diff -r 9fa5be79bb77 -r 976841968d74 targets/Linux/plc_Linux_main.c
--- a/targets/Linux/plc_Linux_main.c	Fri Jun 01 15:46:17 2018 +0300
+++ b/targets/Linux/plc_Linux_main.c	Thu Jun 07 13:45:35 2018 +0300
@@ -82,6 +82,10 @@
 
 int PLC_shutdown = 0;
 
+int ForceSaveRetainReq(void) {
+    return PLC_shutdown;
+}
+
 void PLC_thread_proc(void *arg)
 {
     while (!PLC_shutdown) {
@@ -231,34 +235,3 @@
 {
     pthread_mutex_lock(&python_mutex);
 }
-
-#ifndef HAVE_RETAIN
-void InitRetain(void)
-{
-}
-
-void CleanupRetain(void)
-{
-}
-
-int CheckRetainBuffer(void)
-{
-	return 1;
-}
-
-void ValidateRetainBuffer(void)
-{
-}
-
-void InValidateRetainBuffer(void)
-{
-}
-
-void Retain(unsigned int offset, unsigned int count, void *p)
-{
-}
-
-void Remind(unsigned int offset, unsigned int count, void *p)
-{
-}
-#endif // !HAVE_RETAIN