RFR: 8328866: Add raw monitor rank support to the debug agent. [v4]

[Serguei Spitsyn]

On Wed, 8 May 2024 19:22:31 GMT, Chris Plummer <cjplummer at openjdk.org> wrote:

> The special popFrame check needs to go in the first loop only, so it shouldn't be a problem or add any complexity that we don't already have.

Sounds good.

> One things to resolve is if we enter a regular monitor while holding a leaf monitor, is this a "rank" failure or "leaf" failure. Currently in the code it is a "rank" failure. Your change would make it a "leaf" failure.

A "leaf" failure is more specific than a "rank order" failure, so it is better to report it first. Each "leaf" failure is also  a "rank order" failure (AFAICS).

> I'm not sure why you added the "i != rank" check with the leaf check. We should never be re-entering a leaf monitor. The same "dbg_monitor->ownerThread != NULL" check as in the first loop should be used.

You are right. This check is not needed and has to be removed. I was thinking a leaf monitor can be grabbed recursively.

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PR Review Comment: https://git.openjdk.org/jdk/pull/19044#discussion_r1594583974