storage/blockdevice/source/HeapBlockDevice.cpp - master - githubmirror/mbed-os

storage/blockdevice/source/HeapBlockDevice.cpp
202 строки5 KB
Lingkai Dong
HeapBlockDevice::erase(): free up heap memory
14 апр 2021, 19:00
14 апр 2021, 19:006b5e467
/* mbed Microcontroller Library
 * Copyright (c) 2017 ARM Limited
 * SPDX-License-Identifier: Apache-2.0
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

#include "blockdevice/HeapBlockDevice.h"
#include "platform/mbed_atomic.h"
#include <stdlib.h>
#include <string.h>

namespace mbed {

HeapBlockDevice::HeapBlockDevice(bd_size_t size, bd_size_t block)
    : _read_size(block), _program_size(block), _erase_size(block)
    , _count(size / block), _blocks(0), _init_ref_count(0), _is_initialized(false)
{
    MBED_ASSERT(_count * _erase_size == size);
}

HeapBlockDevice::HeapBlockDevice(bd_size_t size, bd_size_t read, bd_size_t program, bd_size_t erase)
    : _read_size(read), _program_size(program), _erase_size(erase)
    , _count(size / erase), _blocks(0), _init_ref_count(0), _is_initialized(false)
{
    MBED_ASSERT(_count * _erase_size == size);
}

HeapBlockDevice::~HeapBlockDevice()
{
    if (_blocks) {
        for (size_t i = 0; i < _count; i++) {
            delete[] _blocks[i];
        }

        delete[] _blocks;
        _blocks = nullptr;
    }
}

int HeapBlockDevice::init()
{
    uint32_t val = core_util_atomic_incr_u32(&_init_ref_count, 1);

    if (val != 1) {
        return BD_ERROR_OK;
    }

    if (!_blocks) {
        _blocks = new (std::nothrow) uint8_t *[_count];
        if (!_blocks) {
            return BD_ERROR_DEVICE_ERROR;
        }

        for (size_t i = 0; i < _count; i++) {
            _blocks[i] = nullptr;
        }
    }

    _is_initialized = true;
    return BD_ERROR_OK;
}

int HeapBlockDevice::deinit()
{
    if (!_is_initialized) {
        return BD_ERROR_OK;
    }

    uint32_t val = core_util_atomic_decr_u32(&_init_ref_count, 1);

    if (val) {
        return BD_ERROR_OK;
    }

    MBED_ASSERT(_blocks != NULL);
    // Memory is lazily cleaned up in destructor to allow
    // data to live across de/reinitialization
    _is_initialized = false;
    return BD_ERROR_OK;
}

bd_size_t HeapBlockDevice::get_read_size() const
{
    return _read_size;
}

bd_size_t HeapBlockDevice::get_program_size() const
{
    return _program_size;
}

bd_size_t HeapBlockDevice::get_erase_size() const
{
    return _erase_size;
}

bd_size_t HeapBlockDevice::get_erase_size(bd_addr_t addr) const
{
    return _erase_size;
}

bd_size_t HeapBlockDevice::size() const
{
    return _count * _erase_size;
}

int HeapBlockDevice::read(void *b, bd_addr_t addr, bd_size_t size)
{
    if (!_is_initialized) {
        return BD_ERROR_DEVICE_ERROR;
    }
    if (!is_valid_read(addr, size)) {
        return BD_ERROR_DEVICE_ERROR;
    }

    uint8_t *buffer = static_cast<uint8_t *>(b);

    while (size > 0) {
        bd_addr_t hi = addr / _erase_size;
        bd_addr_t lo = addr % _erase_size;

        if (_blocks[hi]) {
            memcpy(buffer, &_blocks[hi][lo], _read_size);
        } else {
            memset(buffer, 0, _read_size);
        }

        buffer += _read_size;
        addr += _read_size;
        size -= _read_size;
    }

    return 0;
}

int HeapBlockDevice::program(const void *b, bd_addr_t addr, bd_size_t size)
{
    if (!_is_initialized) {
        return BD_ERROR_DEVICE_ERROR;
    }
    if (!is_valid_program(addr, size)) {
        return BD_ERROR_DEVICE_ERROR;
    }

    const uint8_t *buffer = static_cast<const uint8_t *>(b);

    while (size > 0) {
        bd_addr_t hi = addr / _erase_size;
        bd_addr_t lo = addr % _erase_size;

        if (!_blocks[hi]) {
            _blocks[hi] = new (std::nothrow) uint8_t[_erase_size];
            if (!_blocks[hi]) {
                return BD_ERROR_DEVICE_ERROR;
            }
        }

        memcpy(&_blocks[hi][lo], buffer, _program_size);

        buffer += _program_size;
        addr += _program_size;
        size -= _program_size;
    }

    return 0;
}

int HeapBlockDevice::erase(bd_addr_t addr, bd_size_t size)
{
    if (!_is_initialized) {
        return BD_ERROR_DEVICE_ERROR;
    }
    if (!is_valid_erase(addr, size)) {
        return BD_ERROR_DEVICE_ERROR;
    }

    for (size_t i = 0; i < (size / _erase_size); i++) {
        size_t index = addr / _erase_size + i;
        delete[] _blocks[index];
        _blocks[index] = nullptr;
    }

    return 0;
}

const char *HeapBlockDevice::get_type() const
{
    return "HEAP";
}

} // namespace mbed