PyMemoTable_Set(PyMemoTable *self, PyObject *key, Py_ssize_t value)
{
    PyMemoEntry *entry;

    assert(key != NULL);

    entry = _PyMemoTable_Lookup(self, key);
    if (entry->me_key != NULL) {
        entry->me_value = value;
        return 0;
    }
    Py_INCREF(key);
    entry->me_key = key;
    entry->me_value = value;
    self->mt_used++;

    /* If we added a key, we can safely resize. Otherwise just return!
     * If used >= 2/3 size, adjust size. Normally, this quaduples the size.
     *
     * Quadrupling the size improves average table sparseness
     * (reducing collisions) at the cost of some memory. It also halves
     * the number of expensive resize operations in a growing memo table.
     *
     * Very large memo tables (over 50K items) use doubling instead.
     * This may help applications with severe memory constraints.
     */
    if (!(self->mt_used * 3 >= (self->mt_mask + 1) * 2))
        return 0;
    return _PyMemoTable_ResizeTable(self,
        (self->mt_used > 50000 ? 2 : 4) * self->mt_used);
}
The software performs a calculation that can produce an integer overflow or wraparound, when the logic assumes that the resulting value will always be larger than the original value. This can introduce other weaknesses when the calculation is used for resource management or execution control.