Hi3861 OpenHarmony嵌入式应用入门--LiteOS Mutex

CMSIS 2.0接口中的Mutex（互斥锁）是用于在多线程环境中保护共享资源的访问机制。Mutex（互斥锁）是一种特殊的信号量，用于确保同一时间只有一个线程可以访问特定的共享资源。在嵌入式系统或多线程应用中，当多个线程需要访问同一资源时，如果没有适当的同步机制，可能会导致数据不一致或其他问题。Mutex就是用来解决这类问题的。这些函数通常不能在中断服务程序（ISR）中调用，因为中断的上下文可能与这些函数的设计不符。在使用Mutex时，必须确保正确地获取和释放锁，以避免死锁或其他同步问题。

Mutex API

API名称	说明
osMutexNew	创建并初始化一个互斥锁
osMutexGetName	获得指定互斥锁的名字
osMutexAcquire	获得指定的互斥锁的访问权限，若互斥锁已经被锁，则返回超时
osMutexRelease	释放指定的互斥锁
osMutexGetOwner	获得指定互斥锁的所有者线程
osMutexDelete	删除指定的互斥锁

代码编写

修改D:\DevEcoProjects\test\src\vendor\rtplay\rt_hi3861\demo\BUILD.gn文件

# Copyright (c) 2023 Beijing HuaQing YuanJian Education Technology Co., Ltd
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
# 
#    http://www.apache.org/licenses/LICENSE-2.0
# 
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License. import("//build/lite/config/component/lite_component.gni")lite_component("demo") {features = [#"base_00_helloworld:base_helloworld_example",#"base_01_led:base_led_example",#"base_02_loopkey:base_loopkey_example",#"base_03_irqkey:base_irqkey_example",#"base_04_adc:base_adc_example",#"base_05_pwm:base_pwm_example",#"base_06_ssd1306:base_ssd1306_example",#"kernel_01_task:kernel_task_example",#"kernel_02_timer:kernel_timer_example",#"kernel_03_event:kernel_event_example","kernel_04_mutex:kernel_mutex_example",]
}

创建D:\DevEcoProjects\test\src\vendor\rtplay\rt_hi3861\demo\kernel_04_mutex文件夹

文件夹中创建D:\DevEcoProjects\test\src\vendor\rtplay\rt_hi3861\demo\kernel_04_mutex\kernel_mutex_example.c文件D:\DevEcoProjects\test\src\vendor\rtplay\rt_hi3861\demo\kernel_04_mutex\BUILD.gn文件

# Copyright (c) 2023 Beijing HuaQing YuanJian Education Technology Co., Ltd
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
# 
#    http://www.apache.org/licenses/LICENSE-2.0
# 
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License. static_library("kernel_mutex_example") {sources = ["kernel_mutex_example.c"]include_dirs = ["//utils/native/lite/include","//kernel/liteos_m/kal/cmsis",]
}

/** Copyright (c) 2023 Beijing HuaQing YuanJian Education Technology Co., Ltd* Licensed under the Apache License, Version 2.0 (the "License");* you may not use this file except in compliance with the License.* You may obtain a copy of the License at**    http://www.apache.org/licenses/LICENSE-2.0** Unless required by applicable law or agreed to in writing, software* distributed under the License is distributed on an "AS IS" BASIS,* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.* See the License for the specific language governing permissions and* limitations under the License.*/#include <stdio.h>
#include <unistd.h>#include "ohos_init.h"
#include "cmsis_os2.h"osThreadId_t Task1_ID; //  任务1 ID
osThreadId_t Task2_ID; //  任务2 ID
osMutexId_t Mutex_ID;       // 定义互斥锁 ID
uint8_t buff[20] = {0};    // 定义一个共享资源
#define TASK_STACK_SIZE 1024
#define TASK_DELAY_TIME 1 // s/*** @description: 任务1* @param {*}* @return {*}*/
void Task1(void)
{int i = 0;printf("enter Task 1.......\n");while (1) {osMutexAcquire(Mutex_ID, osWaitForever);    // 请求互斥锁// 操作共享数据 写数据printf("write Buff Data: \n");for (i = 0; i < sizeof(buff); i++) {buff[i] = i;}printf("\n");osMutexRelease(Mutex_ID);   // 释放互斥锁sleep(TASK_DELAY_TIME);}
}
/*** @description: 任务2* @param {*}* @return {*}*/
void Task2(void)
{int i = 0;printf("enter Task 2.......\n");while (1) {osMutexAcquire(Mutex_ID, osWaitForever);    // 请求互斥锁// 操作共享数据 读数据printf("read Buff Data: \n");for (i = 0; i < sizeof(buff); i++) {printf("%d \n", buff[i]);}printf("\n");osMutexRelease(Mutex_ID);   // 释放互斥锁sleep(TASK_DELAY_TIME);}
}
/*** @description: 初始化并创建任务* @param {*}* @return {*}*/
static void kernel_mutex_example(void)
{printf("Enter kernel_mutex_example()!\n");// 创建互斥锁Mutex_ID = osMutexNew(NULL);if (Mutex_ID != NULL) {printf("ID = %d, Create Mutex_ID is OK!\n", Mutex_ID);}osThreadAttr_t taskOptions;taskOptions.name = "Task1";              // 任务的名字taskOptions.attr_bits = 0;               // 属性位taskOptions.cb_mem = NULL;               // 堆空间地址taskOptions.cb_size = 0;                 // 堆空间大小taskOptions.stack_mem = NULL;            // 栈空间地址taskOptions.stack_size = TASK_STACK_SIZE;           // 栈空间大小 单位:字节taskOptions.priority = osPriorityNormal; // 任务的优先级Task1_ID = osThreadNew((osThreadFunc_t)Task1, NULL, &taskOptions);      // 创建任务1if (Task1_ID != NULL) {printf("ID = %d, Create Task1_ID is OK!\n", Task1_ID);}taskOptions.name = "Task2";              // 任务的名字taskOptions.priority = osPriorityNormal; // 任务的优先级Task2_ID = osThreadNew((osThreadFunc_t)Task2, NULL, &taskOptions);      // 创建任务2if (Task2_ID != NULL) {printf("ID = %d, Create Task2_ID is OK!\n", Task2_ID);}
}
SYS_RUN(kernel_mutex_example);

使用build，编译成功后，使用upload进行烧录。