1 /*
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   3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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   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.
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   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  *
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  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
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  24 
  25 #ifndef SHARE_VM_GC_CMS_PAROOPCLOSURES_INLINE_HPP
  26 #define SHARE_VM_GC_CMS_PAROOPCLOSURES_INLINE_HPP
  27 
  28 #include "gc/cms/parNewGeneration.hpp"
  29 #include "gc/cms/parOopClosures.hpp"
  30 #include "gc/shared/cardTableRS.hpp"
  31 #include "gc/shared/genCollectedHeap.hpp"
  32 #include "gc/shared/genOopClosures.inline.hpp"
  33 
  34 template <class T> inline void ParScanWeakRefClosure::do_oop_work(T* p) {
  35   assert (!oopDesc::is_null(*p), "null weak reference?");
  36   oop obj = oopDesc::load_decode_heap_oop_not_null(p);
  37   // weak references are sometimes scanned twice; must check
  38   // that to-space doesn't already contain this object
  39   if ((HeapWord*)obj < _boundary && !_g->to()->is_in_reserved(obj)) {
  40     // we need to ensure that it is copied (see comment in
  41     // ParScanClosure::do_oop_work).
  42     Klass* objK = obj->klass();
  43     markOop m = obj->mark();
  44     oop new_obj;
  45     if (m->is_marked()) { // Contains forwarding pointer.
  46       new_obj = ParNewGeneration::real_forwardee(obj);
  47     } else {
  48       size_t obj_sz = obj->size_given_klass(objK);
  49       new_obj = ((ParNewGeneration*)_g)->copy_to_survivor_space(_par_scan_state,
  50                                                                 obj, obj_sz, m);
  51     }
  52     oopDesc::encode_store_heap_oop_not_null(p, new_obj);
  53   }
  54 }
  55 
  56 inline void ParScanWeakRefClosure::do_oop_nv(oop* p)       { ParScanWeakRefClosure::do_oop_work(p); }
  57 inline void ParScanWeakRefClosure::do_oop_nv(narrowOop* p) { ParScanWeakRefClosure::do_oop_work(p); }
  58 
  59 template <class T> inline void ParScanClosure::par_do_barrier(T* p) {
  60   assert(generation()->is_in_reserved(p), "expected ref in generation");
  61   assert(!oopDesc::is_null(*p), "expected non-null object");
  62   oop obj = oopDesc::load_decode_heap_oop_not_null(p);
  63   // If p points to a younger generation, mark the card.
  64   if ((HeapWord*)obj < gen_boundary()) {
  65     rs()->write_ref_field_gc_par(p, obj);
  66   }
  67 }
  68 
  69 template <class T>
  70 inline void ParScanClosure::do_oop_work(T* p,
  71                                         bool gc_barrier,
  72                                         bool root_scan) {
  73   assert((!GenCollectedHeap::heap()->is_in_reserved(p) ||
  74           generation()->is_in_reserved(p))
  75          && (GenCollectedHeap::heap()->is_young_gen(generation()) || gc_barrier),
  76          "The gen must be right, and we must be doing the barrier "
  77          "in older generations.");
  78   T heap_oop = oopDesc::load_heap_oop(p);
  79   if (!oopDesc::is_null(heap_oop)) {
  80     oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
  81     if ((HeapWord*)obj < _boundary) {
  82 #ifndef PRODUCT
  83       if (_g->to()->is_in_reserved(obj)) {
  84         tty->print_cr("Scanning field (" PTR_FORMAT ") twice?", p2i(p));
  85         GenCollectedHeap* gch = GenCollectedHeap::heap();
  86         Space* sp = gch->space_containing(p);
  87         oop obj = oop(sp->block_start(p));
  88         assert((HeapWord*)obj < (HeapWord*)p, "Error");
  89         tty->print_cr("Object: " PTR_FORMAT, p2i((void *)obj));
  90         tty->print_cr("-------");
  91         obj->print();
  92         tty->print_cr("-----");
  93         tty->print_cr("Heap:");
  94         tty->print_cr("-----");
  95         gch->print();
  96         ShouldNotReachHere();
  97       }
  98 #endif
  99       // OK, we need to ensure that it is copied.
 100       // We read the klass and mark in this order, so that we can reliably
 101       // get the size of the object: if the mark we read is not a
 102       // forwarding pointer, then the klass is valid: the klass is only
 103       // overwritten with an overflow next pointer after the object is
 104       // forwarded.
 105       Klass* objK = obj->klass();
 106       markOop m = obj->mark();
 107       oop new_obj;
 108       if (m->is_marked()) { // Contains forwarding pointer.
 109         new_obj = ParNewGeneration::real_forwardee(obj);
 110         oopDesc::encode_store_heap_oop_not_null(p, new_obj);
 111 #ifndef PRODUCT
 112         if (TraceScavenge) {
 113           gclog_or_tty->print_cr("{%s %s ( " PTR_FORMAT " ) " PTR_FORMAT " -> " PTR_FORMAT " (%d)}",
 114              "forwarded ",
 115              new_obj->klass()->internal_name(), p2i(p), p2i((void *)obj), p2i((void *)new_obj), new_obj->size());
 116         }
 117 #endif
 118 
 119       } else {
 120         size_t obj_sz = obj->size_given_klass(objK);
 121         new_obj = _g->copy_to_survivor_space(_par_scan_state, obj, obj_sz, m);
 122         oopDesc::encode_store_heap_oop_not_null(p, new_obj);
 123         if (root_scan) {
 124           // This may have pushed an object.  If we have a root
 125           // category with a lot of roots, can't let the queue get too
 126           // full:
 127           (void)_par_scan_state->trim_queues(10 * ParallelGCThreads);
 128         }
 129       }
 130       if (is_scanning_a_klass()) {
 131         do_klass_barrier();
 132       } else if (gc_barrier) {
 133         // Now call parent closure
 134         par_do_barrier(p);
 135       }
 136     }
 137   }
 138 }
 139 
 140 inline void ParScanWithBarrierClosure::do_oop_nv(oop* p)       { ParScanClosure::do_oop_work(p, true, false); }
 141 inline void ParScanWithBarrierClosure::do_oop_nv(narrowOop* p) { ParScanClosure::do_oop_work(p, true, false); }
 142 
 143 inline void ParScanWithoutBarrierClosure::do_oop_nv(oop* p)       { ParScanClosure::do_oop_work(p, false, false); }
 144 inline void ParScanWithoutBarrierClosure::do_oop_nv(narrowOop* p) { ParScanClosure::do_oop_work(p, false, false); }
 145 
 146 #endif // SHARE_VM_GC_CMS_PAROOPCLOSURES_INLINE_HPP