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Diffstat (limited to 'libs/qm-dsp/thread/BlockAllocator.h')
| -rw-r--r-- | libs/qm-dsp/thread/BlockAllocator.h | 189 |
1 files changed, 0 insertions, 189 deletions
diff --git a/libs/qm-dsp/thread/BlockAllocator.h b/libs/qm-dsp/thread/BlockAllocator.h deleted file mode 100644 index 5c311d615d..0000000000 --- a/libs/qm-dsp/thread/BlockAllocator.h +++ /dev/null @@ -1,189 +0,0 @@ -/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*- vi:set ts=8 sts=4 sw=4: */ - -/* - QM DSP Library - - Centre for Digital Music, Queen Mary, University of London. - - This file is derived from the FSB Allocator by Juha Nieminen. The - underlying method is unchanged, but the class has been refactored - to permit multiple separate allocators (e.g. one per thread) - rather than use a single global one (and to fit house style). - -Copyright (c) 2008 Juha Nieminen - -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. -*/ - -#ifndef _BLOCK_ALLOCATOR_H_ -#define _BLOCK_ALLOCATOR_H_ - -#include <cstdlib> - -/** - * BlockAllocator is a simple allocator for fixed-size (usually small) - * chunks of memory. The size of an element is specified in the - * BlockAllocator constructor, and the functions allocate() and - * deallocate() are used to obtain and release a single element at a - * time. - * - * BlockAllocator may be an appropriate class to use in situations - * involving a very large number of allocations and deallocations of - * simple, identical objects across multiple threads (a hard situation - * for a generic system malloc implementation to handle well). Retain - * one BlockAllocator per thread (the class itself is not - * thread-safe), and ensure that each thread uses its own allocator - * exclusively. - * - * BlockAllocator is based on Juha Nieminen's more general - * FSBAllocator. - */ -class BlockAllocator -{ -public: - typedef std::size_t data_t; - - BlockAllocator(int elementSize) : m_sz(elementSize) { } - - void * - allocate() - { - if (m_freelist.empty()) { - m_freelist.push_back(m_blocks.data.size()); - m_blocks.data.push_back(Block(this)); - } - - const data_t index = m_freelist.back(); - Block &block = m_blocks.data[index]; - void *retval = block.allocate(index); - if (block.isFull()) m_freelist.pop_back(); - - return retval; - } - - void - deallocate(void *ptr) - { - if (!ptr) return; - - data_t *unitPtr = (data_t *)ptr; - const data_t blockIndex = unitPtr[elementSizeInDataUnits()]; - Block& block = m_blocks.data[blockIndex]; - - if (block.isFull()) m_freelist.push_back(blockIndex); - block.deallocate(unitPtr); - } - -private: - inline data_t elementsPerBlock() const { - return 512; - } - inline data_t dataSize() const { - return sizeof(data_t); - } - inline data_t elementSizeInDataUnits() const { - return (m_sz + (dataSize() - 1)) / dataSize(); - } - inline data_t unitSizeInDataUnits() const { - return elementSizeInDataUnits() + 1; - } - inline data_t blockSizeInDataUnits() const { - return elementsPerBlock() * unitSizeInDataUnits(); - } - - class Block - { - public: - Block(BlockAllocator *a) : - m_a(a), - m_block(0), - m_firstFreeUnit(data_t(-1)), - m_allocated(0), - m_end(0) - {} - - ~Block() { - delete[] m_block; - } - - bool isFull() const { - return m_allocated == m_a->elementsPerBlock(); - } - - void clear() { - delete[] m_block; - m_block = 0; - m_firstFreeUnit = data_t(-1); - } - - void *allocate(data_t index) { - - if (m_firstFreeUnit == data_t(-1)) { - - if (!m_block) { - m_block = new data_t[m_a->blockSizeInDataUnits()]; - m_end = 0; - } - - data_t *retval = m_block + m_end; - m_end += m_a->unitSizeInDataUnits(); - retval[m_a->elementSizeInDataUnits()] = index; - ++m_allocated; - return retval; - - } else { - - data_t *retval = m_block + m_firstFreeUnit; - m_firstFreeUnit = *retval; - ++m_allocated; - return retval; - } - } - - void deallocate(data_t *ptr) { - - *ptr = m_firstFreeUnit; - m_firstFreeUnit = ptr - m_block; - - if (--m_allocated == 0) clear(); - } - - private: - const BlockAllocator *m_a; - data_t *m_block; - data_t m_firstFreeUnit; - data_t m_allocated; - data_t m_end; - }; - - struct Blocks - { - std::vector<Block> data; - - Blocks() { - data.reserve(1024); - } - }; - - const int m_sz; - Blocks m_blocks; - std::vector<data_t> m_freelist; -}; - -#endif |