1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/src/share/vm/gc_implementation/concurrentMarkSweep/promotionInfo.hpp Wed Apr 27 01:25:04 2016 +0800
1.3 @@ -0,0 +1,214 @@
1.4 +/*
1.5 + * Copyright (c) 2010, 2012, Oracle and/or its affiliates. All rights reserved.
1.6 + * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
1.7 + *
1.8 + * This code is free software; you can redistribute it and/or modify it
1.9 + * under the terms of the GNU General Public License version 2 only, as
1.10 + * published by the Free Software Foundation.
1.11 + *
1.12 + * This code is distributed in the hope that it will be useful, but WITHOUT
1.13 + * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
1.14 + * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
1.15 + * version 2 for more details (a copy is included in the LICENSE file that
1.16 + * accompanied this code).
1.17 + *
1.18 + * You should have received a copy of the GNU General Public License version
1.19 + * 2 along with this work; if not, write to the Free Software Foundation,
1.20 + * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
1.21 + *
1.22 + * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
1.23 + * or visit www.oracle.com if you need additional information or have any
1.24 + * questions.
1.25 + *
1.26 + */
1.27 +
1.28 +#ifndef SHARE_VM_GC_IMPLEMENTATION_CONCURRENTMARKSWEEP_PROMOTIONINFO_HPP
1.29 +#define SHARE_VM_GC_IMPLEMENTATION_CONCURRENTMARKSWEEP_PROMOTIONINFO_HPP
1.30 +
1.31 +#include "gc_implementation/concurrentMarkSweep/freeChunk.hpp"
1.32 +#include "memory/allocation.hpp"
1.33 +
1.34 +// Forward declarations
1.35 +class CompactibleFreeListSpace;
1.36 +
1.37 +class PromotedObject VALUE_OBJ_CLASS_SPEC {
1.38 + private:
1.39 + enum {
1.40 + promoted_mask = right_n_bits(2), // i.e. 0x3
1.41 + displaced_mark = nth_bit(2), // i.e. 0x4
1.42 + next_mask = ~(right_n_bits(3)) // i.e. ~(0x7)
1.43 + };
1.44 +
1.45 + // Below, we want _narrow_next in the "higher" 32 bit slot,
1.46 + // whose position will depend on endian-ness of the platform.
1.47 + // This is so that there is no interference with the
1.48 + // cms_free_bit occupying bit position 7 (lsb == 0)
1.49 + // when we are using compressed oops; see FreeChunk::is_free().
1.50 + // We cannot move the cms_free_bit down because currently
1.51 + // biased locking code assumes that age bits are contiguous
1.52 + // with the lock bits. Even if that assumption were relaxed,
1.53 + // the least position we could move this bit to would be
1.54 + // to bit position 3, which would require 16 byte alignment.
1.55 + typedef struct {
1.56 +#ifdef VM_LITTLE_ENDIAN
1.57 + LP64_ONLY(narrowOop _pad;)
1.58 + narrowOop _narrow_next;
1.59 +#else
1.60 + narrowOop _narrow_next;
1.61 + LP64_ONLY(narrowOop _pad;)
1.62 +#endif
1.63 + } Data;
1.64 +
1.65 + union {
1.66 + intptr_t _next;
1.67 + Data _data;
1.68 + };
1.69 + public:
1.70 + inline PromotedObject* next() const {
1.71 + assert(!((FreeChunk*)this)->is_free(), "Error");
1.72 + PromotedObject* res;
1.73 + if (UseCompressedOops) {
1.74 + // The next pointer is a compressed oop stored in the top 32 bits
1.75 + res = (PromotedObject*)oopDesc::decode_heap_oop(_data._narrow_next);
1.76 + } else {
1.77 + res = (PromotedObject*)(_next & next_mask);
1.78 + }
1.79 + assert(oop(res)->is_oop_or_null(true /* ignore mark word */), "Not an oop?");
1.80 + return res;
1.81 + }
1.82 + inline void setNext(PromotedObject* x) {
1.83 + assert(((intptr_t)x & ~next_mask) == 0, "Conflict in bit usage, "
1.84 + "or insufficient alignment of objects");
1.85 + if (UseCompressedOops) {
1.86 + assert(_data._narrow_next == 0, "Overwrite?");
1.87 + _data._narrow_next = oopDesc::encode_heap_oop(oop(x));
1.88 + } else {
1.89 + _next |= (intptr_t)x;
1.90 + }
1.91 + assert(!((FreeChunk*)this)->is_free(), "Error");
1.92 + }
1.93 + inline void setPromotedMark() {
1.94 + _next |= promoted_mask;
1.95 + assert(!((FreeChunk*)this)->is_free(), "Error");
1.96 + }
1.97 + inline bool hasPromotedMark() const {
1.98 + assert(!((FreeChunk*)this)->is_free(), "Error");
1.99 + return (_next & promoted_mask) == promoted_mask;
1.100 + }
1.101 + inline void setDisplacedMark() {
1.102 + _next |= displaced_mark;
1.103 + assert(!((FreeChunk*)this)->is_free(), "Error");
1.104 + }
1.105 + inline bool hasDisplacedMark() const {
1.106 + assert(!((FreeChunk*)this)->is_free(), "Error");
1.107 + return (_next & displaced_mark) != 0;
1.108 + }
1.109 + inline void clear_next() {
1.110 + _next = 0;
1.111 + assert(!((FreeChunk*)this)->is_free(), "Error");
1.112 + }
1.113 + debug_only(void *next_addr() { return (void *) &_next; })
1.114 +};
1.115 +
1.116 +class SpoolBlock: public FreeChunk {
1.117 + friend class PromotionInfo;
1.118 + protected:
1.119 + SpoolBlock* nextSpoolBlock;
1.120 + size_t bufferSize; // number of usable words in this block
1.121 + markOop* displacedHdr; // the displaced headers start here
1.122 +
1.123 + // Note about bufferSize: it denotes the number of entries available plus 1;
1.124 + // legal indices range from 1 through BufferSize - 1. See the verification
1.125 + // code verify() that counts the number of displaced headers spooled.
1.126 + size_t computeBufferSize() {
1.127 + return (size() * sizeof(HeapWord) - sizeof(*this)) / sizeof(markOop);
1.128 + }
1.129 +
1.130 + public:
1.131 + void init() {
1.132 + bufferSize = computeBufferSize();
1.133 + displacedHdr = (markOop*)&displacedHdr;
1.134 + nextSpoolBlock = NULL;
1.135 + }
1.136 +
1.137 + void print_on(outputStream* st) const;
1.138 + void print() const { print_on(gclog_or_tty); }
1.139 +};
1.140 +
1.141 +class PromotionInfo VALUE_OBJ_CLASS_SPEC {
1.142 + bool _tracking; // set if tracking
1.143 + CompactibleFreeListSpace* _space; // the space to which this belongs
1.144 + PromotedObject* _promoHead; // head of list of promoted objects
1.145 + PromotedObject* _promoTail; // tail of list of promoted objects
1.146 + SpoolBlock* _spoolHead; // first spooling block
1.147 + SpoolBlock* _spoolTail; // last non-full spooling block or null
1.148 + SpoolBlock* _splice_point; // when _spoolTail is null, holds list tail
1.149 + SpoolBlock* _spareSpool; // free spool buffer
1.150 + size_t _firstIndex; // first active index in
1.151 + // first spooling block (_spoolHead)
1.152 + size_t _nextIndex; // last active index + 1 in last
1.153 + // spooling block (_spoolTail)
1.154 + private:
1.155 + // ensure that spooling space exists; return true if there is spooling space
1.156 + bool ensure_spooling_space_work();
1.157 +
1.158 + public:
1.159 + PromotionInfo() :
1.160 + _tracking(0), _space(NULL),
1.161 + _promoHead(NULL), _promoTail(NULL),
1.162 + _spoolHead(NULL), _spoolTail(NULL),
1.163 + _spareSpool(NULL), _firstIndex(1),
1.164 + _nextIndex(1) {}
1.165 +
1.166 + bool noPromotions() const {
1.167 + assert(_promoHead != NULL || _promoTail == NULL, "list inconsistency");
1.168 + return _promoHead == NULL;
1.169 + }
1.170 + void startTrackingPromotions();
1.171 + void stopTrackingPromotions(uint worker_id = 0);
1.172 + bool tracking() const { return _tracking; }
1.173 + void track(PromotedObject* trackOop); // keep track of a promoted oop
1.174 + // The following variant must be used when trackOop is not fully
1.175 + // initialized and has a NULL klass:
1.176 + void track(PromotedObject* trackOop, Klass* klassOfOop); // keep track of a promoted oop
1.177 + void setSpace(CompactibleFreeListSpace* sp) { _space = sp; }
1.178 + CompactibleFreeListSpace* space() const { return _space; }
1.179 + markOop nextDisplacedHeader(); // get next header & forward spool pointer
1.180 + void saveDisplacedHeader(markOop hdr);
1.181 + // save header and forward spool
1.182 +
1.183 + inline size_t refillSize() const;
1.184 +
1.185 + SpoolBlock* getSpoolBlock(); // return a free spooling block
1.186 + inline bool has_spooling_space() {
1.187 + return _spoolTail != NULL && _spoolTail->bufferSize > _nextIndex;
1.188 + }
1.189 + // ensure that spooling space exists
1.190 + bool ensure_spooling_space() {
1.191 + return has_spooling_space() || ensure_spooling_space_work();
1.192 + }
1.193 + #define PROMOTED_OOPS_ITERATE_DECL(OopClosureType, nv_suffix) \
1.194 + void promoted_oops_iterate##nv_suffix(OopClosureType* cl);
1.195 + ALL_SINCE_SAVE_MARKS_CLOSURES(PROMOTED_OOPS_ITERATE_DECL)
1.196 + #undef PROMOTED_OOPS_ITERATE_DECL
1.197 + void promoted_oops_iterate(OopsInGenClosure* cl) {
1.198 + promoted_oops_iterate_v(cl);
1.199 + }
1.200 + void verify() const;
1.201 + void reset() {
1.202 + _promoHead = NULL;
1.203 + _promoTail = NULL;
1.204 + _spoolHead = NULL;
1.205 + _spoolTail = NULL;
1.206 + _spareSpool = NULL;
1.207 + _firstIndex = 0;
1.208 + _nextIndex = 0;
1.209 +
1.210 + }
1.211 +
1.212 + void print_on(outputStream* st) const;
1.213 + void print_statistics(uint worker_id) const;
1.214 +};
1.215 +
1.216 +
1.217 +#endif // SHARE_VM_GC_IMPLEMENTATION_CONCURRENTMARKSWEEP_PROMOTIONINFO_HPP
