26 #define SHARE_VM_MEMORY_SPACE_INLINE_HPP |
26 #define SHARE_VM_MEMORY_SPACE_INLINE_HPP |
27 |
27 |
28 #include "gc_interface/collectedHeap.hpp" |
28 #include "gc_interface/collectedHeap.hpp" |
29 #include "memory/space.hpp" |
29 #include "memory/space.hpp" |
30 #include "memory/universe.hpp" |
30 #include "memory/universe.hpp" |
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31 #include "runtime/prefetch.inline.hpp" |
31 #include "runtime/safepoint.hpp" |
32 #include "runtime/safepoint.hpp" |
32 |
33 |
33 inline HeapWord* Space::block_start(const void* p) { |
34 inline HeapWord* Space::block_start(const void* p) { |
34 return block_start_const(p); |
35 return block_start_const(p); |
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36 } |
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37 |
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38 #define SCAN_AND_FORWARD(cp,scan_limit,block_is_obj,block_size) { \ |
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39 /* Compute the new addresses for the live objects and store it in the mark \ |
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40 * Used by universe::mark_sweep_phase2() \ |
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41 */ \ |
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42 HeapWord* compact_top; /* This is where we are currently compacting to. */ \ |
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43 \ |
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44 /* We're sure to be here before any objects are compacted into this \ |
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45 * space, so this is a good time to initialize this: \ |
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46 */ \ |
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47 set_compaction_top(bottom()); \ |
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48 \ |
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49 if (cp->space == NULL) { \ |
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50 assert(cp->gen != NULL, "need a generation"); \ |
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51 assert(cp->threshold == NULL, "just checking"); \ |
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52 assert(cp->gen->first_compaction_space() == this, "just checking"); \ |
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53 cp->space = cp->gen->first_compaction_space(); \ |
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54 compact_top = cp->space->bottom(); \ |
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55 cp->space->set_compaction_top(compact_top); \ |
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56 cp->threshold = cp->space->initialize_threshold(); \ |
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57 } else { \ |
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58 compact_top = cp->space->compaction_top(); \ |
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59 } \ |
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60 \ |
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61 /* We allow some amount of garbage towards the bottom of the space, so \ |
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62 * we don't start compacting before there is a significant gain to be made.\ |
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63 * Occasionally, we want to ensure a full compaction, which is determined \ |
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64 * by the MarkSweepAlwaysCompactCount parameter. \ |
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65 */ \ |
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66 uint invocations = MarkSweep::total_invocations(); \ |
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67 bool skip_dead = ((invocations % MarkSweepAlwaysCompactCount) != 0); \ |
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68 \ |
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69 size_t allowed_deadspace = 0; \ |
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70 if (skip_dead) { \ |
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71 const size_t ratio = allowed_dead_ratio(); \ |
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72 allowed_deadspace = (capacity() * ratio / 100) / HeapWordSize; \ |
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73 } \ |
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74 \ |
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75 HeapWord* q = bottom(); \ |
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76 HeapWord* t = scan_limit(); \ |
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77 \ |
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78 HeapWord* end_of_live= q; /* One byte beyond the last byte of the last \ |
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79 live object. */ \ |
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80 HeapWord* first_dead = end();/* The first dead object. */ \ |
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81 LiveRange* liveRange = NULL; /* The current live range, recorded in the \ |
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82 first header of preceding free area. */ \ |
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83 _first_dead = first_dead; \ |
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84 \ |
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85 const intx interval = PrefetchScanIntervalInBytes; \ |
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86 \ |
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87 while (q < t) { \ |
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88 assert(!block_is_obj(q) || \ |
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89 oop(q)->mark()->is_marked() || oop(q)->mark()->is_unlocked() || \ |
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90 oop(q)->mark()->has_bias_pattern(), \ |
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91 "these are the only valid states during a mark sweep"); \ |
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92 if (block_is_obj(q) && oop(q)->is_gc_marked()) { \ |
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93 /* prefetch beyond q */ \ |
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94 Prefetch::write(q, interval); \ |
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95 size_t size = block_size(q); \ |
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96 compact_top = cp->space->forward(oop(q), size, cp, compact_top); \ |
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97 q += size; \ |
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98 end_of_live = q; \ |
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99 } else { \ |
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100 /* run over all the contiguous dead objects */ \ |
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101 HeapWord* end = q; \ |
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102 do { \ |
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103 /* prefetch beyond end */ \ |
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104 Prefetch::write(end, interval); \ |
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105 end += block_size(end); \ |
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106 } while (end < t && (!block_is_obj(end) || !oop(end)->is_gc_marked()));\ |
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107 \ |
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108 /* see if we might want to pretend this object is alive so that \ |
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109 * we don't have to compact quite as often. \ |
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110 */ \ |
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111 if (allowed_deadspace > 0 && q == compact_top) { \ |
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112 size_t sz = pointer_delta(end, q); \ |
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113 if (insert_deadspace(allowed_deadspace, q, sz)) { \ |
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114 compact_top = cp->space->forward(oop(q), sz, cp, compact_top); \ |
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115 q = end; \ |
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116 end_of_live = end; \ |
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117 continue; \ |
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118 } \ |
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119 } \ |
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120 \ |
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121 /* otherwise, it really is a free region. */ \ |
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122 \ |
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123 /* for the previous LiveRange, record the end of the live objects. */ \ |
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124 if (liveRange) { \ |
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125 liveRange->set_end(q); \ |
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126 } \ |
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127 \ |
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128 /* record the current LiveRange object. \ |
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129 * liveRange->start() is overlaid on the mark word. \ |
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130 */ \ |
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131 liveRange = (LiveRange*)q; \ |
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132 liveRange->set_start(end); \ |
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133 liveRange->set_end(end); \ |
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134 \ |
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135 /* see if this is the first dead region. */ \ |
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136 if (q < first_dead) { \ |
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137 first_dead = q; \ |
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138 } \ |
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139 \ |
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140 /* move on to the next object */ \ |
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141 q = end; \ |
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142 } \ |
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143 } \ |
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144 \ |
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145 assert(q == t, "just checking"); \ |
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146 if (liveRange != NULL) { \ |
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147 liveRange->set_end(q); \ |
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148 } \ |
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149 _end_of_live = end_of_live; \ |
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150 if (end_of_live < first_dead) { \ |
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151 first_dead = end_of_live; \ |
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152 } \ |
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153 _first_dead = first_dead; \ |
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154 \ |
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155 /* save the compaction_top of the compaction space. */ \ |
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156 cp->space->set_compaction_top(compact_top); \ |
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157 } |
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158 |
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159 #define SCAN_AND_ADJUST_POINTERS(adjust_obj_size) { \ |
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160 /* adjust all the interior pointers to point at the new locations of objects \ |
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161 * Used by MarkSweep::mark_sweep_phase3() */ \ |
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162 \ |
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163 HeapWord* q = bottom(); \ |
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164 HeapWord* t = _end_of_live; /* Established by "prepare_for_compaction". */ \ |
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165 \ |
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166 assert(_first_dead <= _end_of_live, "Stands to reason, no?"); \ |
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167 \ |
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168 if (q < t && _first_dead > q && \ |
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169 !oop(q)->is_gc_marked()) { \ |
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170 /* we have a chunk of the space which hasn't moved and we've \ |
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171 * reinitialized the mark word during the previous pass, so we can't \ |
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172 * use is_gc_marked for the traversal. */ \ |
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173 HeapWord* end = _first_dead; \ |
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174 \ |
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175 while (q < end) { \ |
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176 /* I originally tried to conjoin "block_start(q) == q" to the \ |
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177 * assertion below, but that doesn't work, because you can't \ |
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178 * accurately traverse previous objects to get to the current one \ |
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179 * after their pointers have been \ |
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180 * updated, until the actual compaction is done. dld, 4/00 */ \ |
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181 assert(block_is_obj(q), \ |
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182 "should be at block boundaries, and should be looking at objs"); \ |
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183 \ |
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184 /* point all the oops to the new location */ \ |
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185 size_t size = oop(q)->adjust_pointers(); \ |
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186 size = adjust_obj_size(size); \ |
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187 \ |
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188 q += size; \ |
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189 } \ |
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190 \ |
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191 if (_first_dead == t) { \ |
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192 q = t; \ |
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193 } else { \ |
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194 /* $$$ This is funky. Using this to read the previously written \ |
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195 * LiveRange. See also use below. */ \ |
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196 q = (HeapWord*)oop(_first_dead)->mark()->decode_pointer(); \ |
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197 } \ |
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198 } \ |
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199 \ |
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200 const intx interval = PrefetchScanIntervalInBytes; \ |
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201 \ |
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202 debug_only(HeapWord* prev_q = NULL); \ |
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203 while (q < t) { \ |
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204 /* prefetch beyond q */ \ |
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205 Prefetch::write(q, interval); \ |
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206 if (oop(q)->is_gc_marked()) { \ |
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207 /* q is alive */ \ |
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208 /* point all the oops to the new location */ \ |
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209 size_t size = oop(q)->adjust_pointers(); \ |
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210 size = adjust_obj_size(size); \ |
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211 debug_only(prev_q = q); \ |
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212 q += size; \ |
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213 } else { \ |
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214 /* q is not a live object, so its mark should point at the next \ |
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215 * live object */ \ |
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216 debug_only(prev_q = q); \ |
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217 q = (HeapWord*) oop(q)->mark()->decode_pointer(); \ |
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218 assert(q > prev_q, "we should be moving forward through memory"); \ |
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219 } \ |
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220 } \ |
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221 \ |
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222 assert(q == t, "just checking"); \ |
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223 } |
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224 |
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225 #define SCAN_AND_COMPACT(obj_size) { \ |
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226 /* Copy all live objects to their new location \ |
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227 * Used by MarkSweep::mark_sweep_phase4() */ \ |
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228 \ |
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229 HeapWord* q = bottom(); \ |
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230 HeapWord* const t = _end_of_live; \ |
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231 debug_only(HeapWord* prev_q = NULL); \ |
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232 \ |
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233 if (q < t && _first_dead > q && \ |
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234 !oop(q)->is_gc_marked()) { \ |
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235 debug_only( \ |
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236 /* we have a chunk of the space which hasn't moved and we've reinitialized \ |
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237 * the mark word during the previous pass, so we can't use is_gc_marked for \ |
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238 * the traversal. */ \ |
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239 HeapWord* const end = _first_dead; \ |
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240 \ |
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241 while (q < end) { \ |
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242 size_t size = obj_size(q); \ |
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243 assert(!oop(q)->is_gc_marked(), \ |
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244 "should be unmarked (special dense prefix handling)"); \ |
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245 debug_only(prev_q = q); \ |
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246 q += size; \ |
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247 } \ |
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248 ) /* debug_only */ \ |
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249 \ |
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250 if (_first_dead == t) { \ |
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251 q = t; \ |
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252 } else { \ |
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253 /* $$$ Funky */ \ |
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254 q = (HeapWord*) oop(_first_dead)->mark()->decode_pointer(); \ |
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255 } \ |
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256 } \ |
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257 \ |
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258 const intx scan_interval = PrefetchScanIntervalInBytes; \ |
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259 const intx copy_interval = PrefetchCopyIntervalInBytes; \ |
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260 while (q < t) { \ |
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261 if (!oop(q)->is_gc_marked()) { \ |
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262 /* mark is pointer to next marked oop */ \ |
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263 debug_only(prev_q = q); \ |
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264 q = (HeapWord*) oop(q)->mark()->decode_pointer(); \ |
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265 assert(q > prev_q, "we should be moving forward through memory"); \ |
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266 } else { \ |
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267 /* prefetch beyond q */ \ |
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268 Prefetch::read(q, scan_interval); \ |
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269 \ |
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270 /* size and destination */ \ |
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271 size_t size = obj_size(q); \ |
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272 HeapWord* compaction_top = (HeapWord*)oop(q)->forwardee(); \ |
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273 \ |
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274 /* prefetch beyond compaction_top */ \ |
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275 Prefetch::write(compaction_top, copy_interval); \ |
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276 \ |
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277 /* copy object and reinit its mark */ \ |
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278 assert(q != compaction_top, "everything in this pass should be moving"); \ |
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279 Copy::aligned_conjoint_words(q, compaction_top, size); \ |
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280 oop(compaction_top)->init_mark(); \ |
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281 assert(oop(compaction_top)->klass() != NULL, "should have a class"); \ |
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282 \ |
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283 debug_only(prev_q = q); \ |
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284 q += size; \ |
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285 } \ |
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286 } \ |
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287 \ |
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288 /* Let's remember if we were empty before we did the compaction. */ \ |
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289 bool was_empty = used_region().is_empty(); \ |
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290 /* Reset space after compaction is complete */ \ |
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291 reset_after_compaction(); \ |
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292 /* We do this clear, below, since it has overloaded meanings for some */ \ |
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293 /* space subtypes. For example, OffsetTableContigSpace's that were */ \ |
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294 /* compacted into will have had their offset table thresholds updated */ \ |
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295 /* continuously, but those that weren't need to have their thresholds */ \ |
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296 /* re-initialized. Also mangles unused area for debugging. */ \ |
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297 if (used_region().is_empty()) { \ |
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298 if (!was_empty) clear(SpaceDecorator::Mangle); \ |
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299 } else { \ |
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300 if (ZapUnusedHeapArea) mangle_unused_area(); \ |
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301 } \ |
35 } |
302 } |
36 |
303 |
37 inline HeapWord* OffsetTableContigSpace::allocate(size_t size) { |
304 inline HeapWord* OffsetTableContigSpace::allocate(size_t size) { |
38 HeapWord* res = ContiguousSpace::allocate(size); |
305 HeapWord* res = ContiguousSpace::allocate(size); |
39 if (res != NULL) { |
306 if (res != NULL) { |