Merge pull request #3396 from FernandoS27/prometheus-1

Implement SpinLocks, Fibers and a Host Timer

src/common/CMakeLists.txt

@@ -110,6 +110,8 @@ 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 +145,8 @@ 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 +167,8 @@ 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 +179,15 @@ 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)

src/common/fiber.cpp

@@ -0,0 +1,226 @@
+// 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;
+    u8* stack_limit;
+    alignas(64) std::array<u8, default_stack_size> rewind_stack;
+    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

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

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 thread_pause() {
+#if __x86_64__
+    _mm_pause();
+#elif __aarch64__ && _MSC_VER
+    __yield();
+#elif __aarch64__
+    asm("yield");
+#endif
+}
+
+} // namespace
+
+namespace Common {
+
+void SpinLock::lock() {
+    while (lck.test_and_set(std::memory_order_acquire)) {
+        thread_pause();
+    }
+}
+
+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

src/common/spin_lock.h

@@ -0,0 +1,21 @@
+// 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 {
+
+class SpinLock {
+public:
+    void lock();
+    void unlock();
+    bool try_lock();
+
+private:
+    std::atomic_flag lck = ATOMIC_FLAG_INIT;
+};
+
+} // namespace Common

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;

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

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);
 

src/common/wall_clock.cpp

@@ -0,0 +1,92 @@
+// 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;
+    }
+
+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) {
+        if (caps.base_frequency != 0) {
+            rtsc_frequency = static_cast<u64>(caps.base_frequency) * 1000000U;
+        }
+        if (rtsc_frequency == 0) {
+            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

src/common/wall_clock.h

@@ -0,0 +1,51 @@
+// 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;
+
+    /// 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

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;
 }
 

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;
 };
 
 /**

src/common/x64/native_clock.cpp

@@ -0,0 +1,95 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <chrono>
+#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() {
+    rtsc_serialize.lock();
+    _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;
+    rtsc_serialize.unlock();
+    return accumulated_ticks;
+}
+
+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

src/common/x64/native_clock.h

@@ -0,0 +1,41 @@
+// 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;
+
+private:
+    u64 GetRTSC();
+
+    SpinLock rtsc_serialize{};
+    u64 last_measure{};
+    u64 accumulated_ticks{};
+    u64 rtsc_frequency;
+};
+} // namespace X64
+
+u64 EstimateRDTSCFrequency();
+
+} // namespace Common

src/core/CMakeLists.txt

@@ -547,6 +547,8 @@ add_library(core STATIC
     hle/service/vi/vi_u.h
     hle/service/wlan/wlan.cpp
     hle/service/wlan/wlan.h
+    host_timing.cpp
+    host_timing.h
     loader/deconstructed_rom_directory.cpp
     loader/deconstructed_rom_directory.h
     loader/elf.cpp

src/core/core_timing_util.cpp

@@ -49,6 +49,21 @@ s64 nsToCycles(std::chrono::nanoseconds ns) {
     return (Hardware::BASE_CLOCK_RATE * ns.count()) / 1000000000;
 }
 
+u64 msToClockCycles(std::chrono::milliseconds ns) {
+    const u128 temp = Common::Multiply64Into128(ns.count(), Hardware::CNTFREQ);
+    return Common::Divide128On32(temp, 1000).first;
+}
+
+u64 usToClockCycles(std::chrono::microseconds ns) {
+    const u128 temp = Common::Multiply64Into128(ns.count(), Hardware::CNTFREQ);
+    return Common::Divide128On32(temp, 1000000).first;
+}
+
+u64 nsToClockCycles(std::chrono::nanoseconds ns) {
+    const u128 temp = Common::Multiply64Into128(ns.count(), Hardware::CNTFREQ);
+    return Common::Divide128On32(temp, 1000000000).first;
+}
+
 u64 CpuCyclesToClockCycles(u64 ticks) {
     const u128 temporal = Common::Multiply64Into128(ticks, Hardware::CNTFREQ);
     return Common::Divide128On32(temporal, static_cast<u32>(Hardware::BASE_CLOCK_RATE)).first;

src/core/core_timing_util.h

@@ -13,6 +13,9 @@ namespace Core::Timing {
 s64 msToCycles(std::chrono::milliseconds ms);
 s64 usToCycles(std::chrono::microseconds us);
 s64 nsToCycles(std::chrono::nanoseconds ns);
+u64 msToClockCycles(std::chrono::milliseconds ns);
+u64 usToClockCycles(std::chrono::microseconds ns);
+u64 nsToClockCycles(std::chrono::nanoseconds ns);
 
 inline std::chrono::milliseconds CyclesToMs(s64 cycles) {
     return std::chrono::milliseconds(cycles * 1000 / Hardware::BASE_CLOCK_RATE);

src/core/host_timing.cpp

@@ -0,0 +1,206 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "core/host_timing.h"
+
+#include <algorithm>
+#include <mutex>
+#include <string>
+#include <tuple>
+
+#include "common/assert.h"
+#include "core/core_timing_util.h"
+
+namespace Core::HostTiming {
+
+std::shared_ptr<EventType> CreateEvent(std::string name, TimedCallback&& callback) {
+    return std::make_shared<EventType>(std::move(callback), std::move(name));
+}
+
+struct CoreTiming::Event {
+    u64 time;
+    u64 fifo_order;
+    u64 userdata;
+    std::weak_ptr<EventType> type;
+
+    // Sort by time, unless the times are the same, in which case sort by
+    // the order added to the queue
+    friend bool operator>(const Event& left, const Event& right) {
+        return std::tie(left.time, left.fifo_order) > std::tie(right.time, right.fifo_order);
+    }
+
+    friend bool operator<(const Event& left, const Event& right) {
+        return std::tie(left.time, left.fifo_order) < std::tie(right.time, right.fifo_order);
+    }
+};
+
+CoreTiming::CoreTiming() {
+    clock =
+        Common::CreateBestMatchingClock(Core::Hardware::BASE_CLOCK_RATE, Core::Hardware::CNTFREQ);
+}
+
+CoreTiming::~CoreTiming() = default;
+
+void CoreTiming::ThreadEntry(CoreTiming& instance) {
+    instance.ThreadLoop();
+}
+
+void CoreTiming::Initialize() {
+    event_fifo_id = 0;
+    const auto empty_timed_callback = [](u64, s64) {};
+    ev_lost = CreateEvent("_lost_event", empty_timed_callback);
+    timer_thread = std::make_unique<std::thread>(ThreadEntry, std::ref(*this));
+}
+
+void CoreTiming::Shutdown() {
+    paused = true;
+    shutting_down = true;
+    event.Set();
+    timer_thread->join();
+    ClearPendingEvents();
+    timer_thread.reset();
+    has_started = false;
+}
+
+void CoreTiming::Pause(bool is_paused) {
+    paused = is_paused;
+}
+
+void CoreTiming::SyncPause(bool is_paused) {
+    if (is_paused == paused && paused_set == paused) {
+        return;
+    }
+    Pause(is_paused);
+    event.Set();
+    while (paused_set != is_paused)
+        ;
+}
+
+bool CoreTiming::IsRunning() const {
+    return !paused_set;
+}
+
+bool CoreTiming::HasPendingEvents() const {
+    return !(wait_set && event_queue.empty());
+}
+
+void CoreTiming::ScheduleEvent(s64 ns_into_future, const std::shared_ptr<EventType>& event_type,
+                               u64 userdata) {
+    basic_lock.lock();
+    const u64 timeout = static_cast<u64>(GetGlobalTimeNs().count() + ns_into_future);
+
+    event_queue.emplace_back(Event{timeout, event_fifo_id++, userdata, event_type});
+
+    std::push_heap(event_queue.begin(), event_queue.end(), std::greater<>());
+    basic_lock.unlock();
+    event.Set();
+}
+
+void CoreTiming::UnscheduleEvent(const std::shared_ptr<EventType>& event_type, u64 userdata) {
+    basic_lock.lock();
+    const auto itr = std::remove_if(event_queue.begin(), event_queue.end(), [&](const Event& e) {
+        return e.type.lock().get() == event_type.get() && e.userdata == userdata;
+    });
+
+    // Removing random items breaks the invariant so we have to re-establish it.
+    if (itr != event_queue.end()) {
+        event_queue.erase(itr, event_queue.end());
+        std::make_heap(event_queue.begin(), event_queue.end(), std::greater<>());
+    }
+    basic_lock.unlock();
+}
+
+void CoreTiming::AddTicks(std::size_t core_index, u64 ticks) {
+    ticks_count[core_index] += ticks;
+}
+
+void CoreTiming::ResetTicks(std::size_t core_index) {
+    ticks_count[core_index] = 0;
+}
+
+u64 CoreTiming::GetCPUTicks() const {
+    return clock->GetCPUCycles();
+}
+
+u64 CoreTiming::GetClockTicks() const {
+    return clock->GetClockCycles();
+}
+
+void CoreTiming::ClearPendingEvents() {
+    event_queue.clear();
+}
+
+void CoreTiming::RemoveEvent(const std::shared_ptr<EventType>& event_type) {
+    basic_lock.lock();
+
+    const auto itr = std::remove_if(event_queue.begin(), event_queue.end(), [&](const Event& e) {
+        return e.type.lock().get() == event_type.get();
+    });
+
+    // Removing random items breaks the invariant so we have to re-establish it.
+    if (itr != event_queue.end()) {
+        event_queue.erase(itr, event_queue.end());
+        std::make_heap(event_queue.begin(), event_queue.end(), std::greater<>());
+    }
+    basic_lock.unlock();
+}
+
+std::optional<u64> CoreTiming::Advance() {
+    advance_lock.lock();
+    basic_lock.lock();
+    global_timer = GetGlobalTimeNs().count();
+
+    while (!event_queue.empty() && event_queue.front().time <= global_timer) {
+        Event evt = std::move(event_queue.front());
+        std::pop_heap(event_queue.begin(), event_queue.end(), std::greater<>());
+        event_queue.pop_back();
+        basic_lock.unlock();
+
+        if (auto event_type{evt.type.lock()}) {
+            event_type->callback(evt.userdata, global_timer - evt.time);
+        }
+
+        basic_lock.lock();
+    }
+
+    if (!event_queue.empty()) {
+        const u64 next_time = event_queue.front().time - global_timer;
+        basic_lock.unlock();
+        advance_lock.unlock();
+        return next_time;
+    } else {
+        basic_lock.unlock();
+        advance_lock.unlock();
+        return std::nullopt;
+    }
+}
+
+void CoreTiming::ThreadLoop() {
+    has_started = true;
+    while (!shutting_down) {
+        while (!paused) {
+            paused_set = false;
+            const auto next_time = Advance();
+            if (next_time) {
+                std::chrono::nanoseconds next_time_ns = std::chrono::nanoseconds(*next_time);
+                event.WaitFor(next_time_ns);
+            } else {
+                wait_set = true;
+                event.Wait();
+            }
+            wait_set = false;
+        }
+        paused_set = true;
+    }
+}
+
+std::chrono::nanoseconds CoreTiming::GetGlobalTimeNs() const {
+    return clock->GetTimeNS();
+}
+
+std::chrono::microseconds CoreTiming::GetGlobalTimeUs() const {
+    return clock->GetTimeUS();
+}
+
+} // namespace Core::HostTiming

src/core/host_timing.h

@@ -0,0 +1,160 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <atomic>
+#include <chrono>
+#include <functional>
+#include <memory>
+#include <mutex>
+#include <optional>
+#include <string>
+#include <thread>
+#include <vector>
+
+#include "common/common_types.h"
+#include "common/spin_lock.h"
+#include "common/thread.h"
+#include "common/threadsafe_queue.h"
+#include "common/wall_clock.h"
+#include "core/hardware_properties.h"
+
+namespace Core::HostTiming {
+
+/// A callback that may be scheduled for a particular core timing event.
+using TimedCallback = std::function<void(u64 userdata, s64 cycles_late)>;
+
+/// Contains the characteristics of a particular event.
+struct EventType {
+    EventType(TimedCallback&& callback, std::string&& name)
+        : callback{std::move(callback)}, name{std::move(name)} {}
+
+    /// The event's callback function.
+    TimedCallback callback;
+    /// A pointer to the name of the event.
+    const std::string name;
+};
+
+/**
+ * This is a system to schedule events into the emulated machine's future. Time is measured
+ * in main CPU clock cycles.
+ *
+ * To schedule an event, you first have to register its type. This is where you pass in the
+ * callback. You then schedule events using the type id you get back.
+ *
+ * The int cyclesLate that the callbacks get is how many cycles late it was.
+ * So to schedule a new event on a regular basis:
+ * inside callback:
+ *   ScheduleEvent(periodInCycles - cyclesLate, callback, "whatever")
+ */
+class CoreTiming {
+public:
+    CoreTiming();
+    ~CoreTiming();
+
+    CoreTiming(const CoreTiming&) = delete;
+    CoreTiming(CoreTiming&&) = delete;
+
+    CoreTiming& operator=(const CoreTiming&) = delete;
+    CoreTiming& operator=(CoreTiming&&) = delete;
+
+    /// CoreTiming begins at the boundary of timing slice -1. An initial call to Advance() is
+    /// required to end slice - 1 and start slice 0 before the first cycle of code is executed.
+    void Initialize();
+
+    /// Tears down all timing related functionality.
+    void Shutdown();
+
+    /// Pauses/Unpauses the execution of the timer thread.
+    void Pause(bool is_paused);
+
+    /// Pauses/Unpauses the execution of the timer thread and waits until paused.
+    void SyncPause(bool is_paused);
+
+    /// Checks if core timing is running.
+    bool IsRunning() const;
+
+    /// Checks if the timer thread has started.
+    bool HasStarted() const {
+        return has_started;
+    }
+
+    /// Checks if there are any pending time events.
+    bool HasPendingEvents() const;
+
+    /// Schedules an event in core timing
+    void ScheduleEvent(s64 ns_into_future, const std::shared_ptr<EventType>& event_type,
+                       u64 userdata = 0);
+
+    void UnscheduleEvent(const std::shared_ptr<EventType>& event_type, u64 userdata);
+
+    /// We only permit one event of each type in the queue at a time.
+    void RemoveEvent(const std::shared_ptr<EventType>& event_type);
+
+    void AddTicks(std::size_t core_index, u64 ticks);
+
+    void ResetTicks(std::size_t core_index);
+
+    /// Returns current time in emulated CPU cycles
+    u64 GetCPUTicks() const;
+
+    /// Returns current time in emulated in Clock cycles
+    u64 GetClockTicks() const;
+
+    /// Returns current time in microseconds.
+    std::chrono::microseconds GetGlobalTimeUs() const;
+
+    /// Returns current time in nanoseconds.
+    std::chrono::nanoseconds GetGlobalTimeNs() const;
+
+    /// Checks for events manually and returns time in nanoseconds for next event, threadsafe.
+    std::optional<u64> Advance();
+
+private:
+    struct Event;
+
+    /// Clear all pending events. This should ONLY be done on exit.
+    void ClearPendingEvents();
+
+    static void ThreadEntry(CoreTiming& instance);
+    void ThreadLoop();
+
+    std::unique_ptr<Common::WallClock> clock;
+
+    u64 global_timer = 0;
+
+    std::chrono::nanoseconds start_point;
+
+    // The queue is a min-heap using std::make_heap/push_heap/pop_heap.
+    // We don't use std::priority_queue because we need to be able to serialize, unserialize and
+    // erase arbitrary events (RemoveEvent()) regardless of the queue order. These aren't
+    // accomodated by the standard adaptor class.
+    std::vector<Event> event_queue;
+    u64 event_fifo_id = 0;
+
+    std::shared_ptr<EventType> ev_lost;
+    Common::Event event{};
+    Common::SpinLock basic_lock{};
+    Common::SpinLock advance_lock{};
+    std::unique_ptr<std::thread> timer_thread;
+    std::atomic<bool> paused{};
+    std::atomic<bool> paused_set{};
+    std::atomic<bool> wait_set{};
+    std::atomic<bool> shutting_down{};
+    std::atomic<bool> has_started{};
+
+    std::array<std::atomic<u64>, Core::Hardware::NUM_CPU_CORES> ticks_count{};
+};
+
+/// Creates a core timing event with the given name and callback.
+///
+/// @param name     The name of the core timing event to create.
+/// @param callback The callback to execute for the event.
+///
+/// @returns An EventType instance representing the created event.
+///
+std::shared_ptr<EventType> CreateEvent(std::string name, TimedCallback&& callback);
+
+} // namespace Core::HostTiming

src/tests/CMakeLists.txt

@@ -1,12 +1,14 @@
 add_executable(tests
     common/bit_field.cpp
     common/bit_utils.cpp
+    common/fibers.cpp
     common/multi_level_queue.cpp
     common/param_package.cpp
     common/ring_buffer.cpp
     core/arm/arm_test_common.cpp
     core/arm/arm_test_common.h
     core/core_timing.cpp
+    core/host_timing.cpp
     tests.cpp
 )
 

src/tests/common/fibers.cpp

@@ -0,0 +1,358 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include <atomic>
+#include <cstdlib>
+#include <functional>
+#include <memory>
+#include <thread>
+#include <unordered_map>
+#include <vector>
+
+#include <catch2/catch.hpp>
+#include <math.h>
+#include "common/common_types.h"
+#include "common/fiber.h"
+#include "common/spin_lock.h"
+
+namespace Common {
+
+class TestControl1 {
+public:
+    TestControl1() = default;
+
+    void DoWork();
+
+    void ExecuteThread(u32 id);
+
+    std::unordered_map<std::thread::id, u32> ids;
+    std::vector<std::shared_ptr<Common::Fiber>> thread_fibers;
+    std::vector<std::shared_ptr<Common::Fiber>> work_fibers;
+    std::vector<u32> items;
+    std::vector<u32> results;
+};
+
+static void WorkControl1(void* control) {
+    auto* test_control = static_cast<TestControl1*>(control);
+    test_control->DoWork();
+}
+
+void TestControl1::DoWork() {
+    std::thread::id this_id = std::this_thread::get_id();
+    u32 id = ids[this_id];
+    u32 value = items[id];
+    for (u32 i = 0; i < id; i++) {
+        value++;
+    }
+    results[id] = value;
+    Fiber::YieldTo(work_fibers[id], thread_fibers[id]);
+}
+
+void TestControl1::ExecuteThread(u32 id) {
+    std::thread::id this_id = std::this_thread::get_id();
+    ids[this_id] = id;
+    auto thread_fiber = Fiber::ThreadToFiber();
+    thread_fibers[id] = thread_fiber;
+    work_fibers[id] = std::make_shared<Fiber>(std::function<void(void*)>{WorkControl1}, this);
+    items[id] = rand() % 256;
+    Fiber::YieldTo(thread_fibers[id], work_fibers[id]);
+    thread_fibers[id]->Exit();
+}
+
+static void ThreadStart1(u32 id, TestControl1& test_control) {
+    test_control.ExecuteThread(id);
+}
+
+/** This test checks for fiber setup configuration and validates that fibers are
+ *  doing all the work required.
+ */
+TEST_CASE("Fibers::Setup", "[common]") {
+    constexpr u32 num_threads = 7;
+    TestControl1 test_control{};
+    test_control.thread_fibers.resize(num_threads);
+    test_control.work_fibers.resize(num_threads);
+    test_control.items.resize(num_threads, 0);
+    test_control.results.resize(num_threads, 0);
+    std::vector<std::thread> threads;
+    for (u32 i = 0; i < num_threads; i++) {
+        threads.emplace_back(ThreadStart1, i, std::ref(test_control));
+    }
+    for (u32 i = 0; i < num_threads; i++) {
+        threads[i].join();
+    }
+    for (u32 i = 0; i < num_threads; i++) {
+        REQUIRE(test_control.items[i] + i == test_control.results[i]);
+    }
+}
+
+class TestControl2 {
+public:
+    TestControl2() = default;
+
+    void DoWork1() {
+        trap2 = false;
+        while (trap.load())
+            ;
+        for (u32 i = 0; i < 12000; i++) {
+            value1 += i;
+        }
+        Fiber::YieldTo(fiber1, fiber3);
+        std::thread::id this_id = std::this_thread::get_id();
+        u32 id = ids[this_id];
+        assert1 = id == 1;
+        value2 += 5000;
+        Fiber::YieldTo(fiber1, thread_fibers[id]);
+    }
+
+    void DoWork2() {
+        while (trap2.load())
+            ;
+        value2 = 2000;
+        trap = false;
+        Fiber::YieldTo(fiber2, fiber1);
+        assert3 = false;
+    }
+
+    void DoWork3() {
+        std::thread::id this_id = std::this_thread::get_id();
+        u32 id = ids[this_id];
+        assert2 = id == 0;
+        value1 += 1000;
+        Fiber::YieldTo(fiber3, thread_fibers[id]);
+    }
+
+    void ExecuteThread(u32 id);
+
+    void CallFiber1() {
+        std::thread::id this_id = std::this_thread::get_id();
+        u32 id = ids[this_id];
+        Fiber::YieldTo(thread_fibers[id], fiber1);
+    }
+
+    void CallFiber2() {
+        std::thread::id this_id = std::this_thread::get_id();
+        u32 id = ids[this_id];
+        Fiber::YieldTo(thread_fibers[id], fiber2);
+    }
+
+    void Exit();
+
+    bool assert1{};
+    bool assert2{};
+    bool assert3{true};
+    u32 value1{};
+    u32 value2{};
+    std::atomic<bool> trap{true};
+    std::atomic<bool> trap2{true};
+    std::unordered_map<std::thread::id, u32> ids;
+    std::vector<std::shared_ptr<Common::Fiber>> thread_fibers;
+    std::shared_ptr<Common::Fiber> fiber1;
+    std::shared_ptr<Common::Fiber> fiber2;
+    std::shared_ptr<Common::Fiber> fiber3;
+};
+
+static void WorkControl2_1(void* control) {
+    auto* test_control = static_cast<TestControl2*>(control);
+    test_control->DoWork1();
+}
+
+static void WorkControl2_2(void* control) {
+    auto* test_control = static_cast<TestControl2*>(control);
+    test_control->DoWork2();
+}
+
+static void WorkControl2_3(void* control) {
+    auto* test_control = static_cast<TestControl2*>(control);
+    test_control->DoWork3();
+}
+
+void TestControl2::ExecuteThread(u32 id) {
+    std::thread::id this_id = std::this_thread::get_id();
+    ids[this_id] = id;
+    auto thread_fiber = Fiber::ThreadToFiber();
+    thread_fibers[id] = thread_fiber;
+}
+
+void TestControl2::Exit() {
+    std::thread::id this_id = std::this_thread::get_id();
+    u32 id = ids[this_id];
+    thread_fibers[id]->Exit();
+}
+
+static void ThreadStart2_1(u32 id, TestControl2& test_control) {
+    test_control.ExecuteThread(id);
+    test_control.CallFiber1();
+    test_control.Exit();
+}
+
+static void ThreadStart2_2(u32 id, TestControl2& test_control) {
+    test_control.ExecuteThread(id);
+    test_control.CallFiber2();
+    test_control.Exit();
+}
+
+/** This test checks for fiber thread exchange configuration and validates that fibers are
+ *  that a fiber has been succesfully transfered from one thread to another and that the TLS
+ *  region of the thread is kept while changing fibers.
+ */
+TEST_CASE("Fibers::InterExchange", "[common]") {
+    TestControl2 test_control{};
+    test_control.thread_fibers.resize(2);
+    test_control.fiber1 =
+        std::make_shared<Fiber>(std::function<void(void*)>{WorkControl2_1}, &test_control);
+    test_control.fiber2 =
+        std::make_shared<Fiber>(std::function<void(void*)>{WorkControl2_2}, &test_control);
+    test_control.fiber3 =
+        std::make_shared<Fiber>(std::function<void(void*)>{WorkControl2_3}, &test_control);
+    std::thread thread1(ThreadStart2_1, 0, std::ref(test_control));
+    std::thread thread2(ThreadStart2_2, 1, std::ref(test_control));
+    thread1.join();
+    thread2.join();
+    REQUIRE(test_control.assert1);
+    REQUIRE(test_control.assert2);
+    REQUIRE(test_control.assert3);
+    REQUIRE(test_control.value2 == 7000);
+    u32 cal_value = 0;
+    for (u32 i = 0; i < 12000; i++) {
+        cal_value += i;
+    }
+    cal_value += 1000;
+    REQUIRE(test_control.value1 == cal_value);
+}
+
+class TestControl3 {
+public:
+    TestControl3() = default;
+
+    void DoWork1() {
+        value1 += 1;
+        Fiber::YieldTo(fiber1, fiber2);
+        std::thread::id this_id = std::this_thread::get_id();
+        u32 id = ids[this_id];
+        value3 += 1;
+        Fiber::YieldTo(fiber1, thread_fibers[id]);
+    }
+
+    void DoWork2() {
+        value2 += 1;
+        std::thread::id this_id = std::this_thread::get_id();
+        u32 id = ids[this_id];
+        Fiber::YieldTo(fiber2, thread_fibers[id]);
+    }
+
+    void ExecuteThread(u32 id);
+
+    void CallFiber1() {
+        std::thread::id this_id = std::this_thread::get_id();
+        u32 id = ids[this_id];
+        Fiber::YieldTo(thread_fibers[id], fiber1);
+    }
+
+    void Exit();
+
+    u32 value1{};
+    u32 value2{};
+    u32 value3{};
+    std::unordered_map<std::thread::id, u32> ids;
+    std::vector<std::shared_ptr<Common::Fiber>> thread_fibers;
+    std::shared_ptr<Common::Fiber> fiber1;
+    std::shared_ptr<Common::Fiber> fiber2;
+};
+
+static void WorkControl3_1(void* control) {
+    auto* test_control = static_cast<TestControl3*>(control);
+    test_control->DoWork1();
+}
+
+static void WorkControl3_2(void* control) {
+    auto* test_control = static_cast<TestControl3*>(control);
+    test_control->DoWork2();
+}
+
+void TestControl3::ExecuteThread(u32 id) {
+    std::thread::id this_id = std::this_thread::get_id();
+    ids[this_id] = id;
+    auto thread_fiber = Fiber::ThreadToFiber();
+    thread_fibers[id] = thread_fiber;
+}
+
+void TestControl3::Exit() {
+    std::thread::id this_id = std::this_thread::get_id();
+    u32 id = ids[this_id];
+    thread_fibers[id]->Exit();
+}
+
+static void ThreadStart3(u32 id, TestControl3& test_control) {
+    test_control.ExecuteThread(id);
+    test_control.CallFiber1();
+    test_control.Exit();
+}
+
+/** This test checks for one two threads racing for starting the same fiber.
+ *  It checks execution occured in an ordered manner and by no time there were
+ *  two contexts at the same time.
+ */
+TEST_CASE("Fibers::StartRace", "[common]") {
+    TestControl3 test_control{};
+    test_control.thread_fibers.resize(2);
+    test_control.fiber1 =
+        std::make_shared<Fiber>(std::function<void(void*)>{WorkControl3_1}, &test_control);
+    test_control.fiber2 =
+        std::make_shared<Fiber>(std::function<void(void*)>{WorkControl3_2}, &test_control);
+    std::thread thread1(ThreadStart3, 0, std::ref(test_control));
+    std::thread thread2(ThreadStart3, 1, std::ref(test_control));
+    thread1.join();
+    thread2.join();
+    REQUIRE(test_control.value1 == 1);
+    REQUIRE(test_control.value2 == 1);
+    REQUIRE(test_control.value3 == 1);
+}
+
+class TestControl4;
+
+static void WorkControl4(void* control);
+
+class TestControl4 {
+public:
+    TestControl4() {
+        fiber1 = std::make_shared<Fiber>(std::function<void(void*)>{WorkControl4}, this);
+        goal_reached = false;
+        rewinded = false;
+    }
+
+    void Execute() {
+        thread_fiber = Fiber::ThreadToFiber();
+        Fiber::YieldTo(thread_fiber, fiber1);
+        thread_fiber->Exit();
+    }
+
+    void DoWork() {
+        fiber1->SetRewindPoint(std::function<void(void*)>{WorkControl4}, this);
+        if (rewinded) {
+            goal_reached = true;
+            Fiber::YieldTo(fiber1, thread_fiber);
+        }
+        rewinded = true;
+        fiber1->Rewind();
+    }
+
+    std::shared_ptr<Common::Fiber> fiber1;
+    std::shared_ptr<Common::Fiber> thread_fiber;
+    bool goal_reached;
+    bool rewinded;
+};
+
+static void WorkControl4(void* control) {
+    auto* test_control = static_cast<TestControl4*>(control);
+    test_control->DoWork();
+}
+
+TEST_CASE("Fibers::Rewind", "[common]") {
+    TestControl4 test_control{};
+    test_control.Execute();
+    REQUIRE(test_control.goal_reached);
+    REQUIRE(test_control.rewinded);
+}
+
+} // namespace Common

src/tests/core/host_timing.cpp

@@ -0,0 +1,142 @@
+// Copyright 2016 Dolphin Emulator Project / 2017 Dolphin Emulator Project
+// Licensed under GPLv2+
+// Refer to the license.txt file included.
+
+#include <catch2/catch.hpp>
+
+#include <array>
+#include <bitset>
+#include <cstdlib>
+#include <memory>
+#include <string>
+
+#include "common/file_util.h"
+#include "core/core.h"
+#include "core/host_timing.h"
+
+// Numbers are chosen randomly to make sure the correct one is given.
+static constexpr std::array<u64, 5> CB_IDS{{42, 144, 93, 1026, UINT64_C(0xFFFF7FFFF7FFFF)}};
+static constexpr int MAX_SLICE_LENGTH = 10000; // Copied from CoreTiming internals
+static constexpr std::array<u64, 5> calls_order{{2, 0, 1, 4, 3}};
+static std::array<s64, 5> delays{};
+
+static std::bitset<CB_IDS.size()> callbacks_ran_flags;
+static u64 expected_callback = 0;
+
+template <unsigned int IDX>
+void HostCallbackTemplate(u64 userdata, s64 nanoseconds_late) {
+    static_assert(IDX < CB_IDS.size(), "IDX out of range");
+    callbacks_ran_flags.set(IDX);
+    REQUIRE(CB_IDS[IDX] == userdata);
+    REQUIRE(CB_IDS[IDX] == CB_IDS[calls_order[expected_callback]]);
+    delays[IDX] = nanoseconds_late;
+    ++expected_callback;
+}
+
+struct ScopeInit final {
+    ScopeInit() {
+        core_timing.Initialize();
+    }
+    ~ScopeInit() {
+        core_timing.Shutdown();
+    }
+
+    Core::HostTiming::CoreTiming core_timing;
+};
+
+#pragma optimize("", off)
+
+static u64 TestTimerSpeed(Core::HostTiming::CoreTiming& core_timing) {
+    u64 start = core_timing.GetGlobalTimeNs().count();
+    u64 placebo = 0;
+    for (std::size_t i = 0; i < 1000; i++) {
+        placebo += core_timing.GetGlobalTimeNs().count();
+    }
+    u64 end = core_timing.GetGlobalTimeNs().count();
+    return (end - start);
+}
+
+#pragma optimize("", on)
+
+TEST_CASE("HostTiming[BasicOrder]", "[core]") {
+    ScopeInit guard;
+    auto& core_timing = guard.core_timing;
+    std::vector<std::shared_ptr<Core::HostTiming::EventType>> events{
+        Core::HostTiming::CreateEvent("callbackA", HostCallbackTemplate<0>),
+        Core::HostTiming::CreateEvent("callbackB", HostCallbackTemplate<1>),
+        Core::HostTiming::CreateEvent("callbackC", HostCallbackTemplate<2>),
+        Core::HostTiming::CreateEvent("callbackD", HostCallbackTemplate<3>),
+        Core::HostTiming::CreateEvent("callbackE", HostCallbackTemplate<4>),
+    };
+
+    expected_callback = 0;
+
+    core_timing.SyncPause(true);
+
+    u64 one_micro = 1000U;
+    for (std::size_t i = 0; i < events.size(); i++) {
+        u64 order = calls_order[i];
+        core_timing.ScheduleEvent(i * one_micro + 100U, events[order], CB_IDS[order]);
+    }
+    /// test pause
+    REQUIRE(callbacks_ran_flags.none());
+
+    core_timing.Pause(false); // No need to sync
+
+    while (core_timing.HasPendingEvents())
+        ;
+
+    REQUIRE(callbacks_ran_flags.all());
+
+    for (std::size_t i = 0; i < delays.size(); i++) {
+        const double delay = static_cast<double>(delays[i]);
+        const double micro = delay / 1000.0f;
+        const double mili = micro / 1000.0f;
+        printf("HostTimer Pausing Delay[%zu]: %.3f %.6f\n", i, micro, mili);
+    }
+}
+
+TEST_CASE("HostTiming[BasicOrderNoPausing]", "[core]") {
+    ScopeInit guard;
+    auto& core_timing = guard.core_timing;
+    std::vector<std::shared_ptr<Core::HostTiming::EventType>> events{
+        Core::HostTiming::CreateEvent("callbackA", HostCallbackTemplate<0>),
+        Core::HostTiming::CreateEvent("callbackB", HostCallbackTemplate<1>),
+        Core::HostTiming::CreateEvent("callbackC", HostCallbackTemplate<2>),
+        Core::HostTiming::CreateEvent("callbackD", HostCallbackTemplate<3>),
+        Core::HostTiming::CreateEvent("callbackE", HostCallbackTemplate<4>),
+    };
+
+    core_timing.SyncPause(true);
+    core_timing.SyncPause(false);
+
+    expected_callback = 0;
+
+    u64 start = core_timing.GetGlobalTimeNs().count();
+    u64 one_micro = 1000U;
+    for (std::size_t i = 0; i < events.size(); i++) {
+        u64 order = calls_order[i];
+        core_timing.ScheduleEvent(i * one_micro + 100U, events[order], CB_IDS[order]);
+    }
+    u64 end = core_timing.GetGlobalTimeNs().count();
+    const double scheduling_time = static_cast<double>(end - start);
+    const double timer_time = static_cast<double>(TestTimerSpeed(core_timing));
+
+    while (core_timing.HasPendingEvents())
+        ;
+
+    REQUIRE(callbacks_ran_flags.all());
+
+    for (std::size_t i = 0; i < delays.size(); i++) {
+        const double delay = static_cast<double>(delays[i]);
+        const double micro = delay / 1000.0f;
+        const double mili = micro / 1000.0f;
+        printf("HostTimer No Pausing Delay[%zu]: %.3f %.6f\n", i, micro, mili);
+    }
+
+    const double micro = scheduling_time / 1000.0f;
+    const double mili = micro / 1000.0f;
+    printf("HostTimer No Pausing Scheduling Time: %.3f %.6f\n", micro, mili);
+    printf("HostTimer No Pausing Timer Time: %.3f %.6f\n", timer_time / 1000.f,
+           timer_time / 1000000.f);
+}