rev 14210 : 8154231: Simplify access to System properties from JDK code
Reviewed-by: rriggs

   1 /*
   2  * Copyright (c) 2000, 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 sun.nio.ch;
  27 
  28 import java.io.FileDescriptor;
  29 import java.io.IOException;
  30 import java.security.PrivilegedAction;
  31 import jdk.internal.misc.SharedSecrets;
  32 import jdk.internal.misc.JavaIOFileDescriptorAccess;

  33 
  34 class FileDispatcherImpl extends FileDispatcher {
  35 
  36     private static final JavaIOFileDescriptorAccess fdAccess =
  37         SharedSecrets.getJavaIOFileDescriptorAccess();
  38 
  39     // set to true if fast file transmission (TransmitFile) is enabled
  40     private static final boolean fastFileTransfer;
  41 
  42     FileDispatcherImpl() { }
  43 
  44     @Override
  45     boolean needsPositionLock() {
  46         return true;
  47     }
  48 
  49     int read(FileDescriptor fd, long address, int len)
  50         throws IOException
  51     {
  52         return read0(fd, address, len);
  53     }
  54 
  55     int pread(FileDescriptor fd, long address, int len, long position)
  56         throws IOException
  57     {
  58         return pread0(fd, address, len, position);
  59     }
  60 
  61     long readv(FileDescriptor fd, long address, int len) throws IOException {
  62         return readv0(fd, address, len);
  63     }
  64 
  65     int write(FileDescriptor fd, long address, int len) throws IOException {
  66         return write0(fd, address, len, fdAccess.getAppend(fd));
  67     }
  68 
  69     int pwrite(FileDescriptor fd, long address, int len, long position)
  70         throws IOException
  71     {
  72         return pwrite0(fd, address, len, position);
  73     }
  74 
  75     long writev(FileDescriptor fd, long address, int len) throws IOException {
  76         return writev0(fd, address, len, fdAccess.getAppend(fd));
  77     }
  78 
  79     int force(FileDescriptor fd, boolean metaData) throws IOException {
  80         return force0(fd, metaData);
  81     }
  82 
  83     int truncate(FileDescriptor fd, long size) throws IOException {
  84         return truncate0(fd, size);
  85     }
  86 
  87     long size(FileDescriptor fd) throws IOException {
  88         return size0(fd);
  89     }
  90 
  91     int lock(FileDescriptor fd, boolean blocking, long pos, long size,
  92              boolean shared) throws IOException
  93     {
  94         return lock0(fd, blocking, pos, size, shared);
  95     }
  96 
  97     void release(FileDescriptor fd, long pos, long size) throws IOException {
  98         release0(fd, pos, size);
  99     }
 100 
 101     void close(FileDescriptor fd) throws IOException {
 102         close0(fd);
 103     }
 104 
 105     FileDescriptor duplicateForMapping(FileDescriptor fd) throws IOException {
 106         // on Windows we need to keep a handle to the file
 107         FileDescriptor result = new FileDescriptor();
 108         long handle = duplicateHandle(fdAccess.getHandle(fd));
 109         fdAccess.setHandle(result, handle);
 110         return result;
 111     }
 112 
 113     boolean canTransferToDirectly(java.nio.channels.SelectableChannel sc) {
 114         return fastFileTransfer && sc.isBlocking();
 115     }
 116 
 117     boolean transferToDirectlyNeedsPositionLock() {
 118         return true;
 119     }
 120 
 121     static boolean isFastFileTransferRequested() {
 122         String fileTransferProp = java.security.AccessController.doPrivileged(
 123             new PrivilegedAction<String>() {
 124                 @Override
 125                 public String run() {
 126                     return System.getProperty("jdk.nio.enableFastFileTransfer");
 127                 }
 128             });
 129         boolean enable;
 130         if ("".equals(fileTransferProp)) {
 131             enable = true;
 132         } else {
 133             enable = Boolean.parseBoolean(fileTransferProp);
 134         }
 135         return enable;
 136     }
 137 
 138     static {
 139         IOUtil.load();
 140         fastFileTransfer = isFastFileTransferRequested();
 141     }
 142 
 143     //-- Native methods
 144 
 145     static native int read0(FileDescriptor fd, long address, int len)
 146         throws IOException;
 147 
 148     static native int pread0(FileDescriptor fd, long address, int len,
 149                              long position) throws IOException;
 150 
 151     static native long readv0(FileDescriptor fd, long address, int len)
 152         throws IOException;
 153 
 154     static native int write0(FileDescriptor fd, long address, int len, boolean append)
 155         throws IOException;
 156 
 157     static native int pwrite0(FileDescriptor fd, long address, int len,
 158                              long position) throws IOException;
 159 
 160     static native long writev0(FileDescriptor fd, long address, int len, boolean append)
 161         throws IOException;
 162 
 163     static native int force0(FileDescriptor fd, boolean metaData)
 164         throws IOException;
 165 
 166     static native int truncate0(FileDescriptor fd, long size)
 167         throws IOException;
 168 
 169     static native long size0(FileDescriptor fd) throws IOException;
 170 
 171     static native int lock0(FileDescriptor fd, boolean blocking, long pos,
 172                             long size, boolean shared) throws IOException;
 173 
 174     static native void release0(FileDescriptor fd, long pos, long size)
 175         throws IOException;
 176 
 177     static native void close0(FileDescriptor fd) throws IOException;
 178 
 179     static native void closeByHandle(long fd) throws IOException;
 180 
 181     static native long duplicateHandle(long fd) throws IOException;
 182 }
--- EOF ---