Question

public class Logwriter {
    public Void WriteXml()
    {
        XmlDocument xmlDoc = new XmlDocument();
        xmlDoc.Load(@"C:\Log_Data.xml");

        XmlElement newelement = xmlDoc.CreateElement("entry");
        XmlElement xmldata = xmlDoc.CreateElement("data");
                    XmlElement xmlcontent = xmlDoc.CreateElement("content");

                    xmldata.InnerText ="1234" ;
        xmlcontent.InnerText ="Stackoverflow";

                    newelement.AppendChild(xmldata);
        newelement.AppendChild(xmlcontent);

                    xmlDoc.DocumentElement.AppendChild(newelement);
        xmlDoc.Save(@"C:\Log_Data.xml");
}}

Above WriteXml() function can be called by 100 applications at a time so i have to prevent IOException Error.
I can avod these exception using lock so how can i do it.
please explain which object i have to lock during writing xml

Answer 1

It sounds like you are talking about a named mutex; you can use a Mutex with a name like Global\MySharedLog, which will then be visible to different applications in different sessions on the same machine. This allows each exe to take an exclusive lock (in a managed way) for a period of time.

However!

• having a separate log per application would be a lot simpler and more efficient
• xml is not a great log format, especially if you are going to read/write the entire thing every time to add a row; sounds fine on log-entry #10, not so fine on log-entry #12,301,023

For example:

Mutex m = new Mutex(false, @"Global\MySharedLog");
...

m.WaitOne();
try {
    // do some work here
} finally {
    m.ReleaseMutex();
}