Aren
/
NetBSD
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Fix hash iteration that deletes the current element under the cursor by 

adjusting the position of the iterator appropriately.
XXX: pullup 7
This commit is contained in:
christos 2015-06-22 21:16:02 +00:00
parent 2906f58b81
commit 25bda9e7c1
1 changed files with 34 additions and 4 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

38
lib/libc/db/hash/hash.c
View File

@ -1,4 +1,4 @@
/* $NetBSD: hash.c,v 1.34 2015/06/22 18:50:06 christos Exp $ */
/* $NetBSD: hash.c,v 1.35 2015/06/22 21:16:02 christos Exp $ */
/*-
* Copyright (c) 1990, 1993, 1994
@ -37,7 +37,7 @@
#endif
#include <sys/cdefs.h>
__RCSID("$NetBSD: hash.c,v 1.34 2015/06/22 18:50:06 christos Exp $");
__RCSID("$NetBSD: hash.c,v 1.35 2015/06/22 21:16:02 christos Exp $");
#include "namespace.h"
#include <sys/param.h>
@ -690,6 +690,27 @@ found:
case HASH_DELETE:
if (__delpair(hashp, rbufp, ndx))
return (ERROR);
/*
* Our index lags 2 behind on the same page when we are
* deleting the element pointed to by the index; otherwise
* deleting randomly from an iterated hash produces undefined
* results.
*/
if (ndx != hashp->cndx - 2 || rbufp != hashp->cpage)
break;
if (hashp->cndx > 1) {
/* Move back one element */
hashp->cndx -= 2;
} else {
/*
* Move back one page, and indicate to go to the last
* element of the previous page by setting cndx to -1
*/
hashp->cbucket--;
hashp->cpage = NULL;
hashp->cndx = -1;
}
break;
default:
abort();
@ -725,7 +746,7 @@ next_bucket:
if (!(bufp = hashp->cpage)) {
for (bucket = hashp->cbucket;
bucket <= (uint32_t)hashp->MAX_BUCKET;
bucket++, hashp->cndx = 1) {
bucket++) {
bufp = __get_buf(hashp, bucket, NULL, 0);
if (!bufp)
return (ERROR);
@ -739,10 +760,18 @@ next_bucket:
hashp->cbucket = -1;
return (ABNORMAL);
}
if (hashp->cndx == -1) {
/* move to the last element of the page */
hashp->cndx = 1;
while (bp[hashp->cndx - 1] != 0)
hashp->cndx += 2;
} else {
/* start on the first element */
hashp->cndx = 1;
}
} else {
bp = (uint16_t *)(void *)hashp->cpage->page;
if (flag == R_NEXT || flag == 0) {
hashp->cndx += 2;
if (hashp->cndx > bp[0]) {
hashp->cpage = NULL;
hashp->cbucket++;
@ -781,6 +810,7 @@ next_bucket:
data->data = (uint8_t *)hashp->cpage->page + bp[ndx + 1];
data->size = bp[ndx] - bp[ndx + 1];
}
hashp->cndx += 2;
return (SUCCESS);
}