--- old/src/share/vm/gc_implementation/g1/heapRegionSeq.cpp 2014-08-25 16:17:08.675090515 +0200 +++ /dev/null 2014-08-11 17:55:13.749734341 +0200 @@ -1,450 +0,0 @@ -/* - * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved. - * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. - * - * This code is free software; you can redistribute it and/or modify it - * under the terms of the GNU General Public License version 2 only, as - * published by the Free Software Foundation. - * - * This code is distributed in the hope that it will be useful, but WITHOUT - * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or - * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License - * version 2 for more details (a copy is included in the LICENSE file that - * accompanied this code). - * - * You should have received a copy of the GNU General Public License version - * 2 along with this work; if not, write to the Free Software Foundation, - * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. - * - * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA - * or visit www.oracle.com if you need additional information or have any - * questions. - * - */ - -#include "precompiled.hpp" -#include "gc_implementation/g1/heapRegion.hpp" -#include "gc_implementation/g1/heapRegionSeq.inline.hpp" -#include "gc_implementation/g1/heapRegionSet.inline.hpp" -#include "gc_implementation/g1/g1CollectedHeap.inline.hpp" -#include "gc_implementation/g1/concurrentG1Refine.hpp" -#include "memory/allocation.hpp" - -void HeapRegionSeq::initialize(G1RegionToSpaceMapper* heap_storage, - G1RegionToSpaceMapper* prev_bitmap, - G1RegionToSpaceMapper* next_bitmap, - G1RegionToSpaceMapper* bot, - G1RegionToSpaceMapper* cardtable, - G1RegionToSpaceMapper* card_counts) { - _allocated_heapregions_length = 0; - - _heap_mapper = heap_storage; - - _prev_bitmap_mapper = prev_bitmap; - _next_bitmap_mapper = next_bitmap; - - _bot_mapper = bot; - _cardtable_mapper = cardtable; - - _card_counts_mapper = card_counts; - - MemRegion reserved = heap_storage->reserved(); - _regions.initialize(reserved.start(), reserved.end(), HeapRegion::GrainBytes); - - _available_map.resize(_regions.length(), false); - _available_map.clear(); -} - -bool HeapRegionSeq::is_available(uint region) const { - return _available_map.at(region); -} - -#ifdef ASSERT -bool HeapRegionSeq::is_free(HeapRegion* hr) const { - return _free_list.contains(hr); -} -#endif - -HeapRegion* HeapRegionSeq::new_heap_region(uint hrs_index) { - HeapWord* bottom = G1CollectedHeap::heap()->bottom_addr_for_region(hrs_index); - MemRegion mr(bottom, bottom + HeapRegion::GrainWords); - assert(reserved().contains(mr), "invariant"); - return new HeapRegion(hrs_index, G1CollectedHeap::heap()->bot_shared(), mr); -} - -void HeapRegionSeq::commit_regions(uint index, size_t num_regions) { - guarantee(num_regions > 0, "Must commit more than zero regions"); - guarantee(_num_committed + num_regions <= max_length(), "Cannot commit more than the maximum amount of regions"); - - _num_committed += (uint)num_regions; - - _heap_mapper->commit_regions(index, num_regions); - - // Also commit auxiliary data - _prev_bitmap_mapper->commit_regions(index, num_regions); - _next_bitmap_mapper->commit_regions(index, num_regions); - - _bot_mapper->commit_regions(index, num_regions); - _cardtable_mapper->commit_regions(index, num_regions); - - _card_counts_mapper->commit_regions(index, num_regions); -} - -void HeapRegionSeq::uncommit_regions(uint start, size_t num_regions) { - guarantee(num_regions >= 1, err_msg("Need to specify at least one region to uncommit, tried to uncommit zero regions at %u", start)); - guarantee(_num_committed >= num_regions, "pre-condition"); - - // Print before uncommitting. - if (G1CollectedHeap::heap()->hr_printer()->is_active()) { - for (uint i = start; i < start + num_regions; i++) { - HeapRegion* hr = at(i); - G1CollectedHeap::heap()->hr_printer()->uncommit(hr->bottom(), hr->end()); - } - } - - _num_committed -= (uint)num_regions; - - _available_map.par_clear_range(start, start + num_regions, BitMap::unknown_range); - _heap_mapper->uncommit_regions(start, num_regions); - - // Also uncommit auxiliary data - _prev_bitmap_mapper->uncommit_regions(start, num_regions); - _next_bitmap_mapper->uncommit_regions(start, num_regions); - - _bot_mapper->uncommit_regions(start, num_regions); - _cardtable_mapper->uncommit_regions(start, num_regions); - - _card_counts_mapper->uncommit_regions(start, num_regions); -} - -void HeapRegionSeq::make_regions_available(uint start, uint num_regions) { - guarantee(num_regions > 0, "No point in calling this for zero regions"); - commit_regions(start, num_regions); - for (uint i = start; i < start + num_regions; i++) { - if (_regions.get_by_index(i) == NULL) { - HeapRegion* new_hr = new_heap_region(i); - _regions.set_by_index(i, new_hr); - _allocated_heapregions_length = MAX2(_allocated_heapregions_length, i + 1); - } - } - - _available_map.par_set_range(start, start + num_regions, BitMap::unknown_range); - - for (uint i = start; i < start + num_regions; i++) { - assert(is_available(i), err_msg("Just made region %u available but is apparently not.", i)); - HeapRegion* hr = at(i); - if (G1CollectedHeap::heap()->hr_printer()->is_active()) { - G1CollectedHeap::heap()->hr_printer()->commit(hr->bottom(), hr->end()); - } - HeapWord* bottom = G1CollectedHeap::heap()->bottom_addr_for_region(i); - MemRegion mr(bottom, bottom + HeapRegion::GrainWords); - - hr->initialize(mr); - insert_into_free_list(at(i)); - } -} - -uint HeapRegionSeq::expand_by(uint num_regions) { - return expand_at(0, num_regions); -} - -uint HeapRegionSeq::expand_at(uint start, uint num_regions) { - if (num_regions == 0) { - return 0; - } - - uint cur = start; - uint idx_last_found = 0; - uint num_last_found = 0; - - uint expanded = 0; - - while (expanded < num_regions && - (num_last_found = find_unavailable_from_idx(cur, &idx_last_found)) > 0) { - uint to_expand = MIN2(num_regions - expanded, num_last_found); - make_regions_available(idx_last_found, to_expand); - expanded += to_expand; - cur = idx_last_found + num_last_found + 1; - } - - verify_optional(); - return expanded; -} - -uint HeapRegionSeq::find_contiguous(size_t num, bool empty_only) { - uint found = 0; - size_t length_found = 0; - uint cur = 0; - - while (length_found < num && cur < max_length()) { - HeapRegion* hr = _regions.get_by_index(cur); - if ((!empty_only && !is_available(cur)) || (is_available(cur) && hr != NULL && hr->is_empty())) { - // This region is a potential candidate for allocation into. - length_found++; - } else { - // This region is not a candidate. The next region is the next possible one. - found = cur + 1; - length_found = 0; - } - cur++; - } - - if (length_found == num) { - for (uint i = found; i < (found + num); i++) { - HeapRegion* hr = _regions.get_by_index(i); - // sanity check - guarantee((!empty_only && !is_available(i)) || (is_available(i) && hr != NULL && hr->is_empty()), - err_msg("Found region sequence starting at " UINT32_FORMAT ", length " SIZE_FORMAT - " that is not empty at " UINT32_FORMAT ". Hr is " PTR_FORMAT, found, num, i, p2i(hr))); - } - return found; - } else { - return G1_NO_HRS_INDEX; - } -} - -HeapRegion* HeapRegionSeq::next_region_in_heap(const HeapRegion* r) const { - guarantee(r != NULL, "Start region must be a valid region"); - guarantee(is_available(r->hrs_index()), err_msg("Trying to iterate starting from region %u which is not in the heap", r->hrs_index())); - for (uint i = r->hrs_index() + 1; i < _allocated_heapregions_length; i++) { - HeapRegion* hr = _regions.get_by_index(i); - if (is_available(i)) { - return hr; - } - } - return NULL; -} - -void HeapRegionSeq::iterate(HeapRegionClosure* blk) const { - uint len = max_length(); - - for (uint i = 0; i < len; i++) { - if (!is_available(i)) { - continue; - } - guarantee(at(i) != NULL, err_msg("Tried to access region %u that has a NULL HeapRegion*", i)); - bool res = blk->doHeapRegion(at(i)); - if (res) { - blk->incomplete(); - return; - } - } -} - -uint HeapRegionSeq::find_unavailable_from_idx(uint start_idx, uint* res_idx) const { - guarantee(res_idx != NULL, "checking"); - guarantee(start_idx <= (max_length() + 1), "checking"); - - uint num_regions = 0; - - uint cur = start_idx; - while (cur < max_length() && is_available(cur)) { - cur++; - } - if (cur == max_length()) { - return num_regions; - } - *res_idx = cur; - while (cur < max_length() && !is_available(cur)) { - cur++; - } - num_regions = cur - *res_idx; -#ifdef ASSERT - for (uint i = *res_idx; i < (*res_idx + num_regions); i++) { - assert(!is_available(i), "just checking"); - } - assert(cur == max_length() || num_regions == 0 || is_available(cur), - err_msg("The region at the current position %u must be available or at the end of the heap.", cur)); -#endif - return num_regions; -} - -uint HeapRegionSeq::start_region_for_worker(uint worker_i, uint num_workers, uint num_regions) const { - return num_regions * worker_i / num_workers; -} - -void HeapRegionSeq::par_iterate(HeapRegionClosure* blk, uint worker_id, uint num_workers, jint claim_value) const { - const uint start_index = start_region_for_worker(worker_id, num_workers, _allocated_heapregions_length); - - // Every worker will actually look at all regions, skipping over regions that - // are currently not committed. - // This also (potentially) iterates over regions newly allocated during GC. This - // is no problem except for some extra work. - for (uint count = 0; count < _allocated_heapregions_length; count++) { - const uint index = (start_index + count) % _allocated_heapregions_length; - assert(0 <= index && index < _allocated_heapregions_length, "sanity"); - // Skip over unavailable regions - if (!is_available(index)) { - continue; - } - HeapRegion* r = _regions.get_by_index(index); - // We'll ignore "continues humongous" regions (we'll process them - // when we come across their corresponding "start humongous" - // region) and regions already claimed. - if (r->claim_value() == claim_value || r->continuesHumongous()) { - continue; - } - // OK, try to claim it - if (!r->claimHeapRegion(claim_value)) { - continue; - } - // Success! - if (r->startsHumongous()) { - // If the region is "starts humongous" we'll iterate over its - // "continues humongous" first; in fact we'll do them - // first. The order is important. In one case, calling the - // closure on the "starts humongous" region might de-allocate - // and clear all its "continues humongous" regions and, as a - // result, we might end up processing them twice. So, we'll do - // them first (note: most closures will ignore them anyway) and - // then we'll do the "starts humongous" region. - for (uint ch_index = index + 1; ch_index < index + r->region_num(); ch_index++) { - HeapRegion* chr = _regions.get_by_index(ch_index); - - assert(chr->continuesHumongous(), "Must be humongous region"); - assert(chr->humongous_start_region() == r, - err_msg("Must work on humongous continuation of the original start region " - PTR_FORMAT ", but is " PTR_FORMAT, p2i(r), p2i(chr))); - assert(chr->claim_value() != claim_value, - "Must not have been claimed yet because claiming of humongous continuation first claims the start region"); - - bool claim_result = chr->claimHeapRegion(claim_value); - // We should always be able to claim it; no one else should - // be trying to claim this region. - guarantee(claim_result, "We should always be able to claim the continuesHumongous part of the humongous object"); - - bool res2 = blk->doHeapRegion(chr); - if (res2) { - return; - } - - // Right now, this holds (i.e., no closure that actually - // does something with "continues humongous" regions - // clears them). We might have to weaken it in the future, - // but let's leave these two asserts here for extra safety. - assert(chr->continuesHumongous(), "should still be the case"); - assert(chr->humongous_start_region() == r, "sanity"); - } - } - - bool res = blk->doHeapRegion(r); - if (res) { - return; - } - } -} - -uint HeapRegionSeq::shrink_by(uint num_regions_to_remove) { - assert(length() > 0, "the region sequence should not be empty"); - assert(length() <= _allocated_heapregions_length, "invariant"); - assert(_allocated_heapregions_length > 0, "we should have at least one region committed"); - assert(num_regions_to_remove < length(), "We should never remove all regions"); - - if (num_regions_to_remove == 0) { - return 0; - } - - uint removed = 0; - uint cur = _allocated_heapregions_length - 1; - uint idx_last_found = 0; - uint num_last_found = 0; - - while ((removed < num_regions_to_remove) && - (num_last_found = find_empty_from_idx_reverse(cur, &idx_last_found)) > 0) { - // Only allow uncommit from the end of the heap. - if ((idx_last_found + num_last_found) != _allocated_heapregions_length) { - return 0; - } - uint to_remove = MIN2(num_regions_to_remove - removed, num_last_found); - - uncommit_regions(idx_last_found + num_last_found - to_remove, to_remove); - - cur -= num_last_found; - removed += to_remove; - } - - verify_optional(); - - return removed; -} - -uint HeapRegionSeq::find_empty_from_idx_reverse(uint start_idx, uint* res_idx) const { - guarantee(start_idx < _allocated_heapregions_length, "checking"); - guarantee(res_idx != NULL, "checking"); - - uint num_regions_found = 0; - - jlong cur = start_idx; - while (cur != -1 && !(is_available(cur) && at(cur)->is_empty())) { - cur--; - } - if (cur == -1) { - return num_regions_found; - } - jlong old_cur = cur; - // cur indexes the first empty region - while (cur != -1 && is_available(cur) && at(cur)->is_empty()) { - cur--; - } - *res_idx = cur + 1; - num_regions_found = old_cur - cur; - -#ifdef ASSERT - for (uint i = *res_idx; i < (*res_idx + num_regions_found); i++) { - assert(at(i)->is_empty(), "just checking"); - } -#endif - return num_regions_found; -} - -void HeapRegionSeq::verify() { - guarantee(length() <= _allocated_heapregions_length, - err_msg("invariant: _length: %u _allocated_length: %u", - length(), _allocated_heapregions_length)); - guarantee(_allocated_heapregions_length <= max_length(), - err_msg("invariant: _allocated_length: %u _max_length: %u", - _allocated_heapregions_length, max_length())); - - bool prev_committed = true; - uint num_committed = 0; - HeapWord* prev_end = heap_bottom(); - for (uint i = 0; i < _allocated_heapregions_length; i++) { - if (!is_available(i)) { - prev_committed = false; - continue; - } - num_committed++; - HeapRegion* hr = _regions.get_by_index(i); - guarantee(hr != NULL, err_msg("invariant: i: %u", i)); - guarantee(!prev_committed || hr->bottom() == prev_end, - err_msg("invariant i: %u "HR_FORMAT" prev_end: "PTR_FORMAT, - i, HR_FORMAT_PARAMS(hr), p2i(prev_end))); - guarantee(hr->hrs_index() == i, - err_msg("invariant: i: %u hrs_index(): %u", i, hr->hrs_index())); - // Asserts will fire if i is >= _length - HeapWord* addr = hr->bottom(); - guarantee(addr_to_region(addr) == hr, "sanity"); - // We cannot check whether the region is part of a particular set: at the time - // this method may be called, we have only completed allocation of the regions, - // but not put into a region set. - prev_committed = true; - if (hr->startsHumongous()) { - prev_end = hr->orig_end(); - } else { - prev_end = hr->end(); - } - } - for (uint i = _allocated_heapregions_length; i < max_length(); i++) { - guarantee(_regions.get_by_index(i) == NULL, err_msg("invariant i: %u", i)); - } - - guarantee(num_committed == _num_committed, err_msg("Found %u committed regions, but should be %u", num_committed, _num_committed)); - _free_list.verify(); -} - -#ifndef PRODUCT -void HeapRegionSeq::verify_optional() { - verify(); -} -#endif // PRODUCT - --- /dev/null 2014-08-11 17:55:13.749734341 +0200 +++ new/src/share/vm/gc_implementation/g1/heapRegionManager.cpp 2014-08-25 16:17:08.605088474 +0200 @@ -0,0 +1,450 @@ +/* + * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved. + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. + * + * This code is free software; you can redistribute it and/or modify it + * under the terms of the GNU General Public License version 2 only, as + * published by the Free Software Foundation. + * + * This code is distributed in the hope that it will be useful, but WITHOUT + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License + * version 2 for more details (a copy is included in the LICENSE file that + * accompanied this code). + * + * You should have received a copy of the GNU General Public License version + * 2 along with this work; if not, write to the Free Software Foundation, + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. + * + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA + * or visit www.oracle.com if you need additional information or have any + * questions. + * + */ + +#include "precompiled.hpp" +#include "gc_implementation/g1/heapRegion.hpp" +#include "gc_implementation/g1/heapRegionManager.inline.hpp" +#include "gc_implementation/g1/heapRegionSet.inline.hpp" +#include "gc_implementation/g1/g1CollectedHeap.inline.hpp" +#include "gc_implementation/g1/concurrentG1Refine.hpp" +#include "memory/allocation.hpp" + +void HeapRegionManager::initialize(G1RegionToSpaceMapper* heap_storage, + G1RegionToSpaceMapper* prev_bitmap, + G1RegionToSpaceMapper* next_bitmap, + G1RegionToSpaceMapper* bot, + G1RegionToSpaceMapper* cardtable, + G1RegionToSpaceMapper* card_counts) { + _allocated_heapregions_length = 0; + + _heap_mapper = heap_storage; + + _prev_bitmap_mapper = prev_bitmap; + _next_bitmap_mapper = next_bitmap; + + _bot_mapper = bot; + _cardtable_mapper = cardtable; + + _card_counts_mapper = card_counts; + + MemRegion reserved = heap_storage->reserved(); + _regions.initialize(reserved.start(), reserved.end(), HeapRegion::GrainBytes); + + _available_map.resize(_regions.length(), false); + _available_map.clear(); +} + +bool HeapRegionManager::is_available(uint region) const { + return _available_map.at(region); +} + +#ifdef ASSERT +bool HeapRegionManager::is_free(HeapRegion* hr) const { + return _free_list.contains(hr); +} +#endif + +HeapRegion* HeapRegionManager::new_heap_region(uint hrm_index) { + HeapWord* bottom = G1CollectedHeap::heap()->bottom_addr_for_region(hrm_index); + MemRegion mr(bottom, bottom + HeapRegion::GrainWords); + assert(reserved().contains(mr), "invariant"); + return new HeapRegion(hrm_index, G1CollectedHeap::heap()->bot_shared(), mr); +} + +void HeapRegionManager::commit_regions(uint index, size_t num_regions) { + guarantee(num_regions > 0, "Must commit more than zero regions"); + guarantee(_num_committed + num_regions <= max_length(), "Cannot commit more than the maximum amount of regions"); + + _num_committed += (uint)num_regions; + + _heap_mapper->commit_regions(index, num_regions); + + // Also commit auxiliary data + _prev_bitmap_mapper->commit_regions(index, num_regions); + _next_bitmap_mapper->commit_regions(index, num_regions); + + _bot_mapper->commit_regions(index, num_regions); + _cardtable_mapper->commit_regions(index, num_regions); + + _card_counts_mapper->commit_regions(index, num_regions); +} + +void HeapRegionManager::uncommit_regions(uint start, size_t num_regions) { + guarantee(num_regions >= 1, err_msg("Need to specify at least one region to uncommit, tried to uncommit zero regions at %u", start)); + guarantee(_num_committed >= num_regions, "pre-condition"); + + // Print before uncommitting. + if (G1CollectedHeap::heap()->hr_printer()->is_active()) { + for (uint i = start; i < start + num_regions; i++) { + HeapRegion* hr = at(i); + G1CollectedHeap::heap()->hr_printer()->uncommit(hr->bottom(), hr->end()); + } + } + + _num_committed -= (uint)num_regions; + + _available_map.par_clear_range(start, start + num_regions, BitMap::unknown_range); + _heap_mapper->uncommit_regions(start, num_regions); + + // Also uncommit auxiliary data + _prev_bitmap_mapper->uncommit_regions(start, num_regions); + _next_bitmap_mapper->uncommit_regions(start, num_regions); + + _bot_mapper->uncommit_regions(start, num_regions); + _cardtable_mapper->uncommit_regions(start, num_regions); + + _card_counts_mapper->uncommit_regions(start, num_regions); +} + +void HeapRegionManager::make_regions_available(uint start, uint num_regions) { + guarantee(num_regions > 0, "No point in calling this for zero regions"); + commit_regions(start, num_regions); + for (uint i = start; i < start + num_regions; i++) { + if (_regions.get_by_index(i) == NULL) { + HeapRegion* new_hr = new_heap_region(i); + _regions.set_by_index(i, new_hr); + _allocated_heapregions_length = MAX2(_allocated_heapregions_length, i + 1); + } + } + + _available_map.par_set_range(start, start + num_regions, BitMap::unknown_range); + + for (uint i = start; i < start + num_regions; i++) { + assert(is_available(i), err_msg("Just made region %u available but is apparently not.", i)); + HeapRegion* hr = at(i); + if (G1CollectedHeap::heap()->hr_printer()->is_active()) { + G1CollectedHeap::heap()->hr_printer()->commit(hr->bottom(), hr->end()); + } + HeapWord* bottom = G1CollectedHeap::heap()->bottom_addr_for_region(i); + MemRegion mr(bottom, bottom + HeapRegion::GrainWords); + + hr->initialize(mr); + insert_into_free_list(at(i)); + } +} + +uint HeapRegionManager::expand_by(uint num_regions) { + return expand_at(0, num_regions); +} + +uint HeapRegionManager::expand_at(uint start, uint num_regions) { + if (num_regions == 0) { + return 0; + } + + uint cur = start; + uint idx_last_found = 0; + uint num_last_found = 0; + + uint expanded = 0; + + while (expanded < num_regions && + (num_last_found = find_unavailable_from_idx(cur, &idx_last_found)) > 0) { + uint to_expand = MIN2(num_regions - expanded, num_last_found); + make_regions_available(idx_last_found, to_expand); + expanded += to_expand; + cur = idx_last_found + num_last_found + 1; + } + + verify_optional(); + return expanded; +} + +uint HeapRegionManager::find_contiguous(size_t num, bool empty_only) { + uint found = 0; + size_t length_found = 0; + uint cur = 0; + + while (length_found < num && cur < max_length()) { + HeapRegion* hr = _regions.get_by_index(cur); + if ((!empty_only && !is_available(cur)) || (is_available(cur) && hr != NULL && hr->is_empty())) { + // This region is a potential candidate for allocation into. + length_found++; + } else { + // This region is not a candidate. The next region is the next possible one. + found = cur + 1; + length_found = 0; + } + cur++; + } + + if (length_found == num) { + for (uint i = found; i < (found + num); i++) { + HeapRegion* hr = _regions.get_by_index(i); + // sanity check + guarantee((!empty_only && !is_available(i)) || (is_available(i) && hr != NULL && hr->is_empty()), + err_msg("Found region sequence starting at " UINT32_FORMAT ", length " SIZE_FORMAT + " that is not empty at " UINT32_FORMAT ". Hr is " PTR_FORMAT, found, num, i, p2i(hr))); + } + return found; + } else { + return G1_NO_HRM_INDEX; + } +} + +HeapRegion* HeapRegionManager::next_region_in_heap(const HeapRegion* r) const { + guarantee(r != NULL, "Start region must be a valid region"); + guarantee(is_available(r->hrm_index()), err_msg("Trying to iterate starting from region %u which is not in the heap", r->hrm_index())); + for (uint i = r->hrm_index() + 1; i < _allocated_heapregions_length; i++) { + HeapRegion* hr = _regions.get_by_index(i); + if (is_available(i)) { + return hr; + } + } + return NULL; +} + +void HeapRegionManager::iterate(HeapRegionClosure* blk) const { + uint len = max_length(); + + for (uint i = 0; i < len; i++) { + if (!is_available(i)) { + continue; + } + guarantee(at(i) != NULL, err_msg("Tried to access region %u that has a NULL HeapRegion*", i)); + bool res = blk->doHeapRegion(at(i)); + if (res) { + blk->incomplete(); + return; + } + } +} + +uint HeapRegionManager::find_unavailable_from_idx(uint start_idx, uint* res_idx) const { + guarantee(res_idx != NULL, "checking"); + guarantee(start_idx <= (max_length() + 1), "checking"); + + uint num_regions = 0; + + uint cur = start_idx; + while (cur < max_length() && is_available(cur)) { + cur++; + } + if (cur == max_length()) { + return num_regions; + } + *res_idx = cur; + while (cur < max_length() && !is_available(cur)) { + cur++; + } + num_regions = cur - *res_idx; +#ifdef ASSERT + for (uint i = *res_idx; i < (*res_idx + num_regions); i++) { + assert(!is_available(i), "just checking"); + } + assert(cur == max_length() || num_regions == 0 || is_available(cur), + err_msg("The region at the current position %u must be available or at the end of the heap.", cur)); +#endif + return num_regions; +} + +uint HeapRegionManager::start_region_for_worker(uint worker_i, uint num_workers, uint num_regions) const { + return num_regions * worker_i / num_workers; +} + +void HeapRegionManager::par_iterate(HeapRegionClosure* blk, uint worker_id, uint num_workers, jint claim_value) const { + const uint start_index = start_region_for_worker(worker_id, num_workers, _allocated_heapregions_length); + + // Every worker will actually look at all regions, skipping over regions that + // are currently not committed. + // This also (potentially) iterates over regions newly allocated during GC. This + // is no problem except for some extra work. + for (uint count = 0; count < _allocated_heapregions_length; count++) { + const uint index = (start_index + count) % _allocated_heapregions_length; + assert(0 <= index && index < _allocated_heapregions_length, "sanity"); + // Skip over unavailable regions + if (!is_available(index)) { + continue; + } + HeapRegion* r = _regions.get_by_index(index); + // We'll ignore "continues humongous" regions (we'll process them + // when we come across their corresponding "start humongous" + // region) and regions already claimed. + if (r->claim_value() == claim_value || r->continuesHumongous()) { + continue; + } + // OK, try to claim it + if (!r->claimHeapRegion(claim_value)) { + continue; + } + // Success! + if (r->startsHumongous()) { + // If the region is "starts humongous" we'll iterate over its + // "continues humongous" first; in fact we'll do them + // first. The order is important. In one case, calling the + // closure on the "starts humongous" region might de-allocate + // and clear all its "continues humongous" regions and, as a + // result, we might end up processing them twice. So, we'll do + // them first (note: most closures will ignore them anyway) and + // then we'll do the "starts humongous" region. + for (uint ch_index = index + 1; ch_index < index + r->region_num(); ch_index++) { + HeapRegion* chr = _regions.get_by_index(ch_index); + + assert(chr->continuesHumongous(), "Must be humongous region"); + assert(chr->humongous_start_region() == r, + err_msg("Must work on humongous continuation of the original start region " + PTR_FORMAT ", but is " PTR_FORMAT, p2i(r), p2i(chr))); + assert(chr->claim_value() != claim_value, + "Must not have been claimed yet because claiming of humongous continuation first claims the start region"); + + bool claim_result = chr->claimHeapRegion(claim_value); + // We should always be able to claim it; no one else should + // be trying to claim this region. + guarantee(claim_result, "We should always be able to claim the continuesHumongous part of the humongous object"); + + bool res2 = blk->doHeapRegion(chr); + if (res2) { + return; + } + + // Right now, this holds (i.e., no closure that actually + // does something with "continues humongous" regions + // clears them). We might have to weaken it in the future, + // but let's leave these two asserts here for extra safety. + assert(chr->continuesHumongous(), "should still be the case"); + assert(chr->humongous_start_region() == r, "sanity"); + } + } + + bool res = blk->doHeapRegion(r); + if (res) { + return; + } + } +} + +uint HeapRegionManager::shrink_by(uint num_regions_to_remove) { + assert(length() > 0, "the region sequence should not be empty"); + assert(length() <= _allocated_heapregions_length, "invariant"); + assert(_allocated_heapregions_length > 0, "we should have at least one region committed"); + assert(num_regions_to_remove < length(), "We should never remove all regions"); + + if (num_regions_to_remove == 0) { + return 0; + } + + uint removed = 0; + uint cur = _allocated_heapregions_length - 1; + uint idx_last_found = 0; + uint num_last_found = 0; + + while ((removed < num_regions_to_remove) && + (num_last_found = find_empty_from_idx_reverse(cur, &idx_last_found)) > 0) { + // Only allow uncommit from the end of the heap. + if ((idx_last_found + num_last_found) != _allocated_heapregions_length) { + return 0; + } + uint to_remove = MIN2(num_regions_to_remove - removed, num_last_found); + + uncommit_regions(idx_last_found + num_last_found - to_remove, to_remove); + + cur -= num_last_found; + removed += to_remove; + } + + verify_optional(); + + return removed; +} + +uint HeapRegionManager::find_empty_from_idx_reverse(uint start_idx, uint* res_idx) const { + guarantee(start_idx < _allocated_heapregions_length, "checking"); + guarantee(res_idx != NULL, "checking"); + + uint num_regions_found = 0; + + jlong cur = start_idx; + while (cur != -1 && !(is_available(cur) && at(cur)->is_empty())) { + cur--; + } + if (cur == -1) { + return num_regions_found; + } + jlong old_cur = cur; + // cur indexes the first empty region + while (cur != -1 && is_available(cur) && at(cur)->is_empty()) { + cur--; + } + *res_idx = cur + 1; + num_regions_found = old_cur - cur; + +#ifdef ASSERT + for (uint i = *res_idx; i < (*res_idx + num_regions_found); i++) { + assert(at(i)->is_empty(), "just checking"); + } +#endif + return num_regions_found; +} + +void HeapRegionManager::verify() { + guarantee(length() <= _allocated_heapregions_length, + err_msg("invariant: _length: %u _allocated_length: %u", + length(), _allocated_heapregions_length)); + guarantee(_allocated_heapregions_length <= max_length(), + err_msg("invariant: _allocated_length: %u _max_length: %u", + _allocated_heapregions_length, max_length())); + + bool prev_committed = true; + uint num_committed = 0; + HeapWord* prev_end = heap_bottom(); + for (uint i = 0; i < _allocated_heapregions_length; i++) { + if (!is_available(i)) { + prev_committed = false; + continue; + } + num_committed++; + HeapRegion* hr = _regions.get_by_index(i); + guarantee(hr != NULL, err_msg("invariant: i: %u", i)); + guarantee(!prev_committed || hr->bottom() == prev_end, + err_msg("invariant i: %u "HR_FORMAT" prev_end: "PTR_FORMAT, + i, HR_FORMAT_PARAMS(hr), p2i(prev_end))); + guarantee(hr->hrm_index() == i, + err_msg("invariant: i: %u hrm_index(): %u", i, hr->hrm_index())); + // Asserts will fire if i is >= _length + HeapWord* addr = hr->bottom(); + guarantee(addr_to_region(addr) == hr, "sanity"); + // We cannot check whether the region is part of a particular set: at the time + // this method may be called, we have only completed allocation of the regions, + // but not put into a region set. + prev_committed = true; + if (hr->startsHumongous()) { + prev_end = hr->orig_end(); + } else { + prev_end = hr->end(); + } + } + for (uint i = _allocated_heapregions_length; i < max_length(); i++) { + guarantee(_regions.get_by_index(i) == NULL, err_msg("invariant i: %u", i)); + } + + guarantee(num_committed == _num_committed, err_msg("Found %u committed regions, but should be %u", num_committed, _num_committed)); + _free_list.verify(); +} + +#ifndef PRODUCT +void HeapRegionManager::verify_optional() { + verify(); +} +#endif // PRODUCT +