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| 1 | /* | ||
| 2 | * Copyright (c) 2000, 2002, 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 | /* | ||
| 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 | } | ||