/// <summary>
/// Wait for the completion event or until the timeout datetime has passed.
/// </summary>
/// <param name="timeout">The datetime at which a timeout exception should be raised.</param>
public void WaitForCompletion(DateTime timeout)
{
// Wait until the operation has completed or we time out.
while (!Complete && DateTime.Now < timeout)
{
Thread.Sleep(25);
}
// If the operation did not complete then we must have timed out.
if (!Complete)
{
observer.Cancel();
throw new Exception("The WMI operation did not complete within the time limit.");
}
// The operation completed, but we must check its status.
if (Status != "NoError")
{
throw new Exception("The WMI operation encountered an error. " + Status.ToString());
}
}
private void cancelWorker_DoWork(object sender, DoWorkEventArgs e)
{
queryObserver.Cancel();
}
/// <summary>
/// Gets a list of Dictionaries mapping the property name to the object retrieved
/// for that property.
/// A list is returned because some WMI call return multiple things
///
/// Was recently updated to handle the WMI calls in an asynchronous way, so the
/// data collection can be stopped during a long-running WMI call.
///
/// https://msdn.microsoft.com/en-us/library/cc143292.aspx
/// </summary>
/// <param name="log"></param>
/// <returns></returns>
public RetrievalContext Retrieve(ILog log)
{
string query_str = string.Format("SELECT {0} FROM {1}", Context.Properties, Context.Class);
if (string.IsNullOrEmpty(Context.Where) == false)
{
query_str += " WHERE " + Context.Where;
}
string path = string.Empty;
try
{
SelectQuery query = new SelectQuery(query_str);
ManagementScope scope = Context.GetManagementScope();
using (ManagementObjectSearcher searcher = new ManagementObjectSearcher(scope, query))
{
path = scope.Path.Path;
if (log != null)
{
log.Debug("Executing: " + path + " -- " + query_str);
}
ManagementOperationObserver results = new ManagementOperationObserver();
results.ObjectReady += new ObjectReadyEventHandler(this.OnNewObject);
results.Completed += new CompletedEventHandler(this.OnComplete);
// Start a new Retrieving object so everything is up-to-date right now
m_retrieval_context = new RetrievalContext(Options.Timeout);
searcher.Get(results);
while (m_retrieval_context.IsCompleted == false)
{
if (m_retrieval_context.HasTimedOut)
{
results.Cancel();
throw new Exception($"Timeout executing '{query_str}', path is '{path}'");
}
if (GlobalIsRunning.IsRunning == false)
{
m_retrieval_context.IsCompleted = true;
results.Cancel();
}
else
{
Thread.Sleep(250);
}
}
}
}
catch (Exception e)
{
if (log != null)
{
log.Error(e);
log.Error(query_str);
if (string.IsNullOrEmpty(path) == false)
{
log.Error(path);
}
}
}
finally
{
m_retrieval_context.IsCompleted = true;
}
return(m_retrieval_context);
}