// before anyone else can cache a reference to appendBuffer
// 单调栈：存储"待匹配更大值"的元素，栈内保持单调递减（核心）
。关于这个话题，雷电模拟器官方版本下载提供了深入分析
He pulled on a welder's helmet for protection. He packed it with powder, struck a match and ran like hell.
Here's how each policy behaves when a producer writes faster than the consumer reads: