| /* |
| * |
| * Copyright 2016 gRPC 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 |
| * |
| * http://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 "src/core/lib/backoff/backoff.h" |
| |
| #include <algorithm> |
| |
| #include <grpc/support/log.h> |
| |
| #include <gtest/gtest.h> |
| #include "test/core/util/test_config.h" |
| |
| namespace grpc { |
| namespace testing { |
| namespace { |
| |
| using grpc_core::BackOff; |
| |
| TEST(BackOffTest, ConstantBackOff) { |
| const grpc_millis initial_backoff = 200; |
| const double multiplier = 1.0; |
| const double jitter = 0.0; |
| const grpc_millis max_backoff = 1000; |
| grpc_core::ExecCtx exec_ctx; |
| BackOff::Options options; |
| options.set_initial_backoff(initial_backoff) |
| .set_multiplier(multiplier) |
| .set_jitter(jitter) |
| .set_max_backoff(max_backoff); |
| BackOff backoff(options); |
| |
| grpc_millis next_attempt_start_time = backoff.NextAttemptTime(); |
| EXPECT_EQ(next_attempt_start_time - grpc_core::ExecCtx::Get()->Now(), |
| initial_backoff); |
| for (int i = 0; i < 10000; i++) { |
| next_attempt_start_time = backoff.NextAttemptTime(); |
| EXPECT_EQ(next_attempt_start_time - grpc_core::ExecCtx::Get()->Now(), |
| initial_backoff); |
| } |
| } |
| |
| TEST(BackOffTest, MinConnect) { |
| const grpc_millis initial_backoff = 100; |
| const double multiplier = 1.0; |
| const double jitter = 0.0; |
| const grpc_millis max_backoff = 1000; |
| grpc_core::ExecCtx exec_ctx; |
| BackOff::Options options; |
| options.set_initial_backoff(initial_backoff) |
| .set_multiplier(multiplier) |
| .set_jitter(jitter) |
| .set_max_backoff(max_backoff); |
| BackOff backoff(options); |
| grpc_millis next = backoff.NextAttemptTime(); |
| EXPECT_EQ(next - grpc_core::ExecCtx::Get()->Now(), initial_backoff); |
| } |
| |
| TEST(BackOffTest, NoJitterBackOff) { |
| const grpc_millis initial_backoff = 2; |
| const double multiplier = 2.0; |
| const double jitter = 0.0; |
| const grpc_millis max_backoff = 513; |
| BackOff::Options options; |
| options.set_initial_backoff(initial_backoff) |
| .set_multiplier(multiplier) |
| .set_jitter(jitter) |
| .set_max_backoff(max_backoff); |
| BackOff backoff(options); |
| // x_1 = 2 |
| // x_n = 2**i + x_{i-1} ( = 2**(n+1) - 2 ) |
| grpc_core::ExecCtx exec_ctx; |
| grpc_core::ExecCtx::Get()->TestOnlySetNow(0); |
| grpc_millis next = backoff.NextAttemptTime(); |
| EXPECT_EQ(next, 2); |
| grpc_core::ExecCtx::Get()->TestOnlySetNow(next); |
| next = backoff.NextAttemptTime(); |
| EXPECT_EQ(next, 6); |
| grpc_core::ExecCtx::Get()->TestOnlySetNow(next); |
| next = backoff.NextAttemptTime(); |
| EXPECT_EQ(next, 14); |
| grpc_core::ExecCtx::Get()->TestOnlySetNow(next); |
| next = backoff.NextAttemptTime(); |
| EXPECT_EQ(next, 30); |
| grpc_core::ExecCtx::Get()->TestOnlySetNow(next); |
| next = backoff.NextAttemptTime(); |
| EXPECT_EQ(next, 62); |
| grpc_core::ExecCtx::Get()->TestOnlySetNow(next); |
| next = backoff.NextAttemptTime(); |
| EXPECT_EQ(next, 126); |
| grpc_core::ExecCtx::Get()->TestOnlySetNow(next); |
| next = backoff.NextAttemptTime(); |
| EXPECT_EQ(next, 254); |
| grpc_core::ExecCtx::Get()->TestOnlySetNow(next); |
| next = backoff.NextAttemptTime(); |
| EXPECT_EQ(next, 510); |
| grpc_core::ExecCtx::Get()->TestOnlySetNow(next); |
| next = backoff.NextAttemptTime(); |
| EXPECT_EQ(next, 1022); |
| grpc_core::ExecCtx::Get()->TestOnlySetNow(next); |
| next = backoff.NextAttemptTime(); |
| // Hit the maximum timeout. From this point onwards, retries will increase |
| // only by max timeout. |
| EXPECT_EQ(next, 1535); |
| grpc_core::ExecCtx::Get()->TestOnlySetNow(next); |
| next = backoff.NextAttemptTime(); |
| EXPECT_EQ(next, 2048); |
| grpc_core::ExecCtx::Get()->TestOnlySetNow(next); |
| next = backoff.NextAttemptTime(); |
| EXPECT_EQ(next, 2561); |
| } |
| |
| TEST(BackOffTest, JitterBackOff) { |
| const grpc_millis initial_backoff = 500; |
| grpc_millis current_backoff = initial_backoff; |
| const grpc_millis max_backoff = 1000; |
| const double multiplier = 1.0; |
| const double jitter = 0.1; |
| BackOff::Options options; |
| options.set_initial_backoff(initial_backoff) |
| .set_multiplier(multiplier) |
| .set_jitter(jitter) |
| .set_max_backoff(max_backoff); |
| BackOff backoff(options); |
| |
| backoff.SetRandomSeed(0); // force consistent PRNG |
| |
| grpc_core::ExecCtx exec_ctx; |
| grpc_millis next = backoff.NextAttemptTime(); |
| EXPECT_EQ(next - grpc_core::ExecCtx::Get()->Now(), initial_backoff); |
| |
| grpc_millis expected_next_lower_bound = |
| static_cast<grpc_millis>(static_cast<double>(current_backoff) * (1 - jitter)); |
| grpc_millis expected_next_upper_bound = |
| static_cast<grpc_millis>(static_cast<double>(current_backoff) * (1 + jitter)); |
| |
| for (int i = 0; i < 10000; i++) { |
| next = backoff.NextAttemptTime(); |
| // next-now must be within (jitter*100)% of the current backoff (which |
| // increases by * multiplier up to max_backoff). |
| const grpc_millis timeout_millis = next - grpc_core::ExecCtx::Get()->Now(); |
| EXPECT_GE(timeout_millis, expected_next_lower_bound); |
| EXPECT_LE(timeout_millis, expected_next_upper_bound); |
| current_backoff = std::min( |
| static_cast<grpc_millis>(static_cast<double>(current_backoff) * multiplier), max_backoff); |
| expected_next_lower_bound = |
| static_cast<grpc_millis>(static_cast<double>(current_backoff) * (1 - jitter)); |
| expected_next_upper_bound = |
| static_cast<grpc_millis>(static_cast<double>(current_backoff) * (1 + jitter)); |
| } |
| } |
| |
| } // namespace |
| } // namespace testing |
| } // namespace grpc |
| |
| int main(int argc, char** argv) { |
| grpc_test_init(argc, argv); |
| ::testing::InitGoogleTest(&argc, argv); |
| return RUN_ALL_TESTS(); |
| } |