gwyn@brl-tgr.ARPA (Doug Gwyn <gwyn>) (06/28/85)
BUG FIXES for UNIX System V Release 2.0 libmalloc.a (-lmalloc),
lines added or changed flagged with "DAG", lines omitted "...":
/* @(#)malloc.c 1.5 */
...
char *
malloc(nbytes)
unsigned nbytes;
{
register struct header *blk;
register unsigned nb; /* size of entire block we need */
char *sbrk();
/* on first call, initialize */
if (freeptr[0].nextfree == GROUND) { /* DAG -- clarify */
...
/* temporarily alter maxfast, to avoid
infinite recursion */
maxfast = 0;
holdhead = (struct holdblk **)
malloc(sizeof(struct holdblk *)*
(fastct + 1));
if (holdhead == 0) /* DAG -- bug fix */
return malloc(nbytes); /* DAG leave maxfast==0 */
for(i=1; i<=fastct; i++) { /* DAG -- cosmetic */
...
/* check that a very large request won't cause an inf. loop */
/* DAG NOTE -- following does not work on Gould due to cc bug */
/* DAG -- bug fix next line (casts were omitted): */
if ((char *)freeptr[1].nextblk - (char *)&freeptr[1] < nb)
return NULL;
{
...
/* get memory */
if ((int)sbrk(nget) == -1) { /* DAG */
return NULL;
}
/* add to arena */
...
#endif
if ((int)sbrk(nget) == -1) { /* DAG */
return NULL;
}
/* block must be word aligned */
...
assert(((int)newblk%ALIGNSZ) == 0);
if ((int)sbrk(nget) == -1) { /* DAG */
return NULL;
}
/* combine with last block, put in arena */
...
CHECKQ;
/* DAG -- following statement block added as bug fix: */
{ register struct lblk *lblk =
(struct lblk *)((char *)blk + minhead - MINHEAD);
lblk->header.nextfree = CLRSMAL( lblk->header.nextfree );
}
return (char *)blk + minhead;
}
...
void
free(ptr)
char *ptr;
{
register struct holdblk *holdblk; /* block holding blk */
register struct holdblk *oldhead; /* former head of the hold
block queue containing
blk's holder */
if ( ptr == NULL ) /* DAG -- added safety net */
return; /* DAG */
/* DAG -- bug fix: */
if (TESTSMAL(((struct lblk *)(ptr - MINHEAD))->header.holder)) {
...
struct mallinfo
mallinfo()
{
...
/* examine space in holding blks */
if (holdhead != 0) /* DAG -- bug fix */
for (i=fastct; i>0; i--) { /* loop thru ea. chain */
hblk = holdhead[i];
if (hblk != HGROUND) { /* do only if chain not empty */
/* DAG -- following statement moved, bug fix */
size = hblk->blksz + sizeof(struct lblk) - sizeof(int);
do { /* loop thru 1 hold blk chain */
...
rstalloc()
{
/* struct header *temp; /* DAG -- unused */
/* temp = arena; /* DAG -- unused */
...
if(freeptr[0].nextfree == GROUND) return; /* DAG -- clarify */
brk(CLRBUSY(arena[1].nextblk));
freeptr[0].nextfree = GROUND; /* DAG -- clarify */
}
#endif /*RSTALLOC*/