1 /*
   2  * Copyright (c) 2001, 2013, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #include "precompiled.hpp"
  26 #include "gc_implementation/g1/concurrentG1Refine.hpp"
  27 #include "gc_implementation/g1/concurrentG1RefineThread.hpp"
  28 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
  29 #include "gc_implementation/g1/g1HotCardCache.hpp"
  30 #include "runtime/java.hpp"
  31 
  32 ConcurrentG1Refine::ConcurrentG1Refine(G1CollectedHeap* g1h, CardTableEntryClosure* refine_closure) :
  33   _threads(NULL), _n_threads(0),
  34   _hot_card_cache(g1h)
  35 {
  36   // Ergonomically select initial concurrent refinement parameters
  37   if (FLAG_IS_DEFAULT(G1ConcRefinementGreenZone)) {
  38     FLAG_SET_DEFAULT(G1ConcRefinementGreenZone, MAX2<int>(ParallelGCThreads, 1));
  39   }
  40   set_green_zone(G1ConcRefinementGreenZone);
  41 
  42   if (FLAG_IS_DEFAULT(G1ConcRefinementYellowZone)) {
  43     FLAG_SET_DEFAULT(G1ConcRefinementYellowZone, green_zone() * 3);
  44   }
  45   set_yellow_zone(MAX2<int>(G1ConcRefinementYellowZone, green_zone()));
  46 
  47   if (FLAG_IS_DEFAULT(G1ConcRefinementRedZone)) {
  48     FLAG_SET_DEFAULT(G1ConcRefinementRedZone, yellow_zone() * 2);
  49   }
  50   set_red_zone(MAX2<int>(G1ConcRefinementRedZone, yellow_zone()));
  51 
  52   _n_worker_threads = thread_num();
  53   // We need one extra thread to do the young gen rset size sampling.
  54   _n_threads = _n_worker_threads + 1;
  55 
  56   reset_threshold_step();
  57 
  58   _threads = NEW_C_HEAP_ARRAY(ConcurrentG1RefineThread*, _n_threads, mtGC);
  59 
  60   uint worker_id_offset = DirtyCardQueueSet::num_par_ids();
  61 
  62   ConcurrentG1RefineThread *next = NULL;
  63   for (uint i = _n_threads - 1; i != UINT_MAX; i--) {
  64     ConcurrentG1RefineThread* t = new ConcurrentG1RefineThread(this, next, refine_closure, worker_id_offset, i);
  65     assert(t != NULL, "Conc refine should have been created");
  66     if (t->osthread() == NULL) {
  67         vm_shutdown_during_initialization("Could not create ConcurrentG1RefineThread");
  68     }
  69 
  70     assert(t->cg1r() == this, "Conc refine thread should refer to this");
  71     _threads[i] = t;
  72     next = t;
  73   }
  74 }
  75 
  76 void ConcurrentG1Refine::reset_threshold_step() {
  77   if (FLAG_IS_DEFAULT(G1ConcRefinementThresholdStep)) {
  78     _thread_threshold_step = (yellow_zone() - green_zone()) / (worker_thread_num() + 1);
  79   } else {
  80     _thread_threshold_step = G1ConcRefinementThresholdStep;
  81   }
  82 }
  83 
  84 void ConcurrentG1Refine::init(G1RegionToSpaceMapper* card_counts_storage) {
  85   _hot_card_cache.initialize(card_counts_storage);
  86 }
  87 
  88 void ConcurrentG1Refine::stop() {
  89   if (_threads != NULL) {
  90     for (uint i = 0; i < _n_threads; i++) {
  91       _threads[i]->stop();
  92     }
  93   }
  94 }
  95 
  96 void ConcurrentG1Refine::reinitialize_threads() {
  97   reset_threshold_step();
  98   if (_threads != NULL) {
  99     for (uint i = 0; i < _n_threads; i++) {
 100       _threads[i]->initialize();
 101     }
 102   }
 103 }
 104 
 105 ConcurrentG1Refine::~ConcurrentG1Refine() {
 106   if (_threads != NULL) {
 107     for (uint i = 0; i < _n_threads; i++) {
 108       delete _threads[i];
 109     }
 110     FREE_C_HEAP_ARRAY(ConcurrentG1RefineThread*, _threads, mtGC);
 111   }
 112 }
 113 
 114 void ConcurrentG1Refine::threads_do(ThreadClosure *tc) {
 115   if (_threads != NULL) {
 116     for (uint i = 0; i < _n_threads; i++) {
 117       tc->do_thread(_threads[i]);
 118     }
 119   }
 120 }
 121 
 122 void ConcurrentG1Refine::worker_threads_do(ThreadClosure * tc) {
 123   if (_threads != NULL) {
 124     for (uint i = 0; i < worker_thread_num(); i++) {
 125       tc->do_thread(_threads[i]);
 126     }
 127   }
 128 }
 129 
 130 uint ConcurrentG1Refine::thread_num() {
 131   uint n_threads = (G1ConcRefinementThreads > 0) ? G1ConcRefinementThreads
 132                                                 : ParallelGCThreads;
 133   return MAX2<uint>(n_threads, 1);
 134 }
 135 
 136 void ConcurrentG1Refine::print_worker_threads_on(outputStream* st) const {
 137   for (uint i = 0; i < _n_threads; ++i) {
 138     _threads[i]->print_on(st);
 139     st->cr();
 140   }
 141 }
 142 
 143 ConcurrentG1RefineThread * ConcurrentG1Refine::sampling_thread() const {
 144   return _threads[worker_thread_num()];
 145 }