Xapian InMemoryDatabase Concurrent Control Problem

[Miao LIU]

Dear Members of Xapian Project,

    Sorry for troubling you this time. I am currently facing a challenge that I can not search and update Xapian "InMemoryDatabase" concurrently
via 2 different threads although I have added the critical area mutex which allows only reading/writing at one single time. More specifically,
along with the core dump, the error message was "double free or corruption (!prev): 0x000000000121f3b0" indicated a memory free problem was detected.
    Out of our expectations, the core dump happened when searching thread and writing thread accessed different docs respectively.

    Please feel free to give me any advice. Looking forward to your early reply.

Best Regards,
Miao