1 /* 2 * Copyright (c) 2015, 2017, 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 #include "precompiled.hpp" 25 #include "gc/z/zList.inline.hpp" 26 #include "gc/z/zMemory.inline.hpp" 27 #include "memory/allocation.inline.hpp" 28 29 uintptr_t ZMemoryManager::alloc_from_front(size_t size) { 30 ZListIterator<ZMemory> iter(&_freelist); 31 for (ZMemory* area; iter.next(&area);) { 32 if (area->size() >= size) { 33 if (area->size() == size) { 34 // Exact match, remove area 35 const uintptr_t start = area->start(); 36 _freelist.remove(area); 37 delete area; 38 return start; 39 } else { 40 // Larger than requested, shrink area 41 const uintptr_t start = area->start(); 42 area->shrink_from_front(size); 43 return start; 44 } 45 } 46 } 47 48 // Out of memory 49 return UINTPTR_MAX; 50 } 51 52 uintptr_t ZMemoryManager::alloc_from_back(size_t size) { 53 ZListReverseIterator<ZMemory> iter(&_freelist); 54 for (ZMemory* area; iter.next(&area);) { 55 if (area->size() >= size) { 56 if (area->size() == size) { 57 // Exact match, remove area 58 const uintptr_t start = area->start(); 59 _freelist.remove(area); 60 delete area; 61 return start; 62 } else { 63 // Larger than requested, shrink area 64 area->shrink_from_back(size); 65 return area->end(); 66 } 67 } 68 } 69 70 // Out of memory 71 return UINTPTR_MAX; 72 } 73 74 void ZMemoryManager::free(uintptr_t start, size_t size) { 75 assert(start != UINTPTR_MAX, "Invalid address"); 76 const uintptr_t end = start + size; 77 78 ZListIterator<ZMemory> iter(&_freelist); 79 for (ZMemory* area; iter.next(&area);) { 80 if (start < area->start()) { 81 ZMemory* const prev = _freelist.prev(area); 82 if (prev != NULL && start == prev->end()) { 83 if (end == area->start()) { 84 // Merge with prev and current area 85 prev->grow_from_back(size + area->size()); 86 _freelist.remove(area); 87 delete area; 88 } else { 89 // Merge with prev area 90 prev->grow_from_back(size); 91 } 92 } else if (end == area->start()) { 93 // Merge with current area 94 area->grow_from_front(size); 95 } else { 96 // Insert new area before current area 97 assert(end < area->start(), "Areas must not overlap"); 98 ZMemory* new_area = new ZMemory(start, size); 99 _freelist.insert_before(area, new_area); 100 } 101 102 // Done 103 return; 104 } 105 } 106 107 // Insert last 108 ZMemory* const last = _freelist.last(); 109 if (last != NULL && start == last->end()) { 110 // Merge with last area 111 last->grow_from_back(size); 112 } else { 113 // Insert new area last 114 ZMemory* new_area = new ZMemory(start, size); 115 _freelist.insert_last(new_area); 116 } 117 }