jdk8-mips64-public/hotspot: src/share/vm/gc_implementation/concurrentMarkSweep/promotionInfo.cpp@a9becfeecd1b (annotated)

src/share/vm/gc_implementation/concurrentMarkSweep/promotionInfo.cpp@a9becfeecd1b (annotated)

src/share/vm/gc_implementation/concurrentMarkSweep/promotionInfo.cpp

Wed, 22 Jan 2014 17:42:23 -0800

author: kvn
date: Wed, 22 Jan 2014 17:42:23 -0800
changeset 6503: a9becfeecd1b
parent 4037: da91efe96a93
child 6680: 78bbf4d43a14
permissions: -rw-r--r--

Merge

 /*
  * Copyright (c) 2010, 2012, 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.
  *
  */
 #include "precompiled.hpp"
 #include "gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.hpp"
 #include "gc_implementation/concurrentMarkSweep/promotionInfo.hpp"
 #include "oops/markOop.inline.hpp"
 #include "oops/oop.inline.hpp"
 /////////////////////////////////////////////////////////////////////////
 //// 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, Klass* klassOfOop) {
   // make a copy of header as it may need to be spooled
   markOop mark = oop(trackOop)->mark();
   trackOop->clear_next();
   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).
     assert((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);
 }

Mercurial > jdk8-mips64-public > hotspot / annotate

src/share/vm/gc_implementation/concurrentMarkSweep/promotionInfo.cpp@a9becfeecd1b (annotated)

src/share/vm/gc_implementation/concurrentMarkSweep/promotionInfo.cpp