src/hotspot/share/gc/parallel/psParallelCompact.cpp

@@ -57,10 +57,11 @@
  #include "gc/shared/oopStorageSetParState.inline.hpp"
  #include "gc/shared/preservedMarks.inline.hpp"
  #include "gc/shared/referencePolicy.hpp"
  #include "gc/shared/referenceProcessor.hpp"
  #include "gc/shared/referenceProcessorPhaseTimes.hpp"
+ #include "gc/shared/slidingForwarding.inline.hpp"
  #include "gc/shared/strongRootsScope.hpp"
  #include "gc/shared/taskTerminator.hpp"
  #include "gc/shared/weakProcessor.inline.hpp"
  #include "gc/shared/workerPolicy.hpp"
  #include "gc/shared/workerThread.hpp"

@@ -782,10 +783,14 @@
    //
    // Need to fill in the gap only if it's smaller than min-obj-size, and the
    // filler obj will extend to next region.
  
    // Note: If min-fill-size decreases to 1, this whole method becomes redundant.
+   if (UseCompactObjectHeaders) {
+     // The gap is always equal to min-fill-size, so nothing to do.
+     return;
+   }
    assert(CollectedHeap::min_fill_size() >= 2, "inv");
  #ifndef _LP64
    // In 32-bit system, each heap word is 4 bytes, so MinObjAlignment == 2.
    // The gap is always equal to min-fill-size, so nothing to do.
    return;

@@ -1048,16 +1053,20 @@
  #if COMPILER2_OR_JVMCI
      assert(DerivedPointerTable::is_active(), "Sanity");
      DerivedPointerTable::set_active(false);
  #endif
  
+     SlidingForwarding::begin();
+ 
      forward_to_new_addr();
  
      adjust_pointers();
  
      compact();
  
+     SlidingForwarding::end();
+ 
      ParCompactionManager::_preserved_marks_set->restore(&ParallelScavengeHeap::heap()->workers());
  
      ParCompactionManager::verify_all_region_stack_empty();
  
      // Reset the mark bitmap, summary data, and do other bookkeeping.  Must be

@@ -1593,11 +1602,11 @@
              assert(mark_bitmap()->is_marked(cur_addr), "inv");
              HeapWord* new_addr = destination + live_words;
              oop obj = cast_to_oop(cur_addr);
              if (new_addr != cur_addr) {
                cm->preserved_marks()->push_if_necessary(obj, obj->mark());
-               obj->forward_to(cast_to_oop(new_addr));
+               SlidingForwarding::forward_to(obj, cast_to_oop(new_addr));
              }
              size_t obj_size = obj->size();
              live_words += obj_size;
              cur_addr += obj_size;
            }

@@ -1636,11 +1645,11 @@
          bump_ptr = space(space_id(cur_addr))->bottom();
          bump_ptr_space = space_id(bump_ptr);
        }
        oop obj = cast_to_oop(cur_addr);
        if (cur_addr != bump_ptr) {
-         assert(obj->forwardee() == cast_to_oop(bump_ptr), "inv");
+         assert(SlidingForwarding::forwardee(obj) == cast_to_oop(bump_ptr), "inv");
        }
        bump_ptr += obj->size();
        cur_addr += obj->size();
      }
    }

@@ -2400,11 +2409,11 @@
  
    if (copy_destination() != source()) {
      DEBUG_ONLY(PSParallelCompact::check_new_location(source(), destination());)
      assert(source() != destination(), "inv");
      assert(cast_to_oop(source())->is_forwarded(), "inv");
-     assert(cast_to_oop(source())->forwardee() == cast_to_oop(destination()), "inv");
+     assert(SlidingForwarding::forwardee(cast_to_oop(source())) == cast_to_oop(destination()), "inv");
      Copy::aligned_conjoint_words(source(), copy_destination(), words);
      cast_to_oop(copy_destination())->init_mark();
    }
  
    update_state(words);