1//===----------------------------------------------------------------------===//
2//
3// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4// See https://llvm.org/LICENSE.txt for license information.
5// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
6//
7//===----------------------------------------------------------------------===//
8
9// UNSUPPORTED: c++03, c++11, c++14, c++17
10
11#include "atomic_wait_helper.h"
12
13#include <atomic>
14#include <cstdint>
15#include <numeric>
16#include <stop_token>
17#include <thread>
18#include <chrono>
19#include <array>
20
21#include "benchmark/benchmark.h"
22#include "make_test_thread.h"
23
24using namespace std::chrono_literals;
25
26template <class NotifyPolicy, class NumWaitingThreads, class NumPrioTasks>
27void BM_1_atomic_multi_waiter_1_notifier(benchmark::State& state) {
28 [[maybe_unused]] std::array<HighPrioTask, NumPrioTasks::value> tasks{};
29
30 std::atomic<std::uint64_t> a;
31 auto notify_func = [&](std::stop_token st) { NotifyPolicy::notify(a, st); };
32
33 std::uint64_t total_loop_test_param = state.range(0);
34 constexpr auto num_waiting_threads = NumWaitingThreads::value;
35 std::vector<std::jthread> wait_threads;
36 wait_threads.reserve(num_waiting_threads);
37
38 auto notify_thread = support::make_test_jthread(notify_func);
39
40 std::atomic<std::uint64_t> start_flag = 0;
41 std::atomic<std::uint64_t> done_count = 0;
42 auto wait_func = [&a, &start_flag, &done_count, total_loop_test_param](std::stop_token st) {
43 auto old_start = 0;
44 while (!st.stop_requested()) {
45 start_flag.wait(old_start);
46 old_start = start_flag.load();
47 for (std::uint64_t i = 0; i < total_loop_test_param; ++i) {
48 auto old = a.load(m: std::memory_order_relaxed);
49 a.wait(old);
50 }
51 done_count.fetch_add(i: 1);
52 }
53 };
54
55 for (size_t i = 0; i < num_waiting_threads; ++i) {
56 wait_threads.emplace_back(support::make_test_jthread(wait_func));
57 }
58
59 for (auto _ : state) {
60 done_count = 0;
61 start_flag.fetch_add(1);
62 start_flag.notify_all();
63 while (done_count < num_waiting_threads) {
64 std::this_thread::yield();
65 }
66 }
67 for (auto& t : wait_threads) {
68 t.request_stop();
69 }
70 start_flag.fetch_add(i: 1);
71 start_flag.notify_all();
72 for (auto& t : wait_threads) {
73 t.join();
74 }
75}
76
77BENCHMARK(BM_1_atomic_multi_waiter_1_notifier<KeepNotifying, NumWaitingThreads<3>, NumHighPrioTasks<0>>)
78 ->RangeMultiplier(2)
79 ->Range(1 << 14, 1 << 16);
80BENCHMARK(BM_1_atomic_multi_waiter_1_notifier<KeepNotifying, NumWaitingThreads<7>, NumHighPrioTasks<0>>)
81 ->RangeMultiplier(2)
82 ->Range(1 << 12, 1 << 14);
83BENCHMARK(BM_1_atomic_multi_waiter_1_notifier<KeepNotifying, NumWaitingThreads<15>, NumHighPrioTasks<0>>)
84 ->RangeMultiplier(2)
85 ->Range(1 << 10, 1 << 12);
86
87BENCHMARK(BM_1_atomic_multi_waiter_1_notifier<NotifyEveryNus<50>, NumWaitingThreads<3>, NumHighPrioTasks<0>>)
88 ->RangeMultiplier(2)
89 ->Range(1 << 10, 1 << 12);
90BENCHMARK(BM_1_atomic_multi_waiter_1_notifier<NotifyEveryNus<50>, NumWaitingThreads<7>, NumHighPrioTasks<0>>)
91 ->RangeMultiplier(2)
92 ->Range(1 << 8, 1 << 10);
93BENCHMARK(BM_1_atomic_multi_waiter_1_notifier<NotifyEveryNus<50>, NumWaitingThreads<15>, NumHighPrioTasks<0>>)
94 ->RangeMultiplier(2)
95 ->Range(1 << 6, 1 << 8);
96
97BENCHMARK(BM_1_atomic_multi_waiter_1_notifier<NotifyEveryNus<100>, NumWaitingThreads<3>, NumHighPrioTasks<0>>)
98 ->RangeMultiplier(2)
99 ->Range(1 << 8, 1 << 10);
100BENCHMARK(BM_1_atomic_multi_waiter_1_notifier<NotifyEveryNus<100>, NumWaitingThreads<7>, NumHighPrioTasks<0>>)
101 ->RangeMultiplier(2)
102 ->Range(1 << 6, 1 << 8);
103BENCHMARK(BM_1_atomic_multi_waiter_1_notifier<NotifyEveryNus<100>, NumWaitingThreads<15>, NumHighPrioTasks<0>>)
104 ->RangeMultiplier(2)
105 ->Range(1 << 4, 1 << 6);
106
107BENCHMARK(BM_1_atomic_multi_waiter_1_notifier<KeepNotifying, NumWaitingThreads<3>, NumHighPrioTasks<4>>)
108 ->RangeMultiplier(2)
109 ->Range(1 << 8, 1 << 10);
110BENCHMARK(BM_1_atomic_multi_waiter_1_notifier<KeepNotifying, NumWaitingThreads<7>, NumHighPrioTasks<4>>)
111 ->RangeMultiplier(2)
112 ->Range(1 << 6, 1 << 8);
113BENCHMARK(BM_1_atomic_multi_waiter_1_notifier<KeepNotifying, NumWaitingThreads<15>, NumHighPrioTasks<4>>)
114 ->RangeMultiplier(2)
115 ->Range(1 << 4, 1 << 6);
116
117BENCHMARK(BM_1_atomic_multi_waiter_1_notifier<NotifyEveryNus<50>, NumWaitingThreads<3>, NumHighPrioTasks<4>>)
118 ->RangeMultiplier(2)
119 ->Range(1 << 8, 1 << 10);
120BENCHMARK(BM_1_atomic_multi_waiter_1_notifier<NotifyEveryNus<50>, NumWaitingThreads<7>, NumHighPrioTasks<4>>)
121 ->RangeMultiplier(2)
122 ->Range(1 << 6, 1 << 8);
123BENCHMARK(BM_1_atomic_multi_waiter_1_notifier<NotifyEveryNus<50>, NumWaitingThreads<15>, NumHighPrioTasks<4>>)
124 ->RangeMultiplier(2)
125 ->Range(1 << 4, 1 << 6);
126
127BENCHMARK(BM_1_atomic_multi_waiter_1_notifier<NotifyEveryNus<100>, NumWaitingThreads<3>, NumHighPrioTasks<4>>)
128 ->RangeMultiplier(2)
129 ->Range(1 << 8, 1 << 10);
130BENCHMARK(BM_1_atomic_multi_waiter_1_notifier<NotifyEveryNus<100>, NumWaitingThreads<7>, NumHighPrioTasks<4>>)
131 ->RangeMultiplier(2)
132 ->Range(1 << 6, 1 << 8);
133BENCHMARK(BM_1_atomic_multi_waiter_1_notifier<NotifyEveryNus<100>, NumWaitingThreads<15>, NumHighPrioTasks<4>>)
134 ->RangeMultiplier(2)
135 ->Range(1 << 4, 1 << 6);
136
137BENCHMARK(BM_1_atomic_multi_waiter_1_notifier<KeepNotifying, NumWaitingThreads<3>, NumHighPrioTasks<7>>)
138 ->RangeMultiplier(2)
139 ->Range(1 << 4, 1 << 6);
140BENCHMARK(BM_1_atomic_multi_waiter_1_notifier<KeepNotifying, NumWaitingThreads<7>, NumHighPrioTasks<7>>)
141 ->RangeMultiplier(2)
142 ->Range(1 << 3, 1 << 5);
143BENCHMARK(BM_1_atomic_multi_waiter_1_notifier<KeepNotifying, NumWaitingThreads<15>, NumHighPrioTasks<7>>)
144 ->RangeMultiplier(2)
145 ->Range(1 << 2, 1 << 4);
146
147BENCHMARK(BM_1_atomic_multi_waiter_1_notifier<NotifyEveryNus<50>, NumWaitingThreads<3>, NumHighPrioTasks<7>>)
148 ->RangeMultiplier(2)
149 ->Range(1 << 3, 1 << 5);
150BENCHMARK(BM_1_atomic_multi_waiter_1_notifier<NotifyEveryNus<50>, NumWaitingThreads<7>, NumHighPrioTasks<7>>)
151 ->RangeMultiplier(2)
152 ->Range(1 << 2, 1 << 4);
153BENCHMARK(BM_1_atomic_multi_waiter_1_notifier<NotifyEveryNus<50>, NumWaitingThreads<15>, NumHighPrioTasks<7>>)
154 ->RangeMultiplier(2)
155 ->Range(1 << 1, 1 << 3);
156
157BENCHMARK(BM_1_atomic_multi_waiter_1_notifier<NotifyEveryNus<100>, NumWaitingThreads<3>, NumHighPrioTasks<7>>)
158 ->RangeMultiplier(2)
159 ->Range(1 << 3, 1 << 5);
160BENCHMARK(BM_1_atomic_multi_waiter_1_notifier<NotifyEveryNus<100>, NumWaitingThreads<7>, NumHighPrioTasks<7>>)
161 ->RangeMultiplier(2)
162 ->Range(1 << 2, 1 << 4);
163BENCHMARK(BM_1_atomic_multi_waiter_1_notifier<NotifyEveryNus<100>, NumWaitingThreads<15>, NumHighPrioTasks<7>>)
164 ->RangeMultiplier(2)
165 ->Range(1 << 1, 1 << 3);
166
167BENCHMARK_MAIN();
168

source code of libcxx/test/benchmarks/atomic_wait_multi_waiter_1_notifier.bench.cpp