1.1 --- a/src/share/vm/gc_implementation/g1/heapRegionSeq.cpp Wed Aug 27 09:36:55 2014 +0200
1.2 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000
1.3 @@ -1,450 +0,0 @@
1.4 -/*
1.5 - * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved.
1.6 - * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 - *
1.8 - * This code is free software; you can redistribute it and/or modify it
1.9 - * under the terms of the GNU General Public License version 2 only, as
1.10 - * published by the Free Software Foundation.
1.11 - *
1.12 - * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 - * version 2 for more details (a copy is included in the LICENSE file that
1.16 - * accompanied this code).
1.17 - *
1.18 - * You should have received a copy of the GNU General Public License version
1.19 - * 2 along with this work; if not, write to the Free Software Foundation,
1.20 - * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 - *
1.22 - * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 - * or visit www.oracle.com if you need additional information or have any
1.24 - * questions.
1.25 - *
1.26 - */
1.27 -
1.28 -#include "precompiled.hpp"
1.29 -#include "gc_implementation/g1/heapRegion.hpp"
1.30 -#include "gc_implementation/g1/heapRegionSeq.inline.hpp"
1.31 -#include "gc_implementation/g1/heapRegionSet.inline.hpp"
1.32 -#include "gc_implementation/g1/g1CollectedHeap.inline.hpp"
1.33 -#include "gc_implementation/g1/concurrentG1Refine.hpp"
1.34 -#include "memory/allocation.hpp"
1.35 -
1.36 -void HeapRegionSeq::initialize(G1RegionToSpaceMapper* heap_storage,
1.37 - G1RegionToSpaceMapper* prev_bitmap,
1.38 - G1RegionToSpaceMapper* next_bitmap,
1.39 - G1RegionToSpaceMapper* bot,
1.40 - G1RegionToSpaceMapper* cardtable,
1.41 - G1RegionToSpaceMapper* card_counts) {
1.42 - _allocated_heapregions_length = 0;
1.43 -
1.44 - _heap_mapper = heap_storage;
1.45 -
1.46 - _prev_bitmap_mapper = prev_bitmap;
1.47 - _next_bitmap_mapper = next_bitmap;
1.48 -
1.49 - _bot_mapper = bot;
1.50 - _cardtable_mapper = cardtable;
1.51 -
1.52 - _card_counts_mapper = card_counts;
1.53 -
1.54 - MemRegion reserved = heap_storage->reserved();
1.55 - _regions.initialize(reserved.start(), reserved.end(), HeapRegion::GrainBytes);
1.56 -
1.57 - _available_map.resize(_regions.length(), false);
1.58 - _available_map.clear();
1.59 -}
1.60 -
1.61 -bool HeapRegionSeq::is_available(uint region) const {
1.62 - return _available_map.at(region);
1.63 -}
1.64 -
1.65 -#ifdef ASSERT
1.66 -bool HeapRegionSeq::is_free(HeapRegion* hr) const {
1.67 - return _free_list.contains(hr);
1.68 -}
1.69 -#endif
1.70 -
1.71 -HeapRegion* HeapRegionSeq::new_heap_region(uint hrs_index) {
1.72 - HeapWord* bottom = G1CollectedHeap::heap()->bottom_addr_for_region(hrs_index);
1.73 - MemRegion mr(bottom, bottom + HeapRegion::GrainWords);
1.74 - assert(reserved().contains(mr), "invariant");
1.75 - return new HeapRegion(hrs_index, G1CollectedHeap::heap()->bot_shared(), mr);
1.76 -}
1.77 -
1.78 -void HeapRegionSeq::commit_regions(uint index, size_t num_regions) {
1.79 - guarantee(num_regions > 0, "Must commit more than zero regions");
1.80 - guarantee(_num_committed + num_regions <= max_length(), "Cannot commit more than the maximum amount of regions");
1.81 -
1.82 - _num_committed += (uint)num_regions;
1.83 -
1.84 - _heap_mapper->commit_regions(index, num_regions);
1.85 -
1.86 - // Also commit auxiliary data
1.87 - _prev_bitmap_mapper->commit_regions(index, num_regions);
1.88 - _next_bitmap_mapper->commit_regions(index, num_regions);
1.89 -
1.90 - _bot_mapper->commit_regions(index, num_regions);
1.91 - _cardtable_mapper->commit_regions(index, num_regions);
1.92 -
1.93 - _card_counts_mapper->commit_regions(index, num_regions);
1.94 -}
1.95 -
1.96 -void HeapRegionSeq::uncommit_regions(uint start, size_t num_regions) {
1.97 - guarantee(num_regions >= 1, err_msg("Need to specify at least one region to uncommit, tried to uncommit zero regions at %u", start));
1.98 - guarantee(_num_committed >= num_regions, "pre-condition");
1.99 -
1.100 - // Print before uncommitting.
1.101 - if (G1CollectedHeap::heap()->hr_printer()->is_active()) {
1.102 - for (uint i = start; i < start + num_regions; i++) {
1.103 - HeapRegion* hr = at(i);
1.104 - G1CollectedHeap::heap()->hr_printer()->uncommit(hr->bottom(), hr->end());
1.105 - }
1.106 - }
1.107 -
1.108 - _num_committed -= (uint)num_regions;
1.109 -
1.110 - _available_map.par_clear_range(start, start + num_regions, BitMap::unknown_range);
1.111 - _heap_mapper->uncommit_regions(start, num_regions);
1.112 -
1.113 - // Also uncommit auxiliary data
1.114 - _prev_bitmap_mapper->uncommit_regions(start, num_regions);
1.115 - _next_bitmap_mapper->uncommit_regions(start, num_regions);
1.116 -
1.117 - _bot_mapper->uncommit_regions(start, num_regions);
1.118 - _cardtable_mapper->uncommit_regions(start, num_regions);
1.119 -
1.120 - _card_counts_mapper->uncommit_regions(start, num_regions);
1.121 -}
1.122 -
1.123 -void HeapRegionSeq::make_regions_available(uint start, uint num_regions) {
1.124 - guarantee(num_regions > 0, "No point in calling this for zero regions");
1.125 - commit_regions(start, num_regions);
1.126 - for (uint i = start; i < start + num_regions; i++) {
1.127 - if (_regions.get_by_index(i) == NULL) {
1.128 - HeapRegion* new_hr = new_heap_region(i);
1.129 - _regions.set_by_index(i, new_hr);
1.130 - _allocated_heapregions_length = MAX2(_allocated_heapregions_length, i + 1);
1.131 - }
1.132 - }
1.133 -
1.134 - _available_map.par_set_range(start, start + num_regions, BitMap::unknown_range);
1.135 -
1.136 - for (uint i = start; i < start + num_regions; i++) {
1.137 - assert(is_available(i), err_msg("Just made region %u available but is apparently not.", i));
1.138 - HeapRegion* hr = at(i);
1.139 - if (G1CollectedHeap::heap()->hr_printer()->is_active()) {
1.140 - G1CollectedHeap::heap()->hr_printer()->commit(hr->bottom(), hr->end());
1.141 - }
1.142 - HeapWord* bottom = G1CollectedHeap::heap()->bottom_addr_for_region(i);
1.143 - MemRegion mr(bottom, bottom + HeapRegion::GrainWords);
1.144 -
1.145 - hr->initialize(mr);
1.146 - insert_into_free_list(at(i));
1.147 - }
1.148 -}
1.149 -
1.150 -uint HeapRegionSeq::expand_by(uint num_regions) {
1.151 - return expand_at(0, num_regions);
1.152 -}
1.153 -
1.154 -uint HeapRegionSeq::expand_at(uint start, uint num_regions) {
1.155 - if (num_regions == 0) {
1.156 - return 0;
1.157 - }
1.158 -
1.159 - uint cur = start;
1.160 - uint idx_last_found = 0;
1.161 - uint num_last_found = 0;
1.162 -
1.163 - uint expanded = 0;
1.164 -
1.165 - while (expanded < num_regions &&
1.166 - (num_last_found = find_unavailable_from_idx(cur, &idx_last_found)) > 0) {
1.167 - uint to_expand = MIN2(num_regions - expanded, num_last_found);
1.168 - make_regions_available(idx_last_found, to_expand);
1.169 - expanded += to_expand;
1.170 - cur = idx_last_found + num_last_found + 1;
1.171 - }
1.172 -
1.173 - verify_optional();
1.174 - return expanded;
1.175 -}
1.176 -
1.177 -uint HeapRegionSeq::find_contiguous(size_t num, bool empty_only) {
1.178 - uint found = 0;
1.179 - size_t length_found = 0;
1.180 - uint cur = 0;
1.181 -
1.182 - while (length_found < num && cur < max_length()) {
1.183 - HeapRegion* hr = _regions.get_by_index(cur);
1.184 - if ((!empty_only && !is_available(cur)) || (is_available(cur) && hr != NULL && hr->is_empty())) {
1.185 - // This region is a potential candidate for allocation into.
1.186 - length_found++;
1.187 - } else {
1.188 - // This region is not a candidate. The next region is the next possible one.
1.189 - found = cur + 1;
1.190 - length_found = 0;
1.191 - }
1.192 - cur++;
1.193 - }
1.194 -
1.195 - if (length_found == num) {
1.196 - for (uint i = found; i < (found + num); i++) {
1.197 - HeapRegion* hr = _regions.get_by_index(i);
1.198 - // sanity check
1.199 - guarantee((!empty_only && !is_available(i)) || (is_available(i) && hr != NULL && hr->is_empty()),
1.200 - err_msg("Found region sequence starting at " UINT32_FORMAT ", length " SIZE_FORMAT
1.201 - " that is not empty at " UINT32_FORMAT ". Hr is " PTR_FORMAT, found, num, i, p2i(hr)));
1.202 - }
1.203 - return found;
1.204 - } else {
1.205 - return G1_NO_HRS_INDEX;
1.206 - }
1.207 -}
1.208 -
1.209 -HeapRegion* HeapRegionSeq::next_region_in_heap(const HeapRegion* r) const {
1.210 - guarantee(r != NULL, "Start region must be a valid region");
1.211 - guarantee(is_available(r->hrs_index()), err_msg("Trying to iterate starting from region %u which is not in the heap", r->hrs_index()));
1.212 - for (uint i = r->hrs_index() + 1; i < _allocated_heapregions_length; i++) {
1.213 - HeapRegion* hr = _regions.get_by_index(i);
1.214 - if (is_available(i)) {
1.215 - return hr;
1.216 - }
1.217 - }
1.218 - return NULL;
1.219 -}
1.220 -
1.221 -void HeapRegionSeq::iterate(HeapRegionClosure* blk) const {
1.222 - uint len = max_length();
1.223 -
1.224 - for (uint i = 0; i < len; i++) {
1.225 - if (!is_available(i)) {
1.226 - continue;
1.227 - }
1.228 - guarantee(at(i) != NULL, err_msg("Tried to access region %u that has a NULL HeapRegion*", i));
1.229 - bool res = blk->doHeapRegion(at(i));
1.230 - if (res) {
1.231 - blk->incomplete();
1.232 - return;
1.233 - }
1.234 - }
1.235 -}
1.236 -
1.237 -uint HeapRegionSeq::find_unavailable_from_idx(uint start_idx, uint* res_idx) const {
1.238 - guarantee(res_idx != NULL, "checking");
1.239 - guarantee(start_idx <= (max_length() + 1), "checking");
1.240 -
1.241 - uint num_regions = 0;
1.242 -
1.243 - uint cur = start_idx;
1.244 - while (cur < max_length() && is_available(cur)) {
1.245 - cur++;
1.246 - }
1.247 - if (cur == max_length()) {
1.248 - return num_regions;
1.249 - }
1.250 - *res_idx = cur;
1.251 - while (cur < max_length() && !is_available(cur)) {
1.252 - cur++;
1.253 - }
1.254 - num_regions = cur - *res_idx;
1.255 -#ifdef ASSERT
1.256 - for (uint i = *res_idx; i < (*res_idx + num_regions); i++) {
1.257 - assert(!is_available(i), "just checking");
1.258 - }
1.259 - assert(cur == max_length() || num_regions == 0 || is_available(cur),
1.260 - err_msg("The region at the current position %u must be available or at the end of the heap.", cur));
1.261 -#endif
1.262 - return num_regions;
1.263 -}
1.264 -
1.265 -uint HeapRegionSeq::start_region_for_worker(uint worker_i, uint num_workers, uint num_regions) const {
1.266 - return num_regions * worker_i / num_workers;
1.267 -}
1.268 -
1.269 -void HeapRegionSeq::par_iterate(HeapRegionClosure* blk, uint worker_id, uint num_workers, jint claim_value) const {
1.270 - const uint start_index = start_region_for_worker(worker_id, num_workers, _allocated_heapregions_length);
1.271 -
1.272 - // Every worker will actually look at all regions, skipping over regions that
1.273 - // are currently not committed.
1.274 - // This also (potentially) iterates over regions newly allocated during GC. This
1.275 - // is no problem except for some extra work.
1.276 - for (uint count = 0; count < _allocated_heapregions_length; count++) {
1.277 - const uint index = (start_index + count) % _allocated_heapregions_length;
1.278 - assert(0 <= index && index < _allocated_heapregions_length, "sanity");
1.279 - // Skip over unavailable regions
1.280 - if (!is_available(index)) {
1.281 - continue;
1.282 - }
1.283 - HeapRegion* r = _regions.get_by_index(index);
1.284 - // We'll ignore "continues humongous" regions (we'll process them
1.285 - // when we come across their corresponding "start humongous"
1.286 - // region) and regions already claimed.
1.287 - if (r->claim_value() == claim_value || r->continuesHumongous()) {
1.288 - continue;
1.289 - }
1.290 - // OK, try to claim it
1.291 - if (!r->claimHeapRegion(claim_value)) {
1.292 - continue;
1.293 - }
1.294 - // Success!
1.295 - if (r->startsHumongous()) {
1.296 - // If the region is "starts humongous" we'll iterate over its
1.297 - // "continues humongous" first; in fact we'll do them
1.298 - // first. The order is important. In one case, calling the
1.299 - // closure on the "starts humongous" region might de-allocate
1.300 - // and clear all its "continues humongous" regions and, as a
1.301 - // result, we might end up processing them twice. So, we'll do
1.302 - // them first (note: most closures will ignore them anyway) and
1.303 - // then we'll do the "starts humongous" region.
1.304 - for (uint ch_index = index + 1; ch_index < index + r->region_num(); ch_index++) {
1.305 - HeapRegion* chr = _regions.get_by_index(ch_index);
1.306 -
1.307 - assert(chr->continuesHumongous(), "Must be humongous region");
1.308 - assert(chr->humongous_start_region() == r,
1.309 - err_msg("Must work on humongous continuation of the original start region "
1.310 - PTR_FORMAT ", but is " PTR_FORMAT, p2i(r), p2i(chr)));
1.311 - assert(chr->claim_value() != claim_value,
1.312 - "Must not have been claimed yet because claiming of humongous continuation first claims the start region");
1.313 -
1.314 - bool claim_result = chr->claimHeapRegion(claim_value);
1.315 - // We should always be able to claim it; no one else should
1.316 - // be trying to claim this region.
1.317 - guarantee(claim_result, "We should always be able to claim the continuesHumongous part of the humongous object");
1.318 -
1.319 - bool res2 = blk->doHeapRegion(chr);
1.320 - if (res2) {
1.321 - return;
1.322 - }
1.323 -
1.324 - // Right now, this holds (i.e., no closure that actually
1.325 - // does something with "continues humongous" regions
1.326 - // clears them). We might have to weaken it in the future,
1.327 - // but let's leave these two asserts here for extra safety.
1.328 - assert(chr->continuesHumongous(), "should still be the case");
1.329 - assert(chr->humongous_start_region() == r, "sanity");
1.330 - }
1.331 - }
1.332 -
1.333 - bool res = blk->doHeapRegion(r);
1.334 - if (res) {
1.335 - return;
1.336 - }
1.337 - }
1.338 -}
1.339 -
1.340 -uint HeapRegionSeq::shrink_by(uint num_regions_to_remove) {
1.341 - assert(length() > 0, "the region sequence should not be empty");
1.342 - assert(length() <= _allocated_heapregions_length, "invariant");
1.343 - assert(_allocated_heapregions_length > 0, "we should have at least one region committed");
1.344 - assert(num_regions_to_remove < length(), "We should never remove all regions");
1.345 -
1.346 - if (num_regions_to_remove == 0) {
1.347 - return 0;
1.348 - }
1.349 -
1.350 - uint removed = 0;
1.351 - uint cur = _allocated_heapregions_length - 1;
1.352 - uint idx_last_found = 0;
1.353 - uint num_last_found = 0;
1.354 -
1.355 - while ((removed < num_regions_to_remove) &&
1.356 - (num_last_found = find_empty_from_idx_reverse(cur, &idx_last_found)) > 0) {
1.357 - // Only allow uncommit from the end of the heap.
1.358 - if ((idx_last_found + num_last_found) != _allocated_heapregions_length) {
1.359 - return 0;
1.360 - }
1.361 - uint to_remove = MIN2(num_regions_to_remove - removed, num_last_found);
1.362 -
1.363 - uncommit_regions(idx_last_found + num_last_found - to_remove, to_remove);
1.364 -
1.365 - cur -= num_last_found;
1.366 - removed += to_remove;
1.367 - }
1.368 -
1.369 - verify_optional();
1.370 -
1.371 - return removed;
1.372 -}
1.373 -
1.374 -uint HeapRegionSeq::find_empty_from_idx_reverse(uint start_idx, uint* res_idx) const {
1.375 - guarantee(start_idx < _allocated_heapregions_length, "checking");
1.376 - guarantee(res_idx != NULL, "checking");
1.377 -
1.378 - uint num_regions_found = 0;
1.379 -
1.380 - jlong cur = start_idx;
1.381 - while (cur != -1 && !(is_available(cur) && at(cur)->is_empty())) {
1.382 - cur--;
1.383 - }
1.384 - if (cur == -1) {
1.385 - return num_regions_found;
1.386 - }
1.387 - jlong old_cur = cur;
1.388 - // cur indexes the first empty region
1.389 - while (cur != -1 && is_available(cur) && at(cur)->is_empty()) {
1.390 - cur--;
1.391 - }
1.392 - *res_idx = cur + 1;
1.393 - num_regions_found = old_cur - cur;
1.394 -
1.395 -#ifdef ASSERT
1.396 - for (uint i = *res_idx; i < (*res_idx + num_regions_found); i++) {
1.397 - assert(at(i)->is_empty(), "just checking");
1.398 - }
1.399 -#endif
1.400 - return num_regions_found;
1.401 -}
1.402 -
1.403 -void HeapRegionSeq::verify() {
1.404 - guarantee(length() <= _allocated_heapregions_length,
1.405 - err_msg("invariant: _length: %u _allocated_length: %u",
1.406 - length(), _allocated_heapregions_length));
1.407 - guarantee(_allocated_heapregions_length <= max_length(),
1.408 - err_msg("invariant: _allocated_length: %u _max_length: %u",
1.409 - _allocated_heapregions_length, max_length()));
1.410 -
1.411 - bool prev_committed = true;
1.412 - uint num_committed = 0;
1.413 - HeapWord* prev_end = heap_bottom();
1.414 - for (uint i = 0; i < _allocated_heapregions_length; i++) {
1.415 - if (!is_available(i)) {
1.416 - prev_committed = false;
1.417 - continue;
1.418 - }
1.419 - num_committed++;
1.420 - HeapRegion* hr = _regions.get_by_index(i);
1.421 - guarantee(hr != NULL, err_msg("invariant: i: %u", i));
1.422 - guarantee(!prev_committed || hr->bottom() == prev_end,
1.423 - err_msg("invariant i: %u "HR_FORMAT" prev_end: "PTR_FORMAT,
1.424 - i, HR_FORMAT_PARAMS(hr), p2i(prev_end)));
1.425 - guarantee(hr->hrs_index() == i,
1.426 - err_msg("invariant: i: %u hrs_index(): %u", i, hr->hrs_index()));
1.427 - // Asserts will fire if i is >= _length
1.428 - HeapWord* addr = hr->bottom();
1.429 - guarantee(addr_to_region(addr) == hr, "sanity");
1.430 - // We cannot check whether the region is part of a particular set: at the time
1.431 - // this method may be called, we have only completed allocation of the regions,
1.432 - // but not put into a region set.
1.433 - prev_committed = true;
1.434 - if (hr->startsHumongous()) {
1.435 - prev_end = hr->orig_end();
1.436 - } else {
1.437 - prev_end = hr->end();
1.438 - }
1.439 - }
1.440 - for (uint i = _allocated_heapregions_length; i < max_length(); i++) {
1.441 - guarantee(_regions.get_by_index(i) == NULL, err_msg("invariant i: %u", i));
1.442 - }
1.443 -
1.444 - guarantee(num_committed == _num_committed, err_msg("Found %u committed regions, but should be %u", num_committed, _num_committed));
1.445 - _free_list.verify();
1.446 -}
1.447 -
1.448 -#ifndef PRODUCT
1.449 -void HeapRegionSeq::verify_optional() {
1.450 - verify();
1.451 -}
1.452 -#endif // PRODUCT
1.453 -
