Release native dll when shutting down a VST plugin to ensure resource…

…s get released on right thread - fixes AV on vvvv shutdown Also fixes a ref count leak when passing parameter changes to the audio processor
vvvv · Nov 4, 2024 · 4b01217 · 4b01217
1 parent 064201d
commit 4b01217
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Showing 12 changed files with 108 additions and 83 deletions.
diff --git a/src/AGainFilter.cs b/src/AGainFilter.cs
@@ -35,7 +35,7 @@ public AGainFilter()
         Module.TryCreate("C:\\Users\\elias\\source\\repos\\vst3sdk\\build\\VST3\\Debug\\again.vst3", out var module);
         var factory = module.Factory;
 
-        ComWrappers cw = Utils.comWrappers;
+        ComWrappers cw = VstWrappers.Instance;
 
         var info = module.Factory.ClassInfos[0];
         component = factory.CreateInstance<IComponent>(info.ID);
@@ -163,8 +163,8 @@ unsafe void Process(AudioBufferStereo audioBufferStereo)
                 NumOutputs = 1,
                 Inputs = &inputs,
                 Outputs = &outputs,
-                InputParameterChanges = inputParameterChanges.GetComPtr(in IParameterChanges.Guid),
-                OutputParameterChanges = outputParameterChanges.GetComPtr(in IParameterChanges.Guid)
+                InputParameterChanges = inputParameterChanges.ComInterfacePtr,
+                OutputParameterChanges = outputParameterChanges.ComInterfacePtr
             };
 
             processor.process(in processData);

diff --git a/src/EffectHost.Audio.cs b/src/EffectHost.Audio.cs
@@ -117,9 +117,9 @@ private unsafe void DoFillBuffers(float[][] buffers, int offset, int numSamples)
             NumOutputs = audioOutputBusses.Length,
             Inputs = audioInputBuffers,
             Outputs = audioOutputBuffers,
-            InputParameterChanges = (inputParameterChanges ?? s_noChanges).GetComPtr(in IParameterChanges.Guid),
-            OutputParameterChanges = outputParameterChanges.GetComPtr(in IParameterChanges.Guid),
-            InputEvents = inputEvents.GetComPtr(in IEventList.Guid),
+            InputParameterChanges = (inputParameterChanges ?? s_noChanges).ComInterfacePtr,
+            OutputParameterChanges = outputParameterChanges.ComInterfacePtr,
+            InputEvents = inputEvents.ComInterfacePtr,
             //OutputEvents = outputEvents.GetComPtr(in IEventList.Guid),
             ProcessContext = new nint(&processContext)
         };

diff --git a/src/EffectHost.cs b/src/EffectHost.cs
@@ -1,6 +1,5 @@
 using Microsoft.Extensions.DependencyInjection;
 using Microsoft.Extensions.Logging;
-using Microsoft.Extensions.ObjectPool;
 using Sanford.Multimedia.Midi;
 using System.Collections.Concurrent;
 using System.Collections.Immutable;
@@ -21,26 +20,6 @@ namespace VL.Audio.VST;
 using StatePin = Pin<IChannel<PluginState>>;
 using AudioPin = Pin<IReadOnlyList<AudioSignal>>;
 
-sealed class ParameterChangesPool : DefaultObjectPool<ParameterChanges>
-{
-    public static readonly ParameterChangesPool Default = new();
-
-    public ParameterChangesPool() : base(new Policy())
-    {
-    }
-
-    sealed class Policy : PooledObjectPolicy<ParameterChanges>
-    {
-        public override ParameterChanges Create() => new ParameterChanges();
-
-        public override bool Return(ParameterChanges obj)
-        {
-            obj.Clear();
-            return true;
-        }
-    }
-}
-
 [GeneratedComClass]
 internal partial class EffectHost : FactoryBasedVLNode, IVLNode, IComponentHandler, IComponentHandler2, IDisposable 
 {
@@ -56,6 +35,7 @@ internal partial class EffectHost : FactoryBasedVLNode, IVLNode, IComponentHandl
 
     private readonly NodeContext nodeContext;
     private readonly ILogger logger;
+    private readonly Module module;
     private readonly PlugProvider plugProvider;
     private readonly IComponent component;
     private readonly IAudioProcessor processor;
@@ -102,7 +82,7 @@ public EffectHost(NodeContext nodeContext, IVLNodeDescription nodeDescription, s
 
         NodeDescription = nodeDescription;
 
-        Module.TryCreate(modulePath, out var module);
+        module = Module.Create(modulePath);
         plugProvider = PlugProvider.Create(module.Factory, info, s_context)!;
         component = plugProvider.Component;
         processor = (IAudioProcessor)component;
@@ -203,6 +183,7 @@ public void Dispose()
             component.setActive(false);
 
             plugProvider.Dispose();
+            module.Dispose();
         }
     }
 

diff --git a/src/ParameterChangesPool.cs b/src/ParameterChangesPool.cs
@@ -0,0 +1,25 @@
+using Microsoft.Extensions.ObjectPool;
+using VL.Lib.Reactive;
+using VST3.Hosting;
+
+namespace VL.Audio.VST;
+
+sealed class ParameterChangesPool : DefaultObjectPool<ParameterChanges>
+{
+    public static readonly ParameterChangesPool Default = new();
+
+    public ParameterChangesPool() : base(new Policy())
+    {
+    }
+
+    sealed class Policy : PooledObjectPolicy<ParameterChanges>
+    {
+        public override ParameterChanges Create() => new ParameterChanges();
+
+        public override bool Return(ParameterChanges obj)
+        {
+            obj.Clear();
+            return true;
+        }
+    }
+}
diff --git a/src/Utils.cs b/src/Utils.cs
@@ -11,8 +11,6 @@ namespace VL.Audio.VST;
 
 static class Utils
 {
-    public static readonly ComWrappers comWrappers = new StrategyBasedComWrappers();
-
     public static void ReleaseComObject(this object obj)
     {
         if (obj is ComObject com && IsUniqueInstance(com))
@@ -31,9 +29,9 @@ public static nint GetComPtr(this object? obj, in Guid guid)
         if (obj is null)
             return default;
 
-        var pUnk = comWrappers.GetOrCreateComInterfaceForObject(obj, CreateComInterfaceFlags.None);
+        var pUnk = VstWrappers.Instance.GetOrCreateComInterfaceForObject(obj, CreateComInterfaceFlags.None);
         Marshal.QueryInterface(pUnk, in guid, out var pInt);
-        // TODO: Marshal.Release(pUnk) ?
+        Marshal.Release(pUnk);
         return pInt;
     }
 

diff --git a/src/VST3/Hosting/AttributeList.cs b/src/VST3/Hosting/AttributeList.cs
@@ -4,7 +4,7 @@
 namespace VST3.Hosting;
 
 [GeneratedComClass]
-sealed partial class AttributeList : IAttributeList
+sealed partial class AttributeList : VstObject<IAttributeList>, IAttributeList
 {
     record BinaryBlob(nint Data, uint SizeInBytes);
 

diff --git a/src/VST3/Hosting/EventList.cs b/src/VST3/Hosting/EventList.cs
@@ -3,7 +3,7 @@
 namespace VST3.Hosting;
 
 [GeneratedComClass]
-internal partial class EventList : IEventList
+internal partial class EventList : VstObject<IEventList>, IEventList
 {
     private readonly List<Event> events = new List<Event>();
 

diff --git a/src/VST3/Hosting/HostApp.cs b/src/VST3/Hosting/HostApp.cs
@@ -4,7 +4,7 @@
 namespace VST3.Hosting;
 
 [GeneratedComClass]
-sealed partial class HostApp : IHostApplication, IPlugInterfaceSupport
+sealed partial class HostApp : VstObject<IHostApplication>, IHostApplication, IPlugInterfaceSupport
 {
     private readonly HashSet<Guid> supportedInterfaces;
 
@@ -16,25 +16,12 @@ public HostApp(IEnumerable<Type> supportedInterfaces)
     nint IHostApplication.createInstance(Guid cid, Guid _iid)
     {
         if (cid == typeof(IMessage).GUID && _iid == typeof(IMessage).GUID)
-        {
-            var comObject = VstWrappers.Instance.GetOrCreateComInterfaceForObject(new Message(), CreateComInterfaceFlags.None);
-            return GetInterfacePointerFromComInterface(ref _iid, comObject);
-        }
+            return new Message();
 
         if (cid == typeof(IAttributeList).GUID && _iid == typeof(IAttributeList).GUID)
-        {
-            var comObject = VstWrappers.Instance.GetOrCreateComInterfaceForObject(new AttributeList(), CreateComInterfaceFlags.None);
-            return GetInterfacePointerFromComInterface(ref _iid, comObject);
-        }
+            return new AttributeList();
 
         throw new NotImplementedException();
-
-        static nint GetInterfacePointerFromComInterface(ref Guid _iid, nint comObject)
-        {
-            Marshal.QueryInterface(comObject, ref _iid, out var interfacePtr);
-            Marshal.Release(comObject);
-            return interfacePtr;
-        }
     }
 
     void IHostApplication.getName(Span<char> name)

diff --git a/src/VST3/Hosting/Message.cs b/src/VST3/Hosting/Message.cs
@@ -3,7 +3,7 @@
 namespace VST3.Hosting;
 
 [GeneratedComClass]
-sealed partial class Message : IMessage
+sealed partial class Message : VstObject<IMessage>, IMessage
 {
     private string? id;
     private AttributeList? attributeList;

diff --git a/src/VST3/Hosting/Module.cs b/src/VST3/Hosting/Module.cs
@@ -1,17 +1,12 @@
-using System;
-using System.Collections.Generic;
-using System.Collections.Immutable;
-using System.Diagnostics;
-using System.Diagnostics.CodeAnalysis;
-using System.Linq;
+using System.Diagnostics.CodeAnalysis;
 using System.Runtime.InteropServices;
-using System.Text;
-using System.Threading.Tasks;
 
 namespace VST3.Hosting;
 
-class Module : IDisposable
+sealed class Module : IDisposable
 {
+    private static Dictionary<string, Module?> s_modules = new(StringComparer.OrdinalIgnoreCase);
+
     public static List<string> GetModulePaths()
     {
         // https://steinbergmedia.github.io/vst3_dev_portal/pages/Technical+Documentation/Locations+Format/Plugin+Locations.html
@@ -123,12 +118,28 @@ static string GetArchString()
     const string Arm64XWin = "arm64x-win";
 
     public static unsafe bool TryCreate(string path, [NotNullWhen(true)] out Module? module)
+    {
+        lock (s_modules)
+        {
+            if (!s_modules.TryGetValue(path, out module))
+                s_modules[path] = module = CreateInternal(path);
+            module?.AddRef();
+            return module != null;
+        }
+    }
+
+    public static unsafe Module Create(string path)
+    {
+        if (TryCreate(path, out var module))
+            return module;
+        throw new Exception($"Failed to create module for {path}");
+    }
+
+    private static unsafe Module? CreateInternal(string path)
     {
         nint modulePtr;
         bool isBundle;
 
-        module = null;
-
         if (Directory.Exists(path))
         {
             isBundle = true;
@@ -144,23 +155,22 @@ public static unsafe bool TryCreate(string path, [NotNullWhen(true)] out Module?
         }
 
         if (modulePtr == default)
-            return false;
+            return null;
 
         if (!NativeLibrary.TryGetExport(modulePtr, "GetPluginFactory", out var getPluginFactoryAddress))
-            return false;
+            return null;
 
         if (NativeLibrary.TryGetExport(modulePtr, "InitDll", out var initDllAddress))
         {
             var dllEntry = (delegate* unmanaged[Cdecl]<bool>)initDllAddress;
             if (!dllEntry())
-                return false;
+                return null;
         }
 
         var factoryProc = (delegate* unmanaged[Cdecl]<nint>)getPluginFactoryAddress;
         var pluginFactoryPtr = factoryProc();
         var pluginFactory = VstWrappers.Instance.CreateObjectForComInstance<IPluginFactory>(pluginFactoryPtr);
-        module = new Module(modulePtr, Path.GetFileName(path), path, isBundle, new PluginFactory(pluginFactory));
-        return true;
+        return new Module(modulePtr, Path.GetFileName(path), path, isBundle, new PluginFactory(pluginFactory));
 
         static nint LoadAsDll(string path)
         {
@@ -177,6 +187,7 @@ static nint LoadAsPackage(string path, string archString)
     }
 
     private readonly nint module;
+    private int refCount;
 
     private Module(nint module, string name, string filePath, bool isBundle, PluginFactory factory)
     {
@@ -193,16 +204,27 @@ private Module(nint module, string name, string filePath, bool isBundle, PluginF
     public PluginFactory Factory { get; }
     public bool IsBundle { get; }
 
-    public unsafe void Dispose()
-    {
-        Factory.Dispose();
+    private void AddRef() => Interlocked.Increment(ref refCount);
 
-        if (NativeLibrary.TryGetExport(module, "ExitDll", out var exitDllAddress))
+    private unsafe void Release()
+    {
+        if (Interlocked.Decrement(ref refCount) == 0)
         {
-            var exitDll = (delegate* unmanaged[Cdecl]<bool>)exitDllAddress;
-            exitDll();
-        }
+            lock (s_modules)
+            {
+                s_modules.Remove(FilePath);
+                Factory.Dispose();
 
-        NativeLibrary.Free(module);
+                if (NativeLibrary.TryGetExport(module, "ExitDll", out var exitDllAddress))
+                {
+                    var exitDll = (delegate* unmanaged[Cdecl]<bool>)exitDllAddress;
+                    exitDll();
+                }
+
+                NativeLibrary.Free(module);
+            }
+        }
     }
+
+    public void Dispose() => Release();
 }
diff --git a/src/VST3/Hosting/ParameterChanges.cs b/src/VST3/Hosting/ParameterChanges.cs
@@ -1,19 +1,13 @@
-using System.Collections.Concurrent;
-using System.Collections.Immutable;
-using System.Runtime.InteropServices.Marshalling;
+using System.Runtime.InteropServices.Marshalling;
 
 namespace VST3.Hosting;
 
 [GeneratedComClass]
-sealed partial class ParameterChanges : IParameterChanges
+sealed partial class ParameterChanges : VstObject<IParameterChanges>, IParameterChanges
 {
     private readonly List<ParameterValueQueue> queues = new();
     private int usedQueueCount;
 
-    public ParameterChanges()
-    {
-    }
-
     public ParameterValueQueue AddParameterData(in uint id, out int index)
     {
         for (var i = 0; i < usedQueueCount; i++)

diff --git a/src/VST3/Hosting/VstObject.cs b/src/VST3/Hosting/VstObject.cs
@@ -0,0 +1,18 @@
+using VL.Audio.VST;
+
+namespace VST3.Hosting;
+
+internal abstract class VstObject<TComInterface>
+{
+    private static readonly Guid comInterfaceGuid = typeof(TComInterface).GUID;
+    private readonly nint comInterfacePtr;
+
+    public VstObject()
+    {
+        comInterfacePtr = this.GetComPtr(comInterfaceGuid);
+    }
+
+    public nint ComInterfacePtr => comInterfacePtr;
+
+    public static implicit operator nint(VstObject<TComInterface> obj) => obj.ComInterfacePtr;
+}