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From kahat...@apache.org
Subject svn commit: r1402043 - in /db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests: tests/lang/DeadlockDetectionTest.java tests/lang/ErrorMessageTest.java tests/store/IndexSplitDeadlockTest.java util/Barrier.java
Date Thu, 25 Oct 2012 09:37:38 GMT
Author: kahatlen
Date: Thu Oct 25 09:37:37 2012
New Revision: 1402043

URL: http://svn.apache.org/viewvc?rev=1402043&view=rev
Log:
DERBY-4323: test failure in lang.ErrorMessageTest with IBM iseries IBM 1.5

Make the two threads that race for locks do as little as possible in order
to reduce the risk of missing the two-second window for constructing the
deadlock. That is, move query compilation and thread startup out so that
the participating threads only perform query execution.

Added:
    db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/util/Barrier.java
  (with props)
Modified:
    db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/tests/lang/DeadlockDetectionTest.java
    db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/tests/lang/ErrorMessageTest.java
    db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/tests/store/IndexSplitDeadlockTest.java

Modified: db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/tests/lang/DeadlockDetectionTest.java
URL: http://svn.apache.org/viewvc/db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/tests/lang/DeadlockDetectionTest.java?rev=1402043&r1=1402042&r2=1402043&view=diff
==============================================================================
--- db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/tests/lang/DeadlockDetectionTest.java
(original)
+++ db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/tests/lang/DeadlockDetectionTest.java
Thu Oct 25 09:37:37 2012
@@ -28,6 +28,7 @@ import java.util.Collections;
 import java.util.Iterator;
 import java.util.List;
 import junit.framework.Test;
+import org.apache.derbyTesting.functionTests.util.Barrier;
 import org.apache.derbyTesting.junit.BaseJDBCTestCase;
 import org.apache.derbyTesting.junit.CleanDatabaseTestSetup;
 import org.apache.derbyTesting.junit.DatabasePropertyTestSetup;
@@ -239,38 +240,4 @@ public class DeadlockDetectionTest exten
         // picked as victim, the other ones should be able to complete.)
         assertEquals("Number of victims", 1, exceptions.size());
     }
-
-    /**
-     * In the absence of java.util.concurrent.CyclicBarrier on many of the
-     * platforms we test, create our own barrier class. This class allows
-     * threads to wait for one another on specific locations, so that they
-     * know they're all in the expected state.
-     */
-    private static class Barrier {
-        /** Number of threads to wait for at the barrier. */
-        int numThreads;
-
-        /** Create a barrier for the specified number of threads. */
-        Barrier(int numThreads) {
-            this.numThreads = numThreads;
-        }
-
-        /**
-         * Wait until {@code numThreads} have called {@code await()} on this
-         * barrier, then proceed.
-         */
-        synchronized void await() throws InterruptedException {
-            assertTrue("Too many threads reached the barrier", numThreads > 0);
-
-            if (--numThreads <= 0) {
-                // All threads have reached the barrier. Go ahead!
-                notifyAll();
-            }
-
-            // Some threads haven't reached the barrier yet. Let's wait.
-            while (numThreads > 0) {
-                wait();
-            }
-        }
-    }
 }

Modified: db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/tests/lang/ErrorMessageTest.java
URL: http://svn.apache.org/viewvc/db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/tests/lang/ErrorMessageTest.java?rev=1402043&r1=1402042&r2=1402043&view=diff
==============================================================================
--- db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/tests/lang/ErrorMessageTest.java
(original)
+++ db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/tests/lang/ErrorMessageTest.java
Thu Oct 25 09:37:37 2012
@@ -22,6 +22,7 @@
 package org.apache.derbyTesting.functionTests.tests.lang;
 
 import java.sql.Connection;
+import java.sql.PreparedStatement;
 import java.sql.SQLException;
 import java.sql.Statement;
 import java.util.Properties;
@@ -29,6 +30,7 @@ import java.util.regex.Matcher;
 import java.util.regex.Pattern;
 import junit.framework.Test;
 import junit.framework.TestSuite;
+import org.apache.derbyTesting.functionTests.util.Barrier;
 import org.apache.derbyTesting.junit.BaseJDBCTestCase;
 import org.apache.derbyTesting.junit.CleanDatabaseTestSetup;
 import org.apache.derbyTesting.junit.DatabasePropertyTestSetup;
@@ -130,43 +132,75 @@ public class ErrorMessageTest extends Ba
      */
     public void testDeadlockTimeout()
             throws SQLException, InterruptedException {
-        getConnection().setAutoCommit(false);
+        setAutoCommit(false);
+
+        // Make the main transaction (T1) lock row 1 exclusively
         Statement s = createStatement();
         assertUpdateCount(s, 1, "update t set text='xxx' where id=1");
 
-        // start another transaction that needs to wait for the first one
+        // Start another transaction (T2) that locks row 2 exclusively
         Connection c2 = openDefaultConnection();
         c2.setAutoCommit(false);
-        final Statement s2 = c2.createStatement();
+        Statement s2 = c2.createStatement();
         assertUpdateCount(s2, 1, "update t set text='yyy' where id=2");
+
+        // Prepare statements for T1 to lock row 2 (shared), and for T2 to
+        // lock row 1 (shared).
+        PreparedStatement ps1 = prepareStatement("select * from t where id=2");
+        final PreparedStatement ps2 =
+                c2.prepareStatement("select * from t where id=1");
+
+        // Create a barrier for the two threads to synchronize.
+        final Barrier barrier = new Barrier(2);
+
         final SQLException[] holder = new SQLException[2];
+        final Throwable[] unexpected = new Throwable[1];
         Thread t = new Thread(new Runnable() {
                 public void run() {
                     try {
-                        // will wait since the other transaction has locked the
-                        // row exclusively
-                        JDBC.assertDrainResults(
-                            s2.executeQuery("select * from t where id=1"));
+                        // Let the main thread know the helper thread has
+                        // started. The race for the locks can start.
+                        barrier.await();
+
+                        // This statement will be blocked because T1 holds
+                        // an exclusive lock on the row we want.
+                        JDBC.assertDrainResults(ps2.executeQuery());
                     } catch (SQLException e) {
                         holder[0] = e;
+                    } catch (Throwable t) {
+                        unexpected[0] = t;
                     }
                 }
             });
         t.start();
 
-        // Execute a query that needs to wait for c2 to finish. Now, c1 is
-        // waiting for c2, and c2 is waiting for c1.
+        // Wait until the helper thread has started. Once the call returns,
+        // both threads are ready, and the race for the locks can start.
+        barrier.await();
+
+        // This statement will be blocked because T2 holds an exclusive lock
+        // on the row we want. So now we have T1 waiting for T2, and T2 waiting
+        // for T1, and one of the transactions should be terminated because of
+        // the deadlock.
         try {
-            JDBC.assertDrainResults(
-                s.executeQuery("select * from t where id=2"));
+            JDBC.assertDrainResults(ps1.executeQuery());
         } catch (SQLException e) {
             holder[1] = e;
         }
 
+        // Wait for the helper thread to complete.
         t.join();
 
+        // If the helper thread failed with something other than an
+        // SQLException, report it.
+        if (unexpected[0] != null) {
+            fail("Helper thread failed unexpectedly", unexpected[0]);
+        }
+
+        // Check that exactly one of the threads failed, and that the failure
+        // was caused by a deadlock. It is not deterministic which of the two
+        // threads will be terminated.
         String msg;
-        // check that only one of the transactions failed
         if (holder[0] != null) {
             assertSQLState("Not a deadlock", "40001", holder[0]);
             assertNull("Only one of the waiters should be aborted", holder[1]);

Modified: db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/tests/store/IndexSplitDeadlockTest.java
URL: http://svn.apache.org/viewvc/db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/tests/store/IndexSplitDeadlockTest.java?rev=1402043&r1=1402042&r2=1402043&view=diff
==============================================================================
--- db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/tests/store/IndexSplitDeadlockTest.java
(original)
+++ db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/tests/store/IndexSplitDeadlockTest.java
Thu Oct 25 09:37:37 2012
@@ -28,6 +28,7 @@ import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
 import junit.framework.Test;
+import org.apache.derbyTesting.functionTests.util.Barrier;
 import org.apache.derbyTesting.junit.BaseJDBCTestCase;
 import org.apache.derbyTesting.junit.CleanDatabaseTestSetup;
 import org.apache.derbyTesting.junit.DatabasePropertyTestSetup;
@@ -834,38 +835,4 @@ public class IndexSplitDeadlockTest exte
             }
         }
     }
-
-    /**
-     * A poor man's substitute for java.util.concurrent.CyclicBarrier.
-     */
-    private static class Barrier {
-        /** The number of parties that still haven't reached the barrier. */
-        private int n;
-
-        /**
-         * Create a barrier that blocks until the specified number of threads
-         * have reached the barrier point.
-         *
-         * @param parties the number of parties to wait for at the barrier
-         */
-        Barrier(int parties) {
-            n = parties;
-        }
-
-        /**
-         * Wait until all parties have reached the barrier.
-         *
-         * @throws InterruptedException if the thread is interrupted
-         */
-        synchronized void await() throws InterruptedException {
-            assertTrue("Too many parties at barrier", n > 0);
-
-            n--;
-            notifyAll();
-
-            while (n > 0) {
-                wait();
-            }
-        }
-    }
 }

Added: db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/util/Barrier.java
URL: http://svn.apache.org/viewvc/db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/util/Barrier.java?rev=1402043&view=auto
==============================================================================
--- db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/util/Barrier.java
(added)
+++ db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/util/Barrier.java
Thu Oct 25 09:37:37 2012
@@ -0,0 +1,60 @@
+/*
+ * Derby - Class org.apache.derbyTesting.functionTests.util.Barrier
+ *
+ * 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.derbyTesting.functionTests.util;
+
+import junit.framework.Assert;
+
+/**
+ * In the absence of java.util.concurrent.CyclicBarrier on some of the
+ * platforms we test, create our own barrier class. This class allows
+ * threads to wait for one another on specific locations, so that they
+ * know they're all in the expected state.
+ */
+public class Barrier {
+    /** Number of threads to wait for at the barrier. */
+    private int numThreads;
+
+    /** Create a barrier for the specified number of threads. */
+    public Barrier(int numThreads) {
+        this.numThreads = numThreads;
+    }
+
+    /**
+     * Wait until {@code numThreads} have called {@code await()} on this
+     * barrier, then proceed.
+     *
+     * @throws InterruptedException if the thread is interrupted while
+     * waiting for the other threads to reach the barrier.
+     */
+    public synchronized void await() throws InterruptedException {
+        Assert.assertTrue(
+                "Too many threads reached the barrier", numThreads > 0);
+
+        if (--numThreads <= 0) {
+            // All threads have reached the barrier. Go ahead!
+            notifyAll();
+        }
+
+        // Some threads haven't reached the barrier yet. Let's wait.
+        while (numThreads > 0) {
+            wait();
+        }
+    }
+}

Propchange: db/derby/code/trunk/java/testing/org/apache/derbyTesting/functionTests/util/Barrier.java
------------------------------------------------------------------------------
    svn:eol-style = native



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