From 1c313238d0bf6faba73a9281559ef98233bfafdf Mon Sep 17 00:00:00 2001
From: Cubitect <cubitect@gmail.com>
Date: Wed, 4 Jul 2018 10:53:35 +0100
Subject: [PATCH] improved thread-safety of hills

---
 layers.c | 21 ++++++++++-----------
 layers.h |  1 -
 2 files changed, 10 insertions(+), 12 deletions(-)

diff --git a/layers.c b/layers.c
index 7d37557..aa57756 100644
--- a/layers.c
+++ b/layers.c
@@ -861,7 +861,6 @@ void mapBiomeEdge(Layer *l, int * __restrict out, int areaX, int areaZ, int area
 }
 
 
-/* This function is not threadsafe. */
 void mapHills(Layer *l, int * __restrict out, int areaX, int areaZ, int areaWidth, int areaHeight)
 {
     int pX = areaX - 1;
@@ -878,13 +877,7 @@ void mapHills(Layer *l, int * __restrict out, int areaX, int areaZ, int areaWidt
         exit(1);
     }
 
-    if(bufsize < pWidth*pHeight)
-    {
-        if(buf != NULL) free(buf);
-
-        bufsize = pWidth*pHeight;
-        buf = (int*)malloc(bufsize*sizeof(int));
-    }
+    buf = (int *) malloc(pWidth*pHeight*sizeof(int));
 
     l->p->getMap(l->p, out, pX, pZ, pWidth, pHeight);
     memcpy(buf, out, pWidth*pHeight*sizeof(int));
@@ -982,6 +975,8 @@ void mapHills(Layer *l, int * __restrict out, int areaX, int areaZ, int areaWidt
             }
         }
     }
+
+    free(buf);
 }
 
 
@@ -1202,7 +1197,8 @@ void mapShore(Layer *l, int * __restrict out, int areaX, int areaZ, int areaWidt
 void mapRiverMix(Layer *l, int * __restrict out, int areaX, int areaZ, int areaWidth, int areaHeight)
 {
     int idx;
-    int *buf = (int*)malloc(areaWidth*areaHeight*sizeof(int));
+    int len;
+    int *buf;
 
     if(l->p2 == NULL)
     {
@@ -1210,12 +1206,15 @@ void mapRiverMix(Layer *l, int * __restrict out, int areaX, int areaZ, int areaW
         exit(1);
     }
 
+    len = areaWidth*areaHeight;
+    buf = (int *) malloc(len*sizeof(int));
+
     l->p->getMap(l->p, out, areaX, areaZ, areaWidth, areaHeight); // biome chain
-    memcpy(buf, out, areaWidth*areaHeight*sizeof(int));
+    memcpy(buf, out, len*sizeof(int));
 
     l->p2->getMap(l->p2, out, areaX, areaZ, areaWidth, areaHeight); // rivers
 
-    for(idx = 0; idx < areaHeight*areaWidth; idx++)
+    for(idx = 0; idx < len; idx++)
     {
         if(isOceanic(buf[idx]))
         {
diff --git a/layers.h b/layers.h
index f707efc..9dfefcf 100644
--- a/layers.h
+++ b/layers.h
@@ -376,7 +376,6 @@ void mapDeepOcean(Layer *l, int * __restrict out, int x, int z, int w, int h);
 void mapBiome(Layer *l, int * __restrict out, int x, int z, int w, int h);
 void mapRiverInit(Layer *l, int * __restrict out, int x, int z, int w, int h);
 void mapBiomeEdge(Layer *l, int * __restrict out, int x, int z, int w, int h);
-/* This function is not threadsafe. */
 void mapHills(Layer *l, int * __restrict out, int x, int z, int w, int h);
 void mapRiver(Layer *l, int * __restrict out, int x, int z, int w, int h);
 void mapSmooth(Layer *l, int * __restrict out, int x, int z, int w, int h);