12 RFR(M) 8195635: [Graal] nsk/jvmti/unit/ForceEarlyReturn/earlyretbase crashes with assertion "compilation level out of bounds"

[dean.long at oracle.com]

I'm withdrawing this RFR for 12.

dl

On 1/28/19 5:13 PM, dean.long at oracle.com wrote:
> http://cr.openjdk.java.net/~dlong/8195635/webrev.5/
> https://bugs.openjdk.java.net/browse/JDK-8195635
>
> Please see the bug report for all the gory details.  Here's the short 
> version:
>
> If we allow any safepoint to be a suspend point, we run into trouble 
> with PopFrame and ForceEarlyReturn, which reasonably expect the top 
> frame not to change between the suspend and when the 
> PopFrame/ForceEarlyReturn is executed.  Normally this is not an issue, 
> but certain safepoints cause problems, when we are about to call a new 
> Java method.  In particular, if we safepoint and suspend in 
> JavaCallWrapper, the top frame will still be the caller, but when we 
> execute the PopFrame/ForceEarlyReturn we will be in the callee.
>
> The solution this patch takes is to block suspend around troublesome 
> VM code using a new "allow_suspend" thread flag.  This means 
> JavaThread::java_suspend can't just ask the VMThread to safepoint and 
> be done.  Instead it has wait and allow threads to roll forward to an 
> allowed suspend point.
>
> dl