790 lines
28 KiB
C++
790 lines
28 KiB
C++
/*
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* Copyright (c) 1997, 2015, Oracle and/or its affiliates. All rights reserved.
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* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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*
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* This code is free software; you can redistribute it and/or modify it
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* under the terms of the GNU General Public License version 2 only, as
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* published by the Free Software Foundation.
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*
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* This code is distributed in the hope that it will be useful, but WITHOUT
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* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
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* version 2 for more details (a copy is included in the LICENSE file that
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* accompanied this code).
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*
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* You should have received a copy of the GNU General Public License version
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* 2 along with this work; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
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*
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* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
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* or visit www.oracle.com if you need additional information or have any
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* questions.
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*
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*/
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#include "precompiled.hpp"
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#include "classfile/systemDictionary.hpp"
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#include "classfile/vmSymbols.hpp"
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#include "gc/serial/defNewGeneration.hpp"
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#include "gc/shared/blockOffsetTable.inline.hpp"
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#include "gc/shared/collectedHeap.inline.hpp"
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#include "gc/shared/genCollectedHeap.hpp"
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#include "gc/shared/genOopClosures.inline.hpp"
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#include "gc/shared/liveRange.hpp"
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#include "gc/shared/space.hpp"
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#include "gc/shared/space.inline.hpp"
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#include "gc/shared/spaceDecorator.hpp"
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#include "memory/universe.inline.hpp"
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#include "oops/oop.inline.hpp"
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#include "runtime/atomic.inline.hpp"
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#include "runtime/java.hpp"
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#include "runtime/orderAccess.inline.hpp"
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#include "runtime/prefetch.inline.hpp"
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#include "runtime/safepoint.hpp"
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#include "utilities/copy.hpp"
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#include "utilities/globalDefinitions.hpp"
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#include "utilities/macros.hpp"
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HeapWord* DirtyCardToOopClosure::get_actual_top(HeapWord* top,
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HeapWord* top_obj) {
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if (top_obj != NULL) {
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if (_sp->block_is_obj(top_obj)) {
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if (_precision == CardTableModRefBS::ObjHeadPreciseArray) {
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if (oop(top_obj)->is_objArray() || oop(top_obj)->is_typeArray()) {
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// An arrayOop is starting on the dirty card - since we do exact
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// store checks for objArrays we are done.
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} else {
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// Otherwise, it is possible that the object starting on the dirty
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// card spans the entire card, and that the store happened on a
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// later card. Figure out where the object ends.
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// Use the block_size() method of the space over which
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// the iteration is being done. That space (e.g. CMS) may have
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// specific requirements on object sizes which will
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// be reflected in the block_size() method.
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top = top_obj + oop(top_obj)->size();
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}
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}
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} else {
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top = top_obj;
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}
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} else {
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assert(top == _sp->end(), "only case where top_obj == NULL");
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}
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return top;
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}
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void DirtyCardToOopClosure::walk_mem_region(MemRegion mr,
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HeapWord* bottom,
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HeapWord* top) {
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// 1. Blocks may or may not be objects.
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// 2. Even when a block_is_obj(), it may not entirely
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// occupy the block if the block quantum is larger than
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// the object size.
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// We can and should try to optimize by calling the non-MemRegion
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// version of oop_iterate() for all but the extremal objects
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// (for which we need to call the MemRegion version of
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// oop_iterate()) To be done post-beta XXX
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for (; bottom < top; bottom += _sp->block_size(bottom)) {
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// As in the case of contiguous space above, we'd like to
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// just use the value returned by oop_iterate to increment the
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// current pointer; unfortunately, that won't work in CMS because
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// we'd need an interface change (it seems) to have the space
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// "adjust the object size" (for instance pad it up to its
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// block alignment or minimum block size restrictions. XXX
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if (_sp->block_is_obj(bottom) &&
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!_sp->obj_allocated_since_save_marks(oop(bottom))) {
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oop(bottom)->oop_iterate(_cl, mr);
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}
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}
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}
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// We get called with "mr" representing the dirty region
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// that we want to process. Because of imprecise marking,
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// we may need to extend the incoming "mr" to the right,
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// and scan more. However, because we may already have
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// scanned some of that extended region, we may need to
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// trim its right-end back some so we do not scan what
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// we (or another worker thread) may already have scanned
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// or planning to scan.
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void DirtyCardToOopClosure::do_MemRegion(MemRegion mr) {
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// Some collectors need to do special things whenever their dirty
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// cards are processed. For instance, CMS must remember mutator updates
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// (i.e. dirty cards) so as to re-scan mutated objects.
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// Such work can be piggy-backed here on dirty card scanning, so as to make
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// it slightly more efficient than doing a complete non-destructive pre-scan
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// of the card table.
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MemRegionClosure* pCl = _sp->preconsumptionDirtyCardClosure();
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if (pCl != NULL) {
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pCl->do_MemRegion(mr);
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}
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HeapWord* bottom = mr.start();
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HeapWord* last = mr.last();
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HeapWord* top = mr.end();
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HeapWord* bottom_obj;
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HeapWord* top_obj;
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assert(_precision == CardTableModRefBS::ObjHeadPreciseArray ||
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_precision == CardTableModRefBS::Precise,
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"Only ones we deal with for now.");
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assert(_precision != CardTableModRefBS::ObjHeadPreciseArray ||
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_cl->idempotent() || _last_bottom == NULL ||
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top <= _last_bottom,
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"Not decreasing");
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NOT_PRODUCT(_last_bottom = mr.start());
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bottom_obj = _sp->block_start(bottom);
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top_obj = _sp->block_start(last);
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assert(bottom_obj <= bottom, "just checking");
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assert(top_obj <= top, "just checking");
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// Given what we think is the top of the memory region and
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// the start of the object at the top, get the actual
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// value of the top.
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top = get_actual_top(top, top_obj);
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// If the previous call did some part of this region, don't redo.
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if (_precision == CardTableModRefBS::ObjHeadPreciseArray &&
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_min_done != NULL &&
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_min_done < top) {
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top = _min_done;
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}
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// Top may have been reset, and in fact may be below bottom,
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// e.g. the dirty card region is entirely in a now free object
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// -- something that could happen with a concurrent sweeper.
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bottom = MIN2(bottom, top);
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MemRegion extended_mr = MemRegion(bottom, top);
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assert(bottom <= top &&
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(_precision != CardTableModRefBS::ObjHeadPreciseArray ||
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_min_done == NULL ||
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top <= _min_done),
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"overlap!");
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// Walk the region if it is not empty; otherwise there is nothing to do.
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if (!extended_mr.is_empty()) {
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walk_mem_region(extended_mr, bottom_obj, top);
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}
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// An idempotent closure might be applied in any order, so we don't
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// record a _min_done for it.
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if (!_cl->idempotent()) {
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_min_done = bottom;
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} else {
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assert(_min_done == _last_explicit_min_done,
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"Don't update _min_done for idempotent cl");
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}
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}
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DirtyCardToOopClosure* Space::new_dcto_cl(ExtendedOopClosure* cl,
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CardTableModRefBS::PrecisionStyle precision,
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HeapWord* boundary,
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bool parallel) {
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return new DirtyCardToOopClosure(this, cl, precision, boundary);
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}
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HeapWord* ContiguousSpaceDCTOC::get_actual_top(HeapWord* top,
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HeapWord* top_obj) {
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if (top_obj != NULL && top_obj < (_sp->toContiguousSpace())->top()) {
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if (_precision == CardTableModRefBS::ObjHeadPreciseArray) {
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if (oop(top_obj)->is_objArray() || oop(top_obj)->is_typeArray()) {
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// An arrayOop is starting on the dirty card - since we do exact
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// store checks for objArrays we are done.
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} else {
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// Otherwise, it is possible that the object starting on the dirty
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// card spans the entire card, and that the store happened on a
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// later card. Figure out where the object ends.
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assert(_sp->block_size(top_obj) == (size_t) oop(top_obj)->size(),
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"Block size and object size mismatch");
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top = top_obj + oop(top_obj)->size();
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}
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}
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} else {
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top = (_sp->toContiguousSpace())->top();
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}
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return top;
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}
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void Filtering_DCTOC::walk_mem_region(MemRegion mr,
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HeapWord* bottom,
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HeapWord* top) {
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// Note that this assumption won't hold if we have a concurrent
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// collector in this space, which may have freed up objects after
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// they were dirtied and before the stop-the-world GC that is
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// examining cards here.
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assert(bottom < top, "ought to be at least one obj on a dirty card.");
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if (_boundary != NULL) {
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// We have a boundary outside of which we don't want to look
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// at objects, so create a filtering closure around the
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// oop closure before walking the region.
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FilteringClosure filter(_boundary, _cl);
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walk_mem_region_with_cl(mr, bottom, top, &filter);
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} else {
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// No boundary, simply walk the heap with the oop closure.
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walk_mem_region_with_cl(mr, bottom, top, _cl);
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}
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}
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// We must replicate this so that the static type of "FilteringClosure"
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// (see above) is apparent at the oop_iterate calls.
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#define ContiguousSpaceDCTOC__walk_mem_region_with_cl_DEFN(ClosureType) \
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void ContiguousSpaceDCTOC::walk_mem_region_with_cl(MemRegion mr, \
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HeapWord* bottom, \
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HeapWord* top, \
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ClosureType* cl) { \
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bottom += oop(bottom)->oop_iterate(cl, mr); \
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if (bottom < top) { \
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HeapWord* next_obj = bottom + oop(bottom)->size(); \
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while (next_obj < top) { \
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/* Bottom lies entirely below top, so we can call the */ \
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/* non-memRegion version of oop_iterate below. */ \
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oop(bottom)->oop_iterate(cl); \
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bottom = next_obj; \
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next_obj = bottom + oop(bottom)->size(); \
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} \
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/* Last object. */ \
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oop(bottom)->oop_iterate(cl, mr); \
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} \
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}
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// (There are only two of these, rather than N, because the split is due
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// only to the introduction of the FilteringClosure, a local part of the
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// impl of this abstraction.)
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ContiguousSpaceDCTOC__walk_mem_region_with_cl_DEFN(ExtendedOopClosure)
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ContiguousSpaceDCTOC__walk_mem_region_with_cl_DEFN(FilteringClosure)
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DirtyCardToOopClosure*
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ContiguousSpace::new_dcto_cl(ExtendedOopClosure* cl,
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CardTableModRefBS::PrecisionStyle precision,
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HeapWord* boundary,
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bool parallel) {
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return new ContiguousSpaceDCTOC(this, cl, precision, boundary);
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}
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void Space::initialize(MemRegion mr,
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bool clear_space,
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bool mangle_space) {
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HeapWord* bottom = mr.start();
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HeapWord* end = mr.end();
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assert(Universe::on_page_boundary(bottom) && Universe::on_page_boundary(end),
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"invalid space boundaries");
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set_bottom(bottom);
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set_end(end);
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if (clear_space) clear(mangle_space);
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}
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void Space::clear(bool mangle_space) {
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if (ZapUnusedHeapArea && mangle_space) {
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mangle_unused_area();
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}
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}
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ContiguousSpace::ContiguousSpace(): CompactibleSpace(), _top(NULL),
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_concurrent_iteration_safe_limit(NULL) {
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_mangler = new GenSpaceMangler(this);
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}
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ContiguousSpace::~ContiguousSpace() {
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delete _mangler;
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}
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void ContiguousSpace::initialize(MemRegion mr,
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bool clear_space,
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bool mangle_space)
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{
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CompactibleSpace::initialize(mr, clear_space, mangle_space);
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set_concurrent_iteration_safe_limit(top());
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}
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void ContiguousSpace::clear(bool mangle_space) {
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set_top(bottom());
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set_saved_mark();
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CompactibleSpace::clear(mangle_space);
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}
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bool ContiguousSpace::is_free_block(const HeapWord* p) const {
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return p >= _top;
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}
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void OffsetTableContigSpace::clear(bool mangle_space) {
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ContiguousSpace::clear(mangle_space);
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_offsets.initialize_threshold();
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}
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void OffsetTableContigSpace::set_bottom(HeapWord* new_bottom) {
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Space::set_bottom(new_bottom);
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_offsets.set_bottom(new_bottom);
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}
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void OffsetTableContigSpace::set_end(HeapWord* new_end) {
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// Space should not advertise an increase in size
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// until after the underlying offset table has been enlarged.
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_offsets.resize(pointer_delta(new_end, bottom()));
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Space::set_end(new_end);
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}
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#ifndef PRODUCT
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void ContiguousSpace::set_top_for_allocations(HeapWord* v) {
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mangler()->set_top_for_allocations(v);
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}
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void ContiguousSpace::set_top_for_allocations() {
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mangler()->set_top_for_allocations(top());
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}
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void ContiguousSpace::check_mangled_unused_area(HeapWord* limit) {
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mangler()->check_mangled_unused_area(limit);
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}
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void ContiguousSpace::check_mangled_unused_area_complete() {
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mangler()->check_mangled_unused_area_complete();
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}
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// Mangled only the unused space that has not previously
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// been mangled and that has not been allocated since being
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// mangled.
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void ContiguousSpace::mangle_unused_area() {
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mangler()->mangle_unused_area();
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}
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void ContiguousSpace::mangle_unused_area_complete() {
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mangler()->mangle_unused_area_complete();
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}
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#endif // NOT_PRODUCT
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void CompactibleSpace::initialize(MemRegion mr,
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bool clear_space,
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bool mangle_space) {
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Space::initialize(mr, clear_space, mangle_space);
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set_compaction_top(bottom());
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_next_compaction_space = NULL;
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}
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void CompactibleSpace::clear(bool mangle_space) {
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Space::clear(mangle_space);
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_compaction_top = bottom();
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}
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HeapWord* CompactibleSpace::forward(oop q, size_t size,
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CompactPoint* cp, HeapWord* compact_top) {
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// q is alive
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// First check if we should switch compaction space
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assert(this == cp->space, "'this' should be current compaction space.");
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size_t compaction_max_size = pointer_delta(end(), compact_top);
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while (size > compaction_max_size) {
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// switch to next compaction space
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cp->space->set_compaction_top(compact_top);
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cp->space = cp->space->next_compaction_space();
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if (cp->space == NULL) {
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cp->gen = GenCollectedHeap::heap()->young_gen();
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assert(cp->gen != NULL, "compaction must succeed");
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cp->space = cp->gen->first_compaction_space();
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assert(cp->space != NULL, "generation must have a first compaction space");
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}
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compact_top = cp->space->bottom();
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cp->space->set_compaction_top(compact_top);
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cp->threshold = cp->space->initialize_threshold();
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compaction_max_size = pointer_delta(cp->space->end(), compact_top);
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}
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// store the forwarding pointer into the mark word
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if ((HeapWord*)q != compact_top) {
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q->forward_to(oop(compact_top));
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assert(q->is_gc_marked(), "encoding the pointer should preserve the mark");
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} else {
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// if the object isn't moving we can just set the mark to the default
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// mark and handle it specially later on.
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q->init_mark();
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assert(q->forwardee() == NULL, "should be forwarded to NULL");
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}
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compact_top += size;
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// we need to update the offset table so that the beginnings of objects can be
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// found during scavenge. Note that we are updating the offset table based on
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// where the object will be once the compaction phase finishes.
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if (compact_top > cp->threshold)
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cp->threshold =
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cp->space->cross_threshold(compact_top - size, compact_top);
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return compact_top;
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}
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bool CompactibleSpace::insert_deadspace(size_t& allowed_deadspace_words,
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HeapWord* q, size_t deadlength) {
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if (allowed_deadspace_words >= deadlength) {
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allowed_deadspace_words -= deadlength;
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CollectedHeap::fill_with_object(q, deadlength);
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oop(q)->set_mark(oop(q)->mark()->set_marked());
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assert((int) deadlength == oop(q)->size(), "bad filler object size");
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// Recall that we required "q == compaction_top".
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return true;
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} else {
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allowed_deadspace_words = 0;
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return false;
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}
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}
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void ContiguousSpace::prepare_for_compaction(CompactPoint* cp) {
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scan_and_forward(this, cp);
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}
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void CompactibleSpace::adjust_pointers() {
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// Check first is there is any work to do.
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if (used() == 0) {
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return; // Nothing to do.
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}
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scan_and_adjust_pointers(this);
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}
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void CompactibleSpace::compact() {
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scan_and_compact(this);
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}
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void Space::print_short() const { print_short_on(tty); }
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void Space::print_short_on(outputStream* st) const {
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st->print(" space " SIZE_FORMAT "K, %3d%% used", capacity() / K,
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(int) ((double) used() * 100 / capacity()));
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}
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void Space::print() const { print_on(tty); }
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void Space::print_on(outputStream* st) const {
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print_short_on(st);
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st->print_cr(" [" INTPTR_FORMAT ", " INTPTR_FORMAT ")",
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p2i(bottom()), p2i(end()));
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}
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void ContiguousSpace::print_on(outputStream* st) const {
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print_short_on(st);
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st->print_cr(" [" INTPTR_FORMAT ", " INTPTR_FORMAT ", " INTPTR_FORMAT ")",
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p2i(bottom()), p2i(top()), p2i(end()));
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}
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void OffsetTableContigSpace::print_on(outputStream* st) const {
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print_short_on(st);
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st->print_cr(" [" INTPTR_FORMAT ", " INTPTR_FORMAT ", "
|
|
INTPTR_FORMAT ", " INTPTR_FORMAT ")",
|
|
p2i(bottom()), p2i(top()), p2i(_offsets.threshold()), p2i(end()));
|
|
}
|
|
|
|
void ContiguousSpace::verify() const {
|
|
HeapWord* p = bottom();
|
|
HeapWord* t = top();
|
|
HeapWord* prev_p = NULL;
|
|
while (p < t) {
|
|
oop(p)->verify();
|
|
prev_p = p;
|
|
p += oop(p)->size();
|
|
}
|
|
guarantee(p == top(), "end of last object must match end of space");
|
|
if (top() != end()) {
|
|
guarantee(top() == block_start_const(end()-1) &&
|
|
top() == block_start_const(top()),
|
|
"top should be start of unallocated block, if it exists");
|
|
}
|
|
}
|
|
|
|
void Space::oop_iterate(ExtendedOopClosure* blk) {
|
|
ObjectToOopClosure blk2(blk);
|
|
object_iterate(&blk2);
|
|
}
|
|
|
|
bool Space::obj_is_alive(const HeapWord* p) const {
|
|
assert (block_is_obj(p), "The address should point to an object");
|
|
return true;
|
|
}
|
|
|
|
#if INCLUDE_ALL_GCS
|
|
#define ContigSpace_PAR_OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \
|
|
\
|
|
void ContiguousSpace::par_oop_iterate(MemRegion mr, OopClosureType* blk) {\
|
|
HeapWord* obj_addr = mr.start(); \
|
|
HeapWord* t = mr.end(); \
|
|
while (obj_addr < t) { \
|
|
assert(oop(obj_addr)->is_oop(), "Should be an oop"); \
|
|
obj_addr += oop(obj_addr)->oop_iterate(blk); \
|
|
} \
|
|
}
|
|
|
|
ALL_PAR_OOP_ITERATE_CLOSURES(ContigSpace_PAR_OOP_ITERATE_DEFN)
|
|
|
|
#undef ContigSpace_PAR_OOP_ITERATE_DEFN
|
|
#endif // INCLUDE_ALL_GCS
|
|
|
|
void ContiguousSpace::oop_iterate(ExtendedOopClosure* blk) {
|
|
if (is_empty()) return;
|
|
HeapWord* obj_addr = bottom();
|
|
HeapWord* t = top();
|
|
// Could call objects iterate, but this is easier.
|
|
while (obj_addr < t) {
|
|
obj_addr += oop(obj_addr)->oop_iterate(blk);
|
|
}
|
|
}
|
|
|
|
void ContiguousSpace::object_iterate(ObjectClosure* blk) {
|
|
if (is_empty()) return;
|
|
WaterMark bm = bottom_mark();
|
|
object_iterate_from(bm, blk);
|
|
}
|
|
|
|
// For a ContiguousSpace object_iterate() and safe_object_iterate()
|
|
// are the same.
|
|
void ContiguousSpace::safe_object_iterate(ObjectClosure* blk) {
|
|
object_iterate(blk);
|
|
}
|
|
|
|
void ContiguousSpace::object_iterate_from(WaterMark mark, ObjectClosure* blk) {
|
|
assert(mark.space() == this, "Mark does not match space");
|
|
HeapWord* p = mark.point();
|
|
while (p < top()) {
|
|
blk->do_object(oop(p));
|
|
p += oop(p)->size();
|
|
}
|
|
}
|
|
|
|
HeapWord*
|
|
ContiguousSpace::object_iterate_careful(ObjectClosureCareful* blk) {
|
|
HeapWord * limit = concurrent_iteration_safe_limit();
|
|
assert(limit <= top(), "sanity check");
|
|
for (HeapWord* p = bottom(); p < limit;) {
|
|
size_t size = blk->do_object_careful(oop(p));
|
|
if (size == 0) {
|
|
return p; // failed at p
|
|
} else {
|
|
p += size;
|
|
}
|
|
}
|
|
return NULL; // all done
|
|
}
|
|
|
|
#define ContigSpace_OOP_SINCE_SAVE_MARKS_DEFN(OopClosureType, nv_suffix) \
|
|
\
|
|
void ContiguousSpace:: \
|
|
oop_since_save_marks_iterate##nv_suffix(OopClosureType* blk) { \
|
|
HeapWord* t; \
|
|
HeapWord* p = saved_mark_word(); \
|
|
assert(p != NULL, "expected saved mark"); \
|
|
\
|
|
const intx interval = PrefetchScanIntervalInBytes; \
|
|
do { \
|
|
t = top(); \
|
|
while (p < t) { \
|
|
Prefetch::write(p, interval); \
|
|
debug_only(HeapWord* prev = p); \
|
|
oop m = oop(p); \
|
|
p += m->oop_iterate(blk); \
|
|
} \
|
|
} while (t < top()); \
|
|
\
|
|
set_saved_mark_word(p); \
|
|
}
|
|
|
|
ALL_SINCE_SAVE_MARKS_CLOSURES(ContigSpace_OOP_SINCE_SAVE_MARKS_DEFN)
|
|
|
|
#undef ContigSpace_OOP_SINCE_SAVE_MARKS_DEFN
|
|
|
|
// Very general, slow implementation.
|
|
HeapWord* ContiguousSpace::block_start_const(const void* p) const {
|
|
assert(MemRegion(bottom(), end()).contains(p),
|
|
err_msg("p (" PTR_FORMAT ") not in space [" PTR_FORMAT ", " PTR_FORMAT ")",
|
|
p2i(p), p2i(bottom()), p2i(end())));
|
|
if (p >= top()) {
|
|
return top();
|
|
} else {
|
|
HeapWord* last = bottom();
|
|
HeapWord* cur = last;
|
|
while (cur <= p) {
|
|
last = cur;
|
|
cur += oop(cur)->size();
|
|
}
|
|
assert(oop(last)->is_oop(),
|
|
err_msg(PTR_FORMAT " should be an object start", p2i(last)));
|
|
return last;
|
|
}
|
|
}
|
|
|
|
size_t ContiguousSpace::block_size(const HeapWord* p) const {
|
|
assert(MemRegion(bottom(), end()).contains(p),
|
|
err_msg("p (" PTR_FORMAT ") not in space [" PTR_FORMAT ", " PTR_FORMAT ")",
|
|
p2i(p), p2i(bottom()), p2i(end())));
|
|
HeapWord* current_top = top();
|
|
assert(p <= current_top,
|
|
err_msg("p > current top - p: " PTR_FORMAT ", current top: " PTR_FORMAT,
|
|
p2i(p), p2i(current_top)));
|
|
assert(p == current_top || oop(p)->is_oop(),
|
|
err_msg("p (" PTR_FORMAT ") is not a block start - "
|
|
"current_top: " PTR_FORMAT ", is_oop: %s",
|
|
p2i(p), p2i(current_top), BOOL_TO_STR(oop(p)->is_oop())));
|
|
if (p < current_top) {
|
|
return oop(p)->size();
|
|
} else {
|
|
assert(p == current_top, "just checking");
|
|
return pointer_delta(end(), (HeapWord*) p);
|
|
}
|
|
}
|
|
|
|
// This version requires locking.
|
|
inline HeapWord* ContiguousSpace::allocate_impl(size_t size) {
|
|
assert(Heap_lock->owned_by_self() ||
|
|
(SafepointSynchronize::is_at_safepoint() && Thread::current()->is_VM_thread()),
|
|
"not locked");
|
|
HeapWord* obj = top();
|
|
if (pointer_delta(end(), obj) >= size) {
|
|
HeapWord* new_top = obj + size;
|
|
set_top(new_top);
|
|
assert(is_aligned(obj) && is_aligned(new_top), "checking alignment");
|
|
return obj;
|
|
} else {
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
// This version is lock-free.
|
|
inline HeapWord* ContiguousSpace::par_allocate_impl(size_t size) {
|
|
do {
|
|
HeapWord* obj = top();
|
|
if (pointer_delta(end(), obj) >= size) {
|
|
HeapWord* new_top = obj + size;
|
|
HeapWord* result = (HeapWord*)Atomic::cmpxchg_ptr(new_top, top_addr(), obj);
|
|
// result can be one of two:
|
|
// the old top value: the exchange succeeded
|
|
// otherwise: the new value of the top is returned.
|
|
if (result == obj) {
|
|
assert(is_aligned(obj) && is_aligned(new_top), "checking alignment");
|
|
return obj;
|
|
}
|
|
} else {
|
|
return NULL;
|
|
}
|
|
} while (true);
|
|
}
|
|
|
|
HeapWord* ContiguousSpace::allocate_aligned(size_t size) {
|
|
assert(Heap_lock->owned_by_self() || (SafepointSynchronize::is_at_safepoint() && Thread::current()->is_VM_thread()), "not locked");
|
|
HeapWord* end_value = end();
|
|
|
|
HeapWord* obj = CollectedHeap::align_allocation_or_fail(top(), end_value, SurvivorAlignmentInBytes);
|
|
if (obj == NULL) {
|
|
return NULL;
|
|
}
|
|
|
|
if (pointer_delta(end_value, obj) >= size) {
|
|
HeapWord* new_top = obj + size;
|
|
set_top(new_top);
|
|
assert(is_ptr_aligned(obj, SurvivorAlignmentInBytes) && is_aligned(new_top),
|
|
"checking alignment");
|
|
return obj;
|
|
} else {
|
|
set_top(obj);
|
|
return NULL;
|
|
}
|
|
}
|
|
|
|
// Requires locking.
|
|
HeapWord* ContiguousSpace::allocate(size_t size) {
|
|
return allocate_impl(size);
|
|
}
|
|
|
|
// Lock-free.
|
|
HeapWord* ContiguousSpace::par_allocate(size_t size) {
|
|
return par_allocate_impl(size);
|
|
}
|
|
|
|
void ContiguousSpace::allocate_temporary_filler(int factor) {
|
|
// allocate temporary type array decreasing free size with factor 'factor'
|
|
assert(factor >= 0, "just checking");
|
|
size_t size = pointer_delta(end(), top());
|
|
|
|
// if space is full, return
|
|
if (size == 0) return;
|
|
|
|
if (factor > 0) {
|
|
size -= size/factor;
|
|
}
|
|
size = align_object_size(size);
|
|
|
|
const size_t array_header_size = typeArrayOopDesc::header_size(T_INT);
|
|
if (size >= (size_t)align_object_size(array_header_size)) {
|
|
size_t length = (size - array_header_size) * (HeapWordSize / sizeof(jint));
|
|
// allocate uninitialized int array
|
|
typeArrayOop t = (typeArrayOop) allocate(size);
|
|
assert(t != NULL, "allocation should succeed");
|
|
t->set_mark(markOopDesc::prototype());
|
|
t->set_klass(Universe::intArrayKlassObj());
|
|
t->set_length((int)length);
|
|
} else {
|
|
assert(size == CollectedHeap::min_fill_size(),
|
|
"size for smallest fake object doesn't match");
|
|
instanceOop obj = (instanceOop) allocate(size);
|
|
obj->set_mark(markOopDesc::prototype());
|
|
obj->set_klass_gap(0);
|
|
obj->set_klass(SystemDictionary::Object_klass());
|
|
}
|
|
}
|
|
|
|
HeapWord* OffsetTableContigSpace::initialize_threshold() {
|
|
return _offsets.initialize_threshold();
|
|
}
|
|
|
|
HeapWord* OffsetTableContigSpace::cross_threshold(HeapWord* start, HeapWord* end) {
|
|
_offsets.alloc_block(start, end);
|
|
return _offsets.threshold();
|
|
}
|
|
|
|
OffsetTableContigSpace::OffsetTableContigSpace(BlockOffsetSharedArray* sharedOffsetArray,
|
|
MemRegion mr) :
|
|
_offsets(sharedOffsetArray, mr),
|
|
_par_alloc_lock(Mutex::leaf, "OffsetTableContigSpace par alloc lock", true)
|
|
{
|
|
_offsets.set_contig_space(this);
|
|
initialize(mr, SpaceDecorator::Clear, SpaceDecorator::Mangle);
|
|
}
|
|
|
|
#define OBJ_SAMPLE_INTERVAL 0
|
|
#define BLOCK_SAMPLE_INTERVAL 100
|
|
|
|
void OffsetTableContigSpace::verify() const {
|
|
HeapWord* p = bottom();
|
|
HeapWord* prev_p = NULL;
|
|
int objs = 0;
|
|
int blocks = 0;
|
|
|
|
if (VerifyObjectStartArray) {
|
|
_offsets.verify();
|
|
}
|
|
|
|
while (p < top()) {
|
|
size_t size = oop(p)->size();
|
|
// For a sampling of objects in the space, find it using the
|
|
// block offset table.
|
|
if (blocks == BLOCK_SAMPLE_INTERVAL) {
|
|
guarantee(p == block_start_const(p + (size/2)),
|
|
"check offset computation");
|
|
blocks = 0;
|
|
} else {
|
|
blocks++;
|
|
}
|
|
|
|
if (objs == OBJ_SAMPLE_INTERVAL) {
|
|
oop(p)->verify();
|
|
objs = 0;
|
|
} else {
|
|
objs++;
|
|
}
|
|
prev_p = p;
|
|
p += size;
|
|
}
|
|
guarantee(p == top(), "end of last object must match end of space");
|
|
}
|
|
|
|
|
|
size_t TenuredSpace::allowed_dead_ratio() const {
|
|
return MarkSweepDeadRatio;
|
|
}
|