2 files changed, 22 insertions, 5 deletions

diff --git a/OpenSim/Region/OptionalModules/DataSnapshot/DataRequestHandler.cs b/OpenSim/Region/OptionalModules/DataSnapshot/DataRequestHandler.cs
index 5a01fa9..fb60e9e 100644
--- a/OpenSim/Region/OptionalModules/DataSnapshot/DataRequestHandler.cs
+++ b/OpenSim/Region/OptionalModules/DataSnapshot/DataRequestHandler.cs
@@ -63,18 +63,24 @@ namespace OpenSim.Region.DataSnapshot
 
         public Hashtable OnGetSnapshot(Hashtable keysvals)
         {
-            m_log.Debug("[DATASNAPSHOT] Received collection request");
+            string snapObj = (string)keysvals["region"];
+            m_log.DebugFormat("[DATASNAPSHOT] Received collection request for {0}", snapObj);
             Hashtable reply = new Hashtable();
             int statuscode = 200;
 
-            string snapObj = (string)keysvals["region"];
-
             XmlDocument response = m_externalData.GetSnapshot(snapObj);
+            if(response == null)
+            {
+                reply["str_response_string"] = string.Empty;
+                reply["int_response_code"] = 503;
+                reply["content_type"] = "text";
+                m_log.Debug("[DATASNAPSHOT] Collection request reply try later");
+                return reply;
+            }
 
             reply["str_response_string"] = response.OuterXml;
             reply["int_response_code"] = statuscode;
             reply["content_type"] = "text/xml";
-
             return reply;
         }
 
diff --git a/OpenSim/Region/OptionalModules/DataSnapshot/DataSnapshotManager.cs b/OpenSim/Region/OptionalModules/DataSnapshot/DataSnapshotManager.cs
index 0436f96..88fa1ae 100644
--- a/OpenSim/Region/OptionalModules/DataSnapshot/DataSnapshotManager.cs
+++ b/OpenSim/Region/OptionalModules/DataSnapshot/DataSnapshotManager.cs
@@ -32,6 +32,7 @@ using System.IO;
 using System.Linq;
 using System.Net;
 using System.Reflection;
+using System.Threading;
 using System.Text;
 using System.Xml;
 using log4net;
@@ -64,6 +65,7 @@ namespace OpenSim.Region.DataSnapshot
         //Various internal objects
         private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
         internal object m_syncInit = new object();
+        private object m_serializeGen = new object();
 
         //DataServices and networking
         private string m_dataServices = "noservices";
@@ -321,6 +323,11 @@ namespace OpenSim.Region.DataSnapshot
          */
         public XmlDocument GetSnapshot(string regionName)
         {
+            if(!Monitor.TryEnter(m_serializeGen,30000))
+            {
+                return null;
+            }
+
             CheckStale();
 
             XmlDocument requestedSnap = new XmlDocument();
@@ -360,9 +367,13 @@ namespace OpenSim.Region.DataSnapshot
                 m_log.Warn("[DATASNAPSHOT]: Caught unknown exception while trying to load snapshot: " + e.StackTrace);
                 requestedSnap = GetErrorMessage(regionName, e);
             }
-
+            finally
+            {
+                Monitor.Exit(m_serializeGen);
+            }
 
             return requestedSnap;
+
         }
 
         private XmlDocument GetErrorMessage(string regionName, Exception e)