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comparison: src/share/vm/gc_implementation/concurrentMarkSweep/compactibleFreeListSpace.cpp

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

changeset 1876
a8127dc669ba
parent 1583
05b775309e59
child 1907
c18cbe5936b8
child 1926
2d127394260e
equal deleted inserted replaced
1875:bb843ebc7c55 1876:a8127dc669ba
1924 assert(_promoInfo.noPromotions(), "_promoInfo inconsistency"); \ 1924 assert(_promoInfo.noPromotions(), "_promoInfo inconsistency"); \
1925 } 1925 }
1926 1926
1927 ALL_SINCE_SAVE_MARKS_CLOSURES(CFLS_OOP_SINCE_SAVE_MARKS_DEFN) 1927 ALL_SINCE_SAVE_MARKS_CLOSURES(CFLS_OOP_SINCE_SAVE_MARKS_DEFN)
1928 1928
1929 //////////////////////////////////////////////////////////////////////////////
1930 // We go over the list of promoted objects, removing each from the list,
1931 // and applying the closure (this may, in turn, add more elements to
1932 // the tail of the promoted list, and these newly added objects will
1933 // also be processed) until the list is empty.
1934 // To aid verification and debugging, in the non-product builds
1935 // we actually forward _promoHead each time we process a promoted oop.
1936 // Note that this is not necessary in general (i.e. when we don't need to
1937 // call PromotionInfo::verify()) because oop_iterate can only add to the
1938 // end of _promoTail, and never needs to look at _promoHead.
1939
1940 #define PROMOTED_OOPS_ITERATE_DEFN(OopClosureType, nv_suffix) \
1941 \
1942 void PromotionInfo::promoted_oops_iterate##nv_suffix(OopClosureType* cl) { \
1943 NOT_PRODUCT(verify()); \
1944 PromotedObject *curObj, *nextObj; \
1945 for (curObj = _promoHead; curObj != NULL; curObj = nextObj) { \
1946 if ((nextObj = curObj->next()) == NULL) { \
1947 /* protect ourselves against additions due to closure application \
1948 below by resetting the list. */ \
1949 assert(_promoTail == curObj, "Should have been the tail"); \
1950 _promoHead = _promoTail = NULL; \
1951 } \
1952 if (curObj->hasDisplacedMark()) { \
1953 /* restore displaced header */ \
1954 oop(curObj)->set_mark(nextDisplacedHeader()); \
1955 } else { \
1956 /* restore prototypical header */ \
1957 oop(curObj)->init_mark(); \
1958 } \
1959 /* The "promoted_mark" should now not be set */ \
1960 assert(!curObj->hasPromotedMark(), \
1961 "Should have been cleared by restoring displaced mark-word"); \
1962 NOT_PRODUCT(_promoHead = nextObj); \
1963 if (cl != NULL) oop(curObj)->oop_iterate(cl); \
1964 if (nextObj == NULL) { /* start at head of list reset above */ \
1965 nextObj = _promoHead; \
1966 } \
1967 } \
1968 assert(noPromotions(), "post-condition violation"); \
1969 assert(_promoHead == NULL && _promoTail == NULL, "emptied promoted list");\
1970 assert(_spoolHead == _spoolTail, "emptied spooling buffers"); \
1971 assert(_firstIndex == _nextIndex, "empty buffer"); \
1972 }
1973
1974 // This should have been ALL_SINCE_...() just like the others,
1975 // but, because the body of the method above is somehwat longer,
1976 // the MSVC compiler cannot cope; as a workaround, we split the
1977 // macro into its 3 constituent parts below (see original macro
1978 // definition in specializedOopClosures.hpp).
1979 SPECIALIZED_SINCE_SAVE_MARKS_CLOSURES_YOUNG(PROMOTED_OOPS_ITERATE_DEFN)
1980 PROMOTED_OOPS_ITERATE_DEFN(OopsInGenClosure,_v)
1981
1982 1929
1983 void CompactibleFreeListSpace::object_iterate_since_last_GC(ObjectClosure* cl) { 1930 void CompactibleFreeListSpace::object_iterate_since_last_GC(ObjectClosure* cl) {
1984 // ugghh... how would one do this efficiently for a non-contiguous space? 1931 // ugghh... how would one do this efficiently for a non-contiguous space?
1985 guarantee(false, "NYI"); 1932 guarantee(false, "NYI");
1986 } 1933 }
2502 gclog_or_tty->print("growth: %8.5f deficit: %8.5f\n", 2449 gclog_or_tty->print("growth: %8.5f deficit: %8.5f\n",
2503 (double)(total.splitBirths()+total.coalBirths()-total.splitDeaths()-total.coalDeaths())/ 2450 (double)(total.splitBirths()+total.coalBirths()-total.splitDeaths()-total.coalDeaths())/
2504 (total.prevSweep() != 0 ? (double)total.prevSweep() : 1.0), 2451 (total.prevSweep() != 0 ? (double)total.prevSweep() : 1.0),
2505 (double)(total.desired() - total.count())/(total.desired() != 0 ? (double)total.desired() : 1.0)); 2452 (double)(total.desired() - total.count())/(total.desired() != 0 ? (double)total.desired() : 1.0));
2506 _dictionary->printDictCensus(); 2453 _dictionary->printDictCensus();
2507 }
2508
2509 // Return the next displaced header, incrementing the pointer and
2510 // recycling spool area as necessary.
2511 markOop PromotionInfo::nextDisplacedHeader() {
2512 assert(_spoolHead != NULL, "promotionInfo inconsistency");
2513 assert(_spoolHead != _spoolTail || _firstIndex < _nextIndex,
2514 "Empty spool space: no displaced header can be fetched");
2515 assert(_spoolHead->bufferSize > _firstIndex, "Off by one error at head?");
2516 markOop hdr = _spoolHead->displacedHdr[_firstIndex];
2517 // Spool forward
2518 if (++_firstIndex == _spoolHead->bufferSize) { // last location in this block
2519 // forward to next block, recycling this block into spare spool buffer
2520 SpoolBlock* tmp = _spoolHead->nextSpoolBlock;
2521 assert(_spoolHead != _spoolTail, "Spooling storage mix-up");
2522 _spoolHead->nextSpoolBlock = _spareSpool;
2523 _spareSpool = _spoolHead;
2524 _spoolHead = tmp;
2525 _firstIndex = 1;
2526 NOT_PRODUCT(
2527 if (_spoolHead == NULL) { // all buffers fully consumed
2528 assert(_spoolTail == NULL && _nextIndex == 1,
2529 "spool buffers processing inconsistency");
2530 }
2531 )
2532 }
2533 return hdr;
2534 }
2535
2536 void PromotionInfo::track(PromotedObject* trackOop) {
2537 track(trackOop, oop(trackOop)->klass());
2538 }
2539
2540 void PromotionInfo::track(PromotedObject* trackOop, klassOop klassOfOop) {
2541 // make a copy of header as it may need to be spooled
2542 markOop mark = oop(trackOop)->mark();
2543 trackOop->clearNext();
2544 if (mark->must_be_preserved_for_cms_scavenge(klassOfOop)) {
2545 // save non-prototypical header, and mark oop
2546 saveDisplacedHeader(mark);
2547 trackOop->setDisplacedMark();
2548 } else {
2549 // we'd like to assert something like the following:
2550 // assert(mark == markOopDesc::prototype(), "consistency check");
2551 // ... but the above won't work because the age bits have not (yet) been
2552 // cleared. The remainder of the check would be identical to the
2553 // condition checked in must_be_preserved() above, so we don't really
2554 // have anything useful to check here!
2555 }
2556 if (_promoTail != NULL) {
2557 assert(_promoHead != NULL, "List consistency");
2558 _promoTail->setNext(trackOop);
2559 _promoTail = trackOop;
2560 } else {
2561 assert(_promoHead == NULL, "List consistency");
2562 _promoHead = _promoTail = trackOop;
2563 }
2564 // Mask as newly promoted, so we can skip over such objects
2565 // when scanning dirty cards
2566 assert(!trackOop->hasPromotedMark(), "Should not have been marked");
2567 trackOop->setPromotedMark();
2568 }
2569
2570 // Save the given displaced header, incrementing the pointer and
2571 // obtaining more spool area as necessary.
2572 void PromotionInfo::saveDisplacedHeader(markOop hdr) {
2573 assert(_spoolHead != NULL && _spoolTail != NULL,
2574 "promotionInfo inconsistency");
2575 assert(_spoolTail->bufferSize > _nextIndex, "Off by one error at tail?");
2576 _spoolTail->displacedHdr[_nextIndex] = hdr;
2577 // Spool forward
2578 if (++_nextIndex == _spoolTail->bufferSize) { // last location in this block
2579 // get a new spooling block
2580 assert(_spoolTail->nextSpoolBlock == NULL, "tail should terminate spool list");
2581 _splice_point = _spoolTail; // save for splicing
2582 _spoolTail->nextSpoolBlock = getSpoolBlock(); // might fail
2583 _spoolTail = _spoolTail->nextSpoolBlock; // might become NULL ...
2584 // ... but will attempt filling before next promotion attempt
2585 _nextIndex = 1;
2586 }
2587 }
2588
2589 // Ensure that spooling space exists. Return false if spooling space
2590 // could not be obtained.
2591 bool PromotionInfo::ensure_spooling_space_work() {
2592 assert(!has_spooling_space(), "Only call when there is no spooling space");
2593 // Try and obtain more spooling space
2594 SpoolBlock* newSpool = getSpoolBlock();
2595 assert(newSpool == NULL ||
2596 (newSpool->bufferSize != 0 && newSpool->nextSpoolBlock == NULL),
2597 "getSpoolBlock() sanity check");
2598 if (newSpool == NULL) {
2599 return false;
2600 }
2601 _nextIndex = 1;
2602 if (_spoolTail == NULL) {
2603 _spoolTail = newSpool;
2604 if (_spoolHead == NULL) {
2605 _spoolHead = newSpool;
2606 _firstIndex = 1;
2607 } else {
2608 assert(_splice_point != NULL && _splice_point->nextSpoolBlock == NULL,
2609 "Splice point invariant");
2610 // Extra check that _splice_point is connected to list
2611 #ifdef ASSERT
2612 {
2613 SpoolBlock* blk = _spoolHead;
2614 for (; blk->nextSpoolBlock != NULL;
2615 blk = blk->nextSpoolBlock);
2616 assert(blk != NULL && blk == _splice_point,
2617 "Splice point incorrect");
2618 }
2619 #endif // ASSERT
2620 _splice_point->nextSpoolBlock = newSpool;
2621 }
2622 } else {
2623 assert(_spoolHead != NULL, "spool list consistency");
2624 _spoolTail->nextSpoolBlock = newSpool;
2625 _spoolTail = newSpool;
2626 }
2627 return true;
2628 }
2629
2630 // Get a free spool buffer from the free pool, getting a new block
2631 // from the heap if necessary.
2632 SpoolBlock* PromotionInfo::getSpoolBlock() {
2633 SpoolBlock* res;
2634 if ((res = _spareSpool) != NULL) {
2635 _spareSpool = _spareSpool->nextSpoolBlock;
2636 res->nextSpoolBlock = NULL;
2637 } else { // spare spool exhausted, get some from heap
2638 res = (SpoolBlock*)(space()->allocateScratch(refillSize()));
2639 if (res != NULL) {
2640 res->init();
2641 }
2642 }
2643 assert(res == NULL || res->nextSpoolBlock == NULL, "postcondition");
2644 return res;
2645 }
2646
2647 void PromotionInfo::startTrackingPromotions() {
2648 assert(_spoolHead == _spoolTail && _firstIndex == _nextIndex,
2649 "spooling inconsistency?");
2650 _firstIndex = _nextIndex = 1;
2651 _tracking = true;
2652 }
2653
2654 #define CMSPrintPromoBlockInfo 1
2655
2656 void PromotionInfo::stopTrackingPromotions(uint worker_id) {
2657 assert(_spoolHead == _spoolTail && _firstIndex == _nextIndex,
2658 "spooling inconsistency?");
2659 _firstIndex = _nextIndex = 1;
2660 _tracking = false;
2661 if (CMSPrintPromoBlockInfo > 1) {
2662 print_statistics(worker_id);
2663 }
2664 }
2665
2666 void PromotionInfo::print_statistics(uint worker_id) const {
2667 assert(_spoolHead == _spoolTail && _firstIndex == _nextIndex,
2668 "Else will undercount");
2669 assert(CMSPrintPromoBlockInfo > 0, "Else unnecessary call");
2670 // Count the number of blocks and slots in the free pool
2671 size_t slots = 0;
2672 size_t blocks = 0;
2673 for (SpoolBlock* cur_spool = _spareSpool;
2674 cur_spool != NULL;
2675 cur_spool = cur_spool->nextSpoolBlock) {
2676 // the first entry is just a self-pointer; indices 1 through
2677 // bufferSize - 1 are occupied (thus, bufferSize - 1 slots).
2678 guarantee((void*)cur_spool->displacedHdr == (void*)&cur_spool->displacedHdr,
2679 "first entry of displacedHdr should be self-referential");
2680 slots += cur_spool->bufferSize - 1;
2681 blocks++;
2682 }
2683 if (_spoolHead != NULL) {
2684 slots += _spoolHead->bufferSize - 1;
2685 blocks++;
2686 }
2687 gclog_or_tty->print_cr(" [worker %d] promo_blocks = %d, promo_slots = %d ",
2688 worker_id, blocks, slots);
2689 }
2690
2691 // When _spoolTail is not NULL, then the slot <_spoolTail, _nextIndex>
2692 // points to the next slot available for filling.
2693 // The set of slots holding displaced headers are then all those in the
2694 // right-open interval denoted by:
2695 //
2696 // [ <_spoolHead, _firstIndex>, <_spoolTail, _nextIndex> )
2697 //
2698 // When _spoolTail is NULL, then the set of slots with displaced headers
2699 // is all those starting at the slot <_spoolHead, _firstIndex> and
2700 // going up to the last slot of last block in the linked list.
2701 // In this lartter case, _splice_point points to the tail block of
2702 // this linked list of blocks holding displaced headers.
2703 void PromotionInfo::verify() const {
2704 // Verify the following:
2705 // 1. the number of displaced headers matches the number of promoted
2706 // objects that have displaced headers
2707 // 2. each promoted object lies in this space
2708 debug_only(
2709 PromotedObject* junk = NULL;
2710 assert(junk->next_addr() == (void*)(oop(junk)->mark_addr()),
2711 "Offset of PromotedObject::_next is expected to align with "
2712 " the OopDesc::_mark within OopDesc");
2713 )
2714 // FIXME: guarantee????
2715 guarantee(_spoolHead == NULL || _spoolTail != NULL ||
2716 _splice_point != NULL, "list consistency");
2717 guarantee(_promoHead == NULL || _promoTail != NULL, "list consistency");
2718 // count the number of objects with displaced headers
2719 size_t numObjsWithDisplacedHdrs = 0;
2720 for (PromotedObject* curObj = _promoHead; curObj != NULL; curObj = curObj->next()) {
2721 guarantee(space()->is_in_reserved((HeapWord*)curObj), "Containment");
2722 // the last promoted object may fail the mark() != NULL test of is_oop().
2723 guarantee(curObj->next() == NULL || oop(curObj)->is_oop(), "must be an oop");
2724 if (curObj->hasDisplacedMark()) {
2725 numObjsWithDisplacedHdrs++;
2726 }
2727 }
2728 // Count the number of displaced headers
2729 size_t numDisplacedHdrs = 0;
2730 for (SpoolBlock* curSpool = _spoolHead;
2731 curSpool != _spoolTail && curSpool != NULL;
2732 curSpool = curSpool->nextSpoolBlock) {
2733 // the first entry is just a self-pointer; indices 1 through
2734 // bufferSize - 1 are occupied (thus, bufferSize - 1 slots).
2735 guarantee((void*)curSpool->displacedHdr == (void*)&curSpool->displacedHdr,
2736 "first entry of displacedHdr should be self-referential");
2737 numDisplacedHdrs += curSpool->bufferSize - 1;
2738 }
2739 guarantee((_spoolHead == _spoolTail) == (numDisplacedHdrs == 0),
2740 "internal consistency");
2741 guarantee(_spoolTail != NULL || _nextIndex == 1,
2742 "Inconsistency between _spoolTail and _nextIndex");
2743 // We overcounted (_firstIndex-1) worth of slots in block
2744 // _spoolHead and we undercounted (_nextIndex-1) worth of
2745 // slots in block _spoolTail. We make an appropriate
2746 // adjustment by subtracting the first and adding the
2747 // second: - (_firstIndex - 1) + (_nextIndex - 1)
2748 numDisplacedHdrs += (_nextIndex - _firstIndex);
2749 guarantee(numDisplacedHdrs == numObjsWithDisplacedHdrs, "Displaced hdr count");
2750 }
2751
2752 void PromotionInfo::print_on(outputStream* st) const {
2753 SpoolBlock* curSpool = NULL;
2754 size_t i = 0;
2755 st->print_cr("start & end indices: [" SIZE_FORMAT ", " SIZE_FORMAT ")",
2756 _firstIndex, _nextIndex);
2757 for (curSpool = _spoolHead; curSpool != _spoolTail && curSpool != NULL;
2758 curSpool = curSpool->nextSpoolBlock) {
2759 curSpool->print_on(st);
2760 st->print_cr(" active ");
2761 i++;
2762 }
2763 for (curSpool = _spoolTail; curSpool != NULL;
2764 curSpool = curSpool->nextSpoolBlock) {
2765 curSpool->print_on(st);
2766 st->print_cr(" inactive ");
2767 i++;
2768 }
2769 for (curSpool = _spareSpool; curSpool != NULL;
2770 curSpool = curSpool->nextSpoolBlock) {
2771 curSpool->print_on(st);
2772 st->print_cr(" free ");
2773 i++;
2774 }
2775 st->print_cr(SIZE_FORMAT " header spooling blocks", i);
2776 }
2777
2778 void SpoolBlock::print_on(outputStream* st) const {
2779 st->print("[" PTR_FORMAT "," PTR_FORMAT "), " SIZE_FORMAT " HeapWords -> " PTR_FORMAT,
2780 this, (HeapWord*)displacedHdr + bufferSize,
2781 bufferSize, nextSpoolBlock);
2782 } 2454 }
2783 2455
2784 /////////////////////////////////////////////////////////////////////////// 2456 ///////////////////////////////////////////////////////////////////////////
2785 // CFLS_LAB 2457 // CFLS_LAB
2786 /////////////////////////////////////////////////////////////////////////// 2458 ///////////////////////////////////////////////////////////////////////////

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