1 /*
   2  * Copyright (c) 2018, Oracle and/or its affiliates. All rights reserved.
   3  * Copyright (c) 2017, Red Hat, Inc. and/or its affiliates.
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This code is free software; you can redistribute it and/or modify it
   7  * under the terms of the GNU General Public License version 2 only, as
   8  * published by the Free Software Foundation.
   9  *
  10  * This code is distributed in the hope that it will be useful, but WITHOUT
  11  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  12  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  13  * version 2 for more details (a copy is included in the LICENSE file that
  14  * accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License version
  17  * 2 along with this work; if not, write to the Free Software Foundation,
  18  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  19  *
  20  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  21  * or visit www.oracle.com if you need additional information or have any
  22  * questions.
  23  *
  24  */
  25 
  26 #ifndef SHARE_GC_SHARED_GCARGUMENTS_HPP
  27 #define SHARE_GC_SHARED_GCARGUMENTS_HPP
  28 
  29 #include "memory/allocation.hpp"
  30 
  31 class CollectedHeap;
  32 
  33 extern size_t HeapAlignment;
  34 extern size_t SpaceAlignment;
  35 
  36 class GCArguments {
  37 protected:
  38   // Initialize HeapAlignment, SpaceAlignment, and extra alignments (E.g. GenAlignment)
  39   virtual void initialize_alignments() = 0;
  40   virtual void initialize_heap_flags_and_sizes();
  41   virtual void initialize_size_info();
  42 
  43   DEBUG_ONLY(void assert_flags();)
  44   DEBUG_ONLY(void assert_size_info();)
  45 
  46 public:
  47   virtual void initialize();
  48   virtual size_t conservative_max_heap_alignment() = 0;
  49   virtual CollectedHeap* create_heap() = 0;
  50 
  51   // Allows GCs to tell external code if it's supported or not in the current setup.
  52   virtual bool is_supported() const {
  53     return true;
  54   }
  55 
  56   void initialize_heap_sizes();
  57 
  58   static size_t compute_heap_alignment();
  59 
  60   static bool check_args_consistency();
  61 };
  62 
  63 #endif // SHARE_GC_SHARED_GCARGUMENTS_HPP