--- a/hotspot/src/share/vm/gc_implementation/g1/heapRegionSeq.cpp Thu Sep 04 14:45:48 2014 -0700
+++ /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
-