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 | /* |
| 27 | */ |
| 28 | |
| 29 | package sun.nio.ch; // Formerly in sun.misc |
| 30 | |
| 31 | import java.nio.ByteOrder; |
| 32 | import sun.misc.Unsafe; |
| 33 | |
| 34 | |
| 35 | // ## In the fullness of time, this class will be eliminated |
| 36 | |
| 37 | /** |
| 38 | * Proxies for objects that reside in native memory. |
| 39 | */ |
| 40 | |
| 41 | class NativeObject { // package-private |
| 42 | |
| 43 | protected static final Unsafe unsafe = Unsafe.getUnsafe(); |
| 44 | |
| 45 | // Native allocation address; |
| 46 | // may be smaller than the base address due to page-size rounding |
| 47 | // |
| 48 | protected long allocationAddress; |
| 49 | |
| 50 | // Native base address |
| 51 | // |
| 52 | private final long address; |
| 53 | |
| 54 | /** |
| 55 | * Creates a new native object that is based at the given native address. |
| 56 | */ |
| 57 | NativeObject(long address) { |
| 58 | this.allocationAddress = address; |
| 59 | this.address = address; |
| 60 | } |
| 61 | |
| 62 | /** |
| 63 | * Creates a new native object allocated at the given native address but |
| 64 | * whose base is at the additional offset. |
| 65 | */ |
| 66 | NativeObject(long address, long offset) { |
| 67 | this.allocationAddress = address; |
| 68 | this.address = address + offset; |
| 69 | } |
| 70 | |
| 71 | // Invoked only by AllocatedNativeObject |
| 72 | // |
| 73 | protected NativeObject(int size, boolean pageAligned) { |
| 74 | if (!pageAligned) { |
| 75 | this.allocationAddress = unsafe.allocateMemory(size); |
| 76 | this.address = this.allocationAddress; |
| 77 | } else { |
| 78 | int ps = pageSize(); |
| 79 | long a = unsafe.allocateMemory(size + ps); |
| 80 | this.allocationAddress = a; |
| 81 | this.address = a + ps - (a & (ps - 1)); |
| 82 | } |
| 83 | } |
| 84 | |
| 85 | /** |
| 86 | * Returns the native base address of this native object. |
| 87 | * |
| 88 | * @return The native base address |
| 89 | */ |
| 90 | long address() { |
| 91 | return address; |
| 92 | } |
| 93 | |
| 94 | long allocationAddress() { |
| 95 | return allocationAddress; |
| 96 | } |
| 97 | |
| 98 | /** |
| 99 | * Creates a new native object starting at the given offset from the base |
| 100 | * of this native object. |
| 101 | * |
| 102 | * @param offset |
| 103 | * The offset from the base of this native object that is to be |
| 104 | * the base of the new native object |
| 105 | * |
| 106 | * @return The newly created native object |
| 107 | */ |
| 108 | NativeObject subObject(int offset) { |
| 109 | return new NativeObject(offset + address); |
| 110 | } |
| 111 | |
| 112 | /** |
| 113 | * Reads an address from this native object at the given offset and |
| 114 | * constructs a native object using that address. |
| 115 | * |
| 116 | * @param offset |
| 117 | * The offset of the address to be read. Note that the size of an |
| 118 | * address is implementation-dependent. |
| 119 | * |
| 120 | * @return The native object created using the address read from the |
| 121 | * given offset |
| 122 | */ |
| 123 | NativeObject getObject(int offset) { |
| 124 | long newAddress = 0L; |
| 125 | switch (addressSize()) { |
| 126 | case 8: |
| 127 | newAddress = unsafe.getLong(offset + address); |
| 128 | break; |
| 129 | case 4: |
| 130 | newAddress = unsafe.getInt(offset + address) & 0x00000000FFFFFFFF; |
| 131 | break; |
| 132 | default: |
| 133 | throw new InternalError("Address size not supported"); |
| 134 | } |
| 135 | |
| 136 | return new NativeObject(newAddress); |
| 137 | } |
| 138 | |
| 139 | /** |
| 140 | * Writes the base address of the given native object at the given offset |
| 141 | * of this native object. |
| 142 | * |
| 143 | * @param offset |
| 144 | * The offset at which the address is to be written. Note that the |
| 145 | * size of an address is implementation-dependent. |
| 146 | * |
| 147 | * @param ob |
| 148 | * The native object whose address is to be written |
| 149 | */ |
| 150 | void putObject(int offset, NativeObject ob) { |
| 151 | switch (addressSize()) { |
| 152 | case 8: |
| 153 | putLong(offset, ob.address); |
| 154 | break; |
| 155 | case 4: |
| 156 | putInt(offset, (int)(ob.address & 0x00000000FFFFFFFF)); |
| 157 | break; |
| 158 | default: |
| 159 | throw new InternalError("Address size not supported"); |
| 160 | } |
| 161 | } |
| 162 | |
| 163 | |
| 164 | /* -- Value accessors: No range checking! -- */ |
| 165 | |
| 166 | /** |
| 167 | * Reads a byte starting at the given offset from base of this native |
| 168 | * object. |
| 169 | * |
| 170 | * @param offset |
| 171 | * The offset at which to read the byte |
| 172 | * |
| 173 | * @return The byte value read |
| 174 | */ |
| 175 | final byte getByte(int offset) { |
| 176 | return unsafe.getByte(offset + address); |
| 177 | } |
| 178 | |
| 179 | /** |
| 180 | * Writes a byte at the specified offset from this native object's |
| 181 | * base address. |
| 182 | * |
| 183 | * @param offset |
| 184 | * The offset at which to write the byte |
| 185 | * |
| 186 | * @param value |
| 187 | * The byte value to be written |
| 188 | */ |
| 189 | final void putByte(int offset, byte value) { |
| 190 | unsafe.putByte(offset + address, value); |
| 191 | } |
| 192 | |
| 193 | /** |
| 194 | * Reads a short starting at the given offset from base of this native |
| 195 | * object. |
| 196 | * |
| 197 | * @param offset |
| 198 | * The offset at which to read the short |
| 199 | * |
| 200 | * @return The short value read |
| 201 | */ |
| 202 | final short getShort(int offset) { |
| 203 | return unsafe.getShort(offset + address); |
| 204 | } |
| 205 | |
| 206 | /** |
| 207 | * Writes a short at the specified offset from this native object's |
| 208 | * base address. |
| 209 | * |
| 210 | * @param offset |
| 211 | * The offset at which to write the short |
| 212 | * |
| 213 | * @param value |
| 214 | * The short value to be written |
| 215 | */ |
| 216 | final void putShort(int offset, short value) { |
| 217 | unsafe.putShort(offset + address, value); |
| 218 | } |
| 219 | |
| 220 | /** |
| 221 | * Reads a char starting at the given offset from base of this native |
| 222 | * object. |
| 223 | * |
| 224 | * @param offset |
| 225 | * The offset at which to read the char |
| 226 | * |
| 227 | * @return The char value read |
| 228 | */ |
| 229 | final char getChar(int offset) { |
| 230 | return unsafe.getChar(offset + address); |
| 231 | } |
| 232 | |
| 233 | /** |
| 234 | * Writes a char at the specified offset from this native object's |
| 235 | * base address. |
| 236 | * |
| 237 | * @param offset |
| 238 | * The offset at which to write the char |
| 239 | * |
| 240 | * @param value |
| 241 | * The char value to be written |
| 242 | */ |
| 243 | final void putChar(int offset, char value) { |
| 244 | unsafe.putChar(offset + address, value); |
| 245 | } |
| 246 | |
| 247 | /** |
| 248 | * Reads an int starting at the given offset from base of this native |
| 249 | * object. |
| 250 | * |
| 251 | * @param offset |
| 252 | * The offset at which to read the int |
| 253 | * |
| 254 | * @return The int value read |
| 255 | */ |
| 256 | final int getInt(int offset) { |
| 257 | return unsafe.getInt(offset + address); |
| 258 | } |
| 259 | |
| 260 | /** |
| 261 | * Writes an int at the specified offset from this native object's |
| 262 | * base address. |
| 263 | * |
| 264 | * @param offset |
| 265 | * The offset at which to write the int |
| 266 | * |
| 267 | * @param value |
| 268 | * The int value to be written |
| 269 | */ |
| 270 | final void putInt(int offset, int value) { |
| 271 | unsafe.putInt(offset + address, value); |
| 272 | } |
| 273 | |
| 274 | /** |
| 275 | * Reads a long starting at the given offset from base of this native |
| 276 | * object. |
| 277 | * |
| 278 | * @param offset |
| 279 | * The offset at which to read the long |
| 280 | * |
| 281 | * @return The long value read |
| 282 | */ |
| 283 | final long getLong(int offset) { |
| 284 | return unsafe.getLong(offset + address); |
| 285 | } |
| 286 | |
| 287 | /** |
| 288 | * Writes a long at the specified offset from this native object's |
| 289 | * base address. |
| 290 | * |
| 291 | * @param offset |
| 292 | * The offset at which to write the long |
| 293 | * |
| 294 | * @param value |
| 295 | * The long value to be written |
| 296 | */ |
| 297 | final void putLong(int offset, long value) { |
| 298 | unsafe.putLong(offset + address, value); |
| 299 | } |
| 300 | |
| 301 | /** |
| 302 | * Reads a float starting at the given offset from base of this native |
| 303 | * object. |
| 304 | * |
| 305 | * @param offset |
| 306 | * The offset at which to read the float |
| 307 | * |
| 308 | * @return The float value read |
| 309 | */ |
| 310 | final float getFloat(int offset) { |
| 311 | return unsafe.getFloat(offset + address); |
| 312 | } |
| 313 | |
| 314 | /** |
| 315 | * Writes a float at the specified offset from this native object's |
| 316 | * base address. |
| 317 | * |
| 318 | * @param offset |
| 319 | * The offset at which to write the float |
| 320 | * |
| 321 | * @param value |
| 322 | * The float value to be written |
| 323 | */ |
| 324 | final void putFloat(int offset, float value) { |
| 325 | unsafe.putFloat(offset + address, value); |
| 326 | } |
| 327 | |
| 328 | /** |
| 329 | * Reads a double starting at the given offset from base of this native |
| 330 | * object. |
| 331 | * |
| 332 | * @param offset |
| 333 | * The offset at which to read the double |
| 334 | * |
| 335 | * @return The double value read |
| 336 | */ |
| 337 | final double getDouble(int offset) { |
| 338 | return unsafe.getDouble(offset + address); |
| 339 | } |
| 340 | |
| 341 | /** |
| 342 | * Writes a double at the specified offset from this native object's |
| 343 | * base address. |
| 344 | * |
| 345 | * @param offset |
| 346 | * The offset at which to write the double |
| 347 | * |
| 348 | * @param value |
| 349 | * The double value to be written |
| 350 | */ |
| 351 | final void putDouble(int offset, double value) { |
| 352 | unsafe.putDouble(offset + address, value); |
| 353 | } |
| 354 | |
| 355 | /** |
| 356 | * Returns the native architecture's address size in bytes. |
| 357 | * |
| 358 | * @return The address size of the native architecture |
| 359 | */ |
| 360 | static int addressSize() { |
| 361 | return unsafe.addressSize(); |
| 362 | } |
| 363 | |
| 364 | // Cache for byte order |
| 365 | private static ByteOrder byteOrder = null; |
| 366 | |
| 367 | /** |
| 368 | * Returns the byte order of the underlying hardware. |
| 369 | * |
| 370 | * @return An instance of {@link java.nio.ByteOrder} |
| 371 | */ |
| 372 | static ByteOrder byteOrder() { |
| 373 | if (byteOrder != null) |
| 374 | return byteOrder; |
| 375 | long a = unsafe.allocateMemory(8); |
| 376 | try { |
| 377 | unsafe.putLong(a, 0x0102030405060708L); |
| 378 | byte b = unsafe.getByte(a); |
| 379 | switch (b) { |
| 380 | case 0x01: byteOrder = ByteOrder.BIG_ENDIAN; break; |
| 381 | case 0x08: byteOrder = ByteOrder.LITTLE_ENDIAN; break; |
| 382 | default: |
| 383 | assert false; |
| 384 | } |
| 385 | } finally { |
| 386 | unsafe.freeMemory(a); |
| 387 | } |
| 388 | return byteOrder; |
| 389 | } |
| 390 | |
| 391 | // Cache for page size |
| 392 | private static int pageSize = -1; |
| 393 | |
| 394 | /** |
| 395 | * Returns the page size of the underlying hardware. |
| 396 | * |
| 397 | * @return The page size, in bytes |
| 398 | */ |
| 399 | static int pageSize() { |
| 400 | if (pageSize == -1) |
| 401 | pageSize = unsafe.pageSize(); |
| 402 | return pageSize; |
| 403 | } |
| 404 | |
| 405 | } |