diff -r 2c3cc4b01880 -r c16ac7a2eba4 src/hotspot/share/jfr/utilities/jfrThreadIterator.cpp
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/jfr/utilities/jfrThreadIterator.cpp	Wed Oct 30 19:43:52 2019 +0100
@@ -0,0 +1,87 @@
+/*
+ * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * 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, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "jfr/support/jfrThreadLocal.hpp"
+#include "jfr/utilities/jfrThreadIterator.hpp"
+#include "runtime/thread.inline.hpp"
+
+static bool thread_inclusion_predicate(Thread* t) {
+  assert(t != NULL, "invariant");
+  return !t->jfr_thread_local()->is_dead();
+}
+
+static bool java_thread_inclusion_predicate(JavaThread* jt) {
+  assert(jt != NULL, "invariant");
+  return thread_inclusion_predicate(jt) && jt->thread_state() != _thread_new;
+}
+
+static JavaThread* next_java_thread(JavaThreadIteratorWithHandle& iter) {
+  JavaThread* next = iter.next();
+  while (next != NULL && !java_thread_inclusion_predicate(next)) {
+    next = iter.next();
+  }
+  return next;
+}
+
+static NonJavaThread* next_non_java_thread(NonJavaThread::Iterator& iter) {
+  NonJavaThread* next = NULL;
+  while (!iter.end()) {
+    next = iter.current();
+    iter.step();
+    assert(next != NULL, "invariant");
+    if (!thread_inclusion_predicate(next)) {
+      continue;
+    }
+  }
+  return next;
+}
+
+JfrJavaThreadIteratorAdapter::JfrJavaThreadIteratorAdapter() : _iter(), _next(next_java_thread(_iter)) {}
+
+JavaThread* JfrJavaThreadIteratorAdapter::next() {
+  assert(has_next(), "invariant");
+  Type* const temp = _next;
+  _next = next_java_thread(_iter);
+  assert(temp != _next, "invariant");
+  return temp;
+}
+
+JfrNonJavaThreadIteratorAdapter::JfrNonJavaThreadIteratorAdapter() : _iter(), _next(next_non_java_thread(_iter)) {}
+
+bool JfrNonJavaThreadIteratorAdapter::has_next() const {
+  return _next != NULL;
+}
+
+NonJavaThread* JfrNonJavaThreadIteratorAdapter::next() {
+  assert(has_next(), "invariant");
+  Type* const temp = _next;
+  _next = next_non_java_thread(_iter);
+  assert(temp != _next, "invariant");
+  return temp;
+}
+
+// explicit instantiations
+template class JfrThreadIterator<JfrJavaThreadIteratorAdapter, StackObj>;
+template class JfrThreadIterator<JfrNonJavaThreadIteratorAdapter, StackObj>;