temporarily set number of threads in octave to one, known issue shogu…

…n-toolbox#3772

src/interfaces/octave_modular/swig_typemaps.i

@@ -24,6 +24,10 @@
 #include <octave/Cell.h>
 
 #include <shogun/lib/DataType.h>
+
+// this is for the hack that sets the number of threads to 1 below
+// see #3772
+#include <shogun/io/SGIO.h>
 %}
 
 /* One dimensional input arrays */
@@ -114,7 +118,9 @@ TYPEMAP_OUT_SGVECTOR(uint16NDArray, uint16_t, uint16_t, "Word")
     const octave_value mat_feat=$input;
     if (!mat_feat.is_matrix_type() || !mat_feat.oct_type_check())
     {
-        /*SG_ERROR("Expected " error_string " Matrix as argument\n");*/
+        /*SG_ER%init %{
+	init_variables();
+%}ROR("Expected " error_string " Matrix as argument\n");*/
         SWIG_fail;
     }
 
@@ -486,3 +492,10 @@ TYPEMAP_SPARSEFEATURES_IN(float64_t,     Matrix)
 
 TYPEMAP_SPARSEFEATURES_OUT(float64_t,     NPY_FLOAT64)
 #undef TYPEMAP_SPARSEFEATURES_OUT
+
+%init %{
+	// set number of threads to 1
+	// see issue #3772
+	SG_SWARNING("Using Shogun single-threaded. Multi-threaded Octave is currently broken. See https://github.com/shogun-toolbox/shogun/issues/3772\n");
+	shogun::get_global_parallel()->set_num_threads(1);
+%}