--- a/src/parallel_execution/SingleLinkedQueue.cbc	Wed Jan 27 13:44:47 2021 +0900
+++ b/src/parallel_execution/SingleLinkedQueue.cbc	Wed Jan 27 16:22:19 2021 +0900
@@ -1,5 +1,6 @@
 #include "../context.h"
 #include <stdio.h>
+#include "state_db.h"
 #impl "Queue.h" for "SingleLinkedQueue.h"
 #data "Node.h"
 #data "Element.h"
@@ -92,3 +93,42 @@
     }
     return queue->top;
 }
+
+
+typedef struct task_iterator {
+    struct task_iterator *prev;
+    StateDB state;
+    Element* list;
+    Element* last;
+} TaskIterator, *TaskIteratorPtr;
+
+
+Element* createQueueIterator(struct SingleLinkedQueue* queue) {
+    TaskIteratorPtr new = (TaskIteratorPtr)malloc(sizeof(TaskIterator));
+    if (!new) exit(1);
+
+    new->prev  = queue->top;
+    new->state = NULL;
+    new->list  = queue->top;
+    new->last  = queue->last;
+    return new;
+}
+
+Element* takeNextIterator(struct SingleLinkedQueue* queue, TaskIteratorPtr iterator) {
+  struct Element* elem = iterator->list;
+  if (!elem) {
+    return NULL;
+  }
+
+  struct Element* next = elem->next;
+  if (next == NULL) {
+    return next;
+  }
+
+  if (next == iterator->last) {
+    return NULL;
+  }
+
+  iterator->list = next;
+  return next;
+}

--- a/src/parallel_execution/examples/DPPMC/AtomicTImpl.cbc	Wed Jan 27 13:44:47 2021 +0900
+++ b/src/parallel_execution/examples/DPPMC/AtomicTImpl.cbc	Wed Jan 27 16:22:19 2021 +0900
@@ -14,14 +14,14 @@
 
 }
 
-__code checkAndSet_AtomicT_intImpl(struct AtomicT_intImpl_int* atomicT_int, int oldData, int newData, __code next(...), __code fail(...)) {
+__code checkAndSet(struct AtomicT_intImpl_int* atomicT_int, int oldData, int newData, __code next(...), __code fail(...)) {
     if (__sync_bool_compare_and_swap(&atomicT_int->atomic, oldData, newData)) {
         goto next(...);
     }
     goto fail(...);
 }
 
-__code set_AtomicT_intImpl(struct AtomicT_intImpl_int* atomicT_int, int newData, __code next(...) ) {
+__code set(struct AtomicT_intImpl_int* atomicT_int, int newData, __code next(...) ) {
 	atomicT_int->atomic = newData;
    goto next(...);
 }

--- a/src/parallel_execution/generate_stub.pl	Wed Jan 27 13:44:47 2021 +0900
+++ b/src/parallel_execution/generate_stub.pl	Wed Jan 27 16:22:19 2021 +0900
@@ -156,10 +156,15 @@
                 $generic{$name}  = [];
             } elsif (/^(\w+)(\*)+ create(\w+)\(/) { # this case implementation constructor
                 debug_print("getDataGear",__LINE__, $_) if $opt_debug;
-              #if (defined $implInterfaceInfo->{interface} ) {
-              #     die "duplicate interface $implInterfaceInfo->{interface}\n";
-              #  }
+                #if (defined $implInterfaceInfo->{interface} ) {
+                #   die "duplicate interface $implInterfaceInfo->{interface}\n";
+                #}
                 my $interfaceName = $1;
+                if ($implInterfaceInfo->{interface}) {
+                  if ($implInterfaceInfo->{interface} ne $interfaceName) {
+                    next;
+                  }
+                }
                 $implInterfaceInfo->{isImpl} = 1;
                 $implInterfaceInfo->{interface} = $interfaceName;
                 $implInterfaceInfo->{implementation} = $3;
@@ -646,6 +651,10 @@
             } elsif(/^#impl "(.*)"/) {
               debug_print("generateDataGear",__LINE__, $_) if $opt_debug;
               next unless ($implInterfaceInfo->{genConstructor});
+              if ((!$implInterfaceInfo->{genConstructor}) || $implInterfaceInfo->{interface} ne $1) {
+                next;
+              }
+
 
               my $constructInterface = {
                                          name      => $implInterfaceInfo->{interface},