RFR(S): JDK-8157236 - attach on ARMv7 fails with com.sun.tools.attach.AttachNotSupportedException: Unable to open socket file

David Holmes david.holmes at oracle.com
Sun Aug 7 23:40:46 UTC 2016

Hi Dmitry,

On 5/08/2016 7:25 PM, Dmitry Samersoff wrote:
> Everybody,
> Please review the fix:
>   http://cr.openjdk.java.net/~dsamersoff/JDK-8157236/webrev.02/
> Problem:
>   Tests fail intermittently because it can't attach to child process,
>   these attach failures is hard to debug because attach framework
>   doesn't provide enough diagnostic information.
> Solution:
>   a) Increase attach timeout
>   b) Slightly change attach loop to save a bit of CPU power.
>   c) Add some logging to attach listener.
> It's just a first step in this direction. Complete cleanup of attach
> code (remove LinuxThreads support and convert all printing to UL) is not
> a goal of this fix - I'll file a separate CR for it.

I still think you need more logging now to aid in debugging these cases. 
In particular we want to be able to verify that the path of the attach 
file is what we expect in all cases ie whether we find  the .attach_pid 
file in cwd or whether we are looking in temp directory, and whether we 
ultimately succeed or fail.

Plus whatever you do now should be done consistently for all platforms.


> -Dmitry

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