Re: RFR(XXS): 8236124: Minimal VM slowdebug build failed after JDK-8212160

[Chris Plummer]

Hi Serguei,

JvmtiDeferredEventQueue::enqueue() is a NOP for minimal builds, so it 
can be called even for minimalVM builds:

  void enqueue(JvmtiDeferredEvent event) NOT_JVMTI_RETURN;

The changes for JDK-8212160 seem to have put some wrapper code around 
its use, resulting in ServiceThread::enqueue_deferred_event() and 
JvmtiThreadState::enqueue_event() being added. Shouldn't NOP 
implementations also have been done for them?

thanks,

Chris

On 1/6/20 6:35 PM, Chris Plummer wrote:
Hold your horses. I have questions. Working on them now. Please don't 
push.

thanks,

Chris

On 1/6/20 6:29 PM, coleen.phillim...@oracle.com wrote:
This looks trivial.  Thank you for fixing it.
Coleen

On 1/6/20 9:18 PM, serguei.spit...@oracle.com wrote:
Please, review a trivial fix for bug:
  https://bugs.openjdk.java.net/browse/JDK-8236124

Patch suggested by A. Shipilev:

diff --git a/src/hotspot/share/code/nmethod.cpp 
b/src/hotspot/share/code/nmethod.cpp
--- a/src/hotspot/share/code/nmethod.cpp
+++ b/src/hotspot/share/code/nmethod.cpp
@@ -1601,7 +1601,7 @@
       ServiceThread::enqueue_deferred_event(&event);
     } else {
       // This enters the nmethod barrier outside in the caller.
-      state->enqueue_event(&event);
+      JVMTI_ONLY(state->enqueue_event(&event));
     }
   }
 }


Summary:
  The slowdebug build was broken by the fix of JDK-8212160 which 
introduced new function: enqueue_event().
  The fix is to call it only if the JVM TI is enabled.

Testing:
  Ran slowdebug build locally.

Thanks,
Serguei