src/hotspot/share/gc/g1/g1FullGCPrepareTask.cpp

@@ -32,10 +32,11 @@
  #include "gc/g1/g1FullGCPrepareTask.hpp"
  #include "gc/g1/g1HotCardCache.hpp"
  #include "gc/g1/heapRegion.inline.hpp"
  #include "gc/shared/gcTraceTime.inline.hpp"
  #include "gc/shared/referenceProcessor.hpp"
+ #include "gc/shared/slidingForwarding.inline.hpp"
  #include "logging/log.hpp"
  #include "memory/iterator.inline.hpp"
  #include "oops/oop.inline.hpp"
  #include "utilities/ticks.hpp"
  

@@ -154,39 +155,50 @@
    if (hcc->use_cache()) {
      hcc->reset_card_counts(hr);
    }
  }
  
- G1FullGCPrepareTask::G1PrepareCompactLiveClosure::G1PrepareCompactLiveClosure(G1FullGCCompactionPoint* cp) :
+ template <bool ALT_FWD>
+ G1FullGCPrepareTask::G1PrepareCompactLiveClosure<ALT_FWD>::G1PrepareCompactLiveClosure(G1FullGCCompactionPoint* cp) :
      _cp(cp) { }
  
- size_t G1FullGCPrepareTask::G1PrepareCompactLiveClosure::apply(oop object) {
+ template <bool ALT_FWD>
+ size_t G1FullGCPrepareTask::G1PrepareCompactLiveClosure<ALT_FWD>::apply(oop object) {
    size_t size = object->size();
-   _cp->forward(object, size);
+   _cp->forward<ALT_FWD>(object, size);
    return size;
  }
  
- size_t G1FullGCPrepareTask::G1RePrepareClosure::apply(oop obj) {
+ template <bool ALT_FWD>
+ size_t G1FullGCPrepareTask::G1RePrepareClosure<ALT_FWD>::apply(oop obj) {
    // We only re-prepare objects forwarded within the current region, so
    // skip objects that are already forwarded to another region.
-   oop forwarded_to = obj->forwardee();
-   if (forwarded_to != NULL && !_current->is_in(forwarded_to)) {
-     return obj->size();
+   if (SlidingForwarding::is_forwarded(obj)) {
+     oop forwarded_to = SlidingForwarding::forwardee<ALT_FWD>(obj);
+     assert(forwarded_to != NULL, "must have forwardee");
+     if (!_current->is_in(forwarded_to)) {
+       return obj->size();
+     }
    }
- 
    // Get size and forward.
    size_t size = obj->size();
-   _cp->forward(obj, size);
+   _cp->forward<ALT_FWD>(obj, size);
  
    return size;
  }
  
  void G1FullGCPrepareTask::G1CalculatePointersClosure::prepare_for_compaction_work(G1FullGCCompactionPoint* cp,
                                                                                    HeapRegion* hr) {
-   G1PrepareCompactLiveClosure prepare_compact(cp);
-   hr->set_compaction_top(hr->bottom());
-   hr->apply_to_marked_objects(_bitmap, &prepare_compact);
+   if (UseAltGCForwarding) {
+     G1PrepareCompactLiveClosure<true> prepare_compact(cp);
+     hr->set_compaction_top(hr->bottom());
+     hr->apply_to_marked_objects(_bitmap, &prepare_compact);
+   } else {
+     G1PrepareCompactLiveClosure<false> prepare_compact(cp);
+     hr->set_compaction_top(hr->bottom());
+     hr->apply_to_marked_objects(_bitmap, &prepare_compact);
+   }
  }
  
  void G1FullGCPrepareTask::G1CalculatePointersClosure::prepare_for_compaction(HeapRegion* hr) {
    if (!_cp->is_initialized()) {
      hr->set_compaction_top(hr->bottom());

@@ -195,11 +207,12 @@
    // Add region to the compaction queue and prepare it.
    _cp->add(hr);
    prepare_for_compaction_work(_cp, hr);
  }
  
- void G1FullGCPrepareTask::prepare_serial_compaction() {
+ template <bool ALT_FWD>
+ void G1FullGCPrepareTask::prepare_serial_compaction_impl() {
    GCTraceTime(Debug, gc, phases) debug("Phase 2: Prepare Serial Compaction", collector()->scope()->timer());
    // At this point we know that no regions were completely freed by
    // the parallel compaction. That means that the last region of
    // all compaction queues still have data in them. We try to compact
    // these regions in serial to avoid a premature OOM.

@@ -219,18 +232,26 @@
        // Initialize the compaction point. Nothing more is needed for the first heap region
        // since it is already prepared for compaction.
        cp->initialize(current, false);
      } else {
        assert(!current->is_humongous(), "Should be no humongous regions in compaction queue");
-       G1RePrepareClosure re_prepare(cp, current);
+       G1RePrepareClosure<ALT_FWD> re_prepare(cp, current);
        current->set_compaction_top(current->bottom());
        current->apply_to_marked_objects(collector()->mark_bitmap(), &re_prepare);
      }
    }
    cp->update();
  }
  
+ void G1FullGCPrepareTask::prepare_serial_compaction() {
+   if (UseAltGCForwarding) {
+     prepare_serial_compaction_impl<true>();
+   } else {
+     prepare_serial_compaction_impl<false>();
+   }
+ }
+ 
  bool G1FullGCPrepareTask::G1CalculatePointersClosure::freed_regions() {
    if (_regions_freed) {
      return true;
    }