src/java.base/share/classes/java/net/SocketImpl.java
changeset 47216 71c04702a3d5
parent 36228 a16a22218e23
child 47478 438e0c9f2f17
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/java/net/SocketImpl.java	Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,479 @@
+/*
+ * Copyright (c) 1995, 2016, 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 java.io.IOException;
+import java.io.InputStream;
+import java.io.OutputStream;
+import java.io.FileDescriptor;
+import java.util.Set;
+
+/**
+ * The abstract class {@code SocketImpl} is a common superclass
+ * of all classes that actually implement sockets. It is used to
+ * create both client and server sockets.
+ * <p>
+ * A "plain" socket implements these methods exactly as
+ * described, without attempting to go through a firewall or proxy.
+ *
+ * @author  unascribed
+ * @since   1.0
+ */
+public abstract class SocketImpl implements SocketOptions {
+    /**
+     * The actual Socket object.
+     */
+    Socket socket = null;
+    ServerSocket serverSocket = null;
+
+    /**
+     * The file descriptor object for this socket.
+     */
+    protected FileDescriptor fd;
+
+    /**
+     * The IP address of the remote end of this socket.
+     */
+    protected InetAddress address;
+
+    /**
+     * The port number on the remote host to which this socket is connected.
+     */
+    protected int port;
+
+    /**
+     * The local port number to which this socket is connected.
+     */
+    protected int localport;
+
+    /**
+     * Creates either a stream or a datagram socket.
+     *
+     * @param      stream   if {@code true}, create a stream socket;
+     *                      otherwise, create a datagram socket.
+     * @exception  IOException  if an I/O error occurs while creating the
+     *               socket.
+     */
+    protected abstract void create(boolean stream) throws IOException;
+
+    /**
+     * Connects this socket to the specified port on the named host.
+     *
+     * @param      host   the name of the remote host.
+     * @param      port   the port number.
+     * @exception  IOException  if an I/O error occurs when connecting to the
+     *               remote host.
+     */
+    protected abstract void connect(String host, int port) throws IOException;
+
+    /**
+     * Connects this socket to the specified port number on the specified host.
+     *
+     * @param      address   the IP address of the remote host.
+     * @param      port      the port number.
+     * @exception  IOException  if an I/O error occurs when attempting a
+     *               connection.
+     */
+    protected abstract void connect(InetAddress address, int port) throws IOException;
+
+    /**
+     * Connects this socket to the specified port number on the specified host.
+     * A timeout of zero is interpreted as an infinite timeout. The connection
+     * will then block until established or an error occurs.
+     *
+     * @param      address   the Socket address of the remote host.
+     * @param     timeout  the timeout value, in milliseconds, or zero for no timeout.
+     * @exception  IOException  if an I/O error occurs when attempting a
+     *               connection.
+     * @since 1.4
+     */
+    protected abstract void connect(SocketAddress address, int timeout) throws IOException;
+
+    /**
+     * Binds this socket to the specified local IP address and port number.
+     *
+     * @param      host   an IP address that belongs to a local interface.
+     * @param      port   the port number.
+     * @exception  IOException  if an I/O error occurs when binding this socket.
+     */
+    protected abstract void bind(InetAddress host, int port) throws IOException;
+
+    /**
+     * Sets the maximum queue length for incoming connection indications
+     * (a request to connect) to the {@code count} argument. If a
+     * connection indication arrives when the queue is full, the
+     * connection is refused.
+     *
+     * @param      backlog   the maximum length of the queue.
+     * @exception  IOException  if an I/O error occurs when creating the queue.
+     */
+    protected abstract void listen(int backlog) throws IOException;
+
+    /**
+     * Accepts a connection.
+     *
+     * @param      s   the accepted connection.
+     * @exception  IOException  if an I/O error occurs when accepting the
+     *               connection.
+     */
+    protected abstract void accept(SocketImpl s) throws IOException;
+
+    /**
+     * Returns an input stream for this socket.
+     *
+     * @return     a stream for reading from this socket.
+     * @exception  IOException  if an I/O error occurs when creating the
+     *               input stream.
+    */
+    protected abstract InputStream getInputStream() throws IOException;
+
+    /**
+     * Returns an output stream for this socket.
+     *
+     * @return     an output stream for writing to this socket.
+     * @exception  IOException  if an I/O error occurs when creating the
+     *               output stream.
+     */
+    protected abstract OutputStream getOutputStream() throws IOException;
+
+    /**
+     * Returns the number of bytes that can be read from this socket
+     * without blocking.
+     *
+     * @return     the number of bytes that can be read from this socket
+     *             without blocking.
+     * @exception  IOException  if an I/O error occurs when determining the
+     *               number of bytes available.
+     */
+    protected abstract int available() throws IOException;
+
+    /**
+     * Closes this socket.
+     *
+     * @exception  IOException  if an I/O error occurs when closing this socket.
+     */
+    protected abstract void close() throws IOException;
+
+    /**
+     * Places the input stream for this socket at "end of stream".
+     * Any data sent to this socket is acknowledged and then
+     * silently discarded.
+     *
+     * If you read from a socket input stream after invoking this method on the
+     * socket, the stream's {@code available} method will return 0, and its
+     * {@code read} methods will return {@code -1} (end of stream).
+     *
+     * @exception IOException if an I/O error occurs when shutting down this
+     * socket.
+     * @see java.net.Socket#shutdownOutput()
+     * @see java.net.Socket#close()
+     * @see java.net.Socket#setSoLinger(boolean, int)
+     * @since 1.3
+     */
+    protected void shutdownInput() throws IOException {
+      throw new IOException("Method not implemented!");
+    }
+
+    /**
+     * Disables the output stream for this socket.
+     * For a TCP socket, any previously written data will be sent
+     * followed by TCP's normal connection termination sequence.
+     *
+     * If you write to a socket output stream after invoking
+     * shutdownOutput() on the socket, the stream will throw
+     * an IOException.
+     *
+     * @exception IOException if an I/O error occurs when shutting down this
+     * socket.
+     * @see java.net.Socket#shutdownInput()
+     * @see java.net.Socket#close()
+     * @see java.net.Socket#setSoLinger(boolean, int)
+     * @since 1.3
+     */
+    protected void shutdownOutput() throws IOException {
+      throw new IOException("Method not implemented!");
+    }
+
+    /**
+     * Returns the value of this socket's {@code fd} field.
+     *
+     * @return  the value of this socket's {@code fd} field.
+     * @see     java.net.SocketImpl#fd
+     */
+    protected FileDescriptor getFileDescriptor() {
+        return fd;
+    }
+
+    /**
+     * Returns the value of this socket's {@code address} field.
+     *
+     * @return  the value of this socket's {@code address} field.
+     * @see     java.net.SocketImpl#address
+     */
+    protected InetAddress getInetAddress() {
+        return address;
+    }
+
+    /**
+     * Returns the value of this socket's {@code port} field.
+     *
+     * @return  the value of this socket's {@code port} field.
+     * @see     java.net.SocketImpl#port
+     */
+    protected int getPort() {
+        return port;
+    }
+
+    /**
+     * Returns whether or not this SocketImpl supports sending
+     * urgent data. By default, false is returned
+     * unless the method is overridden in a sub-class
+     *
+     * @return  true if urgent data supported
+     * @see     java.net.SocketImpl#address
+     * @since 1.4
+     */
+    protected boolean supportsUrgentData () {
+        return false; // must be overridden in sub-class
+    }
+
+    /**
+     * Send one byte of urgent data on the socket.
+     * The byte to be sent is the low eight bits of the parameter
+     * @param data The byte of data to send
+     * @exception IOException if there is an error
+     *  sending the data.
+     * @since 1.4
+     */
+    protected abstract void sendUrgentData (int data) throws IOException;
+
+    /**
+     * Returns the value of this socket's {@code localport} field.
+     *
+     * @return  the value of this socket's {@code localport} field.
+     * @see     java.net.SocketImpl#localport
+     */
+    protected int getLocalPort() {
+        return localport;
+    }
+
+    void setSocket(Socket soc) {
+        this.socket = soc;
+    }
+
+    Socket getSocket() {
+        return socket;
+    }
+
+    void setServerSocket(ServerSocket soc) {
+        this.serverSocket = soc;
+    }
+
+    ServerSocket getServerSocket() {
+        return serverSocket;
+    }
+
+    /**
+     * Returns the address and port of this socket as a {@code String}.
+     *
+     * @return  a string representation of this socket.
+     */
+    public String toString() {
+        return "Socket[addr=" + getInetAddress() +
+            ",port=" + getPort() + ",localport=" + getLocalPort()  + "]";
+    }
+
+    void reset() throws IOException {
+        address = null;
+        port = 0;
+        localport = 0;
+    }
+
+    /**
+     * Sets performance preferences for this socket.
+     *
+     * <p> Sockets use the TCP/IP protocol by default.  Some implementations
+     * may offer alternative protocols which have different performance
+     * characteristics than TCP/IP.  This method allows the application to
+     * express its own preferences as to how these tradeoffs should be made
+     * when the implementation chooses from the available protocols.
+     *
+     * <p> Performance preferences are described by three integers
+     * whose values indicate the relative importance of short connection time,
+     * low latency, and high bandwidth.  The absolute values of the integers
+     * are irrelevant; in order to choose a protocol the values are simply
+     * compared, with larger values indicating stronger preferences. Negative
+     * values represent a lower priority than positive values. If the
+     * application prefers short connection time over both low latency and high
+     * bandwidth, for example, then it could invoke this method with the values
+     * {@code (1, 0, 0)}.  If the application prefers high bandwidth above low
+     * latency, and low latency above short connection time, then it could
+     * invoke this method with the values {@code (0, 1, 2)}.
+     *
+     * By default, this method does nothing, unless it is overridden in a
+     * a sub-class.
+     *
+     * @param  connectionTime
+     *         An {@code int} expressing the relative importance of a short
+     *         connection time
+     *
+     * @param  latency
+     *         An {@code int} expressing the relative importance of low
+     *         latency
+     *
+     * @param  bandwidth
+     *         An {@code int} expressing the relative importance of high
+     *         bandwidth
+     *
+     * @since 1.5
+     */
+    protected void setPerformancePreferences(int connectionTime,
+                                          int latency,
+                                          int bandwidth)
+    {
+        /* Not implemented yet */
+    }
+
+    /**
+     * Called to set a socket option.
+     *
+     * @param <T> The type of the socket option value
+     * @param name The socket option
+     *
+     * @param value The value of the socket option. A value of {@code null}
+     *              may be valid for some options.
+     *
+     * @throws UnsupportedOperationException if the SocketImpl does not
+     *         support the option
+     *
+     * @throws IOException if an I/O error occurs, or if the socket is closed.
+     *
+     * @since 9
+     */
+    protected <T> void setOption(SocketOption<T> name, T value) throws IOException {
+        if (name == StandardSocketOptions.SO_KEEPALIVE &&
+                (getSocket() != null)) {
+            setOption(SocketOptions.SO_KEEPALIVE, value);
+        } else if (name == StandardSocketOptions.SO_SNDBUF &&
+                (getSocket() != null)) {
+            setOption(SocketOptions.SO_SNDBUF, value);
+        } else if (name == StandardSocketOptions.SO_RCVBUF) {
+            setOption(SocketOptions.SO_RCVBUF, value);
+        } else if (name == StandardSocketOptions.SO_REUSEADDR) {
+            setOption(SocketOptions.SO_REUSEADDR, value);
+        } else if (name == StandardSocketOptions.SO_REUSEPORT &&
+            supportedOptions().contains(name)) {
+            setOption(SocketOptions.SO_REUSEPORT, value);
+        } else if (name == StandardSocketOptions.SO_LINGER &&
+                (getSocket() != null)) {
+            setOption(SocketOptions.SO_LINGER, value);
+        } else if (name == StandardSocketOptions.IP_TOS) {
+            setOption(SocketOptions.IP_TOS, value);
+        } else if (name == StandardSocketOptions.TCP_NODELAY &&
+                (getSocket() != null)) {
+            setOption(SocketOptions.TCP_NODELAY, value);
+        } else {
+            throw new UnsupportedOperationException("unsupported option");
+        }
+    }
+
+    /**
+     * Called to get a socket option.
+     *
+     * @param <T> The type of the socket option value
+     * @param name The socket option
+     *
+     * @return the value of the named option
+     *
+     * @throws UnsupportedOperationException if the SocketImpl does not
+     *         support the option.
+     *
+     * @throws IOException if an I/O error occurs, or if the socket is closed.
+     *
+     * @since 9
+     */
+    @SuppressWarnings("unchecked")
+    protected <T> T getOption(SocketOption<T> name) throws IOException {
+        if (name == StandardSocketOptions.SO_KEEPALIVE &&
+                (getSocket() != null)) {
+            return (T)getOption(SocketOptions.SO_KEEPALIVE);
+        } else if (name == StandardSocketOptions.SO_SNDBUF &&
+                (getSocket() != null)) {
+            return (T)getOption(SocketOptions.SO_SNDBUF);
+        } else if (name == StandardSocketOptions.SO_RCVBUF) {
+            return (T)getOption(SocketOptions.SO_RCVBUF);
+        } else if (name == StandardSocketOptions.SO_REUSEADDR) {
+            return (T)getOption(SocketOptions.SO_REUSEADDR);
+        } else if (name == StandardSocketOptions.SO_REUSEPORT &&
+            supportedOptions().contains(name)) {
+            return (T)getOption(SocketOptions.SO_REUSEPORT);
+        } else if (name == StandardSocketOptions.SO_LINGER &&
+                (getSocket() != null)) {
+            return (T)getOption(SocketOptions.SO_LINGER);
+        } else if (name == StandardSocketOptions.IP_TOS) {
+            return (T)getOption(SocketOptions.IP_TOS);
+        } else if (name == StandardSocketOptions.TCP_NODELAY &&
+                (getSocket() != null)) {
+            return (T)getOption(SocketOptions.TCP_NODELAY);
+        } else {
+            throw new UnsupportedOperationException("unsupported option");
+        }
+    }
+
+    private static final Set<SocketOption<?>> socketOptions;
+
+    private static final Set<SocketOption<?>> serverSocketOptions;
+
+    static {
+        socketOptions = Set.of(StandardSocketOptions.SO_KEEPALIVE,
+                               StandardSocketOptions.SO_SNDBUF,
+                               StandardSocketOptions.SO_RCVBUF,
+                               StandardSocketOptions.SO_REUSEADDR,
+                               StandardSocketOptions.SO_LINGER,
+                               StandardSocketOptions.IP_TOS,
+                               StandardSocketOptions.TCP_NODELAY);
+
+        serverSocketOptions = Set.of(StandardSocketOptions.SO_RCVBUF,
+                                     StandardSocketOptions.SO_REUSEADDR,
+                                     StandardSocketOptions.IP_TOS);
+    }
+
+    /**
+     * Returns a set of SocketOptions supported by this impl
+     * and by this impl's socket (Socket or ServerSocket)
+     *
+     * @return a Set of SocketOptions
+     *
+     * @since 9
+     */
+    protected Set<SocketOption<?>> supportedOptions() {
+        if (getSocket() != null) {
+            return socketOptions;
+        } else {
+            return serverSocketOptions;
+        }
+    }
+}