When is the blocking RNG called?

[Enzo Michelangeli]

Question for the developing team:

Does "high quality" (i.e., blocking in low-entropy conditions) random number
generation occur only for keypair generation, or also in other circumstances
(e.g., when session keys are generated, DSS signatures computed and session
keys wrapped in ElGamal packets)? When using rndlinux, this is equivalent to
say: when does gnupg read from /dev/random, and when from /dev/urandom? From
the source code it would appear that high-quality RNG is only used for PK
generation, but I'd like to be sure.

TIA --

Enzo