void *xmgetblk(int i)
{
int j,w,*m,*q,**r;
w = i << 3; /* number of words */
/*
* allocate block
*/
/* M01.01a.0708.01 */
if( i >= MAXQUICK )
{
dbggtblk++ ;
return( NULL ) ;
}
if( *(r = &root[i]) )
{
/* there is an item on the list */
m = *r; /* get 1st item on list */
*r = *((int **) m); /* root pts to next item */
}
else
{ /* nothing on list, try pool */
if ( (m = getosm(w+1)) ) /* add size of control word */
*m++ = i; /* put size in control word */
}
/*
* zero out the block
*/
if( (q = m) )
for( j = 0 ; j < w ; j++ )
*q++ = 0;
return(m);
}
/*
* xmgetblk - get a block of memory from the o/s pool.
*
* First try to get a block from the 'fast' list, anchored by root[4],
* a list of blocks of size 64 bytes. This list is singly linked and
* blocks are deleted/removed in LIFO order from the root. If there
* are no free blocks on the list, we call getosm to get a block from
* the os memory pool.
*
* If we cannot get memory for an MDBLOCK, we return NULL (the request
* will fail). Otherwise we will attempt to free up DNDs to make space
* and if that fails, the system will be halted.
*
* Arguments:
* memtype: the type of request
*/
void *xmgetblk(WORD memtype)
{
WORD i, j, w, *m, *q, **r;
if ((memtype < MEMTYPE_MDBLOCK) || (memtype > MEMTYPE_OFD))
{
dbggtblk++;
return NULL;
}
/*
* allocate block
*/
i = 4; /* always from root[4] */
w = 32; /* number of words */
/*
* we should execute the following loop a maximum of twice: the second
* time only if we're allocating a DMD/DND/OFD & no memory is available
*/
for (j = 0; ; j++)
{
if ( *(r = &root[i]) ) /* there is an item on the free list */
{
m = *r; /* get first item on list */
*r = *((WORD **) m); /* root points to next item */
break;
}
/* nothing on free list, try pool */
if ( (m = getosm(w+1)) ) /* include size of control word */
{
*m++ = i; /* put size in control word */
break;
}
/* no memory available for an MDBLOCK, that's (sort of) OK */
if (memtype == MEMTYPE_MDBLOCK)
break;
/*
* no memory for DMD/DND/OFD, try to get some
*
* note defensive programming: if free_available_dnds() said it
* worked, but we're here again, then it lied and we should quit
* to avoid an infinite loop
*/
if ((j >= 2) || (free_available_dnds() == 0))
{
kcprintf(_("\033EOut of internal memory.\nUse FOLDR100.PRG to get more.\nSystem halted!\n"));
halt(); /* halt system */
}
}
/*
* zero out the block
*/
if ( (q = m) )
for (j = 0; j < w; j++)
*q++ = 0;
return m;
}
