Hi, Thread.getName() returns String, and does new String instantiation every time, because the thread name is stored in char[]. Even though we use a private String constructor that shares the char[] array without copying it, this still hurts some use cases (think extra-fast logging). To the extent some people actually maintain Map<Thread, String> to avoid it. https://bugs.openjdk.java.net/browse/JDK-8059677
Here's the attempt to maintain String instead of char[]: http://cr.openjdk.java.net/~shade/8059677/webrev.01.jdk/ http://cr.openjdk.java.net/~shade/8059677/webrev.01.hs/ JDK changes are trivial, but HS changes require some rewiring, since VM treats Thread.name specially. However, it turns out we can make a contained change, since the getter is used sparingly, and setter seems to be not used at all. Any trouble with this change? Testing: JPRT, manual tests, jdk/test/java/lang/Thread jtreg, hotspot/test/runtime/ jtreg, vm.quick.testlist, nsk.jvmti.testlist, svc.quick.testlist Thanks, -Aleksey.
