26 #include "gc_implementation/g1/collectionSetChooser.hpp" |
26 #include "gc_implementation/g1/collectionSetChooser.hpp" |
27 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp" |
27 #include "gc_implementation/g1/g1CollectedHeap.inline.hpp" |
28 #include "gc_implementation/g1/g1CollectorPolicy.hpp" |
28 #include "gc_implementation/g1/g1CollectorPolicy.hpp" |
29 #include "gc_implementation/g1/g1ErgoVerbose.hpp" |
29 #include "gc_implementation/g1/g1ErgoVerbose.hpp" |
30 #include "memory/space.inline.hpp" |
30 #include "memory/space.inline.hpp" |
31 |
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32 CSetChooserCache::CSetChooserCache() { |
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33 for (int i = 0; i < CacheLength; ++i) |
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34 _cache[i] = NULL; |
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35 clear(); |
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36 } |
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37 |
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38 void CSetChooserCache::clear() { |
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39 _occupancy = 0; |
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40 _first = 0; |
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41 for (int i = 0; i < CacheLength; ++i) { |
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42 HeapRegion *hr = _cache[i]; |
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43 if (hr != NULL) |
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44 hr->set_sort_index(-1); |
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45 _cache[i] = NULL; |
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46 } |
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47 } |
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48 |
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49 #ifndef PRODUCT |
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50 bool CSetChooserCache::verify() { |
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51 guarantee(false, "CSetChooserCache::verify(): don't call this any more"); |
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52 |
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53 int index = _first; |
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54 HeapRegion *prev = NULL; |
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55 for (int i = 0; i < _occupancy; ++i) { |
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56 guarantee(_cache[index] != NULL, "cache entry should not be empty"); |
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57 HeapRegion *hr = _cache[index]; |
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58 guarantee(!hr->is_young(), "should not be young!"); |
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59 if (prev != NULL) { |
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60 guarantee(prev->gc_efficiency() >= hr->gc_efficiency(), |
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61 "cache should be correctly ordered"); |
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62 } |
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63 guarantee(hr->sort_index() == get_sort_index(index), |
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64 "sort index should be correct"); |
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65 index = trim_index(index + 1); |
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66 prev = hr; |
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67 } |
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68 |
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69 for (int i = 0; i < (CacheLength - _occupancy); ++i) { |
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70 guarantee(_cache[index] == NULL, "cache entry should be empty"); |
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71 index = trim_index(index + 1); |
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72 } |
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73 |
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74 guarantee(index == _first, "we should have reached where we started from"); |
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75 return true; |
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76 } |
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77 #endif // PRODUCT |
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78 |
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79 void CSetChooserCache::insert(HeapRegion *hr) { |
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80 guarantee(false, "CSetChooserCache::insert(): don't call this any more"); |
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81 |
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82 assert(!is_full(), "cache should not be empty"); |
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83 hr->calc_gc_efficiency(); |
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84 |
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85 int empty_index; |
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86 if (_occupancy == 0) { |
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87 empty_index = _first; |
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88 } else { |
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89 empty_index = trim_index(_first + _occupancy); |
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90 assert(_cache[empty_index] == NULL, "last slot should be empty"); |
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91 int last_index = trim_index(empty_index - 1); |
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92 HeapRegion *last = _cache[last_index]; |
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93 assert(last != NULL,"as the cache is not empty, last should not be empty"); |
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94 while (empty_index != _first && |
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95 last->gc_efficiency() < hr->gc_efficiency()) { |
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96 _cache[empty_index] = last; |
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97 last->set_sort_index(get_sort_index(empty_index)); |
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98 empty_index = last_index; |
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99 last_index = trim_index(last_index - 1); |
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100 last = _cache[last_index]; |
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101 } |
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102 } |
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103 _cache[empty_index] = hr; |
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104 hr->set_sort_index(get_sort_index(empty_index)); |
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105 |
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106 ++_occupancy; |
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107 assert(verify(), "cache should be consistent"); |
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108 } |
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109 |
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110 HeapRegion *CSetChooserCache::remove_first() { |
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111 guarantee(false, "CSetChooserCache::remove_first(): " |
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112 "don't call this any more"); |
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113 |
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114 if (_occupancy > 0) { |
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115 assert(_cache[_first] != NULL, "cache should have at least one region"); |
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116 HeapRegion *ret = _cache[_first]; |
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117 _cache[_first] = NULL; |
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118 ret->set_sort_index(-1); |
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119 --_occupancy; |
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120 _first = trim_index(_first + 1); |
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121 assert(verify(), "cache should be consistent"); |
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122 return ret; |
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123 } else { |
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124 return NULL; |
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125 } |
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126 } |
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127 |
31 |
128 // Even though we don't use the GC efficiency in our heuristics as |
32 // Even though we don't use the GC efficiency in our heuristics as |
129 // much as we used to, we still order according to GC efficiency. This |
33 // much as we used to, we still order according to GC efficiency. This |
130 // will cause regions with a lot of live objects and large RSets to |
34 // will cause regions with a lot of live objects and large RSets to |
131 // end up at the end of the array. Given that we might skip collecting |
35 // end up at the end of the array. Given that we might skip collecting |
132 // the last few old regions, if after a few mixed GCs the remaining |
36 // the last few old regions, if after a few mixed GCs the remaining |
133 // have reclaimable bytes under a certain threshold, the hope is that |
37 // have reclaimable bytes under a certain threshold, the hope is that |
134 // the ones we'll skip are ones with both large RSets and a lot of |
38 // the ones we'll skip are ones with both large RSets and a lot of |
135 // live objects, not the ones with just a lot of live objects if we |
39 // live objects, not the ones with just a lot of live objects if we |
136 // ordered according to the amount of reclaimable bytes per region. |
40 // ordered according to the amount of reclaimable bytes per region. |
137 static int orderRegions(HeapRegion* hr1, HeapRegion* hr2) { |
41 static int order_regions(HeapRegion* hr1, HeapRegion* hr2) { |
138 if (hr1 == NULL) { |
42 if (hr1 == NULL) { |
139 if (hr2 == NULL) { |
43 if (hr2 == NULL) { |
140 return 0; |
44 return 0; |
141 } else { |
45 } else { |
142 return 1; |
46 return 1; |
173 // allow to pass the assert in GenericGrowableArray() which checks |
77 // allow to pass the assert in GenericGrowableArray() which checks |
174 // that a growable array object must be on C heap if elements are. |
78 // that a growable array object must be on C heap if elements are. |
175 // |
79 // |
176 // Note: containing object is allocated on C heap since it is CHeapObj. |
80 // Note: containing object is allocated on C heap since it is CHeapObj. |
177 // |
81 // |
178 _markedRegions((ResourceObj::set_allocation_type((address)&_markedRegions, |
82 _regions((ResourceObj::set_allocation_type((address) &_regions, |
179 ResourceObj::C_HEAP), |
83 ResourceObj::C_HEAP), |
180 100), true /* C_Heap */), |
84 100), true /* C_Heap */), |
181 _curr_index(0), _length(0), |
85 _curr_index(0), _length(0), _first_par_unreserved_idx(0), |
182 _regionLiveThresholdBytes(0), _remainingReclaimableBytes(0), |
86 _region_live_threshold_bytes(0), _remaining_reclaimable_bytes(0) { |
183 _first_par_unreserved_idx(0) { |
87 _region_live_threshold_bytes = |
184 _regionLiveThresholdBytes = |
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185 HeapRegion::GrainBytes * (size_t) G1OldCSetRegionLiveThresholdPercent / 100; |
88 HeapRegion::GrainBytes * (size_t) G1OldCSetRegionLiveThresholdPercent / 100; |
186 } |
89 } |
187 |
90 |
188 #ifndef PRODUCT |
91 #ifndef PRODUCT |
189 bool CollectionSetChooser::verify() { |
92 void CollectionSetChooser::verify() { |
190 guarantee(_length >= 0, err_msg("_length: %d", _length)); |
93 guarantee(_length <= regions_length(), |
191 guarantee(0 <= _curr_index && _curr_index <= _length, |
94 err_msg("_length: %u regions length: %u", _length, regions_length())); |
192 err_msg("_curr_index: %d _length: %d", _curr_index, _length)); |
95 guarantee(_curr_index <= _length, |
193 int index = 0; |
96 err_msg("_curr_index: %u _length: %u", _curr_index, _length)); |
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97 uint index = 0; |
194 size_t sum_of_reclaimable_bytes = 0; |
98 size_t sum_of_reclaimable_bytes = 0; |
195 while (index < _curr_index) { |
99 while (index < _curr_index) { |
196 guarantee(_markedRegions.at(index) == NULL, |
100 guarantee(regions_at(index) == NULL, |
197 "all entries before _curr_index should be NULL"); |
101 "all entries before _curr_index should be NULL"); |
198 index += 1; |
102 index += 1; |
199 } |
103 } |
200 HeapRegion *prev = NULL; |
104 HeapRegion *prev = NULL; |
201 while (index < _length) { |
105 while (index < _length) { |
202 HeapRegion *curr = _markedRegions.at(index++); |
106 HeapRegion *curr = regions_at(index++); |
203 guarantee(curr != NULL, "Regions in _markedRegions array cannot be NULL"); |
107 guarantee(curr != NULL, "Regions in _regions array cannot be NULL"); |
204 int si = curr->sort_index(); |
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205 guarantee(!curr->is_young(), "should not be young!"); |
108 guarantee(!curr->is_young(), "should not be young!"); |
206 guarantee(!curr->isHumongous(), "should not be humongous!"); |
109 guarantee(!curr->isHumongous(), "should not be humongous!"); |
207 guarantee(si > -1 && si == (index-1), "sort index invariant"); |
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208 if (prev != NULL) { |
110 if (prev != NULL) { |
209 guarantee(orderRegions(prev, curr) != 1, |
111 guarantee(order_regions(prev, curr) != 1, |
210 err_msg("GC eff prev: %1.4f GC eff curr: %1.4f", |
112 err_msg("GC eff prev: %1.4f GC eff curr: %1.4f", |
211 prev->gc_efficiency(), curr->gc_efficiency())); |
113 prev->gc_efficiency(), curr->gc_efficiency())); |
212 } |
114 } |
213 sum_of_reclaimable_bytes += curr->reclaimable_bytes(); |
115 sum_of_reclaimable_bytes += curr->reclaimable_bytes(); |
214 prev = curr; |
116 prev = curr; |
215 } |
117 } |
216 guarantee(sum_of_reclaimable_bytes == _remainingReclaimableBytes, |
118 guarantee(sum_of_reclaimable_bytes == _remaining_reclaimable_bytes, |
217 err_msg("reclaimable bytes inconsistent, " |
119 err_msg("reclaimable bytes inconsistent, " |
218 "remaining: "SIZE_FORMAT" sum: "SIZE_FORMAT, |
120 "remaining: "SIZE_FORMAT" sum: "SIZE_FORMAT, |
219 _remainingReclaimableBytes, sum_of_reclaimable_bytes)); |
121 _remaining_reclaimable_bytes, sum_of_reclaimable_bytes)); |
220 return true; |
122 } |
221 } |
123 #endif // !PRODUCT |
222 #endif |
124 |
223 |
125 void CollectionSetChooser::sort_regions() { |
224 void CollectionSetChooser::fillCache() { |
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225 guarantee(false, "fillCache: don't call this any more"); |
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226 |
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227 while (!_cache.is_full() && (_curr_index < _length)) { |
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228 HeapRegion* hr = _markedRegions.at(_curr_index); |
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229 assert(hr != NULL, |
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230 err_msg("Unexpected NULL hr in _markedRegions at index %d", |
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231 _curr_index)); |
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232 _curr_index += 1; |
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233 assert(!hr->is_young(), "should not be young!"); |
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234 assert(hr->sort_index() == _curr_index-1, "sort_index invariant"); |
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235 _markedRegions.at_put(hr->sort_index(), NULL); |
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236 _cache.insert(hr); |
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237 assert(!_cache.is_empty(), "cache should not be empty"); |
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238 } |
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239 assert(verify(), "cache should be consistent"); |
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240 } |
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241 |
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242 void CollectionSetChooser::sortMarkedHeapRegions() { |
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243 // First trim any unused portion of the top in the parallel case. |
126 // First trim any unused portion of the top in the parallel case. |
244 if (_first_par_unreserved_idx > 0) { |
127 if (_first_par_unreserved_idx > 0) { |
245 if (G1PrintParCleanupStats) { |
128 assert(_first_par_unreserved_idx <= regions_length(), |
246 gclog_or_tty->print(" Truncating _markedRegions from %d to %d.\n", |
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247 _markedRegions.length(), _first_par_unreserved_idx); |
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248 } |
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249 assert(_first_par_unreserved_idx <= _markedRegions.length(), |
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250 "Or we didn't reserved enough length"); |
129 "Or we didn't reserved enough length"); |
251 _markedRegions.trunc_to(_first_par_unreserved_idx); |
130 regions_trunc_to(_first_par_unreserved_idx); |
252 } |
131 } |
253 _markedRegions.sort(orderRegions); |
132 _regions.sort(order_regions); |
254 assert(_length <= _markedRegions.length(), "Requirement"); |
133 assert(_length <= regions_length(), "Requirement"); |
255 assert(_length == 0 || _markedRegions.at(_length - 1) != NULL, |
134 #ifdef ASSERT |
256 "Testing _length"); |
135 for (uint i = 0; i < _length; i++) { |
257 assert(_length == _markedRegions.length() || |
136 assert(regions_at(i) != NULL, "Should be true by sorting!"); |
258 _markedRegions.at(_length) == NULL, "Testing _length"); |
137 } |
259 if (G1PrintParCleanupStats) { |
138 #endif // ASSERT |
260 gclog_or_tty->print_cr(" Sorted %d marked regions.", _length); |
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261 } |
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262 for (int i = 0; i < _length; i++) { |
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263 assert(_markedRegions.at(i) != NULL, "Should be true by sorting!"); |
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264 _markedRegions.at(i)->set_sort_index(i); |
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265 } |
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266 if (G1PrintRegionLivenessInfo) { |
139 if (G1PrintRegionLivenessInfo) { |
267 G1PrintRegionLivenessInfoClosure cl(gclog_or_tty, "Post-Sorting"); |
140 G1PrintRegionLivenessInfoClosure cl(gclog_or_tty, "Post-Sorting"); |
268 for (int i = 0; i < _length; ++i) { |
141 for (uint i = 0; i < _length; ++i) { |
269 HeapRegion* r = _markedRegions.at(i); |
142 HeapRegion* r = regions_at(i); |
270 cl.doHeapRegion(r); |
143 cl.doHeapRegion(r); |
271 } |
144 } |
272 } |
145 } |
273 assert(verify(), "CSet chooser verification"); |
146 verify(); |
274 } |
147 } |
275 |
148 |
276 uint CollectionSetChooser::calcMinOldCSetLength() { |
149 uint CollectionSetChooser::calc_min_old_cset_length() { |
277 // The min old CSet region bound is based on the maximum desired |
150 // The min old CSet region bound is based on the maximum desired |
278 // number of mixed GCs after a cycle. I.e., even if some old regions |
151 // number of mixed GCs after a cycle. I.e., even if some old regions |
279 // look expensive, we should add them to the CSet anyway to make |
152 // look expensive, we should add them to the CSet anyway to make |
280 // sure we go through the available old regions in no more than the |
153 // sure we go through the available old regions in no more than the |
281 // maximum desired number of mixed GCs. |
154 // maximum desired number of mixed GCs. |
333 // or some improperly initialized variable with leads to no |
206 // or some improperly initialized variable with leads to no |
334 // active threads, protect against that in a product build. |
207 // active threads, protect against that in a product build. |
335 n_threads = MAX2(G1CollectedHeap::heap()->workers()->active_workers(), |
208 n_threads = MAX2(G1CollectedHeap::heap()->workers()->active_workers(), |
336 1U); |
209 1U); |
337 } |
210 } |
338 uint max_waste = n_threads * chunkSize; |
211 uint max_waste = n_threads * chunk_size; |
339 // it should be aligned with respect to chunkSize |
212 // it should be aligned with respect to chunk_size |
340 uint aligned_n_regions = (n_regions + chunkSize - 1) / chunkSize * chunkSize; |
213 uint aligned_n_regions = (n_regions + chunk_size - 1) / chunk_size * chunk_size; |
341 assert(aligned_n_regions % chunkSize == 0, "should be aligned"); |
214 assert(aligned_n_regions % chunk_size == 0, "should be aligned"); |
342 _markedRegions.at_put_grow((int) (aligned_n_regions + max_waste - 1), NULL); |
215 regions_at_put_grow(aligned_n_regions + max_waste - 1, NULL); |
343 } |
216 } |
344 |
217 |
345 jint CollectionSetChooser::getParMarkedHeapRegionChunk(jint n_regions) { |
218 uint CollectionSetChooser::claim_array_chunk(uint chunk_size) { |
346 // Don't do this assert because this can be called at a point |
219 uint res = (uint) Atomic::add((jint) chunk_size, |
347 // where the loop up stream will not execute again but might |
220 (volatile jint*) &_first_par_unreserved_idx); |
348 // try to claim more chunks (loop test has not been done yet). |
221 assert(regions_length() > res + chunk_size - 1, |
349 // assert(_markedRegions.length() > _first_par_unreserved_idx, |
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350 // "Striding beyond the marked regions"); |
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351 jint res = Atomic::add(n_regions, &_first_par_unreserved_idx); |
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352 assert(_markedRegions.length() > res + n_regions - 1, |
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353 "Should already have been expanded"); |
222 "Should already have been expanded"); |
354 return res - n_regions; |
223 return res - chunk_size; |
355 } |
224 } |
356 |
225 |
357 void CollectionSetChooser::setMarkedHeapRegion(jint index, HeapRegion* hr) { |
226 void CollectionSetChooser::set_region(uint index, HeapRegion* hr) { |
358 assert(_markedRegions.at(index) == NULL, "precondition"); |
227 assert(regions_at(index) == NULL, "precondition"); |
359 assert(!hr->is_young(), "should not be young!"); |
228 assert(!hr->is_young(), "should not be young!"); |
360 _markedRegions.at_put(index, hr); |
229 regions_at_put(index, hr); |
361 hr->calc_gc_efficiency(); |
230 hr->calc_gc_efficiency(); |
362 } |
231 } |
363 |
232 |
364 void CollectionSetChooser::updateTotals(jint region_num, |
233 void CollectionSetChooser::update_totals(uint region_num, |
365 size_t reclaimable_bytes) { |
234 size_t reclaimable_bytes) { |
366 // Only take the lock if we actually need to update the totals. |
235 // Only take the lock if we actually need to update the totals. |
367 if (region_num > 0) { |
236 if (region_num > 0) { |
368 assert(reclaimable_bytes > 0, "invariant"); |
237 assert(reclaimable_bytes > 0, "invariant"); |
369 // We could have just used atomics instead of taking the |
238 // We could have just used atomics instead of taking the |
370 // lock. However, we currently don't have an atomic add for size_t. |
239 // lock. However, we currently don't have an atomic add for size_t. |
371 MutexLockerEx x(ParGCRareEvent_lock, Mutex::_no_safepoint_check_flag); |
240 MutexLockerEx x(ParGCRareEvent_lock, Mutex::_no_safepoint_check_flag); |
372 _length += (int) region_num; |
241 _length += region_num; |
373 _remainingReclaimableBytes += reclaimable_bytes; |
242 _remaining_reclaimable_bytes += reclaimable_bytes; |
374 } else { |
243 } else { |
375 assert(reclaimable_bytes == 0, "invariant"); |
244 assert(reclaimable_bytes == 0, "invariant"); |
376 } |
245 } |
377 } |
246 } |
378 |
247 |
379 void CollectionSetChooser::clearMarkedHeapRegions() { |
248 void CollectionSetChooser::clear() { |
380 for (int i = 0; i < _markedRegions.length(); i++) { |
249 _regions.clear(); |
381 HeapRegion* r = _markedRegions.at(i); |
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382 if (r != NULL) { |
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383 r->set_sort_index(-1); |
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384 } |
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385 } |
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386 _markedRegions.clear(); |
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387 _curr_index = 0; |
250 _curr_index = 0; |
388 _length = 0; |
251 _length = 0; |
389 _remainingReclaimableBytes = 0; |
252 _remaining_reclaimable_bytes = 0; |
390 }; |
253 }; |