57 lines
2.0 KiB
Java
57 lines
2.0 KiB
Java
/*
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* Copyright 2014 The Netty Project
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*
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* The Netty Project licenses this file to you under the Apache License,
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* version 2.0 (the "License"); you may not use this file except in compliance
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* with the License. You may obtain a copy of the License at:
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*
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* http://www.apache.org/licenses/LICENSE-2.0
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*
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* Unless required by applicable law or agreed to in writing, software
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* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
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* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
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* License for the specific language governing permissions and limitations
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* under the License.
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*/
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package io.netty.util.internal;
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import io.netty.util.concurrent.EventExecutor;
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/**
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* {@link Runnable} which represent a one time task which may allow the {@link EventExecutor} to reduce the amount of
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* produced garbage when queue it for execution.
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*
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* <strong>It is important this will not be reused. After submitted it is not allowed to get submitted again!</strong>
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*/
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public abstract class OneTimeTask implements Runnable {
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private static final long nextOffset;
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static {
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if (PlatformDependent0.hasUnsafe()) {
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try {
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nextOffset = PlatformDependent.objectFieldOffset(
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OneTimeTask.class.getDeclaredField("tail"));
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} catch (Throwable t) {
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throw new ExceptionInInitializerError(t);
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}
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} else {
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nextOffset = -1;
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}
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}
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@SuppressWarnings("unused")
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private volatile OneTimeTask tail;
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// Only use from MpscLinkedQueue and so we are sure Unsafe is present
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@SuppressWarnings("unchecked")
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final OneTimeTask next() {
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return (OneTimeTask) PlatformDependent.getObjectVolatile(this, nextOffset);
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}
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// Only use from MpscLinkedQueue and so we are sure Unsafe is present
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final void setNext(final OneTimeTask newNext) {
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PlatformDependent.putOrderedObject(this, nextOffset, newNext);
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}
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}
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