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| 1 | /* | ||
| 2 | * Copyright (c) 2008, 2009, 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.nio.channels.*; | ||
| 29 | import java.util.concurrent.*; | ||
| 30 | import java.nio.ByteBuffer; | ||
| 31 | import java.security.AccessController; | ||
| 32 | import java.security.PrivilegedAction; | ||
| 33 | import java.io.FileDescriptor; | ||
| 34 | import java.io.IOException; | ||
| 35 | |||
| 36 | /** | ||
| 37 | * "Portable" implementation of AsynchronousFileChannel for use on operating | ||
| 38 | * systems that don't support asynchronous file I/O. | ||
| 39 | */ | ||
| 40 | |||
| 41 | public class SimpleAsynchronousFileChannelImpl | ||
| 42 | extends AsynchronousFileChannelImpl | ||
| 43 | { | ||
| 44 | // lazy initialization of default thread pool for file I/O | ||
| 45 | private static class DefaultExecutorHolder { | ||
| 46 | static final ExecutorService defaultExecutor = | ||
| 47 | ThreadPool.createDefault().executor(); | ||
| 48 | } | ||
| 49 | |||
| 50 | // Used to make native read and write calls | ||
| 51 | private static final FileDispatcher nd = new FileDispatcherImpl(); | ||
| 52 | |||
| 53 | // Thread-safe set of IDs of native threads, for signalling | ||
| 54 | private final NativeThreadSet threads = new NativeThreadSet(2); | ||
| 55 | |||
| 56 | |||
| 57 | SimpleAsynchronousFileChannelImpl(FileDescriptor fdObj, | ||
| 58 | boolean reading, | ||
| 59 | boolean writing, | ||
| 60 | ExecutorService executor) | ||
| 61 | { | ||
| 62 | super(fdObj, reading, writing, executor); | ||
| 63 | } | ||
| 64 | |||
| 65 | public static AsynchronousFileChannel open(FileDescriptor fdo, | ||
| 66 | boolean reading, | ||
| 67 | boolean writing, | ||
| 68 | ThreadPool pool) | ||
| 69 | { | ||
| 70 | // Executor is either default or based on pool parameters | ||
| 71 | ExecutorService executor = (pool == null) ? | ||
| 72 | DefaultExecutorHolder.defaultExecutor : pool.executor(); | ||
| 73 | return new SimpleAsynchronousFileChannelImpl(fdo, reading, writing, executor); | ||
| 74 | } | ||
| 75 | |||
| 76 | @Override | ||
| 77 | public void close() throws IOException { | ||
| 78 | // mark channel as closed | ||
| 79 | synchronized (fdObj) { | ||
| 80 | if (closed) | ||
| 81 | return; // already closed | ||
| 82 | closed = true; | ||
| 83 | // from this point on, if another thread invokes the begin() method | ||
| 84 | // then it will throw ClosedChannelException | ||
| 85 | } | ||
| 86 | |||
| 87 | // Invalidate and release any locks that we still hold | ||
| 88 | invalidateAllLocks(); | ||
| 89 | |||
| 90 | // signal any threads blocked on this channel | ||
| 91 | nd.preClose(fdObj); | ||
| 92 | threads.signalAndWait(); | ||
| 93 | |||
| 94 | // wait until all async I/O operations have completely gracefully | ||
| 95 | closeLock.writeLock().lock(); | ||
| 96 | try { | ||
| 97 | // do nothing | ||
| 98 | } finally { | ||
| 99 | closeLock.writeLock().unlock(); | ||
| 100 | } | ||
| 101 | |||
| 102 | // close file | ||
| 103 | nd.close(fdObj); | ||
| 104 | } | ||
| 105 | |||
| 106 | @Override | ||
| 107 | public long size() throws IOException { | ||
| 108 | int ti = threads.add(); | ||
| 109 | try { | ||
| 110 | long n = 0L; | ||
| 111 | try { | ||
| 112 | begin(); | ||
| 113 | do { | ||
| 114 | n = nd.size(fdObj); | ||
| 115 | } while ((n == IOStatus.INTERRUPTED) && isOpen()); | ||
| 116 | return n; | ||
| 117 | } finally { | ||
| 118 | end(n >= 0L); | ||
| 119 | } | ||
| 120 | } finally { | ||
| 121 | threads.remove(ti); | ||
| 122 | } | ||
| 123 | } | ||
| 124 | |||
| 125 | @Override | ||
| 126 | public AsynchronousFileChannel truncate(long size) throws IOException { | ||
| 127 | if (size < 0L) | ||
| 128 | throw new IllegalArgumentException("Negative size"); | ||
| 129 | if (!writing) | ||
| 130 | throw new NonWritableChannelException(); | ||
| 131 | int ti = threads.add(); | ||
| 132 | try { | ||
| 133 | long n = 0L; | ||
| 134 | try { | ||
| 135 | begin(); | ||
| 136 | do { | ||
| 137 | n = nd.size(fdObj); | ||
| 138 | } while ((n == IOStatus.INTERRUPTED) && isOpen()); | ||
| 139 | |||
| 140 | // truncate file if 'size' less than current size | ||
| 141 | if (size < n && isOpen()) { | ||
| 142 | do { | ||
| 143 | n = nd.truncate(fdObj, size); | ||
| 144 | } while ((n == IOStatus.INTERRUPTED) && isOpen()); | ||
| 145 | } | ||
| 146 | return this; | ||
| 147 | } finally { | ||
| 148 | end(n > 0); | ||
| 149 | } | ||
| 150 | } finally { | ||
| 151 | threads.remove(ti); | ||
| 152 | } | ||
| 153 | } | ||
| 154 | |||
| 155 | @Override | ||
| 156 | public void force(boolean metaData) throws IOException { | ||
| 157 | int ti = threads.add(); | ||
| 158 | try { | ||
| 159 | int n = 0; | ||
| 160 | try { | ||
| 161 | begin(); | ||
| 162 | do { | ||
| 163 | n = nd.force(fdObj, metaData); | ||
| 164 | } while ((n == IOStatus.INTERRUPTED) && isOpen()); | ||
| 165 | } finally { | ||
| 166 | end(n >= 0); | ||
| 167 | } | ||
| 168 | } finally { | ||
| 169 | threads.remove(ti); | ||
| 170 | } | ||
| 171 | } | ||
| 172 | |||
| 173 | @Override | ||
| 174 | <A> Future<FileLock> implLock(final long position, | ||
| 175 | final long size, | ||
| 176 | final boolean shared, | ||
| 177 | final A attachment, | ||
| 178 | final CompletionHandler<FileLock,? super A> handler) | ||
| 179 | { | ||
| 180 | if (shared && !reading) | ||
| 181 | throw new NonReadableChannelException(); | ||
| 182 | if (!shared && !writing) | ||
| 183 | throw new NonWritableChannelException(); | ||
| 184 | |||
| 185 | // add to lock table | ||
| 186 | final FileLockImpl fli = addToFileLockTable(position, size, shared); | ||
| 187 | if (fli == null) { | ||
| 188 | Throwable exc = new ClosedChannelException(); | ||
| 189 | if (handler == null) | ||
| 190 | return CompletedFuture.withFailure(exc); | ||
| 191 | Invoker.invokeIndirectly(handler, attachment, null, exc, executor); | ||
| 192 | return null; | ||
| 193 | } | ||
| 194 | |||
| 195 | final PendingFuture<FileLock,A> result = (handler == null) ? | ||
| 196 | new PendingFuture<FileLock,A>(this) : null; | ||
| 197 | Runnable task = new Runnable() { | ||
| 198 | public void run() { | ||
| 199 | Throwable exc = null; | ||
| 200 | |||
| 201 | int ti = threads.add(); | ||
| 202 | try { | ||
| 203 | int n; | ||
| 204 | try { | ||
| 205 | begin(); | ||
| 206 | do { | ||
| 207 | n = nd.lock(fdObj, true, position, size, shared); | ||
| 208 | } while ((n == FileDispatcher.INTERRUPTED) && isOpen()); | ||
| 209 | if (n != FileDispatcher.LOCKED || !isOpen()) { | ||
| 210 | throw new AsynchronousCloseException(); | ||
| 211 | } | ||
| 212 | } catch (IOException x) { | ||
| 213 | removeFromFileLockTable(fli); | ||
| 214 | if (!isOpen()) | ||
| 215 | x = new AsynchronousCloseException(); | ||
| 216 | exc = x; | ||
| 217 | } finally { | ||
| 218 | end(); | ||
| 219 | } | ||
| 220 | } finally { | ||
| 221 | threads.remove(ti); | ||
| 222 | } | ||
| 223 | if (handler == null) { | ||
| 224 | result.setResult(fli, exc); | ||
| 225 | } else { | ||
| 226 | Invoker.invokeUnchecked(handler, attachment, fli, exc); | ||
| 227 | } | ||
| 228 | } | ||
| 229 | }; | ||
| 230 | boolean executed = false; | ||
| 231 | try { | ||
| 232 | executor.execute(task); | ||
| 233 | executed = true; | ||
| 234 | } finally { | ||
| 235 | if (!executed) { | ||
| 236 | // rollback | ||
| 237 | removeFromFileLockTable(fli); | ||
| 238 | } | ||
| 239 | } | ||
| 240 | return result; | ||
| 241 | } | ||
| 242 | |||
| 243 | @Override | ||
| 244 | public FileLock tryLock(long position, long size, boolean shared) | ||
| 245 | throws IOException | ||
| 246 | { | ||
| 247 | if (shared && !reading) | ||
| 248 | throw new NonReadableChannelException(); | ||
| 249 | if (!shared && !writing) | ||
| 250 | throw new NonWritableChannelException(); | ||
| 251 | |||
| 252 | // add to lock table | ||
| 253 | FileLockImpl fli = addToFileLockTable(position, size, shared); | ||
| 254 | if (fli == null) | ||
| 255 | throw new ClosedChannelException(); | ||
| 256 | |||
| 257 | int ti = threads.add(); | ||
| 258 | boolean gotLock = false; | ||
| 259 | try { | ||
| 260 | begin(); | ||
| 261 | int n; | ||
| 262 | do { | ||
| 263 | n = nd.lock(fdObj, false, position, size, shared); | ||
| 264 | } while ((n == FileDispatcher.INTERRUPTED) && isOpen()); | ||
| 265 | if (n == FileDispatcher.LOCKED && isOpen()) { | ||
| 266 | gotLock = true; | ||
| 267 | return fli; // lock acquired | ||
| 268 | } | ||
| 269 | if (n == FileDispatcher.NO_LOCK) | ||
| 270 | return null; // locked by someone else | ||
| 271 | if (n == FileDispatcher.INTERRUPTED) | ||
| 272 | throw new AsynchronousCloseException(); | ||
| 273 | // should not get here | ||
| 274 | throw new AssertionError(); | ||
| 275 | } finally { | ||
| 276 | if (!gotLock) | ||
| 277 | removeFromFileLockTable(fli); | ||
| 278 | end(); | ||
| 279 | threads.remove(ti); | ||
| 280 | } | ||
| 281 | } | ||
| 282 | |||
| 283 | @Override | ||
| 284 | protected void implRelease(FileLockImpl fli) throws IOException { | ||
| 285 | nd.release(fdObj, fli.position(), fli.size()); | ||
| 286 | } | ||
| 287 | |||
| 288 | @Override | ||
| 289 | <A> Future<Integer> implRead(final ByteBuffer dst, | ||
| 290 | final long position, | ||
| 291 | final A attachment, | ||
| 292 | final CompletionHandler<Integer,? super A> handler) | ||
| 293 | { | ||
| 294 | if (position < 0) | ||
| 295 | throw new IllegalArgumentException("Negative position"); | ||
| 296 | if (!reading) | ||
| 297 | throw new NonReadableChannelException(); | ||
| 298 | if (dst.isReadOnly()) | ||
| 299 | throw new IllegalArgumentException("Read-only buffer"); | ||
| 300 | |||
| 301 | // complete immediately if channel closed or no space remaining | ||
| 302 | if (!isOpen() || (dst.remaining() == 0)) { | ||
| 303 | Throwable exc = (isOpen()) ? null : new ClosedChannelException(); | ||
| 304 | if (handler == null) | ||
| 305 | return CompletedFuture.withResult(0, exc); | ||
| 306 | Invoker.invokeIndirectly(handler, attachment, 0, exc, executor); | ||
| 307 | return null; | ||
| 308 | } | ||
| 309 | |||
| 310 | final PendingFuture<Integer,A> result = (handler == null) ? | ||
| 311 | new PendingFuture<Integer,A>(this) : null; | ||
| 312 | Runnable task = new Runnable() { | ||
| 313 | public void run() { | ||
| 314 | int n = 0; | ||
| 315 | Throwable exc = null; | ||
| 316 | |||
| 317 | int ti = threads.add(); | ||
| 318 | try { | ||
| 319 | begin(); | ||
| 320 | do { | ||
| 321 | n = IOUtil.read(fdObj, dst, position, nd, null); | ||
| 322 | } while ((n == IOStatus.INTERRUPTED) && isOpen()); | ||
| 323 | if (n < 0 && !isOpen()) | ||
| 324 | throw new AsynchronousCloseException(); | ||
| 325 | } catch (IOException x) { | ||
| 326 | if (!isOpen()) | ||
| 327 | x = new AsynchronousCloseException(); | ||
| 328 | exc = x; | ||
| 329 | } finally { | ||
| 330 | end(); | ||
| 331 | threads.remove(ti); | ||
| 332 | } | ||
| 333 | if (handler == null) { | ||
| 334 | result.setResult(n, exc); | ||
| 335 | } else { | ||
| 336 | Invoker.invokeUnchecked(handler, attachment, n, exc); | ||
| 337 | } | ||
| 338 | } | ||
| 339 | }; | ||
| 340 | executor.execute(task); | ||
| 341 | return result; | ||
| 342 | } | ||
| 343 | |||
| 344 | @Override | ||
| 345 | <A> Future<Integer> implWrite(final ByteBuffer src, | ||
| 346 | final long position, | ||
| 347 | final A attachment, | ||
| 348 | final CompletionHandler<Integer,? super A> handler) | ||
| 349 | { | ||
| 350 | if (position < 0) | ||
| 351 | throw new IllegalArgumentException("Negative position"); | ||
| 352 | if (!writing) | ||
| 353 | throw new NonWritableChannelException(); | ||
| 354 | |||
| 355 | // complete immediately if channel is closed or no bytes remaining | ||
| 356 | if (!isOpen() || (src.remaining() == 0)) { | ||
| 357 | Throwable exc = (isOpen()) ? null : new ClosedChannelException(); | ||
| 358 | if (handler == null) | ||
| 359 | return CompletedFuture.withResult(0, exc); | ||
| 360 | Invoker.invokeIndirectly(handler, attachment, 0, exc, executor); | ||
| 361 | return null; | ||
| 362 | } | ||
| 363 | |||
| 364 | final PendingFuture<Integer,A> result = (handler == null) ? | ||
| 365 | new PendingFuture<Integer,A>(this) : null; | ||
| 366 | Runnable task = new Runnable() { | ||
| 367 | public void run() { | ||
| 368 | int n = 0; | ||
| 369 | Throwable exc = null; | ||
| 370 | |||
| 371 | int ti = threads.add(); | ||
| 372 | try { | ||
| 373 | begin(); | ||
| 374 | do { | ||
| 375 | n = IOUtil.write(fdObj, src, position, nd, null); | ||
| 376 | } while ((n == IOStatus.INTERRUPTED) && isOpen()); | ||
| 377 | if (n < 0 && !isOpen()) | ||
| 378 | throw new AsynchronousCloseException(); | ||
| 379 | } catch (IOException x) { | ||
| 380 | if (!isOpen()) | ||
| 381 | x = new AsynchronousCloseException(); | ||
| 382 | exc = x; | ||
| 383 | } finally { | ||
| 384 | end(); | ||
| 385 | threads.remove(ti); | ||
| 386 | } | ||
| 387 | if (handler == null) { | ||
| 388 | result.setResult(n, exc); | ||
| 389 | } else { | ||
| 390 | Invoker.invokeUnchecked(handler, attachment, n, exc); | ||
| 391 | } | ||
| 392 | } | ||
| 393 | }; | ||
| 394 | executor.execute(task); | ||
| 395 | return result; | ||
| 396 | } | ||
| 397 | } | ||