;
+                    remoteAddress = sa;
+                    sender = isa;
+                    cachedSenderInetAddress = isa.getAddress();
+                    cachedSenderPort = isa.getPort();
+                }
+            }
+        }
+        return this;
+    }
+
+    public DatagramChannel disconnect() throws IOException {
+        synchronized(readLock) {
+            synchronized(writeLock) {
+                synchronized (stateLock) {
+                    if (!isConnected() || !isOpen())
+                        return this;
+                    InetSocketAddress isa = (InetSocketAddress)remoteAddress;
+                    SecurityManager sm = System.getSecurityManager();
+                    if (sm != null)
+                        sm.checkConnect(isa.getAddress().getHostAddress(),
+                                        isa.getPort());
+                    disconnect0(fd);
+                    remoteAddress = null;
+                    state = ST_UNCONNECTED;
+                }
+            }
+        }
+        return this;
+    }
+
+    protected void implCloseSelectableChannel() throws IOException {
+        synchronized (stateLock) {
+            nd.preClose(fd);
+            long th;
+            if ((th = readerThread) != 0)
+                NativeThread.signal(th);
+            if ((th = writerThread) != 0)
+                NativeThread.signal(th);
+            if (!isRegistered())
+                kill();
+        }
+    }
+
+    public void kill() throws IOException {
+        synchronized (stateLock) {
+            if (state == ST_KILLED)
+                return;
+            if (state == ST_UNINITIALIZED) {
+                state = ST_KILLED;
+                return;
+            }
+            assert !isOpen() && !isRegistered();
+            nd.close(fd);
+            state = ST_KILLED;
+        }
+    }
+
+    protected void finalize() throws IOException {
+        // fd is null if constructor threw exception
+        if (fd != null)
+            close();
+    }
+
+    /**
+     * Translates native poll revent set into a ready operation set
+     */
+    public boolean translateReadyOps(int ops, int initialOps,
+                                     SelectionKeyImpl sk) {
+        int intOps = sk.nioInterestOps(); // Do this just once, it synchronizes
+        int oldOps = sk.nioReadyOps();
+        int newOps = initialOps;
+
+        if ((ops & PollArrayWrapper.POLLNVAL) != 0) {
+            // This should only happen if this channel is pre-closed while a
+            // selection operation is in progress
+            // ## Throw an error if this channel has not been pre-closed
+            return false;
+        }
+
+        if ((ops & (PollArrayWrapper.POLLERR
+                    | PollArrayWrapper.POLLHUP)) != 0) {
+            newOps = intOps;
+            sk.nioReadyOps(newOps);
+            return (newOps & ~oldOps) != 0;
+        }
+
+        if (((ops & PollArrayWrapper.POLLIN) != 0) &&
+            ((intOps & SelectionKey.OP_READ) != 0))
+            newOps |= SelectionKey.OP_READ;
+
+        if (((ops & PollArrayWrapper.POLLOUT) != 0) &&
+            ((intOps & SelectionKey.OP_WRITE) != 0))
+            newOps |= SelectionKey.OP_WRITE;
+
+        sk.nioReadyOps(newOps);
+        return (newOps & ~oldOps) != 0;
+    }
+
+    public boolean translateAndUpdateReadyOps(int ops, SelectionKeyImpl sk) {
+        return translateReadyOps(ops, sk.nioReadyOps(), sk);
+    }
+
+    public boolean translateAndSetReadyOps(int ops, SelectionKeyImpl sk) {
+        return translateReadyOps(ops, 0, sk);
+    }
+
+    /**
+     * Translates an interest operation set into a native poll event set
+     */
+    public void translateAndSetInterestOps(int ops, SelectionKeyImpl sk) {
+        int newOps = 0;
+
+        if ((ops & SelectionKey.OP_READ) != 0)
+            newOps |= PollArrayWrapper.POLLIN;
+        if ((ops & SelectionKey.OP_WRITE) != 0)
+            newOps |= PollArrayWrapper.POLLOUT;
+        if ((ops & SelectionKey.OP_CONNECT) != 0)
+            newOps |= PollArrayWrapper.POLLIN;
+        sk.selector.putEventOps(sk, newOps);
+    }
+
+    public FileDescriptor getFD() {
+        return fd;
+    }
+
+    public int getFDVal() {
+        return fdVal;
+    }
+
+
+    // -- Native methods --
+
+    private static native void initIDs();
+
+    private static native void disconnect0(FileDescriptor fd)
+        throws IOException;
+
+    private native int receive0(FileDescriptor fd, long address, int len,
+                                boolean connected)
+        throws IOException;
+
+    private native int send0(FileDescriptor fd, long address, int len,
+                     SocketAddress sa)
+        throws IOException;
+
+    static {
+        Util.load();
+        initIDs();
+    }
+
+}