ysr@1876: /*
coleenp@4037:  * Copyright (c) 2010, 2012, Oracle and/or its affiliates. All rights reserved.
ysr@1876:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
ysr@1876:  *
ysr@1876:  * This code is free software; you can redistribute it and/or modify it
ysr@1876:  * under the terms of the GNU General Public License version 2 only, as
ysr@1876:  * published by the Free Software Foundation.
ysr@1876:  *
ysr@1876:  * This code is distributed in the hope that it will be useful, but WITHOUT
ysr@1876:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
ysr@1876:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
ysr@1876:  * version 2 for more details (a copy is included in the LICENSE file that
ysr@1876:  * accompanied this code).
ysr@1876:  *
ysr@1876:  * You should have received a copy of the GNU General Public License version
ysr@1876:  * 2 along with this work; if not, write to the Free Software Foundation,
ysr@1876:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
ysr@1876:  *
trims@1907:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
trims@1907:  * or visit www.oracle.com if you need additional information or have any
trims@1907:  * questions.
ysr@1876:  *
ysr@1876:  */
ysr@1876: 
stefank@2314: #ifndef SHARE_VM_GC_IMPLEMENTATION_CONCURRENTMARKSWEEP_PROMOTIONINFO_HPP
stefank@2314: #define SHARE_VM_GC_IMPLEMENTATION_CONCURRENTMARKSWEEP_PROMOTIONINFO_HPP
stefank@2314: 
stefank@2314: #include "gc_implementation/concurrentMarkSweep/freeChunk.hpp"
stefank@2314: #include "memory/allocation.hpp"
stefank@2314: 
ysr@1876: // Forward declarations
ysr@1876: class CompactibleFreeListSpace;
ysr@1876: 
ysr@1876: class PromotedObject VALUE_OBJ_CLASS_SPEC {
ysr@1876:  private:
ysr@1876:   enum {
ysr@1876:     promoted_mask  = right_n_bits(2),   // i.e. 0x3
ysr@1876:     displaced_mark = nth_bit(2),        // i.e. 0x4
ysr@1876:     next_mask      = ~(right_n_bits(3)) // i.e. ~(0x7)
ysr@1876:   };
ysr@1901: 
ysr@1901:   // Below, we want _narrow_next in the "higher" 32 bit slot,
ysr@1901:   // whose position will depend on endian-ness of the platform.
ysr@1901:   // This is so that there is no interference with the
ysr@1901:   // cms_free_bit occupying bit position 7 (lsb == 0)
jmasa@3732:   // when we are using compressed oops; see FreeChunk::is_free().
ysr@1901:   // We cannot move the cms_free_bit down because currently
ysr@1901:   // biased locking code assumes that age bits are contiguous
ysr@1901:   // with the lock bits. Even if that assumption were relaxed,
ysr@1901:   // the least position we could move this bit to would be
ysr@1901:   // to bit position 3, which would require 16 byte alignment.
ysr@1901:   typedef struct {
ysr@1901: #ifdef VM_LITTLE_ENDIAN
ysr@1901:     LP64_ONLY(narrowOop _pad;)
ysr@1901:               narrowOop _narrow_next;
ysr@1901: #else
ysr@1901:               narrowOop _narrow_next;
ysr@1901:     LP64_ONLY(narrowOop _pad;)
ysr@1901: #endif
ysr@1901:   } Data;
ysr@1901: 
ysr@1901:   union {
ysr@1901:     intptr_t _next;
ysr@1901:     Data     _data;
ysr@1901:   };
ysr@1876:  public:
ysr@1876:   inline PromotedObject* next() const {
jmasa@3732:     assert(!((FreeChunk*)this)->is_free(), "Error");
ysr@1901:     PromotedObject* res;
ysr@1901:     if (UseCompressedOops) {
ysr@1901:       // The next pointer is a compressed oop stored in the top 32 bits
ysr@1901:       res = (PromotedObject*)oopDesc::decode_heap_oop(_data._narrow_next);
ysr@1901:     } else {
ysr@1901:       res = (PromotedObject*)(_next & next_mask);
ysr@1901:     }
ysr@1901:     assert(oop(res)->is_oop_or_null(true /* ignore mark word */), "Not an oop?");
ysr@1901:     return res;
ysr@1876:   }
ysr@1876:   inline void setNext(PromotedObject* x) {
ysr@1901:     assert(((intptr_t)x & ~next_mask) == 0, "Conflict in bit usage, "
ysr@1901:            "or insufficient alignment of objects");
ysr@1901:     if (UseCompressedOops) {
ysr@1901:       assert(_data._narrow_next == 0, "Overwrite?");
ysr@1901:       _data._narrow_next = oopDesc::encode_heap_oop(oop(x));
ysr@1901:     } else {
ysr@1901:       _next |= (intptr_t)x;
ysr@1901:     }
jmasa@3732:     assert(!((FreeChunk*)this)->is_free(), "Error");
ysr@1876:   }
ysr@1876:   inline void setPromotedMark() {
ysr@1876:     _next |= promoted_mask;
jmasa@3732:     assert(!((FreeChunk*)this)->is_free(), "Error");
ysr@1876:   }
ysr@1876:   inline bool hasPromotedMark() const {
jmasa@3732:     assert(!((FreeChunk*)this)->is_free(), "Error");
ysr@1876:     return (_next & promoted_mask) == promoted_mask;
ysr@1876:   }
ysr@1876:   inline void setDisplacedMark() {
ysr@1876:     _next |= displaced_mark;
jmasa@3732:     assert(!((FreeChunk*)this)->is_free(), "Error");
ysr@1876:   }
ysr@1876:   inline bool hasDisplacedMark() const {
jmasa@3732:     assert(!((FreeChunk*)this)->is_free(), "Error");
ysr@1876:     return (_next & displaced_mark) != 0;
ysr@1876:   }
jmasa@3732:   inline void clear_next()        {
ysr@1901:     _next = 0;
jmasa@3732:     assert(!((FreeChunk*)this)->is_free(), "Error");
ysr@1901:   }
ysr@1876:   debug_only(void *next_addr() { return (void *) &_next; })
ysr@1876: };
ysr@1876: 
ysr@1876: class SpoolBlock: public FreeChunk {
ysr@1876:   friend class PromotionInfo;
ysr@1876:  protected:
ysr@1876:   SpoolBlock*  nextSpoolBlock;
ysr@1876:   size_t       bufferSize;        // number of usable words in this block
ysr@1876:   markOop*     displacedHdr;      // the displaced headers start here
ysr@1876: 
ysr@1876:   // Note about bufferSize: it denotes the number of entries available plus 1;
ysr@1876:   // legal indices range from 1 through BufferSize - 1.  See the verification
ysr@1876:   // code verify() that counts the number of displaced headers spooled.
ysr@1876:   size_t computeBufferSize() {
ysr@1876:     return (size() * sizeof(HeapWord) - sizeof(*this)) / sizeof(markOop);
ysr@1876:   }
ysr@1876: 
ysr@1876:  public:
ysr@1876:   void init() {
ysr@1876:     bufferSize = computeBufferSize();
ysr@1876:     displacedHdr = (markOop*)&displacedHdr;
ysr@1876:     nextSpoolBlock = NULL;
ysr@1876:   }
ysr@1876: 
ysr@1876:   void print_on(outputStream* st) const;
ysr@1876:   void print() const { print_on(gclog_or_tty); }
ysr@1876: };
ysr@1876: 
ysr@1876: class PromotionInfo VALUE_OBJ_CLASS_SPEC {
ysr@1876:   bool            _tracking;      // set if tracking
ysr@1876:   CompactibleFreeListSpace* _space; // the space to which this belongs
ysr@1876:   PromotedObject* _promoHead;     // head of list of promoted objects
ysr@1876:   PromotedObject* _promoTail;     // tail of list of promoted objects
ysr@1876:   SpoolBlock*     _spoolHead;     // first spooling block
ysr@1876:   SpoolBlock*     _spoolTail;     // last  non-full spooling block or null
ysr@1876:   SpoolBlock*     _splice_point;  // when _spoolTail is null, holds list tail
ysr@1876:   SpoolBlock*     _spareSpool;    // free spool buffer
ysr@1876:   size_t          _firstIndex;    // first active index in
ysr@1876:                                   // first spooling block (_spoolHead)
ysr@1876:   size_t          _nextIndex;     // last active index + 1 in last
ysr@1876:                                   // spooling block (_spoolTail)
ysr@1876:  private:
ysr@1876:   // ensure that spooling space exists; return true if there is spooling space
ysr@1876:   bool ensure_spooling_space_work();
ysr@1876: 
ysr@1876:  public:
ysr@1876:   PromotionInfo() :
ysr@1876:     _tracking(0), _space(NULL),
ysr@1876:     _promoHead(NULL), _promoTail(NULL),
ysr@1876:     _spoolHead(NULL), _spoolTail(NULL),
ysr@1876:     _spareSpool(NULL), _firstIndex(1),
ysr@1876:     _nextIndex(1) {}
ysr@1876: 
ysr@1876:   bool noPromotions() const {
ysr@1876:     assert(_promoHead != NULL || _promoTail == NULL, "list inconsistency");
ysr@1876:     return _promoHead == NULL;
ysr@1876:   }
ysr@1876:   void startTrackingPromotions();
ysr@1876:   void stopTrackingPromotions(uint worker_id = 0);
ysr@1876:   bool tracking() const          { return _tracking;  }
ysr@1876:   void track(PromotedObject* trackOop);      // keep track of a promoted oop
ysr@1876:   // The following variant must be used when trackOop is not fully
ysr@1876:   // initialized and has a NULL klass:
coleenp@4037:   void track(PromotedObject* trackOop, Klass* klassOfOop); // keep track of a promoted oop
ysr@1876:   void setSpace(CompactibleFreeListSpace* sp) { _space = sp; }
ysr@1876:   CompactibleFreeListSpace* space() const     { return _space; }
ysr@1876:   markOop nextDisplacedHeader(); // get next header & forward spool pointer
ysr@1876:   void    saveDisplacedHeader(markOop hdr);
ysr@1876:                                  // save header and forward spool
ysr@1876: 
ysr@1876:   inline size_t refillSize() const;
ysr@1876: 
ysr@1876:   SpoolBlock* getSpoolBlock();   // return a free spooling block
ysr@1876:   inline bool has_spooling_space() {
ysr@1876:     return _spoolTail != NULL && _spoolTail->bufferSize > _nextIndex;
ysr@1876:   }
ysr@1876:   // ensure that spooling space exists
ysr@1876:   bool ensure_spooling_space() {
ysr@1876:     return has_spooling_space() || ensure_spooling_space_work();
ysr@1876:   }
ysr@1876:   #define PROMOTED_OOPS_ITERATE_DECL(OopClosureType, nv_suffix)  \
ysr@1876:     void promoted_oops_iterate##nv_suffix(OopClosureType* cl);
ysr@1876:   ALL_SINCE_SAVE_MARKS_CLOSURES(PROMOTED_OOPS_ITERATE_DECL)
ysr@1876:   #undef PROMOTED_OOPS_ITERATE_DECL
ysr@1876:   void promoted_oops_iterate(OopsInGenClosure* cl) {
ysr@1876:     promoted_oops_iterate_v(cl);
ysr@1876:   }
ysr@1876:   void verify()  const;
ysr@1876:   void reset() {
ysr@1876:     _promoHead = NULL;
ysr@1876:     _promoTail = NULL;
ysr@1876:     _spoolHead = NULL;
ysr@1876:     _spoolTail = NULL;
ysr@1876:     _spareSpool = NULL;
ysr@1876:     _firstIndex = 0;
ysr@1876:     _nextIndex = 0;
ysr@1876: 
ysr@1876:   }
ysr@1876: 
ysr@1876:   void print_on(outputStream* st) const;
ysr@1876:   void print_statistics(uint worker_id) const;
ysr@1876: };
ysr@1876: 
stefank@2314: 
stefank@2314: #endif // SHARE_VM_GC_IMPLEMENTATION_CONCURRENTMARKSWEEP_PROMOTIONINFO_HPP