--- /dev/null	2020-09-04 12:37:41.765504620 +0200
+++ new/src/hotspot/share/memory/metaspace/msInternalStats.hpp	2020-09-04 13:57:56.829394776 +0200
@@ -0,0 +1,124 @@
+/*
+ * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 2020 SAP SE. 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_MSINTERNALSTATS_HPP
+#define SHARE_MEMORY_METASPACE_MSINTERNALSTATS_HPP
+
+#include "memory/allocation.hpp"
+#include "runtime/atomic.hpp"
+#include "utilities/globalDefinitions.hpp"
+
+class outputStream;
+
+namespace metaspace {
+
+// These are some counters useful for debugging and analyzing Metaspace problems.
+// They get printed as part of the Metaspace report (e.g. via jcmd VM.metaspace)
+
+class InternalStats : public AllStatic {
+
+  // Note: all counters which are modified on the classloader local allocation path
+  //   (not under ExpandLock protection) have to be atomic.
+
+#define ALL_MY_COUNTERS(x, x_atomic)                \
+                                                    \
+  /* Number of allocations. */                      \
+  DEBUG_ONLY(x_atomic(num_allocs))                  \
+                                                    \
+  /* Number of external deallocations */            \
+  /* (excluding retired chunk remains) */           \
+  DEBUG_ONLY(x_atomic(num_deallocs))                \
+                                                    \
+  /* Number of times an allocation was satisfied */ \
+  /*  from deallocated blocks. */                   \
+  DEBUG_ONLY(x_atomic(num_allocs_from_deallocated_blocks)) \
+                                                    \
+  /* Number of times an arena retired a chunk */    \
+  DEBUG_ONLY(x_atomic(num_chunks_retired))          \
+                                                    \
+  /* Number of times an allocation failed */        \
+  /*  because we hit a limit. */                    \
+  x_atomic(num_allocs_failed_limit)                 \
+                                                    \
+  /* Number of times an arena was born ... */       \
+  x_atomic(num_arena_births)                        \
+  /* ... and died. */                               \
+  x_atomic(num_arena_deaths)                        \
+                                                    \
+  /* Number of times VirtualSpaceNode were */       \
+  /*  born...  */                                   \
+  x(num_vsnodes_births)                             \
+  /* ... and died. */                               \
+  x(num_vsnodes_deaths)                             \
+                                                    \
+  /* Number of times we committed space. */         \
+  x(num_space_committed)                            \
+  /* Number of times we uncommitted space. */       \
+  x(num_space_uncommitted)                          \
+                                                    \
+  /* Number of times a chunk was returned to the */ \
+  /*  freelist (external only). */                  \
+  x(num_chunks_returned_to_freelist)                \
+  /* Number of times a chunk was taken from */      \
+  /*  freelist (external only) */                   \
+  x(num_chunks_taken_from_freelist)                 \
+                                                    \
+  /* Number of successful chunk merges */           \
+  x(num_chunk_merges)                               \
+  /* Number of chunk splits */                      \
+  x(num_chunk_splits)                               \
+  /* Number of chunk in place enlargements */       \
+  x(num_chunks_enlarged)                            \
+                                                    \
+  /* Number of times we did a purge */              \
+  x(num_purges)                                     \
+
+#define DEFINE_COUNTER(name)          static uint64_t _##name;
+#define DEFINE_ATOMIC_COUNTER(name)   static volatile uint64_t _##name;
+  ALL_MY_COUNTERS(DEFINE_COUNTER, DEFINE_ATOMIC_COUNTER)
+#undef DEFINE_COUNTER
+#undef DEFINE_ATOMIC_COUNTER
+
+public:
+
+// incrementors
+#define INCREMENTOR(name)           static void inc_##name() { _##name++; }
+#define INCREMENTOR_ATOMIC(name)    static void inc_##name() { Atomic::inc(&_##name); }
+  ALL_MY_COUNTERS(INCREMENTOR, INCREMENTOR_ATOMIC)
+#undef INCREMENTOR
+#undef INCREMENTOR_ATOMIC
+
+// getters
+#define GETTER(name)                static uint64_t name() { return _##name; }
+  ALL_MY_COUNTERS(GETTER, GETTER)
+#undef GETTER
+
+  static void print_on(outputStream* st);
+
+};
+
+} // namespace metaspace
+
+#endif // SHARE_MEMORY_METASPACE_MSINTERNALSTATS_HPP