private int UncacheChunks(int maxUncacheCount = 10)
{
var uncachedCount = 0;
if (Interlocked.CompareExchange(ref _uncachingChunks, 1, 0) == 0)
{
try
{
var usedMemoryPercent = ChunkUtil.GetUsedMemoryPercent();
if (usedMemoryPercent <= (ulong)_config.ChunkCacheMinPercent)
{
return(0);
}
if (_logger.IsDebugEnabled)
{
_logger.DebugFormat("Current memory usage {0}% exceed the chunkCacheMinPercent {1}%, try to uncache chunks.", usedMemoryPercent, _config.ChunkCacheMinPercent);
}
var chunks = _chunks.Values.Where(x => x.IsCompleted && !x.IsMemoryChunk && x.HasCachedChunk).OrderBy(x => x.LastActiveTime).ToList();
foreach (var chunk in chunks)
{
if ((DateTime.Now - chunk.LastActiveTime).TotalSeconds >= _config.ChunkInactiveTimeMaxSeconds)
{
if (chunk.UnCacheFromMemory())
{
Thread.Sleep(100); //即便有内存释放了，由于通过API读取到的内存使用数可能不会立即更新，所以等待一定时间后检查内存是否足够
uncachedCount++;
if (uncachedCount >= maxUncacheCount || ChunkUtil.GetUsedMemoryPercent() <= (ulong)_config.ChunkCacheMinPercent)
{
break;
}
}
}
}
if (_logger.IsDebugEnabled)
{
if (uncachedCount > 0)
{
_logger.DebugFormat("Uncached {0} chunks, current memory usage: {1}%", uncachedCount, ChunkUtil.GetUsedMemoryPercent());
}
else
{
_logger.Debug("No chunks uncached.");
}
}
}
catch (Exception ex)
{
_logger.Error("Uncaching chunks has exception.", ex);
}
finally
{
Interlocked.Exchange(ref _uncachingChunks, 0);
}
}
return(uncachedCount);
}
