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--- old/src/share/vm/gc_implementation/shared/mutableSpace.cpp
+++ new/src/share/vm/gc_implementation/shared/mutableSpace.cpp
1 1 /*
2 2 * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved.
3 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 4 *
5 5 * This code is free software; you can redistribute it and/or modify it
6 6 * under the terms of the GNU General Public License version 2 only, as
7 7 * published by the Free Software Foundation.
8 8 *
9 9 * This code is distributed in the hope that it will be useful, but WITHOUT
10 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
11 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
12 12 * version 2 for more details (a copy is included in the LICENSE file that
13 13 * accompanied this code).
14 14 *
15 15 * You should have received a copy of the GNU General Public License version
16 16 * 2 along with this work; if not, write to the Free Software Foundation,
17 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
18 18 *
19 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
20 20 * or visit www.oracle.com if you need additional information or have any
21 21 * questions.
22 22 *
23 23 */
24 24
25 25 #include "precompiled.hpp"
26 26 #ifndef SERIALGC
27 27 #include "gc_implementation/shared/mutableSpace.hpp"
28 28 #include "gc_implementation/shared/spaceDecorator.hpp"
29 29 #include "oops/oop.inline.hpp"
30 30 #include "runtime/safepoint.hpp"
31 31 #include "runtime/thread.hpp"
32 32 #endif
33 33
34 34 MutableSpace::MutableSpace(size_t alignment): ImmutableSpace(), _top(NULL), _alignment(alignment) {
35 35 assert(MutableSpace::alignment() >= 0 &&
36 36 MutableSpace::alignment() % os::vm_page_size() == 0,
37 37 "Space should be aligned");
38 38 _mangler = new MutableSpaceMangler(this);
39 39 }
40 40
41 41 MutableSpace::~MutableSpace() {
42 42 delete _mangler;
43 43 }
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44 44
45 45 void MutableSpace::numa_setup_pages(MemRegion mr, bool clear_space) {
46 46 if (!mr.is_empty()) {
47 47 size_t page_size = UseLargePages ? alignment() : os::vm_page_size();
48 48 HeapWord *start = (HeapWord*)round_to((intptr_t) mr.start(), page_size);
49 49 HeapWord *end = (HeapWord*)round_down((intptr_t) mr.end(), page_size);
50 50 if (end > start) {
51 51 size_t size = pointer_delta(end, start, sizeof(char));
52 52 if (clear_space) {
53 53 // Prefer page reallocation to migration.
54 - os::free_memory((char*)start, size);
54 + os::free_memory((char*)start, size, page_size);
55 55 }
56 56 os::numa_make_global((char*)start, size);
57 57 }
58 58 }
59 59 }
60 60
61 61 void MutableSpace::pretouch_pages(MemRegion mr) {
62 62 for (volatile char *p = (char*)mr.start(); p < (char*)mr.end(); p += os::vm_page_size()) {
63 63 char t = *p; *p = t;
64 64 }
65 65 }
66 66
67 67 void MutableSpace::initialize(MemRegion mr,
68 68 bool clear_space,
69 69 bool mangle_space,
70 70 bool setup_pages) {
71 71
72 72 assert(Universe::on_page_boundary(mr.start()) && Universe::on_page_boundary(mr.end()),
73 73 "invalid space boundaries");
74 74
75 75 if (setup_pages && (UseNUMA || AlwaysPreTouch)) {
76 76 // The space may move left and right or expand/shrink.
77 77 // We'd like to enforce the desired page placement.
78 78 MemRegion head, tail;
79 79 if (last_setup_region().is_empty()) {
80 80 // If it's the first initialization don't limit the amount of work.
81 81 head = mr;
82 82 tail = MemRegion(mr.end(), mr.end());
83 83 } else {
84 84 // Is there an intersection with the address space?
85 85 MemRegion intersection = last_setup_region().intersection(mr);
86 86 if (intersection.is_empty()) {
87 87 intersection = MemRegion(mr.end(), mr.end());
88 88 }
89 89 // All the sizes below are in words.
90 90 size_t head_size = 0, tail_size = 0;
91 91 if (mr.start() <= intersection.start()) {
92 92 head_size = pointer_delta(intersection.start(), mr.start());
93 93 }
94 94 if(intersection.end() <= mr.end()) {
95 95 tail_size = pointer_delta(mr.end(), intersection.end());
96 96 }
97 97 // Limit the amount of page manipulation if necessary.
98 98 if (NUMASpaceResizeRate > 0 && !AlwaysPreTouch) {
99 99 const size_t change_size = head_size + tail_size;
100 100 const float setup_rate_words = NUMASpaceResizeRate >> LogBytesPerWord;
101 101 head_size = MIN2((size_t)(setup_rate_words * head_size / change_size),
102 102 head_size);
103 103 tail_size = MIN2((size_t)(setup_rate_words * tail_size / change_size),
104 104 tail_size);
105 105 }
106 106 head = MemRegion(intersection.start() - head_size, intersection.start());
107 107 tail = MemRegion(intersection.end(), intersection.end() + tail_size);
108 108 }
109 109 assert(mr.contains(head) && mr.contains(tail), "Sanity");
110 110
111 111 if (UseNUMA) {
112 112 numa_setup_pages(head, clear_space);
113 113 numa_setup_pages(tail, clear_space);
114 114 }
115 115
116 116 if (AlwaysPreTouch) {
117 117 pretouch_pages(head);
118 118 pretouch_pages(tail);
119 119 }
120 120
121 121 // Remember where we stopped so that we can continue later.
122 122 set_last_setup_region(MemRegion(head.start(), tail.end()));
123 123 }
124 124
125 125 set_bottom(mr.start());
126 126 set_end(mr.end());
127 127
128 128 if (clear_space) {
129 129 clear(mangle_space);
130 130 }
131 131 }
132 132
133 133 void MutableSpace::clear(bool mangle_space) {
134 134 set_top(bottom());
135 135 if (ZapUnusedHeapArea && mangle_space) {
136 136 mangle_unused_area();
137 137 }
138 138 }
139 139
140 140 #ifndef PRODUCT
141 141 void MutableSpace::check_mangled_unused_area(HeapWord* limit) {
142 142 mangler()->check_mangled_unused_area(limit);
143 143 }
144 144
145 145 void MutableSpace::check_mangled_unused_area_complete() {
146 146 mangler()->check_mangled_unused_area_complete();
147 147 }
148 148
149 149 // Mangle only the unused space that has not previously
150 150 // been mangled and that has not been allocated since being
151 151 // mangled.
152 152 void MutableSpace::mangle_unused_area() {
153 153 mangler()->mangle_unused_area();
154 154 }
155 155
156 156 void MutableSpace::mangle_unused_area_complete() {
157 157 mangler()->mangle_unused_area_complete();
158 158 }
159 159
160 160 void MutableSpace::mangle_region(MemRegion mr) {
161 161 SpaceMangler::mangle_region(mr);
162 162 }
163 163
164 164 void MutableSpace::set_top_for_allocations(HeapWord* v) {
165 165 mangler()->set_top_for_allocations(v);
166 166 }
167 167
168 168 void MutableSpace::set_top_for_allocations() {
169 169 mangler()->set_top_for_allocations(top());
170 170 }
171 171 #endif
172 172
173 173 // This version requires locking. */
174 174 HeapWord* MutableSpace::allocate(size_t size) {
175 175 assert(Heap_lock->owned_by_self() ||
176 176 (SafepointSynchronize::is_at_safepoint() &&
177 177 Thread::current()->is_VM_thread()),
178 178 "not locked");
179 179 HeapWord* obj = top();
180 180 if (pointer_delta(end(), obj) >= size) {
181 181 HeapWord* new_top = obj + size;
182 182 set_top(new_top);
183 183 assert(is_object_aligned((intptr_t)obj) && is_object_aligned((intptr_t)new_top),
184 184 "checking alignment");
185 185 return obj;
186 186 } else {
187 187 return NULL;
188 188 }
189 189 }
190 190
191 191 // This version is lock-free.
192 192 HeapWord* MutableSpace::cas_allocate(size_t size) {
193 193 do {
194 194 HeapWord* obj = top();
195 195 if (pointer_delta(end(), obj) >= size) {
196 196 HeapWord* new_top = obj + size;
197 197 HeapWord* result = (HeapWord*)Atomic::cmpxchg_ptr(new_top, top_addr(), obj);
198 198 // result can be one of two:
199 199 // the old top value: the exchange succeeded
200 200 // otherwise: the new value of the top is returned.
201 201 if (result != obj) {
202 202 continue; // another thread beat us to the allocation, try again
203 203 }
204 204 assert(is_object_aligned((intptr_t)obj) && is_object_aligned((intptr_t)new_top),
205 205 "checking alignment");
206 206 return obj;
207 207 } else {
208 208 return NULL;
209 209 }
210 210 } while (true);
211 211 }
212 212
213 213 // Try to deallocate previous allocation. Returns true upon success.
214 214 bool MutableSpace::cas_deallocate(HeapWord *obj, size_t size) {
215 215 HeapWord* expected_top = obj + size;
216 216 return (HeapWord*)Atomic::cmpxchg_ptr(obj, top_addr(), expected_top) == expected_top;
217 217 }
218 218
219 219 void MutableSpace::oop_iterate(OopClosure* cl) {
220 220 HeapWord* obj_addr = bottom();
221 221 HeapWord* t = top();
222 222 // Could call objects iterate, but this is easier.
223 223 while (obj_addr < t) {
224 224 obj_addr += oop(obj_addr)->oop_iterate(cl);
225 225 }
226 226 }
227 227
228 228 void MutableSpace::object_iterate(ObjectClosure* cl) {
229 229 HeapWord* p = bottom();
230 230 while (p < top()) {
231 231 cl->do_object(oop(p));
232 232 p += oop(p)->size();
233 233 }
234 234 }
235 235
236 236 void MutableSpace::print_short() const { print_short_on(tty); }
237 237 void MutableSpace::print_short_on( outputStream* st) const {
238 238 st->print(" space " SIZE_FORMAT "K, %d%% used", capacity_in_bytes() / K,
239 239 (int) ((double) used_in_bytes() * 100 / capacity_in_bytes()));
240 240 }
241 241
242 242 void MutableSpace::print() const { print_on(tty); }
243 243 void MutableSpace::print_on(outputStream* st) const {
244 244 MutableSpace::print_short_on(st);
245 245 st->print_cr(" [" INTPTR_FORMAT "," INTPTR_FORMAT "," INTPTR_FORMAT ")",
246 246 bottom(), top(), end());
247 247 }
248 248
249 249 void MutableSpace::verify(bool allow_dirty) {
250 250 HeapWord* p = bottom();
251 251 HeapWord* t = top();
252 252 HeapWord* prev_p = NULL;
253 253 while (p < t) {
254 254 oop(p)->verify();
255 255 prev_p = p;
256 256 p += oop(p)->size();
257 257 }
258 258 guarantee(p == top(), "end of last object must match end of space");
259 259 }
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