diff -r 4d3a43351904 -r a8ea2f110d87 src/share/vm/gc_implementation/g1/heapRegionSeq.cpp --- a/src/share/vm/gc_implementation/g1/heapRegionSeq.cpp Wed Aug 27 09:36:55 2014 +0200 +++ /dev/null Thu Jan 01 00:00:00 1970 +0000 @@ -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 -