mono/metadata/sgen-scan-object.h

   1 /*
   2  * Scans one object, using the OBJ_XXX macros.  The start of the
   3  * object must be given in the variable "char* start".  Afterwards,
   4  * "start" will point to the start of the next object.
   5  *
   6  * Modifiers (automatically undefined):
   7  *
   8  * SCAN_OBJECT_NOSCAN - if defined, don't actually scan the object,
   9  * i.e. don't invoke the OBJ_XXX macros.
  10  *
  11  * SCAN_OBJECT_ACTION - is invoked after an object has been scanned.
  12  * The object's start is "start", its length in bytes (including
  13  * padding at the end) is "skip_size".  "desc" is the object's GC
  14  * descriptor.
  15  */
  16
  17 #ifndef SCAN_OBJECT_ACTION
  18 #define SCAN_OBJECT_ACTION
  19 #endif
  20
  21 {
  22         GCVTable *vt;
  23         size_t skip_size;
  24         mword desc;
  25
  26         vt = (GCVTable*)LOAD_VTABLE (start);
  27         //type = vt->desc & 0x7;
  28
  29         /* gcc should be smart enough to remove the bounds check, but it isn't:( */
  30         desc = vt->desc;
  31         switch (desc & 0x7) {
  32         case DESC_TYPE_STRING:
  33                 STRING_SIZE (skip_size, start);
  34                 SCAN_OBJECT_ACTION;
  35                 start += skip_size;
  36                 break;
  37         case DESC_TYPE_RUN_LENGTH:
  38                 OBJ_RUN_LEN_SIZE (skip_size, desc, start);
  39                 g_assert (skip_size);
  40 #ifndef SCAN_OBJECT_NOSCAN
  41                 OBJ_RUN_LEN_FOREACH_PTR (desc, start);
  42 #endif
  43                 SCAN_OBJECT_ACTION;
  44                 start += skip_size;
  45                 break;
  46         case DESC_TYPE_ARRAY:
  47         case DESC_TYPE_VECTOR:
  48                 skip_size = safe_object_get_size ((MonoObject*)start);
  49                 skip_size += (ALLOC_ALIGN - 1);
  50                 skip_size &= ~(ALLOC_ALIGN - 1);
  51 #ifndef SCAN_OBJECT_NOSCAN
  52                 OBJ_VECTOR_FOREACH_PTR (vt, start);
  53 #endif
  54                 SCAN_OBJECT_ACTION;
  55                 start += skip_size;
  56                 break;
  57         case DESC_TYPE_SMALL_BITMAP:
  58                 OBJ_BITMAP_SIZE (skip_size, desc, start);
  59                 g_assert (skip_size);
  60 #ifndef SCAN_OBJECT_NOSCAN
  61                 OBJ_BITMAP_FOREACH_PTR (desc, start);
  62 #endif
  63                 SCAN_OBJECT_ACTION;
  64                 start += skip_size;
  65                 break;
  66         case DESC_TYPE_LARGE_BITMAP:
  67                 skip_size = safe_object_get_size ((MonoObject*)start);
  68                 skip_size += (ALLOC_ALIGN - 1);
  69                 skip_size &= ~(ALLOC_ALIGN - 1);
  70 #ifndef SCAN_OBJECT_NOSCAN
  71                 OBJ_LARGE_BITMAP_FOREACH_PTR (vt,start);
  72 #endif
  73                 SCAN_OBJECT_ACTION;
  74                 start += skip_size;
  75                 break;
  76         case DESC_TYPE_COMPLEX:
  77                 /* this is a complex object */
  78                 skip_size = safe_object_get_size ((MonoObject*)start);
  79                 skip_size += (ALLOC_ALIGN - 1);
  80                 skip_size &= ~(ALLOC_ALIGN - 1);
  81 #ifndef SCAN_OBJECT_NOSCAN
  82                 OBJ_COMPLEX_FOREACH_PTR (vt, start);
  83 #endif
  84                 SCAN_OBJECT_ACTION;
  85                 start += skip_size;
  86                 break;
  87         case DESC_TYPE_COMPLEX_ARR:
  88                 /* this is an array of complex structs */
  89                 skip_size = safe_object_get_size ((MonoObject*)start);
  90                 skip_size += (ALLOC_ALIGN - 1);
  91                 skip_size &= ~(ALLOC_ALIGN - 1);
  92 #ifndef SCAN_OBJECT_NOSCAN
  93                 OBJ_COMPLEX_ARR_FOREACH_PTR (vt, start);
  94 #endif
  95                 SCAN_OBJECT_ACTION;
  96                 start += skip_size;
  97                 break;
  98         default:
  99                 g_assert_not_reached ();
 100         }
 101 }
 102
 103 #undef SCAN_OBJECT_NOSCAN
 104 #undef SCAN_OBJECT_ACTION