1 /* 2 * Copyright (c) 2009, 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_STACK_INLINE_HPP 26 #define SHARE_VM_UTILITIES_STACK_INLINE_HPP 27 28 #include "utilities/stack.hpp" 29 30 template <MEMFLAGS F> StackBase<F>::StackBase(size_t segment_size, size_t max_cache_size, 31 size_t max_size): 32 _seg_size(segment_size), 33 _max_cache_size(max_cache_size), 34 _max_size(adjust_max_size(max_size, segment_size)) 35 { 36 assert(_max_size % _seg_size == 0, "not a multiple"); 37 } 38 39 template <MEMFLAGS F> size_t StackBase<F>::adjust_max_size(size_t max_size, size_t seg_size) 40 { 41 assert(seg_size > 0, "cannot be 0"); 42 assert(max_size >= seg_size || max_size == 0, "max_size too small"); 43 const size_t limit = max_uintx - (seg_size - 1); 44 if (max_size == 0 || max_size > limit) { 45 max_size = limit; 46 } 47 return (max_size + seg_size - 1) / seg_size * seg_size; 48 } 49 50 template <class E, MEMFLAGS F> 51 Stack<E, F>::Stack(size_t segment_size, size_t max_cache_size, size_t max_size): 52 StackBase<F>(adjust_segment_size(segment_size), max_cache_size, max_size) 53 { 54 reset(true); 55 } 56 57 template <class E, MEMFLAGS F> 58 void Stack<E, F>::push(E item) 59 { 60 assert(!is_full(), "pushing onto a full stack"); 61 if (this->_cur_seg_size == this->_seg_size) { 62 push_segment(); 63 } 64 this->_cur_seg[this->_cur_seg_size] = item; 65 ++this->_cur_seg_size; 66 } 67 68 template <class E, MEMFLAGS F> 69 E Stack<E, F>::pop() 70 { 71 assert(!is_empty(), "popping from an empty stack"); 72 if (this->_cur_seg_size == 1) { 73 E tmp = _cur_seg[--this->_cur_seg_size]; 74 pop_segment(); 75 return tmp; 76 } 77 return this->_cur_seg[--this->_cur_seg_size]; 78 } 79 80 template <class E, MEMFLAGS F> 81 void Stack<E, F>::clear(bool clear_cache) 82 { 83 free_segments(_cur_seg); 84 if (clear_cache) free_segments(_cache); 85 reset(clear_cache); 86 } 87 88 template <class E, MEMFLAGS F> 89 size_t Stack<E, F>::adjust_segment_size(size_t seg_size) 90 { 91 const size_t elem_sz = sizeof(E); 92 const size_t ptr_sz = sizeof(E*); 93 assert(elem_sz % ptr_sz == 0 || ptr_sz % elem_sz == 0, "bad element size"); 94 if (elem_sz < ptr_sz) { 95 return align_size_up(seg_size * elem_sz, ptr_sz) / elem_sz; 96 } 97 return seg_size; 98 } 99 100 template <class E, MEMFLAGS F> 101 size_t Stack<E, F>::link_offset() const 102 { 103 return align_size_up(this->_seg_size * sizeof(E), sizeof(E*)); 104 } 105 106 template <class E, MEMFLAGS F> 107 size_t Stack<E, F>::segment_bytes() const 108 { 109 return link_offset() + sizeof(E*); 110 } 111 112 template <class E, MEMFLAGS F> 113 E** Stack<E, F>::link_addr(E* seg) const 114 { 115 return (E**) ((char*)seg + link_offset()); 116 } 117 118 template <class E, MEMFLAGS F> 119 E* Stack<E, F>::get_link(E* seg) const 120 { 121 return *link_addr(seg); 122 } 123 124 template <class E, MEMFLAGS F> 125 E* Stack<E, F>::set_link(E* new_seg, E* old_seg) 126 { 127 *link_addr(new_seg) = old_seg; 128 return new_seg; 129 } 130 131 template <class E, MEMFLAGS F> 132 E* Stack<E, F>::alloc(size_t bytes) 133 { 134 return (E*) NEW_C_HEAP_ARRAY(char, bytes, F); 135 } 136 137 template <class E, MEMFLAGS F> 138 void Stack<E, F>::free(E* addr, size_t bytes) 139 { 140 FREE_C_HEAP_ARRAY(char, (char*) addr); 141 } 142 143 template <class E, MEMFLAGS F> 144 void Stack<E, F>::push_segment() 145 { 146 assert(this->_cur_seg_size == this->_seg_size, "current segment is not full"); 147 E* next; 148 if (this->_cache_size > 0) { 149 // Use a cached segment. 150 next = _cache; 151 _cache = get_link(_cache); 152 --this->_cache_size; 153 } else { 154 next = alloc(segment_bytes()); 155 DEBUG_ONLY(zap_segment(next, true);) 156 } 157 const bool at_empty_transition = is_empty(); 158 this->_cur_seg = set_link(next, _cur_seg); 159 this->_cur_seg_size = 0; 160 this->_full_seg_size += at_empty_transition ? 0 : this->_seg_size; 161 DEBUG_ONLY(verify(at_empty_transition);) 162 } 163 164 template <class E, MEMFLAGS F> 165 void Stack<E, F>::pop_segment() 166 { 167 assert(this->_cur_seg_size == 0, "current segment is not empty"); 168 E* const prev = get_link(_cur_seg); 169 if (this->_cache_size < this->_max_cache_size) { 170 // Add the current segment to the cache. 171 DEBUG_ONLY(zap_segment(_cur_seg, false);) 172 _cache = set_link(_cur_seg, _cache); 173 ++this->_cache_size; 174 } else { 175 DEBUG_ONLY(zap_segment(_cur_seg, true);) 176 free(_cur_seg, segment_bytes()); 177 } 178 const bool at_empty_transition = prev == NULL; 179 this->_cur_seg = prev; 180 this->_cur_seg_size = this->_seg_size; 181 this->_full_seg_size -= at_empty_transition ? 0 : this->_seg_size; 182 DEBUG_ONLY(verify(at_empty_transition);) 183 } 184 185 template <class E, MEMFLAGS F> 186 void Stack<E, F>::free_segments(E* seg) 187 { 188 const size_t bytes = segment_bytes(); 189 while (seg != NULL) { 190 E* const prev = get_link(seg); 191 free(seg, bytes); 192 seg = prev; 193 } 194 } 195 196 template <class E, MEMFLAGS F> 197 void Stack<E, F>::reset(bool reset_cache) 198 { 199 this->_cur_seg_size = this->_seg_size; // So push() will alloc a new segment. 200 this->_full_seg_size = 0; 201 _cur_seg = NULL; 202 if (reset_cache) { 203 this->_cache_size = 0; 204 _cache = NULL; 205 } 206 } 207 208 #ifdef ASSERT 209 template <class E, MEMFLAGS F> 210 void Stack<E, F>::verify(bool at_empty_transition) const 211 { 212 assert(size() <= this->max_size(), "stack exceeded bounds"); 213 assert(this->cache_size() <= this->max_cache_size(), "cache exceeded bounds"); 214 assert(this->_cur_seg_size <= this->segment_size(), "segment index exceeded bounds"); 215 216 assert(this->_full_seg_size % this->_seg_size == 0, "not a multiple"); 217 assert(at_empty_transition || is_empty() == (size() == 0), "mismatch"); 218 assert((_cache == NULL) == (this->cache_size() == 0), "mismatch"); 219 220 if (is_empty()) { 221 assert(this->_cur_seg_size == this->segment_size(), "sanity"); 222 } 223 } 224 225 template <class E, MEMFLAGS F> 226 void Stack<E, F>::zap_segment(E* seg, bool zap_link_field) const 227 { 228 if (!ZapStackSegments) return; 229 const size_t zap_bytes = segment_bytes() - (zap_link_field ? 0 : sizeof(E*)); 230 uint32_t* cur = (uint32_t*)seg; 231 const uint32_t* end = cur + zap_bytes / sizeof(uint32_t); 232 while (cur < end) { 233 *cur++ = 0xfadfaded; 234 } 235 } 236 #endif 237 238 template <class E, MEMFLAGS F> 239 E* ResourceStack<E, F>::alloc(size_t bytes) 240 { 241 return (E*) resource_allocate_bytes(bytes); 242 } 243 244 template <class E, MEMFLAGS F> 245 void ResourceStack<E, F>::free(E* addr, size_t bytes) 246 { 247 resource_free_bytes((char*) addr, bytes); 248 } 249 250 template <class E, MEMFLAGS F> 251 void StackIterator<E, F>::sync() 252 { 253 _full_seg_size = _stack._full_seg_size; 254 _cur_seg_size = _stack._cur_seg_size; 255 _cur_seg = _stack._cur_seg; 256 } 257 258 template <class E, MEMFLAGS F> 259 E* StackIterator<E, F>::next_addr() 260 { 261 assert(!is_empty(), "no items left"); 262 if (_cur_seg_size == 1) { 263 E* addr = _cur_seg; 264 _cur_seg = _stack.get_link(_cur_seg); 265 _cur_seg_size = _stack.segment_size(); 266 _full_seg_size -= _stack.segment_size(); 267 return addr; 268 } 269 return _cur_seg + --_cur_seg_size; 270 } 271 272 #endif // SHARE_VM_UTILITIES_STACK_INLINE_HPP