8369392: Safepoint sync should suspend GC and Java threads concurrently

[pengxiaolong]

WIP

---

Progress

• Change must be properly reviewed (1 review required, with at least 1 Reviewer)
• Change must not contain extraneous whitespace
• Commit message must refer to an issue

Issue

• JDK-8369392: Safepoint sync should suspend GC and Java threads concurrently (Enhancement - P4)

Reviewing

Using git

Checkout this PR locally:
$ git fetch https://git.openjdk.org/jdk.git pull/27924/head:pull/27924
$ git checkout pull/27924

Update a local copy of the PR:
$ git checkout pull/27924
$ git pull https://git.openjdk.org/jdk.git pull/27924/head

Using Skara CLI tools

Checkout this PR locally:
$ git pr checkout 27924

View PR using the GUI difftool:
$ git pr show -t 27924

Using diff file

Download this PR as a diff file:
https://git.openjdk.org/jdk/pull/27924.diff

[bridgekeeper]

👋 Welcome back xpeng! A progress list of the required criteria for merging this PR into master will be added to the body of your pull request. There are additional pull request commands available for use with this pull request.

[openjdk]

❗ This change is not yet ready to be integrated.
See the Progress checklist in the description for automated requirements.

[openjdk]

@pengxiaolong The following label will be automatically applied to this pull request:

• hotspot-runtime

When this pull request is ready to be reviewed, an "RFR" email will be sent to the corresponding mailing list. If you would like to change these labels, use the /label pull request command.