--- a/src/hotspot/share/gc/cms/promotionInfo.cpp Fri Nov 08 14:54:17 2019 +0000
+++ /dev/null Thu Jan 01 00:00:00 1970 +0000
@@ -1,308 +0,0 @@
-/*
- * Copyright (c) 2010, 2018, 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/cms/compactibleFreeListSpace.hpp"
-#include "gc/cms/promotionInfo.hpp"
-#include "gc/shared/genOopClosures.hpp"
-#include "oops/compressedOops.inline.hpp"
-#include "oops/markWord.inline.hpp"
-#include "oops/oop.inline.hpp"
-
-/////////////////////////////////////////////////////////////////////////
-//// PromotionInfo
-/////////////////////////////////////////////////////////////////////////
-
-
-PromotedObject* PromotedObject::next() const {
- assert(!((FreeChunk*)this)->is_free(), "Error");
- PromotedObject* res;
- if (UseCompressedOops) {
- // The next pointer is a compressed oop stored in the top 32 bits
- res = (PromotedObject*)CompressedOops::decode(_data._narrow_next);
- } else {
- res = (PromotedObject*)(_next & next_mask);
- }
- assert(oopDesc::is_oop_or_null(oop(res), true /* ignore mark word */), "Expected an oop or NULL at " PTR_FORMAT, p2i(oop(res)));
- return res;
-}
-
-inline void PromotedObject::setNext(PromotedObject* x) {
- assert(((intptr_t)x & ~next_mask) == 0, "Conflict in bit usage, "
- "or insufficient alignment of objects");
- if (UseCompressedOops) {
- assert(_data._narrow_next == 0, "Overwrite?");
- _data._narrow_next = CompressedOops::encode(oop(x));
- } else {
- _next |= (intptr_t)x;
- }
- assert(!((FreeChunk*)this)->is_free(), "Error");
-}
-
-// Return the next displaced header, incrementing the pointer and
-// recycling spool area as necessary.
-markWord PromotionInfo::nextDisplacedHeader() {
- assert(_spoolHead != NULL, "promotionInfo inconsistency");
- assert(_spoolHead != _spoolTail || _firstIndex < _nextIndex,
- "Empty spool space: no displaced header can be fetched");
- assert(_spoolHead->bufferSize > _firstIndex, "Off by one error at head?");
- markWord hdr = _spoolHead->displacedHdr[_firstIndex];
- // Spool forward
- if (++_firstIndex == _spoolHead->bufferSize) { // last location in this block
- // forward to next block, recycling this block into spare spool buffer
- SpoolBlock* tmp = _spoolHead->nextSpoolBlock;
- assert(_spoolHead != _spoolTail, "Spooling storage mix-up");
- _spoolHead->nextSpoolBlock = _spareSpool;
- _spareSpool = _spoolHead;
- _spoolHead = tmp;
- _firstIndex = 1;
- NOT_PRODUCT(
- if (_spoolHead == NULL) { // all buffers fully consumed
- assert(_spoolTail == NULL && _nextIndex == 1,
- "spool buffers processing inconsistency");
- }
- )
- }
- return hdr;
-}
-
-void PromotionInfo::track(PromotedObject* trackOop) {
- track(trackOop, oop(trackOop)->klass());
-}
-
-void PromotionInfo::track(PromotedObject* trackOop, Klass* klassOfOop) {
- // make a copy of header as it may need to be spooled
- markWord mark = oop(trackOop)->mark_raw();
- trackOop->clear_next();
- if (mark.must_be_preserved_for_cms_scavenge(klassOfOop)) {
- // save non-prototypical header, and mark oop
- saveDisplacedHeader(mark);
- trackOop->setDisplacedMark();
- } else {
- // we'd like to assert something like the following:
- // assert(mark == markWord::prototype(), "consistency check");
- // ... but the above won't work because the age bits have not (yet) been
- // cleared. The remainder of the check would be identical to the
- // condition checked in must_be_preserved() above, so we don't really
- // have anything useful to check here!
- }
- if (_promoTail != NULL) {
- assert(_promoHead != NULL, "List consistency");
- _promoTail->setNext(trackOop);
- _promoTail = trackOop;
- } else {
- assert(_promoHead == NULL, "List consistency");
- _promoHead = _promoTail = trackOop;
- }
- // Mask as newly promoted, so we can skip over such objects
- // when scanning dirty cards
- assert(!trackOop->hasPromotedMark(), "Should not have been marked");
- trackOop->setPromotedMark();
-}
-
-// Save the given displaced header, incrementing the pointer and
-// obtaining more spool area as necessary.
-void PromotionInfo::saveDisplacedHeader(markWord hdr) {
- assert(_spoolHead != NULL && _spoolTail != NULL,
- "promotionInfo inconsistency");
- assert(_spoolTail->bufferSize > _nextIndex, "Off by one error at tail?");
- _spoolTail->displacedHdr[_nextIndex] = hdr;
- // Spool forward
- if (++_nextIndex == _spoolTail->bufferSize) { // last location in this block
- // get a new spooling block
- assert(_spoolTail->nextSpoolBlock == NULL, "tail should terminate spool list");
- _splice_point = _spoolTail; // save for splicing
- _spoolTail->nextSpoolBlock = getSpoolBlock(); // might fail
- _spoolTail = _spoolTail->nextSpoolBlock; // might become NULL ...
- // ... but will attempt filling before next promotion attempt
- _nextIndex = 1;
- }
-}
-
-// Ensure that spooling space exists. Return false if spooling space
-// could not be obtained.
-bool PromotionInfo::ensure_spooling_space_work() {
- assert(!has_spooling_space(), "Only call when there is no spooling space");
- // Try and obtain more spooling space
- SpoolBlock* newSpool = getSpoolBlock();
- assert(newSpool == NULL ||
- (newSpool->bufferSize != 0 && newSpool->nextSpoolBlock == NULL),
- "getSpoolBlock() sanity check");
- if (newSpool == NULL) {
- return false;
- }
- _nextIndex = 1;
- if (_spoolTail == NULL) {
- _spoolTail = newSpool;
- if (_spoolHead == NULL) {
- _spoolHead = newSpool;
- _firstIndex = 1;
- } else {
- assert(_splice_point != NULL && _splice_point->nextSpoolBlock == NULL,
- "Splice point invariant");
- // Extra check that _splice_point is connected to list
- #ifdef ASSERT
- {
- SpoolBlock* blk = _spoolHead;
- for (; blk->nextSpoolBlock != NULL;
- blk = blk->nextSpoolBlock);
- assert(blk != NULL && blk == _splice_point,
- "Splice point incorrect");
- }
- #endif // ASSERT
- _splice_point->nextSpoolBlock = newSpool;
- }
- } else {
- assert(_spoolHead != NULL, "spool list consistency");
- _spoolTail->nextSpoolBlock = newSpool;
- _spoolTail = newSpool;
- }
- return true;
-}
-
-// Get a free spool buffer from the free pool, getting a new block
-// from the heap if necessary.
-SpoolBlock* PromotionInfo::getSpoolBlock() {
- SpoolBlock* res;
- if ((res = _spareSpool) != NULL) {
- _spareSpool = _spareSpool->nextSpoolBlock;
- res->nextSpoolBlock = NULL;
- } else { // spare spool exhausted, get some from heap
- res = (SpoolBlock*)(space()->allocateScratch(refillSize()));
- if (res != NULL) {
- res->init();
- }
- }
- assert(res == NULL || res->nextSpoolBlock == NULL, "postcondition");
- return res;
-}
-
-void PromotionInfo::startTrackingPromotions() {
- assert(noPromotions(), "sanity");
- assert(_spoolHead == _spoolTail && _firstIndex == _nextIndex,
- "spooling inconsistency?");
- _firstIndex = _nextIndex = 1;
- _tracking = true;
-}
-
-void PromotionInfo::stopTrackingPromotions() {
- assert(noPromotions(), "we should have torn down the lists by now");
- assert(_spoolHead == _spoolTail && _firstIndex == _nextIndex,
- "spooling inconsistency?");
- _firstIndex = _nextIndex = 1;
- _tracking = false;
-}
-
-// When _spoolTail is not NULL, then the slot <_spoolTail, _nextIndex>
-// points to the next slot available for filling.
-// The set of slots holding displaced headers are then all those in the
-// right-open interval denoted by:
-//
-// [ <_spoolHead, _firstIndex>, <_spoolTail, _nextIndex> )
-//
-// When _spoolTail is NULL, then the set of slots with displaced headers
-// is all those starting at the slot <_spoolHead, _firstIndex> and
-// going up to the last slot of last block in the linked list.
-// In this latter case, _splice_point points to the tail block of
-// this linked list of blocks holding displaced headers.
-void PromotionInfo::verify() const {
- // Verify the following:
- // 1. the number of displaced headers matches the number of promoted
- // objects that have displaced headers
- // 2. each promoted object lies in this space
- debug_only(
- PromotedObject* junk = NULL;
- assert(junk->next_addr() == (void*)(oop(junk)->mark_addr_raw()),
- "Offset of PromotedObject::_next is expected to align with "
- " the OopDesc::_mark within OopDesc");
- )
- // FIXME: guarantee????
- guarantee(_spoolHead == NULL || _spoolTail != NULL ||
- _splice_point != NULL, "list consistency");
- guarantee(_promoHead == NULL || _promoTail != NULL, "list consistency");
- // count the number of objects with displaced headers
- size_t numObjsWithDisplacedHdrs = 0;
- for (PromotedObject* curObj = _promoHead; curObj != NULL; curObj = curObj->next()) {
- guarantee(space()->is_in_reserved((HeapWord*)curObj), "Containment");
- // the last promoted object may fail the mark() != NULL test of is_oop().
- guarantee(curObj->next() == NULL || oopDesc::is_oop(oop(curObj)), "must be an oop");
- if (curObj->hasDisplacedMark()) {
- numObjsWithDisplacedHdrs++;
- }
- }
- // Count the number of displaced headers
- size_t numDisplacedHdrs = 0;
- for (SpoolBlock* curSpool = _spoolHead;
- curSpool != _spoolTail && curSpool != NULL;
- curSpool = curSpool->nextSpoolBlock) {
- // the first entry is just a self-pointer; indices 1 through
- // bufferSize - 1 are occupied (thus, bufferSize - 1 slots).
- guarantee((void*)curSpool->displacedHdr == (void*)&curSpool->displacedHdr,
- "first entry of displacedHdr should be self-referential");
- numDisplacedHdrs += curSpool->bufferSize - 1;
- }
- guarantee((_spoolHead == _spoolTail) == (numDisplacedHdrs == 0),
- "internal consistency");
- guarantee(_spoolTail != NULL || _nextIndex == 1,
- "Inconsistency between _spoolTail and _nextIndex");
- // We overcounted (_firstIndex-1) worth of slots in block
- // _spoolHead and we undercounted (_nextIndex-1) worth of
- // slots in block _spoolTail. We make an appropriate
- // adjustment by subtracting the first and adding the
- // second: - (_firstIndex - 1) + (_nextIndex - 1)
- numDisplacedHdrs += (_nextIndex - _firstIndex);
- guarantee(numDisplacedHdrs == numObjsWithDisplacedHdrs, "Displaced hdr count");
-}
-
-void PromotionInfo::print_on(outputStream* st) const {
- SpoolBlock* curSpool = NULL;
- size_t i = 0;
- st->print_cr(" start & end indices: [" SIZE_FORMAT ", " SIZE_FORMAT ")",
- _firstIndex, _nextIndex);
- for (curSpool = _spoolHead; curSpool != _spoolTail && curSpool != NULL;
- curSpool = curSpool->nextSpoolBlock) {
- curSpool->print_on(st);
- st->print_cr(" active ");
- i++;
- }
- for (curSpool = _spoolTail; curSpool != NULL;
- curSpool = curSpool->nextSpoolBlock) {
- curSpool->print_on(st);
- st->print_cr(" inactive ");
- i++;
- }
- for (curSpool = _spareSpool; curSpool != NULL;
- curSpool = curSpool->nextSpoolBlock) {
- curSpool->print_on(st);
- st->print_cr(" free ");
- i++;
- }
- st->print_cr(" " SIZE_FORMAT " header spooling blocks", i);
-}
-
-void SpoolBlock::print_on(outputStream* st) const {
- st->print("[" PTR_FORMAT "," PTR_FORMAT "), " SIZE_FORMAT " HeapWords -> " PTR_FORMAT,
- p2i(this), p2i((HeapWord*)displacedHdr + bufferSize),
- bufferSize, p2i(nextSpoolBlock));
-}