diff --git a/OpenSim/Region/CoreModules/Asset/FlotsamAssetCache.cs b/OpenSim/Region/CoreModules/Asset/FlotsamAssetCache.cs index abfc771498..b2f6e135a1 100644 --- a/OpenSim/Region/CoreModules/Asset/FlotsamAssetCache.cs +++ b/OpenSim/Region/CoreModules/Asset/FlotsamAssetCache.cs @@ -593,39 +593,60 @@ namespace Flotsam.RegionModules.AssetCache try { - if (!Directory.Exists(directory)) + try { - Directory.CreateDirectory(directory); + if (!Directory.Exists(directory)) + { + Directory.CreateDirectory(directory); + } + + stream = File.Open(tempname, FileMode.Create); + BinaryFormatter bformatter = new BinaryFormatter(); + bformatter.Serialize(stream, asset); + } + catch (IOException e) + { + m_log.ErrorFormat( + "[FLOTSAM ASSET CACHE]: Failed to write asset {0} to temporary location {1} (final {2}) on cache in {3}. Exception {4} {5}.", + asset.ID, tempname, filename, directory, e.Message, e.StackTrace); + + return; + } + finally + { + if (stream != null) + stream.Close(); } - stream = File.Open(tempname, FileMode.Create); - BinaryFormatter bformatter = new BinaryFormatter(); - bformatter.Serialize(stream, asset); - stream.Close(); - - // Now that it's written, rename it so that it can be found. - // We're doing this as a file copy operation so that if two threads are competing to cache this asset, - // then both suceed instead of one failing when it tries to move the file to a final filename that - // already exists. - // This assumes that the file copy operation is atomic. Assuming this holds, then copying also works - // if another simulator is using the same cache directory. - File.Copy(tempname, filename, true); - File.Delete(tempname); - - if (m_LogLevel >= 2) - m_log.DebugFormat("[FLOTSAM ASSET CACHE]: Cache Stored :: {0}", asset.ID); - } - catch (Exception e) - { - m_log.ErrorFormat( - "[FLOTSAM ASSET CACHE]: Failed to write asset {0} to cache. Directory {1}, tempname {2}, filename {3}. Exception {4} {5}.", - asset.ID, directory, tempname, filename, e.Message, e.StackTrace); + try + { + // Now that it's written, rename it so that it can be found. + // + // File.Copy(tempname, filename, true); + // File.Delete(tempname); + // + // For a brief period, this was done as a separate copy and then temporary file delete operation. + // However, this causes exceptions on Windows when other threads attempt to read a file + // which is still being copied. So instead, go back to moving the file and swallowing any IOException + // that occurs because two threads race to cache the same data (and the second fails because the file + // already exists). + // + // This situation occurs fairly rarely anyway. We assume in this that moves are atomic on the + // filesystem. + File.Move(tempname, filename); + + if (m_LogLevel >= 2) + m_log.DebugFormat("[FLOTSAM ASSET CACHE]: Cache Stored :: {0}", asset.ID); + } + catch (IOException) + { + // If we see an IOException here it's likely that some other competing thread has written the + // cache file first, so ignore. Other IOException errors (e.g. filesystem full) should be + // signally by the earlier temporary file writing code. + } } finally { - if (stream != null) - stream.Close(); - // Even if the write fails with an exception, we need to make sure // that we release the lock on that file, otherwise it'll never get // cached