private void WorkItemDispatchLoop(object threadData)
{
var startinfo = (WorkerThreadStartParams)threadData;
// Register a new WSQ.
var wsq = new ThreadLocalStealQueue<ThreadPoolWorkItem>();
wsq.Name = startinfo.ThreadName;
_mWsq = wsq; // Store in TLS.
AddNewWorkQueue(wsq);
DateTime lastItemProcesTime = DateTime.UtcNow;
try
{
while (true)
{
if (ShouldThreadExit(lastItemProcesTime, startinfo.IsPermenant))
{
return;
}
var wi = default(ThreadPoolWorkItem);
// Search order: (1) local queue, (2) global Queue, (3) steal from another thread.
if (!wsq.LocalPop(ref wi))
{
if (ShouldThreadExit(lastItemProcesTime, startinfo.IsPermenant))
{
return;
}
lock (_mQueue)
{
// If shutdown was requested, exit the thread.
if (_poolStopToken.IsCancellationRequested)
return;
// (2) try the global queue.
if (_mQueue.Count != 0)
{
// We found a work item! Grab it …
wi = _mQueue.Dequeue();
}
}
if (wi == null)
{
lock (_mThreadLocalQueues)
{
// (3) try to steal from neighbour thread.
ThreadLocalStealQueue<ThreadPoolWorkItem>[] wsQueues = _mThreadLocalQueues;
int i;
for (i = 0; i < wsQueues.Length; i++)
{
if (wsQueues[i] != null)
{
if (wsQueues[i] != wsq && wsQueues[i].TrySteal(ref wi))
break;
}
}
}
}
}
try
{
//we got a work item, now try to invoke it.
if (wi != null)
{
wi.Execute();
lastItemProcesTime = DateTime.UtcNow;
}
}
catch (Exception ex)
{
EtwLogger.Log.WorkItemFailure(ex.ToString());
if (UserWorkItemException != null)
{
UserWorkItemException(this, new WorkItemEventArgs
{
Exception = ex,
UserData = wi.UserData,
});
}
}
}
}
finally
{
OnWorkerThreadExit(startinfo.ThreadName);
}
}
