io.undertow.util.ConcurrentDirectDeque Maven / Gradle / Ivy
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* Copyright 2014 Red Hat, Inc., and individual contributors
* as indicated by the @author tags.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package io.undertow.util;
import java.lang.reflect.Constructor;
import java.util.AbstractCollection;
import java.util.Deque;
/**
* A concurrent deque that allows direct item removal without traversal.
*
* @author Jason T. Greene
*/
public abstract class ConcurrentDirectDeque extends AbstractCollection implements Deque, java.io.Serializable {
private static final Constructor CONSTRUCTOR;
static {
boolean fast = false;
try {
new FastConcurrentDirectDeque();
fast = true;
} catch (Throwable t) {
}
Class klazz = fast ? FastConcurrentDirectDeque.class : PortableConcurrentDirectDeque.class;
try {
CONSTRUCTOR = klazz.getConstructor();
} catch (NoSuchMethodException e) {
throw new NoSuchMethodError(e.getMessage());
}
}
public static ConcurrentDirectDeque newInstance() {
try {
return CONSTRUCTOR.newInstance();
} catch (Exception e) {
throw new IllegalStateException(e);
}
}
public abstract Object offerFirstAndReturnToken(E e);
public abstract Object offerLastAndReturnToken(E e);
public abstract void removeToken(Object token);
}