private void CheckWaitingReads()
{
if (!readLocked.HasValue && waitingReads.Count > 0)
{
WaitingRead wr = waitingReads.Peek();
if (items.Count >= wr.desiredItems || (eofSignaled && !writeLocked.HasValue && waitingWrites.Count == 0))
{
waitingReads.Dequeue();
readLocked = Math.Min(wr.desiredItems, items.Count);
wr.k.PostResult(new AcquireReadSucceeded <T>(readPtr, readLocked.Value == 0 ? ImmutableList <T> .Empty : items.GetRange(0, readLocked.Value)));
if (wr.ctr.HasValue)
{
wr.ctr.Value.PostDispose();
}
if (readLocked.Value == 0)
{
while (waitingReads.Count > 0)
{
WaitingRead wr2 = waitingReads.Dequeue();
wr2.k.PostResult(new AcquireReadSucceeded <T>(readPtr, ImmutableList <T> .Empty));
if (wr2.ctr.HasValue)
{
wr2.ctr.Value.PostDispose();
}
}
}
}
}
}
/// <inheritdoc />
public Task <AcquireReadResult> AcquireReadAsync(int desiredItems, CancellationToken ctoken)
{
if (desiredItems < 1)
{
return(Task.FromResult <AcquireReadResult>(new AcquireReadFaulted(new ArgumentOutOfRangeException("desiredItems", "Must be at least one"))));
}
if (ctoken.IsCancellationRequested)
{
return(Task.FromResult <AcquireReadResult>(new AcquireReadCancelled()));
}
else
{
lock (syncRoot) {
if (!readLocked.HasValue && (items.Count >= desiredItems || eofSignaled))
{
readLocked = Math.Min(items.Count, desiredItems);
return(Task.FromResult <AcquireReadResult>(new AcquireReadSucceeded <T>(readPtr, items.GetRange(0, readLocked.Value))));
}
else
{
TaskCompletionSource <AcquireReadResult> k = new TaskCompletionSource <AcquireReadResult>();
WaitingRead wr = new WaitingRead()
{
id = null,
desiredItems = desiredItems,
k = k,
ctr = null,
};
long id = waitingReads.Enqueue(wr);
wr.id = id;
ctoken.PostRegistration(ctr => SetRegistrationForAcquireRead(id, ctr), () => CancelAcquireRead(id));
return(k.Task);
}
}
}
}
