--- a/src/test/twice.cc	Wed Feb 15 11:36:10 2017 +0900
+++ b/src/test/twice.cc	Wed Feb 15 12:34:19 2017 +0900
@@ -2,6 +2,9 @@
 #include <sys/time.h>
 #include <string.h>
 #include <stdlib.h>
+extern "C" {
+#include <pthread.h>
+}
 
 #include <cuda.h>
 
@@ -35,9 +38,12 @@
     }
 }
 
+int num_stream = 1; // number of stream
+int num_exec = 16; // number of executed kernel
+
+static void *start_cuda(void *) ;
+
 int main(int args, char* argv[]) {
-    int num_stream = 1; // number of stream
-    int num_exec = 16; // number of executed kernel
     
     for (int i=1;argv[i];i++) {
         if (strcmp(argv[i], "--stream") == 0 || strcmp(argv[i], "-s") == 0) {
@@ -47,7 +53,17 @@
             num_exec = atoi(argv[++i]);
         }
     }
+#if 0
+    start_cuda(NULL);
+#else
+    pthread_t thread;
+    pthread_create(&thread, NULL, start_cuda, NULL);
+    pthread_join(thread,NULL);
+#endif
+    return 0;
+}
 
+static void *start_cuda(void *args) {
     // initialize and load kernel
     CUdevice device;
     CUcontext context;
@@ -161,7 +177,6 @@
     for (int i=0;i<num_exec;i++)
         delete[] result[i];
     delete[] result;
-
     return 0;
 }