test/hotspot/gtest/memory/test_metachunk.cpp

/*
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 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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 *
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 * 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).
 *
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 * 2 along with this work; if not, write to the Free Software Foundation,
 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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#include "precompiled.hpp"
#include "memory/allocation.hpp"
#include "memory/metaspace/metachunk.hpp"
#include "unittest.hpp"
#include "utilities/align.hpp"
#include "utilities/copy.hpp"
#include "utilities/debug.hpp"

using namespace metaspace;

class MetachunkTest {
 public:
  static MetaWord* initial_top(Metachunk* metachunk) {
    return metachunk->initial_top();
  }
  static MetaWord* top(Metachunk* metachunk) {
    return metachunk->top();
  }

};

TEST(Metachunk, basic) {
  const ChunkIndex chunk_type = MediumIndex;
  const bool is_class = false;
  const size_t word_size = get_size_for_nonhumongous_chunktype(chunk_type, is_class);
  // Allocate the chunk with correct alignment.
  void* memory = malloc(word_size * BytesPerWord * 2);
  ASSERT_TRUE(NULL != memory) << "Failed to malloc 2MB";

  void* p_placement = align_up(memory, word_size * BytesPerWord);

  Metachunk* metachunk = ::new (p_placement) Metachunk(chunk_type, is_class, word_size, NULL);

  EXPECT_EQ((MetaWord*) metachunk, metachunk->bottom());
  EXPECT_EQ((uintptr_t*) metachunk + metachunk->size(), metachunk->end());

  // Check sizes
  EXPECT_EQ(metachunk->size(), metachunk->word_size());
  EXPECT_EQ(pointer_delta(metachunk->end(), metachunk->bottom(),
                          sizeof (MetaWord)),
            metachunk->word_size());

  // Check usage
  EXPECT_EQ(metachunk->used_word_size(), metachunk->overhead());
  EXPECT_EQ(metachunk->word_size() - metachunk->used_word_size(),
            metachunk->free_word_size());
  EXPECT_EQ(MetachunkTest::top(metachunk), MetachunkTest::initial_top(metachunk));
  EXPECT_TRUE(metachunk->is_empty());

  // Allocate
  size_t alloc_size = 64; // Words
  EXPECT_TRUE(is_aligned(alloc_size, Metachunk::object_alignment()));

  MetaWord* mem = metachunk->allocate(alloc_size);

  // Check post alloc
  EXPECT_EQ(MetachunkTest::initial_top(metachunk), mem);
  EXPECT_EQ(MetachunkTest::top(metachunk), mem + alloc_size);
  EXPECT_EQ(metachunk->overhead() + alloc_size, metachunk->used_word_size());
  EXPECT_EQ(metachunk->word_size() - metachunk->used_word_size(),
            metachunk->free_word_size());
  EXPECT_FALSE(metachunk->is_empty());

  // Clear chunk
  metachunk->reset_empty();

  // Check post clear
  EXPECT_EQ(metachunk->used_word_size(), metachunk->overhead());
  EXPECT_EQ(metachunk->word_size() - metachunk->used_word_size(),
            metachunk->free_word_size());
  EXPECT_EQ(MetachunkTest::top(metachunk), MetachunkTest::initial_top(metachunk));
  EXPECT_TRUE(metachunk->is_empty());

  free(memory);
}