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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 | +} | |