1 /*
   2  * Copyright (c) 2001, 2012, 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 
  36 /*
  37  * This really ought to be an inline function, but apparently the C++
  38  * compiler sometimes sees fit to ignore inline declarations.  Sigh.
  39  */
  40 
  41 template <class T>
  42 inline void FilterIntoCSClosure::do_oop_nv(T* p) {
  43   T heap_oop = oopDesc::load_heap_oop(p);
  44   if (!oopDesc::is_null(heap_oop) &&
  45       _g1->obj_in_cs(oopDesc::decode_heap_oop_not_null(heap_oop))) {
  46     _oc->do_oop(p);
  47   }
  48 }
  49 
  50 template <class T>
  51 inline void FilterOutOfRegionClosure::do_oop_nv(T* p) {
  52   T heap_oop = oopDesc::load_heap_oop(p);
  53   if (!oopDesc::is_null(heap_oop)) {
  54     HeapWord* obj_hw = (HeapWord*)oopDesc::decode_heap_oop_not_null(heap_oop);
  55     if (obj_hw < _r_bottom || obj_hw >= _r_end) {
  56       _oc->do_oop(p);
  57     }
  58   }
  59 }
  60 
  61 // This closure is applied to the fields of the objects that have just been copied.
  62 template <class T>
  63 inline void G1ParScanClosure::do_oop_nv(T* p) {
  64   T heap_oop = oopDesc::load_heap_oop(p);
  65 
  66   if (!oopDesc::is_null(heap_oop)) {
  67     oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
  68     if (_g1->in_cset_fast_test(obj)) {
  69       // We're not going to even bother checking whether the object is
  70       // already forwarded or not, as this usually causes an immediate
  71       // stall. We'll try to prefetch the object (for write, given that
  72       // we might need to install the forwarding reference) and we'll
  73       // get back to it when pop it from the queue
  74       Prefetch::write(obj->mark_addr(), 0);
  75       Prefetch::read(obj->mark_addr(), (HeapWordSize*2));
  76 
  77       // slightly paranoid test; I'm trying to catch potential
  78       // problems before we go into push_on_queue to know where the
  79       // problem is coming from
  80       assert((obj == oopDesc::load_decode_heap_oop(p)) ||
  81              (obj->is_forwarded() &&
  82                  obj->forwardee() == oopDesc::load_decode_heap_oop(p)),
  83              "p should still be pointing to obj or to its forwardee");
  84 
  85       _par_scan_state->push_on_queue(p);
  86     } else {
  87       _par_scan_state->update_rs(_from, p, _worker_id);
  88     }
  89   }
  90 }
  91 
  92 template <class T>
  93 inline void G1ParPushHeapRSClosure::do_oop_nv(T* p) {
  94   T heap_oop = oopDesc::load_heap_oop(p);
  95 
  96   if (!oopDesc::is_null(heap_oop)) {
  97     oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
  98     if (_g1->in_cset_fast_test(obj)) {
  99       Prefetch::write(obj->mark_addr(), 0);
 100       Prefetch::read(obj->mark_addr(), (HeapWordSize*2));
 101 
 102       // Place on the references queue
 103       _par_scan_state->push_on_queue(p);
 104     }
 105   }
 106 }
 107 
 108 template <class T>
 109 inline void G1CMOopClosure::do_oop_nv(T* p) {
 110   assert(_g1h->is_in_g1_reserved((HeapWord*) p), "invariant");
 111   assert(!_g1h->is_on_master_free_list(
 112                     _g1h->heap_region_containing((HeapWord*) p)), "invariant");
 113 
 114   oop obj = oopDesc::load_decode_heap_oop(p);
 115   if (_cm->verbose_high()) {
 116     gclog_or_tty->print_cr("[%u] we're looking at location "
 117                            "*"PTR_FORMAT" = "PTR_FORMAT,
 118                            _task->worker_id(), p, (void*) obj);
 119   }
 120   _task->deal_with_reference(obj);
 121 }
 122 
 123 template <class T>
 124 inline void G1RootRegionScanClosure::do_oop_nv(T* p) {
 125   T heap_oop = oopDesc::load_heap_oop(p);
 126   if (!oopDesc::is_null(heap_oop)) {
 127     oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
 128     HeapRegion* hr = _g1h->heap_region_containing((HeapWord*) obj);
 129     _cm->grayRoot(obj, obj->size(), _worker_id, hr);
 130   }
 131 }
 132 
 133 template <class T>
 134 inline void G1Mux2Closure::do_oop_nv(T* p) {
 135   // Apply first closure; then apply the second.
 136   _c1->do_oop(p);
 137   _c2->do_oop(p);
 138 }
 139 
 140 template <class T>
 141 inline void G1TriggerClosure::do_oop_nv(T* p) {
 142   // Record that this closure was actually applied (triggered).
 143   _triggered = true;
 144 }
 145 
 146 template <class T>
 147 inline void G1InvokeIfNotTriggeredClosure::do_oop_nv(T* p) {
 148   if (!_trigger_cl->triggered()) {
 149     _oop_cl->do_oop(p);
 150   }
 151 }
 152 
 153 template <class T>
 154 inline void G1UpdateRSOrPushRefOopClosure::do_oop_nv(T* p) {
 155   oop obj = oopDesc::load_decode_heap_oop(p);
 156   if (obj == NULL) {
 157     return;
 158   }
 159 
 160 #ifdef ASSERT
 161   // can't do because of races
 162   // assert(obj == NULL || obj->is_oop(), "expected an oop");
 163 
 164   // Do the safe subset of is_oop
 165 #ifdef CHECK_UNHANDLED_OOPS
 166   oopDesc* o = obj.obj();
 167 #else
 168   oopDesc* o = obj;
 169 #endif // CHECK_UNHANDLED_OOPS
 170   assert((intptr_t)o % MinObjAlignmentInBytes == 0, "not oop aligned");
 171   assert(Universe::heap()->is_in_reserved(obj), "must be in heap");
 172 #endif // ASSERT
 173 
 174   assert(_from != NULL, "from region must be non-NULL");
 175   assert(_from->is_in_reserved(p), "p is not in from");
 176 
 177   HeapRegion* to = _g1->heap_region_containing(obj);
 178   if (_from == to) {
 179     // Normally this closure should only be called with cross-region references.
 180     // But since Java threads are manipulating the references concurrently and we
 181     // reload the values things may have changed.
 182     return;
 183   }
 184 
 185   // The _record_refs_into_cset flag is true during the RSet
 186   // updating part of an evacuation pause. It is false at all
 187   // other times:
 188   //  * rebuilding the remembered sets after a full GC
 189   //  * during concurrent refinement.
 190   //  * updating the remembered sets of regions in the collection
 191   //    set in the event of an evacuation failure (when deferred
 192   //    updates are enabled).
 193 
 194   if (_record_refs_into_cset && to->in_collection_set()) {
 195     // We are recording references that point into the collection
 196     // set and this particular reference does exactly that...
 197     // If the referenced object has already been forwarded
 198     // to itself, we are handling an evacuation failure and
 199     // we have already visited/tried to copy this object
 200     // there is no need to retry.
 201     if (!self_forwarded(obj)) {
 202       assert(_push_ref_cl != NULL, "should not be null");
 203       // Push the reference in the refs queue of the G1ParScanThreadState
 204       // instance for this worker thread.
 205       _push_ref_cl->do_oop(p);
 206     }
 207 
 208     // Deferred updates to the CSet are either discarded (in the normal case),
 209     // or processed (if an evacuation failure occurs) at the end
 210     // of the collection.
 211     // See G1RemSet::cleanup_after_oops_into_collection_set_do().
 212   } else {
 213     // We either don't care about pushing references that point into the
 214     // collection set (i.e. we're not during an evacuation pause) _or_
 215     // the reference doesn't point into the collection set. Either way
 216     // we add the reference directly to the RSet of the region containing
 217     // the referenced object.
 218     assert(to->rem_set() != NULL, "Need per-region 'into' remsets.");
 219     to->rem_set()->add_reference(p, _worker_i);
 220   }
 221 }
 222 
 223 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1OOPCLOSURES_INLINE_HPP