1 /* 2 * Copyright (c) 2018, 2019, 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_MEMORY_METASPACE_VIRTUALSPACELIST_HPP 26 #define SHARE_MEMORY_METASPACE_VIRTUALSPACELIST_HPP 27 28 #include "memory/allocation.hpp" 29 #include "memory/metaspace/counter.hpp" 30 #include "memory/metaspace/commitLimiter.hpp" 31 #include "memory/metaspace/virtualSpaceNode.hpp" 32 #include "memory/virtualspace.hpp" 33 #include "utilities/globalDefinitions.hpp" 34 35 36 namespace metaspace { 37 38 class Metachunk; 39 40 class VirtualSpaceList : public public CHeapObj<mtClass> { 41 42 // Name 43 const char* const _name; 44 45 // Head of the list. 46 VirtualSpaceNode* _first_node; 47 48 // Node currently being used for allocations. 49 VirtualSpaceNode* _current_node; 50 51 // Whether this list can expand by allocating new nodes. 52 const bool _can_expand; 53 54 // Used to check limits before committing memory. 55 CommitLimiter* const _commit_limiter; 56 57 // Statistics 58 59 // Holds sum of reserved space, in words, over all list nodes. 60 SizeCounter _reserved_words_counter; 61 62 // Holds sum of committed space, in words, over all list nodes. 63 SizeCounter _committed_words_counter; 64 65 // Create a new node and append it to the list. After 66 // this function, _current_node shall point to a new empty node. 67 // List must be expandable for this to work. 68 void create_new_node(); 69 70 public: 71 72 // Create a new, empty, expandable list. 73 VirtualSpaceList(const char* name, CommitLimiter* commit_limiter); 74 75 // Create a new list. The list will contain one node only, which uses the given ReservedSpace. 76 // It will be not expandable beyond that first node. 77 VirtualSpaceList(const char* name, ReservedSpace rs, CommitLimiter* commit_limiter); 78 79 virtual ~VirtualSpaceList(); 80 81 // Allocate a root chunk from this list. 82 // Note: this just returns a chunk whose memory is reserved; no memory is committed yet. 83 // Hence, before using this chunk, it must be committed. 84 // Also, no limits are checked, since no committing takes place. 85 Metachunk* allocate_root_chunk(); 86 87 DEBUG_ONLY(void verify(bool slow) const;) 88 89 //// Statistics //// 90 91 // Return sum of reserved words in all nodes. 92 size_t reserved_words() const { return _reserved_words_counter.get(); } 93 94 // Return sum of committed words in all nodes. 95 size_t committed_words() const { return _committed_words_counter.get(); } 96 97 //// Debug stuff //// 98 DEBUG_ONLY(void verify(bool slow) const;) 99 100 101 102 103 private: 104 105 static VirtualSpaceList* _vslist_class; 106 static VirtualSpaceList* _vslist_nonclass; 107 108 public: 109 110 static VirtualSpaceList* vslist_class() { return _vslist_class; } 111 static VirtualSpaceList* vslist_nonclass() { return _vslist_nonclass; } 112 113 static void initialize(VirtualSpaceList* vslist_class, VirtualSpaceList* vslist_nonclass); 114 115 116 }; 117 118 } // namespace metaspace 119 120 #endif // SHARE_MEMORY_METASPACE_VIRTUALSPACELIST_HPP