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1 /*
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2 * Copyright 2001-2006 Sun Microsystems, Inc. All Rights Reserved.
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3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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4 *
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5 * This code is free software; you can redistribute it and/or modify it
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6 * under the terms of the GNU General Public License version 2 only, as
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7 * published by the Free Software Foundation.
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8 *
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9 * This code is distributed in the hope that it will be useful, but WITHOUT
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10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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12 * version 2 for more details (a copy is included in the LICENSE file that
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13 * accompanied this code).
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14 *
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15 * You should have received a copy of the GNU General Public License version
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16 * 2 along with this work; if not, write to the Free Software Foundation,
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17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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18 *
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19 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
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20 * CA 95054 USA or visit www.sun.com if you need additional information or
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21 * have any questions.
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22 *
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23 */
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24
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25 # include "incls/_precompiled.incl"
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26 # include "incls/_cardTableExtension.cpp.incl"
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27
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28 // Checks an individual oop for missing precise marks. Mark
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29 // may be either dirty or newgen.
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30 class CheckForUnmarkedOops : public OopClosure {
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31 PSYoungGen* _young_gen;
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32 CardTableExtension* _card_table;
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33 HeapWord* _unmarked_addr;
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34 jbyte* _unmarked_card;
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35
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36 public:
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37 CheckForUnmarkedOops( PSYoungGen* young_gen, CardTableExtension* card_table ) :
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38 _young_gen(young_gen), _card_table(card_table), _unmarked_addr(NULL) { }
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39
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40 virtual void do_oop(oop* p) {
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41 if (_young_gen->is_in_reserved(*p) &&
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42 !_card_table->addr_is_marked_imprecise(p)) {
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43 // Don't overwrite the first missing card mark
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44 if (_unmarked_addr == NULL) {
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45 _unmarked_addr = (HeapWord*)p;
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46 _unmarked_card = _card_table->byte_for(p);
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47 }
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48 }
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49 }
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50
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51 bool has_unmarked_oop() {
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52 return _unmarked_addr != NULL;
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53 }
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54 };
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55
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56 // Checks all objects for the existance of some type of mark,
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57 // precise or imprecise, dirty or newgen.
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58 class CheckForUnmarkedObjects : public ObjectClosure {
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59 PSYoungGen* _young_gen;
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60 CardTableExtension* _card_table;
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61
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62 public:
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63 CheckForUnmarkedObjects() {
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64 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
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65 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
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66
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67 _young_gen = heap->young_gen();
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68 _card_table = (CardTableExtension*)heap->barrier_set();
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69 // No point in asserting barrier set type here. Need to make CardTableExtension
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70 // a unique barrier set type.
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71 }
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72
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73 // Card marks are not precise. The current system can leave us with
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74 // a mismash of precise marks and begining of object marks. This means
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75 // we test for missing precise marks first. If any are found, we don't
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76 // fail unless the object head is also unmarked.
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77 virtual void do_object(oop obj) {
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78 CheckForUnmarkedOops object_check( _young_gen, _card_table );
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79 obj->oop_iterate(&object_check);
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80 if (object_check.has_unmarked_oop()) {
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81 assert(_card_table->addr_is_marked_imprecise(obj), "Found unmarked young_gen object");
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82 }
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83 }
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84 };
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85
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86 // Checks for precise marking of oops as newgen.
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87 class CheckForPreciseMarks : public OopClosure {
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88 PSYoungGen* _young_gen;
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89 CardTableExtension* _card_table;
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90
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91 public:
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92 CheckForPreciseMarks( PSYoungGen* young_gen, CardTableExtension* card_table ) :
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93 _young_gen(young_gen), _card_table(card_table) { }
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94
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95 virtual void do_oop(oop* p) {
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96 if (_young_gen->is_in_reserved(*p)) {
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97 assert(_card_table->addr_is_marked_precise(p), "Found unmarked precise oop");
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98 _card_table->set_card_newgen(p);
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99 }
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100 }
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101 };
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102
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103 // We get passed the space_top value to prevent us from traversing into
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104 // the old_gen promotion labs, which cannot be safely parsed.
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105 void CardTableExtension::scavenge_contents(ObjectStartArray* start_array,
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106 MutableSpace* sp,
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107 HeapWord* space_top,
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108 PSPromotionManager* pm)
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109 {
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110 assert(start_array != NULL && sp != NULL && pm != NULL, "Sanity");
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111 assert(start_array->covered_region().contains(sp->used_region()),
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112 "ObjectStartArray does not cover space");
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113 bool depth_first = pm->depth_first();
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114
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115 if (sp->not_empty()) {
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116 oop* sp_top = (oop*)space_top;
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117 oop* prev_top = NULL;
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118 jbyte* current_card = byte_for(sp->bottom());
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119 jbyte* end_card = byte_for(sp_top - 1); // sp_top is exclusive
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120 // scan card marking array
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121 while (current_card <= end_card) {
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122 jbyte value = *current_card;
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123 // skip clean cards
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124 if (card_is_clean(value)) {
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125 current_card++;
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126 } else {
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127 // we found a non-clean card
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128 jbyte* first_nonclean_card = current_card++;
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129 oop* bottom = (oop*)addr_for(first_nonclean_card);
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130 // find object starting on card
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131 oop* bottom_obj = (oop*)start_array->object_start((HeapWord*)bottom);
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132 // bottom_obj = (oop*)start_array->object_start((HeapWord*)bottom);
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133 assert(bottom_obj <= bottom, "just checking");
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134 // make sure we don't scan oops we already looked at
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135 if (bottom < prev_top) bottom = prev_top;
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136 // figure out when to stop scanning
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137 jbyte* first_clean_card;
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138 oop* top;
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139 bool restart_scanning;
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140 do {
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141 restart_scanning = false;
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142 // find a clean card
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143 while (current_card <= end_card) {
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144 value = *current_card;
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145 if (card_is_clean(value)) break;
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146 current_card++;
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147 }
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148 // check if we reached the end, if so we are done
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149 if (current_card >= end_card) {
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150 first_clean_card = end_card + 1;
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151 current_card++;
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152 top = sp_top;
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153 } else {
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154 // we have a clean card, find object starting on that card
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155 first_clean_card = current_card++;
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156 top = (oop*)addr_for(first_clean_card);
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157 oop* top_obj = (oop*)start_array->object_start((HeapWord*)top);
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158 // top_obj = (oop*)start_array->object_start((HeapWord*)top);
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159 assert(top_obj <= top, "just checking");
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160 if (oop(top_obj)->is_objArray() || oop(top_obj)->is_typeArray()) {
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161 // an arrayOop is starting on the clean card - since we do exact store
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162 // checks for objArrays we are done
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163 } else {
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164 // otherwise, it is possible that the object starting on the clean card
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165 // spans the entire card, and that the store happened on a later card.
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166 // figure out where the object ends
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167 top = top_obj + oop(top_obj)->size();
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168 jbyte* top_card = CardTableModRefBS::byte_for(top - 1); // top is exclusive
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169 if (top_card > first_clean_card) {
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170 // object ends a different card
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171 current_card = top_card + 1;
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172 if (card_is_clean(*top_card)) {
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173 // the ending card is clean, we are done
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174 first_clean_card = top_card;
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175 } else {
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176 // the ending card is not clean, continue scanning at start of do-while
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177 restart_scanning = true;
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178 }
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179 } else {
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180 // object ends on the clean card, we are done.
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181 assert(first_clean_card == top_card, "just checking");
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182 }
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183 }
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184 }
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185 } while (restart_scanning);
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186 // we know which cards to scan, now clear them
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187 while (first_nonclean_card < first_clean_card) {
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188 *first_nonclean_card++ = clean_card;
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189 }
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190 // scan oops in objects
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191 // hoisted the if (depth_first) check out of the loop
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192 if (depth_first){
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193 do {
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194 oop(bottom_obj)->push_contents(pm);
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195 bottom_obj += oop(bottom_obj)->size();
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196 assert(bottom_obj <= sp_top, "just checking");
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197 } while (bottom_obj < top);
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198 pm->drain_stacks_cond_depth();
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199 } else {
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200 do {
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201 oop(bottom_obj)->copy_contents(pm);
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202 bottom_obj += oop(bottom_obj)->size();
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203 assert(bottom_obj <= sp_top, "just checking");
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204 } while (bottom_obj < top);
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205 }
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206 // remember top oop* scanned
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207 prev_top = top;
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208 }
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209 }
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210 }
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211 }
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212
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213 void CardTableExtension::scavenge_contents_parallel(ObjectStartArray* start_array,
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214 MutableSpace* sp,
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215 HeapWord* space_top,
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216 PSPromotionManager* pm,
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217 uint stripe_number) {
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218 int ssize = 128; // Naked constant! Work unit = 64k.
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219 int dirty_card_count = 0;
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220 bool depth_first = pm->depth_first();
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221
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222 oop* sp_top = (oop*)space_top;
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223 jbyte* start_card = byte_for(sp->bottom());
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224 jbyte* end_card = byte_for(sp_top - 1) + 1;
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225 oop* last_scanned = NULL; // Prevent scanning objects more than once
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226 for (jbyte* slice = start_card; slice < end_card; slice += ssize*ParallelGCThreads) {
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227 jbyte* worker_start_card = slice + stripe_number * ssize;
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228 if (worker_start_card >= end_card)
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229 return; // We're done.
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230
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231 jbyte* worker_end_card = worker_start_card + ssize;
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232 if (worker_end_card > end_card)
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233 worker_end_card = end_card;
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234
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235 // We do not want to scan objects more than once. In order to accomplish
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236 // this, we assert that any object with an object head inside our 'slice'
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237 // belongs to us. We may need to extend the range of scanned cards if the
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238 // last object continues into the next 'slice'.
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239 //
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240 // Note! ending cards are exclusive!
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241 HeapWord* slice_start = addr_for(worker_start_card);
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242 HeapWord* slice_end = MIN2((HeapWord*) sp_top, addr_for(worker_end_card));
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243
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244 // If there are not objects starting within the chunk, skip it.
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245 if (!start_array->object_starts_in_range(slice_start, slice_end)) {
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246 continue;
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247 }
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248 // Update our begining addr
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249 HeapWord* first_object = start_array->object_start(slice_start);
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250 debug_only(oop* first_object_within_slice = (oop*) first_object;)
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251 if (first_object < slice_start) {
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252 last_scanned = (oop*)(first_object + oop(first_object)->size());
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253 debug_only(first_object_within_slice = last_scanned;)
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254 worker_start_card = byte_for(last_scanned);
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255 }
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256
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257 // Update the ending addr
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258 if (slice_end < (HeapWord*)sp_top) {
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259 // The subtraction is important! An object may start precisely at slice_end.
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260 HeapWord* last_object = start_array->object_start(slice_end - 1);
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261 slice_end = last_object + oop(last_object)->size();
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262 // worker_end_card is exclusive, so bump it one past the end of last_object's
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263 // covered span.
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264 worker_end_card = byte_for(slice_end) + 1;
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265
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266 if (worker_end_card > end_card)
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267 worker_end_card = end_card;
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268 }
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269
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270 assert(slice_end <= (HeapWord*)sp_top, "Last object in slice crosses space boundary");
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271 assert(is_valid_card_address(worker_start_card), "Invalid worker start card");
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272 assert(is_valid_card_address(worker_end_card), "Invalid worker end card");
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273 // Note that worker_start_card >= worker_end_card is legal, and happens when
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274 // an object spans an entire slice.
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275 assert(worker_start_card <= end_card, "worker start card beyond end card");
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276 assert(worker_end_card <= end_card, "worker end card beyond end card");
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277
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278 jbyte* current_card = worker_start_card;
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279 while (current_card < worker_end_card) {
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280 // Find an unclean card.
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281 while (current_card < worker_end_card && card_is_clean(*current_card)) {
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282 current_card++;
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283 }
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284 jbyte* first_unclean_card = current_card;
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285
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286 // Find the end of a run of contiguous unclean cards
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287 while (current_card < worker_end_card && !card_is_clean(*current_card)) {
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288 while (current_card < worker_end_card && !card_is_clean(*current_card)) {
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289 current_card++;
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290 }
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291
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292 if (current_card < worker_end_card) {
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293 // Some objects may be large enough to span several cards. If such
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294 // an object has more than one dirty card, separated by a clean card,
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295 // we will attempt to scan it twice. The test against "last_scanned"
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296 // prevents the redundant object scan, but it does not prevent newly
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297 // marked cards from being cleaned.
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298 HeapWord* last_object_in_dirty_region = start_array->object_start(addr_for(current_card)-1);
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299 size_t size_of_last_object = oop(last_object_in_dirty_region)->size();
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300 HeapWord* end_of_last_object = last_object_in_dirty_region + size_of_last_object;
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301 jbyte* ending_card_of_last_object = byte_for(end_of_last_object);
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302 assert(ending_card_of_last_object <= worker_end_card, "ending_card_of_last_object is greater than worker_end_card");
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303 if (ending_card_of_last_object > current_card) {
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304 // This means the object spans the next complete card.
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305 // We need to bump the current_card to ending_card_of_last_object
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306 current_card = ending_card_of_last_object;
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307 }
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308 }
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309 }
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310 jbyte* following_clean_card = current_card;
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311
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312 if (first_unclean_card < worker_end_card) {
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313 oop* p = (oop*) start_array->object_start(addr_for(first_unclean_card));
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314 assert((HeapWord*)p <= addr_for(first_unclean_card), "checking");
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315 // "p" should always be >= "last_scanned" because newly GC dirtied
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316 // cards are no longer scanned again (see comment at end
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317 // of loop on the increment of "current_card"). Test that
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318 // hypothesis before removing this code.
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319 // If this code is removed, deal with the first time through
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320 // the loop when the last_scanned is the object starting in
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321 // the previous slice.
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322 assert((p >= last_scanned) ||
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323 (last_scanned == first_object_within_slice),
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324 "Should no longer be possible");
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325 if (p < last_scanned) {
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326 // Avoid scanning more than once; this can happen because
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327 // newgen cards set by GC may a different set than the
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328 // originally dirty set
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329 p = last_scanned;
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330 }
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331 oop* to = (oop*)addr_for(following_clean_card);
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332
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333 // Test slice_end first!
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334 if ((HeapWord*)to > slice_end) {
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335 to = (oop*)slice_end;
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336 } else if (to > sp_top) {
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337 to = sp_top;
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338 }
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339
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340 // we know which cards to scan, now clear them
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341 if (first_unclean_card <= worker_start_card+1)
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342 first_unclean_card = worker_start_card+1;
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343 if (following_clean_card >= worker_end_card-1)
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344 following_clean_card = worker_end_card-1;
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345
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346 while (first_unclean_card < following_clean_card) {
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347 *first_unclean_card++ = clean_card;
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348 }
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349
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350 const int interval = PrefetchScanIntervalInBytes;
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351 // scan all objects in the range
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352 if (interval != 0) {
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353 // hoisted the if (depth_first) check out of the loop
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354 if (depth_first) {
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355 while (p < to) {
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356 Prefetch::write(p, interval);
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357 oop m = oop(p);
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358 assert(m->is_oop_or_null(), "check for header");
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359 m->push_contents(pm);
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360 p += m->size();
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361 }
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362 pm->drain_stacks_cond_depth();
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363 } else {
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364 while (p < to) {
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365 Prefetch::write(p, interval);
|
|
|
366 oop m = oop(p);
|
|
|
367 assert(m->is_oop_or_null(), "check for header");
|
|
|
368 m->copy_contents(pm);
|
|
|
369 p += m->size();
|
|
|
370 }
|
|
|
371 }
|
|
|
372 } else {
|
|
|
373 // hoisted the if (depth_first) check out of the loop
|
|
|
374 if (depth_first) {
|
|
|
375 while (p < to) {
|
|
|
376 oop m = oop(p);
|
|
|
377 assert(m->is_oop_or_null(), "check for header");
|
|
|
378 m->push_contents(pm);
|
|
|
379 p += m->size();
|
|
|
380 }
|
|
|
381 pm->drain_stacks_cond_depth();
|
|
|
382 } else {
|
|
|
383 while (p < to) {
|
|
|
384 oop m = oop(p);
|
|
|
385 assert(m->is_oop_or_null(), "check for header");
|
|
|
386 m->copy_contents(pm);
|
|
|
387 p += m->size();
|
|
|
388 }
|
|
|
389 }
|
|
|
390 }
|
|
|
391 last_scanned = p;
|
|
|
392 }
|
|
|
393 // "current_card" is still the "following_clean_card" or
|
|
|
394 // the current_card is >= the worker_end_card so the
|
|
|
395 // loop will not execute again.
|
|
|
396 assert((current_card == following_clean_card) ||
|
|
|
397 (current_card >= worker_end_card),
|
|
|
398 "current_card should only be incremented if it still equals "
|
|
|
399 "following_clean_card");
|
|
|
400 // Increment current_card so that it is not processed again.
|
|
|
401 // It may now be dirty because a old-to-young pointer was
|
|
|
402 // found on it an updated. If it is now dirty, it cannot be
|
|
|
403 // be safely cleaned in the next iteration.
|
|
|
404 current_card++;
|
|
|
405 }
|
|
|
406 }
|
|
|
407 }
|
|
|
408
|
|
|
409 // This should be called before a scavenge.
|
|
|
410 void CardTableExtension::verify_all_young_refs_imprecise() {
|
|
|
411 CheckForUnmarkedObjects check;
|
|
|
412
|
|
|
413 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
|
|
|
414 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
|
|
|
415
|
|
|
416 PSOldGen* old_gen = heap->old_gen();
|
|
|
417 PSPermGen* perm_gen = heap->perm_gen();
|
|
|
418
|
|
|
419 old_gen->object_iterate(&check);
|
|
|
420 perm_gen->object_iterate(&check);
|
|
|
421 }
|
|
|
422
|
|
|
423 // This should be called immediately after a scavenge, before mutators resume.
|
|
|
424 void CardTableExtension::verify_all_young_refs_precise() {
|
|
|
425 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
|
|
|
426 assert(heap->kind() == CollectedHeap::ParallelScavengeHeap, "Sanity");
|
|
|
427
|
|
|
428 PSOldGen* old_gen = heap->old_gen();
|
|
|
429 PSPermGen* perm_gen = heap->perm_gen();
|
|
|
430
|
|
|
431 CheckForPreciseMarks check(heap->young_gen(), (CardTableExtension*)heap->barrier_set());
|
|
|
432
|
|
|
433 old_gen->oop_iterate(&check);
|
|
|
434 perm_gen->oop_iterate(&check);
|
|
|
435
|
|
|
436 verify_all_young_refs_precise_helper(old_gen->object_space()->used_region());
|
|
|
437 verify_all_young_refs_precise_helper(perm_gen->object_space()->used_region());
|
|
|
438 }
|
|
|
439
|
|
|
440 void CardTableExtension::verify_all_young_refs_precise_helper(MemRegion mr) {
|
|
|
441 CardTableExtension* card_table = (CardTableExtension*)Universe::heap()->barrier_set();
|
|
|
442 // FIX ME ASSERT HERE
|
|
|
443
|
|
|
444 jbyte* bot = card_table->byte_for(mr.start());
|
|
|
445 jbyte* top = card_table->byte_for(mr.end());
|
|
|
446 while(bot <= top) {
|
|
|
447 assert(*bot == clean_card || *bot == verify_card, "Found unwanted or unknown card mark");
|
|
|
448 if (*bot == verify_card)
|
|
|
449 *bot = youngergen_card;
|
|
|
450 bot++;
|
|
|
451 }
|
|
|
452 }
|
|
|
453
|
|
|
454 bool CardTableExtension::addr_is_marked_imprecise(void *addr) {
|
|
|
455 jbyte* p = byte_for(addr);
|
|
|
456 jbyte val = *p;
|
|
|
457
|
|
|
458 if (card_is_dirty(val))
|
|
|
459 return true;
|
|
|
460
|
|
|
461 if (card_is_newgen(val))
|
|
|
462 return true;
|
|
|
463
|
|
|
464 if (card_is_clean(val))
|
|
|
465 return false;
|
|
|
466
|
|
|
467 assert(false, "Found unhandled card mark type");
|
|
|
468
|
|
|
469 return false;
|
|
|
470 }
|
|
|
471
|
|
|
472 // Also includes verify_card
|
|
|
473 bool CardTableExtension::addr_is_marked_precise(void *addr) {
|
|
|
474 jbyte* p = byte_for(addr);
|
|
|
475 jbyte val = *p;
|
|
|
476
|
|
|
477 if (card_is_newgen(val))
|
|
|
478 return true;
|
|
|
479
|
|
|
480 if (card_is_verify(val))
|
|
|
481 return true;
|
|
|
482
|
|
|
483 if (card_is_clean(val))
|
|
|
484 return false;
|
|
|
485
|
|
|
486 if (card_is_dirty(val))
|
|
|
487 return false;
|
|
|
488
|
|
|
489 assert(false, "Found unhandled card mark type");
|
|
|
490
|
|
|
491 return false;
|
|
|
492 }
|
|
|
493
|
|
|
494 // Assumes that only the base or the end changes. This allows indentification
|
|
|
495 // of the region that is being resized. The
|
|
|
496 // CardTableModRefBS::resize_covered_region() is used for the normal case
|
|
|
497 // where the covered regions are growing or shrinking at the high end.
|
|
|
498 // The method resize_covered_region_by_end() is analogous to
|
|
|
499 // CardTableModRefBS::resize_covered_region() but
|
|
|
500 // for regions that grow or shrink at the low end.
|
|
|
501 void CardTableExtension::resize_covered_region(MemRegion new_region) {
|
|
|
502
|
|
|
503 for (int i = 0; i < _cur_covered_regions; i++) {
|
|
|
504 if (_covered[i].start() == new_region.start()) {
|
|
|
505 // Found a covered region with the same start as the
|
|
|
506 // new region. The region is growing or shrinking
|
|
|
507 // from the start of the region.
|
|
|
508 resize_covered_region_by_start(new_region);
|
|
|
509 return;
|
|
|
510 }
|
|
|
511 if (_covered[i].start() > new_region.start()) {
|
|
|
512 break;
|
|
|
513 }
|
|
|
514 }
|
|
|
515
|
|
|
516 int changed_region = -1;
|
|
|
517 for (int j = 0; j < _cur_covered_regions; j++) {
|
|
|
518 if (_covered[j].end() == new_region.end()) {
|
|
|
519 changed_region = j;
|
|
|
520 // This is a case where the covered region is growing or shrinking
|
|
|
521 // at the start of the region.
|
|
|
522 assert(changed_region != -1, "Don't expect to add a covered region");
|
|
|
523 assert(_covered[changed_region].byte_size() != new_region.byte_size(),
|
|
|
524 "The sizes should be different here");
|
|
|
525 resize_covered_region_by_end(changed_region, new_region);
|
|
|
526 return;
|
|
|
527 }
|
|
|
528 }
|
|
|
529 // This should only be a new covered region (where no existing
|
|
|
530 // covered region matches at the start or the end).
|
|
|
531 assert(_cur_covered_regions < _max_covered_regions,
|
|
|
532 "An existing region should have been found");
|
|
|
533 resize_covered_region_by_start(new_region);
|
|
|
534 }
|
|
|
535
|
|
|
536 void CardTableExtension::resize_covered_region_by_start(MemRegion new_region) {
|
|
|
537 CardTableModRefBS::resize_covered_region(new_region);
|
|
|
538 debug_only(verify_guard();)
|
|
|
539 }
|
|
|
540
|
|
|
541 void CardTableExtension::resize_covered_region_by_end(int changed_region,
|
|
|
542 MemRegion new_region) {
|
|
|
543 assert(SafepointSynchronize::is_at_safepoint(),
|
|
|
544 "Only expect an expansion at the low end at a GC");
|
|
|
545 debug_only(verify_guard();)
|
|
|
546 #ifdef ASSERT
|
|
|
547 for (int k = 0; k < _cur_covered_regions; k++) {
|
|
|
548 if (_covered[k].end() == new_region.end()) {
|
|
|
549 assert(changed_region == k, "Changed region is incorrect");
|
|
|
550 break;
|
|
|
551 }
|
|
|
552 }
|
|
|
553 #endif
|
|
|
554
|
|
|
555 // Commit new or uncommit old pages, if necessary.
|
|
|
556 resize_commit_uncommit(changed_region, new_region);
|
|
|
557
|
|
|
558 // Update card table entries
|
|
|
559 resize_update_card_table_entries(changed_region, new_region);
|
|
|
560
|
|
|
561 // Set the new start of the committed region
|
|
|
562 resize_update_committed_table(changed_region, new_region);
|
|
|
563
|
|
|
564 // Update the covered region
|
|
|
565 resize_update_covered_table(changed_region, new_region);
|
|
|
566
|
|
|
567 if (TraceCardTableModRefBS) {
|
|
|
568 int ind = changed_region;
|
|
|
569 gclog_or_tty->print_cr("CardTableModRefBS::resize_covered_region: ");
|
|
|
570 gclog_or_tty->print_cr(" "
|
|
|
571 " _covered[%d].start(): " INTPTR_FORMAT
|
|
|
572 " _covered[%d].last(): " INTPTR_FORMAT,
|
|
|
573 ind, _covered[ind].start(),
|
|
|
574 ind, _covered[ind].last());
|
|
|
575 gclog_or_tty->print_cr(" "
|
|
|
576 " _committed[%d].start(): " INTPTR_FORMAT
|
|
|
577 " _committed[%d].last(): " INTPTR_FORMAT,
|
|
|
578 ind, _committed[ind].start(),
|
|
|
579 ind, _committed[ind].last());
|
|
|
580 gclog_or_tty->print_cr(" "
|
|
|
581 " byte_for(start): " INTPTR_FORMAT
|
|
|
582 " byte_for(last): " INTPTR_FORMAT,
|
|
|
583 byte_for(_covered[ind].start()),
|
|
|
584 byte_for(_covered[ind].last()));
|
|
|
585 gclog_or_tty->print_cr(" "
|
|
|
586 " addr_for(start): " INTPTR_FORMAT
|
|
|
587 " addr_for(last): " INTPTR_FORMAT,
|
|
|
588 addr_for((jbyte*) _committed[ind].start()),
|
|
|
589 addr_for((jbyte*) _committed[ind].last()));
|
|
|
590 }
|
|
|
591 debug_only(verify_guard();)
|
|
|
592 }
|
|
|
593
|
|
|
594 void CardTableExtension::resize_commit_uncommit(int changed_region,
|
|
|
595 MemRegion new_region) {
|
|
|
596 // Commit new or uncommit old pages, if necessary.
|
|
|
597 MemRegion cur_committed = _committed[changed_region];
|
|
|
598 assert(_covered[changed_region].end() == new_region.end(),
|
|
|
599 "The ends of the regions are expected to match");
|
|
|
600 // Extend the start of this _committed region to
|
|
|
601 // to cover the start of any previous _committed region.
|
|
|
602 // This forms overlapping regions, but never interior regions.
|
|
|
603 HeapWord* min_prev_start = lowest_prev_committed_start(changed_region);
|
|
|
604 if (min_prev_start < cur_committed.start()) {
|
|
|
605 // Only really need to set start of "cur_committed" to
|
|
|
606 // the new start (min_prev_start) but assertion checking code
|
|
|
607 // below use cur_committed.end() so make it correct.
|
|
|
608 MemRegion new_committed =
|
|
|
609 MemRegion(min_prev_start, cur_committed.end());
|
|
|
610 cur_committed = new_committed;
|
|
|
611 }
|
|
|
612 #ifdef ASSERT
|
|
|
613 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
|
|
|
614 assert(cur_committed.start() ==
|
|
|
615 (HeapWord*) align_size_up((uintptr_t) cur_committed.start(),
|
|
|
616 os::vm_page_size()),
|
|
|
617 "Starts should have proper alignment");
|
|
|
618 #endif
|
|
|
619
|
|
|
620 jbyte* new_start = byte_for(new_region.start());
|
|
|
621 // Round down because this is for the start address
|
|
|
622 HeapWord* new_start_aligned =
|
|
|
623 (HeapWord*)align_size_down((uintptr_t)new_start, os::vm_page_size());
|
|
|
624 // The guard page is always committed and should not be committed over.
|
|
|
625 // This method is used in cases where the generation is growing toward
|
|
|
626 // lower addresses but the guard region is still at the end of the
|
|
|
627 // card table. That still makes sense when looking for writes
|
|
|
628 // off the end of the card table.
|
|
|
629 if (new_start_aligned < cur_committed.start()) {
|
|
|
630 // Expand the committed region
|
|
|
631 //
|
|
|
632 // Case A
|
|
|
633 // |+ guard +|
|
|
|
634 // |+ cur committed +++++++++|
|
|
|
635 // |+ new committed +++++++++++++++++|
|
|
|
636 //
|
|
|
637 // Case B
|
|
|
638 // |+ guard +|
|
|
|
639 // |+ cur committed +|
|
|
|
640 // |+ new committed +++++++|
|
|
|
641 //
|
|
|
642 // These are not expected because the calculation of the
|
|
|
643 // cur committed region and the new committed region
|
|
|
644 // share the same end for the covered region.
|
|
|
645 // Case C
|
|
|
646 // |+ guard +|
|
|
|
647 // |+ cur committed +|
|
|
|
648 // |+ new committed +++++++++++++++++|
|
|
|
649 // Case D
|
|
|
650 // |+ guard +|
|
|
|
651 // |+ cur committed +++++++++++|
|
|
|
652 // |+ new committed +++++++|
|
|
|
653
|
|
|
654 HeapWord* new_end_for_commit =
|
|
|
655 MIN2(cur_committed.end(), _guard_region.start());
|
|
|
656 MemRegion new_committed =
|
|
|
657 MemRegion(new_start_aligned, new_end_for_commit);
|
|
|
658 if(!new_committed.is_empty()) {
|
|
|
659 if (!os::commit_memory((char*)new_committed.start(),
|
|
|
660 new_committed.byte_size())) {
|
|
|
661 vm_exit_out_of_memory(new_committed.byte_size(),
|
|
|
662 "card table expansion");
|
|
|
663 }
|
|
|
664 }
|
|
|
665 } else if (new_start_aligned > cur_committed.start()) {
|
|
|
666 // Shrink the committed region
|
|
|
667 MemRegion uncommit_region = committed_unique_to_self(changed_region,
|
|
|
668 MemRegion(cur_committed.start(), new_start_aligned));
|
|
|
669 if (!uncommit_region.is_empty()) {
|
|
|
670 if (!os::uncommit_memory((char*)uncommit_region.start(),
|
|
|
671 uncommit_region.byte_size())) {
|
|
|
672 vm_exit_out_of_memory(uncommit_region.byte_size(),
|
|
|
673 "card table contraction");
|
|
|
674 }
|
|
|
675 }
|
|
|
676 }
|
|
|
677 assert(_committed[changed_region].end() == cur_committed.end(),
|
|
|
678 "end should not change");
|
|
|
679 }
|
|
|
680
|
|
|
681 void CardTableExtension::resize_update_committed_table(int changed_region,
|
|
|
682 MemRegion new_region) {
|
|
|
683
|
|
|
684 jbyte* new_start = byte_for(new_region.start());
|
|
|
685 // Set the new start of the committed region
|
|
|
686 HeapWord* new_start_aligned =
|
|
|
687 (HeapWord*)align_size_down((uintptr_t)new_start,
|
|
|
688 os::vm_page_size());
|
|
|
689 MemRegion new_committed = MemRegion(new_start_aligned,
|
|
|
690 _committed[changed_region].end());
|
|
|
691 _committed[changed_region] = new_committed;
|
|
|
692 _committed[changed_region].set_start(new_start_aligned);
|
|
|
693 }
|
|
|
694
|
|
|
695 void CardTableExtension::resize_update_card_table_entries(int changed_region,
|
|
|
696 MemRegion new_region) {
|
|
|
697 debug_only(verify_guard();)
|
|
|
698 MemRegion original_covered = _covered[changed_region];
|
|
|
699 // Initialize the card entries. Only consider the
|
|
|
700 // region covered by the card table (_whole_heap)
|
|
|
701 jbyte* entry;
|
|
|
702 if (new_region.start() < _whole_heap.start()) {
|
|
|
703 entry = byte_for(_whole_heap.start());
|
|
|
704 } else {
|
|
|
705 entry = byte_for(new_region.start());
|
|
|
706 }
|
|
|
707 jbyte* end = byte_for(original_covered.start());
|
|
|
708 // If _whole_heap starts at the original covered regions start,
|
|
|
709 // this loop will not execute.
|
|
|
710 while (entry < end) { *entry++ = clean_card; }
|
|
|
711 }
|
|
|
712
|
|
|
713 void CardTableExtension::resize_update_covered_table(int changed_region,
|
|
|
714 MemRegion new_region) {
|
|
|
715 // Update the covered region
|
|
|
716 _covered[changed_region].set_start(new_region.start());
|
|
|
717 _covered[changed_region].set_word_size(new_region.word_size());
|
|
|
718
|
|
|
719 // reorder regions. There should only be at most 1 out
|
|
|
720 // of order.
|
|
|
721 for (int i = _cur_covered_regions-1 ; i > 0; i--) {
|
|
|
722 if (_covered[i].start() < _covered[i-1].start()) {
|
|
|
723 MemRegion covered_mr = _covered[i-1];
|
|
|
724 _covered[i-1] = _covered[i];
|
|
|
725 _covered[i] = covered_mr;
|
|
|
726 MemRegion committed_mr = _committed[i-1];
|
|
|
727 _committed[i-1] = _committed[i];
|
|
|
728 _committed[i] = committed_mr;
|
|
|
729 break;
|
|
|
730 }
|
|
|
731 }
|
|
|
732 #ifdef ASSERT
|
|
|
733 for (int m = 0; m < _cur_covered_regions-1; m++) {
|
|
|
734 assert(_covered[m].start() <= _covered[m+1].start(),
|
|
|
735 "Covered regions out of order");
|
|
|
736 assert(_committed[m].start() <= _committed[m+1].start(),
|
|
|
737 "Committed regions out of order");
|
|
|
738 }
|
|
|
739 #endif
|
|
|
740 }
|
|
|
741
|
|
|
742 // Returns the start of any committed region that is lower than
|
|
|
743 // the target committed region (index ind) and that intersects the
|
|
|
744 // target region. If none, return start of target region.
|
|
|
745 //
|
|
|
746 // -------------
|
|
|
747 // | |
|
|
|
748 // -------------
|
|
|
749 // ------------
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750 // | target |
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|
|
751 // ------------
|
|
|
752 // -------------
|
|
|
753 // | |
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|
754 // -------------
|
|
|
755 // ^ returns this
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|
|
756 //
|
|
|
757 // -------------
|
|
|
758 // | |
|
|
|
759 // -------------
|
|
|
760 // ------------
|
|
|
761 // | target |
|
|
|
762 // ------------
|
|
|
763 // -------------
|
|
|
764 // | |
|
|
|
765 // -------------
|
|
|
766 // ^ returns this
|
|
|
767
|
|
|
768 HeapWord* CardTableExtension::lowest_prev_committed_start(int ind) const {
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|
|
769 assert(_cur_covered_regions >= 0, "Expecting at least on region");
|
|
|
770 HeapWord* min_start = _committed[ind].start();
|
|
|
771 for (int j = 0; j < ind; j++) {
|
|
|
772 HeapWord* this_start = _committed[j].start();
|
|
|
773 if ((this_start < min_start) &&
|
|
|
774 !(_committed[j].intersection(_committed[ind])).is_empty()) {
|
|
|
775 min_start = this_start;
|
|
|
776 }
|
|
|
777 }
|
|
|
778 return min_start;
|
|
|
779 }
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