1 /*
   2  * Copyright (c) 2016, 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_SHARED_PRESERVEDMARKS_INLINE_HPP
  26 #define SHARE_VM_GC_SHARED_PRESERVEDMARKS_INLINE_HPP
  27 
  28 #include "gc/shared/preservedMarks.hpp"
  29 #include "oops/oop.inline.hpp"
  30 #include "utilities/stack.inline.hpp"
  31 
  32 inline bool PreservedMarks::should_preserve_mark(oop obj, markOop m) const {
  33   return m->must_be_preserved_for_promotion_failure(obj);
  34 }
  35 
  36 inline void PreservedMarks::push(oop obj, markOop m) {
  37   assert(should_preserve_mark(obj, m), "pre-condition");
  38   OopAndMarkOop elem(obj, m);
  39   _stack.push(elem);
  40 }
  41 
  42 inline void PreservedMarks::push_if_necessary(oop obj, markOop m) {
  43   if (should_preserve_mark(obj, m)) {
  44     push(obj, m);
  45   }
  46 }
  47 
  48 inline void PreservedMarks::init_forwarded_mark(oop obj) {
  49   obj->init_mark();
  50 }
  51 
  52 template <class E>
  53 inline void PreservedMarksSet::restore(E* executor) {
  54   volatile size_t total_size = 0;
  55 
  56 #ifdef ASSERT
  57   // This is to make sure the total_size we'll calculate below is correct.
  58   size_t total_size_before = 0;
  59   for (uint i = 0; i < _num; i += 1) {
  60     total_size_before += get(i)->size();
  61   }
  62 #endif // def ASSERT
  63 
  64   if (executor == NULL) {
  65     for (uint i = 0; i < _num; i += 1) {
  66       total_size += get(i)->size();
  67       get(i)->restore();
  68     }
  69   } else {
  70     // Right now, if the executor is not NULL we do the work in
  71     // parallel. In the future we might want to do the restoration
  72     // serially, if there's only a small number of marks per stack.
  73     restore_internal(executor, &total_size);
  74   }
  75   assert_empty();
  76 
  77   assert(total_size == total_size_before,
  78          "total_size = " SIZE_FORMAT " before = " SIZE_FORMAT,
  79          total_size, total_size_before);
  80 
  81   log_trace(gc)("Restored " SIZE_FORMAT " marks", total_size);
  82 }
  83 
  84 inline PreservedMarks::PreservedMarks()
  85     : _stack(OopAndMarkOopStack::default_segment_size(),
  86              // This stack should be used very infrequently so there's
  87              // no point in caching stack segments (there will be a
  88              // waste of space most of the time). So we set the max
  89              // cache size to 0.
  90              0 /* max_cache_size */) { }
  91 
  92 #endif // SHARE_VM_GC_SHARED_PRESERVEDMARKS_INLINE_HPP