RFR(trivial): 8231024: Improve the debug info when the output is truncated

[Jie Fu]

Hi David,

Thank you for your review.
Will update the patch soon.
Please seem comments inline.

Best regards,
Jie

On 2019/9/15 上午10:03, David Holmes wrote:
> Looks good. But given this keeps reporting different values, the input 
> buffer size must be different in each case, so printing that size as 
> well could also be useful for tracing back to the callsite. 

OK. Will do.


> There seems to be as assumption that the buffer is always O_BUFLEN in 
> size but as it is set to 2000 that can't be the case. In which case 
> the error message itself seems somewhat misleading.
I agree that the error message itself seems somewhat misleading since 
apart from O_BUFLEN [1], BUFLEN [2] may also be used as the buffer size.

[1] 
http://hg.openjdk.java.net/jdk/jdk/file/24df796eef3d/src/hotspot/share/utilities/ostream.cpp#l124
[2] 
http://hg.openjdk.java.net/jdk/jdk/file/24df796eef3d/src/hotspot/share/utilities/xmlstream.cpp#l138