Defer cache initialization to first usage: mod_dav_svn may have to  call svn_fs_set_cache_config() more than once if the Apache config contains multiple caching related parameters (not today, but in the near future). Also, this reduces the memory footprint if not all server instances actually access FSFS repositories.
Defer cache initialization to first usage: mod_dav_svn may have to 
call svn_fs_set_cache_config() more than once if the Apache config
contains multiple caching related parameters (not today, but in the
near future). Also, this reduces the memory footprint if not all server
instances actually access FSFS repositories.

* subversion/libsvn_fs_util/caching.c
  (svn_fs__get_global_membuffer_cache): make it thread-safe and 
   allow for concurrent initialization.
  (svn_fs_set_cache_config): don't create caches as a side-effect.

jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion,jmckaskill/subversion