HBASE-7377 Clean up TestHBase7051

git-svn-id: https://svn.apache.org/repos/asf/hbase/trunk@1423674 13f79535-47bb-0310-9956-ffa450edef68

hbase-server/src/test/java/org/apache/hadoop/hbase/regionserver/TestHBase7051.java

@@ -16,6 +16,9 @@ import org.apache.hadoop.hbase.HRegionInfo;
 import org.apache.hadoop.hbase.HTableDescriptor;
 import org.apache.hadoop.hbase.KeyValue;
 import org.apache.hadoop.hbase.SmallTests;
+import org.apache.hadoop.hbase.MultithreadedTestUtil;
+import org.apache.hadoop.hbase.MultithreadedTestUtil.TestContext;
+import org.apache.hadoop.hbase.MultithreadedTestUtil.TestThread;
 import org.apache.hadoop.hbase.client.Mutation;
 import org.apache.hadoop.hbase.client.Put;
 import org.apache.hadoop.hbase.client.Scan;
@@ -30,19 +33,32 @@ import org.junit.experimental.categories.Category;
 
 import com.google.common.collect.Lists;
 
+/**
+ * Test of HBASE-7051; that checkAndPuts and puts behave atomically with respect to each other.
+ * Rather than perform a bunch of trials to verify atomicity, this test recreates a race condition
+ * that causes the test to fail if checkAndPut doesn't wait for outstanding put transactions
+ * to complete.  It does this by invasively overriding HRegion function to affect the timing of
+ * the operations.
+ */
 @Category(SmallTests.class)
 public class TestHBase7051 {
 
-  private static volatile boolean putCompleted = false;
   private static CountDownLatch latch = new CountDownLatch(1);
-  private boolean checkAndPutCompleted = false;
+  private enum TestStep {
-  private static int count = 0;
+    INIT,                  // initial put of 10 to set value of the cell
+    PUT_STARTED,           // began doing a put of 50 to cell
+    PUT_COMPLETED,         // put complete (released RowLock, but may not have advanced MVCC).
+    CHECKANDPUT_STARTED,   // began checkAndPut: if 10 -> 11
+    CHECKANDPUT_COMPLETED  // completed checkAndPut
+    // NOTE: at the end of these steps, the value of the cell should be 50, not 11!
+  }
+  private static volatile TestStep testStep = TestStep.INIT;
+  private final String family = "f1";
   	 
   @Test
   public void testPutAndCheckAndPutInParallel() throws Exception {
 
     final String tableName = "testPutAndCheckAndPut";
-    final String family = "f1";
     Configuration conf = HBaseConfiguration.create();
     conf.setClass(HConstants.REGION_IMPL, MockHRegion.class, HeapSize.class);
     final MockHRegion region = (MockHRegion) TestHRegion.initHRegion(Bytes.toBytes(tableName),
@@ -57,14 +73,16 @@ public class TestHBase7051 {
 
     putsAndLocks.add(pair);
 
-    count++;
     region.batchMutate(putsAndLocks.toArray(new Pair[0]));
-    makeCheckAndPut(family, region);
+    MultithreadedTestUtil.TestContext ctx =
-
+      new MultithreadedTestUtil.TestContext(conf);
-    makePut(family, region);
+    ctx.addThread(new PutThread(ctx, region));
-    while (!checkAndPutCompleted) {
+    ctx.addThread(new CheckAndPutThread(ctx, region));
+    ctx.startThreads();
+    while (testStep != TestStep.CHECKANDPUT_COMPLETED) {
       Thread.sleep(100);
     }
+    ctx.stop();
     Scan s = new Scan();
     RegionScanner scanner = region.getScanner(s);
     List<KeyValue> results = new ArrayList<KeyValue>();
@@ -75,55 +93,47 @@ public class TestHBase7051 {
 
   }
 
-  private void makePut(final String family, final MockHRegion region) {
+  private class PutThread extends TestThread {
-    new Thread() {
+    private MockHRegion region;
-      public void run() {
+    PutThread(TestContext ctx, MockHRegion region) {
+      super(ctx);
+      this.region = region;
+    }
+
+    public void doWork() throws Exception {
       List<Pair<Mutation, Integer>> putsAndLocks = Lists.newArrayList();
       Put[] puts = new Put[1];
       Put put = new Put(Bytes.toBytes("r1"));
       put.add(Bytes.toBytes(family), Bytes.toBytes("q1"), Bytes.toBytes("50"));
       puts[0] = put;
-        try {
       Pair<Mutation, Integer> pair = new Pair<Mutation, Integer>(puts[0], null);
       putsAndLocks.add(pair);
-          count++;
+      testStep = TestStep.PUT_STARTED;
       region.batchMutate(putsAndLocks.toArray(new Pair[0]));
-        } catch (IOException e) {
-          // TODO Auto-generated catch block
-          e.printStackTrace();
     }
   }
-    }.start();
-  }
 
-  private void makeCheckAndPut(final String family, final MockHRegion region) {
+  private class CheckAndPutThread extends TestThread {
-    new Thread() {
+    private MockHRegion region;
+    CheckAndPutThread(TestContext ctx, MockHRegion region) {
+      super(ctx);
+      this.region = region;
+   }
 
-      public void run() {
+    public void doWork() throws Exception {
       Put[] puts = new Put[1];
       Put put = new Put(Bytes.toBytes("r1"));
       put.add(Bytes.toBytes(family), Bytes.toBytes("q1"), Bytes.toBytes("11"));
       puts[0] = put;
-        try {
+      while (testStep != TestStep.PUT_COMPLETED) {
-          while (putCompleted == false) {
-            try {
         Thread.sleep(100);
-            } catch (InterruptedException e) {
-              // TODO Auto-generated catch block
-              e.printStackTrace();
       }
-          }
+      testStep = TestStep.CHECKANDPUT_STARTED;
-          count++;
       region.checkAndMutate(Bytes.toBytes("r1"), Bytes.toBytes(family), Bytes.toBytes("q1"),
         CompareOp.EQUAL, new BinaryComparator(Bytes.toBytes("10")), put, null, true);
-          checkAndPutCompleted = true;
+      testStep = TestStep.CHECKANDPUT_COMPLETED;
-        } catch (IOException e) {
-          // TODO Auto-generated catch block
-          e.printStackTrace();
     }
   }
-    }.start();
-  }
 
   public static class MockHRegion extends HRegion {
 
@@ -134,36 +144,39 @@ public class TestHBase7051 {
 
     @Override
     public void releaseRowLock(Integer lockId) {
-      if (count == 1) {
+      if (testStep == TestStep.INIT) {
         super.releaseRowLock(lockId);
         return;
       }
 
-      if (count == 2) {
+      if (testStep == TestStep.PUT_STARTED) {
         try {
-          putCompleted = true;
+          testStep = TestStep.PUT_COMPLETED;
           super.releaseRowLock(lockId);
+          // put has been written to the memstore and the row lock has been released, but the
+          // MVCC has not been advanced.  Prior to fixing HBASE-7051, the following order of
+          // operations would cause the non-atomicity to show up:
+          // 1) Put releases row lock (where we are now)
+          // 2) CheckAndPut grabs row lock and reads the value prior to the put (10)
+          //    because the MVCC has not advanced
+          // 3) Put advances MVCC
+          // So, in order to recreate this order, we wait for the checkAndPut to grab the rowLock
+          // (see below), and then wait some more to give the checkAndPut time to read the old
+          // value.
           latch.await();
-        } catch (InterruptedException e) {
-          // TODO Auto-generated catch block
-          e.printStackTrace();
-        }
-      }
-      if (count == 3) {
-        super.releaseRowLock(lockId);
-        try {
           Thread.sleep(1000);
         } catch (InterruptedException e) {
-          // TODO Auto-generated catch block
+          Thread.currentThread().interrupt();
-          e.printStackTrace();
         }
-        latch.countDown();
+      }
+      else if (testStep == TestStep.CHECKANDPUT_STARTED) {
+        super.releaseRowLock(lockId);
       }
     }
 
     @Override
     public Integer getLock(Integer lockid, byte[] row, boolean waitForLock) throws IOException {
-      if (count == 3) {
+      if (testStep == TestStep.CHECKANDPUT_STARTED) {
         latch.countDown();
       }
       return super.getLock(lockid, row, waitForLock);