public void Execute(WorkerStep step)
{
lock (this)
{
Interlocked.Exchange(ref _batchIndex, -1); // -1 because Interlocked.Increment returns the *incremented* value
_step = step;
if (_outstandingWorkersNeedsSync != 0)
{
throw new InvalidOperationException("There are still outstanding workers!");
}
_outstandingWorkersNeedsSync = _workerCount;
}
for (int i = 1; i < _workerCount; i++) // the current thread will be worker 0
{
ThreadPool.QueueUserWorkItem(_executeImpl, this);
}
ExecuteImpl(); // lend a hand ourselves
lock (this)
{
if (_outstandingWorkersNeedsSync != 0 && !Monitor.Wait(this, millisecondsTimeout: 10_000))
{
throw new TimeoutException("Timeout waiting for parallel workers to complete");
}
}
}
private void Execute(WorkerStep step, int batchIndex, int start, int end)
{
int count = end - start;
// Console.WriteLine($"{step}/{_shift}/{batchIndex}: [{start},{end}] ({count}) on thread {Environment.CurrentManagedThreadId}");
switch (step)
{
case WorkerStep.Copy:
_keys.Span.Slice(start, count).CopyTo(_workspace.Span.Slice(start, count));
break;
case WorkerStep.BucketCountAscending:
case WorkerStep.BucketCountDescending:
{
var keys = _keys.Span.NonPortableCast <T, uint>();
var buckets = _countsOffsets.Span.NonPortableCast <T, uint>().Slice(
batchIndex * _bucketCount, _bucketCount);
if (step == WorkerStep.BucketCountAscending)
{
BucketCountAscending(buckets, keys, start, end, _shift, _groupMask);
}
else
{
BucketCountDescending(buckets, keys, start, end, _shift, _groupMask);
}
}
break;
case WorkerStep.ApplyAscending:
case WorkerStep.ApplyDescending:
{
var offsets = _countsOffsets.Span.NonPortableCast <T, uint>().Slice(
batchIndex * _bucketCount, _bucketCount);
if (NeedsApply(offsets))
{
var keys = _keys.Span.NonPortableCast <T, uint>();
var workspace = _workspace.Span.NonPortableCast <T, uint>();
if (step == WorkerStep.ApplyAscending)
{
ApplyAscending(offsets, keys, workspace, start, end, _shift, _groupMask);
}
else
{
ApplyDescending(offsets, keys, workspace, start, end, _shift, _groupMask);
}
}
else
{
_keys.Span.Slice(start, count).CopyTo(_workspace.Span.Slice((int)offsets[0], count));
}
}
break;
default:
throw new NotImplementedException($"Unknown worker step: {step}");
}
}