/Users/deen/code/yugabyte-db/src/yb/util/backoff_waiter.h
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1 | | // Copyright (c) YugaByte, Inc. |
2 | | // |
3 | | // Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except |
4 | | // in compliance with the License. You may obtain a copy of the License at |
5 | | // |
6 | | // http://www.apache.org/licenses/LICENSE-2.0 |
7 | | // |
8 | | // Unless required by applicable law or agreed to in writing, software distributed under the License |
9 | | // is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express |
10 | | // or implied. See the License for the specific language governing permissions and limitations |
11 | | // under the License. |
12 | | // |
13 | | |
14 | | #ifndef YB_UTIL_BACKOFF_WAITER_H |
15 | | #define YB_UTIL_BACKOFF_WAITER_H |
16 | | |
17 | | #include <chrono> |
18 | | #include <thread> |
19 | | |
20 | | #include "yb/util/monotime.h" |
21 | | #include "yb/util/random_util.h" |
22 | | |
23 | | namespace yb { |
24 | | |
25 | | // Utility class for waiting. |
26 | | // It tracks number of attempts and exponentially increase sleep timeout. |
27 | | template <class Clock> |
28 | | class GenericBackoffWaiter { |
29 | | public: |
30 | | typedef typename Clock::time_point TimePoint; |
31 | | typedef typename Clock::duration Duration; |
32 | | |
33 | | // deadline - time when waiter decides that it is expired. |
34 | | // max_wait - max duration for single wait. |
35 | | // base_delay - multiplier for wait duration. |
36 | | explicit GenericBackoffWaiter( |
37 | | TimePoint deadline, Duration max_wait = Duration::max(), |
38 | | Duration base_delay = std::chrono::milliseconds(1)) |
39 | 95.5k | : deadline_(deadline), max_wait_(max_wait), base_delay_(base_delay) {} _ZN2yb20GenericBackoffWaiterINSt3__16chrono12steady_clockEEC2ENS2_10time_pointIS3_NS2_8durationIxNS1_5ratioILl1ELl1000000000EEEEEEES9_S9_ Line | Count | Source | 39 | 45.8k | : deadline_(deadline), max_wait_(max_wait), base_delay_(base_delay) {} |
_ZN2yb20GenericBackoffWaiterINS_15CoarseMonoClockEEC2ENSt3__16chrono10time_pointIS1_NS4_8durationIxNS3_5ratioILl1ELl1000000000EEEEEEES9_S9_ Line | Count | Source | 39 | 49.7k | : deadline_(deadline), max_wait_(max_wait), base_delay_(base_delay) {} |
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40 | | |
41 | 15.3k | bool ExpiredNow() const { |
42 | 15.3k | return ExpiredAt(Clock::now()); |
43 | 15.3k | } |
44 | | |
45 | 57.3k | bool ExpiredAt(TimePoint time) const { |
46 | 57.3k | return deadline_ < time + ClockResolution<Clock>(); |
47 | 57.3k | } _ZNK2yb20GenericBackoffWaiterINSt3__16chrono12steady_clockEE9ExpiredAtENS2_10time_pointIS3_NS2_8durationIxNS1_5ratioILl1ELl1000000000EEEEEEE Line | Count | Source | 45 | 18.2k | bool ExpiredAt(TimePoint time) const { | 46 | 18.2k | return deadline_ < time + ClockResolution<Clock>(); | 47 | 18.2k | } |
_ZNK2yb20GenericBackoffWaiterINS_15CoarseMonoClockEE9ExpiredAtENSt3__16chrono10time_pointIS1_NS4_8durationIxNS3_5ratioILl1ELl1000000000EEEEEEE Line | Count | Source | 45 | 39.0k | bool ExpiredAt(TimePoint time) const { | 46 | 39.0k | return deadline_ < time + ClockResolution<Clock>(); | 47 | 39.0k | } |
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48 | | |
49 | 42.0k | bool Wait() { |
50 | 42.0k | auto now = Clock::now(); |
51 | 42.0k | if (ExpiredAt(now)) { |
52 | 2 | return false; |
53 | 2 | } |
54 | | |
55 | 42.0k | NextAttempt(); |
56 | | |
57 | 42.0k | std::this_thread::sleep_for(DelayForTime(now)); |
58 | 42.0k | return true; |
59 | 42.0k | } _ZN2yb20GenericBackoffWaiterINSt3__16chrono12steady_clockEE4WaitEv Line | Count | Source | 49 | 18.2k | bool Wait() { | 50 | 18.2k | auto now = Clock::now(); | 51 | 18.2k | if (ExpiredAt(now)) { | 52 | 0 | return false; | 53 | 0 | } | 54 | | | 55 | 18.2k | NextAttempt(); | 56 | | | 57 | 18.2k | std::this_thread::sleep_for(DelayForTime(now)); | 58 | 18.2k | return true; | 59 | 18.2k | } |
_ZN2yb20GenericBackoffWaiterINS_15CoarseMonoClockEE4WaitEv Line | Count | Source | 49 | 23.7k | bool Wait() { | 50 | 23.7k | auto now = Clock::now(); | 51 | 23.7k | if (ExpiredAt(now)) { | 52 | 2 | return false; | 53 | 2 | } | 54 | | | 55 | 23.7k | NextAttempt(); | 56 | | | 57 | 23.7k | std::this_thread::sleep_for(DelayForTime(now)); | 58 | 23.7k | return true; | 59 | 23.7k | } |
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60 | | |
61 | 42.1k | void NextAttempt() { |
62 | 42.1k | ++attempt_; |
63 | 42.1k | } _ZN2yb20GenericBackoffWaiterINSt3__16chrono12steady_clockEE11NextAttemptEv Line | Count | Source | 61 | 18.2k | void NextAttempt() { | 62 | 18.2k | ++attempt_; | 63 | 18.2k | } |
_ZN2yb20GenericBackoffWaiterINS_15CoarseMonoClockEE11NextAttemptEv Line | Count | Source | 61 | 23.9k | void NextAttempt() { | 62 | 23.9k | ++attempt_; | 63 | 23.9k | } |
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64 | | |
65 | | Duration DelayForNow() const { |
66 | | return DelayForTime(Clock::now()); |
67 | | } |
68 | | |
69 | 42.0k | Duration DelayForTime(TimePoint now) const { |
70 | 42.0k | Duration max_wait = std::min(deadline_ - now, max_wait_); |
71 | | // 1st retry delayed 2^4 of base delays, 2nd 2^5 base delays, etc.. |
72 | 42.0k | Duration attempt_delay = |
73 | 42.0k | base_delay_ * |
74 | 41.4k | (attempt_ >= 29 ? std::numeric_limits<int32_t>::max() : 1LL << (attempt_ + 3)); |
75 | 42.0k | Duration jitter = std::chrono::milliseconds(RandomUniformInt(0, 50)); |
76 | 42.0k | return std::min(attempt_delay + jitter, max_wait); |
77 | 42.0k | } _ZNK2yb20GenericBackoffWaiterINSt3__16chrono12steady_clockEE12DelayForTimeENS2_10time_pointIS3_NS2_8durationIxNS1_5ratioILl1ELl1000000000EEEEEEE Line | Count | Source | 69 | 18.2k | Duration DelayForTime(TimePoint now) const { | 70 | 18.2k | Duration max_wait = std::min(deadline_ - now, max_wait_); | 71 | | // 1st retry delayed 2^4 of base delays, 2nd 2^5 base delays, etc.. | 72 | 18.2k | Duration attempt_delay = | 73 | 18.2k | base_delay_ * | 74 | 18.2k | (attempt_ >= 29 ? std::numeric_limits<int32_t>::max() : 1LL << (attempt_ + 3)); | 75 | 18.2k | Duration jitter = std::chrono::milliseconds(RandomUniformInt(0, 50)); | 76 | 18.2k | return std::min(attempt_delay + jitter, max_wait); | 77 | 18.2k | } |
_ZNK2yb20GenericBackoffWaiterINS_15CoarseMonoClockEE12DelayForTimeENSt3__16chrono10time_pointIS1_NS4_8durationIxNS3_5ratioILl1ELl1000000000EEEEEEE Line | Count | Source | 69 | 23.7k | Duration DelayForTime(TimePoint now) const { | 70 | 23.7k | Duration max_wait = std::min(deadline_ - now, max_wait_); | 71 | | // 1st retry delayed 2^4 of base delays, 2nd 2^5 base delays, etc.. | 72 | 23.7k | Duration attempt_delay = | 73 | 23.7k | base_delay_ * | 74 | 23.1k | (attempt_ >= 29 ? std::numeric_limits<int32_t>::max() : 1LL << (attempt_ + 3)); | 75 | 23.7k | Duration jitter = std::chrono::milliseconds(RandomUniformInt(0, 50)); | 76 | 23.7k | return std::min(attempt_delay + jitter, max_wait); | 77 | 23.7k | } |
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78 | | |
79 | 18.1k | size_t attempt() const { |
80 | 18.1k | return attempt_; |
81 | 18.1k | } _ZNK2yb20GenericBackoffWaiterINSt3__16chrono12steady_clockEE7attemptEv Line | Count | Source | 79 | 18.1k | size_t attempt() const { | 80 | 18.1k | return attempt_; | 81 | 18.1k | } |
Unexecuted instantiation: _ZNK2yb20GenericBackoffWaiterINS_15CoarseMonoClockEE7attemptEv |
82 | | |
83 | | // Resets attempt counter, w/o modifying deadline. |
84 | | void Restart() { |
85 | | attempt_ = 0; |
86 | | } |
87 | | |
88 | | private: |
89 | | TimePoint deadline_; |
90 | | size_t attempt_ = 0; |
91 | | Duration max_wait_; |
92 | | Duration base_delay_; |
93 | | }; |
94 | | |
95 | | typedef GenericBackoffWaiter<std::chrono::steady_clock> BackoffWaiter; |
96 | | typedef GenericBackoffWaiter<CoarseMonoClock> CoarseBackoffWaiter; |
97 | | |
98 | | } // namespace yb |
99 | | |
100 | | #endif // YB_UTIL_BACKOFF_WAITER_H |