| /* |
| * Copyright (c) 2010, 2016, 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. |
| * |
| */ |
| |
| #ifndef SHARE_VM_GC_CMS_PROMOTIONINFO_HPP |
| #define SHARE_VM_GC_CMS_PROMOTIONINFO_HPP |
| |
| #include "gc/cms/freeChunk.hpp" |
| #include "memory/allocation.hpp" |
| |
| // Forward declarations |
| class CompactibleFreeListSpace; |
| |
| class PromotedObject VALUE_OBJ_CLASS_SPEC { |
| private: |
| enum { |
| promoted_mask = right_n_bits(2), // i.e. 0x3 |
| displaced_mark = nth_bit(2), // i.e. 0x4 |
| next_mask = ~(right_n_bits(3)) // i.e. ~(0x7) |
| }; |
| |
| // Below, we want _narrow_next in the "higher" 32 bit slot, |
| // whose position will depend on endian-ness of the platform. |
| // This is so that there is no interference with the |
| // cms_free_bit occupying bit position 7 (lsb == 0) |
| // when we are using compressed oops; see FreeChunk::is_free(). |
| // We cannot move the cms_free_bit down because currently |
| // biased locking code assumes that age bits are contiguous |
| // with the lock bits. Even if that assumption were relaxed, |
| // the least position we could move this bit to would be |
| // to bit position 3, which would require 16 byte alignment. |
| typedef struct { |
| #ifdef VM_LITTLE_ENDIAN |
| LP64_ONLY(narrowOop _pad;) |
| narrowOop _narrow_next; |
| #else |
| narrowOop _narrow_next; |
| LP64_ONLY(narrowOop _pad;) |
| #endif |
| } Data; |
| |
| union { |
| intptr_t _next; |
| Data _data; |
| }; |
| public: |
| PromotedObject* next() const; |
| void setNext(PromotedObject* x); |
| inline void setPromotedMark() { |
| _next |= promoted_mask; |
| assert(!((FreeChunk*)this)->is_free(), "Error"); |
| } |
| inline bool hasPromotedMark() const { |
| assert(!((FreeChunk*)this)->is_free(), "Error"); |
| return (_next & promoted_mask) == promoted_mask; |
| } |
| inline void setDisplacedMark() { |
| _next |= displaced_mark; |
| assert(!((FreeChunk*)this)->is_free(), "Error"); |
| } |
| inline bool hasDisplacedMark() const { |
| assert(!((FreeChunk*)this)->is_free(), "Error"); |
| return (_next & displaced_mark) != 0; |
| } |
| inline void clear_next() { |
| _next = 0; |
| assert(!((FreeChunk*)this)->is_free(), "Error"); |
| } |
| debug_only(void *next_addr() { return (void *) &_next; }) |
| }; |
| |
| class SpoolBlock: public FreeChunk { |
| friend class PromotionInfo; |
| protected: |
| SpoolBlock* nextSpoolBlock; |
| size_t bufferSize; // number of usable words in this block |
| markOop* displacedHdr; // the displaced headers start here |
| |
| // Note about bufferSize: it denotes the number of entries available plus 1; |
| // legal indices range from 1 through BufferSize - 1. See the verification |
| // code verify() that counts the number of displaced headers spooled. |
| size_t computeBufferSize() { |
| return (size() * sizeof(HeapWord) - sizeof(*this)) / sizeof(markOop); |
| } |
| |
| public: |
| void init() { |
| bufferSize = computeBufferSize(); |
| displacedHdr = (markOop*)&displacedHdr; |
| nextSpoolBlock = NULL; |
| } |
| |
| void print_on(outputStream* st) const; |
| void print() const { print_on(tty); } |
| }; |
| |
| class PromotionInfo VALUE_OBJ_CLASS_SPEC { |
| bool _tracking; // set if tracking |
| CompactibleFreeListSpace* _space; // the space to which this belongs |
| PromotedObject* _promoHead; // head of list of promoted objects |
| PromotedObject* _promoTail; // tail of list of promoted objects |
| SpoolBlock* _spoolHead; // first spooling block |
| SpoolBlock* _spoolTail; // last non-full spooling block or null |
| SpoolBlock* _splice_point; // when _spoolTail is null, holds list tail |
| SpoolBlock* _spareSpool; // free spool buffer |
| size_t _firstIndex; // first active index in |
| // first spooling block (_spoolHead) |
| size_t _nextIndex; // last active index + 1 in last |
| // spooling block (_spoolTail) |
| private: |
| // ensure that spooling space exists; return true if there is spooling space |
| bool ensure_spooling_space_work(); |
| |
| public: |
| PromotionInfo() : |
| _tracking(0), _space(NULL), |
| _promoHead(NULL), _promoTail(NULL), |
| _spoolHead(NULL), _spoolTail(NULL), |
| _spareSpool(NULL), _firstIndex(1), |
| _nextIndex(1) {} |
| |
| bool noPromotions() const { |
| assert(_promoHead != NULL || _promoTail == NULL, "list inconsistency"); |
| return _promoHead == NULL; |
| } |
| void startTrackingPromotions(); |
| void stopTrackingPromotions(); |
| bool tracking() const { return _tracking; } |
| void track(PromotedObject* trackOop); // keep track of a promoted oop |
| // The following variant must be used when trackOop is not fully |
| // initialized and has a NULL klass: |
| void track(PromotedObject* trackOop, Klass* klassOfOop); // keep track of a promoted oop |
| void setSpace(CompactibleFreeListSpace* sp) { _space = sp; } |
| CompactibleFreeListSpace* space() const { return _space; } |
| markOop nextDisplacedHeader(); // get next header & forward spool pointer |
| void saveDisplacedHeader(markOop hdr); |
| // save header and forward spool |
| |
| inline size_t refillSize() const; |
| |
| SpoolBlock* getSpoolBlock(); // return a free spooling block |
| inline bool has_spooling_space() { |
| return _spoolTail != NULL && _spoolTail->bufferSize > _nextIndex; |
| } |
| // ensure that spooling space exists |
| bool ensure_spooling_space() { |
| return has_spooling_space() || ensure_spooling_space_work(); |
| } |
| #define PROMOTED_OOPS_ITERATE_DECL(OopClosureType, nv_suffix) \ |
| void promoted_oops_iterate##nv_suffix(OopClosureType* cl); |
| ALL_SINCE_SAVE_MARKS_CLOSURES(PROMOTED_OOPS_ITERATE_DECL) |
| #undef PROMOTED_OOPS_ITERATE_DECL |
| void promoted_oops_iterate(OopsInGenClosure* cl) { |
| promoted_oops_iterate_v(cl); |
| } |
| void verify() const; |
| void reset() { |
| _promoHead = NULL; |
| _promoTail = NULL; |
| _spoolHead = NULL; |
| _spoolTail = NULL; |
| _spareSpool = NULL; |
| _firstIndex = 0; |
| _nextIndex = 0; |
| |
| } |
| |
| void print_on(outputStream* st) const; |
| }; |
| |
| |
| #endif // SHARE_VM_GC_CMS_PROMOTIONINFO_HPP |