OPENJPA-1350: Test case (by Rick Curtis) to test early registration of type alias to avoid/minimze risk of multi-threaded repository initialization. Original change was revision 826944

git-svn-id: https://svn.apache.org/repos/asf/openjpa/trunk@882285 13f79535-47bb-0310-9956-ffa450edef68

openjpa-persistence-jdbc/src/test/java/org/apache/openjpa/persistence/meta/TestQueryTypeAliasRegistration.java

@@ -0,0 +1,106 @@
+/*
+ * 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.openjpa.persistence.meta;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+
+import javax.persistence.EntityManagerFactory;
+
+import org.apache.openjpa.meta.MetaDataRepository;
+import org.apache.openjpa.persistence.OpenJPAEntityManagerFactorySPI;
+import org.apache.openjpa.persistence.OpenJPAEntityManagerSPI;
+import org.apache.openjpa.persistence.test.SingleEMFTestCase;
+
+public class TestQueryTypeAliasRegistration extends SingleEMFTestCase {
+    private final int threads = 100;
+
+    @Override
+    public void setUp() throws Exception {
+        super.setUp(MdrTestEntity.class);
+        assertNotNull(emf);
+        // Create the Entity which we're going to try to get MetaData for using
+        // an alias. Do this to ensure that it has been registered to the PCRegistry.
+        new MdrTestEntity();
+    }
+
+    /**
+     * This method tests a timing window where more than one thread requests MetaData using an alias
+     * at the same time. All threads should get data back and no threads should receive an
+     * exception.
+     */
+    public void testMultiThreadGetMetaDataAlias() throws Exception {
+        try {
+            List<Worker> workers = new ArrayList<Worker>();
+            Set<Exception> exceptions = new HashSet<Exception>();
+            for (int i = 0; i < threads; i++) {
+                Worker w = new Worker(emf);
+                workers.add(w);
+            }
+            for (Worker w : workers) {
+                w.start();
+            }
+            for (Worker w : workers) {
+                w.join();
+                Exception e = w.getException();
+                if (e != null) {
+                    exceptions.add(w.getException());
+                }
+            }
+            assertTrue("Caught "  + exceptions.toString(), exceptions.size() == 0);
+        } finally {
+            if (emf != null) {
+                emf.close();
+            }
+        }
+    }
+
+    class Worker extends Thread {
+        OpenJPAEntityManagerFactorySPI emf;
+        OpenJPAEntityManagerSPI em;
+        MetaDataRepository repo;
+        Exception ex;
+
+        Worker(EntityManagerFactory e) {
+            emf = (OpenJPAEntityManagerFactorySPI) e;
+            // Create an EM here because that triggers registering the MDR as a class registration
+            // listener with the PCRegistry.
+            em = emf.createEntityManager();
+            repo = em.getConfiguration().getMetaDataRepositoryInstance();
+        }
+
+        Exception getException() {
+            return ex;
+        }
+
+        @Override
+        public void run() {
+            try {
+                repo.getMetaData("MdrTestEntity", Thread.currentThread().getContextClassLoader(), true);
+            } catch (Exception e) {
+                ex = e;
+                e.printStackTrace();
+            } finally {
+                em.close();
+            }
+        }
+    }
+}