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
-------------
Commit messages:
- update symbol file
- 8305425: Thread.isAlive0 doesn't need to call into the VM
Changes: https://git.openjdk.org/jdk/pull/13287/files
Webrev: https://webrevs.openjdk.org/?repo=jdk&pr=13287&range=00
Issue: https://bugs.openjdk.org/browse/JDK-8305425
Stats: 19 lines in 5 files changed: 3 ins; 12 del; 4 mod
Patch: https://git.openjdk.org/jdk/pull/13287.diff
Fetch: git fetch https://git.openjdk.org/jdk.git pull/13287/head:pull/13287
PR: https://git.openjdk.org/jdk/pull/13287
