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davydm pushed a commit to branch master
in repository https://gitbox.apache.org/repos/asf/logging-log4net.git


The following commit(s) were added to refs/heads/master by this push:
     new 963c29eb :recycle: prefer string interpolation over concatenation
963c29eb is described below

commit 963c29eb3b020668f048e156947b7584f2fe8213
Author: Davyd McColl <[email protected]>
AuthorDate: Sun Aug 21 16:14:38 2022 +0200

    :recycle: prefer string interpolation over concatenation
---
 src/log4net/Appender/FileAppender.cs | 2993 +++++++++++++++++-----------------
 1 file changed, 1516 insertions(+), 1477 deletions(-)

diff --git a/src/log4net/Appender/FileAppender.cs 
b/src/log4net/Appender/FileAppender.cs
index 8853a8cc..bf782713 100644
--- a/src/log4net/Appender/FileAppender.cs
+++ b/src/log4net/Appender/FileAppender.cs
@@ -1,4 +1,5 @@
 #region Apache License
+
 //
 // Licensed to the Apache Software Foundation (ASF) under one or more 
 // contributor license agreements. See the NOTICE file distributed with
@@ -15,6 +16,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 //
+
 #endregion
 
 using System;
@@ -34,54 +36,54 @@ using System.Threading.Tasks;
 namespace log4net.Appender
 {
 #if !NETCF
-       /// <summary>
-       /// Appends logging events to a file.
-       /// </summary>
-       /// <remarks>
-       /// <para>
-       /// Logging events are sent to the file specified by
-       /// the <see cref="File"/> property.
-       /// </para>
-       /// <para>
-       /// The file can be opened in either append or overwrite mode 
-       /// by specifying the <see cref="AppendToFile"/> property.
-       /// If the file path is relative it is taken as relative from 
-       /// the application base directory. The file encoding can be
-       /// specified by setting the <see cref="Encoding"/> property.
-       /// </para>
-       /// <para>
-       /// The layout's <see cref="ILayout.Header"/> and <see 
cref="ILayout.Footer"/>
-       /// values will be written each time the file is opened and closed
-       /// respectively. If the <see cref="AppendToFile"/> property is <see 
langword="true"/>
-       /// then the file may contain multiple copies of the header and footer.
-       /// </para>
-       /// <para>
-       /// This appender will first try to open the file for writing when <see 
cref="ActivateOptions"/>
-       /// is called. This will typically be during configuration.
-       /// If the file cannot be opened for writing the appender will attempt
-       /// to open the file again each time a message is logged to the 
appender.
-       /// If the file cannot be opened for writing when a message is logged 
then
-       /// the message will be discarded by this appender.
-       /// </para>
-       /// <para>
-       /// The <see cref="FileAppender"/> supports pluggable file locking 
models via
-       /// the <see cref="LockingModel"/> property.
-       /// The default behavior, implemented by <see 
cref="FileAppender.ExclusiveLock"/> 
-       /// is to obtain an exclusive write lock on the file until this 
appender is closed.
-       /// The alternative models only hold a
-       /// write lock while the appender is writing a logging event (<see 
cref="FileAppender.MinimalLock"/>)
-       /// or synchronize by using a named system wide Mutex (<see 
cref="FileAppender.InterProcessLock"/>).
-       /// </para>
-       /// <para>
-       /// All locking strategies have issues and you should seriously 
consider using a different strategy that
-       /// avoids having multiple processes logging to the same file.
-       /// </para>
-       /// </remarks>
-       /// <author>Nicko Cadell</author>
-       /// <author>Gert Driesen</author>
-       /// <author>Rodrigo B. de Oliveira</author>
-       /// <author>Douglas de la Torre</author>
-       /// <author>Niall Daley</author>
+    /// <summary>
+    /// Appends logging events to a file.
+    /// </summary>
+    /// <remarks>
+    /// <para>
+    /// Logging events are sent to the file specified by
+    /// the <see cref="File"/> property.
+    /// </para>
+    /// <para>
+    /// The file can be opened in either append or overwrite mode 
+    /// by specifying the <see cref="AppendToFile"/> property.
+    /// If the file path is relative it is taken as relative from 
+    /// the application base directory. The file encoding can be
+    /// specified by setting the <see cref="Encoding"/> property.
+    /// </para>
+    /// <para>
+    /// The layout's <see cref="ILayout.Header"/> and <see 
cref="ILayout.Footer"/>
+    /// values will be written each time the file is opened and closed
+    /// respectively. If the <see cref="AppendToFile"/> property is <see 
langword="true"/>
+    /// then the file may contain multiple copies of the header and footer.
+    /// </para>
+    /// <para>
+    /// This appender will first try to open the file for writing when <see 
cref="ActivateOptions"/>
+    /// is called. This will typically be during configuration.
+    /// If the file cannot be opened for writing the appender will attempt
+    /// to open the file again each time a message is logged to the appender.
+    /// If the file cannot be opened for writing when a message is logged then
+    /// the message will be discarded by this appender.
+    /// </para>
+    /// <para>
+    /// The <see cref="FileAppender"/> supports pluggable file locking models 
via
+    /// the <see cref="LockingModel"/> property.
+    /// The default behavior, implemented by <see 
cref="FileAppender.ExclusiveLock"/> 
+    /// is to obtain an exclusive write lock on the file until this appender 
is closed.
+    /// The alternative models only hold a
+    /// write lock while the appender is writing a logging event (<see 
cref="FileAppender.MinimalLock"/>)
+    /// or synchronize by using a named system wide Mutex (<see 
cref="FileAppender.InterProcessLock"/>).
+    /// </para>
+    /// <para>
+    /// All locking strategies have issues and you should seriously consider 
using a different strategy that
+    /// avoids having multiple processes logging to the same file.
+    /// </para>
+    /// </remarks>
+    /// <author>Nicko Cadell</author>
+    /// <author>Gert Driesen</author>
+    /// <author>Rodrigo B. de Oliveira</author>
+    /// <author>Douglas de la Torre</author>
+    /// <author>Niall Daley</author>
 #else
        /// <summary>
        /// Appends logging events to a file.
@@ -131,56 +133,57 @@ namespace log4net.Appender
        /// <author>Douglas de la Torre</author>
        /// <author>Niall Daley</author>
 #endif
-       public class FileAppender : TextWriterAppender
-       {
-               #region LockingStream Inner Class
-
-               /// <summary>
-               /// Write only <see cref="Stream"/> that uses the <see 
cref="LockingModelBase"/> 
-               /// to manage access to an underlying resource.
-               /// </summary>
-               private sealed class LockingStream : Stream, IDisposable
-               {
+    public class FileAppender : TextWriterAppender
+    {
+        #region LockingStream Inner Class
+
+        /// <summary>
+        /// Write only <see cref="Stream"/> that uses the <see 
cref="LockingModelBase"/> 
+        /// to manage access to an underlying resource.
+        /// </summary>
+        private sealed class LockingStream : Stream, IDisposable
+        {
 #if !NETCR
-                       [Serializable]
+            [Serializable]
 #endif
-                       public sealed class LockStateException : LogException
-                       {
-                               public LockStateException(string message)
-                                       : base(message)
-                               {
-                               }
+            public sealed class LockStateException : LogException
+            {
+                public LockStateException(string message)
+                    : base(message)
+                {
+                }
 
-                               public LockStateException()
-                               {
-                               }
+                public LockStateException()
+                {
+                }
 
-                               public LockStateException(string message, 
Exception innerException) : base(message, innerException)
-                               {
-                               }
+                public LockStateException(string message, Exception 
innerException) : base(message, innerException)
+                {
+                }
 
 #if !NETCR && !NETSTANDARD1_3
-                               private LockStateException(SerializationInfo 
info, StreamingContext context) : base(info, context)
-                               {
-                               }
+                private LockStateException(SerializationInfo info, 
StreamingContext context) : base(info, context)
+                {
+                }
 #endif
-                       }
+            }
 
-                       private Stream m_realStream = null;
-                       private LockingModelBase m_lockingModel = null;
-                       private int m_lockLevel = 0;
+            private Stream m_realStream = null;
+            private LockingModelBase m_lockingModel = null;
+            private int m_lockLevel = 0;
 
-                       public LockingStream(LockingModelBase locking)
-                               : base()
-                       {
-                               if (locking == null)
-                               {
-                                       throw new ArgumentException("Locking 
model may not be null", "locking");
-                               }
-                               m_lockingModel = locking;
-                       }
+            public LockingStream(LockingModelBase locking)
+                : base()
+            {
+                if (locking == null)
+                {
+                    throw new ArgumentException("Locking model may not be 
null", "locking");
+                }
+
+                m_lockingModel = locking;
+            }
 
-                       #region Override Implementation of Stream
+            #region Override Implementation of Stream
 
 #if NETSTANDARD
                        protected override void Dispose(bool disposing)
@@ -190,42 +193,51 @@ namespace log4net.Appender
                        }
 #else
 
-                       private int m_readTotal = -1;
-
-                       // Methods
-                       public override IAsyncResult BeginRead(byte[] buffer, 
int offset, int count, AsyncCallback callback, object state)
-                       {
-                               AssertLocked();
-                               IAsyncResult ret = 
m_realStream.BeginRead(buffer, offset, count, callback, state);
-                               m_readTotal = EndRead(ret);
-                               return ret;
-                       }
-
-                       /// <summary>
-                       /// True asynchronous writes are not supported, the 
implementation forces a synchronous write.
-                       /// </summary>
-                       public override IAsyncResult BeginWrite(byte[] buffer, 
int offset, int count, AsyncCallback callback, object state)
-                       {
-                               AssertLocked();
-                               IAsyncResult ret = 
m_realStream.BeginWrite(buffer, offset, count, callback, state);
-                               EndWrite(ret);
-                               return ret;
-                       }
-
-                       public override void Close()
-                       {
-                               m_lockingModel.CloseFile();
-                       }
-
-                       public override int EndRead(IAsyncResult asyncResult)
-                       {
-                               AssertLocked();
-                               return m_readTotal;
-                       }
-                       public override void EndWrite(IAsyncResult asyncResult)
-                       {
-                               //No-op, it has already been handled
-                       }
+            private int m_readTotal = -1;
+
+            // Methods
+            public override IAsyncResult BeginRead(byte[] buffer,
+                int offset,
+                int count,
+                AsyncCallback callback,
+                object state)
+            {
+                AssertLocked();
+                IAsyncResult ret = m_realStream.BeginRead(buffer, offset, 
count, callback, state);
+                m_readTotal = EndRead(ret);
+                return ret;
+            }
+
+            /// <summary>
+            /// True asynchronous writes are not supported, the implementation 
forces a synchronous write.
+            /// </summary>
+            public override IAsyncResult BeginWrite(byte[] buffer,
+                int offset,
+                int count,
+                AsyncCallback callback,
+                object state)
+            {
+                AssertLocked();
+                IAsyncResult ret = m_realStream.BeginWrite(buffer, offset, 
count, callback, state);
+                EndWrite(ret);
+                return ret;
+            }
+
+            public override void Close()
+            {
+                m_lockingModel.CloseFile();
+            }
+
+            public override int EndRead(IAsyncResult asyncResult)
+            {
+                AssertLocked();
+                return m_readTotal;
+            }
+
+            public override void EndWrite(IAsyncResult asyncResult)
+            {
+                //No-op, it has already been handled
+            }
 #endif
 
 #if NET_4_5 || NETSTANDARD
@@ -242,905 +254,928 @@ namespace log4net.Appender
                        }
 #endif
 
-                       public override void Flush()
-                       {
-                               AssertLocked();
-                               m_realStream.Flush();
-                       }
-                       public override int Read(byte[] buffer, int offset, int 
count)
-                       {
-                               return m_realStream.Read(buffer, offset, count);
-                       }
-                       public override int ReadByte()
-                       {
-                               return m_realStream.ReadByte();
-                       }
-                       public override long Seek(long offset, SeekOrigin 
origin)
-                       {
-                               AssertLocked();
-                               return m_realStream.Seek(offset, origin);
-                       }
-                       public override void SetLength(long value)
-                       {
-                               AssertLocked();
-                               m_realStream.SetLength(value);
-                       }
-                       void IDisposable.Dispose()
-                       {
+            public override void Flush()
+            {
+                AssertLocked();
+                m_realStream.Flush();
+            }
+
+            public override int Read(byte[] buffer, int offset, int count)
+            {
+                return m_realStream.Read(buffer, offset, count);
+            }
+
+            public override int ReadByte()
+            {
+                return m_realStream.ReadByte();
+            }
+
+            public override long Seek(long offset, SeekOrigin origin)
+            {
+                AssertLocked();
+                return m_realStream.Seek(offset, origin);
+            }
+
+            public override void SetLength(long value)
+            {
+                AssertLocked();
+                m_realStream.SetLength(value);
+            }
+
+            void IDisposable.Dispose()
+            {
 #if NETSTANDARD
                                Dispose(true);
 #else
-                               Close();
+                Close();
 #endif
-                       }
-                       public override void Write(byte[] buffer, int offset, 
int count)
-                       {
-                               AssertLocked();
-                               m_realStream.Write(buffer, offset, count);
-                       }
-                       public override void WriteByte(byte value)
-                       {
-                               AssertLocked();
-                               m_realStream.WriteByte(value);
-                       }
-
-                       // Properties
-                       public override bool CanRead
-                       {
-                               get { return false; }
-                       }
-                       public override bool CanSeek
-                       {
-                               get
-                               {
-                                       AssertLocked();
-                                       return m_realStream.CanSeek;
-                               }
-                       }
-                       public override bool CanWrite
-                       {
-                               get
-                               {
-                                       AssertLocked();
-                                       return m_realStream.CanWrite;
-                               }
-                       }
-                       public override long Length
-                       {
-                               get
-                               {
-                                       AssertLocked();
-                                       return m_realStream.Length;
-                               }
-                       }
-                       public override long Position
-                       {
-                               get
-                               {
-                                       AssertLocked();
-                                       return m_realStream.Position;
-                               }
-                               set
-                               {
-                                       AssertLocked();
-                                       m_realStream.Position = value;
-                               }
-                       }
-
-                       #endregion Override Implementation of Stream
-
-                       #region Locking Methods
-
-                       private void AssertLocked()
-                       {
-                               if (m_realStream == null)
-                               {
-                                       throw new LockStateException("The file 
is not currently locked");
-                               }
-                       }
-
-                       public bool AcquireLock()
-                       {
-                               bool ret = false;
-                               lock (this)
-                               {
-                                       if (m_lockLevel == 0)
-                                       {
-                                               // If lock is already acquired, 
nop
-                                               m_realStream = 
m_lockingModel.AcquireLock();
-                                       }
-                                       if (m_realStream != null)
-                                       {
-                                               m_lockLevel++;
-                                               ret = true;
-                                       }
-                               }
-                               return ret;
-                       }
-
-                       public void ReleaseLock()
-                       {
-                               lock (this)
-                               {
-                                       m_lockLevel--;
-                                       if (m_lockLevel == 0)
-                                       {
-                                               // If already unlocked, nop
-                                               m_lockingModel.ReleaseLock();
-                                               m_realStream = null;
-                                       }
-                               }
-                       }
-
-                       #endregion Locking Methods
-               }
-
-               #endregion LockingStream Inner Class
-
-               #region Locking Models
-
-               /// <summary>
-               /// Locking model base class
-               /// </summary>
-               /// <remarks>
-               /// <para>
-               /// Base class for the locking models available to the <see 
cref="FileAppender"/> derived loggers.
-               /// </para>
-               /// </remarks>
-               public abstract class LockingModelBase
-               {
-                       private FileAppender m_appender = null;
-
-                       /// <summary>
-                       /// Open the output file
-                       /// </summary>
-                       /// <param name="filename">The filename to use</param>
-                       /// <param name="append">Whether to append to the file, 
or overwrite</param>
-                       /// <param name="encoding">The encoding to use</param>
-                       /// <remarks>
-                       /// <para>
-                       /// Open the file specified and prepare for logging. 
-                       /// No writes will be made until <see 
cref="AcquireLock"/> is called.
-                       /// Must be called before any calls to <see 
cref="AcquireLock"/>,
-                       /// <see cref="ReleaseLock"/> and <see 
cref="CloseFile"/>.
-                       /// </para>
-                       /// </remarks>
-                       public abstract void OpenFile(string filename, bool 
append, Encoding encoding);
-
-                       /// <summary>
-                       /// Close the file
-                       /// </summary>
-                       /// <remarks>
-                       /// <para>
-                       /// Close the file. No further writes will be made.
-                       /// </para>
-                       /// </remarks>
-                       public abstract void CloseFile();
-
-                       /// <summary>
-                       /// Initializes all resources used by this locking 
model.
-                       /// </summary>
-                       public abstract void ActivateOptions();
-
-                       /// <summary>
-                       /// Disposes all resources that were initialized by 
this locking model.
-                       /// </summary>
-                       public abstract void OnClose();
-
-                       /// <summary>
-                       /// Acquire the lock on the file
-                       /// </summary>
-                       /// <returns>A stream that is ready to be written 
to.</returns>
-                       /// <remarks>
-                       /// <para>
-                       /// Acquire the lock on the file in preparation for 
writing to it. 
-                       /// Return a stream pointing to the file. <see 
cref="ReleaseLock"/>
-                       /// must be called to release the lock on the output 
file.
-                       /// </para>
-                       /// </remarks>
-                       public abstract Stream AcquireLock();
-
-                       /// <summary>
-                       /// Release the lock on the file
-                       /// </summary>
-                       /// <remarks>
-                       /// <para>
-                       /// Release the lock on the file. No further writes 
will be made to the 
-                       /// stream until <see cref="AcquireLock"/> is called 
again.
-                       /// </para>
-                       /// </remarks>
-                       public abstract void ReleaseLock();
-
-                       /// <summary>
-                       /// Gets or sets the <see cref="FileAppender"/> for 
this LockingModel
-                       /// </summary>
-                       /// <value>
-                       /// The <see cref="FileAppender"/> for this LockingModel
-                       /// </value>
-                       /// <remarks>
-                       /// <para>
-                       /// The file appender this locking model is attached to 
and working on
-                       /// behalf of.
-                       /// </para>
-                       /// <para>
-                       /// The file appender is used to locate the security 
context and the error handler to use.
-                       /// </para>
-                       /// <para>
-                       /// The value of this property will be set before <see 
cref="OpenFile"/> is
-                       /// called.
-                       /// </para>
-                       /// </remarks>
-                       public FileAppender CurrentAppender
-                       {
-                               get { return m_appender; }
-                               set { m_appender = value; }
-                       }
-
-                       /// <summary>
-                       /// Helper method that creates a FileStream under 
CurrentAppender's SecurityContext.
-                       /// </summary>
-                       /// <remarks>
-                       /// <para>
-                       /// Typically called during OpenFile or AcquireLock. 
-                       /// </para>
-                       /// <para>
-                       /// If the directory portion of the <paramref 
name="filename"/> does not exist, it is created
-                       /// via Directory.CreateDirecctory.
-                       /// </para>
-                       /// </remarks>
-                       /// <param name="filename"></param>
-                       /// <param name="append"></param>
-                       /// <param name="fileShare"></param>
-                       /// <returns></returns>
-                       protected Stream CreateStream(string filename, bool 
append, FileShare fileShare)
-                       {
-                               filename = 
Environment.ExpandEnvironmentVariables(filename);
-                               using 
(CurrentAppender.SecurityContext.Impersonate(this))
-                               {
-                                       // Ensure that the directory structure 
exists
-                                       string directoryFullName = 
Path.GetDirectoryName(filename);
-
-                                       // Only create the directory if it does 
not exist
-                                       // doing this check here resolves some 
permissions failures
-                                       if 
(!Directory.Exists(directoryFullName))
-                                       {
-                                               
Directory.CreateDirectory(directoryFullName);
-                                       }
-
-                                       FileMode fileOpenMode = append ? 
FileMode.Append : FileMode.Create;
-                                       return new FileStream(filename, 
fileOpenMode, FileAccess.Write, fileShare);
-                               }
-                       }
-
-                       /// <summary>
-                       /// Helper method to close <paramref name="stream"/> 
under CurrentAppender's SecurityContext.
-                       /// </summary>
-                       /// <remarks>
-                       /// Does not set <paramref name="stream"/> to null.
-                       /// </remarks>
-                       /// <param name="stream"></param>
-                       protected void CloseStream(Stream stream)
-                       {
-                               using 
(CurrentAppender.SecurityContext.Impersonate(this))
-                               {
-                                       stream.Dispose();
-                               }
-                       }
-               }
-
-               /// <summary>
-               /// Hold an exclusive lock on the output file
-               /// </summary>
-               /// <remarks>
-               /// <para>
-               /// Open the file once for writing and hold it open until <see 
cref="CloseFile"/> is called. 
-               /// Maintains an exclusive lock on the file during this time.
-               /// </para>
-               /// </remarks>
-               public class ExclusiveLock : LockingModelBase
-               {
-                       private Stream m_stream = null;
-
-                       /// <summary>
-                       /// Open the file specified and prepare for logging.
-                       /// </summary>
-                       /// <param name="filename">The filename to use</param>
-                       /// <param name="append">Whether to append to the file, 
or overwrite</param>
-                       /// <param name="encoding">The encoding to use</param>
-                       /// <remarks>
-                       /// <para>
-                       /// Open the file specified and prepare for logging. 
-                       /// No writes will be made until <see 
cref="AcquireLock"/> is called.
-                       /// Must be called before any calls to <see 
cref="AcquireLock"/>,
-                       /// <see cref="ReleaseLock"/> and <see 
cref="CloseFile"/>.
-                       /// </para>
-                       /// </remarks>
-                       public override void OpenFile(string filename, bool 
append, Encoding encoding)
-                       {
-                               try
-                               {
-                                       m_stream = CreateStream(filename, 
append, FileShare.Read);
-                               }
-                               catch (Exception e1)
-                               {
-                                       
CurrentAppender.ErrorHandler.Error("Unable to acquire lock on file " + filename 
+ ". " + e1.Message);
-                               }
-                       }
-
-                       /// <summary>
-                       /// Close the file
-                       /// </summary>
-                       /// <remarks>
-                       /// <para>
-                       /// Close the file. No further writes will be made.
-                       /// </para>
-                       /// </remarks>
-                       public override void CloseFile()
-                       {
-                               CloseStream(m_stream);
-                               m_stream = null;
-                       }
-
-                       /// <summary>
-                       /// Acquire the lock on the file
-                       /// </summary>
-                       /// <returns>A stream that is ready to be written 
to.</returns>
-                       /// <remarks>
-                       /// <para>
-                       /// Does nothing. The lock is already taken
-                       /// </para>
-                       /// </remarks>
-                       public override Stream AcquireLock()
-                       {
-                               return m_stream;
-                       }
-
-                       /// <summary>
-                       /// Release the lock on the file
-                       /// </summary>
-                       /// <remarks>
-                       /// <para>
-                       /// Does nothing. The lock will be released when the 
file is closed.
-                       /// </para>
-                       /// </remarks>
-                       public override void ReleaseLock()
-                       {
-                               //NOP
-                       }
-
-                       /// <summary>
-                       /// Initializes all resources used by this locking 
model.
-                       /// </summary>
-                       public override void ActivateOptions()
-                       {
-                               //NOP
-                       }
-
-                       /// <summary>
-                       /// Disposes all resources that were initialized by 
this locking model.
-                       /// </summary>
-                       public override void OnClose()
-                       {
-                               //NOP
-                       }
-               }
-
-               /// <summary>
-               /// Acquires the file lock for each write
-               /// </summary>
-               /// <remarks>
-               /// <para>
-               /// Opens the file once for each <see cref="AcquireLock"/>/<see 
cref="ReleaseLock"/> cycle, 
-               /// thus holding the lock for the minimal amount of time. This 
method of locking
-               /// is considerably slower than <see 
cref="FileAppender.ExclusiveLock"/> but allows 
-               /// other processes to move/delete the log file whilst logging 
continues.
-               /// </para>
-               /// </remarks>
-               public class MinimalLock : LockingModelBase
-               {
-                       private string m_filename;
-                       private bool m_append;
-                       private Stream m_stream = null;
-
-                       /// <summary>
-                       /// Prepares to open the file when the first message is 
logged.
-                       /// </summary>
-                       /// <param name="filename">The filename to use</param>
-                       /// <param name="append">Whether to append to the file, 
or overwrite</param>
-                       /// <param name="encoding">The encoding to use</param>
-                       /// <remarks>
-                       /// <para>
-                       /// Open the file specified and prepare for logging. 
-                       /// No writes will be made until <see 
cref="AcquireLock"/> is called.
-                       /// Must be called before any calls to <see 
cref="AcquireLock"/>,
-                       /// <see cref="ReleaseLock"/> and <see 
cref="CloseFile"/>.
-                       /// </para>
-                       /// </remarks>
-                       public override void OpenFile(string filename, bool 
append, Encoding encoding)
-                       {
-                               m_filename = filename;
-                               m_append = append;
-                       }
-
-                       /// <summary>
-                       /// Close the file
-                       /// </summary>
-                       /// <remarks>
-                       /// <para>
-                       /// Close the file. No further writes will be made.
-                       /// </para>
-                       /// </remarks>
-                       public override void CloseFile()
-                       {
-                               // NOP
-                       }
-
-                       /// <summary>
-                       /// Acquire the lock on the file
-                       /// </summary>
-                       /// <returns>A stream that is ready to be written 
to.</returns>
-                       /// <remarks>
-                       /// <para>
-                       /// Acquire the lock on the file in preparation for 
writing to it. 
-                       /// Return a stream pointing to the file. <see 
cref="ReleaseLock"/>
-                       /// must be called to release the lock on the output 
file.
-                       /// </para>
-                       /// </remarks>
-                       public override Stream AcquireLock()
-                       {
-                               if (m_stream == null)
-                               {
-                                       try
-                                       {
-                                               m_stream = 
CreateStream(m_filename, m_append, FileShare.Read);
-                                               m_append = true;
-                                       }
-                                       catch (Exception e1)
-                                       {
-                                               
CurrentAppender.ErrorHandler.Error("Unable to acquire lock on file " + 
m_filename + ". " + e1.Message);
-                                       }
-                               }
-                               return m_stream;
-                       }
-
-                       /// <summary>
-                       /// Release the lock on the file
-                       /// </summary>
-                       /// <remarks>
-                       /// <para>
-                       /// Release the lock on the file. No further writes 
will be made to the 
-                       /// stream until <see cref="AcquireLock"/> is called 
again.
-                       /// </para>
-                       /// </remarks>
-                       public override void ReleaseLock()
-                       {
-                               CloseStream(m_stream);
-                               m_stream = null;
-                       }
-
-                       /// <summary>
-                       /// Initializes all resources used by this locking 
model.
-                       /// </summary>
-                       public override void ActivateOptions()
-                       {
-                               //NOP
-                       }
-
-                       /// <summary>
-                       /// Disposes all resources that were initialized by 
this locking model.
-                       /// </summary>
-                       public override void OnClose()
-                       {
-                               //NOP
-                       }
-               }
+            }
+
+            public override void Write(byte[] buffer, int offset, int count)
+            {
+                AssertLocked();
+                m_realStream.Write(buffer, offset, count);
+            }
+
+            public override void WriteByte(byte value)
+            {
+                AssertLocked();
+                m_realStream.WriteByte(value);
+            }
+
+            // Properties
+            public override bool CanRead
+            {
+                get { return false; }
+            }
+
+            public override bool CanSeek
+            {
+                get
+                {
+                    AssertLocked();
+                    return m_realStream.CanSeek;
+                }
+            }
+
+            public override bool CanWrite
+            {
+                get
+                {
+                    AssertLocked();
+                    return m_realStream.CanWrite;
+                }
+            }
+
+            public override long Length
+            {
+                get
+                {
+                    AssertLocked();
+                    return m_realStream.Length;
+                }
+            }
+
+            public override long Position
+            {
+                get
+                {
+                    AssertLocked();
+                    return m_realStream.Position;
+                }
+                set
+                {
+                    AssertLocked();
+                    m_realStream.Position = value;
+                }
+            }
+
+            #endregion Override Implementation of Stream
+
+            #region Locking Methods
+
+            private void AssertLocked()
+            {
+                if (m_realStream == null)
+                {
+                    throw new LockStateException("The file is not currently 
locked");
+                }
+            }
+
+            public bool AcquireLock()
+            {
+                bool ret = false;
+                lock (this)
+                {
+                    if (m_lockLevel == 0)
+                    {
+                        // If lock is already acquired, nop
+                        m_realStream = m_lockingModel.AcquireLock();
+                    }
+
+                    if (m_realStream != null)
+                    {
+                        m_lockLevel++;
+                        ret = true;
+                    }
+                }
+
+                return ret;
+            }
+
+            public void ReleaseLock()
+            {
+                lock (this)
+                {
+                    m_lockLevel--;
+                    if (m_lockLevel == 0)
+                    {
+                        // If already unlocked, nop
+                        m_lockingModel.ReleaseLock();
+                        m_realStream = null;
+                    }
+                }
+            }
+
+            #endregion Locking Methods
+        }
+
+        #endregion LockingStream Inner Class
+
+        #region Locking Models
+
+        /// <summary>
+        /// Locking model base class
+        /// </summary>
+        /// <remarks>
+        /// <para>
+        /// Base class for the locking models available to the <see 
cref="FileAppender"/> derived loggers.
+        /// </para>
+        /// </remarks>
+        public abstract class LockingModelBase
+        {
+            private FileAppender m_appender = null;
+
+            /// <summary>
+            /// Open the output file
+            /// </summary>
+            /// <param name="filename">The filename to use</param>
+            /// <param name="append">Whether to append to the file, or 
overwrite</param>
+            /// <param name="encoding">The encoding to use</param>
+            /// <remarks>
+            /// <para>
+            /// Open the file specified and prepare for logging. 
+            /// No writes will be made until <see cref="AcquireLock"/> is 
called.
+            /// Must be called before any calls to <see cref="AcquireLock"/>,
+            /// <see cref="ReleaseLock"/> and <see cref="CloseFile"/>.
+            /// </para>
+            /// </remarks>
+            public abstract void OpenFile(string filename, bool append, 
Encoding encoding);
+
+            /// <summary>
+            /// Close the file
+            /// </summary>
+            /// <remarks>
+            /// <para>
+            /// Close the file. No further writes will be made.
+            /// </para>
+            /// </remarks>
+            public abstract void CloseFile();
+
+            /// <summary>
+            /// Initializes all resources used by this locking model.
+            /// </summary>
+            public abstract void ActivateOptions();
+
+            /// <summary>
+            /// Disposes all resources that were initialized by this locking 
model.
+            /// </summary>
+            public abstract void OnClose();
+
+            /// <summary>
+            /// Acquire the lock on the file
+            /// </summary>
+            /// <returns>A stream that is ready to be written to.</returns>
+            /// <remarks>
+            /// <para>
+            /// Acquire the lock on the file in preparation for writing to it. 
+            /// Return a stream pointing to the file. <see cref="ReleaseLock"/>
+            /// must be called to release the lock on the output file.
+            /// </para>
+            /// </remarks>
+            public abstract Stream AcquireLock();
+
+            /// <summary>
+            /// Release the lock on the file
+            /// </summary>
+            /// <remarks>
+            /// <para>
+            /// Release the lock on the file. No further writes will be made 
to the 
+            /// stream until <see cref="AcquireLock"/> is called again.
+            /// </para>
+            /// </remarks>
+            public abstract void ReleaseLock();
+
+            /// <summary>
+            /// Gets or sets the <see cref="FileAppender"/> for this 
LockingModel
+            /// </summary>
+            /// <value>
+            /// The <see cref="FileAppender"/> for this LockingModel
+            /// </value>
+            /// <remarks>
+            /// <para>
+            /// The file appender this locking model is attached to and 
working on
+            /// behalf of.
+            /// </para>
+            /// <para>
+            /// The file appender is used to locate the security context and 
the error handler to use.
+            /// </para>
+            /// <para>
+            /// The value of this property will be set before <see 
cref="OpenFile"/> is
+            /// called.
+            /// </para>
+            /// </remarks>
+            public FileAppender CurrentAppender
+            {
+                get { return m_appender; }
+                set { m_appender = value; }
+            }
+
+            /// <summary>
+            /// Helper method that creates a FileStream under 
CurrentAppender's SecurityContext.
+            /// </summary>
+            /// <remarks>
+            /// <para>
+            /// Typically called during OpenFile or AcquireLock. 
+            /// </para>
+            /// <para>
+            /// If the directory portion of the <paramref name="filename"/> 
does not exist, it is created
+            /// via Directory.CreateDirecctory.
+            /// </para>
+            /// </remarks>
+            /// <param name="filename"></param>
+            /// <param name="append"></param>
+            /// <param name="fileShare"></param>
+            /// <returns></returns>
+            protected Stream CreateStream(string filename, bool append, 
FileShare fileShare)
+            {
+                filename = Environment.ExpandEnvironmentVariables(filename);
+                using (CurrentAppender.SecurityContext.Impersonate(this))
+                {
+                    // Ensure that the directory structure exists
+                    string directoryFullName = Path.GetDirectoryName(filename);
+
+                    // Only create the directory if it does not exist
+                    // doing this check here resolves some permissions failures
+                    if (!Directory.Exists(directoryFullName))
+                    {
+                        Directory.CreateDirectory(directoryFullName);
+                    }
+
+                    FileMode fileOpenMode = append
+                        ? FileMode.Append
+                        : FileMode.Create;
+                    return new FileStream(filename, fileOpenMode, 
FileAccess.Write, fileShare);
+                }
+            }
+
+            /// <summary>
+            /// Helper method to close <paramref name="stream"/> under 
CurrentAppender's SecurityContext.
+            /// </summary>
+            /// <remarks>
+            /// Does not set <paramref name="stream"/> to null.
+            /// </remarks>
+            /// <param name="stream"></param>
+            protected void CloseStream(Stream stream)
+            {
+                using (CurrentAppender.SecurityContext.Impersonate(this))
+                {
+                    stream.Dispose();
+                }
+            }
+        }
+
+        /// <summary>
+        /// Hold an exclusive lock on the output file
+        /// </summary>
+        /// <remarks>
+        /// <para>
+        /// Open the file once for writing and hold it open until <see 
cref="CloseFile"/> is called. 
+        /// Maintains an exclusive lock on the file during this time.
+        /// </para>
+        /// </remarks>
+        public class ExclusiveLock : LockingModelBase
+        {
+            private Stream m_stream = null;
+
+            /// <summary>
+            /// Open the file specified and prepare for logging.
+            /// </summary>
+            /// <param name="filename">The filename to use</param>
+            /// <param name="append">Whether to append to the file, or 
overwrite</param>
+            /// <param name="encoding">The encoding to use</param>
+            /// <remarks>
+            /// <para>
+            /// Open the file specified and prepare for logging. 
+            /// No writes will be made until <see cref="AcquireLock"/> is 
called.
+            /// Must be called before any calls to <see cref="AcquireLock"/>,
+            /// <see cref="ReleaseLock"/> and <see cref="CloseFile"/>.
+            /// </para>
+            /// </remarks>
+            public override void OpenFile(string filename, bool append, 
Encoding encoding)
+            {
+                try
+                {
+                    m_stream = CreateStream(filename, append, FileShare.Read);
+                }
+                catch (Exception e1)
+                {
+                    CurrentAppender.ErrorHandler.Error("Unable to acquire lock 
on file " + filename + ". " +
+                        e1.Message);
+                }
+            }
+
+            /// <summary>
+            /// Close the file
+            /// </summary>
+            /// <remarks>
+            /// <para>
+            /// Close the file. No further writes will be made.
+            /// </para>
+            /// </remarks>
+            public override void CloseFile()
+            {
+                CloseStream(m_stream);
+                m_stream = null;
+            }
+
+            /// <summary>
+            /// Acquire the lock on the file
+            /// </summary>
+            /// <returns>A stream that is ready to be written to.</returns>
+            /// <remarks>
+            /// <para>
+            /// Does nothing. The lock is already taken
+            /// </para>
+            /// </remarks>
+            public override Stream AcquireLock()
+            {
+                return m_stream;
+            }
+
+            /// <summary>
+            /// Release the lock on the file
+            /// </summary>
+            /// <remarks>
+            /// <para>
+            /// Does nothing. The lock will be released when the file is 
closed.
+            /// </para>
+            /// </remarks>
+            public override void ReleaseLock()
+            {
+                //NOP
+            }
+
+            /// <summary>
+            /// Initializes all resources used by this locking model.
+            /// </summary>
+            public override void ActivateOptions()
+            {
+                //NOP
+            }
+
+            /// <summary>
+            /// Disposes all resources that were initialized by this locking 
model.
+            /// </summary>
+            public override void OnClose()
+            {
+                //NOP
+            }
+        }
+
+        /// <summary>
+        /// Acquires the file lock for each write
+        /// </summary>
+        /// <remarks>
+        /// <para>
+        /// Opens the file once for each <see cref="AcquireLock"/>/<see 
cref="ReleaseLock"/> cycle, 
+        /// thus holding the lock for the minimal amount of time. This method 
of locking
+        /// is considerably slower than <see 
cref="FileAppender.ExclusiveLock"/> but allows 
+        /// other processes to move/delete the log file whilst logging 
continues.
+        /// </para>
+        /// </remarks>
+        public class MinimalLock : LockingModelBase
+        {
+            private string m_filename;
+            private bool m_append;
+            private Stream m_stream = null;
+
+            /// <summary>
+            /// Prepares to open the file when the first message is logged.
+            /// </summary>
+            /// <param name="filename">The filename to use</param>
+            /// <param name="append">Whether to append to the file, or 
overwrite</param>
+            /// <param name="encoding">The encoding to use</param>
+            /// <remarks>
+            /// <para>
+            /// Open the file specified and prepare for logging. 
+            /// No writes will be made until <see cref="AcquireLock"/> is 
called.
+            /// Must be called before any calls to <see cref="AcquireLock"/>,
+            /// <see cref="ReleaseLock"/> and <see cref="CloseFile"/>.
+            /// </para>
+            /// </remarks>
+            public override void OpenFile(string filename, bool append, 
Encoding encoding)
+            {
+                m_filename = filename;
+                m_append = append;
+            }
+
+            /// <summary>
+            /// Close the file
+            /// </summary>
+            /// <remarks>
+            /// <para>
+            /// Close the file. No further writes will be made.
+            /// </para>
+            /// </remarks>
+            public override void CloseFile()
+            {
+                // NOP
+            }
+
+            /// <summary>
+            /// Acquire the lock on the file
+            /// </summary>
+            /// <returns>A stream that is ready to be written to.</returns>
+            /// <remarks>
+            /// <para>
+            /// Acquire the lock on the file in preparation for writing to it. 
+            /// Return a stream pointing to the file. <see cref="ReleaseLock"/>
+            /// must be called to release the lock on the output file.
+            /// </para>
+            /// </remarks>
+            public override Stream AcquireLock()
+            {
+                if (m_stream == null)
+                {
+                    try
+                    {
+                        m_stream = CreateStream(m_filename, m_append, 
FileShare.Read);
+                        m_append = true;
+                    }
+                    catch (Exception e1)
+                    {
+                        CurrentAppender.ErrorHandler.Error("Unable to acquire 
lock on file " + m_filename + ". " +
+                            e1.Message);
+                    }
+                }
+
+                return m_stream;
+            }
+
+            /// <summary>
+            /// Release the lock on the file
+            /// </summary>
+            /// <remarks>
+            /// <para>
+            /// Release the lock on the file. No further writes will be made 
to the 
+            /// stream until <see cref="AcquireLock"/> is called again.
+            /// </para>
+            /// </remarks>
+            public override void ReleaseLock()
+            {
+                CloseStream(m_stream);
+                m_stream = null;
+            }
+
+            /// <summary>
+            /// Initializes all resources used by this locking model.
+            /// </summary>
+            public override void ActivateOptions()
+            {
+                //NOP
+            }
+
+            /// <summary>
+            /// Disposes all resources that were initialized by this locking 
model.
+            /// </summary>
+            public override void OnClose()
+            {
+                //NOP
+            }
+        }
 
 #if !NETCF
-               /// <summary>
-               /// Provides cross-process file locking.
-               /// </summary>
-               /// <author>Ron Grabowski</author>
-               /// <author>Steve Wranovsky</author>
-               public class InterProcessLock : LockingModelBase
-               {
-                       private Mutex m_mutex = null;
-                       private Stream m_stream = null;
-                       private int m_recursiveWatch = 0;
-
-                       /// <summary>
-                       /// Open the file specified and prepare for logging.
-                       /// </summary>
-                       /// <param name="filename">The filename to use</param>
-                       /// <param name="append">Whether to append to the file, 
or overwrite</param>
-                       /// <param name="encoding">The encoding to use</param>
-                       /// <remarks>
-                       /// <para>
-                       /// Open the file specified and prepare for logging. 
-                       /// No writes will be made until <see 
cref="AcquireLock"/> is called.
-                       /// Must be called before any calls to <see 
cref="AcquireLock"/>,
-                       /// -<see cref="ReleaseLock"/> and <see 
cref="CloseFile"/>.
-                       /// </para>
-                       /// </remarks>
+        /// <summary>
+        /// Provides cross-process file locking.
+        /// </summary>
+        /// <author>Ron Grabowski</author>
+        /// <author>Steve Wranovsky</author>
+        public class InterProcessLock : LockingModelBase
+        {
+            private Mutex m_mutex = null;
+            private Stream m_stream = null;
+            private int m_recursiveWatch = 0;
+
+            /// <summary>
+            /// Open the file specified and prepare for logging.
+            /// </summary>
+            /// <param name="filename">The filename to use</param>
+            /// <param name="append">Whether to append to the file, or 
overwrite</param>
+            /// <param name="encoding">The encoding to use</param>
+            /// <remarks>
+            /// <para>
+            /// Open the file specified and prepare for logging. 
+            /// No writes will be made until <see cref="AcquireLock"/> is 
called.
+            /// Must be called before any calls to <see cref="AcquireLock"/>,
+            /// -<see cref="ReleaseLock"/> and <see cref="CloseFile"/>.
+            /// </para>
+            /// </remarks>
 #if NET_4_0 || MONO_4_0 || NETSTANDARD
                        [System.Security.SecuritySafeCritical]
 #endif
-                       public override void OpenFile(string filename, bool 
append, Encoding encoding)
-                       {
-                               try
-                               {
-                                       m_stream = CreateStream(filename, 
append, FileShare.ReadWrite);
-                               }
-                               catch (Exception e1)
-                               {
-                                       
CurrentAppender.ErrorHandler.Error("Unable to acquire lock on file " + filename 
+ ". " + e1.Message);
-                               }
-                       }
-
-                       /// <summary>
-                       /// Close the file
-                       /// </summary>
-                       /// <remarks>
-                       /// <para>
-                       /// Close the file. No further writes will be made.
-                       /// </para>
-                       /// </remarks>
-                       public override void CloseFile()
-                       {
-                               try
-                               {
-                                       CloseStream(m_stream);
-                                       m_stream = null;
-                               }
-                               finally
-                               {
-                                       ReleaseLock();
-                               }
-                       }
-
-                       /// <summary>
-                       /// Acquire the lock on the file
-                       /// </summary>
-                       /// <returns>A stream that is ready to be written 
to.</returns>
-                       /// <remarks>
-                       /// <para>
-                       /// Does nothing. The lock is already taken
-                       /// </para>
-                       /// </remarks>
-                       public override Stream AcquireLock()
-                       {
-                               if (m_mutex != null)
-                               {
-                                       // TODO: add timeout?
-                                       m_mutex.WaitOne();
-
-                                       // increment recursive watch
-                                       m_recursiveWatch++;
-
-                                       // should always be true (and fast) for 
FileStream
-                                       if (m_stream != null)
-                                       {
-                                               if (m_stream.CanSeek)
-                                               {
-                                                       m_stream.Seek(0, 
SeekOrigin.End);
-                                               }
-                                       }
-                                       else
-                                       {
-                                               // this can happen when the 
file appender cannot open a file for writing
-                                       }
-                               }
-                               else
-                               {
-                                       
CurrentAppender.ErrorHandler.Error("Programming error, no mutex available to 
acquire lock! From here on things will be dangerous!");
-                               }
-                               return m_stream;
-                       }
-
-                       /// <summary>
-                       /// Releases the lock and allows others to acquire a 
lock.
-                       /// </summary>
-                       public override void ReleaseLock()
-                       {
-                               if (m_mutex != null)
-                               {
-                                       if (m_recursiveWatch > 0)
-                                       {
-                                               m_recursiveWatch--;
-                                               m_mutex.ReleaseMutex();
-                                       }
-                               }
-                               else
-                               {
-                                       
CurrentAppender.ErrorHandler.Error("Programming error, no mutex available to 
release the lock!");
-                               }
-                       }
-
-                       /// <summary>
-                       /// Initializes all resources used by this locking 
model.
-                       /// </summary>
-                       public override void ActivateOptions()
-                       {
-                               if (m_mutex == null)
-                               {
-                                       string mutexFriendlyFilename = 
CurrentAppender.File
-                                                       .Replace("\\", "_")
-                                                       .Replace(":", "_")
-                                                       .Replace("/", "_");
-
-                                       m_mutex = new Mutex(false, 
mutexFriendlyFilename);
-                               }
-                               else
-                               {
-                                       
CurrentAppender.ErrorHandler.Error("Programming error, mutex already 
initialized!");
-                               }
-                       }
-
-                       /// <summary>
-                       /// Disposes all resources that were initialized by 
this locking model.
-                       /// </summary>
-                       public override void OnClose()
-                       {
-                               if (m_mutex != null)
-                               {
+            public override void OpenFile(string filename, bool append, 
Encoding encoding)
+            {
+                try
+                {
+                    m_stream = CreateStream(filename, append, 
FileShare.ReadWrite);
+                }
+                catch (Exception e1)
+                {
+                    CurrentAppender.ErrorHandler.Error("Unable to acquire lock 
on file " + filename + ". " +
+                        e1.Message);
+                }
+            }
+
+            /// <summary>
+            /// Close the file
+            /// </summary>
+            /// <remarks>
+            /// <para>
+            /// Close the file. No further writes will be made.
+            /// </para>
+            /// </remarks>
+            public override void CloseFile()
+            {
+                try
+                {
+                    CloseStream(m_stream);
+                    m_stream = null;
+                }
+                finally
+                {
+                    ReleaseLock();
+                }
+            }
+
+            /// <summary>
+            /// Acquire the lock on the file
+            /// </summary>
+            /// <returns>A stream that is ready to be written to.</returns>
+            /// <remarks>
+            /// <para>
+            /// Does nothing. The lock is already taken
+            /// </para>
+            /// </remarks>
+            public override Stream AcquireLock()
+            {
+                if (m_mutex != null)
+                {
+                    // TODO: add timeout?
+                    m_mutex.WaitOne();
+
+                    // increment recursive watch
+                    m_recursiveWatch++;
+
+                    // should always be true (and fast) for FileStream
+                    if (m_stream != null)
+                    {
+                        if (m_stream.CanSeek)
+                        {
+                            m_stream.Seek(0, SeekOrigin.End);
+                        }
+                    }
+                    else
+                    {
+                        // this can happen when the file appender cannot open 
a file for writing
+                    }
+                }
+                else
+                {
+                    CurrentAppender.ErrorHandler.Error(
+                        "Programming error, no mutex available to acquire 
lock! From here on things will be dangerous!");
+                }
+
+                return m_stream;
+            }
+
+            /// <summary>
+            /// Releases the lock and allows others to acquire a lock.
+            /// </summary>
+            public override void ReleaseLock()
+            {
+                if (m_mutex != null)
+                {
+                    if (m_recursiveWatch > 0)
+                    {
+                        m_recursiveWatch--;
+                        m_mutex.ReleaseMutex();
+                    }
+                }
+                else
+                {
+                    CurrentAppender.ErrorHandler.Error("Programming error, no 
mutex available to release the lock!");
+                }
+            }
+
+            /// <summary>
+            /// Initializes all resources used by this locking model.
+            /// </summary>
+            public override void ActivateOptions()
+            {
+                if (m_mutex == null)
+                {
+                    string mutexFriendlyFilename = CurrentAppender.File
+                        .Replace("\\", "_")
+                        .Replace(":", "_")
+                        .Replace("/", "_");
+
+                    m_mutex = new Mutex(false, mutexFriendlyFilename);
+                }
+                else
+                {
+                    CurrentAppender.ErrorHandler.Error("Programming error, 
mutex already initialized!");
+                }
+            }
+
+            /// <summary>
+            /// Disposes all resources that were initialized by this locking 
model.
+            /// </summary>
+            public override void OnClose()
+            {
+                if (m_mutex != null)
+                {
 #if NET_4_0 || MONO_4_0 || NETSTANDARD
                                        m_mutex.Dispose();
 #else
-                                       m_mutex.Close();
+                    m_mutex.Close();
 #endif
-                                       m_mutex = null;
-                               }
-                               else
-                               {
-                                       
CurrentAppender.ErrorHandler.Error("Programming error, mutex not initialized!");
-                               }
-                       }
-               }
+                    m_mutex = null;
+                }
+                else
+                {
+                    CurrentAppender.ErrorHandler.Error("Programming error, 
mutex not initialized!");
+                }
+            }
+        }
 #endif
 
-               /// <summary>
-               /// Hold no lock on the output file
-               /// </summary>
-               /// <remarks>
-               /// <para>
-               /// Open the file once and hold it open until <see 
cref="CloseFile"/> is called. 
-               /// Maintains no lock on the file during this time.
-               /// </para>
-               /// </remarks>
-               public class NoLock : LockingModelBase
-               {
-                       private Stream m_stream = null;
-
-                       /// <summary>
-                       /// Open the file specified and prepare for logging.
-                       /// </summary>
-                       /// <param name="filename">The filename to use</param>
-                       /// <param name="append">Whether to append to the file, 
or overwrite</param>
-                       /// <param name="encoding">The encoding to use</param>
-                       /// <remarks>
-                       /// <para>
-                       /// Open the file specified and prepare for logging. 
-                       /// No writes will be made until <see 
cref="AcquireLock"/> is called.
-                       /// Must be called before any calls to <see 
cref="AcquireLock"/>,
-                       /// <see cref="ReleaseLock"/> and <see 
cref="CloseFile"/>.
-                       /// </para>
-                       /// </remarks>
-                       public override void OpenFile(string filename, bool 
append, Encoding encoding)
-                       {
-                               try
-                               {
-                                       // no lock
-                                       m_stream = CreateStream(filename, 
append, FileShare.ReadWrite);
-                               }
-                               catch (Exception e1)
-                               {
-                                       
CurrentAppender.ErrorHandler.Error("Unable to acquire lock on file " + filename 
+ ". " + e1.Message);
-                               }
-                       }
-
-                       /// <summary>
-                       /// Close the file
-                       /// </summary>
-                       /// <remarks>
-                       /// <para>
-                       /// Close the file. No further writes will be made.
-                       /// </para>
-                       /// </remarks>
-                       public override void CloseFile()
-                       {
-                               CloseStream(m_stream);
-                               m_stream = null;
-                       }
-
-                       /// <summary>
-                       /// Acquire the lock on the file
-                       /// </summary>
-                       /// <returns>A stream that is ready to be written 
to.</returns>
-                       /// <remarks>
-                       /// <para>
-                       /// Does nothing. The lock is already taken
-                       /// </para>
-                       /// </remarks>
-                       public override Stream AcquireLock()
-                       {
-                               return m_stream;
-                       }
-
-                       /// <summary>
-                       /// Release the lock on the file
-                       /// </summary>
-                       /// <remarks>
-                       /// <para>
-                       /// Does nothing. The lock will be released when the 
file is closed.
-                       /// </para>
-                       /// </remarks>
-                       public override void ReleaseLock()
-                       {
-                               // NOP
-                       }
-
-                       /// <summary>
-                       /// Initializes all resources used by this locking 
model.
-                       /// </summary>
-                       public override void ActivateOptions()
-                       {
-                               // NOP
-                       }
-
-                       /// <summary>
-                       /// Disposes all resources that were initialized by 
this locking model.
-                       /// </summary>
-                       public override void OnClose()
-                       {
-                               // NOP
-                       }
-               }
-
-               /// <summary>
-               /// Default locking model (when no locking model was configured)
-               /// </summary>
-               private static Type defaultLockingModelType = 
typeof(ExclusiveLock);
-
-               /// <summary>
-               /// Specify default locking model
-               /// </summary>
-               /// <typeparam name="TLockingModel">Type of 
LockingModel</typeparam>
-               public static void SetDefaultLockingModelType<TLockingModel>() 
where TLockingModel : LockingModelBase
-               {
-                       defaultLockingModelType = typeof(TLockingModel);
-               }
-
-               #endregion Locking Models
-
-               #region Public Instance Constructors
-
-               /// <summary>
-               /// Default constructor
-               /// </summary>
-               /// <remarks>
-               /// <para>
-               /// Default constructor
-               /// </para>
-               /// </remarks>
-               public FileAppender()
-               {
-               }
-
-               /// <summary>
-               /// Construct a new appender using the layout, file and append 
mode.
-               /// </summary>
-               /// <param name="layout">the layout to use with this 
appender</param>
-               /// <param name="filename">the full path to the file to write 
to</param>
-               /// <param name="append">flag to indicate if the file should be 
appended to</param>
-               /// <remarks>
-               /// <para>
-               /// Obsolete constructor.
-               /// </para>
-               /// </remarks>
-               [Obsolete("Instead use the default constructor and set the 
Layout, File & AppendToFile properties")]
-               public FileAppender(ILayout layout, string filename, bool 
append)
-               {
-                       Layout = layout;
-                       File = filename;
-                       AppendToFile = append;
-                       ActivateOptions();
-               }
-
-               /// <summary>
-               /// Construct a new appender using the layout and file 
specified.
-               /// The file will be appended to.
-               /// </summary>
-               /// <param name="layout">the layout to use with this 
appender</param>
-               /// <param name="filename">the full path to the file to write 
to</param>
-               /// <remarks>
-               /// <para>
-               /// Obsolete constructor.
-               /// </para>
-               /// </remarks>
-               [Obsolete("Instead use the default constructor and set the 
Layout & File properties")]
-               public FileAppender(ILayout layout, string filename)
-                       : this(layout, filename, true)
-               {
-               }
-
-               #endregion Public Instance Constructors
-
-               #region Public Instance Properties
-
-               /// <summary>
-               /// Gets or sets the path to the file that logging will be 
written to.
-               /// </summary>
-               /// <value>
-               /// The path to the file that logging will be written to.
-               /// </value>
-               /// <remarks>
-               /// <para>
-               /// If the path is relative it is taken as relative from 
-               /// the application base directory.
-               /// </para>
-               /// </remarks>
-               public virtual string File
-               {
-                       get { return m_fileName; }
-                       set { m_fileName = value; }
-               }
-
-               /// <summary>
-               /// Gets or sets a flag that indicates whether the file should 
be
-               /// appended to or overwritten.
-               /// </summary>
-               /// <value>
-               /// Indicates whether the file should be appended to or 
overwritten.
-               /// </value>
-               /// <remarks>
-               /// <para>
-               /// If the value is set to false then the file will be 
overwritten, if 
-               /// it is set to true then the file will be appended to.
-               /// </para>
-               /// The default value is true.
-               /// </remarks>
-               public bool AppendToFile
-               {
-                       get { return m_appendToFile; }
-                       set { m_appendToFile = value; }
-               }
-
-               /// <summary>
-               /// Gets or sets <see cref="Encoding"/> used to write to the 
file.
-               /// </summary>
-               /// <value>
-               /// The <see cref="Encoding"/> used to write to the file.
-               /// </value>
-               /// <remarks>
-               /// <para>
-               /// The default encoding set is <see 
cref="System.Text.Encoding.Default"/>
-               /// which is the encoding for the system's current ANSI code 
page.
-               /// </para>
-               /// </remarks>
-               public Encoding Encoding
-               {
-                       get { return m_encoding; }
-                       set { m_encoding = value; }
-               }
-
-               /// <summary>
-               /// Gets or sets the <see cref="SecurityContext"/> used to 
write to the file.
-               /// </summary>
-               /// <value>
-               /// The <see cref="SecurityContext"/> used to write to the file.
-               /// </value>
-               /// <remarks>
-               /// <para>
-               /// Unless a <see cref="SecurityContext"/> specified here for 
this appender
-               /// the <see cref="SecurityContextProvider.DefaultProvider"/> 
is queried for the
-               /// security context to use. The default behavior is to use the 
security context
-               /// of the current thread.
-               /// </para>
-               /// </remarks>
-               public SecurityContext SecurityContext
-               {
-                       get { return m_securityContext; }
-                       set { m_securityContext = value; }
-               }
+        /// <summary>
+        /// Hold no lock on the output file
+        /// </summary>
+        /// <remarks>
+        /// <para>
+        /// Open the file once and hold it open until <see cref="CloseFile"/> 
is called. 
+        /// Maintains no lock on the file during this time.
+        /// </para>
+        /// </remarks>
+        public class NoLock : LockingModelBase
+        {
+            private Stream m_stream = null;
+
+            /// <summary>
+            /// Open the file specified and prepare for logging.
+            /// </summary>
+            /// <param name="filename">The filename to use</param>
+            /// <param name="append">Whether to append to the file, or 
overwrite</param>
+            /// <param name="encoding">The encoding to use</param>
+            /// <remarks>
+            /// <para>
+            /// Open the file specified and prepare for logging. 
+            /// No writes will be made until <see cref="AcquireLock"/> is 
called.
+            /// Must be called before any calls to <see cref="AcquireLock"/>,
+            /// <see cref="ReleaseLock"/> and <see cref="CloseFile"/>.
+            /// </para>
+            /// </remarks>
+            public override void OpenFile(string filename, bool append, 
Encoding encoding)
+            {
+                try
+                {
+                    // no lock
+                    m_stream = CreateStream(filename, append, 
FileShare.ReadWrite);
+                }
+                catch (Exception e1)
+                {
+                    CurrentAppender.ErrorHandler.Error(
+                        $"Unable to acquire lock on file {filename}. 
{e1.Message}"
+                    );
+                }
+            }
+
+            /// <summary>
+            /// Close the file
+            /// </summary>
+            /// <remarks>
+            /// <para>
+            /// Close the file. No further writes will be made.
+            /// </para>
+            /// </remarks>
+            public override void CloseFile()
+            {
+                CloseStream(m_stream);
+                m_stream = null;
+            }
+
+            /// <summary>
+            /// Acquire the lock on the file
+            /// </summary>
+            /// <returns>A stream that is ready to be written to.</returns>
+            /// <remarks>
+            /// <para>
+            /// Does nothing. The lock is already taken
+            /// </para>
+            /// </remarks>
+            public override Stream AcquireLock()
+            {
+                return m_stream;
+            }
+
+            /// <summary>
+            /// Release the lock on the file
+            /// </summary>
+            /// <remarks>
+            /// <para>
+            /// Does nothing. The lock will be released when the file is 
closed.
+            /// </para>
+            /// </remarks>
+            public override void ReleaseLock()
+            {
+                // NOP
+            }
+
+            /// <summary>
+            /// Initializes all resources used by this locking model.
+            /// </summary>
+            public override void ActivateOptions()
+            {
+                // NOP
+            }
+
+            /// <summary>
+            /// Disposes all resources that were initialized by this locking 
model.
+            /// </summary>
+            public override void OnClose()
+            {
+                // NOP
+            }
+        }
+
+        /// <summary>
+        /// Default locking model (when no locking model was configured)
+        /// </summary>
+        private static Type defaultLockingModelType = typeof(ExclusiveLock);
+
+        /// <summary>
+        /// Specify default locking model
+        /// </summary>
+        /// <typeparam name="TLockingModel">Type of LockingModel</typeparam>
+        public static void SetDefaultLockingModelType<TLockingModel>() where 
TLockingModel : LockingModelBase
+        {
+            defaultLockingModelType = typeof(TLockingModel);
+        }
+
+        #endregion Locking Models
+
+        #region Public Instance Constructors
+
+        /// <summary>
+        /// Default constructor
+        /// </summary>
+        /// <remarks>
+        /// <para>
+        /// Default constructor
+        /// </para>
+        /// </remarks>
+        public FileAppender()
+        {
+        }
+
+        /// <summary>
+        /// Construct a new appender using the layout, file and append mode.
+        /// </summary>
+        /// <param name="layout">the layout to use with this appender</param>
+        /// <param name="filename">the full path to the file to write 
to</param>
+        /// <param name="append">flag to indicate if the file should be 
appended to</param>
+        /// <remarks>
+        /// <para>
+        /// Obsolete constructor.
+        /// </para>
+        /// </remarks>
+        [Obsolete("Instead use the default constructor and set the Layout, 
File & AppendToFile properties")]
+        public FileAppender(ILayout layout, string filename, bool append)
+        {
+            Layout = layout;
+            File = filename;
+            AppendToFile = append;
+            ActivateOptions();
+        }
+
+        /// <summary>
+        /// Construct a new appender using the layout and file specified.
+        /// The file will be appended to.
+        /// </summary>
+        /// <param name="layout">the layout to use with this appender</param>
+        /// <param name="filename">the full path to the file to write 
to</param>
+        /// <remarks>
+        /// <para>
+        /// Obsolete constructor.
+        /// </para>
+        /// </remarks>
+        [Obsolete("Instead use the default constructor and set the Layout & 
File properties")]
+        public FileAppender(ILayout layout, string filename)
+            : this(layout, filename, true)
+        {
+        }
+
+        #endregion Public Instance Constructors
+
+        #region Public Instance Properties
+
+        /// <summary>
+        /// Gets or sets the path to the file that logging will be written to.
+        /// </summary>
+        /// <value>
+        /// The path to the file that logging will be written to.
+        /// </value>
+        /// <remarks>
+        /// <para>
+        /// If the path is relative it is taken as relative from 
+        /// the application base directory.
+        /// </para>
+        /// </remarks>
+        public virtual string File
+        {
+            get { return m_fileName; }
+            set { m_fileName = value; }
+        }
+
+        /// <summary>
+        /// Gets or sets a flag that indicates whether the file should be
+        /// appended to or overwritten.
+        /// </summary>
+        /// <value>
+        /// Indicates whether the file should be appended to or overwritten.
+        /// </value>
+        /// <remarks>
+        /// <para>
+        /// If the value is set to false then the file will be overwritten, if 
+        /// it is set to true then the file will be appended to.
+        /// </para>
+        /// The default value is true.
+        /// </remarks>
+        public bool AppendToFile
+        {
+            get { return m_appendToFile; }
+            set { m_appendToFile = value; }
+        }
+
+        /// <summary>
+        /// Gets or sets <see cref="Encoding"/> used to write to the file.
+        /// </summary>
+        /// <value>
+        /// The <see cref="Encoding"/> used to write to the file.
+        /// </value>
+        /// <remarks>
+        /// <para>
+        /// The default encoding set is <see 
cref="System.Text.Encoding.Default"/>
+        /// which is the encoding for the system's current ANSI code page.
+        /// </para>
+        /// </remarks>
+        public Encoding Encoding
+        {
+            get { return m_encoding; }
+            set { m_encoding = value; }
+        }
+
+        /// <summary>
+        /// Gets or sets the <see cref="SecurityContext"/> used to write to 
the file.
+        /// </summary>
+        /// <value>
+        /// The <see cref="SecurityContext"/> used to write to the file.
+        /// </value>
+        /// <remarks>
+        /// <para>
+        /// Unless a <see cref="SecurityContext"/> specified here for this 
appender
+        /// the <see cref="SecurityContextProvider.DefaultProvider"/> is 
queried for the
+        /// security context to use. The default behavior is to use the 
security context
+        /// of the current thread.
+        /// </para>
+        /// </remarks>
+        public SecurityContext SecurityContext
+        {
+            get { return m_securityContext; }
+            set { m_securityContext = value; }
+        }
 
 #if NETCF
                /// <summary>
@@ -1164,475 +1199,479 @@ namespace log4net.Appender
                /// </para>
                /// </remarks>
 #else
-               /// <summary>
-               /// Gets or sets the <see cref="FileAppender.LockingModel"/> 
used to handle locking of the file.
-               /// </summary>
-               /// <value>
-               /// The <see cref="FileAppender.LockingModel"/> used to lock 
the file.
-               /// </value>
-               /// <remarks>
-               /// <para>
-               /// Gets or sets the <see cref="FileAppender.LockingModel"/> 
used to handle locking of the file.
-               /// </para>
-               /// <para>
-               /// There are three built in locking models, <see 
cref="FileAppender.ExclusiveLock"/>, <see cref="FileAppender.MinimalLock"/> and 
<see cref="FileAppender.InterProcessLock"/> .
-               /// The first locks the file from the start of logging to the 
end, the 
-               /// second locks only for the minimal amount of time when 
logging each message
-               /// and the last synchronizes processes using a named system 
wide Mutex.
-               /// </para>
-               /// <para>
-               /// The default locking model is the <see 
cref="FileAppender.ExclusiveLock"/>.
-               /// </para>
-               /// </remarks>
+        /// <summary>
+        /// Gets or sets the <see cref="FileAppender.LockingModel"/> used to 
handle locking of the file.
+        /// </summary>
+        /// <value>
+        /// The <see cref="FileAppender.LockingModel"/> used to lock the file.
+        /// </value>
+        /// <remarks>
+        /// <para>
+        /// Gets or sets the <see cref="FileAppender.LockingModel"/> used to 
handle locking of the file.
+        /// </para>
+        /// <para>
+        /// There are three built in locking models, <see 
cref="FileAppender.ExclusiveLock"/>, <see cref="FileAppender.MinimalLock"/> and 
<see cref="FileAppender.InterProcessLock"/> .
+        /// The first locks the file from the start of logging to the end, the 
+        /// second locks only for the minimal amount of time when logging each 
message
+        /// and the last synchronizes processes using a named system wide 
Mutex.
+        /// </para>
+        /// <para>
+        /// The default locking model is the <see 
cref="FileAppender.ExclusiveLock"/>.
+        /// </para>
+        /// </remarks>
 #endif
-               public FileAppender.LockingModelBase LockingModel
-               {
-                       get { return m_lockingModel; }
-                       set { m_lockingModel = value; }
-               }
-
-               #endregion Public Instance Properties
-
-               #region Override implementation of AppenderSkeleton
-
-               /// <summary>
-               /// Activate the options on the file appender. 
-               /// </summary>
-               /// <remarks>
-               /// <para>
-               /// This is part of the <see cref="IOptionHandler"/> delayed 
object
-               /// activation scheme. The <see cref="ActivateOptions"/> method 
must 
-               /// be called on this object after the configuration properties 
have
-               /// been set. Until <see cref="ActivateOptions"/> is called this
-               /// object is in an undefined state and must not be used. 
-               /// </para>
-               /// <para>
-               /// If any of the configuration properties are modified then 
-               /// <see cref="ActivateOptions"/> must be called again.
-               /// </para>
-               /// <para>
-               /// This will cause the file to be opened.
-               /// </para>
-               /// </remarks>
-               public override void ActivateOptions()
-               {
-                       base.ActivateOptions();
-
-                       if (m_securityContext == null)
-                       {
-                               m_securityContext = 
SecurityContextProvider.DefaultProvider.CreateSecurityContext(this);
-                       }
-
-                       if (m_lockingModel == null)
-                       {
-                               m_lockingModel = 
(LockingModelBase)Activator.CreateInstance(defaultLockingModelType);
-                       }
-
-                       m_lockingModel.CurrentAppender = this;
-                       m_lockingModel.ActivateOptions();
-
-                       if (m_fileName != null)
-                       {
-                               using (SecurityContext.Impersonate(this))
-                               {
-                                       m_fileName = 
ConvertToFullPath(m_fileName.Trim());
-                               }
-                               SafeOpenFile(m_fileName, m_appendToFile);
-                       }
-                       else
-                       {
-                               LogLog.Warn(declaringType, "FileAppender: File 
option not set for appender [" + Name + "].");
-                               LogLog.Warn(declaringType, "FileAppender: Are 
you using FileAppender instead of ConsoleAppender?");
-                       }
-               }
-
-               #endregion Override implementation of AppenderSkeleton
-
-               #region Override implementation of TextWriterAppender
-
-               /// <summary>
-               /// Closes any previously opened file and calls the parent's 
<see cref="TextWriterAppender.Reset"/>.
-               /// </summary>
-               /// <remarks>
-               /// <para>
-               /// Resets the filename and the file stream.
-               /// </para>
-               /// </remarks>
-               protected override void Reset()
-               {
-                       base.Reset();
-                       m_fileName = null;
-               }
-
-               /// <summary>
-               /// Close this appender instance. The underlying stream or 
writer is also closed.
-               /// </summary>
-               protected override void OnClose()
-               {
-                       base.OnClose();
-                       m_lockingModel.OnClose();
-               }
-
-               /// <summary>
-               /// Called to initialize the file writer
-               /// </summary>
-               /// <remarks>
-               /// <para>
-               /// Will be called for each logged message until the file is
-               /// successfully opened.
-               /// </para>
-               /// </remarks>
-               protected override void PrepareWriter()
-               {
-                       SafeOpenFile(m_fileName, m_appendToFile);
-               }
-
-               /// <summary>
-               /// This method is called by the <see 
cref="M:AppenderSkeleton.DoAppend(LoggingEvent)"/>
-               /// method. 
-               /// </summary>
-               /// <param name="loggingEvent">The event to log.</param>
-               /// <remarks>
-               /// <para>
-               /// Writes a log statement to the output stream if the output 
stream exists 
-               /// and is writable.  
-               /// </para>
-               /// <para>
-               /// The format of the output will depend on the appender's 
layout.
-               /// </para>
-               /// </remarks>
-               protected override void Append(LoggingEvent loggingEvent)
-               {
-                       if (m_stream.AcquireLock())
-                       {
-                               try
-                               {
-                                       base.Append(loggingEvent);
-                               }
-                               finally
-                               {
-                                       m_stream.ReleaseLock();
-                               }
-                       }
-               }
-
-               /// <summary>
-               /// This method is called by the <see 
cref="M:AppenderSkeleton.DoAppend(LoggingEvent[])"/>
-               /// method. 
-               /// </summary>
-               /// <param name="loggingEvents">The array of events to 
log.</param>
-               /// <remarks>
-               /// <para>
-               /// Acquires the output file locks once before writing all the 
events to
-               /// the stream.
-               /// </para>
-               /// </remarks>
-               protected override void Append(LoggingEvent[] loggingEvents)
-               {
-                       if (m_stream.AcquireLock())
-                       {
-                               try
-                               {
-                                       base.Append(loggingEvents);
-                               }
-                               finally
-                               {
-                                       m_stream.ReleaseLock();
-                               }
-                       }
-               }
-
-               /// <summary>
-               /// Writes a footer as produced by the embedded layout's <see 
cref="ILayout.Footer"/> property.
-               /// </summary>
-               /// <remarks>
-               /// <para>
-               /// Writes a footer as produced by the embedded layout's <see 
cref="ILayout.Footer"/> property.
-               /// </para>
-               /// </remarks>
-               protected override void WriteFooter()
-               {
-                       if (m_stream != null)
-                       {
-                               //WriteFooter can be called even before a file 
is opened
-                               m_stream.AcquireLock();
-                               try
-                               {
-                                       base.WriteFooter();
-                               }
-                               finally
-                               {
-                                       m_stream.ReleaseLock();
-                               }
-                       }
-               }
-
-               /// <summary>
-               /// Writes a header produced by the embedded layout's <see 
cref="ILayout.Header"/> property.
-               /// </summary>
-               /// <remarks>
-               /// <para>
-               /// Writes a header produced by the embedded layout's <see 
cref="ILayout.Header"/> property.
-               /// </para>
-               /// </remarks>
-               protected override void WriteHeader()
-               {
-                       if (m_stream != null)
-                       {
-                               if (m_stream.AcquireLock())
-                               {
-                                       try
-                                       {
-                                               base.WriteHeader();
-                                       }
-                                       finally
-                                       {
-                                               m_stream.ReleaseLock();
-                                       }
-                               }
-                       }
-               }
-
-               /// <summary>
-               /// Closes the underlying <see cref="TextWriter"/>.
-               /// </summary>
-               /// <remarks>
-               /// <para>
-               /// Closes the underlying <see cref="TextWriter"/>.
-               /// </para>
-               /// </remarks>
-               protected override void CloseWriter()
-               {
-                       if (m_stream != null)
-                       {
-                               m_stream.AcquireLock();
-                               try
-                               {
-                                       base.CloseWriter();
-                               }
-                               finally
-                               {
-                                       m_stream.ReleaseLock();
-                               }
-                       }
-               }
-
-               #endregion Override implementation of TextWriterAppender
-
-               #region Public Instance Methods
-
-               /// <summary>
-               /// Closes the previously opened file.
-               /// </summary>
-               /// <remarks>
-               /// <para>
-               /// Writes the <see cref="ILayout.Footer"/> to the file and then
-               /// closes the file.
-               /// </para>
-               /// </remarks>
-               protected void CloseFile()
-               {
-                       WriteFooterAndCloseWriter();
-               }
-
-               #endregion Public Instance Methods
-
-               #region Protected Instance Methods
-
-               /// <summary>
-               /// Sets and <i>opens</i> the file where the log output will 
go. The specified file must be writable.
-               /// </summary>
-               /// <param name="fileName">The path to the log file. Must be a 
fully qualified path.</param>
-               /// <param name="append">If true will append to fileName. 
Otherwise will truncate fileName</param>
-               /// <remarks>
-               /// <para>
-               /// Calls <see cref="OpenFile"/> but guarantees not to throw an 
exception.
-               /// Errors are passed to the <see 
cref="TextWriterAppender.ErrorHandler"/>.
-               /// </para>
-               /// </remarks>
-               protected virtual void SafeOpenFile(string fileName, bool 
append)
-               {
-                       try
-                       {
-                               OpenFile(fileName, append);
-                       }
-                       catch (Exception e)
-                       {
-                               ErrorHandler.Error("OpenFile(" + fileName + "," 
+ append + ") call failed.", e, ErrorCode.FileOpenFailure);
-                       }
-               }
-
-               /// <summary>
-               /// Sets and <i>opens</i> the file where the log output will 
go. The specified file must be writable.
-               /// </summary>
-               /// <param name="fileName">The path to the log file. Must be a 
fully qualified path.</param>
-               /// <param name="append">If true will append to fileName. 
Otherwise will truncate fileName</param>
-               /// <remarks>
-               /// <para>
-               /// If there was already an opened file, then the previous file
-               /// is closed first.
-               /// </para>
-               /// <para>
-               /// This method will ensure that the directory structure
-               /// for the <paramref name="fileName"/> specified exists.
-               /// </para>
-               /// </remarks>
-               protected virtual void OpenFile(string fileName, bool append)
-               {
-                       if (LogLog.IsErrorEnabled)
-                       {
-                               // Internal check that the fileName passed in 
is a rooted path
-                               bool isPathRooted = false;
-                               using (SecurityContext.Impersonate(this))
-                               {
-                                       isPathRooted = 
Path.IsPathRooted(fileName);
-                               }
-                               if (!isPathRooted)
-                               {
-                                       LogLog.Error(declaringType, "INTERNAL 
ERROR. OpenFile(" + fileName + "): File name is not fully qualified.");
-                               }
-                       }
-
-                       lock (this)
-                       {
-                               Reset();
-
-                               LogLog.Debug(declaringType, "Opening file for 
writing [" + fileName + "] append [" + append + "]");
-
-                               // Save these for later, allowing retries if 
file open fails
-                               m_fileName = fileName;
-                               m_appendToFile = append;
-
-                               LockingModel.CurrentAppender = this;
-                               LockingModel.OpenFile(fileName, append, 
m_encoding);
-                               m_stream = new LockingStream(LockingModel);
-
-                               if (m_stream != null)
-                               {
-                                       m_stream.AcquireLock();
-                                       try
-                                       {
-                                               SetQWForFiles(m_stream);
-                                       }
-                                       finally
-                                       {
-                                               m_stream.ReleaseLock();
-                                       }
-                               }
-
-                               WriteHeader();
-                       }
-               }
-
-               /// <summary>
-               /// Sets the quiet writer used for file output
-               /// </summary>
-               /// <param name="fileStream">the file stream that has been 
opened for writing</param>
-               /// <remarks>
-               /// <para>
-               /// This implementation of <see 
cref="M:SetQWForFiles(Stream)"/> creates a <see cref="StreamWriter"/>
-               /// over the <paramref name="fileStream"/> and passes it to the 
-               /// <see cref="M:SetQWForFiles(TextWriter)"/> method.
-               /// </para>
-               /// <para>
-               /// This method can be overridden by sub classes that want to 
wrap the
-               /// <see cref="Stream"/> in some way, for example to encrypt 
the output
-               /// data using a 
<c>System.Security.Cryptography.CryptoStream</c>.
-               /// </para>
-               /// </remarks>
-               protected virtual void SetQWForFiles(Stream fileStream)
-               {
+        public FileAppender.LockingModelBase LockingModel
+        {
+            get { return m_lockingModel; }
+            set { m_lockingModel = value; }
+        }
+
+        #endregion Public Instance Properties
+
+        #region Override implementation of AppenderSkeleton
+
+        /// <summary>
+        /// Activate the options on the file appender. 
+        /// </summary>
+        /// <remarks>
+        /// <para>
+        /// This is part of the <see cref="IOptionHandler"/> delayed object
+        /// activation scheme. The <see cref="ActivateOptions"/> method must 
+        /// be called on this object after the configuration properties have
+        /// been set. Until <see cref="ActivateOptions"/> is called this
+        /// object is in an undefined state and must not be used. 
+        /// </para>
+        /// <para>
+        /// If any of the configuration properties are modified then 
+        /// <see cref="ActivateOptions"/> must be called again.
+        /// </para>
+        /// <para>
+        /// This will cause the file to be opened.
+        /// </para>
+        /// </remarks>
+        public override void ActivateOptions()
+        {
+            base.ActivateOptions();
+
+            if (m_securityContext == null)
+            {
+                m_securityContext = 
SecurityContextProvider.DefaultProvider.CreateSecurityContext(this);
+            }
+
+            if (m_lockingModel == null)
+            {
+                m_lockingModel = (LockingModelBase) 
Activator.CreateInstance(defaultLockingModelType);
+            }
+
+            m_lockingModel.CurrentAppender = this;
+            m_lockingModel.ActivateOptions();
+
+            if (m_fileName != null)
+            {
+                using (SecurityContext.Impersonate(this))
+                {
+                    m_fileName = ConvertToFullPath(m_fileName.Trim());
+                }
+
+                SafeOpenFile(m_fileName, m_appendToFile);
+            }
+            else
+            {
+                LogLog.Warn(declaringType, "FileAppender: File option not set 
for appender [" + Name + "].");
+                LogLog.Warn(declaringType, "FileAppender: Are you using 
FileAppender instead of ConsoleAppender?");
+            }
+        }
+
+        #endregion Override implementation of AppenderSkeleton
+
+        #region Override implementation of TextWriterAppender
+
+        /// <summary>
+        /// Closes any previously opened file and calls the parent's <see 
cref="TextWriterAppender.Reset"/>.
+        /// </summary>
+        /// <remarks>
+        /// <para>
+        /// Resets the filename and the file stream.
+        /// </para>
+        /// </remarks>
+        protected override void Reset()
+        {
+            base.Reset();
+            m_fileName = null;
+        }
+
+        /// <summary>
+        /// Close this appender instance. The underlying stream or writer is 
also closed.
+        /// </summary>
+        protected override void OnClose()
+        {
+            base.OnClose();
+            m_lockingModel.OnClose();
+        }
+
+        /// <summary>
+        /// Called to initialize the file writer
+        /// </summary>
+        /// <remarks>
+        /// <para>
+        /// Will be called for each logged message until the file is
+        /// successfully opened.
+        /// </para>
+        /// </remarks>
+        protected override void PrepareWriter()
+        {
+            SafeOpenFile(m_fileName, m_appendToFile);
+        }
+
+        /// <summary>
+        /// This method is called by the <see 
cref="M:AppenderSkeleton.DoAppend(LoggingEvent)"/>
+        /// method. 
+        /// </summary>
+        /// <param name="loggingEvent">The event to log.</param>
+        /// <remarks>
+        /// <para>
+        /// Writes a log statement to the output stream if the output stream 
exists 
+        /// and is writable.  
+        /// </para>
+        /// <para>
+        /// The format of the output will depend on the appender's layout.
+        /// </para>
+        /// </remarks>
+        protected override void Append(LoggingEvent loggingEvent)
+        {
+            if (m_stream.AcquireLock())
+            {
+                try
+                {
+                    base.Append(loggingEvent);
+                }
+                finally
+                {
+                    m_stream.ReleaseLock();
+                }
+            }
+        }
+
+        /// <summary>
+        /// This method is called by the <see 
cref="M:AppenderSkeleton.DoAppend(LoggingEvent[])"/>
+        /// method. 
+        /// </summary>
+        /// <param name="loggingEvents">The array of events to log.</param>
+        /// <remarks>
+        /// <para>
+        /// Acquires the output file locks once before writing all the events 
to
+        /// the stream.
+        /// </para>
+        /// </remarks>
+        protected override void Append(LoggingEvent[] loggingEvents)
+        {
+            if (m_stream.AcquireLock())
+            {
+                try
+                {
+                    base.Append(loggingEvents);
+                }
+                finally
+                {
+                    m_stream.ReleaseLock();
+                }
+            }
+        }
+
+        /// <summary>
+        /// Writes a footer as produced by the embedded layout's <see 
cref="ILayout.Footer"/> property.
+        /// </summary>
+        /// <remarks>
+        /// <para>
+        /// Writes a footer as produced by the embedded layout's <see 
cref="ILayout.Footer"/> property.
+        /// </para>
+        /// </remarks>
+        protected override void WriteFooter()
+        {
+            if (m_stream != null)
+            {
+                //WriteFooter can be called even before a file is opened
+                m_stream.AcquireLock();
+                try
+                {
+                    base.WriteFooter();
+                }
+                finally
+                {
+                    m_stream.ReleaseLock();
+                }
+            }
+        }
+
+        /// <summary>
+        /// Writes a header produced by the embedded layout's <see 
cref="ILayout.Header"/> property.
+        /// </summary>
+        /// <remarks>
+        /// <para>
+        /// Writes a header produced by the embedded layout's <see 
cref="ILayout.Header"/> property.
+        /// </para>
+        /// </remarks>
+        protected override void WriteHeader()
+        {
+            if (m_stream != null)
+            {
+                if (m_stream.AcquireLock())
+                {
+                    try
+                    {
+                        base.WriteHeader();
+                    }
+                    finally
+                    {
+                        m_stream.ReleaseLock();
+                    }
+                }
+            }
+        }
+
+        /// <summary>
+        /// Closes the underlying <see cref="TextWriter"/>.
+        /// </summary>
+        /// <remarks>
+        /// <para>
+        /// Closes the underlying <see cref="TextWriter"/>.
+        /// </para>
+        /// </remarks>
+        protected override void CloseWriter()
+        {
+            if (m_stream != null)
+            {
+                m_stream.AcquireLock();
+                try
+                {
+                    base.CloseWriter();
+                }
+                finally
+                {
+                    m_stream.ReleaseLock();
+                }
+            }
+        }
+
+        #endregion Override implementation of TextWriterAppender
+
+        #region Public Instance Methods
+
+        /// <summary>
+        /// Closes the previously opened file.
+        /// </summary>
+        /// <remarks>
+        /// <para>
+        /// Writes the <see cref="ILayout.Footer"/> to the file and then
+        /// closes the file.
+        /// </para>
+        /// </remarks>
+        protected void CloseFile()
+        {
+            WriteFooterAndCloseWriter();
+        }
+
+        #endregion Public Instance Methods
+
+        #region Protected Instance Methods
+
+        /// <summary>
+        /// Sets and <i>opens</i> the file where the log output will go. The 
specified file must be writable.
+        /// </summary>
+        /// <param name="fileName">The path to the log file. Must be a fully 
qualified path.</param>
+        /// <param name="append">If true will append to fileName. Otherwise 
will truncate fileName</param>
+        /// <remarks>
+        /// <para>
+        /// Calls <see cref="OpenFile"/> but guarantees not to throw an 
exception.
+        /// Errors are passed to the <see 
cref="TextWriterAppender.ErrorHandler"/>.
+        /// </para>
+        /// </remarks>
+        protected virtual void SafeOpenFile(string fileName, bool append)
+        {
+            try
+            {
+                OpenFile(fileName, append);
+            }
+            catch (Exception e)
+            {
+                ErrorHandler.Error("OpenFile(" + fileName + "," + append + ") 
call failed.", e,
+                    ErrorCode.FileOpenFailure);
+            }
+        }
+
+        /// <summary>
+        /// Sets and <i>opens</i> the file where the log output will go. The 
specified file must be writable.
+        /// </summary>
+        /// <param name="fileName">The path to the log file. Must be a fully 
qualified path.</param>
+        /// <param name="append">If true will append to fileName. Otherwise 
will truncate fileName</param>
+        /// <remarks>
+        /// <para>
+        /// If there was already an opened file, then the previous file
+        /// is closed first.
+        /// </para>
+        /// <para>
+        /// This method will ensure that the directory structure
+        /// for the <paramref name="fileName"/> specified exists.
+        /// </para>
+        /// </remarks>
+        protected virtual void OpenFile(string fileName, bool append)
+        {
+            if (LogLog.IsErrorEnabled)
+            {
+                // Internal check that the fileName passed in is a rooted path
+                bool isPathRooted = false;
+                using (SecurityContext.Impersonate(this))
+                {
+                    isPathRooted = Path.IsPathRooted(fileName);
+                }
+
+                if (!isPathRooted)
+                {
+                    LogLog.Error(declaringType,
+                        "INTERNAL ERROR. OpenFile(" + fileName + "): File name 
is not fully qualified.");
+                }
+            }
+
+            lock (this)
+            {
+                Reset();
+
+                LogLog.Debug(declaringType, "Opening file for writing [" + 
fileName + "] append [" + append + "]");
+
+                // Save these for later, allowing retries if file open fails
+                m_fileName = fileName;
+                m_appendToFile = append;
+
+                LockingModel.CurrentAppender = this;
+                LockingModel.OpenFile(fileName, append, m_encoding);
+                m_stream = new LockingStream(LockingModel);
+
+                if (m_stream != null)
+                {
+                    m_stream.AcquireLock();
+                    try
+                    {
+                        SetQWForFiles(m_stream);
+                    }
+                    finally
+                    {
+                        m_stream.ReleaseLock();
+                    }
+                }
+
+                WriteHeader();
+            }
+        }
+
+        /// <summary>
+        /// Sets the quiet writer used for file output
+        /// </summary>
+        /// <param name="fileStream">the file stream that has been opened for 
writing</param>
+        /// <remarks>
+        /// <para>
+        /// This implementation of <see cref="M:SetQWForFiles(Stream)"/> 
creates a <see cref="StreamWriter"/>
+        /// over the <paramref name="fileStream"/> and passes it to the 
+        /// <see cref="M:SetQWForFiles(TextWriter)"/> method.
+        /// </para>
+        /// <para>
+        /// This method can be overridden by sub classes that want to wrap the
+        /// <see cref="Stream"/> in some way, for example to encrypt the output
+        /// data using a <c>System.Security.Cryptography.CryptoStream</c>.
+        /// </para>
+        /// </remarks>
+        protected virtual void SetQWForFiles(Stream fileStream)
+        {
 #pragma warning disable CA2000 // Dispose objects before losing scope
-                       StreamWriter writer = new StreamWriter(fileStream, 
m_encoding);
+            StreamWriter writer = new StreamWriter(fileStream, m_encoding);
 #pragma warning restore CA2000 // Dispose objects before losing scope
-                       SetQWForFiles(writer);
-               }
-
-               /// <summary>
-               /// Sets the quiet writer being used.
-               /// </summary>
-               /// <param name="writer">the writer over the file stream that 
has been opened for writing</param>
-               /// <remarks>
-               /// <para>
-               /// This method can be overridden by sub classes that want to
-               /// wrap the <see cref="TextWriter"/> in some way.
-               /// </para>
-               /// </remarks>
-               protected virtual void SetQWForFiles(TextWriter writer)
-               {
-                       QuietWriter = new QuietTextWriter(writer, ErrorHandler);
-               }
-
-               #endregion Protected Instance Methods
-
-               #region Protected Static Methods
-
-               /// <summary>
-               /// Convert a path into a fully qualified path.
-               /// </summary>
-               /// <param name="path">The path to convert.</param>
-               /// <returns>The fully qualified path.</returns>
-               /// <remarks>
-               /// <para>
-               /// Converts the path specified to a fully
-               /// qualified path. If the path is relative it is
-               /// taken as relative from the application base 
-               /// directory.
-               /// </para>
-               /// </remarks>
-               protected static string ConvertToFullPath(string path)
-               {
-                       return SystemInfo.ConvertToFullPath(path);
-               }
-
-               #endregion Protected Static Methods
-
-               #region Private Instance Fields
-
-               /// <summary>
-               /// Flag to indicate if we should append to the file
-               /// or overwrite the file. The default is to append.
-               /// </summary>
-               private bool m_appendToFile = true;
-
-               /// <summary>
-               /// The name of the log file.
-               /// </summary>
-               private string m_fileName = null;
-
-               /// <summary>
-               /// The encoding to use for the file stream.
-               /// </summary>
-               private Encoding m_encoding = Encoding.GetEncoding(0);
-
-               /// <summary>
-               /// The security context to use for privileged calls
-               /// </summary>
-               private SecurityContext m_securityContext;
-
-               /// <summary>
-               /// The stream to log to. Has added locking semantics
-               /// </summary>
-               private FileAppender.LockingStream m_stream = null;
-
-               /// <summary>
-               /// The locking model to use
-               /// </summary>
-               private FileAppender.LockingModelBase m_lockingModel = new 
FileAppender.ExclusiveLock();
-
-               #endregion Private Instance Fields
-
-               #region Private Static Fields
-
-               /// <summary>
-               /// The fully qualified type of the FileAppender class.
-               /// </summary>
-               /// <remarks>
-               /// Used by the internal logger to record the Type of the
-               /// log message.
-               /// </remarks>
-               private static readonly Type declaringType = 
typeof(FileAppender);
-
-               #endregion Private Static Fields
-       }
-}
+            SetQWForFiles(writer);
+        }
+
+        /// <summary>
+        /// Sets the quiet writer being used.
+        /// </summary>
+        /// <param name="writer">the writer over the file stream that has been 
opened for writing</param>
+        /// <remarks>
+        /// <para>
+        /// This method can be overridden by sub classes that want to
+        /// wrap the <see cref="TextWriter"/> in some way.
+        /// </para>
+        /// </remarks>
+        protected virtual void SetQWForFiles(TextWriter writer)
+        {
+            QuietWriter = new QuietTextWriter(writer, ErrorHandler);
+        }
+
+        #endregion Protected Instance Methods
+
+        #region Protected Static Methods
+
+        /// <summary>
+        /// Convert a path into a fully qualified path.
+        /// </summary>
+        /// <param name="path">The path to convert.</param>
+        /// <returns>The fully qualified path.</returns>
+        /// <remarks>
+        /// <para>
+        /// Converts the path specified to a fully
+        /// qualified path. If the path is relative it is
+        /// taken as relative from the application base 
+        /// directory.
+        /// </para>
+        /// </remarks>
+        protected static string ConvertToFullPath(string path)
+        {
+            return SystemInfo.ConvertToFullPath(path);
+        }
+
+        #endregion Protected Static Methods
+
+        #region Private Instance Fields
+
+        /// <summary>
+        /// Flag to indicate if we should append to the file
+        /// or overwrite the file. The default is to append.
+        /// </summary>
+        private bool m_appendToFile = true;
+
+        /// <summary>
+        /// The name of the log file.
+        /// </summary>
+        private string m_fileName = null;
+
+        /// <summary>
+        /// The encoding to use for the file stream.
+        /// </summary>
+        private Encoding m_encoding = Encoding.GetEncoding(0);
+
+        /// <summary>
+        /// The security context to use for privileged calls
+        /// </summary>
+        private SecurityContext m_securityContext;
+
+        /// <summary>
+        /// The stream to log to. Has added locking semantics
+        /// </summary>
+        private FileAppender.LockingStream m_stream = null;
+
+        /// <summary>
+        /// The locking model to use
+        /// </summary>
+        private FileAppender.LockingModelBase m_lockingModel = new 
FileAppender.ExclusiveLock();
+
+        #endregion Private Instance Fields
+
+        #region Private Static Fields
+
+        /// <summary>
+        /// The fully qualified type of the FileAppender class.
+        /// </summary>
+        /// <remarks>
+        /// Used by the internal logger to record the Type of the
+        /// log message.
+        /// </remarks>
+        private static readonly Type declaringType = typeof(FileAppender);
+
+        #endregion Private Static Fields
+    }
+}
\ No newline at end of file

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