--- old/src/hotspot/share/memory/metaspace/metaspaceCommon.hpp	2018-05-09 12:24:29.859546910 +0200
+++ new/src/hotspot/share/memory/metaspace/metaspaceCommon.hpp	2018-05-09 12:24:29.699545554 +0200
@@ -25,14 +25,23 @@
 #ifndef SHARE_MEMORY_METASPACE_METASPACECOMMON_HPP_
 #define SHARE_MEMORY_METASPACE_METASPACECOMMON_HPP_
 
+#include "utilities/debug.hpp"
 #include "utilities/globalDefinitions.hpp"
 
-
 class outputStream;
 
 namespace metaspace {
 namespace internals {
 
+enum ChunkSizes {    // in words.
+  ClassSpecializedChunk = 128,
+  SpecializedChunk = 128,
+  ClassSmallChunk = 256,
+  SmallChunk = 512,
+  ClassMediumChunk = 4 * K,
+  MediumChunk = 8 * K
+};
+
 // Print a size, in words, scaled.
 void print_scaled_words(outputStream* st, size_t word_size, size_t scale = 0, int width = -1);
 
@@ -50,6 +59,72 @@
 // larger than 99% but not 100% are displayed as ">100%".
 void print_percentage(outputStream* st, size_t total, size_t part);
 
+
+#define assert_is_aligned(value, alignment)                  \
+  assert(is_aligned((value), (alignment)),                   \
+         SIZE_FORMAT_HEX " is not aligned to "               \
+         SIZE_FORMAT, (size_t)(uintptr_t)value, (alignment))
+
+// Internal statistics.
+#ifdef ASSERT
+struct  internal_statistics_t {
+  // Number of allocations.
+  uintx num_allocs;
+  // Number of times a ClassLoaderMetaspace was born...
+  uintx num_metaspace_births;
+  // ... and died.
+  uintx num_metaspace_deaths;
+  // Number of times VirtualSpaceListNodes were created...
+  uintx num_vsnodes_created;
+  // ... and purged.
+  uintx num_vsnodes_purged;
+  // Number of times we expanded the committed section of the space.
+  uintx num_committed_space_expanded;
+  // Number of deallocations
+  uintx num_deallocs;
+  // Number of deallocations triggered from outside ("real" deallocations).
+  uintx num_external_deallocs;
+  // Number of times an allocation was satisfied from deallocated blocks.
+  uintx num_allocs_from_deallocated_blocks;
+};
+extern internal_statistics_t g_internal_statistics;
+#endif
+
+// ChunkIndex defines the type of chunk.
+// Chunk types differ by size: specialized < small < medium, chunks
+// larger than medium are humongous chunks of varying size.
+enum ChunkIndex {
+  ZeroIndex = 0,
+  SpecializedIndex = ZeroIndex,
+  SmallIndex = SpecializedIndex + 1,
+  MediumIndex = SmallIndex + 1,
+  HumongousIndex = MediumIndex + 1,
+  NumberOfFreeLists = 3,
+  NumberOfInUseLists = 4
+};
+
+// Utility functions.
+size_t get_size_for_nonhumongous_chunktype(ChunkIndex chunk_type, bool is_class);
+ChunkIndex get_chunk_type_by_size(size_t size, bool is_class);
+
+ChunkIndex next_chunk_index(ChunkIndex i);
+ChunkIndex prev_chunk_index(ChunkIndex i);
+// Returns a descriptive name for a chunk type.
+const char* chunk_size_name(ChunkIndex index);
+
+// Verify chunk type.
+inline bool is_valid_chunktype(ChunkIndex index) {
+  return index == SpecializedIndex || index == SmallIndex ||
+         index == MediumIndex || index == HumongousIndex;
+}
+
+inline bool is_valid_nonhumongous_chunktype(ChunkIndex index) {
+  return is_valid_chunktype(index) && index != HumongousIndex;
+}
+
+
+
+
 } // namespace internals
 } // namespace metaspace