From: Zardosht Kasheff
Date: April 14 2012 3:25pm
Subject: crash we've seen in TC_LOG_MMAP::unlog
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Hello all,

When we run our mysql-test suite with a large number of parallel
threads, sometimes we see a crash in TC_LOG_MMAP::unlog:

int TC_LOG_MMAP::unlog(ulong cookie, my_xid xid)
{
  PAGE *p=pages+(cookie/tc_log_page_size);

The problem is that for some mysterious reason, tc_log_page_size is
set to 0, causing a divide by 0 error. We never see this if we run the
test suite serially.

The test simply creates a transaction does inserts into two engines,
each of which support XA, and commits.

Has anyone seen this before? I am hoping this is a known issues, as I
understand very little about this code. Looking at it, I cannot see
how tc_log_page_size should be 0 in that function, leading me to
believe that there is some memory corruption somewhere.

Any thoughts?

Thanks
-Zardosht