HashMap中的ALT-rt.jar中和rt.jar的区别？ [英] Difference of HashMap in alt-rt.jar and rt.jar?

问题描述

在ALT-rt.jar中的HashMap之间的区别是什么 和rt.jar中。我想我看到了相当加快 在我的应用程序之一，会是什么解释？

What is the difference between HashMap in alt-rt.jar and rt.jar. I think I see a considerable speed up in one of my applications, what would be the explanation?

最好的问候

P.S：我发现了两个不同的* .jar 在JDK 1.6.0_25 64位。最终， 加快也与ALT-string.jar。 这ALT最终可能涉及到一个 命令行选项：

P.S.: I found the two different *.jar in JDK 1.6.0_25 64-bit. Eventually the speed up is also related to alt-string.jar. This alt could eventually be related to a command line option:

<一个href="http://thevirtualmachinist.blogspot.com/2010/09/xxusecom$p$pssedstrings.html">http://thevirtualmachinist.blogspot.com/2010/09/xxusecom$p$pssedstrings.html

不过，我更感兴趣的是理解 ALT-rt.jar中，我不从看 上面的文章，有一个命令行 选择与它有关。

But I am more interested in understanding alt-rt.jar and I don't see from the above article that there is a command line option related to it.

推荐答案

ALT-rt.jar中仅用于在启用AggressiveOpts JVM选项。确实是从交替 - rt.jar中HashMap中比传统的HashMap更快，但是它的内存消耗高得多由于HashMap中$ FrontCache的使用。

alt-rt.jar is used only when AggressiveOpts JVM option is enabled. Indeed the HashMap from alt-rt.jar is faster than the traditional HashMap, however its memory consumption is much higher due to usage of HashMap$FrontCache.

在生产中使用AggressiveOpts参数时要小心，我们有很多的麻烦与它在内存有限的设置。可能有其他隐藏的陷阱。

Be careful when using AggressiveOpts parameter in production, we had a lot of trouble with it in memory limited setups. There could be other pitfalls hiding.

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