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//===----------------------------------------------------------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is dual licensed under the MIT and the University of Illinois Open
// Source Licenses. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// UNSUPPORTED: libcpp-has-no-threads
// UNSUPPORTED: c++98, c++03, c++11
// FLAKY_TEST.
// <shared_mutex>
// class shared_timed_mutex;
// void lock_shared();
#include <shared_mutex>
#include <thread>
#include <vector>
#include <cstdlib>
#include <cassert>
#include "test_macros.h"
std::shared_timed_mutex m;
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
void f()
{
time_point t0 = Clock::now();
m.lock_shared();
time_point t1 = Clock::now();
m.unlock_shared();
ns d = t1 - t0 - WaitTime;
assert(d < Tolerance); // within tolerance
}
void g()
{
time_point t0 = Clock::now();
m.lock_shared();
time_point t1 = Clock::now();
m.unlock_shared();
ns d = t1 - t0;
assert(d < Tolerance); // within tolerance
}
int main()
{
m.lock();
std::vector<std::thread> v;
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();
}
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