From 862da9a55fe94ae70a5bba306139b5eb1bb7f6f7 Mon Sep 17 00:00:00 2001
From: Diva Canto <diva@metaverseink.com>
Date: Wed, 22 Dec 2010 17:55:58 -0800
Subject: [PATCH] Added a counter to NewFiles in Xfers to account for
 simultaneous object inventory requests, which apparently are happening and
 may cause race conditions if the file name is removed after the first
 transfer.

---
 .../CoreModules/Agent/Xfer/XferModule.cs      | 58 ++++++++++++++-----
 1 file changed, 42 insertions(+), 16 deletions(-)

diff --git a/OpenSim/Region/CoreModules/Agent/Xfer/XferModule.cs b/OpenSim/Region/CoreModules/Agent/Xfer/XferModule.cs
index 57875dac26..c5a6e628bd 100644
--- a/OpenSim/Region/CoreModules/Agent/Xfer/XferModule.cs
+++ b/OpenSim/Region/CoreModules/Agent/Xfer/XferModule.cs
@@ -40,8 +40,8 @@ namespace OpenSim.Region.CoreModules.Agent.Xfer
         private Scene m_scene;
         private Dictionary<string, XferRequest> Requests = new Dictionary<string, XferRequest>();
         private List<XferRequest> RequestTime = new List<XferRequest>();
-        public Dictionary<string, byte[]> NewFiles = new Dictionary<string, byte[]>();
-        public Dictionary<ulong, XferDownLoad> Transfers = new Dictionary<ulong, XferDownLoad>();
+        private Dictionary<string, FileData> NewFiles = new Dictionary<string, FileData>();
+        private Dictionary<ulong, XferDownLoad> Transfers = new Dictionary<ulong, XferDownLoad>();
         
 
         public struct XferRequest
@@ -51,6 +51,12 @@ namespace OpenSim.Region.CoreModules.Agent.Xfer
             public string fileName;
             public DateTime timeStamp;
         }
+
+        private class FileData
+        {
+            public byte[] Data;
+            public int Count;
+        }
        
         #region IRegionModule Members
 
@@ -89,21 +95,22 @@ namespace OpenSim.Region.CoreModules.Agent.Xfer
             lock (NewFiles)
             {
                 if (NewFiles.ContainsKey(fileName))
-                {
-                    NewFiles[fileName] = data;
-                }
+                    NewFiles[fileName].Count++;
                 else
                 {
-                    NewFiles.Add(fileName, data);
+                    FileData fd = new FileData();
+                    fd.Count = 1;
+                    fd.Data = data;
+                    NewFiles.Add(fileName, fd);
                 }
             }
-            string filename = string.Empty;
 
-            if (Requests.ContainsKey(fileName))
-            {
-                RequestXfer(Requests[fileName].remoteClient, Requests[fileName].xferID, fileName);
-                Requests.Remove(fileName);
-            }
+            // This should not be here
+            //if (Requests.ContainsKey(fileName))
+            //{
+            //    RequestXfer(Requests[fileName].remoteClient, Requests[fileName].xferID, fileName);
+            //    Requests.Remove(fileName);
+            //}
 
             return true;
         }
@@ -135,6 +142,7 @@ namespace OpenSim.Region.CoreModules.Agent.Xfer
                         ulong zxferid = RequestTime[0].xferID;
                         remoteClient.SendAbortXferPacket(zxferid);
                         RemoveXferData(zxferid);
+                        RemoveOrDecrement(fileName);
                     }
                 }
 
@@ -142,16 +150,19 @@ namespace OpenSim.Region.CoreModules.Agent.Xfer
                 {
                     if (!Transfers.ContainsKey(xferID))
                     {
-                        byte[] fileData = NewFiles[fileName];
+                        byte[] fileData = NewFiles[fileName].Data;
                         XferDownLoad transaction = new XferDownLoad(fileName, fileData, xferID, remoteClient);
 
                         Transfers.Add(xferID, transaction);
-                        NewFiles.Remove(fileName);
 
                         if (transaction.StartSend())
                         {
                             RemoveXferData(xferID);
                         }
+
+                        // The transaction for this file is either complete or on its way
+                        RemoveOrDecrement(fileName);
+
                     }
                 }
                 else
@@ -195,6 +206,7 @@ namespace OpenSim.Region.CoreModules.Agent.Xfer
                     {
                         {
                             RemoveXferData(xferID);
+                            RemoveOrDecrement(dl.FileName);
                         }
                     }
                     else
@@ -226,8 +238,6 @@ namespace OpenSim.Region.CoreModules.Agent.Xfer
                 xferItem.DataPointer = 0;
 
                 // If the abort comes in 
-                if (NewFiles.ContainsKey(xferItem.FileName))
-                    NewFiles.Remove(xferItem.FileName);
 
                 if (Requests.ContainsKey(xferItem.FileName))
                     Requests.Remove(xferItem.FileName);
@@ -239,10 +249,26 @@ namespace OpenSim.Region.CoreModules.Agent.Xfer
         {
             lock (NewFiles)
             {
+                if (Transfers.ContainsKey(xferID))
+                    RemoveOrDecrement(Transfers[xferID].FileName);
+
                 RemoveXferData(xferID);
             }
         }
 
+        private void RemoveOrDecrement(string fileName)
+        {
+            // NewFiles must be locked
+
+            if (NewFiles.ContainsKey(fileName))
+            {
+                if (NewFiles[fileName].Count == 1)
+                    NewFiles.Remove(fileName);
+                else
+                    NewFiles[fileName].Count--;
+            }
+        }
+
         #region Nested type: XferDownLoad
 
         public class XferDownLoad