1 /*
2 * Copyright (c) 2013, 2015, Red Hat, Inc. and/or its affiliates.
3 *
4 * This code is free software; you can redistribute it and/or modify it
5 * under the terms of the GNU General Public License version 2 only, as
6 * published by the Free Software Foundation.
7 *
8 * This code is distributed in the hope that it will be useful, but WITHOUT
9 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
11 * version 2 for more details (a copy is included in the LICENSE file that
12 * accompanied this code).
13 *
14 * You should have received a copy of the GNU General Public License version
15 * 2 along with this work; if not, write to the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
17 *
18 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
19 * or visit www.oracle.com if you need additional information or have any
20 * questions.
21 *
22 */
23
24 #include "memory/allocation.hpp"
25 #include "gc/g1/heapRegionBounds.inline.hpp"
26 #include "gc/shenandoah/brooksPointer.hpp"
27 #include "gc/shenandoah/shenandoahHeapRegion.hpp"
28 #include "gc/shenandoah/shenandoahHeap.inline.hpp"
29 #include "gc/shared/space.inline.hpp"
30 #include "memory/universe.hpp"
31 #include "runtime/mutexLocker.hpp"
32 #include "runtime/os.hpp"
33
34 size_t ShenandoahHeapRegion::RegionSizeShift = 0;
35 size_t ShenandoahHeapRegion::RegionSizeBytes = 0;
36
37 jint ShenandoahHeapRegion::initialize_heap_region(HeapWord* start,
38 size_t regionSizeWords, int index) {
39
40 reserved = MemRegion((HeapWord*) start, regionSizeWords);
41 ContiguousSpace::initialize(reserved, true, false);
42 liveData = 0;
43 _is_in_collection_set = false;
44 _region_number = index;
45 #ifdef ASSERT
46 _mem_protection_level = 1; // Off, level 1.
47 #endif
48 return JNI_OK;
49 }
50
51 int ShenandoahHeapRegion::region_number() const {
52 return _region_number;
53 }
54
55 bool ShenandoahHeapRegion::rollback_allocation(uint size) {
56 set_top(top() - size);
57 return true;
58 }
59
60 void ShenandoahHeapRegion::clearLiveData() {
61 setLiveData(0);
62 }
63
64 void ShenandoahHeapRegion::setLiveData(size_t s) {
65 Atomic::store_ptr(s, (intptr_t*) &liveData);
66 }
67
68 void ShenandoahHeapRegion::increase_live_data(size_t s) {
69 size_t new_live_data = Atomic::add(s, &liveData);
70 assert(new_live_data <= used() || is_humongous(), "can't have more live data than used");
71 }
72
73 size_t ShenandoahHeapRegion::getLiveData() const {
74 return liveData;
75 }
76
77 size_t ShenandoahHeapRegion::garbage() const {
78 assert(used() >= getLiveData() || is_humongous(), err_msg("Live Data must be a subset of used() live: "SIZE_FORMAT" used: "SIZE_FORMAT, getLiveData(), used()));
79 size_t result = used() - getLiveData();
80 return result;
81 }
82
83 bool ShenandoahHeapRegion::is_in_collection_set() const {
84 return _is_in_collection_set;
85 }
86
87 #include <sys/mman.h>
88
89 #ifdef ASSERT
90
91 void ShenandoahHeapRegion::memProtectionOn() {
92 /*
93 tty->print_cr("protect memory on region level: "INT32_FORMAT, _mem_protection_level);
94 print(tty);
95 */
96 MutexLockerEx ml(ShenandoahMemProtect_lock, true);
97 assert(_mem_protection_level >= 1, "invariant");
98
99 if (--_mem_protection_level == 0) {
100 if (ShenandoahVerifyWritesToFromSpace) {
101 assert(! ShenandoahVerifyReadsToFromSpace, "can't verify from-space reads when verifying from-space writes");
102 os::protect_memory((char*) bottom(), end() - bottom(), os::MEM_PROT_READ);
103 } else {
104 assert(ShenandoahVerifyReadsToFromSpace, "need to be verifying reads here");
105 assert(! ShenandoahConcurrentEvacuation, "concurrent evacuation needs to be turned off for verifying from-space-reads");
106 os::protect_memory((char*) bottom(), end() - bottom(), os::MEM_PROT_NONE);
107 }
108 }
109 }
110
111 void ShenandoahHeapRegion::memProtectionOff() {
112 /*
113 tty->print_cr("unprotect memory on region level: "INT32_FORMAT, _mem_protection_level);
114 print(tty);
115 */
116 MutexLockerEx ml(ShenandoahMemProtect_lock, true);
117 assert(_mem_protection_level >= 0, "invariant");
118 if (_mem_protection_level++ == 0) {
119 os::protect_memory((char*) bottom(), end() - bottom(), os::MEM_PROT_RW);
120 }
121 }
122
123 #endif
124
125 void ShenandoahHeapRegion::set_is_in_collection_set(bool b) {
126 assert(! (is_humongous() && b), "never ever enter a humongous region into the collection set");
127
128 _is_in_collection_set = b;
129
130 if (b) {
131 // tty->print_cr("registering region in fast-cset");
132 // print();
133 ShenandoahHeap::heap()->register_region_with_in_cset_fast_test(this);
134 }
135
136 #ifdef ASSERT
137 if (ShenandoahVerifyWritesToFromSpace || ShenandoahVerifyReadsToFromSpace) {
138 if (b) {
139 memProtectionOn();
140 assert(_mem_protection_level == 0, "need to be protected here");
141 } else {
142 assert(_mem_protection_level == 0, "need to be protected here");
143 memProtectionOff();
144 }
145 }
146 #endif
147 }
148
149 ByteSize ShenandoahHeapRegion::is_in_collection_set_offset() {
150 return byte_offset_of(ShenandoahHeapRegion, _is_in_collection_set);
151 }
152
153 void ShenandoahHeapRegion::print_on(outputStream* st) const {
154 st->print_cr("ShenandoahHeapRegion: "PTR_FORMAT"/"INT32_FORMAT, p2i(this), _region_number);
155
156 if (is_in_collection_set())
157 st->print("C");
158 if (is_humongous_start()) {
159 st->print("H");
160 }
161 if (is_humongous_continuation()) {
162 st->print("h");
163 }
164 //else
165 st->print(" ");
166
167 st->print_cr("live = "SIZE_FORMAT" garbage = "SIZE_FORMAT" bottom = "PTR_FORMAT" end = "PTR_FORMAT" top = "PTR_FORMAT,
168 getLiveData(), garbage(), p2i(bottom()), p2i(end()), p2i(top()));
169 }
170
171
172 class SkipUnreachableObjectToOopClosure: public ObjectClosure {
173 ExtendedOopClosure* _cl;
174 bool _skip_unreachable_objects;
175 ShenandoahHeap* _heap;
176
177 public:
178 SkipUnreachableObjectToOopClosure(ExtendedOopClosure* cl, bool skip_unreachable_objects) :
179 _cl(cl), _skip_unreachable_objects(skip_unreachable_objects), _heap(ShenandoahHeap::heap()) {}
180
181 void do_object(oop obj) {
182
183 if ((! _skip_unreachable_objects) || _heap->is_marked_current(obj)) {
184 if (_skip_unreachable_objects) {
185 assert(_heap->is_marked_current(obj), "obj must be live");
186 }
187 obj->oop_iterate(_cl);
188 }
189
190 }
191 };
192
193 void ShenandoahHeapRegion::object_iterate_interruptible(ObjectClosure* blk, bool allow_cancel) {
194 HeapWord* p = bottom() + BrooksPointer::BROOKS_POINTER_OBJ_SIZE;
195 ShenandoahHeap* heap = ShenandoahHeap::heap();
196 while (p < top() && !(allow_cancel && heap->cancelled_concgc())) {
197 blk->do_object(oop(p));
198 #ifdef ASSERT
199 if (ShenandoahVerifyReadsToFromSpace) {
200 memProtectionOff();
201 p += oop(p)->size() + BrooksPointer::BROOKS_POINTER_OBJ_SIZE;
202 memProtectionOn();
203 } else {
204 p += oop(p)->size() + BrooksPointer::BROOKS_POINTER_OBJ_SIZE;
205 }
206 #else
207 p += oop(p)->size() + BrooksPointer::BROOKS_POINTER_OBJ_SIZE;
208 #endif
209 }
210 }
211
212 HeapWord* ShenandoahHeapRegion::object_iterate_careful(ObjectClosureCareful* blk) {
213 HeapWord * limit = concurrent_iteration_safe_limit();
214 assert(limit <= top(), "sanity check");
215 for (HeapWord* p = bottom() + BrooksPointer::BROOKS_POINTER_OBJ_SIZE; p < limit;) {
216 size_t size = blk->do_object_careful(oop(p));
217 if (size == 0) {
218 return p; // failed at p
219 } else {
220 p += size + BrooksPointer::BROOKS_POINTER_OBJ_SIZE;
221 }
222 }
223 return NULL; // all done
224 }
225
226 void ShenandoahHeapRegion::oop_iterate_skip_unreachable(ExtendedOopClosure* cl, bool skip_unreachable_objects) {
227 SkipUnreachableObjectToOopClosure cl2(cl, skip_unreachable_objects);
228 object_iterate_interruptible(&cl2, false);
229 }
230
231 void ShenandoahHeapRegion::fill_region() {
232 ShenandoahHeap* sh = (ShenandoahHeap*) Universe::heap();
233
234 if (free() > (BrooksPointer::BROOKS_POINTER_OBJ_SIZE + CollectedHeap::min_fill_size())) {
235 HeapWord* filler = allocate(BrooksPointer::BROOKS_POINTER_OBJ_SIZE);
236 HeapWord* obj = allocate(end() - top());
237 sh->fill_with_object(obj, end() - obj);
238 sh->initialize_brooks_ptr(filler, obj);
239 }
240 }
241
242 void ShenandoahHeapRegion::set_humongous_start(bool start) {
243 _humongous_start = start;
244 }
245
246 void ShenandoahHeapRegion::set_humongous_continuation(bool continuation) {
247 _humongous_continuation = continuation;
248 }
249
250 bool ShenandoahHeapRegion::is_humongous() const {
251 return _humongous_start || _humongous_continuation;
252 }
253
254 bool ShenandoahHeapRegion::is_humongous_start() const {
255 return _humongous_start;
256 }
257
258 bool ShenandoahHeapRegion::is_humongous_continuation() const {
259 return _humongous_continuation;
260 }
261
262 void ShenandoahHeapRegion::do_reset() {
263 ContiguousSpace::initialize(reserved, true, false);
264 clearLiveData();
265 _humongous_start = false;
266 _humongous_continuation = false;
267 }
268
269 void ShenandoahHeapRegion::recycle() {
270 do_reset();
271 set_is_in_collection_set(false);
272 }
273
274 void ShenandoahHeapRegion::reset() {
275 assert(_mem_protection_level == 1, "needs to be unprotected here");
276 do_reset();
277 _is_in_collection_set = false;
278 }
279
280 HeapWord* ShenandoahHeapRegion::block_start_const(const void* p) const {
281 assert(MemRegion(bottom(), end()).contains(p),
282 err_msg("p ("PTR_FORMAT") not in space ["PTR_FORMAT", "PTR_FORMAT")",
283 p2i(p), p2i(bottom()), p2i(end())));
284 if (p >= top()) {
285 return top();
286 } else {
287 HeapWord* last = bottom() + BrooksPointer::BROOKS_POINTER_OBJ_SIZE;
288 HeapWord* cur = last;
289 while (cur <= p) {
290 last = cur;
291 cur += oop(cur)->size() + BrooksPointer::BROOKS_POINTER_OBJ_SIZE;
292 }
293 assert(oop(last)->is_oop(),
294 err_msg(PTR_FORMAT" should be an object start", p2i(last)));
295 return last;
296 }
297 }
298
299 void ShenandoahHeapRegion::setup_heap_region_size(size_t initial_heap_size, size_t max_heap_size) {
300 uintx region_size = ShenandoahHeapRegionSize;
301 if (FLAG_IS_DEFAULT(ShenandoahHeapRegionSize)) {
302 size_t average_heap_size = (initial_heap_size + max_heap_size) / 2;
303 region_size = MAX2(average_heap_size / HeapRegionBounds::target_number(),
304 (uintx) HeapRegionBounds::min_size());
305 }
306
307 int region_size_log = log2_long((jlong) region_size);
308 // Recalculate the region size to make sure it's a power of
309 // 2. This means that region_size is the largest power of 2 that's
310 // <= what we've calculated so far.
311 region_size = ((uintx)1 << region_size_log);
312
313 // Now make sure that we don't go over or under our limits.
314 if (region_size < HeapRegionBounds::min_size()) {
315 region_size = HeapRegionBounds::min_size();
316 } else if (region_size > HeapRegionBounds::max_size()) {
317 region_size = HeapRegionBounds::max_size();
318 }
319
320 // And recalculate the log.
321 region_size_log = log2_long((jlong) region_size);
322
323 // Now, set up the globals.
324 guarantee(RegionSizeShift == 0, "we should only set it once");
325 RegionSizeShift = region_size_log;
326
327 guarantee(RegionSizeBytes == 0, "we should only set it once");
328 RegionSizeBytes = (size_t)region_size;
329
330 if (ShenandoahLogConfig) {
331 tty->print_cr("Region size in bytes: "SIZE_FORMAT, RegionSizeBytes);
332 tty->print_cr("Region size shift: "SIZE_FORMAT, RegionSizeShift);
333 tty->print_cr("Initial number of regions: "SIZE_FORMAT, initial_heap_size / RegionSizeBytes);
334 tty->print_cr("Maximum number of regions: "SIZE_FORMAT, max_heap_size / RegionSizeBytes);
335 }
336 }
337
338 CompactibleSpace* ShenandoahHeapRegion::next_compaction_space() const {
339 return ShenandoahHeap::heap()->next_compaction_region(this);
340 }
341
342 void ShenandoahHeapRegion::prepare_for_compaction(CompactPoint* cp) {
343 scan_and_forward(this, cp);
344 }
345
346 void ShenandoahHeapRegion::adjust_pointers() {
347 // Check first is there is any work to do.
348 if (used() == 0) {
349 return; // Nothing to do.
350 }
351
352 scan_and_adjust_pointers(this);
353 }
354
355 void ShenandoahHeapRegion::compact() {
356 scan_and_compact(this);
357 }