mono/sgen/sgen-scan-object.h

   1 /*
   2  * sgen-scan-object.h: Generic object scan.
   3  *
   4  * Copyright 2001-2003 Ximian, Inc
   5  * Copyright 2003-2010 Novell, Inc.
   6  * Copyright (C) 2013 Xamarin Inc
   7  *
   8  * Licensed under the MIT license. See LICENSE file in the project root for full license information.
   9  *
  10  *
  11  * Scans one object, using the OBJ_XXX macros.  The start of the
  12  * object must be given in the variable "char* start".  Afterwards,
  13  * "start" will point to the start of the next object, if the scanned
  14  * object contained references.  If not, the value of "start" should
  15  * be considered undefined after executing this code.  The object's
  16  * GC descriptor must be in the variable "mword desc".
  17  *
  18  * The macro `HANDLE_PTR` will be invoked for every reference encountered while scanning the
  19  * object.  It is called with two parameters: The pointer to the reference (not the
  20  * reference itself!) as well as the pointer to the scanned object.
  21  *
  22  * Modifiers (automatically undefined):
  23  *
  24  * SCAN_OBJECT_NOSCAN - if defined, don't actually scan the object,
  25  * i.e. don't invoke the OBJ_XXX macros.
  26  *
  27  * SCAN_OBJECT_NOVTABLE - desc is provided by the includer, instead of
  28  * vt.  Complex arrays cannot not be scanned.
  29  *
  30  * SCAN_OBJECT_PROTOCOL - if defined, binary protocol the scan.
  31  * Should only be used for scanning that's done for the actual
  32  * collection, not for debugging scans.
  33  */
  34
  35 {
  36 #ifndef SCAN_OBJECT_NOVTABLE
  37 #if defined(SGEN_HEAVY_BINARY_PROTOCOL) && defined(SCAN_OBJECT_PROTOCOL)
  38         binary_protocol_scan_begin ((GCObject*)start, SGEN_LOAD_VTABLE ((GCObject*)start), sgen_safe_object_get_size ((GCObject*)start));
  39 #endif
  40 #else
  41 #if defined(SGEN_HEAVY_BINARY_PROTOCOL) && defined(SCAN_OBJECT_PROTOCOL)
  42         binary_protocol_scan_vtype_begin (start + SGEN_CLIENT_OBJECT_HEADER_SIZE, size);
  43 #endif
  44 #endif
  45         switch (desc & DESC_TYPE_MASK) {
  46         case DESC_TYPE_RUN_LENGTH:
  47 #define SCAN OBJ_RUN_LEN_FOREACH_PTR (desc, ((GCObject*)start))
  48 #ifndef SCAN_OBJECT_NOSCAN
  49                 SCAN;
  50 #endif
  51 #undef SCAN
  52                 break;
  53         case DESC_TYPE_VECTOR:
  54 #define SCAN OBJ_VECTOR_FOREACH_PTR (desc, ((GCObject*)start))
  55 #ifndef SCAN_OBJECT_NOSCAN
  56                 SCAN;
  57 #endif
  58 #undef SCAN
  59                 break;
  60         case DESC_TYPE_BITMAP:
  61 #define SCAN OBJ_BITMAP_FOREACH_PTR (desc, ((GCObject*)start))
  62 #ifndef SCAN_OBJECT_NOSCAN
  63                 SCAN;
  64 #endif
  65 #undef SCAN
  66                 break;
  67         case DESC_TYPE_COMPLEX:
  68                 /* this is a complex object */
  69 #define SCAN OBJ_COMPLEX_FOREACH_PTR (desc, ((GCObject*)start))
  70 #ifndef SCAN_OBJECT_NOSCAN
  71                 SCAN;
  72 #endif
  73 #undef SCAN
  74                 break;
  75 #ifndef SCAN_OBJECT_NOVTABLE
  76         case DESC_TYPE_COMPLEX_ARR:
  77                 /* this is an array of complex structs */
  78 #define SCAN OBJ_COMPLEX_ARR_FOREACH_PTR (desc, ((GCObject*)start))
  79 #ifndef SCAN_OBJECT_NOSCAN
  80                 SCAN;
  81 #endif
  82 #undef SCAN
  83                 break;
  84 #endif
  85         case DESC_TYPE_SMALL_PTRFREE:
  86         case DESC_TYPE_COMPLEX_PTRFREE:
  87                 /*Nothing to do*/
  88                 break;
  89         default:
  90                 g_assert_not_reached ();
  91         }
  92 }
  93
  94 #undef SCAN_OBJECT_NOSCAN
  95 #undef SCAN_OBJECT_NOVTABLE
  96 #undef SCAN_OBJECT_PROTOCOL