1 /* 2 * Copyright (c) 2010, Oracle and/or its affiliates. All rights reserved. 3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 4 * 5 * This code is free software; you can redistribute it and/or modify it 6 * under the terms of the GNU General Public License version 2 only, as 7 * published by the Free Software Foundation. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 * 23 */ 24 25 #ifndef SHARE_VM_GC_IMPLEMENTATION_CONCURRENTMARKSWEEP_PROMOTIONINFO_INLINE_HPP 26 #define SHARE_VM_GC_IMPLEMENTATION_CONCURRENTMARKSWEEP_PROMOTIONINFO_INLINE_HPP 27 28 #include "gc_implementation/concurrentMarkSweep/promotionInfo.hpp" 29 #include "oops/oop.inline.hpp" 30 31 ////////////////////////////////////////////////////////////////////////////// 32 // We go over the list of promoted objects, removing each from the list, 33 // and applying the closure (this may, in turn, add more elements to 34 // the tail of the promoted list, and these newly added objects will 35 // also be processed) until the list is empty. 36 // To aid verification and debugging, in the non-product builds 37 // we actually forward _promoHead each time we process a promoted oop. 38 // Note that this is not necessary in general (i.e. when we don't need to 39 // call PromotionInfo::verify()) because oop_iterate can only add to the 40 // end of _promoTail, and never needs to look at _promoHead. 41 42 // Return the next displaced header, incrementing the pointer and 43 // recycling spool area as necessary. 44 inline markOop PromotionInfo::nextDisplacedHeader() { 45 assert(_spoolHead != NULL, "promotionInfo inconsistency"); 46 assert(_spoolHead != _spoolTail || _firstIndex < _nextIndex, 47 "Empty spool space: no displaced header can be fetched"); 48 assert(_spoolHead->bufferSize > _firstIndex, "Off by one error at head?"); 49 markOop hdr = _spoolHead->displacedHdr[_firstIndex]; 50 // Spool forward 51 if (++_firstIndex == _spoolHead->bufferSize) { // last location in this block 52 // forward to next block, recycling this block into spare spool buffer 53 SpoolBlock* tmp = _spoolHead->nextSpoolBlock; 54 assert(_spoolHead != _spoolTail, "Spooling storage mix-up"); 55 _spoolHead->nextSpoolBlock = _spareSpool; 56 _spareSpool = _spoolHead; 57 _spoolHead = tmp; 58 _firstIndex = 1; 59 NOT_PRODUCT( 60 if (_spoolHead == NULL) { // all buffers fully consumed 61 assert(_spoolTail == NULL && _nextIndex == 1, 62 "spool buffers processing inconsistency"); 63 } 64 ) 65 } 66 return hdr; 67 } 68 69 template <bool nv, typename OopClosureType> 70 void PromotionInfo::promoted_oops_iterate(OopClosureType* cl) { 71 NOT_PRODUCT(verify()); 72 PromotedObject *curObj, *nextObj; 73 for (curObj = _promoHead; curObj != NULL; curObj = nextObj) { 74 if ((nextObj = curObj->next()) == NULL) { 75 /* protect ourselves against additions due to closure application 76 below by resetting the list. */ 77 assert(_promoTail == curObj, "Should have been the tail"); 78 _promoHead = _promoTail = NULL; 79 } 80 if (curObj->hasDisplacedMark()) { 81 /* restore displaced header */ 82 oop(curObj)->set_mark(nextDisplacedHeader()); 83 } else { 84 /* restore prototypical header */ 85 oop(curObj)->init_mark(); 86 } 87 /* The "promoted_mark" should now not be set */ 88 assert(!curObj->hasPromotedMark(), 89 "Should have been cleared by restoring displaced mark-word"); 90 NOT_PRODUCT(_promoHead = nextObj); 91 if (cl != NULL) oop(curObj)->oop_iterate<nv>(cl); 92 if (nextObj == NULL) { /* start at head of list reset above */ 93 nextObj = _promoHead; 94 } 95 } 96 assert(noPromotions(), "post-condition violation"); 97 assert(_promoHead == NULL && _promoTail == NULL, "emptied promoted list"); 98 assert(_spoolHead == _spoolTail, "emptied spooling buffers"); 99 assert(_firstIndex == _nextIndex, "empty buffer"); 100 } 101 102 #endif // SHARE_VM_GC_IMPLEMENTATION_CONCURRENTMARKSWEEP_PROMOTIONINFO_INLINE_HPP