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 ***
  }
  
  void G1FullCollector::phase2_prepare_compaction() {
    GCTraceTime(Info, gc, phases) info("Phase 2: Prepare compaction", scope()->timer());
  
    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();
!   }
  }
  
  void G1FullCollector::phase2a_determine_worklists() {
    GCTraceTime(Debug, gc, phases) debug("Phase 2: Determine work lists", scope()->timer());
  
--- 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.
!   // 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 ***
  
    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();
  }
  
  void G1FullCollector::phase3_adjust_pointers() {
    // Adjust the pointers to reflect the new locations
    GCTraceTime(Info, gc, phases) info("Phase 3: Adjust pointers", scope()->timer());
--- 344,41 ---
  
    return task.has_free_compaction_targets();
  }
  
  void G1FullCollector::phase2c_prepare_serial_compaction() {
!   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());