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  * This library is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Library General Public
  10  * License 2.0 as published by the Free Software Foundation;
  11  *
  12  * This library is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * Library General Public License for more details.
  16  *
  17  * You should have received a copy of the GNU Library General Public
  18  * License 2.0 along with this library; if not, write to the Free
  19  * Software Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  *
  21  *
  22  * Scans one object, using the OBJ_XXX macros.  The start of the
  23  * object must be given in the variable "char* start".  Afterwards,
  24  * "start" will point to the start of the next object, if the scanned
  25  * object contained references.  If not, the value of "start" should
  26  * be considered undefined after executing this code.  The object's
  27  * GC descriptor must be in the variable "mword desc".
  28  *
  29  * The macro `HANDLE_PTR` will be invoked for every reference encountered while scanning the
  30  * object.  It is called with two parameters: The pointer to the reference (not the
  31  * reference itself!) as well as the pointer to the scanned object.
  32  *
  33  * Modifiers (automatically undefined):
  34  *
  35  * SCAN_OBJECT_NOSCAN - if defined, don't actually scan the object,
  36  * i.e. don't invoke the OBJ_XXX macros.
  37  *
  38  * SCAN_OBJECT_NOVTABLE - desc is provided by the includer, instead of
  39  * vt.  Complex arrays cannot not be scanned.
  40  *
  41  * SCAN_OBJECT_PROTOCOL - if defined, binary protocol the scan.
  42  * Should only be used for scanning that's done for the actual
  43  * collection, not for debugging scans.
  44  */
  45
  46 {
  47 #ifndef SCAN_OBJECT_NOVTABLE
  48 #if defined(SGEN_HEAVY_BINARY_PROTOCOL) && defined(SCAN_OBJECT_PROTOCOL)
  49         binary_protocol_scan_begin ((GCObject*)start, SGEN_LOAD_VTABLE ((GCObject*)start), sgen_safe_object_get_size ((GCObject*)start));
  50 #endif
  51 #else
  52 #if defined(SGEN_HEAVY_BINARY_PROTOCOL) && defined(SCAN_OBJECT_PROTOCOL)
  53         binary_protocol_scan_vtype_begin (start + SGEN_CLIENT_OBJECT_HEADER_SIZE, size);
  54 #endif
  55 #endif
  56         switch (desc & DESC_TYPE_MASK) {
  57         case DESC_TYPE_RUN_LENGTH:
  58 #define SCAN OBJ_RUN_LEN_FOREACH_PTR (desc, ((GCObject*)start))
  59 #ifndef SCAN_OBJECT_NOSCAN
  60                 SCAN;
  61 #endif
  62 #undef SCAN
  63                 break;
  64         case DESC_TYPE_VECTOR:
  65 #define SCAN OBJ_VECTOR_FOREACH_PTR (desc, ((GCObject*)start))
  66 #ifndef SCAN_OBJECT_NOSCAN
  67                 SCAN;
  68 #endif
  69 #undef SCAN
  70                 break;
  71         case DESC_TYPE_BITMAP:
  72 #define SCAN OBJ_BITMAP_FOREACH_PTR (desc, ((GCObject*)start))
  73 #ifndef SCAN_OBJECT_NOSCAN
  74                 SCAN;
  75 #endif
  76 #undef SCAN
  77                 break;
  78         case DESC_TYPE_COMPLEX:
  79                 /* this is a complex object */
  80 #define SCAN OBJ_COMPLEX_FOREACH_PTR (desc, ((GCObject*)start))
  81 #ifndef SCAN_OBJECT_NOSCAN
  82                 SCAN;
  83 #endif
  84 #undef SCAN
  85                 break;
  86 #ifndef SCAN_OBJECT_NOVTABLE
  87         case DESC_TYPE_COMPLEX_ARR:
  88                 /* this is an array of complex structs */
  89 #define SCAN OBJ_COMPLEX_ARR_FOREACH_PTR (desc, ((GCObject*)start))
  90 #ifndef SCAN_OBJECT_NOSCAN
  91                 SCAN;
  92 #endif
  93 #undef SCAN
  94                 break;
  95 #endif
  96         case DESC_TYPE_SMALL_PTRFREE:
  97         case DESC_TYPE_COMPLEX_PTRFREE:
  98                 /*Nothing to do*/
  99                 break;
 100         default:
 101                 g_assert_not_reached ();
 102         }
 103 }
 104
 105 #undef SCAN_OBJECT_NOSCAN
 106 #undef SCAN_OBJECT_NOVTABLE
 107 #undef SCAN_OBJECT_PROTOCOL