From abe6c072d66777b171399f42548bad75f618f1a3 Mon Sep 17 00:00:00 2001
From: =?utf8?q?B=C5=99etislav=20=C5=A0tec?= <valsiterb@gmail.com>
Date: Sun, 2 Aug 2015 15:08:39 +0200
Subject: [PATCH] src/util/numeric.{cpp,h}: Fix FacePositionCache data race

---
 src/util/numeric.cpp | 4 ++++
 src/util/numeric.h   | 2 ++
 2 files changed, 6 insertions(+)

diff --git a/src/util/numeric.cpp b/src/util/numeric.cpp
index 4ddfede92..3fd1c9cf9 100644
--- a/src/util/numeric.cpp
+++ b/src/util/numeric.cpp
@@ -23,13 +23,17 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "log.h"
 #include "../constants.h" // BS, MAP_BLOCKSIZE
 #include "../noise.h" // PseudoRandom, PcgRandom
+#include "../jthread/jmutexautolock.h"
 #include <string.h>
 #include <iostream>
 
 std::map<u16, std::vector<v3s16> > FacePositionCache::m_cache;
+JMutex FacePositionCache::m_cache_mutex;
 // Calculate the borders of a "d-radius" cube
+// TODO: Make it work without mutex and data races, probably thread-local
 std::vector<v3s16> FacePositionCache::getFacePositions(u16 d)
 {
+	JMutexAutoLock cachelock(m_cache_mutex);
 	if (m_cache.find(d) != m_cache.end())
 		return m_cache[d];
 
diff --git a/src/util/numeric.h b/src/util/numeric.h
index 0eba01359..9fe08434f 100644
--- a/src/util/numeric.h
+++ b/src/util/numeric.h
@@ -24,6 +24,7 @@ with this program; if not, write to the Free Software Foundation, Inc.,
 #include "../irr_v2d.h"
 #include "../irr_v3d.h"
 #include "../irr_aabb3d.h"
+#include "../jthread/jmutex.h"
 #include <list>
 #include <map>
 #include <vector>
@@ -41,6 +42,7 @@ public:
 private:
 	static void generateFacePosition(u16 d);
 	static std::map<u16, std::vector<v3s16> > m_cache;
+	static JMutex m_cache_mutex;
 };
 
 class IndentationRaiser
-- 
2.25.1