1 /*
   2  * Copyright (c) 2007, 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.
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  24 
  25 #ifndef SHARE_VM_GC_IMPLEMENTATION_PARNEW_PAROOPCLOSURES_INLINE_HPP
  26 #define SHARE_VM_GC_IMPLEMENTATION_PARNEW_PAROOPCLOSURES_INLINE_HPP
  27 
  28 #include "gc_implementation/parNew/parNewGeneration.hpp"
  29 #include "gc_implementation/parNew/parOopClosures.hpp"
  30 #include "memory/cardTableRS.hpp"
  31 
  32 template <class T> inline void ParScanWeakRefClosure::do_oop_work(T* p) {
  33   assert (!oopDesc::is_null(*p), "null weak reference?");
  34   oop obj = oopDesc::load_decode_heap_oop_not_null(p);
  35   // weak references are sometimes scanned twice; must check
  36   // that to-space doesn't already contain this object
  37   if ((HeapWord*)obj < _boundary && !_g->to()->is_in_reserved(obj)) {
  38     // we need to ensure that it is copied (see comment in
  39     // ParScanClosure::do_oop_work).
  40     Klass* objK = obj->klass();
  41     markOop m = obj->mark();
  42     oop new_obj;
  43     if (m->is_marked()) { // Contains forwarding pointer.
  44       new_obj = ParNewGeneration::real_forwardee(obj);
  45     } else {
  46       size_t obj_sz = obj->size_given_klass(objK);
  47       new_obj = ((ParNewGeneration*)_g)->copy_to_survivor_space(_par_scan_state,
  48                                                                 obj, obj_sz, m);
  49     }
  50     oopDesc::encode_store_heap_oop_not_null(p, new_obj);
  51   }
  52 }
  53 
  54 inline void ParScanWeakRefClosure::do_oop_nv(oop* p)       { ParScanWeakRefClosure::do_oop_work(p); }
  55 inline void ParScanWeakRefClosure::do_oop_nv(narrowOop* p) { ParScanWeakRefClosure::do_oop_work(p); }
  56 
  57 template <class T> inline void ParScanClosure::par_do_barrier(T* p) {
  58   assert(generation()->is_in_reserved(p), "expected ref in generation");
  59   assert(!oopDesc::is_null(*p), "expected non-null object");
  60   oop obj = oopDesc::load_decode_heap_oop_not_null(p);
  61   // If p points to a younger generation, mark the card.
  62   if ((HeapWord*)obj < gen_boundary()) {
  63     rs()->write_ref_field_gc_par(p, obj);
  64   }
  65 }
  66 
  67 template <class T>
  68 inline void ParScanClosure::do_oop_work(T* p,
  69                                         bool gc_barrier,
  70                                         bool root_scan) {
  71   assert((!Universe::heap()->is_in_reserved(p) ||
  72           generation()->is_in_reserved(p))
  73          && (generation()->level() == 0 || gc_barrier),
  74          "The gen must be right, and we must be doing the barrier "
  75          "in older generations.");
  76   T heap_oop = oopDesc::load_heap_oop(p);
  77   if (!oopDesc::is_null(heap_oop)) {
  78     oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
  79     if ((HeapWord*)obj < _boundary) {
  80 #ifndef PRODUCT
  81       if (_g->to()->is_in_reserved(obj)) {
  82         tty->print_cr("Scanning field (" PTR_FORMAT ") twice?", p2i(p));
  83         GenCollectedHeap* gch =  (GenCollectedHeap*)Universe::heap();
  84         Space* sp = gch->space_containing(p);
  85         oop obj = oop(sp->block_start(p));
  86         assert((HeapWord*)obj < (HeapWord*)p, "Error");
  87         tty->print_cr("Object: " PTR_FORMAT, p2i((void *)obj));
  88         tty->print_cr("-------");
  89         obj->print();
  90         tty->print_cr("-----");
  91         tty->print_cr("Heap:");
  92         tty->print_cr("-----");
  93         gch->print();
  94         ShouldNotReachHere();
  95       }
  96 #endif
  97       // OK, we need to ensure that it is copied.
  98       // We read the klass and mark in this order, so that we can reliably
  99       // get the size of the object: if the mark we read is not a
 100       // forwarding pointer, then the klass is valid: the klass is only
 101       // overwritten with an overflow next pointer after the object is
 102       // forwarded.
 103       Klass* objK = obj->klass();
 104       markOop m = obj->mark();
 105       oop new_obj;
 106       if (m->is_marked()) { // Contains forwarding pointer.
 107         new_obj = ParNewGeneration::real_forwardee(obj);
 108         oopDesc::encode_store_heap_oop_not_null(p, new_obj);
 109 #ifndef PRODUCT
 110         if (TraceScavenge) {
 111           gclog_or_tty->print_cr("{%s %s ( " PTR_FORMAT " ) " PTR_FORMAT " -> " PTR_FORMAT " (%d)}",
 112              "forwarded ",
 113              new_obj->klass()->internal_name(), p2i(p), p2i((void *)obj), p2i((void *)new_obj), new_obj->size());
 114         }
 115 #endif
 116 
 117       } else {
 118         size_t obj_sz = obj->size_given_klass(objK);
 119         new_obj = _g->copy_to_survivor_space(_par_scan_state, obj, obj_sz, m);
 120         oopDesc::encode_store_heap_oop_not_null(p, new_obj);
 121         if (root_scan) {
 122           // This may have pushed an object.  If we have a root
 123           // category with a lot of roots, can't let the queue get too
 124           // full:
 125           (void)_par_scan_state->trim_queues(10 * ParallelGCThreads);
 126         }
 127       }
 128       if (is_scanning_a_klass()) {
 129         do_klass_barrier();
 130       } else if (gc_barrier) {
 131         // Now call parent closure
 132         par_do_barrier(p);
 133       }
 134     }
 135   }
 136 }
 137 
 138 inline void ParScanWithBarrierClosure::do_oop_nv(oop* p)       { ParScanClosure::do_oop_work(p, true, false); }
 139 inline void ParScanWithBarrierClosure::do_oop_nv(narrowOop* p) { ParScanClosure::do_oop_work(p, true, false); }
 140 
 141 inline void ParScanWithoutBarrierClosure::do_oop_nv(oop* p)       { ParScanClosure::do_oop_work(p, false, false); }
 142 inline void ParScanWithoutBarrierClosure::do_oop_nv(narrowOop* p) { ParScanClosure::do_oop_work(p, false, false); }
 143 
 144 #endif // SHARE_VM_GC_IMPLEMENTATION_PARNEW_PAROOPCLOSURES_INLINE_HPP