GPU: Implement a Fence Manager.

src/video_core/fence_manager.h

@@ -0,0 +1,97 @@
+// Copyright 2020 yuzu Emulator Project
+// Licensed under GPLv2 or any later version
+// Refer to the license.txt file included.
+
+#pragma once
+
+#include <algorithm>
+#include <array>
+#include <queue>
+#include <memory>
+
+#include "common/assert.h"
+#include "common/common_types.h"
+#include "core/core.h"
+#include "core/memory.h"
+#include "core/settings.h"
+#include "video_core/gpu.h"
+#include "video_core/memory_manager.h"
+#include "video_core/rasterizer_interface.h"
+
+namespace VideoCommon {
+
+class FenceBase {
+public:
+    FenceBase(GPUVAddr address, u32 payload) : address{address}, payload{payload} {}
+
+    constexpr GPUVAddr GetAddress() const {
+        return address;
+    }
+
+    constexpr u32 GetPayload() const {
+        return payload;
+    }
+
+private:
+    GPUVAddr address;
+    u32 payload;
+};
+
+template <typename TFence, typename TTextureCache>
+class FenceManager {
+public:
+    void SignalFence(GPUVAddr addr, u32 value) {
+        TryReleasePendingFences();
+        TFence new_fence = CreateFence(addr, value);
+        QueueFence(new_fence);
+        fences.push(new_fence);
+        texture_cache.CommitAsyncFlushes();
+        rasterizer.FlushCommands();
+        rasterizer.SyncGuestHost();
+    }
+
+    void WaitPendingFences() {
+        while (!fences.empty()) {
+            TFence& current_fence = fences.front();
+            WaitFence(current_fence);
+            texture_cache.PopAsyncFlushes();
+            auto& gpu{system.GPU()};
+            auto& memory_manager{gpu.MemoryManager()};
+            memory_manager.Write<u32>(current_fence->GetAddress(), current_fence->GetPayload());
+            fences.pop();
+        }
+    }
+
+protected:
+    FenceManager(Core::System& system, VideoCore::RasterizerInterface& rasterizer,
+                 TTextureCache& texture_cache)
+        : system{system}, rasterizer{rasterizer}, texture_cache{texture_cache} {}
+
+    virtual TFence CreateFence(GPUVAddr addr, u32 value) = 0;
+    virtual void QueueFence(TFence& fence) = 0;
+    virtual bool IsFenceSignaled(TFence& fence) = 0;
+    virtual void WaitFence(TFence& fence) = 0;
+
+    Core::System& system;
+    VideoCore::RasterizerInterface& rasterizer;
+    TTextureCache& texture_cache;
+
+private:
+    void TryReleasePendingFences() {
+        while (!fences.empty()) {
+            TFence& current_fence = fences.front();
+            if (!IsFenceSignaled(current_fence)) {
+                return;
+            }
+            texture_cache.PopAsyncFlushes();
+            auto& gpu{system.GPU()};
+            auto& memory_manager{gpu.MemoryManager()};
+            memory_manager.Write<u32>(current_fence->GetAddress(), current_fence->GetPayload());
+            fences.pop();
+        }
+    }
+
+    std::queue<TFence> fences;
+};
+
+} // namespace VideoCommon