1 /* 2 * Copyright (c) 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_VM_JFR_RECORDER_STORAGE_JFRMEMORYSPACERETRIEVAL_HPP 26 #define SHARE_VM_JFR_RECORDER_STORAGE_JFRMEMORYSPACERETRIEVAL_HPP 27 28 #include "memory/allocation.hpp" 29 #include "jfr/recorder/storage/jfrBuffer.hpp" 30 #include "jfr/recorder/repository/jfrChunkWriter.hpp" 31 #include "jfr/utilities/jfrAllocation.hpp" 32 #include "jfr/utilities/jfrTypes.hpp" 33 34 /* 35 * Some policy classes for getting mspace memory 36 */ 37 38 template <typename Mspace> 39 class JfrMspaceRetrieval : AllStatic { 40 public: 41 typedef typename Mspace::Type Type; 42 static Type* get(size_t size, Mspace* mspace, typename Mspace::Iterator& iterator, Thread* thread) { 43 while (iterator.has_next()) { 44 Type* const t = iterator.next(); 45 if (t->retired()) continue; 46 if (t->try_acquire(thread)) { 47 assert(!t->retired(), "invariant"); 48 if (t->free_size() >= size) { 49 return t; 50 } 51 t->set_retired(); 52 mspace->register_full(t, thread); 53 } 54 } 55 return NULL; 56 } 57 }; 58 59 template <typename Mspace> 60 class JfrMspaceAlternatingRetrieval { 61 private: 62 // provides stochastic distribution over "deque" endpoints; racy is ok here 63 static bool _last_access; 64 public: 65 typedef typename Mspace::Type Type; 66 static Type* get(size_t size, Mspace* mspace, Thread* thread) { 67 typename Mspace::Iterator iterator(mspace->free(), (_last_access = !_last_access) ? forward : backward); 68 return JfrMspaceRetrieval<Mspace>::get(size, mspace, iterator, thread); 69 } 70 }; 71 72 template <typename Mspace> 73 bool JfrMspaceAlternatingRetrieval<Mspace>::_last_access = false; 74 75 template <typename Mspace> 76 class JfrMspaceSequentialRetrieval { 77 public: 78 typedef typename Mspace::Type Type; 79 static Type* get(size_t size, Mspace* mspace, Thread* thread) { 80 typename Mspace::Iterator iterator(mspace->free()); 81 return JfrMspaceRetrieval<Mspace>::get(size, mspace, iterator, thread); 82 } 83 }; 84 85 #endif // SHARE_VM_JFR_RECORDER_STORAGE_JFRMEMORYSPACERETRIEVAL_HPP