--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/hotspot/src/share/vm/gc/g1/youngList.cpp	Tue Oct 13 08:37:44 2015 +0200
@@ -0,0 +1,241 @@
+/*
+ * Copyright (c) 2015, Oracle and/or its affiliates. All rights reserved.
+ * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
+ *
+ * This code is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 only, as
+ * published by the Free Software Foundation.
+ *
+ * This code is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
+ * version 2 for more details (a copy is included in the LICENSE file that
+ * accompanied this code).
+ *
+ * You should have received a copy of the GNU General Public License version
+ * 2 along with this work; if not, write to the Free Software Foundation,
+ * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
+ *
+ * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
+ * or visit www.oracle.com if you need additional information or have any
+ * questions.
+ *
+ */
+
+#include "precompiled.hpp"
+#include "gc/g1/g1CollectedHeap.hpp"
+#include "gc/g1/g1CollectorPolicy.hpp"
+#include "gc/g1/heapRegion.hpp"
+#include "gc/g1/heapRegion.inline.hpp"
+#include "gc/g1/heapRegionRemSet.hpp"
+#include "gc/g1/youngList.hpp"
+#include "utilities/ostream.hpp"
+
+YoungList::YoungList(G1CollectedHeap* g1h) :
+    _g1h(g1h), _head(NULL), _length(0), _last_sampled_rs_lengths(0),
+    _survivor_head(NULL), _survivor_tail(NULL), _survivor_length(0) {
+  guarantee(check_list_empty(false), "just making sure...");
+}
+
+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, (int) _length);
+  ++_length;
+}
+
+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!");
+
+  hr->set_next_young_region(_survivor_head);
+  if (_survivor_head == NULL) {
+    _survivor_tail = hr;
+  }
+  _survivor_head = hr;
+  ++_survivor_length;
+}
+
+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;
+
+  empty_list(_survivor_head);
+  _survivor_head = NULL;
+  _survivor_tail = NULL;
+  _survivor_length = 0;
+
+  _last_sampled_rs_lengths = 0;
+
+  assert(check_list_empty(false), "just making sure...");
+}
+
+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()) {
+      gclog_or_tty->print_cr("### 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();
+  }
+  ret = ret && (length == _length);
+
+  if (!ret) {
+    gclog_or_tty->print_cr("### YOUNG LIST seems not well formed!");
+    gclog_or_tty->print_cr("###   list has %u entries, _length is %u",
+                           length, _length);
+  }
+
+  return ret;
+}
+
+bool YoungList::check_list_empty(bool check_sample) {
+  bool ret = true;
+
+  if (_length != 0) {
+    gclog_or_tty->print_cr("### YOUNG LIST should have 0 length, not %u",
+                  _length);
+    ret = false;
+  }
+  if (check_sample && _last_sampled_rs_lengths != 0) {
+    gclog_or_tty->print_cr("### YOUNG LIST has non-zero last sampled RS lengths");
+    ret = false;
+  }
+  if (_head != NULL) {
+    gclog_or_tty->print_cr("### YOUNG LIST does not have a NULL head");
+    ret = false;
+  }
+  if (!ret) {
+    gclog_or_tty->print_cr("### YOUNG LIST does not seem empty");
+  }
+
+  return ret;
+}
+
+void
+YoungList::rs_length_sampling_init() {
+  _sampled_rs_lengths = 0;
+  _curr               = _head;
+}
+
+bool
+YoungList::rs_length_sampling_more() {
+  return _curr != NULL;
+}
+
+void
+YoungList::rs_length_sampling_next() {
+  assert( _curr != NULL, "invariant" );
+  size_t rs_length = _curr->rem_set()->occupied();
+
+  _sampled_rs_lengths += rs_length;
+
+  // The current region may not yet have been added to the
+  // incremental collection set (it gets added when it is
+  // retired as the current allocation region).
+  if (_curr->in_collection_set()) {
+    // Update the collection set policy information for this region
+    _g1h->g1_policy()->update_incremental_cset_info(_curr, rs_length);
+  }
+
+  _curr = _curr->get_next_young_region();
+  if (_curr == NULL) {
+    _last_sampled_rs_lengths = _sampled_rs_lengths;
+    // gclog_or_tty->print_cr("last sampled RS lengths = %d", _last_sampled_rs_lengths);
+  }
+}
+
+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 */);
+
+  int young_index_in_cset = 0;
+  for (HeapRegion* curr = _survivor_head;
+       curr != NULL;
+       curr = curr->get_next_young_region()) {
+    _g1h->g1_policy()->set_region_survivor(curr, young_index_in_cset);
+
+    // The region is a non-empty survivor so let's add it to
+    // the incremental collection set for the next evacuation
+    // pause.
+    _g1h->g1_policy()->add_region_to_incremental_cset_rhs(curr);
+    young_index_in_cset += 1;
+  }
+  assert((uint) young_index_in_cset == _survivor_length, "post-condition");
+  _g1h->g1_policy()->note_stop_adding_survivor_regions();
+
+  _head   = _survivor_head;
+  _length = _survivor_length;
+  if (_survivor_head != NULL) {
+    assert(_survivor_tail != NULL, "cause it shouldn't be");
+    assert(_survivor_length > 0, "invariant");
+    _survivor_tail->set_next_young_region(NULL);
+  }
+
+  // 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 YoungList::print() {
+  HeapRegion* lists[] = {_head,   _survivor_head};
+  const char* names[] = {"YOUNG", "SURVIVOR"};
+
+  for (uint list = 0; list < ARRAY_SIZE(lists); ++list) {
+    gclog_or_tty->print_cr("%s LIST CONTENTS", names[list]);
+    HeapRegion *curr = lists[list];
+    if (curr == NULL) {
+      gclog_or_tty->print_cr("  empty");
+    }
+    while (curr != NULL) {
+      gclog_or_tty->print_cr("  " HR_FORMAT ", P: " PTR_FORMAT ", N: " PTR_FORMAT ", age: %4d",
+                             HR_FORMAT_PARAMS(curr),
+                             p2i(curr->prev_top_at_mark_start()),
+                             p2i(curr->next_top_at_mark_start()),
+                             curr->age_in_surv_rate_group_cond());
+      curr = curr->get_next_young_region();
+    }
+  }
+
+  gclog_or_tty->cr();
+}