1 /*
2 * Copyright (c) 2002, 2018, 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/parallelScavengeHeap.hpp"
29 #include "gc/parallel/psPromotionManager.inline.hpp"
30 #include "gc/parallel/psScavenge.hpp"
31 #include "logging/log.hpp"
32 #include "memory/iterator.hpp"
33 #include "memory/resourceArea.hpp"
34 #include "oops/access.inline.hpp"
35 #include "oops/oop.inline.hpp"
36 #include "utilities/globalDefinitions.hpp"
37
38 inline void PSScavenge::save_to_space_top_before_gc() {
39 ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();
40 _to_space_top_before_gc = heap->young_gen()->to_space()->top();
41 }
42
43 template <class T> inline bool PSScavenge::should_scavenge(T* p) {
44 T heap_oop = RawAccess<>::oop_load(p);
45 return PSScavenge::is_obj_in_young(heap_oop);
46 }
47
48 template <class T>
49 inline bool PSScavenge::should_scavenge(T* p, MutableSpace* to_space) {
50 if (should_scavenge(p)) {
51 oop obj = RawAccess<IS_NOT_NULL>::oop_load(p);
52 // Skip objects copied to to_space since the scavenge started.
53 HeapWord* const addr = (HeapWord*)obj;
54 return addr < to_space_top_before_gc() || addr >= to_space->end();
55 }
56 return false;
57 }
58
59 template <class T>
60 inline bool PSScavenge::should_scavenge(T* p, bool check_to_space) {
61 if (check_to_space) {
62 ParallelScavengeHeap* heap = ParallelScavengeHeap::heap();
63 return should_scavenge(p, heap->young_gen()->to_space());
64 }
65 return should_scavenge(p);
66 }
67
68 template<bool promote_immediately>
69 class PSRootsClosure: public OopClosure {
70 private:
71 PSPromotionManager* _promotion_manager;
72
73 protected:
74 template <class T> void do_oop_work(T *p) {
75 if (PSScavenge::should_scavenge(p)) {
76 // We never card mark roots, maybe call a func without test?
77 _promotion_manager->copy_and_push_safe_barrier<T, promote_immediately>(p);
78 }
79 }
80 public:
81 PSRootsClosure(PSPromotionManager* pm) : _promotion_manager(pm) { }
82 void do_oop(oop* p) { PSRootsClosure::do_oop_work(p); }
83 void do_oop(narrowOop* p) { PSRootsClosure::do_oop_work(p); }
84 };
85
86 typedef PSRootsClosure</*promote_immediately=*/false> PSScavengeRootsClosure;
87 typedef PSRootsClosure</*promote_immediately=*/true> PSPromoteRootsClosure;
88
89 // Scavenges a single oop in a ClassLoaderData.
90 class PSScavengeFromCLDClosure: public OopClosure {
91 private:
92 PSPromotionManager* _pm;
93 // Used to redirty a scanned cld if it has oops
94 // pointing to the young generation after being scanned.
95 ClassLoaderData* _scanned_cld;
96 public:
97 PSScavengeFromCLDClosure(PSPromotionManager* pm) : _pm(pm), _scanned_cld(NULL) { }
98 void do_oop(narrowOop* p) { ShouldNotReachHere(); }
99 void do_oop(oop* p) {
100 ParallelScavengeHeap* psh = ParallelScavengeHeap::heap();
101 assert(!psh->is_in_reserved(p), "GC barrier needed");
102 if (PSScavenge::should_scavenge(p)) {
103 assert(PSScavenge::should_scavenge(p, true), "revisiting object?");
104
105 oop o = *p;
106 oop new_obj;
107 if (o->is_forwarded()) {
108 new_obj = o->forwardee();
109 } else {
110 new_obj = _pm->copy_to_survivor_space</*promote_immediately=*/false>(o);
111 }
112 RawAccess<IS_NOT_NULL>::oop_store(p, new_obj);
113
114 if (PSScavenge::is_obj_in_young(new_obj)) {
115 do_cld_barrier();
116 }
117 }
118 }
119
120 void set_scanned_cld(ClassLoaderData* cld) {
121 assert(_scanned_cld == NULL || cld == NULL, "Should always only handling one cld at a time");
122 _scanned_cld = cld;
123 }
124
125 private:
126 void do_cld_barrier() {
127 assert(_scanned_cld != NULL, "Should not be called without having a scanned cld");
128 _scanned_cld->record_modified_oops();
129 }
130 };
131
132 // Scavenges the oop in a ClassLoaderData.
133 class PSScavengeCLDClosure: public CLDClosure {
134 private:
135 PSScavengeFromCLDClosure _oop_closure;
136 protected:
137 public:
138 PSScavengeCLDClosure(PSPromotionManager* pm) : _oop_closure(pm) { }
139 void do_cld(ClassLoaderData* cld) {
140 // If the cld has not been dirtied we know that there's
141 // no references into the young gen and we can skip it.
142
143 if (cld->has_modified_oops()) {
144 // Setup the promotion manager to redirty this cld
145 // if references are left in the young gen.
146 _oop_closure.set_scanned_cld(cld);
147
148 // Clean the cld since we're going to scavenge all the metadata.
149 cld->oops_do(&_oop_closure, ClassLoaderData::_claim_none, /*clear_modified_oops*/true);
150
151 _oop_closure.set_scanned_cld(NULL);
152 }
153 }
154 };
155
156
157 #endif // SHARE_VM_GC_PARALLEL_PSSCAVENGE_INLINE_HPP