haskal
/
kicad
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Ensure the kiid generator rng is actually uniquely seeded each start 

(cherry picked from commit 2e689901fc)
This commit is contained in:
Marek Roszko 2022-03-23 18:49:19 -04:00 committed by Mark Roszko
parent 375a7303c5
commit 891c919c23
1 changed files with 16 additions and 1 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

17
common/kiid.cpp
View File

@ -25,6 +25,7 @@
#include <kiid.h> #include <kiid.h>
#include <boost/uuid/detail/random_provider.hpp>
#include <boost/uuid/uuid_generators.hpp> #include <boost/uuid/uuid_generators.hpp>
#include <boost/uuid/uuid_io.hpp> #include <boost/uuid/uuid_io.hpp>
#include <boost/functional/hash.hpp> #include <boost/functional/hash.hpp>
@ -40,8 +41,22 @@
// boost:mt19937 is not thread-safe // boost:mt19937 is not thread-safe
static std::mutex rng_mutex; static std::mutex rng_mutex;
// Create only once, as seeding is *very* expensive // We use a little helper class to ensure our static rng object is seeded
// with a random seed on startup before it's passed to the uuid generator object
class GENERATOR_INIT_HELPER
{
public:
GENERATOR_INIT_HELPER( boost::mt19937& aRng )
{
boost::uuids::detail::random_provider seeder;
aRng.seed( seeder );
}
};
// Static rng and generators are used because the overhead of constant seeding is expensive
// We break out the rng separately from the generator because we want to control seeding in cases like unit tests
static boost::mt19937 rng; static boost::mt19937 rng;
static GENERATOR_INIT_HELPER initHelper( rng );
static boost::uuids::basic_random_generator<boost::mt19937> randomGenerator( rng ); static boost::uuids::basic_random_generator<boost::mt19937> randomGenerator( rng );
// These don't have the same performance penalty, but we might as well be consistent // These don't have the same performance penalty, but we might as well be consistent