Re: pack-objects: Fix segfault when object count is less than thread count
- From
Nicolas Pitre <nico@cam.org>
- Date
- Jan 21, 2008, 16:07 UTC
- Message-ID
- <alpine.LFD.1.00.0801211103480.20753@xanadu.home>
- In-Reply-To
- <1200926145-14625-1-git-send-email-vsu@altlinux.ru>
On Mon, 21 Jan 2008, Sergey Vlasov wrote:
Show 5 quoted lines
> When partitioning the work amongst threads, dividing the number of > objects by the number of threads may return 0 when there are less > objects than threads; this will cause the subsequent code to segfault > when accessing list[sub_size-1]. Fix this by ensuring that sub_size > is not zero if there is at least one object to process.
No. Forcing one object in a thread is counter productive since it won't have anything to delta against. Instead, the thread should be allowed to have zero objects and let the other threads have more.
This patch would be a proper fix:
diff --git a/builtin-pack-objects.c b/builtin-pack-objects.c index ec10238..d3efeff 100644 --- a/builtin-pack-objects.c +++ b/builtin-pack-objects.c @@ -1672,7 +1672,8 @@ static void ll_find_deltas(struct object_entry **list, unsigned list_size, p[i].data_ready = 0; /* try to split chunks on "path" boundaries */ - while (sub_size < list_size && list[sub_size]->hash && + while (sub_size && sub_size < list_size && + list[sub_size]->hash && list[sub_size]->hash == list[sub_size-1]->hash) sub_size++;