Re: [riot-devel] To global seed or not to global seed

On Mit, 2017-03-08 at 09:09 +0100, Kaspar Schleiser wrote: > Hey, > > On 03/08/2017 12:18 AM, Cenk Gündoğan wrote: > > > > we rather > > should opt to allow local states for each thread (not excluding a global > > state). > Interesting. Up to now our trouble with RNGs was mostly on how to make >

Re: [riot-devel] To global seed or not to global seed

Hi Oleg, Ludwig, On 08.03.2017 10:30, Oleg Hahm wrote: Hi Ludwig! On Wed, Mar 08, 2017 at 10:28:13AM +0100, Ludwig Knüpfer wrote: Am 8. März 2017 10:21:15 MEZ schrieb Oleg Hahm : Is testing and simulation the only use case you can imagine? I'm somewhat reluctant to add

Re: [riot-devel] To global seed or not to global seed

Hi Ludwig! On Wed, Mar 08, 2017 at 10:28:13AM +0100, Ludwig Knüpfer wrote: > Am 8. März 2017 10:21:15 MEZ schrieb Oleg Hahm : > >Is testing and simulation the only use case you can imagine? I'm somewhat > >reluctant to add code just for non-production purposes. > > Since we

Re: [riot-devel] To global seed or not to global seed

Hi, Am 8. März 2017 10:21:15 MEZ schrieb Oleg Hahm : >Is testing and simulation the only use case you can imagine? I'm >somewhat >reluctant to add code just for non-production purposes. Since we outspokenly target researchers with RIOT this is a production feature. However

Re: [riot-devel] To global seed or not to global seed

Hi, Am 8. März 2017 10:06:17 MEZ schrieb "Cenk Gündoğan" : >On 17-03-08 09:09:34, Kaspar Schleiser wrote: >> That way we'd have: >> >> - user controlled state >> - the ability to overload (e.g., combine hwrng, collected entropy, >prng >> but with the same interface) >

Re: [riot-devel] To global seed or not to global seed

Dear Cenk, thanks for bringing up this discussion. On Wed, Mar 08, 2017 at 12:18:28AM +0100, Cenk Gündoğan wrote: > 1) we can define it as BCP to *not* use `random_init()` if `auto_init` >is used >=> it's hard to guarantee a one-time call to `random_init()` as human >do surely err

Re: [riot-devel] To global seed or not to global seed

Hey, On 03/08/2017 10:06 AM, Cenk Gündoğan wrote: > >> How about an interface a la >> > Looks good at first sight. We also would need some sort of > synchronization for concurrent access, e.g. a mutex in the `rnd_t` > struct, if two threads should use the same local state. Do we need that kind

Re: [riot-devel] To global seed or not to global seed

Hey, On 03/08/2017 12:18 AM, Cenk Gündoğan wrote: > we rather > should opt to allow local states for each thread (not excluding a global > state). Interesting. Up to now our trouble with RNGs was mostly on how to make them more random. Now we're trying to make them predictable. What's your use

Re: [riot-devel] To global seed or not to global seed

Hey, oh sure, here it follows: ``` The ISO C standard rand() and srand() functions allow per-process pseudo-random streams shared by all threads. Those two functions need not change, but there has to be mutual-exclusion that prevents interference between two threads concurrently accessing the