void context::reset()
{
reset_datastack();
reset_retainstack();
reset_callstack();
reset_context_objects();
}
/* called on entry into a compiled callback */
void factor_vm::nest_stacks(stack_frame *magic_frame)
{
context *new_ctx = alloc_context();
new_ctx->callstack_bottom = (stack_frame *)-1;
new_ctx->callstack_top = (stack_frame *)-1;
/* note that these register values are not necessarily valid stack
pointers. they are merely saved non-volatile registers, and are
restored in unnest_stacks(). consider this scenario:
- factor code calls C function
- C function saves ds/cs registers (since they're non-volatile)
- C function clobbers them
- C function calls Factor callback
- Factor callback returns
- C function restores registers
- C function returns to Factor code */
new_ctx->datastack_save = ds;
new_ctx->retainstack_save = rs;
new_ctx->magic_frame = magic_frame;
/* save per-callback special_objects */
new_ctx->current_callback_save = special_objects[OBJ_CURRENT_CALLBACK];
new_ctx->catchstack_save = special_objects[OBJ_CATCHSTACK];
new_ctx->next = ctx;
ctx = new_ctx;
reset_datastack();
reset_retainstack();
}
void context::fix_stacks() {
if (datastack + sizeof(cell) < datastack_seg->start ||
datastack + stack_reserved >= datastack_seg->end)
reset_datastack();
if (retainstack + sizeof(cell) < retainstack_seg->start ||
retainstack + stack_reserved >= retainstack_seg->end)
reset_retainstack();
}
void fix_stacks()
{
if(datastack + sizeof(cell) < datastack_region->start
|| datastack + stack_reserved >= datastack_region->end)
reset_datastack();
if(retainstack + sizeof(cell) < retainstack_region->start
|| retainstack + stack_reserved >= retainstack_region->end)
reset_retainstack();
}
void factor_vm::fix_stacks()
{
if(ds + sizeof(cell) < ds_bot || ds + stack_reserved >= ds_top) reset_datastack();
if(rs + sizeof(cell) < rs_bot || rs + stack_reserved >= rs_top) reset_retainstack();
}