On 23. mars 2015 09:56, Shu, Xinxin wrote:

MDB_BAD_RSLOT: Invalid reuse of reader locktable slot

What I want to know is in which situation this error occur? thanks

You started an RDONLY transaction in a thread which already has one. Either end the current RDONLY transaction first, or use MDB_NOTLS to allow multiple RDONLY transactions in a thread.

Or: The lockfile is screwed up. Maybe because you forked the process or opened the environment in a process where it was already open.

Either way, see lmdb.h for usage restrictions.