range_map_shrink_down_unittest.cc

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// range_map_shrink_down_unittest.cc: Unit tests for RangeMap that specifically
// test shrink down when ranges overlap.
//
// Author: Ivan Penkov

#include <limits.h>
#include <stdio.h>

#include "processor/range_map-inl.h"

#include "breakpad_googletest_includes.h"
#include "common/scoped_ptr.h"
#include "processor/linked_ptr.h"
#include "processor/logging.h"

namespace {

using google_breakpad::linked_ptr;
using google_breakpad::scoped_ptr;
using google_breakpad::RangeMap;

// A CountedObject holds an int.  A global (not thread safe!) count of
// allocated CountedObjects is maintained to help test memory management.
class CountedObject {
 public:
  explicit CountedObject(int id) : id_(id) { ++count_; }
  ~CountedObject() { --count_; }

  static int count() { return count_; }
  int id() const { return id_; }

 private:
  static int count_;
  int id_;
};

int CountedObject::count_;

typedef int AddressType;
typedef RangeMap<AddressType, linked_ptr<CountedObject>> TestMap;

// Same range cannot be stored wice.
TEST(RangeMap, TestShinkDown_SameRange) {
  TestMap range_map;
  range_map.SetEnableShrinkDown(true);
  linked_ptr<CountedObject> object_1(new CountedObject(1));
  EXPECT_TRUE(range_map.StoreRange(0 /* base address */, 100 /* size */,
                                   object_1));

  // Same range cannot be stored wice.
  linked_ptr<CountedObject> object_2(new CountedObject(2));
  EXPECT_FALSE(range_map.StoreRange(0 /* base address */, 100 /* size */,
                                    object_2));
}

// If a range is completely contained by another range, then the larger range
// should be shrinked down.
TEST(RangeMap, TestShinkDown_CompletelyContained) {
  TestMap range_map;
  range_map.SetEnableShrinkDown(true);
  // Larger range is added first.
  linked_ptr<CountedObject> object_1(new CountedObject(1));
  EXPECT_TRUE(range_map.StoreRange(0 /* base address */, 100 /* size */,
                                   object_1));
  // Smaller (contained) range is added second.
  linked_ptr<CountedObject> object_2(new CountedObject(2));
  EXPECT_TRUE(range_map.StoreRange(10 /* base address */, 80 /* size */,
                                   object_2));
  linked_ptr<CountedObject> object;
  AddressType retrieved_base = AddressType();
  AddressType retrieved_delta = AddressType();
  AddressType retrieved_size = AddressType();
  // The first range contains the second, so the first range should have been
  // shrunk to [90, 99].  Range [0, 9] should be free.
  EXPECT_FALSE(range_map.RetrieveRange(0, &object, &retrieved_base,
                                       &retrieved_delta, &retrieved_size));
  EXPECT_FALSE(range_map.RetrieveRange(9, &object, &retrieved_base,
                                       &retrieved_delta, &retrieved_size));
  EXPECT_TRUE(range_map.RetrieveRange(90, &object, &retrieved_base,
                                      &retrieved_delta, &retrieved_size));
  EXPECT_EQ(1, object->id());
  EXPECT_EQ(90, retrieved_base);
  EXPECT_EQ(90, retrieved_delta);
  EXPECT_EQ(10, retrieved_size);
  // Validate the properties of the smaller range (should be untouched).
  EXPECT_TRUE(range_map.RetrieveRange(10, &object, &retrieved_base,
                                      &retrieved_delta, &retrieved_size));
  EXPECT_EQ(2, object->id());
  EXPECT_EQ(10, retrieved_base);
  EXPECT_EQ(0, retrieved_delta);
  EXPECT_EQ(80, retrieved_size);
}

// Same as the previous test, however the larger range is added second.
TEST(RangeMap, TestShinkDown_CompletelyContained_LargerAddedSecond) {
  TestMap range_map;
  range_map.SetEnableShrinkDown(true);
  // Smaller (contained) range is added first.
  linked_ptr<CountedObject> object_1(new CountedObject(1));
  EXPECT_TRUE(range_map.StoreRange(10 /* base address */, 80 /* size */,
                                   object_1));
  // Larger range is added second.
  linked_ptr<CountedObject> object_2(new CountedObject(2));
  EXPECT_TRUE(range_map.StoreRange(0 /* base address */, 100 /* size */,
                                   object_2));
  linked_ptr<CountedObject> object;
  AddressType retrieved_base = AddressType();
  AddressType retrieved_delta = AddressType();
  AddressType retrieved_size = AddressType();
  // The second range contains the first, so the second range should have been
  // shrunk to [90, 99].  Range [0, 9] should be free.
  EXPECT_FALSE(range_map.RetrieveRange(0, &object, &retrieved_base,
                                       &retrieved_delta, &retrieved_size));
  EXPECT_FALSE(range_map.RetrieveRange(9, &object, &retrieved_base,
                                       &retrieved_delta, &retrieved_size));
  EXPECT_TRUE(range_map.RetrieveRange(90, &object, &retrieved_base,
                                      &retrieved_delta, &retrieved_size));
  EXPECT_EQ(2, object->id());
  EXPECT_EQ(90, retrieved_base);
  EXPECT_EQ(90, retrieved_delta);
  EXPECT_EQ(10, retrieved_size);
  // Validate the properties of the smaller range (should be untouched).
  EXPECT_TRUE(range_map.RetrieveRange(10, &object, &retrieved_base,
                                      &retrieved_delta, &retrieved_size));
  EXPECT_EQ(1, object->id());
  EXPECT_EQ(10, retrieved_base);
  EXPECT_EQ(0, retrieved_delta);
  EXPECT_EQ(80, retrieved_size);
}

TEST(RangeMap, TestShinkDown_PartialOverlap_AtBeginning) {
  TestMap range_map;
  range_map.SetEnableShrinkDown(true);
  linked_ptr<CountedObject> object_1(new CountedObject(1));
  EXPECT_TRUE(range_map.StoreRange(0 /* base address */, 100 /* size */,
                                   object_1));

  // Partial overlap at the beginning of the new range.
  linked_ptr<CountedObject> object_2(new CountedObject(2));
  EXPECT_TRUE(range_map.StoreRange(90 /* base address */, 110 /* size */,
                                   object_2));

  linked_ptr<CountedObject> object;
  AddressType retrieved_base = AddressType();
  AddressType retrieved_delta = AddressType();
  AddressType retrieved_size = AddressType();
  // The second range is supposed to be shrunk down so the following address
  // should resize in the first range.
  EXPECT_TRUE(range_map.RetrieveRange(99, &object, &retrieved_base,
                                      &retrieved_delta, &retrieved_size));
  EXPECT_EQ(1, object->id());
  EXPECT_EQ(0, retrieved_base);
  EXPECT_EQ(0, retrieved_delta);
  EXPECT_EQ(100, retrieved_size);
  // Validate the properties of the shrunk down range.
  EXPECT_TRUE(range_map.RetrieveRange(100, &object, &retrieved_base,
                                      &retrieved_delta, &retrieved_size));
  EXPECT_EQ(2, object->id());
  EXPECT_EQ(100, retrieved_base);
  EXPECT_EQ(10, retrieved_delta);
  EXPECT_EQ(100, retrieved_size);
}

TEST(RangeMap, TestShinkDown_PartialOverlap_AtEnd) {
  TestMap range_map;
  range_map.SetEnableShrinkDown(true);
  linked_ptr<CountedObject> object_1(new CountedObject(1));
  EXPECT_TRUE(range_map.StoreRange(50 /* base address */, 50 /* size */,
                                   object_1));

  // Partial overlap at the end of the new range.
  linked_ptr<CountedObject> object_2(new CountedObject(2));
  EXPECT_TRUE(range_map.StoreRange(0 /* base address */, 70 /* size */,
                                   object_2));

  linked_ptr<CountedObject> object;
  AddressType retrieved_base = AddressType();
  AddressType retrieved_delta = AddressType();
  AddressType retrieved_size = AddressType();
  // The first range is supposed to be shrunk down so the following address
  // should resize in the first range.
  EXPECT_TRUE(range_map.RetrieveRange(69, &object, &retrieved_base,
                                      &retrieved_delta, &retrieved_size));
  EXPECT_EQ(2, object->id());
  EXPECT_EQ(0, retrieved_base);
  EXPECT_EQ(0, retrieved_delta);
  EXPECT_EQ(70, retrieved_size);
  // Validate the properties of the shrunk down range.
  EXPECT_TRUE(range_map.RetrieveRange(70, &object, &retrieved_base,
                                      &retrieved_delta, &retrieved_size));
  EXPECT_EQ(1, object->id());
  EXPECT_EQ(70, retrieved_base);
  EXPECT_EQ(20, retrieved_delta);
  EXPECT_EQ(30, retrieved_size);
}

// A new range is overlapped at both ends.  The new range and the range
// that overlaps at the end should be shrink.  The range that overlaps at the
// beginning should be left untouched.
TEST(RangeMap, TestShinkDown_OverlapAtBothEnds) {
  TestMap range_map;
  range_map.SetEnableShrinkDown(true);
  // This should overlap object_3 at the beginning.
  linked_ptr<CountedObject> object_1(new CountedObject(1));
  EXPECT_TRUE(range_map.StoreRange(0 /* base address */, 100 /* size */,
                                   object_1));

  // This should overlap object_3 at the end.
  linked_ptr<CountedObject> object_2(new CountedObject(2));
  EXPECT_TRUE(range_map.StoreRange(100 /* base address */, 100 /* size */,
                                   object_2));

  // This should be overlapped on both ends by object_1 and object_2.
  linked_ptr<CountedObject> object_3(new CountedObject(3));
  EXPECT_TRUE(range_map.StoreRange(50 /* base address */, 100 /* size */,
                                   object_3));

  linked_ptr<CountedObject> object;
  AddressType retrieved_base = AddressType();
  AddressType retrieved_delta = AddressType();
  AddressType retrieved_size = AddressType();
  // The first range should be intact.
  EXPECT_TRUE(range_map.RetrieveRange(0, &object, &retrieved_base,
                                      &retrieved_delta, &retrieved_size));
  EXPECT_EQ(1, object->id());
  EXPECT_EQ(0, retrieved_base);
  EXPECT_EQ(0, retrieved_delta);
  EXPECT_EQ(100, retrieved_size);
  // The second range should be shrunk down by 50.
  EXPECT_TRUE(range_map.RetrieveRange(150, &object, &retrieved_base,
                                      &retrieved_delta, &retrieved_size));
  EXPECT_EQ(2, object->id());
  EXPECT_EQ(150, retrieved_base);
  EXPECT_EQ(50, retrieved_delta);
  EXPECT_EQ(50, retrieved_size);
  // The third range (in the middle) should be shrunk down by 50.
  EXPECT_TRUE(range_map.RetrieveRange(100, &object, &retrieved_base,
                                      &retrieved_delta, &retrieved_size));
  EXPECT_EQ(3, object->id());
  EXPECT_EQ(100, retrieved_base);
  EXPECT_EQ(50, retrieved_delta);
  EXPECT_EQ(50, retrieved_size);
}

TEST(RangeMap, TestShinkDown_MultipleConflicts) {
  TestMap range_map;
  range_map.SetEnableShrinkDown(true);
  // This should overlap with object_3.
  linked_ptr<CountedObject> object_1(new CountedObject(1));
  EXPECT_TRUE(range_map.StoreRange(10 /* base address */, 90 /* size */,
                                   object_1));

  // This should also overlap with object_3 but after object_1.
  linked_ptr<CountedObject> object_2(new CountedObject(2));
  EXPECT_TRUE(range_map.StoreRange(100 /* base address */, 100 /* size */,
                                   object_2));

  // This should be overlapped on both object_1 and object_2.  Since
  // object_3 ends with the higher address it must be shrunk.
  linked_ptr<CountedObject> object_3(new CountedObject(3));
  EXPECT_TRUE(range_map.StoreRange(0 /* base address */, 300 /* size */,
                                   object_3));

  linked_ptr<CountedObject> object;
  AddressType retrieved_base = AddressType();
  AddressType retrieved_delta = AddressType();
  AddressType retrieved_size = AddressType();
  // The first range should be intact.
  EXPECT_TRUE(range_map.RetrieveRange(99, &object, &retrieved_base,
                                      &retrieved_delta, &retrieved_size));
  EXPECT_EQ(1, object->id());
  EXPECT_EQ(10, retrieved_base);
  EXPECT_EQ(0, retrieved_delta);
  EXPECT_EQ(90, retrieved_size);
  // The second range should be intact.
  EXPECT_TRUE(range_map.RetrieveRange(199, &object, &retrieved_base,
                                      &retrieved_delta, &retrieved_size));
  EXPECT_EQ(2, object->id());
  EXPECT_EQ(100, retrieved_base);
  EXPECT_EQ(0, retrieved_delta);
  EXPECT_EQ(100, retrieved_size);
  // The third range should be shrunk down by 200.
  EXPECT_TRUE(range_map.RetrieveRange(299, &object, &retrieved_base,
                                      &retrieved_delta, &retrieved_size));
  EXPECT_EQ(3, object->id());
  EXPECT_EQ(200, retrieved_base);
  EXPECT_EQ(200, retrieved_delta);
  EXPECT_EQ(100, retrieved_size);
}

// Adding two ranges without overlap should succeed and the ranges should
// be left intact.
TEST(RangeMap, TestShinkDown_NoConflicts) {
  TestMap range_map;
  range_map.SetEnableShrinkDown(true);
  // Adding range 1.
  linked_ptr<CountedObject> object_1(new CountedObject(1));
  EXPECT_TRUE(range_map.StoreRange(10 /* base address */, 90 /* size */,
                                   object_1));

  // Adding range 2 - no overlap with range 1.
  linked_ptr<CountedObject> object_2(new CountedObject(2));
  EXPECT_TRUE(range_map.StoreRange(110 /* base address */, 90 /* size */,
                                   object_2));

  linked_ptr<CountedObject> object;
  AddressType retrieved_base = AddressType();
  AddressType retrieved_delta = AddressType();
  AddressType retrieved_size = AddressType();
  // The first range should be intact.
  EXPECT_TRUE(range_map.RetrieveRange(99, &object, &retrieved_base,
                                      &retrieved_delta, &retrieved_size));
  EXPECT_EQ(1, object->id());
  EXPECT_EQ(10, retrieved_base);
  EXPECT_EQ(0, retrieved_delta);
  EXPECT_EQ(90, retrieved_size);
  // The second range should be intact.
  EXPECT_TRUE(range_map.RetrieveRange(199, &object, &retrieved_base,
                                      &retrieved_delta, &retrieved_size));
  EXPECT_EQ(2, object->id());
  EXPECT_EQ(110, retrieved_base);
  EXPECT_EQ(0, retrieved_delta);
  EXPECT_EQ(90, retrieved_size);
}

}  // namespace