17 files changed, 925 insertions, 3 deletions

diff --git a/src/common/CMakeLists.txt b/src/common/CMakeLists.txt
index 0a3e2f4d1..d120c8d3d 100644
--- a/src/common/CMakeLists.txt
+++ b/src/common/CMakeLists.txt
@@ -98,6 +98,8 @@ add_library(common STATIC
     algorithm.h
     alignment.h
     assert.h
+    atomic_ops.cpp
+    atomic_ops.h
     detached_tasks.cpp
     detached_tasks.h
     bit_field.h
@@ -110,6 +112,8 @@ add_library(common STATIC
     common_types.h
     dynamic_library.cpp
     dynamic_library.h
+    fiber.cpp
+    fiber.h
     file_util.cpp
     file_util.h
     hash.h
@@ -143,6 +147,8 @@ add_library(common STATIC
     scm_rev.cpp
     scm_rev.h
     scope_exit.h
+    spin_lock.cpp
+    spin_lock.h
     string_util.cpp
     string_util.h
     swap.h
@@ -163,6 +169,8 @@ add_library(common STATIC
     vector_math.h
     virtual_buffer.cpp
     virtual_buffer.h
+    wall_clock.cpp
+    wall_clock.h
     web_result.h
     zstd_compression.cpp
     zstd_compression.h
@@ -173,12 +181,15 @@ if(ARCHITECTURE_x86_64)
         PRIVATE
             x64/cpu_detect.cpp
             x64/cpu_detect.h
+            x64/native_clock.cpp
+            x64/native_clock.h
             x64/xbyak_abi.h
             x64/xbyak_util.h
     )
 endif()
 
 create_target_directory_groups(common)
+find_package(Boost 1.71 COMPONENTS context headers REQUIRED)
 
-target_link_libraries(common PUBLIC Boost::boost fmt::fmt microprofile)
+target_link_libraries(common PUBLIC ${Boost_LIBRARIES} fmt::fmt microprofile)
 target_link_libraries(common PRIVATE lz4::lz4 zstd::zstd xbyak)
diff --git a/src/common/atomic_ops.cpp b/src/common/atomic_ops.cpp
new file mode 100644
index 000000000..1098e21ff
--- /dev/null
+++ b/src/common/atomic_ops.cpp
@@ -0,0 +1,70 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <cstring>
+
+#include "common/atomic_ops.h"
+
+#if _MSC_VER
+#include <intrin.h>
+#endif
+
+namespace Common {
+
+#if _MSC_VER
+
+bool AtomicCompareAndSwap(u8 volatile* pointer, u8 value, u8 expected) {
+    u8 result = _InterlockedCompareExchange8((char*)pointer, value, expected);
+    return result == expected;
+}
+
+bool AtomicCompareAndSwap(u16 volatile* pointer, u16 value, u16 expected) {
+    u16 result = _InterlockedCompareExchange16((short*)pointer, value, expected);
+    return result == expected;
+}
+
+bool AtomicCompareAndSwap(u32 volatile* pointer, u32 value, u32 expected) {
+    u32 result = _InterlockedCompareExchange((long*)pointer, value, expected);
+    return result == expected;
+}
+
+bool AtomicCompareAndSwap(u64 volatile* pointer, u64 value, u64 expected) {
+    u64 result = _InterlockedCompareExchange64((__int64*)pointer, value, expected);
+    return result == expected;
+}
+
+bool AtomicCompareAndSwap(u64 volatile* pointer, u128 value, u128 expected) {
+    return _InterlockedCompareExchange128((__int64*)pointer, value[1], value[0],
+                                          (__int64*)expected.data()) != 0;
+}
+
+#else
+
+bool AtomicCompareAndSwap(u8 volatile* pointer, u8 value, u8 expected) {
+    return __sync_bool_compare_and_swap(pointer, expected, value);
+}
+
+bool AtomicCompareAndSwap(u16 volatile* pointer, u16 value, u16 expected) {
+    return __sync_bool_compare_and_swap(pointer, expected, value);
+}
+
+bool AtomicCompareAndSwap(u32 volatile* pointer, u32 value, u32 expected) {
+    return __sync_bool_compare_and_swap(pointer, expected, value);
+}
+
+bool AtomicCompareAndSwap(u64 volatile* pointer, u64 value, u64 expected) {
+    return __sync_bool_compare_and_swap(pointer, expected, value);
+}
+
+bool AtomicCompareAndSwap(u64 volatile* pointer, u128 value, u128 expected) {
+    unsigned __int128 value_a;
+    unsigned __int128 expected_a;
+    std::memcpy(&value_a, value.data(), sizeof(u128));
+    std::memcpy(&expected_a, expected.data(), sizeof(u128));
+    return __sync_bool_compare_and_swap((unsigned __int128*)pointer, expected_a, value_a);
+}
+
+#endif
+
+} // namespace Common
diff --git a/src/common/atomic_ops.h b/src/common/atomic_ops.h
new file mode 100644
index 000000000..e6181d521
--- /dev/null
+++ b/src/common/atomic_ops.h
@@ -0,0 +1,17 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "common/common_types.h"
+
+namespace Common {
+
+bool AtomicCompareAndSwap(u8 volatile* pointer, u8 value, u8 expected);
+bool AtomicCompareAndSwap(u16 volatile* pointer, u16 value, u16 expected);
+bool AtomicCompareAndSwap(u32 volatile* pointer, u32 value, u32 expected);
+bool AtomicCompareAndSwap(u64 volatile* pointer, u64 value, u64 expected);
+bool AtomicCompareAndSwap(u64 volatile* pointer, u128 value, u128 expected);
+
+} // namespace Common
diff --git a/src/common/fiber.cpp b/src/common/fiber.cpp
new file mode 100644
index 000000000..1c1d09ccb
--- /dev/null
+++ b/src/common/fiber.cpp
@@ -0,0 +1,222 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "common/assert.h"
+#include "common/fiber.h"
+#if defined(_WIN32) || defined(WIN32)
+#include <windows.h>
+#else
+#include <boost/context/detail/fcontext.hpp>
+#endif
+
+namespace Common {
+
+constexpr std::size_t default_stack_size = 256 * 1024; // 256kb
+
+#if defined(_WIN32) || defined(WIN32)
+
+struct Fiber::FiberImpl {
+    LPVOID handle = nullptr;
+    LPVOID rewind_handle = nullptr;
+};
+
+void Fiber::Start() {
+    ASSERT(previous_fiber != nullptr);
+    previous_fiber->guard.unlock();
+    previous_fiber.reset();
+    entry_point(start_parameter);
+    UNREACHABLE();
+}
+
+void Fiber::OnRewind() {
+    ASSERT(impl->handle != nullptr);
+    DeleteFiber(impl->handle);
+    impl->handle = impl->rewind_handle;
+    impl->rewind_handle = nullptr;
+    rewind_point(rewind_parameter);
+    UNREACHABLE();
+}
+
+void Fiber::FiberStartFunc(void* fiber_parameter) {
+    auto fiber = static_cast<Fiber*>(fiber_parameter);
+    fiber->Start();
+}
+
+void Fiber::RewindStartFunc(void* fiber_parameter) {
+    auto fiber = static_cast<Fiber*>(fiber_parameter);
+    fiber->OnRewind();
+}
+
+Fiber::Fiber(std::function<void(void*)>&& entry_point_func, void* start_parameter)
+    : entry_point{std::move(entry_point_func)}, start_parameter{start_parameter} {
+    impl = std::make_unique<FiberImpl>();
+    impl->handle = CreateFiber(default_stack_size, &FiberStartFunc, this);
+}
+
+Fiber::Fiber() : impl{std::make_unique<FiberImpl>()} {}
+
+Fiber::~Fiber() {
+    if (released) {
+        return;
+    }
+    // Make sure the Fiber is not being used
+    const bool locked = guard.try_lock();
+    ASSERT_MSG(locked, "Destroying a fiber that's still running");
+    if (locked) {
+        guard.unlock();
+    }
+    DeleteFiber(impl->handle);
+}
+
+void Fiber::Exit() {
+    ASSERT_MSG(is_thread_fiber, "Exitting non main thread fiber");
+    if (!is_thread_fiber) {
+        return;
+    }
+    ConvertFiberToThread();
+    guard.unlock();
+    released = true;
+}
+
+void Fiber::SetRewindPoint(std::function<void(void*)>&& rewind_func, void* start_parameter) {
+    rewind_point = std::move(rewind_func);
+    rewind_parameter = start_parameter;
+}
+
+void Fiber::Rewind() {
+    ASSERT(rewind_point);
+    ASSERT(impl->rewind_handle == nullptr);
+    impl->rewind_handle = CreateFiber(default_stack_size, &RewindStartFunc, this);
+    SwitchToFiber(impl->rewind_handle);
+}
+
+void Fiber::YieldTo(std::shared_ptr<Fiber>& from, std::shared_ptr<Fiber>& to) {
+    ASSERT_MSG(from != nullptr, "Yielding fiber is null!");
+    ASSERT_MSG(to != nullptr, "Next fiber is null!");
+    to->guard.lock();
+    to->previous_fiber = from;
+    SwitchToFiber(to->impl->handle);
+    ASSERT(from->previous_fiber != nullptr);
+    from->previous_fiber->guard.unlock();
+    from->previous_fiber.reset();
+}
+
+std::shared_ptr<Fiber> Fiber::ThreadToFiber() {
+    std::shared_ptr<Fiber> fiber = std::shared_ptr<Fiber>{new Fiber()};
+    fiber->guard.lock();
+    fiber->impl->handle = ConvertThreadToFiber(nullptr);
+    fiber->is_thread_fiber = true;
+    return fiber;
+}
+
+#else
+
+struct Fiber::FiberImpl {
+    alignas(64) std::array<u8, default_stack_size> stack;
+    alignas(64) std::array<u8, default_stack_size> rewind_stack;
+    u8* stack_limit;
+    u8* rewind_stack_limit;
+    boost::context::detail::fcontext_t context;
+    boost::context::detail::fcontext_t rewind_context;
+};
+
+void Fiber::Start(boost::context::detail::transfer_t& transfer) {
+    ASSERT(previous_fiber != nullptr);
+    previous_fiber->impl->context = transfer.fctx;
+    previous_fiber->guard.unlock();
+    previous_fiber.reset();
+    entry_point(start_parameter);
+    UNREACHABLE();
+}
+
+void Fiber::OnRewind([[maybe_unused]] boost::context::detail::transfer_t& transfer) {
+    ASSERT(impl->context != nullptr);
+    impl->context = impl->rewind_context;
+    impl->rewind_context = nullptr;
+    u8* tmp = impl->stack_limit;
+    impl->stack_limit = impl->rewind_stack_limit;
+    impl->rewind_stack_limit = tmp;
+    rewind_point(rewind_parameter);
+    UNREACHABLE();
+}
+
+void Fiber::FiberStartFunc(boost::context::detail::transfer_t transfer) {
+    auto fiber = static_cast<Fiber*>(transfer.data);
+    fiber->Start(transfer);
+}
+
+void Fiber::RewindStartFunc(boost::context::detail::transfer_t transfer) {
+    auto fiber = static_cast<Fiber*>(transfer.data);
+    fiber->OnRewind(transfer);
+}
+
+Fiber::Fiber(std::function<void(void*)>&& entry_point_func, void* start_parameter)
+    : entry_point{std::move(entry_point_func)}, start_parameter{start_parameter} {
+    impl = std::make_unique<FiberImpl>();
+    impl->stack_limit = impl->stack.data();
+    impl->rewind_stack_limit = impl->rewind_stack.data();
+    u8* stack_base = impl->stack_limit + default_stack_size;
+    impl->context =
+        boost::context::detail::make_fcontext(stack_base, impl->stack.size(), FiberStartFunc);
+}
+
+void Fiber::SetRewindPoint(std::function<void(void*)>&& rewind_func, void* start_parameter) {
+    rewind_point = std::move(rewind_func);
+    rewind_parameter = start_parameter;
+}
+
+Fiber::Fiber() : impl{std::make_unique<FiberImpl>()} {}
+
+Fiber::~Fiber() {
+    if (released) {
+        return;
+    }
+    // Make sure the Fiber is not being used
+    const bool locked = guard.try_lock();
+    ASSERT_MSG(locked, "Destroying a fiber that's still running");
+    if (locked) {
+        guard.unlock();
+    }
+}
+
+void Fiber::Exit() {
+
+    ASSERT_MSG(is_thread_fiber, "Exitting non main thread fiber");
+    if (!is_thread_fiber) {
+        return;
+    }
+    guard.unlock();
+    released = true;
+}
+
+void Fiber::Rewind() {
+    ASSERT(rewind_point);
+    ASSERT(impl->rewind_context == nullptr);
+    u8* stack_base = impl->rewind_stack_limit + default_stack_size;
+    impl->rewind_context =
+        boost::context::detail::make_fcontext(stack_base, impl->stack.size(), RewindStartFunc);
+    boost::context::detail::jump_fcontext(impl->rewind_context, this);
+}
+
+void Fiber::YieldTo(std::shared_ptr<Fiber>& from, std::shared_ptr<Fiber>& to) {
+    ASSERT_MSG(from != nullptr, "Yielding fiber is null!");
+    ASSERT_MSG(to != nullptr, "Next fiber is null!");
+    to->guard.lock();
+    to->previous_fiber = from;
+    auto transfer = boost::context::detail::jump_fcontext(to->impl->context, to.get());
+    ASSERT(from->previous_fiber != nullptr);
+    from->previous_fiber->impl->context = transfer.fctx;
+    from->previous_fiber->guard.unlock();
+    from->previous_fiber.reset();
+}
+
+std::shared_ptr<Fiber> Fiber::ThreadToFiber() {
+    std::shared_ptr<Fiber> fiber = std::shared_ptr<Fiber>{new Fiber()};
+    fiber->guard.lock();
+    fiber->is_thread_fiber = true;
+    return fiber;
+}
+
+#endif
+} // namespace Common
diff --git a/src/common/fiber.h b/src/common/fiber.h
new file mode 100644
index 000000000..dafc1100e
--- /dev/null
+++ b/src/common/fiber.h
@@ -0,0 +1,92 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <functional>
+#include <memory>
+
+#include "common/common_types.h"
+#include "common/spin_lock.h"
+
+#if !defined(_WIN32) && !defined(WIN32)
+namespace boost::context::detail {
+struct transfer_t;
+}
+#endif
+
+namespace Common {
+
+/**
+ * Fiber class
+ * a fiber is a userspace thread with it's own context. They can be used to
+ * implement coroutines, emulated threading systems and certain asynchronous
+ * patterns.
+ *
+ * This class implements fibers at a low level, thus allowing greater freedom
+ * to implement such patterns. This fiber class is 'threadsafe' only one fiber
+ * can be running at a time and threads will be locked while trying to yield to
+ * a running fiber until it yields. WARNING exchanging two running fibers between
+ * threads will cause a deadlock. In order to prevent a deadlock, each thread should
+ * have an intermediary fiber, you switch to the intermediary fiber of the current
+ * thread and then from it switch to the expected fiber. This way you can exchange
+ * 2 fibers within 2 different threads.
+ */
+class Fiber {
+public:
+    Fiber(std::function<void(void*)>&& entry_point_func, void* start_parameter);
+    ~Fiber();
+
+    Fiber(const Fiber&) = delete;
+    Fiber& operator=(const Fiber&) = delete;
+
+    Fiber(Fiber&&) = default;
+    Fiber& operator=(Fiber&&) = default;
+
+    /// Yields control from Fiber 'from' to Fiber 'to'
+    /// Fiber 'from' must be the currently running fiber.
+    static void YieldTo(std::shared_ptr<Fiber>& from, std::shared_ptr<Fiber>& to);
+    static std::shared_ptr<Fiber> ThreadToFiber();
+
+    void SetRewindPoint(std::function<void(void*)>&& rewind_func, void* start_parameter);
+
+    void Rewind();
+
+    /// Only call from main thread's fiber
+    void Exit();
+
+    /// Changes the start parameter of the fiber. Has no effect if the fiber already started
+    void SetStartParameter(void* new_parameter) {
+        start_parameter = new_parameter;
+    }
+
+private:
+    Fiber();
+
+#if defined(_WIN32) || defined(WIN32)
+    void OnRewind();
+    void Start();
+    static void FiberStartFunc(void* fiber_parameter);
+    static void RewindStartFunc(void* fiber_parameter);
+#else
+    void OnRewind(boost::context::detail::transfer_t& transfer);
+    void Start(boost::context::detail::transfer_t& transfer);
+    static void FiberStartFunc(boost::context::detail::transfer_t transfer);
+    static void RewindStartFunc(boost::context::detail::transfer_t transfer);
+#endif
+
+    struct FiberImpl;
+
+    SpinLock guard{};
+    std::function<void(void*)> entry_point;
+    std::function<void(void*)> rewind_point;
+    void* rewind_parameter{};
+    void* start_parameter{};
+    std::shared_ptr<Fiber> previous_fiber;
+    std::unique_ptr<FiberImpl> impl;
+    bool is_thread_fiber{};
+    bool released{};
+};
+
+} // namespace Common
diff --git a/src/common/spin_lock.cpp b/src/common/spin_lock.cpp
new file mode 100644
index 000000000..c1524220f
--- /dev/null
+++ b/src/common/spin_lock.cpp
@@ -0,0 +1,54 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "common/spin_lock.h"
+
+#if _MSC_VER
+#include <intrin.h>
+#if _M_AMD64
+#define __x86_64__ 1
+#endif
+#if _M_ARM64
+#define __aarch64__ 1
+#endif
+#else
+#if __x86_64__
+#include <xmmintrin.h>
+#endif
+#endif
+
+namespace {
+
+void ThreadPause() {
+#if __x86_64__
+    _mm_pause();
+#elif __aarch64__ && _MSC_VER
+    __yield();
+#elif __aarch64__
+    asm("yield");
+#endif
+}
+
+} // Anonymous namespace
+
+namespace Common {
+
+void SpinLock::lock() {
+    while (lck.test_and_set(std::memory_order_acquire)) {
+        ThreadPause();
+    }
+}
+
+void SpinLock::unlock() {
+    lck.clear(std::memory_order_release);
+}
+
+bool SpinLock::try_lock() {
+    if (lck.test_and_set(std::memory_order_acquire)) {
+        return false;
+    }
+    return true;
+}
+
+} // namespace Common
diff --git a/src/common/spin_lock.h b/src/common/spin_lock.h
new file mode 100644
index 000000000..1df5528c4
--- /dev/null
+++ b/src/common/spin_lock.h
@@ -0,0 +1,26 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <atomic>
+
+namespace Common {
+
+/**
+ * SpinLock class
+ * a lock similar to mutex that forces a thread to spin wait instead calling the
+ * supervisor. Should be used on short sequences of code.
+ */
+class SpinLock {
+public:
+    void lock();
+    void unlock();
+    bool try_lock();
+
+private:
+    std::atomic_flag lck = ATOMIC_FLAG_INIT;
+};
+
+} // namespace Common
diff --git a/src/common/thread.cpp b/src/common/thread.cpp
index 0cd2d10bf..8e5935e6a 100644
--- a/src/common/thread.cpp
+++ b/src/common/thread.cpp
@@ -25,6 +25,52 @@
 
 namespace Common {
 
+#ifdef _WIN32
+
+void SetCurrentThreadPriority(ThreadPriority new_priority) {
+    auto handle = GetCurrentThread();
+    int windows_priority = 0;
+    switch (new_priority) {
+    case ThreadPriority::Low:
+        windows_priority = THREAD_PRIORITY_BELOW_NORMAL;
+        break;
+    case ThreadPriority::Normal:
+        windows_priority = THREAD_PRIORITY_NORMAL;
+        break;
+    case ThreadPriority::High:
+        windows_priority = THREAD_PRIORITY_ABOVE_NORMAL;
+        break;
+    case ThreadPriority::VeryHigh:
+        windows_priority = THREAD_PRIORITY_HIGHEST;
+        break;
+    default:
+        windows_priority = THREAD_PRIORITY_NORMAL;
+        break;
+    }
+    SetThreadPriority(handle, windows_priority);
+}
+
+#else
+
+void SetCurrentThreadPriority(ThreadPriority new_priority) {
+    pthread_t this_thread = pthread_self();
+
+    s32 max_prio = sched_get_priority_max(SCHED_OTHER);
+    s32 min_prio = sched_get_priority_min(SCHED_OTHER);
+    u32 level = static_cast<u32>(new_priority) + 1;
+
+    struct sched_param params;
+    if (max_prio > min_prio) {
+        params.sched_priority = min_prio + ((max_prio - min_prio) * level) / 4;
+    } else {
+        params.sched_priority = min_prio - ((min_prio - max_prio) * level) / 4;
+    }
+
+    pthread_setschedparam(this_thread, SCHED_OTHER, &params);
+}
+
+#endif
+
 #ifdef _MSC_VER
 
 // Sets the debugger-visible name of the current thread.
@@ -70,6 +116,12 @@ void SetCurrentThreadName(const char* name) {
 }
 #endif
 
+#if defined(_WIN32)
+void SetCurrentThreadName(const char* name) {
+    // Do Nothing on MingW
+}
+#endif
+
 #endif
 
 } // namespace Common
diff --git a/src/common/thread.h b/src/common/thread.h
index 2fc071685..52b359413 100644
--- a/src/common/thread.h
+++ b/src/common/thread.h
@@ -9,6 +9,7 @@
 #include <cstddef>
 #include <mutex>
 #include <thread>
+#include "common/common_types.h"
 
 namespace Common {
 
@@ -28,8 +29,7 @@ public:
         is_set = false;
     }
 
-    template <class Duration>
-    bool WaitFor(const std::chrono::duration<Duration>& time) {
+    bool WaitFor(const std::chrono::nanoseconds& time) {
         std::unique_lock lk{mutex};
         if (!condvar.wait_for(lk, time, [this] { return is_set; }))
             return false;
@@ -86,6 +86,15 @@ private:
     std::size_t generation = 0; // Incremented once each time the barrier is used
 };
 
+enum class ThreadPriority : u32 {
+    Low = 0,
+    Normal = 1,
+    High = 2,
+    VeryHigh = 3,
+};
+
+void SetCurrentThreadPriority(ThreadPriority new_priority);
+
 void SetCurrentThreadName(const char* name);
 
 } // namespace Common
diff --git a/src/common/uint128.cpp b/src/common/uint128.cpp
index 32bf56730..16bf7c828 100644
--- a/src/common/uint128.cpp
+++ b/src/common/uint128.cpp
@@ -6,12 +6,38 @@
 #include <intrin.h>
 
 #pragma intrinsic(_umul128)
+#pragma intrinsic(_udiv128)
 #endif
 #include <cstring>
 #include "common/uint128.h"
 
 namespace Common {
 
+#ifdef _MSC_VER
+
+u64 MultiplyAndDivide64(u64 a, u64 b, u64 d) {
+    u128 r{};
+    r[0] = _umul128(a, b, &r[1]);
+    u64 remainder;
+#if _MSC_VER < 1923
+    return udiv128(r[1], r[0], d, &remainder);
+#else
+    return _udiv128(r[1], r[0], d, &remainder);
+#endif
+}
+
+#else
+
+u64 MultiplyAndDivide64(u64 a, u64 b, u64 d) {
+    const u64 diva = a / d;
+    const u64 moda = a % d;
+    const u64 divb = b / d;
+    const u64 modb = b % d;
+    return diva * b + moda * divb + moda * modb / d;
+}
+
+#endif
+
 u128 Multiply64Into128(u64 a, u64 b) {
     u128 result;
 #ifdef _MSC_VER
diff --git a/src/common/uint128.h b/src/common/uint128.h
index a3be2a2cb..503cd2d0c 100644
--- a/src/common/uint128.h
+++ b/src/common/uint128.h
@@ -9,6 +9,9 @@
 
 namespace Common {
 
+// This function multiplies 2 u64 values and divides it by a u64 value.
+u64 MultiplyAndDivide64(u64 a, u64 b, u64 d);
+
 // This function multiplies 2 u64 values and produces a u128 value;
 u128 Multiply64Into128(u64 a, u64 b);
 
diff --git a/src/common/wall_clock.cpp b/src/common/wall_clock.cpp
new file mode 100644
index 000000000..3afbdb898
--- /dev/null
+++ b/src/common/wall_clock.cpp
@@ -0,0 +1,91 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "common/uint128.h"
+#include "common/wall_clock.h"
+
+#ifdef ARCHITECTURE_x86_64
+#include "common/x64/cpu_detect.h"
+#include "common/x64/native_clock.h"
+#endif
+
+namespace Common {
+
+using base_timer = std::chrono::steady_clock;
+using base_time_point = std::chrono::time_point<base_timer>;
+
+class StandardWallClock : public WallClock {
+public:
+    StandardWallClock(u64 emulated_cpu_frequency, u64 emulated_clock_frequency)
+        : WallClock(emulated_cpu_frequency, emulated_clock_frequency, false) {
+        start_time = base_timer::now();
+    }
+
+    std::chrono::nanoseconds GetTimeNS() override {
+        base_time_point current = base_timer::now();
+        auto elapsed = current - start_time;
+        return std::chrono::duration_cast<std::chrono::nanoseconds>(elapsed);
+    }
+
+    std::chrono::microseconds GetTimeUS() override {
+        base_time_point current = base_timer::now();
+        auto elapsed = current - start_time;
+        return std::chrono::duration_cast<std::chrono::microseconds>(elapsed);
+    }
+
+    std::chrono::milliseconds GetTimeMS() override {
+        base_time_point current = base_timer::now();
+        auto elapsed = current - start_time;
+        return std::chrono::duration_cast<std::chrono::milliseconds>(elapsed);
+    }
+
+    u64 GetClockCycles() override {
+        std::chrono::nanoseconds time_now = GetTimeNS();
+        const u128 temporary =
+            Common::Multiply64Into128(time_now.count(), emulated_clock_frequency);
+        return Common::Divide128On32(temporary, 1000000000).first;
+    }
+
+    u64 GetCPUCycles() override {
+        std::chrono::nanoseconds time_now = GetTimeNS();
+        const u128 temporary = Common::Multiply64Into128(time_now.count(), emulated_cpu_frequency);
+        return Common::Divide128On32(temporary, 1000000000).first;
+    }
+
+    void Pause(bool is_paused) override {
+        // Do nothing in this clock type.
+    }
+
+private:
+    base_time_point start_time;
+};
+
+#ifdef ARCHITECTURE_x86_64
+
+std::unique_ptr<WallClock> CreateBestMatchingClock(u32 emulated_cpu_frequency,
+                                                   u32 emulated_clock_frequency) {
+    const auto& caps = GetCPUCaps();
+    u64 rtsc_frequency = 0;
+    if (caps.invariant_tsc) {
+        rtsc_frequency = EstimateRDTSCFrequency();
+    }
+    if (rtsc_frequency == 0) {
+        return std::make_unique<StandardWallClock>(emulated_cpu_frequency,
+                                                   emulated_clock_frequency);
+    } else {
+        return std::make_unique<X64::NativeClock>(emulated_cpu_frequency, emulated_clock_frequency,
+                                                  rtsc_frequency);
+    }
+}
+
+#else
+
+std::unique_ptr<WallClock> CreateBestMatchingClock(u32 emulated_cpu_frequency,
+                                                   u32 emulated_clock_frequency) {
+    return std::make_unique<StandardWallClock>(emulated_cpu_frequency, emulated_clock_frequency);
+}
+
+#endif
+
+} // namespace Common
diff --git a/src/common/wall_clock.h b/src/common/wall_clock.h
new file mode 100644
index 000000000..367d72134
--- /dev/null
+++ b/src/common/wall_clock.h
@@ -0,0 +1,53 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <chrono>
+#include <memory>
+
+#include "common/common_types.h"
+
+namespace Common {
+
+class WallClock {
+public:
+    /// Returns current wall time in nanoseconds
+    virtual std::chrono::nanoseconds GetTimeNS() = 0;
+
+    /// Returns current wall time in microseconds
+    virtual std::chrono::microseconds GetTimeUS() = 0;
+
+    /// Returns current wall time in milliseconds
+    virtual std::chrono::milliseconds GetTimeMS() = 0;
+
+    /// Returns current wall time in emulated clock cycles
+    virtual u64 GetClockCycles() = 0;
+
+    /// Returns current wall time in emulated cpu cycles
+    virtual u64 GetCPUCycles() = 0;
+
+    virtual void Pause(bool is_paused) = 0;
+
+    /// Tells if the wall clock, uses the host CPU's hardware clock
+    bool IsNative() const {
+        return is_native;
+    }
+
+protected:
+    WallClock(u64 emulated_cpu_frequency, u64 emulated_clock_frequency, bool is_native)
+        : emulated_cpu_frequency{emulated_cpu_frequency},
+          emulated_clock_frequency{emulated_clock_frequency}, is_native{is_native} {}
+
+    u64 emulated_cpu_frequency;
+    u64 emulated_clock_frequency;
+
+private:
+    bool is_native;
+};
+
+std::unique_ptr<WallClock> CreateBestMatchingClock(u32 emulated_cpu_frequency,
+                                                   u32 emulated_clock_frequency);
+
+} // namespace Common
diff --git a/src/common/x64/cpu_detect.cpp b/src/common/x64/cpu_detect.cpp
index f35dcb498..fccd2eee5 100644
--- a/src/common/x64/cpu_detect.cpp
+++ b/src/common/x64/cpu_detect.cpp
@@ -62,6 +62,17 @@ static CPUCaps Detect() {
     std::memcpy(&caps.brand_string[0], &cpu_id[1], sizeof(int));
     std::memcpy(&caps.brand_string[4], &cpu_id[3], sizeof(int));
     std::memcpy(&caps.brand_string[8], &cpu_id[2], sizeof(int));
+    if (cpu_id[1] == 0x756e6547 && cpu_id[2] == 0x6c65746e && cpu_id[3] == 0x49656e69)
+        caps.manufacturer = Manufacturer::Intel;
+    else if (cpu_id[1] == 0x68747541 && cpu_id[2] == 0x444d4163 && cpu_id[3] == 0x69746e65)
+        caps.manufacturer = Manufacturer::AMD;
+    else if (cpu_id[1] == 0x6f677948 && cpu_id[2] == 0x656e6975 && cpu_id[3] == 0x6e65476e)
+        caps.manufacturer = Manufacturer::Hygon;
+    else
+        caps.manufacturer = Manufacturer::Unknown;
+
+    u32 family = {};
+    u32 model = {};
 
     __cpuid(cpu_id, 0x80000000);
 
@@ -73,6 +84,14 @@ static CPUCaps Detect() {
     // Detect family and other miscellaneous features
     if (max_std_fn >= 1) {
         __cpuid(cpu_id, 0x00000001);
+        family = (cpu_id[0] >> 8) & 0xf;
+        model = (cpu_id[0] >> 4) & 0xf;
+        if (family == 0xf) {
+            family += (cpu_id[0] >> 20) & 0xff;
+        }
+        if (family >= 6) {
+            model += ((cpu_id[0] >> 16) & 0xf) << 4;
+        }
 
         if ((cpu_id[3] >> 25) & 1)
             caps.sse = true;
@@ -135,6 +154,20 @@ static CPUCaps Detect() {
             caps.fma4 = true;
     }
 
+    if (max_ex_fn >= 0x80000007) {
+        __cpuid(cpu_id, 0x80000007);
+        if (cpu_id[3] & (1 << 8)) {
+            caps.invariant_tsc = true;
+        }
+    }
+
+    if (max_std_fn >= 0x16) {
+        __cpuid(cpu_id, 0x16);
+        caps.base_frequency = cpu_id[0];
+        caps.max_frequency = cpu_id[1];
+        caps.bus_frequency = cpu_id[2];
+    }
+
     return caps;
 }
 
diff --git a/src/common/x64/cpu_detect.h b/src/common/x64/cpu_detect.h
index 7606c3f7b..e3b63302e 100644
--- a/src/common/x64/cpu_detect.h
+++ b/src/common/x64/cpu_detect.h
@@ -6,8 +6,16 @@
 
 namespace Common {
 
+enum class Manufacturer : u32 {
+    Intel = 0,
+    AMD = 1,
+    Hygon = 2,
+    Unknown = 3,
+};
+
 /// x86/x64 CPU capabilities that may be detected by this module
 struct CPUCaps {
+    Manufacturer manufacturer;
     char cpu_string[0x21];
     char brand_string[0x41];
     bool sse;
@@ -25,6 +33,10 @@ struct CPUCaps {
     bool fma;
     bool fma4;
     bool aes;
+    bool invariant_tsc;
+    u32 base_frequency;
+    u32 max_frequency;
+    u32 bus_frequency;
 };
 
 /**
diff --git a/src/common/x64/native_clock.cpp b/src/common/x64/native_clock.cpp
new file mode 100644
index 000000000..424b39b1f
--- /dev/null
+++ b/src/common/x64/native_clock.cpp
@@ -0,0 +1,103 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <chrono>
+#include <mutex>
+#include <thread>
+
+#ifdef _MSC_VER
+#include <intrin.h>
+#else
+#include <x86intrin.h>
+#endif
+
+#include "common/uint128.h"
+#include "common/x64/native_clock.h"
+
+namespace Common {
+
+u64 EstimateRDTSCFrequency() {
+    const auto milli_10 = std::chrono::milliseconds{10};
+    // get current time
+    _mm_mfence();
+    const u64 tscStart = __rdtsc();
+    const auto startTime = std::chrono::high_resolution_clock::now();
+    // wait roughly 3 seconds
+    while (true) {
+        auto milli = std::chrono::duration_cast<std::chrono::milliseconds>(
+            std::chrono::high_resolution_clock::now() - startTime);
+        if (milli.count() >= 3000)
+            break;
+        std::this_thread::sleep_for(milli_10);
+    }
+    const auto endTime = std::chrono::high_resolution_clock::now();
+    _mm_mfence();
+    const u64 tscEnd = __rdtsc();
+    // calculate difference
+    const u64 timer_diff =
+        std::chrono::duration_cast<std::chrono::nanoseconds>(endTime - startTime).count();
+    const u64 tsc_diff = tscEnd - tscStart;
+    const u64 tsc_freq = MultiplyAndDivide64(tsc_diff, 1000000000ULL, timer_diff);
+    return tsc_freq;
+}
+
+namespace X64 {
+NativeClock::NativeClock(u64 emulated_cpu_frequency, u64 emulated_clock_frequency,
+                         u64 rtsc_frequency)
+    : WallClock(emulated_cpu_frequency, emulated_clock_frequency, true), rtsc_frequency{
+                                                                             rtsc_frequency} {
+    _mm_mfence();
+    last_measure = __rdtsc();
+    accumulated_ticks = 0U;
+}
+
+u64 NativeClock::GetRTSC() {
+    std::scoped_lock scope{rtsc_serialize};
+    _mm_mfence();
+    const u64 current_measure = __rdtsc();
+    u64 diff = current_measure - last_measure;
+    diff = diff & ~static_cast<u64>(static_cast<s64>(diff) >> 63); // max(diff, 0)
+    if (current_measure > last_measure) {
+        last_measure = current_measure;
+    }
+    accumulated_ticks += diff;
+    /// The clock cannot be more precise than the guest timer, remove the lower bits
+    return accumulated_ticks & inaccuracy_mask;
+}
+
+void NativeClock::Pause(bool is_paused) {
+    if (!is_paused) {
+        _mm_mfence();
+        last_measure = __rdtsc();
+    }
+}
+
+std::chrono::nanoseconds NativeClock::GetTimeNS() {
+    const u64 rtsc_value = GetRTSC();
+    return std::chrono::nanoseconds{MultiplyAndDivide64(rtsc_value, 1000000000, rtsc_frequency)};
+}
+
+std::chrono::microseconds NativeClock::GetTimeUS() {
+    const u64 rtsc_value = GetRTSC();
+    return std::chrono::microseconds{MultiplyAndDivide64(rtsc_value, 1000000, rtsc_frequency)};
+}
+
+std::chrono::milliseconds NativeClock::GetTimeMS() {
+    const u64 rtsc_value = GetRTSC();
+    return std::chrono::milliseconds{MultiplyAndDivide64(rtsc_value, 1000, rtsc_frequency)};
+}
+
+u64 NativeClock::GetClockCycles() {
+    const u64 rtsc_value = GetRTSC();
+    return MultiplyAndDivide64(rtsc_value, emulated_clock_frequency, rtsc_frequency);
+}
+
+u64 NativeClock::GetCPUCycles() {
+    const u64 rtsc_value = GetRTSC();
+    return MultiplyAndDivide64(rtsc_value, emulated_cpu_frequency, rtsc_frequency);
+}
+
+} // namespace X64
+
+} // namespace Common
diff --git a/src/common/x64/native_clock.h b/src/common/x64/native_clock.h
new file mode 100644
index 000000000..891a3bbfd
--- /dev/null
+++ b/src/common/x64/native_clock.h
@@ -0,0 +1,48 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <optional>
+
+#include "common/spin_lock.h"
+#include "common/wall_clock.h"
+
+namespace Common {
+
+namespace X64 {
+class NativeClock : public WallClock {
+public:
+    NativeClock(u64 emulated_cpu_frequency, u64 emulated_clock_frequency, u64 rtsc_frequency);
+
+    std::chrono::nanoseconds GetTimeNS() override;
+
+    std::chrono::microseconds GetTimeUS() override;
+
+    std::chrono::milliseconds GetTimeMS() override;
+
+    u64 GetClockCycles() override;
+
+    u64 GetCPUCycles() override;
+
+    void Pause(bool is_paused) override;
+
+private:
+    u64 GetRTSC();
+
+    /// value used to reduce the native clocks accuracy as some apss rely on
+    /// undefined behavior where the level of accuracy in the clock shouldn't
+    /// be higher.
+    static constexpr u64 inaccuracy_mask = ~(0x400 - 1);
+
+    SpinLock rtsc_serialize{};
+    u64 last_measure{};
+    u64 accumulated_ticks{};
+    u64 rtsc_frequency;
+};
+} // namespace X64
+
+u64 EstimateRDTSCFrequency();
+
+} // namespace Common