GCAlloc hunt 1

- Removed RegId (caused garbage when used as key in collections)
- Removed List<Chunk> allocation when adding bricks
- Removed some variable captures in lambdas

com.unity.render-pipelines.core/Runtime/Lighting/ProbeVolume/ProbeBrickIndex.cs

@@ -6,7 +6,8 @@
 using UnityEngine.Rendering;
 using System.Collections;
 using Chunk = UnityEngine.Experimental.Rendering.ProbeBrickPool.BrickChunkAlloc;
-using RegId = UnityEngine.Experimental.Rendering.ProbeReferenceVolume.RegId;
+using CellInfo = UnityEngine.Experimental.Rendering.ProbeReferenceVolume.CellInfo;
+using Cell = UnityEngine.Experimental.Rendering.ProbeReferenceVolume.Cell;
 
 namespace UnityEngine.Experimental.Rendering
 {
@@ -52,7 +53,7 @@ struct ReservedBrick
 
         struct VoxelMeta
         {
-            public RegId id;
+            public Cell cell;
             public List<ushort> brickIndices;
         }
 
@@ -65,12 +66,15 @@ struct BrickMeta
         Vector3Int m_CenterRS;   // the anchor in ref space, around which the index is defined. [IMPORTANT NOTE! For now we always have it at 0, so is not passed to the shader, but is kept here until development is active in case we find it useful]
 
         Dictionary<Vector3Int, List<VoxelMeta>> m_VoxelToBricks;
-        Dictionary<RegId, BrickMeta> m_BricksToVoxels;
+        Dictionary<Cell, BrickMeta> m_BricksToVoxels;
 
         int m_VoxelSubdivLevel = 3;
 
         bool m_NeedUpdateIndexComputeBuffer;
 
+        // Static variable required to avoid allocations inside lambda functions
+        static Cell g_Cell = null;
+
         int SizeOfPhysicalIndexFromBudget(ProbeVolumeTextureMemoryBudget memoryBudget)
         {
             switch (memoryBudget)
@@ -96,7 +100,7 @@ internal ProbeBrickIndex(ProbeVolumeTextureMemoryBudget memoryBudget)
             m_CenterRS = new Vector3Int(0, 0, 0);
 
             m_VoxelToBricks = new Dictionary<Vector3Int, List<VoxelMeta>>();
-            m_BricksToVoxels = new Dictionary<RegId, BrickMeta>();
+            m_BricksToVoxels = new Dictionary<Cell, BrickMeta>();
 
             m_NeedUpdateIndexComputeBuffer = false;
 
@@ -260,16 +264,18 @@ internal bool AssignIndexChunksToCell(int bricksCount, ref CellIndexUpdateInfo c
             return true;
         }
 
-        public void AddBricks(RegId id, List<Brick> bricks, List<Chunk> allocations, int allocationSize, int poolWidth, int poolHeight, CellIndexUpdateInfo cellInfo)
+        public void AddBricks(Cell cell, List<Brick> bricks, List<Chunk> allocations, int allocationSize, int poolWidth, int poolHeight, CellIndexUpdateInfo cellInfo)
         {
             Debug.Assert(bricks.Count <= ushort.MaxValue, "Cannot add more than 65K bricks per RegId.");
             int largest_cell = ProbeReferenceVolume.CellSize(kMaxSubdivisionLevels);
 
+            g_Cell = cell;
+
             // create a new copy
             BrickMeta bm = new BrickMeta();
             bm.voxels = new HashSet<Vector3Int>();
             bm.bricks = new List<ReservedBrick>(bricks.Count);
-            m_BricksToVoxels.Add(id, bm);
+            m_BricksToVoxels.Add(cell, bm);
 
             int brick_idx = 0;
             // find all voxels each brick will touch
@@ -302,10 +308,10 @@ public void AddBricks(RegId id, List<Brick> bricks, List<Chunk> allocations, int
                         }
 
                         VoxelMeta vm;
-                        int vm_idx = vm_list.FindIndex((VoxelMeta lhs) => lhs.id == id);
+                        int vm_idx = vm_list.FindIndex((VoxelMeta lhs) => lhs.cell == g_Cell);
                         if (vm_idx == -1) // first time a brick from this id has touched this voxel
                         {
-                            vm.id = id;
+                            vm.cell = cell;
                             vm.brickIndices = new List<ushort>(4);
                             vm_list.Add(vm);
                         }
@@ -326,38 +332,42 @@ public void AddBricks(RegId id, List<Brick> bricks, List<Chunk> allocations, int
             }
         }
 
-        public void RemoveBricks(RegId id, CellIndexUpdateInfo cellInfo)
+        public void RemoveBricks(CellInfo cellInfo)
         {
-            if (!m_BricksToVoxels.ContainsKey(id))
+            if (!m_BricksToVoxels.ContainsKey(cellInfo.cell))
                 return;
 
-            BrickMeta bm = m_BricksToVoxels[id];
+            var cellUpdateInfo = cellInfo.updateInfo;
+
+            g_Cell = cellInfo.cell;
+
+            BrickMeta bm = m_BricksToVoxels[cellInfo.cell];
             foreach (var v in bm.voxels)
             {
                 List<VoxelMeta> vm_list = m_VoxelToBricks[v];
-                int idx = vm_list.FindIndex((VoxelMeta lhs) => lhs.id == id);
+                int idx = vm_list.FindIndex((VoxelMeta lhs) => lhs.cell == g_Cell);
                 if (idx >= 0)
                 {
                     vm_list.RemoveAt(idx);
                     if (vm_list.Count > 0)
                     {
-                        UpdateIndexForVoxel(v, cellInfo);
+                        UpdateIndexForVoxel(v, cellUpdateInfo);
                     }
                     else
                     {
-                        ClearVoxel(v, cellInfo);
+                        ClearVoxel(v, cellUpdateInfo);
                         m_VoxelToBricks.Remove(v);
                     }
                 }
             }
-            m_BricksToVoxels.Remove(id);
+            m_BricksToVoxels.Remove(cellInfo.cell);
 
             // Clear allocated chunks
-            for (int i = cellInfo.firstChunkIndex; i < (cellInfo.firstChunkIndex + cellInfo.numberOfChunks); ++i)
+            for (int i = cellUpdateInfo.firstChunkIndex; i < (cellUpdateInfo.firstChunkIndex + cellUpdateInfo.numberOfChunks); ++i)
             {
                 m_IndexChunks[i] = false;
             }
-            m_AvailableChunkCount += cellInfo.numberOfChunks;
+            m_AvailableChunkCount += cellUpdateInfo.numberOfChunks;
         }
 
         void UpdateIndexForVoxel(Vector3Int voxel, CellIndexUpdateInfo cellInfo)
@@ -367,7 +377,7 @@ void UpdateIndexForVoxel(Vector3Int voxel, CellIndexUpdateInfo cellInfo)
             foreach (var vm in vm_list)
             {
                 // get the list of bricks and indices
-                List<ReservedBrick> bricks = m_BricksToVoxels[vm.id].bricks;
+                List<ReservedBrick> bricks = m_BricksToVoxels[vm.cell].bricks;
                 List<ushort> indcs = vm.brickIndices;
                 UpdateIndexForVoxel(voxel, bricks, indcs, cellInfo);
             }

com.unity.render-pipelines.core/Runtime/Lighting/ProbeVolume/ProbeReferenceVolume.cs

@@ -304,8 +304,7 @@ internal class Cell
         internal class CellInfo
         {
             public Cell cell;
-            public List<Chunk> chunkList;
-            public RegId regId;
+            public List<Chunk> chunkList = new List<Chunk>();
             public int flatIdxInCellIndices = -1;
             public bool loaded = false;
             public ProbeBrickIndex.CellIndexUpdateInfo updateInfo;
@@ -460,41 +459,14 @@ public struct RuntimeResources
             public Texture3D L2_3;
         }
 
-        [DebuggerDisplay("{id}")]
-        internal struct RegId
-        {
-            internal int id;
-
-            public bool IsValid() => id != 0;
-            public void Invalidate() => id = 0;
-            public static bool operator ==(RegId lhs, RegId rhs) => lhs.id == rhs.id;
-            public static bool operator !=(RegId lhs, RegId rhs) => lhs.id != rhs.id;
-            public override bool Equals(object obj)
-            {
-                if ((obj == null) || !this.GetType().Equals(obj.GetType()))
-                {
-                    return false;
-                }
-                else
-                {
-                    RegId p = (RegId)obj;
-                    return p == this;
-                }
-            }
-
-            public override int GetHashCode() => id;
-        }
-
         bool m_IsInitialized = false;
-        int m_ID = 0;
         RefVolTransform m_Transform;
         int m_MaxSubdivision;
         ProbeBrickPool m_Pool;
         ProbeBrickIndex m_Index;
         ProbeCellIndices m_CellIndices;
         List<Chunk> m_TmpSrcChunks = new List<Chunk>();
         float[] m_PositionOffsets = new float[ProbeBrickPool.kBrickProbeCountPerDim];
-        Dictionary<RegId, List<Chunk>> m_Registry = new Dictionary<RegId, List<Chunk>>();
         Bounds m_CurrGlobalBounds = new Bounds();
 
         internal Dictionary<int, CellInfo> cells = new Dictionary<int, CellInfo>();
@@ -1057,11 +1029,12 @@ bool AddBricks(CellInfo cellInfo, ProbeBrickIndex.CellIndexUpdateInfo cellUpdate
             var bricks = cell.bricks;
 
             // calculate the number of chunks necessary
-            int ch_size = ProbeBrickPool.GetChunkSize();
-            var ch_list = new List<Chunk>((bricks.Count + ch_size - 1) / ch_size);
+            int chunkSize = ProbeBrickPool.GetChunkSize();
+            int brickChunksCount = (bricks.Count + chunkSize - 1) / chunkSize;
+            cellInfo.chunkList.Clear();
 
             // Try to allocate texture space
-            if (!m_Pool.Allocate(ch_list.Capacity, ch_list))
+            if (!m_Pool.Allocate(brickChunksCount, cellInfo.chunkList))
                 return false;
 
             // Create temporary allocation to copy SH data over to main atlas.
@@ -1070,17 +1043,16 @@ bool AddBricks(CellInfo cellInfo, ProbeBrickIndex.CellIndexUpdateInfo cellUpdate
 
             // copy chunks into pool
             m_TmpSrcChunks.Clear();
-            m_TmpSrcChunks.Capacity = ch_list.Count;
             Chunk c;
             c.x = 0;
             c.y = 0;
             c.z = 0;
 
             // currently this code assumes that the texture width is a multiple of the allocation chunk size
-            for (int i = 0; i < ch_list.Count; i++)
+            for (int i = 0; i < cellInfo.chunkList.Count; i++)
             {
                 m_TmpSrcChunks.Add(c);
-                c.x += ch_size * ProbeBrickPool.kBrickProbeCountPerDim;
+                c.x += chunkSize * ProbeBrickPool.kBrickProbeCountPerDim;
                 if (c.x >= dataloc.width)
                 {
                     c.x = 0;
@@ -1094,25 +1066,17 @@ bool AddBricks(CellInfo cellInfo, ProbeBrickIndex.CellIndexUpdateInfo cellUpdate
             }
 
             // Update pool textures with incoming SH data and ignore any potential frame latency related issues for now.
-            m_Pool.Update(dataloc, m_TmpSrcChunks, ch_list, m_SHBands);
+            m_Pool.Update(dataloc, m_TmpSrcChunks, cellInfo.chunkList, m_SHBands);
 
             dataloc.Cleanup();
 
             m_BricksLoaded = true;
 
-            // create a registry entry for this request
-            RegId id;
-            m_ID++;
-            id.id = m_ID;
-            m_Registry.Add(id, ch_list);
-
             // Build index
-            m_Index.AddBricks(id, bricks, ch_list, ProbeBrickPool.GetChunkSize(), m_Pool.GetPoolWidth(), m_Pool.GetPoolHeight(), cellUpdateInfo);
+            m_Index.AddBricks(cellInfo.cell, bricks, cellInfo.chunkList, ProbeBrickPool.GetChunkSize(), m_Pool.GetPoolWidth(), m_Pool.GetPoolHeight(), cellUpdateInfo);
 
             // Update CellInfo
-            cellInfo.regId = id;
             cellInfo.updateInfo = cellUpdateInfo;
-            cellInfo.chunkList = ch_list;
             cellInfo.loaded = true;
 
             // Update indirection buffer
@@ -1127,22 +1091,19 @@ bool AddBricks(CellInfo cellInfo, ProbeBrickIndex.CellIndexUpdateInfo cellUpdate
 
         void ReleaseBricks(CellInfo cellInfo)
         {
-            List<Chunk> ch_list;
-            if (!m_Registry.TryGetValue(cellInfo.regId, out ch_list))
+            if (cellInfo.chunkList.Count == 0)
             {
-                Debug.Log("Tried to release bricks with id=" + cellInfo.regId.id + " but no bricks were registered under this id.");
+                Debug.Log("Tried to release bricks from an empty Cell.");
                 return;
             }
 
             // clean up the index
-            m_Index.RemoveBricks(cellInfo.regId, cellInfo.updateInfo);
+            m_Index.RemoveBricks(cellInfo);
 
             // clean up the pool
-            m_Pool.Deallocate(ch_list);
-            m_Registry.Remove(cellInfo.regId);
+            m_Pool.Deallocate(cellInfo.chunkList);
 
-            cellInfo.regId = new RegId();
-            cellInfo.chunkList = null;
+            cellInfo.chunkList.Clear();
         }
 
         /// <summary>