java - 对象如何在 G1(垃圾优先)垃圾收集器上老化？

Question

将年轻对象放入旧区域使其成为旧对象或将其保留在幸存者区域的标准是什么？

official tutorial 的 Young GC 的第 4 点状态:

"Live objects are evacuated (i.e., copied or moved) to one or more survivor regions. If the aging threshold is met, some of the objects are promoted to old generation regions."

但我找不到那个标准是什么。

编辑:

Amit Bhati 向我指出了 MaxTenuringThreshold 参数。我对官方文档了解不多，但我想我开始了解它是如何工作的。

Answer 1

在您的帮助下，我想我找到了答案 here :

-XX:InitialTenuringThreshold=7 Sets the initial tenuring threshold for use in adaptive GC sizing in the parallel young collector. The tenuring threshold is the number of times an object survives a young collection before being promoted to the old, or tenured, generation. -XX:MaxTenuringThreshold=n Sets the maximum tenuring threshold for use in adaptive GC sizing. The current largest value is 15. The default value is 15 for the parallel collector and is 4 for CMS.

它在Debugging Options 标题下:)

在 Garbage First (G1) Garbage Collection Options 下，您可以找到:

-XX:MaxTenuringThreshold=n Maximum value for tenuring threshold. The default value is 15.

如果您没有阅读其他部分的 InitialTenuringThreshold 描述，则描述性不强。似乎 InitialTenuringThreshold 不是有效的 G1 选项，但我认为该算法是在那里描述的。