diff --git a/makefile b/makefile
index 9b7705e8b3..5c7f63fc0f 100644
--- a/makefile
+++ b/makefile
@@ -32,7 +32,7 @@ src = src
 classpath = classpath
 test = test
 
-input = $(cls)/Hello.class
+input = $(cls)/Threads.class
 
 cxx = g++
 cc = gcc
diff --git a/src/builtin.cpp b/src/builtin.cpp
index 01e69f8082..271288f6fd 100644
--- a/src/builtin.cpp
+++ b/src/builtin.cpp
@@ -308,11 +308,12 @@ Java_java_lang_reflect_Method_getCaller(Thread* t, jclass)
 {
   ENTER(t, Thread::ActiveState);
 
-  FrameIterator it; t->m->processor->start(t, &it);
-  t->m->processor->next(t, &it);
-  t->m->processor->next(t, &it);
+  Processor* p = t->m->processor;
+  uintptr_t frame = p->frameStart(t);
+  frame = p->frameNext(t, frame);
+  frame = p->frameNext(t, frame);
 
-  return makeLocalReference(t, it.method);
+  return makeLocalReference(t, p->frameMethod(t, frame));
 }
 
 extern "C" JNIEXPORT jobject JNICALL
@@ -321,7 +322,7 @@ Java_java_lang_reflect_Method_invoke
 {
   ENTER(t, Thread::ActiveState);
 
-  object v = t->m->processor->invoke
+  object v = t->m->processor->invokeArray
     (t, *method, (instance ? *instance : 0), *arguments);
   if (t->exception) {
     t->exception = makeInvocationTargetException(t, t->exception);
@@ -529,25 +530,27 @@ Java_java_lang_Throwable_trace(Thread* t, jclass, jint skipCount)
 {
   ENTER(t, Thread::ActiveState);
 
-  FrameIterator it; t->m->processor->start(t, &it);
+  Processor* p = t->m->processor;
+  uintptr_t frame = p->frameStart(t);
 
-  while (skipCount-- and it.valid()) {
-    t->m->processor->next(t, &it);
+  while (skipCount-- and p->frameValid(t, frame)) {
+    frame = p->frameNext(t, frame);
   }
   
   // skip Throwable constructors
-  while (it.valid()
+  while (p->frameValid(t, frame)
          and isAssignableFrom
          (t, arrayBody(t, t->m->types, Machine::ThrowableType),
-          methodClass(t, it.method))
+          methodClass(t, p->frameMethod(t, frame)))
          and strcmp(reinterpret_cast<const int8_t*>("<init>"),
-                    &byteArrayBody(t, methodName(t, it.method), 0))
+                    &byteArrayBody
+                    (t, methodName(t, p->frameMethod(t, frame)), 0))
          == 0)
   {
-    t->m->processor->next(t, &it);
+    frame = p->frameNext(t, frame);
   }
 
-  return makeLocalReference(t, makeTrace(t, &it));
+  return makeLocalReference(t, makeTrace(t, frame));
 }
 
 extern "C" JNIEXPORT jarray JNICALL
@@ -599,8 +602,7 @@ Java_java_lang_Thread_doStart(Thread* t, jobject this_)
 {
   ENTER(t, Thread::ActiveState);
 
-  Thread* p = new (t->m->system->allocate(sizeof(Thread)))
-    Thread(t->m, *this_, t);
+  Thread* p = t->m->processor->makeThread(t->m, *this_, t);
 
   enter(p, Thread::ActiveState);
 
diff --git a/src/interpret.cpp b/src/interpret.cpp
index 6ad06e7316..3a4fb5ac33 100644
--- a/src/interpret.cpp
+++ b/src/interpret.cpp
@@ -28,45 +28,6 @@ class Thread: public vm::Thread {
   uintptr_t stack[StackSizeInWords];
 };
 
-class MyProcessor: public Processor {
- public:
-  MyProcessor(System* s):
-    s(s)
-  { }
-
-  virtual vm::Thread*
-  makeThread(Machine* m, object javaThread, vm::Thread* parent)
-  {
-    return new (s->allocate(sizeof(Thread))) Thread(m, javaThread, parent);
-  }
-
-  virtual void
-  visitObjects(vm::Thread* t, Heap::Visitor* v);
-
-  virtual void 
-  start(vm::Thread* t, FrameIterator* it);
-
-  virtual void 
-  next(vm::Thread* t, FrameIterator* it);
-
-  virtual object
-  invokeArray(vm::Thread* t, object method, object this_, object arguments);
-
-  virtual object
-  invokeList(vm::Thread* t, object method, object this_, bool indirectObjects,
-             va_list arguments);
-
-  virtual object
-  invokeList(vm::Thread* t, const char* className, const char* methodName,
-             const char* methodSpec, object this_, va_list arguments);
-
-  virtual void dispose() {
-    s->free(this);
-  }
-  
-  System* s;
-};
-
 inline void
 pushObject(Thread* t, object o)
 {
@@ -3039,127 +3000,176 @@ invoke(Thread* t, object method)
   }
 }
 
-void
-MyProcessor::visitObjects(vm::Thread* vmt, Heap::Visitor* v)
-{
-  Thread* t = static_cast<Thread*>(vmt);
+class MyProcessor: public Processor {
+ public:
+  MyProcessor(System* s):
+    s(s)
+  { }
 
-  v->visit(&(t->code));
+  virtual vm::Thread*
+  makeThread(Machine* m, object javaThread, vm::Thread* parent)
+  {
+    return new (s->allocate(sizeof(Thread))) Thread(m, javaThread, parent);
+  }
 
-  for (unsigned i = 0; i < t->sp; ++i) {
-    if (t->stack[i * 2] == ObjectTag) {
-      v->visit(t->stack + (i * 2) + 1);
+  virtual void
+  visitObjects(vm::Thread* vmt, Heap::Visitor* v)
+  {
+    Thread* t = static_cast<Thread*>(vmt);
+
+    v->visit(&(t->code));
+
+    for (unsigned i = 0; i < t->sp; ++i) {
+      if (t->stack[i * 2] == ObjectTag) {
+        v->visit(t->stack + (i * 2) + 1);
+      }
     }
   }
-}
 
-void 
-MyProcessor::start(vm::Thread* vmt, FrameIterator* it)
-{
-  Thread* t = static_cast<Thread*>(vmt);
+  virtual uintptr_t
+  frameStart(vm::Thread* vmt)
+  {
+    Thread* t = static_cast<Thread*>(vmt);
 
-  int f = t->frame;
-  it->base = f + 1;
-  if (it->valid()) {
-    pokeInt(t, t->frame + FrameIpOffset, t->ip);
-    it->method = frameMethod(t, f);
-    it->ip = frameIp(t, f);
+    if (t->frame >= 0) {
+      pokeInt(t, t->frame + FrameIpOffset, t->ip);
+    }
+    return t->frame;
   }
-}
 
-void 
-MyProcessor::next(vm::Thread* vmt, FrameIterator* it)
-{
-  Thread* t = static_cast<Thread*>(vmt);
+  virtual uintptr_t
+  frameNext(vm::Thread* vmt, uintptr_t frame)
+  {
+    Thread* t = static_cast<Thread*>(vmt);
 
-  if (it->valid()) {
-    int f = frameNext(t, it->base - 1);
-    it->base = f + 1;
-    if (it->valid()) {
-      it->method = frameMethod(t, f);
-      it->ip = frameIp(t, f);
+    assert(t, static_cast<intptr_t>(frame) >= 0);
+    return ::frameNext(t, frame);
+  }
+
+  virtual bool
+  frameValid(vm::Thread*, uintptr_t frame)
+  {
+    return static_cast<intptr_t>(frame) >= 0;
+  }
+
+  virtual object
+  frameMethod(vm::Thread* vmt, uintptr_t frame)
+  {
+    Thread* t = static_cast<Thread*>(vmt);
+
+    assert(t, static_cast<intptr_t>(frame) >= 0);
+    return ::frameMethod(t, frame);
+  }
+
+  virtual unsigned
+  frameIp(vm::Thread* vmt, uintptr_t frame)
+  {
+    Thread* t = static_cast<Thread*>(vmt);
+
+    assert(t, static_cast<intptr_t>(frame) >= 0);
+    return ::frameIp(t, frame);
+  }
+
+  virtual object*
+  makeLocalReference(vm::Thread* vmt, object o)
+  {
+    Thread* t = static_cast<Thread*>(vmt);
+
+    return pushReference(t, o);
+  }
+
+  virtual void
+  disposeLocalReference(vm::Thread*, object* r)
+  {
+    if (r) {
+      *r = 0;
     }
   }
-}
 
-object
-MyProcessor::invokeArray(vm::Thread* vmt, object method, object this_,
-                         object arguments)
-{
-  Thread* t = static_cast<Thread*>(vmt);
-
-  assert(t, t->state == Thread::ActiveState
-         or t->state == Thread::ExclusiveState);
-
-  assert(t, ((methodFlags(t, method) & ACC_STATIC) == 0) xor (this_ == 0));
-
-  if (UNLIKELY(t->sp + methodParameterFootprint(t, method) + 1
-               > Thread::StackSizeInWords / 2))
+  virtual object
+  invokeArray(vm::Thread* vmt, object method, object this_, object arguments)
   {
-    t->exception = makeStackOverflowError(t);
-    return 0;
-  }
+    Thread* t = static_cast<Thread*>(vmt);
 
-  const char* spec = reinterpret_cast<char*>
-    (&byteArrayBody(t, methodSpec(t, method), 0));
-  pushArguments(t, this_, spec, arguments);
+    assert(t, t->state == Thread::ActiveState
+           or t->state == Thread::ExclusiveState);
 
-  return ::invoke(t, method);
-}
-
-object
-MyProcessor::invokeList(vm::Thread* vmt, object method, object this_,
-                        bool indirectObjects, va_list arguments)
-{
-  Thread* t = static_cast<Thread*>(vmt);
-
-  assert(t, t->state == Thread::ActiveState
-         or t->state == Thread::ExclusiveState);
-
-  assert(t, ((methodFlags(t, method) & ACC_STATIC) == 0) xor (this_ == 0));
-
-  if (UNLIKELY(t->sp + methodParameterFootprint(t, method) + 1
-               > Thread::StackSizeInWords / 2))
-  {
-    t->exception = makeStackOverflowError(t);
-    return 0;
-  }
-
-  const char* spec = reinterpret_cast<char*>
-    (&byteArrayBody(t, methodSpec(t, method), 0));
-  pushArguments(t, this_, spec, indirectObjects, arguments);
-
-  return ::invoke(t, method);
-}
-
-object
-MyProcessor::invokeList(vm::Thread* vmt, const char* className,
-                        const char* methodName, const char* methodSpec,
-                        object this_, va_list arguments)
-{
-  Thread* t = static_cast<Thread*>(vmt);
-
-  assert(t, t->state == Thread::ActiveState
-         or t->state == Thread::ExclusiveState);
-
-  if (UNLIKELY(t->sp + parameterFootprint(methodSpec) + 1
-               > Thread::StackSizeInWords / 2))
-  {
-    t->exception = makeStackOverflowError(t);
-    return 0;
-  }
-
-  pushArguments(t, this_, methodSpec, false, arguments);
-
-  object method = resolveMethod(t, className, methodName, methodSpec);
-  if (LIKELY(t->exception == 0)) {
     assert(t, ((methodFlags(t, method) & ACC_STATIC) == 0) xor (this_ == 0));
 
+    if (UNLIKELY(t->sp + methodParameterFootprint(t, method) + 1
+                 > Thread::StackSizeInWords / 2))
+    {
+      t->exception = makeStackOverflowError(t);
+      return 0;
+    }
+
+    const char* spec = reinterpret_cast<char*>
+      (&byteArrayBody(t, methodSpec(t, method), 0));
+    pushArguments(t, this_, spec, arguments);
+
     return ::invoke(t, method);
-  } else {
-    return 0;
   }
-}
+
+  virtual object
+  invokeList(vm::Thread* vmt, object method, object this_,
+             bool indirectObjects,
+             va_list arguments)
+  {
+    Thread* t = static_cast<Thread*>(vmt);
+
+    assert(t, t->state == Thread::ActiveState
+           or t->state == Thread::ExclusiveState);
+
+    assert(t, ((methodFlags(t, method) & ACC_STATIC) == 0) xor (this_ == 0));
+
+    if (UNLIKELY(t->sp + methodParameterFootprint(t, method) + 1
+                 > Thread::StackSizeInWords / 2))
+    {
+      t->exception = makeStackOverflowError(t);
+      return 0;
+    }
+
+    const char* spec = reinterpret_cast<char*>
+      (&byteArrayBody(t, methodSpec(t, method), 0));
+    pushArguments(t, this_, spec, indirectObjects, arguments);
+
+    return ::invoke(t, method);
+  }
+
+  virtual object
+  invokeList(vm::Thread* vmt, const char* className, const char* methodName,
+             const char* methodSpec, object this_, va_list arguments)
+  {
+    Thread* t = static_cast<Thread*>(vmt);
+
+    assert(t, t->state == Thread::ActiveState
+           or t->state == Thread::ExclusiveState);
+
+    if (UNLIKELY(t->sp + parameterFootprint(methodSpec) + 1
+                 > Thread::StackSizeInWords / 2))
+    {
+      t->exception = makeStackOverflowError(t);
+      return 0;
+    }
+
+    pushArguments(t, this_, methodSpec, false, arguments);
+
+    object method = resolveMethod(t, className, methodName, methodSpec);
+    if (LIKELY(t->exception == 0)) {
+      assert(t, ((methodFlags(t, method) & ACC_STATIC) == 0) xor (this_ == 0));
+
+      return ::invoke(t, method);
+    } else {
+      return 0;
+    }
+  }
+
+  virtual void dispose() {
+    s->free(this);
+  }
+  
+  System* s;
+};
 
 } // namespace
 
diff --git a/src/machine.cpp b/src/machine.cpp
index 0441ce6837..48011f44ba 100644
--- a/src/machine.cpp
+++ b/src/machine.cpp
@@ -2752,21 +2752,28 @@ run(System* system, Heap* heap, Finder* finder, Processor* processor,
 }
 
 object
-makeTrace(Thread* t, FrameIterator* it)
+makeTrace(Thread* t, uintptr_t start)
 {
+  Processor* p = t->m->processor;
+
   unsigned count = 0;
-  FrameIterator copy(it);
-  while (copy.valid()) {
+  for (uintptr_t frame = start;
+       p->frameValid(t, frame);
+       frame = p->frameNext(t, frame))
+  {
     ++ count;
-    t->m->processor->next(t, &copy);    
   }
 
   object trace = makeArray(t, count, true);
   PROTECT(t, trace);
   
   unsigned index = 0;
-  while (it->valid()) {
-    object e = makeTraceElement(t, it->method, it->ip);
+  for (uintptr_t frame = start;
+       p->frameValid(t, frame);
+       frame = p->frameNext(t, frame))
+  {
+    object e = makeTraceElement
+      (t, p->frameMethod(t, frame), p->frameIp(t, frame));
     set(t, arrayBody(t, trace, index++), e);
   }
 
diff --git a/src/machine.h b/src/machine.h
index ccc391c7fa..890fa7f9c5 100644
--- a/src/machine.h
+++ b/src/machine.h
@@ -1423,13 +1423,12 @@ arrayBodyUnsafe(Thread*, object, unsigned);
 #include "type-declarations.cpp"
 
 object
-makeTrace(Thread* t, FrameIterator* it);
+makeTrace(Thread* t, uintptr_t start);
 
 inline object
 makeTrace(Thread* t)
 {
-  FrameIterator it; t->m->processor->start(t, &it);
-  return makeTrace(t, &it);
+  return makeTrace(t, t->m->processor->frameStart(t));
 }
 
 inline object
@@ -2054,11 +2053,17 @@ int
 run(System* system, Heap* heap, Finder* finder, Processor* processor,
     const char* className, int argc, const char** argv);
 
-jobject
-makeLocalReference(Thread* t, object o);
+inline jobject
+makeLocalReference(Thread* t, object o)
+{
+  return t->m->processor->makeLocalReference(t, o);
+}
 
-void
-disposeLocalReference(Thread* t, jobject r);
+inline void
+disposeLocalReference(Thread* t, jobject r)
+{
+  t->m->processor->disposeLocalReference(t, r);
+}
 
 } // namespace vm
 
diff --git a/src/processor.h b/src/processor.h
index 929215ab1f..fa91fadbdc 100644
--- a/src/processor.h
+++ b/src/processor.h
@@ -7,29 +7,6 @@
 
 namespace vm {
 
-class FrameIterator {
- public:
-  FrameIterator():
-    base(0),
-    method(0),
-    ip(0)
-  { }
-
-  FrameIterator(FrameIterator* it):
-    base(it->base),
-    method(it->method),
-    ip(it->ip)
-  { }
-
-  bool valid() {
-    return base != 0;
-  }
-
-  uintptr_t base;
-  object method;
-  unsigned ip;
-};
-
 class Processor {
  public:
   virtual ~Processor() { }
@@ -40,11 +17,26 @@ class Processor {
   virtual void
   visitObjects(Thread* t, Heap::Visitor* v) = 0;
 
-  virtual void 
-  start(Thread* t, FrameIterator* it) = 0;
+  virtual uintptr_t
+  frameStart(Thread* t) = 0;
 
-  virtual void 
-  next(Thread* t, FrameIterator* it) = 0;
+  virtual uintptr_t
+  frameNext(Thread* t, uintptr_t frame) = 0;
+
+  virtual bool
+  frameValid(Thread* t, uintptr_t frame) = 0;
+
+  virtual object
+  frameMethod(Thread* t, uintptr_t frame) = 0;
+
+  virtual unsigned
+  frameIp(Thread* t, uintptr_t frame) = 0;
+
+  virtual object*
+  makeLocalReference(Thread* t, object o) = 0;
+
+  virtual void
+  disposeLocalReference(Thread* t, object* r) = 0;
 
   virtual object
   invokeArray(Thread* t, object method, object this_, object arguments) = 0;
diff --git a/valgrind.supp b/valgrind.supp
index 69ecd0aba1..9ca17ffbbf 100644
--- a/valgrind.supp
+++ b/valgrind.supp
@@ -17,28 +17,28 @@
    obj:/lib/ld-2.3.6.so
 }
 
-{
-   <insert a suppression name here>
-   Memcheck:Param
-   write(buf)
-   obj:*
-}
+# {
+#    <insert a suppression name here>
+#    Memcheck:Param
+#    write(buf)
+#    obj:*
+# }
 
-{
-   <insert a suppression name here>
-   Memcheck:Param
-   writev(vector[...])
-   obj:*
-}
+# {
+#    <insert a suppression name here>
+#    Memcheck:Param
+#    writev(vector[...])
+#    obj:*
+# }
 
-{
-   <insert a suppression name here>
-   Memcheck:Cond
-   obj:*
-}
+# {
+#    <insert a suppression name here>
+#    Memcheck:Cond
+#    obj:*
+# }
 
-{
-   <insert a suppression name here>
-   Memcheck:Value8
-   obj:*
-}
+# {
+#    <insert a suppression name here>
+#    Memcheck:Value8
+#    obj:*
+# }