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_VIRTUALSPACENODE_HPP 26 #define SHARE_MEMORY_METASPACE_VIRTUALSPACENODE_HPP 27 28 #include "memory/virtualspace.hpp" 29 #include "memory/memRegion.hpp" 30 #include "utilities/debug.hpp" 31 #include "utilities/globalDefinitions.hpp" 32 33 class outputStream; 34 35 namespace metaspace { 36 37 class Metachunk; 38 class ChunkManager; 39 class OccupancyMap; 40 41 // A VirtualSpaceList node. 42 class VirtualSpaceNode : public CHeapObj<mtClass> { 43 friend class VirtualSpaceList; 44 45 // Link to next VirtualSpaceNode 46 VirtualSpaceNode* _next; 47 48 // Whether this node is contained in class or metaspace. 49 const bool _is_class; 50 51 // total in the VirtualSpace 52 ReservedSpace _rs; 53 VirtualSpace _virtual_space; 54 MetaWord* _top; 55 // count of chunks contained in this VirtualSpace 56 uintx _container_count; 57 58 OccupancyMap* _occupancy_map; 59 60 // Convenience functions to access the _virtual_space 61 char* low() const { return virtual_space()->low(); } 62 char* high() const { return virtual_space()->high(); } 63 char* low_boundary() const { return virtual_space()->low_boundary(); } 64 char* high_boundary() const { return virtual_space()->high_boundary(); } 65 66 // The first Metachunk will be allocated at the bottom of the 67 // VirtualSpace 68 Metachunk* first_chunk() { return (Metachunk*) bottom(); } 69 70 // Committed but unused space in the virtual space 71 size_t free_words_in_vs() const; 72 73 // True if this node belongs to class metaspace. 74 bool is_class() const { return _is_class; } 75 76 // Helper function for take_from_committed: allocate padding chunks 77 // until top is at the given address. 78 void allocate_padding_chunks_until_top_is_at(MetaWord* target_top); 79 80 public: 81 82 VirtualSpaceNode(bool is_class, size_t byte_size); 83 VirtualSpaceNode(bool is_class, ReservedSpace rs) : 84 _next(NULL), _is_class(is_class), _rs(rs), _top(NULL), _container_count(0), _occupancy_map(NULL) {} 85 ~VirtualSpaceNode(); 86 87 // Convenience functions for logical bottom and (committed) end 88 MetaWord* bottom() const { return (MetaWord*) _virtual_space.low(); } 89 MetaWord* end() const { return (MetaWord*) _virtual_space.high(); } 90 91 const OccupancyMap* occupancy_map() const { return _occupancy_map; } 92 OccupancyMap* occupancy_map() { return _occupancy_map; } 93 94 bool contains(const void* ptr) { return ptr >= low() && ptr < high(); } 95 96 size_t reserved_words() const { return _virtual_space.reserved_size() / BytesPerWord; } 97 size_t committed_words() const { return _virtual_space.actual_committed_size() / BytesPerWord; } 98 99 bool is_pre_committed() const { return _virtual_space.special(); } 100 101 // address of next available space in _virtual_space; 102 // Accessors 103 VirtualSpaceNode* next() { return _next; } 104 void set_next(VirtualSpaceNode* v) { _next = v; } 105 106 void set_top(MetaWord* v) { _top = v; } 107 108 // Accessors 109 VirtualSpace* virtual_space() const { return (VirtualSpace*) &_virtual_space; } 110 111 // Returns true if "word_size" is available in the VirtualSpace 112 bool is_available(size_t word_size) { return word_size <= pointer_delta(end(), _top, sizeof(MetaWord)); } 113 114 MetaWord* top() const { return _top; } 115 void inc_top(size_t word_size) { _top += word_size; } 116 117 uintx container_count() { return _container_count; } 118 void inc_container_count(); 119 void dec_container_count(); 120 121 // used and capacity in this single entry in the list 122 size_t used_words_in_vs() const; 123 size_t capacity_words_in_vs() const; 124 125 bool initialize(); 126 127 // get space from the virtual space 128 Metachunk* take_from_committed(size_t chunk_word_size); 129 130 // Allocate a chunk from the virtual space and return it. 131 Metachunk* get_chunk_vs(size_t chunk_word_size); 132 133 // Expands the committed space by at least min_words words. 134 bool expand_by(size_t min_words, size_t preferred_words); 135 136 // In preparation for deleting this node, remove all the chunks 137 // in the node from any freelist. 138 void purge(ChunkManager* chunk_manager); 139 140 // If an allocation doesn't fit in the current node a new node is created. 141 // Allocate chunks out of the remaining committed space in this node 142 // to avoid wasting that memory. 143 // This always adds up because all the chunk sizes are multiples of 144 // the smallest chunk size. 145 void retire(ChunkManager* chunk_manager); 146 147 void print_on(outputStream* st) const { print_on(st, K); } 148 void print_on(outputStream* st, size_t scale) const; 149 void print_map(outputStream* st, bool is_class) const; 150 151 // Debug support 152 DEBUG_ONLY(void mangle();) 153 // Verify counters and basic structure. Slow mode: verify all chunks in depth and occupancy map. 154 DEBUG_ONLY(void verify(bool slow);) 155 // Verify that all free chunks in this node are ideally merged 156 // (there should not be multiple small chunks where a large chunk could exist.) 157 DEBUG_ONLY(void verify_free_chunks_are_ideally_merged();) 158 159 }; 160 161 } // namespace metaspace 162 163 #endif // SHARE_MEMORY_METASPACE_VIRTUALSPACENODE_HPP