inline void PSPromotionManager::claim_or_forward_internal_depth(T* p) {
  if (p != NULL) { // XXX: error if p != NULL here
    oop o = oopDesc::load_decode_heap_oop_not_null(p);
    if (o->is_forwarded()) {
      o = o->forwardee();
      // Card mark
      if (PSScavenge::is_obj_in_young((HeapWord*) o)) {
        PSScavenge::card_table()->inline_write_ref_field_gc(p, o);
      }
      oopDesc::encode_store_heap_oop_not_null(p, o);
    } else {
      push_depth(p);
    }
  }
}
Ejemplo n.º 2
0
inline oop PSPromotionManager::copy_to_survivor_space(oop o) {
    assert(should_scavenge(&o), "Sanity");

    oop new_obj = NULL;

    // NOTE! We must be very careful with any methods that access the mark
    // in o. There may be multiple threads racing on it, and it may be forwarded
    // at any time. Do not use oop methods for accessing the mark!
    markOop test_mark = o->mark();

    // The same test as "o->is_forwarded()"
    if (!test_mark->is_marked()) {
        bool new_obj_is_tenured = false;
        size_t new_obj_size = o->size();

        // Find the objects age, MT safe.
        uint age = (test_mark->has_displaced_mark_helper() /* o->has_displaced_mark() */) ?
                   test_mark->displaced_mark_helper()->age() : test_mark->age();

        if (!promote_immediately) {
            // Try allocating obj in to-space (unless too old)
            if (age < PSScavenge::tenuring_threshold()) {
                new_obj = (oop) _young_lab.allocate(new_obj_size);
                if (new_obj == NULL && !_young_gen_is_full) {
                    // Do we allocate directly, or flush and refill?
                    if (new_obj_size > (YoungPLABSize / 2)) {
                        // Allocate this object directly
                        new_obj = (oop)young_space()->cas_allocate(new_obj_size);
                        promotion_trace_event(new_obj, o, new_obj_size, age, false, NULL);
                    } else {
                        // Flush and fill
                        _young_lab.flush();

                        HeapWord* lab_base = young_space()->cas_allocate(YoungPLABSize);
                        if (lab_base != NULL) {
                            _young_lab.initialize(MemRegion(lab_base, YoungPLABSize));
                            // Try the young lab allocation again.
                            new_obj = (oop) _young_lab.allocate(new_obj_size);
                            promotion_trace_event(new_obj, o, new_obj_size, age, false, &_young_lab);
                        } else {
                            _young_gen_is_full = true;
                        }
                    }
                }
            }
        }

        // Otherwise try allocating obj tenured
        if (new_obj == NULL) {
#ifndef PRODUCT
            if (ParallelScavengeHeap::heap()->promotion_should_fail()) {
                return oop_promotion_failed(o, test_mark);
            }
#endif  // #ifndef PRODUCT

            new_obj = (oop) _old_lab.allocate(new_obj_size);
            new_obj_is_tenured = true;

            if (new_obj == NULL) {
                if (!_old_gen_is_full) {
                    // Do we allocate directly, or flush and refill?
                    if (new_obj_size > (OldPLABSize / 2)) {
                        // Allocate this object directly
                        new_obj = (oop)old_gen()->cas_allocate(new_obj_size);
                        promotion_trace_event(new_obj, o, new_obj_size, age, true, NULL);
                    } else {
                        // Flush and fill
                        _old_lab.flush();

                        HeapWord* lab_base = old_gen()->cas_allocate(OldPLABSize);
                        if(lab_base != NULL) {
#ifdef ASSERT
                            // Delay the initialization of the promotion lab (plab).
                            // This exposes uninitialized plabs to card table processing.
                            if (GCWorkerDelayMillis > 0) {
                                os::sleep(Thread::current(), GCWorkerDelayMillis, false);
                            }
#endif
                            _old_lab.initialize(MemRegion(lab_base, OldPLABSize));
                            // Try the old lab allocation again.
                            new_obj = (oop) _old_lab.allocate(new_obj_size);
                            promotion_trace_event(new_obj, o, new_obj_size, age, true, &_old_lab);
                        }
                    }
                }

                // This is the promotion failed test, and code handling.
                // The code belongs here for two reasons. It is slightly
                // different than the code below, and cannot share the
                // CAS testing code. Keeping the code here also minimizes
                // the impact on the common case fast path code.

                if (new_obj == NULL) {
                    _old_gen_is_full = true;
                    return oop_promotion_failed(o, test_mark);
                }
            }
        }

        assert(new_obj != NULL, "allocation should have succeeded");

        // Copy obj
        Copy::aligned_disjoint_words((HeapWord*)o, (HeapWord*)new_obj, new_obj_size);

        // Now we have to CAS in the header.
        if (o->cas_forward_to(new_obj, test_mark)) {
            // We won any races, we "own" this object.
            assert(new_obj == o->forwardee(), "Sanity");

            // Increment age if obj still in new generation. Now that
            // we're dealing with a markOop that cannot change, it is
            // okay to use the non mt safe oop methods.
            if (!new_obj_is_tenured) {
                new_obj->incr_age();
                assert(young_space()->contains(new_obj), "Attempt to push non-promoted obj");
            }

            // Do the size comparison first with new_obj_size, which we
            // already have. Hopefully, only a few objects are larger than
            // _min_array_size_for_chunking, and most of them will be arrays.
            // So, the is->objArray() test would be very infrequent.
            if (new_obj_size > _min_array_size_for_chunking &&
                    new_obj->is_objArray() &&
                    PSChunkLargeArrays) {
                // we'll chunk it
                oop* const masked_o = mask_chunked_array_oop(o);
                push_depth(masked_o);
                TASKQUEUE_STATS_ONLY(++_arrays_chunked; ++_masked_pushes);
            } else {