消息队列

一个线程会从消息队列中收取消息，另一个线程会定时给消息队列发送普通消息和紧急消息

一个线程会从消息队列中收取消息，另一个线程会定时给消息队列发送普通消息和紧急消息

源码

/* * Copyright (c) 2006-2018, RT-Thread Development Team * * SPDX-License-Identifier: Apache-2.0 * * Change Logs: * Date Author Notes * 2018-08-24 yangjie the first version *//* * 程序清单：消息队列例程 * * 这个程序会创建2个动态线程，一个线程会从消息队列中收取消息；一个线程会定时给消 * 息队列发送 普通消息和紧急消息。 */#include <rtthread.h>#define THREAD_PRIORITY 25#define THREAD_TIMESLICE 5/* 消息队列控制块 */static struct rt_messagequeue mq;/* 消息队列中用到的放置消息的内存池 */static rt_uint8_t msg_pool[2048];ALIGN(RT_ALIGN_SIZE)static char thread1_stack[1024];static struct rt_thread thread1;/* 线程1入口函数 */static void thread1_entry(void *parameter){ char buf = 0; rt_uint8_t cnt = 0; while (1) { /* 从消息队列中接收消息 */ if (rt_mq_recv(&mq, &buf, sizeof(buf), RT_WAITING_FOREVER) == RT_EOK) { rt_kprintf("thread1: recv msg from msg queue, the content:%c\n", buf); if (cnt == 19) { break; } } /* 延时50ms */ cnt++; rt_thread_mdelay(50); } rt_kprintf("thread1: detach mq \n"); rt_mq_detach(&mq);}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){ int result; char buf = 'A'; rt_uint8_t cnt = 0; while (1) { if (cnt == 8) { /* 发送紧急消息到消息队列中 */ result = rt_mq_urgent(&mq, &buf, 1); if (result != RT_EOK) { rt_kprintf("rt_mq_urgent ERR\n"); } else { rt_kprintf("thread2: send urgent message - %c\n", buf); } } else if (cnt >= 20)/* 发送20次消息之后退出 */ { rt_kprintf("message queue stop send, thread2 quit\n"); break; } else { /* 发送消息到消息队列中 */ result = rt_mq_send(&mq, &buf, 1); if (result != RT_EOK) { rt_kprintf("rt_mq_send ERR\n"); } rt_kprintf("thread2: send message - %c\n", buf); } buf++; cnt++; /* 延时5ms */ rt_thread_mdelay(5); }}/* 消息队列示例的初始化 */int msgq_sample(void){ rt_err_t result; /* 初始化消息队列 */ result = rt_mq_init(&mq, "mqt", &msg_pool[0], /* 内存池指向msg_pool */ 1, /* 每个消息的大小是 1 字节 */ sizeof(msg_pool), /* 内存池的大小是msg_pool的大小 */ RT_IPC_FLAG_FIFO); /* 如果有多个线程等待，按照先来先得到的方法分配消息 */ if (result != RT_EOK) { rt_kprintf("init message queue 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(msgq_sample, msgq sample);