fix: Fix GCAlloc

Runtime/Scripts/Context.cs

@@ -1,6 +1,8 @@
 using System;
 using System.Runtime.InteropServices;
 using System.Threading;
+using Unity.Collections;
+using Unity.Collections.LowLevel.Unsafe;
 using UnityEngine;
 
 #if UNITY_EDITOR
@@ -61,16 +63,16 @@ internal class Batch
         public struct BatchData
         {
             public int tracksCount;
-            [MarshalAs(UnmanagedType.LPArray, SizeParamIndex = 0)]
-            public IntPtr[] tracks;
+            public IntPtr tracks;
         }
 
-        public BatchData data;
-        public IntPtr ptr;
+        public NativeArray<IntPtr> tracks;
+
+        BatchData data;
 
         public Batch()
         {
-            ResizeCapacity(1);
+            tracks = new NativeArray<IntPtr>(1, Allocator.Persistent);
         }
 
         ~Batch()
@@ -80,40 +82,34 @@ public Batch()
 
         public void Dispose()
         {
-            if (ptr != IntPtr.Zero)
+            if (tracks.IsCreated)
             {
-                Marshal.FreeHGlobal(ptr);
-                ptr = IntPtr.Zero;
+                tracks.Dispose();
+                tracks = default;
             }
         }
 
         public void ResizeCapacity(int totalTracks)
         {
-            const int roundedCapacity = 32;
-            int totalCapacity = ((totalTracks + roundedCapacity) / roundedCapacity) * roundedCapacity;
-
-            if (ptr != IntPtr.Zero && data.tracks.Length >= totalCapacity)
-                return;
-
-            data.tracksCount = 0;
-            data.tracks = new IntPtr[totalCapacity];
-
-            int size = Marshal.SizeOf(typeof(BatchData)) +
-                       Marshal.SizeOf(typeof(IntPtr)) * data.tracks.Length;
+            tracks.Dispose();
+            tracks = new NativeArray<IntPtr>(totalTracks, Allocator.Persistent);
+        }
 
-            if (ptr == IntPtr.Zero)
-                ptr = Marshal.AllocHGlobal(size);
-            else
-                ptr = Marshal.ReAllocHGlobal(ptr, (IntPtr)size);
-            Marshal.StructureToPtr(data, ptr, false);
+        public unsafe IntPtr GetPtr()
+        {
+            data.tracks = new IntPtr(tracks.GetUnsafePtr());
+            data.tracksCount = tracks.Length;
+            fixed (void* ptr = &data)
+            {
+                return new IntPtr(ptr);
+            }
         }
 
-        public void Submit(bool flush = false)
+        public unsafe void Submit(bool flush = false)
         {
-            if (flush == false)
+            if (!flush)
             {
-                Marshal.StructureToPtr(data, ptr, false);
-                WebRTC.Context.BatchUpdate(ptr);
+                WebRTC.Context.BatchUpdate(GetPtr());
             }
             else
             {
@@ -181,6 +177,7 @@ public void Dispose()
 
                 // Release buffers on the rendering thread
                 batch.Submit(true);
+                batch.Dispose();
 
                 NativeMethods.ContextDestroy(id);
                 self = IntPtr.Zero;

Runtime/Scripts/Internal/ExecutableUnitySynchronizationContext.cs

@@ -19,6 +19,8 @@ class ExecutableUnitySynchronizationContext : SynchronizationContext
         const int k_AwqInitialCapacity = 20;
 
         static SynchronizationContext s_MainThreadContext;
+        static object s_CallbackObject;
+        static SendOrPostCallback s_CallbackMethod;
 
         readonly List<WorkRequest> m_AsyncWorkQueue;
         readonly List<WorkRequest> m_CurrentFrameWork = new List<WorkRequest>(k_AwqInitialCapacity);
@@ -32,6 +34,16 @@ internal ExecutableUnitySynchronizationContext(SynchronizationContext context)
                 s_MainThreadContext = context;
             }
 
+            if (s_CallbackObject == null)
+            {
+                s_CallbackObject = new CallbackObject(ExecuteAndAppendNextExecute);
+            }
+
+            if (s_CallbackMethod == null)
+            {
+                s_CallbackMethod = SendOrPostCallback;
+            }
+
             if (s_MainThreadContext == null || s_MainThreadContext != context)
             {
                 throw new InvalidOperationException("Unable to create executable synchronization context without a valid synchronization context.");
@@ -42,7 +54,7 @@ internal ExecutableUnitySynchronizationContext(SynchronizationContext context)
             m_AsyncWorkQueue = new List<WorkRequest>();
 
             // Queue up and Execute work request with the synchronization context.
-            s_MainThreadContext.Post(SendOrPostCallback, new CallbackObject(ExecuteAndAppendNextExecute));
+            s_MainThreadContext.Post(s_CallbackMethod, s_CallbackObject);
         }
 
         ExecutableUnitySynchronizationContext(List<WorkRequest> queue, int mainThreadID)
@@ -191,7 +203,7 @@ void ExecuteAndAppendNextExecute()
             // UnitySynchronizationContext works by performing work in batches so as not to stall the main thread
             // forever. Therefore it is safe to re-add ourselves to the delayed work queue. This is how we hook into
             // the main thread delayed tasks.
-            s_MainThreadContext.Post(SendOrPostCallback, new CallbackObject(ExecuteAndAppendNextExecute));
+            s_MainThreadContext.Post(s_CallbackMethod, s_CallbackObject);
         }
 
         class CallbackObject

Runtime/Scripts/VideoStreamTrack.cs

@@ -1,5 +1,5 @@
 using System;
-using System.Collections.Concurrent;
+using System.Collections.Generic;
 using System.ComponentModel;
 using System.Runtime.InteropServices;
 using UnityEngine;
@@ -30,8 +30,8 @@ public class VideoStreamTrack : MediaStreamTrack
         /// </summary>
         public static bool NeedReceivedVideoFlipVertically { get; set; } = true;
 
-        internal static ConcurrentDictionary<IntPtr, WeakReference<VideoStreamTrack>> s_tracks =
-            new ConcurrentDictionary<IntPtr, WeakReference<VideoStreamTrack>>();
+        internal static Dictionary<IntPtr, WeakReference<VideoStreamTrack>> s_tracks =
+            new Dictionary<IntPtr, WeakReference<VideoStreamTrack>>();
 
         internal enum VideoStreamTrackAction
         {
@@ -148,8 +148,12 @@ internal void UpdateTexture()
         public VideoStreamTrack(Texture texture, CopyTexture copyTexture = null)
             : base(CreateVideoTrack(texture, out var source))
         {
-            if (!s_tracks.TryAdd(self, new WeakReference<VideoStreamTrack>(this)))
-                throw new InvalidOperationException();
+            lock (s_tracks)
+            {
+                if (s_tracks.ContainsKey(self))
+                    throw new InvalidOperationException();
+                s_tracks.Add(self, new WeakReference<VideoStreamTrack>(this));
+            }
 
             m_dataptr = Marshal.AllocHGlobal(Marshal.SizeOf(typeof(VideoStreamTrackData)));
             Marshal.StructureToPtr(m_data, m_dataptr, false);
@@ -170,8 +174,12 @@ public VideoStreamTrack(Texture texture, CopyTexture copyTexture = null)
         internal VideoStreamTrack(IntPtr ptr)
             : base(CreateVideoTrack(ptr))
         {
-            if (!s_tracks.TryAdd(self, new WeakReference<VideoStreamTrack>(this)))
-                throw new InvalidOperationException();
+            lock (s_tracks)
+            {
+                if (s_tracks.ContainsKey(self))
+                    throw new InvalidOperationException();
+                s_tracks.Add(self, new WeakReference<VideoStreamTrack>(this));
+            }
 
             m_dataptr = Marshal.AllocHGlobal(Marshal.SizeOf(typeof(VideoStreamTrackData)));
             Marshal.StructureToPtr(m_data, m_dataptr, false);
@@ -205,7 +213,10 @@ public override void Dispose()
                     }, 0.1f);
                 }
 
-                s_tracks.TryRemove(self, out var value);
+                lock (s_tracks)
+                {
+                    s_tracks.Remove(self);
+                }
             }
             base.Dispose();
         }

Runtime/Scripts/WebRTC.cs

@@ -679,23 +679,23 @@ public static IEnumerator Update()
                     RenderTexture.active = null;
 
                     var batch = Context.batch;
-                    batch.ResizeCapacity(VideoStreamTrack.s_tracks.Count);
-
                     int trackIndex = 0;
-                    foreach (var reference in VideoStreamTrack.s_tracks.Values)
+                    lock (VideoStreamTrack.s_tracks)
                     {
-                        if (!reference.TryGetTarget(out var track))
-                            continue;
-
-                        track.UpdateTexture();
-                        if (track.DataPtr != IntPtr.Zero)
+                        batch.ResizeCapacity(VideoStreamTrack.s_tracks.Count);
+                        foreach (var pair in VideoStreamTrack.s_tracks)
                         {
-                            batch.data.tracks[trackIndex] = track.DataPtr;
-                            trackIndex++;
+                            if (!pair.Value.TryGetTarget(out var track))
+                                continue;
+
+                            track.UpdateTexture();
+                            if (track.DataPtr != IntPtr.Zero)
+                            {
+                                batch.tracks[trackIndex] = track.DataPtr;
+                                trackIndex++;
+                            }
                         }
                     }
-
-                    batch.data.tracksCount = trackIndex;
                     if (trackIndex > 0)
                         batch.Submit();
 

Tests/Runtime/NativeAPITest.cs

@@ -359,13 +359,11 @@ public IEnumerator CallVideoUpdateMethodsEncode()
             Batch batch = new Batch();
 
             int trackIndex = 0;
-            batch.data.tracks[trackIndex] = ptr;
-            batch.data.tracksCount = ++trackIndex;
+            batch.tracks[trackIndex] = ptr;
 
             yield return new WaitForSeconds(1.0f);
 
-            Marshal.StructureToPtr(batch.data, batch.ptr, false);
-            VideoUpdateMethods.BatchUpdate(batchUpdateEvent, batchUpdateEventID, batch.ptr);
+            VideoUpdateMethods.BatchUpdate(batchUpdateEvent, batchUpdateEventID, batch.GetPtr());
             VideoUpdateMethods.Flush();
 
             yield return new WaitForSeconds(1.0f);
@@ -414,15 +412,11 @@ public IEnumerator CallVideoUpdateMethodsUpdateRenderer()
             Batch batch = new Batch();
 
             int trackIndex = 0;
-            batch.data.tracks[trackIndex] = ptr;
-            batch.data.tracksCount = ++trackIndex;
+            batch.tracks[trackIndex] = ptr;
 
             yield return new WaitForSeconds(1.0f);
 
-            Marshal.StructureToPtr(batch.data, batch.ptr, false);
-            VideoUpdateMethods.BatchUpdate(batchUpdateEvent, batchUpdateEventID, batch.ptr);
-
-            // this method is not supported on Direct3D12
+            VideoUpdateMethods.BatchUpdate(batchUpdateEvent, batchUpdateEventID, batch.GetPtr());
             VideoUpdateMethods.UpdateRendererTexture(updateTextureEvent, receiveTexture, rendererId);
             VideoUpdateMethods.Flush();