zzgrim@gmail.com wrote:

Full_Name: zgrim Version: 2.4.40 OS: Linux URL: ftp://ftp.openldap.org/incoming/ Submission from: (NULL) (79.115.186.237)

Hello, thank you for lmdb. I'm using lmdb via a Go wrapper and under some not-yet-clear circumstances, under high concurrency stress testing, I sometimes get "double free or corruption" SIGABRT related to mdb_dbis_update(). The setup is using the NOTLS and RDONLY flags on a 64bit 3.17.0 Arch Linux system. If I protect the free() inside mdb_dbis_update() (in mdb.c) with a mutex (code inline below), the symptom disappears. I'm sorry I can't provide a simple test case, but in my code, without the mutex, launching some tens of test clients simultaneously trigger the corruption fairly quick, i.e. a few minutes or even seconds.

Sounds like you have not read the mdb_dbi_open() doc closely. The code in mdb_dbis_update() only triggers if you've opened new DBs in a transaction. The doc for mdb_dbi_open() specifically says you cannot call it from multiple concurrent transactions.

Closing this ITS.