rt-thread/components/drivers/src/completion.c

/*
 * File      : completion.c
 * This file is part of RT-Thread RTOS
 * COPYRIGHT (C) 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
 * 2012-09-30     Bernard      first version.
 */

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

#define RT_COMPLETED    1
#define RT_UNCOMPLETED  0

void rt_completion_init(struct rt_completion *completion)
{
    rt_base_t level;
    RT_ASSERT(completion != RT_NULL);

    level = rt_hw_interrupt_disable();
    completion->flag = RT_UNCOMPLETED;
    rt_list_init(&completion->suspended_list);
    rt_hw_interrupt_enable(level);
}

rt_err_t rt_completion_wait(struct rt_completion *completion,
                            rt_int32_t            timeout)
{
    rt_err_t result;
    rt_base_t level;
    rt_thread_t thread;
    RT_ASSERT(completion != RT_NULL);

    result = RT_EOK;
    thread = rt_thread_self();

    level = rt_hw_interrupt_disable();
    if (completion->flag != RT_COMPLETED)
    {
        /* only one thread can suspend on complete */
        RT_ASSERT(rt_list_isempty(&(completion->suspended_list)));

        if (timeout == 0)
        {
            result = -RT_ETIMEOUT;
            goto __exit;
        }
        else
        {
            /* reset thread error number */
            thread->error = RT_EOK;

            /* suspend thread */
            rt_thread_suspend(thread);
            /* add to suspended list */
            rt_list_insert_before(&(completion->suspended_list), &(thread->tlist));

            /* current context checking */
            RT_DEBUG_NOT_IN_INTERRUPT;

            /* start timer */
            if (timeout > 0)
            {
                /* reset the timeout of thread timer and start it */
                rt_timer_control(&(thread->thread_timer), RT_TIMER_CTRL_SET_TIME, &timeout);
                rt_timer_start(&(thread->thread_timer));
            }
            /* enable interrupt */
            rt_hw_interrupt_enable(level);

            /* do schedule */
            rt_schedule();

            /* thread is waked up */
            result = thread->error;

            level = rt_hw_interrupt_disable();
            /* clean completed flag */
            completion->flag = RT_UNCOMPLETED;
        }
    }

__exit:
    rt_hw_interrupt_enable(level);

    return result;
}

void rt_completion_done(struct rt_completion *completion)
{
    rt_base_t level;
    RT_ASSERT(completion != RT_NULL);

    if (completion->flag == RT_COMPLETED)
        return;

    level = rt_hw_interrupt_disable();
    completion->flag = RT_COMPLETED;

    if (!rt_list_isempty(&(completion->suspended_list)))
    {
        /* there is one thread in suspended list */
        struct rt_thread *thread;

        /* get thread entry */
        thread = rt_list_entry(completion->suspended_list.next, struct rt_thread, tlist);
        
        /* resume it */
        rt_thread_resume(thread);
        rt_hw_interrupt_enable(level);

        /* perform a schedule */
        rt_schedule();
    }
    else
    {
        rt_hw_interrupt_enable(level);
    }
}