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Posted to dev@subversion.apache.org by David Glasser <gl...@davidglasser.net> on 2007/10/12 00:22:27 UTC
Threading in mod_dav_svn
I'm trying to track down some FSFS corruptions. I am looking at this
bit of mod_dav_svn/repos.c(getresource):
/* Retrieve/cache open repository */
repos_key = apr_pstrcat(r->pool, "mod_dav_svn:", fs_path, NULL);
apr_pool_userdata_get(&userdata, repos_key, r->connection->pool);
repos->repos = userdata;
if (repos->repos == NULL)
{
serr = svn_repos_open(&(repos->repos), fs_path, r->connection->pool);
if (serr != NULL)
{
/* The error returned by svn_repos_open might contain the
actual path to the failed repository. We don't want to
leak that path back to the client, because that would be
a security risk, but we do want to log the real error on
the server side. */
return dav_svn__sanitize_error(serr, "Could not open the requested "
"SVN filesystem",
HTTP_INTERNAL_SERVER_ERROR, r);
}
/* Cache the open repos for the next request on this connection */
apr_pool_userdata_set(repos->repos, repos_key,
NULL, r->connection->pool);
}
OK, so svn_repos_t's are cached inside the userdata of
"r->connection->pool". "r" here is a request_rec (defined in
httpd.h).
My question is: is it ever possible for multiple threads to be sharing
the same r->connection->pool?
Because if it is, then the threads will share the same repos, and thus
share the same svn_fs_t, and thus (for FSFS) the same
dir_cache/dir_cache_id/dir_cache_pool (not to mention the other caches
I added this week).
And access to these caches is neither atomic nor protected by a mutex.
Which certainly strikes me as bad.
So is it ever possible for two threads to share the same r->connection->pool?
--dave
--
David Glasser | glasser@davidglasser.net | http://www.davidglasser.net/
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Re: Threading in mod_dav_svn
Posted by Justin Erenkrantz <ju...@erenkrantz.com>.
On Oct 11, 2007 5:22 PM, David Glasser <gl...@davidglasser.net> wrote:
> So is it ever possible for two threads to share the same r->connection->pool?
No. -- justin
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