Please review -XshowSettings a java launcher option.

Mandy Chung mandy.chung at
Fri Nov 12 01:57:28 UTC 2010

  On 11/11/10 4:42 PM, Kumar Srinivasan wrote:
>> line 1032: Perhaps you could store the suboption ("all", "vm", etc) 
>> rather than the entire option string.
> I want to keep all the parsing logic as much as possible  in java.

It depends when you are going to detect if the option is valid or not.  
If java.c does the check, I think the suboption value is available; or 
you could do the check in LauncherHelper too.

>> line 106-109: if optionFlag is just the suboption to -XshowSettings, 
>> these lines can be removed.
>> line 150-152: Runtime.maxMemory() is not equivalent to -Xmx value.  
>> Perhaps -XshowSettings always prints Runtime.maxMemory() and print 
>> -Xmx if set in the command line?
> That is exactly what is happening ie. if the launcher has been given 
> the -Xmx flag
> then that is displayed, if not LauncherHelper will use some means to 
> display any
> value it can get from Java libraries so for now we use 
> Runtime.maxMemory().

What I meant is that it should make it clear that they are two different 
values.  Perhaps you can show two lines:
    -Xmx : VM default
    Runtime.maxMemory : xxx GB

The default -Xmx value (i.e. MaxHeapSize) is available in the VM.  It 
could include the default MaxHeapSize in the future.


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