jdk-sandbox: comparison hotspot/src/share/vm/memory/referenceProcessor.cpp

equal deleted inserted replaced

-:dfbfc5483c3e
+:383a5bdef99d
 bool      discovered_list_needs_barrier)  :
 _discovering_refs(false),
 _enqueuing_is_done(false),
 _is_alive_non_header(is_alive_non_header),
 _discovered_list_needs_barrier(discovered_list_needs_barrier),
-_bs(NULL),
 _processing_is_mt(mt_processing),
 _next_id(0)
 {
 _span = span;
 _discovery_is_atomic = atomic_discovery;
 for (uint i = 0; i < _max_num_q * number_of_subclasses_of_ref(); i++) {
 _discovered_refs[i].set_head(NULL);
 _discovered_refs[i].set_length(0);
 }
-// If we do barriers, cache a copy of the barrier set.
-if (discovered_list_needs_barrier) {
-_bs = Universe::heap()->barrier_set();
-}
 setup_policy(false /* default soft ref policy */);
 }
 #ifndef PRODUCT
 void ReferenceProcessor::verify_no_references_recorded() {
 T old_pending_list_value = *pending_list_addr;
 // Enqueue references that are not made active again, and
 // clear the decks for the next collection (cycle).
 ref->enqueue_discovered_reflists((HeapWord*)pending_list_addr, task_executor);
-// Do the oop-check on pending_list_addr missed in
+// Do the post-barrier on pending_list_addr missed in
-// enqueue_discovered_reflist. We should probably
+// enqueue_discovered_reflist.
-// do a raw oop_check so that future such idempotent
+oopDesc::bs()->write_ref_field(pending_list_addr, oopDesc::load_decode_heap_oop(pending_list_addr));
-// oop_stores relying on the oop-check side-effect
-// may be elided automatically and safely without
-// affecting correctness.
-oop_store(pending_list_addr, oopDesc::load_decode_heap_oop(pending_list_addr));
 // Stop treating discovered references specially.
 ref->disable_discovery();
 // Return true if new pending references were added
 (void *)obj, (void *)next_d);
 }
 assert(java_lang_ref_Reference::next(obj) == NULL,
 "Reference not active; should not be discovered");
 // Self-loop next, so as to make Ref not active.
-java_lang_ref_Reference::set_next(obj, obj);
+// Post-barrier not needed when looping to self.
+java_lang_ref_Reference::set_next_raw(obj, obj);
 if (next_d == obj) {  // obj is last
 // Swap refs_list into pendling_list_addr and
 // set obj's discovered to what we read from pending_list_addr.
 oop old = oopDesc::atomic_exchange_oop(refs_list.head(), pending_list_addr);
-// Need oop_check on pending_list_addr above;
+// Need post-barrier on pending_list_addr above;
-// see special oop-check code at the end of
+// see special post-barrier code at the end of
 // enqueue_discovered_reflists() further below.
-java_lang_ref_Reference::set_discovered(obj, old); // old may be NULL
+java_lang_ref_Reference::set_discovered_raw(obj, old); // old may be NULL
+oopDesc::bs()->write_ref_field(java_lang_ref_Reference::discovered_addr(obj), old);
 }
 }
 } else { // Old behaviour
 // Walk down the list, copying the discovered field into
 // the next field and clearing the discovered field.
 // For G1 we don't want to use set_next - it
 // will dirty the card for the next field of
 // the reference object and will fail
 // CT verification.
 if (UseG1GC) {
-BarrierSet* bs = oopDesc::bs();
 HeapWord* next_addr = java_lang_ref_Reference::next_addr(_ref);
 if (UseCompressedOops) {
-bs->write_ref_field_pre((narrowOop*)next_addr, NULL);
+oopDesc::bs()->write_ref_field_pre((narrowOop*)next_addr, NULL);
 } else {
-bs->write_ref_field_pre((oop*)next_addr, NULL);
+oopDesc::bs()->write_ref_field_pre((oop*)next_addr, NULL);
 }
 java_lang_ref_Reference::set_next_raw(_ref, NULL);
 } else {
 java_lang_ref_Reference::set_next(_ref, NULL);
 }
 private:
 bool _clear_referent;
 };
 void ReferenceProcessor::set_discovered(oop ref, oop value) {
+java_lang_ref_Reference::set_discovered_raw(ref, value);
 if (_discovered_list_needs_barrier) {
-java_lang_ref_Reference::set_discovered(ref, value);
+oopDesc::bs()->write_ref_field(ref, value);
-} else {
-java_lang_ref_Reference::set_discovered_raw(ref, value);
 }
 }
 // Balances reference queues.
 // Move entries from all queues[0, 1, ..., _max_num_q-1] to
 // not necessary because the only case we are interested in
 // here is when *discovered_addr is NULL (see the CAS further below),
 // so this will expand to nothing. As a result, we have manually
 // elided this out for G1, but left in the test for some future
 // collector that might have need for a pre-barrier here, e.g.:-
-// _bs->write_ref_field_pre((oop* or narrowOop*)discovered_addr, next_discovered);
+// oopDesc::bs()->write_ref_field_pre((oop* or narrowOop*)discovered_addr, next_discovered);
 assert(!_discovered_list_needs_barrier || UseG1GC,
 "Need to check non-G1 collector: "
 "may need a pre-write-barrier for CAS from NULL below");
 oop retest = oopDesc::atomic_compare_exchange_oop(next_discovered, discovered_addr,
 NULL);
 // We have separate lists for enqueueing, so no synchronization
 // is necessary.
 refs_list.set_head(obj);
 refs_list.inc_length(1);
 if (_discovered_list_needs_barrier) {
-_bs->write_ref_field((void*)discovered_addr, next_discovered);
+oopDesc::bs()->write_ref_field((void*)discovered_addr, next_discovered);
 }
 if (TraceReferenceGC) {
 gclog_or_tty->print_cr("Discovered reference (mt) (" INTPTR_FORMAT ": %s)",
 (void *)obj, obj->klass()->internal_name());
 // The last ref must have its discovered field pointing to itself.
 oop next_discovered = (current_head != NULL) ? current_head : obj;
 // As in the case further above, since we are over-writing a NULL
 // pre-value, we can safely elide the pre-barrier here for the case of G1.
-// e.g.:- _bs->write_ref_field_pre((oop* or narrowOop*)discovered_addr, next_discovered);
+// e.g.:- oopDesc::bs()->write_ref_field_pre((oop* or narrowOop*)discovered_addr, next_discovered);
 assert(discovered == NULL, "control point invariant");
 assert(!_discovered_list_needs_barrier || UseG1GC,
 "For non-G1 collector, may need a pre-write-barrier for CAS from NULL below");
 oop_store_raw(discovered_addr, next_discovered);
 if (_discovered_list_needs_barrier) {
-_bs->write_ref_field((void*)discovered_addr, next_discovered);
+oopDesc::bs()->write_ref_field((void*)discovered_addr, next_discovered);
 }
 list->set_head(obj);
 list->inc_length(1);
 if (TraceReferenceGC) {

changeset 22496	383a5bdef99d
parent 20282	7f9cbdf89af2
child 22551	9bf46d16dcc6