From 7be1d57200e9672910ae0cef74ee0074e171dbf1 Mon Sep 17 00:00:00 2001
From: Joshua Judson Rosen
Date: Sun, 26 Mar 2017 22:24:41 -0400
Subject: Invert GTK+/guile thread relationship

Making the GTK+ thread the main thread, and subordinating the guile thread,
lets the GUI continue to live after the robot has died--
which means that we'll be able to switch to just doing
everything in the GUI without requiring a separate xterm
to see the final stats after the robot dies.
---
 include/ui-window.h |  2 +-
 src/main.c          | 67 ++++++++++++++++++++++++++++-------------------------
 src/ui-window.c     | 13 +++++++----
 3 files changed, 45 insertions(+), 37 deletions(-)

diff --git a/include/ui-window.h b/include/ui-window.h
index d9740a2..c8fa337 100644
--- a/include/ui-window.h
+++ b/include/ui-window.h
@@ -54,7 +54,7 @@ struct _UIWindowClass
 GType ui_window_get_type(void) G_GNUC_CONST;
 
 GtkWidget *ui_window_new();
-void ui_window_postinit(UIWindow *window, Map* map);
+void ui_window_postinit(UIWindow *window, Map* volatile* map);
 
 G_END_DECLS
 
diff --git a/src/main.c b/src/main.c
index 8710ca1..f8ea6d4 100644
--- a/src/main.c
+++ b/src/main.c
@@ -49,9 +49,13 @@ GList *robots = NULL;
 GRobot *robot = NULL;		/* The current robot */
 UIWindow *ui;
 UIArena *arena;
-Map *map;
+Map *map = NULL;
+gboolean loading = TRUE;
+volatile gboolean *ploading = &loading;
 
-gpointer callback(gpointer data);
+gpointer callback_scm(gpointer data);
+void gui_init();
+void gui_main();
 SCM catch_handler(void *data, SCM tag, SCM throw_args);
 gint is_file_readable(const gchar * filename);
 
@@ -67,6 +71,7 @@ gint main(gint argc, gchar *argv[])
 
 	gchar maps_path[MAX_PATH], scripts_path[MAX_PATH];
 
+	static
 	gchar *main_argv[5] = { "GNU Robots",
 		NULL,
 		NULL,
@@ -252,7 +257,20 @@ gint main(gint argc, gchar *argv[])
 		main_argv[2] = "";
 	}
 
+	gui_init();
+
+	g_thread_unref(g_thread_new(NULL, callback_scm, main_argv));
+
+	gui_main();
+
+	return 0;				/* never gets here, but keeps compiler happy */
+}
+
+gpointer callback_scm(gpointer data)
+{
 	/* Start Guile environment.  Does not exit */
+	char **main_argv = data;
+
 	g_printf("%s\n", PKGINFO);
 	g_printf("%s\n", COPYRIGHT);
 	g_printf("GNU Robots comes with ABSOLUTELY NO WARRANTY\n");
@@ -264,7 +282,7 @@ gint main(gint argc, gchar *argv[])
 
 	scm_boot_guile(3, main_argv, main_prog, NULL);
 
-	return 0;				/* never gets here, but keeps compiler happy */
+	return NULL; /* never gets here, but keeps compiler happy */
 }
 
 /************************************************************************
@@ -278,8 +296,6 @@ void main_prog(void *closure, gint argc, gchar *argv[])
 {
 	gchar *map_file = argv[1];
 	gchar *robot_program = argv[2];
-	gboolean loading = TRUE;
-	volatile gboolean *ploading = &loading;
 
 	api_init();
 
@@ -293,9 +309,6 @@ void main_prog(void *closure, gint argc, gchar *argv[])
 		exit_nicely();
 	}
 
-	gdk_threads_init();
-	g_thread_unref(g_thread_new(NULL, callback, &loading));
-
 	/* ensure the robot is placed properly */
 	MAP_SET_OBJECT(map, G_ROBOT_POSITION_Y(robot),
 		G_ROBOT_POSITION_X(robot), ROBOT);
@@ -339,27 +352,33 @@ void main_prog(void *closure, gint argc, gchar *argv[])
 	exit_nicely();
 }
 
-gpointer callback(gpointer data)
+void gui_init()
 {
+	g_printf("Loading GTK Interface ... Please wait\n\n");
+
+	gdk_threads_init();
+	gdk_threads_enter();
 	gtk_init(0, NULL);
 
 	ui = UI_WINDOW(ui_window_new());
-	ui_window_postinit(ui, map);
-
 	arena = UI_ARENA(ui->priv->arena);
+	gdk_threads_leave();
+}
+
+void gui_main()
+{
+	gdk_threads_enter();
+	ui_window_postinit(ui, &map); /* waits for guile to load map... */
 
 	/* draw the map */
 	ui_arena_draw(arena);
 	ui_arena_update_status(arena, "Welcome to GNU Robots",
 	                       robot->energy, robot->score, robot->shields);
 
-	*(gboolean*)data = FALSE;
+	*ploading = FALSE;
 
-	gdk_threads_enter();
 	gtk_main();
 	gdk_threads_leave();
-
-	return NULL;
 }
 
 /************************************************************************
@@ -410,27 +429,12 @@ void exit_nicely()
 {
 	glong score, energy, shields, shots, units;
 
-	/* Stop the UI */
-	if (ui != NULL)
-	{
-		g_object_unref(G_OBJECT(ui));
-	}
-
-	/* Get rid of the map object */
-	if (map != NULL)
-	{
-		g_object_unref(G_OBJECT(map));
-	}
-
 	/* Show statistics */
 	g_object_get(G_OBJECT(robot),
 		"shields", &shields,
 		"energy", &energy,
 		"units", &units, "shots", &shots, "score", &score, NULL);
 
-	g_list_foreach(robots, (GFunc) g_object_unref, NULL);
-	g_list_free(robots);
-
 	g_printf(
 		"\n-----------------------STATISTICS-----------------------\n");
 	g_printf("Shields: %ld\n", (shields < 0 ? 0 : shields));
@@ -450,8 +454,7 @@ void exit_nicely()
 		g_printf("** Robot ran out of energy.\n");
 	}
 
-	/* Quit program */
-	exit(0);
+	g_thread_exit(0);
 }
 
 /************************************************************************
diff --git a/src/ui-window.c b/src/ui-window.c
index fb6f2ed..e923c24 100644
--- a/src/ui-window.c
+++ b/src/ui-window.c
@@ -56,16 +56,21 @@ static void ui_window_init(UIWindow *window)
 
 	gtk_window_set_title(GTK_WINDOW(window), "GNU Robots");
 	gtk_window_set_resizable(GTK_WINDOW(window), FALSE);
+
+	window->priv->cmdwin = ui_cmdwin_new();
+	window->priv->arena = ui_arena_new();
 }
 
-void ui_window_postinit(UIWindow *window, Map* map)
+void ui_window_postinit(UIWindow *window, Map* volatile* map)
 {
 	GtkWidget *vbox;
 
 	vbox = gtk_vbox_new(FALSE, 2);
-	window->priv->cmdwin = ui_cmdwin_new();
-	window->priv->arena = ui_arena_new();
-	ui_arena_set_map(UI_ARENA(window->priv->arena), map);
+
+	while(!*map); /* wait for map object creation by guile thread */
+
+	/* ... because we need guile to load the map before we do this: */
+	ui_arena_set_map(UI_ARENA(window->priv->arena), *map);
 
 	/* TODO: Add menu first etc */
 	gtk_box_pack_start(GTK_BOX(vbox), window->priv->arena, TRUE, TRUE, 0);
-- 
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