fix(session): Fix CGO pointer rules

It seems that Go needs to keep track of memory allocated by itself.
However, when this gets mixed with memory allocated from external
functions (eg C), things get complicated. In order to avoid these
issues, we define all internal structs as pointers to C structures
instead of allocated C structure in Go.

Signed-off-by: Kostis Papazafeiropoulos <papazof@nubificus.co.uk>
Signed-off-by: Apostolos Giannousas <agian@nubificus.co.uk>
Signed-off-by: Anastassios Nanos <ananos@nubificus.co.uk>

Author: ananos

vaccel/exec.go

@@ -20,7 +20,7 @@ func ExecWithResource(sess *Session, res *Resource, funcname string,
 	cNrRead := C.size_t(read.cList.size)
 	cNrWrite := C.size_t(write.cList.size)
 
-	cRet := C.vaccel_exec_with_resource(&sess.cSess, res.cRes, cfunc, cread, cNrRead, cwrite, cNrWrite) //nolint:gocritic
+	cRet := C.vaccel_exec_with_resource(sess.cSess, res.cRes, cfunc, cread, cNrRead, cwrite, cNrWrite) //nolint:gocritic
 
 	return int(cRet)
 

vaccel/genop.go

@@ -18,7 +18,7 @@ func Genop(sess *Session, read *ArgList, write *ArgList) int {
 	cNrRead := C.int(read.cList.size)
 	cNrWrite := C.int(write.cList.size)
 
-	cRet := C.vaccel_genop(&sess.cSess, cRead, cNrRead, cWrite, cNrWrite) //nolint:gocritic
+	cRet := C.vaccel_genop(sess.cSess, cRead, cNrRead, cWrite, cNrWrite) //nolint:gocritic
 	return int(cRet)
 
 }

vaccel/image_classification.go

@@ -35,7 +35,7 @@ func ImageClassificationFromFile(sess *Session, imagePath string) (string, int)
 	defer C.free(unsafe.Pointer(cOutImageName))
 
 	cRet := C.vaccel_image_classification(
-		&sess.cSess, cImgBuf, cText, cOutImageName,
+		sess.cSess, cImgBuf, cText, cOutImageName,
 		cImgLen, C.size_t(256), C.size_t(256)) //nolint:gocritic
 
 	var golangOut string
@@ -66,7 +66,7 @@ func ImageClassification(sess *Session, image []byte) (string, int) {
 	defer C.free(unsafe.Pointer(cOutImageName))
 
 	cRet := C.vaccel_image_classification(
-		&sess.cSess, cImgBuf, cText, cOutImageName,
+		sess.cSess, cImgBuf, cText, cOutImageName,
 		cImgLen, C.size_t(256), C.size_t(256)) //nolint:gocritic
 
 	var golangOut string

vaccel/noop.go

@@ -11,5 +11,5 @@ package vaccel
 import "C"
 
 func NoOp(sess *Session) int {
-	return int(C.vaccel_noop(&sess.cSess)) //nolint:gocritic
+	return int(C.vaccel_noop(sess.cSess)) //nolint:gocritic
 }

vaccel/session.go

@@ -11,31 +11,31 @@ package vaccel
 import "C"
 
 type Session struct {
-	cSess C.struct_vaccel_session
+	cSess *C.struct_vaccel_session
 }
 
 func (s *Session) Init(flags uint32) int {
-	return int(C.vaccel_session_init(&s.cSess, C.uint32_t(flags))) //nolint:gocritic
+	return int(C.vaccel_session_new(&s.cSess, C.uint32_t(flags))) //nolint:gocritic
 }
 
 func (s *Session) Release() int {
-	return int(C.vaccel_session_release(&s.cSess)) //nolint:gocritic
+	return int(C.vaccel_session_delete(s.cSess)) //nolint:gocritic
 }
 
 func (s *Session) Register(r *Resource) int {
-	return int(C.vaccel_resource_register(r.cRes, &s.cSess)) //nolint:gocritic
+	return int(C.vaccel_resource_register(r.cRes, s.cSess)) //nolint:gocritic
 }
 
 func (s *Session) Unregister(r *Resource) int {
-	return int(C.vaccel_resource_unregister(r.cRes, &s.cSess)) //nolint:gocritic
+	return int(C.vaccel_resource_unregister(r.cRes, s.cSess)) //nolint:gocritic
 }
 
 func (s *Session) GetID() int64 {
 	return int64(s.cSess.id)
 }
 
 func (s *Session) Update(flags uint32) int {
-	return int(C.vaccel_session_update(&s.cSess, C.uint32_t(flags))) //nolint:gocritic
+	return int(C.vaccel_session_update(s.cSess, C.uint32_t(flags))) //nolint:gocritic
 }
 
 func (s *Session) GetFlags() int32 {

vaccel/tf.go

@@ -300,7 +300,7 @@ func TFModelLoad(sess *Session, model *Resource, status *TFStatus) int {
 		return EINVAL
 	}
 
-	return int(C.vaccel_tf_model_load(&sess.cSess, model.cRes, &status.cTFStatus)) //nolint:gocritic
+	return int(C.vaccel_tf_model_load(sess.cSess, model.cRes, &status.cTFStatus)) //nolint:gocritic
 }
 
 func TFModelRun(
@@ -337,7 +337,7 @@ func TFModelRun(
 	defer C.free(cOutPtr)
 
 	ret := int(C.vaccel_tf_model_run(
-		&sess.cSess,
+		sess.cSess,
 		model.cRes,
 		func() *C.struct_vaccel_tf_buffer {
 			if runOptions != nil {
@@ -402,6 +402,6 @@ func TFModelRun(
 }
 
 func TFModelUnload(sess *Session, model *Resource, status *TFStatus) int {
-	err := int(C.vaccel_tf_model_unload(&sess.cSess, model.cRes, &status.cTFStatus)) //nolint:gocritic
+	err := int(C.vaccel_tf_model_unload(sess.cSess, model.cRes, &status.cTFStatus)) //nolint:gocritic
 	return err
 }

vaccel/tflite.go

@@ -230,7 +230,7 @@ func TFLiteModelLoad(sess *Session, model *Resource) int {
 		return EINVAL
 	}
 
-	return int(C.vaccel_tflite_model_load(&sess.cSess, model.cRes)) //nolint:gocritic
+	return int(C.vaccel_tflite_model_load(sess.cSess, model.cRes)) //nolint:gocritic
 }
 
 func TFLiteModelRun(
@@ -264,7 +264,7 @@ func TFLiteModelRun(
 
 	var cStatus C.uint8_t
 	ret := int(C.vaccel_tflite_model_run(
-		&sess.cSess,
+		sess.cSess,
 		model.cRes,
 		(**C.struct_vaccel_tflite_tensor)(cInPtr),
 		C.int(nrInputs),
@@ -321,6 +321,6 @@ func TFLiteModelRun(
 }
 
 func TFLiteModelUnload(sess *Session, model *Resource) int {
-	err := int(C.vaccel_tflite_model_unload(&sess.cSess, model.cRes)) //nolint:gocritic
+	err := int(C.vaccel_tflite_model_unload(sess.cSess, model.cRes)) //nolint:gocritic
 	return err
 }

vaccel/torch.go

@@ -190,7 +190,7 @@ func TorchModelLoad(sess *Session, model *Resource) int {
 		return EINVAL
 	}
 
-	return int(C.vaccel_torch_model_load(&sess.cSess, model.cRes)) //nolint:gocritic
+	return int(C.vaccel_torch_model_load(sess.cSess, model.cRes)) //nolint:gocritic
 }
 
 func TorchModelRun(
@@ -231,7 +231,7 @@ func TorchModelRun(
 	}
 
 	ret := int(C.vaccel_torch_model_run(
-		&sess.cSess,
+		sess.cSess,
 		model.cRes,
 		bufPtr,
 		(**C.struct_vaccel_torch_tensor)(cInPtr),