safe DecRef Python objects

Author: cpunion

function.go

@@ -36,10 +36,12 @@ func (f Func) callOneArg(arg Objecter) Object {
 }
 
 func (f Func) CallObject(args Tuple) Object {
+	defer getCurrentThreadData().decRefObjectsIfNeeded()
 	return newObject(C.PyObject_CallObject(f.obj, args.obj))
 }
 
 func (f Func) CallObjectKw(args Tuple, kw KwArgs) Object {
+	defer getCurrentThreadData().decRefObjectsIfNeeded()
 	// Convert keyword arguments to Python dict
 	kwDict := MakeDict(nil)
 	for k, v := range kw {
@@ -51,6 +53,7 @@ func (f Func) CallObjectKw(args Tuple, kw KwArgs) Object {
 func (f Func) Call(args ...any) Object {
 	argsTuple, kwArgs := splitArgs(args...)
 	if kwArgs == nil {
+		defer getCurrentThreadData().decRefObjectsIfNeeded()
 		switch len(args) {
 		case 0:
 			return f.callNoArgs()

object.go

@@ -15,6 +15,7 @@ import (
 // the Python Object's DecRef method during garbage collection.
 type pyObject struct {
 	obj *C.PyObject
+	gid int64
 }
 
 func (obj *pyObject) Obj() *PyObject {
@@ -54,11 +55,12 @@ func newObject(obj *PyObject) Object {
 		C.PyErr_Print()
 		panic("nil Python object")
 	}
-	o := &pyObject{obj: obj}
+	o := &pyObject{obj: obj, gid: getThreadID()}
 	p := Object{o}
+
 	runtime.SetFinalizer(o, func(o *pyObject) {
-		// TODO: need better auto-release mechanism
-		// C.Py_DecRef(o.obj)
+		maps := getThreadData(o.gid)
+		maps.addPyObject(o.obj)
 	})
 	return p
 }

python.go

@@ -21,9 +21,9 @@ func Initialize() {
 }
 
 func Finalize() {
+	cleanupThreadLocal()
 	r := C.Py_FinalizeEx()
 	check(r == 0, "failed to finalize Python")
-	cleanupThreadLocal()
 }
 
 // ----------------------------------------------------------------------------

thread_local.go

@@ -35,17 +35,59 @@ func (l *holderList) Remove(holder *objectHolder) {
 	}
 }
 
+type decRefList struct {
+	objects []*C.PyObject
+	mu      sync.Mutex
+}
+
+func (l *decRefList) add(obj *C.PyObject) {
+	l.mu.Lock()
+	l.objects = append(l.objects, obj)
+	l.mu.Unlock()
+}
+
+func (l *decRefList) decRefAll() {
+	var list []*C.PyObject
+
+	l.mu.Lock()
+	list = l.objects
+	l.objects = make([]*C.PyObject, 0, maxPyObjects*2)
+	l.mu.Unlock()
+
+	for _, obj := range list {
+		C.Py_DecRef(obj)
+	}
+}
+
 type threadData struct {
-	typeMetas map[*C.PyObject]*typeMeta
-	pyTypes   map[reflect.Type]*C.PyObject
-	holders   holderList
+	typeMetas  map[*C.PyObject]*typeMeta
+	pyTypes    map[reflect.Type]*C.PyObject
+	holders    holderList
+	decRefList decRefList
+}
+
+const maxPyObjects = 128
+
+func (td *threadData) addPyObject(obj *C.PyObject) {
+	td.decRefList.add(obj)
+}
+
+func (td *threadData) decRefObjectsIfNeeded() {
+	if len(td.decRefList.objects) > maxPyObjects {
+		td.decRefList.decRefAll()
+	}
 }
 
 var (
 	globalThreadData sync.Map // map[int64]*threadData
 )
 
 func getCurrentThreadData() *threadData {
+	id := getThreadID()
+	return getThreadData(id)
+}
+
+func getThreadData(gid int64) *threadData {
 	id := getThreadID()
 	maps, ok := globalThreadData.Load(id)
 	if !ok {