xref: /llvm-project/libcxx/test/std/atomics/atomics.ref/notify_all.pass.cpp (revision 42ba740afffa16f991be6aa36626bd872d41ebc0)
1*42ba740aSDamien L-G //
2*42ba740aSDamien L-G // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
3*42ba740aSDamien L-G // See https://llvm.org/LICENSE.txt for license information.
4*42ba740aSDamien L-G // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
5*42ba740aSDamien L-G //
6*42ba740aSDamien L-G //===----------------------------------------------------------------------===//
7*42ba740aSDamien L-G 
8*42ba740aSDamien L-G // UNSUPPORTED: c++03, c++11, c++14, c++17
9*42ba740aSDamien L-G // UNSUPPORTED: no-threads
10*42ba740aSDamien L-G // XFAIL: availability-synchronization_library-missing
11*42ba740aSDamien L-G // XFAIL: !has-64-bit-atomics
12*42ba740aSDamien L-G // XFAIL: !has-1024-bit-atomics
13*42ba740aSDamien L-G 
14*42ba740aSDamien L-G // void notify_all() const noexcept;
15*42ba740aSDamien L-G 
16*42ba740aSDamien L-G #include <atomic>
17*42ba740aSDamien L-G #include <cassert>
18*42ba740aSDamien L-G #include <thread>
19*42ba740aSDamien L-G #include <type_traits>
20*42ba740aSDamien L-G #include <vector>
21*42ba740aSDamien L-G 
22*42ba740aSDamien L-G #include "atomic_helpers.h"
23*42ba740aSDamien L-G #include "make_test_thread.h"
24*42ba740aSDamien L-G #include "test_macros.h"
25*42ba740aSDamien L-G 
26*42ba740aSDamien L-G template <typename T>
27*42ba740aSDamien L-G struct TestNotifyAll {
operator ()TestNotifyAll28*42ba740aSDamien L-G   void operator()() const {
29*42ba740aSDamien L-G     T x(T(1));
30*42ba740aSDamien L-G     std::atomic_ref<T> const a(x);
31*42ba740aSDamien L-G 
32*42ba740aSDamien L-G     bool done                      = false;
33*42ba740aSDamien L-G     std::atomic<int> started_num   = 0;
34*42ba740aSDamien L-G     std::atomic<int> wait_done_num = 0;
35*42ba740aSDamien L-G 
36*42ba740aSDamien L-G     constexpr auto number_of_threads = 8;
37*42ba740aSDamien L-G     std::vector<std::thread> threads;
38*42ba740aSDamien L-G     threads.reserve(number_of_threads);
39*42ba740aSDamien L-G 
40*42ba740aSDamien L-G     for (auto j = 0; j < number_of_threads; ++j) {
41*42ba740aSDamien L-G       threads.push_back(support::make_test_thread([&a, &started_num, &done, &wait_done_num] {
42*42ba740aSDamien L-G         started_num.fetch_add(1, std::memory_order::relaxed);
43*42ba740aSDamien L-G 
44*42ba740aSDamien L-G         a.wait(T(1));
45*42ba740aSDamien L-G         wait_done_num.fetch_add(1, std::memory_order::relaxed);
46*42ba740aSDamien L-G 
47*42ba740aSDamien L-G         // likely to fail if wait did not block
48*42ba740aSDamien L-G         assert(done);
49*42ba740aSDamien L-G       }));
50*42ba740aSDamien L-G     }
51*42ba740aSDamien L-G 
52*42ba740aSDamien L-G     while (started_num.load(std::memory_order::relaxed) != number_of_threads) {
53*42ba740aSDamien L-G       std::this_thread::yield();
54*42ba740aSDamien L-G     }
55*42ba740aSDamien L-G 
56*42ba740aSDamien L-G     std::this_thread::sleep_for(std::chrono::milliseconds(1));
57*42ba740aSDamien L-G 
58*42ba740aSDamien L-G     done = true;
59*42ba740aSDamien L-G     a.store(T(3));
60*42ba740aSDamien L-G     a.notify_all();
61*42ba740aSDamien L-G 
62*42ba740aSDamien L-G     // notify_all should unblock all the threads so that the loop below won't stuck
63*42ba740aSDamien L-G     while (wait_done_num.load(std::memory_order::relaxed) != number_of_threads) {
64*42ba740aSDamien L-G       std::this_thread::yield();
65*42ba740aSDamien L-G     }
66*42ba740aSDamien L-G 
67*42ba740aSDamien L-G     for (auto& thread : threads) {
68*42ba740aSDamien L-G       thread.join();
69*42ba740aSDamien L-G     }
70*42ba740aSDamien L-G 
71*42ba740aSDamien L-G     ASSERT_NOEXCEPT(a.notify_all());
72*42ba740aSDamien L-G   }
73*42ba740aSDamien L-G };
74*42ba740aSDamien L-G 
main(int,char **)75*42ba740aSDamien L-G int main(int, char**) {
76*42ba740aSDamien L-G   TestEachAtomicType<TestNotifyAll>()();
77*42ba740aSDamien L-G   return 0;
78*42ba740aSDamien L-G }
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