public async Task MaxParallelismDefaultIsRespected()
{
ThreadPool.SetMinThreads(100, 100);
var inputValues = AsyncEnumerableProvider.GetInts(100);
int parallelism = 10;
int maxSeenParallelism = 0;
int parallelCounter = 0;
Func <int, Task> action = async(int i) =>
{
Interlocked.Increment(ref parallelCounter);
if (parallelCounter > maxSeenParallelism)
{
// This is not threadsafe but should be good enough for this
maxSeenParallelism = parallelCounter;
}
await Task.Delay(200); // Need substantially slower work here to see the parallelism
parallelCounter.ShouldBeLessThanOrEqualTo(parallelism);
Interlocked.Decrement(ref parallelCounter);
};
await inputValues.SafeParallelAsync(action, parallelism);
maxSeenParallelism.ShouldBe(parallelism);
}
public async Task MaxParallelismDefaultIsRespected()
{
var inputValues = AsyncEnumerableProvider.GetInts(100);
int parallelism = 10;
int maxSeenParallelism = 0;
int parallelCounter = 0;
Func <int, Task <int> > action = async(int i) =>
{
Interlocked.Increment(ref parallelCounter);
if (parallelCounter > maxSeenParallelism)
{
// This is not threadsafe but should be good enough for this
maxSeenParallelism = parallelCounter;
}
await Task.Delay(200);
parallelCounter.ShouldBeLessThanOrEqualTo(parallelism);
Interlocked.Decrement(ref parallelCounter);
return(i * 2);
};
await foreach (var result in inputValues.SafeParallelAsyncWithResult(action, parallelism))
{
}
maxSeenParallelism.ShouldBe(parallelism);
}
public async Task ReportsExceptionsWithValueTypes()
{
var inputValues = AsyncEnumerableProvider.GetInts(100);
Func <int, Task <int> > action = async(int i) =>
{
await Task.Delay(10);
if (i % 10 == 0)
{
throw new Exception("We don't like 10s");
}
return(i * 2);
};
ConcurrentBag <Result <int, int> > results = new ConcurrentBag <Result <int, int> >();
await foreach (var result in inputValues.SafeParallelAsyncWithResult(action))
{
results.Add(result);
}
results.Count().ShouldBe(100);
results.Count(r => r.Success).ShouldBe(90);
results.Count(r => !r.Success).ShouldBe(10);
results.First(r => !r.Success).Exception.ShouldNotBeNull();
results.First(r => !r.Success).Exception.Message.ShouldBe("We don't like 10s");
results.Select(r => r.Input).ShouldBe(Enumerable.Range(1, 100), true);
results.First(r => !r.Success).Output.ShouldBe(default(int));
}
public async Task MaxParallelismDefaultIsRespectedWhenChangedGlobally()
{
var inputValues = AsyncEnumerableProvider.GetInts(100);
Parallelizer.MaxParallelismDefault = 10;
int maxSeenParallelism = 0;
int parallelCounter = 0;
Func <int, Task> action = async(int i) =>
{
Interlocked.Increment(ref parallelCounter);
if (parallelCounter > maxSeenParallelism)
{
// This is not threadsafe but should be good enough for this
maxSeenParallelism = parallelCounter;
}
await Task.Delay(200);
parallelCounter.ShouldBeLessThanOrEqualTo(Parallelizer.MaxParallelismDefault);
Interlocked.Decrement(ref parallelCounter);
};
await foreach (var result in inputValues.SafeParallelAsyncWithResult(action))
{
}
maxSeenParallelism.ShouldBe(Parallelizer.MaxParallelismDefault);
// Restore it's value to default
Parallelizer.MaxParallelismDefault = 100;
}
public async Task EachItemIsProcessedOnce()
{
var inputValues = AsyncEnumerableProvider.GetInts(100);
ConcurrentBag <int> usedValues = new ConcurrentBag <int>();
Func <int, Task> action = async(int i) =>
{
await Task.Delay(10);
usedValues.Add(i);
};
await inputValues.SafeParallelAsync(action);
usedValues.Count().ShouldBe(100);
usedValues.ShouldBe(Enumerable.Range(1, 100), true);
}
public async Task RespectCancellationToken()
{
var inputValues = AsyncEnumerableProvider.GetInts(100);
var cancellationTokenSource = new CancellationTokenSource();
ConcurrentBag <int> usedValues = new ConcurrentBag <int>();
Func <int, Task> action = async(int i) =>
{
await Task.Delay(200);
usedValues.Add(i);
};
var task = inputValues.SafeParallelAsync(action, 10, cancellationTokenSource.Token);
cancellationTokenSource.CancelAfter(500);
await task;
usedValues.Count().ShouldBeLessThan(100);
usedValues.Count().ShouldBeGreaterThan(0);
}
public async Task HandlesValueTypes()
{
var inputValues = AsyncEnumerableProvider.GetInts(100);
var expected = Enumerable.Range(1, 100).Sum(i => i) * 2;
int actual = 0;
Func <int, Task <int> > action = async(int i) =>
{
await Task.Delay(10);
return(i * 2);
};
await foreach (var result in inputValues.SafeParallelAsyncWithResult(action))
{
actual += result.Output;
}
actual.ShouldBe(expected);
}
public async Task EachItemIsProcessedOnce()
{
var inputValues = AsyncEnumerableProvider.GetInts(100);
Func <int, Task> action = async(int i) =>
{
await Task.Delay(10);
};
ConcurrentBag <Result <int> > results = new ConcurrentBag <Result <int> >();
await foreach (var result in inputValues.SafeParallelAsyncWithResult(action))
{
results.Add(result);
}
results.Count().ShouldBe(100);
results.Select(r => r.Input).ShouldBe(Enumerable.Range(1, 100), true);
results.ShouldAllBe(r => r.Success);
}
public async Task RespectsCancellationToken()
{
var inputValues = AsyncEnumerableProvider.GetInts(100);
var cancellationTokenSource = new CancellationTokenSource();
Func <int, Task> action = async(int i) =>
{
await Task.Delay(100);
};
ConcurrentBag <Result <int> > results = new ConcurrentBag <Result <int> >();
cancellationTokenSource.CancelAfter(500);
var asyncEnumerable = inputValues.SafeParallelAsyncWithResult(action, 10);
await foreach (var result in asyncEnumerable.WithCancellation(cancellationTokenSource.Token))
{
results.Add(result);
}
results.Count().ShouldBeLessThan(100);
results.Count().ShouldBeGreaterThan(0);
}