[9] [XXS] RFR 8137230: TEST_BUG: java/nio/channels/FileChannel/LoopingTruncate.java timed out

[Ivan Gerasimov]

Hello!

The just added test started to intermittently fail on some machines.
It appears that creating a temporary file and doing some simple IO with 
it can sometimes take more than 10 seconds even without an infinite loop.

The proposal is:
- increase the timeout;
- limit the amount of work to only truncation of the file;
- if a case of failure, print a stacktrace of the frozen thread for a 
better diagnostic.

With this change, the test passed on all the platforms.

Would you please help review the fix?

BUGURL: https://bugs.openjdk.java.net/browse/JDK-8137230
WEBREV: http://cr.openjdk.java.net/~igerasim/8137230/00/webrev/


Sincerely yours,
Ivan