Backends: DX12: Rework synchronization logic. (master) (#8961)

This commit is contained in:
Rémy Tassoux
2025-09-26 16:07:38 +02:00
committed by ocornut
parent 3ff195f702
commit bab3ebec14
2 changed files with 22 additions and 40 deletions

View File

@@ -91,6 +91,7 @@ Other Changes:
- Examples: SDL2+DirectX11: Try WARP software driver if hardware driver is
not available. (#5924, #5562)
- Examples: SDL3+DirectX11: Added SDL3+DirectX11 example. (#8956, #8957) [@tomaz82]
- Examples: Win32+DirectX12: Rework synchronization logic. (#8961) [@RT2Code]
- Examples: made examples's main.cpp consistent with returning 1 on error.

View File

@@ -102,8 +102,8 @@ bool CreateDeviceD3D(HWND hWnd);
void CleanupDeviceD3D();
void CreateRenderTarget();
void CleanupRenderTarget();
void WaitForLastSubmittedFrame();
FrameContext* WaitForNextFrameResources();
void WaitForPendingOperations();
FrameContext* WaitForNextFrameContext();
LRESULT WINAPI WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam);
// Main code
@@ -256,7 +256,7 @@ int main(int, char**)
// Rendering
ImGui::Render();
FrameContext* frameCtx = WaitForNextFrameResources();
FrameContext* frameCtx = WaitForNextFrameContext();
UINT backBufferIdx = g_pSwapChain->GetCurrentBackBufferIndex();
frameCtx->CommandAllocator->Reset();
@@ -282,19 +282,17 @@ int main(int, char**)
g_pd3dCommandList->Close();
g_pd3dCommandQueue->ExecuteCommandLists(1, (ID3D12CommandList* const*)&g_pd3dCommandList);
g_pd3dCommandQueue->Signal(g_fence, ++g_fenceLastSignaledValue);
frameCtx->FenceValue = g_fenceLastSignaledValue;
// Present
HRESULT hr = g_pSwapChain->Present(1, 0); // Present with vsync
//HRESULT hr = g_pSwapChain->Present(0, 0); // Present without vsync
g_SwapChainOccluded = (hr == DXGI_STATUS_OCCLUDED);
UINT64 fenceValue = g_fenceLastSignaledValue + 1;
g_pd3dCommandQueue->Signal(g_fence, fenceValue);
g_fenceLastSignaledValue = fenceValue;
frameCtx->FenceValue = fenceValue;
g_frameIndex++;
}
WaitForLastSubmittedFrame();
WaitForPendingOperations();
// Cleanup
ImGui_ImplDX12_Shutdown();
@@ -465,49 +463,33 @@ void CreateRenderTarget()
void CleanupRenderTarget()
{
WaitForLastSubmittedFrame();
WaitForPendingOperations();
for (UINT i = 0; i < APP_NUM_BACK_BUFFERS; i++)
if (g_mainRenderTargetResource[i]) { g_mainRenderTargetResource[i]->Release(); g_mainRenderTargetResource[i] = nullptr; }
}
void WaitForLastSubmittedFrame()
void WaitForPendingOperations()
{
FrameContext* frameCtx = &g_frameContext[g_frameIndex % APP_NUM_FRAMES_IN_FLIGHT];
g_pd3dCommandQueue->Signal(g_fence, ++g_fenceLastSignaledValue);
UINT64 fenceValue = frameCtx->FenceValue;
if (fenceValue == 0)
return; // No fence was signaled
frameCtx->FenceValue = 0;
if (g_fence->GetCompletedValue() >= fenceValue)
return;
g_fence->SetEventOnCompletion(fenceValue, g_fenceEvent);
WaitForSingleObject(g_fenceEvent, INFINITE);
g_fence->SetEventOnCompletion(g_fenceLastSignaledValue, g_fenceEvent);
::WaitForSingleObject(g_fenceEvent, INFINITE);
}
FrameContext* WaitForNextFrameResources()
FrameContext* WaitForNextFrameContext()
{
UINT nextFrameIndex = g_frameIndex + 1;
g_frameIndex = nextFrameIndex;
HANDLE waitableObjects[] = { g_hSwapChainWaitableObject, nullptr };
DWORD numWaitableObjects = 1;
FrameContext* frameCtx = &g_frameContext[nextFrameIndex % APP_NUM_FRAMES_IN_FLIGHT];
UINT64 fenceValue = frameCtx->FenceValue;
if (fenceValue != 0) // means no fence was signaled
FrameContext* frame_context = &g_frameContext[g_frameIndex % APP_NUM_FRAMES_IN_FLIGHT];
if (g_fence->GetCompletedValue() < frame_context->FenceValue)
{
frameCtx->FenceValue = 0;
g_fence->SetEventOnCompletion(fenceValue, g_fenceEvent);
waitableObjects[1] = g_fenceEvent;
numWaitableObjects = 2;
g_fence->SetEventOnCompletion(frame_context->FenceValue, g_fenceEvent);
HANDLE waitableObjects[] = { g_hSwapChainWaitableObject, g_fenceEvent };
::WaitForMultipleObjects(2, waitableObjects, TRUE, INFINITE);
}
else
::WaitForSingleObject(g_hSwapChainWaitableObject, INFINITE);
WaitForMultipleObjects(numWaitableObjects, waitableObjects, TRUE, INFINITE);
return frameCtx;
return frame_context;
}
// Forward declare message handler from imgui_impl_win32.cpp
@@ -528,7 +510,6 @@ LRESULT WINAPI WndProc(HWND hWnd, UINT msg, WPARAM wParam, LPARAM lParam)
case WM_SIZE:
if (g_pd3dDevice != nullptr && wParam != SIZE_MINIMIZED)
{
WaitForLastSubmittedFrame();
CleanupRenderTarget();
HRESULT result = g_pSwapChain->ResizeBuffers(0, (UINT)LOWORD(lParam), (UINT)HIWORD(lParam), DXGI_FORMAT_UNKNOWN, DXGI_SWAP_CHAIN_FLAG_FRAME_LATENCY_WAITABLE_OBJECT);
assert(SUCCEEDED(result) && "Failed to resize swapchain.");