internalStats.hpp

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 * Copyright (c) 2020, Oracle and/or its affiliates. All rights reserved.
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
 *
 * This code is free software; you can redistribute it and/or modify it
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 * 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
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#ifndef SHARE_MEMORY_METASPACE_INTERNALSTATS_HPP
#define SHARE_MEMORY_METASPACE_INTERNALSTATS_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)                                     \
                                                    \
  /* Number of times we read inconsistent stats. */ \
  x(num_inconsistent_stats)                         \

// Note: We use uintx since 32bit platforms lack 64bit atomic add; this increases
//  the possibility of counter overflows but the probability is very low for any counter
//  but num_allocs; note that these counters are for human eyes only.
#define DEFINE_COUNTER(name)          static uintx _##name;
#define DEFINE_ATOMIC_COUNTER(name)   static volatile uintx _##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_INTERNALSTATS_HPP