--- /dev/null	2016-10-25 08:46:44.038854975 +0200
+++ new/src/share/vm/evtrace/traceMetadata.cpp	2016-10-25 10:40:14.984781369 +0200
@@ -0,0 +1,79 @@
+/*
+ * Copyright (c) 2014, 2015, Dynatrace and/or its affiliates. All rights reserved.
+ *
+ * This file is part of the Lock Contention Tracing Subsystem for the HotSpot
+ * Virtual Machine, which is developed at Christian Doppler Laboratory on
+ * Monitoring and Evolution of Very-Large-Scale Software Systems. Please
+ * contact us at <http://mevss.jku.at/> if you need additional information
+ * or have any questions.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work. If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#include "evtrace/traceMetadata.hpp"
+
+TraceMetadata::TraceMetadata() {
+  _stack_cache = new TraceStackCache(this);
+  _last_stack_id = 0;
+  _last_global_seq = 0;
+}
+
+TraceMetadata::~TraceMetadata() {
+  delete _stack_cache;
+}
+
+class TraceMetadata::MarkKlassUnknownClosure: public KlassClosure {
+  static void mark_unknown(Method *m) {
+    m->reset_tracing_known();
+  }
+
+public:
+  virtual void do_klass(Klass *k) {
+    k->reset_tracing_known();
+    if (k->oop_is_instance()) {
+      InstanceKlass::cast(k)->methods_do(mark_unknown);
+    }
+  }
+};
+
+class TraceMetadata::ClearInvalidatedMementoStacksClosure: public ThreadClosure {
+  virtual void do_thread(Thread *t) {
+    assert(t != NULL, "null thread");
+    if (t->memento_stack_trace() != NULL && !t->memento_stack_trace()->is_valid()) {
+      t->set_memento_stack_trace(NULL);
+    }
+  }
+};
+
+void TraceMetadata::purge_all() {
+  assert(SafepointSynchronize::is_at_safepoint() && Thread::current()->is_VM_thread(), "must be done in VM thread at safepoint");
+
+  MarkKlassUnknownClosure mark_unknown;
+  ClassLoaderDataGraph::classes_do(&mark_unknown);
+
+  _stack_cache->purge_all();
+}
+
+void TraceMetadata::do_maintenance() {
+  assert(SafepointSynchronize::is_at_safepoint() && Thread::current()->is_VM_thread(), "must be done in VM thread at safepoint");
+
+  if (_stack_cache->has_invalid_stacks()) {
+    ClearInvalidatedMementoStacksClosure clear_invalid;
+    Threads::threads_do(&clear_invalid);
+  }
+
+  _stack_cache->do_maintenance();
+  assert(!_stack_cache->has_invalid_stacks(), "sanity");
+}