* Added static mutex to terrain load-tile to prevent file IO locking issues.

OpenSim/Region/Terrain.BasicTerrain/TerrainEngine.cs

@@ -51,6 +51,8 @@ namespace OpenSim.Region.Terrain
 
     public class TerrainEngine
     {
+        public static System.Threading.Mutex fileIOLock = new System.Threading.Mutex();
+
         /// <summary>
         /// Plugin library for scripts
         /// </summary>
@@ -731,6 +733,10 @@ namespace OpenSim.Region.Terrain
         /// <param name="lowerboundY">Where do the region coords start for this terrain?</param>
         public void LoadFromFileF32(string filename, int dimensionX, int dimensionY, int lowerboundX, int lowerboundY)
         {
+            fileIOLock.WaitOne();
+            try
+            {
+
                 int sectionToLoadX = ((this.offsetX - lowerboundX) * this.w);
                 int sectionToLoadY = ((this.offsetY - lowerboundY) * this.h);
 
@@ -745,7 +751,7 @@ namespace OpenSim.Region.Terrain
                 {
                     for (y = 0; y < dimensionY; y++)
                     {
-                    tempMap[x,y] = (double)bs.ReadSingle();
+                        tempMap[x, y] = (double)bs.ReadSingle();
                     }
                 }
 
@@ -762,6 +768,11 @@ namespace OpenSim.Region.Terrain
 
                 tainted++;
             }
+            finally
+            {
+                fileIOLock.ReleaseMutex();
+            }
+        }
 
         /// <summary>
         /// Loads a larger tiled image across a terrain