fix non-OpenMP mode

gridder_cxx.h

@@ -739,6 +739,9 @@ class Lock
     void lock() { omp_set_lock(&lck); }
     void unlock() { omp_unset_lock(&lck); }
   };
+int my_max_threads() { return omp_get_max_threads(); }
+int my_num_threads() { return omp_get_num_threads(); }
+int my_thread_num() { return omp_get_thread_num(); }
 #else
 class Lock
   {
@@ -746,8 +749,11 @@ class Lock
     Lock() {}
     ~Lock() {}
     void lock() {}
-    void unlock {}
+    void unlock() {}
   };
+int my_max_threads() { return 1; }
+int my_num_threads() { return 1; }
+int my_thread_num() { return 0; }
 #endif
 
 template<typename T, typename T2=complex<T>> class Helper
@@ -1315,7 +1321,11 @@ template<typename Serv> void wstack_common(
   double wmax;
 
   wminmax(gconf, srv, wmin, wmax);
+#ifdef _OPENMP
   if (verbosity>0) cout << "Using " << nthreads << " threads" << endl;
+#else
+  if (verbosity>0) cout << "Using single-threaded mode" << endl;
+#endif
   if (verbosity>0) cout << "W range: " << wmin << " to " << wmax << endl;
   double x0 = -0.5*gconf.Nxdirty()*gconf.Pixsize_x(),
          y0 = -0.5*gconf.Nydirty()*gconf.Pixsize_y();
@@ -1333,12 +1343,12 @@ template<typename Serv> void wstack_common(
   nvis_plane.resize(nplanes,0);
 
   minplane.resize(nplanes);
-  vector<size_t> tcnt(omp_get_max_threads()*nplanes,0);
+  vector<size_t> tcnt(my_max_threads()*nplanes,0);
 #pragma omp parallel num_threads(nthreads)
 {
   vector<size_t> mytcnt(nplanes,0);
   vector<size_t> nvp(nplanes,0);
-  auto mythread = omp_get_thread_num();
+  auto mythread = my_thread_num();
 #pragma omp for schedule(static)
   for (size_t ipart=0; ipart<nvis; ++ipart)
     {
@@ -1359,7 +1369,7 @@ template<typename Serv> void wstack_common(
   for (size_t j=0; j<nplanes; ++j)
     {
     size_t l=0;
-    for (size_t i=0; i<nthreads; ++i)
+    for (size_t i=0; i<my_num_threads(); ++i)
       l+=tcnt[i*nplanes+j];
     minplane[j].resize(l);
     }