From f6b979c8e4d343693cb361c9b7560f126f3f5d20 Mon Sep 17 00:00:00 2001
From: Powei Feng <powei@google.com>
Date: Wed, 27 Sep 2023 15:01:33 -0700
Subject: [PATCH] vk: refactor VulkanResources.h (#7206)

- Make the size of FixedSizedVulkanResources declarable
- Rename `acquire`
---
 filament/backend/src/vulkan/VulkanCommands.h  |  2 +-
 filament/backend/src/vulkan/VulkanHandles.h   |  5 +--
 .../src/vulkan/VulkanPipelineCache.cpp        |  2 +-
 filament/backend/src/vulkan/VulkanResources.h | 31 ++++++++++++++-----
 4 files changed, 28 insertions(+), 12 deletions(-)

diff --git a/filament/backend/src/vulkan/VulkanCommands.h b/filament/backend/src/vulkan/VulkanCommands.h
index 660e3e106c5..29de6f772fc 100644
--- a/filament/backend/src/vulkan/VulkanCommands.h
+++ b/filament/backend/src/vulkan/VulkanCommands.h
@@ -83,7 +83,7 @@ struct VulkanCommandBuffer {
     }
 
     inline void acquire(VulkanAcquireOnlyResourceManager* srcResources) {
-        mResourceManager.acquire(srcResources);
+        mResourceManager.acquireAll(srcResources);
     }
 
     inline void reset() {
diff --git a/filament/backend/src/vulkan/VulkanHandles.h b/filament/backend/src/vulkan/VulkanHandles.h
index 1d3d032444d..223a13dbd60 100644
--- a/filament/backend/src/vulkan/VulkanHandles.h
+++ b/filament/backend/src/vulkan/VulkanHandles.h
@@ -139,7 +139,7 @@ struct VulkanVertexBuffer : public HwVertexBuffer, VulkanResource {
     };
 
     PipelineInfo* mInfo;
-    FixedSizeVulkanResourceManager mResources;
+    FixedSizeVulkanResourceManager<MAX_VERTEX_BUFFER_COUNT> mResources;
 };
 
 struct VulkanIndexBuffer : public HwIndexBuffer, VulkanResource {
@@ -186,7 +186,8 @@ struct VulkanRenderPrimitive : public HwRenderPrimitive, VulkanResource {
     VkPrimitiveTopology primitiveTopology;
 
 private:
-    FixedSizeVulkanResourceManager mResources;
+    // Keep references to the vertex buffer and the index buffer.
+    FixedSizeVulkanResourceManager<2> mResources;
 };
 
 struct VulkanFence : public HwFence, VulkanResource {
diff --git a/filament/backend/src/vulkan/VulkanPipelineCache.cpp b/filament/backend/src/vulkan/VulkanPipelineCache.cpp
index b554af2b54b..fb0ef037c4c 100644
--- a/filament/backend/src/vulkan/VulkanPipelineCache.cpp
+++ b/filament/backend/src/vulkan/VulkanPipelineCache.cpp
@@ -156,7 +156,7 @@ bool VulkanPipelineCache::bindDescriptors(VkCommandBuffer cmdbuffer) noexcept {
                 = std::make_unique<VulkanAcquireOnlyResourceManager>(mResourceAllocator);
         resourceEntry = mDescriptorResources.find(cacheEntry->id);
     }
-    resourceEntry->second->acquire(&mPipelineBoundResources);
+    resourceEntry->second->acquireAll(&mPipelineBoundResources);
 
     vkCmdBindDescriptorSets(cmdbuffer, VK_PIPELINE_BIND_POINT_GRAPHICS,
             getOrCreatePipelineLayout()->handle, 0, VulkanPipelineCache::DESCRIPTOR_TYPE_COUNT,
diff --git a/filament/backend/src/vulkan/VulkanResources.h b/filament/backend/src/vulkan/VulkanResources.h
index 538b07a82a4..77b6498b860 100644
--- a/filament/backend/src/vulkan/VulkanResources.h
+++ b/filament/backend/src/vulkan/VulkanResources.h
@@ -17,7 +17,6 @@
 #ifndef TNT_FILAMENT_BACKEND_VULKANRESOURCES_H
 #define TNT_FILAMENT_BACKEND_VULKANRESOURCES_H
 
-#include <backend/DriverEnums.h>// For MAX_VERTEX_BUFFER_COUNT
 #include <backend/Handle.h>
 
 #include <tsl/robin_set.h>
@@ -156,13 +155,13 @@ namespace {
 
 // When the size of the resource set is known to be small, (for example for VulkanRenderPrimitive),
 // we just use a std::array to back the set.
+template<std::size_t SIZE>
 class FixedCapacityResourceSet {
 private:
-    constexpr static size_t const SIZE = MAX_VERTEX_BUFFER_COUNT;
     using FixedSizeArray = std::array<VulkanResource*, SIZE>;
 
 public:
-    using const_iterator = FixedSizeArray::const_iterator;
+    using const_iterator = typename FixedSizeArray::const_iterator;
 
     inline ~FixedCapacityResourceSet() {
         clear();
@@ -186,7 +185,7 @@ class FixedCapacityResourceSet {
     }
 
     inline const_iterator find(VulkanResource* resource) {
-        return std::find(mArray.begin(), mArray.end(), resource);
+        return std::find(begin(), end(), resource);
     }
 
     inline void insert(VulkanResource* resource) {
@@ -205,6 +204,10 @@ class FixedCapacityResourceSet {
         mInd = 0;
     }
 
+    inline size_t size() {
+        return mInd;
+    }
+
 private:
     FixedSizeArray mArray{nullptr};
     size_t mInd = 0;
@@ -272,14 +275,21 @@ class VulkanResourceManagerImpl {
     }
 
     // Transfers ownership from one resource set to another
-    inline void acquire(VulkanResourceManagerImpl<ResourceType, SetType>* srcResources) {
+    template <typename tSetType>
+    inline void acquireAll(VulkanResourceManagerImpl<ResourceType, tSetType>* srcResources) {
+        copyAll(srcResources);
+        srcResources->clear();
+    }
+
+    // Transfers ownership from one resource set to another
+    template <typename tSetType>
+    inline void copyAll(VulkanResourceManagerImpl<ResourceType, tSetType>* srcResources) {
         LOCK_IF_NEEDED();
         for (auto iter = srcResources->mResources.begin(); iter != srcResources->mResources.end();
                 iter++) {
             acquire(*iter);
         }
         UNLOCK_IF_NEEDED();
-        srcResources->clear();
     }
 
     inline void release(ResourceType* resource) {
@@ -323,13 +333,18 @@ class VulkanResourceManagerImpl {
     VulkanResourceAllocator* mAllocator;
     SetType mResources;
     std::unique_ptr<utils::Mutex> mMutex;
+
+    template <typename, typename> friend class VulkanResourceManagerImpl;
 };
 
 using VulkanAcquireOnlyResourceManager
         = VulkanResourceManagerImpl<VulkanResource, FastIterationResourceSet>;
 using VulkanResourceManager = VulkanResourceManagerImpl<VulkanResource, ResourceSet>;
-using FixedSizeVulkanResourceManager
-        = VulkanResourceManagerImpl<VulkanResource, FixedCapacityResourceSet>;
+
+template<std::size_t SIZE>
+using FixedSizeVulkanResourceManager =
+        VulkanResourceManagerImpl<VulkanResource, FixedCapacityResourceSet<SIZE>>;
+
 using VulkanThreadSafeResourceManager
         = VulkanResourceManagerImpl<VulkanThreadSafeResource, ThreadSafeResourceSet>;