public async Task TryProcess_IncrementsExecutedMetric()
{
// Arrange
var metricsRegistry = new Mock <IMetricsRegistry> {
DefaultValue = DefaultValue.Mock
};
var limit = new FixedLimit(5, metricsRegistry.Object);
var operationsExecuted = new Mock <ICounter>();
metricsRegistry.Setup(r => r.CreateCounter(
SimpleLimiter.Metrics.Executed.Name,
It.IsAny <string>(),
It.IsAny <string[]>())
.WithLabels(It.IsAny <string[]>())).Returns(operationsExecuted.Object);
var limiter = new SimpleLimiter(limit, metricsRegistry.Object);
// Act
await limiter.TryProcess(() => Task.FromResult(0));
await limiter.TryProcess(() => Task.FromResult(0));
await limiter.TryProcess(() => Task.FromResult(0));
await limiter.TryProcess(() => Task.FromResult(0));
// Assert
operationsExecuted.Verify(c => c.Increment(), Times.Exactly(4));
}
public void TryProcess_IncrementsLimitedMetric()
{
// Arrange
var metricsRegistry = new Mock <IMetricsRegistry> {
DefaultValue = DefaultValue.Mock
};
var limit = new FixedLimit(2, metricsRegistry.Object);
var operationsLimited = new Mock <ICounter>();
metricsRegistry.Setup(r => r.CreateCounter(
SimpleLimiter.Metrics.Limited.Name,
It.IsAny <string>(),
It.IsAny <string[]>())
.WithLabels(It.IsAny <string[]>())).Returns(operationsLimited.Object);
var limiter = new SimpleLimiter(limit, metricsRegistry.Object);
var requestBlocker = new ManualResetEvent(false);
var taskExecutedWaitHandles = new List <WaitHandle>
{
this.ProcessBlockingTask(limiter, requestBlocker),
this.ProcessBlockingTask(limiter, requestBlocker)
};
WaitHandle.WaitAll(taskExecutedWaitHandles.ToArray());
// Act
// Temporarily ignore the warning about not awaiting Tasks since we actually
// want the tasks to block so that we can build up the current operation count
#pragma warning disable CS4014
// Limit reached - the following requests will be limited
limiter.TryProcess(() => Task.FromResult(0));
limiter.TryProcess(() => Task.FromResult(0));
#pragma warning restore CS4014
// Assert
operationsLimited.Verify(c => c.Increment(), Times.Exactly(2));
requestBlocker.Set();
}
/// <summary>
/// Calls <see cref="SimpleLimiter.TryProcess(System.Func{Task})" /> with an
/// operation that blocks until <paramref ref="blockUntil" /> is signalled.
/// </summary>
/// <param name="limiter">The limiter.</param>
/// <param name="blockUntil">
/// A <see cref="WaitHandle" /> handle that signals when the operation can complete.
/// </param>
/// <returns>
/// A <see cref="WaitHandle" /> that can be waited on to ensure that the
/// operation has begun executing before continuing.
/// </returns>
private WaitHandle ProcessBlockingTask(SimpleLimiter limiter, WaitHandle blockUntil)
{
var executedHandle = new ManualResetEvent(false);
Task.Run(() => limiter.TryProcess(() =>
{
executedHandle.Set();
blockUntil.WaitOne();
return(Task.FromResult(0));
}));
return(executedHandle);
}