Tue, 24 Dec 2013 11:48:39 -0800
8029233: Update copyright year to match last edit in jdk8 hotspot repository for 2013
Summary: Copyright year updated for files modified during 2013
Reviewed-by: twisti, iveresov
1 /*
2 * Copyright (c) 2001, 2013, 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 */
25 #include "precompiled.hpp"
26 #include "utilities/macros.hpp"
27 #if INCLUDE_ALL_GCS
28 #include "gc_implementation/shared/mutableSpace.hpp"
29 #include "gc_implementation/shared/spaceDecorator.hpp"
30 #include "oops/oop.inline.hpp"
31 #include "runtime/safepoint.hpp"
32 #include "runtime/thread.hpp"
33 #endif // INCLUDE_ALL_GCS
35 MutableSpace::MutableSpace(size_t alignment): ImmutableSpace(), _top(NULL), _alignment(alignment) {
36 assert(MutableSpace::alignment() >= 0 &&
37 MutableSpace::alignment() % os::vm_page_size() == 0,
38 "Space should be aligned");
39 _mangler = new MutableSpaceMangler(this);
40 }
42 MutableSpace::~MutableSpace() {
43 delete _mangler;
44 }
46 void MutableSpace::numa_setup_pages(MemRegion mr, bool clear_space) {
47 if (!mr.is_empty()) {
48 size_t page_size = UseLargePages ? alignment() : os::vm_page_size();
49 HeapWord *start = (HeapWord*)round_to((intptr_t) mr.start(), page_size);
50 HeapWord *end = (HeapWord*)round_down((intptr_t) mr.end(), page_size);
51 if (end > start) {
52 size_t size = pointer_delta(end, start, sizeof(char));
53 if (clear_space) {
54 // Prefer page reallocation to migration.
55 os::free_memory((char*)start, size, page_size);
56 }
57 os::numa_make_global((char*)start, size);
58 }
59 }
60 }
62 void MutableSpace::pretouch_pages(MemRegion mr) {
63 for (volatile char *p = (char*)mr.start(); p < (char*)mr.end(); p += os::vm_page_size()) {
64 char t = *p; *p = t;
65 }
66 }
68 void MutableSpace::initialize(MemRegion mr,
69 bool clear_space,
70 bool mangle_space,
71 bool setup_pages) {
73 assert(Universe::on_page_boundary(mr.start()) && Universe::on_page_boundary(mr.end()),
74 "invalid space boundaries");
76 if (setup_pages && (UseNUMA || AlwaysPreTouch)) {
77 // The space may move left and right or expand/shrink.
78 // We'd like to enforce the desired page placement.
79 MemRegion head, tail;
80 if (last_setup_region().is_empty()) {
81 // If it's the first initialization don't limit the amount of work.
82 head = mr;
83 tail = MemRegion(mr.end(), mr.end());
84 } else {
85 // Is there an intersection with the address space?
86 MemRegion intersection = last_setup_region().intersection(mr);
87 if (intersection.is_empty()) {
88 intersection = MemRegion(mr.end(), mr.end());
89 }
90 // All the sizes below are in words.
91 size_t head_size = 0, tail_size = 0;
92 if (mr.start() <= intersection.start()) {
93 head_size = pointer_delta(intersection.start(), mr.start());
94 }
95 if(intersection.end() <= mr.end()) {
96 tail_size = pointer_delta(mr.end(), intersection.end());
97 }
98 // Limit the amount of page manipulation if necessary.
99 if (NUMASpaceResizeRate > 0 && !AlwaysPreTouch) {
100 const size_t change_size = head_size + tail_size;
101 const float setup_rate_words = NUMASpaceResizeRate >> LogBytesPerWord;
102 head_size = MIN2((size_t)(setup_rate_words * head_size / change_size),
103 head_size);
104 tail_size = MIN2((size_t)(setup_rate_words * tail_size / change_size),
105 tail_size);
106 }
107 head = MemRegion(intersection.start() - head_size, intersection.start());
108 tail = MemRegion(intersection.end(), intersection.end() + tail_size);
109 }
110 assert(mr.contains(head) && mr.contains(tail), "Sanity");
112 if (UseNUMA) {
113 numa_setup_pages(head, clear_space);
114 numa_setup_pages(tail, clear_space);
115 }
117 if (AlwaysPreTouch) {
118 pretouch_pages(head);
119 pretouch_pages(tail);
120 }
122 // Remember where we stopped so that we can continue later.
123 set_last_setup_region(MemRegion(head.start(), tail.end()));
124 }
126 set_bottom(mr.start());
127 set_end(mr.end());
129 if (clear_space) {
130 clear(mangle_space);
131 }
132 }
134 void MutableSpace::clear(bool mangle_space) {
135 set_top(bottom());
136 if (ZapUnusedHeapArea && mangle_space) {
137 mangle_unused_area();
138 }
139 }
141 #ifndef PRODUCT
142 void MutableSpace::check_mangled_unused_area(HeapWord* limit) {
143 mangler()->check_mangled_unused_area(limit);
144 }
146 void MutableSpace::check_mangled_unused_area_complete() {
147 mangler()->check_mangled_unused_area_complete();
148 }
150 // Mangle only the unused space that has not previously
151 // been mangled and that has not been allocated since being
152 // mangled.
153 void MutableSpace::mangle_unused_area() {
154 mangler()->mangle_unused_area();
155 }
157 void MutableSpace::mangle_unused_area_complete() {
158 mangler()->mangle_unused_area_complete();
159 }
161 void MutableSpace::mangle_region(MemRegion mr) {
162 SpaceMangler::mangle_region(mr);
163 }
165 void MutableSpace::set_top_for_allocations(HeapWord* v) {
166 mangler()->set_top_for_allocations(v);
167 }
169 void MutableSpace::set_top_for_allocations() {
170 mangler()->set_top_for_allocations(top());
171 }
172 #endif
174 // This version requires locking. */
175 HeapWord* MutableSpace::allocate(size_t size) {
176 assert(Heap_lock->owned_by_self() ||
177 (SafepointSynchronize::is_at_safepoint() &&
178 Thread::current()->is_VM_thread()),
179 "not locked");
180 HeapWord* obj = top();
181 if (pointer_delta(end(), obj) >= size) {
182 HeapWord* new_top = obj + size;
183 set_top(new_top);
184 assert(is_object_aligned((intptr_t)obj) && is_object_aligned((intptr_t)new_top),
185 "checking alignment");
186 return obj;
187 } else {
188 return NULL;
189 }
190 }
192 // This version is lock-free.
193 HeapWord* MutableSpace::cas_allocate(size_t size) {
194 do {
195 HeapWord* obj = top();
196 if (pointer_delta(end(), obj) >= size) {
197 HeapWord* new_top = obj + size;
198 HeapWord* result = (HeapWord*)Atomic::cmpxchg_ptr(new_top, top_addr(), obj);
199 // result can be one of two:
200 // the old top value: the exchange succeeded
201 // otherwise: the new value of the top is returned.
202 if (result != obj) {
203 continue; // another thread beat us to the allocation, try again
204 }
205 assert(is_object_aligned((intptr_t)obj) && is_object_aligned((intptr_t)new_top),
206 "checking alignment");
207 return obj;
208 } else {
209 return NULL;
210 }
211 } while (true);
212 }
214 // Try to deallocate previous allocation. Returns true upon success.
215 bool MutableSpace::cas_deallocate(HeapWord *obj, size_t size) {
216 HeapWord* expected_top = obj + size;
217 return (HeapWord*)Atomic::cmpxchg_ptr(obj, top_addr(), expected_top) == expected_top;
218 }
220 void MutableSpace::oop_iterate(ExtendedOopClosure* cl) {
221 HeapWord* obj_addr = bottom();
222 HeapWord* t = top();
223 // Could call objects iterate, but this is easier.
224 while (obj_addr < t) {
225 obj_addr += oop(obj_addr)->oop_iterate(cl);
226 }
227 }
229 void MutableSpace::oop_iterate_no_header(OopClosure* cl) {
230 HeapWord* obj_addr = bottom();
231 HeapWord* t = top();
232 // Could call objects iterate, but this is easier.
233 while (obj_addr < t) {
234 obj_addr += oop(obj_addr)->oop_iterate_no_header(cl);
235 }
236 }
238 void MutableSpace::object_iterate(ObjectClosure* cl) {
239 HeapWord* p = bottom();
240 while (p < top()) {
241 cl->do_object(oop(p));
242 p += oop(p)->size();
243 }
244 }
246 void MutableSpace::print_short() const { print_short_on(tty); }
247 void MutableSpace::print_short_on( outputStream* st) const {
248 st->print(" space " SIZE_FORMAT "K, %d%% used", capacity_in_bytes() / K,
249 (int) ((double) used_in_bytes() * 100 / capacity_in_bytes()));
250 }
252 void MutableSpace::print() const { print_on(tty); }
253 void MutableSpace::print_on(outputStream* st) const {
254 MutableSpace::print_short_on(st);
255 st->print_cr(" [" INTPTR_FORMAT "," INTPTR_FORMAT "," INTPTR_FORMAT ")",
256 bottom(), top(), end());
257 }
259 void MutableSpace::verify() {
260 HeapWord* p = bottom();
261 HeapWord* t = top();
262 HeapWord* prev_p = NULL;
263 while (p < t) {
264 oop(p)->verify();
265 prev_p = p;
266 p += oop(p)->size();
267 }
268 guarantee(p == top(), "end of last object must match end of space");
269 }