kernel-sample/zh/mailbox_urgent_sample.c

/*
 * Copyright (c) 2006-2022, RT-Thread Development Team
 *
 * SPDX-License-Identifier: Apache-2.0
 *
 * Change Logs:
 * Date           Author       Notes
 * 2018-08-24     yangjie      the first version
 * 2021-01-03     Meco Man     add the demo of rt_mb_urgent()
 */

/*
 * 程序清单：邮箱例程
 *
 * 这个程序会创建2个动态线程，一个静态的邮箱对象，其中一个线程往邮箱中发送邮件，
 * 一个线程往邮箱中收取邮件。
 * 本例程也会展示紧急邮件和正常邮件的区别。
 */
#include <rtthread.h>

#define THREAD_PRIORITY      10
#define THREAD_TIMESLICE     5

/* 邮箱控制块 */
static struct rt_mailbox mb;
/* 用于放邮件的内存池 */
static char mb_pool[128];

static char mb_urgent[] = "I'm a urgent mail!";
static char mb_normal[] = "I'm a normal mail!";
static char mb_str3[] = "over";

ALIGN(RT_ALIGN_SIZE)
static char thread1_stack[1024];
static struct rt_thread thread1;

/* 线程1入口 */
static void thread1_entry(void *parameter)
{
    char *str;

    while (1)
    {
        rt_kprintf("thread1: try to recv a mail\n");

        /* 从邮箱中收取邮件 */
        if (rt_mb_recv(&mb, (rt_ubase_t *)&str, RT_WAITING_FOREVER) == RT_EOK)
        {
            rt_kprintf("thread1: get a mail from mailbox, the content:%s\n", str);
            if (str == mb_str3)
                break;

            /* 延时100ms */
            rt_thread_mdelay(100);
        }
    }
    /* 执行邮箱对象脱离 */
    rt_mb_detach(&mb);
}

ALIGN(RT_ALIGN_SIZE)
static char thread2_stack[1024];
static struct rt_thread thread2;

/* 线程2入口 */
static void thread2_entry(void *parameter)
{
    rt_uint8_t count;

    count = 0;
    while (count < 10)
    {
        count ++;

        /* 分别发送正常邮件和紧急邮件到邮箱中 */
        /* 关调度器是为了同时给线程1两封邮件，观察线程1如何处理紧急邮件和正常邮件 */
        rt_enter_critical();
        rt_mb_send(&mb, (rt_uint32_t)&mb_normal);
        rt_mb_urgent(&mb, (rt_uint32_t)&mb_urgent);
        rt_exit_critical();
        /* 可以看到虽然正常邮件和紧急优先同时发送，但是邮箱选择优先处理紧急邮件 */

        /* 延时200ms */
        rt_thread_mdelay(200);
    }

    /* 发送邮件告诉线程1，线程2已经运行结束 */
    rt_mb_send(&mb, (rt_uint32_t)&mb_str3);
}

int mailbox_urgent_sample(void)
{
    rt_err_t result;

    /* 初始化一个mailbox */
    result = rt_mb_init(&mb,
                        "mbt",                      /* 名称是mbt */
                        &mb_pool[0],                /* 邮箱用到的内存池是mb_pool */
                        sizeof(mb_pool) / sizeof(rt_ubase_t), /* 邮箱中的邮件数目,sizeof(rt_ubase_t)表示指针大小 */
                        RT_IPC_FLAG_PRIO);          /* 采用PRIO方式进行线程等待 */
    if (result != RT_EOK)
    {
        rt_kprintf("init mailbox failed.\n");
        return -1;
    }

    rt_thread_init(&thread1,
                   "thread1",
                   thread1_entry,
                   RT_NULL,
                   &thread1_stack[0],
                   sizeof(thread1_stack),
                   THREAD_PRIORITY, THREAD_TIMESLICE);
    rt_thread_startup(&thread1);

    rt_thread_init(&thread2,
                   "thread2",
                   thread2_entry,
                   RT_NULL,
                   &thread2_stack[0],
                   sizeof(thread2_stack),
                   THREAD_PRIORITY, THREAD_TIMESLICE);
    rt_thread_startup(&thread2);
    return 0;
}

/* 导出到 msh 命令列表中 */
MSH_CMD_EXPORT(mailbox_urgent_sample, mailbox urgent sample);