--- a/hotspot/src/share/vm/gc/g1/youngList.cpp	Mon May 02 19:38:15 2016 -0400
+++ b/hotspot/src/share/vm/gc/g1/youngList.cpp	Tue May 03 12:33:10 2016 +0200
@@ -23,156 +23,37 @@
  */
 
 #include "precompiled.hpp"
-#include "gc/g1/g1CollectedHeap.hpp"
-#include "gc/g1/g1CollectionSet.hpp"
-#include "gc/g1/g1Policy.hpp"
 #include "gc/g1/heapRegion.hpp"
-#include "gc/g1/heapRegion.inline.hpp"
-#include "gc/g1/heapRegionRemSet.hpp"
 #include "gc/g1/youngList.hpp"
-#include "logging/log.hpp"
 #include "utilities/growableArray.hpp"
-#include "utilities/ostream.hpp"
+#include "utilities/debug.hpp"
 
-YoungList::YoungList(G1CollectedHeap* g1h) :
-    _g1h(g1h),
-    _survivor_regions(new (ResourceObj::C_HEAP, mtGC) GrowableArray<HeapRegion*>(8, true, mtGC)),
-    _head(NULL),
-    _length(0) {
-  guarantee(check_list_empty(), "just making sure...");
-}
+G1SurvivorRegions::G1SurvivorRegions() : _regions(new (ResourceObj::C_HEAP, mtGC) GrowableArray<HeapRegion*>(8, true, mtGC)) {}
 
-void YoungList::push_region(HeapRegion *hr) {
-  assert(!hr->is_young(), "should not already be young");
-  assert(hr->get_next_young_region() == NULL, "cause it should!");
-
-  hr->set_next_young_region(_head);
-  _head = hr;
-
-  _g1h->g1_policy()->set_region_eden(hr);
-  ++_length;
+void G1SurvivorRegions::add(HeapRegion* hr) {
+  assert(hr->is_survivor(), "should be flagged as survivor region");
+  _regions->append(hr);
 }
 
-void YoungList::add_survivor_region(HeapRegion* hr) {
-  assert(hr->is_survivor(), "should be flagged as survivor region");
-  assert(hr->get_next_young_region() == NULL, "cause it should!");
-
-  _survivor_regions->append(hr);
-}
-
-void YoungList::empty_list(HeapRegion* list) {
-  while (list != NULL) {
-    HeapRegion* next = list->get_next_young_region();
-    list->set_next_young_region(NULL);
-    list->uninstall_surv_rate_group();
-    // This is called before a Full GC and all the non-empty /
-    // non-humongous regions at the end of the Full GC will end up as
-    // old anyway.
-    list->set_old();
-    list = next;
-  }
-}
-
-void YoungList::empty_list() {
-  assert(check_list_well_formed(), "young list should be well formed");
-
-  empty_list(_head);
-  _head = NULL;
-  _length = 0;
-
-  if (survivor_length() > 0) {
-    empty_list(_survivor_regions->last());
-  }
-  _survivor_regions->clear();
-
-  assert(check_list_empty(), "just making sure...");
-}
-
-uint YoungList::survivor_length() {
-  return _survivor_regions->length();
+uint G1SurvivorRegions::length() const {
+  return (uint)_regions->length();
 }
 
-bool YoungList::check_list_well_formed() {
-  bool ret = true;
-
-  uint length = 0;
-  HeapRegion* curr = _head;
-  HeapRegion* last = NULL;
-  while (curr != NULL) {
-    if (!curr->is_young()) {
-      log_error(gc, verify)("### YOUNG REGION " PTR_FORMAT "-" PTR_FORMAT " "
-                            "incorrectly tagged (y: %d, surv: %d)",
-                            p2i(curr->bottom()), p2i(curr->end()),
-                            curr->is_young(), curr->is_survivor());
-      ret = false;
-    }
-    ++length;
-    last = curr;
-    curr = curr->get_next_young_region();
+void G1SurvivorRegions::convert_to_eden() {
+  for (GrowableArrayIterator<HeapRegion*> it = _regions->begin();
+       it != _regions->end();
+       ++it) {
+    HeapRegion* hr = *it;
+    hr->set_eden_pre_gc();
   }
-  ret = ret && (length == _length);
-
-  if (!ret) {
-    log_error(gc, verify)("### YOUNG LIST seems not well formed!");
-    log_error(gc, verify)("###   list has %u entries, _length is %u", length, _length);
-  }
-
-  return ret;
+  clear();
 }
 
-bool YoungList::check_list_empty() {
-  bool ret = true;
-
-  if (_length != 0) {
-    log_error(gc, verify)("### YOUNG LIST should have 0 length, not %u", _length);
-    ret = false;
-  }
-  if (_head != NULL) {
-    log_error(gc, verify)("### YOUNG LIST does not have a NULL head");
-    ret = false;
-  }
-  if (!ret) {
-    log_error(gc, verify)("### YOUNG LIST does not seem empty");
-  }
-
-  return ret;
+void G1SurvivorRegions::clear() {
+  _regions->clear();
 }
 
-void
-YoungList::reset_auxilary_lists() {
-  guarantee( is_empty(), "young list should be empty" );
-  assert(check_list_well_formed(), "young list should be well formed");
-
-  // Add survivor regions to SurvRateGroup.
-  _g1h->g1_policy()->note_start_adding_survivor_regions();
-  _g1h->g1_policy()->finished_recalculating_age_indexes(true /* is_survivors */);
-
-  HeapRegion* last = NULL;
-  for (GrowableArrayIterator<HeapRegion*> it = _survivor_regions->begin();
-       it != _survivor_regions->end();
-       ++it) {
-    HeapRegion* curr = *it;
-    _g1h->g1_policy()->set_region_survivor(curr);
-
-    // The region is a non-empty survivor so let's add it to
-    // the incremental collection set for the next evacuation
-    // pause.
-    _g1h->collection_set()->add_survivor_regions(curr);
-
-    curr->set_next_young_region(last);
-    last = curr;
-  }
-  _g1h->g1_policy()->note_stop_adding_survivor_regions();
-
-  _head   = last;
-  _length = _survivor_regions->length();
-
-  // Don't clear the survivor list handles until the start of
-  // the next evacuation pause - we need it in order to re-tag
-  // the survivor regions from this evacuation pause as 'young'
-  // at the start of the next.
-
-  _g1h->g1_policy()->finished_recalculating_age_indexes(false /* is_survivors */);
-
-  assert(check_list_well_formed(), "young list should be well formed");
+void G1EdenRegions::add(HeapRegion* hr) {
+  assert(!hr->is_eden(), "should not already be set");
+  _length++;
 }