fix: Fix memory leak on macOS/iOS when streaming high resolution video (#872)

* add limit of buffer count for texture pool

* fix MetalTexture2D destructor

* fix changelog

* [skip ci] Update plugins

Author: karasusan

CHANGELOG.md

@@ -4,12 +4,13 @@ All notable changes to the webrtc package will be documented in this file.
 The format is based on [Keep a Changelog](http://keepachangelog.com/en/1.0.0/)
 and this project adheres to [Semantic Versioning](http://semver.org/spec/v2.0.0.html).
 
-## [3.0.0-pre.4] - 2023-01-06
+## [3.0.0-pre.4] - 2023-01-13
 
 ### Fixed
 
 - Fix KeyNotFoundException in `RTCPeerConnection` when firing the callback after disposing the its instance.
 - Fix crash when streaming high resolution video on Android device.
+- Fix memory leak on macOS/iOS when streaming high resolution video.
 
 ## [3.0.0-pre.3] - 2022-12-16
 

Plugin~/WebRTCPlugin/GpuMemoryBufferPool.cpp

@@ -72,15 +72,14 @@ namespace webrtc
         (*result)->MarkUnused(clock_->CurrentTime());
     }
 
-    void GpuMemoryBufferPool::ReleaseStaleBuffers(Timestamp now)
+    void GpuMemoryBufferPool::ReleaseStaleBuffers(Timestamp now, TimeDelta timeLimit)
     {
         auto it = resourcesPool_.begin();
         while (it != resourcesPool_.end())
         {
             FrameResources* resources = (*it).get();
 
-            constexpr TimeDelta kStaleFrameLimit = TimeDelta::Seconds(10);
-            if (!resources->IsUsed() && now - resources->lastUseTime() > kStaleFrameLimit)
+            if (!resources->IsUsed() && now - resources->lastUseTime() > timeLimit)
             {
                 resourcesPool_.erase(it++);
             }

Plugin~/WebRTCPlugin/GpuMemoryBufferPool.h

@@ -22,7 +22,7 @@ namespace webrtc
 
         rtc::scoped_refptr<VideoFrame>
         CreateFrame(NativeTexPtr ptr, const Size& size, UnityRenderingExtTextureFormat format, Timestamp timestamp);
-        void ReleaseStaleBuffers(Timestamp timestamp);
+        void ReleaseStaleBuffers(Timestamp timestamp, TimeDelta timeLimit);
 
         size_t bufferCount() { return resourcesPool_.size(); }
 

Plugin~/WebRTCPlugin/GraphicsDevice/Metal/MetalTexture2D.h

@@ -12,7 +12,7 @@ namespace webrtc
     {
     public:
         MetalTexture2D(uint32_t w, uint32_t h, id<MTLTexture> tex);
-        virtual ~MetalTexture2D();
+        virtual ~MetalTexture2D() override;
 
         inline void* GetNativeTexturePtrV() override;
         inline const void* GetNativeTexturePtrV() const override;

Plugin~/WebRTCPlugin/GraphicsDevice/Metal/MetalTexture2D.mm

@@ -15,7 +15,7 @@
 
     MetalTexture2D::~MetalTexture2D()
     {
-        m_texture = nullptr;
+        [m_texture release];
     }
 
 } // end namespace webrtc

Plugin~/WebRTCPlugin/UnityRenderEvent.cpp

@@ -35,6 +35,8 @@ namespace webrtc
     static std::map<const uint32_t, std::shared_ptr<UnityVideoRenderer>> s_mapVideoRenderer;
     static std::unique_ptr<Clock> s_clock;
 
+    static const size_t kLimitBufferCount = 10;
+    static constexpr TimeDelta kStaleFrameLimit = TimeDelta::Seconds(10);
     static const UnityProfilerMarkerDesc* s_MarkerEncode = nullptr;
     static const UnityProfilerMarkerDesc* s_MarkerDecode = nullptr;
     static std::unique_ptr<IGraphicsDevice> s_gfxDevice;
@@ -250,6 +252,8 @@ static void UNITY_INTERFACE_API OnRenderEvent(int eventID, void* data)
     UnityGfxRenderer gfxRenderer = device->GetGfxRenderer();
     void* ptr = GraphicsUtility::TextureHandleToNativeGraphicsPtr(encodeData->texture, device, gfxRenderer);
     unity::webrtc::Size size(encodeData->width, encodeData->height);
+
+    if (s_bufferPool->bufferCount() < kLimitBufferCount)
     {
         std::unique_ptr<const ScopedProfiler> profiler;
         if (s_ProfilerMarkerFactory)
@@ -258,14 +262,14 @@ static void UNITY_INTERFACE_API OnRenderEvent(int eventID, void* data)
         auto frame = s_bufferPool->CreateFrame(ptr, size, encodeData->format, timestamp);
         source->OnFrameCaptured(std::move(frame));
     }
-    s_bufferPool->ReleaseStaleBuffers(timestamp);
+    s_bufferPool->ReleaseStaleBuffers(timestamp, kStaleFrameLimit);
 }
 
 static void UNITY_INTERFACE_API OnReleaseBuffers(int eventID, void* data)
 {
     // Release all buffers.
     if (s_bufferPool)
-        s_bufferPool->ReleaseStaleBuffers(Timestamp::PlusInfinity());
+        s_bufferPool->ReleaseStaleBuffers(Timestamp::PlusInfinity(), kStaleFrameLimit);
 }
 
 extern "C" UnityRenderingEventAndData UNITY_INTERFACE_EXPORT UNITY_INTERFACE_API GetRenderEventFunc(Context* context)

Plugin~/WebRTCPluginTest/GpuMemoryBufferPoolTest.cpp

@@ -38,7 +38,10 @@ namespace webrtc
             return std::unique_ptr<ITexture2D>(tex);
         }
 
-        void ReleaseStaleBuffers(Timestamp timestamp) { bufferPool_->ReleaseStaleBuffers(timestamp); }
+        void ReleaseStaleBuffers(Timestamp timestamp)
+        {
+            bufferPool_->ReleaseStaleBuffers(timestamp, TimeDelta::Seconds(10));
+        }
 
         std::unique_ptr<GraphicsDeviceContainer> container_;
         IGraphicsDevice* device_;