rev 10457 : 8054720: Modifications of I/O methods for instrumentation purposes
Summary: Wrap some native methods in Java methods and change native method names to a consistent form.
Reviewed-by: TBD

   1 /*
   2  * Copyright (c) 1995, 2013, 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.net.ConnectionResetException;
  34 
  35 /**
  36  * This stream extends FileInputStream to implement a
  37  * SocketInputStream. Note that this class should <b>NOT</b> be
  38  * public.
  39  *
  40  * @author      Jonathan Payne
  41  * @author      Arthur van Hoff
  42  */
  43 class SocketInputStream extends FileInputStream
  44 {
  45     static {
  46         init();
  47     }
  48 
  49     private boolean eof;
  50     private AbstractPlainSocketImpl impl = null;
  51     private byte temp[];
  52     private Socket socket = null;
  53 
  54     /**
  55      * Creates a new SocketInputStream. Can only be called
  56      * by a Socket. This method needs to hang on to the owner Socket so
  57      * that the fd will not be closed.
  58      * @param impl the implemented socket input stream
  59      */
  60     SocketInputStream(AbstractPlainSocketImpl impl) throws IOException {
  61         super(impl.getFileDescriptor());
  62         this.impl = impl;
  63         socket = impl.getSocket();
  64     }
  65 
  66     /**
  67      * Returns the unique {@link java.nio.channels.FileChannel FileChannel}
  68      * object associated with this file input stream.</p>
  69      *
  70      * The {@code getChannel} method of {@code SocketInputStream}
  71      * returns {@code null} since it is a socket based stream.</p>
  72      *
  73      * @return  the file channel associated with this file input stream
  74      *
  75      * @since 1.4
  76      * @spec JSR-51
  77      */
  78     public final FileChannel getChannel() {
  79         return null;
  80     }
  81 
  82     /**
  83      * Reads into an array of bytes at the specified offset using
  84      * the received socket primitive.
  85      * @param fd the FileDescriptor
  86      * @param b the buffer into which the data is read
  87      * @param off the start offset of the data
  88      * @param len the maximum number of bytes read
  89      * @param timeout the read timeout in ms
  90      * @return the actual number of bytes read, -1 is
  91      *          returned when the end of the stream is reached.
  92      * @exception IOException If an I/O error has occurred.
  93      */
  94     private native int socketRead0(FileDescriptor fd,
  95                                    byte b[], int off, int len,
  96                                    int timeout)
  97         throws IOException;

















  98 
  99     /**
 100      * Reads into a byte array data from the socket.
 101      * @param b the buffer into which the data is read
 102      * @return the actual number of bytes read, -1 is
 103      *          returned when the end of the stream is reached.
 104      * @exception IOException If an I/O error has occurred.
 105      */
 106     public int read(byte b[]) throws IOException {
 107         return read(b, 0, b.length);
 108     }
 109 
 110     /**
 111      * Reads into a byte array <i>b</i> at offset <i>off</i>,
 112      * <i>length</i> bytes of data.
 113      * @param b the buffer into which the data is read
 114      * @param off the start offset of the data
 115      * @param length the maximum number of bytes read
 116      * @return the actual number of bytes read, -1 is
 117      *          returned when the end of the stream is reached.
 118      * @exception IOException If an I/O error has occurred.
 119      */
 120     public int read(byte b[], int off, int length) throws IOException {
 121         return read(b, off, length, impl.getTimeout());
 122     }
 123 
 124     int read(byte b[], int off, int length, int timeout) throws IOException {
 125         int n;
 126 
 127         // EOF already encountered
 128         if (eof) {
 129             return -1;
 130         }
 131 
 132         // connection reset
 133         if (impl.isConnectionReset()) {
 134             throw new SocketException("Connection reset");
 135         }
 136 
 137         // bounds check
 138         if (length <= 0 || off < 0 || off + length > b.length) {
 139             if (length == 0) {
 140                 return 0;
 141             }
 142             throw new ArrayIndexOutOfBoundsException();
 143         }
 144 
 145         boolean gotReset = false;
 146 
 147         // acquire file descriptor and do the read
 148         FileDescriptor fd = impl.acquireFD();
 149         try {
 150             n = socketRead0(fd, b, off, length, timeout);
 151             if (n > 0) {
 152                 return n;
 153             }
 154         } catch (ConnectionResetException rstExc) {
 155             gotReset = true;
 156         } finally {
 157             impl.releaseFD();
 158         }
 159 
 160         /*
 161          * We receive a "connection reset" but there may be bytes still
 162          * buffered on the socket
 163          */
 164         if (gotReset) {
 165             impl.setConnectionResetPending();
 166             impl.acquireFD();
 167             try {
 168                 n = socketRead0(fd, b, off, length, timeout);
 169                 if (n > 0) {
 170                     return n;
 171                 }
 172             } catch (ConnectionResetException rstExc) {
 173             } finally {
 174                 impl.releaseFD();
 175             }
 176         }
 177 
 178         /*
 179          * If we get here we are at EOF, the socket has been closed,
 180          * or the connection has been reset.
 181          */
 182         if (impl.isClosedOrPending()) {
 183             throw new SocketException("Socket closed");
 184         }
 185         if (impl.isConnectionResetPending()) {
 186             impl.setConnectionReset();
 187         }
 188         if (impl.isConnectionReset()) {
 189             throw new SocketException("Connection reset");
 190         }
 191         eof = true;
 192         return -1;
 193     }
 194 
 195     /**
 196      * Reads a single byte from the socket.
 197      */
 198     public int read() throws IOException {
 199         if (eof) {
 200             return -1;
 201         }
 202         temp = new byte[1];
 203         int n = read(temp, 0, 1);
 204         if (n <= 0) {
 205             return -1;
 206         }
 207         return temp[0] & 0xff;
 208     }
 209 
 210     /**
 211      * Skips n bytes of input.
 212      * @param numbytes the number of bytes to skip
 213      * @return  the actual number of bytes skipped.
 214      * @exception IOException If an I/O error has occurred.
 215      */
 216     public long skip(long numbytes) throws IOException {
 217         if (numbytes <= 0) {
 218             return 0;
 219         }
 220         long n = numbytes;
 221         int buflen = (int) Math.min(1024, n);
 222         byte data[] = new byte[buflen];
 223         while (n > 0) {
 224             int r = read(data, 0, (int) Math.min((long) buflen, n));
 225             if (r < 0) {
 226                 break;
 227             }
 228             n -= r;
 229         }
 230         return numbytes - n;
 231     }
 232 
 233     /**
 234      * Returns the number of bytes that can be read without blocking.
 235      * @return the number of immediately available bytes
 236      */
 237     public int available() throws IOException {
 238         return impl.available();
 239     }
 240 
 241     /**
 242      * Closes the stream.
 243      */
 244     private boolean closing = false;
 245     public void close() throws IOException {
 246         // Prevent recursion. See BugId 4484411
 247         if (closing)
 248             return;
 249         closing = true;
 250         if (socket != null) {
 251             if (!socket.isClosed())
 252                 socket.close();
 253         } else
 254             impl.close();
 255         closing = false;
 256     }
 257 
 258     void setEOF(boolean eof) {
 259         this.eof = eof;
 260     }
 261 
 262     /**
 263      * Overrides finalize, the fd is closed by the Socket.
 264      */
 265     protected void finalize() {}
 266 
 267     /**
 268      * Perform class load-time initializations.
 269      */
 270     private native static void init();
 271 }
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