1 /*
   2  * Copyright (c) 2001, 2010, 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_G1REMSET_INLINE_HPP
  26 #define SHARE_VM_GC_IMPLEMENTATION_G1_G1REMSET_INLINE_HPP
  27 
  28 #include "gc_implementation/g1/g1RemSet.hpp"
  29 #include "gc_implementation/g1/heapRegionRemSet.hpp"
  30 #include "oops/oop.inline.hpp"
  31 
  32 inline size_t G1RemSet::n_workers() {
  33   if (_g1->workers() != NULL) {
  34     return _g1->workers()->total_workers();
  35   } else {
  36     return 1;
  37   }
  38 }
  39 
  40 template <class T>
  41 inline void G1RemSet::write_ref_nv(HeapRegion* from, T* p) {
  42   par_write_ref_nv(from, p, 0);
  43 }
  44 
  45 inline bool G1RemSet::self_forwarded(oop obj) {
  46   bool result =  (obj->is_forwarded() && (obj->forwardee()== obj));
  47   return result;
  48 }
  49 
  50 template <class T>
  51 inline void G1RemSet::par_write_ref_nv(HeapRegion* from, T* p, int tid) {
  52   oop obj = oopDesc::load_decode_heap_oop(p);
  53 #ifdef ASSERT
  54   // can't do because of races
  55   // assert(obj == NULL || obj->is_oop(), "expected an oop");
  56 
  57   // Do the safe subset of is_oop
  58   if (obj != NULL) {
  59 #ifdef CHECK_UNHANDLED_OOPS
  60     oopDesc* o = obj.obj();
  61 #else
  62     oopDesc* o = obj;
  63 #endif // CHECK_UNHANDLED_OOPS
  64     assert((intptr_t)o % MinObjAlignmentInBytes == 0, "not oop aligned");
  65     assert(Universe::heap()->is_in_reserved(obj), "must be in heap");
  66   }
  67 #endif // ASSERT
  68 
  69   assert(from == NULL || from->is_in_reserved(p), "p is not in from");
  70 
  71   HeapRegion* to = _g1->heap_region_containing(obj);
  72   // The test below could be optimized by applying a bit op to to and from.
  73   if (to != NULL && from != NULL && from != to) {
  74     // The _traversal_in_progress flag is true during the collection pause,
  75     // false during the evacuation failure handling. This should avoid a
  76     // potential loop if we were to add the card containing 'p' to the DCQS
  77     // that's used to regenerate the remembered sets for the collection set,
  78     // in the event of an evacuation failure, here. The UpdateRSImmediate
  79     // closure will eventally call this routine.
  80     if (_traversal_in_progress &&
  81         to->in_collection_set() && !self_forwarded(obj)) {
  82 
  83       assert(_cset_rs_update_cl[tid] != NULL, "should have been set already");
  84       _cset_rs_update_cl[tid]->do_oop(p);
  85 
  86       // Deferred updates to the CSet are either discarded (in the normal case),
  87       // or processed (if an evacuation failure occurs) at the end
  88       // of the collection.
  89       // See G1RemSet::cleanup_after_oops_into_collection_set_do().
  90     } else {
  91 #if G1_REM_SET_LOGGING
  92       gclog_or_tty->print_cr("Adding " PTR_FORMAT " (" PTR_FORMAT ") to RS"
  93                              " for region [" PTR_FORMAT ", " PTR_FORMAT ")",
  94                              p, obj,
  95                              to->bottom(), to->end());
  96 #endif
  97       assert(to->rem_set() != NULL, "Need per-region 'into' remsets.");
  98       to->rem_set()->add_reference(p, tid);
  99     }
 100   }
 101 }
 102 
 103 template <class T>
 104 inline void UpdateRSOopClosure::do_oop_work(T* p) {
 105   assert(_from != NULL, "from region must be non-NULL");
 106   _rs->par_write_ref(_from, p, _worker_i);
 107 }
 108 
 109 template <class T>
 110 inline void UpdateRSetImmediate::do_oop_work(T* p) {
 111   assert(_from->is_in_reserved(p), "paranoia");
 112   T heap_oop = oopDesc::load_heap_oop(p);
 113   if (!oopDesc::is_null(heap_oop) && !_from->is_survivor()) {
 114     _g1_rem_set->par_write_ref(_from, p, 0);
 115   }
 116 }
 117 
 118 
 119 #endif // SHARE_VM_GC_IMPLEMENTATION_G1_G1REMSET_INLINE_HPP