Various fixes for recent callback-related runtime changes

TODO.FACTOR.txt

@@ -37,6 +37,7 @@
 - better line spacing in ui
 - use vertex arrays and display lists to speed up ui
 - tabular formatting
+- don't multiplex in the event loop if there is no pending i/o
 
 + compiler/ffi:
 

native/compiler.c

@@ -18,7 +18,7 @@ void primitive_set_compiled_offset(void)
 {
 	CELL offset = unbox_unsigned_cell();
 	compiling.here = offset;
-	if(compiling.here > compiling.limit)
+	if(compiling.here >= compiling.limit)
 	{
 		fprintf(stderr,"Code space exhausted\n");
 		factorbug();

native/run.c

@@ -6,12 +6,8 @@ INLINE void execute(F_WORD* word)
 }
 
 /* Called from platform_run() */
-void init_errors(void)
+void handle_error(void)
 {
-	thrown_error = F;
-	
-	SETJMP(toplevel);
-	
 	if(throwing)
 	{
 		if(thrown_keep_stacks)
@@ -35,15 +31,23 @@ void init_errors(void)
 	}
 }
 
-void run_once(void)
+void run(bool handle_errors)
 {
 	CELL next;
 
+	if(handle_errors)
+	{
+		thrown_error = F;
+		SETJMP(toplevel);
+	}
+	
+	handle_error();
+	
 	for(;;)
 	{
 		if(callframe == F)
 		{
-			if(cs == cs_bot)
+			if(cs_bot - cs == CELLS)
 				return;
 
 			callframe = cpop();
@@ -70,17 +74,16 @@ void run_once(void)
 	}
 }
 
-void run(void)
+void run_toplevel(void)
 {
-	init_errors();
+	run(true);
-	run_once();
 }
 
 /* Called by compiled callbacks after nest_stacks() and boxing registers */
 void run_nullary_callback(CELL quot)
 {
 	call(quot);
-	run_once();
+	run(false);
 	unnest_stacks();
 }
 
@@ -91,7 +94,7 @@ CELL run_unary_callback(CELL quot)
 	
 	nest_stacks();
 	call(quot);
-	run_once();
+	run(false);
 	retval = dpeek();
 	unnest_stacks();
 	return retval;

native/run.h

@@ -78,7 +78,8 @@ INLINE void call(CELL quot)
 	callframe = quot;
 }
 
-void run(void);
+void run(bool handle_errors);
+void run_toplevel(void);
 void run_nullary_callback(CELL quot);
 CELL run_unary_callback(CELL quot);
 void platform_run(void);

native/unix/run.c

@@ -2,6 +2,6 @@
 
 void platform_run()
 {
-	run();
+	run_toplevel();
 }
 

native/win32/run.c

@@ -26,5 +26,5 @@ static long exception_handler(void *rec, void *frame, void *ctx, void *dispatch)
 
 void platform_run ()
 {
-	seh_call(run, exception_handler);
+	seh_call(run_toplevel, exception_handler);
 }