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libcxx_old/test/std/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/mutex.pass.cpp

106 lines
2.4 KiB
C++

//===----------------------------------------------------------------------===//
//
// 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: libcpp-has-no-threads
// UNSUPPORTED: c++98, c++03, c++11
// XFAIL: dylib-has-no-shared_mutex
// FLAKY_TEST.
// <shared_mutex>
// template <class Mutex> class shared_lock;
// explicit shared_lock(mutex_type& m);
// template<class _Mutex> shared_lock(shared_lock<_Mutex>)
// -> shared_lock<_Mutex>; // C++17
#include <shared_mutex>
#include <thread>
#include <vector>
#include <cstdlib>
#include <cassert>
#include "test_macros.h"
typedef std::chrono::system_clock Clock;
typedef Clock::time_point time_point;
typedef Clock::duration duration;
typedef std::chrono::milliseconds ms;
typedef std::chrono::nanoseconds ns;
ms WaitTime = ms(250);
// Thread sanitizer causes more overhead and will sometimes cause this test
// to fail. To prevent this we give Thread sanitizer more time to complete the
// test.
#if !defined(TEST_HAS_SANITIZERS)
ms Tolerance = ms(50);
#else
ms Tolerance = ms(50 * 5);
#endif
std::shared_timed_mutex m;
void f()
{
time_point t0 = Clock::now();
time_point t1;
{
std::shared_lock<std::shared_timed_mutex> ul(m);
t1 = Clock::now();
}
ns d = t1 - t0 - WaitTime;
assert(d < Tolerance); // within tolerance
}
void g()
{
time_point t0 = Clock::now();
time_point t1;
{
std::shared_lock<std::shared_timed_mutex> ul(m);
t1 = Clock::now();
}
ns d = t1 - t0;
assert(d < Tolerance); // within tolerance
}
int main(int, char**)
{
std::vector<std::thread> v;
{
m.lock();
for (int i = 0; i < 5; ++i)
v.push_back(std::thread(f));
std::this_thread::sleep_for(WaitTime);
m.unlock();
for (auto& t : v)
t.join();
}
{
m.lock_shared();
for (auto& t : v)
t = std::thread(g);
std::thread q(f);
std::this_thread::sleep_for(WaitTime);
m.unlock_shared();
for (auto& t : v)
t.join();
q.join();
}
#ifdef __cpp_deduction_guides
std::shared_lock sl(m);
static_assert((std::is_same<decltype(sl), std::shared_lock<decltype(m)>>::value), "" );
#endif
return 0;
}