Re: Resizing of LMDB map

Daniel Kraft wrote:

Hi!

I'm trying to use LMDB in a way that automatically resizes the map whenever it becomes too small, i.e. a function fails with MDB_MAP_FULL. I've created and attached a program that resembles my real usecase in a very simplified fashion: It just writes data to the database, and tries to double the map size whenever MDB_MAP_FULL is received.

However, for me this program (as well as my real code) produces a segfault in the mdb_put call that follows after the first resize. What am I doing wrong here, and how can I correctly implement a resize when full?

You're attempting to use the txn after committing it. This is basically a use-after-free attempt, which is why you get a SEGV.