Make the PRNG thread-safe.

Turns out that the C++ PRNGs aren't thread-safe.  So lock
calls to m_mersenneTwisterRng.  Makes Thread Sanitizer happy.

1 files changed, 3 insertions, 0 deletions

diff --git a/datamanager.cpp b/datamanager.cpp
index 2dea169..55d1166 100644
--- a/datamanager.cpp
+++ b/datamanager.cpp
@@ -178,15 +178,18 @@ string DataManager::makeDataFilename(const string &subDirectory, const string &f
 
 void DataManager::seedRandomNumbers(unsigned int seed)
 {
+	lock_guard<mutex> lock(m_RngMutex);
 	m_mersenneTwisterRng.seed(seed);
 }
 
 void DataManager::seedRandomNumbers(seed_seq& seed)
 {
+	lock_guard<mutex> lock(m_RngMutex);
 	m_mersenneTwisterRng.seed(seed);
 }
 
 int DataManager::randomInteger(int low, int high)
 {
+	lock_guard<mutex> lock(m_RngMutex);
 	return uniform_int_distribution<>(low, high)(m_mersenneTwisterRng);
 }