J. Duke | 319a3b9 | 2007-12-01 00:00:00 +0000 | [diff] [blame^] | 1 | /* |
| 2 | * Copyright 2000-2006 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.FileInputStream; |
| 30 | import java.io.FileOutputStream; |
| 31 | import java.io.RandomAccessFile; |
| 32 | import java.io.IOException; |
| 33 | import java.nio.ByteBuffer; |
| 34 | import java.nio.MappedByteBuffer; |
| 35 | import java.nio.channels.*; |
| 36 | import java.nio.channels.spi.*; |
| 37 | import java.util.ArrayList; |
| 38 | import java.util.List; |
| 39 | import java.util.Iterator; |
| 40 | import java.util.concurrent.ConcurrentHashMap; |
| 41 | import java.lang.ref.WeakReference; |
| 42 | import java.lang.ref.ReferenceQueue; |
| 43 | import java.lang.reflect.Field; |
| 44 | import java.security.AccessController; |
| 45 | import java.security.PrivilegedAction; |
| 46 | import sun.misc.Cleaner; |
| 47 | import sun.security.action.GetPropertyAction; |
| 48 | |
| 49 | |
| 50 | public class FileChannelImpl |
| 51 | extends FileChannel |
| 52 | { |
| 53 | |
| 54 | // Used to make native read and write calls |
| 55 | private static NativeDispatcher nd; |
| 56 | |
| 57 | // Memory allocation size for mapping buffers |
| 58 | private static long allocationGranularity; |
| 59 | |
| 60 | // Cached field for MappedByteBuffer.isAMappedBuffer |
| 61 | private static Field isAMappedBufferField; |
| 62 | |
| 63 | // File descriptor |
| 64 | private FileDescriptor fd; |
| 65 | |
| 66 | // File access mode (immutable) |
| 67 | private boolean writable; |
| 68 | private boolean readable; |
| 69 | private boolean appending; |
| 70 | |
| 71 | // Required to prevent finalization of creating stream (immutable) |
| 72 | private Object parent; |
| 73 | |
| 74 | // Thread-safe set of IDs of native threads, for signalling |
| 75 | private NativeThreadSet threads = new NativeThreadSet(2); |
| 76 | |
| 77 | // Lock for operations involving position and size |
| 78 | private Object positionLock = new Object(); |
| 79 | |
| 80 | private FileChannelImpl(FileDescriptor fd, boolean readable, |
| 81 | boolean writable, Object parent, boolean append) |
| 82 | { |
| 83 | this.fd = fd; |
| 84 | this.readable = readable; |
| 85 | this.writable = writable; |
| 86 | this.parent = parent; |
| 87 | this.appending = append; |
| 88 | } |
| 89 | |
| 90 | // Invoked by getChannel() methods |
| 91 | // of java.io.File{Input,Output}Stream and RandomAccessFile |
| 92 | // |
| 93 | public static FileChannel open(FileDescriptor fd, |
| 94 | boolean readable, boolean writable, |
| 95 | Object parent) |
| 96 | { |
| 97 | return new FileChannelImpl(fd, readable, writable, parent, false); |
| 98 | } |
| 99 | |
| 100 | public static FileChannel open(FileDescriptor fd, |
| 101 | boolean readable, boolean writable, |
| 102 | Object parent, boolean append) |
| 103 | { |
| 104 | return new FileChannelImpl(fd, readable, writable, parent, append); |
| 105 | } |
| 106 | |
| 107 | private void ensureOpen() throws IOException { |
| 108 | if (!isOpen()) |
| 109 | throw new ClosedChannelException(); |
| 110 | } |
| 111 | |
| 112 | |
| 113 | // -- Standard channel operations -- |
| 114 | |
| 115 | protected void implCloseChannel() throws IOException { |
| 116 | |
| 117 | nd.preClose(fd); |
| 118 | threads.signal(); |
| 119 | |
| 120 | // Invalidate and release any locks that we still hold |
| 121 | if (fileLockTable != null) { |
| 122 | fileLockTable.removeAll( new FileLockTable.Releaser() { |
| 123 | public void release(FileLock fl) throws IOException { |
| 124 | ((FileLockImpl)fl).invalidate(); |
| 125 | release0(fd, fl.position(), fl.size()); |
| 126 | } |
| 127 | }); |
| 128 | } |
| 129 | |
| 130 | if (parent != null) { |
| 131 | |
| 132 | // Close the fd via the parent stream's close method. The parent |
| 133 | // will reinvoke our close method, which is defined in the |
| 134 | // superclass AbstractInterruptibleChannel, but the isOpen logic in |
| 135 | // that method will prevent this method from being reinvoked. |
| 136 | // |
| 137 | if (parent instanceof FileInputStream) |
| 138 | ((FileInputStream)parent).close(); |
| 139 | else if (parent instanceof FileOutputStream) |
| 140 | ((FileOutputStream)parent).close(); |
| 141 | else if (parent instanceof RandomAccessFile) |
| 142 | ((RandomAccessFile)parent).close(); |
| 143 | else |
| 144 | assert false; |
| 145 | |
| 146 | } else { |
| 147 | nd.close(fd); |
| 148 | } |
| 149 | |
| 150 | } |
| 151 | |
| 152 | public int read(ByteBuffer dst) throws IOException { |
| 153 | ensureOpen(); |
| 154 | if (!readable) |
| 155 | throw new NonReadableChannelException(); |
| 156 | synchronized (positionLock) { |
| 157 | int n = 0; |
| 158 | int ti = -1; |
| 159 | try { |
| 160 | begin(); |
| 161 | if (!isOpen()) |
| 162 | return 0; |
| 163 | ti = threads.add(); |
| 164 | do { |
| 165 | n = IOUtil.read(fd, dst, -1, nd, positionLock); |
| 166 | } while ((n == IOStatus.INTERRUPTED) && isOpen()); |
| 167 | return IOStatus.normalize(n); |
| 168 | } finally { |
| 169 | threads.remove(ti); |
| 170 | end(n > 0); |
| 171 | assert IOStatus.check(n); |
| 172 | } |
| 173 | } |
| 174 | } |
| 175 | |
| 176 | private long read0(ByteBuffer[] dsts) throws IOException { |
| 177 | ensureOpen(); |
| 178 | if (!readable) |
| 179 | throw new NonReadableChannelException(); |
| 180 | synchronized (positionLock) { |
| 181 | long n = 0; |
| 182 | int ti = -1; |
| 183 | try { |
| 184 | begin(); |
| 185 | if (!isOpen()) |
| 186 | return 0; |
| 187 | ti = threads.add(); |
| 188 | do { |
| 189 | n = IOUtil.read(fd, dsts, nd); |
| 190 | } while ((n == IOStatus.INTERRUPTED) && isOpen()); |
| 191 | return IOStatus.normalize(n); |
| 192 | } finally { |
| 193 | threads.remove(ti); |
| 194 | end(n > 0); |
| 195 | assert IOStatus.check(n); |
| 196 | } |
| 197 | } |
| 198 | } |
| 199 | |
| 200 | public long read(ByteBuffer[] dsts, int offset, int length) |
| 201 | throws IOException |
| 202 | { |
| 203 | if ((offset < 0) || (length < 0) || (offset > dsts.length - length)) |
| 204 | throw new IndexOutOfBoundsException(); |
| 205 | // ## Fix IOUtil.write so that we can avoid this array copy |
| 206 | return read0(Util.subsequence(dsts, offset, length)); |
| 207 | } |
| 208 | |
| 209 | public int write(ByteBuffer src) throws IOException { |
| 210 | ensureOpen(); |
| 211 | if (!writable) |
| 212 | throw new NonWritableChannelException(); |
| 213 | synchronized (positionLock) { |
| 214 | int n = 0; |
| 215 | int ti = -1; |
| 216 | try { |
| 217 | begin(); |
| 218 | if (!isOpen()) |
| 219 | return 0; |
| 220 | ti = threads.add(); |
| 221 | if (appending) |
| 222 | position(size()); |
| 223 | do { |
| 224 | n = IOUtil.write(fd, src, -1, nd, positionLock); |
| 225 | } while ((n == IOStatus.INTERRUPTED) && isOpen()); |
| 226 | return IOStatus.normalize(n); |
| 227 | } finally { |
| 228 | threads.remove(ti); |
| 229 | end(n > 0); |
| 230 | assert IOStatus.check(n); |
| 231 | } |
| 232 | } |
| 233 | } |
| 234 | |
| 235 | private long write0(ByteBuffer[] srcs) throws IOException { |
| 236 | ensureOpen(); |
| 237 | if (!writable) |
| 238 | throw new NonWritableChannelException(); |
| 239 | synchronized (positionLock) { |
| 240 | long n = 0; |
| 241 | int ti = -1; |
| 242 | try { |
| 243 | begin(); |
| 244 | if (!isOpen()) |
| 245 | return 0; |
| 246 | ti = threads.add(); |
| 247 | if (appending) |
| 248 | position(size()); |
| 249 | do { |
| 250 | n = IOUtil.write(fd, srcs, nd); |
| 251 | } while ((n == IOStatus.INTERRUPTED) && isOpen()); |
| 252 | return IOStatus.normalize(n); |
| 253 | } finally { |
| 254 | threads.remove(ti); |
| 255 | end(n > 0); |
| 256 | assert IOStatus.check(n); |
| 257 | } |
| 258 | } |
| 259 | } |
| 260 | |
| 261 | public long write(ByteBuffer[] srcs, int offset, int length) |
| 262 | throws IOException |
| 263 | { |
| 264 | if ((offset < 0) || (length < 0) || (offset > srcs.length - length)) |
| 265 | throw new IndexOutOfBoundsException(); |
| 266 | // ## Fix IOUtil.write so that we can avoid this array copy |
| 267 | return write0(Util.subsequence(srcs, offset, length)); |
| 268 | } |
| 269 | |
| 270 | |
| 271 | // -- Other operations -- |
| 272 | |
| 273 | public long position() throws IOException { |
| 274 | ensureOpen(); |
| 275 | synchronized (positionLock) { |
| 276 | long p = -1; |
| 277 | int ti = -1; |
| 278 | try { |
| 279 | begin(); |
| 280 | if (!isOpen()) |
| 281 | return 0; |
| 282 | ti = threads.add(); |
| 283 | do { |
| 284 | p = position0(fd, -1); |
| 285 | } while ((p == IOStatus.INTERRUPTED) && isOpen()); |
| 286 | return IOStatus.normalize(p); |
| 287 | } finally { |
| 288 | threads.remove(ti); |
| 289 | end(p > -1); |
| 290 | assert IOStatus.check(p); |
| 291 | } |
| 292 | } |
| 293 | } |
| 294 | |
| 295 | public FileChannel position(long newPosition) throws IOException { |
| 296 | ensureOpen(); |
| 297 | if (newPosition < 0) |
| 298 | throw new IllegalArgumentException(); |
| 299 | synchronized (positionLock) { |
| 300 | long p = -1; |
| 301 | int ti = -1; |
| 302 | try { |
| 303 | begin(); |
| 304 | if (!isOpen()) |
| 305 | return null; |
| 306 | ti = threads.add(); |
| 307 | do { |
| 308 | p = position0(fd, newPosition); |
| 309 | } while ((p == IOStatus.INTERRUPTED) && isOpen()); |
| 310 | return this; |
| 311 | } finally { |
| 312 | threads.remove(ti); |
| 313 | end(p > -1); |
| 314 | assert IOStatus.check(p); |
| 315 | } |
| 316 | } |
| 317 | } |
| 318 | |
| 319 | public long size() throws IOException { |
| 320 | ensureOpen(); |
| 321 | synchronized (positionLock) { |
| 322 | long s = -1; |
| 323 | int ti = -1; |
| 324 | try { |
| 325 | begin(); |
| 326 | if (!isOpen()) |
| 327 | return -1; |
| 328 | ti = threads.add(); |
| 329 | do { |
| 330 | s = size0(fd); |
| 331 | } while ((s == IOStatus.INTERRUPTED) && isOpen()); |
| 332 | return IOStatus.normalize(s); |
| 333 | } finally { |
| 334 | threads.remove(ti); |
| 335 | end(s > -1); |
| 336 | assert IOStatus.check(s); |
| 337 | } |
| 338 | } |
| 339 | } |
| 340 | |
| 341 | public FileChannel truncate(long size) throws IOException { |
| 342 | ensureOpen(); |
| 343 | if (size < 0) |
| 344 | throw new IllegalArgumentException(); |
| 345 | if (size > size()) |
| 346 | return this; |
| 347 | if (!writable) |
| 348 | throw new NonWritableChannelException(); |
| 349 | synchronized (positionLock) { |
| 350 | int rv = -1; |
| 351 | long p = -1; |
| 352 | int ti = -1; |
| 353 | try { |
| 354 | begin(); |
| 355 | if (!isOpen()) |
| 356 | return null; |
| 357 | ti = threads.add(); |
| 358 | |
| 359 | // get current position |
| 360 | do { |
| 361 | p = position0(fd, -1); |
| 362 | } while ((p == IOStatus.INTERRUPTED) && isOpen()); |
| 363 | if (!isOpen()) |
| 364 | return null; |
| 365 | assert p >= 0; |
| 366 | |
| 367 | // truncate file |
| 368 | do { |
| 369 | rv = truncate0(fd, size); |
| 370 | } while ((rv == IOStatus.INTERRUPTED) && isOpen()); |
| 371 | if (!isOpen()) |
| 372 | return null; |
| 373 | |
| 374 | // set position to size if greater than size |
| 375 | if (p > size) |
| 376 | p = size; |
| 377 | do { |
| 378 | rv = (int)position0(fd, p); |
| 379 | } while ((rv == IOStatus.INTERRUPTED) && isOpen()); |
| 380 | return this; |
| 381 | } finally { |
| 382 | threads.remove(ti); |
| 383 | end(rv > -1); |
| 384 | assert IOStatus.check(rv); |
| 385 | } |
| 386 | } |
| 387 | } |
| 388 | |
| 389 | public void force(boolean metaData) throws IOException { |
| 390 | ensureOpen(); |
| 391 | int rv = -1; |
| 392 | int ti = -1; |
| 393 | try { |
| 394 | begin(); |
| 395 | if (!isOpen()) |
| 396 | return; |
| 397 | ti = threads.add(); |
| 398 | do { |
| 399 | rv = force0(fd, metaData); |
| 400 | } while ((rv == IOStatus.INTERRUPTED) && isOpen()); |
| 401 | } finally { |
| 402 | threads.remove(ti); |
| 403 | end(rv > -1); |
| 404 | assert IOStatus.check(rv); |
| 405 | } |
| 406 | } |
| 407 | |
| 408 | // Assume at first that the underlying kernel supports sendfile(); |
| 409 | // set this to false if we find out later that it doesn't |
| 410 | // |
| 411 | private static volatile boolean transferSupported = true; |
| 412 | |
| 413 | // Assume that the underlying kernel sendfile() will work if the target |
| 414 | // fd is a pipe; set this to false if we find out later that it doesn't |
| 415 | // |
| 416 | private static volatile boolean pipeSupported = true; |
| 417 | |
| 418 | // Assume that the underlying kernel sendfile() will work if the target |
| 419 | // fd is a file; set this to false if we find out later that it doesn't |
| 420 | // |
| 421 | private static volatile boolean fileSupported = true; |
| 422 | |
| 423 | private long transferToDirectly(long position, int icount, |
| 424 | WritableByteChannel target) |
| 425 | throws IOException |
| 426 | { |
| 427 | if (!transferSupported) |
| 428 | return IOStatus.UNSUPPORTED; |
| 429 | |
| 430 | FileDescriptor targetFD = null; |
| 431 | if (target instanceof FileChannelImpl) { |
| 432 | if (!fileSupported) |
| 433 | return IOStatus.UNSUPPORTED_CASE; |
| 434 | targetFD = ((FileChannelImpl)target).fd; |
| 435 | } else if (target instanceof SelChImpl) { |
| 436 | // Direct transfer to pipe causes EINVAL on some configurations |
| 437 | if ((target instanceof SinkChannelImpl) && !pipeSupported) |
| 438 | return IOStatus.UNSUPPORTED_CASE; |
| 439 | targetFD = ((SelChImpl)target).getFD(); |
| 440 | } |
| 441 | if (targetFD == null) |
| 442 | return IOStatus.UNSUPPORTED; |
| 443 | int thisFDVal = IOUtil.fdVal(fd); |
| 444 | int targetFDVal = IOUtil.fdVal(targetFD); |
| 445 | if (thisFDVal == targetFDVal) // Not supported on some configurations |
| 446 | return IOStatus.UNSUPPORTED; |
| 447 | |
| 448 | long n = -1; |
| 449 | int ti = -1; |
| 450 | try { |
| 451 | begin(); |
| 452 | if (!isOpen()) |
| 453 | return -1; |
| 454 | ti = threads.add(); |
| 455 | do { |
| 456 | n = transferTo0(thisFDVal, position, icount, targetFDVal); |
| 457 | } while ((n == IOStatus.INTERRUPTED) && isOpen()); |
| 458 | if (n == IOStatus.UNSUPPORTED_CASE) { |
| 459 | if (target instanceof SinkChannelImpl) |
| 460 | pipeSupported = false; |
| 461 | if (target instanceof FileChannelImpl) |
| 462 | fileSupported = false; |
| 463 | return IOStatus.UNSUPPORTED_CASE; |
| 464 | } |
| 465 | if (n == IOStatus.UNSUPPORTED) { |
| 466 | // Don't bother trying again |
| 467 | transferSupported = false; |
| 468 | return IOStatus.UNSUPPORTED; |
| 469 | } |
| 470 | return IOStatus.normalize(n); |
| 471 | } finally { |
| 472 | threads.remove(ti); |
| 473 | end (n > -1); |
| 474 | } |
| 475 | } |
| 476 | |
| 477 | private long transferToTrustedChannel(long position, int icount, |
| 478 | WritableByteChannel target) |
| 479 | throws IOException |
| 480 | { |
| 481 | if ( !((target instanceof FileChannelImpl) |
| 482 | || (target instanceof SelChImpl))) |
| 483 | return IOStatus.UNSUPPORTED; |
| 484 | |
| 485 | // Trusted target: Use a mapped buffer |
| 486 | MappedByteBuffer dbb = null; |
| 487 | try { |
| 488 | dbb = map(MapMode.READ_ONLY, position, icount); |
| 489 | // ## Bug: Closing this channel will not terminate the write |
| 490 | return target.write(dbb); |
| 491 | } finally { |
| 492 | if (dbb != null) |
| 493 | unmap(dbb); |
| 494 | } |
| 495 | } |
| 496 | |
| 497 | private long transferToArbitraryChannel(long position, int icount, |
| 498 | WritableByteChannel target) |
| 499 | throws IOException |
| 500 | { |
| 501 | // Untrusted target: Use a newly-erased buffer |
| 502 | int c = Math.min(icount, TRANSFER_SIZE); |
| 503 | ByteBuffer bb = Util.getTemporaryDirectBuffer(c); |
| 504 | long tw = 0; // Total bytes written |
| 505 | long pos = position; |
| 506 | try { |
| 507 | Util.erase(bb); |
| 508 | while (tw < icount) { |
| 509 | bb.limit(Math.min((int)(icount - tw), TRANSFER_SIZE)); |
| 510 | int nr = read(bb, pos); |
| 511 | if (nr <= 0) |
| 512 | break; |
| 513 | bb.flip(); |
| 514 | // ## Bug: Will block writing target if this channel |
| 515 | // ## is asynchronously closed |
| 516 | int nw = target.write(bb); |
| 517 | tw += nw; |
| 518 | if (nw != nr) |
| 519 | break; |
| 520 | pos += nw; |
| 521 | bb.clear(); |
| 522 | } |
| 523 | return tw; |
| 524 | } catch (IOException x) { |
| 525 | if (tw > 0) |
| 526 | return tw; |
| 527 | throw x; |
| 528 | } finally { |
| 529 | Util.releaseTemporaryDirectBuffer(bb); |
| 530 | } |
| 531 | } |
| 532 | |
| 533 | public long transferTo(long position, long count, |
| 534 | WritableByteChannel target) |
| 535 | throws IOException |
| 536 | { |
| 537 | ensureOpen(); |
| 538 | if (!target.isOpen()) |
| 539 | throw new ClosedChannelException(); |
| 540 | if (!readable) |
| 541 | throw new NonReadableChannelException(); |
| 542 | if (target instanceof FileChannelImpl && |
| 543 | !((FileChannelImpl)target).writable) |
| 544 | throw new NonWritableChannelException(); |
| 545 | if ((position < 0) || (count < 0)) |
| 546 | throw new IllegalArgumentException(); |
| 547 | long sz = size(); |
| 548 | if (position > sz) |
| 549 | return 0; |
| 550 | int icount = (int)Math.min(count, Integer.MAX_VALUE); |
| 551 | if ((sz - position) < icount) |
| 552 | icount = (int)(sz - position); |
| 553 | |
| 554 | long n; |
| 555 | |
| 556 | // Attempt a direct transfer, if the kernel supports it |
| 557 | if ((n = transferToDirectly(position, icount, target)) >= 0) |
| 558 | return n; |
| 559 | |
| 560 | // Attempt a mapped transfer, but only to trusted channel types |
| 561 | if ((n = transferToTrustedChannel(position, icount, target)) >= 0) |
| 562 | return n; |
| 563 | |
| 564 | // Slow path for untrusted targets |
| 565 | return transferToArbitraryChannel(position, icount, target); |
| 566 | } |
| 567 | |
| 568 | private long transferFromFileChannel(FileChannelImpl src, |
| 569 | long position, long count) |
| 570 | throws IOException |
| 571 | { |
| 572 | // Note we could loop here to accumulate more at once |
| 573 | synchronized (src.positionLock) { |
| 574 | long p = src.position(); |
| 575 | int icount = (int)Math.min(Math.min(count, Integer.MAX_VALUE), |
| 576 | src.size() - p); |
| 577 | // ## Bug: Closing this channel will not terminate the write |
| 578 | MappedByteBuffer bb = src.map(MapMode.READ_ONLY, p, icount); |
| 579 | try { |
| 580 | long n = write(bb, position); |
| 581 | src.position(p + n); |
| 582 | return n; |
| 583 | } finally { |
| 584 | unmap(bb); |
| 585 | } |
| 586 | } |
| 587 | } |
| 588 | |
| 589 | private static final int TRANSFER_SIZE = 8192; |
| 590 | |
| 591 | private long transferFromArbitraryChannel(ReadableByteChannel src, |
| 592 | long position, long count) |
| 593 | throws IOException |
| 594 | { |
| 595 | // Untrusted target: Use a newly-erased buffer |
| 596 | int c = (int)Math.min(count, TRANSFER_SIZE); |
| 597 | ByteBuffer bb = Util.getTemporaryDirectBuffer(c); |
| 598 | long tw = 0; // Total bytes written |
| 599 | long pos = position; |
| 600 | try { |
| 601 | Util.erase(bb); |
| 602 | while (tw < count) { |
| 603 | bb.limit((int)Math.min((count - tw), (long)TRANSFER_SIZE)); |
| 604 | // ## Bug: Will block reading src if this channel |
| 605 | // ## is asynchronously closed |
| 606 | int nr = src.read(bb); |
| 607 | if (nr <= 0) |
| 608 | break; |
| 609 | bb.flip(); |
| 610 | int nw = write(bb, pos); |
| 611 | tw += nw; |
| 612 | if (nw != nr) |
| 613 | break; |
| 614 | pos += nw; |
| 615 | bb.clear(); |
| 616 | } |
| 617 | return tw; |
| 618 | } catch (IOException x) { |
| 619 | if (tw > 0) |
| 620 | return tw; |
| 621 | throw x; |
| 622 | } finally { |
| 623 | Util.releaseTemporaryDirectBuffer(bb); |
| 624 | } |
| 625 | } |
| 626 | |
| 627 | public long transferFrom(ReadableByteChannel src, |
| 628 | long position, long count) |
| 629 | throws IOException |
| 630 | { |
| 631 | ensureOpen(); |
| 632 | if (!src.isOpen()) |
| 633 | throw new ClosedChannelException(); |
| 634 | if (!writable) |
| 635 | throw new NonWritableChannelException(); |
| 636 | if ((position < 0) || (count < 0)) |
| 637 | throw new IllegalArgumentException(); |
| 638 | if (position > size()) |
| 639 | return 0; |
| 640 | if (src instanceof FileChannelImpl) |
| 641 | return transferFromFileChannel((FileChannelImpl)src, |
| 642 | position, count); |
| 643 | |
| 644 | return transferFromArbitraryChannel(src, position, count); |
| 645 | } |
| 646 | |
| 647 | public int read(ByteBuffer dst, long position) throws IOException { |
| 648 | if (dst == null) |
| 649 | throw new NullPointerException(); |
| 650 | if (position < 0) |
| 651 | throw new IllegalArgumentException("Negative position"); |
| 652 | if (!readable) |
| 653 | throw new NonReadableChannelException(); |
| 654 | ensureOpen(); |
| 655 | int n = 0; |
| 656 | int ti = -1; |
| 657 | try { |
| 658 | begin(); |
| 659 | if (!isOpen()) |
| 660 | return -1; |
| 661 | ti = threads.add(); |
| 662 | do { |
| 663 | n = IOUtil.read(fd, dst, position, nd, positionLock); |
| 664 | } while ((n == IOStatus.INTERRUPTED) && isOpen()); |
| 665 | return IOStatus.normalize(n); |
| 666 | } finally { |
| 667 | threads.remove(ti); |
| 668 | end(n > 0); |
| 669 | assert IOStatus.check(n); |
| 670 | } |
| 671 | } |
| 672 | |
| 673 | public int write(ByteBuffer src, long position) throws IOException { |
| 674 | if (src == null) |
| 675 | throw new NullPointerException(); |
| 676 | if (position < 0) |
| 677 | throw new IllegalArgumentException("Negative position"); |
| 678 | if (!writable) |
| 679 | throw new NonWritableChannelException(); |
| 680 | ensureOpen(); |
| 681 | int n = 0; |
| 682 | int ti = -1; |
| 683 | try { |
| 684 | begin(); |
| 685 | if (!isOpen()) |
| 686 | return -1; |
| 687 | ti = threads.add(); |
| 688 | do { |
| 689 | n = IOUtil.write(fd, src, position, nd, positionLock); |
| 690 | } while ((n == IOStatus.INTERRUPTED) && isOpen()); |
| 691 | return IOStatus.normalize(n); |
| 692 | } finally { |
| 693 | threads.remove(ti); |
| 694 | end(n > 0); |
| 695 | assert IOStatus.check(n); |
| 696 | } |
| 697 | } |
| 698 | |
| 699 | |
| 700 | // -- Memory-mapped buffers -- |
| 701 | |
| 702 | private static class Unmapper |
| 703 | implements Runnable |
| 704 | { |
| 705 | |
| 706 | private long address; |
| 707 | private long size; |
| 708 | |
| 709 | private Unmapper(long address, long size) { |
| 710 | assert (address != 0); |
| 711 | this.address = address; |
| 712 | this.size = size; |
| 713 | } |
| 714 | |
| 715 | public void run() { |
| 716 | if (address == 0) |
| 717 | return; |
| 718 | unmap0(address, size); |
| 719 | address = 0; |
| 720 | } |
| 721 | |
| 722 | } |
| 723 | |
| 724 | private static void unmap(MappedByteBuffer bb) { |
| 725 | Cleaner cl = ((DirectBuffer)bb).cleaner(); |
| 726 | if (cl != null) |
| 727 | cl.clean(); |
| 728 | } |
| 729 | |
| 730 | private static final int MAP_RO = 0; |
| 731 | private static final int MAP_RW = 1; |
| 732 | private static final int MAP_PV = 2; |
| 733 | |
| 734 | public MappedByteBuffer map(MapMode mode, long position, long size) |
| 735 | throws IOException |
| 736 | { |
| 737 | ensureOpen(); |
| 738 | if (position < 0L) |
| 739 | throw new IllegalArgumentException("Negative position"); |
| 740 | if (size < 0L) |
| 741 | throw new IllegalArgumentException("Negative size"); |
| 742 | if (position + size < 0) |
| 743 | throw new IllegalArgumentException("Position + size overflow"); |
| 744 | if (size > Integer.MAX_VALUE) |
| 745 | throw new IllegalArgumentException("Size exceeds Integer.MAX_VALUE"); |
| 746 | int imode = -1; |
| 747 | if (mode == MapMode.READ_ONLY) |
| 748 | imode = MAP_RO; |
| 749 | else if (mode == MapMode.READ_WRITE) |
| 750 | imode = MAP_RW; |
| 751 | else if (mode == MapMode.PRIVATE) |
| 752 | imode = MAP_PV; |
| 753 | assert (imode >= 0); |
| 754 | if ((mode != MapMode.READ_ONLY) && !writable) |
| 755 | throw new NonWritableChannelException(); |
| 756 | if (!readable) |
| 757 | throw new NonReadableChannelException(); |
| 758 | |
| 759 | long addr = -1; |
| 760 | int ti = -1; |
| 761 | try { |
| 762 | begin(); |
| 763 | if (!isOpen()) |
| 764 | return null; |
| 765 | ti = threads.add(); |
| 766 | if (size() < position + size) { // Extend file size |
| 767 | if (!writable) { |
| 768 | throw new IOException("Channel not open for writing " + |
| 769 | "- cannot extend file to required size"); |
| 770 | } |
| 771 | int rv; |
| 772 | do { |
| 773 | rv = truncate0(fd, position + size); |
| 774 | } while ((rv == IOStatus.INTERRUPTED) && isOpen()); |
| 775 | } |
| 776 | if (size == 0) { |
| 777 | addr = 0; |
| 778 | if ((!writable) || (imode == MAP_RO)) |
| 779 | return Util.newMappedByteBufferR(0, 0, null); |
| 780 | else |
| 781 | return Util.newMappedByteBuffer(0, 0, null); |
| 782 | } |
| 783 | |
| 784 | int pagePosition = (int)(position % allocationGranularity); |
| 785 | long mapPosition = position - pagePosition; |
| 786 | long mapSize = size + pagePosition; |
| 787 | try { |
| 788 | // If no exception was thrown from map0, the address is valid |
| 789 | addr = map0(imode, mapPosition, mapSize); |
| 790 | } catch (OutOfMemoryError x) { |
| 791 | // An OutOfMemoryError may indicate that we've exhausted memory |
| 792 | // so force gc and re-attempt map |
| 793 | System.gc(); |
| 794 | try { |
| 795 | Thread.sleep(100); |
| 796 | } catch (InterruptedException y) { |
| 797 | Thread.currentThread().interrupt(); |
| 798 | } |
| 799 | try { |
| 800 | addr = map0(imode, mapPosition, mapSize); |
| 801 | } catch (OutOfMemoryError y) { |
| 802 | // After a second OOME, fail |
| 803 | throw new IOException("Map failed", y); |
| 804 | } |
| 805 | } |
| 806 | |
| 807 | assert (IOStatus.checkAll(addr)); |
| 808 | assert (addr % allocationGranularity == 0); |
| 809 | int isize = (int)size; |
| 810 | Unmapper um = new Unmapper(addr, size + pagePosition); |
| 811 | if ((!writable) || (imode == MAP_RO)) |
| 812 | return Util.newMappedByteBufferR(isize, addr + pagePosition, um); |
| 813 | else |
| 814 | return Util.newMappedByteBuffer(isize, addr + pagePosition, um); |
| 815 | } finally { |
| 816 | threads.remove(ti); |
| 817 | end(IOStatus.checkAll(addr)); |
| 818 | } |
| 819 | } |
| 820 | |
| 821 | |
| 822 | // -- Locks -- |
| 823 | |
| 824 | public static final int NO_LOCK = -1; // Failed to lock |
| 825 | public static final int LOCKED = 0; // Obtained requested lock |
| 826 | public static final int RET_EX_LOCK = 1; // Obtained exclusive lock |
| 827 | public static final int INTERRUPTED = 2; // Request interrupted |
| 828 | |
| 829 | // keeps track of locks on this file |
| 830 | private volatile FileLockTable fileLockTable; |
| 831 | |
| 832 | // indicates if file locks are maintained system-wide (as per spec) |
| 833 | private static boolean isSharedFileLockTable; |
| 834 | |
| 835 | // indicates if the disableSystemWideOverlappingFileLockCheck property |
| 836 | // has been checked |
| 837 | private static volatile boolean propertyChecked; |
| 838 | |
| 839 | // The lock list in J2SE 1.4/5.0 was local to each FileChannel instance so |
| 840 | // the overlap check wasn't system wide when there were multiple channels to |
| 841 | // the same file. This property is used to get 1.4/5.0 behavior if desired. |
| 842 | private static boolean isSharedFileLockTable() { |
| 843 | if (!propertyChecked) { |
| 844 | synchronized (FileChannelImpl.class) { |
| 845 | if (!propertyChecked) { |
| 846 | String value = AccessController.doPrivileged( |
| 847 | new GetPropertyAction( |
| 848 | "sun.nio.ch.disableSystemWideOverlappingFileLockCheck")); |
| 849 | isSharedFileLockTable = ((value == null) || value.equals("false")); |
| 850 | propertyChecked = true; |
| 851 | } |
| 852 | } |
| 853 | } |
| 854 | return isSharedFileLockTable; |
| 855 | } |
| 856 | |
| 857 | private FileLockTable fileLockTable() { |
| 858 | if (fileLockTable == null) { |
| 859 | synchronized (this) { |
| 860 | if (fileLockTable == null) { |
| 861 | fileLockTable = isSharedFileLockTable() ? |
| 862 | new SharedFileLockTable(this) : new SimpleFileLockTable(); |
| 863 | } |
| 864 | } |
| 865 | } |
| 866 | return fileLockTable; |
| 867 | } |
| 868 | |
| 869 | public FileLock lock(long position, long size, boolean shared) |
| 870 | throws IOException |
| 871 | { |
| 872 | ensureOpen(); |
| 873 | if (shared && !readable) |
| 874 | throw new NonReadableChannelException(); |
| 875 | if (!shared && !writable) |
| 876 | throw new NonWritableChannelException(); |
| 877 | FileLockImpl fli = new FileLockImpl(this, position, size, shared); |
| 878 | FileLockTable flt = fileLockTable(); |
| 879 | flt.add(fli); |
| 880 | boolean i = true; |
| 881 | int ti = -1; |
| 882 | try { |
| 883 | begin(); |
| 884 | if (!isOpen()) |
| 885 | return null; |
| 886 | ti = threads.add(); |
| 887 | int result = lock0(fd, true, position, size, shared); |
| 888 | if (result == RET_EX_LOCK) { |
| 889 | assert shared; |
| 890 | FileLockImpl fli2 = new FileLockImpl(this, position, size, |
| 891 | false); |
| 892 | flt.replace(fli, fli2); |
| 893 | return fli2; |
| 894 | } |
| 895 | if (result == INTERRUPTED || result == NO_LOCK) { |
| 896 | flt.remove(fli); |
| 897 | i = false; |
| 898 | } |
| 899 | } catch (IOException e) { |
| 900 | flt.remove(fli); |
| 901 | throw e; |
| 902 | } finally { |
| 903 | threads.remove(ti); |
| 904 | try { |
| 905 | end(i); |
| 906 | } catch (ClosedByInterruptException e) { |
| 907 | throw new FileLockInterruptionException(); |
| 908 | } |
| 909 | } |
| 910 | return fli; |
| 911 | } |
| 912 | |
| 913 | public FileLock tryLock(long position, long size, boolean shared) |
| 914 | throws IOException |
| 915 | { |
| 916 | ensureOpen(); |
| 917 | if (shared && !readable) |
| 918 | throw new NonReadableChannelException(); |
| 919 | if (!shared && !writable) |
| 920 | throw new NonWritableChannelException(); |
| 921 | FileLockImpl fli = new FileLockImpl(this, position, size, shared); |
| 922 | FileLockTable flt = fileLockTable(); |
| 923 | flt.add(fli); |
| 924 | int result = lock0(fd, false, position, size, shared); |
| 925 | if (result == NO_LOCK) { |
| 926 | flt.remove(fli); |
| 927 | return null; |
| 928 | } |
| 929 | if (result == RET_EX_LOCK) { |
| 930 | assert shared; |
| 931 | FileLockImpl fli2 = new FileLockImpl(this, position, size, |
| 932 | false); |
| 933 | flt.replace(fli, fli2); |
| 934 | return fli2; |
| 935 | } |
| 936 | return fli; |
| 937 | } |
| 938 | |
| 939 | void release(FileLockImpl fli) throws IOException { |
| 940 | ensureOpen(); |
| 941 | release0(fd, fli.position(), fli.size()); |
| 942 | assert fileLockTable != null; |
| 943 | fileLockTable.remove(fli); |
| 944 | } |
| 945 | |
| 946 | |
| 947 | // -- File lock support -- |
| 948 | |
| 949 | /** |
| 950 | * A table of FileLocks. |
| 951 | */ |
| 952 | private interface FileLockTable { |
| 953 | /** |
| 954 | * Adds a file lock to the table. |
| 955 | * |
| 956 | * @throws OverlappingFileLockException if the file lock overlaps |
| 957 | * with an existing file lock in the table |
| 958 | */ |
| 959 | void add(FileLock fl) throws OverlappingFileLockException; |
| 960 | |
| 961 | /** |
| 962 | * Remove an existing file lock from the table. |
| 963 | */ |
| 964 | void remove(FileLock fl); |
| 965 | |
| 966 | /** |
| 967 | * An implementation of this interface releases a given file lock. |
| 968 | * Used with removeAll. |
| 969 | */ |
| 970 | interface Releaser { |
| 971 | void release(FileLock fl) throws IOException; |
| 972 | } |
| 973 | |
| 974 | /** |
| 975 | * Removes all file locks from the table. |
| 976 | * <p> |
| 977 | * The Releaser#release method is invoked for each file lock before |
| 978 | * it is removed. |
| 979 | * |
| 980 | * @throws IOException if the release method throws IOException |
| 981 | */ |
| 982 | void removeAll(Releaser r) throws IOException; |
| 983 | |
| 984 | /** |
| 985 | * Replaces an existing file lock in the table. |
| 986 | */ |
| 987 | void replace(FileLock fl1, FileLock fl2); |
| 988 | } |
| 989 | |
| 990 | /** |
| 991 | * A simple file lock table that maintains a list of FileLocks obtained by a |
| 992 | * FileChannel. Use to get 1.4/5.0 behaviour. |
| 993 | */ |
| 994 | private static class SimpleFileLockTable implements FileLockTable { |
| 995 | // synchronize on list for access |
| 996 | private List<FileLock> lockList = new ArrayList<FileLock>(2); |
| 997 | |
| 998 | public SimpleFileLockTable() { |
| 999 | } |
| 1000 | |
| 1001 | private void checkList(long position, long size) |
| 1002 | throws OverlappingFileLockException |
| 1003 | { |
| 1004 | assert Thread.holdsLock(lockList); |
| 1005 | for (FileLock fl: lockList) { |
| 1006 | if (fl.overlaps(position, size)) { |
| 1007 | throw new OverlappingFileLockException(); |
| 1008 | } |
| 1009 | } |
| 1010 | } |
| 1011 | |
| 1012 | public void add(FileLock fl) throws OverlappingFileLockException { |
| 1013 | synchronized (lockList) { |
| 1014 | checkList(fl.position(), fl.size()); |
| 1015 | lockList.add(fl); |
| 1016 | } |
| 1017 | } |
| 1018 | |
| 1019 | public void remove(FileLock fl) { |
| 1020 | synchronized (lockList) { |
| 1021 | lockList.remove(fl); |
| 1022 | } |
| 1023 | } |
| 1024 | |
| 1025 | public void removeAll(Releaser releaser) throws IOException { |
| 1026 | synchronized(lockList) { |
| 1027 | Iterator<FileLock> i = lockList.iterator(); |
| 1028 | while (i.hasNext()) { |
| 1029 | FileLock fl = i.next(); |
| 1030 | releaser.release(fl); |
| 1031 | i.remove(); |
| 1032 | } |
| 1033 | } |
| 1034 | } |
| 1035 | |
| 1036 | public void replace(FileLock fl1, FileLock fl2) { |
| 1037 | synchronized (lockList) { |
| 1038 | lockList.remove(fl1); |
| 1039 | lockList.add(fl2); |
| 1040 | } |
| 1041 | } |
| 1042 | } |
| 1043 | |
| 1044 | /** |
| 1045 | * A weak reference to a FileLock. |
| 1046 | * <p> |
| 1047 | * SharedFileLockTable uses a list of file lock references to avoid keeping the |
| 1048 | * FileLock (and FileChannel) alive. |
| 1049 | */ |
| 1050 | private static class FileLockReference extends WeakReference<FileLock> { |
| 1051 | private FileKey fileKey; |
| 1052 | |
| 1053 | FileLockReference(FileLock referent, |
| 1054 | ReferenceQueue queue, |
| 1055 | FileKey key) { |
| 1056 | super(referent, queue); |
| 1057 | this.fileKey = key; |
| 1058 | } |
| 1059 | |
| 1060 | private FileKey fileKey() { |
| 1061 | return fileKey; |
| 1062 | } |
| 1063 | } |
| 1064 | |
| 1065 | /** |
| 1066 | * A file lock table that is over a system-wide map of all file locks. |
| 1067 | */ |
| 1068 | private static class SharedFileLockTable implements FileLockTable { |
| 1069 | // The system-wide map is a ConcurrentHashMap that is keyed on the FileKey. |
| 1070 | // The map value is a list of file locks represented by FileLockReferences. |
| 1071 | // All access to the list must be synchronized on the list. |
| 1072 | private static ConcurrentHashMap<FileKey, ArrayList<FileLockReference>> lockMap = |
| 1073 | new ConcurrentHashMap<FileKey, ArrayList<FileLockReference>>(); |
| 1074 | |
| 1075 | // reference queue for cleared refs |
| 1076 | private static ReferenceQueue queue = new ReferenceQueue(); |
| 1077 | |
| 1078 | // the enclosing file channel |
| 1079 | private FileChannelImpl fci; |
| 1080 | |
| 1081 | // File key for the file that this channel is connected to |
| 1082 | private FileKey fileKey; |
| 1083 | |
| 1084 | public SharedFileLockTable(FileChannelImpl fci) { |
| 1085 | this.fci = fci; |
| 1086 | this.fileKey = FileKey.create(fci.fd); |
| 1087 | } |
| 1088 | |
| 1089 | public void add(FileLock fl) throws OverlappingFileLockException { |
| 1090 | ArrayList<FileLockReference> list = lockMap.get(fileKey); |
| 1091 | |
| 1092 | for (;;) { |
| 1093 | |
| 1094 | // The key isn't in the map so we try to create it atomically |
| 1095 | if (list == null) { |
| 1096 | list = new ArrayList<FileLockReference>(2); |
| 1097 | ArrayList<FileLockReference> prev; |
| 1098 | synchronized (list) { |
| 1099 | prev = lockMap.putIfAbsent(fileKey, list); |
| 1100 | if (prev == null) { |
| 1101 | // we successfully created the key so we add the file lock |
| 1102 | list.add(new FileLockReference(fl, queue, fileKey)); |
| 1103 | break; |
| 1104 | } |
| 1105 | } |
| 1106 | // someone else got there first |
| 1107 | list = prev; |
| 1108 | } |
| 1109 | |
| 1110 | // There is already a key. It is possible that some other thread |
| 1111 | // is removing it so we re-fetch the value from the map. If it |
| 1112 | // hasn't changed then we check the list for overlapping locks |
| 1113 | // and add the new lock to the list. |
| 1114 | synchronized (list) { |
| 1115 | ArrayList<FileLockReference> current = lockMap.get(fileKey); |
| 1116 | if (list == current) { |
| 1117 | checkList(list, fl.position(), fl.size()); |
| 1118 | list.add(new FileLockReference(fl, queue, fileKey)); |
| 1119 | break; |
| 1120 | } |
| 1121 | list = current; |
| 1122 | } |
| 1123 | |
| 1124 | } |
| 1125 | |
| 1126 | // process any stale entries pending in the reference queue |
| 1127 | removeStaleEntries(); |
| 1128 | } |
| 1129 | |
| 1130 | private void removeKeyIfEmpty(FileKey fk, ArrayList<FileLockReference> list) { |
| 1131 | assert Thread.holdsLock(list); |
| 1132 | assert lockMap.get(fk) == list; |
| 1133 | if (list.isEmpty()) { |
| 1134 | lockMap.remove(fk); |
| 1135 | } |
| 1136 | } |
| 1137 | |
| 1138 | public void remove(FileLock fl) { |
| 1139 | assert fl != null; |
| 1140 | |
| 1141 | // the lock must exist so the list of locks must be present |
| 1142 | ArrayList<FileLockReference> list = lockMap.get(fileKey); |
| 1143 | assert list != null; |
| 1144 | |
| 1145 | synchronized (list) { |
| 1146 | int index = 0; |
| 1147 | while (index < list.size()) { |
| 1148 | FileLockReference ref = list.get(index); |
| 1149 | FileLock lock = ref.get(); |
| 1150 | if (lock == fl) { |
| 1151 | assert (lock != null) && (lock.channel() == fci); |
| 1152 | ref.clear(); |
| 1153 | list.remove(index); |
| 1154 | break; |
| 1155 | } |
| 1156 | index++; |
| 1157 | } |
| 1158 | } |
| 1159 | } |
| 1160 | |
| 1161 | public void removeAll(Releaser releaser) throws IOException { |
| 1162 | ArrayList<FileLockReference> list = lockMap.get(fileKey); |
| 1163 | if (list != null) { |
| 1164 | synchronized (list) { |
| 1165 | int index = 0; |
| 1166 | while (index < list.size()) { |
| 1167 | FileLockReference ref = list.get(index); |
| 1168 | FileLock lock = ref.get(); |
| 1169 | |
| 1170 | // remove locks obtained by this channel |
| 1171 | if (lock != null && lock.channel() == fci) { |
| 1172 | // invoke the releaser to invalidate/release the lock |
| 1173 | releaser.release(lock); |
| 1174 | |
| 1175 | // remove the lock from the list |
| 1176 | ref.clear(); |
| 1177 | list.remove(index); |
| 1178 | } else { |
| 1179 | index++; |
| 1180 | } |
| 1181 | } |
| 1182 | |
| 1183 | // once the lock list is empty we remove it from the map |
| 1184 | removeKeyIfEmpty(fileKey, list); |
| 1185 | } |
| 1186 | } |
| 1187 | } |
| 1188 | |
| 1189 | public void replace(FileLock fromLock, FileLock toLock) { |
| 1190 | // the lock must exist so there must be a list |
| 1191 | ArrayList<FileLockReference> list = lockMap.get(fileKey); |
| 1192 | assert list != null; |
| 1193 | |
| 1194 | synchronized (list) { |
| 1195 | for (int index=0; index<list.size(); index++) { |
| 1196 | FileLockReference ref = list.get(index); |
| 1197 | FileLock lock = ref.get(); |
| 1198 | if (lock == fromLock) { |
| 1199 | ref.clear(); |
| 1200 | list.set(index, new FileLockReference(toLock, queue, fileKey)); |
| 1201 | break; |
| 1202 | } |
| 1203 | } |
| 1204 | } |
| 1205 | } |
| 1206 | |
| 1207 | // Check for overlapping file locks |
| 1208 | private void checkList(List<FileLockReference> list, long position, long size) |
| 1209 | throws OverlappingFileLockException |
| 1210 | { |
| 1211 | assert Thread.holdsLock(list); |
| 1212 | for (FileLockReference ref: list) { |
| 1213 | FileLock fl = ref.get(); |
| 1214 | if (fl != null && fl.overlaps(position, size)) |
| 1215 | throw new OverlappingFileLockException(); |
| 1216 | } |
| 1217 | } |
| 1218 | |
| 1219 | // Process the reference queue |
| 1220 | private void removeStaleEntries() { |
| 1221 | FileLockReference ref; |
| 1222 | while ((ref = (FileLockReference)queue.poll()) != null) { |
| 1223 | FileKey fk = ref.fileKey(); |
| 1224 | ArrayList<FileLockReference> list = lockMap.get(fk); |
| 1225 | if (list != null) { |
| 1226 | synchronized (list) { |
| 1227 | list.remove(ref); |
| 1228 | removeKeyIfEmpty(fk, list); |
| 1229 | } |
| 1230 | } |
| 1231 | } |
| 1232 | } |
| 1233 | } |
| 1234 | |
| 1235 | // -- Native methods -- |
| 1236 | |
| 1237 | // Grabs a file lock |
| 1238 | native int lock0(FileDescriptor fd, boolean blocking, long pos, long size, |
| 1239 | boolean shared) throws IOException; |
| 1240 | |
| 1241 | // Releases a file lock |
| 1242 | native void release0(FileDescriptor fd, long pos, long size) |
| 1243 | throws IOException; |
| 1244 | |
| 1245 | // Creates a new mapping |
| 1246 | private native long map0(int prot, long position, long length) |
| 1247 | throws IOException; |
| 1248 | |
| 1249 | // Removes an existing mapping |
| 1250 | private static native int unmap0(long address, long length); |
| 1251 | |
| 1252 | // Forces output to device |
| 1253 | private native int force0(FileDescriptor fd, boolean metaData); |
| 1254 | |
| 1255 | // Truncates a file |
| 1256 | private native int truncate0(FileDescriptor fd, long size); |
| 1257 | |
| 1258 | // Transfers from src to dst, or returns -2 if kernel can't do that |
| 1259 | private native long transferTo0(int src, long position, long count, int dst); |
| 1260 | |
| 1261 | // Sets or reports this file's position |
| 1262 | // If offset is -1, the current position is returned |
| 1263 | // otherwise the position is set to offset |
| 1264 | private native long position0(FileDescriptor fd, long offset); |
| 1265 | |
| 1266 | // Reports this file's size |
| 1267 | private native long size0(FileDescriptor fd); |
| 1268 | |
| 1269 | // Caches fieldIDs |
| 1270 | private static native long initIDs(); |
| 1271 | |
| 1272 | static { |
| 1273 | Util.load(); |
| 1274 | allocationGranularity = initIDs(); |
| 1275 | nd = new FileDispatcher(); |
| 1276 | isAMappedBufferField = Reflect.lookupField("java.nio.MappedByteBuffer", |
| 1277 | "isAMappedBuffer"); |
| 1278 | } |
| 1279 | |
| 1280 | } |