--- /dev/null Thu Jan 01 00:00:00 1970 +0000
+++ b/src/java.base/share/classes/sun/nio/ch/AsynchronousFileChannelImpl.java Tue Sep 12 19:03:39 2017 +0200
@@ -0,0 +1,253 @@
+/*
+ * Copyright (c) 2008, 2009, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation. Oracle designates this
+ * particular file as subject to the "Classpath" exception as provided
+ * by Oracle in the LICENSE file that accompanied this code.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ */
+
+package sun.nio.ch;
+
+import java.nio.ByteBuffer;
+import java.nio.channels.*;
+import java.util.concurrent.ExecutorService;
+import java.util.concurrent.Future;
+import java.util.concurrent.locks.*;
+import java.io.FileDescriptor;
+import java.io.IOException;
+
+/**
+ * Base implementation of AsynchronousFileChannel.
+ */
+
+abstract class AsynchronousFileChannelImpl
+ extends AsynchronousFileChannel
+{
+ // close support
+ protected final ReadWriteLock closeLock = new ReentrantReadWriteLock();
+ protected volatile boolean closed;
+
+ // file descriptor
+ protected final FileDescriptor fdObj;
+
+ // indicates if open for reading/writing
+ protected final boolean reading;
+ protected final boolean writing;
+
+ // associated Executor
+ protected final ExecutorService executor;
+
+ protected AsynchronousFileChannelImpl(FileDescriptor fdObj,
+ boolean reading,
+ boolean writing,
+ ExecutorService executor)
+ {
+ this.fdObj = fdObj;
+ this.reading = reading;
+ this.writing = writing;
+ this.executor = executor;
+ }
+
+ final ExecutorService executor() {
+ return executor;
+ }
+
+ @Override
+ public final boolean isOpen() {
+ return !closed;
+ }
+
+ /**
+ * Marks the beginning of an I/O operation.
+ *
+ * @throws ClosedChannelException If channel is closed
+ */
+ protected final void begin() throws IOException {
+ closeLock.readLock().lock();
+ if (closed)
+ throw new ClosedChannelException();
+ }
+
+ /**
+ * Marks the end of an I/O operation.
+ */
+ protected final void end() {
+ closeLock.readLock().unlock();
+ }
+
+ /**
+ * Marks end of I/O operation
+ */
+ protected final void end(boolean completed) throws IOException {
+ end();
+ if (!completed && !isOpen())
+ throw new AsynchronousCloseException();
+ }
+
+ // -- file locking --
+
+ abstract <A> Future<FileLock> implLock(long position,
+ long size,
+ boolean shared,
+ A attachment,
+ CompletionHandler<FileLock,? super A> handler);
+
+ @Override
+ public final Future<FileLock> lock(long position,
+ long size,
+ boolean shared)
+
+ {
+ return implLock(position, size, shared, null, null);
+ }
+
+ @Override
+ public final <A> void lock(long position,
+ long size,
+ boolean shared,
+ A attachment,
+ CompletionHandler<FileLock,? super A> handler)
+ {
+ if (handler == null)
+ throw new NullPointerException("'handler' is null");
+ implLock(position, size, shared, attachment, handler);
+ }
+
+ private volatile FileLockTable fileLockTable;
+
+ final void ensureFileLockTableInitialized() throws IOException {
+ if (fileLockTable == null) {
+ synchronized (this) {
+ if (fileLockTable == null) {
+ fileLockTable = FileLockTable.newSharedFileLockTable(this, fdObj);
+ }
+ }
+ }
+ }
+
+ final void invalidateAllLocks() throws IOException {
+ if (fileLockTable != null) {
+ for (FileLock fl: fileLockTable.removeAll()) {
+ synchronized (fl) {
+ if (fl.isValid()) {
+ FileLockImpl fli = (FileLockImpl)fl;
+ implRelease(fli);
+ fli.invalidate();
+ }
+ }
+ }
+ }
+ }
+
+ /**
+ * Adds region to lock table
+ */
+ protected final FileLockImpl addToFileLockTable(long position, long size, boolean shared) {
+ final FileLockImpl fli;
+ try {
+ // like begin() but returns null instead of exception
+ closeLock.readLock().lock();
+ if (closed)
+ return null;
+
+ try {
+ ensureFileLockTableInitialized();
+ } catch (IOException x) {
+ // should not happen
+ throw new AssertionError(x);
+ }
+ fli = new FileLockImpl(this, position, size, shared);
+ // may throw OverlappedFileLockException
+ fileLockTable.add(fli);
+ } finally {
+ end();
+ }
+ return fli;
+ }
+
+ protected final void removeFromFileLockTable(FileLockImpl fli) {
+ fileLockTable.remove(fli);
+ }
+
+ /**
+ * Releases the given file lock.
+ */
+ protected abstract void implRelease(FileLockImpl fli) throws IOException;
+
+ /**
+ * Invoked by FileLockImpl to release the given file lock and remove it
+ * from the lock table.
+ */
+ final void release(FileLockImpl fli) throws IOException {
+ try {
+ begin();
+ implRelease(fli);
+ removeFromFileLockTable(fli);
+ } finally {
+ end();
+ }
+ }
+
+
+ // -- reading and writing --
+
+ abstract <A> Future<Integer> implRead(ByteBuffer dst,
+ long position,
+ A attachment,
+ CompletionHandler<Integer,? super A> handler);
+
+ @Override
+ public final Future<Integer> read(ByteBuffer dst, long position) {
+ return implRead(dst, position, null, null);
+ }
+
+ @Override
+ public final <A> void read(ByteBuffer dst,
+ long position,
+ A attachment,
+ CompletionHandler<Integer,? super A> handler)
+ {
+ if (handler == null)
+ throw new NullPointerException("'handler' is null");
+ implRead(dst, position, attachment, handler);
+ }
+
+ abstract <A> Future<Integer> implWrite(ByteBuffer src,
+ long position,
+ A attachment,
+ CompletionHandler<Integer,? super A> handler);
+
+
+ @Override
+ public final Future<Integer> write(ByteBuffer src, long position) {
+ return implWrite(src, position, null, null);
+ }
+
+ @Override
+ public final <A> void write(ByteBuffer src,
+ long position,
+ A attachment,
+ CompletionHandler<Integer,? super A> handler)
+ {
+ if (handler == null)
+ throw new NullPointerException("'handler' is null");
+ implWrite(src, position, attachment, handler);
+ }
+}