【LiteOS】小白进阶之 LiteOS 队列、任务、定时器综合实验

1、功能说明

创建一个打印队列和 3 个任务，其中两个 Task 负责写入数据 1/2，另外一个用于输出字符串。

同时还在 Tick 任务每触发 200 次，向打印队列（首部）写入数据 3。

2、代码讲解

1）创建队列、定时器、任务

      UINT32 Example15_Entry(VOID) {
          UINT32 uwRet = LOS_OK;
          TSK_INIT_PARAM_S stInitParam = {0};
          puts("Example15_Entry\r\n");
          // 创建队列
          uwRet = LOS_QueueCreate(
                      "queue",                // 队列名称
                      3,                      // 队列大小
                      &s_uwQueueID,           // 队列ID
                      0,                      // 不使用
                      sizeof(UINT32)          // 队列消息大小
                      );
          if (uwRet != LOS_OK) {
              printf("create queue failure!,error:%x\n", uwRet);
              return LOS_NOK;
          }
          // 创建定时器
          uwRet = LOS_SwtmrCreate(
                      PERIODIC_TIMER_VALUE,
                      LOS_SWTMR_MODE_PERIOD,
                      Timer_Callback,
                      &s_usSwTmrID,
                      (UINT32)s_pStringsToPrint[2]
                      #if (LOSCFG_BASE_CORE_SWTMR_ALIGN == YES)
                      , OS_SWTMR_ROUSES_ALLOW,
                      OS_SWTMR_ALIGN_SENSITIVE
                      #endif
                      );
          if(LOS_OK != uwRet)
          {
              printf("create Timer failed.\r\n");
              return LOS_NOK;
          }
          // 创建发送任务
          stInitParam.pfnTaskEntry = Example_TaskSend;
          stInitParam.usTaskPrio = TASK_PRIO_SEND;
          stInitParam.pcName = "TaskSend1";
          stInitParam.uwStackSize = TASK_STK_SIZE;
          stInitParam.uwArg = (UINT32)s_pStringsToPrint[0];
          uwRet = LOS_TaskCreate(&s_uwTskLoID, &stInitParam);
          if (uwRet != LOS_OK) {
              printf("Example_TaskSend create Failed!\r\n");
              return LOS_NOK;
          }
          stInitParam.pcName = "TaskSend2";
          stInitParam.uwArg = (UINT32)s_pStringsToPrint[1];
          uwRet = LOS_TaskCreate(&s_uwTskLoID, &stInitParam);
          if (uwRet != LOS_OK) {
              printf("Example_TaskSend create Failed!\r\n");
              return LOS_NOK;
          }
          // 创建接收任务
          stInitParam.pfnTaskEntry = Example_TaskRecv;
          stInitParam.usTaskPrio = TASK_PRIO_RECV;
          stInitParam.pcName = "TaskRecv";
          stInitParam.uwStackSize = TASK_STK_SIZE;
          uwRet = LOS_TaskCreate(&s_uwTskHiID, &stInitParam);
          if (uwRet != LOS_OK) {
              printf("Example_TaskRecv create Failed!\r\n");
              return LOS_NOK;
          }
          // 启动定时器
          uwRet = LOS_SwtmrStart(s_usSwTmrID);
          if(LOS_OK != uwRet)
          {
              printf("Start Timer failed.\r\n");
              return LOS_NOK;
          }
          return uwRet;
      }
  
 

2）发送任务将 Task1、Task2 字符串发送到队列，接收任务从队列中读取数据

      static VOID *Example_TaskRecv(UINT32 uwArg) {
          UINT32 uwRet = LOS_OK;
          UINT32 uwReadbuf = NULL;
          UINT32 uwBufferSize = sizeof(UINT32*);
          for (;;) {
              uwRet = LOS_QueueRead(s_uwQueueID, (VOID*)&uwReadbuf, uwBufferSize, LOS_WAIT_FOREVER);
              if (LOS_OK != uwRet) {
                  printf("recv value failure,error:%x\r\n", uwRet);
              } else {
                  if (uwBufferSize == sizeof(UINT32)) {
                      puts((const CHAR*)uwReadbuf);
                  }
              }
          }
      }
      static VOID * Example_TaskSend(UINT32 uwArg) {
          UINT32 uwRet = LOS_OK;
          for (;;) {
              uwRet = LOS_QueueWrite(s_uwQueueID, (VOID*)uwArg, sizeof(UINT32*), 0);
              if (LOS_OK != uwRet) {
                  printf("send value failure,error:%x\r\n", uwRet);
              }
              LOS_TaskDelay(2000);
          }
      }
  
 

3）周期定时器回调任务将数据写入到队列头部

      static void Timer_Callback(UINT32 uwArg)
      {
          UINT32 uwRet = LOS_OK;
          uwRet = LOS_QueueWriteHead(s_uwQueueID, (VOID*)uwArg, sizeof(UINT32*), 0);
          if (LOS_OK != uwRet) {
              printf("send value failure,error:%x\r\n", uwRet);
          }
      }
  
 

4）效果演示

refer：

https://liteos.github.io/tutorials/kernel/example15.html#代码讲解

文章来源: blog.csdn.net，作者：简一商业，版权归原作者所有，如需转载，请联系作者。

原文链接：blog.csdn.net/liwei16611/article/details/86705215