188 // The xxx140 variants for backward compatibility do not allow a full-width offset.

   188 // These functions allow a null base pointer with an arbitrary address.

   189 UNSAFE_ENTRY(jobject, Unsafe_GetObject140(JNIEnv *env, jobject unsafe, jobject obj, jint offset))

   190   UnsafeWrapper("Unsafe_GetObject");

   191   if (obj == NULL)  THROW_0(vmSymbols::java_lang_NullPointerException());

   192   GET_OOP_FIELD(obj, offset, v)

   193   jobject ret = JNIHandles::make_local(env, v);

   194 #if INCLUDE_ALL_GCS

   195   // We could be accessing the referent field in a reference

   196   // object. If G1 is enabled then we need to register a non-null

   197   // referent with the SATB barrier.

   198   if (UseG1GC) {

   199     bool needs_barrier = false;

   200 

   201     if (ret != NULL) {

   202       if (offset == java_lang_ref_Reference::referent_offset) {

   203         oop o = JNIHandles::resolve_non_null(obj);

   204         Klass* k = o->klass();

   205         if (InstanceKlass::cast(k)->reference_type() != REF_NONE) {

   206           assert(InstanceKlass::cast(k)->is_subclass_of(SystemDictionary::Reference_klass()), "sanity");

   207           needs_barrier = true;

   208         }

   209       }

   210     }

   211 

   212     if (needs_barrier) {

   213       oop referent = JNIHandles::resolve(ret);

   214       G1SATBCardTableModRefBS::enqueue(referent);

   215     }

   216   }

   217 #endif // INCLUDE_ALL_GCS

   218   return ret;

   219 UNSAFE_END

   220 

   221 UNSAFE_ENTRY(void, Unsafe_SetObject140(JNIEnv *env, jobject unsafe, jobject obj, jint offset, jobject x_h))

   222   UnsafeWrapper("Unsafe_SetObject");

   223   if (obj == NULL)  THROW(vmSymbols::java_lang_NullPointerException());

   224   oop x = JNIHandles::resolve(x_h);

   225   //SET_FIELD(obj, offset, oop, x);

   226   oop p = JNIHandles::resolve(obj);

   227   if (UseCompressedOops) {

   228     if (x != NULL) {

   229       // If there is a heap base pointer, we are obliged to emit a store barrier.

   230       oop_store((narrowOop*)index_oop_from_field_offset_long(p, offset), x);

   231     } else {

   232       narrowOop n = oopDesc::encode_heap_oop_not_null(x);

   233       *(narrowOop*)index_oop_from_field_offset_long(p, offset) = n;

   234     }

   235   } else {

   236     if (x != NULL) {

   237       // If there is a heap base pointer, we are obliged to emit a store barrier.

   238       oop_store((oop*)index_oop_from_field_offset_long(p, offset), x);

   239     } else {

   240       *(oop*)index_oop_from_field_offset_long(p, offset) = x;

   241     }

   242   }

   243 UNSAFE_END

   244 

   245 // The normal variants allow a null base pointer with an arbitrary address.