private static void OvercapacityCompaction(MemoryCache cache)
{
CoherentState coherentState = cache._coherentState; // Clear() can update the reference in the meantime
long currentSize = coherentState.Size;
cache._logger.LogDebug($"Overcapacity compaction executing. Current size {currentSize}");
double?lowWatermark = cache._options.SizeLimit * (1 - cache._options.CompactionPercentage);
if (currentSize > lowWatermark)
{
cache.Compact(currentSize - (long)lowWatermark, entry => entry.Size.Value, coherentState);
}
cache._logger.LogDebug($"Overcapacity compaction executed. New size {coherentState.Size}");
}
public void CompactLastAccessedRaceCondition()
{
const int numEntries = 100;
MemoryCache cache = new MemoryCache(new MemoryCacheOptions());
Random random = new Random();
void FillCache()
{
for (int i = 0; i < numEntries; i++)
{
cache.Set($"key{i}", $"value{i}");
}
}
// start a few tasks to access entries in the background
Task[] backgroundAccessTasks = new Task[Environment.ProcessorCount];
bool done = false;
for (int i = 0; i < backgroundAccessTasks.Length; i++)
{
backgroundAccessTasks[i] = Task.Run(async() =>
{
while (!done)
{
cache.TryGetValue($"key{random.Next(numEntries)}", out _);
await Task.Yield();
}
});
}
for (int i = 0; i < 1000; i++)
{
FillCache();
cache.Compact(1);
}
done = true;
Task.WaitAll(backgroundAccessTasks);
}