buffer_cache: Return handles instead of pointer to handles

The original idea of returning pointers is that handles can be moved.
The problem is that the implementation didn't take that in mind and made
everything harder to work with. This commit drops pointer to handles and
returns the handles themselves. While it is still true that handles can
be invalidated, this way we get an old handle instead of a dangling
pointer.

This problem can be solved in the future with sparse buffers.

1 files changed, 22 insertions, 25 deletions

diff --git a/src/video_core/buffer_cache/buffer_cache.h b/src/video_core/buffer_cache/buffer_cache.h
index b57c0d4d4..83e7a1cde 100644
--- a/src/video_core/buffer_cache/buffer_cache.h
+++ b/src/video_core/buffer_cache/buffer_cache.h
@@ -29,10 +29,10 @@ namespace VideoCommon {
 
 using MapInterval = std::shared_ptr<MapIntervalBase>;
 
-template <typename TBuffer, typename TBufferType, typename StreamBuffer>
+template <typename OwnerBuffer, typename BufferType, typename StreamBuffer>
 class BufferCache {
 public:
-    using BufferInfo = std::pair<const TBufferType*, u64>;
+    using BufferInfo = std::pair<BufferType, u64>;
 
     BufferInfo UploadMemory(GPUVAddr gpu_addr, std::size_t size, std::size_t alignment = 4,
                             bool is_written = false, bool use_fast_cbuf = false) {
@@ -89,9 +89,7 @@ public:
             }
         }
 
-        const u64 offset = static_cast<u64>(block->GetOffset(cpu_addr));
-
-        return {ToHandle(block), offset};
+        return {ToHandle(block), static_cast<u64>(block->GetOffset(cpu_addr))};
     }
 
     /// Uploads from a host memory. Returns the OpenGL buffer where it's located and its offset.
@@ -156,7 +154,7 @@ public:
         }
     }
 
-    virtual const TBufferType* GetEmptyBuffer(std::size_t size) = 0;
+    virtual BufferType GetEmptyBuffer(std::size_t size) = 0;
 
 protected:
     explicit BufferCache(VideoCore::RasterizerInterface& rasterizer, Core::System& system,
@@ -166,19 +164,19 @@ protected:
 
     ~BufferCache() = default;
 
-    virtual const TBufferType* ToHandle(const TBuffer& storage) = 0;
+    virtual BufferType ToHandle(const OwnerBuffer& storage) = 0;
 
     virtual void WriteBarrier() = 0;
 
-    virtual TBuffer CreateBlock(VAddr cpu_addr, std::size_t size) = 0;
+    virtual OwnerBuffer CreateBlock(VAddr cpu_addr, std::size_t size) = 0;
 
-    virtual void UploadBlockData(const TBuffer& buffer, std::size_t offset, std::size_t size,
+    virtual void UploadBlockData(const OwnerBuffer& buffer, std::size_t offset, std::size_t size,
                                  const u8* data) = 0;
 
-    virtual void DownloadBlockData(const TBuffer& buffer, std::size_t offset, std::size_t size,
+    virtual void DownloadBlockData(const OwnerBuffer& buffer, std::size_t offset, std::size_t size,
                                    u8* data) = 0;
 
-    virtual void CopyBlock(const TBuffer& src, const TBuffer& dst, std::size_t src_offset,
+    virtual void CopyBlock(const OwnerBuffer& src, const OwnerBuffer& dst, std::size_t src_offset,
                            std::size_t dst_offset, std::size_t size) = 0;
 
     virtual BufferInfo ConstBufferUpload(const void* raw_pointer, std::size_t size) {
@@ -221,9 +219,8 @@ private:
         return std::make_shared<MapIntervalBase>(start, end, gpu_addr);
     }
 
-    MapInterval MapAddress(const TBuffer& block, const GPUVAddr gpu_addr, const VAddr cpu_addr,
+    MapInterval MapAddress(const OwnerBuffer& block, const GPUVAddr gpu_addr, const VAddr cpu_addr,
                            const std::size_t size) {
-
         std::vector<MapInterval> overlaps = GetMapsInRange(cpu_addr, size);
         if (overlaps.empty()) {
             auto& memory_manager = system.GPU().MemoryManager();
@@ -272,7 +269,7 @@ private:
         return new_map;
     }
 
-    void UpdateBlock(const TBuffer& block, VAddr start, VAddr end,
+    void UpdateBlock(const OwnerBuffer& block, VAddr start, VAddr end,
                      std::vector<MapInterval>& overlaps) {
         const IntervalType base_interval{start, end};
         IntervalSet interval_set{};
@@ -313,7 +310,7 @@ private:
 
     void FlushMap(MapInterval map) {
         std::size_t size = map->GetEnd() - map->GetStart();
-        TBuffer block = blocks[map->GetStart() >> block_page_bits];
+        OwnerBuffer block = blocks[map->GetStart() >> block_page_bits];
         staging_buffer.resize(size);
         DownloadBlockData(block, block->GetOffset(map->GetStart()), size, staging_buffer.data());
         system.Memory().WriteBlockUnsafe(map->GetStart(), staging_buffer.data(), size);
@@ -328,7 +325,7 @@ private:
 
         buffer_ptr += size;
         buffer_offset += size;
-        return {&stream_buffer_handle, uploaded_offset};
+        return {stream_buffer_handle, uploaded_offset};
     }
 
     void AlignBuffer(std::size_t alignment) {
@@ -338,11 +335,11 @@ private:
         buffer_offset = offset_aligned;
     }
 
-    TBuffer EnlargeBlock(TBuffer buffer) {
+    OwnerBuffer EnlargeBlock(OwnerBuffer buffer) {
         const std::size_t old_size = buffer->GetSize();
         const std::size_t new_size = old_size + block_page_size;
         const VAddr cpu_addr = buffer->GetCpuAddr();
-        TBuffer new_buffer = CreateBlock(cpu_addr, new_size);
+        OwnerBuffer new_buffer = CreateBlock(cpu_addr, new_size);
         CopyBlock(buffer, new_buffer, 0, 0, old_size);
         buffer->SetEpoch(epoch);
         pending_destruction.push_back(buffer);
@@ -356,14 +353,14 @@ private:
         return new_buffer;
     }
 
-    TBuffer MergeBlocks(TBuffer first, TBuffer second) {
+    OwnerBuffer MergeBlocks(OwnerBuffer first, OwnerBuffer second) {
         const std::size_t size_1 = first->GetSize();
         const std::size_t size_2 = second->GetSize();
         const VAddr first_addr = first->GetCpuAddr();
         const VAddr second_addr = second->GetCpuAddr();
         const VAddr new_addr = std::min(first_addr, second_addr);
         const std::size_t new_size = size_1 + size_2;
-        TBuffer new_buffer = CreateBlock(new_addr, new_size);
+        OwnerBuffer new_buffer = CreateBlock(new_addr, new_size);
         CopyBlock(first, new_buffer, 0, new_buffer->GetOffset(first_addr), size_1);
         CopyBlock(second, new_buffer, 0, new_buffer->GetOffset(second_addr), size_2);
         first->SetEpoch(epoch);
@@ -380,8 +377,8 @@ private:
         return new_buffer;
     }
 
-    TBuffer GetBlock(const VAddr cpu_addr, const std::size_t size) {
-        TBuffer found{};
+    OwnerBuffer GetBlock(const VAddr cpu_addr, const std::size_t size) {
+        OwnerBuffer found;
         const VAddr cpu_addr_end = cpu_addr + size - 1;
         u64 page_start = cpu_addr >> block_page_bits;
         const u64 page_end = cpu_addr_end >> block_page_bits;
@@ -457,7 +454,7 @@ private:
     Core::System& system;
 
     std::unique_ptr<StreamBuffer> stream_buffer;
-    TBufferType stream_buffer_handle{};
+    BufferType stream_buffer_handle{};
 
     bool invalidated = false;
 
@@ -475,9 +472,9 @@ private:
 
     static constexpr u64 block_page_bits = 21;
     static constexpr u64 block_page_size = 1ULL << block_page_bits;
-    std::unordered_map<u64, TBuffer> blocks;
+    std::unordered_map<u64, OwnerBuffer> blocks;
 
-    std::list<TBuffer> pending_destruction;
+    std::list<OwnerBuffer> pending_destruction;
     u64 epoch = 0;
     u64 modified_ticks = 0;