| // Copyright 2022 The Centipede Authors. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // https://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| #include "./centipede/knobs.h" |
| |
| #include <cstddef> |
| |
| #include "gtest/gtest.h" |
| #include "absl/container/flat_hash_map.h" |
| |
| namespace centipede { |
| |
| static const KnobId knob0 = Knobs::NewId("kn0"); |
| static const KnobId knob1 = Knobs::NewId("kn1"); |
| static const KnobId knob2 = Knobs::NewId("kn2"); |
| static const KnobId knob3 = Knobs::NewId("kn3"); |
| |
| TEST(Knobs, Name) { |
| EXPECT_EQ(Knobs::Name(knob0), "kn0"); |
| EXPECT_EQ(Knobs::Name(knob1), "kn1"); |
| EXPECT_EQ(Knobs::Name(knob2), "kn2"); |
| EXPECT_EQ(Knobs::Name(knob3), "kn3"); |
| } |
| |
| // Depends on FRIEND_TEST in KnobId - don't rename. |
| TEST(Knobs, Choose) { |
| Knobs knobs; |
| |
| EXPECT_EQ(knob0.id(), 0); |
| EXPECT_EQ(knob1.id(), 1); |
| EXPECT_EQ(knobs.Choose({knob3, knob2, knob1}, 0), knob3); |
| EXPECT_EQ(knobs.Choose({knob3, knob2, knob1}, 1), knob2); |
| EXPECT_EQ(knobs.Choose({knob3, knob2, knob1}, 2), knob1); |
| |
| constexpr size_t kNumIter = 1000000; |
| knobs.Set(16); |
| absl::flat_hash_map<size_t, size_t> id_to_freq; |
| for (size_t iter = 0; iter < kNumIter; ++iter) { |
| ++id_to_freq[knobs.Choose({knob3, knob2, knob1}, iter).id()]; |
| } |
| EXPECT_EQ(id_to_freq[knob0.id()], 0); |
| EXPECT_GE(id_to_freq[knob1.id()], kNumIter / 4); |
| EXPECT_GE(id_to_freq[knob2.id()], kNumIter / 4); |
| EXPECT_GE(id_to_freq[knob3.id()], kNumIter / 4); |
| |
| knobs.Set({100, 0, 10, 1}); |
| id_to_freq.clear(); |
| for (size_t iter = 0; iter < kNumIter; ++iter) { |
| ++id_to_freq[knobs.Choose({knob0, knob1, knob2, knob3}, iter).id()]; |
| } |
| EXPECT_EQ(id_to_freq[knob1.id()], 0); |
| EXPECT_GT(id_to_freq[knob0.id()], 9 * id_to_freq[knob2.id()]); |
| EXPECT_GT(id_to_freq[knob2.id()], 9 * id_to_freq[knob3.id()]); |
| EXPECT_GT(id_to_freq[knob3.id()], kNumIter / 200); |
| |
| absl::flat_hash_map<std::string, size_t> str_to_freq; |
| for (size_t iter = 0; iter < kNumIter; ++iter) { |
| ++str_to_freq[knobs.Choose<std::string>({knob0, knob2}, {"AAA", "BBB"}, |
| iter)]; |
| } |
| EXPECT_GT(str_to_freq["AAA"], 9 * str_to_freq["BBB"]); |
| EXPECT_GT(str_to_freq["BBB"], kNumIter / 200); |
| } |
| |
| TEST(Knobs, GenerateBool) { |
| Knobs knobs; |
| constexpr size_t kNumIter = 255; |
| // Checks the GenerateBool on kNumIter different (fake) random values, |
| // verifies the expected number of "true" results. |
| auto check = [&](Knobs::value_type knob_value, |
| size_t expected_num_true_results) { |
| knobs.Set(knob_value); |
| size_t num_true = 0; |
| for (size_t fake_random = 0; fake_random < kNumIter; ++fake_random) { |
| if (knobs.GenerateBool(knob0, fake_random)) ++num_true; |
| } |
| EXPECT_EQ(num_true, expected_num_true_results); |
| }; |
| |
| check(0, kNumIter / 2 + 1); // true half the time |
| check(-128, 0); // Never true |
| check(127, kNumIter); // Always true. |
| for (int8_t i = -127; i < 127; i++) { |
| // The greater the knob value, the more frequently we see true. |
| check(i, 128 + i); |
| } |
| } |
| |
| TEST(KnobsDeathTest, NewId) { |
| auto allocate_too_many_knob_ids = []() { |
| for (size_t i = 0; i < Knobs::kNumKnobs; ++i) { |
| Knobs::NewId(absl::StrCat("kn", i)); |
| } |
| }; |
| EXPECT_DEATH(allocate_too_many_knob_ids(), |
| "Knobs::NewId: no more IDs left, aborting"); |
| } |
| |
| TEST(KnobsDeathTest, Choose) { |
| Knobs knobs; |
| EXPECT_DEATH(knobs.Choose<int>({}, {}, 0), ""); |
| EXPECT_DEATH(knobs.Choose<int>({knob1, knob2}, {1}, 0), ""); |
| } |
| |
| } // namespace centipede |