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//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
//
// UNSUPPORTED: no-threads
// UNSUPPORTED: c++03, c++11, c++14, c++17
// UNSUPPORTED: libcpp-has-no-experimental-stop_token
// XFAIL: availability-synchronization_library-missing
// <condition_variable>
// class condition_variable_any;
// template<class Lock, class Predicate>
// bool wait(Lock& lock, stop_token stoken, Predicate pred);
#include <cassert>
#include <concepts>
#include <condition_variable>
#include <functional>
#include <mutex>
#include <shared_mutex>
#include <stop_token>
#include <thread>
#include "make_test_thread.h"
#include "test_macros.h"
template <class Mutex, class Lock>
void test() {
// stop_requested before hand
{
std::stop_source ss;
std::condition_variable_any cv;
Mutex mutex;
Lock lock{mutex};
ss.request_stop();
// [Note 1: The returned value indicates whether the predicate evaluated to true regardless of whether there was a stop request.]
std::same_as<bool> auto r1 = cv.wait(lock, ss.get_token(), []() { return false; });
assert(!r1);
std::same_as<bool> auto r2 = cv.wait(lock, ss.get_token(), []() { return true; });
assert(r2);
// Postconditions: lock is locked by the calling thread.
assert(lock.owns_lock());
}
// no stop request
{
std::stop_source ss;
std::condition_variable_any cv;
Mutex mutex;
Lock lock{mutex};
std::same_as<bool> auto r1 = cv.wait(lock, ss.get_token(), []() { return true; });
assert(r1);
bool flag = false;
auto thread = support::make_test_thread([&]() {
std::this_thread::sleep_for(std::chrono::milliseconds(2));
std::unique_lock<Mutex> lock2{mutex};
flag = true;
cv.notify_all();
});
std::same_as<bool> auto r2 = cv.wait(lock, ss.get_token(), [&]() { return flag; });
assert(flag);
assert(r2);
thread.join();
assert(lock.owns_lock());
}
// stop request comes while waiting
{
std::stop_source ss;
std::condition_variable_any cv;
Mutex mutex;
Lock lock{mutex};
std::atomic_bool start = false;
std::atomic_bool done = false;
auto thread = support::make_test_thread([&]() {
start.wait(false);
ss.request_stop();
while (!done) {
cv.notify_all();
std::this_thread::sleep_for(std::chrono::milliseconds(2));
}
});
std::same_as<bool> auto r = cv.wait(lock, ss.get_token(), [&]() {
start.store(true);
start.notify_all();
return false;
});
assert(!r);
done = true;
thread.join();
assert(lock.owns_lock());
}
// #76807 Hangs in std::condition_variable_any when used with std::stop_token
{
class MyThread {
public:
MyThread() {
thread_ = support::make_test_jthread([this](std::stop_token st) {
while (!st.stop_requested()) {
std::unique_lock lock{m_};
cv_.wait(lock, st, [] { return false; });
}
});
}
private:
std::mutex m_;
std::condition_variable_any cv_;
std::jthread thread_;
};
[[maybe_unused]] MyThread my_thread;
}
// request_stop potentially in-between check and wait
{
std::stop_source ss;
std::condition_variable_any cv;
Mutex mutex;
Lock lock{mutex};
std::atomic_bool pred_started = false;
std::atomic_bool request_stop_called = false;
auto thread = support::make_test_thread([&]() {
pred_started.wait(false);
ss.request_stop();
request_stop_called.store(true);
request_stop_called.notify_all();
});
std::same_as<bool> auto r = cv.wait(lock, ss.get_token(), [&]() {
pred_started.store(true);
pred_started.notify_all();
request_stop_called.wait(false);
return false;
});
assert(!r);
thread.join();
assert(lock.owns_lock());
}
#if !defined(TEST_HAS_NO_EXCEPTIONS)
// Throws: Any exception thrown by pred.
{
std::stop_source ss;
std::condition_variable_any cv;
Mutex mutex;
Lock lock{mutex};
try {
cv.wait(lock, ss.get_token(), []() -> bool { throw 5; });
assert(false);
} catch (int i) {
assert(i == 5);
}
}
#endif //!defined(TEST_HAS_NO_EXCEPTIONS)
}
int main(int, char**) {
test<std::mutex, std::unique_lock<std::mutex>>();
test<std::shared_mutex, std::shared_lock<std::shared_mutex>>();
return 0;
}
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