Index: test/std/thread/futures/futures.shared_future/wait_until.pass.cpp
===================================================================
--- test/std/thread/futures/futures.shared_future/wait_until.pass.cpp
+++ test/std/thread/futures/futures.shared_future/wait_until.pass.cpp
@@ -1,97 +1,129 @@
-//===----------------------------------------------------------------------===//
-//
-//                     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
-
-// <future>
-
-// class shared_future<R>
-
-// template <class Clock, class Duration>
-//   future_status
-//   wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;
-
-#include <future>
-#include <cassert>
-
-typedef std::chrono::milliseconds ms;
-
-void func1(std::promise<int> p)
-{
-    std::this_thread::sleep_for(ms(500));
-    p.set_value(3);
-}
-
-int j = 0;
-
-void func3(std::promise<int&> p)
-{
-    std::this_thread::sleep_for(ms(500));
-    j = 5;
-    p.set_value(j);
-}
-
-void func5(std::promise<void> p)
-{
-    std::this_thread::sleep_for(ms(500));
-    p.set_value();
-}
-
-int main()
-{
-    typedef std::chrono::high_resolution_clock Clock;
-    {
-        typedef int T;
-        std::promise<T> p;
-        std::shared_future<T> f = p.get_future();
-        std::thread(func1, std::move(p)).detach();
-        assert(f.valid());
-        assert(f.wait_until(Clock::now() + ms(300)) == std::future_status::timeout);
-        assert(f.valid());
-        assert(f.wait_until(Clock::now() + ms(300)) == std::future_status::ready);
-        assert(f.valid());
-        Clock::time_point t0 = Clock::now();
-        f.wait();
-        Clock::time_point t1 = Clock::now();
-        assert(f.valid());
-        assert(t1-t0 < ms(5));
-    }
-    {
-        typedef int& T;
-        std::promise<T> p;
-        std::shared_future<T> f = p.get_future();
-        std::thread(func3, std::move(p)).detach();
-        assert(f.valid());
-        assert(f.wait_until(Clock::now() + ms(300)) == std::future_status::timeout);
-        assert(f.valid());
-        assert(f.wait_until(Clock::now() + ms(300)) == std::future_status::ready);
-        assert(f.valid());
-        Clock::time_point t0 = Clock::now();
-        f.wait();
-        Clock::time_point t1 = Clock::now();
-        assert(f.valid());
-        assert(t1-t0 < ms(5));
-    }
-    {
-        typedef void T;
-        std::promise<T> p;
-        std::shared_future<T> f = p.get_future();
-        std::thread(func5, std::move(p)).detach();
-        assert(f.valid());
-        assert(f.wait_until(Clock::now() + ms(300)) == std::future_status::timeout);
-        assert(f.valid());
-        assert(f.wait_until(Clock::now() + ms(300)) == std::future_status::ready);
-        assert(f.valid());
-        Clock::time_point t0 = Clock::now();
-        f.wait();
-        Clock::time_point t1 = Clock::now();
-        assert(f.valid());
-        assert(t1-t0 < ms(5));
-    }
-}
+//===----------------------------------------------------------------------===//
+//
+//                     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
+
+// <future>
+
+// class shared_future<R>
+
+// template <class Clock, class Duration>
+//   future_status
+//   wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;
+
+#include <future>
+#include <atomic>
+#include <cassert>
+
+enum class WorkerThreadState { Uninitialized, AllowedToRun, Exiting };
+typedef std::chrono::milliseconds ms;
+
+std::atomic<WorkerThreadState> thread_state(WorkerThreadState::Uninitialized);
+
+void set_worker_thread_state(WorkerThreadState state)
+{
+    thread_state.store(state, std::memory_order_relaxed);
+}
+
+void wait_for_worker_thread_state(WorkerThreadState state)
+{
+    while (thread_state.load(std::memory_order_relaxed) != state);
+}
+
+void func1(std::promise<int> p)
+{
+    wait_for_worker_thread_state(WorkerThreadState::AllowedToRun);
+    p.set_value(3);
+    set_worker_thread_state(WorkerThreadState::Exiting);
+}
+
+int j = 0;
+
+void func3(std::promise<int&> p)
+{
+    wait_for_worker_thread_state(WorkerThreadState::AllowedToRun);
+    j = 5;
+    p.set_value(j);
+    set_worker_thread_state(WorkerThreadState::Exiting);
+}
+
+void func5(std::promise<void> p)
+{
+    wait_for_worker_thread_state(WorkerThreadState::AllowedToRun);
+    p.set_value();
+    set_worker_thread_state(WorkerThreadState::Exiting);
+}
+
+int main()
+{
+    typedef std::chrono::high_resolution_clock Clock;
+    {
+        typedef int T;
+        std::promise<T> p;
+        std::shared_future<T> f = p.get_future();
+        std::thread(func1, std::move(p)).detach();
+        assert(f.valid());
+        assert(f.wait_until(Clock::now() + ms(10)) == std::future_status::timeout);
+        assert(f.valid());
+
+        // allow the worker thread to produce the result and wait until the worker is done
+        set_worker_thread_state(WorkerThreadState::AllowedToRun);
+        wait_for_worker_thread_state(WorkerThreadState::Exiting);
+
+        assert(f.wait_until(Clock::now() + ms(10)) == std::future_status::ready);
+        assert(f.valid());
+        Clock::time_point t0 = Clock::now();
+        f.wait();
+        Clock::time_point t1 = Clock::now();
+        assert(f.valid());
+        assert(t1-t0 < ms(5));
+    }
+    {
+        typedef int& T;
+        std::promise<T> p;
+        std::shared_future<T> f = p.get_future();
+        std::thread(func3, std::move(p)).detach();
+        assert(f.valid());
+        assert(f.wait_until(Clock::now() + ms(10)) == std::future_status::timeout);
+        assert(f.valid());
+
+        // allow the worker thread to produce the result and wait until the worker is done
+        set_worker_thread_state(WorkerThreadState::AllowedToRun);
+        wait_for_worker_thread_state(WorkerThreadState::Exiting);
+
+        assert(f.wait_until(Clock::now() + ms(10)) == std::future_status::ready);
+        assert(f.valid());
+        Clock::time_point t0 = Clock::now();
+        f.wait();
+        Clock::time_point t1 = Clock::now();
+        assert(f.valid());
+        assert(t1-t0 < ms(5));
+    }
+    {
+        typedef void T;
+        std::promise<T> p;
+        std::shared_future<T> f = p.get_future();
+        std::thread(func5, std::move(p)).detach();
+        assert(f.valid());
+        assert(f.wait_until(Clock::now() + ms(10)) == std::future_status::timeout);
+        assert(f.valid());
+
+        // allow the worker thread to produce the result and wait until the worker is done
+        set_worker_thread_state(WorkerThreadState::AllowedToRun);
+        wait_for_worker_thread_state(WorkerThreadState::Exiting);
+
+        assert(f.wait_until(Clock::now() + ms(10)) == std::future_status::ready);
+        assert(f.valid());
+        Clock::time_point t0 = Clock::now();
+        f.wait();
+        Clock::time_point t1 = Clock::now();
+        assert(f.valid());
+        assert(t1-t0 < ms(5));
+    }
+}
Index: test/std/thread/futures/futures.unique_future/wait_until.pass.cpp
===================================================================
--- test/std/thread/futures/futures.unique_future/wait_until.pass.cpp
+++ test/std/thread/futures/futures.unique_future/wait_until.pass.cpp
@@ -1,97 +1,129 @@
-//===----------------------------------------------------------------------===//
-//
-//                     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
-
-// <future>
-
-// class future<R>
-
-// template <class Clock, class Duration>
-//   future_status
-//   wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;
-
-#include <future>
-#include <cassert>
-
-typedef std::chrono::milliseconds ms;
-
-void func1(std::promise<int> p)
-{
-    std::this_thread::sleep_for(ms(500));
-    p.set_value(3);
-}
-
-int j = 0;
-
-void func3(std::promise<int&> p)
-{
-    std::this_thread::sleep_for(ms(500));
-    j = 5;
-    p.set_value(j);
-}
-
-void func5(std::promise<void> p)
-{
-    std::this_thread::sleep_for(ms(500));
-    p.set_value();
-}
-
-int main()
-{
-    typedef std::chrono::high_resolution_clock Clock;
-    {
-        typedef int T;
-        std::promise<T> p;
-        std::future<T> f = p.get_future();
-        std::thread(func1, std::move(p)).detach();
-        assert(f.valid());
-        assert(f.wait_until(Clock::now() + ms(300)) == std::future_status::timeout);
-        assert(f.valid());
-        assert(f.wait_until(Clock::now() + ms(300)) == std::future_status::ready);
-        assert(f.valid());
-        Clock::time_point t0 = Clock::now();
-        f.wait();
-        Clock::time_point t1 = Clock::now();
-        assert(f.valid());
-        assert(t1-t0 < ms(5));
-    }
-    {
-        typedef int& T;
-        std::promise<T> p;
-        std::future<T> f = p.get_future();
-        std::thread(func3, std::move(p)).detach();
-        assert(f.valid());
-        assert(f.wait_until(Clock::now() + ms(300)) == std::future_status::timeout);
-        assert(f.valid());
-        assert(f.wait_until(Clock::now() + ms(300)) == std::future_status::ready);
-        assert(f.valid());
-        Clock::time_point t0 = Clock::now();
-        f.wait();
-        Clock::time_point t1 = Clock::now();
-        assert(f.valid());
-        assert(t1-t0 < ms(5));
-    }
-    {
-        typedef void T;
-        std::promise<T> p;
-        std::future<T> f = p.get_future();
-        std::thread(func5, std::move(p)).detach();
-        assert(f.valid());
-        assert(f.wait_until(Clock::now() + ms(300)) == std::future_status::timeout);
-        assert(f.valid());
-        assert(f.wait_until(Clock::now() + ms(300)) == std::future_status::ready);
-        assert(f.valid());
-        Clock::time_point t0 = Clock::now();
-        f.wait();
-        Clock::time_point t1 = Clock::now();
-        assert(f.valid());
-        assert(t1-t0 < ms(5));
-    }
-}
+//===----------------------------------------------------------------------===//
+//
+//                     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
+
+// <future>
+
+// class future<R>
+
+// template <class Clock, class Duration>
+//   future_status
+//   wait_until(const chrono::time_point<Clock, Duration>& abs_time) const;
+
+#include <future>
+#include <atomic>
+#include <cassert>
+
+enum class WorkerThreadState { Uninitialized, AllowedToRun, Exiting };
+typedef std::chrono::milliseconds ms;
+
+std::atomic<WorkerThreadState> thread_state(WorkerThreadState::Uninitialized);
+
+void set_worker_thread_state(WorkerThreadState state)
+{
+    thread_state.store(state, std::memory_order_relaxed);
+}
+
+void wait_for_worker_thread_state(WorkerThreadState state)
+{
+    while (thread_state.load(std::memory_order_relaxed) != state);
+}
+
+void func1(std::promise<int> p)
+{
+    wait_for_worker_thread_state(WorkerThreadState::AllowedToRun);
+    p.set_value(3);
+    set_worker_thread_state(WorkerThreadState::Exiting);
+}
+
+int j = 0;
+
+void func3(std::promise<int&> p)
+{
+    wait_for_worker_thread_state(WorkerThreadState::AllowedToRun);
+    j = 5;
+    p.set_value(j);
+    set_worker_thread_state(WorkerThreadState::Exiting);
+}
+
+void func5(std::promise<void> p)
+{
+    wait_for_worker_thread_state(WorkerThreadState::AllowedToRun);
+    p.set_value();
+    set_worker_thread_state(WorkerThreadState::Exiting);
+}
+
+int main()
+{
+    typedef std::chrono::high_resolution_clock Clock;
+    {
+        typedef int T;
+        std::promise<T> p;
+        std::future<T> f = p.get_future();
+        std::thread(func1, std::move(p)).detach();
+        assert(f.valid());
+        assert(f.wait_until(Clock::now() + ms(10)) == std::future_status::timeout);
+        assert(f.valid());
+
+        // allow the worker thread to produce the result and wait until the worker is done
+        set_worker_thread_state(WorkerThreadState::AllowedToRun);
+        wait_for_worker_thread_state(WorkerThreadState::Exiting);
+
+        assert(f.wait_until(Clock::now() + ms(10)) == std::future_status::ready);
+        assert(f.valid());
+        Clock::time_point t0 = Clock::now();
+        f.wait();
+        Clock::time_point t1 = Clock::now();
+        assert(f.valid());
+        assert(t1-t0 < ms(5));
+    }
+    {
+        typedef int& T;
+        std::promise<T> p;
+        std::future<T> f = p.get_future();
+        std::thread(func3, std::move(p)).detach();
+        assert(f.valid());
+        assert(f.wait_until(Clock::now() + ms(10)) == std::future_status::timeout);
+        assert(f.valid());
+
+        // allow the worker thread to produce the result and wait until the worker is done
+        set_worker_thread_state(WorkerThreadState::AllowedToRun);
+        wait_for_worker_thread_state(WorkerThreadState::Exiting);
+
+        assert(f.wait_until(Clock::now() + ms(10)) == std::future_status::ready);
+        assert(f.valid());
+        Clock::time_point t0 = Clock::now();
+        f.wait();
+        Clock::time_point t1 = Clock::now();
+        assert(f.valid());
+        assert(t1-t0 < ms(5));
+    }
+    {
+        typedef void T;
+        std::promise<T> p;
+        std::future<T> f = p.get_future();
+        std::thread(func5, std::move(p)).detach();
+        assert(f.valid());
+        assert(f.wait_until(Clock::now() + ms(10)) == std::future_status::timeout);
+        assert(f.valid());
+
+        // allow the worker thread to produce the result and wait until the worker is done
+        set_worker_thread_state(WorkerThreadState::AllowedToRun);
+        wait_for_worker_thread_state(WorkerThreadState::Exiting);
+
+        assert(f.wait_until(Clock::now() + ms(10)) == std::future_status::ready);
+        assert(f.valid());
+        Clock::time_point t0 = Clock::now();
+        f.wait();
+        Clock::time_point t1 = Clock::now();
+        assert(f.valid());
+        assert(t1-t0 < ms(5));
+    }
+}