1 /*
   2  * Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "utilities/bitMap.inline.hpp"
  27 #include "utilities/debug.hpp"
  28 #include "utilities/globalDefinitions.hpp"
  29 #include "unittest.hpp"
  30 
  31 typedef BitMap::idx_t idx_t;
  32 typedef BitMap::bm_word_t bm_word_t;
  33 
  34 static const idx_t BITMAP_SIZE = 1024;
  35 
  36 static const size_t search_chunk_size = 64;
  37 
  38 // Entries must be monotonically increasing.
  39 // Maximum entry must be < search_chunk_size.
  40 // Cluster values around possible word-size boundaries.
  41 static const size_t search_offsets[] =
  42   { 0, 1, 2, 29, 30, 31, 32, 33, 34, 60, 62, 63 };
  43 
  44 static const size_t search_noffsets = ARRAY_SIZE(search_offsets);
  45 
  46 static const size_t search_nchunks = BITMAP_SIZE / search_chunk_size;
  47 STATIC_ASSERT(search_nchunks * search_chunk_size == BITMAP_SIZE);
  48 
  49 namespace {
  50 class TestIteratorFn : public BitMapClosure {
  51 public:
  52   TestIteratorFn(size_t start, size_t end, size_t left, size_t right);
  53   virtual bool do_bit(size_t offset);
  54 
  55 private:
  56   size_t _entries[2];
  57   size_t _index;
  58   size_t _count;
  59   size_t _start;
  60   size_t _end;
  61   size_t _left;
  62   size_t _right;
  63 
  64   void do_bit_aux(size_t offset);
  65 
  66 };
  67 } // anonymous namespace
  68 
  69 TestIteratorFn::TestIteratorFn(size_t start, size_t end,
  70                                size_t left, size_t right) :
  71   _index(0), _count(0), _start(start), _end(end), _left(left), _right(right)
  72 {
  73   if ((_start <= _left) && (_left < _end)) {
  74     _entries[_count++] = _left;
  75   }
  76   if ((_start <= _right) && (_right < _end)) {
  77     _entries[_count++] = _right;
  78   }
  79 }
  80 
  81 void TestIteratorFn::do_bit_aux(size_t offset) {
  82   EXPECT_LT(_index, _count);
  83   if (_index < _count) {
  84     EXPECT_EQ(_entries[_index], offset);
  85     _index += 1;
  86   }
  87 }
  88 
  89 bool TestIteratorFn::do_bit(size_t offset) {
  90   do_bit_aux(offset);
  91   return true;
  92 }
  93 
  94 static idx_t compute_expected(idx_t search_start,
  95                               idx_t search_end,
  96                               idx_t left_bit,
  97                               idx_t right_bit) {
  98   idx_t expected = search_end;
  99   if (search_start <= left_bit) {
 100     if (left_bit < search_end) {
 101       expected = left_bit;
 102     }
 103   } else if (search_start <= right_bit) {
 104     if (right_bit < search_end) {
 105       expected = right_bit;
 106     }
 107   }
 108   return expected;
 109 }
 110 
 111 static void test_search_ranges(BitMap& test_ones,
 112                                BitMap& test_zeros,
 113                                idx_t left,
 114                                idx_t right) {
 115   // Test get_next_one_offset with full range of map.
 116   EXPECT_EQ(left, test_ones.get_next_one_offset(0));
 117   EXPECT_EQ(right, test_ones.get_next_one_offset(left + 1));
 118   EXPECT_EQ(BITMAP_SIZE, test_ones.get_next_one_offset(right + 1));
 119 
 120   // Test get_next_one_offset_inline_aligned_right with full range of map.
 121   EXPECT_EQ(left, test_ones.get_next_one_offset_inline_aligned_right(0, BITMAP_SIZE));
 122   EXPECT_EQ(right, test_ones.get_next_one_offset_inline_aligned_right(left + 1, BITMAP_SIZE));
 123   EXPECT_EQ(BITMAP_SIZE, test_ones.get_next_one_offset_inline_aligned_right(right + 1, BITMAP_SIZE));
 124 
 125   // Test get_next_zero_offset with full range of map.
 126   EXPECT_EQ(left, test_zeros.get_next_zero_offset(0));
 127   EXPECT_EQ(right, test_zeros.get_next_zero_offset(left + 1));
 128   EXPECT_EQ(BITMAP_SIZE, test_zeros.get_next_zero_offset(right + 1));
 129 
 130   // Check that iterate invokes the closure function on left and right values.
 131   TestIteratorFn test_iteration(0, BITMAP_SIZE, left, right);
 132   test_ones.iterate(&test_iteration, 0, BITMAP_SIZE);
 133 
 134   // Test searches with various start and end ranges.
 135   for (size_t c_start = 0; c_start < search_nchunks; ++c_start) {
 136     for (size_t o_start = 0; o_start < search_noffsets; ++o_start) {
 137       idx_t start = c_start * search_chunk_size + search_offsets[o_start];
 138       // Terminate start iteration if start is more than two full
 139       // chunks beyond left.  There isn't anything new to learn by
 140       // continuing the iteration, and this noticably reduces the
 141       // time to run the test.
 142       if (left + 2 * search_chunk_size < start) {
 143         c_start = search_nchunks; // Set to limit to terminate iteration.
 144         break;
 145       }
 146 
 147       for (size_t c_end = c_start; c_end < search_nchunks; ++c_end) {
 148         for (size_t o_end = (c_start == c_end) ? o_start : 0;
 149              o_end < search_noffsets;
 150              ++o_end) {
 151           idx_t end = c_end * search_chunk_size + search_offsets[o_end];
 152           // Similarly to start and left, terminate end iteration if
 153           // end is more than two full chunks beyond right.
 154           if (right + 2 * search_chunk_size < end) {
 155             c_end = search_nchunks; // Set to limit to terminate iteration.
 156             break;
 157           }
 158           // Skip this chunk if right is much larger than max(left, start)
 159           // and this chunk is one of many similar chunks in between,
 160           // again to reduce testing time.
 161           if (MAX2(start, left) + 2 * search_chunk_size < end) {
 162             if (end + 2 * search_chunk_size < right) {
 163               break;
 164             }
 165           }
 166 
 167           bool aligned_right = search_offsets[o_end] == 0;
 168           ASSERT_LE(start, end);       // test bug if fail
 169           ASSERT_LT(end, BITMAP_SIZE); // test bug if fail
 170 
 171           idx_t expected = compute_expected(start, end, left, right);
 172 
 173           EXPECT_EQ(expected, test_ones.get_next_one_offset(start, end));
 174           EXPECT_EQ(expected, test_zeros.get_next_zero_offset(start, end));
 175           if (aligned_right) {
 176             EXPECT_EQ(
 177               expected,
 178               test_ones.get_next_one_offset_inline_aligned_right(start, end));
 179           }
 180 
 181           idx_t start2 = MIN2(expected + 1, end);
 182           idx_t expected2 = compute_expected(start2, end, left, right);
 183 
 184           EXPECT_EQ(expected2, test_ones.get_next_one_offset(start2, end));
 185           EXPECT_EQ(expected2, test_zeros.get_next_zero_offset(start2, end));
 186           if (aligned_right) {
 187             EXPECT_EQ(
 188               expected2,
 189               test_ones.get_next_one_offset_inline_aligned_right(start2, end));
 190           }
 191         }
 192       }
 193     }
 194   }
 195 }
 196 
 197 TEST(BitMap, search) {
 198   CHeapBitMap test_ones(BITMAP_SIZE);
 199   CHeapBitMap test_zeros(BITMAP_SIZE);
 200 
 201   // test_ones is used to test searching for 1s in a region of 0s.
 202   // test_zeros is used to test searching for 0s in a region of 1s.
 203   test_ones.clear_range(0, test_ones.size());
 204   test_zeros.set_range(0, test_zeros.size());
 205 
 206   // Searching "empty" sequence should return size.
 207   EXPECT_EQ(BITMAP_SIZE, test_ones.get_next_one_offset(0));
 208   EXPECT_EQ(BITMAP_SIZE, test_zeros.get_next_zero_offset(0));
 209 
 210   // With left being in the first or second chunk...
 211   for (size_t c_left = 0; c_left < 2; ++c_left) {
 212     // Right bit is in the same chunk as left, or next chunk, or far away...
 213     for (size_t c_right = c_left;
 214          c_right < search_nchunks;
 215          (c_right == c_left + 1) ? c_right = search_nchunks - 1 : ++c_right) {
 216       // For each offset within the left chunk...
 217       for (size_t o_left = 0; o_left < search_noffsets; ++o_left) {
 218         // left is start of left chunk + offset.
 219         idx_t left = c_left * search_chunk_size + search_offsets[o_left];
 220 
 221         // Install the left bit.
 222         test_ones.set_bit(left);
 223         test_zeros.clear_bit(left);
 224         EXPECT_TRUE(test_ones.at(left));
 225         EXPECT_FALSE(test_zeros.at(left));
 226 
 227         // For each offset within the right chunk and > left...
 228         for (size_t o_right = (c_left == c_right) ? o_left + 1 : 0;
 229              o_right < search_noffsets;
 230              ++o_right) {
 231           // right is start of right chunk + offset.
 232           idx_t right = c_right * search_chunk_size + search_offsets[o_right];
 233 
 234           // Install the right bit.
 235           test_ones.set_bit(right);
 236           test_zeros.clear_bit(right);
 237           EXPECT_TRUE(test_ones.at(right));
 238           EXPECT_FALSE(test_zeros.at(right));
 239 
 240           // Apply the test.
 241           test_search_ranges(test_ones, test_zeros, left, right);
 242 
 243           // Remove the right bit.
 244           test_ones.clear_bit(right);
 245           test_zeros.set_bit(right);
 246           EXPECT_FALSE(test_ones.at(right));
 247           EXPECT_TRUE(test_zeros.at(right));
 248         }
 249 
 250         // Remove the left bit.
 251         test_ones.clear_bit(left);
 252         test_zeros.set_bit(left);
 253         EXPECT_FALSE(test_ones.at(left));
 254         EXPECT_TRUE(test_zeros.at(left));
 255       }
 256     }
 257   }
 258 }