RFR: 8298377: JfrVframeStream causes deadlocks in ZGC [v2]

[Erik Österlund]

On Wed, 4 Jan 2023 16:10:39 GMT, Erik Österlund <eosterlund at openjdk.org> wrote:

>> src/hotspot/share/runtime/disableStackTracingMark.hpp line 36:
>> 
>>> 34: // Use this class to mark a section of code where stack tracing is not safe
>>> 35: // and should be avoided.
>>> 36: class DisableStackTracingMark : public StackObj {
>> 
>> One thing that could perhaps be a bit of a gotcha with this is the name selection, "DisableStackTracingMark". One could get the impression that this disables stack traces entirely. But this is not the case for asynchronous operations, like AsyncGetCallTrace and JFR - they fetch the information from the CPU context to produce a stacktrace, if there is no ljf. Not a biggie, but might be confusing. Perhaps "NoLastJavaFrame" or something?
>
> Good point. I'll try to think of a better name.

Trying out ClearFrameAnchorMark in the latest commit - what do you think?

-------------

PR: https://git.openjdk.org/jdk/pull/11778