synchronizing both access to the timer object. Thanks Romain.

4 jobs for master in 40 minutes and 43 seconds (queued for 6 minutes and 12 seconds)
Status Job ID Name Coverage
  Build
passed #6673
jars-j8

00:00:34

passed #6672
java8

00:12:49

 
  Test
passed #6675
java10

00:14:10

passed #6674
java7

00:13:08