public void ForceUpdateDynamicState_ConcurrentCalls_AllCallsMakeChanges()
{
var testTimeout = TimeSpan.FromSeconds(30);
var destinationManager = new Mock <IDestinationManager>();
var itemsCalled = new SemaphoreSlim(0);
destinationManager.SetupGet(d => d.Items).Returns(() =>
{
itemsCalled.Wait();
return(new DestinationInfo[0]);
});
var destManagerfactory = new Mock <IDestinationManagerFactory>();
destManagerfactory.Setup(f => f.CreateDestinationManager()).Returns(destinationManager.Object);
var clusterManager = new ClusterManager(destManagerfactory.Object, Array.Empty <IClusterChangeListener>());
var cluster = clusterManager.GetOrCreateItem("cluster0", c => EnableHealthChecks(c));
var taskCount = Environment.ProcessorCount * 2;
var concurrentTasks = Enumerable.Repeat(0, taskCount)
.Select(_ => Task.Factory.StartNew(() => cluster.ForceUpdateDynamicState(), TaskCreationOptions.RunContinuationsAsynchronously))
.ToArray();
itemsCalled.Release(taskCount);
// Assert all concurrent tasks complete without a call to DestinationManager.Items getter.
Assert.True(Task.WaitAll(concurrentTasks, testTimeout));
destinationManager.VerifyGet(d => d.Items, Times.Exactly(taskCount));
destinationManager.VerifyNoOtherCalls();
}
public void UpdateDynamicState_ConcurrentCalls_FirstAndLastCallsMakeChanges()
{
var testTimeout = TimeSpan.FromSeconds(30);
var destinationManager = new Mock <IDestinationManager>();
var itemsCalled = new AutoResetEvent(false);
var returnItems = new ManualResetEvent(false);
destinationManager.SetupGet(d => d.Items).Returns(() =>
{
itemsCalled.Set();
returnItems.WaitOne();
return(new DestinationInfo[0]);
});
var destManagerfactory = new Mock <IDestinationManagerFactory>();
destManagerfactory.Setup(f => f.CreateDestinationManager()).Returns(destinationManager.Object);
var clusterManager = new ClusterManager(destManagerfactory.Object, Array.Empty <IClusterChangeListener>());
var cluster = clusterManager.GetOrCreateItem("cluster0", c => EnableHealthChecks(c));
var mainTask = Task.Factory.StartNew(() => cluster.UpdateDynamicState(), TaskCreationOptions.RunContinuationsAsynchronously);
Assert.True(itemsCalled.WaitOne(testTimeout));
var allTaskCount = Environment.ProcessorCount * 2;
var pendingTasks = allTaskCount;
var allButOneCompleted = new ManualResetEventSlim(false);
var concurrentTasks = Enumerable.Repeat(0, allTaskCount)
.Select(_ => Task.Factory.StartNew(() =>
{
cluster.UpdateDynamicState();
if (Interlocked.Decrement(ref pendingTasks) == 1)
{
allButOneCompleted.Set();
}
}, TaskCreationOptions.RunContinuationsAsynchronously))
.ToArray();
Assert.True(allButOneCompleted.Wait(testTimeout));
returnItems.Set();
// Assert all concurrent tasks complete without a call to DestinationManager.Items getter.
Assert.True(Task.WaitAll(concurrentTasks, testTimeout));
Assert.Equal(0, Volatile.Read(ref pendingTasks));
// Assert the main task that acquired the ClusterInfo lock completes.
Assert.True(mainTask.Wait(testTimeout));
destinationManager.VerifyGet(d => d.Items, Times.Exactly(2));
destinationManager.VerifyNoOtherCalls();
}
