public void SingleCounter()
{
var collection = new CounterCollection(1);
XAssert.AreEqual(0, collection.GetCounterValueInternal(0));
collection.AddToCounterInternal(0, 123);
collection.AddToCounterInternal(0, 1);
XAssert.AreEqual(124, collection.GetCounterValueInternal(0));
}
public void MultipleCounters()
{
const ushort NumCounters = 65; // Not a multiple of 64
var collection = new CounterCollection(NumCounters);
for (ushort i = 0; i < NumCounters; i++)
{
XAssert.AreEqual(0, collection.GetCounterValueInternal(i));
collection.AddToCounterInternal(i, i);
XAssert.AreEqual(i, collection.GetCounterValueInternal(i));
}
}
public void SingleCounterUnderflow()
{
var collection = new CounterCollection(1);
XAssert.AreEqual(0, collection.GetCounterValueInternal(0));
collection.AddToCounterInternal(0, long.MinValue + 3);
collection.AddToCounterInternal(0, -3);
ExpectOverflow(
() =>
{
// Since the counter is sharded, overflow may manifest in Add (single shard overflow) or Get (overflow of shards only in aggregate).
collection.AddToCounterInternal(0, -1);
collection.GetCounterValueInternal(0);
});
}
public void SingleCounterWithContention()
{
var collection = new CounterCollection(1);
XAssert.AreEqual(0, collection.GetCounterValueInternal(0));
var threads = new Thread[Environment.ProcessorCount];
long expected = 0;
bool[] allStarted = new[] { false };
for (int i = 0; i < threads.Length; i++)
{
threads[i] = new Thread(
() =>
{
long thisThreadAdded = 0;
while (!Volatile.Read(ref allStarted[0]))
{
collection.AddToCounterInternal(0, 1);
thisThreadAdded++;
}
for (int j = 0; j < 30; j++)
{
collection.AddToCounterInternal(0, 1);
thisThreadAdded++;
}
Interlocked.Add(ref expected, thisThreadAdded);
});
threads[i].Start();
}
Volatile.Write(ref allStarted[0], true);
for (int i = 0; i < threads.Length; i++)
{
threads[i].Join();
}
XAssert.AreEqual(expected, collection.GetCounterValueInternal(0));
}
/// <summary>
/// Get the counter value.
/// </summary>
public long GetDifference(CounterCollection <TEnum> subtrahend, TEnum counterId)
{
ushort counterIndex = s_info.GetCounterIndex(counterId);
return(GetCounterValueInternal(counterIndex) - subtrahend.GetCounterValueInternal(counterIndex));
}