Mercurial > hg > truffle
view src/share/vm/gc_implementation/g1/heapRegionManager.cpp @ 21738:28943e5044b5
Merge
author | Tom Rodriguez <tom.rodriguez@oracle.com> |
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date | Thu, 04 Jun 2015 19:49:45 -0700 |
parents | 7848fc12602b |
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/* * 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) { G1CollectedHeap* g1h = G1CollectedHeap::heap(); HeapWord* bottom = g1h->bottom_addr_for_region(hrm_index); MemRegion mr(bottom, bottom + HeapRegion::GrainWords); assert(reserved().contains(mr), "invariant"); return g1h->allocator()->new_heap_region(hrm_index, g1h->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) { 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