On 10/11/2014 9:52 PM, Chris Hegarty wrote:
Aleksey,
I have only looked at the libraries changes, and I think they make sense
. As in, I can find no reason why the name cannot be changed to be a
String.
Very quick response, but IIRC this has been examined in the past and
there were reasons why it can't/shouldn't be done. Will try to dig out
more details in the morning.
If String construction is a bottleneck just cache it.
David
-----
Trivially, after your changes will NPE be thrown if setName(null), as it
is today ?
-Chris.
On 09/11/14 18:45, Aleksey Shipilev wrote:
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.
