Re: [Bug-apl] An inventory of entropy

[Kacper Gutowski]

On Sat, Jun 22, 2019 at 01:59:18PM +0200, Dr. Jürgen Sauermann wrote:
> Looking at getrandom() and friends it seems like they have considerable
> portability problems (e.g. the header files are missing on Mint-17 but
> available on Mint-19). From that perspective using /dev/urandom seems
> to be a better approach in the moment. I will look into adding ⎕FIO[60].

Indeed, you need not only kernel's support, but also libc wrapper and
most likely Mint 17 uses older glibc which doesn't support it yet. But
I don't suppose the lack of portability should be a problem in itself,
as we already have code in GNU APL using non-portable atomic primitives
on different systems, or even using rdtsc instruction when available,
falling back to gettimeofday when not. Likewise getentropy could be
detected at configure time.

But in any case, being part of ⎕FIO makes that an implementation detail
which could be changed at any later time when situation looks better.

The good thing is that ⎕RL←⎕FIO[60]8 is now a relatively effortless
way to correctly seed the generator.


-k