rev 5501 : imported patch io-trace

   1 /*
   2  * Copyright (c) 1995, 2010, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.  Oracle designates this
   8  * particular file as subject to the "Classpath" exception as provided
   9  * by Oracle in the LICENSE file that accompanied this code.
  10  *
  11  * This code is distributed in the hope that it will be useful, but WITHOUT
  12  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  14  * version 2 for more details (a copy is included in the LICENSE file that
  15  * accompanied this code).
  16  *
  17  * You should have received a copy of the GNU General Public License version
  18  * 2 along with this work; if not, write to the Free Software Foundation,
  19  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  20  *
  21  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  22  * or visit www.oracle.com if you need additional information or have any
  23  * questions.
  24  */
  25 
  26 package java.net;
  27 
  28 import java.io.FileDescriptor;
  29 import java.io.FileInputStream;
  30 import java.io.IOException;
  31 import java.nio.channels.FileChannel;
  32 
  33 import sun.misc.IoTrace;
  34 import sun.net.ConnectionResetException;
  35 
  36 /**
  37  * This stream extends FileInputStream to implement a
  38  * SocketInputStream. Note that this class should <b>NOT</b> be
  39  * public.
  40  *
  41  * @author      Jonathan Payne
  42  * @author      Arthur van Hoff
  43  */
  44 class SocketInputStream extends FileInputStream
  45 {
  46     static {
  47         init();
  48     }
  49 
  50     private boolean eof;
  51     private AbstractPlainSocketImpl impl = null;
  52     private byte temp[];
  53     private Socket socket = null;
  54 
  55     /**
  56      * Creates a new SocketInputStream. Can only be called
  57      * by a Socket. This method needs to hang on to the owner Socket so
  58      * that the fd will not be closed.
  59      * @param impl the implemented socket input stream
  60      */
  61     SocketInputStream(AbstractPlainSocketImpl impl) throws IOException {
  62         super(impl.getFileDescriptor());
  63         this.impl = impl;
  64         socket = impl.getSocket();
  65     }
  66 
  67     /**
  68      * Returns the unique {@link java.nio.channels.FileChannel FileChannel}
  69      * object associated with this file input stream.</p>
  70      *
  71      * The <code>getChannel</code> method of <code>SocketInputStream</code>
  72      * returns <code>null</code> since it is a socket based stream.</p>
  73      *
  74      * @return  the file channel associated with this file input stream
  75      *
  76      * @since 1.4
  77      * @spec JSR-51
  78      */
  79     public final FileChannel getChannel() {
  80         return null;
  81     }
  82 
  83     /**
  84      * Reads into an array of bytes at the specified offset using
  85      * the received socket primitive.
  86      * @param fd the FileDescriptor
  87      * @param b the buffer into which the data is read
  88      * @param off the start offset of the data
  89      * @param len the maximum number of bytes read
  90      * @param timeout the read timeout in ms
  91      * @return the actual number of bytes read, -1 is
  92      *          returned when the end of the stream is reached.
  93      * @exception IOException If an I/O error has occurred.
  94      */
  95     private native int socketRead0(FileDescriptor fd,
  96                                    byte b[], int off, int len,
  97                                    int timeout)
  98         throws IOException;
  99 
 100     /**
 101      * Reads into a byte array data from the socket.
 102      * @param b the buffer into which the data is read
 103      * @return the actual number of bytes read, -1 is
 104      *          returned when the end of the stream is reached.
 105      * @exception IOException If an I/O error has occurred.
 106      */
 107     public int read(byte b[]) throws IOException {
 108         return read(b, 0, b.length);
 109     }
 110 
 111     /**
 112      * Reads into a byte array <i>b</i> at offset <i>off</i>,
 113      * <i>length</i> bytes of data.
 114      * @param b the buffer into which the data is read
 115      * @param off the start offset of the data
 116      * @param len the maximum number of bytes read
 117      * @return the actual number of bytes read, -1 is
 118      *          returned when the end of the stream is reached.
 119      * @exception IOException If an I/O error has occurred.
 120      */
 121     public int read(byte b[], int off, int length) throws IOException {
 122         return read(b, off, length, impl.getTimeout());
 123     }
 124 
 125     int read(byte b[], int off, int length, int timeout) throws IOException {
 126         int n = 0;
 127 
 128         // EOF already encountered
 129         if (eof) {
 130             return -1;
 131         }
 132 
 133         // connection reset
 134         if (impl.isConnectionReset()) {
 135             throw new SocketException("Connection reset");
 136         }
 137 
 138         // bounds check
 139         if (length <= 0 || off < 0 || off + length > b.length) {
 140             if (length == 0) {
 141                 return 0;
 142             }
 143             throw new ArrayIndexOutOfBoundsException();
 144         }
 145 
 146         boolean gotReset = false;
 147 
 148         Object traceContext = IoTrace.socketReadBegin(impl.address, impl.port, timeout);
 149         // acquire file descriptor and do the read
 150         FileDescriptor fd = impl.acquireFD();
 151         try {
 152             n = socketRead0(fd, b, off, length, timeout);
 153             if (n > 0) {
 154                 return n;
 155             }
 156         } catch (ConnectionResetException rstExc) {
 157             gotReset = true;
 158         } finally {
 159             impl.releaseFD();
 160             IoTrace.socketReadEnd(traceContext, n > 0 ? n : 0);
 161         }
 162 
 163         /*
 164          * We receive a "connection reset" but there may be bytes still
 165          * buffered on the socket
 166          */
 167         if (gotReset) {
 168             traceContext = IoTrace.socketReadBegin(impl.address, impl.port, timeout);
 169             impl.setConnectionResetPending();
 170             impl.acquireFD();
 171             try {
 172                 n = socketRead0(fd, b, off, length, timeout);
 173                 if (n > 0) {
 174                     return n;
 175                 }
 176             } catch (ConnectionResetException rstExc) {
 177             } finally {
 178                 impl.releaseFD();
 179                 IoTrace.socketReadEnd(traceContext, n > 0 ? n : 0);
 180             }
 181         }
 182 
 183         /*
 184          * If we get here we are at EOF, the socket has been closed,
 185          * or the connection has been reset.
 186          */
 187         if (impl.isClosedOrPending()) {
 188             throw new SocketException("Socket closed");
 189         }
 190         if (impl.isConnectionResetPending()) {
 191             impl.setConnectionReset();
 192         }
 193         if (impl.isConnectionReset()) {
 194             throw new SocketException("Connection reset");
 195         }
 196         eof = true;
 197         return -1;
 198     }
 199 
 200     /**
 201      * Reads a single byte from the socket.
 202      */
 203     public int read() throws IOException {
 204         if (eof) {
 205             return -1;
 206         }
 207         temp = new byte[1];
 208         int n = read(temp, 0, 1);
 209         if (n <= 0) {
 210             return -1;
 211         }
 212         return temp[0] & 0xff;
 213     }
 214 
 215     /**
 216      * Skips n bytes of input.
 217      * @param n the number of bytes to skip
 218      * @return  the actual number of bytes skipped.
 219      * @exception IOException If an I/O error has occurred.
 220      */
 221     public long skip(long numbytes) throws IOException {
 222         if (numbytes <= 0) {
 223             return 0;
 224         }
 225         long n = numbytes;
 226         int buflen = (int) Math.min(1024, n);
 227         byte data[] = new byte[buflen];
 228         while (n > 0) {
 229             int r = read(data, 0, (int) Math.min((long) buflen, n));
 230             if (r < 0) {
 231                 break;
 232             }
 233             n -= r;
 234         }
 235         return numbytes - n;
 236     }
 237 
 238     /**
 239      * Returns the number of bytes that can be read without blocking.
 240      * @return the number of immediately available bytes
 241      */
 242     public int available() throws IOException {
 243         return impl.available();
 244     }
 245 
 246     /**
 247      * Closes the stream.
 248      */
 249     private boolean closing = false;
 250     public void close() throws IOException {
 251         // Prevent recursion. See BugId 4484411
 252         if (closing)
 253             return;
 254         closing = true;
 255         if (socket != null) {
 256             if (!socket.isClosed())
 257                 socket.close();
 258         } else
 259             impl.close();
 260         closing = false;
 261     }
 262 
 263     void setEOF(boolean eof) {
 264         this.eof = eof;
 265     }
 266 
 267     /**
 268      * Overrides finalize, the fd is closed by the Socket.
 269      */
 270     protected void finalize() {}
 271 
 272     /**
 273      * Perform class load-time initializations.
 274      */
 275     private native static void init();
 276 }
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