public void EnqueueMany(ArraySegment <T> data, bool notifyChanged = true)
{
#if DEBUG
if (IsMainThreadWorkItem && !IsMainThreadQueue)
{
throw new InvalidOperationException("This work item must be queued on the main thread");
}
#endif
lock (ItemsLock) {
AssertCanEnqueue();
Interlocked.Add(ref ItemsQueued, data.Count);
var wi = new InternalWorkItem <T>();
wi.Queue = this;
wi.OnComplete = null;
for (var i = 0; i < data.Count; i++)
{
wi.Data = data.Array[data.Offset + i];
AddInternal(ref wi);
}
}
if (notifyChanged)
{
NotifyChanged();
}
}
public void Enqueue(ref T data, OnWorkItemComplete <T> onComplete = null, WorkQueueNotifyMode notifyChanged = WorkQueueNotifyMode.Always)
{
#if DEBUG
if (IsMainThreadWorkItem && !IsMainThreadQueue)
{
throw new InvalidOperationException("This work item must be queued on the main thread");
}
#endif
var wi = new InternalWorkItem <T>(this, ref data, onComplete);
var newCount = AddInternal(ref wi);
NotifyChanged(notifyChanged, newCount, wakeAll: false);
}
public static void Execute(ref InternalWorkItem <T> item)
{
#if DEBUG
if (!item.Valid)
{
throw new WorkQueueException(item.Queue, "Invalid work item");
}
#endif
item.Data.Execute();
if (item.OnComplete != null)
{
item.OnComplete(ref item.Data);
}
}
public void EnqueueMany(ArraySegment <T> data)
{
lock (Queue) {
ManageDrain();
var wi = new InternalWorkItem <T>();
wi.Queue = this;
wi.OnComplete = null;
for (var i = 0; i < data.Count; i++)
{
wi.Data = data.Array[data.Offset + i];
Queue.Enqueue(wi);
}
}
}
private int AddInternal(ref InternalWorkItem <T> item)
{
AssertCanEnqueue();
var result = Interlocked.Increment(ref ItemsQueued);
lock (ItemsLock) {
// Any existing read operations are irrelevant, we're inside the lock so we own the semilock state
Volatile.Write(ref _Semilock, Semilock_Adding);
EnsureCapacityLocked(_Count + 1);
_Items[_Tail] = item;
AdvanceLocked(ref _Tail);
_Count++;
Interlocked.CompareExchange(ref _Semilock, Semilock_Open, Semilock_Adding);
}
return(result);
}
public int Step(out bool exhausted, int?maximumCount = null)
{
int result = 0, count = 0;
int actualMaximumCount = maximumCount.GetValueOrDefault(DefaultStepCount);
InternalWorkItem <T> item = default(InternalWorkItem <T>);
bool running = true;
do
{
lock (Queue) {
running = ((count = Queue.Count) > 0) &&
(result < actualMaximumCount);
if (running)
{
InFlightTasks++;
item = Queue.Dequeue();
}
}
if (running)
{
item.Data.Execute();
if (item.OnComplete != null)
{
item.OnComplete(ref item.Data);
}
result++;
lock (Queue) {
InFlightTasks--;
if ((Queue.Count == 0) && (InFlightTasks <= 0))
{
DrainComplete.Set();
}
}
}
} while (running);
lock (Queue)
exhausted = Queue.Count == 0;
return(result);
}
private bool TryDequeue(out InternalWorkItem <T> item, out bool empty)
{
// Attempt to transition the semilock into read mode, and as long as it wasn't in add mode,
if (Interlocked.CompareExchange(ref _Semilock, Semilock_Reading, Semilock_Open) != 3)
{
// Determine whether we can early-out this dequeue operation because we successfully entered
// the semilock either during an enqueue or when it wasn't held at all
// FIXME: Is it safe to do this check during a dequeue? I think so
empty = Volatile.Read(ref _Count) <= 0;
// We may have entered this block without acquiring the semilock in open mode, in which case
// whoever has it (in dequeue mode) will release it when they're done
Interlocked.CompareExchange(ref _Semilock, Semilock_Open, Semilock_Reading);
if (empty)
{
item = default(InternalWorkItem <T>);
#if INSTRUMENT_FAST_PATH
Interlocked.Increment(ref EarlyOutCount);
#endif
return(false);
}
}
lock (ItemsLock) {
// We've successfully acquired the state lock, so we own the semilock state now
Volatile.Write(ref _Semilock, Semilock_Dequeuing);
if (_Count <= 0)
{
empty = true;
item = default(InternalWorkItem <T>);
#if INSTRUMENT_FAST_PATH
Interlocked.Increment(ref SlowOutCount);
#endif
Volatile.Write(ref _Semilock, Semilock_Open);
return(false);
}
item = _Items[_Head];
_Items[_Head] = default(InternalWorkItem <T>);
AdvanceLocked(ref _Head);
_Count--;
empty = _Count <= 0;
Volatile.Write(ref _Semilock, Semilock_Open);
return(true);
}
}
private void GrowLocked(int capacity)
{
var newSize = UnorderedList <T> .PickGrowthSize(_Items.Length, capacity);
var newItems = new InternalWorkItem <T> [newSize];
if (_Count > 0)
{
if (_Head < _Tail)
{
Array.Copy(_Items, _Head, newItems, 0, _Count);
}
else
{
Array.Copy(_Items, _Head, newItems, 0, _Items.Length - _Head);
Array.Copy(_Items, 0, newItems, _Items.Length - _Head, _Tail);
}
}
_Items = newItems;
_Head = 0;
_Tail = (_Count == capacity) ? 0 : _Count;
}
private void StepInternal(out int result, out bool exhausted, int actualMaximumCount)
{
// We eat an extra lock acquisition this way, but it skips a lot of extra work
// FIXME: Optimize this out since in profiles it eats like 2% of CPU, probably not worth it anymore
if (IsEmpty)
{
result = 0;
exhausted = true;
return;
}
InternalWorkItem <T> item = default(InternalWorkItem <T>);
int numProcessed = 0;
bool running = true, signalDrained = false;
var padded = Owner.Count - (Configuration.ConcurrencyPadding ?? Owner.DefaultConcurrencyPadding);
var lesser = Math.Min(Configuration.MaxConcurrency ?? 9999, padded);
var maxConcurrency = Math.Max(lesser, 1);
exhausted = false;
result = 0;
// TODO: Move this into the loop so we do it at the start of processing the first item?
if (Interlocked.Increment(ref _NumProcessing) > maxConcurrency)
{
Interlocked.Decrement(ref _NumProcessing);
return;
}
int processedCounter = -1;
do
{
try {
bool empty = false;
running = (actualMaximumCount > 0) &&
(numProcessed < actualMaximumCount) &&
TryDequeue(out item, out empty);
if (empty)
{
signalDrained = true;
exhausted = true;
}
if (running)
{
try {
numProcessed++;
InternalWorkItem <T> .Execute(ref item);
result++;
} finally {
processedCounter = Interlocked.Increment(ref ItemsProcessed);
}
}
} catch (Exception exc) {
UnhandledException = ExceptionDispatchInfo.Capture(exc);
signalDrained = true;
break;
}
} while (running);
actualMaximumCount -= numProcessed;
var wasLast = Interlocked.Decrement(ref _NumProcessing) == 0;
// The following would be ideal but I think it could produce a hang in some cases
/*
* // This is a race, but that's probably OK since anyone waiting for the queue to drain will verify and spin if
* // we lose the race
* var signalDone = wasLast && (Volatile.Read(ref ItemsQueued) <= processedCounter);
*/
if (signalDrained)
{
// FIXME: Should we do this first? Assumption is that in a very bad case, the future's
// complete handler might begin waiting
DrainedSignal.Set();
}
if (wasLast)
{
FinishedProcessingSignal.Set();
}
}
