src/hotspot/share/gc/serial/serialFullGC.cpp

*** 49,10 ***
--- 49,11 ---
  #include "gc/shared/gc_globals.hpp"
  #include "gc/shared/modRefBarrierSet.hpp"
  #include "gc/shared/preservedMarks.inline.hpp"
  #include "gc/shared/referencePolicy.hpp"
  #include "gc/shared/referenceProcessorPhaseTimes.hpp"
+ #include "gc/shared/slidingForwarding.inline.hpp"
  #include "gc/shared/space.inline.hpp"
  #include "gc/shared/strongRootsScope.hpp"
  #include "gc/shared/weakProcessor.hpp"
  #include "memory/iterator.inline.hpp"
  #include "memory/universe.hpp"

*** 226,11 ***
    }
  
    static void forward_obj(oop obj, HeapWord* new_addr) {
      prefetch_write_scan(obj);
      if (cast_from_oop<HeapWord*>(obj) != new_addr) {
!       obj->forward_to(cast_to_oop(new_addr));
      } else {
        assert(obj->is_gc_marked(), "inv");
        // This obj will stay in-place. Fix the markword.
        obj->init_mark();
      }
--- 227,11 ---
    }
  
    static void forward_obj(oop obj, HeapWord* new_addr) {
      prefetch_write_scan(obj);
      if (cast_from_oop<HeapWord*>(obj) != new_addr) {
!       SlidingForwarding::forward_to(obj, cast_to_oop(new_addr));
      } else {
        assert(obj->is_gc_marked(), "inv");
        // This obj will stay in-place. Fix the markword.
        obj->init_mark();
      }

*** 251,11 ***
    static size_t relocate(HeapWord* addr) {
      // Prefetch source and destination
      prefetch_read_scan(addr);
  
      oop obj = cast_to_oop(addr);
!     oop new_obj = obj->forwardee();
      HeapWord* new_addr = cast_from_oop<HeapWord*>(new_obj);
      assert(addr != new_addr, "inv");
      prefetch_write_copy(new_addr);
  
      size_t obj_size = obj->size();
--- 252,11 ---
    static size_t relocate(HeapWord* addr) {
      // Prefetch source and destination
      prefetch_read_scan(addr);
  
      oop obj = cast_to_oop(addr);
!     oop new_obj = SlidingForwarding::forwardee(obj);
      HeapWord* new_addr = cast_from_oop<HeapWord*>(new_obj);
      assert(addr != new_addr, "inv");
      prefetch_write_copy(new_addr);
  
      size_t obj_size = obj->size();

*** 347,17 ***
        ContiguousSpace* space = get_space(i);
        HeapWord* cur_addr = space->bottom();
        HeapWord* top = space->top();
  
        // Check if the first obj inside this space is forwarded.
!       if (!cast_to_oop(cur_addr)->is_forwarded()) {
          // Jump over consecutive (in-place) live-objs-chunk
          cur_addr = get_first_dead(i);
        }
  
        while (cur_addr < top) {
!         if (!cast_to_oop(cur_addr)->is_forwarded()) {
            cur_addr = *(HeapWord**) cur_addr;
            continue;
          }
          cur_addr += relocate(cur_addr);
        }
--- 348,17 ---
        ContiguousSpace* space = get_space(i);
        HeapWord* cur_addr = space->bottom();
        HeapWord* top = space->top();
  
        // Check if the first obj inside this space is forwarded.
!       if (SlidingForwarding::is_not_forwarded(cast_to_oop(cur_addr))) {
          // Jump over consecutive (in-place) live-objs-chunk
          cur_addr = get_first_dead(i);
        }
  
        while (cur_addr < top) {
!         if (SlidingForwarding::is_not_forwarded(cast_to_oop(cur_addr))) {
            cur_addr = *(HeapWord**) cur_addr;
            continue;
          }
          cur_addr += relocate(cur_addr);
        }

*** 584,16 ***
        java_lang_String::is_instance(obj) &&
        SerialStringDedup::is_candidate_from_mark(obj)) {
      _string_dedup_requests->add(obj);
    }
  
    // some marks may contain information we need to preserve so we store them away
    // and overwrite the mark.  We'll restore it at the end of serial full GC.
    markWord mark = obj->mark();
!   obj->set_mark(markWord::prototype().set_marked());
- 
-   ContinuationGCSupport::transform_stack_chunk(obj);
  
    if (obj->mark_must_be_preserved(mark)) {
      preserve_mark(obj, mark);
    }
  }
--- 585,18 ---
        java_lang_String::is_instance(obj) &&
        SerialStringDedup::is_candidate_from_mark(obj)) {
      _string_dedup_requests->add(obj);
    }
  
+   // Do the transform while we still have the header intact,
+   // which might include important class information.
+   ContinuationGCSupport::transform_stack_chunk(obj);
+ 
    // some marks may contain information we need to preserve so we store them away
    // and overwrite the mark.  We'll restore it at the end of serial full GC.
    markWord mark = obj->mark();
!   obj->set_mark(obj->prototype_mark().set_marked());
  
    if (obj->mark_must_be_preserved(mark)) {
      preserve_mark(obj, mark);
    }
  }

*** 618,12 ***
    T heap_oop = RawAccess<>::oop_load(p);
    if (!CompressedOops::is_null(heap_oop)) {
      oop obj = CompressedOops::decode_not_null(heap_oop);
      assert(Universe::heap()->is_in(obj), "should be in heap");
  
!     if (obj->is_forwarded()) {
!       oop new_obj = obj->forwardee();
        assert(is_object_aligned(new_obj), "oop must be aligned");
        RawAccess<IS_NOT_NULL>::oop_store(p, new_obj);
      }
    }
  }
--- 621,12 ---
    T heap_oop = RawAccess<>::oop_load(p);
    if (!CompressedOops::is_null(heap_oop)) {
      oop obj = CompressedOops::decode_not_null(heap_oop);
      assert(Universe::heap()->is_in(obj), "should be in heap");
  
!     if (SlidingForwarding::is_forwarded(obj)) {
!       oop new_obj = SlidingForwarding::forwardee(obj);
        assert(is_object_aligned(new_obj), "oop must be aligned");
        RawAccess<IS_NOT_NULL>::oop_store(p, new_obj);
      }
    }
  }

*** 698,10 ***
--- 701,12 ---
  
    allocate_stacks();
  
    phase1_mark(clear_all_softrefs);
  
+   SlidingForwarding::begin();
+ 
    Compacter compacter{gch};
  
    {
      // Now all live objects are marked, compute the new object addresses.
      GCTraceTime(Info, gc, phases) tm("Phase 2: Compute new object addresses", _gc_timer);

*** 745,10 ***
--- 750,12 ---
  
    // Set saved marks for allocation profiler (and other things? -- dld)
    // (Should this be in general part?)
    gch->save_marks();
  
+   SlidingForwarding::end();
+ 
    deallocate_stacks();
  
    SerialFullGC::_string_dedup_requests->flush();
  
    bool is_young_gen_empty = (gch->young_gen()->used() == 0);