Leakage vs Cyclops

[Tim Peters]

Note that in the 2.3a1 source distribution, the file

    Misc/SpecialBuilds.txt

documents the special Python builds you can make to get more info about
references and objects.  There are several.  All except the PYMALLOC_DEBUG
build are also doable in 2.2.2, and some have been available since 0.9.9.

I don't expect it would really help to get a total count of live objects in
the release build:  if that keeps going up, you have a leak, but your memory
use will keep going up too then, so it wouldn't tell you much you didn't
already know ("I have a leak").  In that case, the COUNT_ALLOCS build is
much more helpful:  it keeps track of how many of each type of object is
alive, a measure of throughput for each type of object, and the allocation
highwater mark for each type of object.  It adds a function sys.getcounts()
to let you get at that info too.  COUNT_ALLOCS is relatively lightweight
(compared to a debug build), but still more expensive than you'd like for
production mode, and has the side effect of making new-style class objects
immortal.