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 }