YARN-11765. Refactor: Move Clock Class from hadoop-mapreduce-project to hadoop-common-project for Reusability (#7352) Contributed by Jiandan Yang.

Refactor: Move Clock Class from hadoop-mapreduce-project to hadoop-common-project for Reusability

Reviewed-by: Chris Nauroth <[email protected]>
Reviewed-by: Steve Loughran <[email protected]>
Signed-off-by: Shilun Fan <[email protected]>

Author: yangjiandan

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/Clock.java

@@ -0,0 +1,32 @@
+/**
+* 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;
+
+/**
+ * A simple clock interface that gives you time.
+ */
+@Public
+@Stable
+public interface Clock {
+
+  long getTime();
+}

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/MonotonicClock.java

@@ -0,0 +1,45 @@
+/**
+ * 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.Evolving;
+
+/**
+ * A monotonic clock from some arbitrary time base in the past, counting in
+ * milliseconds, and not affected by settimeofday or similar system clock
+ * changes.
+ * This is appropriate to use when computing how much longer to wait for an
+ * interval to expire.
+ * This function can return a negative value and it must be handled correctly
+ * by callers. See the documentation of System#nanoTime for caveats.
+ */
+@Public
+@Evolving
+public class MonotonicClock implements Clock {
+
+  /**
+   * Get current time from some arbitrary time base in the past, counting in
+   * milliseconds, and not affected by settimeofday or similar system clock
+   * changes.
+   * @return a monotonic clock that counts in milliseconds.
+   */
+  public long getTime() {
+    return Time.monotonicNow();
+  }
+}

hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/SystemClock.java

@@ -0,0 +1,48 @@
+/**
+* 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;
+  }
+
+  private SystemClock() {
+    // do nothing
+  }
+
+  public long getTime() {
+    return System.currentTimeMillis();
+  }
+}

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-core/src/test/java/org/apache/hadoop/mapred/TestClock.java renamed to hadoop-common-project/hadoop-common/src/main/java/org/apache/hadoop/util/UTCClock.java

@@ -16,24 +16,25 @@
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
-package org.apache.hadoop.mapred;
+package org.apache.hadoop.util;
 
-import org.junit.jupiter.api.Test;
-import org.junit.jupiter.api.Timeout;
+import java.util.Calendar;
+import java.util.TimeZone;
 
-import static org.junit.jupiter.api.Assertions.assertEquals;
+import org.apache.hadoop.classification.InterfaceAudience.Public;
+import org.apache.hadoop.classification.InterfaceStability.Evolving;
 
 /**
- * test Clock class
+ * Implementation of {@link Clock} that gives the current UTC time in
+ * milliseconds.
  */
-public class TestClock {
+@Public
+@Evolving
+public class UTCClock implements Clock {
 
-  @Test
-  @Timeout(value = 10)
-  public void testClock(){
-    Clock clock = new Clock();
-    long templateTime = System.currentTimeMillis();
-    long time = clock.getTime();
-    assertEquals(templateTime, time, 30);
+  private final TimeZone utcZone = TimeZone.getTimeZone("UTC");
+
+  public long getTime() {
+    return Calendar.getInstance(utcZone).getTimeInMillis();
   }
-}
+}

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/main/java/org/apache/hadoop/mapred/MapTaskAttemptImpl.java

@@ -30,7 +30,7 @@
 import org.apache.hadoop.security.Credentials;
 import org.apache.hadoop.security.token.Token;
 import org.apache.hadoop.yarn.event.EventHandler;
-import org.apache.hadoop.yarn.util.Clock;
+import org.apache.hadoop.util.Clock;
 
 @SuppressWarnings("rawtypes")
 public class MapTaskAttemptImpl extends TaskAttemptImpl {

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/main/java/org/apache/hadoop/mapred/ReduceTaskAttemptImpl.java

@@ -29,7 +29,7 @@
 import org.apache.hadoop.security.Credentials;
 import org.apache.hadoop.security.token.Token;
 import org.apache.hadoop.yarn.event.EventHandler;
-import org.apache.hadoop.yarn.util.Clock;
+import org.apache.hadoop.util.Clock;
 
 @SuppressWarnings("rawtypes")
 public class ReduceTaskAttemptImpl extends TaskAttemptImpl {

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/main/java/org/apache/hadoop/mapreduce/v2/app/AppContext.java

@@ -29,7 +29,7 @@
 import org.apache.hadoop.yarn.event.Event;
 import org.apache.hadoop.yarn.event.EventHandler;
 import org.apache.hadoop.yarn.security.client.ClientToAMTokenSecretManager;
-import org.apache.hadoop.yarn.util.Clock;
+import org.apache.hadoop.util.Clock;
 
 
 /**

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/main/java/org/apache/hadoop/mapreduce/v2/app/MRAppMaster.java

@@ -150,8 +150,8 @@
 import org.apache.hadoop.yarn.exceptions.YarnRuntimeException;
 import org.apache.hadoop.yarn.security.AMRMTokenIdentifier;
 import org.apache.hadoop.yarn.security.client.ClientToAMTokenSecretManager;
-import org.apache.hadoop.yarn.util.Clock;
-import org.apache.hadoop.yarn.util.SystemClock;
+import org.apache.hadoop.util.Clock;
+import org.apache.hadoop.util.SystemClock;
 
 import org.apache.hadoop.classification.VisibleForTesting;
 import org.slf4j.Logger;

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/main/java/org/apache/hadoop/mapreduce/v2/app/TaskAttemptFinishingMonitor.java

@@ -25,7 +25,7 @@
 import org.apache.hadoop.mapreduce.v2.app.job.event.TaskAttemptEventType;
 import org.apache.hadoop.yarn.event.EventHandler;
 import org.apache.hadoop.yarn.util.AbstractLivelinessMonitor;
-import org.apache.hadoop.yarn.util.SystemClock;
+import org.apache.hadoop.util.SystemClock;
 
 /**
  * This class generates TA_TIMED_OUT if the task attempt stays in FINISHING

hadoop-mapreduce-project/hadoop-mapreduce-client/hadoop-mapreduce-client-app/src/main/java/org/apache/hadoop/mapreduce/v2/app/TaskHeartbeatHandler.java

@@ -34,7 +34,7 @@
 import org.apache.hadoop.mapreduce.v2.app.job.event.TaskAttemptEventType;
 import org.apache.hadoop.service.AbstractService;
 import org.apache.hadoop.yarn.event.EventHandler;
-import org.apache.hadoop.yarn.util.Clock;
+import org.apache.hadoop.util.Clock;
 import org.slf4j.Logger;
 import org.slf4j.LoggerFactory;