14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_VM_MEMORY_CARDGENERATION_HPP
26 #define SHARE_VM_MEMORY_CARDGENERATION_HPP
27
28 // Class CardGeneration is a generation that is covered by a card table,
29 // and uses a card-size block-offset array to implement block_start.
30
31 #include "memory/generation.hpp"
32
33 class BlockOffsetSharedArray;
34
35 class CardGeneration: public Generation {
36 friend class VMStructs;
37 protected:
38 // This is shared with other generations.
39 GenRemSet* _rs;
40 // This is local to this generation.
41 BlockOffsetSharedArray* _bts;
42
43 // current shrinking effect: this damps shrinking when the heap gets empty.
44 size_t _shrink_factor;
45
46 size_t _min_heap_delta_bytes; // Minimum amount to expand.
47
48 // Some statistics from before gc started.
49 // These are gathered in the gc_prologue (and should_collect)
50 // to control growing/shrinking policy in spite of promotions.
51 size_t _capacity_at_prologue;
52 size_t _used_at_prologue;
53
54 CardGeneration(ReservedSpace rs, size_t initial_byte_size, int level,
55 GenRemSet* remset);
56
57 public:
58
59 // Attempt to expand the generation by "bytes". Expand by at a
60 // minimum "expand_bytes". Return true if some amount (not
61 // necessarily the full "bytes") was done.
62 virtual bool expand(size_t bytes, size_t expand_bytes);
63
64 // Shrink generation with specified size
65 virtual void shrink(size_t bytes) = 0;
66
67 virtual void compute_new_size();
68
69 virtual void clear_remembered_set();
70
71 virtual void invalidate_remembered_set();
72
73 virtual void prepare_for_verify();
74
75 // Grow generation with specified size (returns false if unable to grow)
76 virtual bool grow_by(size_t bytes) = 0;
77 // Grow generation to reserved size.
78 virtual bool grow_to_reserved() = 0;
79 };
80
81 #endif // SHARE_VM_MEMORY_CARDGENERATION_HPP
|
14 *
15 * You should have received a copy of the GNU General Public License version
16 * 2 along with this work; if not, write to the Free Software Foundation,
17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 *
19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_VM_MEMORY_CARDGENERATION_HPP
26 #define SHARE_VM_MEMORY_CARDGENERATION_HPP
27
28 // Class CardGeneration is a generation that is covered by a card table,
29 // and uses a card-size block-offset array to implement block_start.
30
31 #include "memory/generation.hpp"
32
33 class BlockOffsetSharedArray;
34 class CompactibleSpace;
35
36 class CardGeneration: public Generation {
37 friend class VMStructs;
38 protected:
39 // This is shared with other generations.
40 GenRemSet* _rs;
41 // This is local to this generation.
42 BlockOffsetSharedArray* _bts;
43
44 // current shrinking effect: this damps shrinking when the heap gets empty.
45 size_t _shrink_factor;
46
47 size_t _min_heap_delta_bytes; // Minimum amount to expand.
48
49 // Some statistics from before gc started.
50 // These are gathered in the gc_prologue (and should_collect)
51 // to control growing/shrinking policy in spite of promotions.
52 size_t _capacity_at_prologue;
53 size_t _used_at_prologue;
54
55 CardGeneration(ReservedSpace rs, size_t initial_byte_size, int level,
56 GenRemSet* remset);
57
58 virtual void assert_correct_size_change_locking() = 0;
59
60 virtual CompactibleSpace* space() const = 0;
61
62 public:
63
64 // Attempt to expand the generation by "bytes". Expand by at a
65 // minimum "expand_bytes". Return true if some amount (not
66 // necessarily the full "bytes") was done.
67 virtual bool expand(size_t bytes, size_t expand_bytes);
68
69 // Shrink generation with specified size
70 virtual void shrink(size_t bytes);
71
72 virtual void compute_new_size();
73
74 virtual void clear_remembered_set();
75
76 virtual void invalidate_remembered_set();
77
78 virtual void prepare_for_verify();
79
80 // Grow generation with specified size (returns false if unable to grow)
81 bool grow_by(size_t bytes);
82 // Grow generation to reserved size.
83 bool grow_to_reserved();
84
85 size_t capacity() const;
86 size_t used() const;
87 size_t free() const;
88 MemRegion used_region() const;
89
90 void space_iterate(SpaceClosure* blk, bool usedOnly = false);
91
92 void younger_refs_iterate(OopsInGenClosure* blk);
93
94 bool is_in(const void* p) const;
95
96 CompactibleSpace* first_compaction_space() const;
97 };
98
99 #endif // SHARE_VM_MEMORY_CARDGENERATION_HPP
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