Mercurial > hg > graal-compiler
view src/share/vm/gc_implementation/concurrentMarkSweep/promotionInfo.cpp @ 2142:8012aa3ccede
4926272: methodOopDesc::method_from_bcp is unsafe
Reviewed-by: coleenp, jrose, kvn, dcubed
author | never |
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date | Thu, 13 Jan 2011 22:15:41 -0800 |
parents | f95d63e2154a |
children | f69a5d43dc19 |
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/* * Copyright (c) 2010, 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/concurrentMarkSweep/compactibleFreeListSpace.hpp" #include "gc_implementation/concurrentMarkSweep/promotionInfo.hpp" #include "oops/markOop.inline.hpp" #include "oops/oop.inline.hpp" ///////////////////////////////////////////////////////////////////////// //// PromotionInfo ///////////////////////////////////////////////////////////////////////// ////////////////////////////////////////////////////////////////////////////// // We go over the list of promoted objects, removing each from the list, // and applying the closure (this may, in turn, add more elements to // the tail of the promoted list, and these newly added objects will // also be processed) until the list is empty. // To aid verification and debugging, in the non-product builds // we actually forward _promoHead each time we process a promoted oop. // Note that this is not necessary in general (i.e. when we don't need to // call PromotionInfo::verify()) because oop_iterate can only add to the // end of _promoTail, and never needs to look at _promoHead. #define PROMOTED_OOPS_ITERATE_DEFN(OopClosureType, nv_suffix) \ \ void PromotionInfo::promoted_oops_iterate##nv_suffix(OopClosureType* cl) { \ NOT_PRODUCT(verify()); \ PromotedObject *curObj, *nextObj; \ for (curObj = _promoHead; curObj != NULL; curObj = nextObj) { \ if ((nextObj = curObj->next()) == NULL) { \ /* protect ourselves against additions due to closure application \ below by resetting the list. */ \ assert(_promoTail == curObj, "Should have been the tail"); \ _promoHead = _promoTail = NULL; \ } \ if (curObj->hasDisplacedMark()) { \ /* restore displaced header */ \ oop(curObj)->set_mark(nextDisplacedHeader()); \ } else { \ /* restore prototypical header */ \ oop(curObj)->init_mark(); \ } \ /* The "promoted_mark" should now not be set */ \ assert(!curObj->hasPromotedMark(), \ "Should have been cleared by restoring displaced mark-word"); \ NOT_PRODUCT(_promoHead = nextObj); \ if (cl != NULL) oop(curObj)->oop_iterate(cl); \ if (nextObj == NULL) { /* start at head of list reset above */ \ nextObj = _promoHead; \ } \ } \ assert(noPromotions(), "post-condition violation"); \ assert(_promoHead == NULL && _promoTail == NULL, "emptied promoted list");\ assert(_spoolHead == _spoolTail, "emptied spooling buffers"); \ assert(_firstIndex == _nextIndex, "empty buffer"); \ } // This should have been ALL_SINCE_...() just like the others, // but, because the body of the method above is somehwat longer, // the MSVC compiler cannot cope; as a workaround, we split the // macro into its 3 constituent parts below (see original macro // definition in specializedOopClosures.hpp). SPECIALIZED_SINCE_SAVE_MARKS_CLOSURES_YOUNG(PROMOTED_OOPS_ITERATE_DEFN) PROMOTED_OOPS_ITERATE_DEFN(OopsInGenClosure,_v) // Return the next displaced header, incrementing the pointer and // recycling spool area as necessary. markOop 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?"); markOop 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, klassOop klassOfOop) { // make a copy of header as it may need to be spooled markOop mark = oop(trackOop)->mark(); trackOop->clearNext(); 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 == markOopDesc::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(markOop 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(_spoolHead == _spoolTail && _firstIndex == _nextIndex, "spooling inconsistency?"); _firstIndex = _nextIndex = 1; _tracking = true; } #define CMSPrintPromoBlockInfo 1 void PromotionInfo::stopTrackingPromotions(uint worker_id) { assert(_spoolHead == _spoolTail && _firstIndex == _nextIndex, "spooling inconsistency?"); _firstIndex = _nextIndex = 1; _tracking = false; if (CMSPrintPromoBlockInfo > 1) { print_statistics(worker_id); } } void PromotionInfo::print_statistics(uint worker_id) const { assert(_spoolHead == _spoolTail && _firstIndex == _nextIndex, "Else will undercount"); assert(CMSPrintPromoBlockInfo > 0, "Else unnecessary call"); // Count the number of blocks and slots in the free pool size_t slots = 0; size_t blocks = 0; for (SpoolBlock* cur_spool = _spareSpool; cur_spool != NULL; cur_spool = cur_spool->nextSpoolBlock) { // the first entry is just a self-pointer; indices 1 through // bufferSize - 1 are occupied (thus, bufferSize - 1 slots). assert((void*)cur_spool->displacedHdr == (void*)&cur_spool->displacedHdr, "first entry of displacedHdr should be self-referential"); slots += cur_spool->bufferSize - 1; blocks++; } if (_spoolHead != NULL) { slots += _spoolHead->bufferSize - 1; blocks++; } gclog_or_tty->print_cr(" [worker %d] promo_blocks = %d, promo_slots = %d ", worker_id, blocks, slots); } // 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 lartter 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()), "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 || oop(curObj)->is_oop(), "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, this, (HeapWord*)displacedHdr + bufferSize, bufferSize, nextSpoolBlock); }