1 /*
2 * Copyright (c) 2002, 2015, 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_PARALLEL_PSSCAVENGE_INLINE_HPP
26 #define SHARE_VM_GC_PARALLEL_PSSCAVENGE_INLINE_HPP
27
28 #include "gc/parallel/cardTableExtension.hpp"
29 #include "gc/parallel/parallelScavengeHeap.hpp"
30 #include "gc/parallel/psPromotionManager.inline.hpp"
31 #include "gc/parallel/psScavenge.hpp"
32 #include "logging/log.hpp"
33 #include "memory/iterator.hpp"
34 #include "memory/resourceArea.hpp"
35 #include "utilities/globalDefinitions.hpp"
36
37 inline void PSScavenge::save_to_space_top_before_gc() {
38 ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();
39 _to_space_top_before_gc = heap->young_gen()->to_space()->top();
40 }
41
42 template <class T> inline bool PSScavenge::should_scavenge(T* p) {
43 T heap_oop = oopDesc::load_heap_oop(p);
44 return PSScavenge::is_obj_in_young(heap_oop);
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::heap();
62 return should_scavenge(p, heap->young_gen()->to_space());
63 }
64 return should_scavenge(p);
65 }
66
67 template<bool promote_immediately>
68 class PSRootsClosure: public OopClosure {
69 private:
70 PSPromotionManager* _promotion_manager;
71
72 protected:
73 template <class T> void do_oop_work(T *p) {
74 if (PSScavenge::should_scavenge(p)) {
75 // We never card mark roots, maybe call a func without test?
76 _promotion_manager->copy_and_push_safe_barrier<T, promote_immediately>(p);
77 }
78 }
79 public:
80 PSRootsClosure(PSPromotionManager* pm) : _promotion_manager(pm) { }
81 void do_oop(oop* p) { PSRootsClosure::do_oop_work(p); }
82 void do_oop(narrowOop* p) { PSRootsClosure::do_oop_work(p); }
83 };
84
85 typedef PSRootsClosure</*promote_immediately=*/false> PSScavengeRootsClosure;
86 typedef PSRootsClosure</*promote_immediately=*/true> PSPromoteRootsClosure;
87
88 // Scavenges a single oop in a Klass.
89 class PSScavengeFromKlassClosure: public OopClosure {
90 private:
91 PSPromotionManager* _pm;
92 // Used to redirty a scanned klass if it has oops
93 // pointing to the young generation after being scanned.
94 Klass* _scanned_klass;
95 public:
96 PSScavengeFromKlassClosure(PSPromotionManager* pm) : _pm(pm), _scanned_klass(NULL) { }
97 void do_oop(narrowOop* p) { ShouldNotReachHere(); }
98 void do_oop(oop* p) {
99 ParallelScavengeHeap* psh = ParallelScavengeHeap::heap();
100 assert(!psh->is_in_reserved(p), "GC barrier needed");
101 if (PSScavenge::should_scavenge(p)) {
102 assert(PSScavenge::should_scavenge(p, true), "revisiting object?");
103
104 oop o = *p;
105 if (!o->is_forwarded()) {
106 _pm->copy_to_survivor_space</*promote_immediately=*/false>(o);
107 }
108 oop new_obj = o->forwardee();
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 if (klass->has_modified_oops()) {
142 // Clean the klass since we're going to scavenge all the metadata.
143 klass->clear_modified_oops();
144
145 // Setup the promotion manager to redirty this klass
146 // if references are left in the young gen.
147 _oop_closure.set_scanned_klass(klass);
148
149 klass->oops_do(&_oop_closure);
150
151 _oop_closure.set_scanned_klass(NULL);
152 }
153 }
154 };
155
156 #endif // SHARE_VM_GC_PARALLEL_PSSCAVENGE_INLINE_HPP