From b6f4d53126d3f0ad522df5fc77da4ac919ea43f6 Mon Sep 17 00:00:00 2001
From: Brandon Jones <brandon1.jones@intel.com>
Date: Fri, 13 Nov 2020 02:11:12 +0000
Subject: [PATCH] Only Increment Serials When Necessary On D3D12

Only increments last submitted and last completed serials from the D3D12
backend when commands were submitted to the GPU.

Bug: dawn:119
Change-Id: I01748b7f4ac90443adac4cdef29016184f992e9c
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/32162
Commit-Queue: Brandon Jones <brandon1.jones@intel.com>
Reviewed-by: Corentin Wallez <cwallez@chromium.org>
---
 src/dawn_native/Device.h                         |  4 ++--
 src/dawn_native/d3d12/DeviceD3D12.cpp            | 15 ++++++++++++---
 src/tests/white_box/D3D12DescriptorHeapTests.cpp | 11 ++++++++---
 3 files changed, 22 insertions(+), 8 deletions(-)

diff --git a/src/dawn_native/Device.h b/src/dawn_native/Device.h
index ee73000608..6408a90a97 100644
--- a/src/dawn_native/Device.h
+++ b/src/dawn_native/Device.h
@@ -238,6 +238,8 @@ namespace dawn_native {
         // still check if we have pending work to take care of, rather than hanging and never
         // reaching the serial the work will be executed on.
         void AddFutureSerial(ExecutionSerial serial);
+        // Check for passed fences and set the new completed serial
+        void CheckPassedSerials();
 
         virtual uint32_t GetOptimalBytesPerRowAlignment() const = 0;
         virtual uint64_t GetOptimalBufferToTextureCopyOffsetAlignment() const = 0;
@@ -251,8 +253,6 @@ namespace dawn_native {
 
         // Incrememt mLastSubmittedSerial when we submit the next serial
         void IncrementLastSubmittedCommandSerial();
-        // Check for passed fences and set the new completed serial
-        void CheckPassedSerials();
 
       private:
         virtual ResultOrError<BindGroupBase*> CreateBindGroupImpl(
diff --git a/src/dawn_native/d3d12/DeviceD3D12.cpp b/src/dawn_native/d3d12/DeviceD3D12.cpp
index 3b2689d01a..753d5779dd 100644
--- a/src/dawn_native/d3d12/DeviceD3D12.cpp
+++ b/src/dawn_native/d3d12/DeviceD3D12.cpp
@@ -228,8 +228,11 @@ namespace dawn_native { namespace d3d12 {
         mRenderTargetViewAllocator->Tick(completedSerial);
         mDepthStencilViewAllocator->Tick(completedSerial);
         mUsedComObjectRefs.ClearUpTo(completedSerial);
-        DAWN_TRY(ExecutePendingCommandContext());
-        DAWN_TRY(NextSerial());
+
+        if (mPendingCommands.IsOpen()) {
+            DAWN_TRY(ExecutePendingCommandContext());
+            DAWN_TRY(NextSerial());
+        }
 
         DAWN_TRY(CheckDebugLayerAndGenerateErrors());
 
@@ -256,7 +259,13 @@ namespace dawn_native { namespace d3d12 {
     }
 
     ExecutionSerial Device::CheckAndUpdateCompletedSerials() {
-        return ExecutionSerial(mFence->GetCompletedValue());
+        ExecutionSerial completeSerial = ExecutionSerial(mFence->GetCompletedValue());
+
+        if (completeSerial <= GetCompletedCommandSerial()) {
+            return ExecutionSerial(0);
+        }
+
+        return completeSerial;
     }
 
     void Device::ReferenceUntilUnused(ComPtr<IUnknown> object) {
diff --git a/src/tests/white_box/D3D12DescriptorHeapTests.cpp b/src/tests/white_box/D3D12DescriptorHeapTests.cpp
index 341ca3f45a..b9bc8f723b 100644
--- a/src/tests/white_box/D3D12DescriptorHeapTests.cpp
+++ b/src/tests/white_box/D3D12DescriptorHeapTests.cpp
@@ -14,6 +14,7 @@
 
 #include "tests/DawnTest.h"
 
+#include "dawn_native/Device.h"
 #include "dawn_native/Toggles.h"
 #include "dawn_native/d3d12/BindGroupLayoutD3D12.h"
 #include "dawn_native/d3d12/DeviceD3D12.h"
@@ -230,13 +231,16 @@ TEST_P(D3D12DescriptorHeapTests, PoolHeapsInMultipleSubmits) {
 
     EXPECT_EQ(allocator->GetShaderVisiblePoolSizeForTesting(), 0u);
 
-    // Allocate + Tick() up to |kFrameDepth| and ensure heaps are always unique.
+    // Allocate + increment internal serials up to |kFrameDepth| and ensure heaps are always unique.
     for (uint32_t i = 0; i < kFrameDepth; i++) {
         EXPECT_TRUE(allocator->AllocateAndSwitchShaderVisibleHeap().IsSuccess());
         ComPtr<ID3D12DescriptorHeap> heap = allocator->GetShaderVisibleHeap();
         EXPECT_TRUE(std::find(heaps.begin(), heaps.end(), heap) == heaps.end());
         heaps.push_back(heap);
-        mD3DDevice->Tick();
+        // CheckPassedSerials() will update the last internally completed serial.
+        mD3DDevice->CheckPassedSerials();
+        // NextSerial() will increment the last internally submitted serial.
+        EXPECT_TRUE(mD3DDevice->NextSerial().IsSuccess());
     }
 
     // Repeat up to |kFrameDepth| again but ensure heaps are the same in the expected order
@@ -247,7 +251,8 @@ TEST_P(D3D12DescriptorHeapTests, PoolHeapsInMultipleSubmits) {
         ComPtr<ID3D12DescriptorHeap> heap = allocator->GetShaderVisibleHeap();
         EXPECT_TRUE(heaps.front() == heap);
         heaps.pop_front();
-        mD3DDevice->Tick();
+        mD3DDevice->CheckPassedSerials();
+        EXPECT_TRUE(mD3DDevice->NextSerial().IsSuccess());
     }
 
     EXPECT_TRUE(heaps.empty());