/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
*
* 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
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*/
/**
* 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. </p>
*/
protected AbstractSelectionKey() { }
private volatile boolean valid = true;
public final boolean isValid() {
return valid;
}
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;
}
}
}
}