On Mon, 3 Apr 2023 07:17:59 GMT, David Holmes <dhol...@openjdk.org> wrote:
> We have the strange situation where calling `t.isAlive()` on a
> `java.lang.Thread` `t`, will call into the VM (via `alive()` then
> `isAlive0()`) where the VM then examines the `eetop` field of `t` to extract
> its `JavaThread` pointer and compare it to null. We can simply read `eetop`
> directly in `Thread.alive()`:
>
> boolean alive() {
> return eetop != 0;
> }
>
> I also updated a comment in relation to `eetop`.
>
> Testing: tiers 1-3
>
> Thanks
This pull request has now been integrated.
Changeset: 35cb303a
Author: David Holmes <dhol...@openjdk.org>
URL:
https://git.openjdk.org/jdk/commit/35cb303a2c0c8b32de257c02e012a1928a6b4594
Stats: 142 lines in 7 files changed: 123 ins; 12 del; 7 mod
8305425: Thread.isAlive0 doesn't need to call into the VM
Co-authored-by: Aleksey Shipilev <sh...@openjdk.org>
Reviewed-by: shade, coleenp, alanb
-------------
PR: https://git.openjdk.org/jdk/pull/13287
