Optimizations

5 files changed, 123 insertions, 118 deletions

diff --git a/OpenSim/Region/ScriptEngine/Interfaces/ICompiler.cs b/OpenSim/Region/ScriptEngine/Interfaces/ICompiler.cs
index f8af902..e4ca635 100644
--- a/OpenSim/Region/ScriptEngine/Interfaces/ICompiler.cs
+++ b/OpenSim/Region/ScriptEngine/Interfaces/ICompiler.cs
@@ -34,9 +34,7 @@ namespace OpenSim.Region.ScriptEngine.Interfaces
 {
     public interface ICompiler
     {
-        object PerformScriptCompile(string source, string asset, UUID ownerID);
+        void PerformScriptCompile(string source, string asset, UUID ownerID, out string assembly, out Dictionary<KeyValuePair<int, int>, KeyValuePair<int, int>> linemap);
         string[] GetWarnings();
-        Dictionary<KeyValuePair<int, int>, KeyValuePair<int, int>>
-                LineMap();
     }
 }
diff --git a/OpenSim/Region/ScriptEngine/Shared/Api/Runtime/ScriptBase.cs b/OpenSim/Region/ScriptEngine/Shared/Api/Runtime/ScriptBase.cs
index 917ca44..121159c 100644
--- a/OpenSim/Region/ScriptEngine/Shared/Api/Runtime/ScriptBase.cs
+++ b/OpenSim/Region/ScriptEngine/Shared/Api/Runtime/ScriptBase.cs
@@ -113,7 +113,7 @@ namespace OpenSim.Region.ScriptEngine.Shared.ScriptBase
                 return;
 
             //ILease lease = (ILease)RemotingServices.GetLifetimeService(data as MarshalByRefObject);
-            RemotingServices.GetLifetimeService(data as MarshalByRefObject);
+            //RemotingServices.GetLifetimeService(data as MarshalByRefObject);
 //            lease.Register(m_sponser);
 
             MethodInfo mi = inits[api];
diff --git a/OpenSim/Region/ScriptEngine/Shared/CodeTools/Compiler.cs b/OpenSim/Region/ScriptEngine/Shared/CodeTools/Compiler.cs
index fe26429..d781a1a 100644
--- a/OpenSim/Region/ScriptEngine/Shared/CodeTools/Compiler.cs
+++ b/OpenSim/Region/ScriptEngine/Shared/CodeTools/Compiler.cs
@@ -74,7 +74,6 @@ namespace OpenSim.Region.ScriptEngine.Shared.CodeTools
         private string FilePrefix;
         private string ScriptEnginesPath = "ScriptEngines";
         // mapping between LSL and C# line/column numbers
-        private Dictionary<KeyValuePair<int, int>, KeyValuePair<int, int>> m_positionMap; 
         private ICodeConverter LSL_Converter;
 
         private List<string> m_warnings = new List<string>();
@@ -91,6 +90,9 @@ namespace OpenSim.Region.ScriptEngine.Shared.CodeTools
         private static UInt64 scriptCompileCounter = 0;                                     // And a counter
 
         public IScriptEngine m_scriptEngine;
+        private Dictionary<string, Dictionary<KeyValuePair<int, int>, KeyValuePair<int, int>>> m_lineMaps =
+            new Dictionary<string, Dictionary<KeyValuePair<int, int>, KeyValuePair<int, int>>>();
+
         public Compiler(IScriptEngine scriptEngine)
         {
             m_scriptEngine = scriptEngine;
@@ -271,16 +273,15 @@ namespace OpenSim.Region.ScriptEngine.Shared.CodeTools
         /// </summary>
         /// <param name="Script">LSL script</param>
         /// <returns>Filename to .dll assembly</returns>
-        public object PerformScriptCompile(string Script, string asset, UUID ownerUUID)
+        public void PerformScriptCompile(string Script, string asset, UUID ownerUUID, 
+            out string assembly, out Dictionary<KeyValuePair<int,int>, KeyValuePair<int,int>> linemap)
         {
-            m_positionMap = null;
+            linemap = null;
             m_warnings.Clear();
-                
-            string OutFile = Path.Combine(ScriptEnginesPath, Path.Combine(
+
+            assembly = Path.Combine(ScriptEnginesPath, Path.Combine(
                     m_scriptEngine.World.RegionInfo.RegionID.ToString(),
                     FilePrefix + "_compiled_" + asset + ".dll"));
-//            string OutFile = Path.Combine(ScriptEnginesPath,
-//                    FilePrefix + "_compiled_" + asset + ".dll");
 
             if (!Directory.Exists(ScriptEnginesPath))
             {
@@ -305,51 +306,53 @@ namespace OpenSim.Region.ScriptEngine.Shared.CodeTools
                 }
             }
 
-            if (Script == String.Empty)
+            // Don't recompile if we already have it
+            // Performing 3 file exists tests for every script can still be slow
+            if (File.Exists(assembly) && File.Exists(assembly + ".text") && File.Exists(assembly + ".map"))
             {
-                if (File.Exists(OutFile))
-                    return OutFile;
-
-                throw new Exception("Cannot find script assembly and no script text present");
+                // If we have already read this linemap file, then it will be in our dictionary. 
+                // Don't build another copy of the dictionary (saves memory) and certainly
+                // don't keep reading the same file from disk multiple times. 
+                if (!m_lineMaps.ContainsKey(assembly))
+                    m_lineMaps[assembly] = ReadMapFile(assembly + ".map");
+                linemap = m_lineMaps[assembly];
+                return;
             }
 
-            // Don't recompile if we already have it
-            //
-            if (File.Exists(OutFile) && File.Exists(OutFile+".text") && File.Exists(OutFile+".map"))
+            if (Script == String.Empty)
             {
-                ReadMapFile(OutFile+".map");
-                return OutFile;
+                throw new Exception("Cannot find script assembly and no script text present");
             }
 
-            enumCompileType l = DefaultCompileLanguage;
+            enumCompileType language = DefaultCompileLanguage;
 
             if (Script.StartsWith("//c#", true, CultureInfo.InvariantCulture))
-                l = enumCompileType.cs;
+                language = enumCompileType.cs;
             if (Script.StartsWith("//vb", true, CultureInfo.InvariantCulture))
             {
-                l = enumCompileType.vb;
+                language = enumCompileType.vb;
                 // We need to remove //vb, it won't compile with that
 
                 Script = Script.Substring(4, Script.Length - 4);
             }
             if (Script.StartsWith("//lsl", true, CultureInfo.InvariantCulture))
-                l = enumCompileType.lsl;
+                language = enumCompileType.lsl;
 
             if (Script.StartsWith("//js", true, CultureInfo.InvariantCulture))
-                l = enumCompileType.js;
+                language = enumCompileType.js;
 
             if (Script.StartsWith("//yp", true, CultureInfo.InvariantCulture))
-                l = enumCompileType.yp;
+                language = enumCompileType.yp;
 
-            if (!AllowedCompilers.ContainsKey(l.ToString()))
+            if (!AllowedCompilers.ContainsKey(language.ToString()))
             {
                 // Not allowed to compile to this language!
                 string errtext = String.Empty;
-                errtext += "The compiler for language \"" + l.ToString() + "\" is not in list of allowed compilers. Script will not be executed!";
+                errtext += "The compiler for language \"" + language.ToString() + "\" is not in list of allowed compilers. Script will not be executed!";
                 throw new Exception(errtext);
             }
 
-            if (m_scriptEngine.World.Permissions.CanCompileScript(ownerUUID, (int)l) == false) {
+            if (m_scriptEngine.World.Permissions.CanCompileScript(ownerUUID, (int)language) == false) {
                 // Not allowed to compile to this language!
                 string errtext = String.Empty;
                 errtext += ownerUUID + " is not in list of allowed users for this scripting language. Script will not be executed!";
@@ -358,7 +361,7 @@ namespace OpenSim.Region.ScriptEngine.Shared.CodeTools
             
             string compileScript = Script;
 
-            if (l == enumCompileType.lsl)
+            if (language == enumCompileType.lsl)
             {
                 // Its LSL, convert it to C#
                 LSL_Converter = (ICodeConverter)new CSCodeGenerator();
@@ -370,16 +373,19 @@ namespace OpenSim.Region.ScriptEngine.Shared.CodeTools
                     AddWarning(warning);
                 }
 
-                m_positionMap = ((CSCodeGenerator) LSL_Converter).PositionMap;
+                linemap = ((CSCodeGenerator) LSL_Converter).PositionMap;
+                // Write the linemap to a file and save it in our dictionary for next time. 
+                m_lineMaps[assembly] = linemap;
+                WriteMapFile(assembly + ".map", linemap);
             }
 
-            if (l == enumCompileType.yp)
+            if (language == enumCompileType.yp)
             {
                 // Its YP, convert it to C#
                 compileScript = YP_Converter.Convert(Script);
             }
 
-            switch (l)
+            switch (language)
             {
                 case enumCompileType.cs:
                 case enumCompileType.lsl:
@@ -396,7 +402,8 @@ namespace OpenSim.Region.ScriptEngine.Shared.CodeTools
                     break;
             }
 
-            return CompileFromDotNetText(compileScript, l, asset);
+            assembly = CompileFromDotNetText(compileScript, language, asset, assembly);
+            return;
         }
 
         public string[] GetWarnings()
@@ -468,18 +475,15 @@ namespace OpenSim.Region.ScriptEngine.Shared.CodeTools
         /// </summary>
         /// <param name="Script">CS script</param>
         /// <returns>Filename to .dll assembly</returns>
-        internal string CompileFromDotNetText(string Script, enumCompileType lang, string asset)
+        internal string CompileFromDotNetText(string Script, enumCompileType lang, string asset, string assembly)
         {
             string ext = "." + lang.ToString();
 
             // Output assembly name
             scriptCompileCounter++;
-            string OutFile = Path.Combine(ScriptEnginesPath, Path.Combine(
-                    m_scriptEngine.World.RegionInfo.RegionID.ToString(),
-                    FilePrefix + "_compiled_" + asset + ".dll"));
             try
             {
-                File.Delete(OutFile);
+                File.Delete(assembly);
             }
             catch (Exception e) // NOTLEGIT - Should be just FileIOException
             {
@@ -492,7 +496,7 @@ namespace OpenSim.Region.ScriptEngine.Shared.CodeTools
             if (WriteScriptSourceToDebugFile)
             {
                 string srcFileName = FilePrefix + "_source_" +
-                        Path.GetFileNameWithoutExtension(OutFile) + ext;
+                        Path.GetFileNameWithoutExtension(assembly) + ext;
                 try
                 {
                     File.WriteAllText(Path.Combine(Path.Combine(
@@ -528,7 +532,7 @@ namespace OpenSim.Region.ScriptEngine.Shared.CodeTools
             }
 
             parameters.GenerateExecutable = false;
-            parameters.OutputAssembly = OutFile;
+            parameters.OutputAssembly = assembly;
             parameters.IncludeDebugInformation = CompileWithDebugInformation;
             //parameters.WarningLevel = 1; // Should be 4?
             parameters.TreatWarningsAsErrors = false;
@@ -609,7 +613,7 @@ namespace OpenSim.Region.ScriptEngine.Shared.CodeTools
 
                     if (severity == "Error")
                     {
-                        lslPos = FindErrorPosition(CompErr.Line, CompErr.Column);
+                        lslPos = FindErrorPosition(CompErr.Line, CompErr.Column, m_lineMaps[assembly]);
                         string text = CompErr.ErrorText;
 
                         // Use LSL type names
@@ -635,14 +639,14 @@ namespace OpenSim.Region.ScriptEngine.Shared.CodeTools
             //  the compile may not be immediately apparent. Wait a 
             //  reasonable amount of time before giving up on it.
 
-            if (!File.Exists(OutFile))
+            if (!File.Exists(assembly))
             {
-                for (int i=0; i<20 && !File.Exists(OutFile); i++)
+                for (int i=0; i<20 && !File.Exists(assembly); i++)
                 {
                     System.Threading.Thread.Sleep(250);
                 }
                 // One final chance...
-                if (!File.Exists(OutFile))
+                if (!File.Exists(assembly))
                 {
                     errtext = String.Empty;
                     errtext += "No compile error. But not able to locate compiled file.";
@@ -658,7 +662,7 @@ namespace OpenSim.Region.ScriptEngine.Shared.CodeTools
             //
             // Read the binary file into a buffer
             //
-            FileInfo fi = new FileInfo(OutFile);
+            FileInfo fi = new FileInfo(assembly);
 
             if (fi == null)
             {
@@ -671,7 +675,7 @@ namespace OpenSim.Region.ScriptEngine.Shared.CodeTools
 
             try
             {
-                FileStream fs = File.Open(OutFile, FileMode.Open, FileAccess.Read);
+                FileStream fs = File.Open(assembly, FileMode.Open, FileAccess.Read);
                 fs.Read(data, 0, data.Length);
                 fs.Close();
             }
@@ -690,34 +694,11 @@ namespace OpenSim.Region.ScriptEngine.Shared.CodeTools
 
             Byte[] buf = enc.GetBytes(filetext);
 
-            FileStream sfs = File.Create(OutFile+".text");
+            FileStream sfs = File.Create(assembly+".text");
             sfs.Write(buf, 0, buf.Length);
             sfs.Close();
 
-            string posmap = String.Empty;
-            if (m_positionMap != null)
-            {
-                foreach (KeyValuePair<KeyValuePair<int, int>, KeyValuePair<int, int>> kvp in m_positionMap)
-                {
-                    KeyValuePair<int, int> k = kvp.Key;
-                    KeyValuePair<int, int> v = kvp.Value;
-                    posmap += String.Format("{0},{1},{2},{3}\n",
-                            k.Key, k.Value, v.Key, v.Value);
-                }
-            }
-
-            buf = enc.GetBytes(posmap);
-
-            FileStream mfs = File.Create(OutFile+".map");
-            mfs.Write(buf, 0, buf.Length);
-            mfs.Close();
-
-            return OutFile;
-        }
-
-        public KeyValuePair<int, int> FindErrorPosition(int line, int col)
-        {
-            return FindErrorPosition(line, col, m_positionMap);
+            return assembly;
         }
 
         private class kvpSorter : IComparer<KeyValuePair<int,int>>
@@ -791,27 +772,32 @@ namespace OpenSim.Region.ScriptEngine.Shared.CodeTools
             return message;
         }
 
-        public Dictionary<KeyValuePair<int, int>, KeyValuePair<int, int>> LineMap()
+
+        private static void WriteMapFile(string filename, Dictionary<KeyValuePair<int, int>, KeyValuePair<int, int>> linemap)
         {
-            if (m_positionMap == null)
-                return null;
-            
-            Dictionary<KeyValuePair<int, int>, KeyValuePair<int, int>> ret =
-                new Dictionary<KeyValuePair<int,int>, KeyValuePair<int, int>>();
-            
-            foreach (KeyValuePair<int, int> kvp in m_positionMap.Keys)
-                ret.Add(kvp, m_positionMap[kvp]);
-            
-            return ret;
+            string mapstring = String.Empty;
+            foreach (KeyValuePair<KeyValuePair<int, int>, KeyValuePair<int, int>> kvp in linemap)
+            {
+                KeyValuePair<int, int> k = kvp.Key;
+                KeyValuePair<int, int> v = kvp.Value;
+                mapstring += String.Format("{0},{1},{2},{3}\n", k.Key, k.Value, v.Key, v.Value);
+            }
+
+            System.Text.ASCIIEncoding enc = new System.Text.ASCIIEncoding();
+            Byte[] mapbytes = enc.GetBytes(mapstring);
+            FileStream mfs = File.Create(filename);
+            mfs.Write(mapbytes, 0, mapbytes.Length);
+            mfs.Close();
         }
 
-        private void ReadMapFile(string filename)
+
+        private static Dictionary<KeyValuePair<int,int>, KeyValuePair<int,int>> ReadMapFile(string filename)
         {
+            Dictionary<KeyValuePair<int, int>, KeyValuePair<int, int>> linemap;
             try
             {
                 StreamReader r = File.OpenText(filename);
-
-                m_positionMap = new Dictionary<KeyValuePair<int,int>, KeyValuePair<int, int>>();
+                linemap = new Dictionary<KeyValuePair<int, int>, KeyValuePair<int, int>>();
                 
                 string line;
                 while ((line = r.ReadLine()) != null)
@@ -825,12 +811,14 @@ namespace OpenSim.Region.ScriptEngine.Shared.CodeTools
                     KeyValuePair<int, int> k = new KeyValuePair<int, int>(kk, kv);
                     KeyValuePair<int, int> v = new KeyValuePair<int, int>(vk, vv);
 
-                    m_positionMap[k] = v;
+                    linemap[k] = v;
                 }
             }
             catch
             {
+                linemap = new Dictionary<KeyValuePair<int, int>, KeyValuePair<int, int>>();
             }
+            return linemap;
         }
     }
 }
diff --git a/OpenSim/Region/ScriptEngine/Shared/Instance/ScriptInstance.cs b/OpenSim/Region/ScriptEngine/Shared/Instance/ScriptInstance.cs
index 2b858ec..37ec5df 100644
--- a/OpenSim/Region/ScriptEngine/Shared/Instance/ScriptInstance.cs
+++ b/OpenSim/Region/ScriptEngine/Shared/Instance/ScriptInstance.cs
@@ -93,7 +93,7 @@ namespace OpenSim.Region.ScriptEngine.Shared.Instance
         private StateSource m_stateSource;
         private bool m_postOnRez;
         private bool m_startedFromSavedState = false;
-        private string m_CurrentState = String.Empty;
+        private int m_CurrentStateHash;
         private UUID m_RegionID = UUID.Zero;
 
         private Dictionary<KeyValuePair<int, int>, KeyValuePair<int, int>>
@@ -252,16 +252,22 @@ namespace OpenSim.Region.ScriptEngine.Shared.Instance
             {
                 m_Apis[api] = am.CreateApi(api);
                 m_Apis[api].Initialize(engine, part, m_LocalID, itemID);
-            }
+            }
+
+            try
+            {
+                    if (dom != System.AppDomain.CurrentDomain)
+                            m_Script = (IScript)dom.CreateInstanceAndUnwrap(
+                                            Path.GetFileNameWithoutExtension(assembly),
+                                            "SecondLife.Script");
+                    else
+                            m_Script = (IScript)Assembly.Load(
+                                            Path.GetFileNameWithoutExtension(assembly)).CreateInstance(
+                                            "SecondLife.Script");
 
-            try
-            {
-                m_Script = (IScript)dom.CreateInstanceAndUnwrap(
-                    Path.GetFileNameWithoutExtension(assembly),
-                    "SecondLife.Script");
 
                 //ILease lease = (ILease)RemotingServices.GetLifetimeService(m_Script as ScriptBaseClass);
-                RemotingServices.GetLifetimeService(m_Script as ScriptBaseClass);
+                //RemotingServices.GetLifetimeService(m_Script as ScriptBaseClass);
 //                lease.Register(this);
             }
             catch (Exception)
@@ -893,7 +899,9 @@ namespace OpenSim.Region.ScriptEngine.Shared.Instance
 
             string xml = ScriptSerializer.Serialize(this);
 
-            if (m_CurrentState != xml)
+            // Compare hash of the state we just just created with the state last written to disk
+            // If the state is different, update the disk file.
+            if(xml.GetHashCode() != m_CurrentStateHash)
             {
                 try
                 {
@@ -911,7 +919,7 @@ namespace OpenSim.Region.ScriptEngine.Shared.Instance
                 //{
                 //    throw new Exception("Completed persistence save, but no file was created");
                 //}
-                m_CurrentState = xml;
+                m_CurrentStateHash = xml.GetHashCode();
             }
         }
 
diff --git a/OpenSim/Region/ScriptEngine/XEngine/XEngine.cs b/OpenSim/Region/ScriptEngine/XEngine/XEngine.cs
index 7b19ce3..57042e9 100644
--- a/OpenSim/Region/ScriptEngine/XEngine/XEngine.cs
+++ b/OpenSim/Region/ScriptEngine/XEngine/XEngine.cs
@@ -73,9 +73,11 @@ namespace OpenSim.Region.ScriptEngine.XEngine
         private bool m_InitialStartup = true;
         private int m_ScriptFailCount; // Number of script fails since compile queue was last empty
         private string m_ScriptErrorMessage;
+        private Dictionary<string, string> m_uniqueScripts = new Dictionary<string, string>();
+        private bool m_AppDomainLoading;
 
-// disable warning: need to keep a reference to XEngine.EventManager
-// alive to avoid it being garbage collected
+        // disable warning: need to keep a reference to XEngine.EventManager
+        // alive to avoid it being garbage collected
 #pragma warning disable 414
         private EventManager m_EventManager;
 #pragma warning restore 414
@@ -201,6 +203,7 @@ namespace OpenSim.Region.ScriptEngine.XEngine
             m_MaxScriptQueue = m_ScriptConfig.GetInt("MaxScriptEventQueue",300);
             m_StackSize = m_ScriptConfig.GetInt("ThreadStackSize", 262144);
             m_SleepTime = m_ScriptConfig.GetInt("MaintenanceInterval", 10) * 1000;
+            m_AppDomainLoading = m_ScriptConfig.GetBoolean("AppDomainLoading", true);
 
             m_EventLimit = m_ScriptConfig.GetInt("EventLimit", 30);
             m_KillTimedOutScripts = m_ScriptConfig.GetBoolean("KillTimedOutScripts", false);
@@ -470,6 +473,12 @@ namespace OpenSim.Region.ScriptEngine.XEngine
             if (engine != ScriptEngineName)
                 return;
 
+            // If we've seen this exact script text before, use that reference instead
+            if (m_uniqueScripts.ContainsKey(script))
+                script = m_uniqueScripts[script];
+            else
+                m_uniqueScripts[script] = script;
+
             Object[] parms = new Object[]{localID, itemID, script, startParam, postOnRez, (StateSource)stateSource};
 
             if (stateSource == (int)StateSource.ScriptedRez)
@@ -590,14 +599,12 @@ namespace OpenSim.Region.ScriptEngine.XEngine
             {
                 lock (m_AddingAssemblies) 
                 {
-                    assembly = (string)m_Compiler.PerformScriptCompile(script,
-                            assetID.ToString(), item.OwnerID);
+                    m_Compiler.PerformScriptCompile(script, assetID.ToString(), item.OwnerID, out assembly, out linemap);
                     if (!m_AddingAssemblies.ContainsKey(assembly)) {
                         m_AddingAssemblies[assembly] = 1;
                     } else {
                         m_AddingAssemblies[assembly]++;
                     }
-                    linemap = m_Compiler.LineMap();
                 }
 
                 string[] warnings = m_Compiler.GetWarnings();
@@ -696,19 +703,22 @@ namespace OpenSim.Region.ScriptEngine.XEngine
                             Evidence baseEvidence = AppDomain.CurrentDomain.Evidence;
                             Evidence evidence = new Evidence(baseEvidence);
 
-                            AppDomain sandbox =
-                                AppDomain.CreateDomain(
-                                    m_Scene.RegionInfo.RegionID.ToString(),
-                                    evidence, appSetup);
-/*
-                            PolicyLevel sandboxPolicy = PolicyLevel.CreateAppDomainLevel();
-                            AllMembershipCondition sandboxMembershipCondition = new AllMembershipCondition();
-                            PermissionSet sandboxPermissionSet = sandboxPolicy.GetNamedPermissionSet("Internet");
-                            PolicyStatement sandboxPolicyStatement = new PolicyStatement(sandboxPermissionSet);
-                            CodeGroup sandboxCodeGroup = new UnionCodeGroup(sandboxMembershipCondition, sandboxPolicyStatement);
-                            sandboxPolicy.RootCodeGroup = sandboxCodeGroup;
-                            sandbox.SetAppDomainPolicy(sandboxPolicy);
-*/
+                            AppDomain sandbox;
+                            if (m_AppDomainLoading)
+                                sandbox = AppDomain.CreateDomain(
+                                                m_Scene.RegionInfo.RegionID.ToString(),
+                                                evidence, appSetup);
+                            else
+                                sandbox = AppDomain.CurrentDomain;
+                            /*
+                                                        PolicyLevel sandboxPolicy = PolicyLevel.CreateAppDomainLevel();
+                                                        AllMembershipCondition sandboxMembershipCondition = new AllMembershipCondition();
+                                                        PermissionSet sandboxPermissionSet = sandboxPolicy.GetNamedPermissionSet("Internet");
+                                                        PolicyStatement sandboxPolicyStatement = new PolicyStatement(sandboxPermissionSet);
+                                                        CodeGroup sandboxCodeGroup = new UnionCodeGroup(sandboxMembershipCondition, sandboxPolicyStatement);
+                                                        sandboxPolicy.RootCodeGroup = sandboxCodeGroup;
+                                                        sandbox.SetAppDomainPolicy(sandboxPolicy);
+                            */
                             m_AppDomains[appDomain] = sandbox;
 
                             m_AppDomains[appDomain].AssemblyResolve +=
@@ -905,9 +915,10 @@ namespace OpenSim.Region.ScriptEngine.XEngine
                 AppDomain domain = m_AppDomains[id];
                 m_AppDomains.Remove(id);
 
-                AppDomain.Unload(domain);
+                if (domain != AppDomain.CurrentDomain)
+                    AppDomain.Unload(domain);
                 domain = null;
-//                m_log.DebugFormat("[XEngine] Unloaded app domain {0}", id.ToString());
+                // m_log.DebugFormat("[XEngine] Unloaded app domain {0}", id.ToString());
             }
         }