rt-thread/src/mempool.c

/*
 * File      : mempool.c
 * This file is part of RT-Thread RTOS
 * COPYRIGHT (C) 2006 - 2012, RT-Thread Development Team
 *
 * The license and distribution terms for this file may be
 * found in the file LICENSE in this distribution or at
 * http://www.rt-thread.org/license/LICENSE
 *
 * Change Logs:
 * Date           Author       Notes
 * 2006-05-27     Bernard      implement memory pool
 * 2006-06-03     Bernard      fix the thread timer init bug
 * 2006-06-30     Bernard      fix the allocate/free block bug
 * 2006-08-04     Bernard      add hook support
 * 2006-08-10     Bernard      fix interrupt bug in rt_mp_alloc
 * 2010-07-13     Bernard      fix RT_ALIGN issue found by kuronca
 * 2010-10-26     yi.qiu       add module support in rt_mp_delete
 * 2011-01-24     Bernard      add object allocation check.
 * 2012-03-22     Bernard      fix align issue in rt_mp_init and rt_mp_create.
 */

#include <rthw.h>
#include <rtthread.h>

#ifdef RT_USING_MEMPOOL

#ifdef RT_USING_HOOK
static void (*rt_mp_alloc_hook)(struct rt_mempool *mp, void *block);
static void (*rt_mp_free_hook)(struct rt_mempool *mp, void *block);

/**
 * @addtogroup Hook
 */

/*@{*/

/**
 * This function will set a hook function, which will be invoked when a memory
 * block is allocated from memory pool.
 *
 * @param hook the hook function
 */
void rt_mp_alloc_sethook(void (*hook)(struct rt_mempool *mp, void *block))
{
    rt_mp_alloc_hook = hook;
}

/**
 * This function will set a hook function, which will be invoked when a memory
 * block is released to memory pool.
 *
 * @param hook the hook function
 */
void rt_mp_free_sethook(void (*hook)(struct rt_mempool *mp, void *block))
{
    rt_mp_free_hook = hook;
}

/*@}*/
#endif

/**
 * @addtogroup MM
 */

/*@{*/

/**
 * This function will initialize a memory pool object, normally which is used
 * for static object.
 *
 * @param mp the memory pool object
 * @param name the name of memory pool
 * @param start the star address of memory pool
 * @param size the total size of memory pool
 * @param block_size the size for each block
 *
 * @return RT_EOK
 */
rt_err_t rt_mp_init(struct rt_mempool *mp,
                    const char        *name,
                    void              *start,
                    rt_size_t          size,
                    rt_size_t          block_size)
{
    rt_uint8_t *block_ptr;
    register rt_base_t offset;

    /* parameter check */
    RT_ASSERT(mp != RT_NULL);

    /* initialize object */
    rt_object_init(&(mp->parent), RT_Object_Class_MemPool, name);

    /* initialize memory pool */
    mp->start_address = start;
    mp->size = RT_ALIGN_DOWN(size, RT_ALIGN_SIZE);

    /* align the block size */
    block_size = RT_ALIGN(block_size, RT_ALIGN_SIZE);
    mp->block_size = block_size;

    /* align to align size byte */
    mp->block_total_count = mp->size / (mp->block_size + sizeof(rt_uint8_t *));
    mp->block_free_count  = mp->block_total_count;

    /* initialize suspended thread list */
    rt_list_init(&(mp->suspend_thread));
    mp->suspend_thread_count = 0;

    /* initialize free block list */
    block_ptr = (rt_uint8_t *)mp->start_address;
    for (offset = 0; offset < mp->block_total_count; offset ++)
    {
        *(rt_uint8_t **)(block_ptr + offset * (block_size + sizeof(rt_uint8_t *))) =
            (rt_uint8_t *)(block_ptr + (offset + 1) * (block_size + sizeof(rt_uint8_t *)));
    }

    *(rt_uint8_t **)(block_ptr + (offset - 1) * (block_size + sizeof(rt_uint8_t *))) =
        RT_NULL;

    mp->block_list = block_ptr;

    return RT_EOK;
}
RTM_EXPORT(rt_mp_init);

/**
 * This function will detach a memory pool from system object management.
 *
 * @param mp the memory pool object
 *
 * @return RT_EOK
 */
rt_err_t rt_mp_detach(struct rt_mempool *mp)
{
    struct rt_thread *thread;
    register rt_ubase_t temp;

    /* parameter check */
    RT_ASSERT(mp != RT_NULL);

    /* wake up all suspended threads */
    while (!rt_list_isempty(&(mp->suspend_thread)))
    {
        /* disable interrupt */
        temp = rt_hw_interrupt_disable();

        /* get next suspend thread */
        thread = rt_list_entry(mp->suspend_thread.next, struct rt_thread, tlist);
        /* set error code to RT_ERROR */
        thread->error = -RT_ERROR;

        /*
         * resume thread
         * In rt_thread_resume function, it will remove current thread from
         * suspend list
         */
        rt_thread_resume(thread);

        /* decrease suspended thread count */
        mp->suspend_thread_count --;

        /* enable interrupt */
        rt_hw_interrupt_enable(temp);
    }

    /* detach object */
    rt_object_detach(&(mp->parent));

    return RT_EOK;
}
RTM_EXPORT(rt_mp_detach);

#ifdef RT_USING_HEAP
/**
 * This function will create a mempool object and allocate the memory pool from
 * heap.
 *
 * @param name the name of memory pool
 * @param block_count the count of blocks in memory pool
 * @param block_size the size for each block
 *
 * @return the created mempool object
 */
rt_mp_t rt_mp_create(const char *name,
                     rt_size_t   block_count,
                     rt_size_t   block_size)
{
    rt_uint8_t *block_ptr;
    struct rt_mempool *mp;
    register rt_base_t offset;

    RT_DEBUG_NOT_IN_INTERRUPT;

    /* allocate object */
    mp = (struct rt_mempool *)rt_object_allocate(RT_Object_Class_MemPool, name);
    /* allocate object failed */
    if (mp == RT_NULL)
        return RT_NULL;

    /* initialize memory pool */
    block_size     = RT_ALIGN(block_size, RT_ALIGN_SIZE);
    mp->block_size = block_size;
    mp->size       = (block_size + sizeof(rt_uint8_t *)) * block_count;

    /* allocate memory */
    mp->start_address = rt_malloc((block_size + sizeof(rt_uint8_t *)) *
                                  block_count);
    if (mp->start_address == RT_NULL)
    {
        /* no memory, delete memory pool object */
        rt_object_delete(&(mp->parent));

        return RT_NULL;
    }

    mp->block_total_count = block_count;
    mp->block_free_count  = mp->block_total_count;

    /* initialize suspended thread list */
    rt_list_init(&(mp->suspend_thread));
    mp->suspend_thread_count = 0;

    /* initialize free block list */
    block_ptr = (rt_uint8_t *)mp->start_address;
    for (offset = 0; offset < mp->block_total_count; offset ++)
    {
        *(rt_uint8_t **)(block_ptr + offset * (block_size + sizeof(rt_uint8_t *)))
            = block_ptr + (offset + 1) * (block_size + sizeof(rt_uint8_t *));
    }

    *(rt_uint8_t **)(block_ptr + (offset - 1) * (block_size + sizeof(rt_uint8_t *)))
        = RT_NULL;

    mp->block_list = block_ptr;

    return mp;
}
RTM_EXPORT(rt_mp_create);

/**
 * This function will delete a memory pool and release the object memory.
 *
 * @param mp the memory pool object
 *
 * @return RT_EOK
 */
rt_err_t rt_mp_delete(rt_mp_t mp)
{
    struct rt_thread *thread;
    register rt_ubase_t temp;

    RT_DEBUG_NOT_IN_INTERRUPT;

    /* parameter check */
    RT_ASSERT(mp != RT_NULL);

    /* wake up all suspended threads */
    while (!rt_list_isempty(&(mp->suspend_thread)))
    {
        /* disable interrupt */
        temp = rt_hw_interrupt_disable();

        /* get next suspend thread */
        thread = rt_list_entry(mp->suspend_thread.next, struct rt_thread, tlist);
        /* set error code to RT_ERROR */
        thread->error = -RT_ERROR;

        /*
         * resume thread
         * In rt_thread_resume function, it will remove current thread from
         * suspend list
         */
        rt_thread_resume(thread);

        /* decrease suspended thread count */
        mp->suspend_thread_count --;

        /* enable interrupt */
        rt_hw_interrupt_enable(temp);
    }

#if defined(RT_USING_MODULE) && defined(RT_USING_SLAB)
    /* the mp object belongs to an application module */
    if (mp->parent.flag & RT_OBJECT_FLAG_MODULE) 
        rt_module_free(mp->parent.module_id, mp->start_address);
    else
#endif

    /* release allocated room */
    rt_free(mp->start_address);

    /* detach object */
    rt_object_delete(&(mp->parent));

    return RT_EOK;
}
RTM_EXPORT(rt_mp_delete);
#endif

/**
 * This function will allocate a block from memory pool
 *
 * @param mp the memory pool object
 * @param time the waiting time
 *
 * @return the allocated memory block or RT_NULL on allocated failed
 */
void *rt_mp_alloc(rt_mp_t mp, rt_int32_t time)
{
    rt_uint8_t *block_ptr;
    register rt_base_t level;
    struct rt_thread *thread;

    /* disable interrupt */
    level = rt_hw_interrupt_disable();

    if (mp->block_free_count)
    {
        /* memory block is available. decrease the free block counter */
        mp->block_free_count --;

        /* get block from block list */
        block_ptr      = mp->block_list;
        mp->block_list = *(rt_uint8_t **)block_ptr;

        /* point to memory pool */
        *(rt_uint8_t **)block_ptr = (rt_uint8_t *)mp;
    }
    else
    {
        /* memory block is unavailable. */
        if (time == 0)
        {
            /* enable interrupt */
            rt_hw_interrupt_enable(level);

            return RT_NULL;
        }
        else
        {
            RT_DEBUG_NOT_IN_INTERRUPT;

            /* get current thread */
            thread = rt_thread_self();

            /* need suspend thread */
            rt_thread_suspend(thread);
            rt_list_insert_after(&(mp->suspend_thread), &(thread->tlist));
            mp->suspend_thread_count ++;

            if (time > 0)
            {
                /* init thread timer and start it */
                rt_timer_control(&(thread->thread_timer),
                                 RT_TIMER_CTRL_SET_TIME,
                                 &time);
                rt_timer_start(&(thread->thread_timer));
            }

            /* enable interrupt */
            rt_hw_interrupt_enable(level);

            /* do a schedule */
            rt_schedule();

            if (thread->error != RT_EOK)
                return RT_NULL;

            /* disable interrupt */
            level = rt_hw_interrupt_disable();

            /* decrease free block */
            mp->block_free_count --;

            /* get block from block list */
            block_ptr      = mp->block_list;
            mp->block_list = *(rt_uint8_t **)block_ptr;

            /* point to memory pool */
            *(rt_uint8_t **)block_ptr = (rt_uint8_t *)mp;
        }
    }

    /* enable interrupt */
    rt_hw_interrupt_enable(level);

    RT_OBJECT_HOOK_CALL(rt_mp_alloc_hook,
                        (mp, (rt_uint8_t *)(block_ptr + sizeof(rt_uint8_t *))));

    return (rt_uint8_t *)(block_ptr + sizeof(rt_uint8_t *));
}
RTM_EXPORT(rt_mp_alloc);

/**
 * This function will release a memory block
 *
 * @param block the address of memory block to be released
 */
void rt_mp_free(void *block)
{
    rt_uint8_t **block_ptr;
    struct rt_mempool *mp;
    struct rt_thread *thread;
    register rt_base_t level;

    /* get the control block of pool which the block belongs to */
    block_ptr = (rt_uint8_t **)((rt_uint8_t *)block - sizeof(rt_uint8_t *));
    mp        = (struct rt_mempool *)*block_ptr;

    RT_OBJECT_HOOK_CALL(rt_mp_free_hook, (mp, block));

    /* disable interrupt */
    level = rt_hw_interrupt_disable();

    /* increase the free block count */
    mp->block_free_count ++;

    /* link the block into the block list */
    *block_ptr = mp->block_list;
    mp->block_list = (rt_uint8_t *)block_ptr;

    if (mp->suspend_thread_count > 0)
    {
        /* get the suspended thread */
        thread = rt_list_entry(mp->suspend_thread.next,
                               struct rt_thread,
                               tlist);

        /* set error */
        thread->error = RT_EOK;

        /* resume thread */
        rt_thread_resume(thread);

        /* decrease suspended thread count */
        mp->suspend_thread_count --;

        /* enable interrupt */
        rt_hw_interrupt_enable(level);

        /* do a schedule */
        rt_schedule();

        return;
    }

    /* enable interrupt */
    rt_hw_interrupt_enable(level);
}
RTM_EXPORT(rt_mp_free);

/*@}*/

#endif