EmbeddedPkg: Extend NvVarStoreFormattedLib LIBRARY_CLASS

[mirror_edk2.git] / AppPkg / Applications / Python / Python-2.7.2 / Lib / test / crashers / gc_inspection.py

"""\r
gc.get_referrers() can be used to see objects before they are fully built.\r
\r
Note that this is only an example.  There are many ways to crash Python\r
by using gc.get_referrers(), as well as many extension modules (even\r
when they are using perfectly documented patterns to build objects).\r
\r
Identifying and removing all places that expose to the GC a\r
partially-built object is a long-term project.  A patch was proposed on\r
SF specifically for this example but I consider fixing just this single\r
example a bit pointless (#1517042).\r
\r
A fix would include a whole-scale code review, possibly with an API\r
change to decouple object creation and GC registration, and according\r
fixes to the documentation for extension module writers.  It's unlikely\r
to happen, though.  So this is currently classified as\r
"gc.get_referrers() is dangerous, use only for debugging".\r
"""\r
\r
import gc\r
\r
\r
def g():\r
    marker = object()\r
    yield marker\r
    # now the marker is in the tuple being constructed\r
    [tup] = [x for x in gc.get_referrers(marker) if type(x) is tuple]\r
    print tup\r
    print tup[1]\r
\r
\r
tuple(g())\r