public void GetCurrentKeyRing_WithExpiredExistingKeyRing_AllowsOneThreadToUpdate_ReturnsExistingKeyRingToOtherCallersWithoutBlocking()
{
// Arrange
var originalKeyRing = new Mock <IKeyRing>().Object;
var originalKeyRingTime = StringToDateTime("2015-03-01 00:00:00Z");
var updatedKeyRing = new Mock <IKeyRing>().Object;
var updatedKeyRingTime = StringToDateTime("2015-03-02 00:00:00Z");
var mockCacheableKeyRingProvider = new Mock <ICacheableKeyRingProvider>();
var keyRingProvider = CreateKeyRingProvider(mockCacheableKeyRingProvider.Object);
// In this test, the foreground thread acquires the critial section in GetCurrentKeyRing,
// and the background thread returns the original key ring rather than blocking while
// waiting for the foreground thread to update the key ring.
TimeSpan testTimeout = TimeSpan.FromSeconds(10);
IKeyRing keyRingReturnedToBackgroundThread = null;
mockCacheableKeyRingProvider.Setup(o => o.GetCacheableKeyRing(originalKeyRingTime))
.Returns(new CacheableKeyRing(CancellationToken.None, StringToDateTime("2015-03-02 00:00:00Z"), originalKeyRing));
mockCacheableKeyRingProvider.Setup(o => o.GetCacheableKeyRing(updatedKeyRingTime))
.Returns <DateTimeOffset>(dto =>
{
// at this point we're inside the critical section - spawn the background thread now
var backgroundGetKeyRingTask = Task.Run(() =>
{
keyRingReturnedToBackgroundThread = keyRingProvider.GetCurrentKeyRingCore(updatedKeyRingTime);
});
Assert.True(backgroundGetKeyRingTask.Wait(testTimeout), "Test timed out.");
return(new CacheableKeyRing(CancellationToken.None, StringToDateTime("2015-03-03 00:00:00Z"), updatedKeyRing));
});
// Assert - underlying provider only should have been called once with the updated time (by the foreground thread)
Assert.Same(originalKeyRing, keyRingProvider.GetCurrentKeyRingCore(originalKeyRingTime));
Assert.Same(updatedKeyRing, keyRingProvider.GetCurrentKeyRingCore(updatedKeyRingTime));
Assert.Same(originalKeyRing, keyRingReturnedToBackgroundThread);
mockCacheableKeyRingProvider.Verify(o => o.GetCacheableKeyRing(updatedKeyRingTime), Times.Once);
}
internal CacheableKeyRing(CancellationToken expirationToken, DateTimeOffset expirationTime, IKeyRing keyRing)
{
_expirationToken = expirationToken;
ExpirationTimeUtc = expirationTime.UtcDateTime;
KeyRing = keyRing;
}
internal CacheableKeyRing(CancellationToken expirationToken, DateTimeOffset expirationTime, IKeyRing keyRing)
{
_expirationToken = expirationToken;
ExpirationTimeUtc = expirationTime.UtcDateTime;
KeyRing = keyRing;
}
