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.
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.inline.hpp"
31 #include "gc_implementation/parallelScavenge/psScavenge.hpp"
32 #include "memory/iterator.hpp"
33 #include "utilities/globalDefinitions.hpp"
34
35 inline void PSScavenge::save_to_space_top_before_gc() {
36 ParallelScavengeHeap* heap = ParallelScavengeHeap::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 return PSScavenge::is_obj_in_young(heap_oop);
43 }
44
45 template <class T>
46 inline bool PSScavenge::should_scavenge(T* p, MutableSpace* to_space) {
47 if (should_scavenge(p)) {
48 oop obj = oopDesc::load_decode_heap_oop_not_null(p);
49 // Skip objects copied to to_space since the scavenge started.
50 HeapWord* const addr = (HeapWord*)obj;
51 return addr < to_space_top_before_gc() || addr >= to_space->end();
52 }
53 return false;
54 }
55
56 template <class T>
57 inline bool PSScavenge::should_scavenge(T* p, bool check_to_space) {
58 if (check_to_space) {
59 ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();
60 return should_scavenge(p, heap->young_gen()->to_space());
61 }
62 return should_scavenge(p);
63 }
64
65 template<bool promote_immediately>
66 class PSRootsClosure: public OopClosure {
67 private:
68 PSPromotionManager* _promotion_manager;
69
70 protected:
71 template <class T> void do_oop_work(T *p) {
72 if (PSScavenge::should_scavenge(p)) {
73 // We never card mark roots, maybe call a func without test?
74 _promotion_manager->copy_and_push_safe_barrier<T, promote_immediately>(p);
75 }
76 }
77 public:
78 PSRootsClosure(PSPromotionManager* pm) : _promotion_manager(pm) { }
79 void do_oop(oop* p) { PSRootsClosure::do_oop_work(p); }
80 void do_oop(narrowOop* p) { PSRootsClosure::do_oop_work(p); }
81 };
82
83 typedef PSRootsClosure</*promote_immediately=*/false> PSScavengeRootsClosure;
84 typedef PSRootsClosure</*promote_immediately=*/true> PSPromoteRootsClosure;
85
86 // Scavenges a single oop in a Klass.
87 class PSScavengeFromKlassClosure: public OopClosure {
88 private:
89 PSPromotionManager* _pm;
90 // Used to redirty a scanned klass if it has oops
91 // pointing to the young generation after being scanned.
92 Klass* _scanned_klass;
93 public:
94 PSScavengeFromKlassClosure(PSPromotionManager* pm) : _pm(pm), _scanned_klass(NULL) { }
95 void do_oop(narrowOop* p) { ShouldNotReachHere(); }
96 void do_oop(oop* p) {
97 ParallelScavengeHeap* psh = ParallelScavengeHeap::heap();
98 assert(!psh->is_in_reserved(p), "GC barrier needed");
99 if (PSScavenge::should_scavenge(p)) {
100 assert(PSScavenge::should_scavenge(p, true), "revisiting object?");
101
102 oop o = *p;
103 oop new_obj;
104 if (o->is_forwarded()) {
105 new_obj = o->forwardee();
106 } else {
107 new_obj = _pm->copy_to_survivor_space</*promote_immediately=*/false>(o);
108 }
109 oopDesc::encode_store_heap_oop_not_null(p, new_obj);
110
111 if (PSScavenge::is_obj_in_young(new_obj)) {
112 do_klass_barrier();
113 }
114 }
115 }
116
117 void set_scanned_klass(Klass* klass) {
118 assert(_scanned_klass == NULL || klass == NULL, "Should always only handling one klass at a time");
119 _scanned_klass = klass;
120 }
121
122 private:
123 void do_klass_barrier() {
124 assert(_scanned_klass != NULL, "Should not be called without having a scanned klass");
125 _scanned_klass->record_modified_oops();
126 }
127
128 };
129
130 // Scavenges the oop in a Klass.
131 class PSScavengeKlassClosure: public KlassClosure {
132 private:
133 PSScavengeFromKlassClosure _oop_closure;
134 protected:
135 public:
136 PSScavengeKlassClosure(PSPromotionManager* pm) : _oop_closure(pm) { }
137 void do_klass(Klass* klass) {
138 // If the klass has not been dirtied we know that there's
139 // no references into the young gen and we can skip it.
140
141 #ifndef PRODUCT
142 if (TraceScavenge) {
143 ResourceMark rm;
144 gclog_or_tty->print_cr("PSScavengeKlassClosure::do_klass " PTR_FORMAT ", %s, dirty: %s",
145 p2i(klass),
146 klass->external_name(),
147 klass->has_modified_oops() ? "true" : "false");
148 }
149 #endif
150
151 if (klass->has_modified_oops()) {
152 // Clean the klass since we're going to scavenge all the metadata.
153 klass->clear_modified_oops();
154
155 // Setup the promotion manager to redirty this klass
156 // if references are left in the young gen.
157 _oop_closure.set_scanned_klass(klass);
158
159 klass->oops_do(&_oop_closure);
160
161 _oop_closure.set_scanned_klass(NULL);
162 }
163 }
164 };
165
166 #endif // SHARE_VM_GC_IMPLEMENTATION_PARALLELSCAVENGE_PSSCAVENGE_INLINE_HPP