Two X Errors on termination

I have a test program which creates a lot of objects (7**3 * 2 spheres with level-of-detail = 2). It exposes a few problems, eg it takes a long time to launch. But the problem I'm reporting here is that, after termination, the console log on an N9 reads as follows:

X Error: BadAccess (attempt to access private resource denied) 10
Extension: 135 (MIT-SHM)
Minor opcode: 1 (X_ShmAttach)
Resource id: 0x3200007
X Error: BadShmSeg (invalid shared segment parameter) 135
Extension: 135 (MIT-SHM)
Minor opcode: 2 (X_ShmDetach)
Resource id: 0x3200016
Killing remote process(es)...
Finished running remote process. Exit code was 0.

Possibly this is a result of some resource allocation issue which might be worth looking into. It doesn't cause any harm for me but (a) it might cause harm to others and (b) my code is easy enough to work with for diagnosis.