RFR: JDK-8188856: Incorrect file path in an exception message when .java_pid is not accessible on Unix

[gary.adams at oracle.com]

On 12/18/17 2:26 PM, Chris Plummer wrote:
> Hi Gary,
>
> On 12/18/17 6:47 AM, Gary Adams wrote:
>> Here's a simple fix to correct the error message when the java_pid 
>> socket
>> is not found. The code previously reported the attach_pid file name
>> rather than the socket file name that was not found.
>>
>>   Issue: https://bugs.openjdk.java.net/browse/JDK-8188856
>>   Webrev: http://cr.openjdk.java.net/~gadams/8188856/webrev.00/
>
> I don't understand why you couldn't simply have changed the 
> f.getPath() reference to "path". From what I can see, there is no 
> difference between "path" and "socket_name". The problem you are 
> fixing is that the error message prints f.getPath(), but that refers 
> to the attach file and the error message should refer to the socket 
> file. You've correct this, but have done so in a round about way. 
> Above the error message (in two places) exists:
>
>            path = findSocketFile(pid, ns_pid);
>
> So "path" is what you want. You have indirectly fixed the problem by 
> having findSocketFile() store the path in socket_name, and then you 
> print socket_name, but why not just do the direct fix and print "path".
>
> Also, the copyrights need to be updated.
>
> thanks,
>
> Chris
>
>
The problem was path is used to hold the constructed file name
if it is confirmed to exist in the file system. Otherwise it is passed 
back from
findSocketFile as a null to indicate the socket file was not found.

I could refactor where the existence check is handled, but it seemed 
like the least
invasive change to simply save the socket name for the printing in the 
error case.