Let all 3 modules built with Glib use max number of cores by default like the OMP case.

Author: joa-quim

doc/rst/source/explain_core.rst_

@@ -1,2 +1,3 @@
 **-x**\ [[-]\ *n*] :ref:`(more ...) <core_full>`
-    Limit number of cores used in multi-threaded algorithms (OpenMP required).
+    Limit number of cores used in multi-threaded algorithms (OpenMP required for most of modules,
+    or Glib for grdfilter, gmt|grdgravmag3d).

src/grdfilter.c

@@ -893,6 +893,11 @@ static int parse (struct GMT_CTRL *GMT, struct GRDFILTER_CTRL *Ctrl, struct GMT_
 		}
 	}
 
+#ifdef HAVE_GLIB_GTHREAD
+	/* Make the default equal to the OMP case where we use all threads if not stated otherwise. */
+	if (!GMT->common.x.active) GMT->common.x.n_threads = gmtlib_get_num_processors();
+#endif
+
 	n_errors += gmt_M_check_condition (GMT, !Ctrl->G.active, "Option -G: Must specify output file\n");
 	n_errors += gmt_M_check_condition (GMT, !Ctrl->In.file, "Must specify input file\n");
 	n_errors += gmt_M_check_condition (GMT, !Ctrl->D.active, "Option -D: Choose from p or 0-5\n");

src/potential/gmtgravmag3d.c

@@ -252,7 +252,7 @@ static int usage (struct GMTAPI_CTRL *API, int level) {
 	return (GMT_MODULE_USAGE);
 }
 
-static int parse (struct GMT_CTRL *GMT, struct GMTGRAVMAG3D_CTRL *Ctrl, struct GMT_OPTION *options) {
+static int parse(struct GMT_CTRL *GMT, struct GMTGRAVMAG3D_CTRL *Ctrl, struct GMT_OPTION *options) {
 
 	/* This parses the options provided to gmtgravmag3d and sets parameters in Ctrl.
 	 * Note Ctrl has already been initialized and non-zero default values set.
@@ -453,6 +453,11 @@ static int parse (struct GMT_CTRL *GMT, struct GMTGRAVMAG3D_CTRL *Ctrl, struct G
 		}
 	}
 
+#ifdef HAVE_GLIB_GTHREAD
+	/* Make the default equal to the OMP case where we use all threads if not stated otherwise. */
+	if (!GMT->common.x.active) GMT->common.x.n_threads = gmtlib_get_num_processors();
+#endif
+
 	n_errors += gmt_M_check_condition(GMT, Ctrl->S.active && (Ctrl->S.radius <= 0.0 || gmt_M_is_dnan (Ctrl->S.radius)),
 	                                  "Option -S: Radius is NaN or negative\n");
 	n_errors += gmt_M_check_condition(GMT, !Ctrl->T.active && !Ctrl->M.active, "Options -T or -M are mandatory\n");

src/potential/grdgravmag3d.c

@@ -262,7 +262,7 @@ static int usage (struct GMTAPI_CTRL *API, int level) {
 	return (GMT_MODULE_USAGE);
 }
 
-static int parse (struct GMT_CTRL *GMT, struct GRDGRAVMAG3D_CTRL *Ctrl, struct GMT_OPTION *options) {
+static int parse(struct GMT_CTRL *GMT, struct GRDGRAVMAG3D_CTRL *Ctrl, struct GMT_OPTION *options) {
 
 	/* This parses the options provided to grdgravmag3d and sets parameters in Ctrl.
 	 * Note Ctrl has already been initialized and non-zero default values set.
@@ -448,6 +448,11 @@ static int parse (struct GMT_CTRL *GMT, struct GRDGRAVMAG3D_CTRL *Ctrl, struct G
 		}
 	}
 
+#ifdef HAVE_GLIB_GTHREAD
+	/* Make the default equal to the OMP case where we use all threads if not stated otherwise. */
+	if (!GMT->common.x.active) GMT->common.x.n_threads = gmtlib_get_num_processors();
+#endif
+
 	n_errors += gmt_M_check_condition(GMT, !Ctrl->In.file[0], "Must specify input file\n");
 	n_errors += gmt_M_check_condition(GMT, Ctrl->S.active && (Ctrl->S.radius <= 0.0 || gmt_M_is_dnan(Ctrl->S.radius)),
 	                                "Option -S: Radius is NaN or negative\n");