When using SYSV-based shmem in APR (shmget, et.al.), APR uses
the standard ftok() call to generate a key. The issue is
that it always uses the constant 1 which can lead to key
collisions.
To work around that, 1.5.1 and 2.0-dev have been updated to
instead use an APR hash of the filename as the key.
http://svn.apache.org/r1542731
http://svn.apache.org/r1542732
As far as I know, this isn't exposed anyway outside of
APR except for in Apache httpd and the slotmem module,
which has been updated to account for this possibility.
