org.apache.flink.runtime.rpc.MainThreadValidatorUtil Maven / Gradle / Ivy
/*
* 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.flink.runtime.rpc;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import javax.annotation.Nullable;
import static org.apache.flink.util.Preconditions.checkNotNull;
/**
* This utility exists to bridge between the visibility of the
* {@code currentMainThread} field in the {@link RpcEndpoint}.
*
* The {@code currentMainThread} can be hidden from {@code RpcEndpoint} implementations
* and only be accessed via this utility from other packages.
*/
public final class MainThreadValidatorUtil {
private static final Logger LOG = LoggerFactory.getLogger(MainThreadValidatorUtil.class);
private final RpcEndpoint endpoint;
public MainThreadValidatorUtil(RpcEndpoint endpoint) {
this.endpoint = checkNotNull(endpoint);
}
public void enterMainThread() {
assert(endpoint.currentMainThread.compareAndSet(null, Thread.currentThread())) :
"The RpcEndpoint has concurrent access from " + endpoint.currentMainThread.get();
}
public void exitMainThread() {
assert(endpoint.currentMainThread.compareAndSet(Thread.currentThread(), null)) :
"The RpcEndpoint has concurrent access from " + endpoint.currentMainThread.get();
}
/**
* Returns true iff the current thread is equals to the provided expected thread and logs violations.
*
* @param expected the expected main thread.
* @return true iff the current thread is equals to the provided expected thread.
*/
public static boolean isRunningInExpectedThread(@Nullable Thread expected) {
Thread actual = Thread.currentThread();
if (expected != actual) {
String violationMsg = "Violation of main thread constraint detected: expected <"
+ expected + "> but running in <" + actual + ">.";
LOG.warn(violationMsg, new Exception(violationMsg));
return false;
}
return true;
}
}