1 /*
2 * Copyright (c) 2001, 2019, 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 *
53 } else {
54 fl = _free_list;
55 }
56 }
57 assert(fl == NULL, "Loop condition.");
58 return new PerRegionTable(hr);
59 }
60
61 PerRegionTable* volatile PerRegionTable::_free_list = NULL;
62
63 size_t OtherRegionsTable::_max_fine_entries = 0;
64 size_t OtherRegionsTable::_mod_max_fine_entries_mask = 0;
65 size_t OtherRegionsTable::_fine_eviction_stride = 0;
66 size_t OtherRegionsTable::_fine_eviction_sample_size = 0;
67
68 OtherRegionsTable::OtherRegionsTable(Mutex* m) :
69 _g1h(G1CollectedHeap::heap()),
70 _m(m),
71 _num_occupied(0),
72 _coarse_map(mtGC),
73 _n_coarse_entries(0),
74 _fine_grain_regions(NULL),
75 _n_fine_entries(0),
76 _first_all_fine_prts(NULL),
77 _last_all_fine_prts(NULL),
78 _fine_eviction_start(0),
79 _sparse_table()
80 {
81 typedef PerRegionTable* PerRegionTablePtr;
82
83 if (_max_fine_entries == 0) {
84 assert(_mod_max_fine_entries_mask == 0, "Both or none.");
85 size_t max_entries_log = (size_t)log2_long((jlong)G1RSetRegionEntries);
86 _max_fine_entries = (size_t)1 << max_entries_log;
87 _mod_max_fine_entries_mask = _max_fine_entries - 1;
88
89 assert(_fine_eviction_sample_size == 0
90 && _fine_eviction_stride == 0, "All init at same time.");
91 _fine_eviction_sample_size = MAX2((size_t)4, max_entries_log);
92 _fine_eviction_stride = _max_fine_entries / _fine_eviction_sample_size;
93 }
244 max = cur;
245 max_prev = prev;
246 max_occ = cur_occ;
247 }
248 prev = cur->collision_list_next_addr();
249 cur = cur->collision_list_next();
250 }
251 i = i + _fine_eviction_stride;
252 if (i >= _n_fine_entries) i = i - _n_fine_entries;
253 }
254
255 _fine_eviction_start++;
256
257 if (_fine_eviction_start >= _n_fine_entries) {
258 _fine_eviction_start -= _n_fine_entries;
259 }
260
261 guarantee(max != NULL, "Since _n_fine_entries > 0");
262 guarantee(max_prev != NULL, "Since max != NULL.");
263
264 // Set the corresponding coarse bit.
265 size_t max_hrm_index = (size_t) max->hr()->hrm_index();
266 if (_n_coarse_entries == 0) {
267 // This will lazily initialize an uninitialized bitmap
268 _coarse_map.reinitialize(G1CollectedHeap::heap()->max_regions());
269 _coarse_map.at_put(max_hrm_index, true);
270 // Release store guarantees that the bitmap has initialized before any
271 // concurrent reader will ever see a non-zero value for _n_coarse_entries
272 // (when read with load_acquire)
273 Atomic::release_store(&_n_coarse_entries, _n_coarse_entries + 1);
274 } else if (!_coarse_map.at(max_hrm_index)) {
275 _coarse_map.at_put(max_hrm_index, true);
276 _n_coarse_entries++;
277 }
278
279 added_by_deleted = HeapRegion::CardsPerRegion - max_occ;
280 // Unsplice.
281 *max_prev = max->collision_list_next();
282 Atomic::inc(&_n_coarsenings);
283 _n_fine_entries--;
284 return max;
285 }
286
287 bool OtherRegionsTable::occupancy_less_or_equal_than(size_t limit) const {
288 return occupied() <= limit;
289 }
290
291 bool OtherRegionsTable::is_empty() const {
292 return occupied() == 0;
293 }
294
295 size_t OtherRegionsTable::occupied() const {
296 return _num_occupied;
314 size_t OtherRegionsTable::static_mem_size() {
315 return G1FromCardCache::static_mem_size();
316 }
317
318 size_t OtherRegionsTable::fl_mem_size() {
319 return PerRegionTable::fl_mem_size();
320 }
321
322 void OtherRegionsTable::clear() {
323 // if there are no entries, skip this step
324 if (_first_all_fine_prts != NULL) {
325 guarantee(_first_all_fine_prts != NULL && _last_all_fine_prts != NULL, "just checking");
326 PerRegionTable::bulk_free(_first_all_fine_prts, _last_all_fine_prts);
327 memset(_fine_grain_regions, 0, _max_fine_entries * sizeof(_fine_grain_regions[0]));
328 } else {
329 guarantee(_first_all_fine_prts == NULL && _last_all_fine_prts == NULL, "just checking");
330 }
331
332 _first_all_fine_prts = _last_all_fine_prts = NULL;
333 _sparse_table.clear();
334 if (_n_coarse_entries > 0) {
335 _coarse_map.clear();
336 }
337 _n_fine_entries = 0;
338 _n_coarse_entries = 0;
339
340 _num_occupied = 0;
341 }
342
343 bool OtherRegionsTable::contains_reference(OopOrNarrowOopStar from) const {
344 // Cast away const in this case.
345 MutexLocker x((Mutex*)_m, Mutex::_no_safepoint_check_flag);
346 return contains_reference_locked(from);
347 }
348
349 bool OtherRegionsTable::contains_reference_locked(OopOrNarrowOopStar from) const {
350 HeapRegion* hr = _g1h->heap_region_containing(from);
351 RegionIdx_t hr_ind = (RegionIdx_t) hr->hrm_index();
352 // Is this region in the coarse map?
353 if (is_region_coarsened(hr_ind)) return true;
354
355 PerRegionTable* prt = find_region_table(hr_ind & _mod_max_fine_entries_mask,
356 hr);
357 if (prt != NULL) {
358 return prt->contains_reference(from);
359 } else {
360 CardIdx_t card_index = card_within_region(from, hr);
361 return _sparse_table.contains_card(hr_ind, card_index);
362 }
363 }
364
365 // A load_acquire on _n_coarse_entries - coupled with the release_store in
366 // delete_region_table - guarantees we don't access _coarse_map before
367 // it's been properly initialized.
368 bool OtherRegionsTable::is_region_coarsened(RegionIdx_t from_hrm_ind) const {
369 return Atomic::load_acquire(&_n_coarse_entries) > 0 && _coarse_map.at(from_hrm_ind);
370 }
371
372 HeapRegionRemSet::HeapRegionRemSet(G1BlockOffsetTable* bot,
373 HeapRegion* hr)
374 : _bot(bot),
375 _code_roots(),
376 _m(Mutex::leaf, FormatBuffer<128>("HeapRegionRemSet lock #%u", hr->hrm_index()), true, Mutex::_safepoint_check_never),
377 _other_regions(&_m),
378 _hr(hr),
379 _state(Untracked)
380 {
381 }
382
383 void HeapRegionRemSet::clear_fcc() {
384 G1FromCardCache::clear(_hr->hrm_index());
385 }
386
387 void HeapRegionRemSet::setup_remset_size() {
388 const int LOG_M = 20;
389 guarantee(HeapRegion::LogOfHRGrainBytes >= LOG_M, "Code assumes the region size >= 1M, but is " SIZE_FORMAT "B", HeapRegion::GrainBytes);
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1 /*
2 * Copyright (c) 2001, 2020, 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 *
53 } else {
54 fl = _free_list;
55 }
56 }
57 assert(fl == NULL, "Loop condition.");
58 return new PerRegionTable(hr);
59 }
60
61 PerRegionTable* volatile PerRegionTable::_free_list = NULL;
62
63 size_t OtherRegionsTable::_max_fine_entries = 0;
64 size_t OtherRegionsTable::_mod_max_fine_entries_mask = 0;
65 size_t OtherRegionsTable::_fine_eviction_stride = 0;
66 size_t OtherRegionsTable::_fine_eviction_sample_size = 0;
67
68 OtherRegionsTable::OtherRegionsTable(Mutex* m) :
69 _g1h(G1CollectedHeap::heap()),
70 _m(m),
71 _num_occupied(0),
72 _coarse_map(mtGC),
73 _has_coarse_entries(false),
74 _fine_grain_regions(NULL),
75 _n_fine_entries(0),
76 _first_all_fine_prts(NULL),
77 _last_all_fine_prts(NULL),
78 _fine_eviction_start(0),
79 _sparse_table()
80 {
81 typedef PerRegionTable* PerRegionTablePtr;
82
83 if (_max_fine_entries == 0) {
84 assert(_mod_max_fine_entries_mask == 0, "Both or none.");
85 size_t max_entries_log = (size_t)log2_long((jlong)G1RSetRegionEntries);
86 _max_fine_entries = (size_t)1 << max_entries_log;
87 _mod_max_fine_entries_mask = _max_fine_entries - 1;
88
89 assert(_fine_eviction_sample_size == 0
90 && _fine_eviction_stride == 0, "All init at same time.");
91 _fine_eviction_sample_size = MAX2((size_t)4, max_entries_log);
92 _fine_eviction_stride = _max_fine_entries / _fine_eviction_sample_size;
93 }
244 max = cur;
245 max_prev = prev;
246 max_occ = cur_occ;
247 }
248 prev = cur->collision_list_next_addr();
249 cur = cur->collision_list_next();
250 }
251 i = i + _fine_eviction_stride;
252 if (i >= _n_fine_entries) i = i - _n_fine_entries;
253 }
254
255 _fine_eviction_start++;
256
257 if (_fine_eviction_start >= _n_fine_entries) {
258 _fine_eviction_start -= _n_fine_entries;
259 }
260
261 guarantee(max != NULL, "Since _n_fine_entries > 0");
262 guarantee(max_prev != NULL, "Since max != NULL.");
263
264 // Ensure the corresponding coarse bit is set.
265 size_t max_hrm_index = (size_t) max->hr()->hrm_index();
266 if (Atomic::load(&_has_coarse_entries)) {
267 _coarse_map.at_put(max_hrm_index, true);
268 } else {
269 // This will lazily initialize an uninitialized bitmap
270 _coarse_map.reinitialize(G1CollectedHeap::heap()->max_regions());
271 assert(!_coarse_map.at(max_hrm_index), "No coarse entries");
272 _coarse_map.at_put(max_hrm_index, true);
273 // Release store guarantees that the bitmap has initialized before any
274 // concurrent reader will ever see _has_coarse_entries is true
275 // (when read with load_acquire)
276 Atomic::release_store(&_has_coarse_entries, true);
277 }
278
279 added_by_deleted = HeapRegion::CardsPerRegion - max_occ;
280 // Unsplice.
281 *max_prev = max->collision_list_next();
282 Atomic::inc(&_n_coarsenings);
283 _n_fine_entries--;
284 return max;
285 }
286
287 bool OtherRegionsTable::occupancy_less_or_equal_than(size_t limit) const {
288 return occupied() <= limit;
289 }
290
291 bool OtherRegionsTable::is_empty() const {
292 return occupied() == 0;
293 }
294
295 size_t OtherRegionsTable::occupied() const {
296 return _num_occupied;
314 size_t OtherRegionsTable::static_mem_size() {
315 return G1FromCardCache::static_mem_size();
316 }
317
318 size_t OtherRegionsTable::fl_mem_size() {
319 return PerRegionTable::fl_mem_size();
320 }
321
322 void OtherRegionsTable::clear() {
323 // if there are no entries, skip this step
324 if (_first_all_fine_prts != NULL) {
325 guarantee(_first_all_fine_prts != NULL && _last_all_fine_prts != NULL, "just checking");
326 PerRegionTable::bulk_free(_first_all_fine_prts, _last_all_fine_prts);
327 memset(_fine_grain_regions, 0, _max_fine_entries * sizeof(_fine_grain_regions[0]));
328 } else {
329 guarantee(_first_all_fine_prts == NULL && _last_all_fine_prts == NULL, "just checking");
330 }
331
332 _first_all_fine_prts = _last_all_fine_prts = NULL;
333 _sparse_table.clear();
334 if (Atomic::load(&_has_coarse_entries)) {
335 _coarse_map.clear();
336 }
337 _n_fine_entries = 0;
338 Atomic::store(&_has_coarse_entries, false);
339
340 _num_occupied = 0;
341 }
342
343 bool OtherRegionsTable::contains_reference(OopOrNarrowOopStar from) const {
344 // Cast away const in this case.
345 MutexLocker x((Mutex*)_m, Mutex::_no_safepoint_check_flag);
346 return contains_reference_locked(from);
347 }
348
349 bool OtherRegionsTable::contains_reference_locked(OopOrNarrowOopStar from) const {
350 HeapRegion* hr = _g1h->heap_region_containing(from);
351 RegionIdx_t hr_ind = (RegionIdx_t) hr->hrm_index();
352 // Is this region in the coarse map?
353 if (is_region_coarsened(hr_ind)) return true;
354
355 PerRegionTable* prt = find_region_table(hr_ind & _mod_max_fine_entries_mask,
356 hr);
357 if (prt != NULL) {
358 return prt->contains_reference(from);
359 } else {
360 CardIdx_t card_index = card_within_region(from, hr);
361 return _sparse_table.contains_card(hr_ind, card_index);
362 }
363 }
364
365 // A load_acquire on _has_coarse_entries - coupled with the release_store in
366 // delete_region_table - guarantees we don't access _coarse_map before
367 // it's been properly initialized.
368 bool OtherRegionsTable::is_region_coarsened(RegionIdx_t from_hrm_ind) const {
369 return Atomic::load_acquire(&_has_coarse_entries) && _coarse_map.at(from_hrm_ind);
370 }
371
372 HeapRegionRemSet::HeapRegionRemSet(G1BlockOffsetTable* bot,
373 HeapRegion* hr)
374 : _bot(bot),
375 _code_roots(),
376 _m(Mutex::leaf, FormatBuffer<128>("HeapRegionRemSet lock #%u", hr->hrm_index()), true, Mutex::_safepoint_check_never),
377 _other_regions(&_m),
378 _hr(hr),
379 _state(Untracked)
380 {
381 }
382
383 void HeapRegionRemSet::clear_fcc() {
384 G1FromCardCache::clear(_hr->hrm_index());
385 }
386
387 void HeapRegionRemSet::setup_remset_size() {
388 const int LOG_M = 20;
389 guarantee(HeapRegion::LogOfHRGrainBytes >= LOG_M, "Code assumes the region size >= 1M, but is " SIZE_FORMAT "B", HeapRegion::GrainBytes);
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