1 /*
2 * Copyright (C) 2017 The Android Open Source Project
3 *
4 * Licensed under the Apache License, Version 2.0 (the "License");
5 * you may not use this file except in compliance with the License.
6 * You may obtain a copy of the License at
7 *
8 * http://www.apache.org/licenses/LICENSE-2.0
9 *
10 * Unless required by applicable law or agreed to in writing, software
11 * distributed under the License is distributed on an "AS IS" BASIS,
12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13 * See the License for the specific language governing permissions and
14 * limitations under the License.
15 */
16
17 #include <limits>
18 #include "gtest/gtest.h"
19
20 #include "include/random_generator.h"
21
22 template <typename TestType>
23 class RandomGeneratorTest : public testing::Test {
24 public:
25 wifi_offload_test::RandomGenerator random_gen_;
26
GeneratedNumbersAreSmallerOrEqualTypeMaxValue()27 void GeneratedNumbersAreSmallerOrEqualTypeMaxValue() {
28 uint64_t rand_val = random_gen_.get<TestType>();
29 uint64_t max_val = std::numeric_limits<TestType>::max();
30
31 EXPECT_TRUE(rand_val <= max_val);
32 }
33
AllRandomGeneratorsGenerateTheSameSequence()34 void AllRandomGeneratorsGenerateTheSameSequence() {
35 constexpr size_t num_values = 10;
36 TestType rand_values[num_values];
37
38 for (size_t i = 0; i < num_values; i++) {
39 rand_values[i] = random_gen_.get<TestType>();
40 }
41
42 wifi_offload_test::RandomGenerator another_random_gen_;
43 for (size_t i = 0; i < num_values; i++) {
44 ASSERT_EQ(rand_values[i], another_random_gen_.get<TestType>());
45 }
46 }
47
AfterResetGeneratesTheSameSequence()48 void AfterResetGeneratesTheSameSequence() {
49 constexpr size_t num_values = 10;
50 TestType rand_values[num_values];
51
52 for (size_t i = 0; i < num_values; i++) {
53 rand_values[i] = random_gen_.get<TestType>();
54 }
55
56 random_gen_.Reset();
57 for (size_t i = 0; i < num_values; i++) {
58 ASSERT_EQ(rand_values[i], random_gen_.get<TestType>());
59 }
60 }
61
GeneratesDifferentNumbersIn8Bytes()62 void GeneratesDifferentNumbersIn8Bytes() {
63 constexpr size_t num_values = 10;
64 uint64_t rand_values[num_values];
65
66 constexpr size_t repeats_to_fill_8_bytes =
67 sizeof(uint64_t) / sizeof(TestType);
68 constexpr size_t shift_size =
69 (sizeof(TestType) * 8) % (sizeof(uint64_t) * 8);
70
71 for (size_t i = 0; i < num_values; i++) {
72 rand_values[i] = 0;
73 for (size_t j = 0; j < repeats_to_fill_8_bytes; j++) {
74 rand_values[i] <<= shift_size;
75 rand_values[i] |= random_gen_.get<TestType>();
76 }
77 }
78
79 // The probability of choosing equal random numbers out of 2 ^ 64 values
80 // is "extremely" small. Smaller than the change of memory failure.
81 for (size_t i = 0; i < num_values - 1; i++) {
82 for (size_t j = i + 1; j < num_values; j++) {
83 ASSERT_NE(rand_values[i], rand_values[j]);
84 }
85 }
86 }
87 };
88
89 typedef testing::Types<uint8_t, uint16_t, uint32_t, uint64_t> Implementations;
90
91 TYPED_TEST_CASE(RandomGeneratorTest, Implementations);
92
TYPED_TEST(RandomGeneratorTest,GeneratedNumbersAreSmallerOrEqualTypeMaxValue)93 TYPED_TEST(RandomGeneratorTest, GeneratedNumbersAreSmallerOrEqualTypeMaxValue) {
94 this->GeneratedNumbersAreSmallerOrEqualTypeMaxValue();
95 }
96
TYPED_TEST(RandomGeneratorTest,AllRandomGeneratorsGenerateTheSameSequence)97 TYPED_TEST(RandomGeneratorTest, AllRandomGeneratorsGenerateTheSameSequence) {
98 this->AllRandomGeneratorsGenerateTheSameSequence();
99 }
100
TYPED_TEST(RandomGeneratorTest,AfterResetGeneratesTheSameSequence)101 TYPED_TEST(RandomGeneratorTest, AfterResetGeneratesTheSameSequence) {
102 this->AfterResetGeneratesTheSameSequence();
103 }
104
TYPED_TEST(RandomGeneratorTest,GeneratesDifferentNumbersIn8Bytes)105 TYPED_TEST(RandomGeneratorTest, GeneratesDifferentNumbersIn8Bytes) {
106 this->GeneratesDifferentNumbersIn8Bytes();
107 }
108
