aoqi@0: /*
aoqi@0:  * Copyright (c) 1997, 2014, Oracle and/or its affiliates. All rights reserved.
aoqi@0:  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
aoqi@0:  *
aoqi@0:  * This code is free software; you can redistribute it and/or modify it
aoqi@0:  * under the terms of the GNU General Public License version 2 only, as
aoqi@0:  * published by the Free Software Foundation.
aoqi@0:  *
aoqi@0:  * This code is distributed in the hope that it will be useful, but WITHOUT
aoqi@0:  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
aoqi@0:  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
aoqi@0:  * version 2 for more details (a copy is included in the LICENSE file that
aoqi@0:  * accompanied this code).
aoqi@0:  *
aoqi@0:  * You should have received a copy of the GNU General Public License version
aoqi@0:  * 2 along with this work; if not, write to the Free Software Foundation,
aoqi@0:  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
aoqi@0:  *
aoqi@0:  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
aoqi@0:  * or visit www.oracle.com if you need additional information or have any
aoqi@0:  * questions.
aoqi@0:  *
aoqi@0:  */
aoqi@0: 
aoqi@0: #include "precompiled.hpp"
aoqi@0: #include "classfile/systemDictionary.hpp"
aoqi@0: #include "classfile/vmSymbols.hpp"
aoqi@0: #include "gc_implementation/shared/liveRange.hpp"
aoqi@0: #include "gc_implementation/shared/markSweep.hpp"
aoqi@0: #include "gc_implementation/shared/spaceDecorator.hpp"
jmasa@7031: #include "gc_interface/collectedHeap.inline.hpp"
aoqi@0: #include "memory/blockOffsetTable.inline.hpp"
aoqi@0: #include "memory/defNewGeneration.hpp"
aoqi@0: #include "memory/genCollectedHeap.hpp"
aoqi@0: #include "memory/space.hpp"
aoqi@0: #include "memory/space.inline.hpp"
aoqi@0: #include "memory/universe.inline.hpp"
aoqi@0: #include "oops/oop.inline.hpp"
aoqi@0: #include "oops/oop.inline2.hpp"
aoqi@0: #include "runtime/java.hpp"
goetz@6912: #include "runtime/prefetch.inline.hpp"
goetz@6911: #include "runtime/orderAccess.inline.hpp"
aoqi@0: #include "runtime/safepoint.hpp"
aoqi@0: #include "utilities/copy.hpp"
aoqi@0: #include "utilities/globalDefinitions.hpp"
aoqi@0: #include "utilities/macros.hpp"
aoqi@0: 
aoqi@0: PRAGMA_FORMAT_MUTE_WARNINGS_FOR_GCC
aoqi@0: 
aoqi@0: HeapWord* DirtyCardToOopClosure::get_actual_top(HeapWord* top,
aoqi@0:                                                 HeapWord* top_obj) {
aoqi@0:   if (top_obj != NULL) {
aoqi@0:     if (_sp->block_is_obj(top_obj)) {
aoqi@0:       if (_precision == CardTableModRefBS::ObjHeadPreciseArray) {
aoqi@0:         if (oop(top_obj)->is_objArray() || oop(top_obj)->is_typeArray()) {
aoqi@0:           // An arrayOop is starting on the dirty card - since we do exact
aoqi@0:           // store checks for objArrays we are done.
aoqi@0:         } else {
aoqi@0:           // Otherwise, it is possible that the object starting on the dirty
aoqi@0:           // card spans the entire card, and that the store happened on a
aoqi@0:           // later card.  Figure out where the object ends.
aoqi@0:           // Use the block_size() method of the space over which
aoqi@0:           // the iteration is being done.  That space (e.g. CMS) may have
aoqi@0:           // specific requirements on object sizes which will
aoqi@0:           // be reflected in the block_size() method.
aoqi@0:           top = top_obj + oop(top_obj)->size();
aoqi@0:         }
aoqi@0:       }
aoqi@0:     } else {
aoqi@0:       top = top_obj;
aoqi@0:     }
aoqi@0:   } else {
aoqi@0:     assert(top == _sp->end(), "only case where top_obj == NULL");
aoqi@0:   }
aoqi@0:   return top;
aoqi@0: }
aoqi@0: 
aoqi@0: void DirtyCardToOopClosure::walk_mem_region(MemRegion mr,
aoqi@0:                                             HeapWord* bottom,
aoqi@0:                                             HeapWord* top) {
aoqi@0:   // 1. Blocks may or may not be objects.
aoqi@0:   // 2. Even when a block_is_obj(), it may not entirely
aoqi@0:   //    occupy the block if the block quantum is larger than
aoqi@0:   //    the object size.
aoqi@0:   // We can and should try to optimize by calling the non-MemRegion
aoqi@0:   // version of oop_iterate() for all but the extremal objects
aoqi@0:   // (for which we need to call the MemRegion version of
aoqi@0:   // oop_iterate()) To be done post-beta XXX
aoqi@0:   for (; bottom < top; bottom += _sp->block_size(bottom)) {
aoqi@0:     // As in the case of contiguous space above, we'd like to
aoqi@0:     // just use the value returned by oop_iterate to increment the
aoqi@0:     // current pointer; unfortunately, that won't work in CMS because
aoqi@0:     // we'd need an interface change (it seems) to have the space
aoqi@0:     // "adjust the object size" (for instance pad it up to its
aoqi@0:     // block alignment or minimum block size restrictions. XXX
aoqi@0:     if (_sp->block_is_obj(bottom) &&
aoqi@0:         !_sp->obj_allocated_since_save_marks(oop(bottom))) {
aoqi@0:       oop(bottom)->oop_iterate(_cl, mr);
aoqi@0:     }
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: // We get called with "mr" representing the dirty region
aoqi@0: // that we want to process. Because of imprecise marking,
aoqi@0: // we may need to extend the incoming "mr" to the right,
aoqi@0: // and scan more. However, because we may already have
aoqi@0: // scanned some of that extended region, we may need to
aoqi@0: // trim its right-end back some so we do not scan what
aoqi@0: // we (or another worker thread) may already have scanned
aoqi@0: // or planning to scan.
aoqi@0: void DirtyCardToOopClosure::do_MemRegion(MemRegion mr) {
aoqi@0: 
aoqi@0:   // Some collectors need to do special things whenever their dirty
aoqi@0:   // cards are processed. For instance, CMS must remember mutator updates
aoqi@0:   // (i.e. dirty cards) so as to re-scan mutated objects.
aoqi@0:   // Such work can be piggy-backed here on dirty card scanning, so as to make
aoqi@0:   // it slightly more efficient than doing a complete non-detructive pre-scan
aoqi@0:   // of the card table.
aoqi@0:   MemRegionClosure* pCl = _sp->preconsumptionDirtyCardClosure();
aoqi@0:   if (pCl != NULL) {
aoqi@0:     pCl->do_MemRegion(mr);
aoqi@0:   }
aoqi@0: 
aoqi@0:   HeapWord* bottom = mr.start();
aoqi@0:   HeapWord* last = mr.last();
aoqi@0:   HeapWord* top = mr.end();
aoqi@0:   HeapWord* bottom_obj;
aoqi@0:   HeapWord* top_obj;
aoqi@0: 
aoqi@0:   assert(_precision == CardTableModRefBS::ObjHeadPreciseArray ||
aoqi@0:          _precision == CardTableModRefBS::Precise,
aoqi@0:          "Only ones we deal with for now.");
aoqi@0: 
aoqi@0:   assert(_precision != CardTableModRefBS::ObjHeadPreciseArray ||
aoqi@0:          _cl->idempotent() || _last_bottom == NULL ||
aoqi@0:          top <= _last_bottom,
aoqi@0:          "Not decreasing");
aoqi@0:   NOT_PRODUCT(_last_bottom = mr.start());
aoqi@0: 
aoqi@0:   bottom_obj = _sp->block_start(bottom);
aoqi@0:   top_obj    = _sp->block_start(last);
aoqi@0: 
aoqi@0:   assert(bottom_obj <= bottom, "just checking");
aoqi@0:   assert(top_obj    <= top,    "just checking");
aoqi@0: 
aoqi@0:   // Given what we think is the top of the memory region and
aoqi@0:   // the start of the object at the top, get the actual
aoqi@0:   // value of the top.
aoqi@0:   top = get_actual_top(top, top_obj);
aoqi@0: 
aoqi@0:   // If the previous call did some part of this region, don't redo.
aoqi@0:   if (_precision == CardTableModRefBS::ObjHeadPreciseArray &&
aoqi@0:       _min_done != NULL &&
aoqi@0:       _min_done < top) {
aoqi@0:     top = _min_done;
aoqi@0:   }
aoqi@0: 
aoqi@0:   // Top may have been reset, and in fact may be below bottom,
aoqi@0:   // e.g. the dirty card region is entirely in a now free object
aoqi@0:   // -- something that could happen with a concurrent sweeper.
aoqi@0:   bottom = MIN2(bottom, top);
aoqi@0:   MemRegion extended_mr = MemRegion(bottom, top);
aoqi@0:   assert(bottom <= top &&
aoqi@0:          (_precision != CardTableModRefBS::ObjHeadPreciseArray ||
aoqi@0:           _min_done == NULL ||
aoqi@0:           top <= _min_done),
aoqi@0:          "overlap!");
aoqi@0: 
aoqi@0:   // Walk the region if it is not empty; otherwise there is nothing to do.
aoqi@0:   if (!extended_mr.is_empty()) {
aoqi@0:     walk_mem_region(extended_mr, bottom_obj, top);
aoqi@0:   }
aoqi@0: 
aoqi@0:   // An idempotent closure might be applied in any order, so we don't
aoqi@0:   // record a _min_done for it.
aoqi@0:   if (!_cl->idempotent()) {
aoqi@0:     _min_done = bottom;
aoqi@0:   } else {
aoqi@0:     assert(_min_done == _last_explicit_min_done,
aoqi@0:            "Don't update _min_done for idempotent cl");
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: DirtyCardToOopClosure* Space::new_dcto_cl(ExtendedOopClosure* cl,
aoqi@0:                                           CardTableModRefBS::PrecisionStyle precision,
aoqi@0:                                           HeapWord* boundary) {
aoqi@0:   return new DirtyCardToOopClosure(this, cl, precision, boundary);
aoqi@0: }
aoqi@0: 
aoqi@0: HeapWord* ContiguousSpaceDCTOC::get_actual_top(HeapWord* top,
aoqi@0:                                                HeapWord* top_obj) {
aoqi@0:   if (top_obj != NULL && top_obj < (_sp->toContiguousSpace())->top()) {
aoqi@0:     if (_precision == CardTableModRefBS::ObjHeadPreciseArray) {
aoqi@0:       if (oop(top_obj)->is_objArray() || oop(top_obj)->is_typeArray()) {
aoqi@0:         // An arrayOop is starting on the dirty card - since we do exact
aoqi@0:         // store checks for objArrays we are done.
aoqi@0:       } else {
aoqi@0:         // Otherwise, it is possible that the object starting on the dirty
aoqi@0:         // card spans the entire card, and that the store happened on a
aoqi@0:         // later card.  Figure out where the object ends.
aoqi@0:         assert(_sp->block_size(top_obj) == (size_t) oop(top_obj)->size(),
aoqi@0:           "Block size and object size mismatch");
aoqi@0:         top = top_obj + oop(top_obj)->size();
aoqi@0:       }
aoqi@0:     }
aoqi@0:   } else {
aoqi@0:     top = (_sp->toContiguousSpace())->top();
aoqi@0:   }
aoqi@0:   return top;
aoqi@0: }
aoqi@0: 
aoqi@0: void Filtering_DCTOC::walk_mem_region(MemRegion mr,
aoqi@0:                                       HeapWord* bottom,
aoqi@0:                                       HeapWord* top) {
aoqi@0:   // Note that this assumption won't hold if we have a concurrent
aoqi@0:   // collector in this space, which may have freed up objects after
aoqi@0:   // they were dirtied and before the stop-the-world GC that is
aoqi@0:   // examining cards here.
aoqi@0:   assert(bottom < top, "ought to be at least one obj on a dirty card.");
aoqi@0: 
aoqi@0:   if (_boundary != NULL) {
aoqi@0:     // We have a boundary outside of which we don't want to look
aoqi@0:     // at objects, so create a filtering closure around the
aoqi@0:     // oop closure before walking the region.
aoqi@0:     FilteringClosure filter(_boundary, _cl);
aoqi@0:     walk_mem_region_with_cl(mr, bottom, top, &filter);
aoqi@0:   } else {
aoqi@0:     // No boundary, simply walk the heap with the oop closure.
aoqi@0:     walk_mem_region_with_cl(mr, bottom, top, _cl);
aoqi@0:   }
aoqi@0: 
aoqi@0: }
aoqi@0: 
aoqi@0: // We must replicate this so that the static type of "FilteringClosure"
aoqi@0: // (see above) is apparent at the oop_iterate calls.
aoqi@0: #define ContiguousSpaceDCTOC__walk_mem_region_with_cl_DEFN(ClosureType) \
aoqi@0: void ContiguousSpaceDCTOC::walk_mem_region_with_cl(MemRegion mr,        \
aoqi@0:                                                    HeapWord* bottom,    \
aoqi@0:                                                    HeapWord* top,       \
aoqi@0:                                                    ClosureType* cl) {   \
aoqi@0:   bottom += oop(bottom)->oop_iterate(cl, mr);                           \
aoqi@0:   if (bottom < top) {                                                   \
aoqi@0:     HeapWord* next_obj = bottom + oop(bottom)->size();                  \
aoqi@0:     while (next_obj < top) {                                            \
aoqi@0:       /* Bottom lies entirely below top, so we can call the */          \
aoqi@0:       /* non-memRegion version of oop_iterate below. */                 \
aoqi@0:       oop(bottom)->oop_iterate(cl);                                     \
aoqi@0:       bottom = next_obj;                                                \
aoqi@0:       next_obj = bottom + oop(bottom)->size();                          \
aoqi@0:     }                                                                   \
aoqi@0:     /* Last object. */                                                  \
aoqi@0:     oop(bottom)->oop_iterate(cl, mr);                                   \
aoqi@0:   }                                                                     \
aoqi@0: }
aoqi@0: 
aoqi@0: // (There are only two of these, rather than N, because the split is due
aoqi@0: // only to the introduction of the FilteringClosure, a local part of the
aoqi@0: // impl of this abstraction.)
aoqi@0: ContiguousSpaceDCTOC__walk_mem_region_with_cl_DEFN(ExtendedOopClosure)
aoqi@0: ContiguousSpaceDCTOC__walk_mem_region_with_cl_DEFN(FilteringClosure)
aoqi@0: 
aoqi@0: DirtyCardToOopClosure*
aoqi@0: ContiguousSpace::new_dcto_cl(ExtendedOopClosure* cl,
aoqi@0:                              CardTableModRefBS::PrecisionStyle precision,
aoqi@0:                              HeapWord* boundary) {
aoqi@0:   return new ContiguousSpaceDCTOC(this, cl, precision, boundary);
aoqi@0: }
aoqi@0: 
aoqi@0: void Space::initialize(MemRegion mr,
aoqi@0:                        bool clear_space,
aoqi@0:                        bool mangle_space) {
aoqi@0:   HeapWord* bottom = mr.start();
aoqi@0:   HeapWord* end    = mr.end();
aoqi@0:   assert(Universe::on_page_boundary(bottom) && Universe::on_page_boundary(end),
aoqi@0:          "invalid space boundaries");
aoqi@0:   set_bottom(bottom);
aoqi@0:   set_end(end);
aoqi@0:   if (clear_space) clear(mangle_space);
aoqi@0: }
aoqi@0: 
aoqi@0: void Space::clear(bool mangle_space) {
aoqi@0:   if (ZapUnusedHeapArea && mangle_space) {
aoqi@0:     mangle_unused_area();
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: ContiguousSpace::ContiguousSpace(): CompactibleSpace(), _top(NULL),
aoqi@0:     _concurrent_iteration_safe_limit(NULL) {
aoqi@0:   _mangler = new GenSpaceMangler(this);
aoqi@0: }
aoqi@0: 
aoqi@0: ContiguousSpace::~ContiguousSpace() {
aoqi@0:   delete _mangler;
aoqi@0: }
aoqi@0: 
aoqi@0: void ContiguousSpace::initialize(MemRegion mr,
aoqi@0:                                  bool clear_space,
aoqi@0:                                  bool mangle_space)
aoqi@0: {
aoqi@0:   CompactibleSpace::initialize(mr, clear_space, mangle_space);
aoqi@0:   set_concurrent_iteration_safe_limit(top());
aoqi@0: }
aoqi@0: 
aoqi@0: void ContiguousSpace::clear(bool mangle_space) {
aoqi@0:   set_top(bottom());
aoqi@0:   set_saved_mark();
aoqi@0:   CompactibleSpace::clear(mangle_space);
aoqi@0: }
aoqi@0: 
aoqi@0: bool ContiguousSpace::is_free_block(const HeapWord* p) const {
aoqi@0:   return p >= _top;
aoqi@0: }
aoqi@0: 
aoqi@0: void OffsetTableContigSpace::clear(bool mangle_space) {
aoqi@0:   ContiguousSpace::clear(mangle_space);
aoqi@0:   _offsets.initialize_threshold();
aoqi@0: }
aoqi@0: 
aoqi@0: void OffsetTableContigSpace::set_bottom(HeapWord* new_bottom) {
aoqi@0:   Space::set_bottom(new_bottom);
aoqi@0:   _offsets.set_bottom(new_bottom);
aoqi@0: }
aoqi@0: 
aoqi@0: void OffsetTableContigSpace::set_end(HeapWord* new_end) {
aoqi@0:   // Space should not advertize an increase in size
aoqi@0:   // until after the underlying offest table has been enlarged.
aoqi@0:   _offsets.resize(pointer_delta(new_end, bottom()));
aoqi@0:   Space::set_end(new_end);
aoqi@0: }
aoqi@0: 
aoqi@0: #ifndef PRODUCT
aoqi@0: 
aoqi@0: void ContiguousSpace::set_top_for_allocations(HeapWord* v) {
aoqi@0:   mangler()->set_top_for_allocations(v);
aoqi@0: }
aoqi@0: void ContiguousSpace::set_top_for_allocations() {
aoqi@0:   mangler()->set_top_for_allocations(top());
aoqi@0: }
aoqi@0: void ContiguousSpace::check_mangled_unused_area(HeapWord* limit) {
aoqi@0:   mangler()->check_mangled_unused_area(limit);
aoqi@0: }
aoqi@0: 
aoqi@0: void ContiguousSpace::check_mangled_unused_area_complete() {
aoqi@0:   mangler()->check_mangled_unused_area_complete();
aoqi@0: }
aoqi@0: 
aoqi@0: // Mangled only the unused space that has not previously
aoqi@0: // been mangled and that has not been allocated since being
aoqi@0: // mangled.
aoqi@0: void ContiguousSpace::mangle_unused_area() {
aoqi@0:   mangler()->mangle_unused_area();
aoqi@0: }
aoqi@0: void ContiguousSpace::mangle_unused_area_complete() {
aoqi@0:   mangler()->mangle_unused_area_complete();
aoqi@0: }
aoqi@0: void ContiguousSpace::mangle_region(MemRegion mr) {
aoqi@0:   // Although this method uses SpaceMangler::mangle_region() which
aoqi@0:   // is not specific to a space, the when the ContiguousSpace version
aoqi@0:   // is called, it is always with regard to a space and this
aoqi@0:   // bounds checking is appropriate.
aoqi@0:   MemRegion space_mr(bottom(), end());
aoqi@0:   assert(space_mr.contains(mr), "Mangling outside space");
aoqi@0:   SpaceMangler::mangle_region(mr);
aoqi@0: }
aoqi@0: #endif  // NOT_PRODUCT
aoqi@0: 
aoqi@0: void CompactibleSpace::initialize(MemRegion mr,
aoqi@0:                                   bool clear_space,
aoqi@0:                                   bool mangle_space) {
aoqi@0:   Space::initialize(mr, clear_space, mangle_space);
aoqi@0:   set_compaction_top(bottom());
aoqi@0:   _next_compaction_space = NULL;
aoqi@0: }
aoqi@0: 
aoqi@0: void CompactibleSpace::clear(bool mangle_space) {
aoqi@0:   Space::clear(mangle_space);
aoqi@0:   _compaction_top = bottom();
aoqi@0: }
aoqi@0: 
aoqi@0: HeapWord* CompactibleSpace::forward(oop q, size_t size,
aoqi@0:                                     CompactPoint* cp, HeapWord* compact_top) {
aoqi@0:   // q is alive
aoqi@0:   // First check if we should switch compaction space
aoqi@0:   assert(this == cp->space, "'this' should be current compaction space.");
aoqi@0:   size_t compaction_max_size = pointer_delta(end(), compact_top);
aoqi@0:   while (size > compaction_max_size) {
aoqi@0:     // switch to next compaction space
aoqi@0:     cp->space->set_compaction_top(compact_top);
aoqi@0:     cp->space = cp->space->next_compaction_space();
aoqi@0:     if (cp->space == NULL) {
aoqi@0:       cp->gen = GenCollectedHeap::heap()->prev_gen(cp->gen);
aoqi@0:       assert(cp->gen != NULL, "compaction must succeed");
aoqi@0:       cp->space = cp->gen->first_compaction_space();
aoqi@0:       assert(cp->space != NULL, "generation must have a first compaction space");
aoqi@0:     }
aoqi@0:     compact_top = cp->space->bottom();
aoqi@0:     cp->space->set_compaction_top(compact_top);
aoqi@0:     cp->threshold = cp->space->initialize_threshold();
aoqi@0:     compaction_max_size = pointer_delta(cp->space->end(), compact_top);
aoqi@0:   }
aoqi@0: 
aoqi@0:   // store the forwarding pointer into the mark word
aoqi@0:   if ((HeapWord*)q != compact_top) {
aoqi@0:     q->forward_to(oop(compact_top));
aoqi@0:     assert(q->is_gc_marked(), "encoding the pointer should preserve the mark");
aoqi@0:   } else {
aoqi@0:     // if the object isn't moving we can just set the mark to the default
aoqi@0:     // mark and handle it specially later on.
aoqi@0:     q->init_mark();
aoqi@0:     assert(q->forwardee() == NULL, "should be forwarded to NULL");
aoqi@0:   }
aoqi@0: 
aoqi@0:   compact_top += size;
aoqi@0: 
aoqi@0:   // we need to update the offset table so that the beginnings of objects can be
aoqi@0:   // found during scavenge.  Note that we are updating the offset table based on
aoqi@0:   // where the object will be once the compaction phase finishes.
aoqi@0:   if (compact_top > cp->threshold)
aoqi@0:     cp->threshold =
aoqi@0:       cp->space->cross_threshold(compact_top - size, compact_top);
aoqi@0:   return compact_top;
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: bool CompactibleSpace::insert_deadspace(size_t& allowed_deadspace_words,
aoqi@0:                                         HeapWord* q, size_t deadlength) {
aoqi@0:   if (allowed_deadspace_words >= deadlength) {
aoqi@0:     allowed_deadspace_words -= deadlength;
aoqi@0:     CollectedHeap::fill_with_object(q, deadlength);
aoqi@0:     oop(q)->set_mark(oop(q)->mark()->set_marked());
aoqi@0:     assert((int) deadlength == oop(q)->size(), "bad filler object size");
aoqi@0:     // Recall that we required "q == compaction_top".
aoqi@0:     return true;
aoqi@0:   } else {
aoqi@0:     allowed_deadspace_words = 0;
aoqi@0:     return false;
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: #define block_is_always_obj(q) true
aoqi@0: #define obj_size(q) oop(q)->size()
aoqi@0: #define adjust_obj_size(s) s
aoqi@0: 
aoqi@0: void CompactibleSpace::prepare_for_compaction(CompactPoint* cp) {
aoqi@0:   SCAN_AND_FORWARD(cp, end, block_is_obj, block_size);
aoqi@0: }
aoqi@0: 
aoqi@0: // Faster object search.
aoqi@0: void ContiguousSpace::prepare_for_compaction(CompactPoint* cp) {
aoqi@0:   SCAN_AND_FORWARD(cp, top, block_is_always_obj, obj_size);
aoqi@0: }
aoqi@0: 
aoqi@0: void Space::adjust_pointers() {
aoqi@0:   // adjust all the interior pointers to point at the new locations of objects
aoqi@0:   // Used by MarkSweep::mark_sweep_phase3()
aoqi@0: 
aoqi@0:   // First check to see if there is any work to be done.
aoqi@0:   if (used() == 0) {
aoqi@0:     return;  // Nothing to do.
aoqi@0:   }
aoqi@0: 
aoqi@0:   // Otherwise...
aoqi@0:   HeapWord* q = bottom();
aoqi@0:   HeapWord* t = end();
aoqi@0: 
aoqi@0:   debug_only(HeapWord* prev_q = NULL);
aoqi@0:   while (q < t) {
aoqi@0:     if (oop(q)->is_gc_marked()) {
aoqi@0:       // q is alive
aoqi@0: 
aoqi@0:       // point all the oops to the new location
aoqi@0:       size_t size = oop(q)->adjust_pointers();
aoqi@0: 
aoqi@0:       debug_only(prev_q = q);
aoqi@0: 
aoqi@0:       q += size;
aoqi@0:     } else {
aoqi@0:       // q is not a live object.  But we're not in a compactible space,
aoqi@0:       // So we don't have live ranges.
aoqi@0:       debug_only(prev_q = q);
aoqi@0:       q += block_size(q);
aoqi@0:       assert(q > prev_q, "we should be moving forward through memory");
aoqi@0:     }
aoqi@0:   }
aoqi@0:   assert(q == t, "just checking");
aoqi@0: }
aoqi@0: 
aoqi@0: void CompactibleSpace::adjust_pointers() {
aoqi@0:   // Check first is there is any work to do.
aoqi@0:   if (used() == 0) {
aoqi@0:     return;   // Nothing to do.
aoqi@0:   }
aoqi@0: 
aoqi@0:   SCAN_AND_ADJUST_POINTERS(adjust_obj_size);
aoqi@0: }
aoqi@0: 
aoqi@0: void CompactibleSpace::compact() {
aoqi@0:   SCAN_AND_COMPACT(obj_size);
aoqi@0: }
aoqi@0: 
aoqi@0: void Space::print_short() const { print_short_on(tty); }
aoqi@0: 
aoqi@0: void Space::print_short_on(outputStream* st) const {
aoqi@0:   st->print(" space " SIZE_FORMAT "K, %3d%% used", capacity() / K,
aoqi@0:               (int) ((double) used() * 100 / capacity()));
aoqi@0: }
aoqi@0: 
aoqi@0: void Space::print() const { print_on(tty); }
aoqi@0: 
aoqi@0: void Space::print_on(outputStream* st) const {
aoqi@0:   print_short_on(st);
aoqi@0:   st->print_cr(" [" INTPTR_FORMAT ", " INTPTR_FORMAT ")",
aoqi@0:                 bottom(), end());
aoqi@0: }
aoqi@0: 
aoqi@0: void ContiguousSpace::print_on(outputStream* st) const {
aoqi@0:   print_short_on(st);
aoqi@0:   st->print_cr(" [" INTPTR_FORMAT ", " INTPTR_FORMAT ", " INTPTR_FORMAT ")",
aoqi@0:                 bottom(), top(), end());
aoqi@0: }
aoqi@0: 
aoqi@0: void OffsetTableContigSpace::print_on(outputStream* st) const {
aoqi@0:   print_short_on(st);
aoqi@0:   st->print_cr(" [" INTPTR_FORMAT ", " INTPTR_FORMAT ", "
aoqi@0:                 INTPTR_FORMAT ", " INTPTR_FORMAT ")",
aoqi@0:               bottom(), top(), _offsets.threshold(), end());
aoqi@0: }
aoqi@0: 
aoqi@0: void ContiguousSpace::verify() const {
aoqi@0:   HeapWord* p = bottom();
aoqi@0:   HeapWord* t = top();
aoqi@0:   HeapWord* prev_p = NULL;
aoqi@0:   while (p < t) {
aoqi@0:     oop(p)->verify();
aoqi@0:     prev_p = p;
aoqi@0:     p += oop(p)->size();
aoqi@0:   }
aoqi@0:   guarantee(p == top(), "end of last object must match end of space");
aoqi@0:   if (top() != end()) {
aoqi@0:     guarantee(top() == block_start_const(end()-1) &&
aoqi@0:               top() == block_start_const(top()),
aoqi@0:               "top should be start of unallocated block, if it exists");
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: void Space::oop_iterate(ExtendedOopClosure* blk) {
aoqi@0:   ObjectToOopClosure blk2(blk);
aoqi@0:   object_iterate(&blk2);
aoqi@0: }
aoqi@0: 
aoqi@0: bool Space::obj_is_alive(const HeapWord* p) const {
aoqi@0:   assert (block_is_obj(p), "The address should point to an object");
aoqi@0:   return true;
aoqi@0: }
aoqi@0: 
aoqi@0: #if INCLUDE_ALL_GCS
aoqi@0: #define ContigSpace_PAR_OOP_ITERATE_DEFN(OopClosureType, nv_suffix)         \
aoqi@0:                                                                             \
aoqi@0:   void ContiguousSpace::par_oop_iterate(MemRegion mr, OopClosureType* blk) {\
aoqi@0:     HeapWord* obj_addr = mr.start();                                        \
aoqi@0:     HeapWord* t = mr.end();                                                 \
aoqi@0:     while (obj_addr < t) {                                                  \
aoqi@0:       assert(oop(obj_addr)->is_oop(), "Should be an oop");                  \
aoqi@0:       obj_addr += oop(obj_addr)->oop_iterate(blk);                          \
aoqi@0:     }                                                                       \
aoqi@0:   }
aoqi@0: 
aoqi@0:   ALL_PAR_OOP_ITERATE_CLOSURES(ContigSpace_PAR_OOP_ITERATE_DEFN)
aoqi@0: 
aoqi@0: #undef ContigSpace_PAR_OOP_ITERATE_DEFN
aoqi@0: #endif // INCLUDE_ALL_GCS
aoqi@0: 
aoqi@0: void ContiguousSpace::oop_iterate(ExtendedOopClosure* blk) {
aoqi@0:   if (is_empty()) return;
aoqi@0:   HeapWord* obj_addr = bottom();
aoqi@0:   HeapWord* t = top();
aoqi@0:   // Could call objects iterate, but this is easier.
aoqi@0:   while (obj_addr < t) {
aoqi@0:     obj_addr += oop(obj_addr)->oop_iterate(blk);
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: void ContiguousSpace::object_iterate(ObjectClosure* blk) {
aoqi@0:   if (is_empty()) return;
aoqi@0:   WaterMark bm = bottom_mark();
aoqi@0:   object_iterate_from(bm, blk);
aoqi@0: }
aoqi@0: 
aoqi@0: // For a continguous space object_iterate() and safe_object_iterate()
aoqi@0: // are the same.
aoqi@0: void ContiguousSpace::safe_object_iterate(ObjectClosure* blk) {
aoqi@0:   object_iterate(blk);
aoqi@0: }
aoqi@0: 
aoqi@0: void ContiguousSpace::object_iterate_from(WaterMark mark, ObjectClosure* blk) {
aoqi@0:   assert(mark.space() == this, "Mark does not match space");
aoqi@0:   HeapWord* p = mark.point();
aoqi@0:   while (p < top()) {
aoqi@0:     blk->do_object(oop(p));
aoqi@0:     p += oop(p)->size();
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: HeapWord*
aoqi@0: ContiguousSpace::object_iterate_careful(ObjectClosureCareful* blk) {
aoqi@0:   HeapWord * limit = concurrent_iteration_safe_limit();
aoqi@0:   assert(limit <= top(), "sanity check");
aoqi@0:   for (HeapWord* p = bottom(); p < limit;) {
aoqi@0:     size_t size = blk->do_object_careful(oop(p));
aoqi@0:     if (size == 0) {
aoqi@0:       return p;  // failed at p
aoqi@0:     } else {
aoqi@0:       p += size;
aoqi@0:     }
aoqi@0:   }
aoqi@0:   return NULL; // all done
aoqi@0: }
aoqi@0: 
aoqi@0: #define ContigSpace_OOP_SINCE_SAVE_MARKS_DEFN(OopClosureType, nv_suffix)  \
aoqi@0:                                                                           \
aoqi@0: void ContiguousSpace::                                                    \
aoqi@0: oop_since_save_marks_iterate##nv_suffix(OopClosureType* blk) {            \
aoqi@0:   HeapWord* t;                                                            \
aoqi@0:   HeapWord* p = saved_mark_word();                                        \
aoqi@0:   assert(p != NULL, "expected saved mark");                               \
aoqi@0:                                                                           \
aoqi@0:   const intx interval = PrefetchScanIntervalInBytes;                      \
aoqi@0:   do {                                                                    \
aoqi@0:     t = top();                                                            \
aoqi@0:     while (p < t) {                                                       \
aoqi@0:       Prefetch::write(p, interval);                                       \
aoqi@0:       debug_only(HeapWord* prev = p);                                     \
aoqi@0:       oop m = oop(p);                                                     \
aoqi@0:       p += m->oop_iterate(blk);                                           \
aoqi@0:     }                                                                     \
aoqi@0:   } while (t < top());                                                    \
aoqi@0:                                                                           \
aoqi@0:   set_saved_mark_word(p);                                                 \
aoqi@0: }
aoqi@0: 
aoqi@0: ALL_SINCE_SAVE_MARKS_CLOSURES(ContigSpace_OOP_SINCE_SAVE_MARKS_DEFN)
aoqi@0: 
aoqi@0: #undef ContigSpace_OOP_SINCE_SAVE_MARKS_DEFN
aoqi@0: 
aoqi@0: // Very general, slow implementation.
aoqi@0: HeapWord* ContiguousSpace::block_start_const(const void* p) const {
aoqi@0:   assert(MemRegion(bottom(), end()).contains(p),
aoqi@0:          err_msg("p (" PTR_FORMAT ") not in space [" PTR_FORMAT ", " PTR_FORMAT ")",
aoqi@0:                   p, bottom(), end()));
aoqi@0:   if (p >= top()) {
aoqi@0:     return top();
aoqi@0:   } else {
aoqi@0:     HeapWord* last = bottom();
aoqi@0:     HeapWord* cur = last;
aoqi@0:     while (cur <= p) {
aoqi@0:       last = cur;
aoqi@0:       cur += oop(cur)->size();
aoqi@0:     }
aoqi@0:     assert(oop(last)->is_oop(),
aoqi@0:            err_msg(PTR_FORMAT " should be an object start", last));
aoqi@0:     return last;
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: size_t ContiguousSpace::block_size(const HeapWord* p) const {
aoqi@0:   assert(MemRegion(bottom(), end()).contains(p),
aoqi@0:          err_msg("p (" PTR_FORMAT ") not in space [" PTR_FORMAT ", " PTR_FORMAT ")",
aoqi@0:                   p, bottom(), end()));
aoqi@0:   HeapWord* current_top = top();
aoqi@0:   assert(p <= current_top,
aoqi@0:          err_msg("p > current top - p: " PTR_FORMAT ", current top: " PTR_FORMAT,
aoqi@0:                   p, current_top));
aoqi@0:   assert(p == current_top || oop(p)->is_oop(),
aoqi@0:          err_msg("p (" PTR_FORMAT ") is not a block start - "
aoqi@0:                  "current_top: " PTR_FORMAT ", is_oop: %s",
aoqi@0:                  p, current_top, BOOL_TO_STR(oop(p)->is_oop())));
aoqi@0:   if (p < current_top) {
aoqi@0:     return oop(p)->size();
aoqi@0:   } else {
aoqi@0:     assert(p == current_top, "just checking");
aoqi@0:     return pointer_delta(end(), (HeapWord*) p);
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: // This version requires locking.
aoqi@0: inline HeapWord* ContiguousSpace::allocate_impl(size_t size,
aoqi@0:                                                 HeapWord* const end_value) {
aoqi@0:   assert(Heap_lock->owned_by_self() ||
mgerdin@6990:          (SafepointSynchronize::is_at_safepoint() && Thread::current()->is_VM_thread()),
aoqi@0:          "not locked");
aoqi@0:   HeapWord* obj = top();
aoqi@0:   if (pointer_delta(end_value, obj) >= size) {
aoqi@0:     HeapWord* new_top = obj + size;
aoqi@0:     set_top(new_top);
aoqi@0:     assert(is_aligned(obj) && is_aligned(new_top), "checking alignment");
aoqi@0:     return obj;
aoqi@0:   } else {
aoqi@0:     return NULL;
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: // This version is lock-free.
aoqi@0: inline HeapWord* ContiguousSpace::par_allocate_impl(size_t size,
aoqi@0:                                                     HeapWord* const end_value) {
aoqi@0:   do {
aoqi@0:     HeapWord* obj = top();
aoqi@0:     if (pointer_delta(end_value, obj) >= size) {
aoqi@0:       HeapWord* new_top = obj + size;
aoqi@0:       HeapWord* result = (HeapWord*)Atomic::cmpxchg_ptr(new_top, top_addr(), obj);
aoqi@0:       // result can be one of two:
aoqi@0:       //  the old top value: the exchange succeeded
aoqi@0:       //  otherwise: the new value of the top is returned.
aoqi@0:       if (result == obj) {
aoqi@0:         assert(is_aligned(obj) && is_aligned(new_top), "checking alignment");
aoqi@0:         return obj;
aoqi@0:       }
aoqi@0:     } else {
aoqi@0:       return NULL;
aoqi@0:     }
aoqi@0:   } while (true);
aoqi@0: }
aoqi@0: 
jmasa@7031: HeapWord* ContiguousSpace::allocate_aligned(size_t size) {
jmasa@7031:   assert(Heap_lock->owned_by_self() || (SafepointSynchronize::is_at_safepoint() && Thread::current()->is_VM_thread()), "not locked");
jmasa@7031:   HeapWord* end_value = end();
jmasa@7031: 
jmasa@7031:   HeapWord* obj = CollectedHeap::align_allocation_or_fail(top(), end_value, SurvivorAlignmentInBytes);
jmasa@7031:   if (obj == NULL) {
jmasa@7031:     return NULL;
jmasa@7031:   }
jmasa@7031: 
jmasa@7031:   if (pointer_delta(end_value, obj) >= size) {
jmasa@7031:     HeapWord* new_top = obj + size;
jmasa@7031:     set_top(new_top);
jmasa@7031:     assert(is_ptr_aligned(obj, SurvivorAlignmentInBytes) && is_aligned(new_top),
jmasa@7031:       "checking alignment");
jmasa@7031:     return obj;
jmasa@7031:   } else {
jmasa@7031:     set_top(obj);
jmasa@7031:     return NULL;
jmasa@7031:   }
jmasa@7031: }
jmasa@7031: 
aoqi@0: // Requires locking.
aoqi@0: HeapWord* ContiguousSpace::allocate(size_t size) {
aoqi@0:   return allocate_impl(size, end());
aoqi@0: }
aoqi@0: 
aoqi@0: // Lock-free.
aoqi@0: HeapWord* ContiguousSpace::par_allocate(size_t size) {
aoqi@0:   return par_allocate_impl(size, end());
aoqi@0: }
aoqi@0: 
aoqi@0: void ContiguousSpace::allocate_temporary_filler(int factor) {
aoqi@0:   // allocate temporary type array decreasing free size with factor 'factor'
aoqi@0:   assert(factor >= 0, "just checking");
aoqi@0:   size_t size = pointer_delta(end(), top());
aoqi@0: 
aoqi@0:   // if space is full, return
aoqi@0:   if (size == 0) return;
aoqi@0: 
aoqi@0:   if (factor > 0) {
aoqi@0:     size -= size/factor;
aoqi@0:   }
aoqi@0:   size = align_object_size(size);
aoqi@0: 
aoqi@0:   const size_t array_header_size = typeArrayOopDesc::header_size(T_INT);
aoqi@0:   if (size >= (size_t)align_object_size(array_header_size)) {
aoqi@0:     size_t length = (size - array_header_size) * (HeapWordSize / sizeof(jint));
aoqi@0:     // allocate uninitialized int array
aoqi@0:     typeArrayOop t = (typeArrayOop) allocate(size);
aoqi@0:     assert(t != NULL, "allocation should succeed");
aoqi@0:     t->set_mark(markOopDesc::prototype());
aoqi@0:     t->set_klass(Universe::intArrayKlassObj());
aoqi@0:     t->set_length((int)length);
aoqi@0:   } else {
aoqi@0:     assert(size == CollectedHeap::min_fill_size(),
aoqi@0:            "size for smallest fake object doesn't match");
aoqi@0:     instanceOop obj = (instanceOop) allocate(size);
aoqi@0:     obj->set_mark(markOopDesc::prototype());
aoqi@0:     obj->set_klass_gap(0);
aoqi@0:     obj->set_klass(SystemDictionary::Object_klass());
aoqi@0:   }
aoqi@0: }
aoqi@0: 
aoqi@0: void EdenSpace::clear(bool mangle_space) {
aoqi@0:   ContiguousSpace::clear(mangle_space);
aoqi@0:   set_soft_end(end());
aoqi@0: }
aoqi@0: 
aoqi@0: // Requires locking.
aoqi@0: HeapWord* EdenSpace::allocate(size_t size) {
aoqi@0:   return allocate_impl(size, soft_end());
aoqi@0: }
aoqi@0: 
aoqi@0: // Lock-free.
aoqi@0: HeapWord* EdenSpace::par_allocate(size_t size) {
aoqi@0:   return par_allocate_impl(size, soft_end());
aoqi@0: }
aoqi@0: 
aoqi@0: HeapWord* ConcEdenSpace::par_allocate(size_t size)
aoqi@0: {
aoqi@0:   do {
aoqi@0:     // The invariant is top() should be read before end() because
aoqi@0:     // top() can't be greater than end(), so if an update of _soft_end
aoqi@0:     // occurs between 'end_val = end();' and 'top_val = top();' top()
aoqi@0:     // also can grow up to the new end() and the condition
aoqi@0:     // 'top_val > end_val' is true. To ensure the loading order
aoqi@0:     // OrderAccess::loadload() is required after top() read.
aoqi@0:     HeapWord* obj = top();
aoqi@0:     OrderAccess::loadload();
aoqi@0:     if (pointer_delta(*soft_end_addr(), obj) >= size) {
aoqi@0:       HeapWord* new_top = obj + size;
aoqi@0:       HeapWord* result = (HeapWord*)Atomic::cmpxchg_ptr(new_top, top_addr(), obj);
aoqi@0:       // result can be one of two:
aoqi@0:       //  the old top value: the exchange succeeded
aoqi@0:       //  otherwise: the new value of the top is returned.
aoqi@0:       if (result == obj) {
aoqi@0:         assert(is_aligned(obj) && is_aligned(new_top), "checking alignment");
aoqi@0:         return obj;
aoqi@0:       }
aoqi@0:     } else {
aoqi@0:       return NULL;
aoqi@0:     }
aoqi@0:   } while (true);
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: HeapWord* OffsetTableContigSpace::initialize_threshold() {
aoqi@0:   return _offsets.initialize_threshold();
aoqi@0: }
aoqi@0: 
aoqi@0: HeapWord* OffsetTableContigSpace::cross_threshold(HeapWord* start, HeapWord* end) {
aoqi@0:   _offsets.alloc_block(start, end);
aoqi@0:   return _offsets.threshold();
aoqi@0: }
aoqi@0: 
aoqi@0: OffsetTableContigSpace::OffsetTableContigSpace(BlockOffsetSharedArray* sharedOffsetArray,
aoqi@0:                                                MemRegion mr) :
aoqi@0:   _offsets(sharedOffsetArray, mr),
aoqi@0:   _par_alloc_lock(Mutex::leaf, "OffsetTableContigSpace par alloc lock", true)
aoqi@0: {
aoqi@0:   _offsets.set_contig_space(this);
aoqi@0:   initialize(mr, SpaceDecorator::Clear, SpaceDecorator::Mangle);
aoqi@0: }
aoqi@0: 
aoqi@0: #define OBJ_SAMPLE_INTERVAL 0
aoqi@0: #define BLOCK_SAMPLE_INTERVAL 100
aoqi@0: 
aoqi@0: void OffsetTableContigSpace::verify() const {
aoqi@0:   HeapWord* p = bottom();
aoqi@0:   HeapWord* prev_p = NULL;
aoqi@0:   int objs = 0;
aoqi@0:   int blocks = 0;
aoqi@0: 
aoqi@0:   if (VerifyObjectStartArray) {
aoqi@0:     _offsets.verify();
aoqi@0:   }
aoqi@0: 
aoqi@0:   while (p < top()) {
aoqi@0:     size_t size = oop(p)->size();
aoqi@0:     // For a sampling of objects in the space, find it using the
aoqi@0:     // block offset table.
aoqi@0:     if (blocks == BLOCK_SAMPLE_INTERVAL) {
aoqi@0:       guarantee(p == block_start_const(p + (size/2)),
aoqi@0:                 "check offset computation");
aoqi@0:       blocks = 0;
aoqi@0:     } else {
aoqi@0:       blocks++;
aoqi@0:     }
aoqi@0: 
aoqi@0:     if (objs == OBJ_SAMPLE_INTERVAL) {
aoqi@0:       oop(p)->verify();
aoqi@0:       objs = 0;
aoqi@0:     } else {
aoqi@0:       objs++;
aoqi@0:     }
aoqi@0:     prev_p = p;
aoqi@0:     p += size;
aoqi@0:   }
aoqi@0:   guarantee(p == top(), "end of last object must match end of space");
aoqi@0: }
aoqi@0: 
aoqi@0: 
aoqi@0: size_t TenuredSpace::allowed_dead_ratio() const {
aoqi@0:   return MarkSweepDeadRatio;
aoqi@0: }