1 /* 2 * Copyright (c) 2016, 2018, 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_JFR_WRITERS_JFRSTORAGEADAPTER_HPP 26 #define SHARE_VM_JFR_WRITERS_JFRSTORAGEADAPTER_HPP 27 28 #include "jfr/utilities/jfrAllocation.hpp" 29 30 class Thread; 31 32 // 33 // The adapters present writers with a uniform interface over storage. 34 // 35 // Adapter policy 36 // 37 // StorageType* storage(); 38 // const u1* start() const; 39 // const u1* pos(); 40 // const u1* end() const; 41 // void commit(u1* position); 42 // bool flush(size_t used, size_t requested); 43 // void release(); 44 // 45 46 template <typename Flush> 47 class Adapter { 48 public: 49 typedef typename Flush::Type StorageType; 50 Adapter(StorageType* storage, Thread* thread) : _storage(storage), _thread(thread) {} 51 Adapter(Thread* thread) : _storage(NULL), _thread(thread) {} 52 53 void set_storage(StorageType* storage) { 54 _storage = storage; 55 } 56 57 StorageType* storage() { 58 return _storage; 59 } 60 61 const u1* start() const { 62 assert(_storage != NULL, "invariant"); 63 return _storage->start(); 64 } 65 66 u1* pos() { 67 assert(_storage != NULL, "invariant"); 68 return _storage->pos(); 69 } 70 71 const u1* end() const { 72 assert(_storage != NULL, "invariant"); 73 return _storage->end(); 74 } 75 76 void commit(u1* position) { 77 assert(_storage != NULL, "invariant"); 78 _storage->set_pos(position); 79 } 80 81 bool flush(size_t used, size_t requested) { 82 assert(_thread != NULL, "invariant"); 83 Flush f(_storage, used, requested, _thread); 84 _storage = f.result(); 85 return _storage != NULL; 86 } 87 88 void release() { 89 if (_storage != NULL && _storage->lease()) { 90 // This flush call will return the lease 91 // of a temporary storage area. 92 // Since the requested size is 0, 93 // the flush implementation will accomodate 94 // that 'size' request in the 95 // original thread local storage, 96 // by implication restoring the original 97 // in the process of returning a lease. 98 flush(0, 0); 99 } 100 } 101 102 private: 103 StorageType* _storage; 104 Thread* _thread; 105 }; 106 107 template <size_t DEFAULT_SIZE = K> 108 class MallocAdapter { 109 private: 110 u1* _start; 111 u1* _pos; 112 u1* _end; 113 size_t _initial_size; 114 bool _has_ownership; 115 116 bool allocate(size_t size); 117 void deallocate(); 118 119 public: 120 typedef u1 StorageType; 121 MallocAdapter(u1* storage, Thread* thread); 122 MallocAdapter(u1* storage, size_t size); 123 MallocAdapter(Thread* thread); 124 ~MallocAdapter(); 125 126 StorageType* storage() { return _start; } 127 const u1* start() const { return _start; } 128 u1* pos() { return _pos; } 129 void commit(u1* position) { _pos = position; } 130 const u1* end() const { return _end; } 131 void release() {} 132 bool flush(size_t used, size_t requested); 133 }; 134 135 template <size_t DEFAULT_SIZE> 136 MallocAdapter<DEFAULT_SIZE>::MallocAdapter(u1* storage, size_t size) : 137 _start(storage), 138 _pos(storage), 139 _end(storage + size), 140 _initial_size(size), 141 _has_ownership(false) { 142 } 143 144 template <size_t DEFAULT_SIZE> 145 MallocAdapter<DEFAULT_SIZE> ::MallocAdapter(u1* storage, Thread* thread) : 146 _start(storage), 147 _pos(storage), 148 _end(storage), 149 _initial_size(0), 150 _has_ownership(false) { 151 } 152 153 template <size_t DEFAULT_SIZE> 154 MallocAdapter<DEFAULT_SIZE>::MallocAdapter(Thread* thread) : 155 _start(NULL), 156 _pos(NULL), 157 _end(NULL), 158 _initial_size(DEFAULT_SIZE), 159 _has_ownership(true) { 160 allocate(DEFAULT_SIZE); 161 } 162 163 template <size_t DEFAULT_SIZE> 164 MallocAdapter<DEFAULT_SIZE>::~MallocAdapter() { 165 if (_has_ownership) { 166 deallocate(); 167 } 168 } 169 170 template <size_t DEFAULT_SIZE> 171 bool MallocAdapter<DEFAULT_SIZE>::allocate(size_t size) { 172 if (NULL == _start) { 173 _start = JfrCHeapObj::new_array<u1>(size); 174 if (_start) { 175 _pos = _start; 176 _end = _start + size; 177 _initial_size = size; 178 } 179 } 180 return _start != NULL; 181 } 182 183 template <size_t DEFAULT_SIZE> 184 void MallocAdapter<DEFAULT_SIZE>::deallocate() { 185 if (_start != NULL) { 186 JfrCHeapObj::free(_start, (size_t)(_end - _start)); 187 } 188 } 189 190 template <size_t DEFAULT_SIZE> 191 bool MallocAdapter<DEFAULT_SIZE>::flush(size_t used, size_t requested) { 192 if (!_has_ownership) { 193 // can't just realloc a storage that we don't own 194 return false; 195 } 196 assert(_start != NULL, "invariant"); 197 assert(used <= (size_t)(_end - _pos), "invariant"); 198 assert(_pos + used <= _end, "invariant"); 199 const size_t previous_storage_size = _end - _start; 200 const size_t new_storage_size = used + requested + (previous_storage_size * 2); 201 u1* const new_storage = JfrCHeapObj::new_array<u1>(new_storage_size); 202 if (!new_storage) { 203 return false; 204 } 205 const size_t previous_pos_offset = _pos - _start; 206 // migrate in-flight data 207 memcpy(new_storage, _start, previous_pos_offset + used); 208 JfrCHeapObj::free(_start, previous_storage_size); 209 _start = new_storage; 210 _pos = _start + previous_pos_offset; 211 _end = _start + new_storage_size; 212 return true; 213 } 214 215 class NoOwnershipAdapter { 216 private: 217 u1* _start; 218 u1* _pos; 219 u1* _end; 220 size_t _size; 221 222 public: 223 typedef u1 StorageType; 224 NoOwnershipAdapter(u1* storage, size_t size) : _start(storage), _pos(storage), _end(storage + size), _size(size) {} 225 NoOwnershipAdapter(u1* storage, Thread* thread) : _start(storage), _pos(storage), _end(storage), _size(0) { 226 ShouldNotCallThis(); 227 } 228 NoOwnershipAdapter(Thread* thread) : _start(NULL), _pos(NULL), _end(NULL), _size(0) { 229 ShouldNotCallThis(); 230 } 231 StorageType* storage() { return _start; } 232 const u1* start() const { return _start; } 233 u1* pos() { return _pos; } 234 void commit(u1* position) { _pos = position; } 235 const u1* end() const { return _end; } 236 void release() {} 237 bool flush(size_t used, size_t requested) { 238 // don't flush/expand a buffer that is not our own 239 return false; 240 } 241 }; 242 243 #endif // SHARE_VM_JFR_WRITERS_JFRSTORAGEADAPTER_HPP