1 /*
2 * Copyright (c) 2002, 2014, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.
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.
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23 */
24
25 #ifndef SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSSCAVENGE_INLINE_HPP
26 #define SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSSCAVENGE_INLINE_HPP
27
28 #include "gc_implementation/parallelScavenge/cardTableExtension.hpp"
29 #include "gc_implementation/parallelScavenge/parallelScavengeHeap.hpp"
30 #include "gc_implementation/parallelScavenge/psPromotionManager.hpp"
31 #include "gc_implementation/parallelScavenge/psPromotionManager.inline.hpp"
32 #include "gc_implementation/parallelScavenge/psScavenge.hpp"
33 #include "memory/iterator.hpp"
34 #include "utilities/globalDefinitions.hpp"
35
36 inline void PSScavenge::save_to_space_top_before_gc() {
37 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
38 _to_space_top_before_gc = heap->young_gen()->to_space()->top();
39 }
40
41 template <class T> inline bool PSScavenge::should_scavenge(T* p) {
42 T heap_oop = oopDesc::load_heap_oop(p);
43 return PSScavenge::is_obj_in_young(heap_oop);
44 }
45
46 template <class T>
47 inline bool PSScavenge::should_scavenge(T* p, MutableSpace* to_space) {
48 if (should_scavenge(p)) {
49 oop obj = oopDesc::load_decode_heap_oop_not_null(p);
50 // Skip objects copied to to_space since the scavenge started.
51 HeapWord* const addr = (HeapWord*)obj;
52 return addr < to_space_top_before_gc() || addr >= to_space->end();
53 }
54 return false;
55 }
56
57 template <class T>
58 inline bool PSScavenge::should_scavenge(T* p, bool check_to_space) {
59 if (check_to_space) {
60 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
61 return should_scavenge(p, heap->young_gen()->to_space());
62 }
63 return should_scavenge(p);
64 }
65
66 // Attempt to "claim" oop at p via CAS, push the new obj if successful
67 // This version tests the oop* to make sure it is within the heap before
68 // attempting marking.
69 template <class T, bool promote_immediately>
70 inline void PSScavenge::copy_and_push_safe_barrier(PSPromotionManager* pm,
71 T* p) {
72 assert(should_scavenge(p, true), "revisiting object?");
73
74 oop o = oopDesc::load_decode_heap_oop_not_null(p);
75 oop new_obj = o->is_forwarded()
76 ? o->forwardee()
77 : pm->copy_to_survivor_space<promote_immediately>(o);
78
79 #ifndef PRODUCT
80 // This code must come after the CAS test, or it will print incorrect
81 // information.
82 if (TraceScavenge && o->is_forwarded()) {
83 gclog_or_tty->print_cr("{%s %s " PTR_FORMAT " -> " PTR_FORMAT " (%d)}",
84 "forwarding",
85 new_obj->klass()->internal_name(), p2i((void *)o), p2i((void *)new_obj), new_obj->size());
86 }
87 #endif
88
89 oopDesc::encode_store_heap_oop_not_null(p, new_obj);
90
91 // We cannot mark without test, as some code passes us pointers
92 // that are outside the heap. These pointers are either from roots
93 // or from metadata.
94 if ((!PSScavenge::is_obj_in_young((HeapWord*)p)) &&
95 Universe::heap()->is_in_reserved(p)) {
96 if (PSScavenge::is_obj_in_young(new_obj)) {
97 card_table()->inline_write_ref_field_gc(p, new_obj);
98 }
99 }
100 }
101
102 template<bool promote_immediately>
103 class PSRootsClosure: public OopClosure {
104 private:
105 PSPromotionManager* _promotion_manager;
106
107 protected:
108 template <class T> void do_oop_work(T *p) {
109 if (PSScavenge::should_scavenge(p)) {
110 // We never card mark roots, maybe call a func without test?
111 PSScavenge::copy_and_push_safe_barrier<T, promote_immediately>(_promotion_manager, p);
112 }
113 }
114 public:
115 PSRootsClosure(PSPromotionManager* pm) : _promotion_manager(pm) { }
116 void do_oop(oop* p) { PSRootsClosure::do_oop_work(p); }
117 void do_oop(narrowOop* p) { PSRootsClosure::do_oop_work(p); }
118 };
119
120 typedef PSRootsClosure</*promote_immediately=*/false> PSScavengeRootsClosure;
121 typedef PSRootsClosure</*promote_immediately=*/true> PSPromoteRootsClosure;
122
123 // Scavenges a single oop in a Klass.
124 class PSScavengeFromKlassClosure: public OopClosure {
125 private:
126 PSPromotionManager* _pm;
127 // Used to redirty a scanned klass if it has oops
128 // pointing to the young generation after being scanned.
129 Klass* _scanned_klass;
130 public:
131 PSScavengeFromKlassClosure(PSPromotionManager* pm) : _pm(pm), _scanned_klass(NULL) { }
132 void do_oop(narrowOop* p) { ShouldNotReachHere(); }
133 void do_oop(oop* p) {
134 ParallelScavengeHeap* psh = ParallelScavengeHeap::heap();
135 assert(!psh->is_in_reserved(p), "GC barrier needed");
136 if (PSScavenge::should_scavenge(p)) {
137 assert(!Universe::heap()->is_in_reserved(p), "Not from meta-data?");
138 assert(PSScavenge::should_scavenge(p, true), "revisiting object?");
139
140 oop o = *p;
141 oop new_obj;
142 if (o->is_forwarded()) {
143 new_obj = o->forwardee();
144 } else {
145 new_obj = _pm->copy_to_survivor_space</*promote_immediately=*/false>(o);
146 }
147 oopDesc::encode_store_heap_oop_not_null(p, new_obj);
148
149 if (PSScavenge::is_obj_in_young(new_obj)) {
150 do_klass_barrier();
151 }
152 }
153 }
154
155 void set_scanned_klass(Klass* klass) {
156 assert(_scanned_klass == NULL || klass == NULL, "Should always only handling one klass at a time");
157 _scanned_klass = klass;
158 }
159
160 private:
161 void do_klass_barrier() {
162 assert(_scanned_klass != NULL, "Should not be called without having a scanned klass");
163 _scanned_klass->record_modified_oops();
164 }
165
166 };
167
168 // Scavenges the oop in a Klass.
169 class PSScavengeKlassClosure: public KlassClosure {
170 private:
171 PSScavengeFromKlassClosure _oop_closure;
172 protected:
173 public:
174 PSScavengeKlassClosure(PSPromotionManager* pm) : _oop_closure(pm) { }
175 void do_klass(Klass* klass) {
176 // If the klass has not been dirtied we know that there's
177 // no references into the young gen and we can skip it.
178
179 #ifndef PRODUCT
180 if (TraceScavenge) {
181 ResourceMark rm;
182 gclog_or_tty->print_cr("PSScavengeKlassClosure::do_klass " PTR_FORMAT ", %s, dirty: %s",
183 p2i(klass),
184 klass->external_name(),
185 klass->has_modified_oops() ? "true" : "false");
186 }
187 #endif
188
189 if (klass->has_modified_oops()) {
190 // Clean the klass since we're going to scavenge all the metadata.
191 klass->clear_modified_oops();
192
193 // Setup the promotion manager to redirty this klass
194 // if references are left in the young gen.
195 _oop_closure.set_scanned_klass(klass);
196
197 klass->oops_do(&_oop_closure);
198
199 _oop_closure.set_scanned_klass(NULL);
200 }
201 }
202 };
203
204 #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSSCAVENGE_INLINE_HPP