On Mon, Dec 22, 2014 at 1:01 PM, Ivan Zhakov <i...@visualsvn.com> wrote:
> On 17 July 2014 at 18:00, <stef...@apache.org> wrote: > > Author: stefan2 > > Date: Thu Jul 17 15:00:33 2014 > > New Revision: 1611380 > > > > URL: http://svn.apache.org/r1611380 > > Log: > > Work around for the poor performance of APR reader / writer locks on > Windows. > > Basically, fall back to 1.7 code on Win32 by using a simple mutex. > > > > This resulted in a 35% increase in throughput for a 'null-export' over > > ra_serf from hot SVN caches with revprop caching enabled. OTOH, this may > > cost us some scalability with ra_svn on high-speed (>1Gb) networks. > > > > * subversion/libsvn_subr/cache-membuffer.c > > (USE_SIMPLE_MUTEX): New flag. Set depending on whether we need to fall > > back to a simple locking scheme. > > (svn_membuffer_t): Select lock type at compile time. > > (read_lock_cache, > > write_lock_cache, > > force_write_lock_cache, > > unlock_cache): Use the simple mutex lock when selected. > > (svn_cache__membuffer_cache_create): Initialize the correct lock type > and > > disable the counter_mutex if > redundant. > > > > Modified: > > subversion/trunk/subversion/libsvn_subr/cache-membuffer.c > > > [...] > > @@ -674,6 +712,12 @@ static svn_error_t * > > unlock_cache(svn_membuffer_t *cache, svn_error_t *err) > > { > > #if APR_HAS_THREADS > > +# if USE_SIMPLE_MUTEX > > + > > + return svn_mutex__unlock(cache->lock, SVN_NO_ERROR); > > + > > +# else > > + > > if (cache->lock) > > { > > apr_status_t status = apr_thread_rwlock_unlock(cache->lock); > > @@ -683,6 +727,8 @@ unlock_cache(svn_membuffer_t *cache, svn > > if (status) > > return svn_error_wrap_apr(status, _("Can't unlock cache mutex")); > > } > > + > > +# endif > > #endif > > return err; > > } > The provided ERR argument is ignored in USE_SIMPLE_MUTEX codepath. So > any error from cache serializer will be ignored and invalid result > will be used. > Thanks for fixing! -- Stefan^2.
