1 files changed, 70 insertions, 0 deletions

diff --git a/src/video_core/renderer_vulkan/vk_master_semaphore.h b/src/video_core/renderer_vulkan/vk_master_semaphore.h
new file mode 100644
index 000000000..0e93706d7
--- /dev/null
+++ b/src/video_core/renderer_vulkan/vk_master_semaphore.h
@@ -0,0 +1,70 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <atomic>
+#include <thread>
+
+#include "common/common_types.h"
+#include "video_core/renderer_vulkan/wrapper.h"
+
+namespace Vulkan {
+
+class VKDevice;
+
+class MasterSemaphore {
+public:
+    explicit MasterSemaphore(const VKDevice& device);
+    ~MasterSemaphore();
+
+    /// Returns the current logical tick.
+    [[nodiscard]] u64 CurrentTick() const noexcept {
+        return current_tick;
+    }
+
+    /// Returns the timeline semaphore handle.
+    [[nodiscard]] VkSemaphore Handle() const noexcept {
+        return *semaphore;
+    }
+
+    /// Returns true when a tick has been hit by the GPU.
+    [[nodiscard]] bool IsFree(u64 tick) {
+        return gpu_tick >= tick;
+    }
+
+    /// Advance to the logical tick.
+    void NextTick() noexcept {
+        ++current_tick;
+    }
+
+    /// Refresh the known GPU tick
+    void Refresh() {
+        gpu_tick = semaphore.GetCounter();
+    }
+
+    /// Waits for a tick to be hit on the GPU
+    void Wait(u64 tick) {
+        // No need to wait if the GPU is ahead of the tick
+        if (IsFree(tick)) {
+            return;
+        }
+        // Update the GPU tick and try again
+        Refresh();
+        if (IsFree(tick)) {
+            return;
+        }
+        // If none of the above is hit, fallback to a regular wait
+        semaphore.Wait(tick);
+    }
+
+private:
+    vk::Semaphore semaphore;           ///< Timeline semaphore.
+    std::atomic<u64> gpu_tick{0};      ///< Current known GPU tick.
+    std::atomic<u64> current_tick{1};  ///< Current logical tick.
+    std::atomic<bool> shutdown{false}; ///< True when the object is being destroyed.
+    std::thread debug_thread;          ///< Debug thread to workaround validation layer bugs.
+};
+
+} // namespace Vulkan