| /* |
| * Copyright (c) 2000, 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.spi; |
| |
| import java.nio.channels.*; |
| |
| |
| /** |
| * Base implementation class for selection keys. |
| * |
| * <p> This class tracks the validity of the key and implements cancellation. |
| * |
| * @author Mark Reinhold |
| * @author JSR-51 Expert Group |
| * @since 1.4 |
| */ |
| |
| public abstract class AbstractSelectionKey |
| extends SelectionKey |
| { |
| |
| /** |
| * Initializes a new instance of this class. |
| */ |
| protected AbstractSelectionKey() { } |
| |
| private volatile boolean valid = true; |
| |
| public final boolean isValid() { |
| return valid; |
| } |
| |
| void invalidate() { // package-private |
| valid = false; |
| } |
| |
| /** |
| * Cancels this key. |
| * |
| * <p> If this key has not yet been cancelled then it is added to its |
| * selector's cancelled-key set while synchronized on that set. </p> |
| */ |
| public final void cancel() { |
| // Synchronizing "this" to prevent this key from getting canceled |
| // multiple times by different threads, which might cause race |
| // condition between selector's select() and channel's close(). |
| synchronized (this) { |
| if (valid) { |
| valid = false; |
| ((AbstractSelector)selector()).cancel(this); |
| } |
| } |
| } |
| } |