1 /* 2 * Copyright 2010 Google Inc. 3 * 4 * Use of this source code is governed by a BSD-style license that can be 5 * found in the LICENSE file. 6 */ 7 8 #include "GrAllocPool.h" 9 10 #include "GrTypes.h" 11 12 #define GrAllocPool_MIN_BLOCK_SIZE ((size_t)128) 13 14 struct GrAllocPool::Block { 15 Block* fNext; 16 char* fPtr; 17 size_t fBytesFree; 18 size_t fBytesTotal; 19 CreateGrAllocPool::Block20 static Block* Create(size_t size, Block* next) { 21 SkASSERT(size >= GrAllocPool_MIN_BLOCK_SIZE); 22 23 Block* block = (Block*)sk_malloc_throw(sizeof(Block) + size); 24 block->fNext = next; 25 block->fPtr = (char*)block + sizeof(Block); 26 block->fBytesFree = size; 27 block->fBytesTotal = size; 28 return block; 29 } 30 canAllocGrAllocPool::Block31 bool canAlloc(size_t bytes) const { 32 return bytes <= fBytesFree; 33 } 34 allocGrAllocPool::Block35 void* alloc(size_t bytes) { 36 SkASSERT(bytes <= fBytesFree); 37 fBytesFree -= bytes; 38 void* ptr = fPtr; 39 fPtr += bytes; 40 return ptr; 41 } 42 releaseGrAllocPool::Block43 size_t release(size_t bytes) { 44 SkASSERT(bytes > 0); 45 size_t free = SkTMin(bytes, fBytesTotal - fBytesFree); 46 fBytesFree += free; 47 fPtr -= free; 48 return bytes - free; 49 } 50 emptyGrAllocPool::Block51 bool empty() const { return fBytesTotal == fBytesFree; } 52 }; 53 54 /////////////////////////////////////////////////////////////////////////////// 55 GrAllocPool(size_t blockSize)56GrAllocPool::GrAllocPool(size_t blockSize) { 57 fBlock = NULL; 58 fMinBlockSize = SkTMax(blockSize, GrAllocPool_MIN_BLOCK_SIZE); 59 SkDEBUGCODE(fBlocksAllocated = 0;) 60 } 61 ~GrAllocPool()62GrAllocPool::~GrAllocPool() { 63 this->reset(); 64 } 65 reset()66void GrAllocPool::reset() { 67 this->validate(); 68 69 Block* block = fBlock; 70 while (block) { 71 Block* next = block->fNext; 72 sk_free(block); 73 block = next; 74 } 75 fBlock = NULL; 76 SkDEBUGCODE(fBlocksAllocated = 0;) 77 } 78 alloc(size_t size)79void* GrAllocPool::alloc(size_t size) { 80 this->validate(); 81 82 if (!fBlock || !fBlock->canAlloc(size)) { 83 size_t blockSize = SkTMax(fMinBlockSize, size); 84 fBlock = Block::Create(blockSize, fBlock); 85 SkDEBUGCODE(fBlocksAllocated += 1;) 86 } 87 return fBlock->alloc(size); 88 } 89 release(size_t bytes)90void GrAllocPool::release(size_t bytes) { 91 this->validate(); 92 93 while (bytes && fBlock) { 94 bytes = fBlock->release(bytes); 95 if (fBlock->empty()) { 96 Block* next = fBlock->fNext; 97 sk_free(fBlock); 98 fBlock = next; 99 SkDEBUGCODE(fBlocksAllocated -= 1;) 100 } 101 } 102 } 103 104 #ifdef SK_DEBUG 105 validate() const106void GrAllocPool::validate() const { 107 Block* block = fBlock; 108 int count = 0; 109 while (block) { 110 count += 1; 111 block = block->fNext; 112 } 113 SkASSERT(fBlocksAllocated == count); 114 } 115 116 #endif 117