20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_VM_MEMORY_MODREFBARRIERSET_HPP
26 #define SHARE_VM_MEMORY_MODREFBARRIERSET_HPP
27
28 #include "memory/barrierSet.hpp"
29
30 // This kind of "BarrierSet" allows a "CollectedHeap" to detect and
31 // enumerate ref fields that have been modified (since the last
32 // enumeration), using a card table.
33
34 class OopClosure;
35 class Generation;
36
37 class ModRefBarrierSet: public BarrierSet {
38 public:
39
40 ModRefBarrierSet() { _kind = BarrierSet::ModRef; }
41
42 bool is_a(BarrierSet::Name bsn) {
43 return bsn == BarrierSet::ModRef;
44 }
45
46 // Barriers only on ref writes.
47 bool has_read_ref_barrier() { return false; }
48 bool has_read_prim_barrier() { return false; }
49 bool has_write_ref_barrier() { return true; }
50 bool has_write_prim_barrier() { return false; }
51
52 bool read_ref_needs_barrier(void* field) { return false; }
53 bool read_prim_needs_barrier(HeapWord* field, size_t bytes) { return false; }
54 bool write_prim_needs_barrier(HeapWord* field, size_t bytes,
55 juint val1, juint val2) { return false; }
56
57 void write_prim_field(oop obj, size_t offset, size_t bytes,
58 juint val1, juint val2) {}
59
60 void read_ref_field(void* field) {}
78 assert(false, "can't call");
79 }
80 void read_prim_array(MemRegion mr) {
81 assert(false, "can't call");
82 }
83 void write_prim_array(MemRegion mr) {
84 assert(false, "can't call");
85 }
86 void read_region(MemRegion mr) {
87 assert(false, "can't call");
88 }
89
90 // Causes all refs in "mr" to be assumed to be modified. If "whole_heap"
91 // is true, the caller asserts that the entire heap is being invalidated,
92 // which may admit an optimized implementation for some barriers.
93 virtual void invalidate(MemRegion mr, bool whole_heap = false) = 0;
94
95 // The caller guarantees that "mr" contains no references. (Perhaps it's
96 // objects have been moved elsewhere.)
97 virtual void clear(MemRegion mr) = 0;
98
99 // Pass along the argument to the superclass.
100 ModRefBarrierSet(int max_covered_regions) :
101 BarrierSet(max_covered_regions) {}
102 };
103
104 #endif // SHARE_VM_MEMORY_MODREFBARRIERSET_HPP
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20 * or visit www.oracle.com if you need additional information or have any
21 * questions.
22 *
23 */
24
25 #ifndef SHARE_VM_MEMORY_MODREFBARRIERSET_HPP
26 #define SHARE_VM_MEMORY_MODREFBARRIERSET_HPP
27
28 #include "memory/barrierSet.hpp"
29
30 // This kind of "BarrierSet" allows a "CollectedHeap" to detect and
31 // enumerate ref fields that have been modified (since the last
32 // enumeration), using a card table.
33
34 class OopClosure;
35 class Generation;
36
37 class ModRefBarrierSet: public BarrierSet {
38 public:
39
40 ModRefBarrierSet() : BarrierSet() { _kind = BarrierSet::ModRef; }
41
42 bool is_a(BarrierSet::Name bsn) {
43 return bsn == BarrierSet::ModRef;
44 }
45
46 // Barriers only on ref writes.
47 bool has_read_ref_barrier() { return false; }
48 bool has_read_prim_barrier() { return false; }
49 bool has_write_ref_barrier() { return true; }
50 bool has_write_prim_barrier() { return false; }
51
52 bool read_ref_needs_barrier(void* field) { return false; }
53 bool read_prim_needs_barrier(HeapWord* field, size_t bytes) { return false; }
54 bool write_prim_needs_barrier(HeapWord* field, size_t bytes,
55 juint val1, juint val2) { return false; }
56
57 void write_prim_field(oop obj, size_t offset, size_t bytes,
58 juint val1, juint val2) {}
59
60 void read_ref_field(void* field) {}
78 assert(false, "can't call");
79 }
80 void read_prim_array(MemRegion mr) {
81 assert(false, "can't call");
82 }
83 void write_prim_array(MemRegion mr) {
84 assert(false, "can't call");
85 }
86 void read_region(MemRegion mr) {
87 assert(false, "can't call");
88 }
89
90 // Causes all refs in "mr" to be assumed to be modified. If "whole_heap"
91 // is true, the caller asserts that the entire heap is being invalidated,
92 // which may admit an optimized implementation for some barriers.
93 virtual void invalidate(MemRegion mr, bool whole_heap = false) = 0;
94
95 // The caller guarantees that "mr" contains no references. (Perhaps it's
96 // objects have been moved elsewhere.)
97 virtual void clear(MemRegion mr) = 0;
98 };
99
100 #endif // SHARE_VM_MEMORY_MODREFBARRIERSET_HPP
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