Mercurial > hg > truffle
diff src/share/vm/gc_implementation/concurrentMarkSweep/promotionInfo.cpp @ 1521:a8127dc669ba
6951188: CMS: move PromotionInfo into its own file
Summary: Moved PromotionInfo and friends into new files promotionInfo.{h,c}pp from their previous compactibleFreeListSpace.{h,c}pp home.
Reviewed-by: apetrusenko
author | ysr |
---|---|
date | Mon, 10 May 2010 12:31:52 -0700 |
parents | |
children | a00b51b2dda4 |
line wrap: on
line diff
--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/share/vm/gc_implementation/concurrentMarkSweep/promotionInfo.cpp Mon May 10 12:31:52 2010 -0700 @@ -0,0 +1,360 @@ +/* + * Copyright 2001-2009 Sun Microsystems, Inc. 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 Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, + * CA 95054 USA or visit www.sun.com if you need additional information or + * have any questions. + * + */ + +# include "incls/_precompiled.incl" +# include "incls/_promotionInfo.cpp.incl" + +///////////////////////////////////////////////////////////////////////// +//// 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). + guarantee((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); +}