text: /*
   * Copyright (c) 2018, 2021, 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.
   */
  
  #include "precompiled.hpp"
  #include "memory/virtualspace.hpp"
  #include "runtime/os.hpp"
  #include "oops/oop.hpp"
  #include "utilities/align.hpp"
  #include "concurrentTestRunner.inline.hpp"
  #include "unittest.hpp"
  
  namespace {
    class MemoryReleaser {
      ReservedSpace* const _rs;
     public:
      MemoryReleaser(ReservedSpace* rs) : _rs(rs) { }
      ~MemoryReleaser() {
        if (_rs->special()) {
          EXPECT_TRUE(os::release_memory_special(_rs->base(), _rs->size()));
        } else {
          EXPECT_TRUE(os::release_memory(_rs->base(), _rs->size()));
        }
      }
    };
  
    static void small_page_write(void* addr, size_t size) {
      size_t page_size = os::vm_page_size();
  
      char* end = (char*) addr + size;
      for (char* p = (char*) addr; p < end; p += page_size) {
        *p = 1;
      }
    }
  
    // have to use these functions, as gtest's _PRED macros don't like is_aligned
    // nor (is_aligned<size_t, size_t>)
    static bool is_size_aligned(size_t size, size_t alignment) {
      return is_aligned(size, alignment);
    }
    static bool is_ptr_aligned(void* ptr, size_t alignment) {
      return is_aligned(ptr, alignment);
    }
  
    static void test_reserved_size(size_t size) {
      ASSERT_PRED2(is_size_aligned, size, os::vm_allocation_granularity());
  
      ReservedSpace rs(size);
      MemoryReleaser releaser(&rs);
  
      EXPECT_TRUE(rs.base() != NULL) << "rs.special: " << rs.special();
      EXPECT_EQ(size, rs.size()) << "rs.special: " << rs.special();
  
      if (rs.special()) {
        small_page_write(rs.base(), size);
      }
    }
  
    static void test_reserved_size_alignment(size_t size, size_t alignment) {
      ASSERT_PRED2(is_size_aligned, size, alignment) << "Incorrect input parameters";
      size_t page_size = UseLargePages ? os::large_page_size() : os::vm_page_size();
      ReservedSpace rs(size, alignment, page_size, (char *) NULL);
  
      ASSERT_TRUE(rs.base() != NULL) << "rs.special = " << rs.special();
      ASSERT_EQ(size, rs.size()) << "rs.special = " << rs.special();
  
      EXPECT_PRED2(is_ptr_aligned, rs.base(), alignment)
              << "aligned sizes should always give aligned addresses";
      EXPECT_PRED2(is_ptr_aligned, (void*) rs.size(), alignment)
              << "aligned sizes should always give aligned addresses";
  
      if (rs.special()) {
        small_page_write(rs.base(), size);
      }
    }
  
    static void test_reserved_size_alignment_page_type(size_t size, size_t alignment, bool maybe_large) {
      if (size < alignment) {
        // Tests might set -XX:LargePageSizeInBytes=<small pages> and cause unexpected input arguments for this test.
        ASSERT_EQ((size_t) os::vm_page_size(), os::large_page_size()) << "Test needs further refinement";
        return;
      }
  
      ASSERT_PRED2(is_size_aligned, size, os::vm_allocation_granularity()) << "Must be at least AG aligned";
      ASSERT_PRED2(is_size_aligned, size, alignment) << "Must be at least AG aligned";
  
      bool large = maybe_large && UseLargePages && size >= os::large_page_size();
      size_t page_size = large ? os::large_page_size() : os::vm_page_size();
  
      ReservedSpace rs(size, alignment, page_size);
      MemoryReleaser releaser(&rs);
  
      EXPECT_TRUE(rs.base() != NULL) << "rs.special: " << rs.special();
      EXPECT_EQ(size, rs.size()) << "rs.special: " << rs.special();
  
      if (rs.special()) {
        small_page_write(rs.base(), size);
      }
    }
  }
  
  TEST_VM(ReservedSpace, size_alignment) {
    size_t size = 2 * 1024 * 1024;
    size_t ag   = os::vm_allocation_granularity();
  
    EXPECT_NO_FATAL_FAILURE(test_reserved_size_alignment(size,      ag));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size_alignment(size * 2,  ag));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size_alignment(size * 10, ag));
  }
  
  TEST_VM(ReservedSpace, size) {
    size_t size = 2 * 1024 * 1024;
    size_t ag = os::vm_allocation_granularity();
  
    EXPECT_NO_FATAL_FAILURE(test_reserved_size(size * 1));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size(size * 2));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size(size * 10));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size(ag));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size(size - ag));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size(size));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size(size + ag));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size(size * 2));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size(size * 2 - ag));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size(size * 2 + ag));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size(size * 3));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size(size * 3 - ag));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size(size * 3 + ag));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size(size * 10));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size(size * 10 + size / 2));
  }
  
  TEST_VM(ReservedSpace, size_alignment_page_type) {
    size_t ag = os::vm_allocation_granularity();
  
    EXPECT_NO_FATAL_FAILURE(test_reserved_size_alignment_page_type(ag,      ag    , false));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size_alignment_page_type(ag * 2,  ag    , false));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size_alignment_page_type(ag * 3,  ag    , false));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size_alignment_page_type(ag * 2,  ag * 2, false));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size_alignment_page_type(ag * 4,  ag * 2, false));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size_alignment_page_type(ag * 8,  ag * 2, false));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size_alignment_page_type(ag * 4,  ag * 4, false));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size_alignment_page_type(ag * 8,  ag * 4, false));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size_alignment_page_type(ag * 16, ag * 4, false));
  }
  
  TEST_VM(ReservedSpace, size_alignment_page_type_large_page) {
    if (!UseLargePages) {
      return;
    }
  
    size_t ag = os::vm_allocation_granularity();
    size_t lp = os::large_page_size();
  
    // Without large pages
    EXPECT_NO_FATAL_FAILURE(test_reserved_size_alignment_page_type(lp,     ag * 4, false));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size_alignment_page_type(lp * 2, ag * 4, false));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size_alignment_page_type(lp * 4, ag * 4, false));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size_alignment_page_type(lp,     lp    , false));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size_alignment_page_type(lp * 2, lp    , false));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size_alignment_page_type(lp * 3, lp    , false));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size_alignment_page_type(lp * 2, lp * 2, false));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size_alignment_page_type(lp * 4, lp * 2, false));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size_alignment_page_type(lp * 8, lp * 2, false));
  
    // With large pages
    EXPECT_NO_FATAL_FAILURE(test_reserved_size_alignment_page_type(lp, ag * 4    , true));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size_alignment_page_type(lp * 2, ag * 4, true));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size_alignment_page_type(lp * 4, ag * 4, true));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size_alignment_page_type(lp, lp        , true));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size_alignment_page_type(lp * 2, lp    , true));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size_alignment_page_type(lp * 3, lp    , true));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size_alignment_page_type(lp * 2, lp * 2, true));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size_alignment_page_type(lp * 4, lp * 2, true));
    EXPECT_NO_FATAL_FAILURE(test_reserved_size_alignment_page_type(lp * 8, lp * 2, true));
  }
  
  namespace {
    enum TestLargePages {
      Default,
      Disable,
      Reserve,
      Commit
    };
  
    class ReservedSpaceReleaser {
      ReservedSpace* const _rs;
     public:
      ReservedSpaceReleaser(ReservedSpace* rs) : _rs(rs) { }
      ~ReservedSpaceReleaser() {
        _rs->release();
      }
    };
  
    ReservedSpace reserve_memory(size_t reserve_size_aligned, TestLargePages mode) {
      switch(mode) {
        default:
        case Default:
        case Reserve:
          return ReservedSpace(reserve_size_aligned);
        case Disable:
        case Commit:
          return ReservedSpace(reserve_size_aligned,
                               os::vm_allocation_granularity(),
                               os::vm_page_size());
      }
    }
  
    bool initialize_virtual_space(VirtualSpace& vs, ReservedSpace rs, TestLargePages mode) {
      switch(mode) {
        default:
        case Default:
        case Reserve:
          return vs.initialize(rs, 0);
        case Disable:
          return vs.initialize_with_granularity(rs, 0, os::vm_page_size());
        case Commit:
          return vs.initialize_with_granularity(rs, 0, os::page_size_for_region_unaligned(rs.size(), 1));
      }
    }
  
   void test_virtual_space_actual_committed_space(size_t reserve_size, size_t commit_size,
                                                  TestLargePages mode = Default) {
      size_t granularity = os::vm_allocation_granularity();
      size_t reserve_size_aligned = align_up(reserve_size, granularity);
  
      ReservedSpace reserved = reserve_memory(reserve_size_aligned, mode);
      ReservedSpaceReleaser releaser(&reserved);
  
      ASSERT_TRUE(reserved.is_reserved());
  
      VirtualSpace vs;
      ASSERT_TRUE(initialize_virtual_space(vs, reserved, mode)) << "Failed to initialize VirtualSpace";
      vs.expand_by(commit_size, false);
  
      if (vs.special()) {
        EXPECT_EQ(reserve_size_aligned, vs.actual_committed_size());
      } else {
        EXPECT_GE(vs.actual_committed_size(), commit_size);
        // Approximate the commit granularity.
        // Make sure that we don't commit using large pages
        // if large pages has been disabled for this VirtualSpace.
        size_t commit_granularity = (mode == Disable || !UseLargePages) ?
                                     os::vm_page_size() : os::large_page_size();
        EXPECT_LT(vs.actual_committed_size(), commit_size + commit_granularity);
      }
    }
  }
  
  TEST_VM(VirtualSpace, actual_committed_space) {
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(4 * K,  0));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(4 * K,  4 * K));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(8 * K,  0));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(8 * K,  4 * K));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(8 * K,  8 * K));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(12 * K, 0));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(12 * K, 4 * K));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(12 * K, 8 * K));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(12 * K, 12 * K));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(64 * K, 0));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(64 * K, 32 * K));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(64 * K, 64 * K));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(2 * M,  0));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(2 * M,  4 * K));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(2 * M,  64 * K));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(2 * M,  1 * M));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(2 * M,  2 * M));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(10 * M, 0));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(10 * M, 4 * K));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(10 * M, 8 * K));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(10 * M, 1 * M));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(10 * M, 2 * M));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(10 * M, 5 * M));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(10 * M, 10 * M));
  }
  
  TEST_VM(VirtualSpace, actual_committed_space_one_large_page) {
    if (!UseLargePages) {
      return;
    }
  
    size_t large_page_size = os::large_page_size();
  
    ReservedSpace reserved(large_page_size, large_page_size, large_page_size);
    ReservedSpaceReleaser releaser(&reserved);
    ASSERT_TRUE(reserved.is_reserved());
  
    VirtualSpace vs;
    ASSERT_TRUE(vs.initialize(reserved, 0)) << "Failed to initialize VirtualSpace";
    vs.expand_by(large_page_size, false);
  
    EXPECT_EQ(large_page_size, vs.actual_committed_size());
  }
  
  TEST_VM(VirtualSpace, disable_large_pages) {
    if (!UseLargePages) {
      return;
    }
    // These test cases verify that if we force VirtualSpace to disable large pages
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(10 * M, 0,      Disable));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(10 * M, 4 * K,  Disable));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(10 * M, 8 * K,  Disable));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(10 * M, 1 * M,  Disable));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(10 * M, 2 * M,  Disable));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(10 * M, 5 * M,  Disable));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(10 * M, 10 * M, Disable));
  
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(10 * M, 0,      Reserve));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(10 * M, 4 * K,  Reserve));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(10 * M, 8 * K,  Reserve));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(10 * M, 1 * M,  Reserve));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(10 * M, 2 * M,  Reserve));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(10 * M, 5 * M,  Reserve));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(10 * M, 10 * M, Reserve));
  
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(10 * M, 0,      Commit));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(10 * M, 4 * K,  Commit));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(10 * M, 8 * K,  Commit));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(10 * M, 1 * M,  Commit));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(10 * M, 2 * M,  Commit));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(10 * M, 5 * M,  Commit));
    EXPECT_NO_FATAL_FAILURE(test_virtual_space_actual_committed_space(10 * M, 10 * M, Commit));
  }
  
  
  // ========================= concurrent virtual space memory tests
  // This class have been imported from the original "internal VM test" with minor modification,
  // specifically using GTest asserts instead of native HotSpot asserts.
  class TestReservedSpace : AllStatic {
   public:
    static void small_page_write(void* addr, size_t size) {
      size_t page_size = os::vm_page_size();
  
      char* end = (char*)addr + size;
      for (char* p = (char*)addr; p < end; p += page_size) {
        *p = 1;
      }
    }
  
    static void release_memory_for_test(ReservedSpace rs) {
      if (rs.special()) {
        EXPECT_TRUE(os::release_memory_special(rs.base(), rs.size()));
      } else {
        EXPECT_TRUE(os::release_memory(rs.base(), rs.size()));
      }
    }
  
    static void test_reserved_space1(size_t size, size_t alignment) {
      ASSERT_TRUE(is_aligned(size, alignment)) << "Incorrect input parameters";
      size_t page_size = UseLargePages ? os::large_page_size() : os::vm_page_size();
      ReservedSpace rs(size,          // size
                       alignment,     // alignment
                       page_size, // page size
                       (char *)NULL); // requested_address
  
      EXPECT_TRUE(rs.base() != NULL);
      EXPECT_EQ(rs.size(), size) <<  "rs.size: " << rs.size();
  
      EXPECT_TRUE(is_aligned(rs.base(), alignment)) << "aligned sizes should always give aligned addresses";
      EXPECT_TRUE(is_aligned(rs.size(), alignment)) <<  "aligned sizes should always give aligned addresses";
  
      if (rs.special()) {
        small_page_write(rs.base(), size);
      }
  
      release_memory_for_test(rs);
    }
  
    static void test_reserved_space2(size_t size) {
      ASSERT_TRUE(is_aligned(size, os::vm_allocation_granularity())) << "Must be at least AG aligned";
  
      ReservedSpace rs(size);
  
      EXPECT_TRUE(rs.base() != NULL);
      EXPECT_EQ(rs.size(), size) <<  "rs.size: " << rs.size();
  
      if (rs.special()) {
        small_page_write(rs.base(), size);
      }
  
      release_memory_for_test(rs);
    }
  
    static void test_reserved_space3(size_t size, size_t alignment, bool maybe_large) {
      if (size < alignment) {
        // Tests might set -XX:LargePageSizeInBytes=<small pages> and cause unexpected input arguments for this test.
        ASSERT_EQ((size_t)os::vm_page_size(), os::large_page_size()) << "Test needs further refinement";
        return;
      }
  
      EXPECT_TRUE(is_aligned(size, os::vm_allocation_granularity())) << "Must be at least AG aligned";
      EXPECT_TRUE(is_aligned(size, alignment)) << "Must be at least aligned against alignment";
  
      bool large = maybe_large && UseLargePages && size >= os::large_page_size();
      size_t page_size = large ? os::large_page_size() : os::vm_page_size();
  
      ReservedSpace rs(size, alignment, page_size);
  
      EXPECT_TRUE(rs.base() != NULL);
      EXPECT_EQ(rs.size(), size) <<  "rs.size: " << rs.size();
  
      if (rs.special()) {
        small_page_write(rs.base(), size);
      }
  
      release_memory_for_test(rs);
    }
  
  
    static void test_reserved_space1() {
      size_t size = 2 * 1024 * 1024;
      size_t ag   = os::vm_allocation_granularity();
  
      test_reserved_space1(size,      ag);
      test_reserved_space1(size * 2,  ag);
      test_reserved_space1(size * 10, ag);
    }
  
    static void test_reserved_space2() {
      size_t size = 2 * 1024 * 1024;
      size_t ag = os::vm_allocation_granularity();
  
      test_reserved_space2(size * 1);
      test_reserved_space2(size * 2);
      test_reserved_space2(size * 10);
      test_reserved_space2(ag);
      test_reserved_space2(size - ag);
      test_reserved_space2(size);
      test_reserved_space2(size + ag);
      test_reserved_space2(size * 2);
      test_reserved_space2(size * 2 - ag);
      test_reserved_space2(size * 2 + ag);
      test_reserved_space2(size * 3);
      test_reserved_space2(size * 3 - ag);
      test_reserved_space2(size * 3 + ag);
      test_reserved_space2(size * 10);
      test_reserved_space2(size * 10 + size / 2);
    }
  
    static void test_reserved_space3() {
      size_t ag = os::vm_allocation_granularity();
  
      test_reserved_space3(ag,      ag    , false);
      test_reserved_space3(ag * 2,  ag    , false);
      test_reserved_space3(ag * 3,  ag    , false);
      test_reserved_space3(ag * 2,  ag * 2, false);
      test_reserved_space3(ag * 4,  ag * 2, false);
      test_reserved_space3(ag * 8,  ag * 2, false);
      test_reserved_space3(ag * 4,  ag * 4, false);
      test_reserved_space3(ag * 8,  ag * 4, false);
      test_reserved_space3(ag * 16, ag * 4, false);
  
      if (UseLargePages) {
        size_t lp = os::large_page_size();
  
        // Without large pages
        test_reserved_space3(lp,     ag * 4, false);
        test_reserved_space3(lp * 2, ag * 4, false);
        test_reserved_space3(lp * 4, ag * 4, false);
        test_reserved_space3(lp,     lp    , false);
        test_reserved_space3(lp * 2, lp    , false);
        test_reserved_space3(lp * 3, lp    , false);
        test_reserved_space3(lp * 2, lp * 2, false);
        test_reserved_space3(lp * 4, lp * 2, false);
        test_reserved_space3(lp * 8, lp * 2, false);
  
        // With large pages
        test_reserved_space3(lp, ag * 4    , true);
        test_reserved_space3(lp * 2, ag * 4, true);
        test_reserved_space3(lp * 4, ag * 4, true);
        test_reserved_space3(lp, lp        , true);
        test_reserved_space3(lp * 2, lp    , true);
        test_reserved_space3(lp * 3, lp    , true);
        test_reserved_space3(lp * 2, lp * 2, true);
        test_reserved_space3(lp * 4, lp * 2, true);
        test_reserved_space3(lp * 8, lp * 2, true);
      }
    }
  
    static void test_reserved_space() {
      test_reserved_space1();
      test_reserved_space2();
      test_reserved_space3();
    }
  };
  
  
  class TestVirtualSpace : AllStatic {
    enum TestLargePages {
      Default,
      Disable,
      Reserve,
      Commit
    };
  
    static ReservedSpace reserve_memory(size_t reserve_size_aligned, TestLargePages mode) {
      switch(mode) {
      default:
      case Default:
      case Reserve:
        return ReservedSpace(reserve_size_aligned);
      case Disable:
      case Commit:
        return ReservedSpace(reserve_size_aligned,
                             os::vm_allocation_granularity(),
                             os::vm_page_size());
      }
    }
  
    static bool initialize_virtual_space(VirtualSpace& vs, ReservedSpace rs, TestLargePages mode) {
      switch(mode) {
      default:
      case Default:
      case Reserve:
        return vs.initialize(rs, 0);
      case Disable:
        return vs.initialize_with_granularity(rs, 0, os::vm_page_size());
      case Commit:
        return vs.initialize_with_granularity(rs, 0, os::page_size_for_region_unaligned(rs.size(), 1));
      }
    }
  
   public:
    static void test_virtual_space_actual_committed_space(size_t reserve_size, size_t commit_size,
                                                          TestLargePages mode = Default) {
      size_t granularity = os::vm_allocation_granularity();
      size_t reserve_size_aligned = align_up(reserve_size, granularity);
  
      ReservedSpace reserved = reserve_memory(reserve_size_aligned, mode);
  
      EXPECT_TRUE(reserved.is_reserved());
  
      VirtualSpace vs;
      bool initialized = initialize_virtual_space(vs, reserved, mode);
      EXPECT_TRUE(initialized) << "Failed to initialize VirtualSpace";
  
      vs.expand_by(commit_size, false);
  
      if (vs.special()) {
        EXPECT_EQ(vs.actual_committed_size(), reserve_size_aligned);
      } else {
        EXPECT_GE(vs.actual_committed_size(), commit_size);
        // Approximate the commit granularity.
        // Make sure that we don't commit using large pages
        // if large pages has been disabled for this VirtualSpace.
        size_t commit_granularity = (mode == Disable || !UseLargePages) ?
                                     os::vm_page_size() : os::large_page_size();
        EXPECT_LT(vs.actual_committed_size(), commit_size + commit_granularity);
      }
  
      reserved.release();
    }
  
    static void test_virtual_space_actual_committed_space_one_large_page() {
      if (!UseLargePages) {
        return;
      }
  
      size_t large_page_size = os::large_page_size();
  
      ReservedSpace reserved(large_page_size, large_page_size, large_page_size);
  
      EXPECT_TRUE(reserved.is_reserved());
  
      VirtualSpace vs;
      bool initialized = vs.initialize(reserved, 0);
      EXPECT_TRUE(initialized) << "Failed to initialize VirtualSpace";
  
      vs.expand_by(large_page_size, false);
  
      EXPECT_EQ(vs.actual_committed_size(), large_page_size);
  
      reserved.release();
    }
  
    static void test_virtual_space_actual_committed_space() {
      test_virtual_space_actual_committed_space(4 * K, 0);
      test_virtual_space_actual_committed_space(4 * K, 4 * K);
      test_virtual_space_actual_committed_space(8 * K, 0);
      test_virtual_space_actual_committed_space(8 * K, 4 * K);
      test_virtual_space_actual_committed_space(8 * K, 8 * K);
      test_virtual_space_actual_committed_space(12 * K, 0);
      test_virtual_space_actual_committed_space(12 * K, 4 * K);
      test_virtual_space_actual_committed_space(12 * K, 8 * K);
      test_virtual_space_actual_committed_space(12 * K, 12 * K);
      test_virtual_space_actual_committed_space(64 * K, 0);
      test_virtual_space_actual_committed_space(64 * K, 32 * K);
      test_virtual_space_actual_committed_space(64 * K, 64 * K);
      test_virtual_space_actual_committed_space(2 * M, 0);
      test_virtual_space_actual_committed_space(2 * M, 4 * K);
      test_virtual_space_actual_committed_space(2 * M, 64 * K);
      test_virtual_space_actual_committed_space(2 * M, 1 * M);
      test_virtual_space_actual_committed_space(2 * M, 2 * M);
      test_virtual_space_actual_committed_space(10 * M, 0);
      test_virtual_space_actual_committed_space(10 * M, 4 * K);
      test_virtual_space_actual_committed_space(10 * M, 8 * K);
      test_virtual_space_actual_committed_space(10 * M, 1 * M);
      test_virtual_space_actual_committed_space(10 * M, 2 * M);
      test_virtual_space_actual_committed_space(10 * M, 5 * M);
      test_virtual_space_actual_committed_space(10 * M, 10 * M);
    }
  
    static void test_virtual_space_disable_large_pages() {
      if (!UseLargePages) {
        return;
      }
      // These test cases verify that if we force VirtualSpace to disable large pages
      test_virtual_space_actual_committed_space(10 * M, 0, Disable);
      test_virtual_space_actual_committed_space(10 * M, 4 * K, Disable);
      test_virtual_space_actual_committed_space(10 * M, 8 * K, Disable);
      test_virtual_space_actual_committed_space(10 * M, 1 * M, Disable);
      test_virtual_space_actual_committed_space(10 * M, 2 * M, Disable);
      test_virtual_space_actual_committed_space(10 * M, 5 * M, Disable);
      test_virtual_space_actual_committed_space(10 * M, 10 * M, Disable);
  
      test_virtual_space_actual_committed_space(10 * M, 0, Reserve);
      test_virtual_space_actual_committed_space(10 * M, 4 * K, Reserve);
      test_virtual_space_actual_committed_space(10 * M, 8 * K, Reserve);
      test_virtual_space_actual_committed_space(10 * M, 1 * M, Reserve);
      test_virtual_space_actual_committed_space(10 * M, 2 * M, Reserve);
      test_virtual_space_actual_committed_space(10 * M, 5 * M, Reserve);
      test_virtual_space_actual_committed_space(10 * M, 10 * M, Reserve);
  
      test_virtual_space_actual_committed_space(10 * M, 0, Commit);
      test_virtual_space_actual_committed_space(10 * M, 4 * K, Commit);
      test_virtual_space_actual_committed_space(10 * M, 8 * K, Commit);
      test_virtual_space_actual_committed_space(10 * M, 1 * M, Commit);
      test_virtual_space_actual_committed_space(10 * M, 2 * M, Commit);
      test_virtual_space_actual_committed_space(10 * M, 5 * M, Commit);
      test_virtual_space_actual_committed_space(10 * M, 10 * M, Commit);
    }
  
    static void test_virtual_space() {
      test_virtual_space_actual_committed_space();
      test_virtual_space_actual_committed_space_one_large_page();
      test_virtual_space_disable_large_pages();
    }
  };
  
  class ReservedSpaceRunnable : public TestRunnable {
  public:
    void runUnitTest() const {
      TestReservedSpace::test_reserved_space();
    }
  };
  
  TEST_VM(VirtualSpace, os_reserve_space_concurrent) {
    ReservedSpaceRunnable runnable;
    ConcurrentTestRunner testRunner(&runnable, 5, 3000);
    testRunner.run();
  }
  
  class VirtualSpaceRunnable : public TestRunnable {
  public:
    void runUnitTest() const {
      TestVirtualSpace::test_virtual_space();
    }
  };
  
  TEST_VM(VirtualSpace, os_virtual_space_concurrent) {
    VirtualSpaceRunnable runnable;
    ConcurrentTestRunner testRunner(&runnable, 5, 3000);
    testRunner.run();
  }
  