public void GetBulkhead_WhenInitializingBulkheadAndMaxConcurrentConfigIsInvalid_AndThenConfigChangedToValidValue_CreatesBulkhead()
{
// Arrange
var key = AnyGroupKey;
const int invalidMaxConcurrent = -1;
const int validMaxConcurrent = 1;
var mockMetricEvents = new Mock <IMetricEvents>(MockBehavior.Strict);
var mockConfig = new MjolnirConfiguration
{
BulkheadConfigurations = new Dictionary <string, BulkheadConfiguration>
{
{
key.Name,
new BulkheadConfiguration
{
MaxConcurrent = invalidMaxConcurrent
}
}
}
};
var mockLogFactory = new Mock <IMjolnirLogFactory>(MockBehavior.Strict);
mockLogFactory.Setup(m => m.CreateLog <BulkheadFactory>()).Returns(new DefaultMjolnirLog <BulkheadFactory>());
mockLogFactory.Setup(m => m.CreateLog <SemaphoreBulkheadHolder>()).Returns(new DefaultMjolnirLog <SemaphoreBulkheadHolder>());
var factory = new BulkheadFactory(mockMetricEvents.Object, mockConfig, mockLogFactory.Object);
try
{
factory.GetBulkhead(key);
}
catch (ArgumentOutOfRangeException)
{
// Expected, config is invalid for the first attempt.
}
mockConfig.BulkheadConfigurations = new Dictionary <string, BulkheadConfiguration>
{
{
key.Name,
new BulkheadConfiguration
{
MaxConcurrent = validMaxConcurrent
}
}
};
mockConfig.NotifyAfterConfigUpdate();
// Act
var bulkhead = factory.GetBulkhead(key); // Should not throw.
// Assert
Assert.Equal(validMaxConcurrent, bulkhead.CountAvailable);
}
private async Task ReloadConfig()
{
while (true)
{
_root = LoadConfigFromJsonFile();
// We can add some deep comparision between _currentConfig and new config here so
// we notify our observers only when config really changes
_currentConfig?.NotifyAfterConfigUpdate();
await Task.Delay(_updateTimeInterval);
}
}
public void GetBulkhead_ReturnsNewBulkheadWhenConfigChanges()
{
// Config can be used to resize the bulkhead at runtime, which results in a new
// bulkhead being created.
// To ensure consistency, callers who retrieve a bulkhead and call TryEnter()
// on it should keep a local reference to the same bulkhead to later call
// Release() on (rather than re-retrieving the bulkhead from the context).
// That behavior is tested elsewhere (with the BulkheadInvoker tests).
// Arrange
var key = AnyString;
var groupKey = GroupKey.Named(key);
const int initialExpectedCount = 5;
const int newExpectedCount = 6;
var mockMetricEvents = new Mock <IMetricEvents>(MockBehavior.Strict);
var mockConfig = new MjolnirConfiguration
{
BulkheadConfigurations = new Dictionary <string, BulkheadConfiguration>
{
{
groupKey.Name,
new BulkheadConfiguration
{
MaxConcurrent = initialExpectedCount
}
}
}
};
var mockLogFactory = new Mock <IMjolnirLogFactory>(MockBehavior.Strict);
mockLogFactory.Setup(m => m.CreateLog <BulkheadFactory>()).Returns(new DefaultMjolnirLog <BulkheadFactory>());
mockLogFactory.Setup(m => m.CreateLog <SemaphoreBulkheadHolder>()).Returns(new DefaultMjolnirLog <SemaphoreBulkheadHolder>());
var factory = new BulkheadFactory(mockMetricEvents.Object, mockConfig, mockLogFactory.Object);
// Act
var firstBulkhead = factory.GetBulkhead(groupKey);
mockConfig.BulkheadConfigurations = new Dictionary <string, BulkheadConfiguration>
{
{
groupKey.Name,
new BulkheadConfiguration
{
MaxConcurrent = newExpectedCount
}
}
};
mockConfig.NotifyAfterConfigUpdate();
// Give the change handler callback enough time to create and reassign the bulkhead.
Thread.Sleep(500);
var secondBulkhead = factory.GetBulkhead(groupKey);
// Assert
// Shouldn't change any existing referenced bulkheads...
Assert.Equal(initialExpectedCount, firstBulkhead.CountAvailable);
// ...but newly-retrieved bulkheads should get a new instance
// with the updated count.
Assert.Equal(newExpectedCount, secondBulkhead.CountAvailable);
// And they shouldn't be the same bulkhead (which should be obvious by this point).
Assert.False(firstBulkhead == secondBulkhead);
}