* include/apr_dbm.h: Document that drivers don't guarantee

  cross-process/thread-safe locking for concurrent r/w use.


git-svn-id: https://svn.apache.org/repos/asf/apr/apr/trunk@1915093 13f79535-47bb-0310-9956-ffa450edef68

Author: notroj

include/apr_dbm.h

@@ -154,6 +154,11 @@ APR_DECLARE(apr_status_t) apr_dbm_open2(apr_dbm_t **pdb,
  * @param cntxt The pool to use when creating the dbm
  * @remark The dbm name may not be a true file name, as many dbm packages
  * append suffixes for separate data and index files.
+ * @warning DBM drivers do not guarantee thread-safe or cross-process
+ * locking; multiple threads or processes reading and writing
+ * concurrently to the database is not safe and results in
+ * undefined behaviour (likely database corruption and possible
+ * crashes).
  */
 APR_DECLARE(apr_status_t) apr_dbm_open(apr_dbm_t **dbm, const char *name,
                                        apr_int32_t mode, apr_fileperms_t perm,