J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2000-2002 Sun Microsystems, Inc. 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. Sun designates this |
| 8 | * particular file as subject to the "Classpath" exception as provided |
| 9 | * by Sun 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, |
| 22 | * CA 95054 USA or visit www.sun.com if you need additional information or |
| 23 | * have any questions. |
| 24 | */ |
| 25 | |
| 26 | package sun.nio.ch; |
| 27 | |
| 28 | import java.io.FileDescriptor; |
| 29 | import java.io.IOException; |
| 30 | import java.net.*; |
| 31 | import java.nio.ByteBuffer; |
| 32 | import java.nio.channels.*; |
| 33 | import java.nio.channels.spi.*; |
| 34 | |
| 35 | |
| 36 | /** |
| 37 | * File-descriptor based I/O utilities that are shared by NIO classes. |
| 38 | */ |
| 39 | |
| 40 | class IOUtil { |
| 41 | |
| 42 | private IOUtil() { } // No instantiation |
| 43 | |
| 44 | /* |
| 45 | * Returns the index of first buffer in bufs with remaining, |
| 46 | * or -1 if there is nothing left |
| 47 | */ |
| 48 | private static int remaining(ByteBuffer[] bufs) { |
| 49 | int numBufs = bufs.length; |
| 50 | boolean remaining = false; |
| 51 | for (int i=0; i<numBufs; i++) { |
| 52 | if (bufs[i].hasRemaining()) { |
| 53 | return i; |
| 54 | } |
| 55 | } |
| 56 | return -1; |
| 57 | } |
| 58 | |
| 59 | /* |
| 60 | * Returns a new ByteBuffer array with only unfinished buffers in it |
| 61 | */ |
| 62 | private static ByteBuffer[] skipBufs(ByteBuffer[] bufs, |
| 63 | int nextWithRemaining) |
| 64 | { |
| 65 | int newSize = bufs.length - nextWithRemaining; |
| 66 | ByteBuffer[] temp = new ByteBuffer[newSize]; |
| 67 | for (int i=0; i<newSize; i++) { |
| 68 | temp[i] = bufs[i + nextWithRemaining]; |
| 69 | } |
| 70 | return temp; |
| 71 | } |
| 72 | |
| 73 | static int write(FileDescriptor fd, ByteBuffer src, long position, |
| 74 | NativeDispatcher nd, Object lock) |
| 75 | throws IOException |
| 76 | { |
| 77 | if (src instanceof DirectBuffer) |
| 78 | return writeFromNativeBuffer(fd, src, position, nd, lock); |
| 79 | |
| 80 | // Substitute a native buffer |
| 81 | int pos = src.position(); |
| 82 | int lim = src.limit(); |
| 83 | assert (pos <= lim); |
| 84 | int rem = (pos <= lim ? lim - pos : 0); |
| 85 | ByteBuffer bb = null; |
| 86 | try { |
| 87 | bb = Util.getTemporaryDirectBuffer(rem); |
| 88 | bb.put(src); |
| 89 | bb.flip(); |
| 90 | // Do not update src until we see how many bytes were written |
| 91 | src.position(pos); |
| 92 | |
| 93 | int n = writeFromNativeBuffer(fd, bb, position, nd, lock); |
| 94 | if (n > 0) { |
| 95 | // now update src |
| 96 | src.position(pos + n); |
| 97 | } |
| 98 | return n; |
| 99 | } finally { |
| 100 | Util.releaseTemporaryDirectBuffer(bb); |
| 101 | } |
| 102 | } |
| 103 | |
| 104 | private static int writeFromNativeBuffer(FileDescriptor fd, ByteBuffer bb, |
| 105 | long position, NativeDispatcher nd, |
| 106 | Object lock) |
| 107 | throws IOException |
| 108 | { |
| 109 | int pos = bb.position(); |
| 110 | int lim = bb.limit(); |
| 111 | assert (pos <= lim); |
| 112 | int rem = (pos <= lim ? lim - pos : 0); |
| 113 | |
| 114 | int written = 0; |
| 115 | if (rem == 0) |
| 116 | return 0; |
| 117 | if (position != -1) { |
| 118 | written = nd.pwrite(fd, |
| 119 | ((DirectBuffer)bb).address() + pos, |
| 120 | rem, position, lock); |
| 121 | } else { |
| 122 | written = nd.write(fd, ((DirectBuffer)bb).address() + pos, rem); |
| 123 | } |
| 124 | if (written > 0) |
| 125 | bb.position(pos + written); |
| 126 | return written; |
| 127 | } |
| 128 | |
| 129 | static long write(FileDescriptor fd, ByteBuffer[] bufs, NativeDispatcher nd) |
| 130 | throws IOException |
| 131 | { |
| 132 | int nextWithRemaining = remaining(bufs); |
| 133 | // if all bufs are empty we should return immediately |
| 134 | if (nextWithRemaining < 0) |
| 135 | return 0; |
| 136 | // If some bufs are empty we should skip them |
| 137 | if (nextWithRemaining > 0) |
| 138 | bufs = skipBufs(bufs, nextWithRemaining); |
| 139 | |
| 140 | int numBufs = bufs.length; |
| 141 | int bytesReadyToWrite = 0; |
| 142 | |
| 143 | // Create shadow to ensure DirectByteBuffers are used |
| 144 | ByteBuffer[] shadow = new ByteBuffer[numBufs]; |
| 145 | for (int i=0; i<numBufs; i++) { |
| 146 | if (!(bufs[i] instanceof DirectBuffer)) { |
| 147 | int pos = bufs[i].position(); |
| 148 | int lim = bufs[i].limit(); |
| 149 | assert (pos <= lim); |
| 150 | int rem = (pos <= lim ? lim - pos : 0); |
| 151 | |
| 152 | ByteBuffer bb = ByteBuffer.allocateDirect(rem); |
| 153 | shadow[i] = bb; |
| 154 | // Leave slow buffer position untouched; it will be updated |
| 155 | // after we see how many bytes were really written out |
| 156 | bb.put(bufs[i]); |
| 157 | bufs[i].position(pos); |
| 158 | bb.flip(); |
| 159 | } else { |
| 160 | shadow[i] = bufs[i]; |
| 161 | } |
| 162 | } |
| 163 | |
| 164 | IOVecWrapper vec = null; |
| 165 | long bytesWritten = 0; |
| 166 | try { |
| 167 | // Create a native iovec array |
| 168 | vec= new IOVecWrapper(numBufs); |
| 169 | |
| 170 | // Fill in the iovec array with appropriate data |
| 171 | for (int i=0; i<numBufs; i++) { |
| 172 | ByteBuffer nextBuffer = shadow[i]; |
| 173 | // put in the buffer addresses |
| 174 | long pos = nextBuffer.position(); |
| 175 | long len = nextBuffer.limit() - pos; |
| 176 | bytesReadyToWrite += len; |
| 177 | vec.putBase(i, ((DirectBuffer)nextBuffer).address() + pos); |
| 178 | vec.putLen(i, len); |
| 179 | } |
| 180 | |
| 181 | // Invoke native call to fill the buffers |
| 182 | bytesWritten = nd.writev(fd, vec.address, numBufs); |
| 183 | } finally { |
| 184 | vec.free(); |
| 185 | } |
| 186 | long returnVal = bytesWritten; |
| 187 | |
| 188 | // Notify the buffers how many bytes were taken |
| 189 | for (int i=0; i<numBufs; i++) { |
| 190 | ByteBuffer nextBuffer = bufs[i]; |
| 191 | int pos = nextBuffer.position(); |
| 192 | int lim = nextBuffer.limit(); |
| 193 | assert (pos <= lim); |
| 194 | int len = (pos <= lim ? lim - pos : lim); |
| 195 | if (bytesWritten >= len) { |
| 196 | bytesWritten -= len; |
| 197 | int newPosition = pos + len; |
| 198 | nextBuffer.position(newPosition); |
| 199 | } else { // Buffers not completely filled |
| 200 | if (bytesWritten > 0) { |
| 201 | assert(pos + bytesWritten < (long)Integer.MAX_VALUE); |
| 202 | int newPosition = (int)(pos + bytesWritten); |
| 203 | nextBuffer.position(newPosition); |
| 204 | } |
| 205 | break; |
| 206 | } |
| 207 | } |
| 208 | return returnVal; |
| 209 | } |
| 210 | |
| 211 | static int read(FileDescriptor fd, ByteBuffer dst, long position, |
| 212 | NativeDispatcher nd, Object lock) |
| 213 | throws IOException |
| 214 | { |
| 215 | if (dst.isReadOnly()) |
| 216 | throw new IllegalArgumentException("Read-only buffer"); |
| 217 | if (dst instanceof DirectBuffer) |
| 218 | return readIntoNativeBuffer(fd, dst, position, nd, lock); |
| 219 | |
| 220 | // Substitute a native buffer |
| 221 | ByteBuffer bb = null; |
| 222 | try { |
| 223 | bb = Util.getTemporaryDirectBuffer(dst.remaining()); |
| 224 | int n = readIntoNativeBuffer(fd, bb, position, nd, lock); |
| 225 | bb.flip(); |
| 226 | if (n > 0) |
| 227 | dst.put(bb); |
| 228 | return n; |
| 229 | } finally { |
| 230 | Util.releaseTemporaryDirectBuffer(bb); |
| 231 | } |
| 232 | } |
| 233 | |
| 234 | private static int readIntoNativeBuffer(FileDescriptor fd, ByteBuffer bb, |
| 235 | long position, NativeDispatcher nd, |
| 236 | Object lock) |
| 237 | throws IOException |
| 238 | { |
| 239 | int pos = bb.position(); |
| 240 | int lim = bb.limit(); |
| 241 | assert (pos <= lim); |
| 242 | int rem = (pos <= lim ? lim - pos : 0); |
| 243 | |
| 244 | if (rem == 0) |
| 245 | return 0; |
| 246 | int n = 0; |
| 247 | if (position != -1) { |
| 248 | n = nd.pread(fd, ((DirectBuffer)bb).address() + pos, |
| 249 | rem, position, lock); |
| 250 | } else { |
| 251 | n = nd.read(fd, ((DirectBuffer)bb).address() + pos, rem); |
| 252 | } |
| 253 | if (n > 0) |
| 254 | bb.position(pos + n); |
| 255 | return n; |
| 256 | } |
| 257 | |
| 258 | static long read(FileDescriptor fd, ByteBuffer[] bufs, NativeDispatcher nd) |
| 259 | throws IOException |
| 260 | { |
| 261 | int nextWithRemaining = remaining(bufs); |
| 262 | // if all bufs are empty we should return immediately |
| 263 | if (nextWithRemaining < 0) |
| 264 | return 0; |
| 265 | // If some bufs are empty we should skip them |
| 266 | if (nextWithRemaining > 0) |
| 267 | bufs = skipBufs(bufs, nextWithRemaining); |
| 268 | |
| 269 | int numBufs = bufs.length; |
| 270 | |
| 271 | // Read into the shadow to ensure DirectByteBuffers are used |
| 272 | ByteBuffer[] shadow = new ByteBuffer[numBufs]; |
| 273 | for (int i=0; i<numBufs; i++) { |
| 274 | if (bufs[i].isReadOnly()) |
| 275 | throw new IllegalArgumentException("Read-only buffer"); |
| 276 | if (!(bufs[i] instanceof DirectBuffer)) { |
| 277 | shadow[i] = ByteBuffer.allocateDirect(bufs[i].remaining()); |
| 278 | } else { |
| 279 | shadow[i] = bufs[i]; |
| 280 | } |
| 281 | } |
| 282 | |
| 283 | IOVecWrapper vec = null; |
| 284 | long bytesRead = 0; |
| 285 | try { |
| 286 | // Create a native iovec array |
| 287 | vec = new IOVecWrapper(numBufs); |
| 288 | |
| 289 | // Fill in the iovec array with appropriate data |
| 290 | for (int i=0; i<numBufs; i++) { |
| 291 | ByteBuffer nextBuffer = shadow[i]; |
| 292 | // put in the buffer addresses |
| 293 | long pos = nextBuffer.position(); |
| 294 | long len = nextBuffer.remaining(); |
| 295 | vec.putBase(i, ((DirectBuffer)nextBuffer).address() + pos); |
| 296 | vec.putLen(i, len); |
| 297 | } |
| 298 | |
| 299 | // Invoke native call to fill the buffers |
| 300 | bytesRead = nd.readv(fd, vec.address, numBufs); |
| 301 | } finally { |
| 302 | vec.free(); |
| 303 | } |
| 304 | long returnVal = bytesRead; |
| 305 | |
| 306 | // Notify the buffers how many bytes were read |
| 307 | for (int i=0; i<numBufs; i++) { |
| 308 | ByteBuffer nextBuffer = shadow[i]; |
| 309 | // Note: should this have been cached from above? |
| 310 | int pos = nextBuffer.position(); |
| 311 | int len = nextBuffer.remaining(); |
| 312 | if (bytesRead >= len) { |
| 313 | bytesRead -= len; |
| 314 | int newPosition = pos + len; |
| 315 | nextBuffer.position(newPosition); |
| 316 | } else { // Buffers not completely filled |
| 317 | if (bytesRead > 0) { |
| 318 | assert(pos + bytesRead < (long)Integer.MAX_VALUE); |
| 319 | int newPosition = (int)(pos + bytesRead); |
| 320 | nextBuffer.position(newPosition); |
| 321 | } |
| 322 | break; |
| 323 | } |
| 324 | } |
| 325 | |
| 326 | // Put results from shadow into the slow buffers |
| 327 | for (int i=0; i<numBufs; i++) { |
| 328 | if (!(bufs[i] instanceof DirectBuffer)) { |
| 329 | shadow[i].flip(); |
| 330 | bufs[i].put(shadow[i]); |
| 331 | } |
| 332 | } |
| 333 | |
| 334 | return returnVal; |
| 335 | } |
| 336 | |
| 337 | static FileDescriptor newFD(int i) { |
| 338 | FileDescriptor fd = new FileDescriptor(); |
| 339 | setfdVal(fd, i); |
| 340 | return fd; |
| 341 | } |
| 342 | |
| 343 | static native boolean randomBytes(byte[] someBytes); |
| 344 | |
| 345 | static native void initPipe(int[] fda, boolean blocking); |
| 346 | |
| 347 | static native boolean drain(int fd) throws IOException; |
| 348 | |
| 349 | static native void configureBlocking(FileDescriptor fd, boolean blocking) |
| 350 | throws IOException; |
| 351 | |
| 352 | static native int fdVal(FileDescriptor fd); |
| 353 | |
| 354 | static native void setfdVal(FileDescriptor fd, int value); |
| 355 | |
| 356 | static native void initIDs(); |
| 357 | |
| 358 | static { |
| 359 | // Note that IOUtil.initIDs is called from within Util.load. |
| 360 | Util.load(); |
| 361 | } |
| 362 | |
| 363 | } |