Subj : Re: [.NET] Lock Object
To   : comp.programming.threads
From : David Hopwood
Date : Sat Sep 24 2005 04:48 pm

Cool Guy wrote:
>>Actually I should've mentioned that I had a Singleton with lazy
>>instantiation in mind when I wrote that.
> 
> Here's the code:
> 
> sealed class LogFile
> {
>     #region Singleton functionality
>     public static readonly LogFile Instance = new LogFile();
> 
>     static LogFile() {
>     }
>     #endregion
> 
>     StreamWriter streamWriter;
>     readonly object streamWriterLock;
> 
>     LogFile() {
>         streamWriterLock = new Object();
>         FileStream fileStream = File.Open(...);
>         lock (streamWriterLock) {  // lock for write memory barrier
>                                    // (not sure whether this is needed)
>             streamWriter = new StreamWriter(fileStream, Encoding.ASCII);
>         }
>     }
> 
>     public void AddEntry(string text) {
>         lock (streamWriterLock) {
>             streamWriter.WriteLine(text);
>             streamWriter.Flush();
>         }
>     }
> }

No problem as long as you only ever access streamWriter within the lock.
Accessing it outside the lock won't work.

-- 
David Hopwood <david.nospam.hopwood@blueyonder.co.uk>

.