9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
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_GC_SHARED_MODREFBARRIERSET_HPP
26 #define SHARE_VM_GC_SHARED_MODREFBARRIERSET_HPP
27
28 #include "gc/shared/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 // Barriers only on ref writes.
41 bool has_read_ref_barrier() { return false; }
42 bool has_read_prim_barrier() { return false; }
43 bool has_write_ref_barrier() { return true; }
44 bool has_write_prim_barrier() { return false; }
45
46 bool read_ref_needs_barrier(void* field) { return false; }
47 bool read_prim_needs_barrier(HeapWord* field, size_t bytes) { return false; }
48 bool write_prim_needs_barrier(HeapWord* field, size_t bytes,
49 juint val1, juint val2) { return false; }
50
51 void write_prim_field(oop obj, size_t offset, size_t bytes,
52 juint val1, juint val2) {}
53
54 void read_ref_field(void* field) {}
55 void read_prim_field(HeapWord* field, size_t bytes) {}
56
57 protected:
58
59 ModRefBarrierSet(const BarrierSet::FakeRtti& fake_rtti)
60 : BarrierSet(fake_rtti.add_tag(BarrierSet::ModRef)) { }
61 ~ModRefBarrierSet() { }
62
63 public:
64 void write_prim_field(HeapWord* field, size_t bytes,
65 juint val1, juint val2) {}
66
67 bool has_read_ref_array_opt() { return false; }
68 bool has_read_prim_array_opt() { return false; }
69 bool has_write_prim_array_opt() { return false; }
70
71 bool has_read_region_opt() { return false; }
72
73
74 // These operations should assert false unless the corresponding operation
75 // above returns true.
76 void read_ref_array(MemRegion mr) {
77 assert(false, "can't call");
78 }
79 void read_prim_array(MemRegion mr) {
80 assert(false, "can't call");
81 }
82 void write_prim_array(MemRegion mr) {
83 assert(false, "can't call");
84 }
85 void read_region(MemRegion mr) {
86 assert(false, "can't call");
87 }
88
89 // Causes all refs in "mr" to be assumed to be modified.
90 virtual void invalidate(MemRegion mr) = 0;
91
92 // The caller guarantees that "mr" contains no references. (Perhaps it's
93 // objects have been moved elsewhere.)
94 virtual void clear(MemRegion mr) = 0;
95 };
96
97 template<>
98 struct BarrierSet::GetName<ModRefBarrierSet> {
99 static const BarrierSet::Name value = BarrierSet::ModRef;
100 };
101
102 #endif // SHARE_VM_GC_SHARED_MODREFBARRIERSET_HPP
|
9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 * version 2 for more details (a copy is included in the LICENSE file that
13 * accompanied this code).
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_GC_SHARED_MODREFBARRIERSET_HPP
26 #define SHARE_VM_GC_SHARED_MODREFBARRIERSET_HPP
27
28 #include "gc/shared/barrierSet.hpp"
29 #include "memory/memRegion.hpp"
30
31 class Klass;
32
33 class ModRefBarrierSet: public BarrierSet {
34 protected:
35 ModRefBarrierSet(const BarrierSet::FakeRtti& fake_rtti)
36 : BarrierSet(fake_rtti.add_tag(BarrierSet::ModRef)) { }
37 ~ModRefBarrierSet() { }
38
39 virtual void write_ref_array_region(MemRegion mr) = 0;
40
41 // These methods serve the only purpose of speeding up build times by reducing
42 // included files
43 static Klass* bound_for_array(oop obj);
44 static bool is_bounded_by(oop obj, Klass* klass);
45
46 public:
47 // Causes all refs in "mr" to be assumed to be modified.
48 virtual void invalidate(MemRegion mr) = 0;
49
50 // Operations on arrays, or general regions (e.g., for "clone") may be
51 // optimized by some barriers.
52
53 // Below length is the # array elements being written
54 virtual void write_ref_array_pre(oop* dst, int length,
55 bool dest_uninitialized = false) {}
56 virtual void write_ref_array_pre(narrowOop* dst, int length,
57 bool dest_uninitialized = false) {}
58 // Below count is the # array elements being written, starting
59 // at the address "start", which may not necessarily be HeapWord-aligned
60 inline void write_ref_array(HeapWord* start, size_t count);
61
62 // Static versions, suitable for calling from generated code;
63 // count is # array elements being written, starting with "start",
64 // which may not necessarily be HeapWord-aligned.
65 static void static_write_ref_array_pre(HeapWord* start, size_t count);
66 static void static_write_ref_array_post(HeapWord* start, size_t count);
67
68 template <DecoratorSet decorators>
69 inline void write_ref_field_pre(void* addr) {}
70
71 template <DecoratorSet decorators>
72 inline void write_ref_field_post(void *addr, oop new_value) {}
73
74 // barriers used by klass_oop_store
75 void klass_update_barrier_set_pre(Klass* klass, oop* p) {}
76 void klass_update_barrier_set(Klass* klass, oop* p, oop v);
77
78 template <DecoratorSet decorators, typename BarrierSetT>
79 class AccessBarrier: public BarrierSet::AccessBarrier<decorators> {
80 typedef BarrierSet::AccessBarrier<decorators> Basic;
81
82 public:
83 typedef Basic SuperAccessBarrier;
84
85 static void oop_store(void* addr, oop value);
86
87 static oop oop_cas(oop new_value, void* addr, oop compare_value);
88
89 static oop oop_swap(oop new_value, void* addr);
90
91 template <typename T>
92 static bool oop_copy(arrayOop src_obj, arrayOop dst_obj, T* src, T* dst, size_t length);
93
94 static void clone(oop src, oop dst, size_t size);
95
96 static inline void oop_store_at(oop base, ptrdiff_t offset, oop value) {
97 oop_store(Basic::field_addr(base, offset), value);
98 }
99
100 static inline void oop_store_at(Klass* base, ptrdiff_t offset, oop value);
101
102 static inline oop oop_swap_at(oop new_value, oop base, ptrdiff_t offset) {
103 return oop_swap(new_value, Basic::field_addr(base, offset));
104 }
105
106 static inline oop oop_cas_at(oop new_value, oop base, ptrdiff_t offset, oop compare_value) {
107 return oop_cas(new_value, Basic::field_addr(base, offset), compare_value);
108 }
109 };
110 };
111
112 template<>
113 struct BSTypeToName<ModRefBarrierSet> {
114 static const BarrierSet::Name value = BarrierSet::ModRef;
115 };
116
117 template<>
118 struct BSNameToType<BarrierSet::ModRef> {
119 typedef ModRefBarrierSet type;
120 };
121
122 #endif // SHARE_VM_GC_SHARED_MODREFBARRIERSET_HPP
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