public void Populate_ConcurrentPopulateIsCalledEveryTimeAndSeesOwnValues(bool useGetOrPopulate,
int numberOfConsumers)
{
ManualResetEvent sem = new ManualResetEvent(false);
int populationCount = 0;
Populator populator = delegate(string key, out CacheOptions options)
{
if (populationCount == 0)
{
sem.Set();
Thread.Sleep(200);
}
populationCount += 1;
Assert.AreEqual("key", key);
options = CacheOptions.NoExpiration;
return("value" + Thread.CurrentThread.ManagedThreadId);
};
// Prepare a bunch of threads to concurrently populate the same key.
// They should all see their own populated values when released
// regardless of what the others are doing.
Procedure proc = delegate
{
sem.WaitOne();
Assert.AreEqual("value" + Thread.CurrentThread.ManagedThreadId,
Cache.Populate("key", populator));
};
IAsyncResult[] consumers = new IAsyncResult[numberOfConsumers];
for (int i = 0; i < numberOfConsumers; i++)
{
consumers[i] = proc.BeginInvoke(null, this);
}
// Now actually go populate it.
Assert.AreEqual("value" + Thread.CurrentThread.ManagedThreadId,
useGetOrPopulate ? Cache.GetOrPopulate("key", populator) :
Cache.Populate("key", populator));
// Wait for the consumers to finish and ensure they did not fail.
foreach (IAsyncResult consumer in consumers)
{
proc.EndInvoke(consumer);
}
// Ensure population happened the expected number of times.
Assert.AreEqual(1 + numberOfConsumers, populationCount);
}
