8187443: Forest Consolidation: Move files to unified layout

Reviewed-by: darcy, ihse

src/java.base/share/classes/java/nio/channels/AsynchronousChannel.java

@@ -0,0 +1,117 @@
+/*
+ * Copyright (c) 2007, 2013, 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 java.nio.channels;
+
+import java.io.IOException;
+import java.util.concurrent.Future;  // javadoc
+
+/**
+ * A channel that supports asynchronous I/O operations. Asynchronous I/O
+ * operations will usually take one of two forms:
+ *
+ * <ol>
+ * <li><pre>{@link Future}&lt;V&gt; <em>operation</em>(<em>...</em>)</pre></li>
+ * <li><pre>void <em>operation</em>(<em>...</em> A attachment, {@link
+ *   CompletionHandler}&lt;V,? super A&gt; handler)</pre></li>
+ * </ol>
+ *
+ * where <i>operation</i> is the name of the I/O operation (read or write for
+ * example), <i>V</i> is the result type of the I/O operation, and <i>A</i> is
+ * the type of an object attached to the I/O operation to provide context when
+ * consuming the result. The attachment is important for cases where a
+ * <em>state-less</em> {@code CompletionHandler} is used to consume the result
+ * of many I/O operations.
+ *
+ * <p> In the first form, the methods defined by the {@link Future Future}
+ * interface may be used to check if the operation has completed, wait for its
+ * completion, and to retrieve the result. In the second form, a {@link
+ * CompletionHandler} is invoked to consume the result of the I/O operation when
+ * it completes or fails.
+ *
+ * <p> A channel that implements this interface is <em>asynchronously
+ * closeable</em>: If an I/O operation is outstanding on the channel and the
+ * channel's {@link #close close} method is invoked, then the I/O operation
+ * fails with the exception {@link AsynchronousCloseException}.
+ *
+ * <p> Asynchronous channels are safe for use by multiple concurrent threads.
+ * Some channel implementations may support concurrent reading and writing, but
+ * may not allow more than one read and one write operation to be outstanding at
+ * any given time.
+ *
+ * <h2>Cancellation</h2>
+ *
+ * <p> The {@code Future} interface defines the {@link Future#cancel cancel}
+ * method to cancel execution. This causes all threads waiting on the result of
+ * the I/O operation to throw {@link java.util.concurrent.CancellationException}.
+ * Whether the underlying I/O operation can be cancelled is highly implementation
+ * specific and therefore not specified. Where cancellation leaves the channel,
+ * or the entity to which it is connected, in an inconsistent state, then the
+ * channel is put into an implementation specific <em>error state</em> that
+ * prevents further attempts to initiate I/O operations that are <i>similar</i>
+ * to the operation that was cancelled. For example, if a read operation is
+ * cancelled but the implementation cannot guarantee that bytes have not been
+ * read from the channel then it puts the channel into an error state; further
+ * attempts to initiate a {@code read} operation cause an unspecified runtime
+ * exception to be thrown. Similarly, if a write operation is cancelled but the
+ * implementation cannot guarantee that bytes have not been written to the
+ * channel then subsequent attempts to initiate a {@code write} will fail with
+ * an unspecified runtime exception.
+ *
+ * <p> Where the {@link Future#cancel cancel} method is invoked with the {@code
+ * mayInterruptIfRunning} parameter set to {@code true} then the I/O operation
+ * may be interrupted by closing the channel. In that case all threads waiting
+ * on the result of the I/O operation throw {@code CancellationException} and
+ * any other I/O operations outstanding on the channel complete with the
+ * exception {@link AsynchronousCloseException}.
+ *
+ * <p> Where the {@code cancel} method is invoked to cancel read or write
+ * operations then it is recommended that all buffers used in the I/O operations
+ * be discarded or care taken to ensure that the buffers are not accessed while
+ * the channel remains open.
+ *
+ *  @since 1.7
+ */
+
+public interface AsynchronousChannel
+    extends Channel
+{
+    /**
+     * Closes this channel.
+     *
+     * <p> Any outstanding asynchronous operations upon this channel will
+     * complete with the exception {@link AsynchronousCloseException}. After a
+     * channel is closed, further attempts to initiate asynchronous I/O
+     * operations complete immediately with cause {@link ClosedChannelException}.
+     *
+     * <p>  This method otherwise behaves exactly as specified by the {@link
+     * Channel} interface.
+     *
+     * @throws  IOException
+     *          If an I/O error occurs
+     */
+    @Override
+    void close() throws IOException;
+}