/// <summary>
/// 定时添加令牌
/// </summary>
private void TokenProcess()
{
int sleep = 1000 / MaxQPS;
if (sleep == 0)
{
sleep = 1; //测试过只要不是while(true)且不sleep，就算sleep(1)CPU也没什么开销
}
sleep += 1; //不能卡那么准
DateTime start = DateTime.Now;
while (cancellationToken.Token.IsCancellationRequested == false)
{
lock (lockObject)
{
var isSuccess = limitedQueue.Enqueue(new object());
}
if (DateTime.Now - start < TimeSpan.FromMilliseconds(sleep)) //如果因为等待lock而大于需要的sleep了那就不需要sleep可以直接开始放令牌
{
int newSleep = sleep - (int)(DateTime.Now - start).TotalMilliseconds;
if (newSleep >= 0)
{
Thread.Sleep(newSleep); //做损失时间补偿（等待造成的时间丢失补偿回来）例如sleep是500ms，等待花费了200ms，那么只需要sleep300ms就够了
}
}
start = DateTime.Now;
}
}
public bool RequestWithRetry(int retryCount)
{
if (retryCount < 0)
{
return(false);
}
RequestObject requestObject = new RequestObject();
bool isInBucket = false;
while (retryCount != 0)
{
if (limitedQueue.Count < LimitSize && !isInBucket)
{
lock (lockObject)
{
if (limitedQueue.Count < LimitSize)
{
limitedQueue.Enqueue(requestObject);
isInBucket = true;
}
}
}
if (requestObject.HasHandle)
{
return(true);
}
Thread.Sleep(System.Math.Max(0, limitedQueue.Count * 1000 / MaxQPS));
retryCount--;
}
return(false);
}
private readonly object lockObject = new object();//用于加锁
/// <summary>
/// 构造方法
/// </summary>
/// <param name="maxQPS">最大QPS</param>
/// <param name="limitSize">最大限制同时并发数</param>
public TokenBucketLimitingService(int maxQPS, int limitSize)
{
MaxQPS = maxQPS;
LimitSize = limitSize;
limitedQueue = new LimitedQueue <object>(limitSize);
for (int i = 0; i < limitSize; i++)//先放满令牌
{
limitedQueue.Enqueue(new object());
}
cancellationToken = new CancellationTokenSource();
task = Task.Factory.StartNew(new Action(TokenProcess), cancellationToken.Token);
}
