WebGPU: Replaced std::vector<Uint8> with std::unique_ptr<Uint8[]> in upload and dynamic memory managers to avoid zero-initialization overhead

Author: MikhailGorobets

Graphics/GraphicsEngineWebGPU/include/DynamicMemoryManagerWebGPU.hpp

@@ -30,6 +30,7 @@
 /// Declaration of Diligent::DynamicMemoryManagerWebGPU class
 
 #include <mutex>
+#include <memory>
 #include <vector>
 
 #include "WebGPUObjectWrappers.hpp"
@@ -111,9 +112,9 @@ class DynamicMemoryManagerWebGPU
     size_t              m_CurrentOffset = 0;
     WebGPUBufferWrapper m_wgpuBuffer;
 
-    std::mutex         m_AvailablePagesMtx;
-    std::vector<Page>  m_AvailablePages;
-    std::vector<Uint8> m_MappedData;
+    std::mutex               m_AvailablePagesMtx;
+    std::vector<Page>        m_AvailablePages;
+    std::unique_ptr<Uint8[]> m_MappedData;
 };
 
 } // namespace Diligent

Graphics/GraphicsEngineWebGPU/include/UploadMemoryManagerWebGPU.hpp

@@ -30,8 +30,9 @@
 /// Declaration of Diligent::UploadMemoryManagerWebGPU class
 
 #include <mutex>
-#include <vector>
+#include <memory>
 #include <atomic>
+#include <vector>
 
 #include "WebGPUObjectWrappers.hpp"
 #include "BasicTypes.h"
@@ -83,13 +84,14 @@ class UploadMemoryManagerWebGPU
 
         size_t GetSize() const
         {
-            return m_Data.size();
+            return m_DataSize;
         }
 
     private:
         UploadMemoryManagerWebGPU* m_pMgr = nullptr;
         WebGPUBufferWrapper        m_wgpuBuffer;
-        std::vector<Uint8>         m_Data;
+        std::unique_ptr<Uint8[]>   m_Data;
+        size_t                     m_DataSize   = 0;
         size_t                     m_CurrOffset = 0;
     };
 

Graphics/GraphicsEngineWebGPU/src/DynamicMemoryManagerWebGPU.cpp

@@ -133,7 +133,7 @@ DynamicMemoryManagerWebGPU::DynamicMemoryManagerWebGPU(WGPUDevice wgpuDevice, si
         WGPUBufferUsage_Index |
         WGPUBufferUsage_Indirect;
     m_wgpuBuffer.Reset(wgpuDeviceCreateBuffer(wgpuDevice, &wgpuBufferDesc));
-    m_MappedData.resize(BufferSize);
+    m_MappedData.reset(new Uint8[BufferSize]);
 
     LOG_INFO_MESSAGE("Created dynamic buffer: ", BufferSize >> 10, " KB");
 }

Graphics/GraphicsEngineWebGPU/src/UploadMemoryManagerWebGPU.cpp

@@ -36,7 +36,8 @@ namespace Diligent
 
 UploadMemoryManagerWebGPU::Page::Page(UploadMemoryManagerWebGPU& Mgr, size_t Size) :
     m_pMgr{&Mgr},
-    m_Data(Size)
+    m_Data{new Uint8[Size]},
+    m_DataSize{Size}
 {
     WGPUBufferDescriptor wgpuBufferDesc{};
     wgpuBufferDesc.label = GetWGPUStringView("Upload memory page");
@@ -58,10 +59,13 @@ UploadMemoryManagerWebGPU::Page::Page(Page&& RHS) noexcept :
     m_pMgr{RHS.m_pMgr},
     m_wgpuBuffer{std::move(RHS.m_wgpuBuffer)},
     m_Data{std::move(RHS.m_Data)},
+    m_DataSize{RHS.m_DataSize},
     m_CurrOffset{RHS.m_CurrOffset}
 // clang-format on
 {
-    RHS = Page{};
+    RHS.m_pMgr       = nullptr;
+    RHS.m_DataSize   = 0;
+    RHS.m_CurrOffset = 0;
 }
 
 UploadMemoryManagerWebGPU::Page& UploadMemoryManagerWebGPU::Page::operator=(Page&& RHS) noexcept
@@ -72,9 +76,11 @@ UploadMemoryManagerWebGPU::Page& UploadMemoryManagerWebGPU::Page::operator=(Page
     m_pMgr       = RHS.m_pMgr;
     m_wgpuBuffer = std::move(RHS.m_wgpuBuffer);
     m_Data       = std::move(RHS.m_Data);
+    m_DataSize   = RHS.m_DataSize;
     m_CurrOffset = RHS.m_CurrOffset;
 
     RHS.m_pMgr       = nullptr;
+    RHS.m_DataSize   = 0;
     RHS.m_CurrOffset = 0;
 
     return *this;
@@ -91,7 +97,7 @@ UploadMemoryManagerWebGPU::Allocation UploadMemoryManagerWebGPU::Page::Allocate(
     Allocation Alloc;
     Alloc.Offset = AlignUp(m_CurrOffset, Alignment);
     Alloc.Size   = AlignUp(Size, Alignment);
-    if (Alloc.Offset + Alloc.Size <= m_Data.size())
+    if (Alloc.Offset + Alloc.Size <= m_DataSize)
     {
         Alloc.wgpuBuffer = m_wgpuBuffer;
         Alloc.pData      = &m_Data[Alloc.Offset];
@@ -105,7 +111,7 @@ void UploadMemoryManagerWebGPU::Page::FlushWrites(WGPUQueue wgpuQueue)
 {
     if (m_CurrOffset > 0)
     {
-        wgpuQueueWriteBuffer(wgpuQueue, m_wgpuBuffer, 0, m_Data.data(), m_CurrOffset);
+        wgpuQueueWriteBuffer(wgpuQueue, m_wgpuBuffer, 0, m_Data.get(), m_CurrOffset);
     }
 }