public IThreadPoolWorkItem Dequeue(ThreadPoolWorkQueueThreadLocals tl, ref bool missedSteal)
{
WorkStealingQueue localWsq = tl.workStealingQueue;
IThreadPoolWorkItem callback;
if ((callback = localWsq.LocalPop()) == null && // first try the local queue
!workItems.TryDequeue(out callback)) // then try the global queue
{
// finally try to steal from another thread's local queue
WorkStealingQueue[] queues = WorkStealingQueueList.Queues;
int c = queues.Length;
Debug.Assert(c > 0, "There must at least be a queue for this thread.");
int maxIndex = c - 1;
int i = tl.random.Next(c);
while (c > 0)
{
i = (i < maxIndex) ? i + 1 : 0;
WorkStealingQueue otherQueue = queues[i];
if (otherQueue != localWsq && otherQueue.CanSteal)
{
callback = otherQueue.TrySteal(ref missedSteal);
if (callback != null)
{
break;
}
}
c--;
}
}
return(callback);
}
public void Enqueue(IThreadPoolWorkItem callback, bool forceGlobal)
{
ThreadPoolWorkQueueThreadLocals tl = null;
if (!forceGlobal)
{
tl = ThreadPoolWorkQueueThreadLocals.threadLocals;
}
if (null != tl)
{
tl.workStealingQueue.LocalPush(callback);
}
else
{
workItems.Enqueue(callback);
}
EnsureThreadRequested();
}
internal void Dispatch()
{
// Set up our thread-local data
ThreadPoolWorkQueueThreadLocals tl = EnsureCurrentThreadHasQueue();
while (true)
{
bool missedSteal = false;
var completableCtx = Dequeue(tl, ref missedSteal);
if (completableCtx == null)
{
if (IsAddingCompleted)
{
if (!missedSteal)
{
break;
}
}
else
{
_semaphore.Wait();
MarkThreadRequestSatisfied();
}
continue;
}
// this is called before Enqueue: EnsureThreadRequested();
try
{
completableCtx.Execute();
}
catch (Exception ex)
{
_pool.Settings.ExceptionHandler(ex);
}
}
}
internal bool LocalFindAndPop(IThreadPoolWorkItem callback)
{
ThreadPoolWorkQueueThreadLocals tl = ThreadPoolWorkQueueThreadLocals.threadLocals;
return(tl != null && tl.workStealingQueue.LocalFindAndPop(callback));
}
