1 /*
2 * Copyright (c) 2002, 2012, 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.
22 *
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
35 inline void PSScavenge::save_to_space_top_before_gc() {
36 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
37 _to_space_top_before_gc = heap->young_gen()->to_space()->top();
38 }
39
40 template <class T> inline bool PSScavenge::should_scavenge(T* p) {
41 T heap_oop = oopDesc::load_heap_oop(p);
42 if (oopDesc::is_null(heap_oop)) return false;
43 oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
44 return PSScavenge::is_obj_in_young((HeapWord*)obj);
45 }
46
47 template <class T>
48 inline bool PSScavenge::should_scavenge(T* p, MutableSpace* to_space) {
49 if (should_scavenge(p)) {
50 oop obj = oopDesc::load_decode_heap_oop_not_null(p);
51 // Skip objects copied to to_space since the scavenge started.
52 HeapWord* const addr = (HeapWord*)obj;
53 return addr < to_space_top_before_gc() || addr >= to_space->end();
54 }
55 return false;
56 }
57
58 template <class T>
59 inline bool PSScavenge::should_scavenge(T* p, bool check_to_space) {
60 if (check_to_space) {
61 ParallelScavengeHeap* heap = (ParallelScavengeHeap*)Universe::heap();
62 return should_scavenge(p, heap->young_gen()->to_space());
63 }
64 return should_scavenge(p);
65 }
66
67 // Attempt to "claim" oop at p via CAS, push the new obj if successful
68 // This version tests the oop* to make sure it is within the heap before
69 // attempting marking.
70 template <class T, bool promote_immediately>
71 inline void PSScavenge::copy_and_push_safe_barrier(PSPromotionManager* pm,
72 T* p) {
73 assert(should_scavenge(p, true), "revisiting object?");
74
75 oop o = oopDesc::load_decode_heap_oop_not_null(p);
76 oop new_obj = o->is_forwarded()
77 ? o->forwardee()
78 : pm->copy_to_survivor_space<promote_immediately>(o);
79
80 #ifndef PRODUCT
81 // This code must come after the CAS test, or it will print incorrect
82 // information.
83 if (TraceScavenge && o->is_forwarded()) {
84 gclog_or_tty->print_cr("{%s %s " PTR_FORMAT " -> " PTR_FORMAT " (%d)}",
85 "forwarding",
86 new_obj->klass()->internal_name(), o, new_obj, new_obj->size());
87 }
88 #endif
89
90 oopDesc::encode_store_heap_oop_not_null(p, new_obj);
91
92 // We cannot mark without test, as some code passes us pointers
93 // that are outside the heap. These pointers are either from roots
94 // or from metadata.
95 if ((!PSScavenge::is_obj_in_young((HeapWord*)p)) &&
96 Universe::heap()->is_in_reserved(p)) {
97 if (PSScavenge::is_obj_in_young((HeapWord*)new_obj)) {
98 card_table()->inline_write_ref_field_gc(p, new_obj);
99 }
100 }
101 }
102
103 template<bool promote_immediately>
104 class PSRootsClosure: public OopClosure {
105 private:
106 PSPromotionManager* _promotion_manager;
107
108 protected:
109 template <class T> void do_oop_work(T *p) {
110 if (PSScavenge::should_scavenge(p)) {
111 // We never card mark roots, maybe call a func without test?
112 PSScavenge::copy_and_push_safe_barrier<T, promote_immediately>(_promotion_manager, p);
113 }
114 }
115 public:
116 PSRootsClosure(PSPromotionManager* pm) : _promotion_manager(pm) { }
117 void do_oop(oop* p) { PSRootsClosure::do_oop_work(p); }
118 void do_oop(narrowOop* p) { PSRootsClosure::do_oop_work(p); }
119 };
120
121 typedef PSRootsClosure</*promote_immediately=*/false> PSScavengeRootsClosure;
122 typedef PSRootsClosure</*promote_immediately=*/true> PSPromoteRootsClosure;
123
124 // Scavenges a single oop in a Klass.
125 class PSScavengeFromKlassClosure: public OopClosure {
126 private:
127 PSPromotionManager* _pm;
128 // Used to redirty a scanned klass if it has oops
129 // pointing to the young generation after being scanned.
130 Klass* _scanned_klass;
131 public:
132 PSScavengeFromKlassClosure(PSPromotionManager* pm) : _pm(pm), _scanned_klass(NULL) { }
133 void do_oop(narrowOop* p) { ShouldNotReachHere(); }
134 void do_oop(oop* p) {
135 ParallelScavengeHeap* psh = ParallelScavengeHeap::heap();
136 assert(!psh->is_in_reserved(p), "GC barrier needed");
137 if (PSScavenge::should_scavenge(p)) {
138 assert(!Universe::heap()->is_in_reserved(p), "Not from meta-data?");
139 assert(PSScavenge::should_scavenge(p, true), "revisiting object?");
140
141 oop o = *p;
142 oop new_obj;
143 if (o->is_forwarded()) {
144 new_obj = o->forwardee();
145 } else {
146 new_obj = _pm->copy_to_survivor_space</*promote_immediately=*/false>(o);
147 }
148 oopDesc::encode_store_heap_oop_not_null(p, new_obj);
149
150 if (PSScavenge::is_obj_in_young((HeapWord*)new_obj)) {
151 do_klass_barrier();
152 }
153 }
154 }
155
156 void set_scanned_klass(Klass* klass) {
157 assert(_scanned_klass == NULL || klass == NULL, "Should always only handling one klass at a time");
158 _scanned_klass = klass;
159 }
160
161 private:
162 void do_klass_barrier() {
163 assert(_scanned_klass != NULL, "Should not be called without having a scanned klass");
164 _scanned_klass->record_modified_oops();
165 }
166
167 };
168
169 // Scavenges the oop in a Klass.
170 class PSScavengeKlassClosure: public KlassClosure {
171 private:
172 PSScavengeFromKlassClosure _oop_closure;
173 protected:
174 public:
175 PSScavengeKlassClosure(PSPromotionManager* pm) : _oop_closure(pm) { }
176 void do_klass(Klass* klass) {
177 // If the klass has not been dirtied we know that there's
178 // no references into the young gen and we can skip it.
179
180 #ifndef PRODUCT
181 if (TraceScavenge) {
182 ResourceMark rm;
183 gclog_or_tty->print_cr("PSScavengeKlassClosure::do_klass %p, %s, dirty: %s",
184 klass,
185 klass->external_name(),
186 klass->has_modified_oops() ? "true" : "false");
187 }
188 #endif
189
190 if (klass->has_modified_oops()) {
191 // Clean the klass since we're going to scavenge all the metadata.
192 klass->clear_modified_oops();
193
194 // Setup the promotion manager to redirty this klass
195 // if references are left in the young gen.
196 _oop_closure.set_scanned_klass(klass);
197
198 klass->oops_do(&_oop_closure);
199
200 _oop_closure.set_scanned_klass(NULL);
201 }
202 }
203 };
204
205 #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSSCAVENGE_INLINE_HPP