diff --git a/include/__mutex_base b/include/__mutex_base
index a73e400e6..d4023a64f 100644
--- a/include/__mutex_base
+++ b/include/__mutex_base
@@ -20,16 +20,6 @@
 #pragma GCC system_header
 #endif
 
-#ifdef _LIBCPP_SHARED_LOCK
-
-namespace ting {
-template <class _Mutex> class shared_lock;
-template <class _Mutex> class upgrade_lock;
-}
-
-#endif  // _LIBCPP_SHARED_LOCK
-
-
 _LIBCPP_BEGIN_NAMESPACE_STD
 
 class _LIBCPP_TYPE_VIS mutex
@@ -162,27 +152,6 @@ public:
             return *this;
         }
 
-#ifdef _LIBCPP_SHARED_LOCK
-
-    unique_lock(ting::shared_lock<mutex_type>&&, try_to_lock_t);
-    template <class _Clock, class _Duration>
-        unique_lock(ting::shared_lock<mutex_type>&&,
-                    const chrono::time_point<_Clock, _Duration>&);
-    template <class _Rep, class _Period>
-        unique_lock(ting::shared_lock<mutex_type>&&,
-                    const chrono::duration<_Rep, _Period>&);
-
-    explicit unique_lock(ting::upgrade_lock<mutex_type>&&);
-    unique_lock(ting::upgrade_lock<mutex_type>&&, try_to_lock_t);
-    template <class _Clock, class _Duration>
-        unique_lock(ting::upgrade_lock<mutex_type>&&,
-                    const chrono::time_point<_Clock, _Duration>&);
-    template <class _Rep, class _Period>
-        unique_lock(ting::upgrade_lock<mutex_type>&&,
-                    const chrono::duration<_Rep, _Period>&);
-
-#endif  // _LIBCPP_SHARED_LOCK
-
 #endif  // _LIBCPP_HAS_NO_RVALUE_REFERENCES
 
     void lock();
diff --git a/include/shared_mutex b/include/shared_mutex
new file mode 100644
index 000000000..5b1f53aaf
--- /dev/null
+++ b/include/shared_mutex
@@ -0,0 +1,419 @@
+// -*- C++ -*-
+//===------------------------ shared_mutex --------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef _LIBCPP_SHARED_MUTEX
+#define _LIBCPP_SHARED_MUTEX
+
+/*
+    shared_mutex synopsis
+
+// C++1y
+
+namespace std
+{
+
+class shared_mutex
+{
+public:
+    shared_mutex();
+    ~shared_mutex();
+
+    shared_mutex(const shared_mutex&) = delete;
+    shared_mutex& operator=(const shared_mutex&) = delete;
+
+    // Exclusive ownership
+    void lock(); // blocking
+    bool try_lock();
+    template <class Rep, class Period>
+        bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
+    template <class Clock, class Duration>
+        bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
+    void unlock();
+
+    // Shared ownership
+    void lock_shared(); // blocking
+    bool try_lock_shared();
+    template <class Rep, class Period>
+        bool
+        try_lock_shared_for(const chrono::duration<Rep, Period>& rel_time);
+    template <class Clock, class Duration>
+        bool
+        try_lock_shared_until(const chrono::time_point<Clock, Duration>& abs_time);
+    void unlock_shared();
+};
+
+template <class Mutex>
+class shared_lock
+{
+public:
+    typedef Mutex mutex_type;
+
+    // Shared locking
+    shared_lock() noexcept;
+    explicit shared_lock(mutex_type& m); // blocking
+    shared_lock(mutex_type& m, defer_lock_t) noexcept;
+    shared_lock(mutex_type& m, try_to_lock_t);
+    shared_lock(mutex_type& m, adopt_lock_t);
+    template <class Clock, class Duration>
+        shared_lock(mutex_type& m,
+                    const chrono::time_point<Clock, Duration>& abs_time);
+    template <class Rep, class Period>
+        shared_lock(mutex_type& m,
+                    const chrono::duration<Rep, Period>& rel_time);
+    ~shared_lock();
+
+    shared_lock(shared_lock const&) = delete;
+    shared_lock& operator=(shared_lock const&) = delete;
+
+    shared_lock(shared_lock&& u) noexcept;
+    shared_lock& operator=(shared_lock&& u) noexcept;
+
+    void lock(); // blocking
+    bool try_lock();
+    template <class Rep, class Period>
+        bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
+    template <class Clock, class Duration>
+        bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
+    void unlock();
+
+    // Setters
+    void swap(shared_lock& u) noexcept;
+    mutex_type* release() noexcept;
+
+    // Getters
+    bool owns_lock() const noexcept;
+    explicit operator bool () const noexcept;
+    mutex_type* mutex() const noexcept;
+};
+
+template <class Mutex>
+    void swap(shared_lock<Mutex>& x, shared_lock<Mutex>& y) noexcept;
+
+}  // std
+
+*/
+
+#include <__config>
+
+#if _LIBCPP_STD_VER > 11 || defined(_LIBCPP_BUILDING_SHARED_MUTEX)
+
+#include <__mutex_base>
+
+#include <__undef_min_max>
+
+#if !defined(_LIBCPP_HAS_NO_PRAGMA_SYSTEM_HEADER)
+#pragma GCC system_header
+#endif
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+class _LIBCPP_TYPE_VIS shared_mutex
+{
+    mutex               __mut_;
+    condition_variable  __gate1_;
+    condition_variable  __gate2_;
+    unsigned            __state_;
+
+    static const unsigned __write_entered_ = 1U << (sizeof(unsigned)*__CHAR_BIT__ - 1);
+    static const unsigned __n_readers_ = ~__write_entered_;
+public:
+    shared_mutex();
+    _LIBCPP_INLINE_VISIBILITY ~shared_mutex() = default;
+
+    shared_mutex(const shared_mutex&) = delete;
+    shared_mutex& operator=(const shared_mutex&) = delete;
+
+    // Exclusive ownership
+    void lock();
+    bool try_lock();
+    template <class _Rep, class _Period>
+        _LIBCPP_INLINE_VISIBILITY
+        bool
+        try_lock_for(const chrono::duration<_Rep, _Period>& __rel_time)
+        {
+            return try_lock_until(chrono::steady_clock::now() + __rel_time);
+        }
+    template <class _Clock, class _Duration>
+        bool
+        try_lock_until(const chrono::time_point<_Clock, _Duration>& __abs_time);
+    void unlock();
+
+    // Shared ownership
+    void lock_shared();
+    bool try_lock_shared();
+    template <class _Rep, class _Period>
+        _LIBCPP_INLINE_VISIBILITY
+        bool
+        try_lock_shared_for(const chrono::duration<_Rep, _Period>& __rel_time)
+        {
+            return try_lock_shared_until(chrono::steady_clock::now() + __rel_time);
+        }
+    template <class _Clock, class _Duration>
+        bool
+        try_lock_shared_until(const chrono::time_point<_Clock, _Duration>& __abs_time);
+    void unlock_shared();
+};
+
+template <class _Clock, class _Duration>
+bool
+shared_mutex::try_lock_until(
+                        const chrono::time_point<_Clock, _Duration>& __abs_time)
+{
+    unique_lock<mutex> __lk(__mut_);
+    if (__state_ & __write_entered_)
+    {
+        while (true)
+        {
+            cv_status __status = __gate1_.wait_until(__lk, __abs_time);
+            if ((__state_ & __write_entered_) == 0)
+                break;
+            if (__status == cv_status::timeout)
+                return false;
+        }
+    }
+    __state_ |= __write_entered_;
+    if (__state_ & __n_readers_)
+    {
+        while (true)
+        {
+            cv_status __status = __gate2_.wait_until(__lk, __abs_time);
+            if ((__state_ & __n_readers_) == 0)
+                break;
+            if (__status == cv_status::timeout)
+            {
+                __state_ &= ~__write_entered_;
+                return false;
+            }
+        }
+    }
+    return true;
+}
+
+template <class _Clock, class _Duration>
+bool
+shared_mutex::try_lock_shared_until(
+                        const chrono::time_point<_Clock, _Duration>& __abs_time)
+{
+    unique_lock<mutex> __lk(__mut_);
+    if ((__state_ & __write_entered_) || (__state_ & __n_readers_) == __n_readers_)
+    {
+        while (true)
+        {
+            cv_status status = __gate1_.wait_until(__lk, __abs_time);
+            if ((__state_ & __write_entered_) == 0 &&
+                                       (__state_ & __n_readers_) < __n_readers_)
+                break;
+            if (status == cv_status::timeout)
+                return false;
+        }
+    }
+    unsigned __num_readers = (__state_ & __n_readers_) + 1;
+    __state_ &= ~__n_readers_;
+    __state_ |= __num_readers;
+    return true;
+}
+
+template <class _Mutex>
+class shared_lock
+{
+public:
+    typedef _Mutex mutex_type;
+
+private:
+    mutex_type* __m_;
+    bool __owns_;
+
+public:
+    _LIBCPP_INLINE_VISIBILITY
+    shared_lock() noexcept
+        : __m_(nullptr),
+          __owns_(false)
+        {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    explicit shared_lock(mutex_type& __m)
+        : __m_(&__m),
+          __owns_(true)
+        {__m_->lock_shared();}
+
+    _LIBCPP_INLINE_VISIBILITY
+    shared_lock(mutex_type& __m, defer_lock_t) noexcept
+        : __m_(&__m),
+          __owns_(false)
+        {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    shared_lock(mutex_type& __m, try_to_lock_t)
+        : __m_(&__m),
+          __owns_(__m.try_lock_shared())
+        {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    shared_lock(mutex_type& __m, adopt_lock_t)
+        : __m_(&__m),
+          __owns_(true)
+        {}
+
+    template <class _Clock, class _Duration>
+        _LIBCPP_INLINE_VISIBILITY
+        shared_lock(mutex_type& __m,
+                    const chrono::time_point<_Clock, _Duration>& __abs_time)
+            : __m_(&__m),
+              __owns_(__m.try_lock_shared_until(__abs_time))
+            {}
+
+    template <class _Rep, class _Period>
+        _LIBCPP_INLINE_VISIBILITY
+        shared_lock(mutex_type& __m,
+                    const chrono::duration<_Rep, _Period>& __rel_time)
+            : __m_(&__m),
+              __owns_(__m.try_lock_shared_for(__rel_time))
+            {}
+
+    _LIBCPP_INLINE_VISIBILITY
+    ~shared_lock()
+    {
+        if (__owns_)
+            __m_->unlock_shared();
+    }
+
+    shared_lock(shared_lock const&) = delete;
+    shared_lock& operator=(shared_lock const&) = delete;
+
+    _LIBCPP_INLINE_VISIBILITY
+    shared_lock(shared_lock&& __u) noexcept
+        : __m_(__u.__m_),
+          __owns_(__u.__owns_)
+        {
+            __u.__m_ = nullptr;
+            __u.__owns_ = false;
+        }
+
+    _LIBCPP_INLINE_VISIBILITY
+    shared_lock& operator=(shared_lock&& __u) noexcept
+    {
+        if (__owns_)
+            __m_->unlock_shared();
+        __m_ = nullptr;
+        __owns_ = false;
+        __m_ = __u.__m_;
+        __owns_ = __u.__owns_;
+        __u.__m_ = nullptr;
+        __u.__owns_ = false;
+        return *this;
+    }
+
+    void lock();
+    bool try_lock();
+    template <class Rep, class Period>
+        bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
+    template <class Clock, class Duration>
+        bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
+    void unlock();
+
+    // Setters
+    _LIBCPP_INLINE_VISIBILITY
+    void swap(shared_lock& __u) noexcept
+    {
+        _VSTD::swap(__m_, __u.__m_);
+        _VSTD::swap(__owns_, __u.__owns_);
+    }
+
+    _LIBCPP_INLINE_VISIBILITY
+    mutex_type* release() noexcept
+    {
+        mutex_type* __m = __m_;
+        __m_ = nullptr;
+        __owns_ = false;
+        return __m;
+    }
+
+    // Getters
+    _LIBCPP_INLINE_VISIBILITY
+    bool owns_lock() const noexcept {return __owns_;}
+
+    _LIBCPP_INLINE_VISIBILITY
+    explicit operator bool () const noexcept {return __owns_;}
+
+    _LIBCPP_INLINE_VISIBILITY
+    mutex_type* mutex() const noexcept {return __m_;}
+};
+
+template <class _Mutex>
+void
+shared_lock<_Mutex>::lock()
+{
+    if (__m_ == nullptr)
+        __throw_system_error(EPERM, "shared_lock::lock: references null mutex");
+    if (__owns_)
+        __throw_system_error(EDEADLK, "shared_lock::lock: already locked");
+    __m_->lock_shared();
+    __owns_ = true;
+}
+
+template <class _Mutex>
+bool
+shared_lock<_Mutex>::try_lock()
+{
+    if (__m_ == nullptr)
+        __throw_system_error(EPERM, "shared_lock::try_lock: references null mutex");
+    if (__owns_)
+        __throw_system_error(EDEADLK, "shared_lock::try_lock: already locked");
+    __owns_ = __m_->try_lock_shared();
+    return __owns_;
+}
+
+template <class _Mutex>
+template <class _Rep, class _Period>
+bool
+shared_lock<_Mutex>::try_lock_for(const chrono::duration<_Rep, _Period>& __d)
+{
+    if (__m_ == nullptr)
+        __throw_system_error(EPERM, "shared_lock::try_lock_for: references null mutex");
+    if (__owns_)
+        __throw_system_error(EDEADLK, "shared_lock::try_lock_for: already locked");
+    __owns_ = __m_->try_lock_shared_for(__d);
+    return __owns_;
+}
+
+template <class _Mutex>
+template <class _Clock, class _Duration>
+bool
+shared_lock<_Mutex>::try_lock_until(const chrono::time_point<_Clock, _Duration>& __t)
+{
+    if (__m_ == nullptr)
+        __throw_system_error(EPERM, "shared_lock::try_lock_until: references null mutex");
+    if (__owns_)
+        __throw_system_error(EDEADLK, "shared_lock::try_lock_until: already locked");
+    __owns_ = __m_->try_lock_shared_until(__t);
+    return __owns_;
+}
+
+template <class _Mutex>
+void
+shared_lock<_Mutex>::unlock()
+{
+    if (!__owns_)
+        __throw_system_error(EPERM, "shared_lock::unlock: not locked");
+    __m_->unlock_shared();
+    __owns_ = false;
+}
+
+template <class _Mutex>
+inline _LIBCPP_INLINE_VISIBILITY
+void
+swap(shared_lock<_Mutex>& __x, shared_lock<_Mutex>& __y) noexcept
+    {__x.swap(__y);}
+
+_LIBCPP_END_NAMESPACE_STD
+
+#endif  // _LIBCPP_STD_VER > 11
+
+#endif  // _LIBCPP_SHARED_MUTEX
diff --git a/src/shared_mutex.cpp b/src/shared_mutex.cpp
new file mode 100644
index 000000000..5fb22e445
--- /dev/null
+++ b/src/shared_mutex.cpp
@@ -0,0 +1,101 @@
+//===---------------------- shared_mutex.cpp ------------------------------===//
+//
+//                     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.
+//
+//===----------------------------------------------------------------------===//
+
+#define _LIBCPP_BUILDING_SHARED_MUTEX
+#include "shared_mutex"
+
+_LIBCPP_BEGIN_NAMESPACE_STD
+
+shared_mutex::shared_mutex()
+    : __state_(0)
+{
+}
+
+// Exclusive ownership
+
+void
+shared_mutex::lock()
+{
+    unique_lock<mutex> lk(__mut_);
+    while (__state_ & __write_entered_)
+        __gate1_.wait(lk);
+    __state_ |= __write_entered_;
+    while (__state_ & __n_readers_)
+        __gate2_.wait(lk);
+}
+
+bool
+shared_mutex::try_lock()
+{
+    unique_lock<mutex> lk(__mut_);
+    if (__state_ == 0)
+    {
+        __state_ = __write_entered_;
+        return true;
+    }
+    return false;
+}
+
+void
+shared_mutex::unlock()
+{
+    lock_guard<mutex> _(__mut_);
+    __state_ = 0;
+    __gate1_.notify_all();
+}
+
+// Shared ownership
+
+void
+shared_mutex::lock_shared()
+{
+    unique_lock<mutex> lk(__mut_);
+    while ((__state_ & __write_entered_) || (__state_ & __n_readers_) == __n_readers_)
+        __gate1_.wait(lk);
+    unsigned num_readers = (__state_ & __n_readers_) + 1;
+    __state_ &= ~__n_readers_;
+    __state_ |= num_readers;
+}
+
+bool
+shared_mutex::try_lock_shared()
+{
+    unique_lock<mutex> lk(__mut_);
+    unsigned num_readers = __state_ & __n_readers_;
+    if (!(__state_ & __write_entered_) && num_readers != __n_readers_)
+    {
+        ++num_readers;
+        __state_ &= ~__n_readers_;
+        __state_ |= num_readers;
+        return true;
+    }
+    return false;
+}
+
+void
+shared_mutex::unlock_shared()
+{
+    lock_guard<mutex> _(__mut_);
+    unsigned num_readers = (__state_ & __n_readers_) - 1;
+    __state_ &= ~__n_readers_;
+    __state_ |= num_readers;
+    if (__state_ & __write_entered_)
+    {
+        if (num_readers == 0)
+            __gate2_.notify_one();
+    }
+    else
+    {
+        if (num_readers == __n_readers_ - 1)
+            __gate1_.notify_one();
+    }
+}
+
+
+_LIBCPP_END_NAMESPACE_STD
diff --git a/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/copy_assign.fail.cpp b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/copy_assign.fail.cpp
new file mode 100644
index 000000000..0bd347d0b
--- /dev/null
+++ b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/copy_assign.fail.cpp
@@ -0,0 +1,34 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+// template <class Mutex> class shared_lock;
+
+// shared_lock& operator=(shared_lock const&) = delete;
+
+#include <shared_mutex>
+
+#if _LIBCPP_STD_VER > 11
+
+std::shared_mutex m0;
+std::shared_mutex m1;
+
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    std::shared_lock<std::shared_mutex> lk0(m0);
+    std::shared_lock<std::shared_mutex> lk1(m1);
+    lk1 = lk0;
+#else
+#   error
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/copy_ctor.fail.cpp b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/copy_ctor.fail.cpp
new file mode 100644
index 000000000..66cec9ec5
--- /dev/null
+++ b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/copy_ctor.fail.cpp
@@ -0,0 +1,30 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+// template <class Mutex> class shared_lock;
+
+// shared_lock(shared_lock const&) = delete;
+
+#include <shared_mutex>
+
+#if _LIBCPP_STD_VER > 11
+std::shared_mutex m;
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    std::shared_lock<std::shared_mutex> lk0(m);
+    std::shared_lock<std::shared_mutex> lk = lk0;
+#else
+#   error
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/default.pass.cpp b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/default.pass.cpp
new file mode 100644
index 000000000..2adef5f76
--- /dev/null
+++ b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/default.pass.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>
+
+// template <class Mutex> class shared_lock;
+
+// shared_lock();
+
+#include <shared_mutex>
+#include <cassert>
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    std::shared_lock<std::shared_mutex> ul;
+    assert(!ul.owns_lock());
+    assert(ul.mutex() == nullptr);
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/move_assign.pass.cpp b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/move_assign.pass.cpp
new file mode 100644
index 000000000..1fcc98fce
--- /dev/null
+++ b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/move_assign.pass.cpp
@@ -0,0 +1,37 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+// template <class Mutex> class shared_lock;
+
+// shared_lock& operator=(shared_lock&& u);
+
+#include <shared_mutex>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+std::shared_mutex m0;
+std::shared_mutex m1;
+
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    std::shared_lock<std::shared_mutex> lk0(m0);
+    std::shared_lock<std::shared_mutex> lk1(m1);
+    lk1 = std::move(lk0);
+    assert(lk1.mutex() == &m0);
+    assert(lk1.owns_lock() == true);
+    assert(lk0.mutex() == nullptr);
+    assert(lk0.owns_lock() == false);
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/move_ctor.pass.cpp b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/move_ctor.pass.cpp
new file mode 100644
index 000000000..7e801da20
--- /dev/null
+++ b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/move_ctor.pass.cpp
@@ -0,0 +1,33 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+// template <class Mutex> class shared_lock;
+
+// shared_lock(shared_lock&& u);
+
+#include <shared_mutex>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+std::shared_mutex m;
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    std::shared_lock<std::shared_mutex> lk0(m);
+    std::shared_lock<std::shared_mutex> lk = std::move(lk0);
+    assert(lk.mutex() == &m);
+    assert(lk.owns_lock() == true);
+    assert(lk0.mutex() == nullptr);
+    assert(lk0.owns_lock() == false);
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/mutex.pass.cpp b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/mutex.pass.cpp
new file mode 100644
index 000000000..fd1dad426
--- /dev/null
+++ b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/mutex.pass.cpp
@@ -0,0 +1,79 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+// template <class Mutex> class shared_lock;
+
+// explicit shared_lock(mutex_type& m);
+
+#include <shared_mutex>
+#include <thread>
+#include <vector>
+#include <cstdlib>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+std::shared_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();
+    time_point t1;
+    {
+    std::shared_lock<std::shared_mutex> ul(m);
+    t1 = Clock::now();
+    }
+    ns d = t1 - t0 - ms(250);
+    assert(d < ms(50));  // within 50ms
+}
+
+void g()
+{
+    time_point t0 = Clock::now();
+    time_point t1;
+    {
+    std::shared_lock<std::shared_mutex> ul(m);
+    t1 = Clock::now();
+    }
+    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/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/mutex_adopt_lock.pass.cpp b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/mutex_adopt_lock.pass.cpp
new file mode 100644
index 000000000..9c4400555
--- /dev/null
+++ b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/mutex_adopt_lock.pass.cpp
@@ -0,0 +1,28 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+// template <class Mutex> class shared_lock;
+
+// shared_lock(mutex_type& m, adopt_lock_t);
+
+#include <shared_mutex>
+#include <cassert>
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    std::shared_mutex m;
+    m.lock();
+    std::shared_lock<std::shared_mutex> lk(m, std::adopt_lock);
+    assert(lk.mutex() == &m);
+    assert(lk.owns_lock() == true);
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/mutex_defer_lock.pass.cpp b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/mutex_defer_lock.pass.cpp
new file mode 100644
index 000000000..2f2247a0e
--- /dev/null
+++ b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/mutex_defer_lock.pass.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>
+
+// template <class Mutex> class shared_lock;
+
+// shared_lock(mutex_type& m, defer_lock_t);
+
+#include <shared_mutex>
+#include <cassert>
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    std::shared_mutex m;
+    std::shared_lock<std::shared_mutex> lk(m, std::defer_lock);
+    assert(lk.mutex() == &m);
+    assert(lk.owns_lock() == false);
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/mutex_duration.pass.cpp b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/mutex_duration.pass.cpp
new file mode 100644
index 000000000..f3798af9c
--- /dev/null
+++ b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/mutex_duration.pass.cpp
@@ -0,0 +1,79 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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 timed_mutex;
+
+// template <class Rep, class Period>
+//   shared_lock(mutex_type& m, 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_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();
+    std::shared_lock<std::shared_mutex> lk(m, ms(300));
+    assert(lk.owns_lock() == true);
+    time_point t1 = Clock::now();
+    ns d = t1 - t0 - ms(250);
+    assert(d < ms(50));  // within 50ms
+}
+
+void f2()
+{
+    time_point t0 = Clock::now();
+    std::shared_lock<std::shared_mutex> lk(m, ms(250));
+    assert(lk.owns_lock() == 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/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/mutex_time_point.pass.cpp b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/mutex_time_point.pass.cpp
new file mode 100644
index 000000000..44eaee22c
--- /dev/null
+++ b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/mutex_time_point.pass.cpp
@@ -0,0 +1,79 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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_mutex;
+
+// template <class Clock, class Duration>
+//   shared_lock(mutex_type& m, 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_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();
+    std::shared_lock<std::shared_mutex> lk(m, Clock::now() + ms(300));
+    assert(lk.owns_lock() == true);
+    time_point t1 = Clock::now();
+    ns d = t1 - t0 - ms(250);
+    assert(d < ns(50000000));  // within 50ms
+}
+
+void f2()
+{
+    time_point t0 = Clock::now();
+    std::shared_lock<std::shared_mutex> lk(m, Clock::now() + ms(250));
+    assert(lk.owns_lock() == 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/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/mutex_try_to_lock.pass.cpp b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/mutex_try_to_lock.pass.cpp
new file mode 100644
index 000000000..9dae3f96b
--- /dev/null
+++ b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.cons/mutex_try_to_lock.pass.cpp
@@ -0,0 +1,72 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+// template <class Mutex> class shared_lock;
+
+// shared_lock(mutex_type& m, try_to_lock_t);
+
+#include <shared_mutex>
+#include <thread>
+#include <vector>
+#include <cstdlib>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+std::shared_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();
+    {
+        std::shared_lock<std::shared_mutex> lk(m, std::try_to_lock);
+        assert(lk.owns_lock() == false);
+    }
+    {
+        std::shared_lock<std::shared_mutex> lk(m, std::try_to_lock);
+        assert(lk.owns_lock() == false);
+    }
+    {
+        std::shared_lock<std::shared_mutex> lk(m, std::try_to_lock);
+        assert(lk.owns_lock() == false);
+    }
+    while (true)
+    {
+        std::shared_lock<std::shared_mutex> lk(m, std::try_to_lock);
+        if (lk.owns_lock())
+            break;
+    }
+    time_point t1 = Clock::now();
+    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/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.locking/lock.pass.cpp b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.locking/lock.pass.cpp
new file mode 100644
index 000000000..c6617a519
--- /dev/null
+++ b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.locking/lock.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.
+//
+//===----------------------------------------------------------------------===//
+
+// <shared_mutex>
+
+// template <class Mutex> class shared_lock;
+
+// void lock();
+
+#include <shared_mutex>
+#include <thread>
+#include <vector>
+#include <cstdlib>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+std::shared_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()
+{
+    std::shared_lock<std::shared_mutex> lk(m, std::defer_lock);
+    time_point t0 = Clock::now();
+    lk.lock();
+    time_point t1 = Clock::now();
+    assert(lk.owns_lock() == true);
+    ns d = t1 - t0 - ms(250);
+    assert(d < ms(25));  // within 25ms
+    try
+    {
+        lk.lock();
+        assert(false);
+    }
+    catch (std::system_error& e)
+    {
+        assert(e.code().value() == EDEADLK);
+    }
+    lk.unlock();
+    lk.release();
+    try
+    {
+        lk.lock();
+        assert(false);
+    }
+    catch (std::system_error& e)
+    {
+        assert(e.code().value() == EPERM);
+    }
+}
+
+#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/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.locking/try_lock.pass.cpp b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.locking/try_lock.pass.cpp
new file mode 100644
index 000000000..d65fbfafe
--- /dev/null
+++ b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.locking/try_lock.pass.cpp
@@ -0,0 +1,68 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+// template <class Mutex> class shared_lock;
+
+// bool try_lock();
+
+#include <shared_mutex>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+bool try_lock_called = false;
+
+struct mutex
+{
+    bool try_lock_shared()
+    {
+        try_lock_called = !try_lock_called;
+        return try_lock_called;
+    }
+    void unlock_shared() {}
+};
+
+mutex m;
+
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    std::shared_lock<mutex> lk(m, std::defer_lock);
+    assert(lk.try_lock() == true);
+    assert(try_lock_called == true);
+    assert(lk.owns_lock() == true);
+    try
+    {
+        lk.try_lock();
+        assert(false);
+    }
+    catch (std::system_error& e)
+    {
+        assert(e.code().value() == EDEADLK);
+    }
+    lk.unlock();
+    assert(lk.try_lock() == false);
+    assert(try_lock_called == false);
+    assert(lk.owns_lock() == false);
+    lk.release();
+    try
+    {
+        lk.try_lock();
+        assert(false);
+    }
+    catch (std::system_error& e)
+    {
+        assert(e.code().value() == EPERM);
+    }
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.locking/try_lock_for.pass.cpp b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.locking/try_lock_for.pass.cpp
new file mode 100644
index 000000000..d076e5296
--- /dev/null
+++ b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.locking/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.
+//
+//===----------------------------------------------------------------------===//
+
+// <shared_mutex>
+
+// template <class Mutex> class shared_lock;
+
+// template <class Rep, class Period>
+//   bool try_lock_for(const chrono::duration<Rep, Period>& rel_time);
+
+#include <shared_mutex>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+bool try_lock_for_called = false;
+
+typedef std::chrono::milliseconds ms;
+
+struct mutex
+{
+    template <class Rep, class Period>
+        bool try_lock_shared_for(const std::chrono::duration<Rep, Period>& rel_time)
+    {
+        assert(rel_time == ms(5));
+        try_lock_for_called = !try_lock_for_called;
+        return try_lock_for_called;
+    }
+    void unlock_shared() {}
+};
+
+mutex m;
+
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    std::shared_lock<mutex> lk(m, std::defer_lock);
+    assert(lk.try_lock_for(ms(5)) == true);
+    assert(try_lock_for_called == true);
+    assert(lk.owns_lock() == true);
+    try
+    {
+        lk.try_lock_for(ms(5));
+        assert(false);
+    }
+    catch (std::system_error& e)
+    {
+        assert(e.code().value() == EDEADLK);
+    }
+    lk.unlock();
+    assert(lk.try_lock_for(ms(5)) == false);
+    assert(try_lock_for_called == false);
+    assert(lk.owns_lock() == false);
+    lk.release();
+    try
+    {
+        lk.try_lock_for(ms(5));
+        assert(false);
+    }
+    catch (std::system_error& e)
+    {
+        assert(e.code().value() == EPERM);
+    }
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.locking/try_lock_until.pass.cpp b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.locking/try_lock_until.pass.cpp
new file mode 100644
index 000000000..8efffc460
--- /dev/null
+++ b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.locking/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.
+//
+//===----------------------------------------------------------------------===//
+
+// <shared_mutex>
+
+// template <class Mutex> class shared_lock;
+
+// template <class Clock, class Duration>
+//   bool try_lock_until(const chrono::time_point<Clock, Duration>& abs_time);
+
+#include <shared_mutex>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+bool try_lock_until_called = false;
+
+struct mutex
+{
+    template <class Clock, class Duration>
+        bool try_lock_shared_until(const std::chrono::time_point<Clock, Duration>& abs_time)
+    {
+        typedef std::chrono::milliseconds ms;
+        assert(Clock::now() - abs_time < ms(5));
+        try_lock_until_called = !try_lock_until_called;
+        return try_lock_until_called;
+    }
+    void unlock_shared() {}
+};
+
+mutex m;
+
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    typedef std::chrono::steady_clock Clock;
+    std::shared_lock<mutex> lk(m, std::defer_lock);
+    assert(lk.try_lock_until(Clock::now()) == true);
+    assert(try_lock_until_called == true);
+    assert(lk.owns_lock() == true);
+    try
+    {
+        lk.try_lock_until(Clock::now());
+        assert(false);
+    }
+    catch (std::system_error& e)
+    {
+        assert(e.code().value() == EDEADLK);
+    }
+    lk.unlock();
+    assert(lk.try_lock_until(Clock::now()) == false);
+    assert(try_lock_until_called == false);
+    assert(lk.owns_lock() == false);
+    lk.release();
+    try
+    {
+        lk.try_lock_until(Clock::now());
+        assert(false);
+    }
+    catch (std::system_error& e)
+    {
+        assert(e.code().value() == EPERM);
+    }
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.locking/unlock.pass.cpp b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.locking/unlock.pass.cpp
new file mode 100644
index 000000000..9e4b3c8b9
--- /dev/null
+++ b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.locking/unlock.pass.cpp
@@ -0,0 +1,60 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+// template <class Mutex> class shared_lock;
+
+// void unlock();
+
+#include <shared_mutex>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+bool unlock_called = false;
+
+struct mutex
+{
+    void lock_shared() {}
+    void unlock_shared() {unlock_called = true;}
+};
+
+mutex m;
+
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    std::shared_lock<mutex> lk(m);
+    lk.unlock();
+    assert(unlock_called == true);
+    assert(lk.owns_lock() == false);
+    try
+    {
+        lk.unlock();
+        assert(false);
+    }
+    catch (std::system_error& e)
+    {
+        assert(e.code().value() == EPERM);
+    }
+    lk.release();
+    try
+    {
+        lk.unlock();
+        assert(false);
+    }
+    catch (std::system_error& e)
+    {
+        assert(e.code().value() == EPERM);
+    }
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.mod/member_swap.pass.cpp b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.mod/member_swap.pass.cpp
new file mode 100644
index 000000000..6a7a39e96
--- /dev/null
+++ b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.mod/member_swap.pass.cpp
@@ -0,0 +1,43 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+// template <class Mutex> class shared_lock;
+
+// void swap(shared_lock& u) noexcept;
+
+#include <shared_mutex>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+struct mutex
+{
+    void lock_shared() {}
+    void unlock_shared() {}
+};
+
+mutex m;
+
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    std::shared_lock<mutex> lk1(m);
+    std::shared_lock<mutex> lk2;
+    lk1.swap(lk2);
+    assert(lk1.mutex() == nullptr);
+    assert(lk1.owns_lock() == false);
+    assert(lk2.mutex() == &m);
+    assert(lk2.owns_lock() == true);
+    static_assert(noexcept(lk1.swap(lk2)), "member swap must be noexcept");
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.mod/nonmember_swap.pass.cpp b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.mod/nonmember_swap.pass.cpp
new file mode 100644
index 000000000..03bf5e89b
--- /dev/null
+++ b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.mod/nonmember_swap.pass.cpp
@@ -0,0 +1,44 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+// template <class Mutex> class shared_lock;
+
+// template <class Mutex>
+//   void swap(shared_lock<Mutex>& x, shared_lock<Mutex>& y) noexcept;
+
+#include <shared_mutex>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+struct mutex
+{
+    void lock_shared() {}
+    void unlock_shared() {}
+};
+
+mutex m;
+
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    std::shared_lock<mutex> lk1(m);
+    std::shared_lock<mutex> lk2;
+    swap(lk1, lk2);
+    assert(lk1.mutex() == nullptr);
+    assert(lk1.owns_lock() == false);
+    assert(lk2.mutex() == &m);
+    assert(lk2.owns_lock() == true);
+    static_assert(noexcept(swap(lk1, lk2)), "non-member swap must be noexcept");
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.mod/release.pass.cpp b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.mod/release.pass.cpp
new file mode 100644
index 000000000..a836b35df
--- /dev/null
+++ b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.mod/release.pass.cpp
@@ -0,0 +1,51 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+// template <class Mutex> class shared_lock;
+
+// mutex_type* release() noexcept;
+
+#include <shared_mutex>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+struct mutex
+{
+    static int lock_count;
+    static int unlock_count;
+    void lock_shared() {++lock_count;}
+    void unlock_shared() {++unlock_count;}
+};
+
+int mutex::lock_count = 0;
+int mutex::unlock_count = 0;
+
+mutex m;
+
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    std::shared_lock<mutex> lk(m);
+    assert(lk.mutex() == &m);
+    assert(lk.owns_lock() == true);
+    assert(mutex::lock_count == 1);
+    assert(mutex::unlock_count == 0);
+    assert(lk.release() == &m);
+    assert(lk.mutex() == nullptr);
+    assert(lk.owns_lock() == false);
+    assert(mutex::lock_count == 1);
+    assert(mutex::unlock_count == 0);
+    static_assert(noexcept(lk.release()), "release must be noexcept");
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.obs/mutex.pass.cpp b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.obs/mutex.pass.cpp
new file mode 100644
index 000000000..927e9d1d4
--- /dev/null
+++ b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.obs/mutex.pass.cpp
@@ -0,0 +1,36 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+// template <class Mutex> class shared_lock;
+
+// mutex_type *mutex() const noexcept;
+
+#include <shared_mutex>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+std::shared_mutex m;
+
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    std::shared_lock<std::shared_mutex> lk0;
+    assert(lk0.mutex() == nullptr);
+    std::shared_lock<std::shared_mutex> lk1(m);
+    assert(lk1.mutex() == &m);
+    lk1.unlock();
+    assert(lk1.mutex() == &m);
+    static_assert(noexcept(lk0.mutex()), "mutex() must be noexcept");
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.obs/op_bool.pass.cpp b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.obs/op_bool.pass.cpp
new file mode 100644
index 000000000..901ccbc15
--- /dev/null
+++ b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.obs/op_bool.pass.cpp
@@ -0,0 +1,36 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+// template <class Mutex> class shared_lock;
+
+// explicit operator bool() const noexcept;
+
+#include <shared_mutex>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+std::shared_mutex m;
+
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    std::shared_lock<std::shared_mutex> lk0;
+    assert(static_cast<bool>(lk0) == false);
+    std::shared_lock<std::shared_mutex> lk1(m);
+    assert(static_cast<bool>(lk1) == true);
+    lk1.unlock();
+    assert(static_cast<bool>(lk1) == false);
+    static_assert(noexcept(static_cast<bool>(lk0)), "explicit operator bool() must be noexcept");
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.obs/owns_lock.pass.cpp b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.obs/owns_lock.pass.cpp
new file mode 100644
index 000000000..ca4715b67
--- /dev/null
+++ b/test/thread/thread.mutex/thread.lock/thread.lock.shared/thread.lock.shared.obs/owns_lock.pass.cpp
@@ -0,0 +1,36 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+// template <class Mutex> class shared_lock;
+
+// bool owns_lock() const noexcept;
+
+#include <shared_mutex>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+std::shared_mutex m;
+
+#endif  // _LIBCPP_STD_VER > 11
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    std::shared_lock<std::shared_mutex> lk0;
+    assert(lk0.owns_lock() == false);
+    std::shared_lock<std::shared_mutex> lk1(m);
+    assert(lk1.owns_lock() == true);
+    lk1.unlock();
+    assert(lk1.owns_lock() == false);
+    static_assert(noexcept(lk0.owns_lock()), "owns_lock must be noexcept");
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/test/thread/thread.mutex/thread.lock/thread.lock.shared/types.pass.cpp b/test/thread/thread.mutex/thread.lock/thread.lock.shared/types.pass.cpp
new file mode 100644
index 000000000..353735739
--- /dev/null
+++ b/test/thread/thread.mutex/thread.lock/thread.lock.shared/types.pass.cpp
@@ -0,0 +1,29 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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>
+
+// template <class Mutex>
+// class shared_lock
+// {
+// public:
+//     typedef Mutex mutex_type;
+//     ...
+// };
+
+#include <shared_mutex>
+#include <type_traits>
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    static_assert((std::is_same<std::shared_lock<std::mutex>::mutex_type,
+                   std::mutex>::value), "");
+#endif  // _LIBCPP_STD_VER > 11
+}
diff --git a/test/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.mod/release.pass.cpp b/test/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.mod/release.pass.cpp
index 0efe7d64d..4252de151 100644
--- a/test/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.mod/release.pass.cpp
+++ b/test/thread/thread.mutex/thread.lock/thread.lock.unique/thread.lock.unique.mod/release.pass.cpp
@@ -11,7 +11,7 @@
 
 // template <class Mutex> class unique_lock;
 
-// void swap(unique_lock& u);
+// mutex_type* release() noexcept;
 
 #include <mutex>
 #include <cassert>
diff --git a/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/nothing_to_do.pass.cpp b/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/nothing_to_do.pass.cpp
new file mode 100644
index 000000000..b58f5c55b
--- /dev/null
+++ b/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.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/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.class/assign.fail.cpp b/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.class/assign.fail.cpp
new file mode 100644
index 000000000..1405a22c5
--- /dev/null
+++ b/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.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_mutex;
+
+// shared_mutex& operator=(const shared_mutex&) = delete;
+
+#include <shared_mutex>
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    std::shared_mutex m0;
+    std::shared_mutex m1;
+    m1 = m0;
+#else
+#   error
+#endif
+}
diff --git a/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.class/copy.fail.cpp b/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.class/copy.fail.cpp
new file mode 100644
index 000000000..7e699232a
--- /dev/null
+++ b/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.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_mutex;
+
+// shared_mutex(const shared_mutex&) = delete;
+
+#include <shared_mutex>
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    std::shared_mutex m0;
+    std::shared_mutex m1(m0);
+#else
+#   error
+#endif
+}
diff --git a/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.class/default.pass.cpp b/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.class/default.pass.cpp
new file mode 100644
index 000000000..060fb9243
--- /dev/null
+++ b/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.class/default.pass.cpp
@@ -0,0 +1,23 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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_mutex;
+
+// shared_mutex();
+
+#include <shared_mutex>
+
+int main()
+{
+#if _LIBCPP_STD_VER > 11
+    std::shared_mutex m;
+#endif
+}
diff --git a/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.class/lock.pass.cpp b/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.class/lock.pass.cpp
new file mode 100644
index 000000000..2fd780081
--- /dev/null
+++ b/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.class/lock.pass.cpp
@@ -0,0 +1,52 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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_mutex;
+
+// void lock();
+
+#include <shared_mutex>
+#include <thread>
+#include <cstdlib>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+std::shared_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/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.class/lock_shared.pass.cpp b/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.class/lock_shared.pass.cpp
new file mode 100644
index 000000000..6fe1b4469
--- /dev/null
+++ b/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.class/lock_shared.pass.cpp
@@ -0,0 +1,75 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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_mutex;
+
+// void lock_shared();
+
+#include <shared_mutex>
+#include <thread>
+#include <vector>
+#include <cstdlib>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+std::shared_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/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.class/try_lock.pass.cpp b/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.class/try_lock.pass.cpp
new file mode 100644
index 000000000..86aa0c4e5
--- /dev/null
+++ b/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.class/try_lock.pass.cpp
@@ -0,0 +1,56 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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_mutex;
+
+// bool try_lock();
+
+#include <shared_mutex>
+#include <thread>
+#include <cstdlib>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+std::shared_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/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.class/try_lock_for.pass.cpp b/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.class/try_lock_for.pass.cpp
new file mode 100644
index 000000000..156035996
--- /dev/null
+++ b/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.class/try_lock_for.pass.cpp
@@ -0,0 +1,71 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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_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_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/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.class/try_lock_shared.pass.cpp b/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.class/try_lock_shared.pass.cpp
new file mode 100644
index 000000000..da859ab99
--- /dev/null
+++ b/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.class/try_lock_shared.pass.cpp
@@ -0,0 +1,60 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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_mutex;
+
+// bool try_lock_shared();
+
+#include <shared_mutex>
+#include <thread>
+#include <vector>
+#include <cstdlib>
+#include <cassert>
+
+#if _LIBCPP_STD_VER > 11
+
+std::shared_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/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.class/try_lock_shared_for.pass.cpp b/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.class/try_lock_shared_for.pass.cpp
new file mode 100644
index 000000000..b1d6e4c6a
--- /dev/null
+++ b/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.class/try_lock_shared_for.pass.cpp
@@ -0,0 +1,78 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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_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_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/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.class/try_lock_shared_until.pass.cpp b/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.class/try_lock_shared_until.pass.cpp
new file mode 100644
index 000000000..3dbf0c7bd
--- /dev/null
+++ b/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.class/try_lock_shared_until.pass.cpp
@@ -0,0 +1,78 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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_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_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/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.class/try_lock_until.pass.cpp b/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.class/try_lock_until.pass.cpp
new file mode 100644
index 000000000..44f91f0af
--- /dev/null
+++ b/test/thread/thread.mutex/thread.mutex.requirements/thread.sharedmutex.requirements/thread.sharedmutex.class/try_lock_until.pass.cpp
@@ -0,0 +1,71 @@
+//===----------------------------------------------------------------------===//
+//
+//                     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_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_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
+}