| /* |
| * Copyright (c) 1997, 2014, 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 "classfile/systemDictionary.hpp" |
| #include "classfile/vmSymbols.hpp" |
| #include "gc_implementation/shared/liveRange.hpp" |
| #include "gc_implementation/shared/markSweep.hpp" |
| #include "gc_implementation/shared/spaceDecorator.hpp" |
| #include "gc_interface/collectedHeap.inline.hpp" |
| #include "memory/blockOffsetTable.inline.hpp" |
| #include "memory/defNewGeneration.hpp" |
| #include "memory/genCollectedHeap.hpp" |
| #include "memory/space.hpp" |
| #include "memory/space.inline.hpp" |
| #include "memory/universe.inline.hpp" |
| #include "oops/oop.inline.hpp" |
| #include "oops/oop.inline2.hpp" |
| #include "runtime/java.hpp" |
| #include "runtime/prefetch.inline.hpp" |
| #include "runtime/orderAccess.inline.hpp" |
| #include "runtime/safepoint.hpp" |
| #include "utilities/copy.hpp" |
| #include "utilities/globalDefinitions.hpp" |
| #include "utilities/macros.hpp" |
| |
| PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC |
| |
| HeapWord* DirtyCardToOopClosure::get_actual_top(HeapWord* top, |
| HeapWord* top_obj) { |
| if (top_obj != NULL) { |
| if (_sp->block_is_obj(top_obj)) { |
| if (_precision == CardTableModRefBS::ObjHeadPreciseArray) { |
| if (oop(top_obj)->is_objArray() || oop(top_obj)->is_typeArray()) { |
| // An arrayOop is starting on the dirty card - since we do exact |
| // store checks for objArrays we are done. |
| } else { |
| // Otherwise, it is possible that the object starting on the dirty |
| // card spans the entire card, and that the store happened on a |
| // later card. Figure out where the object ends. |
| // Use the block_size() method of the space over which |
| // the iteration is being done. That space (e.g. CMS) may have |
| // specific requirements on object sizes which will |
| // be reflected in the block_size() method. |
| top = top_obj + oop(top_obj)->size(); |
| } |
| } |
| } else { |
| top = top_obj; |
| } |
| } else { |
| assert(top == _sp->end(), "only case where top_obj == NULL"); |
| } |
| return top; |
| } |
| |
| void DirtyCardToOopClosure::walk_mem_region(MemRegion mr, |
| HeapWord* bottom, |
| HeapWord* top) { |
| // 1. Blocks may or may not be objects. |
| // 2. Even when a block_is_obj(), it may not entirely |
| // occupy the block if the block quantum is larger than |
| // the object size. |
| // We can and should try to optimize by calling the non-MemRegion |
| // version of oop_iterate() for all but the extremal objects |
| // (for which we need to call the MemRegion version of |
| // oop_iterate()) To be done post-beta XXX |
| for (; bottom < top; bottom += _sp->block_size(bottom)) { |
| // As in the case of contiguous space above, we'd like to |
| // just use the value returned by oop_iterate to increment the |
| // current pointer; unfortunately, that won't work in CMS because |
| // we'd need an interface change (it seems) to have the space |
| // "adjust the object size" (for instance pad it up to its |
| // block alignment or minimum block size restrictions. XXX |
| if (_sp->block_is_obj(bottom) && |
| !_sp->obj_allocated_since_save_marks(oop(bottom))) { |
| oop(bottom)->oop_iterate(_cl, mr); |
| } |
| } |
| } |
| |
| // We get called with "mr" representing the dirty region |
| // that we want to process. Because of imprecise marking, |
| // we may need to extend the incoming "mr" to the right, |
| // and scan more. However, because we may already have |
| // scanned some of that extended region, we may need to |
| // trim its right-end back some so we do not scan what |
| // we (or another worker thread) may already have scanned |
| // or planning to scan. |
| void DirtyCardToOopClosure::do_MemRegion(MemRegion mr) { |
| |
| // Some collectors need to do special things whenever their dirty |
| // cards are processed. For instance, CMS must remember mutator updates |
| // (i.e. dirty cards) so as to re-scan mutated objects. |
| // Such work can be piggy-backed here on dirty card scanning, so as to make |
| // it slightly more efficient than doing a complete non-detructive pre-scan |
| // of the card table. |
| MemRegionClosure* pCl = _sp->preconsumptionDirtyCardClosure(); |
| if (pCl != NULL) { |
| pCl->do_MemRegion(mr); |
| } |
| |
| HeapWord* bottom = mr.start(); |
| HeapWord* last = mr.last(); |
| HeapWord* top = mr.end(); |
| HeapWord* bottom_obj; |
| HeapWord* top_obj; |
| |
| assert(_precision == CardTableModRefBS::ObjHeadPreciseArray || |
| _precision == CardTableModRefBS::Precise, |
| "Only ones we deal with for now."); |
| |
| assert(_precision != CardTableModRefBS::ObjHeadPreciseArray || |
| _cl->idempotent() || _last_bottom == NULL || |
| top <= _last_bottom, |
| "Not decreasing"); |
| NOT_PRODUCT(_last_bottom = mr.start()); |
| |
| bottom_obj = _sp->block_start(bottom); |
| top_obj = _sp->block_start(last); |
| |
| assert(bottom_obj <= bottom, "just checking"); |
| assert(top_obj <= top, "just checking"); |
| |
| // Given what we think is the top of the memory region and |
| // the start of the object at the top, get the actual |
| // value of the top. |
| top = get_actual_top(top, top_obj); |
| |
| // If the previous call did some part of this region, don't redo. |
| if (_precision == CardTableModRefBS::ObjHeadPreciseArray && |
| _min_done != NULL && |
| _min_done < top) { |
| top = _min_done; |
| } |
| |
| // Top may have been reset, and in fact may be below bottom, |
| // e.g. the dirty card region is entirely in a now free object |
| // -- something that could happen with a concurrent sweeper. |
| bottom = MIN2(bottom, top); |
| MemRegion extended_mr = MemRegion(bottom, top); |
| assert(bottom <= top && |
| (_precision != CardTableModRefBS::ObjHeadPreciseArray || |
| _min_done == NULL || |
| top <= _min_done), |
| "overlap!"); |
| |
| // Walk the region if it is not empty; otherwise there is nothing to do. |
| if (!extended_mr.is_empty()) { |
| walk_mem_region(extended_mr, bottom_obj, top); |
| } |
| |
| // An idempotent closure might be applied in any order, so we don't |
| // record a _min_done for it. |
| if (!_cl->idempotent()) { |
| _min_done = bottom; |
| } else { |
| assert(_min_done == _last_explicit_min_done, |
| "Don't update _min_done for idempotent cl"); |
| } |
| } |
| |
| DirtyCardToOopClosure* Space::new_dcto_cl(ExtendedOopClosure* cl, |
| CardTableModRefBS::PrecisionStyle precision, |
| HeapWord* boundary) { |
| return new DirtyCardToOopClosure(this, cl, precision, boundary); |
| } |
| |
| HeapWord* ContiguousSpaceDCTOC::get_actual_top(HeapWord* top, |
| HeapWord* top_obj) { |
| if (top_obj != NULL && top_obj < (_sp->toContiguousSpace())->top()) { |
| if (_precision == CardTableModRefBS::ObjHeadPreciseArray) { |
| if (oop(top_obj)->is_objArray() || oop(top_obj)->is_typeArray()) { |
| // An arrayOop is starting on the dirty card - since we do exact |
| // store checks for objArrays we are done. |
| } else { |
| // Otherwise, it is possible that the object starting on the dirty |
| // card spans the entire card, and that the store happened on a |
| // later card. Figure out where the object ends. |
| assert(_sp->block_size(top_obj) == (size_t) oop(top_obj)->size(), |
| "Block size and object size mismatch"); |
| top = top_obj + oop(top_obj)->size(); |
| } |
| } |
| } else { |
| top = (_sp->toContiguousSpace())->top(); |
| } |
| return top; |
| } |
| |
| void Filtering_DCTOC::walk_mem_region(MemRegion mr, |
| HeapWord* bottom, |
| HeapWord* top) { |
| // Note that this assumption won't hold if we have a concurrent |
| // collector in this space, which may have freed up objects after |
| // they were dirtied and before the stop-the-world GC that is |
| // examining cards here. |
| assert(bottom < top, "ought to be at least one obj on a dirty card."); |
| |
| if (_boundary != NULL) { |
| // We have a boundary outside of which we don't want to look |
| // at objects, so create a filtering closure around the |
| // oop closure before walking the region. |
| FilteringClosure filter(_boundary, _cl); |
| walk_mem_region_with_cl(mr, bottom, top, &filter); |
| } else { |
| // No boundary, simply walk the heap with the oop closure. |
| walk_mem_region_with_cl(mr, bottom, top, _cl); |
| } |
| |
| } |
| |
| // We must replicate this so that the static type of "FilteringClosure" |
| // (see above) is apparent at the oop_iterate calls. |
| #define ContiguousSpaceDCTOC__walk_mem_region_with_cl_DEFN(ClosureType) \ |
| void ContiguousSpaceDCTOC::walk_mem_region_with_cl(MemRegion mr, \ |
| HeapWord* bottom, \ |
| HeapWord* top, \ |
| ClosureType* cl) { \ |
| bottom += oop(bottom)->oop_iterate(cl, mr); \ |
| if (bottom < top) { \ |
| HeapWord* next_obj = bottom + oop(bottom)->size(); \ |
| while (next_obj < top) { \ |
| /* Bottom lies entirely below top, so we can call the */ \ |
| /* non-memRegion version of oop_iterate below. */ \ |
| oop(bottom)->oop_iterate(cl); \ |
| bottom = next_obj; \ |
| next_obj = bottom + oop(bottom)->size(); \ |
| } \ |
| /* Last object. */ \ |
| oop(bottom)->oop_iterate(cl, mr); \ |
| } \ |
| } |
| |
| // (There are only two of these, rather than N, because the split is due |
| // only to the introduction of the FilteringClosure, a local part of the |
| // impl of this abstraction.) |
| ContiguousSpaceDCTOC__walk_mem_region_with_cl_DEFN(ExtendedOopClosure) |
| ContiguousSpaceDCTOC__walk_mem_region_with_cl_DEFN(FilteringClosure) |
| |
| DirtyCardToOopClosure* |
| ContiguousSpace::new_dcto_cl(ExtendedOopClosure* cl, |
| CardTableModRefBS::PrecisionStyle precision, |
| HeapWord* boundary) { |
| return new ContiguousSpaceDCTOC(this, cl, precision, boundary); |
| } |
| |
| void Space::initialize(MemRegion mr, |
| bool clear_space, |
| bool mangle_space) { |
| HeapWord* bottom = mr.start(); |
| HeapWord* end = mr.end(); |
| assert(Universe::on_page_boundary(bottom) && Universe::on_page_boundary(end), |
| "invalid space boundaries"); |
| set_bottom(bottom); |
| set_end(end); |
| if (clear_space) clear(mangle_space); |
| } |
| |
| void Space::clear(bool mangle_space) { |
| if (ZapUnusedHeapArea && mangle_space) { |
| mangle_unused_area(); |
| } |
| } |
| |
| ContiguousSpace::ContiguousSpace(): CompactibleSpace(), _top(NULL), |
| _concurrent_iteration_safe_limit(NULL) { |
| _mangler = new GenSpaceMangler(this); |
| } |
| |
| ContiguousSpace::~ContiguousSpace() { |
| delete _mangler; |
| } |
| |
| void ContiguousSpace::initialize(MemRegion mr, |
| bool clear_space, |
| bool mangle_space) |
| { |
| CompactibleSpace::initialize(mr, clear_space, mangle_space); |
| set_concurrent_iteration_safe_limit(top()); |
| } |
| |
| void ContiguousSpace::clear(bool mangle_space) { |
| set_top(bottom()); |
| set_saved_mark(); |
| CompactibleSpace::clear(mangle_space); |
| } |
| |
| bool ContiguousSpace::is_free_block(const HeapWord* p) const { |
| return p >= _top; |
| } |
| |
| void OffsetTableContigSpace::clear(bool mangle_space) { |
| ContiguousSpace::clear(mangle_space); |
| _offsets.initialize_threshold(); |
| } |
| |
| void OffsetTableContigSpace::set_bottom(HeapWord* new_bottom) { |
| Space::set_bottom(new_bottom); |
| _offsets.set_bottom(new_bottom); |
| } |
| |
| void OffsetTableContigSpace::set_end(HeapWord* new_end) { |
| // Space should not advertize an increase in size |
| // until after the underlying offest table has been enlarged. |
| _offsets.resize(pointer_delta(new_end, bottom())); |
| Space::set_end(new_end); |
| } |
| |
| #ifndef PRODUCT |
| |
| void ContiguousSpace::set_top_for_allocations(HeapWord* v) { |
| mangler()->set_top_for_allocations(v); |
| } |
| void ContiguousSpace::set_top_for_allocations() { |
| mangler()->set_top_for_allocations(top()); |
| } |
| void ContiguousSpace::check_mangled_unused_area(HeapWord* limit) { |
| mangler()->check_mangled_unused_area(limit); |
| } |
| |
| void ContiguousSpace::check_mangled_unused_area_complete() { |
| mangler()->check_mangled_unused_area_complete(); |
| } |
| |
| // Mangled only the unused space that has not previously |
| // been mangled and that has not been allocated since being |
| // mangled. |
| void ContiguousSpace::mangle_unused_area() { |
| mangler()->mangle_unused_area(); |
| } |
| void ContiguousSpace::mangle_unused_area_complete() { |
| mangler()->mangle_unused_area_complete(); |
| } |
| void ContiguousSpace::mangle_region(MemRegion mr) { |
| // Although this method uses SpaceMangler::mangle_region() which |
| // is not specific to a space, the when the ContiguousSpace version |
| // is called, it is always with regard to a space and this |
| // bounds checking is appropriate. |
| MemRegion space_mr(bottom(), end()); |
| assert(space_mr.contains(mr), "Mangling outside space"); |
| SpaceMangler::mangle_region(mr); |
| } |
| #endif // NOT_PRODUCT |
| |
| void CompactibleSpace::initialize(MemRegion mr, |
| bool clear_space, |
| bool mangle_space) { |
| Space::initialize(mr, clear_space, mangle_space); |
| set_compaction_top(bottom()); |
| _next_compaction_space = NULL; |
| } |
| |
| void CompactibleSpace::clear(bool mangle_space) { |
| Space::clear(mangle_space); |
| _compaction_top = bottom(); |
| } |
| |
| HeapWord* CompactibleSpace::forward(oop q, size_t size, |
| CompactPoint* cp, HeapWord* compact_top) { |
| // q is alive |
| // First check if we should switch compaction space |
| assert(this == cp->space, "'this' should be current compaction space."); |
| size_t compaction_max_size = pointer_delta(end(), compact_top); |
| while (size > compaction_max_size) { |
| // switch to next compaction space |
| cp->space->set_compaction_top(compact_top); |
| cp->space = cp->space->next_compaction_space(); |
| if (cp->space == NULL) { |
| cp->gen = GenCollectedHeap::heap()->prev_gen(cp->gen); |
| assert(cp->gen != NULL, "compaction must succeed"); |
| cp->space = cp->gen->first_compaction_space(); |
| assert(cp->space != NULL, "generation must have a first compaction space"); |
| } |
| compact_top = cp->space->bottom(); |
| cp->space->set_compaction_top(compact_top); |
| cp->threshold = cp->space->initialize_threshold(); |
| compaction_max_size = pointer_delta(cp->space->end(), compact_top); |
| } |
| |
| // store the forwarding pointer into the mark word |
| if ((HeapWord*)q != compact_top) { |
| q->forward_to(oop(compact_top)); |
| assert(q->is_gc_marked(), "encoding the pointer should preserve the mark"); |
| } else { |
| // if the object isn't moving we can just set the mark to the default |
| // mark and handle it specially later on. |
| q->init_mark(); |
| assert(q->forwardee() == NULL, "should be forwarded to NULL"); |
| } |
| |
| compact_top += size; |
| |
| // we need to update the offset table so that the beginnings of objects can be |
| // found during scavenge. Note that we are updating the offset table based on |
| // where the object will be once the compaction phase finishes. |
| if (compact_top > cp->threshold) |
| cp->threshold = |
| cp->space->cross_threshold(compact_top - size, compact_top); |
| return compact_top; |
| } |
| |
| |
| bool CompactibleSpace::insert_deadspace(size_t& allowed_deadspace_words, |
| HeapWord* q, size_t deadlength) { |
| if (allowed_deadspace_words >= deadlength) { |
| allowed_deadspace_words -= deadlength; |
| CollectedHeap::fill_with_object(q, deadlength); |
| oop(q)->set_mark(oop(q)->mark()->set_marked()); |
| assert((int) deadlength == oop(q)->size(), "bad filler object size"); |
| // Recall that we required "q == compaction_top". |
| return true; |
| } else { |
| allowed_deadspace_words = 0; |
| return false; |
| } |
| } |
| |
| #define block_is_always_obj(q) true |
| #define obj_size(q) oop(q)->size() |
| #define adjust_obj_size(s) s |
| |
| void CompactibleSpace::prepare_for_compaction(CompactPoint* cp) { |
| SCAN_AND_FORWARD(cp, end, block_is_obj, block_size); |
| } |
| |
| // Faster object search. |
| void ContiguousSpace::prepare_for_compaction(CompactPoint* cp) { |
| SCAN_AND_FORWARD(cp, top, block_is_always_obj, obj_size); |
| } |
| |
| void Space::adjust_pointers() { |
| // adjust all the interior pointers to point at the new locations of objects |
| // Used by MarkSweep::mark_sweep_phase3() |
| |
| // First check to see if there is any work to be done. |
| if (used() == 0) { |
| return; // Nothing to do. |
| } |
| |
| // Otherwise... |
| HeapWord* q = bottom(); |
| HeapWord* t = end(); |
| |
| debug_only(HeapWord* prev_q = NULL); |
| while (q < t) { |
| if (oop(q)->is_gc_marked()) { |
| // q is alive |
| |
| // point all the oops to the new location |
| size_t size = oop(q)->adjust_pointers(); |
| |
| debug_only(prev_q = q); |
| |
| q += size; |
| } else { |
| // q is not a live object. But we're not in a compactible space, |
| // So we don't have live ranges. |
| debug_only(prev_q = q); |
| q += block_size(q); |
| assert(q > prev_q, "we should be moving forward through memory"); |
| } |
| } |
| assert(q == t, "just checking"); |
| } |
| |
| void CompactibleSpace::adjust_pointers() { |
| // Check first is there is any work to do. |
| if (used() == 0) { |
| return; // Nothing to do. |
| } |
| |
| SCAN_AND_ADJUST_POINTERS(adjust_obj_size); |
| } |
| |
| void CompactibleSpace::compact() { |
| SCAN_AND_COMPACT(obj_size); |
| } |
| |
| void Space::print_short() const { print_short_on(tty); } |
| |
| void Space::print_short_on(outputStream* st) const { |
| st->print(" space " SIZE_FORMAT "K, %3d%% used", capacity() / K, |
| (int) ((double) used() * 100 / capacity())); |
| } |
| |
| void Space::print() const { print_on(tty); } |
| |
| void Space::print_on(outputStream* st) const { |
| print_short_on(st); |
| st->print_cr(" [" INTPTR_FORMAT ", " INTPTR_FORMAT ")", |
| bottom(), end()); |
| } |
| |
| void ContiguousSpace::print_on(outputStream* st) const { |
| print_short_on(st); |
| st->print_cr(" [" INTPTR_FORMAT ", " INTPTR_FORMAT ", " INTPTR_FORMAT ")", |
| bottom(), top(), end()); |
| } |
| |
| void OffsetTableContigSpace::print_on(outputStream* st) const { |
| print_short_on(st); |
| st->print_cr(" [" INTPTR_FORMAT ", " INTPTR_FORMAT ", " |
| INTPTR_FORMAT ", " INTPTR_FORMAT ")", |
| bottom(), top(), _offsets.threshold(), end()); |
| } |
| |
| void ContiguousSpace::verify() const { |
| HeapWord* p = bottom(); |
| HeapWord* t = top(); |
| HeapWord* prev_p = NULL; |
| while (p < t) { |
| oop(p)->verify(); |
| prev_p = p; |
| p += oop(p)->size(); |
| } |
| guarantee(p == top(), "end of last object must match end of space"); |
| if (top() != end()) { |
| guarantee(top() == block_start_const(end()-1) && |
| top() == block_start_const(top()), |
| "top should be start of unallocated block, if it exists"); |
| } |
| } |
| |
| void Space::oop_iterate(ExtendedOopClosure* blk) { |
| ObjectToOopClosure blk2(blk); |
| object_iterate(&blk2); |
| } |
| |
| bool Space::obj_is_alive(const HeapWord* p) const { |
| assert (block_is_obj(p), "The address should point to an object"); |
| return true; |
| } |
| |
| #if INCLUDE_ALL_GCS |
| #define ContigSpace_PAR_OOP_ITERATE_DEFN(OopClosureType, nv_suffix) \ |
| \ |
| void ContiguousSpace::par_oop_iterate(MemRegion mr, OopClosureType* blk) {\ |
| HeapWord* obj_addr = mr.start(); \ |
| HeapWord* t = mr.end(); \ |
| while (obj_addr < t) { \ |
| assert(oop(obj_addr)->is_oop(), "Should be an oop"); \ |
| obj_addr += oop(obj_addr)->oop_iterate(blk); \ |
| } \ |
| } |
| |
| ALL_PAR_OOP_ITERATE_CLOSURES(ContigSpace_PAR_OOP_ITERATE_DEFN) |
| |
| #undef ContigSpace_PAR_OOP_ITERATE_DEFN |
| #endif // INCLUDE_ALL_GCS |
| |
| void ContiguousSpace::oop_iterate(ExtendedOopClosure* blk) { |
| if (is_empty()) return; |
| HeapWord* obj_addr = bottom(); |
| HeapWord* t = top(); |
| // Could call objects iterate, but this is easier. |
| while (obj_addr < t) { |
| obj_addr += oop(obj_addr)->oop_iterate(blk); |
| } |
| } |
| |
| void ContiguousSpace::object_iterate(ObjectClosure* blk) { |
| if (is_empty()) return; |
| WaterMark bm = bottom_mark(); |
| object_iterate_from(bm, blk); |
| } |
| |
| // For a continguous space object_iterate() and safe_object_iterate() |
| // are the same. |
| void ContiguousSpace::safe_object_iterate(ObjectClosure* blk) { |
| object_iterate(blk); |
| } |
| |
| void ContiguousSpace::object_iterate_from(WaterMark mark, ObjectClosure* blk) { |
| assert(mark.space() == this, "Mark does not match space"); |
| HeapWord* p = mark.point(); |
| while (p < top()) { |
| blk->do_object(oop(p)); |
| p += oop(p)->size(); |
| } |
| } |
| |
| HeapWord* |
| ContiguousSpace::object_iterate_careful(ObjectClosureCareful* blk) { |
| HeapWord * limit = concurrent_iteration_safe_limit(); |
| assert(limit <= top(), "sanity check"); |
| for (HeapWord* p = bottom(); p < limit;) { |
| size_t size = blk->do_object_careful(oop(p)); |
| if (size == 0) { |
| return p; // failed at p |
| } else { |
| p += size; |
| } |
| } |
| return NULL; // all done |
| } |
| |
| #define ContigSpace_OOP_SINCE_SAVE_MARKS_DEFN(OopClosureType, nv_suffix) \ |
| \ |
| void ContiguousSpace:: \ |
| oop_since_save_marks_iterate##nv_suffix(OopClosureType* blk) { \ |
| HeapWord* t; \ |
| HeapWord* p = saved_mark_word(); \ |
| assert(p != NULL, "expected saved mark"); \ |
| \ |
| const intx interval = PrefetchScanIntervalInBytes; \ |
| do { \ |
| t = top(); \ |
| while (p < t) { \ |
| Prefetch::write(p, interval); \ |
| debug_only(HeapWord* prev = p); \ |
| oop m = oop(p); \ |
| p += m->oop_iterate(blk); \ |
| } \ |
| } while (t < top()); \ |
| \ |
| set_saved_mark_word(p); \ |
| } |
| |
| ALL_SINCE_SAVE_MARKS_CLOSURES(ContigSpace_OOP_SINCE_SAVE_MARKS_DEFN) |
| |
| #undef ContigSpace_OOP_SINCE_SAVE_MARKS_DEFN |
| |
| // Very general, slow implementation. |
| HeapWord* ContiguousSpace::block_start_const(const void* p) const { |
| assert(MemRegion(bottom(), end()).contains(p), |
| err_msg("p (" PTR_FORMAT ") not in space [" PTR_FORMAT ", " PTR_FORMAT ")", |
| p, bottom(), end())); |
| if (p >= top()) { |
| return top(); |
| } else { |
| HeapWord* last = bottom(); |
| HeapWord* cur = last; |
| while (cur <= p) { |
| last = cur; |
| cur += oop(cur)->size(); |
| } |
| assert(oop(last)->is_oop(), |
| err_msg(PTR_FORMAT " should be an object start", last)); |
| return last; |
| } |
| } |
| |
| size_t ContiguousSpace::block_size(const HeapWord* p) const { |
| assert(MemRegion(bottom(), end()).contains(p), |
| err_msg("p (" PTR_FORMAT ") not in space [" PTR_FORMAT ", " PTR_FORMAT ")", |
| p, bottom(), end())); |
| HeapWord* current_top = top(); |
| assert(p <= current_top, |
| err_msg("p > current top - p: " PTR_FORMAT ", current top: " PTR_FORMAT, |
| p, current_top)); |
| assert(p == current_top || oop(p)->is_oop(), |
| err_msg("p (" PTR_FORMAT ") is not a block start - " |
| "current_top: " PTR_FORMAT ", is_oop: %s", |
| p, current_top, BOOL_TO_STR(oop(p)->is_oop()))); |
| if (p < current_top) { |
| return oop(p)->size(); |
| } else { |
| assert(p == current_top, "just checking"); |
| return pointer_delta(end(), (HeapWord*) p); |
| } |
| } |
| |
| // This version requires locking. |
| inline HeapWord* ContiguousSpace::allocate_impl(size_t size, |
| HeapWord* const end_value) { |
| assert(Heap_lock->owned_by_self() || |
| (SafepointSynchronize::is_at_safepoint() && Thread::current()->is_VM_thread()), |
| "not locked"); |
| HeapWord* obj = top(); |
| if (pointer_delta(end_value, obj) >= size) { |
| HeapWord* new_top = obj + size; |
| set_top(new_top); |
| assert(is_aligned(obj) && is_aligned(new_top), "checking alignment"); |
| return obj; |
| } else { |
| return NULL; |
| } |
| } |
| |
| // This version is lock-free. |
| inline HeapWord* ContiguousSpace::par_allocate_impl(size_t size, |
| HeapWord* const end_value) { |
| do { |
| HeapWord* obj = top(); |
| if (pointer_delta(end_value, obj) >= size) { |
| HeapWord* new_top = obj + size; |
| HeapWord* result = (HeapWord*)Atomic::cmpxchg_ptr(new_top, top_addr(), obj); |
| // result can be one of two: |
| // the old top value: the exchange succeeded |
| // otherwise: the new value of the top is returned. |
| if (result == obj) { |
| assert(is_aligned(obj) && is_aligned(new_top), "checking alignment"); |
| return obj; |
| } |
| } else { |
| return NULL; |
| } |
| } while (true); |
| } |
| |
| HeapWord* ContiguousSpace::allocate_aligned(size_t size) { |
| assert(Heap_lock->owned_by_self() || (SafepointSynchronize::is_at_safepoint() && Thread::current()->is_VM_thread()), "not locked"); |
| HeapWord* end_value = end(); |
| |
| HeapWord* obj = CollectedHeap::align_allocation_or_fail(top(), end_value, SurvivorAlignmentInBytes); |
| if (obj == NULL) { |
| return NULL; |
| } |
| |
| if (pointer_delta(end_value, obj) >= size) { |
| HeapWord* new_top = obj + size; |
| set_top(new_top); |
| assert(is_ptr_aligned(obj, SurvivorAlignmentInBytes) && is_aligned(new_top), |
| "checking alignment"); |
| return obj; |
| } else { |
| set_top(obj); |
| return NULL; |
| } |
| } |
| |
| // Requires locking. |
| HeapWord* ContiguousSpace::allocate(size_t size) { |
| return allocate_impl(size, end()); |
| } |
| |
| // Lock-free. |
| HeapWord* ContiguousSpace::par_allocate(size_t size) { |
| return par_allocate_impl(size, end()); |
| } |
| |
| void ContiguousSpace::allocate_temporary_filler(int factor) { |
| // allocate temporary type array decreasing free size with factor 'factor' |
| assert(factor >= 0, "just checking"); |
| size_t size = pointer_delta(end(), top()); |
| |
| // if space is full, return |
| if (size == 0) return; |
| |
| if (factor > 0) { |
| size -= size/factor; |
| } |
| size = align_object_size(size); |
| |
| const size_t array_header_size = typeArrayOopDesc::header_size(T_INT); |
| if (size >= (size_t)align_object_size(array_header_size)) { |
| size_t length = (size - array_header_size) * (HeapWordSize / sizeof(jint)); |
| // allocate uninitialized int array |
| typeArrayOop t = (typeArrayOop) allocate(size); |
| assert(t != NULL, "allocation should succeed"); |
| t->set_mark(markOopDesc::prototype()); |
| t->set_klass(Universe::intArrayKlassObj()); |
| t->set_length((int)length); |
| } else { |
| assert(size == CollectedHeap::min_fill_size(), |
| "size for smallest fake object doesn't match"); |
| instanceOop obj = (instanceOop) allocate(size); |
| obj->set_mark(markOopDesc::prototype()); |
| obj->set_klass_gap(0); |
| obj->set_klass(SystemDictionary::Object_klass()); |
| } |
| } |
| |
| void EdenSpace::clear(bool mangle_space) { |
| ContiguousSpace::clear(mangle_space); |
| set_soft_end(end()); |
| } |
| |
| // Requires locking. |
| HeapWord* EdenSpace::allocate(size_t size) { |
| return allocate_impl(size, soft_end()); |
| } |
| |
| // Lock-free. |
| HeapWord* EdenSpace::par_allocate(size_t size) { |
| return par_allocate_impl(size, soft_end()); |
| } |
| |
| HeapWord* ConcEdenSpace::par_allocate(size_t size) |
| { |
| do { |
| // The invariant is top() should be read before end() because |
| // top() can't be greater than end(), so if an update of _soft_end |
| // occurs between 'end_val = end();' and 'top_val = top();' top() |
| // also can grow up to the new end() and the condition |
| // 'top_val > end_val' is true. To ensure the loading order |
| // OrderAccess::loadload() is required after top() read. |
| HeapWord* obj = top(); |
| OrderAccess::loadload(); |
| if (pointer_delta(*soft_end_addr(), obj) >= size) { |
| HeapWord* new_top = obj + size; |
| HeapWord* result = (HeapWord*)Atomic::cmpxchg_ptr(new_top, top_addr(), obj); |
| // result can be one of two: |
| // the old top value: the exchange succeeded |
| // otherwise: the new value of the top is returned. |
| if (result == obj) { |
| assert(is_aligned(obj) && is_aligned(new_top), "checking alignment"); |
| return obj; |
| } |
| } else { |
| return NULL; |
| } |
| } while (true); |
| } |
| |
| |
| HeapWord* OffsetTableContigSpace::initialize_threshold() { |
| return _offsets.initialize_threshold(); |
| } |
| |
| HeapWord* OffsetTableContigSpace::cross_threshold(HeapWord* start, HeapWord* end) { |
| _offsets.alloc_block(start, end); |
| return _offsets.threshold(); |
| } |
| |
| OffsetTableContigSpace::OffsetTableContigSpace(BlockOffsetSharedArray* sharedOffsetArray, |
| MemRegion mr) : |
| _offsets(sharedOffsetArray, mr), |
| _par_alloc_lock(Mutex::leaf, "OffsetTableContigSpace par alloc lock", true) |
| { |
| _offsets.set_contig_space(this); |
| initialize(mr, SpaceDecorator::Clear, SpaceDecorator::Mangle); |
| } |
| |
| #define OBJ_SAMPLE_INTERVAL 0 |
| #define BLOCK_SAMPLE_INTERVAL 100 |
| |
| void OffsetTableContigSpace::verify() const { |
| HeapWord* p = bottom(); |
| HeapWord* prev_p = NULL; |
| int objs = 0; |
| int blocks = 0; |
| |
| if (VerifyObjectStartArray) { |
| _offsets.verify(); |
| } |
| |
| while (p < top()) { |
| size_t size = oop(p)->size(); |
| // For a sampling of objects in the space, find it using the |
| // block offset table. |
| if (blocks == BLOCK_SAMPLE_INTERVAL) { |
| guarantee(p == block_start_const(p + (size/2)), |
| "check offset computation"); |
| blocks = 0; |
| } else { |
| blocks++; |
| } |
| |
| if (objs == OBJ_SAMPLE_INTERVAL) { |
| oop(p)->verify(); |
| objs = 0; |
| } else { |
| objs++; |
| } |
| prev_p = p; |
| p += size; |
| } |
| guarantee(p == top(), "end of last object must match end of space"); |
| } |
| |
| |
| size_t TenuredSpace::allowed_dead_ratio() const { |
| return MarkSweepDeadRatio; |
| } |
