internal/atlas: bug fix: (*Image).Deallocate (*Shader).Deallocate were not concurrent-safe

Updates #2162

internal/atlas/image.go

@@ -547,6 +547,14 @@ func (i *Image) MarkDisposed() {
 	backendsM.Lock()
 	defer backendsM.Unlock()
 
+	if !inFrame {
+		appendDeferred(func() {
+			i.deallocate()
+			runtime.SetFinalizer(i, nil)
+		})
+		return
+	}
+
 	i.deallocate()
 	runtime.SetFinalizer(i, nil)
 }

internal/atlas/shader.go

@@ -50,6 +50,16 @@ func (s *Shader) ensureShader() *restorable.Shader {
 
 // Deallocate deallocates the internal state.
 func (s *Shader) Deallocate() {
+	backendsM.Lock()
+	defer backendsM.Unlock()
+
+	if !inFrame {
+		appendDeferred(func() {
+			s.deallocate()
+		})
+		return
+	}
+
 	s.deallocate()
 }
 

internal/processtest/testdata/issue1753.go

@@ -56,10 +56,10 @@ func Fragment(dstPos vec4, srcPos vec2, color vec4) vec4 {
 			return fmt.Errorf("phase: %d, got: %v, want: %v", g.phase, got, want)
 		}
 
-		// Dispose the shader. When a new shader is created in the next phase, the underlying shader ID might be reused.
+		// Deallocate the shader. When a new shader is created in the next phase, the underlying shader ID might be reused.
 		// This test checks that the new shader works in this situation.
 		// The actual disposal will happen after this frame and before the next frame in the current implementation.
-		s.Dispose()
+		s.Deallocate()
 
 		g.phase++
 

internal/processtest/testdata/issue2129.go

@@ -41,7 +41,7 @@ func Fragment(dstPos vec4, srcPos vec2, color vec4) vec4 {
 			if err != nil {
 				panic(err)
 			}
-			s.Dispose()
+			s.Deallocate()
 		}()
 		return nil
 	}

internal/processtest/testdata/issue2162.go

@@ -28,7 +28,7 @@ func Fragment(dstPos vec4, srcPos vec2, color vec4) vec4 {
 	if err != nil {
 		panic(err)
 	}
-	s.Dispose()
+	s.Deallocate()
 }
 
 type Game struct {