[Python-Dev] BDFL ruling request: should we block forever waiting for high-quality random bits?

M.-A. Lemburg mal at egenix.com
Fri Jun 10 16:30:29 EDT 2016

On 10.06.2016 20:55, Donald Stufft wrote:
> Ok, so you’re looking for how would you replicate the blocking behavior of os.urandom that exists in 3.5.0 and 3.5.1?
> In that case, it’s hard. I don’t think linux provides any way to externally determine if /dev/urandom has been initialized or not. Probably the easiest thing to do would be to interface with the getrandom() function using a c-ext, CFFI, or ctypes. If you’re looking for a way of doing this without calling the getrandom() function.. I believe the answer is you can’t.

Well, you can see the effect by running Python early in the boot process.

See e.g. http://bugs.python.org/issue26839#msg267749

and if you look at the system log file, you'll find a notice
entry "random: %s pool is initialized" which gets written once the
pool is initialized:


Marc-Andre Lemburg

Professional Python Services directly from the Experts (#1, Jun 10 2016)
>>> Python Projects, Coaching and Consulting ...  http://www.egenix.com/
>>> Python Database Interfaces ...           http://products.egenix.com/
>>> Plone/Zope Database Interfaces ...           http://zope.egenix.com/

::: We implement business ideas - efficiently in both time and costs :::

   eGenix.com Software, Skills and Services GmbH  Pastor-Loeh-Str.48
    D-40764 Langenfeld, Germany. CEO Dipl.-Math. Marc-Andre Lemburg
           Registered at Amtsgericht Duesseldorf: HRB 46611

More information about the Python-Dev mailing list