Guile GC behaviour

[Greg Badros <gjb at cs dot washington dot edu>]

I'd really appreciate some Guile guru's help on this.  I am trying to
investigate Scwm's memory leaks a bit more, and I'm confused about the
behaviour I'm seeing in Scwm when I evaluate this s-exp:

(let ((i 0))	
  (while (< i 100000)
	 (gc-stats)
	 (set! i (+ i 1))))


This causes Scwm's process image size to grow dramatically (this is
against guile-1.3.4). We evaluate the string in a fairly contorted way.
I'm also very interested in knowing what might be the "supported" way to
do this very normal task.

We use scwm_safe_eval_str:

SCM scwm_safe_eval_str (char *string)
{
  SCM_STACKITEM stack_item;
  return scm_internal_cwdr_no_unwind(scwm_body_eval_str, string,
				     scm_handle_by_message_noexit, "scwm", 
				     &stack_item);
}


and here is scwm_body_eval_str:

static SCM
scwm_body_eval_str (void *body_data)
{
  char *string = (char *) body_data;
  SCM port = scm_mkstrport (SCM_MAKINUM (0), gh_str02scm(string), 
			    SCM_OPN | SCM_RDNG, "scwm_safe_eval_str");
  return scwm_catching_load_from_port (port);
}


and here is scwm_catching_load_from_port:

__inline__ static SCM 
scwm_catching_load_from_port (SCM port)
{
  SCM expr;
  SCM answer = SCM_UNSPECIFIED;
  int i = 0;

  while (!SCM_EOF_OBJECT_P(expr = scm_read (port))) {  
    answer = scwm_catching_eval_x (expr);
    if (++i % clnsProcessingHook == 0) {
      call1_hooks(load_processing_hook, gh_int2scm(i));
    }
  }
  scm_close_port (port);

  return answer;
}


and here is scwm_catching_eval_x:

__inline__ static SCM 
scwm_catching_eval_x (SCM expr) {
  return scm_internal_stack_catch (SCM_BOOL_T, scwm_body_eval_x, &expr,
			  scwm_handle_error, "scwm");
}


Thanks for any suggestions and/or thoughts about this!

Greg