diff options
| -rw-r--r-- | lib/libc/stdlib/malloc.c | 56 |
1 files changed, 24 insertions, 32 deletions
diff --git a/lib/libc/stdlib/malloc.c b/lib/libc/stdlib/malloc.c index 84ca2be7183..0d1b2290be5 100644 --- a/lib/libc/stdlib/malloc.c +++ b/lib/libc/stdlib/malloc.c @@ -1,4 +1,4 @@ -/* $OpenBSD: malloc.c,v 1.129 2011/04/30 15:46:46 otto Exp $ */ +/* $OpenBSD: malloc.c,v 1.130 2011/05/05 12:11:20 otto Exp $ */ /* * Copyright (c) 2008 Otto Moerbeek <otto@drijf.net> * @@ -113,6 +113,7 @@ struct dir_info { struct region_info free_regions[MALLOC_MAXCACHE]; /* delayed free chunk slots */ void *delayed_chunks[MALLOC_DELAYED_CHUNKS + 1]; + u_short chunk_start; #ifdef MALLOC_STATS size_t inserts; size_t insert_collisions; @@ -1013,40 +1014,31 @@ malloc_bytes(struct dir_info *d, size_t size) if (bp->canary != d->canary1) wrterror("chunk info corrupted", NULL); - /* Find first word of bitmap which isn't empty */ - for (lp = bp->bits; !*lp; lp++) - /* EMPTY */; - - /* Find that bit, and tweak it */ - u = 1; - k = 0; - while (!(*lp & u)) { - u += u; - k++; - } - /* advance a random # of positions */ - if (bp->free > 1) { - i = getrnibble() % bp->free; - while (i > 0) { - u += u; - k++; - if (k >= MALLOC_BITS) { - while (!*++lp) - /* EMPTY */; - u = 1; - k = 0; - if (lp - bp->bits > (bp->total - 1) / - MALLOC_BITS) { - wrterror("chunk overflow", NULL); - errno = EFAULT; - return (NULL); - } - } - if (*lp & u) - i--; + i = d->chunk_start; + if (bp->free > 1) + i += getrnibble(); + if (i >= bp->total) + i &= bp->total - 1; + for (;;) { + for (;;) { + lp = &bp->bits[i / MALLOC_BITS]; + if (!*lp) { + i += MALLOC_BITS; + i &= ~(MALLOC_BITS - 1); + if (i >= bp->total) + i = 0; + } else + break; } + k = i % MALLOC_BITS; + u = 1 << k; + if (*lp & u) + break; + if (++i >= bp->total) + i = 0; } + d->chunk_start += i + 1; *lp ^= u; |