rename to servicepoint, new dir structure, WIP build.rs

crates/servicepoint_binding_cs/src/SpNativeInstance.cs

@@ -0,0 +1,51 @@
+namespace ServicePoint;
+
+public abstract class SpNativeInstance<T>
+    : IDisposable
+    where T : unmanaged
+{
+    private unsafe T* _instance;
+
+    internal unsafe T* Instance
+    {
+        get
+        {
+            if (_instance == null)
+                throw new NullReferenceException("instance is null");
+            return _instance;
+        }
+    }
+
+    private protected unsafe SpNativeInstance(T* instance)
+    {
+        ArgumentNullException.ThrowIfNull(instance);
+        _instance = instance;
+    }
+
+    private protected abstract void Dealloc();
+
+    internal unsafe T* Into()
+    {
+        var instance = _instance;
+        _instance = null;
+        return instance;
+    }
+
+    private unsafe void ReleaseUnmanagedResources()
+    {
+        if (_instance != null)
+            Dealloc();
+        _instance = null;
+    }
+
+    public void Dispose()
+    {
+        ReleaseUnmanagedResources();
+        GC.SuppressFinalize(this);
+    }
+
+    ~SpNativeInstance()
+    {
+        ReleaseUnmanagedResources();
+    }
+}