protected override long reserveEarliestAvailable(int requiredPermits, long nowMicros)
{
//重新计算桶内令牌数storedPermits
lock (mutex())
{
resync(nowMicros);
}
lock (mutex())
{
long returnValue = nextFreeTicketMicros; //下一次请求可以获取令牌的起始时间
//本次消耗的令牌数
double storedPermitsToSpend = Math.Min(requiredPermits, this.storedPermits); //本次消耗的令牌数=min(申请令牌数,当前存储令牌数)
#region 预支逻辑 //重新计算下次可获取时间nextFreeTicketMicros
double freshPermits = requiredPermits - storedPermitsToSpend; //缺少令牌数=申请令牌数-本次可以消耗的令牌数
long waitMicros =
storedPermitsToWaitTime(this.storedPermits, storedPermitsToSpend)
+ (long)(freshPermits * stableIntervalMicros); //缺少令牌数*生成令牌的时间间隔(提前预支)
this.nextFreeTicketMicros = LongHelper.SaturatedAdd(nextFreeTicketMicros, waitMicros); //防止溢出 下一次分配时间+预支分配令牌的时间
#endregion //Console.WriteLine("nextFreeTicketMicros:" + this.nextFreeTicketMicros+"_"+ waitMicros);
this.storedPermits -= storedPermitsToSpend;
return(returnValue);
}
}
public void SaturateCalculationTest()
{
Assert.IsTrue(LongHelper.SaturatedAdd(5, 5) == 10);
Assert.IsTrue(LongHelper.SaturatedAdd(long.MaxValue, 5) == long.MaxValue);
Assert.IsTrue(LongHelper.SaturatedAdd(long.MinValue, -5) == long.MinValue);
Assert.IsTrue(LongHelper.SaturatedSubtract(long.MinValue, 5) == long.MinValue);
Assert.IsTrue(LongHelper.SaturatedMultiply(5, 5) == 25);
Assert.IsTrue(LongHelper.SaturatedMultiply(long.MaxValue / 2, 3) == long.MaxValue);
}