35 class G1HeapRegionTable : public G1BiasedMappedArray<HeapRegion*> { |
36 class G1HeapRegionTable : public G1BiasedMappedArray<HeapRegion*> { |
36 protected: |
37 protected: |
37 virtual HeapRegion* default_value() const { return NULL; } |
38 virtual HeapRegion* default_value() const { return NULL; } |
38 }; |
39 }; |
39 |
40 |
40 // This class keeps track of the region metadata (i.e., HeapRegion |
41 // This class keeps track of the actual heap memory, auxiliary data |
41 // instances). They are kept in the _regions array in address |
42 // and its metadata (i.e., HeapRegion instances) and the list of free regions. |
42 // order. A region's index in the array corresponds to its index in |
43 // |
43 // the heap (i.e., 0 is the region at the bottom of the heap, 1 is |
44 // This allows maximum flexibility for deciding what to commit or uncommit given |
44 // the one after it, etc.). Two regions that are consecutive in the |
45 // a request from outside. |
45 // array should also be adjacent in the address space (i.e., |
46 // |
46 // region(i).end() == region(i+1).bottom(). |
47 // HeapRegions are kept in the _regions array in address order. A region's |
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48 // index in the array corresponds to its index in the heap (i.e., 0 is the |
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49 // region at the bottom of the heap, 1 is the one after it, etc.). Two |
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50 // regions that are consecutive in the array should also be adjacent in the |
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51 // address space (i.e., region(i).end() == region(i+1).bottom(). |
47 // |
52 // |
48 // We create a HeapRegion when we commit the region's address space |
53 // We create a HeapRegion when we commit the region's address space |
49 // for the first time. When we uncommit the address space of a |
54 // for the first time. When we uncommit the address space of a |
50 // region we retain the HeapRegion to be able to re-use it in the |
55 // region we retain the HeapRegion to be able to re-use it in the |
51 // future (in case we recommit it). |
56 // future (in case we recommit it). |
52 // |
57 // |
53 // We keep track of three lengths: |
58 // We keep track of three lengths: |
54 // |
59 // |
55 // * _committed_length (returned by length()) is the number of currently |
60 // * _num_committed (returned by length()) is the number of currently |
56 // committed regions. |
61 // committed regions. These may not be contiguous. |
57 // * _allocated_length (not exposed outside this class) is the |
62 // * _allocated_heapregions_length (not exposed outside this class) is the |
58 // number of regions for which we have HeapRegions. |
63 // number of regions+1 for which we have HeapRegions. |
59 // * max_length() returns the maximum number of regions the heap can have. |
64 // * max_length() returns the maximum number of regions the heap can have. |
60 // |
65 // |
61 // and maintain that: _committed_length <= _allocated_length <= max_length() |
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62 |
66 |
63 class HeapRegionSeq: public CHeapObj<mtGC> { |
67 class HeapRegionSeq: public CHeapObj<mtGC> { |
64 friend class VMStructs; |
68 friend class VMStructs; |
65 |
69 |
66 G1HeapRegionTable _regions; |
70 G1HeapRegionTable _regions; |
67 |
71 |
68 ReservedSpace _reserved; |
72 G1RegionToSpaceMapper* _heap_mapper; |
69 VirtualSpace _storage; |
73 G1RegionToSpaceMapper* _prev_bitmap_mapper; |
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74 G1RegionToSpaceMapper* _next_bitmap_mapper; |
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75 G1RegionToSpaceMapper* _bot_mapper; |
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76 G1RegionToSpaceMapper* _cardtable_mapper; |
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77 G1RegionToSpaceMapper* _card_counts_mapper; |
70 |
78 |
71 FreeRegionList _free_list; |
79 FreeRegionList _free_list; |
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80 |
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81 // Each bit in this bitmap indicates that the corresponding region is available |
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82 // for allocation. |
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83 BitMap _available_map; |
72 |
84 |
73 // The number of regions committed in the heap. |
85 // The number of regions committed in the heap. |
74 uint _num_committed; |
86 uint _num_committed; |
75 |
87 |
76 // Internal only. The highest heap region +1 we allocated a HeapRegion instance for. |
88 // Internal only. The highest heap region +1 we allocated a HeapRegion instance for. |
77 uint _allocated_heapregions_length; |
89 uint _allocated_heapregions_length; |
78 |
90 |
79 HeapWord* heap_bottom() const { return _regions.bottom_address_mapped(); } |
91 HeapWord* heap_bottom() const { return _regions.bottom_address_mapped(); } |
80 HeapWord* heap_top() const { return heap_bottom() + _num_committed * HeapRegion::GrainWords; } |
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81 HeapWord* heap_end() const {return _regions.end_address_mapped(); } |
92 HeapWord* heap_end() const {return _regions.end_address_mapped(); } |
82 |
93 |
83 void make_regions_available(uint index, uint num_regions = 1); |
94 void make_regions_available(uint index, uint num_regions = 1); |
84 |
95 |
85 // Pass down commit calls to the VirtualSpace. |
96 // Pass down commit calls to the VirtualSpace. |
90 void update_committed_space(HeapWord* old_end, HeapWord* new_end); |
101 void update_committed_space(HeapWord* old_end, HeapWord* new_end); |
91 // Calculate the starting region for each worker during parallel iteration so |
102 // Calculate the starting region for each worker during parallel iteration so |
92 // that they do not all start from the same region. |
103 // that they do not all start from the same region. |
93 uint start_region_for_worker(uint worker_i, uint num_workers, uint num_regions) const; |
104 uint start_region_for_worker(uint worker_i, uint num_workers, uint num_regions) const; |
94 |
105 |
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106 // Find a contiguous set of empty or uncommitted regions of length num and return |
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107 // the index of the first region or G1_NO_HRS_INDEX if the search was unsuccessful. |
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108 // If only_empty is true, only empty regions are considered. |
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109 // Searches from bottom to top of the heap, doing a first-fit. |
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110 uint find_contiguous(size_t num, bool only_empty); |
95 // Finds the next sequence of unavailable regions starting from start_idx. Returns the |
111 // Finds the next sequence of unavailable regions starting from start_idx. Returns the |
96 // length of the sequence found. If this result is zero, no such sequence could be found, |
112 // length of the sequence found. If this result is zero, no such sequence could be found, |
97 // otherwise res_idx indicates the start index of these regions. |
113 // otherwise res_idx indicates the start index of these regions. |
98 uint find_unavailable_from_idx(uint start_idx, uint* res_idx) const; |
114 uint find_unavailable_from_idx(uint start_idx, uint* res_idx) const; |
99 // Finds the next sequence of empty regions starting from start_idx, going backwards in |
115 // Finds the next sequence of empty regions starting from start_idx, going backwards in |
100 // the heap. Returns the length of the sequence found. If this value is zero, no |
116 // the heap. Returns the length of the sequence found. If this value is zero, no |
101 // sequence could be found, otherwise res_idx contains the start index of this range. |
117 // sequence could be found, otherwise res_idx contains the start index of this range. |
102 uint find_empty_from_idx_reverse(uint start_idx, uint* res_idx) const; |
118 uint find_empty_from_idx_reverse(uint start_idx, uint* res_idx) const; |
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119 // Allocate a new HeapRegion for the given index. |
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120 HeapRegion* new_heap_region(uint hrs_index); |
103 #ifdef ASSERT |
121 #ifdef ASSERT |
104 public: |
122 public: |
105 bool is_free(HeapRegion* hr) const; |
123 bool is_free(HeapRegion* hr) const; |
106 #endif |
124 #endif |
107 // Returns whether the given region is available for allocation. |
125 // Returns whether the given region is available for allocation. |
108 bool is_available(uint region) const; |
126 bool is_available(uint region) const; |
109 |
127 |
110 // Allocate a new HeapRegion for the given index. |
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111 HeapRegion* new_heap_region(uint hrs_index); |
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112 public: |
128 public: |
113 // Empty constructor, we'll initialize it with the initialize() method. |
129 // Empty constructor, we'll initialize it with the initialize() method. |
114 HeapRegionSeq() : _regions(), _reserved(), _storage(), _num_committed(0), |
130 HeapRegionSeq() : _regions(), _heap_mapper(NULL), _num_committed(0), |
115 _free_list("Master Free List", new MasterFreeRegionListMtSafeChecker()), |
131 _next_bitmap_mapper(NULL), _prev_bitmap_mapper(NULL), _bot_mapper(NULL), |
116 _allocated_heapregions_length(0) |
132 _allocated_heapregions_length(0), _available_map(), |
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133 _free_list("Free list", new MasterFreeRegionListMtSafeChecker()) |
117 { } |
134 { } |
118 |
135 |
119 void initialize(ReservedSpace reserved); |
136 void initialize(G1RegionToSpaceMapper* heap_storage, |
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137 G1RegionToSpaceMapper* prev_bitmap, |
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138 G1RegionToSpaceMapper* next_bitmap, |
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139 G1RegionToSpaceMapper* bot, |
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140 G1RegionToSpaceMapper* cardtable, |
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141 G1RegionToSpaceMapper* card_counts); |
120 |
142 |
121 // Return the "dummy" region used for G1AllocRegion. This is currently a hardwired |
143 // Return the "dummy" region used for G1AllocRegion. This is currently a hardwired |
122 // new HeapRegion that owns HeapRegion at index 0. Since at the moment we commit |
144 // new HeapRegion that owns HeapRegion at index 0. Since at the moment we commit |
123 // the heap from the lowest address, this region (and its associated data |
145 // the heap from the lowest address, this region (and its associated data |
124 // structures) are available and we do not need to check further. |
146 // structures) are available and we do not need to check further. |
173 uint length() const { return _num_committed; } |
195 uint length() const { return _num_committed; } |
174 |
196 |
175 // Return the maximum number of regions in the heap. |
197 // Return the maximum number of regions in the heap. |
176 uint max_length() const { return (uint)_regions.length(); } |
198 uint max_length() const { return (uint)_regions.length(); } |
177 |
199 |
178 MemRegion committed() const { return MemRegion(heap_bottom(), heap_top()); } |
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179 |
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180 MemRegion reserved() const { return MemRegion(heap_bottom(), heap_end()); } |
200 MemRegion reserved() const { return MemRegion(heap_bottom(), heap_end()); } |
181 |
201 |
182 // Expand the sequence to reflect that the heap has grown. Either create new |
202 // Expand the sequence to reflect that the heap has grown. Either create new |
183 // HeapRegions, or re-use existing ones. Returns the number of regions the |
203 // HeapRegions, or re-use existing ones. Returns the number of regions the |
184 // sequence was expanded by. If a HeapRegion allocation fails, the resulting |
204 // sequence was expanded by. If a HeapRegion allocation fails, the resulting |
188 // Makes sure that the regions from start to start+num_regions-1 are available |
208 // Makes sure that the regions from start to start+num_regions-1 are available |
189 // for allocation. Returns the number of regions that were committed to achieve |
209 // for allocation. Returns the number of regions that were committed to achieve |
190 // this. |
210 // this. |
191 uint expand_at(uint start, uint num_regions); |
211 uint expand_at(uint start, uint num_regions); |
192 |
212 |
193 // Find a contiguous set of empty or uncommitted regions of length num and return |
213 // Find a contiguous set of empty regions of length num. Returns the start index of |
194 // the index of the first region or G1_NO_HRS_INDEX if the search was unsuccessful. |
214 // that set, or G1_NO_HRS_INDEX. |
195 // If only_empty is true, only empty regions are considered. |
215 uint find_contiguous_only_empty(size_t num) { return find_contiguous(num, true); } |
196 // Searches from bottom to top of the heap, doing a first-fit. |
216 // Find a contiguous set of empty or unavailable regions of length num. Returns the |
197 uint find_contiguous(size_t num, bool only_empty); |
217 // start index of that set, or G1_NO_HRS_INDEX. |
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218 uint find_contiguous_empty_or_unavailable(size_t num) { return find_contiguous(num, false); } |
198 |
219 |
199 HeapRegion* next_region_in_heap(const HeapRegion* r) const; |
220 HeapRegion* next_region_in_heap(const HeapRegion* r) const; |
200 |
221 |
201 // Apply blk->doHeapRegion() on all committed regions in address order, |
222 // Apply blk->doHeapRegion() on all committed regions in address order, |
202 // terminating the iteration early if doHeapRegion() returns true. |
223 // terminating the iteration early if doHeapRegion() returns true. |