Multi threaded random generator

nano/core_test/CMakeLists.txt

@@ -40,6 +40,7 @@ add_executable(
   optimistic_scheduler.cpp
   processing_queue.cpp
   processor_service.cpp
+  random.cpp
   random_pool.cpp
   rep_crawler.cpp
   receivable.cpp

nano/core_test/random.cpp

@@ -0,0 +1,3 @@
+#include <nano/lib/random.hpp>
+
+#include <gtest/gtest.h>

nano/lib/random.hpp

@@ -1,5 +1,6 @@
 #pragma once
 
+#include <mutex>
 #include <random>
 
 namespace nano
@@ -28,4 +29,32 @@ private:
 	std::random_device device;
 	std::default_random_engine rng{ device () };
 };
+
+/**
+ * Not safe for any crypto related code, use for non-crypto PRNG only.
+ * Thread safe.
+ */
+class random_generator_mt final
+{
+public:
+	/// Generate a random number in the range [min, max)
+	auto random (auto min, auto max)
+	{
+		release_assert (min < max);
+		std::lock_guard<std::mutex> lock{ mutex };
+		std::uniform_int_distribution<decltype (min)> dist (min, max - 1);
+		return dist (rng);
+	}
+
+	/// Generate a random number in the range [0, max)
+	auto random (auto max)
+	{
+		return random (decltype (max){ 0 }, max);
+	}
+
+private:
+	std::random_device device;
+	std::default_random_engine rng{ device () };
+	std::mutex mutex;
+};
 }