1 /*
   2  * Copyright (c) 2001, 2014, Oracle and/or its affiliates. All rights reserved.
   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   4  *
   5  * This code is free software; you can redistribute it and/or modify it
   6  * under the terms of the GNU General Public License version 2 only, as
   7  * published by the Free Software Foundation.
   8  *
   9  * This code is distributed in the hope that it will be useful, but WITHOUT
  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).
  14  *
  15  * You should have received a copy of the GNU General Public License version
  16  * 2 along with this work; if not, write to the Free Software Foundation,
  17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  18  *
  19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  20  * or visit www.oracle.com if you need additional information or have any
  21  * questions.
  22  *
  23  */
  24 
  25 #ifndef SHARE_VM_GC_IMPLEMENTATION_G1_G1OOPCLOSURES_INLINE_HPP
  26 #define SHARE_VM_GC_IMPLEMENTATION_G1_G1OOPCLOSURES_INLINE_HPP
  27 
  28 #include "gc_implementation/g1/concurrentMark.inline.hpp"
  29 #include "gc_implementation/g1/g1CollectedHeap.hpp"
  30 #include "gc_implementation/g1/g1OopClosures.hpp"
  31 #include "gc_implementation/g1/g1ParScanThreadState.inline.hpp"
  32 #include "gc_implementation/g1/g1RemSet.hpp"
  33 #include "gc_implementation/g1/g1RemSet.inline.hpp"
  34 #include "gc_implementation/g1/heapRegionRemSet.hpp"
  35 #include "memory/iterator.inline.hpp"
  36 #include "runtime/prefetch.inline.hpp"
  37 
  38 /*
  39  * This really ought to be an inline function, but apparently the C++
  40  * compiler sometimes sees fit to ignore inline declarations.  Sigh.
  41  */
  42 
  43 template <class T>
  44 inline void FilterIntoCSClosure::do_oop_nv(T* p) {
  45   T heap_oop = oopDesc::load_heap_oop(p);
  46   if (!oopDesc::is_null(heap_oop) &&
  47       _g1->is_in_cset_or_humongous(oopDesc::decode_heap_oop_not_null(heap_oop))) {
  48     _oc->do_oop(p);
  49   }
  50 }
  51 
  52 template <class T>
  53 inline void FilterOutOfRegionClosure::do_oop_nv(T* p) {
  54   T heap_oop = oopDesc::load_heap_oop(p);
  55   if (!oopDesc::is_null(heap_oop)) {
  56     HeapWord* obj_hw = (HeapWord*)oopDesc::decode_heap_oop_not_null(heap_oop);
  57     if (obj_hw < _r_bottom || obj_hw >= _r_end) {
  58       _oc->do_oop(p);
  59     }
  60   }
  61 }
  62 
  63 // This closure is applied to the fields of the objects that have just been copied.
  64 template <class T>
  65 inline void G1ParScanClosure::do_oop_nv(T* p) {
  66   T heap_oop = oopDesc::load_heap_oop(p);
  67 
  68   if (!oopDesc::is_null(heap_oop)) {
  69     oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
  70     const InCSetState state = _g1->in_cset_state(obj);
  71     if (state.is_in_cset()) {
  72       // We're not going to even bother checking whether the object is
  73       // already forwarded or not, as this usually causes an immediate
  74       // stall. We'll try to prefetch the object (for write, given that
  75       // we might need to install the forwarding reference) and we'll
  76       // get back to it when pop it from the queue
  77       Prefetch::write(obj->mark_addr(), 0);
  78       Prefetch::read(obj->mark_addr(), (HeapWordSize*2));
  79 
  80       // slightly paranoid test; I'm trying to catch potential
  81       // problems before we go into push_on_queue to know where the
  82       // problem is coming from
  83       assert((obj == oopDesc::load_decode_heap_oop(p)) ||
  84              (obj->is_forwarded() &&
  85                  obj->forwardee() == oopDesc::load_decode_heap_oop(p)),
  86              "p should still be pointing to obj or to its forwardee");
  87 
  88       _par_scan_state->push_on_queue(p);
  89     } else {
  90       if (state.is_humongous()) {
  91         _g1->set_humongous_is_live(obj);
  92       }
  93       _par_scan_state->update_rs(_from, p, _worker_id);
  94     }
  95   }
  96 }
  97 
  98 template <class T>
  99 inline void G1ParPushHeapRSClosure::do_oop_nv(T* p) {
 100   T heap_oop = oopDesc::load_heap_oop(p);
 101 
 102   if (!oopDesc::is_null(heap_oop)) {
 103     oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
 104     if (_g1->is_in_cset_or_humongous(obj)) {
 105       Prefetch::write(obj->mark_addr(), 0);
 106       Prefetch::read(obj->mark_addr(), (HeapWordSize*2));
 107 
 108       // Place on the references queue
 109       _par_scan_state->push_on_queue(p);
 110     } else {
 111       assert(!_g1->obj_in_cs(obj), "checking");
 112     }
 113   }
 114 }
 115 
 116 template <class T>
 117 inline void G1CMOopClosure::do_oop_nv(T* p) {
 118   oop obj = oopDesc::load_decode_heap_oop(p);
 119   if (_cm->verbose_high()) {
 120     gclog_or_tty->print_cr("[%u] we're looking at location "
 121                            "*"PTR_FORMAT" = "PTR_FORMAT,
 122                            _task->worker_id(), p2i(p), p2i((void*) obj));
 123   }
 124   _task->deal_with_reference(obj);
 125 }
 126 
 127 template <class T>
 128 inline void G1RootRegionScanClosure::do_oop_nv(T* p) {
 129   T heap_oop = oopDesc::load_heap_oop(p);
 130   if (!oopDesc::is_null(heap_oop)) {
 131     oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
 132     HeapRegion* hr = _g1h->heap_region_containing((HeapWord*) obj);
 133     _cm->grayRoot(obj, obj->size(), _worker_id, hr);
 134   }
 135 }
 136 
 137 template <class T>
 138 inline void G1Mux2Closure::do_oop_nv(T* p) {
 139   // Apply first closure; then apply the second.
 140   _c1->do_oop(p);
 141   _c2->do_oop(p);
 142 }
 143 
 144 template <class T>
 145 inline void G1TriggerClosure::do_oop_nv(T* p) {
 146   // Record that this closure was actually applied (triggered).
 147   _triggered = true;
 148 }
 149 
 150 template <class T>
 151 inline void G1InvokeIfNotTriggeredClosure::do_oop_nv(T* p) {
 152   if (!_trigger_cl->triggered()) {
 153     _oop_cl->do_oop(p);
 154   }
 155 }
 156 
 157 template <class T>
 158 inline void G1UpdateRSOrPushRefOopClosure::do_oop_nv(T* p) {
 159   oop obj = oopDesc::load_decode_heap_oop(p);
 160   if (obj == NULL) {
 161     return;
 162   }
 163 
 164 #ifdef ASSERT
 165   // can't do because of races
 166   // assert(obj == NULL || obj->is_oop(), "expected an oop");
 167 
 168   // Do the safe subset of is_oop
 169 #ifdef CHECK_UNHANDLED_OOPS
 170   oopDesc* o = obj.obj();
 171 #else
 172   oopDesc* o = obj;
 173 #endif // CHECK_UNHANDLED_OOPS
 174   assert((intptr_t)o % MinObjAlignmentInBytes == 0, "not oop aligned");
 175   assert(Universe::heap()->is_in_reserved(obj), "must be in heap");
 176 #endif // ASSERT
 177 
 178   assert(_from != NULL, "from region must be non-NULL");
 179   assert(_from->is_in_reserved(p), "p is not in from");
 180 
 181   HeapRegion* to = _g1->heap_region_containing(obj);
 182   if (_from == to) {
 183     // Normally this closure should only be called with cross-region references.
 184     // But since Java threads are manipulating the references concurrently and we
 185     // reload the values things may have changed.
 186     return;
 187   }
 188 
 189   // The _record_refs_into_cset flag is true during the RSet
 190   // updating part of an evacuation pause. It is false at all
 191   // other times:
 192   //  * rebuilding the remembered sets after a full GC
 193   //  * during concurrent refinement.
 194   //  * updating the remembered sets of regions in the collection
 195   //    set in the event of an evacuation failure (when deferred
 196   //    updates are enabled).
 197 
 198   if (_record_refs_into_cset && to->in_collection_set()) {
 199     // We are recording references that point into the collection
 200     // set and this particular reference does exactly that...
 201     // If the referenced object has already been forwarded
 202     // to itself, we are handling an evacuation failure and
 203     // we have already visited/tried to copy this object
 204     // there is no need to retry.
 205     if (!self_forwarded(obj)) {
 206       assert(_push_ref_cl != NULL, "should not be null");
 207       // Push the reference in the refs queue of the G1ParScanThreadState
 208       // instance for this worker thread.
 209       _push_ref_cl->do_oop(p);
 210     }
 211 
 212     // Deferred updates to the CSet are either discarded (in the normal case),
 213     // or processed (if an evacuation failure occurs) at the end
 214     // of the collection.
 215     // See G1RemSet::cleanup_after_oops_into_collection_set_do().
 216   } else {
 217     // We either don't care about pushing references that point into the
 218     // collection set (i.e. we're not during an evacuation pause) _or_
 219     // the reference doesn't point into the collection set. Either way
 220     // we add the reference directly to the RSet of the region containing
 221     // the referenced object.
 222     assert(to->rem_set() != NULL, "Need per-region 'into' remsets.");
 223     to->rem_set()->add_reference(p, _worker_i);
 224   }
 225 }
 226 
 227 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1OOPCLOSURES_INLINE_HPP