0
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1 /*
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2 * Copyright 1997-2006 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/_space.cpp.incl"
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27
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28 HeapWord* DirtyCardToOopClosure::get_actual_top(HeapWord* top,
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29 HeapWord* top_obj) {
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30 if (top_obj != NULL) {
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31 if (_sp->block_is_obj(top_obj)) {
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32 if (_precision == CardTableModRefBS::ObjHeadPreciseArray) {
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33 if (oop(top_obj)->is_objArray() || oop(top_obj)->is_typeArray()) {
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34 // An arrayOop is starting on the dirty card - since we do exact
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35 // store checks for objArrays we are done.
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36 } else {
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37 // Otherwise, it is possible that the object starting on the dirty
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38 // card spans the entire card, and that the store happened on a
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39 // later card. Figure out where the object ends.
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40 // Use the block_size() method of the space over which
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41 // the iteration is being done. That space (e.g. CMS) may have
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42 // specific requirements on object sizes which will
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43 // be reflected in the block_size() method.
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44 top = top_obj + oop(top_obj)->size();
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45 }
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46 }
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47 } else {
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48 top = top_obj;
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49 }
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50 } else {
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51 assert(top == _sp->end(), "only case where top_obj == NULL");
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52 }
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53 return top;
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54 }
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55
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56 void DirtyCardToOopClosure::walk_mem_region(MemRegion mr,
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57 HeapWord* bottom,
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58 HeapWord* top) {
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59 // 1. Blocks may or may not be objects.
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60 // 2. Even when a block_is_obj(), it may not entirely
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61 // occupy the block if the block quantum is larger than
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62 // the object size.
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63 // We can and should try to optimize by calling the non-MemRegion
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64 // version of oop_iterate() for all but the extremal objects
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65 // (for which we need to call the MemRegion version of
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66 // oop_iterate()) To be done post-beta XXX
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67 for (; bottom < top; bottom += _sp->block_size(bottom)) {
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68 // As in the case of contiguous space above, we'd like to
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69 // just use the value returned by oop_iterate to increment the
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70 // current pointer; unfortunately, that won't work in CMS because
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71 // we'd need an interface change (it seems) to have the space
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72 // "adjust the object size" (for instance pad it up to its
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73 // block alignment or minimum block size restrictions. XXX
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74 if (_sp->block_is_obj(bottom) &&
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75 !_sp->obj_allocated_since_save_marks(oop(bottom))) {
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76 oop(bottom)->oop_iterate(_cl, mr);
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77 }
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78 }
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79 }
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80
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81 void DirtyCardToOopClosure::do_MemRegion(MemRegion mr) {
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82
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83 // Some collectors need to do special things whenever their dirty
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84 // cards are processed. For instance, CMS must remember mutator updates
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85 // (i.e. dirty cards) so as to re-scan mutated objects.
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86 // Such work can be piggy-backed here on dirty card scanning, so as to make
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87 // it slightly more efficient than doing a complete non-detructive pre-scan
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88 // of the card table.
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89 MemRegionClosure* pCl = _sp->preconsumptionDirtyCardClosure();
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90 if (pCl != NULL) {
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91 pCl->do_MemRegion(mr);
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92 }
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93
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94 HeapWord* bottom = mr.start();
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95 HeapWord* last = mr.last();
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96 HeapWord* top = mr.end();
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97 HeapWord* bottom_obj;
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98 HeapWord* top_obj;
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99
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100 assert(_precision == CardTableModRefBS::ObjHeadPreciseArray ||
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101 _precision == CardTableModRefBS::Precise,
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102 "Only ones we deal with for now.");
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103
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104 assert(_precision != CardTableModRefBS::ObjHeadPreciseArray ||
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105 _last_bottom == NULL ||
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106 top <= _last_bottom,
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107 "Not decreasing");
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108 NOT_PRODUCT(_last_bottom = mr.start());
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109
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110 bottom_obj = _sp->block_start(bottom);
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111 top_obj = _sp->block_start(last);
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112
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113 assert(bottom_obj <= bottom, "just checking");
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114 assert(top_obj <= top, "just checking");
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115
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116 // Given what we think is the top of the memory region and
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117 // the start of the object at the top, get the actual
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118 // value of the top.
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119 top = get_actual_top(top, top_obj);
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120
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121 // If the previous call did some part of this region, don't redo.
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122 if (_precision == CardTableModRefBS::ObjHeadPreciseArray &&
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123 _min_done != NULL &&
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124 _min_done < top) {
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125 top = _min_done;
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126 }
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127
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128 // Top may have been reset, and in fact may be below bottom,
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129 // e.g. the dirty card region is entirely in a now free object
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130 // -- something that could happen with a concurrent sweeper.
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131 bottom = MIN2(bottom, top);
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132 mr = MemRegion(bottom, top);
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133 assert(bottom <= top &&
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134 (_precision != CardTableModRefBS::ObjHeadPreciseArray ||
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135 _min_done == NULL ||
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136 top <= _min_done),
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137 "overlap!");
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138
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139 // Walk the region if it is not empty; otherwise there is nothing to do.
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140 if (!mr.is_empty()) {
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141 walk_mem_region(mr, bottom_obj, top);
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142 }
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143
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144 _min_done = bottom;
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145 }
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146
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147 DirtyCardToOopClosure* Space::new_dcto_cl(OopClosure* cl,
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148 CardTableModRefBS::PrecisionStyle precision,
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149 HeapWord* boundary) {
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150 return new DirtyCardToOopClosure(this, cl, precision, boundary);
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151 }
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152
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153 void FilteringClosure::do_oop(oop* p) {
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154 do_oop_nv(p);
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155 }
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156
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157 HeapWord* ContiguousSpaceDCTOC::get_actual_top(HeapWord* top,
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158 HeapWord* top_obj) {
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159 if (top_obj != NULL && top_obj < (_sp->toContiguousSpace())->top()) {
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160 if (_precision == CardTableModRefBS::ObjHeadPreciseArray) {
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161 if (oop(top_obj)->is_objArray() || oop(top_obj)->is_typeArray()) {
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162 // An arrayOop is starting on the dirty card - since we do exact
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163 // store checks for objArrays we are done.
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164 } else {
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165 // Otherwise, it is possible that the object starting on the dirty
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166 // card spans the entire card, and that the store happened on a
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167 // later card. Figure out where the object ends.
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168 assert(_sp->block_size(top_obj) == (size_t) oop(top_obj)->size(),
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169 "Block size and object size mismatch");
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170 top = top_obj + oop(top_obj)->size();
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171 }
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172 }
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173 } else {
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174 top = (_sp->toContiguousSpace())->top();
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175 }
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176 return top;
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177 }
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178
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179 void Filtering_DCTOC::walk_mem_region(MemRegion mr,
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180 HeapWord* bottom,
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181 HeapWord* top) {
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182 // Note that this assumption won't hold if we have a concurrent
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183 // collector in this space, which may have freed up objects after
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184 // they were dirtied and before the stop-the-world GC that is
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185 // examining cards here.
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186 assert(bottom < top, "ought to be at least one obj on a dirty card.");
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187
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188 if (_boundary != NULL) {
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189 // We have a boundary outside of which we don't want to look
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190 // at objects, so create a filtering closure around the
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191 // oop closure before walking the region.
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192 FilteringClosure filter(_boundary, _cl);
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193 walk_mem_region_with_cl(mr, bottom, top, &filter);
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194 } else {
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195 // No boundary, simply walk the heap with the oop closure.
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196 walk_mem_region_with_cl(mr, bottom, top, _cl);
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197 }
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198
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199 }
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200
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201 // We must replicate this so that the static type of "FilteringClosure"
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202 // (see above) is apparent at the oop_iterate calls.
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203 #define ContiguousSpaceDCTOC__walk_mem_region_with_cl_DEFN(ClosureType) \
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204 void ContiguousSpaceDCTOC::walk_mem_region_with_cl(MemRegion mr, \
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205 HeapWord* bottom, \
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206 HeapWord* top, \
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207 ClosureType* cl) { \
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208 bottom += oop(bottom)->oop_iterate(cl, mr); \
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209 if (bottom < top) { \
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210 HeapWord* next_obj = bottom + oop(bottom)->size(); \
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211 while (next_obj < top) { \
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212 /* Bottom lies entirely below top, so we can call the */ \
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213 /* non-memRegion version of oop_iterate below. */ \
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214 oop(bottom)->oop_iterate(cl); \
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215 bottom = next_obj; \
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216 next_obj = bottom + oop(bottom)->size(); \
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217 } \
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218 /* Last object. */ \
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219 oop(bottom)->oop_iterate(cl, mr); \
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220 } \
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221 }
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222
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223 // (There are only two of these, rather than N, because the split is due
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224 // only to the introduction of the FilteringClosure, a local part of the
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225 // impl of this abstraction.)
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226 ContiguousSpaceDCTOC__walk_mem_region_with_cl_DEFN(OopClosure)
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227 ContiguousSpaceDCTOC__walk_mem_region_with_cl_DEFN(FilteringClosure)
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228
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229 DirtyCardToOopClosure*
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230 ContiguousSpace::new_dcto_cl(OopClosure* cl,
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231 CardTableModRefBS::PrecisionStyle precision,
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232 HeapWord* boundary) {
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233 return new ContiguousSpaceDCTOC(this, cl, precision, boundary);
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234 }
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235
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236 void Space::initialize(MemRegion mr, bool clear_space) {
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237 HeapWord* bottom = mr.start();
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238 HeapWord* end = mr.end();
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239 assert(Universe::on_page_boundary(bottom) && Universe::on_page_boundary(end),
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240 "invalid space boundaries");
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241 set_bottom(bottom);
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242 set_end(end);
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243 if (clear_space) clear();
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244 }
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245
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246 void Space::clear() {
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247 if (ZapUnusedHeapArea) mangle_unused_area();
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248 }
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249
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250 void ContiguousSpace::initialize(MemRegion mr, bool clear_space)
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251 {
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252 CompactibleSpace::initialize(mr, clear_space);
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253 _concurrent_iteration_safe_limit = top();
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254 }
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255
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256 void ContiguousSpace::clear() {
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257 set_top(bottom());
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258 set_saved_mark();
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259 Space::clear();
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260 }
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261
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262 bool Space::is_in(const void* p) const {
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263 HeapWord* b = block_start(p);
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264 return b != NULL && block_is_obj(b);
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265 }
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266
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267 bool ContiguousSpace::is_in(const void* p) const {
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268 return _bottom <= p && p < _top;
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269 }
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270
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271 bool ContiguousSpace::is_free_block(const HeapWord* p) const {
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272 return p >= _top;
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273 }
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274
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275 void OffsetTableContigSpace::clear() {
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276 ContiguousSpace::clear();
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277 _offsets.initialize_threshold();
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278 }
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279
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280 void OffsetTableContigSpace::set_bottom(HeapWord* new_bottom) {
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281 Space::set_bottom(new_bottom);
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282 _offsets.set_bottom(new_bottom);
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283 }
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284
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285 void OffsetTableContigSpace::set_end(HeapWord* new_end) {
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286 // Space should not advertize an increase in size
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287 // until after the underlying offest table has been enlarged.
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288 _offsets.resize(pointer_delta(new_end, bottom()));
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289 Space::set_end(new_end);
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290 }
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291
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292 void ContiguousSpace::mangle_unused_area() {
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293 // to-space is used for storing marks during mark-sweep
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294 mangle_region(MemRegion(top(), end()));
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295 }
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296
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297 void ContiguousSpace::mangle_region(MemRegion mr) {
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298 debug_only(Copy::fill_to_words(mr.start(), mr.word_size(), badHeapWord));
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299 }
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300
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301 void CompactibleSpace::initialize(MemRegion mr, bool clear_space) {
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302 Space::initialize(mr, clear_space);
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303 _compaction_top = bottom();
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304 _next_compaction_space = NULL;
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305 }
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306
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307 HeapWord* CompactibleSpace::forward(oop q, size_t size,
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308 CompactPoint* cp, HeapWord* compact_top) {
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309 // q is alive
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310 // First check if we should switch compaction space
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311 assert(this == cp->space, "'this' should be current compaction space.");
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312 size_t compaction_max_size = pointer_delta(end(), compact_top);
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313 while (size > compaction_max_size) {
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314 // switch to next compaction space
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315 cp->space->set_compaction_top(compact_top);
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316 cp->space = cp->space->next_compaction_space();
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317 if (cp->space == NULL) {
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318 cp->gen = GenCollectedHeap::heap()->prev_gen(cp->gen);
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319 assert(cp->gen != NULL, "compaction must succeed");
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320 cp->space = cp->gen->first_compaction_space();
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321 assert(cp->space != NULL, "generation must have a first compaction space");
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322 }
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323 compact_top = cp->space->bottom();
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324 cp->space->set_compaction_top(compact_top);
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325 cp->threshold = cp->space->initialize_threshold();
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326 compaction_max_size = pointer_delta(cp->space->end(), compact_top);
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327 }
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328
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329 // store the forwarding pointer into the mark word
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330 if ((HeapWord*)q != compact_top) {
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331 q->forward_to(oop(compact_top));
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332 assert(q->is_gc_marked(), "encoding the pointer should preserve the mark");
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333 } else {
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334 // if the object isn't moving we can just set the mark to the default
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335 // mark and handle it specially later on.
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336 q->init_mark();
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337 assert(q->forwardee() == NULL, "should be forwarded to NULL");
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338 }
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339
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340 debug_only(MarkSweep::register_live_oop(q, size));
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341 compact_top += size;
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342
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343 // we need to update the offset table so that the beginnings of objects can be
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344 // found during scavenge. Note that we are updating the offset table based on
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345 // where the object will be once the compaction phase finishes.
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346 if (compact_top > cp->threshold)
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347 cp->threshold =
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348 cp->space->cross_threshold(compact_top - size, compact_top);
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349 return compact_top;
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350 }
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351
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352
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353 bool CompactibleSpace::insert_deadspace(size_t& allowed_deadspace_words,
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354 HeapWord* q, size_t deadlength) {
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355 if (allowed_deadspace_words >= deadlength) {
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356 allowed_deadspace_words -= deadlength;
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357 oop(q)->set_mark(markOopDesc::prototype()->set_marked());
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358 const size_t min_int_array_size = typeArrayOopDesc::header_size(T_INT);
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359 if (deadlength >= min_int_array_size) {
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360 oop(q)->set_klass(Universe::intArrayKlassObj());
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361 typeArrayOop(q)->set_length((int)((deadlength - min_int_array_size)
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362 * (HeapWordSize/sizeof(jint))));
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363 } else {
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364 assert((int) deadlength == instanceOopDesc::header_size(),
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365 "size for smallest fake dead object doesn't match");
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366 oop(q)->set_klass(SystemDictionary::object_klass());
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367 }
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368 assert((int) deadlength == oop(q)->size(),
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369 "make sure size for fake dead object match");
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370 // Recall that we required "q == compaction_top".
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371 return true;
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372 } else {
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373 allowed_deadspace_words = 0;
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374 return false;
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375 }
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376 }
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377
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378 #define block_is_always_obj(q) true
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379 #define obj_size(q) oop(q)->size()
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380 #define adjust_obj_size(s) s
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381
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382 void CompactibleSpace::prepare_for_compaction(CompactPoint* cp) {
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383 SCAN_AND_FORWARD(cp, end, block_is_obj, block_size);
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384 }
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385
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386 // Faster object search.
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387 void ContiguousSpace::prepare_for_compaction(CompactPoint* cp) {
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388 SCAN_AND_FORWARD(cp, top, block_is_always_obj, obj_size);
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389 }
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390
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391 void Space::adjust_pointers() {
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392 // adjust all the interior pointers to point at the new locations of objects
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393 // Used by MarkSweep::mark_sweep_phase3()
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394
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395 // First check to see if there is any work to be done.
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396 if (used() == 0) {
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397 return; // Nothing to do.
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398 }
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399
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400 // Otherwise...
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401 HeapWord* q = bottom();
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402 HeapWord* t = end();
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403
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404 debug_only(HeapWord* prev_q = NULL);
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405 while (q < t) {
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406 if (oop(q)->is_gc_marked()) {
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407 // q is alive
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408
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409 debug_only(MarkSweep::track_interior_pointers(oop(q)));
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410 // point all the oops to the new location
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411 size_t size = oop(q)->adjust_pointers();
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412 debug_only(MarkSweep::check_interior_pointers());
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413
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414 debug_only(prev_q = q);
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415 debug_only(MarkSweep::validate_live_oop(oop(q), size));
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416
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417 q += size;
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418 } else {
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419 // q is not a live object. But we're not in a compactible space,
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420 // So we don't have live ranges.
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421 debug_only(prev_q = q);
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422 q += block_size(q);
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423 assert(q > prev_q, "we should be moving forward through memory");
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424 }
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425 }
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426 assert(q == t, "just checking");
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427 }
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428
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429 void CompactibleSpace::adjust_pointers() {
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430 // Check first is there is any work to do.
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431 if (used() == 0) {
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432 return; // Nothing to do.
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433 }
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434
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435 SCAN_AND_ADJUST_POINTERS(adjust_obj_size);
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436 }
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437
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438 void CompactibleSpace::compact() {
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439 SCAN_AND_COMPACT(obj_size);
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440 }
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441
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442 void Space::print_short() const { print_short_on(tty); }
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443
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444 void Space::print_short_on(outputStream* st) const {
|
|
445 st->print(" space " SIZE_FORMAT "K, %3d%% used", capacity() / K,
|
|
446 (int) ((double) used() * 100 / capacity()));
|
|
447 }
|
|
448
|
|
449 void Space::print() const { print_on(tty); }
|
|
450
|
|
451 void Space::print_on(outputStream* st) const {
|
|
452 print_short_on(st);
|
|
453 st->print_cr(" [" INTPTR_FORMAT ", " INTPTR_FORMAT ")",
|
|
454 bottom(), end());
|
|
455 }
|
|
456
|
|
457 void ContiguousSpace::print_on(outputStream* st) const {
|
|
458 print_short_on(st);
|
|
459 st->print_cr(" [" INTPTR_FORMAT ", " INTPTR_FORMAT ", " INTPTR_FORMAT ")",
|
|
460 bottom(), top(), end());
|
|
461 }
|
|
462
|
|
463 void OffsetTableContigSpace::print_on(outputStream* st) const {
|
|
464 print_short_on(st);
|
|
465 st->print_cr(" [" INTPTR_FORMAT ", " INTPTR_FORMAT ", "
|
|
466 INTPTR_FORMAT ", " INTPTR_FORMAT ")",
|
|
467 bottom(), top(), _offsets.threshold(), end());
|
|
468 }
|
|
469
|
|
470 void ContiguousSpace::verify(bool allow_dirty) const {
|
|
471 HeapWord* p = bottom();
|
|
472 HeapWord* t = top();
|
|
473 HeapWord* prev_p = NULL;
|
|
474 while (p < t) {
|
|
475 oop(p)->verify();
|
|
476 prev_p = p;
|
|
477 p += oop(p)->size();
|
|
478 }
|
|
479 guarantee(p == top(), "end of last object must match end of space");
|
|
480 if (top() != end()) {
|
|
481 guarantee(top() == block_start(end()-1) &&
|
|
482 top() == block_start(top()),
|
|
483 "top should be start of unallocated block, if it exists");
|
|
484 }
|
|
485 }
|
|
486
|
|
487 void Space::oop_iterate(OopClosure* blk) {
|
|
488 ObjectToOopClosure blk2(blk);
|
|
489 object_iterate(&blk2);
|
|
490 }
|
|
491
|
|
492 HeapWord* Space::object_iterate_careful(ObjectClosureCareful* cl) {
|
|
493 guarantee(false, "NYI");
|
|
494 return bottom();
|
|
495 }
|
|
496
|
|
497 HeapWord* Space::object_iterate_careful_m(MemRegion mr,
|
|
498 ObjectClosureCareful* cl) {
|
|
499 guarantee(false, "NYI");
|
|
500 return bottom();
|
|
501 }
|
|
502
|
|
503
|
|
504 void Space::object_iterate_mem(MemRegion mr, UpwardsObjectClosure* cl) {
|
|
505 assert(!mr.is_empty(), "Should be non-empty");
|
|
506 // We use MemRegion(bottom(), end()) rather than used_region() below
|
|
507 // because the two are not necessarily equal for some kinds of
|
|
508 // spaces, in particular, certain kinds of free list spaces.
|
|
509 // We could use the more complicated but more precise:
|
|
510 // MemRegion(used_region().start(), round_to(used_region().end(), CardSize))
|
|
511 // but the slight imprecision seems acceptable in the assertion check.
|
|
512 assert(MemRegion(bottom(), end()).contains(mr),
|
|
513 "Should be within used space");
|
|
514 HeapWord* prev = cl->previous(); // max address from last time
|
|
515 if (prev >= mr.end()) { // nothing to do
|
|
516 return;
|
|
517 }
|
|
518 // This assert will not work when we go from cms space to perm
|
|
519 // space, and use same closure. Easy fix deferred for later. XXX YSR
|
|
520 // assert(prev == NULL || contains(prev), "Should be within space");
|
|
521
|
|
522 bool last_was_obj_array = false;
|
|
523 HeapWord *blk_start_addr, *region_start_addr;
|
|
524 if (prev > mr.start()) {
|
|
525 region_start_addr = prev;
|
|
526 blk_start_addr = prev;
|
|
527 assert(blk_start_addr == block_start(region_start_addr), "invariant");
|
|
528 } else {
|
|
529 region_start_addr = mr.start();
|
|
530 blk_start_addr = block_start(region_start_addr);
|
|
531 }
|
|
532 HeapWord* region_end_addr = mr.end();
|
|
533 MemRegion derived_mr(region_start_addr, region_end_addr);
|
|
534 while (blk_start_addr < region_end_addr) {
|
|
535 const size_t size = block_size(blk_start_addr);
|
|
536 if (block_is_obj(blk_start_addr)) {
|
|
537 last_was_obj_array = cl->do_object_bm(oop(blk_start_addr), derived_mr);
|
|
538 } else {
|
|
539 last_was_obj_array = false;
|
|
540 }
|
|
541 blk_start_addr += size;
|
|
542 }
|
|
543 if (!last_was_obj_array) {
|
|
544 assert((bottom() <= blk_start_addr) && (blk_start_addr <= end()),
|
|
545 "Should be within (closed) used space");
|
|
546 assert(blk_start_addr > prev, "Invariant");
|
|
547 cl->set_previous(blk_start_addr); // min address for next time
|
|
548 }
|
|
549 }
|
|
550
|
|
551 bool Space::obj_is_alive(const HeapWord* p) const {
|
|
552 assert (block_is_obj(p), "The address should point to an object");
|
|
553 return true;
|
|
554 }
|
|
555
|
|
556 void ContiguousSpace::object_iterate_mem(MemRegion mr, UpwardsObjectClosure* cl) {
|
|
557 assert(!mr.is_empty(), "Should be non-empty");
|
|
558 assert(used_region().contains(mr), "Should be within used space");
|
|
559 HeapWord* prev = cl->previous(); // max address from last time
|
|
560 if (prev >= mr.end()) { // nothing to do
|
|
561 return;
|
|
562 }
|
|
563 // See comment above (in more general method above) in case you
|
|
564 // happen to use this method.
|
|
565 assert(prev == NULL || is_in_reserved(prev), "Should be within space");
|
|
566
|
|
567 bool last_was_obj_array = false;
|
|
568 HeapWord *obj_start_addr, *region_start_addr;
|
|
569 if (prev > mr.start()) {
|
|
570 region_start_addr = prev;
|
|
571 obj_start_addr = prev;
|
|
572 assert(obj_start_addr == block_start(region_start_addr), "invariant");
|
|
573 } else {
|
|
574 region_start_addr = mr.start();
|
|
575 obj_start_addr = block_start(region_start_addr);
|
|
576 }
|
|
577 HeapWord* region_end_addr = mr.end();
|
|
578 MemRegion derived_mr(region_start_addr, region_end_addr);
|
|
579 while (obj_start_addr < region_end_addr) {
|
|
580 oop obj = oop(obj_start_addr);
|
|
581 const size_t size = obj->size();
|
|
582 last_was_obj_array = cl->do_object_bm(obj, derived_mr);
|
|
583 obj_start_addr += size;
|
|
584 }
|
|
585 if (!last_was_obj_array) {
|
|
586 assert((bottom() <= obj_start_addr) && (obj_start_addr <= end()),
|
|
587 "Should be within (closed) used space");
|
|
588 assert(obj_start_addr > prev, "Invariant");
|
|
589 cl->set_previous(obj_start_addr); // min address for next time
|
|
590 }
|
|
591 }
|
|
592
|
|
593 #ifndef SERIALGC
|
|
594 #define ContigSpace_PAR_OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \
|
|
595 \
|
|
596 void ContiguousSpace::par_oop_iterate(MemRegion mr, OopClosureType* blk) {\
|
|
597 HeapWord* obj_addr = mr.start(); \
|
|
598 HeapWord* t = mr.end(); \
|
|
599 while (obj_addr < t) { \
|
|
600 assert(oop(obj_addr)->is_oop(), "Should be an oop"); \
|
|
601 obj_addr += oop(obj_addr)->oop_iterate(blk); \
|
|
602 } \
|
|
603 }
|
|
604
|
|
605 ALL_PAR_OOP_ITERATE_CLOSURES(ContigSpace_PAR_OOP_ITERATE_DEFN)
|
|
606
|
|
607 #undef ContigSpace_PAR_OOP_ITERATE_DEFN
|
|
608 #endif // SERIALGC
|
|
609
|
|
610 void ContiguousSpace::oop_iterate(OopClosure* blk) {
|
|
611 if (is_empty()) return;
|
|
612 HeapWord* obj_addr = bottom();
|
|
613 HeapWord* t = top();
|
|
614 // Could call objects iterate, but this is easier.
|
|
615 while (obj_addr < t) {
|
|
616 obj_addr += oop(obj_addr)->oop_iterate(blk);
|
|
617 }
|
|
618 }
|
|
619
|
|
620 void ContiguousSpace::oop_iterate(MemRegion mr, OopClosure* blk) {
|
|
621 if (is_empty()) {
|
|
622 return;
|
|
623 }
|
|
624 MemRegion cur = MemRegion(bottom(), top());
|
|
625 mr = mr.intersection(cur);
|
|
626 if (mr.is_empty()) {
|
|
627 return;
|
|
628 }
|
|
629 if (mr.equals(cur)) {
|
|
630 oop_iterate(blk);
|
|
631 return;
|
|
632 }
|
|
633 assert(mr.end() <= top(), "just took an intersection above");
|
|
634 HeapWord* obj_addr = block_start(mr.start());
|
|
635 HeapWord* t = mr.end();
|
|
636
|
|
637 // Handle first object specially.
|
|
638 oop obj = oop(obj_addr);
|
|
639 SpaceMemRegionOopsIterClosure smr_blk(blk, mr);
|
|
640 obj_addr += obj->oop_iterate(&smr_blk);
|
|
641 while (obj_addr < t) {
|
|
642 oop obj = oop(obj_addr);
|
|
643 assert(obj->is_oop(), "expected an oop");
|
|
644 obj_addr += obj->size();
|
|
645 // If "obj_addr" is not greater than top, then the
|
|
646 // entire object "obj" is within the region.
|
|
647 if (obj_addr <= t) {
|
|
648 obj->oop_iterate(blk);
|
|
649 } else {
|
|
650 // "obj" extends beyond end of region
|
|
651 obj->oop_iterate(&smr_blk);
|
|
652 break;
|
|
653 }
|
|
654 };
|
|
655 }
|
|
656
|
|
657 void ContiguousSpace::object_iterate(ObjectClosure* blk) {
|
|
658 if (is_empty()) return;
|
|
659 WaterMark bm = bottom_mark();
|
|
660 object_iterate_from(bm, blk);
|
|
661 }
|
|
662
|
|
663 void ContiguousSpace::object_iterate_from(WaterMark mark, ObjectClosure* blk) {
|
|
664 assert(mark.space() == this, "Mark does not match space");
|
|
665 HeapWord* p = mark.point();
|
|
666 while (p < top()) {
|
|
667 blk->do_object(oop(p));
|
|
668 p += oop(p)->size();
|
|
669 }
|
|
670 }
|
|
671
|
|
672 HeapWord*
|
|
673 ContiguousSpace::object_iterate_careful(ObjectClosureCareful* blk) {
|
|
674 HeapWord * limit = concurrent_iteration_safe_limit();
|
|
675 assert(limit <= top(), "sanity check");
|
|
676 for (HeapWord* p = bottom(); p < limit;) {
|
|
677 size_t size = blk->do_object_careful(oop(p));
|
|
678 if (size == 0) {
|
|
679 return p; // failed at p
|
|
680 } else {
|
|
681 p += size;
|
|
682 }
|
|
683 }
|
|
684 return NULL; // all done
|
|
685 }
|
|
686
|
|
687 #define ContigSpace_OOP_SINCE_SAVE_MARKS_DEFN(OopClosureType, nv_suffix) \
|
|
688 \
|
|
689 void ContiguousSpace:: \
|
|
690 oop_since_save_marks_iterate##nv_suffix(OopClosureType* blk) { \
|
|
691 HeapWord* t; \
|
|
692 HeapWord* p = saved_mark_word(); \
|
|
693 assert(p != NULL, "expected saved mark"); \
|
|
694 \
|
|
695 const intx interval = PrefetchScanIntervalInBytes; \
|
|
696 do { \
|
|
697 t = top(); \
|
|
698 while (p < t) { \
|
|
699 Prefetch::write(p, interval); \
|
|
700 debug_only(HeapWord* prev = p); \
|
|
701 oop m = oop(p); \
|
|
702 p += m->oop_iterate(blk); \
|
|
703 } \
|
|
704 } while (t < top()); \
|
|
705 \
|
|
706 set_saved_mark_word(p); \
|
|
707 }
|
|
708
|
|
709 ALL_SINCE_SAVE_MARKS_CLOSURES(ContigSpace_OOP_SINCE_SAVE_MARKS_DEFN)
|
|
710
|
|
711 #undef ContigSpace_OOP_SINCE_SAVE_MARKS_DEFN
|
|
712
|
|
713 // Very general, slow implementation.
|
|
714 HeapWord* ContiguousSpace::block_start(const void* p) const {
|
|
715 assert(MemRegion(bottom(), end()).contains(p), "p not in space");
|
|
716 if (p >= top()) {
|
|
717 return top();
|
|
718 } else {
|
|
719 HeapWord* last = bottom();
|
|
720 HeapWord* cur = last;
|
|
721 while (cur <= p) {
|
|
722 last = cur;
|
|
723 cur += oop(cur)->size();
|
|
724 }
|
|
725 assert(oop(last)->is_oop(), "Should be an object start");
|
|
726 return last;
|
|
727 }
|
|
728 }
|
|
729
|
|
730 size_t ContiguousSpace::block_size(const HeapWord* p) const {
|
|
731 assert(MemRegion(bottom(), end()).contains(p), "p not in space");
|
|
732 HeapWord* current_top = top();
|
|
733 assert(p <= current_top, "p is not a block start");
|
|
734 assert(p == current_top || oop(p)->is_oop(), "p is not a block start");
|
|
735 if (p < current_top)
|
|
736 return oop(p)->size();
|
|
737 else {
|
|
738 assert(p == current_top, "just checking");
|
|
739 return pointer_delta(end(), (HeapWord*) p);
|
|
740 }
|
|
741 }
|
|
742
|
|
743 // This version requires locking.
|
|
744 inline HeapWord* ContiguousSpace::allocate_impl(size_t size,
|
|
745 HeapWord* const end_value) {
|
|
746 assert(Heap_lock->owned_by_self() ||
|
|
747 (SafepointSynchronize::is_at_safepoint() &&
|
|
748 Thread::current()->is_VM_thread()),
|
|
749 "not locked");
|
|
750 HeapWord* obj = top();
|
|
751 if (pointer_delta(end_value, obj) >= size) {
|
|
752 HeapWord* new_top = obj + size;
|
|
753 set_top(new_top);
|
|
754 assert(is_aligned(obj) && is_aligned(new_top), "checking alignment");
|
|
755 return obj;
|
|
756 } else {
|
|
757 return NULL;
|
|
758 }
|
|
759 }
|
|
760
|
|
761 // This version is lock-free.
|
|
762 inline HeapWord* ContiguousSpace::par_allocate_impl(size_t size,
|
|
763 HeapWord* const end_value) {
|
|
764 do {
|
|
765 HeapWord* obj = top();
|
|
766 if (pointer_delta(end_value, obj) >= size) {
|
|
767 HeapWord* new_top = obj + size;
|
|
768 HeapWord* result = (HeapWord*)Atomic::cmpxchg_ptr(new_top, top_addr(), obj);
|
|
769 // result can be one of two:
|
|
770 // the old top value: the exchange succeeded
|
|
771 // otherwise: the new value of the top is returned.
|
|
772 if (result == obj) {
|
|
773 assert(is_aligned(obj) && is_aligned(new_top), "checking alignment");
|
|
774 return obj;
|
|
775 }
|
|
776 } else {
|
|
777 return NULL;
|
|
778 }
|
|
779 } while (true);
|
|
780 }
|
|
781
|
|
782 // Requires locking.
|
|
783 HeapWord* ContiguousSpace::allocate(size_t size) {
|
|
784 return allocate_impl(size, end());
|
|
785 }
|
|
786
|
|
787 // Lock-free.
|
|
788 HeapWord* ContiguousSpace::par_allocate(size_t size) {
|
|
789 return par_allocate_impl(size, end());
|
|
790 }
|
|
791
|
|
792 void ContiguousSpace::allocate_temporary_filler(int factor) {
|
|
793 // allocate temporary type array decreasing free size with factor 'factor'
|
|
794 assert(factor >= 0, "just checking");
|
|
795 size_t size = pointer_delta(end(), top());
|
|
796
|
|
797 // if space is full, return
|
|
798 if (size == 0) return;
|
|
799
|
|
800 if (factor > 0) {
|
|
801 size -= size/factor;
|
|
802 }
|
|
803 size = align_object_size(size);
|
|
804
|
|
805 const size_t min_int_array_size = typeArrayOopDesc::header_size(T_INT);
|
|
806 if (size >= min_int_array_size) {
|
|
807 size_t length = (size - min_int_array_size) * (HeapWordSize / sizeof(jint));
|
|
808 // allocate uninitialized int array
|
|
809 typeArrayOop t = (typeArrayOop) allocate(size);
|
|
810 assert(t != NULL, "allocation should succeed");
|
|
811 t->set_mark(markOopDesc::prototype());
|
|
812 t->set_klass(Universe::intArrayKlassObj());
|
|
813 t->set_length((int)length);
|
|
814 } else {
|
|
815 assert((int) size == instanceOopDesc::header_size(),
|
|
816 "size for smallest fake object doesn't match");
|
|
817 instanceOop obj = (instanceOop) allocate(size);
|
|
818 obj->set_mark(markOopDesc::prototype());
|
|
819 obj->set_klass(SystemDictionary::object_klass());
|
|
820 }
|
|
821 }
|
|
822
|
|
823 void EdenSpace::clear() {
|
|
824 ContiguousSpace::clear();
|
|
825 set_soft_end(end());
|
|
826 }
|
|
827
|
|
828 // Requires locking.
|
|
829 HeapWord* EdenSpace::allocate(size_t size) {
|
|
830 return allocate_impl(size, soft_end());
|
|
831 }
|
|
832
|
|
833 // Lock-free.
|
|
834 HeapWord* EdenSpace::par_allocate(size_t size) {
|
|
835 return par_allocate_impl(size, soft_end());
|
|
836 }
|
|
837
|
|
838 HeapWord* ConcEdenSpace::par_allocate(size_t size)
|
|
839 {
|
|
840 do {
|
|
841 // The invariant is top() should be read before end() because
|
|
842 // top() can't be greater than end(), so if an update of _soft_end
|
|
843 // occurs between 'end_val = end();' and 'top_val = top();' top()
|
|
844 // also can grow up to the new end() and the condition
|
|
845 // 'top_val > end_val' is true. To ensure the loading order
|
|
846 // OrderAccess::loadload() is required after top() read.
|
|
847 HeapWord* obj = top();
|
|
848 OrderAccess::loadload();
|
|
849 if (pointer_delta(*soft_end_addr(), obj) >= size) {
|
|
850 HeapWord* new_top = obj + size;
|
|
851 HeapWord* result = (HeapWord*)Atomic::cmpxchg_ptr(new_top, top_addr(), obj);
|
|
852 // result can be one of two:
|
|
853 // the old top value: the exchange succeeded
|
|
854 // otherwise: the new value of the top is returned.
|
|
855 if (result == obj) {
|
|
856 assert(is_aligned(obj) && is_aligned(new_top), "checking alignment");
|
|
857 return obj;
|
|
858 }
|
|
859 } else {
|
|
860 return NULL;
|
|
861 }
|
|
862 } while (true);
|
|
863 }
|
|
864
|
|
865
|
|
866 HeapWord* OffsetTableContigSpace::initialize_threshold() {
|
|
867 return _offsets.initialize_threshold();
|
|
868 }
|
|
869
|
|
870 HeapWord* OffsetTableContigSpace::cross_threshold(HeapWord* start, HeapWord* end) {
|
|
871 _offsets.alloc_block(start, end);
|
|
872 return _offsets.threshold();
|
|
873 }
|
|
874
|
|
875 OffsetTableContigSpace::OffsetTableContigSpace(BlockOffsetSharedArray* sharedOffsetArray,
|
|
876 MemRegion mr) :
|
|
877 _offsets(sharedOffsetArray, mr),
|
|
878 _par_alloc_lock(Mutex::leaf, "OffsetTableContigSpace par alloc lock", true)
|
|
879 {
|
|
880 _offsets.set_contig_space(this);
|
|
881 initialize(mr, true);
|
|
882 }
|
|
883
|
|
884
|
|
885 class VerifyOldOopClosure : public OopClosure {
|
|
886 public:
|
|
887 oop the_obj;
|
|
888 bool allow_dirty;
|
|
889 void do_oop(oop* p) {
|
|
890 the_obj->verify_old_oop(p, allow_dirty);
|
|
891 }
|
|
892 };
|
|
893
|
|
894 #define OBJ_SAMPLE_INTERVAL 0
|
|
895 #define BLOCK_SAMPLE_INTERVAL 100
|
|
896
|
|
897 void OffsetTableContigSpace::verify(bool allow_dirty) const {
|
|
898 HeapWord* p = bottom();
|
|
899 HeapWord* prev_p = NULL;
|
|
900 VerifyOldOopClosure blk; // Does this do anything?
|
|
901 blk.allow_dirty = allow_dirty;
|
|
902 int objs = 0;
|
|
903 int blocks = 0;
|
|
904
|
|
905 if (VerifyObjectStartArray) {
|
|
906 _offsets.verify();
|
|
907 }
|
|
908
|
|
909 while (p < top()) {
|
|
910 size_t size = oop(p)->size();
|
|
911 // For a sampling of objects in the space, find it using the
|
|
912 // block offset table.
|
|
913 if (blocks == BLOCK_SAMPLE_INTERVAL) {
|
|
914 guarantee(p == block_start(p + (size/2)), "check offset computation");
|
|
915 blocks = 0;
|
|
916 } else {
|
|
917 blocks++;
|
|
918 }
|
|
919
|
|
920 if (objs == OBJ_SAMPLE_INTERVAL) {
|
|
921 oop(p)->verify();
|
|
922 blk.the_obj = oop(p);
|
|
923 oop(p)->oop_iterate(&blk);
|
|
924 objs = 0;
|
|
925 } else {
|
|
926 objs++;
|
|
927 }
|
|
928 prev_p = p;
|
|
929 p += size;
|
|
930 }
|
|
931 guarantee(p == top(), "end of last object must match end of space");
|
|
932 }
|
|
933
|
|
934 void OffsetTableContigSpace::serialize_block_offset_array_offsets(
|
|
935 SerializeOopClosure* soc) {
|
|
936 _offsets.serialize(soc);
|
|
937 }
|
|
938
|
|
939
|
|
940 int TenuredSpace::allowed_dead_ratio() const {
|
|
941 return MarkSweepDeadRatio;
|
|
942 }
|
|
943
|
|
944
|
|
945 int ContigPermSpace::allowed_dead_ratio() const {
|
|
946 return PermMarkSweepDeadRatio;
|
|
947 }
|