1 /*
   2  * Copyright (c) 2000, 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_SHARED_MARKSWEEP_INLINE_HPP
  26 #define SHARE_VM_GC_IMPLEMENTATION_SHARED_MARKSWEEP_INLINE_HPP
  27 
  28 #include "gc_implementation/shared/markSweep.hpp"
  29 #include "gc_interface/collectedHeap.hpp"
  30 #include "utilities/stack.inline.hpp"
  31 #include "utilities/macros.hpp"
  32 #if INCLUDE_ALL_GCS
  33 #include "gc_implementation/g1/g1StringDedup.hpp"
  34 #include "gc_implementation/parallelScavenge/psParallelCompact.hpp"
  35 #endif // INCLUDE_ALL_GCS
  36 
  37 inline void MarkSweep::mark_object(oop obj) {
  38 #if INCLUDE_ALL_GCS
  39   if (G1StringDedup::is_enabled()) {
  40     // We must enqueue the object before it is marked
  41     // as we otherwise can't read the object's age.
  42     G1StringDedup::enqueue_from_mark(obj);
  43   }
  44 #endif
  45   // some marks may contain information we need to preserve so we store them away
  46   // and overwrite the mark.  We'll restore it at the end of markSweep.
  47   markOop mark = obj->mark();
  48   obj->set_mark(markOopDesc::prototype()->set_marked());
  49 
  50   if (mark->must_be_preserved(obj)) {
  51     preserve_mark(obj, mark);
  52   }
  53 }
  54 
  55 inline void MarkSweep::follow_klass(Klass* klass) {
  56   oop op = klass->klass_holder();
  57   MarkSweep::mark_and_push(&op);
  58 }
  59 
  60 template <class T> inline void MarkSweep::follow_root(T* p) {
  61   assert(!Universe::heap()->is_in_reserved(p),
  62          "roots shouldn't be things within the heap");
  63   T heap_oop = oopDesc::load_heap_oop(p);
  64   if (!oopDesc::is_null(heap_oop)) {
  65     oop obj = oopDesc::decode_heap_oop_not_null(heap_oop);
  66     if (!obj->mark()->is_marked()) {
  67       mark_object(obj);
  68       obj->follow_contents();
  69     }
  70   }
  71   follow_stack();
  72 }
  73 
  74 template <class T> inline void MarkSweep::mark_and_push(T* p) {
  75 //  assert(Universe::heap()->is_in_reserved(p), "should be in object space");
  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 (!obj->mark()->is_marked()) {
  80       mark_object(obj);
  81       _marking_stack.push(obj);
  82     }
  83   }
  84 }
  85 
  86 void MarkSweep::push_objarray(oop obj, size_t index) {
  87   ObjArrayTask task(obj, index);
  88   assert(task.is_valid(), "bad ObjArrayTask");
  89   _objarray_stack.push(task);
  90 }
  91 
  92 template <class T> inline void MarkSweep::adjust_pointer(T* p) {
  93   T heap_oop = oopDesc::load_heap_oop(p);
  94   if (!oopDesc::is_null(heap_oop)) {
  95     oop obj     = oopDesc::decode_heap_oop_not_null(heap_oop);
  96     oop new_obj = oop(obj->mark()->decode_pointer());
  97     assert(new_obj != NULL ||                         // is forwarding ptr?
  98            obj->mark() == markOopDesc::prototype() || // not gc marked?
  99            (UseBiasedLocking && obj->mark()->has_bias_pattern()),
 100                                                       // not gc marked?
 101            "should be forwarded");
 102     if (new_obj != NULL) {
 103       assert(Universe::heap()->is_in_reserved(new_obj),
 104              "should be in object space");
 105       oopDesc::encode_store_heap_oop_not_null(p, new_obj);
 106     }
 107   }
 108 }
 109 
 110 template <class T> inline void MarkSweep::KeepAliveClosure::do_oop_work(T* p) {
 111   mark_and_push(p);
 112 }
 113 
 114 #endif // SHARE_VM_GC_IMPLEMENTATION_SHARED_MARKSWEEP_INLINE_HPP