1.1 --- a/src/share/vm/prims/unsafe.cpp Thu May 03 18:59:48 2018 +0200
1.2 +++ b/src/share/vm/prims/unsafe.cpp Tue Sep 06 13:01:27 2016 +0200
1.3 @@ -199,37 +199,40 @@
1.4
1.5 // Get/SetObject must be special-cased, since it works with handles.
1.6
1.7 +// We could be accessing the referent field in a reference
1.8 +// object. If G1 is enabled then we need to register non-null
1.9 +// referent with the SATB barrier.
1.10 +
1.11 +#if INCLUDE_ALL_GCS
1.12 +static bool is_java_lang_ref_Reference_access(oop o, jlong offset) {
1.13 + if (offset == java_lang_ref_Reference::referent_offset && o != NULL) {
1.14 + Klass* k = o->klass();
1.15 + if (InstanceKlass::cast(k)->reference_type() != REF_NONE) {
1.16 + assert(InstanceKlass::cast(k)->is_subclass_of(SystemDictionary::Reference_klass()), "sanity");
1.17 + return true;
1.18 + }
1.19 + }
1.20 + return false;
1.21 +}
1.22 +#endif
1.23 +
1.24 +static void ensure_satb_referent_alive(oop o, jlong offset, oop v) {
1.25 +#if INCLUDE_ALL_GCS
1.26 + if (UseG1GC && v != NULL && is_java_lang_ref_Reference_access(o, offset)) {
1.27 + G1SATBCardTableModRefBS::enqueue(v);
1.28 + }
1.29 +#endif
1.30 +}
1.31 +
1.32 // The xxx140 variants for backward compatibility do not allow a full-width offset.
1.33 UNSAFE_ENTRY(jobject, Unsafe_GetObject140(JNIEnv *env, jobject unsafe, jobject obj, jint offset))
1.34 UnsafeWrapper("Unsafe_GetObject");
1.35 if (obj == NULL) THROW_0(vmSymbols::java_lang_NullPointerException());
1.36 GET_OOP_FIELD(obj, offset, v)
1.37 - jobject ret = JNIHandles::make_local(env, v);
1.38 -#if INCLUDE_ALL_GCS
1.39 - // We could be accessing the referent field in a reference
1.40 - // object. If G1 is enabled then we need to register a non-null
1.41 - // referent with the SATB barrier.
1.42 - if (UseG1GC) {
1.43 - bool needs_barrier = false;
1.44
1.45 - if (ret != NULL) {
1.46 - if (offset == java_lang_ref_Reference::referent_offset) {
1.47 - oop o = JNIHandles::resolve_non_null(obj);
1.48 - Klass* k = o->klass();
1.49 - if (InstanceKlass::cast(k)->reference_type() != REF_NONE) {
1.50 - assert(InstanceKlass::cast(k)->is_subclass_of(SystemDictionary::Reference_klass()), "sanity");
1.51 - needs_barrier = true;
1.52 - }
1.53 - }
1.54 - }
1.55 + ensure_satb_referent_alive(p, offset, v);
1.56
1.57 - if (needs_barrier) {
1.58 - oop referent = JNIHandles::resolve(ret);
1.59 - G1SATBCardTableModRefBS::enqueue(referent);
1.60 - }
1.61 - }
1.62 -#endif // INCLUDE_ALL_GCS
1.63 - return ret;
1.64 + return JNIHandles::make_local(env, v);
1.65 UNSAFE_END
1.66
1.67 UNSAFE_ENTRY(void, Unsafe_SetObject140(JNIEnv *env, jobject unsafe, jobject obj, jint offset, jobject x_h))
1.68 @@ -262,32 +265,10 @@
1.69 UNSAFE_ENTRY(jobject, Unsafe_GetObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset))
1.70 UnsafeWrapper("Unsafe_GetObject");
1.71 GET_OOP_FIELD(obj, offset, v)
1.72 - jobject ret = JNIHandles::make_local(env, v);
1.73 -#if INCLUDE_ALL_GCS
1.74 - // We could be accessing the referent field in a reference
1.75 - // object. If G1 is enabled then we need to register non-null
1.76 - // referent with the SATB barrier.
1.77 - if (UseG1GC) {
1.78 - bool needs_barrier = false;
1.79
1.80 - if (ret != NULL) {
1.81 - if (offset == java_lang_ref_Reference::referent_offset && obj != NULL) {
1.82 - oop o = JNIHandles::resolve(obj);
1.83 - Klass* k = o->klass();
1.84 - if (InstanceKlass::cast(k)->reference_type() != REF_NONE) {
1.85 - assert(InstanceKlass::cast(k)->is_subclass_of(SystemDictionary::Reference_klass()), "sanity");
1.86 - needs_barrier = true;
1.87 - }
1.88 - }
1.89 - }
1.90 + ensure_satb_referent_alive(p, offset, v);
1.91
1.92 - if (needs_barrier) {
1.93 - oop referent = JNIHandles::resolve(ret);
1.94 - G1SATBCardTableModRefBS::enqueue(referent);
1.95 - }
1.96 - }
1.97 -#endif // INCLUDE_ALL_GCS
1.98 - return ret;
1.99 + return JNIHandles::make_local(env, v);
1.100 UNSAFE_END
1.101
1.102 UNSAFE_ENTRY(void, Unsafe_SetObject(JNIEnv *env, jobject unsafe, jobject obj, jlong offset, jobject x_h))
1.103 @@ -312,6 +293,9 @@
1.104 } else {
1.105 (void)const_cast<oop&>(v = *(volatile oop*) addr);
1.106 }
1.107 +
1.108 + ensure_satb_referent_alive(p, offset, v);
1.109 +
1.110 OrderAccess::acquire();
1.111 return JNIHandles::make_local(env, v);
1.112 UNSAFE_END
