RFR(XXS): 8234433: TestUnloadEventClassCount fails with "assert(SafepointSynchronize::is_at_safepoint()) failed: invariant"

[Markus Gronlund]

Hi,

Please help review this small change:

Bug: https://bugs.openjdk.java.net/browse/JDK-8234433
Webrev: http://cr.openjdk.java.net/~mgronlun/8234433/webrev/
Diff:

diff -r 7567ce83f3b5 -r f48ca1c7feda src/hotspot/share/jfr/jni/jfrGetAllEventClasses.cpp
--- a/src/hotspot/share/jfr/jni/jfrGetAllEventClasses.cpp       Thu Nov 21 13:50:11 2019 +0530
+++ b/src/hotspot/share/jfr/jni/jfrGetAllEventClasses.cpp       Thu Nov 21 11:13:34 2019 +0100
@@ -33,12 +33,11 @@
 #include "memory/resourceArea.hpp"
 #include "runtime/handles.inline.hpp"
 #include "runtime/mutexLocker.hpp"
-#include "runtime/safepoint.hpp"
 #include "runtime/thread.inline.hpp"
 #include "utilities/growableArray.hpp"
 #include "utilities/stack.inline.hpp"

- // incremented during class unloading (safepoint) for each unloaded event class
+ // incremented during class unloading for each unloaded event class
 static jlong unloaded_event_classes = 0;

 jlong JfrEventClasses::unloaded_event_classes_count() {
@@ -46,8 +45,7 @@
 }

 void JfrEventClasses::increment_unloaded_event_class() {
-  // incremented during class unloading (safepoint) for each unloaded event class
-  assert(SafepointSynchronize::is_at_safepoint(), "invariant");
+  assert_locked_or_safepoint(ClassLoaderDataGraph_lock);
   ++unloaded_event_classes;
 }

Thanks
Markus