1 /* 2 * Copyright (c) 2014, 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_UTILITIES_CHUNKED_LIST_HPP 26 #define SHARE_VM_UTILITIES_CHUNKED_LIST_HPP 27 28 #include "memory/allocation.hpp" 29 #include "utilities/debug.hpp" 30 31 template <class T, MEMFLAGS F> class ChunkedList : public CHeapObj<F> { 32 template <class U> friend class TestChunkedList; 33 34 static const size_t BufferSize = 64; 35 36 T _values[BufferSize]; 37 T* _top; 38 39 ChunkedList<T, F>* _next_used; 40 ChunkedList<T, F>* _next_free; 41 42 T const * end() const { 43 return &_values[BufferSize]; 44 } 45 46 public: 47 ChunkedList<T, F>() : _top(_values), _next_used(NULL), _next_free(NULL) {} 48 49 bool is_full() const { 50 return _top == end(); 51 } 52 53 void clear() { 54 _top = _values; 55 // Don't clear the next pointers since that would interfere 56 // with other threads trying to iterate through the lists. 57 } 58 59 void push(T m) { 60 assert(!is_full(), "Buffer is full"); 61 *_top = m; 62 _top++; 63 } 64 65 void set_next_used(ChunkedList<T, F>* buffer) { _next_used = buffer; } 66 void set_next_free(ChunkedList<T, F>* buffer) { _next_free = buffer; } 67 68 ChunkedList<T, F>* next_used() const { return _next_used; } 69 ChunkedList<T, F>* next_free() const { return _next_free; } 70 71 size_t size() const { 72 return pointer_delta(_top, _values, sizeof(T)); 73 } 74 75 T at(size_t i) { 76 assert(i < size(), "IOOBE i: " SIZE_FORMAT " size(): " SIZE_FORMAT, i, size()); 77 return _values[i]; 78 } 79 }; 80 81 #endif // SHARE_VM_UTILITIES_CHUNKED_LIST_HPP