How to: Log Events for Multithreaded Components
When logging events from multithreaded components, special considerations come into play. You must supply a means of identifying the thread from which the event came. You must also ensure that the threads do not interfere with one another when logging events. For details, see.
To use event logs in multithreaded applications
Declare and create the event log. For details, see.
Set theproperty of each thread to a unique identifier.
Dim X as Integer X = 0 Dim MyThread as New Threading.Thread(AddressOf MyMethod) MyThread.Name = "Thread number " & X.ToString ' Increments X so no other threads will share the same name. X += 1
Create a newfor the event log, and set the to a unique string value that corresponds to the thread. For details on creating a Source, see .
Imports System.Threading ' Checks to see if there already is a source with the name of the ' thread. If Not EventLog.SourceExists(Thread.CurrentThread.Name.ToString, _ "myApplication") Then ' Creates a source with the name of the thread EventLog.CreateEventSource(Thread.CurrentThread.Name.ToString, _ "MyApplication") End If
// These lines go at the top of the code using System.Threading; using System.Diagnostics; // Checks to see if there already is a source with the name of the // thread. if (!EventLog.SourceExists(CurrentThread.Name.ToString())) // Creates a source with the name of the thread. EventLog.CreateEventSource(CurrentThread.Name.ToString(), "MyApplication");
Set the Source property of the event log to the name of the thread and call themethod.
Be sure to obtain an exclusive lock on the event log before proceeding with these operations.
' Use the SyncLock keyword to obtain an exclusive lock on an object. SyncLock MyEventLog MyEventLog.Source = Thread.CurrentThread.Name.ToString EventLog.WriteEntry(Thread.CurrentThread.Name.ToString, _ "Error in Widget 42") End SyncLock