Implement Time::GetSharedMemoryNativeHandle

This PR attempts to implement the shared memory provided by GetSharedMemoryNativeHandle. There is still more work to be done however that requires a rehaul of the current time module to handle clock contexts. This PR is mainly to get the basic functionality of the SharedMemory working and allow the use of addition to it whilst things get improved on.

Things to note:
Memory Barriers are used in the SharedMemory and a better solution would need to be done to implement this. Currently in this PR I’m faking the memory barriers as everything is sync and single threaded. They work by incrementing the counter and just populate the two data slots. On data reading, it will read the last added data.

Specific values in the shared memory would need to be updated periodically. This isn't included in this PR since we don't actively do this yet. In a later PR when time is refactored this should be done.

Finally, as we don't handle clock contexts. When time is refactored, we will need to update the shared memory for specific contexts. This PR does this already however since the contexts are all identical and not separated. We're just updating the same values for each context which in this case is empty.

Tiime:SetStandardUserSystemClockAutomaticCorrectionEnabled, Time:IsStandardUserSystemClockAutomaticCorrectionEnabled are also partially implemented in this PR. The reason the implementation is partial is because once again, a lack of clock contexts. This will be improved on in a future PR.

This PR closes issue #2556

8 files changed, 245 insertions, 29 deletions

diff --git a/src/core/CMakeLists.txt b/src/core/CMakeLists.txt
index cdb3bf6ab..5430b7169 100644
--- a/src/core/CMakeLists.txt
+++ b/src/core/CMakeLists.txt
@@ -422,6 +422,8 @@ add_library(core STATIC
     hle/service/time/interface.h
     hle/service/time/time.cpp
     hle/service/time/time.h
+    hle/service/time/time_sharedmemory.cpp
+    hle/service/time/time_sharedmemory.h
     hle/service/usb/usb.cpp
     hle/service/usb/usb.h
     hle/service/vi/display/vi_display.cpp
diff --git a/src/core/hle/service/service.cpp b/src/core/hle/service/service.cpp
index b2954eb34..545abe9ac 100644
--- a/src/core/hle/service/service.cpp
+++ b/src/core/hle/service/service.cpp
@@ -249,7 +249,7 @@ void Init(std::shared_ptr<SM::ServiceManager>& sm, Core::System& system,
     Sockets::InstallInterfaces(*sm);
     SPL::InstallInterfaces(*sm);
     SSL::InstallInterfaces(*sm);
-    Time::InstallInterfaces(*sm);
+    Time::InstallInterfaces(system);
     USB::InstallInterfaces(*sm);
     VI::InstallInterfaces(*sm, nv_flinger);
     WLAN::InstallInterfaces(*sm);
diff --git a/src/core/hle/service/time/interface.cpp b/src/core/hle/service/time/interface.cpp
index 8d122ae33..1030185e0 100644
--- a/src/core/hle/service/time/interface.cpp
+++ b/src/core/hle/service/time/interface.cpp
@@ -6,8 +6,9 @@
 
 namespace Service::Time {
 
-Time::Time(std::shared_ptr<Module> time, const char* name)
-    : Module::Interface(std::move(time), name) {
+Time::Time(std::shared_ptr<Module> time, std::shared_ptr<SharedMemory> shared_memory,
+           const char* name)
+    : Module::Interface(std::move(time), std::move(shared_memory), name) {
     // clang-format off
     static const FunctionInfo functions[] = {
         {0, &Time::GetStandardUserSystemClock, "GetStandardUserSystemClock"},
@@ -16,12 +17,12 @@ Time::Time(std::shared_ptr<Module> time, const char* name)
         {3, &Time::GetTimeZoneService, "GetTimeZoneService"},
         {4, &Time::GetStandardLocalSystemClock, "GetStandardLocalSystemClock"},
         {5, nullptr, "GetEphemeralNetworkSystemClock"},
-        {20, nullptr, "GetSharedMemoryNativeHandle"},
+        {20, &Time::GetSharedMemoryNativeHandle, "GetSharedMemoryNativeHandle"},
         {30, nullptr, "GetStandardNetworkClockOperationEventReadableHandle"},
         {31, nullptr, "GetEphemeralNetworkClockOperationEventReadableHandle"},
         {50, nullptr, "SetStandardSteadyClockInternalOffset"},
-        {100, nullptr, "IsStandardUserSystemClockAutomaticCorrectionEnabled"},
-        {101, nullptr, "SetStandardUserSystemClockAutomaticCorrectionEnabled"},
+        {100, &Time::IsStandardUserSystemClockAutomaticCorrectionEnabled, "IsStandardUserSystemClockAutomaticCorrectionEnabled"},
+        {101, &Time::SetStandardUserSystemClockAutomaticCorrectionEnabled, "SetStandardUserSystemClockAutomaticCorrectionEnabled"},
         {102, nullptr, "GetStandardUserSystemClockInitialYear"},
         {200, nullptr, "IsStandardNetworkSystemClockAccuracySufficient"},
         {201, nullptr, "GetStandardUserSystemClockAutomaticCorrectionUpdatedTime"},
diff --git a/src/core/hle/service/time/interface.h b/src/core/hle/service/time/interface.h
index cd6b44dec..407acf960 100644
--- a/src/core/hle/service/time/interface.h
+++ b/src/core/hle/service/time/interface.h
@@ -7,10 +7,11 @@
 #include "core/hle/service/time/time.h"
 
 namespace Service::Time {
-
+class SharedMemory;
 class Time final : public Module::Interface {
 public:
-    explicit Time(std::shared_ptr<Module> time, const char* name);
+    explicit Time(std::shared_ptr<Module> time, std::shared_ptr<SharedMemory> shared_memory,
+                  const char* name);
     ~Time() override;
 };
 
diff --git a/src/core/hle/service/time/time.cpp b/src/core/hle/service/time/time.cpp
index 346bad80d..10a7e6c97 100644
--- a/src/core/hle/service/time/time.cpp
+++ b/src/core/hle/service/time/time.cpp
@@ -13,6 +13,7 @@
 #include "core/hle/kernel/client_session.h"
 #include "core/hle/service/time/interface.h"
 #include "core/hle/service/time/time.h"
+#include "core/hle/service/time/time_sharedmemory.h"
 #include "core/settings.h"
 
 namespace Service::Time {
@@ -61,9 +62,18 @@ static u64 CalendarToPosix(const CalendarTime& calendar_time,
     return static_cast<u64>(epoch_time);
 }
 
+enum class ClockContextType {
+    StandardSteady,
+    StandardUserSystem,
+    StandardNetworkSystem,
+    StandardLocalSystem,
+};
+
 class ISystemClock final : public ServiceFramework<ISystemClock> {
 public:
-    ISystemClock() : ServiceFramework("ISystemClock") {
+    ISystemClock(std::shared_ptr<Service::Time::SharedMemory> shared_memory,
+                 ClockContextType clock_type)
+        : ServiceFramework("ISystemClock"), shared_memory(shared_memory), clock_type(clock_type) {
         static const FunctionInfo functions[] = {
             {0, &ISystemClock::GetCurrentTime, "GetCurrentTime"},
             {1, nullptr, "SetCurrentTime"},
@@ -72,6 +82,8 @@ public:
 
         };
         RegisterHandlers(functions);
+
+        UpdateSharedMemoryContext(system_clock_context);
     }
 
 private:
@@ -87,34 +99,63 @@ private:
     void GetSystemClockContext(Kernel::HLERequestContext& ctx) {
         LOG_WARNING(Service_Time, "(STUBBED) called");
 
-        SystemClockContext system_clock_ontext{};
+        // TODO(ogniK): This should be updated periodically however since we have it stubbed we'll
+        // only update when we get a new context
+        UpdateSharedMemoryContext(system_clock_context);
+
         IPC::ResponseBuilder rb{ctx, (sizeof(SystemClockContext) / 4) + 2};
         rb.Push(RESULT_SUCCESS);
-        rb.PushRaw(system_clock_ontext);
+        rb.PushRaw(system_clock_context);
     }
+
+    void UpdateSharedMemoryContext(const SystemClockContext& clock_context) {
+        switch (clock_type) {
+        case ClockContextType::StandardLocalSystem:
+            shared_memory->SetStandardLocalSystemClockContext(clock_context);
+            break;
+        case ClockContextType::StandardNetworkSystem:
+            shared_memory->SetStandardNetworkSystemClockContext(clock_context);
+            break;
+        }
+    }
+
+    SystemClockContext system_clock_context{};
+    std::shared_ptr<Service::Time::SharedMemory> shared_memory;
+    ClockContextType clock_type;
 };
 
 class ISteadyClock final : public ServiceFramework<ISteadyClock> {
 public:
-    ISteadyClock() : ServiceFramework("ISteadyClock") {
+    ISteadyClock(std::shared_ptr<SharedMemory> shared_memory)
+        : ServiceFramework("ISteadyClock"), shared_memory(shared_memory) {
         static const FunctionInfo functions[] = {
             {0, &ISteadyClock::GetCurrentTimePoint, "GetCurrentTimePoint"},
         };
         RegisterHandlers(functions);
+
+        shared_memory->SetStandardSteadyClockTimepoint(GetCurrentTimePoint());
     }
 
 private:
     void GetCurrentTimePoint(Kernel::HLERequestContext& ctx) {
         LOG_DEBUG(Service_Time, "called");
 
-        const auto& core_timing = Core::System::GetInstance().CoreTiming();
-        const auto ms = Core::Timing::CyclesToMs(core_timing.GetTicks());
-        const SteadyClockTimePoint steady_clock_time_point{static_cast<u64_le>(ms.count() / 1000),
-                                                           {}};
+        const auto time_point = GetCurrentTimePoint();
+        // TODO(ogniK): This should be updated periodically
+        shared_memory->SetStandardSteadyClockTimepoint(time_point);
+
         IPC::ResponseBuilder rb{ctx, (sizeof(SteadyClockTimePoint) / 4) + 2};
         rb.Push(RESULT_SUCCESS);
-        rb.PushRaw(steady_clock_time_point);
+        rb.PushRaw(time_point);
     }
+
+    SteadyClockTimePoint GetCurrentTimePoint() const {
+        const auto& core_timing = Core::System::GetInstance().CoreTiming();
+        const auto ms = Core::Timing::CyclesToMs(core_timing.GetTicks());
+        return {static_cast<u64_le>(ms.count() / 1000), {}};
+    }
+
+    std::shared_ptr<SharedMemory> shared_memory;
 };
 
 class ITimeZoneService final : public ServiceFramework<ITimeZoneService> {
@@ -233,7 +274,7 @@ void Module::Interface::GetStandardUserSystemClock(Kernel::HLERequestContext& ct
 
     IPC::ResponseBuilder rb{ctx, 2, 0, 1};
     rb.Push(RESULT_SUCCESS);
-    rb.PushIpcInterface<ISystemClock>();
+    rb.PushIpcInterface<ISystemClock>(shared_memory, ClockContextType::StandardUserSystem);
 }
 
 void Module::Interface::GetStandardNetworkSystemClock(Kernel::HLERequestContext& ctx) {
@@ -241,7 +282,7 @@ void Module::Interface::GetStandardNetworkSystemClock(Kernel::HLERequestContext&
 
     IPC::ResponseBuilder rb{ctx, 2, 0, 1};
     rb.Push(RESULT_SUCCESS);
-    rb.PushIpcInterface<ISystemClock>();
+    rb.PushIpcInterface<ISystemClock>(shared_memory, ClockContextType::StandardNetworkSystem);
 }
 
 void Module::Interface::GetStandardSteadyClock(Kernel::HLERequestContext& ctx) {
@@ -249,7 +290,7 @@ void Module::Interface::GetStandardSteadyClock(Kernel::HLERequestContext& ctx) {
 
     IPC::ResponseBuilder rb{ctx, 2, 0, 1};
     rb.Push(RESULT_SUCCESS);
-    rb.PushIpcInterface<ISteadyClock>();
+    rb.PushIpcInterface<ISteadyClock>(shared_memory);
 }
 
 void Module::Interface::GetTimeZoneService(Kernel::HLERequestContext& ctx) {
@@ -265,7 +306,7 @@ void Module::Interface::GetStandardLocalSystemClock(Kernel::HLERequestContext& c
 
     IPC::ResponseBuilder rb{ctx, 2, 0, 1};
     rb.Push(RESULT_SUCCESS);
-    rb.PushIpcInterface<ISystemClock>();
+    rb.PushIpcInterface<ISystemClock>(shared_memory, ClockContextType::StandardLocalSystem);
 }
 
 void Module::Interface::GetClockSnapshot(Kernel::HLERequestContext& ctx) {
@@ -333,16 +374,51 @@ void Module::Interface::CalculateStandardUserSystemClockDifferenceByUser(
     rb.PushRaw<u64>(difference);
 }
 
-Module::Interface::Interface(std::shared_ptr<Module> time, const char* name)
-    : ServiceFramework(name), time(std::move(time)) {}
+void Module::Interface::GetSharedMemoryNativeHandle(Kernel::HLERequestContext& ctx) {
+    LOG_DEBUG(Service_Time, "called");
+    IPC::ResponseBuilder rb{ctx, 2, 1};
+    rb.Push(RESULT_SUCCESS);
+    rb.PushCopyObjects(shared_memory->GetSharedMemoryHolder());
+}
+
+void Module::Interface::IsStandardUserSystemClockAutomaticCorrectionEnabled(
+    Kernel::HLERequestContext& ctx) {
+    // ogniK(TODO): When clock contexts are implemented, the value should be read from the context
+    // instead of our shared memory holder
+    LOG_DEBUG(Service_Time, "called");
+
+    IPC::ResponseBuilder rb{ctx, 3};
+    rb.Push(RESULT_SUCCESS);
+    rb.Push<u8>(shared_memory->GetStandardUserSystemClockAutomaticCorrectionEnabled());
+}
+
+void Module::Interface::SetStandardUserSystemClockAutomaticCorrectionEnabled(
+    Kernel::HLERequestContext& ctx) {
+    IPC::RequestParser rp{ctx};
+    const auto enabled = rp.Pop<u8>();
+
+    LOG_WARNING(Service_Time, "(PARTIAL IMPLEMENTATION) called");
+
+    // TODO(ogniK): Update clock contexts and correct timespans
+
+    shared_memory->SetStandardUserSystemClockAutomaticCorrectionEnabled(enabled > 0);
+    IPC::ResponseBuilder rb{ctx, 2};
+    rb.Push(RESULT_SUCCESS);
+}
+
+Module::Interface::Interface(std::shared_ptr<Module> time,
+                             std::shared_ptr<SharedMemory> shared_memory, const char* name)
+    : ServiceFramework(name), time(std::move(time)), shared_memory(std::move(shared_memory)) {}
 
 Module::Interface::~Interface() = default;
 
-void InstallInterfaces(SM::ServiceManager& service_manager) {
+void InstallInterfaces(Core::System& system) {
     auto time = std::make_shared<Module>();
-    std::make_shared<Time>(time, "time:a")->InstallAsService(service_manager);
-    std::make_shared<Time>(time, "time:s")->InstallAsService(service_manager);
-    std::make_shared<Time>(time, "time:u")->InstallAsService(service_manager);
+    auto shared_mem = std::make_shared<SharedMemory>(system);
+
+    std::make_shared<Time>(time, shared_mem, "time:a")->InstallAsService(system.ServiceManager());
+    std::make_shared<Time>(time, shared_mem, "time:s")->InstallAsService(system.ServiceManager());
+    std::make_shared<Time>(time, shared_mem, "time:u")->InstallAsService(system.ServiceManager());
 }
 
 } // namespace Service::Time
diff --git a/src/core/hle/service/time/time.h b/src/core/hle/service/time/time.h
index f11affe95..6a05a22b9 100644
--- a/src/core/hle/service/time/time.h
+++ b/src/core/hle/service/time/time.h
@@ -9,6 +9,7 @@
 #include "core/hle/service/service.h"
 
 namespace Service::Time {
+class SharedMemory;
 
 struct LocationName {
     std::array<u8, 0x24> name;
@@ -77,7 +78,8 @@ class Module final {
 public:
     class Interface : public ServiceFramework<Interface> {
     public:
-        explicit Interface(std::shared_ptr<Module> time, const char* name);
+        explicit Interface(std::shared_ptr<Module> time,
+                           std::shared_ptr<SharedMemory> shared_memory, const char* name);
         ~Interface() override;
 
         void GetStandardUserSystemClock(Kernel::HLERequestContext& ctx);
@@ -87,13 +89,17 @@ public:
         void GetStandardLocalSystemClock(Kernel::HLERequestContext& ctx);
         void GetClockSnapshot(Kernel::HLERequestContext& ctx);
         void CalculateStandardUserSystemClockDifferenceByUser(Kernel::HLERequestContext& ctx);
+        void GetSharedMemoryNativeHandle(Kernel::HLERequestContext& ctx);
+        void IsStandardUserSystemClockAutomaticCorrectionEnabled(Kernel::HLERequestContext& ctx);
+        void SetStandardUserSystemClockAutomaticCorrectionEnabled(Kernel::HLERequestContext& ctx);
 
     protected:
         std::shared_ptr<Module> time;
+        std::shared_ptr<SharedMemory> shared_memory;
     };
 };
 
 /// Registers all Time services with the specified service manager.
-void InstallInterfaces(SM::ServiceManager& service_manager);
+void InstallInterfaces(Core::System& system);
 
 } // namespace Service::Time
diff --git a/src/core/hle/service/time/time_sharedmemory.cpp b/src/core/hle/service/time/time_sharedmemory.cpp
new file mode 100644
index 000000000..650c9af7a
--- /dev/null
+++ b/src/core/hle/service/time/time_sharedmemory.cpp
@@ -0,0 +1,59 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#include "core/core.h"
+#include "core/hle/service/time/time_sharedmemory.h"
+
+namespace Service::Time {
+
+SharedMemory::SharedMemory(Core::System& system) : system(system) {
+    shared_memory_holder = Kernel::SharedMemory::Create(
+        system.Kernel(), nullptr, SHARED_MEMORY_SIZE, Kernel::MemoryPermission::ReadWrite,
+        Kernel::MemoryPermission::Read, 0, Kernel::MemoryRegion::BASE, "Time:SharedMemory");
+    shared_memory_format = reinterpret_cast<Format*>(shared_memory_holder->GetPointer());
+    shared_memory_format->format_version =
+        14; // Seems static from 1.0.0 -> 8.1.0. Specific games seem to check this value and crash
+            // if it's set to anything else
+}
+
+SharedMemory::~SharedMemory() = default;
+
+Kernel::SharedPtr<Kernel::SharedMemory> SharedMemory::GetSharedMemoryHolder() const {
+    return shared_memory_holder;
+}
+
+void SharedMemory::SetStandardSteadyClockTimepoint(const SteadyClockTimePoint& timepoint) {
+    shared_memory_format->standard_steady_clock_timepoint.StoreData(timepoint);
+}
+
+void SharedMemory::SetStandardLocalSystemClockContext(const SystemClockContext& context) {
+    shared_memory_format->standard_local_system_clock_context.StoreData(context);
+}
+
+void SharedMemory::SetStandardNetworkSystemClockContext(const SystemClockContext& context) {
+    shared_memory_format->standard_network_system_clock_context.StoreData(context);
+}
+
+void SharedMemory::SetStandardUserSystemClockAutomaticCorrectionEnabled(const bool enabled) {
+    shared_memory_format->standard_user_system_clock_automatic_correction.StoreData(enabled ? 1
+                                                                                            : 0);
+}
+
+SteadyClockTimePoint SharedMemory::GetStandardSteadyClockTimepoint() const {
+    return shared_memory_format->standard_steady_clock_timepoint.ReadData();
+}
+
+SystemClockContext SharedMemory::GetStandardLocalSystemClockContext() const {
+    return shared_memory_format->standard_local_system_clock_context.ReadData();
+}
+
+SystemClockContext SharedMemory::GetStandardNetworkSystemClockContext() const {
+    return shared_memory_format->standard_network_system_clock_context.ReadData();
+}
+
+bool SharedMemory::GetStandardUserSystemClockAutomaticCorrectionEnabled() const {
+    return shared_memory_format->standard_user_system_clock_automatic_correction.ReadData() > 0;
+}
+
+} // namespace Service::Time
diff --git a/src/core/hle/service/time/time_sharedmemory.h b/src/core/hle/service/time/time_sharedmemory.h
new file mode 100644
index 000000000..ab536005c
--- /dev/null
+++ b/src/core/hle/service/time/time_sharedmemory.h
@@ -0,0 +1,71 @@
+// Copyright 2018 yuzu emulator team
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include "common/common_types.h"
+#include "core/hle/kernel/shared_memory.h"
+#include "core/hle/service/time/time.h"
+
+namespace Service::Time {
+class SharedMemory {
+public:
+    SharedMemory(Core::System& system);
+    ~SharedMemory();
+
+    // Return the shared memory handle
+    Kernel::SharedPtr<Kernel::SharedMemory> GetSharedMemoryHolder() const;
+
+    // Set memory barriers in shared memory and update them
+    void SetStandardSteadyClockTimepoint(const SteadyClockTimePoint& timepoint);
+    void SetStandardLocalSystemClockContext(const SystemClockContext& context);
+    void SetStandardNetworkSystemClockContext(const SystemClockContext& context);
+    void SetStandardUserSystemClockAutomaticCorrectionEnabled(const bool enabled);
+
+    // Pull from memory barriers in the shared memory
+    SteadyClockTimePoint GetStandardSteadyClockTimepoint() const;
+    SystemClockContext GetStandardLocalSystemClockContext() const;
+    SystemClockContext GetStandardNetworkSystemClockContext() const;
+    bool GetStandardUserSystemClockAutomaticCorrectionEnabled() const;
+
+    // TODO(ogniK): We have to properly simulate memory barriers, how are we going to do this?
+    template <typename T>
+    struct MemoryBarrier {
+        u32_le read_attempt{};
+        T data[2]{};
+
+        // These are not actually memory barriers at the moment as we don't have multicore and all
+        // HLE is mutexed. This will need to properly be implemented when we start updating the time
+        // points on threads. As of right now, we'll be updated both values synchronously and just
+        // incrementing the read_attempt to indicate that we waited.
+        void StoreData(T data_to_store) {
+            read_attempt++;
+            data[read_attempt & 1] = data_to_store;
+        }
+
+        // For reading we're just going to read the last stored value. If there was no value stored
+        // it will just end up reading an empty value as intended.
+        T ReadData() const {
+            return data[(read_attempt - 1) & 1];
+        }
+    };
+
+    // Shared memory format
+    struct Format {
+        MemoryBarrier<SteadyClockTimePoint> standard_steady_clock_timepoint;
+        MemoryBarrier<SystemClockContext> standard_local_system_clock_context;
+        MemoryBarrier<SystemClockContext> standard_network_system_clock_context;
+        MemoryBarrier<u8> standard_user_system_clock_automatic_correction;
+        u32_le format_version;
+    };
+    static_assert(sizeof(Format) == 0xd8, "Format is an invalid size");
+
+private:
+    const std::size_t SHARED_MEMORY_SIZE = 0x1000;
+    Kernel::SharedPtr<Kernel::SharedMemory> shared_memory_holder{};
+    Core::System& system;
+    Format* shared_memory_format;
+};
+
+} // namespace Service::Time