CRR (XS): 7123165: G1: output during parallel verification can get messed up

[Tony Printezis]

Hi all,

Can I have a couple of quick reviews for this very small change (< 10 
lines changed)?

http://cr.openjdk.java.net/~tonyp/7123165/webrev.0/

During parallel verification each worker now takes a lock after it 
detects a failure and while it's generating output. This way the output 
from separate workers is not interleaved and it's easier to read. I came 
across this issue while testing some recent changes and this patch made 
my life easier. It might make your life easier some day too. :-)

Tony