1 files changed, 74 insertions, 0 deletions
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..cb8253541
--- /dev/null
+++ b/src/core/hle/service/time/time_sharedmemory.h
@@ -0,0 +1,74 @@
+// Copyright 2019 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:
+    explicit 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(bool enabled);
+
+    // Pull from memory barriers in the shared memory
+    SteadyClockTimePoint GetStandardSteadyClockTimepoint();
+    SystemClockContext GetStandardLocalSystemClockContext();
+    SystemClockContext GetStandardNetworkSystemClockContext();
+    bool GetStandardUserSystemClockAutomaticCorrectionEnabled();
+
+    // TODO(ogniK): We have to properly simulate memory barriers, how are we going to do this?
+    template <typename T, std::size_t Offset>
+    struct MemoryBarrier {
+        static_assert(std::is_trivially_constructible_v<T>, "T must be trivially constructable");
+        u32_le read_attempt{};
+        std::array<T, 2> data{};
+
+        // 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(u8* shared_memory, T data_to_store) {
+            std::memcpy(this, shared_memory + Offset, sizeof(*this));
+            read_attempt++;
+            data[read_attempt & 1] = data_to_store;
+            std::memcpy(shared_memory + Offset, this, sizeof(*this));
+        }
+
+        // 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(u8* shared_memory) {
+            std::memcpy(this, shared_memory + Offset, sizeof(*this));
+            return data[(read_attempt - 1) & 1];
+        }
+    };
+
+    // Shared memory format
+    struct Format {
+        MemoryBarrier<SteadyClockTimePoint, 0x0> standard_steady_clock_timepoint;
+        MemoryBarrier<SystemClockContext, 0x38> standard_local_system_clock_context;
+        MemoryBarrier<SystemClockContext, 0x80> standard_network_system_clock_context;
+        MemoryBarrier<bool, 0xc8> standard_user_system_clock_automatic_correction;
+        u32_le format_version;
+    };
+    static_assert(sizeof(Format) == 0xd8, "Format is an invalid size");
+
+private:
+    Kernel::SharedPtr<Kernel::SharedMemory> shared_memory_holder{};
+    Core::System& system;
+    Format shared_memory_format{};
+};
+
+} // namespace Service::Time