#ifndef CC_ALLOCATOR_STRATEGY_GLOBAL_SMALL_BLOCK_H #define CC_ALLOCATOR_STRATEGY_GLOBAL_SMALL_BLOCK_H /**************************************************************************** Copyright (c) 2014 Chukong Technologies Inc. Author: Justin Graham (https://github.com/mannewalis) http://www.cocos2d-x.org Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions: The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software. THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. ****************************************************************************/ /**************************************************************************** WARNING! Do not use Console::log or any other methods that use NEW inside of this allocator. Failure to do so will result in recursive memory allocation. ****************************************************************************/ #include "base/allocator/CCAllocatorMacros.h" #include "base/allocator/CCAllocatorBase.h" #include "base/allocator/CCAllocatorGlobal.h" #include "base/allocator/CCAllocatorStrategyFixedBlock.h" NS_CC_BEGIN NS_CC_ALLOCATOR_BEGIN #if CC_ENABLE_ALLOCATOR_DIAGNOSTICS #define TRACK(slot, size, op) _smallBlockAllocations[slot] op size #else #define TRACK(...) #endif // @brief class AllocatorStrategyGlobalSmallBlock : public AllocatorBase { public: // default number of block to allocate per page. static constexpr size_t kDefaultSmallBlockCount = 100; // default max small block size pool. static constexpr size_t kMaxSmallBlockPower = 13; // 2^13 8kb // @brief define for allocator strategy, cannot be typedef because we want to eval at use #define SType(size) AllocatorStrategyFixedBlock void _lazy_init() { // this gets called before static constructors // so make sure we only get called once. static bool once = true; if (once) { once = false; // call our own constructor. Global new can be called before the constructors are called. // Make sure it gets called by having it done lazily in the call to allocate. new (this) AllocatorStrategyGlobalSmallBlock(); } } AllocatorStrategyGlobalSmallBlock() { // this gets called before static constructors // so make sure we only get called once. static bool once = true; if (once) { once = false; _maxBlockSize = 1 << kMaxSmallBlockPower; #if CC_ENABLE_ALLOCATOR_DIAGNOSTICS AllocatorDiagnostics::instance()->trackAllocator(this); AllocatorBase::setTag("GlobalSmallBlock"); #endif memset(_smallBlockAllocators, 0, sizeof(_smallBlockAllocators)); #if CC_ENABLE_ALLOCATOR_DIAGNOSTICS memset(_smallBlockAllocations, 0, sizeof(_smallBlockAllocations)); #endif // cannot call new on the allocator here because it will recurse // so instead we allocate from the global allocator and construct in place. #define SBA(n, size) \ if (size <= _maxBlockSize) \ { \ auto v = ccAllocatorGlobal.allocate(sizeof(SType(size))); \ _smallBlockAllocators[n] = (AllocatorBase*)(new (v) SType(size)("GlobalSmallBlock::"#size)); \ } SBA(2, 4) SBA(3, 8); SBA(4, 16); SBA(5, 32); SBA(6, 64); SBA(7, 128); SBA(8, 256); SBA(9, 512); SBA(10, 1024); SBA(11, 2048); SBA(12, 4096); SBA(13, 8192); #undef SBA } } virtual ~AllocatorStrategyGlobalSmallBlock() { for (int i = 0; i <= kMaxSmallBlockPower; ++i) if (_smallBlockAllocators[i]) ccAllocatorGlobal.deallocate(_smallBlockAllocators[i]); #if CC_ENABLE_ALLOCATOR_DIAGNOSTICS AllocatorDiagnostics::instance()->untrackAllocator(this); #endif } // @brief Allocate a block of some size. If the block is <= 8192 it is allocated out of an array // of fixed size block allocators. If larger, then we default back to the global allocator. // @param size Size of block to allocate. This will be rounded to the next power of two. CC_ALLOCATOR_INLINE void* allocate(size_t size) { _lazy_init(); if (size < sizeof(intptr_t)) // always allocate at least enough space to store a pointer. this is size = sizeof(intptr_t); // so we can link the empty blocks together in the block allocator. // if the size is greater than what we determine to be a small block // size then fall through to calling the global allocator instead. if (size > _maxBlockSize) return ccAllocatorGlobal.allocate(size); // make sure the size fits into one of the // fixed sized block allocators we have above. size_t adjusted_size = AllocatorBase::nextPow2BlockSize(size); #define ALLOCATE(slot, size) \ case size: \ { \ void* v = _smallBlockAllocators[slot]; \ CC_ASSERT(nullptr != v); \ auto a = (SType(size)*)v; \ address = a->allocate(adjusted_size); \ TRACK(slot, size, +=); \ } \ break; void* address; switch (adjusted_size) { ALLOCATE(2, 4); ALLOCATE(3, 8); ALLOCATE(4, 16); ALLOCATE(5, 32); ALLOCATE(6, 64); ALLOCATE(7, 128); ALLOCATE(8, 256); ALLOCATE(9, 512); ALLOCATE(10, 1024); ALLOCATE(11, 2048); ALLOCATE(12, 4096); ALLOCATE(13, 8192); default: CC_ASSERT(false); break; } #undef ALLOCATE CC_ASSERT(adjusted_size < AllocatorBase::kDefaultAlignment || 0 == ((intptr_t)address & (AllocatorBase::kDefaultAlignment - 1))); CC_ASSERT(nullptr != address); return address; } // @brief Deallocate a block by choosing one of the fixed size block allocators // or defaulting to the global allocator if we do not own this block. CC_ALLOCATOR_INLINE void deallocate(void* address, size_t size = 0) { // if we didn't get a size, then we need to find the allocator // by asking each if they own the block. For allocators that // have few large pages, this is extremely fast. if (0 == size) { #define OWNS(slot, S, address) \ case S: \ { \ void* v = _smallBlockAllocators[slot]; \ if (v) \ { \ auto a = (SType(S)*)v; \ if (a->owns(address)) \ { \ size = SType(S)::block_size; \ break; \ } \ } \ } // falls through until found switch (sizeof(uint32_t)) { OWNS(2, 4, address); OWNS(3, 8, address); OWNS(4, 16, address); OWNS(5, 32, address); OWNS(6, 64, address); OWNS(7, 128, address); OWNS(8, 256, address); OWNS(9, 512, address); OWNS(10, 1024, address); OWNS(11, 2048, address); OWNS(12, 4096, address); OWNS(13, 8192, address); } } // if the size is greater than what we determine to be a small block // size then default to calling the global allocator instead. if (0 == size || size > _maxBlockSize) return ccAllocatorGlobal.deallocate(address, size); if (size < sizeof(intptr_t)) // always allocate at least enough space to store a pointer. this is size = sizeof(intptr_t); // so we can link the empty blocks together in the block allocator. // make sure the size fits into one of the // fixed sized block allocators we have above. size_t adjusted_size = AllocatorBase::nextPow2BlockSize(size); #define DEALLOCATE(slot, size, address) \ case size: \ { \ void* v = _smallBlockAllocators[slot]; \ CC_ASSERT(nullptr != v); \ auto a = (SType(size)*)v; \ a->deallocate(address, size); \ TRACK(slot, size, -=); \ } \ break; switch (adjusted_size) { DEALLOCATE(2, 4, address); DEALLOCATE(3, 8, address); DEALLOCATE(4, 16, address); DEALLOCATE(5, 32, address); DEALLOCATE(6, 64, address); DEALLOCATE(7, 128, address); DEALLOCATE(8, 256, address); DEALLOCATE(9, 512, address); DEALLOCATE(10, 1024, address); DEALLOCATE(11, 2048, address); DEALLOCATE(12, 4096, address); DEALLOCATE(13, 8192, address); default: CC_ASSERT(false); } #undef DEALLOCATE } #if CC_ENABLE_ALLOCATOR_DIAGNOSTICS std::string diagnostics() const { std::stringstream s; size_t total = 0; for (auto i = 2; i <= kMaxSmallBlockPower; ++i) { auto a = _smallBlockAllocators[i]; if (a) { total += _smallBlockAllocations[i]; s << a->tag() << " allocated:" << _smallBlockAllocations[i] << "\n"; } } s << "Total:" << total << "\n"; return s.str(); } size_t _highestCount; #endif protected: // @brief the max size of a block this allocator will pool before using global allocator size_t _maxBlockSize; // @brief array of small block allocators from 2^0 -> 2^kMaxSmallBlockPower AllocatorBase* _smallBlockAllocators[kMaxSmallBlockPower + 1]; #if CC_ENABLE_ALLOCATOR_DIAGNOSTICS size_t _smallBlockAllocations[kMaxSmallBlockPower + 1]; #endif }; NS_CC_ALLOCATOR_END NS_CC_END #endif//CC_ALLOCATOR_STRATEGY_GLOBAL_SMALL_BLOCK_H