src/share/vm/prims/jni.cpp

rev 2241 : [mq]: jni-read-barrier
rev 2242 : [mq]: reflection-unsafe-read-barrier

*** 1722,1731 ****
--- 1722,1750 ----
    // jni_GetField_probe() assumes that is okay to create handles.
    if (JvmtiExport::should_post_field_access()) {
      o = JvmtiExport::jni_GetField_probe(thread, obj, o, k, fieldID, false);
    }
    jobject ret = JNIHandles::make_local(env, o->obj_field(offset));
+ #ifndef SERIALGC
+   // If G1 is enabled and we are accessing the value of the referent
+   // field in a reference object then we need to register the
+   // referent with the SATB barrier.
+   if (UseG1GC) {
+     bool needs_barrier = false;
+ 
+     if (offset == java_lang_ref_Reference::referent_offset &&
+         instanceKlass::cast(k)->reference_type() != REF_NONE) {
+       assert(instanceKlass::cast(k)->is_subclass_of(SystemDictionary::Reference_klass()), "sanity");
+       needs_barrier = true;
+     }
+     
+     if (needs_barrier) {
+       BarrierSet* bs = Universe::heap()->barrier_set();
+       bs->write_ref_field_pre((oop*)o->obj_field_addr<oop>(offset), JNIHandles::resolve(ret));
+     }
+   }
+ #endif // SERIALGC
    DTRACE_PROBE1(hotspot_jni, GetObjectField__return, ret);
    return ret;
  JNI_END