Mercurial > jdk8-mips64-public > hotspot / file revision

 /*

  * 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();

     // 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);

 }