RFR: 8201179: Regression due loading java.nio.charset.StandardCharsets during bootstrap

[Xueming Shen]

On 4/9/18, 6:45 AM, Claes Redestad wrote:
> Hi,
>
> JDK-8200310 cleaned up java.nio.charset.StandardCharsets to not use 
> Charset.forName, but also removed the optimization to have 
> unconditionally loaded charsets set up static INSTANCE constants, 
> which means that many systems the java.nio.charset.StandardCharsets 
> will be initialized in System.initPhase1.
>
> This should be avoided since at this point the VM is just booting up 
> and any code executed delays initialization of JIT etc.
>
> Webrev: http://cr.openjdk.java.net/~redestad/8201179/open.00/
> Bug: https://bugs.openjdk.java.net/browse/JDK-8201179
>
> This patch makes all the constants in j.n.c.StandardCharsets use new 
> INSTANCE fields of each respective Charset and adds some comments as 
> to why they exist.
this is fine.

>
> I also think we should avoid depending on j.n.c.StandardCharsets 
> within java.base as to not accidentally execute more code in 
> initPhase1 than absolutely necessary, so I've changed uses in core 
> packages (java.lang, java.util, java.zip...) to use the internal 
> alternative.

is this really necessary? it appears to introduces in an unnecessary 
dependency on the location of
the internal implementation of .UTF_8.

sherman

>
> Thanks!
>
> /Claes
>