Mercurial > hg > openjdk > hsx20
changeset 2017:ffd725ff6943
Merge
| author | johnc |
|---|---|
| date | Thu, 13 Jan 2011 17:19:21 -0800 |
| parents | 856ecff79cf7 (current diff) c91cc404ca46 (diff) |
| children | 0915f9be781c 7e37af9d69ef 182e9624aa42 |
| files | src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp |
| diffstat | 10 files changed, 514 insertions(+), 341 deletions(-) [+] |
line wrap: on
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--- a/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp Thu Jan 13 08:32:15 2011 -0800 +++ b/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.cpp Thu Jan 13 17:19:21 2011 -0800 @@ -7879,25 +7879,23 @@ } // We need this destructor to reclaim any space at the end -// of the space, which do_blk below may not have added back to -// the free lists. [basically dealing with the "fringe effect"] +// of the space, which do_blk below may not yet have added back to +// the free lists. SweepClosure::~SweepClosure() { assert_lock_strong(_freelistLock); - // this should be treated as the end of a free run if any - // The current free range should be returned to the free lists - // as one coalesced chunk. + assert(_limit >= _sp->bottom() && _limit <= _sp->end(), + "sweep _limit out of bounds"); + // Flush any remaining coterminal free run as a single + // coalesced chunk to the appropriate free list. if (inFreeRange()) { - flushCurFreeChunk(freeFinger(), - pointer_delta(_limit, freeFinger())); - assert(freeFinger() < _limit, "the finger pointeth off base"); + assert(freeFinger() < _limit, "freeFinger points too high"); + flush_cur_free_chunk(freeFinger(), pointer_delta(_limit, freeFinger())); if (CMSTraceSweeper) { - gclog_or_tty->print("destructor:"); - gclog_or_tty->print("Sweep:put_free_blk 0x%x ("SIZE_FORMAT") " - "[coalesced:"SIZE_FORMAT"]\n", - freeFinger(), pointer_delta(_limit, freeFinger()), - lastFreeRangeCoalesced()); - } - } + gclog_or_tty->print("Sweep: last chunk: "); + gclog_or_tty->print("put_free_blk 0x%x ("SIZE_FORMAT") [coalesced:"SIZE_FORMAT"]\n", + freeFinger(), pointer_delta(_limit, freeFinger()), lastFreeRangeCoalesced()); + } + } // else nothing to flush NOT_PRODUCT( if (Verbose && PrintGC) { gclog_or_tty->print("Collected "SIZE_FORMAT" objects, " @@ -7934,9 +7932,8 @@ void SweepClosure::initialize_free_range(HeapWord* freeFinger, bool freeRangeInFreeLists) { if (CMSTraceSweeper) { - gclog_or_tty->print("---- Start free range 0x%x with free block [%d] (%d)\n", - freeFinger, _sp->block_size(freeFinger), - freeRangeInFreeLists); + gclog_or_tty->print("---- Start free range at 0x%x with free block (%d)\n", + freeFinger, freeRangeInFreeLists); } assert(!inFreeRange(), "Trampling existing free range"); set_inFreeRange(true); @@ -7991,21 +7988,36 @@ // may have caused us to coalesce the block ending at the address _limit // with a newly expanded chunk (this happens when _limit was set to the // previous _end of the space), so we may have stepped past _limit; see CR 6977970. - if (addr >= _limit) { // we have swept up to or past the limit, do nothing more + if (addr >= _limit) { // we have swept up to or past the limit: finish up assert(_limit >= _sp->bottom() && _limit <= _sp->end(), "sweep _limit out of bounds"); assert(addr < _sp->end(), "addr out of bounds"); - // help the closure application finish + // Flush any remaining coterminal free run as a single + // coalesced chunk to the appropriate free list. + if (inFreeRange()) { + assert(freeFinger() < _limit, "finger points too high"); + flush_cur_free_chunk(freeFinger(), + pointer_delta(addr, freeFinger())); + if (CMSTraceSweeper) { + gclog_or_tty->print("Sweep: last chunk: "); + gclog_or_tty->print("put_free_blk 0x%x ("SIZE_FORMAT") " + "[coalesced:"SIZE_FORMAT"]\n", + freeFinger(), pointer_delta(addr, freeFinger()), + lastFreeRangeCoalesced()); + } + } + + // help the iterator loop finish return pointer_delta(_sp->end(), addr); } + assert(addr < _limit, "sweep invariant"); - // check if we should yield do_yield_check(addr); if (fc->isFree()) { // Chunk that is already free res = fc->size(); - doAlreadyFreeChunk(fc); + do_already_free_chunk(fc); debug_only(_sp->verifyFreeLists()); assert(res == fc->size(), "Don't expect the size to change"); NOT_PRODUCT( @@ -8015,7 +8027,7 @@ NOT_PRODUCT(_last_fc = fc;) } else if (!_bitMap->isMarked(addr)) { // Chunk is fresh garbage - res = doGarbageChunk(fc); + res = do_garbage_chunk(fc); debug_only(_sp->verifyFreeLists()); NOT_PRODUCT( _numObjectsFreed++; @@ -8023,7 +8035,7 @@ ) } else { // Chunk that is alive. - res = doLiveChunk(fc); + res = do_live_chunk(fc); debug_only(_sp->verifyFreeLists()); NOT_PRODUCT( _numObjectsLive++; @@ -8076,7 +8088,7 @@ // to a free list which may be overpopulated. // -void SweepClosure::doAlreadyFreeChunk(FreeChunk* fc) { +void SweepClosure::do_already_free_chunk(FreeChunk* fc) { size_t size = fc->size(); // Chunks that cannot be coalesced are not in the // free lists. @@ -8092,23 +8104,23 @@ // addr and purported end of this block. _bitMap->verifyNoOneBitsInRange(addr + 1, addr + size); - // Some chunks cannot be coalesced in under any circumstances. + // Some chunks cannot be coalesced under any circumstances. // See the definition of cantCoalesce(). if (!fc->cantCoalesce()) { // This chunk can potentially be coalesced. if (_sp->adaptive_freelists()) { // All the work is done in - doPostIsFreeOrGarbageChunk(fc, size); + do_post_free_or_garbage_chunk(fc, size); } else { // Not adaptive free lists // this is a free chunk that can potentially be coalesced by the sweeper; if (!inFreeRange()) { // if the next chunk is a free block that can't be coalesced // it doesn't make sense to remove this chunk from the free lists FreeChunk* nextChunk = (FreeChunk*)(addr + size); - assert((HeapWord*)nextChunk <= _limit, "sweep invariant"); - if ((HeapWord*)nextChunk < _limit && // there's a next chunk... - nextChunk->isFree() && // which is free... - nextChunk->cantCoalesce()) { // ... but cant be coalesced + assert((HeapWord*)nextChunk <= _sp->end(), "Chunk size out of bounds?"); + if ((HeapWord*)nextChunk < _sp->end() && // There is another free chunk to the right ... + nextChunk->isFree() && // ... which is free... + nextChunk->cantCoalesce()) { // ... but can't be coalesced // nothing to do } else { // Potentially the start of a new free range: @@ -8154,14 +8166,14 @@ // as the end of a free run if any if (inFreeRange()) { // we kicked some butt; time to pick up the garbage - assert(freeFinger() < addr, "the finger pointeth off base"); - flushCurFreeChunk(freeFinger(), pointer_delta(addr, freeFinger())); + assert(freeFinger() < addr, "freeFinger points too high"); + flush_cur_free_chunk(freeFinger(), pointer_delta(addr, freeFinger())); } // else, nothing to do, just continue } } -size_t SweepClosure::doGarbageChunk(FreeChunk* fc) { +size_t SweepClosure::do_garbage_chunk(FreeChunk* fc) { // This is a chunk of garbage. It is not in any free list. // Add it to a free list or let it possibly be coalesced into // a larger chunk. @@ -8173,7 +8185,7 @@ // addr and purported end of just dead object. _bitMap->verifyNoOneBitsInRange(addr + 1, addr + size); - doPostIsFreeOrGarbageChunk(fc, size); + do_post_free_or_garbage_chunk(fc, size); } else { if (!inFreeRange()) { // start of a new free range @@ -8212,35 +8224,16 @@ return size; } -size_t SweepClosure::doLiveChunk(FreeChunk* fc) { +size_t SweepClosure::do_live_chunk(FreeChunk* fc) { HeapWord* addr = (HeapWord*) fc; // The sweeper has just found a live object. Return any accumulated // left hand chunk to the free lists. if (inFreeRange()) { - if (_sp->adaptive_freelists()) { - flushCurFreeChunk(freeFinger(), - pointer_delta(addr, freeFinger())); - } else { // not adaptive freelists - set_inFreeRange(false); - // Add the free range back to the free list if it is not already - // there. - if (!freeRangeInFreeLists()) { - assert(freeFinger() < addr, "the finger pointeth off base"); - if (CMSTraceSweeper) { - gclog_or_tty->print("Sweep:put_free_blk 0x%x (%d) " - "[coalesced:%d]\n", - freeFinger(), pointer_delta(addr, freeFinger()), - lastFreeRangeCoalesced()); - } - _sp->addChunkAndRepairOffsetTable(freeFinger(), - pointer_delta(addr, freeFinger()), lastFreeRangeCoalesced()); - } - } - } - - // Common code path for original and adaptive free lists. - - // this object is live: we'd normally expect this to be + assert(freeFinger() < addr, "freeFinger points too high"); + flush_cur_free_chunk(freeFinger(), pointer_delta(addr, freeFinger())); + } + + // This object is live: we'd normally expect this to be // an oop, and like to assert the following: // assert(oop(addr)->is_oop(), "live block should be an oop"); // However, as we commented above, this may be an object whose @@ -8255,7 +8248,7 @@ assert(size == CompactibleFreeListSpace::adjustObjectSize(size), "alignment problem"); - #ifdef DEBUG +#ifdef DEBUG if (oop(addr)->klass_or_null() != NULL && ( !_collector->should_unload_classes() || (oop(addr)->is_parsable()) && @@ -8269,7 +8262,7 @@ CompactibleFreeListSpace::adjustObjectSize(oop(addr)->size()), "P-mark and computed size do not agree"); } - #endif +#endif } else { // This should be an initialized object that's alive. @@ -8296,18 +8289,16 @@ return size; } -void SweepClosure::doPostIsFreeOrGarbageChunk(FreeChunk* fc, - size_t chunkSize) { - // doPostIsFreeOrGarbageChunk() should only be called in the smart allocation - // scheme. +void SweepClosure::do_post_free_or_garbage_chunk(FreeChunk* fc, + size_t chunkSize) { + // do_post_free_or_garbage_chunk() should only be called in the case + // of the adaptive free list allocator. bool fcInFreeLists = fc->isFree(); assert(_sp->adaptive_freelists(), "Should only be used in this case."); assert((HeapWord*)fc <= _limit, "sweep invariant"); if (CMSTestInFreeList && fcInFreeLists) { - assert(_sp->verifyChunkInFreeLists(fc), - "free chunk is not in free lists"); - } - + assert(_sp->verifyChunkInFreeLists(fc), "free chunk is not in free lists"); + } if (CMSTraceSweeper) { gclog_or_tty->print_cr(" -- pick up another chunk at 0x%x (%d)", fc, chunkSize); @@ -8380,20 +8371,21 @@ if (inFreeRange()) { // In a free range but cannot coalesce with the right hand chunk. // Put the current free range into the free lists. - flushCurFreeChunk(freeFinger(), - pointer_delta(addr, freeFinger())); + flush_cur_free_chunk(freeFinger(), + pointer_delta(addr, freeFinger())); } // Set up for new free range. Pass along whether the right hand // chunk is in the free lists. initialize_free_range((HeapWord*)fc, fcInFreeLists); } } -void SweepClosure::flushCurFreeChunk(HeapWord* chunk, size_t size) { + +void SweepClosure::flush_cur_free_chunk(HeapWord* chunk, size_t size) { assert(inFreeRange(), "Should only be called if currently in a free range."); assert(size > 0, "A zero sized chunk cannot be added to the free lists."); if (!freeRangeInFreeLists()) { - if(CMSTestInFreeList) { + if (CMSTestInFreeList) { FreeChunk* fc = (FreeChunk*) chunk; fc->setSize(size); assert(!_sp->verifyChunkInFreeLists(fc), @@ -8428,7 +8420,7 @@ // chunk just flushed, they will need to wait for the next // sweep to be coalesced. if (inFreeRange()) { - flushCurFreeChunk(freeFinger(), pointer_delta(addr, freeFinger())); + flush_cur_free_chunk(freeFinger(), pointer_delta(addr, freeFinger())); } // First give up the locks, then yield, then re-lock.
--- a/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp Thu Jan 13 08:32:15 2011 -0800 +++ b/src/share/vm/gc_implementation/concurrentMarkSweep/concurrentMarkSweepGeneration.hpp Thu Jan 13 17:19:21 2011 -0800 @@ -1701,7 +1701,9 @@ CMSCollector* _collector; // collector doing the work ConcurrentMarkSweepGeneration* _g; // Generation being swept CompactibleFreeListSpace* _sp; // Space being swept - HeapWord* _limit; + HeapWord* _limit;// the address at which the sweep should stop because + // we do not expect blocks eligible for sweeping past + // that address. Mutex* _freelistLock; // Free list lock (in space) CMSBitMap* _bitMap; // Marking bit map (in // generation) @@ -1745,14 +1747,13 @@ private: // Code that is common to a free chunk or garbage when // encountered during sweeping. - void doPostIsFreeOrGarbageChunk(FreeChunk *fc, - size_t chunkSize); + void do_post_free_or_garbage_chunk(FreeChunk *fc, size_t chunkSize); // Process a free chunk during sweeping. - void doAlreadyFreeChunk(FreeChunk *fc); + void do_already_free_chunk(FreeChunk *fc); // Process a garbage chunk during sweeping. - size_t doGarbageChunk(FreeChunk *fc); + size_t do_garbage_chunk(FreeChunk *fc); // Process a live chunk during sweeping. - size_t doLiveChunk(FreeChunk* fc); + size_t do_live_chunk(FreeChunk* fc); // Accessors. HeapWord* freeFinger() const { return _freeFinger; } @@ -1769,7 +1770,7 @@ // Initialize a free range. void initialize_free_range(HeapWord* freeFinger, bool freeRangeInFreeLists); // Return this chunk to the free lists. - void flushCurFreeChunk(HeapWord* chunk, size_t size); + void flush_cur_free_chunk(HeapWord* chunk, size_t size); // Check if we should yield and do so when necessary. inline void do_yield_check(HeapWord* addr);
--- a/src/share/vm/gc_implementation/g1/g1BlockOffsetTable.cpp Thu Jan 13 08:32:15 2011 -0800 +++ b/src/share/vm/gc_implementation/g1/g1BlockOffsetTable.cpp Thu Jan 13 17:19:21 2011 -0800 @@ -1,5 +1,5 @@ /* - * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2001, 2011, 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 @@ -222,7 +222,7 @@ // Action_mark - update the BOT for the block [blk_start, blk_end). // Current typical use is for splitting a block. -// Action_single - udpate the BOT for an allocation. +// Action_single - update the BOT for an allocation. // Action_verify - BOT verification. void G1BlockOffsetArray::do_block_internal(HeapWord* blk_start, HeapWord* blk_end, @@ -331,47 +331,6 @@ do_block_internal(blk_start, blk_end, Action_mark); } -void G1BlockOffsetArray::join_blocks(HeapWord* blk1, HeapWord* blk2) { - HeapWord* blk1_start = Universe::heap()->block_start(blk1); - HeapWord* blk2_start = Universe::heap()->block_start(blk2); - assert(blk1 == blk1_start && blk2 == blk2_start, - "Must be block starts."); - assert(blk1 + _sp->block_size(blk1) == blk2, "Must be contiguous."); - size_t blk1_start_index = _array->index_for(blk1); - size_t blk2_start_index = _array->index_for(blk2); - assert(blk1_start_index <= blk2_start_index, "sanity"); - HeapWord* blk2_card_start = _array->address_for_index(blk2_start_index); - if (blk2 == blk2_card_start) { - // blk2 starts a card. Does blk1 start on the prevous card, or futher - // back? - assert(blk1_start_index < blk2_start_index, "must be lower card."); - if (blk1_start_index + 1 == blk2_start_index) { - // previous card; new value for blk2 card is size of blk1. - _array->set_offset_array(blk2_start_index, (u_char) _sp->block_size(blk1)); - } else { - // Earlier card; go back a card. - _array->set_offset_array(blk2_start_index, N_words); - } - } else { - // blk2 does not start a card. Does it cross a card? If not, nothing - // to do. - size_t blk2_end_index = - _array->index_for(blk2 + _sp->block_size(blk2) - 1); - assert(blk2_end_index >= blk2_start_index, "sanity"); - if (blk2_end_index > blk2_start_index) { - // Yes, it crosses a card. The value for the next card must change. - if (blk1_start_index + 1 == blk2_start_index) { - // previous card; new value for second blk2 card is size of blk1. - _array->set_offset_array(blk2_start_index + 1, - (u_char) _sp->block_size(blk1)); - } else { - // Earlier card; go back a card. - _array->set_offset_array(blk2_start_index + 1, N_words); - } - } - } -} - HeapWord* G1BlockOffsetArray::block_start_unsafe(const void* addr) { assert(_bottom <= addr && addr < _end, "addr must be covered by this Array"); @@ -580,15 +539,50 @@ #endif } -void -G1BlockOffsetArray::set_for_starts_humongous(HeapWord* new_end) { - assert(_end == new_end, "_end should have already been updated"); +bool +G1BlockOffsetArray::verify_for_object(HeapWord* obj_start, + size_t word_size) const { + size_t first_card = _array->index_for(obj_start); + size_t last_card = _array->index_for(obj_start + word_size - 1); + if (!_array->is_card_boundary(obj_start)) { + // If the object is not on a card boundary the BOT entry of the + // first card should point to another object so we should not + // check that one. + first_card += 1; + } + for (size_t card = first_card; card <= last_card; card += 1) { + HeapWord* card_addr = _array->address_for_index(card); + HeapWord* block_start = block_start_const(card_addr); + if (block_start != obj_start) { + gclog_or_tty->print_cr("block start: "PTR_FORMAT" is incorrect - " + "card index: "SIZE_FORMAT" " + "card addr: "PTR_FORMAT" BOT entry: %u " + "obj: "PTR_FORMAT" word size: "SIZE_FORMAT" " + "cards: ["SIZE_FORMAT","SIZE_FORMAT"]", + block_start, card, card_addr, + _array->offset_array(card), + obj_start, word_size, first_card, last_card); + return false; + } + } + return true; +} - // The first BOT entry should have offset 0. - _array->set_offset_array(_array->index_for(_bottom), 0); - // The rest should point to the first one. - set_remainder_to_point_to_start(_bottom + N_words, new_end); +#ifndef PRODUCT +void +G1BlockOffsetArray::print_on(outputStream* out) { + size_t from_index = _array->index_for(_bottom); + size_t to_index = _array->index_for(_end); + out->print_cr(">> BOT for area ["PTR_FORMAT","PTR_FORMAT") " + "cards ["SIZE_FORMAT","SIZE_FORMAT")", + _bottom, _end, from_index, to_index); + for (size_t i = from_index; i < to_index; ++i) { + out->print_cr(" entry "SIZE_FORMAT_W(8)" | "PTR_FORMAT" : %3u", + i, _array->address_for_index(i), + (uint) _array->offset_array(i)); + } } +#endif // !PRODUCT ////////////////////////////////////////////////////////////////////// // G1BlockOffsetArrayContigSpace @@ -641,10 +635,20 @@ } void -G1BlockOffsetArrayContigSpace::set_for_starts_humongous(HeapWord* new_end) { - G1BlockOffsetArray::set_for_starts_humongous(new_end); +G1BlockOffsetArrayContigSpace::set_for_starts_humongous(HeapWord* new_top) { + assert(new_top <= _end, "_end should have already been updated"); + + // The first BOT entry should have offset 0. + zero_bottom_entry(); + initialize_threshold(); + alloc_block(_bottom, new_top); + } - // Make sure _next_offset_threshold and _next_offset_index point to new_end. - _next_offset_threshold = new_end; - _next_offset_index = _array->index_for(new_end); +#ifndef PRODUCT +void +G1BlockOffsetArrayContigSpace::print_on(outputStream* out) { + G1BlockOffsetArray::print_on(out); + out->print_cr(" next offset threshold: "PTR_FORMAT, _next_offset_threshold); + out->print_cr(" next offset index: "SIZE_FORMAT, _next_offset_index); } +#endif // !PRODUCT
--- a/src/share/vm/gc_implementation/g1/g1BlockOffsetTable.hpp Thu Jan 13 08:32:15 2011 -0800 +++ b/src/share/vm/gc_implementation/g1/g1BlockOffsetTable.hpp Thu Jan 13 17:19:21 2011 -0800 @@ -1,5 +1,5 @@ /* - * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2001, 2011, 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 @@ -352,11 +352,6 @@ // The following methods are useful and optimized for a // general, non-contiguous space. - // The given arguments are required to be the starts of adjacent ("blk1" - // before "blk2") well-formed blocks covered by "this". After this call, - // they should be considered to form one block. - virtual void join_blocks(HeapWord* blk1, HeapWord* blk2); - // Given a block [blk_start, blk_start + full_blk_size), and // a left_blk_size < full_blk_size, adjust the BOT to show two // blocks [blk_start, blk_start + left_blk_size) and @@ -429,6 +424,12 @@ verify_single_block(blk, blk + size); } + // Used by region verification. Checks that the contents of the + // BOT reflect that there's a single object that spans the address + // range [obj_start, obj_start + word_size); returns true if this is + // the case, returns false if it's not. + bool verify_for_object(HeapWord* obj_start, size_t word_size) const; + // Verify that the given block is before _unallocated_block inline void verify_not_unallocated(HeapWord* blk_start, HeapWord* blk_end) const { @@ -444,7 +445,7 @@ void check_all_cards(size_t left_card, size_t right_card) const; - virtual void set_for_starts_humongous(HeapWord* new_end); + virtual void print_on(outputStream* out) PRODUCT_RETURN; }; // A subtype of BlockOffsetArray that takes advantage of the fact @@ -494,7 +495,9 @@ HeapWord* block_start_unsafe(const void* addr); HeapWord* block_start_unsafe_const(const void* addr) const; - virtual void set_for_starts_humongous(HeapWord* new_end); + void set_for_starts_humongous(HeapWord* new_top); + + virtual void print_on(outputStream* out) PRODUCT_RETURN; }; #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1BLOCKOFFSETTABLE_HPP
--- a/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp Thu Jan 13 08:32:15 2011 -0800 +++ b/src/share/vm/gc_implementation/g1/g1CollectedHeap.cpp Thu Jan 13 17:19:21 2011 -0800 @@ -1,5 +1,5 @@ /* - * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2001, 2011, 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 @@ -610,6 +610,39 @@ // of the free region list is revamped as part of CR 6977804. wait_for_cleanup_complete(); + // Other threads might still be trying to allocate using CASes out + // of the region we are retiring, as they can do so without holding + // the Heap_lock. So we first have to make sure that noone else can + // allocate in it by doing a maximal allocation. Even if our CAS + // attempt fails a few times, we'll succeed sooner or later given + // that a failed CAS attempt mean that the region is getting closed + // to being full (someone else succeeded in allocating into it). + size_t free_word_size = cur_alloc_region->free() / HeapWordSize; + + // This is the minimum free chunk we can turn into a dummy + // object. If the free space falls below this, then noone can + // allocate in this region anyway (all allocation requests will be + // of a size larger than this) so we won't have to perform the dummy + // allocation. + size_t min_word_size_to_fill = CollectedHeap::min_fill_size(); + + while (free_word_size >= min_word_size_to_fill) { + HeapWord* dummy = + cur_alloc_region->par_allocate_no_bot_updates(free_word_size); + if (dummy != NULL) { + // If the allocation was successful we should fill in the space. + CollectedHeap::fill_with_object(dummy, free_word_size); + break; + } + + free_word_size = cur_alloc_region->free() / HeapWordSize; + // It's also possible that someone else beats us to the + // allocation and they fill up the region. In that case, we can + // just get out of the loop + } + assert(cur_alloc_region->free() / HeapWordSize < min_word_size_to_fill, + "sanity"); + retire_cur_alloc_region_common(cur_alloc_region); assert(_cur_alloc_region == NULL, "post-condition"); } @@ -661,27 +694,29 @@ // young type. OrderAccess::storestore(); - // Now allocate out of the new current alloc region. We could - // have re-used allocate_from_cur_alloc_region() but its - // operation is slightly different to what we need here. First, - // allocate_from_cur_alloc_region() is only called outside a - // safepoint and will always unlock the Heap_lock if it returns - // a non-NULL result. Second, it assumes that the current alloc - // region is what's already assigned in _cur_alloc_region. What - // we want here is to actually do the allocation first before we - // assign the new region to _cur_alloc_region. This ordering is - // not currently important, but it will be essential when we - // change the code to support CAS allocation in the future (see - // CR 6994297). - // - // This allocate method does BOT updates and we don't need them in - // the young generation. This will be fixed in the near future by - // CR 6994297. - HeapWord* result = new_cur_alloc_region->allocate(word_size); + // Now, perform the allocation out of the region we just + // allocated. Note that noone else can access that region at + // this point (as _cur_alloc_region has not been updated yet), + // so we can just go ahead and do the allocation without any + // atomics (and we expect this allocation attempt to + // suceeded). Given that other threads can attempt an allocation + // with a CAS and without needing the Heap_lock, if we assigned + // the new region to _cur_alloc_region before first allocating + // into it other threads might have filled up the new region + // before we got a chance to do the allocation ourselves. In + // that case, we would have needed to retire the region, grab a + // new one, and go through all this again. Allocating out of the + // new region before assigning it to _cur_alloc_region avoids + // all this. + HeapWord* result = + new_cur_alloc_region->allocate_no_bot_updates(word_size); assert(result != NULL, "we just allocate out of an empty region " "so allocation should have been successful"); assert(is_in(result), "result should be in the heap"); + // Now make sure that the store to _cur_alloc_region does not + // float above the store to top. + OrderAccess::storestore(); _cur_alloc_region = new_cur_alloc_region; if (!at_safepoint) { @@ -718,6 +753,9 @@ for (int try_count = 1; /* we'll return or break */; try_count += 1) { bool succeeded = true; + // Every time we go round the loop we should be holding the Heap_lock. + assert_heap_locked(); + { // We may have concurrent cleanup working at the time. Wait for // it to complete. In the future we would probably want to make @@ -734,7 +772,8 @@ // attempt as it's redundant (we only reach here after an // allocation attempt has been unsuccessful). wait_for_cleanup_complete(); - HeapWord* result = attempt_allocation(word_size); + + HeapWord* result = attempt_allocation_locked(word_size); if (result != NULL) { assert_heap_not_locked(); return result; @@ -748,7 +787,6 @@ if (g1_policy()->can_expand_young_list()) { // Yes, we are allowed to expand the young gen. Let's try to // allocate a new current alloc region. - HeapWord* result = replace_cur_alloc_region_and_allocate(word_size, false, /* at_safepoint */ @@ -771,20 +809,23 @@ // rather than causing more, now probably unnecessary, GC attempts. JavaThread* jthr = JavaThread::current(); assert(jthr != NULL, "sanity"); - if (!jthr->in_critical()) { - MutexUnlocker mul(Heap_lock); - GC_locker::stall_until_clear(); - - // We'll then fall off the end of the ("if GC locker active") - // if-statement and retry the allocation further down in the - // loop. - } else { + if (jthr->in_critical()) { if (CheckJNICalls) { fatal("Possible deadlock due to allocating while" " in jni critical section"); } + // We are returning NULL so the protocol is that we're still + // holding the Heap_lock. + assert_heap_locked(); return NULL; } + + Heap_lock->unlock(); + GC_locker::stall_until_clear(); + + // No need to relock the Heap_lock. We'll fall off to the code + // below the else-statement which assumes that we are not + // holding the Heap_lock. } else { // We are not locked out. So, let's try to do a GC. The VM op // will retry the allocation before it completes. @@ -805,11 +846,10 @@ dirty_young_block(result, word_size); return result; } - - Heap_lock->lock(); } - assert_heap_locked(); + // Both paths that get us here from above unlock the Heap_lock. + assert_heap_not_locked(); // We can reach here when we were unsuccessful in doing a GC, // because another thread beat us to it, or because we were locked @@ -948,10 +988,8 @@ if (!expect_null_cur_alloc_region) { HeapRegion* cur_alloc_region = _cur_alloc_region; if (cur_alloc_region != NULL) { - // This allocate method does BOT updates and we don't need them in - // the young generation. This will be fixed in the near future by - // CR 6994297. - HeapWord* result = cur_alloc_region->allocate(word_size); + // We are at a safepoint so no reason to use the MT-safe version. + HeapWord* result = cur_alloc_region->allocate_no_bot_updates(word_size); if (result != NULL) { assert(is_in(result), "result should be in the heap"); @@ -983,20 +1021,17 @@ assert_heap_not_locked_and_not_at_safepoint(); assert(!isHumongous(word_size), "we do not allow TLABs of humongous size"); - Heap_lock->lock(); - - // First attempt: try allocating out of the current alloc region or - // after replacing the current alloc region. + // First attempt: Try allocating out of the current alloc region + // using a CAS. If that fails, take the Heap_lock and retry the + // allocation, potentially replacing the current alloc region. HeapWord* result = attempt_allocation(word_size); if (result != NULL) { assert_heap_not_locked(); return result; } - assert_heap_locked(); - - // Second attempt: go into the even slower path where we might - // try to schedule a collection. + // Second attempt: Go to the slower path where we might try to + // schedule a collection. result = attempt_allocation_slow(word_size); if (result != NULL) { assert_heap_not_locked(); @@ -1004,6 +1039,7 @@ } assert_heap_locked(); + // Need to unlock the Heap_lock before returning. Heap_lock->unlock(); return NULL; } @@ -1022,11 +1058,10 @@ for (int try_count = 1; /* we'll return */; try_count += 1) { unsigned int gc_count_before; { - Heap_lock->lock(); - if (!isHumongous(word_size)) { - // First attempt: try allocating out of the current alloc - // region or after replacing the current alloc region. + // First attempt: Try allocating out of the current alloc region + // using a CAS. If that fails, take the Heap_lock and retry the + // allocation, potentially replacing the current alloc region. HeapWord* result = attempt_allocation(word_size); if (result != NULL) { assert_heap_not_locked(); @@ -1035,14 +1070,17 @@ assert_heap_locked(); - // Second attempt: go into the even slower path where we might - // try to schedule a collection. + // Second attempt: Go to the slower path where we might try to + // schedule a collection. result = attempt_allocation_slow(word_size); if (result != NULL) { assert_heap_not_locked(); return result; } } else { + // attempt_allocation_humongous() requires the Heap_lock to be held. + Heap_lock->lock(); + HeapWord* result = attempt_allocation_humongous(word_size, false /* at_safepoint */); if (result != NULL) { @@ -1054,7 +1092,8 @@ assert_heap_locked(); // Read the gc count while the heap lock is held. gc_count_before = SharedHeap::heap()->total_collections(); - // We cannot be at a safepoint, so it is safe to unlock the Heap_lock + + // Release the Heap_lock before attempting the collection. Heap_lock->unlock(); } @@ -1868,7 +1907,7 @@ ReservedSpace heap_rs(max_byte_size + pgs->max_size(), HeapRegion::GrainBytes, - false /*ism*/, addr); + UseLargePages, addr); if (UseCompressedOops) { if (addr != NULL && !heap_rs.is_reserved()) { @@ -1877,13 +1916,13 @@ // Try again to reserver heap higher. addr = Universe::preferred_heap_base(total_reserved, Universe::ZeroBasedNarrowOop); ReservedSpace heap_rs0(total_reserved, HeapRegion::GrainBytes, - false /*ism*/, addr); + UseLargePages, addr); if (addr != NULL && !heap_rs0.is_reserved()) { // Failed to reserve at specified address again - give up. addr = Universe::preferred_heap_base(total_reserved, Universe::HeapBasedNarrowOop); assert(addr == NULL, ""); ReservedSpace heap_rs1(total_reserved, HeapRegion::GrainBytes, - false /*ism*/, addr); + UseLargePages, addr); heap_rs = heap_rs1; } else { heap_rs = heap_rs0; @@ -3856,13 +3895,15 @@ size_t _next_marked_bytes; OopsInHeapRegionClosure *_cl; public: - RemoveSelfPointerClosure(G1CollectedHeap* g1, OopsInHeapRegionClosure* cl) : - _g1(g1), _cm(_g1->concurrent_mark()), _prev_marked_bytes(0), + RemoveSelfPointerClosure(G1CollectedHeap* g1, HeapRegion* hr, + OopsInHeapRegionClosure* cl) : + _g1(g1), _hr(hr), _cm(_g1->concurrent_mark()), _prev_marked_bytes(0), _next_marked_bytes(0), _cl(cl) {} size_t prev_marked_bytes() { return _prev_marked_bytes; } size_t next_marked_bytes() { return _next_marked_bytes; } + // <original comment> // The original idea here was to coalesce evacuated and dead objects. // However that caused complications with the block offset table (BOT). // In particular if there were two TLABs, one of them partially refined. @@ -3871,15 +3912,24 @@ // of TLAB_2. If the last object of the TLAB_1 and the first object // of TLAB_2 are coalesced, then the cards of the unrefined part // would point into middle of the filler object. + // The current approach is to not coalesce and leave the BOT contents intact. + // </original comment> // - // The current approach is to not coalesce and leave the BOT contents intact. + // We now reset the BOT when we start the object iteration over the + // region and refine its entries for every object we come across. So + // the above comment is not really relevant and we should be able + // to coalesce dead objects if we want to. void do_object(oop obj) { + HeapWord* obj_addr = (HeapWord*) obj; + assert(_hr->is_in(obj_addr), "sanity"); + size_t obj_size = obj->size(); + _hr->update_bot_for_object(obj_addr, obj_size); if (obj->is_forwarded() && obj->forwardee() == obj) { // The object failed to move. assert(!_g1->is_obj_dead(obj), "We should not be preserving dead objs."); _cm->markPrev(obj); assert(_cm->isPrevMarked(obj), "Should be marked!"); - _prev_marked_bytes += (obj->size() * HeapWordSize); + _prev_marked_bytes += (obj_size * HeapWordSize); if (_g1->mark_in_progress() && !_g1->is_obj_ill(obj)) { _cm->markAndGrayObjectIfNecessary(obj); } @@ -3901,7 +3951,7 @@ } else { // The object has been either evacuated or is dead. Fill it with a // dummy object. - MemRegion mr((HeapWord*)obj, obj->size()); + MemRegion mr((HeapWord*)obj, obj_size); CollectedHeap::fill_with_object(mr); _cm->clearRangeBothMaps(mr); } @@ -3921,10 +3971,13 @@ HeapRegion* cur = g1_policy()->collection_set(); while (cur != NULL) { assert(g1_policy()->assertMarkedBytesDataOK(), "Should be!"); - - RemoveSelfPointerClosure rspc(_g1h, cl); + assert(!cur->isHumongous(), "sanity"); + if (cur->evacuation_failed()) { assert(cur->in_collection_set(), "bad CS"); + RemoveSelfPointerClosure rspc(_g1h, cur, cl); + + cur->reset_bot(); cl->set_region(cur); cur->object_iterate(&rspc); @@ -3989,15 +4042,6 @@ } } -void G1CollectedHeap::handle_evacuation_failure(oop old) { - markOop m = old->mark(); - // forward to self - assert(!old->is_forwarded(), "precondition"); - - old->forward_to(old); - handle_evacuation_failure_common(old, m); -} - oop G1CollectedHeap::handle_evacuation_failure_par(OopsInHeapRegionClosure* cl, oop old) {
--- a/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp Thu Jan 13 08:32:15 2011 -0800 +++ b/src/share/vm/gc_implementation/g1/g1CollectedHeap.hpp Thu Jan 13 17:19:21 2011 -0800 @@ -1,5 +1,5 @@ /* - * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2001, 2011, 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 @@ -430,7 +430,8 @@ bool* gc_overhead_limit_was_exceeded); // The following methods, allocate_from_cur_allocation_region(), - // attempt_allocation(), replace_cur_alloc_region_and_allocate(), + // attempt_allocation(), attempt_allocation_locked(), + // replace_cur_alloc_region_and_allocate(), // attempt_allocation_slow(), and attempt_allocation_humongous() // have very awkward pre- and post-conditions with respect to // locking: @@ -481,20 +482,30 @@ // successfully manage to allocate it, or NULL. // It tries to satisfy an allocation request out of the current - // allocating region, which is passed as a parameter. It assumes - // that the caller has checked that the current allocating region is - // not NULL. Given that the caller has to check the current - // allocating region for at least NULL, it might as well pass it as - // the first parameter so that the method doesn't have to read it - // from the _cur_alloc_region field again. + // alloc region, which is passed as a parameter. It assumes that the + // caller has checked that the current alloc region is not NULL. + // Given that the caller has to check the current alloc region for + // at least NULL, it might as well pass it as the first parameter so + // that the method doesn't have to read it from the + // _cur_alloc_region field again. It is called from both + // attempt_allocation() and attempt_allocation_locked() and the + // with_heap_lock parameter indicates whether the caller was holding + // the heap lock when it called it or not. inline HeapWord* allocate_from_cur_alloc_region(HeapRegion* cur_alloc_region, - size_t word_size); + size_t word_size, + bool with_heap_lock); - // It attempts to allocate out of the current alloc region. If that - // fails, it retires the current alloc region (if there is one), - // tries to get a new one and retries the allocation. + // First-level of allocation slow path: it attempts to allocate out + // of the current alloc region in a lock-free manner using a CAS. If + // that fails it takes the Heap_lock and calls + // attempt_allocation_locked() for the second-level slow path. inline HeapWord* attempt_allocation(size_t word_size); + // Second-level of allocation slow path: while holding the Heap_lock + // it tries to allocate out of the current alloc region and, if that + // fails, tries to allocate out of a new current alloc region. + inline HeapWord* attempt_allocation_locked(size_t word_size); + // It assumes that the current alloc region has been retired and // tries to allocate a new one. If it's successful, it performs the // allocation out of the new current alloc region and updates @@ -506,11 +517,11 @@ bool do_dirtying, bool can_expand); - // The slow path when we are unable to allocate a new current alloc - // region to satisfy an allocation request (i.e., when - // attempt_allocation() fails). It will try to do an evacuation - // pause, which might stall due to the GC locker, and retry the - // allocation attempt when appropriate. + // Third-level of allocation slow path: when we are unable to + // allocate a new current alloc region to satisfy an allocation + // request (i.e., when attempt_allocation_locked() fails). It will + // try to do an evacuation pause, which might stall due to the GC + // locker, and retry the allocation attempt when appropriate. HeapWord* attempt_allocation_slow(size_t word_size); // The method that tries to satisfy a humongous allocation @@ -826,7 +837,6 @@ void finalize_for_evac_failure(); // An attempt to evacuate "obj" has failed; take necessary steps. - void handle_evacuation_failure(oop obj); oop handle_evacuation_failure_par(OopsInHeapRegionClosure* cl, oop obj); void handle_evacuation_failure_common(oop obj, markOop m);
--- a/src/share/vm/gc_implementation/g1/g1CollectedHeap.inline.hpp Thu Jan 13 08:32:15 2011 -0800 +++ b/src/share/vm/gc_implementation/g1/g1CollectedHeap.inline.hpp Thu Jan 13 17:19:21 2011 -0800 @@ -1,5 +1,5 @@ /* - * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2001, 2011, 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 @@ -63,10 +63,12 @@ // assumptions of this method (and other related ones). inline HeapWord* G1CollectedHeap::allocate_from_cur_alloc_region(HeapRegion* cur_alloc_region, - size_t word_size) { - assert_heap_locked_and_not_at_safepoint(); + size_t word_size, + bool with_heap_lock) { + assert_not_at_safepoint(); + assert(with_heap_lock == Heap_lock->owned_by_self(), + "with_heap_lock and Heap_lock->owned_by_self() should be a tautology"); assert(cur_alloc_region != NULL, "pre-condition of the method"); - assert(cur_alloc_region == _cur_alloc_region, "pre-condition of the method"); assert(cur_alloc_region->is_young(), "we only support young current alloc regions"); assert(!isHumongous(word_size), "allocate_from_cur_alloc_region() " @@ -76,20 +78,24 @@ assert(!cur_alloc_region->is_empty(), err_msg("region ["PTR_FORMAT","PTR_FORMAT"] should not be empty", cur_alloc_region->bottom(), cur_alloc_region->end())); - // This allocate method does BOT updates and we don't need them in - // the young generation. This will be fixed in the near future by - // CR 6994297. - HeapWord* result = cur_alloc_region->allocate(word_size); + HeapWord* result = cur_alloc_region->par_allocate_no_bot_updates(word_size); if (result != NULL) { assert(is_in(result), "result should be in the heap"); - Heap_lock->unlock(); + if (with_heap_lock) { + Heap_lock->unlock(); + } + assert_heap_not_locked(); // Do the dirtying after we release the Heap_lock. dirty_young_block(result, word_size); return result; } - assert_heap_locked(); + if (with_heap_lock) { + assert_heap_locked(); + } else { + assert_heap_not_locked(); + } return NULL; } @@ -97,31 +103,27 @@ // assumptions of this method (and other related ones). inline HeapWord* G1CollectedHeap::attempt_allocation(size_t word_size) { - assert_heap_locked_and_not_at_safepoint(); + assert_heap_not_locked_and_not_at_safepoint(); assert(!isHumongous(word_size), "attempt_allocation() should not be called " "for humongous allocation requests"); HeapRegion* cur_alloc_region = _cur_alloc_region; if (cur_alloc_region != NULL) { HeapWord* result = allocate_from_cur_alloc_region(cur_alloc_region, - word_size); + word_size, + false /* with_heap_lock */); + assert_heap_not_locked(); if (result != NULL) { - assert_heap_not_locked(); return result; } - - assert_heap_locked(); - - // Since we couldn't successfully allocate into it, retire the - // current alloc region. - retire_cur_alloc_region(cur_alloc_region); } - // Try to get a new region and allocate out of it - HeapWord* result = replace_cur_alloc_region_and_allocate(word_size, - false, /* at_safepoint */ - true, /* do_dirtying */ - false /* can_expand */); + // Our attempt to allocate lock-free failed as the current + // allocation region is either NULL or full. So, we'll now take the + // Heap_lock and retry. + Heap_lock->lock(); + + HeapWord* result = attempt_allocation_locked(word_size); if (result != NULL) { assert_heap_not_locked(); return result; @@ -145,6 +147,45 @@ _cur_alloc_region = NULL; } +inline HeapWord* +G1CollectedHeap::attempt_allocation_locked(size_t word_size) { + assert_heap_locked_and_not_at_safepoint(); + assert(!isHumongous(word_size), "attempt_allocation_locked() " + "should not be called for humongous allocation requests"); + + // First, reread the current alloc region and retry the allocation + // in case somebody replaced it while we were waiting to get the + // Heap_lock. + HeapRegion* cur_alloc_region = _cur_alloc_region; + if (cur_alloc_region != NULL) { + HeapWord* result = allocate_from_cur_alloc_region( + cur_alloc_region, word_size, + true /* with_heap_lock */); + if (result != NULL) { + assert_heap_not_locked(); + return result; + } + + // We failed to allocate out of the current alloc region, so let's + // retire it before getting a new one. + retire_cur_alloc_region(cur_alloc_region); + } + + assert_heap_locked(); + // Try to get a new region and allocate out of it + HeapWord* result = replace_cur_alloc_region_and_allocate(word_size, + false, /* at_safepoint */ + true, /* do_dirtying */ + false /* can_expand */); + if (result != NULL) { + assert_heap_not_locked(); + return result; + } + + assert_heap_locked(); + return NULL; +} + // It dirties the cards that cover the block so that so that the post // write barrier never queues anything when updating objects on this // block. It is assumed (and in fact we assert) that the block
--- a/src/share/vm/gc_implementation/g1/heapRegion.cpp Thu Jan 13 08:32:15 2011 -0800 +++ b/src/share/vm/gc_implementation/g1/heapRegion.cpp Thu Jan 13 17:19:21 2011 -0800 @@ -1,5 +1,5 @@ /* - * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2001, 2011, 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 @@ -386,26 +386,27 @@ } // </PREDICTION> -void HeapRegion::set_startsHumongous(HeapWord* new_end) { +void HeapRegion::set_startsHumongous(HeapWord* new_top, HeapWord* new_end) { assert(end() == _orig_end, "Should be normal before the humongous object allocation"); assert(top() == bottom(), "should be empty"); + assert(bottom() <= new_top && new_top <= new_end, "pre-condition"); _humongous_type = StartsHumongous; _humongous_start_region = this; set_end(new_end); - _offsets.set_for_starts_humongous(new_end); + _offsets.set_for_starts_humongous(new_top); } -void HeapRegion::set_continuesHumongous(HeapRegion* start) { +void HeapRegion::set_continuesHumongous(HeapRegion* first_hr) { assert(end() == _orig_end, "Should be normal before the humongous object allocation"); assert(top() == bottom(), "should be empty"); - assert(start->startsHumongous(), "pre-condition"); + assert(first_hr->startsHumongous(), "pre-condition"); _humongous_type = ContinuesHumongous; - _humongous_start_region = start; + _humongous_start_region = first_hr; } bool HeapRegion::claimHeapRegion(jint claimValue) { @@ -782,9 +783,6 @@ verify(allow_dirty, /* use_prev_marking */ true, /* failures */ &dummy); } -#define OBJ_SAMPLE_INTERVAL 0 -#define BLOCK_SAMPLE_INTERVAL 100 - // This really ought to be commoned up into OffsetTableContigSpace somehow. // We would need a mechanism to make that code skip dead objects. @@ -795,83 +793,125 @@ *failures = false; HeapWord* p = bottom(); HeapWord* prev_p = NULL; - int objs = 0; - int blocks = 0; VerifyLiveClosure vl_cl(g1, use_prev_marking); bool is_humongous = isHumongous(); + bool do_bot_verify = !is_young(); size_t object_num = 0; while (p < top()) { - size_t size = oop(p)->size(); - if (is_humongous != g1->isHumongous(size)) { + oop obj = oop(p); + size_t obj_size = obj->size(); + object_num += 1; + + if (is_humongous != g1->isHumongous(obj_size)) { gclog_or_tty->print_cr("obj "PTR_FORMAT" is of %shumongous size (" SIZE_FORMAT" words) in a %shumongous region", - p, g1->isHumongous(size) ? "" : "non-", - size, is_humongous ? "" : "non-"); + p, g1->isHumongous(obj_size) ? "" : "non-", + obj_size, is_humongous ? "" : "non-"); *failures = true; + return; + } + + // If it returns false, verify_for_object() will output the + // appropriate messasge. + if (do_bot_verify && !_offsets.verify_for_object(p, obj_size)) { + *failures = true; + return; } - object_num += 1; - if (blocks == BLOCK_SAMPLE_INTERVAL) { - HeapWord* res = block_start_const(p + (size/2)); - if (p != res) { - gclog_or_tty->print_cr("offset computation 1 for "PTR_FORMAT" and " - SIZE_FORMAT" returned "PTR_FORMAT, - p, size, res); + + if (!g1->is_obj_dead_cond(obj, this, use_prev_marking)) { + if (obj->is_oop()) { + klassOop klass = obj->klass(); + if (!klass->is_perm()) { + gclog_or_tty->print_cr("klass "PTR_FORMAT" of object "PTR_FORMAT" " + "not in perm", klass, obj); + *failures = true; + return; + } else if (!klass->is_klass()) { + gclog_or_tty->print_cr("klass "PTR_FORMAT" of object "PTR_FORMAT" " + "not a klass", klass, obj); + *failures = true; + return; + } else { + vl_cl.set_containing_obj(obj); + obj->oop_iterate(&vl_cl); + if (vl_cl.failures()) { + *failures = true; + } + if (G1MaxVerifyFailures >= 0 && + vl_cl.n_failures() >= G1MaxVerifyFailures) { + return; + } + } + } else { + gclog_or_tty->print_cr(PTR_FORMAT" no an oop", obj); *failures = true; return; } - blocks = 0; - } else { - blocks++; - } - if (objs == OBJ_SAMPLE_INTERVAL) { - oop obj = oop(p); - if (!g1->is_obj_dead_cond(obj, this, use_prev_marking)) { - if (obj->is_oop()) { - klassOop klass = obj->klass(); - if (!klass->is_perm()) { - gclog_or_tty->print_cr("klass "PTR_FORMAT" of object "PTR_FORMAT" " - "not in perm", klass, obj); - *failures = true; - return; - } else if (!klass->is_klass()) { - gclog_or_tty->print_cr("klass "PTR_FORMAT" of object "PTR_FORMAT" " - "not a klass", klass, obj); - *failures = true; - return; - } else { - vl_cl.set_containing_obj(obj); - obj->oop_iterate(&vl_cl); - if (vl_cl.failures()) { - *failures = true; - } - if (G1MaxVerifyFailures >= 0 && - vl_cl.n_failures() >= G1MaxVerifyFailures) { - return; - } - } - } else { - gclog_or_tty->print_cr(PTR_FORMAT" no an oop", obj); - *failures = true; - return; - } - } - objs = 0; - } else { - objs++; } prev_p = p; - p += size; + p += obj_size; + } + + if (p != top()) { + gclog_or_tty->print_cr("end of last object "PTR_FORMAT" " + "does not match top "PTR_FORMAT, p, top()); + *failures = true; + return; } - HeapWord* rend = end(); - HeapWord* rtop = top(); - if (rtop < rend) { - HeapWord* res = block_start_const(rtop + (rend - rtop) / 2); - if (res != rtop) { - gclog_or_tty->print_cr("offset computation 2 for "PTR_FORMAT" and " - PTR_FORMAT" returned "PTR_FORMAT, - rtop, rend, res); + + HeapWord* the_end = end(); + assert(p == top(), "it should still hold"); + // Do some extra BOT consistency checking for addresses in the + // range [top, end). BOT look-ups in this range should yield + // top. No point in doing that if top == end (there's nothing there). + if (p < the_end) { + // Look up top + HeapWord* addr_1 = p; + HeapWord* b_start_1 = _offsets.block_start_const(addr_1); + if (b_start_1 != p) { + gclog_or_tty->print_cr("BOT look up for top: "PTR_FORMAT" " + " yielded "PTR_FORMAT", expecting "PTR_FORMAT, + addr_1, b_start_1, p); + *failures = true; + return; + } + + // Look up top + 1 + HeapWord* addr_2 = p + 1; + if (addr_2 < the_end) { + HeapWord* b_start_2 = _offsets.block_start_const(addr_2); + if (b_start_2 != p) { + gclog_or_tty->print_cr("BOT look up for top + 1: "PTR_FORMAT" " + " yielded "PTR_FORMAT", expecting "PTR_FORMAT, + addr_2, b_start_2, p); *failures = true; return; + } + } + + // Look up an address between top and end + size_t diff = pointer_delta(the_end, p) / 2; + HeapWord* addr_3 = p + diff; + if (addr_3 < the_end) { + HeapWord* b_start_3 = _offsets.block_start_const(addr_3); + if (b_start_3 != p) { + gclog_or_tty->print_cr("BOT look up for top + diff: "PTR_FORMAT" " + " yielded "PTR_FORMAT", expecting "PTR_FORMAT, + addr_3, b_start_3, p); + *failures = true; + return; + } + } + + // Loook up end - 1 + HeapWord* addr_4 = the_end - 1; + HeapWord* b_start_4 = _offsets.block_start_const(addr_4); + if (b_start_4 != p) { + gclog_or_tty->print_cr("BOT look up for end - 1: "PTR_FORMAT" " + " yielded "PTR_FORMAT", expecting "PTR_FORMAT, + addr_4, b_start_4, p); + *failures = true; + return; } } @@ -880,12 +920,6 @@ "but has "SIZE_FORMAT", objects", bottom(), end(), object_num); *failures = true; - } - - if (p != top()) { - gclog_or_tty->print_cr("end of last object "PTR_FORMAT" " - "does not match top "PTR_FORMAT, p, top()); - *failures = true; return; } }
--- a/src/share/vm/gc_implementation/g1/heapRegion.hpp Thu Jan 13 08:32:15 2011 -0800 +++ b/src/share/vm/gc_implementation/g1/heapRegion.hpp Thu Jan 13 17:19:21 2011 -0800 @@ -1,5 +1,5 @@ /* - * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2001, 2011, 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 @@ -173,6 +173,19 @@ virtual HeapWord* cross_threshold(HeapWord* start, HeapWord* end); virtual void print() const; + + void reset_bot() { + _offsets.zero_bottom_entry(); + _offsets.initialize_threshold(); + } + + void update_bot_for_object(HeapWord* start, size_t word_size) { + _offsets.alloc_block(start, word_size); + } + + void print_bot_on(outputStream* out) { + _offsets.print_on(out); + } }; class HeapRegion: public G1OffsetTableContigSpace { @@ -359,6 +372,15 @@ Allocated }; + inline HeapWord* par_allocate_no_bot_updates(size_t word_size) { + assert(is_young(), "we can only skip BOT updates on young regions"); + return ContiguousSpace::par_allocate(word_size); + } + inline HeapWord* allocate_no_bot_updates(size_t word_size) { + assert(is_young(), "we can only skip BOT updates on young regions"); + return ContiguousSpace::allocate(word_size); + } + // If this region is a member of a HeapRegionSeq, the index in that // sequence, otherwise -1. int hrs_index() const { return _hrs_index; } @@ -404,13 +426,35 @@ return _humongous_start_region; } - // Causes the current region to represent a humongous object spanning "n" - // regions. - void set_startsHumongous(HeapWord* new_end); + // Makes the current region be a "starts humongous" region, i.e., + // the first region in a series of one or more contiguous regions + // that will contain a single "humongous" object. The two parameters + // are as follows: + // + // new_top : The new value of the top field of this region which + // points to the end of the humongous object that's being + // allocated. If there is more than one region in the series, top + // will lie beyond this region's original end field and on the last + // region in the series. + // + // new_end : The new value of the end field of this region which + // points to the end of the last region in the series. If there is + // one region in the series (namely: this one) end will be the same + // as the original end of this region. + // + // Updating top and end as described above makes this region look as + // if it spans the entire space taken up by all the regions in the + // series and an single allocation moved its top to new_top. This + // ensures that the space (capacity / allocated) taken up by all + // humongous regions can be calculated by just looking at the + // "starts humongous" regions and by ignoring the "continues + // humongous" regions. + void set_startsHumongous(HeapWord* new_top, HeapWord* new_end); - // The regions that continue a humongous sequence should be added using - // this method, in increasing address order. - void set_continuesHumongous(HeapRegion* start); + // Makes the current region be a "continues humongous' + // region. first_hr is the "start humongous" region of the series + // which this region will be part of. + void set_continuesHumongous(HeapRegion* first_hr); // If the region has a remembered set, return a pointer to it. HeapRegionRemSet* rem_set() const {
--- a/src/share/vm/gc_implementation/g1/heapRegionSeq.cpp Thu Jan 13 08:32:15 2011 -0800 +++ b/src/share/vm/gc_implementation/g1/heapRegionSeq.cpp Thu Jan 13 17:19:21 2011 -0800 @@ -1,5 +1,5 @@ /* - * Copyright (c) 2001, 2010, Oracle and/or its affiliates. All rights reserved. + * Copyright (c) 2001, 2011, 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 @@ -144,7 +144,7 @@ // will also update the BOT covering all the regions to reflect // that there is a single object that starts at the bottom of the // first region. - first_hr->set_startsHumongous(new_end); + first_hr->set_startsHumongous(new_top, new_end); // Then, if there are any, we will set up the "continues // humongous" regions.