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.  The action can use the macro
  15  * "SCAN" to scan the object.
  16  */
  17
  18 #ifndef SCAN_OBJECT_ACTION
  19 #define SCAN_OBJECT_ACTION
  20 #endif
  21
  22 {
  23         GCVTable *vt;
  24         size_t skip_size;
  25         mword desc;
  26
  27         vt = (GCVTable*)LOAD_VTABLE (start);
  28         //type = vt->desc & 0x7;
  29
  30         /* gcc should be smart enough to remove the bounds check, but it isn't:( */
  31         desc = vt->desc;
  32         switch (desc & 0x7) {
  33         case DESC_TYPE_STRING:
  34                 STRING_SIZE (skip_size, start);
  35 #define SCAN
  36                 SCAN_OBJECT_ACTION;
  37 #undef SCAN
  38                 start += skip_size;
  39                 break;
  40         case DESC_TYPE_RUN_LENGTH:
  41                 OBJ_RUN_LEN_SIZE (skip_size, desc, start);
  42                 g_assert (skip_size);
  43 #define SCAN OBJ_RUN_LEN_FOREACH_PTR (desc, start)
  44 #ifndef SCAN_OBJECT_NOSCAN
  45                 SCAN;
  46 #endif
  47                 SCAN_OBJECT_ACTION;
  48 #undef SCAN
  49                 start += skip_size;
  50                 break;
  51         case DESC_TYPE_ARRAY:
  52         case DESC_TYPE_VECTOR:
  53                 skip_size = safe_object_get_size ((MonoObject*)start);
  54                 skip_size += (ALLOC_ALIGN - 1);
  55                 skip_size &= ~(ALLOC_ALIGN - 1);
  56 #define SCAN OBJ_VECTOR_FOREACH_PTR (vt, start)
  57 #ifndef SCAN_OBJECT_NOSCAN
  58                 SCAN;
  59 #endif
  60                 SCAN_OBJECT_ACTION;
  61 #undef SCAN
  62                 start += skip_size;
  63                 break;
  64         case DESC_TYPE_SMALL_BITMAP:
  65                 OBJ_BITMAP_SIZE (skip_size, desc, start);
  66                 g_assert (skip_size);
  67 #define SCAN OBJ_BITMAP_FOREACH_PTR (desc, start)
  68 #ifndef SCAN_OBJECT_NOSCAN
  69                 SCAN;
  70 #endif
  71                 SCAN_OBJECT_ACTION;
  72 #undef SCAN
  73                 start += skip_size;
  74                 break;
  75         case DESC_TYPE_LARGE_BITMAP:
  76                 skip_size = safe_object_get_size ((MonoObject*)start);
  77                 skip_size += (ALLOC_ALIGN - 1);
  78                 skip_size &= ~(ALLOC_ALIGN - 1);
  79 #define SCAN OBJ_LARGE_BITMAP_FOREACH_PTR (vt,start)
  80 #ifndef SCAN_OBJECT_NOSCAN
  81                 SCAN;
  82 #endif
  83                 SCAN_OBJECT_ACTION;
  84 #undef SCAN
  85                 start += skip_size;
  86                 break;
  87         case DESC_TYPE_COMPLEX:
  88                 /* this is a complex object */
  89                 skip_size = safe_object_get_size ((MonoObject*)start);
  90                 skip_size += (ALLOC_ALIGN - 1);
  91                 skip_size &= ~(ALLOC_ALIGN - 1);
  92 #define SCAN OBJ_COMPLEX_FOREACH_PTR (vt, start)
  93 #ifndef SCAN_OBJECT_NOSCAN
  94                 SCAN;
  95 #endif
  96                 SCAN_OBJECT_ACTION;
  97 #undef SCAN
  98                 start += skip_size;
  99                 break;
 100         case DESC_TYPE_COMPLEX_ARR:
 101                 /* this is an array of complex structs */
 102                 skip_size = safe_object_get_size ((MonoObject*)start);
 103                 skip_size += (ALLOC_ALIGN - 1);
 104                 skip_size &= ~(ALLOC_ALIGN - 1);
 105 #define SCAN OBJ_COMPLEX_ARR_FOREACH_PTR (vt, start)
 106 #ifndef SCAN_OBJECT_NOSCAN
 107                 SCAN;
 108 #endif
 109                 SCAN_OBJECT_ACTION;
 110 #undef SCAN
 111                 start += skip_size;
 112                 break;
 113         default:
 114                 g_assert_not_reached ();
 115         }
 116 }
 117
 118 #undef SCAN_OBJECT_NOSCAN
 119 #undef SCAN_OBJECT_ACTION