1 #include "gtest/gtest.h"
2
3 #include "chre/util/memory_pool.h"
4
5 #include <random>
6 #include <vector>
7
8 using chre::MemoryPool;
9
TEST(MemoryPool,ExhaustPool)10 TEST(MemoryPool, ExhaustPool) {
11 MemoryPool<int, 3> memoryPool;
12 ASSERT_NE(memoryPool.allocate(), nullptr);
13 ASSERT_NE(memoryPool.allocate(), nullptr);
14 ASSERT_NE(memoryPool.allocate(), nullptr);
15 ASSERT_EQ(memoryPool.allocate(), nullptr);
16 }
17
TEST(MemoryPool,ExhaustPoolThenDeallocateOneAndAllocateOne)18 TEST(MemoryPool, ExhaustPoolThenDeallocateOneAndAllocateOne) {
19 MemoryPool<int, 3> memoryPool;
20
21 // Exhaust the pool.
22 int *element1 = memoryPool.allocate();
23 int *element2 = memoryPool.allocate();
24 int *element3 = memoryPool.allocate();
25
26 // Perform some simple assignments. There is a chance we crash here if things
27 // are not implemented correctly.
28 *element1 = 0xcafe;
29 *element2 = 0xbeef;
30 *element3 = 0xface;
31
32 // Free one element and then allocate another.
33 memoryPool.deallocate(element1);
34 element1 = memoryPool.allocate();
35 ASSERT_NE(element1, nullptr);
36
37 // Ensure that the pool remains exhausted.
38 ASSERT_EQ(memoryPool.allocate(), nullptr);
39
40 // Perform another simple assignment. There is a hope that this can crash if
41 // the pointer returned is very bad (like nullptr).
42 *element1 = 0xfade;
43
44 // Verify that the values stored were not corrupted by the deallocate
45 // allocate cycle.
46 ASSERT_EQ(*element1, 0xfade);
47 ASSERT_EQ(*element2, 0xbeef);
48 ASSERT_EQ(*element3, 0xface);
49 }
50
51 /*
52 * Pair an allocated pointer with the expected value that should be stored in
53 * that location.
54 */
55 struct AllocationExpectedValuePair {
56 size_t *allocation;
57 size_t expectedValue;
58 };
59
TEST(MemoryPool,ExhaustPoolThenRandomDeallocate)60 TEST(MemoryPool, ExhaustPoolThenRandomDeallocate) {
61 // The number of times to allocate and deallocate in random order.
62 const size_t kStressTestCount = 64;
63
64 // Construct a memory pool and a vector to maintain a list of all allocations.
65 const size_t kMemoryPoolSize = 64;
66 MemoryPool<size_t, kMemoryPoolSize> memoryPool;
67 std::vector<AllocationExpectedValuePair> allocations;
68
69 for (size_t i = 0; i < kStressTestCount; i++) {
70 // Exhaust the memory pool.
71 for (size_t j = 0; j < kMemoryPoolSize; j++) {
72 AllocationExpectedValuePair allocation = {
73 .allocation = memoryPool.allocate(),
74 .expectedValue = j,
75 };
76
77 *allocation.allocation = j;
78 allocations.push_back(allocation);
79 }
80
81 // Seed a random number generator with the loop iteration so that order is
82 // preserved across test runs.
83 std::mt19937 randomGenerator(i);
84
85 while (!allocations.empty()) {
86 // Generate a number with a uniform distribution between zero and the number
87 // of allocations remaining.
88 std::uniform_int_distribution<> distribution(0, allocations.size() - 1);
89 size_t deallocateIndex = distribution(randomGenerator);
90
91 // Verify the expected value and free the allocation.
92 ASSERT_EQ(*allocations[deallocateIndex].allocation,
93 allocations[deallocateIndex].expectedValue);
94 memoryPool.deallocate(allocations[deallocateIndex].allocation);
95
96 // Remove the freed allocation from the allocation list.
97 allocations.erase(allocations.begin() + deallocateIndex);
98 }
99 }
100 }
101
102