How to handling the file concurrency issue?

[Mullin Yu]

I create a component to write the error log as follow, but it seems
sometimes locked by other processes, and pop up the I/O exception.

How can we handling the concurrency issue at file level? Retry accessing the
file if catch error => like waiting and polling.

Thanks!

private void LogError2File(string errorMessage, string LogFilePath)

{

FileInfo oFileInfo = new FileInfo(LogFilePath);

DirectoryInfo oDirInfo = new DirectoryInfo(oFileInfo.DirectoryName);
if(!oDirInfo.Exists)

oDirInfo.Create();

if(!oFileInfo.Exists)

oFileInfo.Create();

StreamWriter w = File.AppendText(LogFilePath);

w.Write("\r\nLog Entry : ");

w.WriteLine("{0} {1}", DateTime.Now.ToLongTimeString(),

DateTime.Now.ToLongDateString());

w.WriteLine(" :");

w.WriteLine(" :{0}", errorMessage);

w.WriteLine
("----------------------------------------------------------------");

// Update the underlying file.

w.Flush();

// Close

w.Close();

}

[Nicholas Paldino [.NET/C# MVP]]

Mullin,

Instead of calling AppendText, open the FileStream yourself, allowing it
to be shared for read-only access, but you maintain the write access.

Hope this helps.
--
- Nicholas Paldino [.NET/C# MVP]
- mv*@spam.guard.caspershouse.com

"Mullin Yu" <mu*******@ctil.com> wrote in message
news:%2****************@TK2MSFTNGP10.phx.gbl...

I create a component to write the error log as follow, but it seems
sometimes locked by other processes, and pop up the I/O exception.

How can we handling the concurrency issue at file level? Retry accessing the file if catch error => like waiting and polling.

Thanks!

private void LogError2File(string errorMessage, string LogFilePath)

{

FileInfo oFileInfo = new FileInfo(LogFilePath);

DirectoryInfo oDirInfo = new DirectoryInfo(oFileInfo.DirectoryName);
if(!oDirInfo.Exists)

oDirInfo.Create();

if(!oFileInfo.Exists)

oFileInfo.Create();

StreamWriter w = File.AppendText(LogFilePath);

w.Write("\r\nLog Entry : ");

w.WriteLine("{0} {1}", DateTime.Now.ToLongTimeString(),

DateTime.Now.ToLongDateString());

w.WriteLine(" :");

w.WriteLine(" :{0}", errorMessage);

w.WriteLine
("----------------------------------------------------------------");

// Update the underlying file.

w.Flush();

// Close

w.Close();

}

[Mullin Yu]

do i need to implement any multiple-producer-consumer pattern at this case?

more than one process/application will write to the error log file.

what's the implementation of commercial software then? like iis log, tomcat
log?

thanks!

regards,
mullin

"Nicholas Paldino [.NET/C# MVP]" <mv*@spam.guard.caspershouse.com> wrote in
message news:up**************@TK2MSFTNGP09.phx.gbl...

Mullin,

Instead of calling AppendText, open the FileStream yourself, allowing it to be shared for read-only access, but you maintain the write access.

Hope this helps.
--
- Nicholas Paldino [.NET/C# MVP]
- mv*@spam.guard.caspershouse.com

"Mullin Yu" <mu*******@ctil.com> wrote in message
news:%2****************@TK2MSFTNGP10.phx.gbl...

I create a component to write the error log as follow, but it seems
sometimes locked by other processes, and pop up the I/O exception.

How can we handling the concurrency issue at file level? Retry accessing

the

file if catch error => like waiting and polling.

Thanks!

private void LogError2File(string errorMessage, string LogFilePath)

{

FileInfo oFileInfo = new FileInfo(LogFilePath);

DirectoryInfo oDirInfo = new DirectoryInfo(oFileInfo.DirectoryName);
if(!oDirInfo.Exists)

oDirInfo.Create();

if(!oFileInfo.Exists)

oFileInfo.Create();

StreamWriter w = File.AppendText(LogFilePath);

w.Write("\r\nLog Entry : ");

w.WriteLine("{0} {1}", DateTime.Now.ToLongTimeString(),

DateTime.Now.ToLongDateString());

w.WriteLine(" :");

w.WriteLine(" :{0}", errorMessage);

w.WriteLine
("----------------------------------------------------------------");

// Update the underlying file.

w.Flush();

// Close

w.Close();

}