1 /* 2 * Copyright (C) 2009 The Android Open Source Project 3 * 4 * Licensed under the Apache License, Version 2.0 (the "License"); 5 * you may not use this file except in compliance with the License. 6 * You may obtain a copy of the License at 7 * 8 * http://www.apache.org/licenses/LICENSE-2.0 9 * 10 * Unless required by applicable law or agreed to in writing, software 11 * distributed under the License is distributed on an "AS IS" BASIS, 12 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13 * See the License for the specific language governing permissions and 14 * limitations under the License. 15 */ 16 17 18 #ifndef GRALLOC_ALLOCATOR_H_ 19 #define GRALLOC_ALLOCATOR_H_ 20 21 #include <stdint.h> 22 #include <sys/types.h> 23 24 #include "gr.h" 25 #include "pmemalloc.h" 26 27 // ---------------------------------------------------------------------------- 28 29 /* 30 * A simple templatized doubly linked-list implementation 31 */ 32 33 template <typename NODE> 34 class LinkedList 35 { 36 NODE* mFirst; 37 NODE* mLast; 38 39 public: LinkedList()40 LinkedList() : mFirst(0), mLast(0) { } isEmpty()41 bool isEmpty() const { return mFirst == 0; } head()42 NODE const* head() const { return mFirst; } head()43 NODE* head() { return mFirst; } tail()44 NODE const* tail() const { return mLast; } tail()45 NODE* tail() { return mLast; } 46 insertAfter(NODE * node,NODE * newNode)47 void insertAfter(NODE* node, NODE* newNode) { 48 newNode->prev = node; 49 newNode->next = node->next; 50 if (node->next == 0) mLast = newNode; 51 else node->next->prev = newNode; 52 node->next = newNode; 53 } 54 insertBefore(NODE * node,NODE * newNode)55 void insertBefore(NODE* node, NODE* newNode) { 56 newNode->prev = node->prev; 57 newNode->next = node; 58 if (node->prev == 0) mFirst = newNode; 59 else node->prev->next = newNode; 60 node->prev = newNode; 61 } 62 insertHead(NODE * newNode)63 void insertHead(NODE* newNode) { 64 if (mFirst == 0) { 65 mFirst = mLast = newNode; 66 newNode->prev = newNode->next = 0; 67 } else { 68 newNode->prev = 0; 69 newNode->next = mFirst; 70 mFirst->prev = newNode; 71 mFirst = newNode; 72 } 73 } 74 insertTail(NODE * newNode)75 void insertTail(NODE* newNode) { 76 if (mLast == 0) { 77 insertHead(newNode); 78 } else { 79 newNode->prev = mLast; 80 newNode->next = 0; 81 mLast->next = newNode; 82 mLast = newNode; 83 } 84 } 85 remove(NODE * node)86 NODE* remove(NODE* node) { 87 if (node->prev == 0) mFirst = node->next; 88 else node->prev->next = node->next; 89 if (node->next == 0) mLast = node->prev; 90 else node->next->prev = node->prev; 91 return node; 92 } 93 }; 94 95 class SimpleBestFitAllocator : public PmemUserspaceAllocator::Deps::Allocator 96 { 97 public: 98 99 SimpleBestFitAllocator(); 100 SimpleBestFitAllocator(size_t size); 101 virtual ~SimpleBestFitAllocator(); 102 103 virtual ssize_t setSize(size_t size); 104 105 virtual ssize_t allocate(size_t size, uint32_t flags = 0); 106 virtual ssize_t deallocate(size_t offset); 107 virtual size_t size() const; 108 109 private: 110 struct chunk_t { chunk_tchunk_t111 chunk_t(size_t start, size_t size) 112 : start(start), size(size), free(1), prev(0), next(0) { 113 } 114 size_t start; 115 size_t size : 28; 116 int free : 4; 117 mutable chunk_t* prev; 118 mutable chunk_t* next; 119 }; 120 121 ssize_t alloc(size_t size, uint32_t flags); 122 chunk_t* dealloc(size_t start); 123 124 static const int kMemoryAlign; 125 mutable Locker mLock; 126 LinkedList<chunk_t> mList; 127 size_t mHeapSize; 128 }; 129 130 #endif /* GRALLOC_ALLOCATOR_H_ */ 131