1 /*
2 * Copyright (c) 2016, 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 #include "precompiled.hpp"
26 #include "gc/shared/preservedMarks.inline.hpp"
27 #include "gc/shared/workgroup.hpp"
28 #include "memory/allocation.inline.hpp"
29 #include "memory/resourceArea.hpp"
30 #include "utilities/macros.hpp"
31 #if INCLUDE_ALL_GCS
32 #include "gc/parallel/gcTaskManager.hpp"
33 #endif
34
35 void PreservedMarks::restore() {
36 while (!_stack.is_empty()) {
37 const OopAndMarkOop elem = _stack.pop();
38 elem.set_mark();
39 }
40 assert_empty();
41 }
42
43 #ifndef PRODUCT
44 void PreservedMarks::assert_empty() {
45 assert(_stack.is_empty(), "stack expected to be empty, size = "SIZE_FORMAT,
46 _stack.size());
47 assert(_stack.cache_size() == 0,
48 "stack expected to have no cached segments, cache size = "SIZE_FORMAT,
49 _stack.cache_size());
50 }
51 #endif // ndef PRODUCT
52
53 void RemoveForwardedPointerClosure::do_object(oop obj) {
54 if (obj->is_forwarded()) {
55 PreservedMarks::init_forwarded_mark(obj);
56 }
57 }
58
59 void PreservedMarksSet::init(uint num) {
60 assert(_stacks == NULL && _num == 0, "do not re-initialize");
61 assert(num > 0, "pre-condition");
62 if (_in_c_heap) {
63 _stacks = NEW_C_HEAP_ARRAY(Padded<PreservedMarks>, num, mtGC);
64 } else {
65 _stacks = NEW_RESOURCE_ARRAY(Padded<PreservedMarks>, num);
66 }
67 for (uint i = 0; i < num; i += 1) {
68 ::new (_stacks + i) PreservedMarks();
69 }
70 _num = num;
71
72 assert_empty();
73 }
74
75 class ParRestoreTask : public AbstractGangTask {
76 private:
77 PreservedMarksSet* const _preserved_marks_set;
78 SequentialSubTasksDone _sub_tasks;
79 volatile size_t* const _total_size_addr;
80
81 public:
82 virtual void work(uint worker_id) {
83 uint task_id = 0;
84 while (!_sub_tasks.is_task_claimed(/* reference */ task_id)) {
85 PreservedMarks* const preserved_marks = _preserved_marks_set->get(task_id);
86 const size_t size = preserved_marks->size();
87 preserved_marks->restore();
88 // Only do the atomic add if the size is > 0.
89 if (size > 0) {
90 Atomic::add(size, _total_size_addr);
91 }
92 }
93 _sub_tasks.all_tasks_completed();
94 }
95
96 ParRestoreTask(uint worker_num,
97 PreservedMarksSet* preserved_marks_set,
98 volatile size_t* total_size_addr)
99 : AbstractGangTask("Parallel Preserved Mark Restoration"),
100 _preserved_marks_set(preserved_marks_set),
101 _total_size_addr(total_size_addr) {
102 _sub_tasks.set_n_threads(worker_num);
103 _sub_tasks.set_n_tasks(preserved_marks_set->num());
104 }
105 };
106
107 void PreservedMarksSet::restore_internal(WorkGang* workers,
108 volatile size_t* total_size_addr) {
109 assert(workers != NULL, "pre-condition");
110 ParRestoreTask task(workers->active_workers(), this, total_size_addr);
111 workers->run_task(&task);
112 }
113
114 #if INCLUDE_ALL_GCS
115 class ParRestoreGCTask : public GCTask {
116 private:
117 const uint _id;
118 PreservedMarksSet* const _preserved_marks_set;
119 volatile size_t* const _total_size_addr;
120
121 public:
122 virtual char* name() { return (char*) "preserved mark restoration task"; }
123
124 virtual void do_it(GCTaskManager* manager, uint which) {
125 PreservedMarks* const preserved_marks = _preserved_marks_set->get(_id);
126 const size_t size = preserved_marks->size();
127 preserved_marks->restore();
128 // Only do the atomic add if the size is > 0.
129 if (size > 0) {
130 Atomic::add(size, _total_size_addr);
131 }
132 }
133
134 ParRestoreGCTask(uint id,
135 PreservedMarksSet* preserved_marks_set,
136 volatile size_t* total_size_addr)
137 : _id(id),
138 _preserved_marks_set(preserved_marks_set),
139 _total_size_addr(total_size_addr) { }
140 };
141
142 void PreservedMarksSet::restore_internal(GCTaskManager* gc_task_manager,
143 volatile size_t* total_size_addr) {
144 // GCTask / GCTaskQueue are ResourceObjs
145 ResourceMark rm;
146
147 GCTaskQueue* q = GCTaskQueue::create();
148 for (uint i = 0; i < num(); i += 1) {
149 q->enqueue(new ParRestoreGCTask(i, this, total_size_addr));
150 }
151 gc_task_manager->execute_and_wait(q);
152 }
153 #endif
154
155 void PreservedMarksSet::reclaim() {
156 assert_empty();
157
158 for (uint i = 0; i < _num; i += 1) {
159 _stacks[i].~Padded<PreservedMarks>();
160 }
161
162 if (_in_c_heap) {
163 FREE_C_HEAP_ARRAY(Padded<PreservedMarks>, _stacks);
164 } else {
165 // the array was resource-allocated, so nothing to do
166 }
167 _stacks = NULL;
168 _num = 0;
169 }
170
171 #ifndef PRODUCT
172 void PreservedMarksSet::assert_empty() {
173 assert(_stacks != NULL && _num > 0, "should have been initialized");
174 for (uint i = 0; i < _num; i += 1) {
175 get(i)->assert_empty();
176 }
177 }
178 #endif // ndef PRODUCT