Patch to suppress valgrind error notifications + more entropy on Win

[Antony Polukhin]

Valgrind reports "read of unitialized memory" while running the regression tests of uuid library:

==11806== Conditional jump or move depends on uninitialised value(s)
==11806==    at 0x407AF2: boost::random::mersenne_twister_engine<unsigned int, 32ul, 624ul, 397ul, 31ul, 2567483615u, 11ul, 4294967295u, 7ul, 2636928640u, 15ul, 4022730752u, 18ul, 1812433253u>::normalize_state() (mersenne_twister.hpp:341)
==11806==    by 0x40715E: void boost::random::mersenne_twister_engine<unsigned int, 32ul, 624ul, 397ul, 31ul, 2567483615u, 11ul, 4294967295u, 7ul, 2636928640u, 15ul, 4022730752u, 18ul, 1812433253u>::seed<boost::uuids::detail::generator_iterator<boost::uuids::detail::seed_rng> >(boost::uuids::detail::generator_iterator<boost::uuids::detail::seed_rng>&, boost::uuids::detail::generator_iterator<boost::uuids::detail::seed_rng>) (mersenne_twister.hpp:173)
==11806==    by 0x40611E: void boost::uuids::detail::seed<boost::random::mersenne_twister_engine<unsigned int, 32ul, 624ul, 397ul, 31ul, 2567483615u, 11ul, 4294967295u, 7ul, 2636928640u, 15ul, 4022730752u, 18ul, 1812433253u> >(boost::random::mersenne_twister_engine<unsigned int, 32ul, 624ul, 397ul, 31ul, 2567483615u, 11ul, 4294967295u, 7ul, 2636928640u, 15ul, 4022730752u, 18ul, 1812433253u>&) (seed_rng.hpp:249)
==11806==    by 0x404FE8: boost::uuids::basic_random_generator<boost::random::mersenne_twister_engine<unsigned int, 32ul, 624ul, 397ul, 31ul, 2567483615u, 11ul, 4294967295u, 7ul, 2636928640u, 15ul, 4022730752u, 18ul, 1812433253u> >::basic_random_generator() (random_generator.hpp:50)
==11806==    by 0x402B8A: main (test_random_generator.cpp:38)

This is done intentionally, however it hardens debugging of code. Attached patch adds ability to gather entropy using CryptGenRandom and replaces read of initialized memory with two other operations that gather entropy in more valgrind-friendly way.

After applying that patch valgrind reports no errors:

==13997== Command: ./test_random_generator
==13997== 
No errors detected.
==13997== 

[Antony Polukhin]

​Pull request on github with fix for this issue.

[nigel.stewart@…]

+1 for this

I needed to exclude boost uuid test coverage due to these UMRs. It undermines confidence in boost to be relying on that for entropy, IMHO.

[xyzdragon@…]

Hi, I also have this problem. Seeing that the last post was almost 2 years ago, is there still progress on this one?

[James E. King, III]

This patch was merged into boost-1.59, so I am marking this as resolved. I will have someone else fix the milestone.