diff --git a/Packages/com.github.homuler.mediapipe/Tests/EditMode/Gpu/GlCalculatorHelperTest.cs b/Packages/com.github.homuler.mediapipe/Tests/EditMode/Gpu/GlCalculatorHelperTest.cs
index 9b6b3b8dd..bb3283cab 100644
--- a/Packages/com.github.homuler.mediapipe/Tests/EditMode/Gpu/GlCalculatorHelperTest.cs
+++ b/Packages/com.github.homuler.mediapipe/Tests/EditMode/Gpu/GlCalculatorHelperTest.cs
@@ -7,18 +7,18 @@ public class GlCalculatorHelperTest {
     #region Constructor
     [Test, GpuOnly]
     public void Ctor_ShouldInstantiateGlCalculatorHelper() {
-      var glCalculatorHelper = new GlCalculatorHelper();
-
-      Assert.AreNotEqual(glCalculatorHelper.mpPtr, IntPtr.Zero);
+      using (var glCalculatorHelper = new GlCalculatorHelper()) {
+        Assert.AreNotEqual(glCalculatorHelper.mpPtr, IntPtr.Zero);
+      }
     }
     #endregion
 
     #region #isDisposed
     [Test, GpuOnly]
     public void isDisposed_ShouldReturnFalse_When_NotDisposedYet() {
-      var glCalculatorHelper = new GlCalculatorHelper();
-
-      Assert.False(glCalculatorHelper.isDisposed);
+      using (var glCalculatorHelper = new GlCalculatorHelper()) {
+        Assert.False(glCalculatorHelper.isDisposed);
+      }
     }
 
     [Test, GpuOnly]
@@ -33,125 +33,133 @@ public void isDisposed_ShouldReturnTrue_When_AlreadyDisposed() {
     #region #InitializeForTest
     [Test, GpuOnly]
     public void InitializeForTest_ShouldInitialize() {
-      var glCalculatorHelper = new GlCalculatorHelper();
-
-      Assert.False(glCalculatorHelper.Initialized());
-      glCalculatorHelper.InitializeForTest(GpuResources.Create().Value());
-      Assert.True(glCalculatorHelper.Initialized());
+      using (var glCalculatorHelper = new GlCalculatorHelper()) {
+        Assert.False(glCalculatorHelper.Initialized());
+        glCalculatorHelper.InitializeForTest(GpuResources.Create().Value());
+        Assert.True(glCalculatorHelper.Initialized());
+      }
     }
     #endregion
 
     #region #RunInGlContext
     [Test, GpuOnly]
     public void RunInGlContext_ShouldReturnOk_When_FunctionReturnsOk() {
-      var glCalculatorHelper = new GlCalculatorHelper();
-      glCalculatorHelper.InitializeForTest(GpuResources.Create().Value());
+      using (var glCalculatorHelper = new GlCalculatorHelper()) {
+        glCalculatorHelper.InitializeForTest(GpuResources.Create().Value());
 
-      var status = glCalculatorHelper.RunInGlContext(() => { return Status.Ok(); });
-      Assert.True(status.ok);
+        var status = glCalculatorHelper.RunInGlContext(() => { return Status.Ok(); });
+        Assert.True(status.ok);
+      }
     }
 
     [Test, GpuOnly]
     public void RunInGlContext_ShouldReturnInternal_When_FunctionReturnsInternal() {
-      var glCalculatorHelper = new GlCalculatorHelper();
-      glCalculatorHelper.InitializeForTest(GpuResources.Create().Value());
+      using (var glCalculatorHelper = new GlCalculatorHelper()) {
+        glCalculatorHelper.InitializeForTest(GpuResources.Create().Value());
 
-      var status = glCalculatorHelper.RunInGlContext(() => { return Status.Build(Status.StatusCode.Internal, "error"); });
-      Assert.AreEqual(status.code, Status.StatusCode.Internal);
+        var status = glCalculatorHelper.RunInGlContext(() => { return Status.Build(Status.StatusCode.Internal, "error"); });
+        Assert.AreEqual(status.code, Status.StatusCode.Internal);
+      }
     }
 
     [Test, GpuOnly]
     public void RunInGlContext_ShouldReturnFailedPreCondition_When_FunctionThrows() {
-      var glCalculatorHelper = new GlCalculatorHelper();
-      glCalculatorHelper.InitializeForTest(GpuResources.Create().Value());
+      using (var glCalculatorHelper = new GlCalculatorHelper()) {
+        glCalculatorHelper.InitializeForTest(GpuResources.Create().Value());
 
-      GlCalculatorHelper.GlStatusFunction glStatusFunction = () => { throw new InvalidProgramException(); };
-      var status = glCalculatorHelper.RunInGlContext(glStatusFunction);
-      Assert.AreEqual(status.code, Status.StatusCode.FailedPrecondition);
+        GlCalculatorHelper.GlStatusFunction glStatusFunction = () => { throw new InvalidProgramException(); };
+        var status = glCalculatorHelper.RunInGlContext(glStatusFunction);
+        Assert.AreEqual(status.code, Status.StatusCode.FailedPrecondition);
+      }
     }
     #endregion
 
     #region #CreateSourceTexture
     [Test, GpuOnly]
     public void CreateSourceTexture_ShouldReturnGlTexture_When_CalledWithImageFrame() {
-      var glCalculatorHelper = new GlCalculatorHelper();
-      glCalculatorHelper.InitializeForTest(GpuResources.Create().Value());
+      using (var glCalculatorHelper = new GlCalculatorHelper()) {
+        glCalculatorHelper.InitializeForTest(GpuResources.Create().Value());
 
-      var imageFrame = new ImageFrame(ImageFormat.Format.SRGBA, 32, 24);
-      var status = glCalculatorHelper.RunInGlContext(() => {
-        var texture = glCalculatorHelper.CreateSourceTexture(imageFrame);
+        var imageFrame = new ImageFrame(ImageFormat.Format.SRGBA, 32, 24);
+        var status = glCalculatorHelper.RunInGlContext(() => {
+          var texture = glCalculatorHelper.CreateSourceTexture(imageFrame);
 
-        Assert.AreEqual(texture.width, 32);
-        Assert.AreEqual(texture.height, 24);
+          Assert.AreEqual(texture.width, 32);
+          Assert.AreEqual(texture.height, 24);
 
-        texture.Dispose();
-        return Status.Ok();
-      });
+          texture.Dispose();
+          return Status.Ok();
+        });
 
-      Assert.True(status.ok);
+        Assert.True(status.ok);
+      }
     }
 
     [Test, GpuOnly]
     [Ignore("Skip because a thread hangs")]
     public void CreateSourceTexture_ShouldFail_When_ImageFrameFormatIsInvalid() {
-      var glCalculatorHelper = new GlCalculatorHelper();
-      glCalculatorHelper.InitializeForTest(GpuResources.Create().Value());
-
-      var imageFrame = new ImageFrame(ImageFormat.Format.SBGRA, 32, 24);
-      var status = glCalculatorHelper.RunInGlContext(() => {
-        using (var texture = glCalculatorHelper.CreateSourceTexture(imageFrame)) {
-          texture.Release();
-        }
-        return Status.Ok();
-      });
-
-      Assert.AreEqual(status.code, Status.StatusCode.FailedPrecondition);
+      using (var glCalculatorHelper = new GlCalculatorHelper()) {
+        glCalculatorHelper.InitializeForTest(GpuResources.Create().Value());
+
+        var imageFrame = new ImageFrame(ImageFormat.Format.SBGRA, 32, 24);
+        var status = glCalculatorHelper.RunInGlContext(() => {
+          using (var texture = glCalculatorHelper.CreateSourceTexture(imageFrame)) {
+            texture.Release();
+          }
+          return Status.Ok();
+        });
+
+        Assert.AreEqual(status.code, Status.StatusCode.FailedPrecondition);
+      }
     }
     #endregion
 
     #region #CreateDestinationTexture
     [Test, GpuOnly]
     public void CreateDestinationTexture_ShouldReturnGlTexture_When_GpuBufferFormatIsValid() {
-      var glCalculatorHelper = new GlCalculatorHelper();
-      glCalculatorHelper.InitializeForTest(GpuResources.Create().Value());
+      using (var glCalculatorHelper = new GlCalculatorHelper()) {
+        glCalculatorHelper.InitializeForTest(GpuResources.Create().Value());
 
-      var status = glCalculatorHelper.RunInGlContext(() => {
-        var glTexture = glCalculatorHelper.CreateDestinationTexture(32, 24, GpuBufferFormat.kBGRA32);
+        var status = glCalculatorHelper.RunInGlContext(() => {
+          var glTexture = glCalculatorHelper.CreateDestinationTexture(32, 24, GpuBufferFormat.kBGRA32);
 
-        Assert.AreEqual(glTexture.width, 32);
-        Assert.AreEqual(glTexture.height, 24);
-        return Status.Ok();
-      });
+          Assert.AreEqual(glTexture.width, 32);
+          Assert.AreEqual(glTexture.height, 24);
+          return Status.Ok();
+        });
 
-      Assert.True(status.ok);
+        Assert.True(status.ok);
+      }
     }
     #endregion
 
     #region #framebuffer
     [Test, GpuOnly]
     public void framebuffer_ShouldReturnGLName() {
-      var glCalculatorHelper = new GlCalculatorHelper();
-      glCalculatorHelper.InitializeForTest(GpuResources.Create().Value());
+      using (var glCalculatorHelper = new GlCalculatorHelper()) {
+        glCalculatorHelper.InitializeForTest(GpuResources.Create().Value());
 
-      // default frame buffer
-      Assert.AreEqual(glCalculatorHelper.framebuffer, 0);
+        // default frame buffer
+        Assert.AreEqual(glCalculatorHelper.framebuffer, 0);
+      }
     }
     #endregion
 
     #region #GetGlContext
     [Test, GpuOnly]
     public void GetGlContext_ShouldReturnCurrentContext() {
-      var glCalculatorHelper = new GlCalculatorHelper();
-      glCalculatorHelper.InitializeForTest(GpuResources.Create().Value());
+      using (var glCalculatorHelper = new GlCalculatorHelper()) {
+        glCalculatorHelper.InitializeForTest(GpuResources.Create().Value());
 
-      var glContext = glCalculatorHelper.GetGlContext();
+        var glContext = glCalculatorHelper.GetGlContext();
 #if UNITY_EDITOR_LINUX || UNITY_STANDALONE_LINUX || UNITY_ANDROID
-      Assert.AreNotEqual(glContext.eglContext, IntPtr.Zero);
+        Assert.AreNotEqual(glContext.eglContext, IntPtr.Zero);
 #elif UNITY_STANDALONE_OSX
-      Assert.AreNotEqual(glContext.nsglContext, IntPtr.Zero);
+        Assert.AreNotEqual(glContext.nsglContext, IntPtr.Zero);
 #elif UNITY_IOS
-      Assert.AreNotEqual(glContext.eaglContext, IntPtr.Zero);
+        Assert.AreNotEqual(glContext.eaglContext, IntPtr.Zero);
 #endif
+      }
     }
     #endregion
   }
diff --git a/Packages/com.github.homuler.mediapipe/Tests/EditMode/Gpu/GlContextTest.cs b/Packages/com.github.homuler.mediapipe/Tests/EditMode/Gpu/GlContextTest.cs
index 2e982913e..e209d668f 100644
--- a/Packages/com.github.homuler.mediapipe/Tests/EditMode/Gpu/GlContextTest.cs
+++ b/Packages/com.github.homuler.mediapipe/Tests/EditMode/Gpu/GlContextTest.cs
@@ -14,16 +14,17 @@ public void GetCurrent_ShouldReturnNull_When_CalledOutOfGlContext() {
 
     [Test, GpuOnly]
     public void GetCurrent_ShouldReturnCurrentContext_When_CalledInGlContext() {
-      var glCalculatorHelper = new GlCalculatorHelper();
-      glCalculatorHelper.InitializeForTest(GpuResources.Create().Value());
+      using (var glCalculatorHelper = new GlCalculatorHelper()) {
+        glCalculatorHelper.InitializeForTest(GpuResources.Create().Value());
 
-      glCalculatorHelper.RunInGlContext(() => {
-        var glContext = GlContext.GetCurrent();
+        glCalculatorHelper.RunInGlContext(() => {
+          var glContext = GlContext.GetCurrent();
 
-        Assert.NotNull(glContext);
-        Assert.True(glContext.IsCurrent());
-        return Status.Ok();
-      }).AssertOk();
+          Assert.NotNull(glContext);
+          Assert.True(glContext.IsCurrent());
+          return Status.Ok();
+        }).AssertOk();
+      }
     }
     #endregion
 
@@ -56,17 +57,11 @@ public void ShouldReturnProperties() {
     #endregion
 
     private GlContext GetGlContext() {
-      GlContext glContext = null;
+      using (var glCalculatorHelper = new GlCalculatorHelper()) {
+        glCalculatorHelper.InitializeForTest(GpuResources.Create().Value());
 
-      var glCalculatorHelper = new GlCalculatorHelper();
-      glCalculatorHelper.InitializeForTest(GpuResources.Create().Value());
-
-      glCalculatorHelper.RunInGlContext(() => {
-        glContext = GlContext.GetCurrent();
-        return Status.Ok();
-      }).AssertOk();
-
-      return glContext;
+        return glCalculatorHelper.GetGlContext();
+      }
     }
   }
 }
diff --git a/Packages/com.github.homuler.mediapipe/Tests/EditMode/Gpu/GpuResourcesTest.cs b/Packages/com.github.homuler.mediapipe/Tests/EditMode/Gpu/GpuResourcesTest.cs
index 3ceaf61fc..79787acae 100644
--- a/Packages/com.github.homuler.mediapipe/Tests/EditMode/Gpu/GpuResourcesTest.cs
+++ b/Packages/com.github.homuler.mediapipe/Tests/EditMode/Gpu/GpuResourcesTest.cs
@@ -6,18 +6,18 @@ public class GpuResourcesTest {
     #region Create
     [Test, GpuOnly]
     public void Create_ShouldReturnStatusOrGpuResources() {
-      var statusOrGpuResources = GpuResources.Create();
-
-      Assert.True(statusOrGpuResources.ok);
+      using (var statusOrGpuResources = GpuResources.Create()) {
+        Assert.True(statusOrGpuResources.ok);
+      }
     }
     #endregion
 
     #region #isDisposed
     [Test, GpuOnly]
     public void isDisposed_ShouldReturnFalse_When_NotDisposedYet() {
-      var gpuResources = GpuResources.Create().Value();
-
-      Assert.False(gpuResources.isDisposed);
+      using (var gpuResources = GpuResources.Create().Value()) {
+        Assert.False(gpuResources.isDisposed);
+      }
     }
 
     [Test, GpuOnly]