| /* |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you 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 org.apache.cassandra.concurrent; |
| |
| import org.apache.cassandra.service.ClientWarn; |
| import org.apache.cassandra.tracing.TraceState; |
| import org.apache.cassandra.tracing.Tracing; |
| |
| public interface ExecutorLocal<T> |
| { |
| ExecutorLocal[] all = { Tracing.instance, ClientWarn.instance }; |
| |
| /** |
| * This is called when scheduling the task, and also before calling {@link ExecutorLocal#set(T)} when running on a |
| * executor thread. |
| * |
| * @return The thread-local value that we want to copy across executor boundaries; may be null if not set. |
| */ |
| T get(); |
| |
| /** |
| * Before a task has been run, this will be called with the value from the thread that scheduled the task, and after |
| * the task is finished, the value that was previously retrieved from this thread is restored. |
| * |
| * @param value Value to use for the executor local state; may be null. |
| */ |
| void set(T value); |
| } |