HBASE-12148 Remove TimeRangeTracker as point of contention when many threads writing a Store

hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestTimeRangeTracker.java

@@ -0,0 +1,111 @@
+/**
+ * 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.hbase.regionserver;
+
+import static org.junit.Assert.assertTrue;
+
+import org.apache.hadoop.hbase.io.TimeRange;
+import org.apache.hadoop.hbase.testclassification.SmallTests;
+import org.apache.hadoop.hbase.testclassification.RegionServerTests;
+import org.junit.Test;
+import org.junit.experimental.categories.Category;
+
+@Category({RegionServerTests.class, SmallTests.class})
+public class TestTimeRangeTracker {
+  @Test
+  public void testAlwaysDecrementingSetsMaximum() {
+    TimeRangeTracker trr = new TimeRangeTracker();
+    trr.includeTimestamp(3);
+    trr.includeTimestamp(2);
+    trr.includeTimestamp(1);
+    assertTrue(trr.getMinimumTimestamp() != TimeRangeTracker.INITIAL_MINIMUM_TIMESTAMP);
+    assertTrue(trr.getMaximumTimestamp() != -1 /*The initial max value*/);
+  }
+
+  @Test
+  public void testSimpleInRange() {
+    TimeRangeTracker trr = new TimeRangeTracker();
+    trr.includeTimestamp(0);
+    trr.includeTimestamp(2);
+    assertTrue(trr.includesTimeRange(new TimeRange(1)));
+  }
+
+  /**
+   * Run a bunch of threads against a single TimeRangeTracker and ensure we arrive
+   * at right range.  Here we do ten threads each incrementing over 100k at an offset
+   * of the thread index; max is 10 * 10k and min is 0.
+   * @throws InterruptedException
+   */
+  @Test
+  public void testArriveAtRightAnswer() throws InterruptedException {
+    final TimeRangeTracker trr = new TimeRangeTracker();
+    final int threadCount = 10;
+    final int calls = 1000 * 1000;
+    Thread [] threads = new Thread[threadCount];
+    for (int i = 0; i < threads.length; i++) {
+      Thread t = new Thread("" + i) {
+        @Override
+        public void run() {
+          int offset = Integer.parseInt(getName());
+          boolean even = offset % 2 == 0;
+          if (even) {
+            for (int i = (offset * calls); i < calls; i++) trr.includeTimestamp(i);
+          } else {
+            int base = offset * calls;
+            for (int i = base + calls; i >= base; i--) trr.includeTimestamp(i);
+          }
+        }
+      };
+      t.start();
+      threads[i] = t;
+    }
+    for (int i = 0; i < threads.length; i++) {
+      threads[i].join();
+    }
+    assertTrue(trr.getMaximumTimestamp() == calls * threadCount);
+    assertTrue(trr.getMinimumTimestamp() == 0);
+  }
+
+  /**
+   * Bit of code to test concurrent access on this class.
+   * @param args
+   * @throws InterruptedException
+   */
+  public static void main(String[] args) throws InterruptedException {
+    long start = System.currentTimeMillis();
+    final TimeRangeTracker trr = new TimeRangeTracker();
+    final int threadCount = 5;
+    final int calls = 1024 * 1024 * 128;
+    Thread [] threads = new Thread[threadCount];
+    for (int i = 0; i < threads.length; i++) {
+      Thread t = new Thread("" + i) {
+        @Override
+        public void run() {
+          for (int i = 0; i < calls; i++) trr.includeTimestamp(i);
+        }
+      };
+      t.start();
+      threads[i] = t;
+    }
+    for (int i = 0; i < threads.length; i++) {
+      threads[i].join();
+    }
+    System.out.println(trr.getMinimumTimestamp() + " " + trr.getMaximumTimestamp() + " " +
+      (System.currentTimeMillis() - start));
+  }
+}