8 *
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_BARRIERSET_HPP
26 #define SHARE_VM_GC_SHARED_BARRIERSET_HPP
27
28 #include "memory/memRegion.hpp"
29 #include "oops/oopsHierarchy.hpp"
30 #include "utilities/fakeRttiSupport.hpp"
31
32 // This class provides the interface between a barrier implementation and
33 // the rest of the system.
34
35 class BarrierSet: public CHeapObj<mtGC> {
36 friend class VMStructs;
37 public:
38 // Fake RTTI support. For a derived class T to participate
39 // - T must have a corresponding Name entry.
40 // - GetName<T> must be specialized to return the corresponding Name
41 // entry.
42 // - If T is a base class, the constructor must have a FakeRtti
43 // parameter and pass it up to its base class, with the tag set
44 // augmented with the corresponding Name entry.
45 // - If T is a concrete class, the constructor must create a
46 // FakeRtti object whose tag set includes the corresponding Name
47 // entry, and pass it up to its base class.
48
49 enum Name { // associated class
50 ModRef, // ModRefBarrierSet
51 CardTableModRef, // CardTableModRefBS
52 CardTableForRS, // CardTableModRefBSForCTRS
53 CardTableExtension, // CardTableExtension
54 G1SATBCT, // G1SATBCardTableModRefBS
55 G1SATBCTLogging // G1SATBCardTableLoggingModRefBS
56 };
57
58 protected:
59 typedef FakeRttiSupport<BarrierSet, Name> FakeRtti;
60
61 private:
62 FakeRtti _fake_rtti;
63
64 // Metafunction mapping a class derived from BarrierSet to the
65 // corresponding Name enum tag.
66 template<typename T> struct GetName;
67
68 // Downcast argument to a derived barrier set type.
69 // The cast is checked in a debug build.
70 // T must have a specialization for BarrierSet::GetName<T>.
71 template<typename T> friend T* barrier_set_cast(BarrierSet* bs);
72
73 public:
74 // Note: This is not presently the Name corresponding to the
75 // concrete class of this object.
76 BarrierSet::Name kind() const { return _fake_rtti.concrete_tag(); }
77
78 // Test whether this object is of the type corresponding to bsn.
79 bool is_a(BarrierSet::Name bsn) const { return _fake_rtti.has_tag(bsn); }
80
81 // End of fake RTTI support.
82
83 public:
84 enum Flags {
85 None = 0,
86 TargetUninitialized = 1
87 };
88
89 protected:
90 // Some barrier sets create tables whose elements correspond to parts of
91 // the heap; the CardTableModRefBS is an example. Such barrier sets will
92 // normally reserve space for such tables, and commit parts of the table
93 // "covering" parts of the heap that are committed. At most one covered
94 // region per generation is needed.
95 static const int _max_covered_regions = 2;
96
97 BarrierSet(const FakeRtti& fake_rtti) : _fake_rtti(fake_rtti) { }
98 ~BarrierSet() { }
99
100 public:
101
102 // These operations indicate what kind of barriers the BarrierSet has.
103 virtual bool has_read_ref_barrier() = 0;
104 virtual bool has_read_prim_barrier() = 0;
105 virtual bool has_write_ref_barrier() = 0;
106 virtual bool has_write_ref_pre_barrier() = 0;
107 virtual bool has_write_prim_barrier() = 0;
108
109 // These functions indicate whether a particular access of the given
110 // kinds requires a barrier.
111 virtual bool read_ref_needs_barrier(void* field) = 0;
112 virtual bool read_prim_needs_barrier(HeapWord* field, size_t bytes) = 0;
113 virtual bool write_prim_needs_barrier(HeapWord* field, size_t bytes,
114 juint val1, juint val2) = 0;
115
116 // The first four operations provide a direct implementation of the
117 // barrier set. An interpreter loop, for example, could call these
118 // directly, as appropriate.
119
120 // Invoke the barrier, if any, necessary when reading the given ref field.
121 virtual void read_ref_field(void* field) = 0;
122
123 // Invoke the barrier, if any, necessary when reading the given primitive
124 // "field" of "bytes" bytes in "obj".
125 virtual void read_prim_field(HeapWord* field, size_t bytes) = 0;
126
127 // Invoke the barrier, if any, necessary when writing "new_val" into the
128 // ref field at "offset" in "obj".
129 // (For efficiency reasons, this operation is specialized for certain
130 // barrier types. Semantically, it should be thought of as a call to the
131 // virtual "_work" function below, which must implement the barrier.)
132 // First the pre-write versions...
133 template <class T> inline void write_ref_field_pre(T* field, oop new_val);
134 private:
135 // Helper for write_ref_field_pre and friends, testing for specialized cases.
136 bool devirtualize_reference_writes() const;
137
138 // Keep this private so as to catch violations at build time.
139 virtual void write_ref_field_pre_work( void* field, oop new_val) { guarantee(false, "Not needed"); };
140 protected:
141 virtual void write_ref_field_pre_work( oop* field, oop new_val) {};
142 virtual void write_ref_field_pre_work(narrowOop* field, oop new_val) {};
143 public:
144
145 // ...then the post-write version.
146 inline void write_ref_field(void* field, oop new_val, bool release = false);
147 protected:
148 virtual void write_ref_field_work(void* field, oop new_val, bool release) = 0;
149 public:
150
151 // Invoke the barrier, if any, necessary when writing the "bytes"-byte
152 // value(s) "val1" (and "val2") into the primitive "field".
153 virtual void write_prim_field(HeapWord* field, size_t bytes,
154 juint val1, juint val2) = 0;
155
156 // Operations on arrays, or general regions (e.g., for "clone") may be
157 // optimized by some barriers.
158
159 // The first six operations tell whether such an optimization exists for
160 // the particular barrier.
161 virtual bool has_read_ref_array_opt() = 0;
162 virtual bool has_read_prim_array_opt() = 0;
163 virtual bool has_write_ref_array_pre_opt() { return true; }
164 virtual bool has_write_ref_array_opt() = 0;
165 virtual bool has_write_prim_array_opt() = 0;
166
167 virtual bool has_read_region_opt() = 0;
168 virtual bool has_write_region_opt() = 0;
169
170 // These operations should assert false unless the corresponding operation
171 // above returns true. Otherwise, they should perform an appropriate
172 // barrier for an array whose elements are all in the given memory region.
173 virtual void read_ref_array(MemRegion mr) = 0;
174 virtual void read_prim_array(MemRegion mr) = 0;
175
176 // Below length is the # array elements being written
177 virtual void write_ref_array_pre(oop* dst, int length,
178 bool dest_uninitialized = false) {}
179 virtual void write_ref_array_pre(narrowOop* dst, int length,
180 bool dest_uninitialized = false) {}
181 // Below count is the # array elements being written, starting
182 // at the address "start", which may not necessarily be HeapWord-aligned
183 inline void write_ref_array(HeapWord* start, size_t count);
184
185 // Static versions, suitable for calling from generated code;
186 // count is # array elements being written, starting with "start",
187 // which may not necessarily be HeapWord-aligned.
188 static void static_write_ref_array_pre(HeapWord* start, size_t count);
189 static void static_write_ref_array_post(HeapWord* start, size_t count);
190
191 virtual void write_ref_nmethod_pre(oop* dst, nmethod* nm) {}
192 virtual void write_ref_nmethod_post(oop* dst, nmethod* nm) {}
193
194 protected:
195 virtual void write_ref_array_work(MemRegion mr) = 0;
196 public:
197 virtual void write_prim_array(MemRegion mr) = 0;
198
199 virtual void read_region(MemRegion mr) = 0;
200
201 // (For efficiency reasons, this operation is specialized for certain
202 // barrier types. Semantically, it should be thought of as a call to the
203 // virtual "_work" function below, which must implement the barrier.)
204 void write_region(MemRegion mr);
205 protected:
206 virtual void write_region_work(MemRegion mr) = 0;
207 public:
208 // Inform the BarrierSet that the the covered heap region that starts
209 // with "base" has been changed to have the given size (possibly from 0,
210 // for initialization.)
211 virtual void resize_covered_region(MemRegion new_region) = 0;
212
213 // If the barrier set imposes any alignment restrictions on boundaries
214 // within the heap, this function tells whether they are met.
215 virtual bool is_aligned(HeapWord* addr) = 0;
216
217 // Print a description of the memory for the barrier set
218 virtual void print_on(outputStream* st) const = 0;
219 };
220
221 template<typename T>
222 inline T* barrier_set_cast(BarrierSet* bs) {
223 assert(bs->is_a(BarrierSet::GetName<T>::value), "wrong type of barrier set");
224 return static_cast<T*>(bs);
225 }
226
227 #endif // SHARE_VM_GC_SHARED_BARRIERSET_HPP
|
8 *
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_BARRIERSET_HPP
26 #define SHARE_VM_GC_SHARED_BARRIERSET_HPP
27
28 #include "gc/shared/barrierSetConfig.hpp"
29 #include "runtime/access.hpp"
30 #include "runtime/accessBackend.hpp"
31 #include "utilities/fakeRttiSupport.hpp"
32
33 class JavaThread;
34 class BarrierSetCodeGen;
35 class C1BarrierSetCodeGen;
36 class C2BarrierSetCodeGen;
37
38 // This class provides the interface between a barrier implementation and
39 // the rest of the system.
40
41 class BarrierSet: public CHeapObj<mtGC> {
42 friend class VMStructs;
43 public:
44 enum Name {
45 #define BARRIER_SET_DECLARE_BS_ENUM(bs_name) bs_name ,
46 FOR_EACH_BARRIER_SET_DO(BARRIER_SET_DECLARE_BS_ENUM)
47 #undef BARRIER_SET_DECLARE_BS_ENUM
48 UnknownBS
49 };
50 protected:
51 // Fake RTTI support. For a derived class T to participate
52 // - T must have a corresponding Name entry.
53 // - GetName<T> must be specialized to return the corresponding Name
54 // entry.
55 // - If T is a base class, the constructor must have a FakeRtti
56 // parameter and pass it up to its base class, with the tag set
57 // augmented with the corresponding Name entry.
58 // - If T is a concrete class, the constructor must create a
59 // FakeRtti object whose tag set includes the corresponding Name
60 // entry, and pass it up to its base class.
61 typedef FakeRttiSupport<BarrierSet, Name> FakeRtti;
62
63 private:
64 FakeRtti _fake_rtti;
65
66 // Downcast argument to a derived barrier set type.
67 // The cast is checked in a debug build.
68 // T must have a specialization for BarrierSet::GetName<T>.
69 template<typename T> friend T* barrier_set_cast(BarrierSet* bs);
70
71 public:
72 // Note: This is not presently the Name corresponding to the
73 // concrete class of this object.
74 BarrierSet::Name kind() const { return _fake_rtti.concrete_tag(); }
75
76 // Test whether this object is of the type corresponding to bsn.
77 bool is_a(BarrierSet::Name bsn) const { return _fake_rtti.has_tag(bsn); }
78
79 // End of fake RTTI support.
80
81 protected:
82 BarrierSet(const FakeRtti& fake_rtti) : _fake_rtti(fake_rtti), _code_gen(NULL), _c1_code_gen(NULL), _c2_code_gen(NULL) { }
83 ~BarrierSet() { }
84
85 static BarrierSet* _bs;
86
87 BarrierSetCodeGen* _code_gen;
88 C1BarrierSetCodeGen* _c1_code_gen;
89 C2BarrierSetCodeGen* _c2_code_gen;
90
91 virtual BarrierSetCodeGen* make_code_gen() = 0;
92 virtual C1BarrierSetCodeGen* make_c1_code_gen() = 0;
93 virtual C2BarrierSetCodeGen* make_c2_code_gen() = 0;
94
95 public:
96 static BarrierSet* barrier_set() { return _bs; }
97
98 // Print a description of the memory for the barrier set
99 virtual void print_on(outputStream* st) const = 0;
100
101 virtual void initialize();
102
103 BarrierSetCodeGen* code_gen() {
104 assert(_code_gen != NULL, "should be set");
105 return _code_gen;
106 }
107
108 C1BarrierSetCodeGen* c1_code_gen() {
109 assert(_c1_code_gen != NULL, "should be set");
110 return _c1_code_gen;
111 }
112
113 C2BarrierSetCodeGen* c2_code_gen() {
114 assert(_c2_code_gen != NULL, "should be set");
115 return _c2_code_gen;
116 }
117
118 // The AccessBarrier of a BarrierSet subclass is called by the Access API
119 // to perform decorated accesses.
120 template <DecoratorSet decorators>
121 class AccessBarrier: public BasicAccessBarrier<decorators> {
122 typedef BasicAccessBarrier<decorators> Basic;
123 public:
124 static void oop_store(void* addr, oop value);
125 static void oop_store_at(oop base, ptrdiff_t offset, oop value);
126 static void oop_store_at(nmethod* base, ptrdiff_t offset, oop value);
127 static void oop_store_at(Klass* base, ptrdiff_t offset, oop value);
128
129 static oop oop_load(void* addr);
130 static oop oop_load_at(oop base, ptrdiff_t offset);
131
132 static oop oop_cas(oop new_value, void* addr, oop compare_value);
133 static oop oop_cas_at(oop new_value, oop base, ptrdiff_t offset, oop compare_value);
134
135 static oop oop_swap(oop new_value, void* addr);
136 static oop oop_swap_at(oop new_value, oop base, ptrdiff_t offset);
137 };
138
139 // Support for optimizing compilers to call the barrier set on slow path allocations
140 // that did not enter a TLAB. Used for e.g. ReduceInitialCardMarks
141 virtual void on_slowpath_allocation(JavaThread* thread, oop new_obj) {}
142 virtual void on_add_thread(JavaThread* thread) {}
143 virtual void on_destroy_thread(JavaThread* thread) {}
144 virtual void make_parsable(JavaThread* thread) {}
145
146 // Resolve runtime paths for GC barriers accessible through the Access interface
147 // in runtime/access.hpp
148 template <DecoratorSet decorators, typename T, BarrierType barrier_type>
149 void* resolve_barrier();
150
151 template <DecoratorSet decorators>
152 void* resolve_clone_barrier();
153 };
154
155 // Metafunction mapping a class derived from BarrierSet to the
156 // corresponding Name enum tag.
157 template<typename T> struct BSTypeToName;
158 template<BarrierSet::Name T> struct BSNameToType;
159
160 template<typename T>
161 inline T* barrier_set_cast(BarrierSet* bs) {
162 assert(bs->is_a(BSTypeToName<T>::value), "wrong type of barrier set");
163 return static_cast<T*>(bs);
164 }
165
166 #endif // SHARE_VM_GC_SHARED_BARRIERSET_HPP
|