--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/hotspot/share/memory/metaspace/commitLimiter.hpp	Tue Sep 10 09:24:05 2019 +0200
@@ -0,0 +1,65 @@
+/*
+ * Copyright (c) 2019, SAP SE. All rights reserved.
+ * 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.
+ *
+ */
+
+#ifndef SHARE_MEMORY_METASPACE_COMMITLIMITER_HPP
+#define SHARE_MEMORY_METASPACE_COMMITLIMITER_HPP
+
+#include "memory/allocation.hpp"
+#include "memory/metaspace/counter.hpp"
+
+namespace metaspace {
+
+class CommitLimiter : public CHeapObj<mtInternal> {
+
+  // Counts total words committed for metaspace
+  SizeCounter _cnt;
+
+  // Purely for testing purposes: cap, in words.
+  const size_t _cap;
+
+public:
+
+  // Create a commit limiter. This is only useful for testing, with a cap != 0,
+  // since normal code should use the global commit limiter.
+  // If cap != 0 (word size), the cap replaces the internal logic of limiting.
+  CommitLimiter(size_t cap = 0) : _cnt(), _cap(cap) {}
+
+  // Returns the size, in words, by which we may expand the metaspace committed area without:
+  // - _cap == 0: hitting GC threshold or the MaxMetaspaceSize
+  // - _cap > 0: hitting cap (this is just for testing purposes)
+  size_t possible_expansion_words() const;
+
+  void increase_committed(size_t word_size)   { _cnt.increment_by(word_size); }
+  void decrease_committed(size_t word_size)   { _cnt.decrement_by(word_size); }
+  size_t committed_words() const              { return _cnt.get(); }
+
+  // Returns the global metaspace commit counter
+  static CommitLimiter* globalLimiter();
+
+};
+
+} // namespace metaspace
+
+#endif // SHARE_MEMORY_METASPACE_COMMITLIMITER_HPP