Re: [ANNOUNCE] CGit v0.1-pre

On Mon, 11 Dec 2006, Lars Hjemli wrote:

Ok. Code speeks louder than words, so I'll blatantly paste the key functions:

Yeah, they're still buggy:

int cache_unlock(struct cacheitem *item)
{
	close(item->fd);
	return (rename(fmt("%s.lock", item->name), item->name) == 0);
}

...

	if (!cache_exist(item)) {
		if (!cache_lock(item)) {
			sleep(1);
			goto top;
		}
		if (!cache_exist(item))
			cgit_fill_cache(item);
		cache_unlock(item);

What do you think happens if that last "cache_exist()" returned true?

That's right: the "cache_unlock()" will now OVERWRITE the valid cache with 
the (empty) lock-file that you didn't fill in.

Oops.

So you really have two different cases:

 - the "I created the file" case: rename lockfile to final name
 - the "somebody else created the file": remove the lockfile

and you can't use the same "cache_unlock()" for both of them.