src/hotspot/share/gc/g1/g1FullCollector.cpp

@@ -38,10 +38,11 @@
  #include "gc/g1/g1Policy.hpp"
  #include "gc/g1/g1RegionMarkStatsCache.inline.hpp"
  #include "gc/shared/gcTraceTime.inline.hpp"
  #include "gc/shared/preservedMarks.hpp"
  #include "gc/shared/referenceProcessor.hpp"
+ #include "gc/shared/slidingForwarding.hpp"
  #include "gc/shared/verifyOption.hpp"
  #include "gc/shared/weakProcessor.inline.hpp"
  #include "gc/shared/workerPolicy.hpp"
  #include "logging/log.hpp"
  #include "runtime/continuation.hpp"

@@ -311,20 +312,23 @@
  }
  
  void G1FullCollector::phase2_prepare_compaction() {
    GCTraceTime(Info, gc, phases) info("Phase 2: Prepare compaction", scope()->timer());
  
+   _heap->forwarding()->clear();
+ 
    phase2a_determine_worklists();
  
    bool has_free_compaction_targets = phase2b_forward_oops();
  
    // Try to avoid OOM immediately after Full GC in case there are no free regions
    // left after determining the result locations (i.e. this phase). Prepare to
    // maximally compact the tail regions of the compaction queues serially.
-   if (!has_free_compaction_targets) {
-     phase2c_prepare_serial_compaction();
-   }
+   // TODO: Disabled for now because it violates sliding-forwarding assumption.
+   // if (!has_free_compaction_targets) {
+   //   phase2c_prepare_serial_compaction();
+   // }
  }
  
  void G1FullCollector::phase2a_determine_worklists() {
    GCTraceTime(Debug, gc, phases) debug("Phase 2: Determine work lists", scope()->timer());
  

@@ -340,40 +344,41 @@
  
    return task.has_free_compaction_targets();
  }
  
  void G1FullCollector::phase2c_prepare_serial_compaction() {
-   GCTraceTime(Debug, gc, phases) debug("Phase 2: Prepare serial compaction", scope()->timer());
-   // At this point we know that after parallel compaction there will be no
-   // completely free regions. 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 when the mutator wants
-   // to allocate the first eden region after gc.
-   for (uint i = 0; i < workers(); i++) {
-     G1FullGCCompactionPoint* cp = compaction_point(i);
-     if (cp->has_regions()) {
-       serial_compaction_point()->add(cp->remove_last());
-     }
-   }
- 
-   // Update the forwarding information for the regions in the serial
-   // compaction point.
-   G1FullGCCompactionPoint* cp = serial_compaction_point();
-   for (GrowableArrayIterator<HeapRegion*> it = cp->regions()->begin(); it != cp->regions()->end(); ++it) {
-     HeapRegion* current = *it;
-     if (!cp->is_initialized()) {
-       // Initialize the compaction point. Nothing more is needed for the first heap region
-       // since it is already prepared for compaction.
-       cp->initialize(current);
-     } else {
-       assert(!current->is_humongous(), "Should be no humongous regions in compaction queue");
-       G1SerialRePrepareClosure re_prepare(cp, current);
-       current->set_compaction_top(current->bottom());
-       current->apply_to_marked_objects(mark_bitmap(), &re_prepare);
-     }
-   }
-   cp->update();
+   ShouldNotReachHere(); // Disabled in Lilliput.
+ //  GCTraceTime(Debug, gc, phases) debug("Phase 2: Prepare serial compaction", scope()->timer());
+ //  // At this point we know that after parallel compaction there will be no
+ //  // completely free regions. 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 when the mutator wants
+ //  // to allocate the first eden region after gc.
+ //  for (uint i = 0; i < workers(); i++) {
+ //    G1FullGCCompactionPoint* cp = compaction_point(i);
+ //    if (cp->has_regions()) {
+ //      serial_compaction_point()->add(cp->remove_last());
+ //    }
+ //  }
+ //
+ //  // Update the forwarding information for the regions in the serial
+ //  // compaction point.
+ //  G1FullGCCompactionPoint* cp = serial_compaction_point();
+ //  for (GrowableArrayIterator<HeapRegion*> it = cp->regions()->begin(); it != cp->regions()->end(); ++it) {
+ //    HeapRegion* current = *it;
+ //    if (!cp->is_initialized()) {
+ //      // Initialize the compaction point. Nothing more is needed for the first heap region
+ //      // since it is already prepared for compaction.
+ //      cp->initialize(current);
+ //    } else {
+ //      assert(!current->is_humongous(), "Should be no humongous regions in compaction queue");
+ //      G1SerialRePrepareClosure re_prepare(cp, current);
+ //      current->set_compaction_top(current->bottom());
+ //      current->apply_to_marked_objects(mark_bitmap(), &re_prepare);
+ //    }
+ //  }
+ //  cp->update();
  }
  
  void G1FullCollector::phase3_adjust_pointers() {
    // Adjust the pointers to reflect the new locations
    GCTraceTime(Info, gc, phases) info("Phase 3: Adjust pointers", scope()->timer());