From eb91fb04b3d0ca8124b9bea375e3bf72963fa172 Mon Sep 17 00:00:00 2001
From: Marcus Müller <mmueller@gnuradio.org>
Date: Mon, 22 Mar 2021 00:37:47 +0100
Subject: runtime: fix gr::random API to be fixed-width 64 bit, use
XOROSHIRO128+
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Seeding being inconsistent between gr::random and things like fastnoise
source is an outstanding issue (#1559).
Fix that by fixing the API, and pivoting to our built-in XOROSHIRO128+,
which is also substantially faster than MT19937.
For that purpose, introduce, and python-bind, a wrapper class that can
be used with STL distribution shapers.
Add a unit test for the (P)RNG.
Signed-off-by: Marcus Müller <mmueller@gnuradio.org>
---
gnuradio-runtime/python/gnuradio/gr/qa_random.py | 36 ++++++++++++++++++++++++
1 file changed, 36 insertions(+)
(limited to 'gnuradio-runtime/python/gnuradio/gr/qa_random.py')
diff --git a/gnuradio-runtime/python/gnuradio/gr/qa_random.py b/gnuradio-runtime/python/gnuradio/gr/qa_random.py
index fa8c44917b..d7f4bb65a5 100644
--- a/gnuradio-runtime/python/gnuradio/gr/qa_random.py
+++ b/gnuradio-runtime/python/gnuradio/gr/qa_random.py
@@ -63,6 +63,42 @@ class test_random(gr_unittest.TestCase):
self.assertGreaterEqual(minimum, np.min(rnd_vals))
self.assertLess(np.max(rnd_vals), maximum)
+ def test_005_xoroshiro128p_seed_stability(self):
+ """
+ Test that seeding is stable.
+ It's basically an API break if it isn't.
+
+ We simply check for the first value of a sequence
+ being the same as it was when the module was integrated.
+ """
+ rng = gr.xoroshiro128p_prng(42)
+ self.assertEqual(3520422898491873512, rng())
+
+ def test_006_xoroshiro128p_reproducibility(self):
+ """
+ Make sure two RNGs with the same seed yield the same
+ sequence
+ """
+ seed = 123456
+ N = 10000
+ rng1 = gr.xoroshiro128p_prng(123456)
+ rng2 = gr.xoroshiro128p_prng(123456)
+ self.assertSequenceEqual(
+ tuple(rng1() for _ in range(N)),
+ tuple(rng2() for _ in range(N)))
+
+ def test_007_xoroshiro128p_range(self):
+ """
+ Check bounds.
+ Check whether a long sequence of values are within that bounds.
+ """
+ N = 10**6
+
+ self.assertEqual(gr.xoroshiro128p_prng.min(), 0)
+ self.assertEqual(gr.xoroshiro128p_prng.max(), 2**64-1)
+ rng = gr.xoroshiro128p_prng(42)
+ arr = all((0 <= rng() <= 2**64 - 1 for _ in range(N)))
+ self.assertTrue(arr)
if __name__ == '__main__':
gr_unittest.run(test_random)
--
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