From ae96f04c0a9ce142da191a4d7ad91d85bf3b3d58 Mon Sep 17 00:00:00 2001
From: Austin Eng <enga@chromium.org>
Date: Fri, 13 Mar 2020 23:34:40 +0000
Subject: [PATCH] Slab-allocate frontend D3D12 bind groups

Bug: dawn:340
Change-Id: Ie613a1b8e445a385c10eb377983440ace9ad3f4a
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/16746
Commit-Queue: Austin Eng <enga@chromium.org>
Reviewed-by: Kai Ninomiya <kainino@chromium.org>
---
 src/dawn_native/d3d12/BindGroupD3D12.cpp       | 13 +++++++++++++
 src/dawn_native/d3d12/BindGroupD3D12.h         |  8 ++++++--
 src/dawn_native/d3d12/BindGroupLayoutD3D12.cpp | 14 +++++++++++++-
 src/dawn_native/d3d12/BindGroupLayoutD3D12.h   |  7 +++++++
 src/dawn_native/d3d12/DeviceD3D12.cpp          |  2 +-
 5 files changed, 40 insertions(+), 4 deletions(-)

diff --git a/src/dawn_native/d3d12/BindGroupD3D12.cpp b/src/dawn_native/d3d12/BindGroupD3D12.cpp
index 29def10dfd..6a708133c2 100644
--- a/src/dawn_native/d3d12/BindGroupD3D12.cpp
+++ b/src/dawn_native/d3d12/BindGroupD3D12.cpp
@@ -24,6 +24,19 @@
 
 namespace dawn_native { namespace d3d12 {
 
+    // static
+    BindGroup* BindGroup::Create(Device* device, const BindGroupDescriptor* descriptor) {
+        return ToBackend(descriptor->layout)->AllocateBindGroup(device, descriptor);
+    }
+
+    BindGroup::BindGroup(Device* device, const BindGroupDescriptor* descriptor)
+        : BindGroupBase(this, device, descriptor) {
+    }
+
+    BindGroup::~BindGroup() {
+        ToBackend(GetLayout())->DeallocateBindGroup(this);
+    }
+
     ResultOrError<bool> BindGroup::Populate(ShaderVisibleDescriptorAllocator* allocator) {
         Device* device = ToBackend(GetDevice());
 
diff --git a/src/dawn_native/d3d12/BindGroupD3D12.h b/src/dawn_native/d3d12/BindGroupD3D12.h
index b65af78c23..dc5fb75665 100644
--- a/src/dawn_native/d3d12/BindGroupD3D12.h
+++ b/src/dawn_native/d3d12/BindGroupD3D12.h
@@ -15,6 +15,7 @@
 #ifndef DAWNNATIVE_D3D12_BINDGROUPD3D12_H_
 #define DAWNNATIVE_D3D12_BINDGROUPD3D12_H_
 
+#include "common/PlacementAllocated.h"
 #include "common/Serial.h"
 #include "dawn_native/BindGroup.h"
 #include "dawn_native/d3d12/d3d12_platform.h"
@@ -24,9 +25,12 @@ namespace dawn_native { namespace d3d12 {
     class Device;
     class ShaderVisibleDescriptorAllocator;
 
-    class BindGroup : public BindGroupBaseOwnBindingData {
+    class BindGroup : public BindGroupBase, public PlacementAllocated {
       public:
-        using BindGroupBaseOwnBindingData::BindGroupBaseOwnBindingData;
+        static BindGroup* Create(Device* device, const BindGroupDescriptor* descriptor);
+
+        BindGroup(Device* device, const BindGroupDescriptor* descriptor);
+        ~BindGroup() override;
 
         // Returns true if the BindGroup was successfully populated.
         ResultOrError<bool> Populate(ShaderVisibleDescriptorAllocator* allocator);
diff --git a/src/dawn_native/d3d12/BindGroupLayoutD3D12.cpp b/src/dawn_native/d3d12/BindGroupLayoutD3D12.cpp
index 80e9d8c430..6f8e000655 100644
--- a/src/dawn_native/d3d12/BindGroupLayoutD3D12.cpp
+++ b/src/dawn_native/d3d12/BindGroupLayoutD3D12.cpp
@@ -15,12 +15,15 @@
 #include "dawn_native/d3d12/BindGroupLayoutD3D12.h"
 
 #include "common/BitSetIterator.h"
+#include "dawn_native/d3d12/BindGroupD3D12.h"
 #include "dawn_native/d3d12/DeviceD3D12.h"
 
 namespace dawn_native { namespace d3d12 {
 
     BindGroupLayout::BindGroupLayout(Device* device, const BindGroupLayoutDescriptor* descriptor)
-        : BindGroupLayoutBase(device, descriptor), mDescriptorCounts{} {
+        : BindGroupLayoutBase(device, descriptor),
+          mDescriptorCounts{},
+          mBindGroupAllocator(MakeFrontendBindGroupAllocator<BindGroup>(4096)) {
         const auto& groupInfo = GetBindingInfo();
 
         for (uint32_t binding : IterateBitSet(groupInfo.mask)) {
@@ -143,6 +146,15 @@ namespace dawn_native { namespace d3d12 {
         }
     }
 
+    BindGroup* BindGroupLayout::AllocateBindGroup(Device* device,
+                                                  const BindGroupDescriptor* descriptor) {
+        return mBindGroupAllocator.Allocate(device, descriptor);
+    }
+
+    void BindGroupLayout::DeallocateBindGroup(BindGroup* bindGroup) {
+        mBindGroupAllocator.Deallocate(bindGroup);
+    }
+
     const std::array<uint32_t, kMaxBindingsPerGroup>& BindGroupLayout::GetBindingOffsets() const {
         return mBindingOffsets;
     }
diff --git a/src/dawn_native/d3d12/BindGroupLayoutD3D12.h b/src/dawn_native/d3d12/BindGroupLayoutD3D12.h
index e5766e635d..7d393ec65d 100644
--- a/src/dawn_native/d3d12/BindGroupLayoutD3D12.h
+++ b/src/dawn_native/d3d12/BindGroupLayoutD3D12.h
@@ -17,16 +17,21 @@
 
 #include "dawn_native/BindGroupLayout.h"
 
+#include "common/SlabAllocator.h"
 #include "dawn_native/d3d12/d3d12_platform.h"
 
 namespace dawn_native { namespace d3d12 {
 
+    class BindGroup;
     class Device;
 
     class BindGroupLayout : public BindGroupLayoutBase {
       public:
         BindGroupLayout(Device* device, const BindGroupLayoutDescriptor* descriptor);
 
+        BindGroup* AllocateBindGroup(Device* device, const BindGroupDescriptor* descriptor);
+        void DeallocateBindGroup(BindGroup* bindGroup);
+
         enum DescriptorType {
             CBV,
             UAV,
@@ -47,6 +52,8 @@ namespace dawn_native { namespace d3d12 {
         std::array<uint32_t, kMaxBindingsPerGroup> mBindingOffsets;
         std::array<uint32_t, DescriptorType::Count> mDescriptorCounts;
         D3D12_DESCRIPTOR_RANGE mRanges[DescriptorType::Count];
+
+        SlabAllocator<BindGroup> mBindGroupAllocator;
     };
 
 }}  // namespace dawn_native::d3d12
diff --git a/src/dawn_native/d3d12/DeviceD3D12.cpp b/src/dawn_native/d3d12/DeviceD3D12.cpp
index 4715bbd85a..91cc8f6988 100644
--- a/src/dawn_native/d3d12/DeviceD3D12.cpp
+++ b/src/dawn_native/d3d12/DeviceD3D12.cpp
@@ -219,7 +219,7 @@ namespace dawn_native { namespace d3d12 {
 
     ResultOrError<BindGroupBase*> Device::CreateBindGroupImpl(
         const BindGroupDescriptor* descriptor) {
-        return new BindGroup(this, descriptor);
+        return BindGroup::Create(this, descriptor);
     }
     ResultOrError<BindGroupLayoutBase*> Device::CreateBindGroupLayoutImpl(
         const BindGroupLayoutDescriptor* descriptor) {