--- a/src/parallel_execution/context.h	Sun Sep 03 00:21:16 2017 +0900
+++ b/src/parallel_execution/context.h	Tue Sep 05 16:46:31 2017 +0900
@@ -137,6 +137,8 @@
         enum Code spawn;      // start NEW context on the worker
         enum Code spawnTasks; // start NEW tasks on the worker
         enum Code shutdown;
+        enum Code incrementTaskCount;
+        enum Code decrementTaskCount;
         enum Code next;
         enum Code next1;
         enum Code task;
@@ -153,6 +155,7 @@
         enum Code next;
         int numWorker;
         int sendWorkerIndex;
+        int taskCount;
         pthread_mutex_t mutex;
         struct Queue* activeQueue;
         struct Queue* taskQueue;
@@ -246,7 +249,6 @@
     } Element;
     struct Array {
         int size; 
-        int index; 
         int prefix; 
         int* array;
     } Array;