RFR (S): Make uncaught exception in child threads trigger test failure

[Man Cao]

Hi all,

Can I have reviews for this:
https://cr.openjdk.java.net/~manc/tsan20190725/webrev.00/

Currently, if a child thread terminates due to an uncaught exception, such
as NullPointerException due to memory corruption, the TSAN test would still
pass. This change makes sure the test fail in such cases.

Tested with the following local modification:
--- a/test/hotspot/jtreg/tsan/NonRacyIntMemberLoopTest.java
+++ b/test/hotspot/jtreg/tsan/NonRacyIntMemberLoopTest.java
@@ -45,6 +45,9 @@ class NonRacyIntMemberLoopRunner extends
   @Override
   protected synchronized void run(int i) {
     x = x + 1;
+    if (i % 100 == 0) {
+      throw new NullPointerException();
+    }
   }

   public static void main(String[] args) throws InterruptedException

The test would pass without this change, and properly fails with this
change.

-Man