--- a/src/parallel_execution/generate_stub.pl	Thu Feb 02 18:29:50 2017 +0900
+++ b/src/parallel_execution/generate_stub.pl	Thu Feb 02 20:27:56 2017 +0900
@@ -149,11 +149,12 @@
 
     my $prevCodeGearName;
     my $inTypedef = 0;
+    my $inStub = 0;
     my %stub;
     my $codeGearName;
 
     while (<$in>) {
-        if (! $inTypedef) {
+        if (! $inTypedef && ! $inStub) {
             if (/^typedef struct (\w+) {/) {
                 $inTypedef = 1;
             } elsif (/^\_\_code (\w+)\((.*)\)(.*)/) {
@@ -162,6 +163,7 @@
                 my $tail = $3;
                 if ($codeGearName =~ /_stub$/) {
                     # don't touch already existing stub
+                    $inStub = 1;
                     $stub{$codeGearName} = 1;
                     print $fd $_;
                     next;
@@ -170,10 +172,10 @@
                     # stub is generated just before next CodeGear
                     if (defined $stub{$prevCodeGearName."_stub"}) {
                         undef $prevCodeGearName;
-                        print $fd $_;
-                        next;
+                    } else {
+                        &generateStub($fd,$prevCodeGearName,$dataGearName{$prevCodeGearName});
+                        $stub{$prevCodeGearName."_stub"} = 1;
                     }
-                    $stub{$prevCodeGearName."_stub"} = &generateStub($fd,$prevCodeGearName,$dataGearName{$prevCodeGearName});
                 }
                 # analyzing CodeGear argument
                 #      these arguments are extract from current context's arugment DataGear Interface
@@ -239,24 +241,27 @@
                 }
                 next;
             } elsif (/^(.*)goto (\w+)\((.*)\);/) {
-                # handling got statement  
+                # handling goto statement  
                 # convert it to the meta call form with two arugments, that is context and enum Code
                 my $prev = $1;
                 my $next = $2;
                 my @args = split(/,/,$3);
-                # write continuation's arguments into the interface arguments
-                # we may need a commit for a shared DataGear
-                for my $arg ( @{$outputArgs{$codeGearName}->{$next}} ) {
-                    my $v = shift(@args);
-                    print $fd "\t*O_$arg = $v;\n";
+                if (defined $code{$interface}->{$next}) { 
+                    # write continuation's arguments into the interface arguments
+                    # we may need a commit for a shared DataGear
+                    for my $arg ( @{$outputArgs{$codeGearName}->{$next}} ) {
+                        my $v = shift(@args);
+                        print $fd "\t*O_$arg = $v;\n";
+                    }
+                    print $fd "${prev}goto meta(context, $next);\n";
+                    next;
                 }
-                print $fd "${prev}goto meta(context, $next);\n";
-                next;
             } else {
                 s/new\s+(\w+)\(\)/\&ALLOCATE(context, \1)->\1/g;   # replacing new
             }
         # gather type name and type
         } elsif (/^}/) {
+            $inStub = 0;
             $inTypedef = 0;
         }
         print $fd $_;