diff --git a/java/execution/impl/testDiscovery/org/jetbrains/testme/instrumentation/Instrumenter.java b/java/execution/impl/testDiscovery/org/jetbrains/testme/instrumentation/Instrumenter.java
index b9c68c17b098..a7c731e46990 100755
--- a/java/execution/impl/testDiscovery/org/jetbrains/testme/instrumentation/Instrumenter.java
+++ b/java/execution/impl/testDiscovery/org/jetbrains/testme/instrumentation/Instrumenter.java
@@ -17,11 +17,11 @@
 package org.jetbrains.testme.instrumentation;
 
 import org.jetbrains.org.objectweb.asm.ClassVisitor;
-import org.jetbrains.org.objectweb.asm.Label;
 import org.jetbrains.org.objectweb.asm.MethodVisitor;
 import org.jetbrains.org.objectweb.asm.Opcodes;
 
 public class Instrumenter extends ClassVisitor {
+  private static final int ADDED_CODE_STACK_SIZE = 6;
   protected final ClassVisitor myClassVisitor;
   private final String myClassName;
   private final String myInternalClassName;
@@ -88,7 +88,7 @@ public class Instrumenter extends ClassVisitor {
       mv = new StaticBlockMethodVisitor(mv);
       mv.visitCode();
       mv.visitInsn(Opcodes.RETURN);
-      mv.visitMaxs(myMethodNames.length + 2, 1);
+      mv.visitMaxs(ADDED_CODE_STACK_SIZE, 0);
       mv.visitEnd();
     }
     super.visitEnd();
@@ -102,12 +102,11 @@ public class Instrumenter extends ClassVisitor {
     public void visitCode() {
       super.visitCode();
 
+      visitLdcInsn(myClassName);
       pushInstruction(this, myMethodNames.length);
       visitIntInsn(Opcodes.NEWARRAY, Opcodes.T_BOOLEAN);
-      visitFieldInsn(Opcodes.PUTSTATIC, myInternalClassName, METHODS_VISITED, METHODS_VISITED_CLASS);
 
       pushInstruction(this, myMethodNames.length);
-
       visitTypeInsn(Opcodes.ANEWARRAY, "java/lang/String");
 
       for(int i = 0; i < myMethodNames.length; ++i) {
@@ -117,28 +116,16 @@ public class Instrumenter extends ClassVisitor {
         visitInsn(Opcodes.AASTORE);
       }
 
-      visitVarInsn(Opcodes.ASTORE, 0);
+      visitMethodInsn(Opcodes.INVOKESTATIC, ProjectData.PROJECT_DATA_OWNER, "trace", "(Ljava/lang/String;[Z[Ljava/lang/String;)[Z", false);
+      visitFieldInsn(Opcodes.PUTSTATIC, myInternalClassName, METHODS_VISITED, METHODS_VISITED_CLASS);
 
-      Label startLabel = new Label();
-      visitLabel(startLabel);
-
-      visitLdcInsn(myClassName);
-      visitFieldInsn(Opcodes.GETSTATIC, myInternalClassName, METHODS_VISITED, METHODS_VISITED_CLASS);
-      visitVarInsn(Opcodes.ALOAD, 0);
-      visitMethodInsn(Opcodes.INVOKESTATIC, ProjectData.PROJECT_DATA_OWNER, "trace", "(Ljava/lang/String;[Z[Ljava/lang/String;)V", false);
-
-      Label endLabel = new Label();
-      visitLabel(endLabel);
-
-      visitLocalVariable("methodNames", "[Ljava/lang/String;", null, startLabel, endLabel, 0);
       // no return here
     }
 
     public void visitMaxs(int maxStack, int maxLocals) {
-      final int ourMaxStack = myMethodNames.length + 2;
-      final int ourMaxLocals = 1;
+      final int ourMaxStack = ADDED_CODE_STACK_SIZE;
 
-      super.visitMaxs(Math.max(ourMaxStack, maxStack), Math.max(ourMaxLocals, maxLocals));
+      super.visitMaxs(Math.max(ourMaxStack, maxStack), maxLocals);
     }
   }
 
diff --git a/java/execution/impl/testDiscovery/org/jetbrains/testme/instrumentation/ProjectData.java b/java/execution/impl/testDiscovery/org/jetbrains/testme/instrumentation/ProjectData.java
index b05a9cfcedca..9d57b2893f13 100644
--- a/java/execution/impl/testDiscovery/org/jetbrains/testme/instrumentation/ProjectData.java
+++ b/java/execution/impl/testDiscovery/org/jetbrains/testme/instrumentation/ProjectData.java
@@ -17,42 +17,31 @@ public class ProjectData {
         myTraceDir = traceDir;
     }
 
-    private ConcurrentMap<String, Set<String>> myTrace;
     private final ConcurrentMap<String, boolean[]> myTrace2 = new ConcurrentHashMap<String, boolean[]>();
     private final ConcurrentMap<String, String[]> myTrace3 = new ConcurrentHashMap<String, String[]>();
 
     public static ProjectData getProjectData() {
         return ourData;
     }
-    
-    public static void trace(String className, String methodSignature) {
-        ourData.traceLines(className, methodSignature);
-    }
 
     // called from instrumented code during class's static init
-    public static void trace(String className, boolean[] methodFlags, String[] methodNames) {
-        ourData.traceLines(className, methodFlags, methodNames);
-    }
-    
-    public void traceLines(String className, String methodSignature) {
-        if (myTrace != null) {
-            Set<String> methods = myTrace.get(className);
-            if (methods == null) {
-                methods = new HashSet<String>();
-                Set<String> previousMethods = myTrace.putIfAbsent(className, methods);
-                if (previousMethods != null) methods = previousMethods;
-            }
-            synchronized (methods) {
-                methods.add(methodSignature);
-            }
-        }
+    public static boolean[] trace(String className, boolean[] methodFlags, String[] methodNames) {
+        return ourData.traceLines(className, methodFlags, methodNames);
     }
 
-    public synchronized void traceLines(String className, boolean[] methodFlags, String[] methodNames) {
+    private synchronized boolean[] traceLines(String className, boolean[] methodFlags, String[] methodNames) {
         //System.out.println("Registering " + className);
         assert methodFlags.length == methodNames.length;
-        myTrace2.put(className, methodFlags);
-        myTrace3.put(className, methodNames);
+        final boolean[] previousMethodFlags = myTrace2.putIfAbsent(className, methodFlags);
+
+        if (previousMethodFlags != null) {
+            assert previousMethodFlags.length == methodFlags.length;
+            final String[] previousMethodNames = myTrace3.get(className);
+            assert previousMethodNames != null && previousMethodNames.length == methodNames.length;
+        } else {
+            myTrace3.put(className, methodNames);
+        }
+        return previousMethodFlags != null ? previousMethodFlags : methodFlags;
     }
 
     private static final int STRING_LENGTH_THRESHOLD = 255;
@@ -163,22 +152,6 @@ public class ProjectData {
         catch (IOException e) {
            e.printStackTrace();
         }
-        finally {
-            myTrace = null;
-        }
-    }
-
-    private void saveOldTrace(DataOutputStream os) throws IOException {
-        os.writeInt(myTrace.size());
-        for (Iterator<String> it = myTrace.keySet().iterator(); it.hasNext();) {
-            final String classData = it.next();
-            os.writeUTF(classData);
-            final Set<String> methods = myTrace.get(classData);
-            os.writeInt(methods.size());
-            for (Iterator<String> iterator = methods.iterator(); iterator.hasNext(); ) {
-                os.writeUTF(iterator.next());
-            }
-        }
     }
 
     public synchronized void testStarted(final String name) {
@@ -190,8 +163,4 @@ public class ProjectData {
             }
         }
     }
-
-    private void clearOldTrace() {
-        myTrace = new ConcurrentHashMap<String, Set<String>>();
-    }
 }