report some statistics after test execution is completed

platform/core-api/src/com/intellij/openapi/application/ApplicationManager.java

@@ -26,6 +26,7 @@ import org.jetbrains.annotations.NotNull;
  */
 public class ApplicationManager {
   protected static Application ourApplication = null;
+  public static int ourApplicationChanges = 0;
 
   /**
    * Gets Application.
@@ -38,6 +39,7 @@ public class ApplicationManager {
 
   private static void setApplication(@NotNull Application instance) {
     ourApplication = instance;
+    ourApplicationChanges++;
     CachedSingletonsRegistry.cleanupCachedFields();
   }
 

platform/platform-impl/src/com/intellij/openapi/project/impl/ProjectManagerImpl.java

@@ -109,6 +109,8 @@ public class ProjectManagerImpl extends ProjectManagerEx implements PersistentSt
   private final ProgressManager myProgressManager;
   private volatile boolean myDefaultProjectWasDisposed = false;
 
+  public static int TEST_PROJECTS_OPENED = 0;
+
   private final Runnable restartApplicationOrReloadProjectTask = new Runnable() {
     @Override
     public void run() {
@@ -718,6 +720,7 @@ public class ProjectManagerImpl extends ProjectManagerEx implements PersistentSt
     synchronized (myOpenProjects) {
       assert ApplicationManager.getApplication().isUnitTestMode();
       assert !project.isDisposed() : "Must not open already disposed project";
+      TEST_PROJECTS_OPENED++;
       myTestProjects.add(project);
     }
   }

platform/testFramework/src/_LastInSuiteTest.java

@@ -17,6 +17,7 @@
 import com.intellij.openapi.application.ApplicationManager;
 import com.intellij.openapi.application.impl.ApplicationImpl;
 import com.intellij.openapi.command.WriteCommandAction;
+import com.intellij.openapi.project.impl.ProjectManagerImpl;
 import com.intellij.openapi.util.Disposer;
 import com.intellij.testFramework.LeakHunter;
 import com.intellij.testFramework.LightPlatformTestCase;
@@ -24,6 +25,8 @@ import com.intellij.util.ReflectionUtil;
 import com.intellij.util.ui.UIUtil;
 import junit.framework.TestCase;
 
+import java.lang.management.GarbageCollectorMXBean;
+import java.lang.management.ManagementFactory;
 import java.lang.reflect.Method;
 
 /**
@@ -61,6 +64,17 @@ public class _LastInSuiteTest extends TestCase {
     }
   }
 
+  @SuppressWarnings("UseOfSystemOutOrSystemErr")
+  public void testStatistics() throws Exception {
+    System.out.println("----- TEST STATISTICS -----");
+    System.out.println(String.format("Application reinitializations: %d", ApplicationManager.ourApplicationChanges));
+    System.out.println(String.format("Test projects opened: %d", ProjectManagerImpl.TEST_PROJECTS_OPENED));
+    for (GarbageCollectorMXBean mxBean : ManagementFactory.getGarbageCollectorMXBeans()) {
+      System.out.println(String.format("Garbage collection in memory pool %s: %d ms", mxBean.getName(), mxBean.getCollectionTime()));
+    }
+    System.out.println(String.format("Total classes loaded: %d", ManagementFactory.getClassLoadingMXBean().getTotalLoadedClassCount()));
+  }
+
   private static void captureMemorySnapshot() {
     try {
       Method snapshot = ReflectionUtil.getMethod(Class.forName("com.intellij.util.ProfilingUtil"), "forceCaptureMemorySnapshot");