It seems that we can not change the registryProtocol to be singleton. If we do...

It seems that we can not change the registryProtocol to be singleton. If we do tthat, the listen, speciall zk registry listener doesn't work.

registry/protocol/protocol.go

@@ -338,10 +338,10 @@ func setProviderUrl(regURL *common.URL, providerURL *common.URL) {
 }
 
 func GetProtocol() protocol.Protocol {
-	if regProtocol == nil {
-		regProtocol = newRegistryProtocol()
+	if regProtocol != nil {
+		return regProtocol
 	}
-	return regProtocol
+	return newRegistryProtocol()
 }
 
 type wrappedInvoker struct {

registry/protocol/protocol_test.go

@@ -291,8 +291,3 @@ func TestExportWithApplicationConfig(t *testing.T) {
 	v2, _ := regProtocol.bounds.Load(getCacheKey(newUrl))
 	assert.NotNil(t, v2)
 }
-
-func TestGetProtocol(t *testing.T) {
-	singleton := GetProtocol()
-	assert.True(t, singleton == GetProtocol())
-}