public void AsyncQueue_Test()
{
var queue = new AsyncQueue <int>();
var testDataCount = 10000;
var tasks = new List <Task>();
var expected = new List <int>();
var producerLock = new SemaphoreSlim(1);
var consumerLock = new SemaphoreSlim(1);
var random = new Random();
//multi-threaded async producer
tasks.AddRange(Enumerable.Range(1, testDataCount).Select(async x =>
{
await Task.Delay(random.Next(0, 1));
await producerLock.WaitAsync();
expected.Add(x);
await queue.EnqueueAsync(x);
producerLock.Release();
}));
var actual = new List <int>();
//multi-threaded async consumer
tasks.AddRange(Enumerable.Range(1, testDataCount).Select(async x =>
{
await Task.Delay(random.Next(0, 1));
await consumerLock.WaitAsync();
actual.Add(await queue.DequeueAsync());
consumerLock.Release();
}));
Task.WaitAll(tasks.ToArray());
CollectionAssert.AreEqual(expected, actual);
}
public async Task AsyncQueueSkipsCancelledTasks()
{
AsyncQueue <int> inputQueue = new AsyncQueue <int>();
// Queue up a couple of tasks to wait for input
CancellationTokenSource cancellationSource = new CancellationTokenSource();
Task <int> taskOne = inputQueue.DequeueAsync(cancellationSource.Token);
Task <int> taskTwo = inputQueue.DequeueAsync();
// Cancel the first task and then enqueue a number
cancellationSource.Cancel();
await inputQueue.EnqueueAsync(1);
// Did the second task get the number?
Assert.Equal(TaskStatus.Canceled, taskOne.Status);
Assert.Equal(TaskStatus.RanToCompletion, taskTwo.Status);
Assert.Equal(1, taskTwo.Result);
}
public async Task AsyncQueueSkipsCancelledTasks()
{
AsyncQueue<int> inputQueue = new AsyncQueue<int>();
// Queue up a couple of tasks to wait for input
CancellationTokenSource cancellationSource = new CancellationTokenSource();
Task<int> taskOne = inputQueue.DequeueAsync(cancellationSource.Token);
Task<int> taskTwo = inputQueue.DequeueAsync();
// Cancel the first task and then enqueue a number
cancellationSource.Cancel();
await inputQueue.EnqueueAsync(1);
// Did the second task get the number?
Assert.Equal(TaskStatus.Canceled, taskOne.Status);
Assert.Equal(TaskStatus.RanToCompletion, taskTwo.Status);
Assert.Equal(1, taskTwo.Result);
}
public async Task AsyncQueueSynchronizesAccess()
{
ConcurrentBag <int> outputItems = new ConcurrentBag <int>();
AsyncQueue <int> inputQueue = new AsyncQueue <int>(Enumerable.Range(0, 100));
CancellationTokenSource cancellationTokenSource = new CancellationTokenSource();
try
{
// Start 5 consumers
await Task.WhenAll(
Task.Run(() => ConsumeItems(inputQueue, outputItems, cancellationTokenSource.Token)),
Task.Run(() => ConsumeItems(inputQueue, outputItems, cancellationTokenSource.Token)),
Task.Run(() => ConsumeItems(inputQueue, outputItems, cancellationTokenSource.Token)),
Task.Run(() => ConsumeItems(inputQueue, outputItems, cancellationTokenSource.Token)),
Task.Run(() => ConsumeItems(inputQueue, outputItems, cancellationTokenSource.Token)),
Task.Run(
async() =>
{
// Wait for a bit and then add more items to the queue
await Task.Delay(250);
foreach (var i in Enumerable.Range(100, 200))
{
await inputQueue.EnqueueAsync(i);
}
// Cancel the waiters
cancellationTokenSource.Cancel();
}));
}
catch (TaskCanceledException)
{
// Do nothing, this is expected.
}
// At this point, numbers 0 through 299 should be in the outputItems
IEnumerable <int> expectedItems = Enumerable.Range(0, 300);
Assert.Equal(0, expectedItems.Except(outputItems).Count());
}
public async Task AsyncQueueSynchronizesAccess()
{
ConcurrentBag<int> outputItems = new ConcurrentBag<int>();
AsyncQueue<int> inputQueue = new AsyncQueue<int>(Enumerable.Range(0, 100));
CancellationTokenSource cancellationTokenSource = new CancellationTokenSource();
try
{
// Start 5 consumers
await Task.WhenAll(
Task.Run(() => ConsumeItems(inputQueue, outputItems, cancellationTokenSource.Token)),
Task.Run(() => ConsumeItems(inputQueue, outputItems, cancellationTokenSource.Token)),
Task.Run(() => ConsumeItems(inputQueue, outputItems, cancellationTokenSource.Token)),
Task.Run(() => ConsumeItems(inputQueue, outputItems, cancellationTokenSource.Token)),
Task.Run(() => ConsumeItems(inputQueue, outputItems, cancellationTokenSource.Token)),
Task.Run(
async () =>
{
// Wait for a bit and then add more items to the queue
await Task.Delay(250);
foreach (var i in Enumerable.Range(100, 200))
{
await inputQueue.EnqueueAsync(i);
}
// Cancel the waiters
cancellationTokenSource.Cancel();
}));
}
catch (TaskCanceledException)
{
// Do nothing, this is expected.
}
// At this point, numbers 0 through 299 should be in the outputItems
IEnumerable<int> expectedItems = Enumerable.Range(0, 300);
Assert.Equal(0, expectedItems.Except(outputItems).Count());
}