Mercurial > jdk8-mips64-public > hotspot / file comparison
comparison: src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp
src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp
- changeset 2293
- 899bbbdcb6ea
- parent 2188
- 8b10f48633dc
- child 2294
- 4df7f8cba524
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| 2246:9de67bf4244d | 2293:899bbbdcb6ea |
|---|---|
| 1091 // the main marking bitmap in the sweeping phase or, if it's a permanent | 1091 // the main marking bitmap in the sweeping phase or, if it's a permanent |
| 1092 // generation and we're not in the sweeping phase, by checking the | 1092 // generation and we're not in the sweeping phase, by checking the |
| 1093 // perm_gen_verify_bit_map where we store the "deadness" information if | 1093 // perm_gen_verify_bit_map where we store the "deadness" information if |
| 1094 // we did not sweep the perm gen in the most recent previous GC cycle. | 1094 // we did not sweep the perm gen in the most recent previous GC cycle. |
| 1095 bool CompactibleFreeListSpace::obj_is_alive(const HeapWord* p) const { | 1095 bool CompactibleFreeListSpace::obj_is_alive(const HeapWord* p) const { |
| 1096 assert (block_is_obj(p), "The address should point to an object"); | 1096 assert(block_is_obj(p), "The address should point to an object"); |
| 1097 assert(SafepointSynchronize::is_at_safepoint(), "Else races are possible"); | |
| 1097 | 1098 |
| 1098 // If we're sweeping, we use object liveness information from the main bit map | 1099 // If we're sweeping, we use object liveness information from the main bit map |
| 1099 // for both perm gen and old gen. | 1100 // for both perm gen and old gen. |
| 1100 // We don't need to lock the bitmap (live_map or dead_map below), because | 1101 // We don't need to lock the bitmap (live_map or dead_map below), because |
| 1101 // EITHER we are in the middle of the sweeping phase, and the | 1102 // EITHER we are in the middle of the sweeping phase, and the |
| 1102 // main marking bit map (live_map below) is locked, | 1103 // main marking bit map (live_map below) is locked, |
| 1103 // OR we're in other phases and perm_gen_verify_bit_map (dead_map below) | 1104 // OR we're in other phases and perm_gen_verify_bit_map (dead_map below) |
| 1104 // is stable, because it's mutated only in the sweeping phase. | 1105 // is stable, because it's mutated only in the sweeping phase. |
| 1106 // NOTE: This method is also used by jmap where, if class unloading is | |
| 1107 // off, the results can return "false" for legitimate perm objects, | |
| 1108 // when we are not in the midst of a sweeping phase, which can result | |
| 1109 // in jmap not reporting certain perm gen objects. This will be moot | |
| 1110 // if/when the perm gen goes away in the future. | |
| 1105 if (_collector->abstract_state() == CMSCollector::Sweeping) { | 1111 if (_collector->abstract_state() == CMSCollector::Sweeping) { |
| 1106 CMSBitMap* live_map = _collector->markBitMap(); | 1112 CMSBitMap* live_map = _collector->markBitMap(); |
| 1107 return live_map->isMarked((HeapWord*) p); | 1113 return live_map->par_isMarked((HeapWord*) p); |
| 1108 } else { | 1114 } else { |
| 1109 // If we're not currently sweeping and we haven't swept the perm gen in | 1115 // If we're not currently sweeping and we haven't swept the perm gen in |
| 1110 // the previous concurrent cycle then we may have dead but unswept objects | 1116 // the previous concurrent cycle then we may have dead but unswept objects |
| 1111 // in the perm gen. In this case, we use the "deadness" information | 1117 // in the perm gen. In this case, we use the "deadness" information |
| 1112 // that we had saved in perm_gen_verify_bit_map at the last sweep. | 1118 // that we had saved in perm_gen_verify_bit_map at the last sweep. |
