Libgcrypt threads model

[Dmitry Eremin-Solenikov]

Hello,

While adapting old GnuTLS gcrypt backend to current libgcrypt codebase,
I stumbled upon current Libgcrypt threading code.

After carving through ath.c, I have the following impression:

Despite all definitions in ath.c gcrypt does not really support
either W32 threads or pthreads on systems which do not
support weak symbols (are there any of them?). Is it true?
Is it intentional?

How would ath mutexes behave if libgcrypt is linked into
an application with static pthreads? With pth or npth?
With w32?

Is it correct that GCRYCTL_SET_THREAD_CBS gcry_control
is also deprecated and should not be used in contemporary code?

-- 
With best wishes
Dmitry