1 /*
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   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
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  10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  12  * version 2 for more details (a copy is included in the LICENSE file that
  13  * accompanied this code).
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  24 
  25 #ifndef SHARE_VM_GC_G1_G1OOPCLOSURES_INLINE_HPP
  26 #define SHARE_VM_GC_G1_G1OOPCLOSURES_INLINE_HPP
  27 
  28 #include "gc/g1/g1CollectedHeap.hpp"
  29 #include "gc/g1/g1ConcurrentMark.inline.hpp"
  30 #include "gc/g1/g1OopClosures.hpp"
  31 #include "gc/g1/g1ParScanThreadState.inline.hpp"
  32 #include "gc/g1/g1RemSet.hpp"
  33 #include "gc/g1/g1RemSet.inline.hpp"
  34 #include "gc/g1/heapRegion.inline.hpp"
  35 #include "gc/g1/heapRegionRemSet.hpp"
  36 #include "memory/iterator.inline.hpp"
  37 #include "runtime/prefetch.inline.hpp"
  38 
  39 template <class T>
  40 inline void G1ScanClosureBase::prefetch_and_push(T* p, const oop obj) {
  41   // We're not going to even bother checking whether the object is
  42   // already forwarded or not, as this usually causes an immediate
  43   // stall. We'll try to prefetch the object (for write, given that
  44   // we might need to install the forwarding reference) and we'll
  45   // get back to it when pop it from the queue
  46   Prefetch::write(obj->mark_addr(), 0);
  47   Prefetch::read(obj->mark_addr(), (HeapWordSize*2));
  48 
  49   // slightly paranoid test; I'm trying to catch potential
  50   // problems before we go into push_on_queue to know where the
  51   // problem is coming from
  52   assert((obj == oopDesc::load_decode_heap_oop(p)) ||
  53          (obj->is_forwarded() &&
  54          obj->forwardee() == oopDesc::load_decode_heap_oop(p)),
  55          "p should still be pointing to obj or to its forwardee");
  56 
  57   _par_scan_state->push_on_queue(p);
  58 }
  59 
  60 template <class T>
  61 inline void G1ScanClosureBase::handle_non_cset_obj_common(InCSetState const state, T* p, oop const obj) {
  62   if (state.is_humongous()) {
  63     _g1->set_humongous_is_live(obj);
  64   } else if (state.is_ext()) {
  65     _par_scan_state->do_oop_ext(p);
  66   }
  67 }
  68 
  69 template <class T>
  70 inline void G1ScanEvacuatedObjClosure::do_oop_nv(T* p) {
  71   T heap_oop = oopDesc::load_heap_oop(p);
  72 
  73   if (oopDesc::is_null(heap_oop)) {
  74     return;
  75   }
  76   oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
  77   const InCSetState state = _g1->in_cset_state(obj);
  78   if (state.is_in_cset()) {
  79     prefetch_and_push(p, obj);
  80   } else {
  81     if (HeapRegion::is_in_same_region(p, obj)) {
  82       return;
  83     }
  84     handle_non_cset_obj_common(state, p, obj);
  85     _par_scan_state->update_rs(_from, p, obj);
  86   }
  87 }
  88 
  89 template <class T>
  90 inline void G1CMOopClosure::do_oop_nv(T* p) {
  91   oop obj = oopDesc::load_decode_heap_oop(p);
  92   _task->deal_with_reference(obj);
  93 }
  94 
  95 template <class T>
  96 inline void G1RootRegionScanClosure::do_oop_nv(T* p) {
  97   T heap_oop = oopDesc::load_heap_oop(p);
  98   if (oopDesc::is_null(heap_oop)) {
  99     return;
 100   }
 101   oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
 102   _cm->mark_in_next_bitmap(obj);
 103 }
 104 
 105 template <class T>
 106 inline static void check_obj_during_refinement(T* p, oop const obj) {
 107 #ifdef ASSERT
 108   G1CollectedHeap* g1 = G1CollectedHeap::heap();
 109   // can't do because of races
 110   // assert(oopDesc::is_oop_or_null(obj), "expected an oop");
 111   assert(check_obj_alignment(obj), "not oop aligned");
 112   assert(g1->is_in_reserved(obj), "must be in heap");
 113 
 114   HeapRegion* from = g1->heap_region_containing(p);
 115 
 116   assert(from != NULL, "from region must be non-NULL");
 117   assert(from->is_in_reserved(p) ||
 118          (from->is_humongous() &&
 119           g1->heap_region_containing(p)->is_humongous() &&
 120           from->humongous_start_region() == g1->heap_region_containing(p)->humongous_start_region()),
 121          "p " PTR_FORMAT " is not in the same region %u or part of the correct humongous object starting at region %u.",
 122          p2i(p), from->hrm_index(), from->humongous_start_region()->hrm_index());
 123 #endif // ASSERT
 124 }
 125 
 126 template <class T>
 127 inline void G1ConcurrentRefineOopClosure::do_oop_nv(T* p) {
 128   T o = oopDesc::load_heap_oop(p);
 129   if (oopDesc::is_null(o)) {
 130     return;
 131   }
 132   oop obj = oopDesc::decode_heap_oop_not_null(o);
 133 
 134   check_obj_during_refinement(p, obj);
 135 
 136   if (HeapRegion::is_in_same_region(p, obj)) {
 137     // Normally this closure should only be called with cross-region references.
 138     // But since Java threads are manipulating the references concurrently and we
 139     // reload the values things may have changed.
 140     // Also this check lets slip through references from a humongous continues region
 141     // to its humongous start region, as they are in different regions, and adds a
 142     // remembered set entry. This is benign (apart from memory usage), as we never
 143     // try to either evacuate or eager reclaim humonguous arrays of j.l.O.
 144     return;
 145   }
 146 
 147   HeapRegion* to = _g1->heap_region_containing(obj);
 148 
 149   assert(to->rem_set() != NULL, "Need per-region 'into' remsets.");
 150   to->rem_set()->add_reference(p, _worker_i);
 151 }
 152 
 153 template <class T>
 154 inline void G1ScanObjsDuringUpdateRSClosure::do_oop_nv(T* p) {
 155   T o = oopDesc::load_heap_oop(p);
 156   if (oopDesc::is_null(o)) {
 157     return;
 158   }
 159   oop obj = oopDesc::decode_heap_oop_not_null(o);
 160 
 161   check_obj_during_refinement(p, obj);
 162 
 163   assert(!_g1->is_in_cset((HeapWord*)p), "Oop originates from " PTR_FORMAT " (region: %u) which is in the collection set.", p2i(p), _g1->addr_to_region((HeapWord*)p));
 164   const InCSetState state = _g1->in_cset_state(obj);
 165   if (state.is_in_cset()) {
 166     // Since the source is always from outside the collection set, here we implicitly know
 167     // that this is a cross-region reference too.
 168     prefetch_and_push(p, obj);
 169   } else {
 170     HeapRegion* to = _g1->heap_region_containing(obj);
 171     if (_from == to) {
 172       return;
 173     }
 174     handle_non_cset_obj_common(state, p, obj);
 175     to->rem_set()->add_reference(p, _worker_i);
 176   }
 177 }
 178 
 179 template <class T>
 180 inline void G1ScanObjsDuringScanRSClosure::do_oop_nv(T* p) {
 181   T heap_oop = oopDesc::load_heap_oop(p);
 182   if (oopDesc::is_null(heap_oop)) {
 183     return;
 184   }
 185   oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
 186 
 187   const InCSetState state = _g1->in_cset_state(obj);
 188   if (state.is_in_cset()) {
 189     prefetch_and_push(p, obj);
 190   } else {
 191     if (HeapRegion::is_in_same_region(p, obj)) {
 192       return;
 193     }
 194     handle_non_cset_obj_common(state, p, obj);
 195   }
 196 }
 197 
 198 void G1ParCopyHelper::do_cld_barrier(oop new_obj) {
 199   if (_g1->heap_region_containing(new_obj)->is_young()) {
 200     _scanned_cld->record_modified_oops();
 201   }
 202 }
 203 
 204 void G1ParCopyHelper::mark_object(oop obj) {
 205   assert(!_g1->heap_region_containing(obj)->in_collection_set(), "should not mark objects in the CSet");
 206 
 207   _cm->mark_in_next_bitmap(obj);
 208 }
 209 
 210 void G1ParCopyHelper::mark_forwarded_object(oop from_obj, oop to_obj) {
 211   assert(from_obj->is_forwarded(), "from obj should be forwarded");
 212   assert(from_obj->forwardee() == to_obj, "to obj should be the forwardee");
 213   assert(from_obj != to_obj, "should not be self-forwarded");
 214 
 215   assert(_g1->heap_region_containing(from_obj)->in_collection_set(), "from obj should be in the CSet");
 216   assert(!_g1->heap_region_containing(to_obj)->in_collection_set(), "should not mark objects in the CSet");
 217 
 218   _cm->mark_in_next_bitmap(to_obj);
 219 }
 220 
 221 template <G1Barrier barrier, G1Mark do_mark_object, bool use_ext>
 222 template <class T>
 223 void G1ParCopyClosure<barrier, do_mark_object, use_ext>::do_oop_work(T* p) {
 224   T heap_oop = oopDesc::load_heap_oop(p);
 225 
 226   if (oopDesc::is_null(heap_oop)) {
 227     return;
 228   }
 229 
 230   oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
 231 
 232   assert(_worker_id == _par_scan_state->worker_id(), "sanity");
 233 
 234   const InCSetState state = _g1->in_cset_state(obj);
 235   if (state.is_in_cset()) {
 236     oop forwardee;
 237     markOop m = obj->mark();
 238     if (m->is_marked()) {
 239       forwardee = (oop) m->decode_pointer();
 240     } else {
 241       forwardee = _par_scan_state->copy_to_survivor_space(state, obj, m);
 242     }
 243     assert(forwardee != NULL, "forwardee should not be NULL");
 244     oopDesc::encode_store_heap_oop(p, forwardee);
 245     if (do_mark_object != G1MarkNone && forwardee != obj) {
 246       // If the object is self-forwarded we don't need to explicitly
 247       // mark it, the evacuation failure protocol will do so.
 248       mark_forwarded_object(obj, forwardee);
 249     }
 250 
 251     if (barrier == G1BarrierCLD) {
 252       do_cld_barrier(forwardee);
 253     }
 254   } else {
 255     if (state.is_humongous()) {
 256       _g1->set_humongous_is_live(obj);
 257     }
 258 
 259     if (use_ext && state.is_ext()) {
 260       _par_scan_state->do_oop_ext(p);
 261     }
 262     // The object is not in collection set. If we're a root scanning
 263     // closure during an initial mark pause then attempt to mark the object.
 264     if (do_mark_object == G1MarkFromRoot) {
 265       mark_object(obj);
 266     }
 267   }
 268 }
 269 #endif // SHARE_VM_GC_G1_G1OOPCLOSURES_INLINE_HPP