Wed, 25 Jun 2014 16:53:13 +0200
8047820: G1 Block offset table does not need to support generic Space classes
Reviewed-by: tschatzl, stefank
1 /*
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25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1BLOCKOFFSETTABLE_INLINE_HPP
26 #define SHARE_VM_GC_IMPLEMENTATION_G1_G1BLOCKOFFSETTABLE_INLINE_HPP
28 #include "gc_implementation/g1/g1BlockOffsetTable.hpp"
29 #include "gc_implementation/g1/heapRegion.hpp"
30 #include "memory/space.hpp"
32 inline HeapWord* G1BlockOffsetTable::block_start(const void* addr) {
33 if (addr >= _bottom && addr < _end) {
34 return block_start_unsafe(addr);
35 } else {
36 return NULL;
37 }
38 }
40 inline HeapWord*
41 G1BlockOffsetTable::block_start_const(const void* addr) const {
42 if (addr >= _bottom && addr < _end) {
43 return block_start_unsafe_const(addr);
44 } else {
45 return NULL;
46 }
47 }
49 inline size_t G1BlockOffsetSharedArray::index_for(const void* p) const {
50 char* pc = (char*)p;
51 assert(pc >= (char*)_reserved.start() &&
52 pc < (char*)_reserved.end(),
53 err_msg("p (" PTR_FORMAT ") not in reserved [" PTR_FORMAT ", " PTR_FORMAT ")",
54 p2i(p), p2i(_reserved.start()), p2i(_reserved.end())));
55 size_t delta = pointer_delta(pc, _reserved.start(), sizeof(char));
56 size_t result = delta >> LogN;
57 check_index(result, "bad index from address");
58 return result;
59 }
61 inline HeapWord*
62 G1BlockOffsetSharedArray::address_for_index(size_t index) const {
63 check_index(index, "index out of range");
64 HeapWord* result = _reserved.start() + (index << LogN_words);
65 assert(result >= _reserved.start() && result < _reserved.end(),
66 err_msg("bad address from index result " PTR_FORMAT
67 " _reserved.start() " PTR_FORMAT " _reserved.end() "
68 PTR_FORMAT,
69 p2i(result), p2i(_reserved.start()), p2i(_reserved.end())));
70 return result;
71 }
73 inline size_t
74 G1BlockOffsetArray::block_size(const HeapWord* p) const {
75 return gsp()->block_size(p);
76 }
78 inline HeapWord*
79 G1BlockOffsetArray::block_at_or_preceding(const void* addr,
80 bool has_max_index,
81 size_t max_index) const {
82 assert(_array->offset_array(0) == 0, "objects can't cross covered areas");
83 size_t index = _array->index_for(addr);
84 // We must make sure that the offset table entry we use is valid. If
85 // "addr" is past the end, start at the last known one and go forward.
86 if (has_max_index) {
87 index = MIN2(index, max_index);
88 }
89 HeapWord* q = _array->address_for_index(index);
91 uint offset = _array->offset_array(index); // Extend u_char to uint.
92 while (offset >= N_words) {
93 // The excess of the offset from N_words indicates a power of Base
94 // to go back by.
95 size_t n_cards_back = BlockOffsetArray::entry_to_cards_back(offset);
96 q -= (N_words * n_cards_back);
97 assert(q >= gsp()->bottom(), "Went below bottom!");
98 index -= n_cards_back;
99 offset = _array->offset_array(index);
100 }
101 assert(offset < N_words, "offset too large");
102 q -= offset;
103 return q;
104 }
106 inline HeapWord*
107 G1BlockOffsetArray::
108 forward_to_block_containing_addr_const(HeapWord* q, HeapWord* n,
109 const void* addr) const {
110 if (addr >= gsp()->top()) return gsp()->top();
111 while (n <= addr) {
112 q = n;
113 oop obj = oop(q);
114 if (obj->klass_or_null() == NULL) return q;
115 n += obj->size();
116 }
117 assert(q <= n, "wrong order for q and addr");
118 assert(addr < n, "wrong order for addr and n");
119 return q;
120 }
122 inline HeapWord*
123 G1BlockOffsetArray::forward_to_block_containing_addr(HeapWord* q,
124 const void* addr) {
125 if (oop(q)->klass_or_null() == NULL) return q;
126 HeapWord* n = q + block_size(q);
127 // In the normal case, where the query "addr" is a card boundary, and the
128 // offset table chunks are the same size as cards, the block starting at
129 // "q" will contain addr, so the test below will fail, and we'll fall
130 // through quickly.
131 if (n <= addr) {
132 q = forward_to_block_containing_addr_slow(q, n, addr);
133 }
134 assert(q <= addr, "wrong order for current and arg");
135 return q;
136 }
138 //////////////////////////////////////////////////////////////////////////
139 // BlockOffsetArrayNonContigSpace inlines
140 //////////////////////////////////////////////////////////////////////////
141 inline void G1BlockOffsetArray::freed(HeapWord* blk_start, HeapWord* blk_end) {
142 // Verify that the BOT shows [blk_start, blk_end) to be one block.
143 verify_single_block(blk_start, blk_end);
144 // adjust _unallocated_block upward or downward
145 // as appropriate
146 if (BlockOffsetArrayUseUnallocatedBlock) {
147 assert(_unallocated_block <= _end,
148 "Inconsistent value for _unallocated_block");
149 if (blk_end >= _unallocated_block && blk_start <= _unallocated_block) {
150 // CMS-specific note: a block abutting _unallocated_block to
151 // its left is being freed, a new block is being added or
152 // we are resetting following a compaction
153 _unallocated_block = blk_start;
154 }
155 }
156 }
158 inline void G1BlockOffsetArray::freed(HeapWord* blk, size_t size) {
159 freed(blk, blk + size);
160 }
162 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1BLOCKOFFSETTABLE_INLINE_HPP