The problem is that in the case of threaded builds for every fifo
a head and tail lock will be allocated inside the shared memory
segment and the ptr is stored inside the fifo. In the case that the sm backend
file will be mapped in all processes at the same address (mostly the
case for non-thread builds) this is fine, but in the cases when the
processes map the file at different addresses this addresses cause big
trouble in other processes than the one that allocted the locks.
Therefore the send lock addresses have to be recalculated to match
the local mapping of the processes that use them.
This commit was SVN r15291.
21f12f29f8