kernel cleanup: add NUM_TYPES and T_DUMMY

src/boehm_gc.c

@@ -42,9 +42,7 @@
 
 
 
-enum { NTYPES = 256 };
-
-TNumInfoBags InfoBags[NTYPES];
+TNumInfoBags InfoBags[NUM_TYPES];
 
 UInt8 SizeAllBags;
 
@@ -59,7 +57,7 @@ static inline Bag * DATA(BagHeader * bag)
 *V  DSInfoBags[<type>]  . . . .  . . . . . . . . . .  region info for bags
 */
 
-static char DSInfoBags[NTYPES];
+static char DSInfoBags[NUM_TYPES];
 
 #define DSI_TL 0
 #define DSI_PUBLIC 1
@@ -101,7 +99,7 @@ Region * RegionBag(Bag bag)
 *F  InitFreeFuncBag(<type>,<free-func>)
 */
 
-TNumFreeFuncBags TabFreeFuncBags[NTYPES];
+TNumFreeFuncBags TabFreeFuncBags[NUM_TYPES];
 
 void InitFreeFuncBag(UInt type, TNumFreeFuncBags finalizer_func)
 {
@@ -291,7 +289,7 @@ void * AllocateMemoryBlock(UInt size)
     return GC_malloc(size);
 }
 
-int TabMarkTypeBags[NTYPES];
+int TabMarkTypeBags[NUM_TYPES];
 
 void InitMarkFuncBags(UInt type, TNumMarkFuncBags mark_func)
 {
@@ -320,7 +318,7 @@ void InitBags(UInt              initial_size,
     UInt i; /* loop variable                   */
 
     /* install the marking functions                                       */
-    for (i = 0; i < 255; i++) {
+    for (i = 0; i < NUM_TYPES; i++) {
         TabMarkTypeBags[i] = -1;
     }
 #ifndef DISABLE_GC

src/gap.c

@@ -914,7 +914,7 @@ Obj FuncGASMAN (
             Pr( "%40s ", (Int)"type",  0L          );
             Pr( "%8s %8s ",  (Int)"alive", (Int)"kbyte" );
             Pr( "%8s %8s\n",  (Int)"total", (Int)"kbyte" );
-            for ( UInt k = 0; k < 256; k++ ) {
+            for ( UInt k = 0; k < NUM_TYPES; k++ ) {
                 if ( InfoBags[k].name != 0 ) {
                     Char buf[41];
                     buf[0] = '\0';
@@ -935,7 +935,7 @@ Obj FuncGASMAN (
             Pr( "%40s ", (Int)"type",  0L          );
             Pr( "%8s %8s ",  (Int)"alive", (Int)"kbyte" );
             Pr( "%8s %8s\n",  (Int)"total", (Int)"kbyte" );
-            for ( UInt k = 0; k < 256; k++ ) {
+            for ( UInt k = 0; k < NUM_TYPES; k++ ) {
                 if ( InfoBags[k].name != 0 && 
                      (InfoBags[k].nrLive != 0 ||
                       InfoBags[k].sizeLive != 0 ||
@@ -957,7 +957,7 @@ Obj FuncGASMAN (
         /* if request display the statistics                               */
         else if ( strcmp( CSTR_STRING(cmd), "clear" ) == 0 ) {
 #ifdef COUNT_BAGS
-            for ( UInt k = 0; k < 256; k++ ) {
+            for ( UInt k = 0; k < NUM_TYPES; k++ ) {
 #ifdef GASMAN_CLEAR_TO_LIVE
                 InfoBags[k].nrAll    = InfoBags[k].nrLive;
                 InfoBags[k].sizeAll  = InfoBags[k].sizeLive;
@@ -1737,7 +1737,7 @@ StructInitInfo * InitInfoGap ( void )
 **  `PostRestore'.  This function is only used when restoring.
 */
 #ifdef USE_GASMAN
-extern TNumMarkFuncBags TabMarkFuncBags [ 256 ];
+extern TNumMarkFuncBags TabMarkFuncBags [ NUM_TYPES ];
 #endif
 
 static Obj POST_RESTORE;
@@ -1789,7 +1789,7 @@ void InitializeGap (
             Pr( "#W  %36s ", (Int)"type",  0L          );
             Pr( "%8s %8s ",  (Int)"alive", (Int)"kbyte" );
             Pr( "%8s %8s\n",  (Int)"total", (Int)"kbyte" );
-            for ( Int i = 0;  i < 256;  i++ ) {
+            for ( Int i = 0;  i < NUM_TYPES;  i++ ) {
                 if ( InfoBags[i].name != 0 && InfoBags[i].nrAll != 0 ) {
                     char    buf[41];
 

src/gasman.c

@@ -179,7 +179,7 @@
 **  returns the number  of words occupied  by the data  area and padding of a
 **  bag of size <size>.
 **
-**  A body in the workspace whose type byte contains the value 255 is the
+**  A body in the workspace whose type byte contains the value T_DUMMY is the
 **  remainder of a 'ResizeBag'. That is it consists either of the unused words
 **  after a bag has been shrunk, or of the old body of the bag after the
 **  contents of the body have been copied elsewhere for an extension. The
@@ -195,23 +195,25 @@
 **
 */
 
-#define SIZE_MPTR_BAGS  1
+enum {
+    SIZE_MPTR_BAGS = 1,
+
+    T_DUMMY = NUM_TYPES - 1,
+};
+
 
 static inline UInt WORDS_BAG(UInt size)
 {
     return (size + sizeof(Bag) - 1) / sizeof(Bag);
 }
 
-/* This could be 65536, but would waste memory in various tables */
-
-#define NTYPES 256
-
 
 static inline Bag *DATA(BagHeader *bag)
 {
     return (Bag *)(((char *)bag) + sizeof(BagHeader));
 }
 
+
 /****************************************************************************
 **
 *V  MptrBags  . . . . . . . . . . . . . . beginning of the masterpointer area
@@ -462,7 +464,7 @@ UInt                    NrHalfDeadBags;
 **
 *V  InfoBags[<type>]  . . . . . . . . . . . . . . . . .  information for bags
 */
-TNumInfoBags            InfoBags [ NTYPES ];
+TNumInfoBags            InfoBags [ NUM_TYPES ];
 
 /****************************************************************************
 **
@@ -505,7 +507,7 @@ void            InitMsgsFuncBags (
 *F  InitSweepFuncBags(<type>,<mark-func>)  . . . .  install sweeping function
 */
 
-static TNumSweepFuncBags TabSweepFuncBags[NTYPES];
+static TNumSweepFuncBags TabSweepFuncBags[NUM_TYPES];
 
 
 void InitSweepFuncBags (
@@ -537,7 +539,7 @@ void InitSweepFuncBags (
 **  by GASMAN as default.  This will allow to catch type clashes.
 */
 
-TNumMarkFuncBags TabMarkFuncBags [ NTYPES ];
+TNumMarkFuncBags TabMarkFuncBags [ NUM_TYPES ];
 
 void InitMarkFuncBags (
     UInt                type,
@@ -964,7 +966,7 @@ void FinishedRestoringBags( void )
 **
 **  'InitFreeFuncBag' is really too simple for an explanation.
 */
-static TNumFreeFuncBags TabFreeFuncBags[256];
+static TNumFreeFuncBags TabFreeFuncBags[NUM_TYPES];
 
 void            InitFreeFuncBag (
     UInt                type,
@@ -1182,7 +1184,7 @@ void            InitBags (
     AllocSizeBags = 256;
 
     /* install the marking functions                                       */
-    for ( i = 0; i < 255; i++ )
+    for ( i = 0; i < NUM_TYPES; i++ )
         TabMarkFuncBags[i] = MarkAllSubBagsDefault;
 
     /* Set ChangedBags to a proper initial value */
@@ -1248,6 +1250,8 @@ Bag NewBag (
         Panic("cannot extend the workspace any more!!!!");
     }
 
+    GAP_ASSERT(type < T_DUMMY);
+
 #ifdef COUNT_BAGS
     /* update the statistics                                               */
     NrAllBags               += 1;
@@ -1342,9 +1346,9 @@ void            RetypeBag (
 **  If  the bag  is  to be  shrunk  and at  least   one  word becomes   free,
 **  'ResizeBag'  changes  the  size word of  the bag, and stores a magic
 **  size-type word in  the first free word.  This  magic size-type  word  has
-**  type 255 and the size  is the number  of  following  free bytes, which is
-**  always divisible by 'sizeof(Bag)'.  The  type 255 allows 'CollectBags' to
-**  detect that  this body  is the remainder of a   resize operation, and the
+**  type T_DUMMY and the size is the number of following free bytes, which is
+**  always divisible by 'sizeof(Bag)'. The type T_DUMMY allows 'CollectBags'
+**  to detect that this body is the remainder of a resize operation, and the
 **  size allows  it  to know how  many  bytes  there  are  in this  body (see
 **  "Implementation of CollectBags").
 **
@@ -1369,9 +1373,9 @@ void            RetypeBag (
 **         \_____________
 **                       \
 **                        V
-**    +---------+---------+------------------------+----+---------+---------+
-**    | 10  . 7 |  <link> |         .         .    | pad|  4  .255|         |
-**    +---------+---------+------------------------+----+---------+---------+
+**    +---------+---------+------------------------+----+-------------+-----+
+**    | 10  . 7 |  <link> |         .         .    | pad| 4 . T_DUMMY |     |
+**    +---------+---------+------------------------+----+-------------+-----+
 **
 **  If the bag is to be extended and it  is that last  allocated bag, so that
 **  it  is  immediately adjacent  to the allocation  area, 'ResizeBag' simply
@@ -1382,7 +1386,7 @@ void            RetypeBag (
 **  'ResizeBag'  first allocates a  new bag  similar to 'NewBag', but without
 **  using  a new masterpointer.   Then it copies the old  contents to the new
 **  bag.  Finally it resets the masterpointer of the bag to  point to the new
-**  address.  Then it changes the type of the old body  to  255,  so that the
+**  address. Then it changes the type of the old body to T_DUMMY, so that the
 **  garbage collection can detect that this body is the remainder of a resize
 **  (see "Implementation of NewBag" and "Implementation of CollectBags").
 **
@@ -1441,9 +1445,9 @@ UInt ResizeBag (
     // memory may not be zero filled, and zeroing it out would cost us
     else if ( diff < 0 ) {
 
-        // leave magic size-type word for the sweeper, type must be 255
+        // leave magic size-type word for the sweeper, type must be T_DUMMY
         BagHeader * freeHeader = (BagHeader *)(DATA(header) + WORDS_BAG(new_size));
-        freeHeader->type = 255;
+        freeHeader->type = T_DUMMY;
         if ( diff == -1 ) {
             // if there is only one free word, avoid setting the size in
             // the header: there is no space for it on 32bit systems;
@@ -1505,8 +1509,8 @@ UInt ResizeBag (
         // update header pointer in case bag moved
         header = BAG_HEADER(bag);
 
-        // leave magic size-type word  for the sweeper, type must be 255
-        header->type = 255;
+        // leave magic size-type word  for the sweeper, type must be T_DUMMY
+        header->type = T_DUMMY;
         header->flags = 0;
         header->size = sizeof(BagHeader) + (WORDS_BAG(old_size) - 1) * sizeof(Bag);
 #if SIZEOF_VOID_P == 4
@@ -1697,9 +1701,9 @@ UInt ResizeBag (
 **  initially   point to  the   beginning  of  the   young bags area.    Then
 **  'CollectBags' looks at the body pointed to by the source pointer.
 **
-**  If this body has type 255, it is the remainder of a resize operation.  In
-**  this case 'CollectBags' simply moves the source pointer to the  next body
-**  (see "Implementation of ResizeBag").
+**  If this body has type T_DUMMY, it is the remainder of a resize operation.
+**  In this case 'CollectBags' simply moves the source pointer to the next
+**  body (see "Implementation of ResizeBag").
 **
 **
 **  Otherwise, if the  link word contains the  identifier of the bag  itself,
@@ -1993,7 +1997,7 @@ UInt CollectBags (
         BagHeader * header = (BagHeader *)src;
 
         /* leftover of a resize of <n> bytes                               */
-        if ( header->type == 255 ) {
+        if ( header->type == T_DUMMY ) {
 
             /* advance src                                                 */
             if (header->flags == 1)

src/gasman.h

@@ -93,6 +93,17 @@ typedef struct {
 } BagHeader;
 
 
+/****************************************************************************
+**
+**  'NUM_TYPES' is the maximal number of different types supported, and
+**  depends on the number of bits in the type member of struct BagHeader.
+**  It must be a power of two.
+*/
+enum {
+    NUM_TYPES = 256,
+};
+
+
 /****************************************************************************
 **
 *F  BAG_HEADER(<bag>) . . . . . . . . . . . . . . . . . . . . header of a bag

src/objects.c

@@ -1503,7 +1503,7 @@ Obj FuncIS_IDENTICAL_OBJ (
 **  No saving function may allocate any bag
 */
 
-void (*SaveObjFuncs[256]) ( Obj obj );
+void (*SaveObjFuncs[LAST_REAL_TNUM+1]) ( Obj obj );
 
 void SaveObjError( Obj obj )
 {
@@ -1528,7 +1528,7 @@ void SaveObjError( Obj obj )
 **  No loading function may allocate any bag
 */
 
-void (*LoadObjFuncs[256]) ( Obj obj );
+void (*LoadObjFuncs[LAST_REAL_TNUM+1]) ( Obj obj );
 
 void LoadObjError( Obj obj )
 {
@@ -1872,7 +1872,7 @@ Obj FuncDEBUG_TNUM_NAMES(Obj self)
 {
     UInt indentLvl = 0;
     Char indentStr[20] = "";
-    for (UInt k = 0; k < 256; k++) {
+    for (UInt k = 0; k < NUM_TYPES; k++) {
         START_SYMBOLIC_TNUM(FIRST_REAL_TNUM);
         START_SYMBOLIC_TNUM(FIRST_CONSTANT_TNUM);
         START_SYMBOLIC_TNUM(FIRST_MULT_TNUM);

src/objects.h

@@ -591,7 +591,7 @@ extern Int IsInternallyMutableObj(Obj obj);
 **  No saving function may allocate any bag.
 */
 
-extern void (*SaveObjFuncs[256]) ( Obj obj );
+extern void (*SaveObjFuncs[LAST_REAL_TNUM+1]) ( Obj obj );
 
 extern void SaveObjError( Obj obj );
 
@@ -611,7 +611,7 @@ extern void SaveObjError( Obj obj );
 **  No loading function may allocate any bag.
 */
 
-extern void (*LoadObjFuncs[256]) ( Obj obj );
+extern void (*LoadObjFuncs[LAST_REAL_TNUM+1]) ( Obj obj );
 
 extern void LoadObjError( Obj obj );
 
@@ -710,7 +710,7 @@ extern Obj CopyObj (
 **  already unmarked object, it should simply return.
 */
 #if !defined(USE_THREADSAFE_COPYING)
-extern Obj (*CopyObjFuncs[LAST_REAL_TNUM+COPYING+1]) ( Obj obj, Int mut );
+extern Obj (*CopyObjFuncs[LAST_COPYING_TNUM+1]) ( Obj obj, Int mut );
 #endif
 
 
@@ -719,7 +719,7 @@ extern Obj (*CopyObjFuncs[LAST_REAL_TNUM+COPYING+1]) ( Obj obj, Int mut );
 *V  CleanObjFuncs[<type>] . . . . . . . . . . . . table of cleaning functions
 */
 #if !defined(USE_THREADSAFE_COPYING)
-extern void (*CleanObjFuncs[LAST_REAL_TNUM+COPYING+1]) ( Obj obj );
+extern void (*CleanObjFuncs[LAST_COPYING_TNUM+1]) ( Obj obj );
 #endif