Category : C Source Code
Archive   : HEAPMAN.ZIP
Filename : COMPACTH.C

#include "mm.h"

CompactHeap()

/*
This function defragments the heap. It accomplishes this by first
sorting the mpt addresses highest to lowest. Next, it checks allocated
blocks looking for gaps between them. If any gaps are found, it then
moves one or more blocks to close the gap.

calling params:
none

return params:
err | noErr

Author: Byro
Created: 01/11/91
Modified: 01/24/91 (debug phase)
Revision: (enhancement, bug fix info; date, who, nature of change)
*/

{
long *baseAdrs = NIL,
*lastHighest = NIL,
*nuAdrs = NIL;
void SortMPT();
dataStruct *tmpPtr = NIL;

extern long *gTableSizeCountAdrs,
*gTopOfHeap;

lastHighest = gTopOfHeap;
SortMPT();

/* pt to highest blk of mem */

baseAdrs = gTableSizeCountAdrs;
baseAdrs++;
nuAdrs = (long *) *baseAdrs;

/* parse through mpt looking for gaps */

while (nuAdrs != NIL)
{
tmpPtr = (dataStruct *) *nuAdrs; /* look at data blk */

/* check for gap */

if (lastHighest != (long *) (tmpPtr->blkSize + tmpPtr))
{
/* gap detected! */

if (MoveHigh(&nuAdrs, lastHighest) != NO_ERR)
return(COMPACT_HEAP);

if (UpdateBlk(nuAdrs, MINUS_ONE) != NO_ERR)
return(COMPACT_HEAP);
}

lastHighest = (long *) *nuAdrs; /* look for next gap */
nuAdrs++;
nuAdrs = (long *) *nuAdrs; /* pt to next lowest adrs */
}
return(NO_ERR);
}