[Numpy-discussion] Merge of date-time branch completed

[Robert Kern]

On Fri, Aug 28, 2009 at 10:39, Charles R
Harris<charlesr.harris at gmail.com> wrote:

> What does UFUNC_OBJ_NEEDS_API do?

It specifies that the ufunc loops need access to the Python C API, so
the dispatcher should not release the GIL before running the loop.

> Hmm, "can also have an additional key called "metadata" which can be any
> dictionary", is this new functionality? What does it do?

It adds a dictionary to the dtype. This can potentially be used for a
couple of applications, but here is used to hold the datetime
frequency information.

> There are a lot of changes like this : !(loop->obj & UFUNC_OBJ_ISOBJECT).
> What is the meaning of UFUNC_OBJ_ISOBJECT and why is this test necessary?

Previously, loop->obj was an int, but only took 0 or 1 to specify that
the ufunc loop was for object dtypes. This was used for two distinct
things: reference counting and keeping hold of the GIL. The datetime
loops require the latter but not the former. loop->obj is now a bitset
which can be 0, UFUNC_OBJ_ISOBJECT, UFUNC_OBJ_NEEDS_API, or
UFUNC_OBJ_ISOBJECT|UFUNC_OBJ_NEEDS_API. The tests were modified to
test for the most specific required flag(s) for the particular
operation it was going to do.

-- 
Robert Kern

"I have come to believe that the whole world is an enigma, a harmless
enigma that is made terrible by our own mad attempt to interpret it as
though it had an underlying truth."
  -- Umberto Eco