| /* |
| * 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 io.netty.util.concurrent.FastThreadLocal; |
| import org.apache.cassandra.service.ClientWarn; |
| import org.apache.cassandra.tracing.TraceState; |
| import org.apache.cassandra.utils.Closeable; |
| import org.apache.cassandra.utils.WithResources; |
| |
| /* |
| * This class only knows about Tracing and ClientWarn, so if any different executor locals are added, it must be |
| * updated. |
| * |
| * We don't enumerate the ExecutorLocal.all array each time because it would be much slower. |
| */ |
| public class ExecutorLocals implements WithResources, Closeable |
| { |
| private static final ExecutorLocals none = new ExecutorLocals(null, null); |
| private static final FastThreadLocal<ExecutorLocals> locals = new FastThreadLocal<ExecutorLocals>() |
| { |
| @Override |
| protected ExecutorLocals initialValue() |
| { |
| return none; |
| } |
| }; |
| |
| public static class Impl |
| { |
| @SuppressWarnings("resource") |
| protected static void set(TraceState traceState, ClientWarn.State clientWarnState) |
| { |
| if (traceState == null && clientWarnState == null) locals.set(none); |
| else locals.set(new ExecutorLocals(traceState, clientWarnState)); |
| } |
| } |
| |
| public final TraceState traceState; |
| public final ClientWarn.State clientWarnState; |
| |
| protected ExecutorLocals(TraceState traceState, ClientWarn.State clientWarnState) |
| { |
| this.traceState = traceState; |
| this.clientWarnState = clientWarnState; |
| } |
| |
| /** |
| * @return an ExecutorLocals object which has the current trace state and client warn state. |
| */ |
| public static ExecutorLocals current() |
| { |
| return locals.get(); |
| } |
| |
| /** |
| * The {@link #current}Locals, if any; otherwise {@link WithResources#none()}. |
| * Used to propagate current to other executors as a {@link WithResources}. |
| */ |
| public static WithResources propagate() |
| { |
| ExecutorLocals locals = current(); |
| return locals == none ? WithResources.none() : locals; |
| } |
| |
| @SuppressWarnings("resource") |
| public static ExecutorLocals create(TraceState traceState) |
| { |
| ExecutorLocals current = locals.get(); |
| return current.traceState == traceState ? current : new ExecutorLocals(traceState, current.clientWarnState); |
| } |
| |
| public static void clear() |
| { |
| locals.set(none); |
| } |
| |
| /** |
| * Overwrite current locals, and return the previous ones |
| */ |
| public Closeable get() |
| { |
| ExecutorLocals old = current(); |
| if (old != this) |
| locals.set(this); |
| return old; |
| } |
| |
| public void close() |
| { |
| locals.set(this); |
| } |
| } |