--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/src/share/vm/gc_implementation/g1/concurrentG1Refine.cpp	Thu Jun 05 15:57:56 2008 -0700
@@ -0,0 +1,355 @@
+/*
+ * Copyright 2001-2007 Sun Microsystems, Inc.  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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
+ * CA 95054 USA or visit www.sun.com if you need additional information or
+ * have any questions.
+ *
+ */
+
+#include "incls/_precompiled.incl"
+#include "incls/_concurrentG1Refine.cpp.incl"
+
+bool ConcurrentG1Refine::_enabled = false;
+
+ConcurrentG1Refine::ConcurrentG1Refine() :
+  _pya(PYA_continue), _last_pya(PYA_continue),
+  _last_cards_during(), _first_traversal(false),
+  _card_counts(NULL), _cur_card_count_histo(NULL), _cum_card_count_histo(NULL),
+  _hot_cache(NULL),
+  _def_use_cache(false), _use_cache(false),
+  _n_periods(0), _total_cards(0), _total_travs(0)
+{
+  if (G1ConcRefine) {
+    _cg1rThread = new ConcurrentG1RefineThread(this);
+    assert(cg1rThread() != NULL, "Conc refine should have been created");
+    assert(cg1rThread()->cg1r() == this,
+           "Conc refine thread should refer to this");
+  } else {
+    _cg1rThread = NULL;
+  }
+}
+
+void ConcurrentG1Refine::init() {
+  if (G1ConcRSLogCacheSize > 0 || G1ConcRSCountTraversals) {
+    G1CollectedHeap* g1h = G1CollectedHeap::heap();
+    _n_card_counts =
+      (unsigned) (g1h->g1_reserved_obj_bytes() >> CardTableModRefBS::card_shift);
+    _card_counts = NEW_C_HEAP_ARRAY(unsigned char, _n_card_counts);
+    for (size_t i = 0; i < _n_card_counts; i++) _card_counts[i] = 0;
+    ModRefBarrierSet* bs = g1h->mr_bs();
+    guarantee(bs->is_a(BarrierSet::CardTableModRef), "Precondition");
+    CardTableModRefBS* ctbs = (CardTableModRefBS*)bs;
+    _ct_bot = ctbs->byte_for_const(g1h->reserved_region().start());
+    if (G1ConcRSCountTraversals) {
+      _cur_card_count_histo = NEW_C_HEAP_ARRAY(unsigned, 256);
+      _cum_card_count_histo = NEW_C_HEAP_ARRAY(unsigned, 256);
+      for (int i = 0; i < 256; i++) {
+        _cur_card_count_histo[i] = 0;
+        _cum_card_count_histo[i] = 0;
+      }
+    }
+  }
+  if (G1ConcRSLogCacheSize > 0) {
+    _def_use_cache = true;
+    _use_cache = true;
+    _hot_cache_size = (1 << G1ConcRSLogCacheSize);
+    _hot_cache = NEW_C_HEAP_ARRAY(jbyte*, _hot_cache_size);
+    _n_hot = 0;
+    _hot_cache_idx = 0;
+  }
+}
+
+ConcurrentG1Refine::~ConcurrentG1Refine() {
+  if (G1ConcRSLogCacheSize > 0 || G1ConcRSCountTraversals) {
+    assert(_card_counts != NULL, "Logic");
+    FREE_C_HEAP_ARRAY(unsigned char, _card_counts);
+    assert(_cur_card_count_histo != NULL, "Logic");
+    FREE_C_HEAP_ARRAY(unsigned, _cur_card_count_histo);
+    assert(_cum_card_count_histo != NULL, "Logic");
+    FREE_C_HEAP_ARRAY(unsigned, _cum_card_count_histo);
+  }
+  if (G1ConcRSLogCacheSize > 0) {
+    assert(_hot_cache != NULL, "Logic");
+    FREE_C_HEAP_ARRAY(jbyte*, _hot_cache);
+  }
+}
+
+bool ConcurrentG1Refine::refine() {
+  G1CollectedHeap* g1h = G1CollectedHeap::heap();
+  unsigned cards_before = g1h->g1_rem_set()->conc_refine_cards();
+  clear_hot_cache();  // Any previous values in this are now invalid.
+  g1h->g1_rem_set()->concurrentRefinementPass(this);
+  _traversals++;
+  unsigned cards_after = g1h->g1_rem_set()->conc_refine_cards();
+  unsigned cards_during = cards_after-cards_before;
+  // If this is the first traversal in the current enabling
+  // and we did some cards, or if the number of cards found is decreasing
+  // sufficiently quickly, then keep going.  Otherwise, sleep a while.
+  bool res =
+    (_first_traversal && cards_during > 0)
+    ||
+    (!_first_traversal && cards_during * 3 < _last_cards_during * 2);
+  _last_cards_during = cards_during;
+  _first_traversal = false;
+  return res;
+}
+
+void ConcurrentG1Refine::enable() {
+  MutexLocker x(G1ConcRefine_mon);
+  if (!_enabled) {
+    _enabled = true;
+    _first_traversal = true; _last_cards_during = 0;
+    G1ConcRefine_mon->notify_all();
+  }
+}
+
+unsigned ConcurrentG1Refine::disable() {
+  MutexLocker x(G1ConcRefine_mon);
+  if (_enabled) {
+    _enabled = false;
+    return _traversals;
+  } else {
+    return 0;
+  }
+}
+
+void ConcurrentG1Refine::wait_for_ConcurrentG1Refine_enabled() {
+  G1ConcRefine_mon->lock();
+  while (!_enabled) {
+    G1ConcRefine_mon->wait(Mutex::_no_safepoint_check_flag);
+  }
+  G1ConcRefine_mon->unlock();
+  _traversals = 0;
+};
+
+void ConcurrentG1Refine::set_pya_restart() {
+  // If we're using the log-based RS barrier, the above will cause
+  // in-progress traversals of completed log buffers to quit early; we will
+  // also abandon all other buffers.
+  if (G1RSBarrierUseQueue) {
+    DirtyCardQueueSet& dcqs = JavaThread::dirty_card_queue_set();
+    dcqs.abandon_logs();
+    if (_cg1rThread->do_traversal()) {
+      _pya = PYA_restart;
+    } else {
+      _cg1rThread->set_do_traversal(true);
+      // Reset the post-yield actions.
+      _pya = PYA_continue;
+      _last_pya = PYA_continue;
+    }
+  } else {
+    _pya = PYA_restart;
+  }
+}
+
+void ConcurrentG1Refine::set_pya_cancel() {
+  _pya = PYA_cancel;
+}
+
+PostYieldAction ConcurrentG1Refine::get_pya() {
+  if (_pya != PYA_continue) {
+    jint val = _pya;
+    while (true) {
+      jint val_read = Atomic::cmpxchg(PYA_continue, &_pya, val);
+      if (val_read == val) {
+        PostYieldAction res = (PostYieldAction)val;
+        assert(res != PYA_continue, "Only the refine thread should reset.");
+        _last_pya = res;
+        return res;
+      } else {
+        val = val_read;
+      }
+    }
+  }
+  // QQQ WELL WHAT DO WE RETURN HERE???
+  // make up something!
+  return PYA_continue;
+}
+
+PostYieldAction ConcurrentG1Refine::get_last_pya() {
+  PostYieldAction res = _last_pya;
+  _last_pya = PYA_continue;
+  return res;
+}
+
+bool ConcurrentG1Refine::do_traversal() {
+  return _cg1rThread->do_traversal();
+}
+
+int ConcurrentG1Refine::add_card_count(jbyte* card_ptr) {
+  size_t card_num = (card_ptr - _ct_bot);
+  guarantee(0 <= card_num && card_num < _n_card_counts, "Bounds");
+  unsigned char cnt = _card_counts[card_num];
+  if (cnt < 255) _card_counts[card_num]++;
+  return cnt;
+  _total_travs++;
+}
+
+jbyte* ConcurrentG1Refine::cache_insert(jbyte* card_ptr) {
+  int count = add_card_count(card_ptr);
+  // Count previously unvisited cards.
+  if (count == 0) _total_cards++;
+  // We'll assume a traversal unless we store it in the cache.
+  if (count < G1ConcRSHotCardLimit) {
+    _total_travs++;
+    return card_ptr;
+  }
+  // Otherwise, it's hot.
+  jbyte* res = NULL;
+  MutexLockerEx x(HotCardCache_lock, Mutex::_no_safepoint_check_flag);
+  if (_n_hot == _hot_cache_size) {
+    _total_travs++;
+    res = _hot_cache[_hot_cache_idx];
+    _n_hot--;
+  }
+  // Now _n_hot < _hot_cache_size, and we can insert at _hot_cache_idx.
+  _hot_cache[_hot_cache_idx] = card_ptr;
+  _hot_cache_idx++;
+  if (_hot_cache_idx == _hot_cache_size) _hot_cache_idx = 0;
+  _n_hot++;
+  return res;
+}
+
+
+void ConcurrentG1Refine::clean_up_cache(int worker_i, G1RemSet* g1rs) {
+  assert(!use_cache(), "cache should be disabled");
+  int start_ind = _hot_cache_idx-1;
+  for (int i = 0; i < _n_hot; i++) {
+    int ind = start_ind - i;
+    if (ind < 0) ind = ind + _hot_cache_size;
+    jbyte* entry = _hot_cache[ind];
+    if (entry != NULL) {
+      g1rs->concurrentRefineOneCard(entry, worker_i);
+    }
+  }
+  _n_hot = 0;
+  _hot_cache_idx = 0;
+}
+
+void ConcurrentG1Refine::clear_and_record_card_counts() {
+  if (G1ConcRSLogCacheSize == 0 && !G1ConcRSCountTraversals) return;
+  _n_periods++;
+  if (G1ConcRSCountTraversals) {
+    for (size_t i = 0; i < _n_card_counts; i++) {
+      unsigned char bucket = _card_counts[i];
+      _cur_card_count_histo[bucket]++;
+      _card_counts[i] = 0;
+    }
+    gclog_or_tty->print_cr("Card counts:");
+    for (int i = 0; i < 256; i++) {
+      if (_cur_card_count_histo[i] > 0) {
+        gclog_or_tty->print_cr("  %3d: %9d", i, _cur_card_count_histo[i]);
+        _cum_card_count_histo[i] += _cur_card_count_histo[i];
+        _cur_card_count_histo[i] = 0;
+      }
+    }
+  } else {
+    assert(G1ConcRSLogCacheSize > 0, "Logic");
+    Copy::fill_to_words((HeapWord*)(&_card_counts[0]),
+                        _n_card_counts / HeapWordSize);
+  }
+}
+
+void
+ConcurrentG1Refine::
+print_card_count_histo_range(unsigned* histo, int from, int to,
+                             float& cum_card_pct,
+                             float& cum_travs_pct) {
+  unsigned cards = 0;
+  unsigned travs = 0;
+  guarantee(to <= 256, "Precondition");
+  for (int i = from; i < to-1; i++) {
+    cards += histo[i];
+    travs += histo[i] * i;
+  }
+  if (to == 256) {
+    unsigned histo_card_sum = 0;
+    unsigned histo_trav_sum = 0;
+    for (int i = 1; i < 255; i++) {
+      histo_trav_sum += histo[i] * i;
+    }
+    cards += histo[255];
+    // correct traversals for the last one.
+    unsigned travs_255 = (unsigned) (_total_travs - histo_trav_sum);
+    travs += travs_255;
+
+  } else {
+    cards += histo[to-1];
+    travs += histo[to-1] * (to-1);
+  }
+  float fperiods = (float)_n_periods;
+  float f_tot_cards = (float)_total_cards/fperiods;
+  float f_tot_travs = (float)_total_travs/fperiods;
+  if (cards > 0) {
+    float fcards = (float)cards/fperiods;
+    float ftravs = (float)travs/fperiods;
+    if (to == 256) {
+      gclog_or_tty->print(" %4d-       %10.2f%10.2f", from, fcards, ftravs);
+    } else {
+      gclog_or_tty->print(" %4d-%4d   %10.2f%10.2f", from, to-1, fcards, ftravs);
+    }
+    float pct_cards = fcards*100.0/f_tot_cards;
+    cum_card_pct += pct_cards;
+    float pct_travs = ftravs*100.0/f_tot_travs;
+    cum_travs_pct += pct_travs;
+    gclog_or_tty->print_cr("%10.2f%10.2f%10.2f%10.2f",
+                  pct_cards, cum_card_pct,
+                  pct_travs, cum_travs_pct);
+  }
+}
+
+void ConcurrentG1Refine::print_final_card_counts() {
+  if (!G1ConcRSCountTraversals) return;
+
+  gclog_or_tty->print_cr("Did %d total traversals of %d distinct cards.",
+                _total_travs, _total_cards);
+  float fperiods = (float)_n_periods;
+  gclog_or_tty->print_cr("  This is an average of %8.2f traversals, %8.2f cards, "
+                "per collection.", (float)_total_travs/fperiods,
+                (float)_total_cards/fperiods);
+  gclog_or_tty->print_cr("  This is an average of %8.2f traversals/distinct "
+                "dirty card.\n",
+                _total_cards > 0 ?
+                (float)_total_travs/(float)_total_cards : 0.0);
+
+
+  gclog_or_tty->print_cr("Histogram:\n\n%10s   %10s%10s%10s%10s%10s%10s",
+                "range", "# cards", "# travs", "% cards", "(cum)",
+                "% travs", "(cum)");
+  gclog_or_tty->print_cr("------------------------------------------------------------"
+                "-------------");
+  float cum_cards_pct = 0.0;
+  float cum_travs_pct = 0.0;
+  for (int i = 1; i < 10; i++) {
+    print_card_count_histo_range(_cum_card_count_histo, i, i+1,
+                                 cum_cards_pct, cum_travs_pct);
+  }
+  for (int i = 10; i < 100; i += 10) {
+    print_card_count_histo_range(_cum_card_count_histo, i, i+10,
+                                 cum_cards_pct, cum_travs_pct);
+  }
+  print_card_count_histo_range(_cum_card_count_histo, 100, 150,
+                               cum_cards_pct, cum_travs_pct);
+  print_card_count_histo_range(_cum_card_count_histo, 150, 200,
+                               cum_cards_pct, cum_travs_pct);
+  print_card_count_histo_range(_cum_card_count_histo, 150, 255,
+                               cum_cards_pct, cum_travs_pct);
+  print_card_count_histo_range(_cum_card_count_histo, 255, 256,
+                               cum_cards_pct, cum_travs_pct);
+}