https://bugs.openjdk.java.net/browse/JDK-8021335 http://cr.openjdk.java.net/~dlong/8021335/webrev.3/
This change attempts to fix an old and intermittent problem with ThreadMXBean thread counts.
Changes have 3 main parts: 1. Make sure hidden threads don't affect counts (even when exiting) 2. Fix race reading counts using atomic counters 3. Remove some workarounds in test (because they hide bugs) dl
