yangjiandan commented on code in PR #7352: URL: https://github.com/apache/hadoop/pull/7352#discussion_r1955506616
########## hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/SystemClock.java: ########## @@ -0,0 +1,49 @@ +/** +* 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.hadoop.util; + +import org.apache.hadoop.classification.InterfaceAudience.Public; +import org.apache.hadoop.classification.InterfaceStability.Stable; + +/** + * Implementation of {@link Clock} that gives the current time from the system + * clock in milliseconds. + * + * NOTE: Do not use this to calculate a duration of expire or interval to sleep, + * because it will be broken by settimeofday. Please use {@link MonotonicClock} + * instead. + */ +@Public +@Stable +public final class SystemClock implements Clock { + + private static final SystemClock INSTANCE = new SystemClock(); + + public static SystemClock getInstance() { + return INSTANCE; + } + + @Deprecated Review Comment: Thanks for the suggestion! I think SystemClock should be a singleton, and the constructor should be private. Since this constructor is not used by any other class, I will make the constructor private. You’re right! Introducing a new API with a deprecated method does seem unusual. I will remove the @Deprecated annotation to avoid confusion. Thanks for the review! -- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. To unsubscribe, e-mail: [email protected] For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
