Merge pull request #1624 from Expensify/tyler-non-static-randoms

Allocate RNG when called, not at startup
Expensify · Dec 8, 2023 · 41e204a · 41e204a
2 parents 17af25a + 61a6532
commit 41e204a
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Showing 2 changed files with 12 additions and 8 deletions.
diff --git a/libstuff/SRandom.cpp b/libstuff/SRandom.cpp
@@ -1,20 +1,25 @@
 #include "SRandom.h"
 
-#ifdef VALGRIND
-// random_device breaks valgrind.
-mt19937_64 SRandom::_generator = mt19937_64();
-#else
-mt19937_64 SRandom::_generator = mt19937_64(random_device()());
-#endif
-
 uniform_int_distribution<uint64_t> SRandom::_distribution64 = uniform_int_distribution<uint64_t>();
 
 uint64_t SRandom::limitedRand64(uint64_t minNum, uint64_t maxNum) {
      uniform_int_distribution<uint64_t> limitedRandom(minNum, maxNum);
+#ifdef VALGRIND
+    // random_device breaks valgrind.
+    mt19937_64 _generator = mt19937_64();
+#else
+    mt19937_64 _generator = mt19937_64(random_device()());
+#endif
      return limitedRandom(_generator);
 }
 
 uint64_t SRandom::rand64() {
+#ifdef VALGRIND
+    // random_device breaks valgrind.
+    mt19937_64 _generator = mt19937_64();
+#else
+    mt19937_64 _generator = mt19937_64(random_device()());
+#endif
     return _distribution64(_generator);
 }
 

diff --git a/libstuff/SRandom.h b/libstuff/SRandom.h
@@ -13,6 +13,5 @@ class SRandom {
     static string randStr(uint& length);
 
   private:
-    static mt19937_64 _generator;
     static uniform_int_distribution<uint64_t> _distribution64;
 };