src/share/vm/prims/unsafe.cpp
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rev 2242 : [mq]: reflection-unsafe-read-barrier
@@ -191,11 +191,40 @@
// The xxx140 variants for backward compatibility do not allow a full-width offset.
UNSAFE_ENTRY(jobject, Unsafe_GetObject140(JNIEnv *env, jobject unsafe, jobject obj, jint offset))
UnsafeWrapper("Unsafe_GetObject");
if (obj == NULL) THROW_0(vmSymbols::java_lang_NullPointerException());
GET_OOP_FIELD(obj, offset, v)
- return JNIHandles::make_local(env, v);
+ jobject ret = JNIHandles::make_local(env, v);
+#ifndef SERIALGC
+ // We could be accessing the the referent field in a reference
+ // object. If G1 is enabled then we need to register the
+ // referent with the SATB barrier.
+ if (UseG1GC) {
+ bool needs_barrier = false;
+ oop o = JNIHandles::resolve_non_null(obj);
+
+ if (offset == java_lang_ref_Reference::referent_offset) {
+ klassOop k = o->klass();
+ if (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();
+ if (UseCompressedOops) {
+ bs->write_ref_field_pre((narrowOop*)index_oop_from_field_offset_long(o, offset),
+ JNIHandles::resolve(ret));
+ } else {
+ bs->write_ref_field_pre((oop*)index_oop_from_field_offset_long(o, offset),
+ JNIHandles::resolve(ret));
+ }
+ }
+ }
+#endif // SERIALGC
+ return ret;
UNSAFE_END
UNSAFE_ENTRY(void, Unsafe_SetObject140(JNIEnv *env, jobject unsafe, jobject obj, jint offset, jobject x_h))
UnsafeWrapper("Unsafe_SetObject");
if (obj == NULL) THROW(vmSymbols::java_lang_NullPointerException());
@@ -223,12 +252,42 @@
// The normal variants allow a null base pointer with an arbitrary address.
// But if the base pointer is non-null, the offset should make some sense.
// That is, it should be in the range [0, MAX_OBJECT_SIZE].
UNSAFE_ENTRY(jobject, Unsafe_GetObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset))
UnsafeWrapper("Unsafe_GetObject");
+ tty->print_cr("####### Unsafe_GetObject: offset = " INTX_FORMAT, offset);
GET_OOP_FIELD(obj, offset, v)
- return JNIHandles::make_local(env, v);
+ jobject ret = JNIHandles::make_local(env, v);
+#ifndef SERIALGC
+ // We could be accessing the referent field in a reference
+ // object. If G1 is enabled then we need to register the
+ // referent with the SATB barrier.
+ if (UseG1GC) {
+ bool needs_barrier = false;
+ oop o = JNIHandles::resolve(obj);
+
+ if (offset == java_lang_ref_Reference::referent_offset && o != NULL) {
+ klassOop k = o->klass();
+ if (instanceKlass::cast(k)->reference_type() != REF_NONE) {
+ assert(instanceKlass::cast(k)->is_subclass_of(SystemDictionary::Reference_klass()), "sanity"); tty->print_cr("####### Unsafe_GetObject: need a G1 barrier");
+ needs_barrier = true;
+ }
+ }
+
+ if (needs_barrier) {
+ BarrierSet* bs = Universe::heap()->barrier_set();
+ if (UseCompressedOops) {
+ bs->write_ref_field_pre((narrowOop*)index_oop_from_field_offset_long(o, offset),
+ JNIHandles::resolve(ret));
+ } else {
+ bs->write_ref_field_pre((oop*)index_oop_from_field_offset_long(o, offset),
+ JNIHandles::resolve(ret));
+ }
+ }
+ }
+#endif // SERIALGC
+ return ret;
UNSAFE_END
UNSAFE_ENTRY(void, Unsafe_SetObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h))
UnsafeWrapper("Unsafe_SetObject");
oop x = JNIHandles::resolve(x_h);