Move test into test/std subdirectory.

llvm-svn: 224658

12 files changed, 647 insertions, 0 deletions

diff --git a/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/nothing_to_do.pass.cpp b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/nothing_to_do.pass.cpp
new file mode 100644
index 00000000000..b58f5c55b64
--- /dev/null
+++ b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/nothing_to_do.pass.cpp
@@ -0,0 +1,12 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+
+int main()
+{
+}
diff --git a/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/assign.fail.cpp b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/assign.fail.cpp
new file mode 100644
index 00000000000..528aaca6d9e
--- /dev/null
+++ b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/assign.fail.cpp
@@ -0,0 +1,27 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+
+// <shared_mutex>
+
+// class shared_timed_mutex;
+
+// shared_timed_mutex& operator=(const shared_timed_mutex&) = delete;
+
+#include <shared_mutex>
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    std::shared_timed_mutex m0;
+    std::shared_timed_mutex m1;
+    m1 = m0;
+#else
+#   error
+#endif
+}
diff --git a/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/copy.fail.cpp b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/copy.fail.cpp
new file mode 100644
index 00000000000..dbf01002e69
--- /dev/null
+++ b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/copy.fail.cpp
@@ -0,0 +1,26 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+
+// <shared_mutex>
+
+// class shared_timed_mutex;
+
+// shared_timed_mutex(const shared_timed_mutex&) = delete;
+
+#include <shared_mutex>
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    std::shared_timed_mutex m0;
+    std::shared_timed_mutex m1(m0);
+#else
+#   error
+#endif
+}
diff --git a/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/default.pass.cpp b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/default.pass.cpp
new file mode 100644
index 00000000000..a90b6c9c829
--- /dev/null
+++ b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/default.pass.cpp
@@ -0,0 +1,25 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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
+
+// <shared_mutex>
+
+// class shared_timed_mutex;
+
+// shared_timed_mutex();
+
+#include <shared_mutex>
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    std::shared_timed_mutex m;
+#endif
+}
diff --git a/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/lock.pass.cpp b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/lock.pass.cpp
new file mode 100644
index 00000000000..b4f9ba38ebf
--- /dev/null
+++ b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/lock.pass.cpp
@@ -0,0 +1,54 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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
+
+// <shared_mutex>
+
+// class shared_timed_mutex;
+
+// void lock();
+
+#include <shared_mutex>
+#include <thread>
+#include <cstdlib>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+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;
+
+void f()
+{
+    time_point t0 = Clock::now();
+    m.lock();
+    time_point t1 = Clock::now();
+    m.unlock();
+    ns d = t1 - t0 - ms(250);
+    assert(d < ms(50));  // within 50ms
+}
+
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    m.lock();
+    std::thread t(f);
+    std::this_thread::sleep_for(ms(250));
+    m.unlock();
+    t.join();
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/lock_shared.pass.cpp b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/lock_shared.pass.cpp
new file mode 100644
index 00000000000..ac5e2064776
--- /dev/null
+++ b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/lock_shared.pass.cpp
@@ -0,0 +1,77 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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
+
+// <shared_mutex>
+
+// class shared_timed_mutex;
+
+// void lock_shared();
+
+#include <shared_mutex>
+#include <thread>
+#include <vector>
+#include <cstdlib>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+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;
+
+void f()
+{
+    time_point t0 = Clock::now();
+    m.lock_shared();
+    time_point t1 = Clock::now();
+    m.unlock_shared();
+    ns d = t1 - t0 - ms(250);
+    assert(d < ms(50));  // within 50ms
+}
+
+void g()
+{
+    time_point t0 = Clock::now();
+    m.lock_shared();
+    time_point t1 = Clock::now();
+    m.unlock_shared();
+    ns d = t1 - t0;
+    assert(d < ms(50));  // within 50ms
+}
+
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    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(ms(250));
+    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(ms(250));
+    m.unlock_shared();
+    for (auto& t : v)
+        t.join();
+    q.join();
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/try_lock.pass.cpp b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/try_lock.pass.cpp
new file mode 100644
index 00000000000..33b069600e2
--- /dev/null
+++ b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/try_lock.pass.cpp
@@ -0,0 +1,58 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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
+
+// <shared_mutex>
+
+// class shared_timed_mutex;
+
+// bool try_lock();
+
+#include <shared_mutex>
+#include <thread>
+#include <cstdlib>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+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;
+
+void f()
+{
+    time_point t0 = Clock::now();
+    assert(!m.try_lock());
+    assert(!m.try_lock());
+    assert(!m.try_lock());
+    while(!m.try_lock())
+        ;
+    time_point t1 = Clock::now();
+    m.unlock();
+    ns d = t1 - t0 - ms(250);
+    assert(d < ms(200));  // within 200ms
+}
+
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    m.lock();
+    std::thread t(f);
+    std::this_thread::sleep_for(ms(250));
+    m.unlock();
+    t.join();
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/try_lock_for.pass.cpp b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/try_lock_for.pass.cpp
new file mode 100644
index 00000000000..98cd8f975b5
--- /dev/null
+++ b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/try_lock_for.pass.cpp
@@ -0,0 +1,73 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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
+
+// <shared_mutex>
+
+// class shared_timed_mutex;
+
+// template <class Rep, class Period>
+//     bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
+
+#include <shared_mutex>
+#include <thread>
+#include <cstdlib>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+std::shared_timed_mutex m;
+
+typedef std::chrono::steady_clock Clock;
+typedef Clock::time_point time_point;
+typedef Clock::duration duration;
+typedef std::chrono::milliseconds ms;
+typedef std::chrono::nanoseconds ns;
+
+void f1()
+{
+    time_point t0 = Clock::now();
+    assert(m.try_lock_for(ms(300)) == true);
+    time_point t1 = Clock::now();
+    m.unlock();
+    ns d = t1 - t0 - ms(250);
+    assert(d < ms(50));  // within 50ms
+}
+
+void f2()
+{
+    time_point t0 = Clock::now();
+    assert(m.try_lock_for(ms(250)) == false);
+    time_point t1 = Clock::now();
+    ns d = t1 - t0 - ms(250);
+    assert(d < ms(50));  // within 50ms
+}
+
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    {
+        m.lock();
+        std::thread t(f1);
+        std::this_thread::sleep_for(ms(250));
+        m.unlock();
+        t.join();
+    }
+    {
+        m.lock();
+        std::thread t(f2);
+        std::this_thread::sleep_for(ms(300));
+        m.unlock();
+        t.join();
+    }
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/try_lock_shared.pass.cpp b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/try_lock_shared.pass.cpp
new file mode 100644
index 00000000000..a006e176857
--- /dev/null
+++ b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/try_lock_shared.pass.cpp
@@ -0,0 +1,62 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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
+
+// <shared_mutex>
+
+// class shared_timed_mutex;
+
+// bool try_lock_shared();
+
+#include <shared_mutex>
+#include <thread>
+#include <vector>
+#include <cstdlib>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+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;
+
+void f()
+{
+    time_point t0 = Clock::now();
+    assert(!m.try_lock_shared());
+    assert(!m.try_lock_shared());
+    assert(!m.try_lock_shared());
+    while(!m.try_lock_shared())
+        ;
+    time_point t1 = Clock::now();
+    m.unlock_shared();
+    ns d = t1 - t0 - ms(250);
+    assert(d < ms(200));  // within 200ms
+}
+
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    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(ms(250));
+    m.unlock();
+    for (auto& t : v)
+        t.join();
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/try_lock_shared_for.pass.cpp b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/try_lock_shared_for.pass.cpp
new file mode 100644
index 00000000000..b2cc15e53e3
--- /dev/null
+++ b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/try_lock_shared_for.pass.cpp
@@ -0,0 +1,80 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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
+
+// <shared_mutex>
+
+// class shared_timed_mutex;
+
+// template <class Rep, class Period>
+//     bool try_lock_shared_for(const chrono::duration<Rep, Period>& rel_time);
+
+#include <shared_mutex>
+#include <thread>
+#include <vector>
+#include <cstdlib>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+std::shared_timed_mutex m;
+
+typedef std::chrono::steady_clock Clock;
+typedef Clock::time_point time_point;
+typedef Clock::duration duration;
+typedef std::chrono::milliseconds ms;
+typedef std::chrono::nanoseconds ns;
+
+void f1()
+{
+    time_point t0 = Clock::now();
+    assert(m.try_lock_shared_for(ms(300)) == true);
+    time_point t1 = Clock::now();
+    m.unlock_shared();
+    ns d = t1 - t0 - ms(250);
+    assert(d < ms(50));  // within 50ms
+}
+
+void f2()
+{
+    time_point t0 = Clock::now();
+    assert(m.try_lock_shared_for(ms(250)) == false);
+    time_point t1 = Clock::now();
+    ns d = t1 - t0 - ms(250);
+    assert(d < ms(50));  // within 50ms
+}
+
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    {
+        m.lock();
+        std::vector<std::thread> v;
+        for (int i = 0; i < 5; ++i)
+            v.push_back(std::thread(f1));
+        std::this_thread::sleep_for(ms(250));
+        m.unlock();
+        for (auto& t : v)
+            t.join();
+    }
+    {
+        m.lock();
+        std::vector<std::thread> v;
+        for (int i = 0; i < 5; ++i)
+            v.push_back(std::thread(f2));
+        std::this_thread::sleep_for(ms(300));
+        m.unlock();
+        for (auto& t : v)
+            t.join();
+    }
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/try_lock_shared_until.pass.cpp b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/try_lock_shared_until.pass.cpp
new file mode 100644
index 00000000000..d1b11210466
--- /dev/null
+++ b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/try_lock_shared_until.pass.cpp
@@ -0,0 +1,80 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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
+
+// <shared_mutex>
+
+// class shared_timed_mutex;
+
+// template <class Clock, class Duration>
+//     bool try_lock_shared_until(const chrono::time_point<Clock, Duration>& abs_time);
+
+#include <shared_mutex>
+#include <thread>
+#include <vector>
+#include <cstdlib>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+std::shared_timed_mutex m;
+
+typedef std::chrono::steady_clock Clock;
+typedef Clock::time_point time_point;
+typedef Clock::duration duration;
+typedef std::chrono::milliseconds ms;
+typedef std::chrono::nanoseconds ns;
+
+void f1()
+{
+    time_point t0 = Clock::now();
+    assert(m.try_lock_shared_until(Clock::now() + ms(300)) == true);
+    time_point t1 = Clock::now();
+    m.unlock_shared();
+    ns d = t1 - t0 - ms(250);
+    assert(d < ms(50));  // within 50ms
+}
+
+void f2()
+{
+    time_point t0 = Clock::now();
+    assert(m.try_lock_shared_until(Clock::now() + ms(250)) == false);
+    time_point t1 = Clock::now();
+    ns d = t1 - t0 - ms(250);
+    assert(d < ms(50));  // within 50ms
+}
+
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    {
+        m.lock();
+        std::vector<std::thread> v;
+        for (int i = 0; i < 5; ++i)
+            v.push_back(std::thread(f1));
+        std::this_thread::sleep_for(ms(250));
+        m.unlock();
+        for (auto& t : v)
+            t.join();
+    }
+    {
+        m.lock();
+        std::vector<std::thread> v;
+        for (int i = 0; i < 5; ++i)
+            v.push_back(std::thread(f2));
+        std::this_thread::sleep_for(ms(300));
+        m.unlock();
+        for (auto& t : v)
+            t.join();
+    }
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/try_lock_until.pass.cpp b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/try_lock_until.pass.cpp
new file mode 100644
index 00000000000..5a8e62408f6
--- /dev/null
+++ b/libcxx/test/std/thread/thread.mutex/thread.mutex.requirements/thread.sharedtimedmutex.requirements/thread.sharedtimedmutex.class/try_lock_until.pass.cpp
@@ -0,0 +1,73 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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
+
+// <shared_mutex>
+
+// class shared_timed_mutex;
+
+// template <class Clock, class Duration>
+//     bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
+
+#include <shared_mutex>
+#include <thread>
+#include <cstdlib>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+std::shared_timed_mutex m;
+
+typedef std::chrono::steady_clock Clock;
+typedef Clock::time_point time_point;
+typedef Clock::duration duration;
+typedef std::chrono::milliseconds ms;
+typedef std::chrono::nanoseconds ns;
+
+void f1()
+{
+    time_point t0 = Clock::now();
+    assert(m.try_lock_until(Clock::now() + ms(300)) == true);
+    time_point t1 = Clock::now();
+    m.unlock();
+    ns d = t1 - t0 - ms(250);
+    assert(d < ms(50));  // within 50ms
+}
+
+void f2()
+{
+    time_point t0 = Clock::now();
+    assert(m.try_lock_until(Clock::now() + ms(250)) == false);
+    time_point t1 = Clock::now();
+    ns d = t1 - t0 - ms(250);
+    assert(d < ms(50));  // within 50ms
+}
+
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    {
+        m.lock();
+        std::thread t(f1);
+        std::this_thread::sleep_for(ms(250));
+        m.unlock();
+        t.join();
+    }
+    {
+        m.lock();
+        std::thread t(f2);
+        std::this_thread::sleep_for(ms(300));
+        m.unlock();
+        t.join();
+    }
+#endif  // _LIBCPP_STD_VER > 11
+}