1 /*
2 * Copyright (c) 2013, 2015, Red Hat, Inc. and/or its affiliates.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation.
7 *
8 * This code is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
11 * version 2 for more details (a copy is included in the LICENSE file that
12 * accompanied this code).
13 *
14 * You should have received a copy of the GNU General Public License version
15 * 2 along with this work; if not, write to the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
17 *
18 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
19 * or visit www.oracle.com if you need additional information or have any
20 * questions.
21 *
22 */
23
24 #ifndef SHARE_VM_GC_SHENANDOAH_SHENANDOAHBARRIERSET_HPP
25 #define SHARE_VM_GC_SHENANDOAH_SHENANDOAHBARRIERSET_HPP
26
27 #include "gc/shenandoah/shenandoahHeap.hpp"
28 #include "gc/shared/barrierSet.hpp"
29
30 class ShenandoahBarrierSet: public BarrierSet {
31 private:
32
33 static inline oop get_shenandoah_forwardee_helper(oop p) {
34 assert(UseShenandoahGC, "must only be called when Shenandoah is used.");
35 assert(Universe::heap()->is_in(p), "We shouldn't be calling this on objects not in the heap");
36 oop forwardee;
37 #ifdef ASSERT
38 if (ShenandoahVerifyReadsToFromSpace) {
39 ShenandoahHeap* heap = (ShenandoahHeap *) Universe::heap();
40 ShenandoahHeapRegion* region = heap->heap_region_containing(p);
41 {
42 region->memProtectionOff();
43 forwardee = oop( *((HeapWord**) ((HeapWord*) p) - 1));
44 region->memProtectionOn();
45 }
46 } else {
47 forwardee = oop( *((HeapWord**) ((HeapWord*) p) - 1));
48 }
49 #else
50 forwardee = oop( *((HeapWord**) ((HeapWord*) p) - 1));
51 #endif
52 return forwardee;
53 }
54
55 public:
56
57 ShenandoahBarrierSet();
58
59 void print_on(outputStream* st) const;
60
61 bool is_a(BarrierSet::Name bsn);
62
63 bool has_read_prim_array_opt();
64 bool has_read_prim_barrier();
65 bool has_read_ref_array_opt();
66 bool has_read_ref_barrier();
67 bool has_read_region_opt();
68 bool has_write_prim_array_opt();
69 bool has_write_prim_barrier();
70 bool has_write_ref_array_opt();
71 bool has_write_ref_barrier();
72 bool has_write_ref_pre_barrier();
73 bool has_write_region_opt();
74 bool is_aligned(HeapWord* hw);
75 void read_prim_array(MemRegion mr);
76 void read_prim_field(HeapWord* hw, size_t s);
77 bool read_prim_needs_barrier(HeapWord* hw, size_t s);
78 void read_ref_array(MemRegion mr);
79
80 void read_ref_field(void* v);
81
82 bool read_ref_needs_barrier(void* v);
83 void read_region(MemRegion mr);
84 void resize_covered_region(MemRegion mr);
85 void write_prim_array(MemRegion mr);
86 void write_prim_field(HeapWord* hw, size_t s , juint x, juint y);
87 bool write_prim_needs_barrier(HeapWord* hw, size_t s, juint x, juint y);
88 void write_ref_array_work(MemRegion mr);
89
90 template <class T> void
91 write_ref_array_pre_work(T* dst, int count);
92
93 void write_ref_array_pre(oop* dst, int count, bool dest_uninitialized);
94
95 void write_ref_array_pre(narrowOop* dst, int count, bool dest_uninitialized);
96
97
98 template <class T> static void write_ref_field_pre_static(T* field, oop newVal);
99
100 // We export this to make it available in cases where the static
101 // type of the barrier set is known. Note that it is non-virtual.
102 template <class T> inline void inline_write_ref_field_pre(T* field, oop newVal);
103
104 // These are the more general virtual versions.
105 void write_ref_field_pre_work(oop* field, oop new_val);
106 void write_ref_field_pre_work(narrowOop* field, oop new_val);
107 void write_ref_field_pre_work(void* field, oop new_val);
108
109 void write_ref_field_work(void* v, oop o, bool release = false);
110 void write_region_work(MemRegion mr);
111
112 virtual oop read_barrier(oop src);
113
114 template <class T>
115 static inline oop resolve_and_update_oop_static(T p, oop obj) {
116 oop forw = ShenandoahBarrierSet::resolve_oop_static_not_null(obj);
117 if (forw != obj) {
118 obj = forw;
119 oopDesc::encode_store_heap_oop_not_null(p, obj);
120 }
121 return obj;
122 }
123
124 static inline oop resolve_oop_static_not_null(oop p) {
125 assert(p != NULL, "Must be NULL checked");
126
127 oop result = get_shenandoah_forwardee_helper(p);
128
129 if (result != NULL) {
130 #ifdef ASSERT
131 if (result != p) {
132 oop second_forwarding = get_shenandoah_forwardee_helper(result);
133
134 // We should never be forwarded more than once.
135 if (result != second_forwarding) {
136 ShenandoahHeap* sh = (ShenandoahHeap*) Universe::heap();
137 tty->print("first reference "PTR_FORMAT" is in heap region:\n", p2i((HeapWord*) p));
138 sh->heap_region_containing(p)->print();
139 tty->print("first_forwarding "PTR_FORMAT" is in heap region:\n", p2i((HeapWord*) result));
140 sh->heap_region_containing(result)->print();
141 tty->print("final reference "PTR_FORMAT" is in heap region:\n", p2i((HeapWord*) second_forwarding));
142 sh->heap_region_containing(second_forwarding)->print();
143 assert(get_shenandoah_forwardee_helper(result) == result, "Only one fowarding per customer");
144 }
145 }
146 #endif
147 if (! ShenandoahVerifyReadsToFromSpace) {
148 // is_oop() would trigger a SEGFAULT when we're checking from-space-access.
149 assert(ShenandoahHeap::heap()->is_in(result) && result->is_oop(), "resolved oop must be a valid oop in the heap");
150 }
151 }
152 return result;
153 }
154
155 static inline oop resolve_oop_static(oop p) {
156 if (((HeapWord*) p) != NULL) {
157 return resolve_oop_static_not_null(p);
158 } else {
159 return p;
160 }
161 }
162
163 static inline oop resolve_oop_static_no_check(oop p) {
164 if (((HeapWord*) p) != NULL) {
165 return get_shenandoah_forwardee_helper(p);
166 } else {
167 return p;
168 }
169 }
170
171
172 oop resolve_and_maybe_copy_oopHelper(oop src);
173 oop resolve_and_maybe_copy_oop_work(oop src);
174 oop resolve_and_maybe_copy_oop_work2(oop src);
175 virtual oop write_barrier(oop src);
176
177 static oopDesc* resolve_and_maybe_copy_oop_c2(oopDesc* src);
178 static oopDesc* resolve_and_maybe_copy_oop_interp(oopDesc* src);
179 static oopDesc* resolve_and_maybe_copy_oop_c1(JavaThread* thread, oopDesc* src);
180
181 private:
182 bool need_update_refs_barrier();
183
184 #ifndef CC_INTERP
185 public:
186 virtual void interpreter_read_barrier(MacroAssembler* masm, Register dst);
187 virtual void interpreter_read_barrier_not_null(MacroAssembler* masm, Register dst);
188 void interpreter_write_barrier(MacroAssembler* masm, Register dst);
189
190 private:
191 void compile_resolve_oop_runtime(MacroAssembler* masm, Register dst);
192
193 #endif
194 };
195
196 #endif //SHARE_VM_GC_SHENANDOAH_SHENANDOAHBARRIERSET_HPP