lily/smobs.cc

   1 /*
   2   smobs.cc -- implement Smob protection
   3
   4   source file of the GNU LilyPond music typesetter
   5
   6   (c) 2005--2009 Han-Wen Nienhuys <hanwen@xs4all.nl>
   7 */
   8
   9 #include "smobs.hh"
  10
  11 /*
  12   The CDR contains the actual protected list.
  13  */
  14 static SCM smob_protection_list = SCM_EOL;
  15
  16 void
  17 init_smob_protection ()
  18 {
  19   smob_protection_list = scm_cons (SCM_BOOL_F, SCM_EOL);
  20   scm_gc_protect_object (smob_protection_list);
  21 }
  22 ADD_SCM_INIT_FUNC (init_smob_protection, init_smob_protection);
  23
  24 LY_DEFINE (ly_smob_protects, "ly:smob-protects",
  25           0, 0, 0, (),
  26           "Return LilyPond's internal smob protection list.")
  27 {
  28   return scm_is_pair (smob_protection_list)
  29     ? scm_cdr (smob_protection_list)
  30     : SCM_EOL;
  31 }
  32
  33 void
  34 protect_smob (SCM smob, SCM *prot_cons)
  35 {
  36 #if 0
  37   SCM s = scm_cdr (smob_protection_list);
  38   while (scm_is_pair (s) && scm_car (s) == SCM_BOOL_F)
  39     {
  40       s = scm_cdr (s);
  41     }
  42   SCM prot = scm_cons (smob, s);
  43   scm_set_cdr_x (smob_protection_list,
  44                  prot);
  45   *prot_cons = prot;
  46 #else
  47   (void) prot_cons;
  48   scm_gc_protect_object (smob);
  49 #endif
  50 }
  51
  52 void
  53 unprotect_smob (SCM smob, SCM *prot_cons)
  54 {
  55 #if 1
  56   (void) prot_cons;
  57   scm_gc_unprotect_object (smob);
  58 #else
  59   SCM next = scm_cdr (*prot_cons);
  60
  61   if (next == SCM_EOL)
  62     scm_set_car_x (*prot_cons, SCM_BOOL_F);
  63   else
  64     {
  65       scm_set_car_x (*prot_cons, SCM_BOOL_F);
  66       while (scm_is_pair (next)
  67              && scm_car (next) == SCM_BOOL_F)
  68
  69         next = scm_cdr (next);
  70
  71       scm_set_cdr_x (*prot_cons, next);
  72     }
  73
  74   *prot_cons = SCM_EOL;
  75 #endif
  76 }