1 //
2 //
3 // Copyright 2016 gRPC authors.
4 //
5 // Licensed under the Apache License, Version 2.0 (the "License");
6 // you may not use this file except in compliance with the License.
7 // You may obtain a copy of the License at
8 //
9 // http://www.apache.org/licenses/LICENSE-2.0
10 //
11 // Unless required by applicable law or agreed to in writing, software
12 // distributed under the License is distributed on an "AS IS" BASIS,
13 // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14 // See the License for the specific language governing permissions and
15 // limitations under the License.
16 //
17 //
18
19 #include "src/core/util/backoff.h"
20
21 #include <grpc/grpc.h>
22
23 #include <algorithm>
24 #include <memory>
25
26 #include "gmock/gmock.h"
27 #include "gtest/gtest.h"
28 #include "src/core/lib/experiments/experiments.h"
29 #include "src/core/util/time.h"
30 #include "test/core/test_util/test_config.h"
31
32 namespace grpc_core {
33 namespace testing {
34 namespace {
35
TEST(BackOffTest,ConstantBackOff)36 TEST(BackOffTest, ConstantBackOff) {
37 const auto kInitialBackoff = Duration::Milliseconds(200);
38 const double kMultiplier = 1.0;
39 const double kJitter = 0.0;
40 const auto kMaxBackoff = Duration::Seconds(1);
41 BackOff::Options options;
42 options.set_initial_backoff(kInitialBackoff)
43 .set_multiplier(kMultiplier)
44 .set_jitter(kJitter)
45 .set_max_backoff(kMaxBackoff);
46 BackOff backoff(options);
47 EXPECT_EQ(backoff.NextAttemptDelay(), kInitialBackoff);
48 EXPECT_EQ(backoff.NextAttemptDelay(), kInitialBackoff);
49 EXPECT_EQ(backoff.NextAttemptDelay(), kInitialBackoff);
50 EXPECT_EQ(backoff.NextAttemptDelay(), kInitialBackoff);
51 EXPECT_EQ(backoff.NextAttemptDelay(), kInitialBackoff);
52 }
53
TEST(BackOffTest,InitialBackoffCappedByMaxBackoff)54 TEST(BackOffTest, InitialBackoffCappedByMaxBackoff) {
55 if (!IsBackoffCapInitialAtMaxEnabled()) {
56 GTEST_SKIP() << "test requires backoff_cap_initial_at_max experiment";
57 }
58 const auto kInitialBackoff = Duration::Seconds(2);
59 const auto kMaxBackoff = Duration::Seconds(1);
60 const double kMultiplier = 1.0;
61 const double kJitter = 0.0;
62 BackOff::Options options;
63 options.set_initial_backoff(kInitialBackoff)
64 .set_multiplier(kMultiplier)
65 .set_jitter(kJitter)
66 .set_max_backoff(kMaxBackoff);
67 BackOff backoff(options);
68 EXPECT_EQ(backoff.NextAttemptDelay(), kMaxBackoff);
69 EXPECT_EQ(backoff.NextAttemptDelay(), kMaxBackoff);
70 EXPECT_EQ(backoff.NextAttemptDelay(), kMaxBackoff);
71 EXPECT_EQ(backoff.NextAttemptDelay(), kMaxBackoff);
72 EXPECT_EQ(backoff.NextAttemptDelay(), kMaxBackoff);
73 }
74
TEST(BackOffTest,NoJitterBackOff)75 TEST(BackOffTest, NoJitterBackOff) {
76 const auto kInitialBackoff = Duration::Milliseconds(2);
77 const double kMultiplier = 2.0;
78 const double kJitter = 0.0;
79 const auto kMaxBackoff = Duration::Milliseconds(32);
80 BackOff::Options options;
81 options.set_initial_backoff(kInitialBackoff)
82 .set_multiplier(kMultiplier)
83 .set_jitter(kJitter)
84 .set_max_backoff(kMaxBackoff);
85 BackOff backoff(options);
86 EXPECT_EQ(backoff.NextAttemptDelay(), Duration::Milliseconds(2));
87 EXPECT_EQ(backoff.NextAttemptDelay(), Duration::Milliseconds(4));
88 EXPECT_EQ(backoff.NextAttemptDelay(), Duration::Milliseconds(8));
89 EXPECT_EQ(backoff.NextAttemptDelay(), Duration::Milliseconds(16));
90 EXPECT_EQ(backoff.NextAttemptDelay(), Duration::Milliseconds(32));
91 // No more increases after kMaxBackoff.
92 EXPECT_EQ(backoff.NextAttemptDelay(), Duration::Milliseconds(32));
93 EXPECT_EQ(backoff.NextAttemptDelay(), Duration::Milliseconds(32));
94 }
95
96 MATCHER_P2(InJitterRange, value, jitter, "") {
97 bool ok = true;
98 ok &= ::testing::ExplainMatchResult(::testing::Ge(arg * (1 - jitter)), arg,
99 result_listener);
100 ok &= ::testing::ExplainMatchResult(::testing::Le(arg * (1 + jitter)), arg,
101 result_listener);
102 return ok;
103 }
104
TEST(BackOffTest,JitterBackOff)105 TEST(BackOffTest, JitterBackOff) {
106 const auto kInitialBackoff = Duration::Milliseconds(2);
107 const double kMultiplier = 2.0;
108 const double kJitter = 0.1;
109 const auto kMaxBackoff = Duration::Milliseconds(32);
110 BackOff::Options options;
111 options.set_initial_backoff(kInitialBackoff)
112 .set_multiplier(kMultiplier)
113 .set_jitter(kJitter)
114 .set_max_backoff(kMaxBackoff);
115 BackOff backoff(options);
116 EXPECT_THAT(backoff.NextAttemptDelay(),
117 InJitterRange(Duration::Milliseconds(2), kJitter));
118 EXPECT_THAT(backoff.NextAttemptDelay(),
119 InJitterRange(Duration::Milliseconds(4), kJitter));
120 EXPECT_THAT(backoff.NextAttemptDelay(),
121 InJitterRange(Duration::Milliseconds(8), kJitter));
122 EXPECT_THAT(backoff.NextAttemptDelay(),
123 InJitterRange(Duration::Milliseconds(16), kJitter));
124 EXPECT_THAT(backoff.NextAttemptDelay(),
125 InJitterRange(Duration::Milliseconds(32), kJitter));
126 // No more increases after kMaxBackoff.
127 EXPECT_THAT(backoff.NextAttemptDelay(),
128 InJitterRange(Duration::Milliseconds(32), kJitter));
129 EXPECT_THAT(backoff.NextAttemptDelay(),
130 InJitterRange(Duration::Milliseconds(32), kJitter));
131 }
132
133 } // namespace
134 } // namespace testing
135 } // namespace grpc_core
136
main(int argc,char ** argv)137 int main(int argc, char** argv) {
138 ::testing::InitGoogleTest(&argc, argv);
139 grpc::testing::TestEnvironment env(&argc, argv);
140 grpc_init();
141 int ret = RUN_ALL_TESTS();
142 grpc_shutdown();
143 return ret;
144 }
145