Integrated: 8356251: Need minor cleanup for interp_only_mode

[Serguei Spitsyn]

On Tue, 6 May 2025 08:29:36 GMT, Serguei Spitsyn <sspitsyn at openjdk.org> wrote:

> This is a minor cleanup for the JVMTI `interp_only_mode` implementation which includes the following changes:
>  - The `interp_only_mode` in `JavaThread` is represented with a counter which is incremented and decremented. This is confusing because this value should only take values `0` or `1`. Asserts are placed to make sure it is never going out of bounds. The `interp_only_mode` in a `JavaThread` is checked by the interpreter chunks which expect it to be an `integer`. This cleanup has no intention to make it a boolean.
>  - The function `JvmtiThreadState::process_pending_interp_only()` does a sync on the `JvmtiThreadState_lock` which is not really needed and is being removed. It is called in a `VTMS` transition and so, can not clash with the `SetEventNotificationMode` because it sets a `JvmtiVTMSTransitionDisabler`.
>  
>  Testing:
>   - TBD: Mach5 tiers 1-6

This pull request has now been integrated.

Changeset: 411a63ea
Author:    Serguei Spitsyn <sspitsyn at openjdk.org>
URL:       https://git.openjdk.org/jdk/commit/411a63ea1b0c6e8bfea219427bf1c317c5dadabf
Stats:     20 lines in 4 files changed: 3 ins; 8 del; 9 mod

8356251: Need minor cleanup for interp_only_mode

Reviewed-by: lmesnik, cjplummer

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PR: https://git.openjdk.org/jdk/pull/25060